The development of cell-based devices using mammalian cells is becoming increasingly feasible. To remotely control such sophisticated devices, an interface between digital computer/internet networks and cellular/organ networks is essential. This study explores the electrochemical manipulation of insulin secretion-a regulatory hormone for the control of blood sugar levels-using pancreatic β cells as a model. iGL cells, expressing insulin fused with Gaussia Luciferase (INS-GLase), were directly cultured on a custom-made cell culture device coated with a transparent poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) electrode. Luminescence imaging was employed to evaluate insulin secretion in response to applied potentials. Results showed that insulin secretion could be induced by regulating membrane potential through an applied potential. The addition of nicardipine, an L-type voltage-dependent Ca2+ channel inhibitor, suppressed insulin secretion, suggesting the involvement of Ca2+ channels in this electrochemical system. Additionally, changes in membrane potential were directly visualized with the membrane potential-sensitive dye FluoVolt™, which confirmed both the forced depolarization and the forced restoration of the membrane potential to its non-excited state upon potential application to the electrode. The reported electrochemical technique, in which cells are directly cultured on an electrode, offers significant promise for designing advanced bio-hybrid systems that integrate cellular functions with digital networks.

Glycine acts in an autocrine positive feedback loop in human β cells through its ionotropic receptors (GlyRs). In type 2 diabetes (T2D), islet GlyR activity is impaired by unknown mechanisms. We sought to investigate if the GlyR dysfunction in T2D is replicated by hyperglycemia per se, and to further characterize its action in β cells and islets.

GlyR-mediated currents were measured using whole-cell patch-clamp in human β cells from donors with or without T2D, or after high glucose (15 mM) culture. We also correlated glycine-induced current amplitude with transcript expression levels through patch-seq. The expression of the GlyR α1, α3, and β subunit mRNA splice variants was compared between islets from donors with and without T2D, and after high glucose culture. Insulin secretion from human islets was measured in the presence or absence of the GlyR antagonist strychnine.

Although gene expression of GlyRs was decreased in T2D islets, and β cell GlyR-mediated currents were smaller, we found no evidence for a shift in GlyR subunit splicing. Glycine-induced currents are also reduced after 48 h culture of islets from donors without diabetes in high glucose, where we also find the reduction of the α1 subunit expression, but an increase in the α3 subunit. We discovered that glycine-evoked currents are highly heterogeneous amongst β cells, inversely correlate with donor HbA1c, and are significantly correlated to the expression of 92 different transcripts and gene regulatory networks (GRNs) that include CREB3(+), RREB1(+) and ZNF697(+). Finally, glucose-stimulated insulin secretion is decreased in the presence of the GlyR antagonist strychnine.

We demonstrate that glucose can modulate GlyR expression, and that the current decrease in T2D is likely due to the receptor gene expression downregulation, and not a change in transcript splicing. Moreover, we define a previously unknown set of genes and regulons that are correlated to GlyR-mediated currents and could be involved in GlyR downregulation in T2D. Among those we validate the negative impact of EIF4EBP1 expression on GlyR activity.

This work describes a computer study that looks at how different amounts of cholesterol (0%, 25%, and 50%) in cell membranes change the relationship between ATP and the KATP channel. This could explain why pancreatic beta-cells secrete insulin differently. We use computer simulations of molecular dynamics, calculations of binding free energy, and an integrated oscillator model to look at the electrical activity of beta-cells. There is a need for this kind of multiscale approach right now because cholesterol plays a part in metabolic syndrome and early type 2 diabetes. Our results showed that the increase in cholesterol concentration in the cell membrane affects the electrostatic interactions between ATP and the KATP channel, especially with charged residues in the binding site. Cholesterol can influence the properties of a membrane, including its local charge distribution near the channel. This affects the electrostatic environment around the ATP-binding site, increasing  the affinity of ATP for the channel as our results indicated from 0 to 25 and 50% cholesterol (- 141 to - 113 kJ/mol, respectively). Simulating this change in the affinity to ATP of the KATP channels in a model of the electrical activity of the pancreatic beta-cell indicates that even a minimal increase could produce hyperinsulism. The study answers an important research question about how the structure of the membrane affects the function of KATP and, in turn, insulin releases a common feature of metabolic syndrome and early stages of type 2 diabetes.

Optogenetics is an interdisciplinary field wherein optical and genetic engineering methods are employed together to impart photounresponsive cells (usually of higher animals) the ability to respond to light through expression of light-sensitive proteins sourced generally from algae or bacteria. It enables precise spatiotemporal control of various cellular activities through light stimulation. Recently, emerging as a synthetic biology-based approach for diabetes management, optogenetics can provide user-control of hormonal secretion by photoactivation of a suitably modified cell. For around a decade, studies have been performed on the applicability of various light-sensitive proteins and their incorporation into pancreatic and nonpancreatic cells for photoinduced insulin secretion. Further, in vivo studies demonstrated amelioration of diabetes in mouse models through photoactivation of the implanted engineered cells. Here, we attempt to highlight the various optogenetic approaches explored in terms of influencing the insulin secretion pathway at different points in light of the natural insulin secretion pathway in pancreatic β cells. We also discuss how transgenic cells of both pancreatic as well as nonpancreatic origin are exploited for photoinduced secretion of insulin. Recent advances on integration of "smart" technologies for remote control of light irradiation and thereby insulin secretion from implanted engineered cells in preclinical models are also described. Additionally, the need for further comprehensive studies on irradiation parameters, red-shifted opsins, and host-cell interaction is stressed to realize the full potential of optogenetics as a clinically applicable modality providing user-controlled "on demand" hormonal secretion for better management of diabetes.

Enteroendocrine cells (EECs) secrete over 20 different gut hormones in response to changes to the gut environment. They detect a range of nutritional stimuli through activation of a host of nutrient-sensing G-protein-coupled receptors and electrogenic nutrient cotransport. These activate intracellular signalling pathways which converge on membrane depolarisation and action potential generation, which elicit secretion. Emerging evidence has demonstrated that EECs also respond to non-nutritional stimuli, including mechanosensation, pH changes, and metabolites produced by the gut microbiome. EECs are polyhormonal cells, in which hormone expression is plastic and dependent on location in the gut. Hormones and small-molecule neurotransmitters secreted by EECs can activate extrinsic vagal afferents, modulating central processes such as appetite and food preference. While neuronal afferents are sometimes found in close proximity to EECs, the extent to which EEC/neuronal connections recapitulate traditional synaptic connections remains undefined.

Precise regulation of insulin secretion by pancreatic β cells is essential to prevent excessive insulin release. Here, we show that the nutrient sensor mechanistic Target of Rapamycin Complex 1 (mTORC1) is rapidly activated by glucose in β cells via the insulin secretion machinery, positioning mTORC1 as a sensor of β cell activity. Acute pharmacological inhibition of mTORC1 during glucose stimulation enhances insulin release, suggesting that mTORC1 acts as an intrinsic feedback regulator that restrains insulin secretion. Phosphoproteomic profiling reveals that mTORC1 modulates the phosphorylation of proteins involved in actin remodeling and vesicle trafficking, with a prominent role in the RhoA-GTPase pathway. Mechanistically, mTORC1 promotes RhoA activation and F-actin polymerization, limiting vesicle movement and dampening the second phase of insulin secretion. These findings identify a glucose-mTORC1-RhoA signaling axis that forms an autonomous feedback loop to constrain insulin exocytosis, providing insight into how β cells prevent excessive insulin release and maintain metabolic balance.

Synthetic cells offer a versatile platform for addressing biomedical and environmental challenges, due to their modular design and capability to mimic cellular processes such as biosensing, intercellular communication, and metabolism. Constructing synthetic cells capable of stimuli-responsive secretion is vital for applications in targeted drug delivery and biosensor development. Previous attempts at engineering secretion for synthetic cells have been confined to non-specific cargo release via membrane pores, limiting the spatiotemporal precision and specificity necessary for selective secretion. Here, a protein-based platform termed TEV Protease-mediated Releasable Actin-binding Protein (TRAP) is designed and constructed for selective, rapid, and triggerable secretion in synthetic cells. TRAP is designed to bind tightly to reconstituted actin networks and is proteolytically released from bound actin, followed by secretion via cell-penetrating peptide membrane translocation. TRAP's efficacy in facilitating light-activated secretion of both fluorescent and luminescent proteins is demonstrated. By equipping synthetic cells with a controlled secretion mechanism, TRAP paves the way for the development of stimuli-responsive biomaterials, versatile synthetic cell-based biosensing systems, and therapeutic applications through the integration of synthetic cells with living cells for targeted delivery of protein therapeutics.

Type 2 diabetes mellites (T2DM) is the most common form of diabetes and affects a significant portion of the population. Obesity-related increases in free fatty acids and glucose in the diet contribute to β-cell dysfunction and loss, ultimately leading to the onset of T2DM. The endocannabinoid system, which is present throughout the body, plays a vital role in regulating various physiological processes, including those in the pancreas. This system has been implicated in metabolic disorders like obesity and diabetes, as it helps to regulate appetite, food intake, and fat production. Phytocannabinoids from Cannabis sativa have the potential to influence the endocannabinoid system, offering a promising therapeutic approach for diabetes and its complications. Using high-glucose-high-lipid (HGHL)-induced INS-1 β-cells, we investigated the protective effects of two major (THC and CBD) and three minor (THCV, CBC, and CBG) phytocannabinoids on high glucose-high lipid (HGHL)-induced apoptosis, cell cycle disruption, and impaired function of beta-cells. Our results showed that all five phytocannabinoids reduced HGHL-induced apoptosis, likely by decreasing TXNIP protein levels. Additionally, THC and all three minor phytocannabinoids provided protective effects against functional impairments caused by HGHL exposure.

Bestrophin-1 (BEST1) is a chloride channel expressed in the eye and other tissues of the body. A link between BEST1 and the principal inhibitory neurotransmitter γ-aminobutyric acid (GABA) has been proposed. The most appreciated receptors for extracellular GABA are the GABAB G-protein-coupled receptors and the pentameric GABAA chloride channels, both of which have fundamental roles in the central nervous system. Here, we demonstrate that BEST1 is directly activated by GABA. Through functional studies and atomic-resolution structures of human and chicken BEST1, we identify a GABA binding site on the channel's extracellular side and determine the mechanism by which GABA binding stabilizes opening of the channel's central gate. This same gate, "the neck," is activated by intracellular [Ca2+], indicating that BEST1 is controlled by ligands from both sides of the membrane. The studies demonstrate that BEST1, which shares no structural homology with GABAA receptors, is a GABA-activated chloride channel. The physiological implications of this finding remain to be studied.

Type 1 diabetes (T1D) is a chronic hyperglycemia disorder emerging from beta-cell (insulin secreting cells of the pancreas) targeted autoimmunity. As the blood glucose levels significantly increase and the insulin secretion is gradually lost, the entire body suffers from the complications. Although various advances in the insulin analogs, blood glucose monitoring and insulin application practices have been achieved in the last few decades, a cure for the disease is not obtained. Alternatively, pancreas/islet transplantation is an attractive therapeutic approach based on the patient prognosis, yet this treatment is also limited mainly by donor shortage, life-long use of immunosuppressive drugs and risk of disease transmission. In research and clinics, such drawbacks are addressed by the endocrine tissue engineering of the pancreas. One arm of this engineering is scaffold-free models which often utilize highly developed cell-cell junctions, soluble factors and 3D arrangement of islets with the cellular heterogeneity to prepare the transplant formulations. In this review, taking T1D as a model autoimmune disease, techniques to produce so-called pseudoislets and their applications are studied in detail with the aim of understanding the role of mimicry and pointing out the promising efforts which can be translated from benchside to bedside to achieve exogenous insulin-free patient treatment. Likewise, these developments in the pseudoislet formation are tools for the research to elucidate underlying mechanisms in pancreas (patho)biology, as platforms to screen drugs and to introduce immunoisolation barrier-based hybrid strategies.

Cystic fibrosis related diabetes (CFRD) is the most common comorbidity of cystic fibrosis (CF) still, its pathogenesis is poorly understood. Recent studies have suggested that although pancreatic insufficiency is an important explanation for CFRD development, inherent pancreatic islet cell dysfunction may play a role. This study aimed to systematically compile current data regarding the impact of pancreatic islet cell dysfunction on the development of CFRD.

A systematic search was conducted in PubMed and Embase. The resulting articles were screened for relevant experimental design and outcomes. Articles underwent data extraction and quality assessment before compilation and analysis of the results.

A total of 268 articles were initially screened and 19 studies conducted between 2006-2022 were finally included in this review. Half of the studies in human tissue and most of the studies in animal tissue could detect CFTR in the islets. Similarly, half of the publications in human islets and most studies in animal islets detect decreased insulin secretion with inhibition/mutation of CFTR.

The literature on the role of islet CFTR is contradictory. However, a pattern emerges where CFTR loss-of-function mutations have the potential to negatively affect islet cell function in a way that, together with previously described exocrine damage occurring in CF, could play a part in the development of CFRD.

The intricate link between glucose metabolism, ATP production, and glucose-stimulated insulin secretion (GIIS) in pancreatic β-cells has been well established. However, the effects of other digestible monosaccharides on this mechanism remain unclear. This study examined the interaction between intracellular fructose metabolism and GIIS using MIN6-K8 β-cell lines and mouse pancreatic islets. Fructose at millimolar concentrations potentiated insulin secretion in the presence of stimulatory levels (8.8 mM) of glucose. This potentiation was dependent on sweet taste receptor-activated phospholipase Cβ2 (PLCβ2) signaling. Concurrently, metabolic tracing using 13C-labeled fructose and glucose in conjunction with biochemical analyses demonstrated that fructose blunted the glucose-induced increase in the ATP/ADP ratio. Mechanistically, fructose is substantially converted to fructose 1-phosphate (F1P) at the expense of ATP. F1P directly inhibited PKM2 (pyruvate kinase M2), thereby reducing the later glycolytic flux used for ATP production. Remarkably, F1P-mediated PKM2 inhibition was counteracted by TEPP-46, a small-molecule PKM2 activator. TEPP-46 restored glycolytic flux and the ATP/ADP ratio, leading to the enhancement of fructose-potentiated GIIS in MIN6-K8 cells, normal mouse islets, and fructose-unresponsive diabetic mouse islets. These findings reveal an antagonistic interplay between glucose and fructose metabolism in β-cells, highlighting PKM2 as a crucial regulator and broadening our understanding of the relationship between β-cell fuel metabolism and insulin secretion.

Oxidative stress plays a critical role in the development of insulin resistance (IR), a key factor in metabolic disorders such as diabetes. Plant active ingredients play a crucial role in protecting organisms from environmental stressors and have shown promising therapeutic potential against various metabolic disorders. Artemisinin (ART), a sesquiterpenoid with a lactone ring obtained from the herb Artemisia annua, exhibits promising therapeutic properties. This study investigates the potential of ART on Luperox (LUP)-induced oxidative stress and the resulting IR in zebrafish larvae, specifically investigating the involvement of the PI3K/AKT signaling pathway. Zebrafish larvae were chosen due to their high sensitivity to oxidative stress, well-characterized glucose metabolism, and genetic similarity to human metabolic pathways. They were exposed to LUP to induce oxidative stress, followed by treatment with ART. The effects were evaluated through biochemical assays, fluorescence staining and gene expression analysis. ART effectively restored key antioxidant enzymes (SOD, CAT, GSH) and mitigated oxidative stress evidenced by reduction in intercellular ROS and lipid peroxidation, as confirmed through DCFDA and DPPP staining assays. Additionally, ART improved glucose uptake and lowered blood glucose levels. Gene expression analysis further indicated increased levels of PI3K/Akt signalling components and antioxidant-related genes (NRF2, HO-1, GPx, and GSR). Our results indicate that artemisinin significantly alleviates oxidative stress by reducing ROS levels and enhancing antioxidant enzyme activity. Furthermore, artemisinin mitigates IR by restoring glucose metabolism and upregulating PI3K/AKT pathway components. These findings highlight the translational potential of plant active ingredients, particularly artemisinin, for the development of therapies targeting IR and oxidative stress-related metabolic disorders.

Traditional Chinese Medicine (TCM) theory posits that type 2 diabetes mellitus (T2DM) characterized by Qi and Yin deficiency, is associated with elevated blood lipid levels. The Xinmaitong formula (XMT) is a folk remedy believed to lower blood lipid levels. However, the functional components and molecular mechanisms through which XMT exerts its anti-diabetic effects remain to be elucidated. This study aimed to investigate the therapeutic effects and potential mechanisms of XMT in the treatment of T2DM, focusing on the glucagon-like peptide-1 receptor (GLP-1R) signaling pathway.

A TCM formula that promotes GLP-1R expression was screened using a GLP-1R promoter-dependent luciferase reporter gene vector (PGL3-GLP-1R-luc). The T2DM mouse model was established using a high-fat diet and streptozotocin (STZ). Blood glucose levels were measured using a glucometer and oral glucose tolerance test (OGTT). Serum biochemical parameters and insulin levels were also assessed. Organ pathology in mice was evaluated using hematoxylin and eosin (H&E) staining. Immunofluorescence (IF) was employed to observe changes in insulin and GLP-1R expression in the pancreas of mice. The effects of medicated serum on Min6 cell growth were examined using a methyl thiazolyl tetrazolium (MTT) assay. A Min6 cell injury model was established to detect cAMP and Ca2+ concentrations. Ultra high-performance liquid chromatography-mass spectrometry (UHPLC-MS) was used to identify blood-absorbed components of XMT.

Luciferase reporter constructs driven by GLP-1R promoter response elements analysis identified that TCM formula XMT promoted GLP-1R expression. In vivo experiments demonstrated that XMT significantly reduced fasting blood glucose levels in T2DM mice and improved OGTT results. It also exhibited protective effects on islet tissues, notably increasing GLP-1R expression and insulin secretion in the pancreas. Biochemical markers indicated no significant adverse effects on liver or kidney function following XMT administration. After treatment with palmitic acid (PA), GLP-1R expression in Min6 cells was significantly decreased. However, treatment with XMT upregulated GLP-1R expression. Additionally, cyclic adenosine monophosphate (cAMP) and Ca2+ exhibited substantial improvements, and the key pancreatic growth protein PDX1 was activated.

XMT exerts hypoglycemic effects by upregulating GLP-1R gene expression, enhancing GLP-1R protein synthesis, and subsequently promoting cAMP release. This process activates Ca2+ influx in pancreatic β-cells, triggering insulin exocytosis from islet cells.

The coordinated function of beta cells within the pancreatic islet is required for the normal regulation of insulin secretion and is partly controlled by specialized "leader" and highly connected "hub" beta-cell subpopulations. Whether cells within these subpopulations are functionally stable in vivo remains unclear. Here, we establish an approach to monitor Ca 2+ dynamics within individual beta cells over time, after engraftment into the anterior eye chamber, where continuous blood perfusion and near normal innervation pertain. Under normoglycemic conditions, islet network dynamics, and the behavior of individual leaders and hubs, remain stable for at least seven days. Hyperglycemia, resulting from high-fat diet feeding or the loss of a host Gck allele, caused engrafted islets to display incomplete and abortive Ca 2+ waves and overall connectivity was diminished. Whereas hub cell numbers were lowered profoundly in both disease models, leaders largely persisted. Treatment with the GLP1R agonist Exendin-4 led to a recovery of islet-wide Ca 2+ dynamics and the re-emergence of hub cells within minutes, with the effects of the incretin mimetic being more marked than those observed after analogous treatments in vitro . Similar observations were made using 3-dimensional imaging across the whole islet. Our findings thus suggest that incretins may act both directly and indirectly on beta cells in vivo. The approach described may provide broad applicability to the exploration of individual cell function over time in the living animal.

Type 1 diabetes (T1D) is an autoimmune disease that leads to the progressive destruction of insulin-producing β cells, resulting in lifelong insulin dependence and a range of severe complications. Beyond conventional glycemic control, innovative therapeutic strategies are needed to address the underlying disease mechanisms. Recent research has highlighted gamma-aminobutyric acid (GABA) as a promising therapeutic target for T1D due to its dual role in modulating both β cell survival and immune response within pancreatic islets. GABA signaling supports β cell regeneration, inhibits α cell hyperactivity, and promotes α-to-β cell transdifferentiation, contributing to improved islet function. Moreover, GABA's influence extends to mitigating T1D complications, including nephropathy, neuropathy, and retinopathy, as well as regulating central nervous system pathways involved in glucose metabolism. This review consolidates the latest advances in GABA-related T1D therapies, covering animal preclinical and human clinical studies and examining the therapeutic potential of GABA receptor modulation, combination therapies, and dietary interventions. Emphasis is placed on the translational potential of GABA-based approaches to enhance β cell viability and counteract autoimmune processes in T1D. Our findings underscore the therapeutic promise of GABA signaling modulation as a novel approach for T1D treatment and encourage further investigation into this pathway's role in comprehensive diabetes management.

Significance: Type 2 diabetes as a world-wide epidemic is characterized by the insulin resistance concomitant to a gradual impairment of β-cell mass and function (prominently declining insulin secretion) with dysregulated fatty acids (FAs) and lipids, all involved in multiple pathological development. Recent Advances: Recently, redox signaling was recognized to be essential for insulin secretion stimulated with glucose (GSIS), branched-chain keto-acids, and FAs. FA-stimulated insulin secretion (FASIS) is a normal physiological event upon postprandial incoming chylomicrons. This contrasts with the frequent lipotoxicity observed in rodents. Critical Issues: Overfeeding causes FASIS to overlap with GSIS providing repeating hyperinsulinemia, initiates prediabetic states by lipotoxic effects and low-grade inflammation. In contrast the protective effects of lipid droplets in human β-cells counteract excessive lipids. Insulin by FASIS allows FATP1 recruitment into adipocyte plasma membranes when postprandial chylomicrons come late at already low glycemia. Future Directions: Impaired states of pancreatic β-cells and peripheral organs at prediabetes and type 2 diabetes should be revealed, including the inter-organ crosstalk by extracellular vesicles. Details of FA/lipid molecular physiology are yet to be uncovered, such as complex phenomena of FA uptake into cells, postabsorptive inactivity of G-protein-coupled receptor 40, carnitine carrier substrate specificity, the role of carnitine-O-acetyltransferase in β-cells, and lipid droplet interactions with mitochondria. Antioxid. Redox Signal. 42, 566-622.

β-adrenergic blockers (β-blockers) are extensively used to inhibit β-adrenoceptor activation and subsequent cAMP production in many cell types. In this study, we characterized the effects of β-blockers on mouse pancreatic β-cells. Unexpectedly, high concentrations (100 μM) of β-blockers (propranolol and bisoprolol) paradoxically increased cAMP levels 5-10 fold, enhanced Ca2+ influx, and stimulated a 2-4 fold increase in glucose- and glimepiride-induced insulin secretion in MIN6-K8 clonal β-cells and isolated mouse pancreatic islets. These effects were observed despite minimal expression of β-adrenoceptors in these cells. Mechanistically, the cAMP increase led to ryanodine receptor 2 (RYR2) phosphorylation via protein kinase A (PKA), triggering Ca2+-induced Ca2+ release (CICR). CICR then activates transient receptor potential cation channel subfamily M member 5 (TRPM5), resulting in increased Ca2+ influx via voltage-dependent Ca2+ channels. These effects contradict the conventional understanding of the pharmacology of β-blockers, highlighting the variability in β-blocker actions depending on the experimental context.

Pancreatic islets play a major role in glucose homeostasis as well as in diabetes, and islets-on-chip devices have been mainly developed using optical means for on-line monitoring. In contrast, no well-characterized electrophysiological platform for on-line analysis with unrivalled temporal resolution has been reported. Extracellular electrophysiology monitors two crucial parameters, islet β-cell activity and β-to-β-cell coupling, does not require chemical or genetic probes with inherent potential bias, is non-invasive and permits repetitive long-term monitoring. We have now developed and characterized a microfluidic islets-on-chip for combined electrophysiology (on-line) and hormone monitoring (off-line) with two chambers for concomitant monitoring. Fabrication of the device, based on commercial or easily manufacturable components, is within the reach of non-specialized laboratories. The chip permits convenient loading as well as long-term culture with comparable glucose kinetics and low shear stress in both chambers. An optimized flow rate did not alter islet β-cell electrical activity or coupling in response to glucose. Culturing for up to 8 days did not change islet survival as well as glucose-induced electrical or secretory kinetics of islet β-cells. The addition of a physiological amino acid mix, in the presence of elevated glucose, made a considerable change in the functional organisation of islet β-cell activity in terms of frequency and coupling, which explains the ensuing strong increase in insulin secretion. This device thus allows reliable long-term multiparametric on-line monitoring in two islet populations. The ease of fabrication, assembly and handling should permit widespread long-term on-line monitoring of islet activity in native micro-organs (e.g. controls/mutants), pseudo-islets or stem-cell-derived islet-like organoids.

Glucose-stimulated β-cells exhibit synchronized calcium dynamics across the islet that recruit β-cells to enhance insulin secretion. Compared with calcium dynamics, the formation and cell-to-cell propagation of electrical signals within the islet are poorly characterized. To determine factors that influence the propagation of electrical activity across the islet underlying calcium oscillations and β-cell synchronization, we used high-resolution complementary metal-oxide-semiconductor multielectrode arrays (CMOS-MEA) to measure voltage changes associated with the membrane potential of individual cells within intact C57BL6 mouse islets. We measured fast (milliseconds, spikes) and slow (seconds, waves) voltage dynamics. Single spike activity and wave signal velocity were both glucose-dependent, but only spike activity was influenced by N-methyl-d-aspartate receptor activation or inhibition. A repeated glucose stimulus revealed a highly responsive subset of cells in spike activity. When islets were pretreated for 72 h with glucolipotoxic medium, the wave velocity was significantly reduced. Network analysis confirmed that in response to glucolipotoxicity the synchrony of islet cells was affected due to slower propagating electrical waves and not due to altered spike activity. In summary, this approach provided novel insight regarding the propagation of electrical activity and the disruption of cell-to-cell communication due to excessive stimulation.

The high-resolution complementary metal-oxide-semiconductor multielectrode array is suited to track the spatiotemporal propagation of electrical activity through the islet on a cellular scale. A highly responsive subpopulation of islet cells was identified by action potential-like spike activity and proved to be robust to glucolipotoxicity. Electrical waves revealed synchronized electrical activity and their propagation through the islet was slowed down by glucolipotoxicity. The N-methyl-d-aspartate receptor did not influence islet synchronization since modulation of the receptor only affected electrical spikes. The technique is a useful tool for exploring the pancreatic islet network in health and disease.

After a century of extensive scientific investigations, there is still no curative or disease-modifying treatment available that can provide long-lasting remission for patients diagnosed with type 1 diabetes (T1D). Although T1D has historically been regarded as a classic autoimmune disorder targeting and destroying pancreatic islet β-cells, significant research has recently demonstrated that β-cells themselves also play a substantial role in the disease's progression, which could explain some of the unfavorable clinical outcomes. We offer a thorough review of scientific and clinical insights pertaining to molecular mechanisms behind pathogenesis and the different therapeutic interventions in T1D covering over 20 possible pharmaceutical intervention treatments. The interventions are categorized as immune therapies, treatments targeting islet endocrine dysfunctions, medications with dual modes of action in immune and islet endocrine cells, and combination treatments with a broader spectrum of activity. We suggest that these collective findings can provide a valuable platform to discover new combinatorial synergies in search of the curative disease-modifying intervention for T1D. SIGNIFICANCE STATEMENT: This research delves into the underlying causes of T1D and identifies critical mechanisms governing β-cell function in both healthy and diseased states. Thus, we identify specific pathways that could be manipulated by existing or new pharmacological interventions. These interventions fall into several categories: (1) immunomodifying therapies individually targeting immune cell processes, (2) interventions targeting β-cells, (3) compounds that act simultaneously on both immune cell and β-cell pathways, and (4) combinations of compounds simultaneously targeting immune and β-cell pathways.

Abnormal glucose metabolism inevitably disrupts normal neuronal function, a phenomenon widely observed in Alzheimer's disease (AD). Investigating the mechanisms of metabolic adaptation during disease progression has become a central focus of research. Considering that impaired glucose metabolism is closely related to decreased insulin signaling and insulin resistance, a new concept "type 3 diabetes mellitus (T3DM)" has been coined. T3DM specifically refers to the brain's neurons becoming unresponsive to insulin, underscoring the strong link between diabetes and AD. Recent studies reveal that during brain insulin resistance, neurons exhibit mitochondrial dysfunction, reduced glucose metabolism, and elevated lactate levels. These findings suggest that impaired insulin signaling caused by T3DM may lead to a compensatory metabolic shift in neurons toward glycolysis. Consequently, this review aims to explore the underlying causes of T3DM and elucidate how insulin resistance drives metabolic reprogramming in neurons during AD progression. Additionally, it highlights therapeutic strategies targeting insulin sensitivity and mitochondrial function as promising avenues for the successful development of AD treatments.

Circular RNAs (circRNAs) are stable, covalently closed non-coding RNAs formed by reverse splicing of precursor mRNA. They play critical roles in various biological processes, including insulin secretion and metabolism. However, their function in avian skeletal muscle's response to insulin remains poorly understood. This study aimed to comprehensively identify insulin-responsive circRNAs and explore their temporal and breed-specific regulation in poultry.

Using strand-specific RNA sequencing (ssRNA-Seq) on the pectoralis muscles of both Arbor Acres (AA) broilers and Silky fowls following insulin administration (5 IU/kg.BW, PBS as control). We identified 2,027 muscle circRNAs. Insulin-responsive circRNAs were detected in Silky fowls (29) and broilers (45) at 120 min, and in broilers (20) at 15 min post-injection. These circRNAs are enriched in processes such as exocrine pancreas development, response to exogenous stimuli, and regulation of intracellular signal transduction, likely mediated through a circRNA-miRNA network. Fewer insulin-responsive circRNAs were shared between time points in broilers (1) or between breeds (3) at 120 min. We further characterized a conserved insulin-responsive circRNA (circINSR), formed by exon 2 of the Insulin Receptor (INSR). The circINSR showed a similar spatiotemporal expression pattern to INSR, but exhibited distinct changes post-insulin administration. In broilers, INSR expression was dynamically modulated, while circINSR was downregulated only at 15 min (P < 0.01). Conversely, glucose did not change muscle circINSR but increased INSR at 10 min (P < 0.01). Energy restriction significantly downregulated circINSR (P < 0.01) without affecting INSR levels, and pyruvate had no effect on either circINSR or INSR levels.

This study reveals the dynamic and breed-specific roles of circRNAs, particularly circINSR, in avian skeletal muscle's response to insulin. The distinct regulation of circINSR and INSR under various metabolic conditions suggests a complex regulatory mechanism. These findings provide novel insights into the molecular basis of insulin signaling in avian species and highlight the potential of circRNAs as biomarkers for metabolic regulation.

Glucose-stimulated insulin secretion (GSIS) in pancreatic β cells is vital to metabolic homeostasis. Recent evidence has highlighted the critical role of the cells' microtubule (MT) cytoskeleton in regulating transport and availability of insulin containing vesicles. How these vesicles move within the cell and how that mobility is influenced by the MT network is however not well understood. The MT network in these cells is dense and randomly oriented. Further insulin vesicles are relatively large compared to the spaces in this dense meshwork. Here we develop a 3D computational model that simulates vesicle motions in the dense MT network of the β cell. The structure of this MT network, along with the dynamics of vesicle motions, are calibrated to microscopy data from β cells to ensure physiological relevance. Our results reveal a number of key observations. 1) The MT network in β cells likely impairs motion of larger vesicles (200 - 300 nm in diameter). 2) This is in part a consequence of their "caging" by the MT network. 3) This results in a substantial reduction in the likelihood of vesicles transiting from the cells interior to the plasma membrane, a pre-cursor to GSIS. 4) Dynamic remodeling of the MT network reduces the strength of these effects. 5) That same remodeling however introduces anomalous (sub-diffusion) motion characteristics. Taken together, these results indicate that the dense MT network of the β cell substantially inhibits mobility and availability (for GSIS) of insulin. It further sheds light on how the complex filament network in cells leads to statistically anomalous motions. Finally, this modeling further provides a test-bed for determining how potential manipulations of the structure and dynamics of this network would tune GSIS.

Insulin release from pancreatic β cells is crucial for blood sugar regulation, and recent research suggests the microtubule network inside these cells plays a key role in how insulin is transported and released. This study developed a 3D computational model to explore how insulin vesicles move through this dense network. Results show that the microtubules can "cage" larger vesicles, making it difficult for them to reach the cell surface for insulin release. Dynamic remodeling of the network can however increase insulin mobility and availability. These findings highlight the impact of the microtubule network on insulin transport and secretion and provide insight into potential ways to tune this process.

The adenosine triphosphate (ATP)-sensitive potassium (KATP) channels, composed of Kir6.2 and sulfonylurea receptor 1 (SUR1) subunits, are essential for glucose homeostasis. While the role of pancreatic KATP channels in regulating insulin secretion is well-documented, the specific contributions of neuronal KATP channels remain unclear due to challenges in precisely targeting neuronal subpopulations. In this study, we utilized a Kir6.2 conditional knockout mouse model to distinguish the roles of KATP channels in different cell types. Our findings demonstrate that deletion of neuronal KATP channels does not impair glucose homeostasis, as glucose-sensing neurons retained their responsiveness despite the absence of functional KATP channels. In contrast, the deletion of KATP channels in pancreatic β cells led to significant hyperglycemia and glucose intolerance, indicating unstable blood glucose levels under varying physiological conditions. Importantly, we showed that restoring KATP channel function exclusively in pancreatic β cells within a global Kir6.2 knockout background effectively reversed glucose regulation defects. This underscores the critical role of pancreatic KATP channels in maintaining systemic glucose homeostasis. Our results challenge the previous hypothesis that neuronal KATP channels are essential for glucose regulation, suggesting that their primary function may be neuroprotective rather than homeostatic. These findings highlight pancreatic KATP channels as key regulators of glucose balance and potential therapeutic targets for correcting glucose dysregulation.

The Cullin-3 E3 ligase adaptor protein SPOP targets proteins for ubiquitination and proteasomal degradation. We previously established the β-cell transcription factor (TF) and human diabetes gene PDX1 as an SPOP substrate, suggesting a functional role for SPOP in the β cell. Here, we generated a β-cell-specific Spop deletion mouse strain (Spop βKO) and found that Spop is necessary to prevent aberrant basal insulin secretion and for maintaining glucose-stimulated insulin secretion through impacts on glycolysis and glucose-stimulated calcium flux. Integration of proteomic, TF-regulatory gene network, and biochemical analyses identified XBP1 as a functionally important SPOP substrate in pancreatic β cells. Furthermore, loss of SPOP strengthened the IRE1α-XBP1 axis of unfolded protein response (UPR) signaling. ER stress promoted proteasomal degradation of SPOP, supporting a model whereby SPOP fine-tunes XBP1 activation during the UPR. These results position SPOP as a regulator of β-cell function and proper UPR activation.

The crucial steps in beta cell stimulus-secretion coupling upon stimulation with glucose are oscillatory changes in metabolism, membrane potential, intracellular calcium concentration, and exocytosis. The changes in membrane potential consist of bursts of spikes, with silent phases between them being dominated by membrane repolarization and absence of spikes. Assessing intra- and intercellular coupling at the multicellular level is possible with ever-increasing detail, but our current ability to simultaneously resolve spikes from many beta cells remains limited to double-impalement electrophysiological recordings.

Since multicellular calcium imaging of spikes would enable a better understanding of coupling between changes in membrane potential and calcium concentration in beta cell collectives, we set out to design an appropriate methodological approach.

Combining the acute tissue slice method with ultrafast calcium imaging, we were able to resolve and quantify individual spikes within bursts at a temporal resolution of >150 Hz over prolonged periods, as well as describe their glucose-dependent properties. In addition, by simultaneous patch-clamp recordings we were able to show that calcium spikes closely follow membrane potential changes. Both bursts and spikes coordinate across islets in the form of intercellular waves, with bursts typically displaying global and spikes more local patterns.

This method and the associated findings provide additional insight into the complex signaling within beta cell networks. Once extended to tissue from diabetic animals and human donors, this approach could help us better understand the mechanistic basis of diabetes and find new molecular targets.

Intermittent hypoxemia (IH), a pathophysiologic consequence of obstructive sleep apnea (OSA), adversely affects insulin sensitivity, insulin secretion, and glucose tolerance. Nifedipine, an L-type calcium channel blocker frequently used for the treatment of hypertension, can also impair insulin sensitivity and secretion. However, the cumulative and interactive repercussions of IH and nifedipine on glucose homeostasis have not been previously investigated. Adult male C57BL6/J mice were exposed to either nifedipine or vehicle concurrently with IH or intermittent air (IA) over 5 days. IH exposure entailed cycling fractional-inspired oxygen levels between 0.21 and 0.055 at a rate of 60 events/h. Nifedipine (20 mg/kg/day) or vehicle was administered via subcutaneous osmotic pumps resulting in four groups of mice: IA-vehicle (control), IA-nifedipine, IH-vehicle, and IH-nifedipine. Compared with IA (control), IH increased fasting glucose (mean Δ: 33.0 mg/dL; P < 0.001) and insulin (mean Δ: 0.53 ng/mL; P < 0.001) with nifedipine having no independent effect. Furthermore, glucose tolerance was worse with nifedipine alone, and IH further exacerbated the impairment in glucose disposal (P = 0.013 for interaction). Nifedipine also decreased glucose-stimulated insulin secretion and the insulinogenic index, with addition of IH attenuating those measures further. There were no discernible alterations in insulin biosynthesis/processing, insulin content, or islet morphology. These findings underscore the detrimental impact of IH on insulin sensitivity and glucose tolerance while highlighting that nifedipine exacerbates these disturbances through impaired β-cell function. Consequently, cautious use of L-type calcium channel blockers is warranted in patients with OSA, particularly in those at risk for type 2 diabetes.NEW & NOTEWORTHY The results of this study demonstrate the interaction between intermittent hypoxemia (IH) and nifedipine in a murine model. IH raises fasting glucose and insulin levels, with nifedipine exacerbating these disturbances. Glucose tolerance worsens when nifedipine is administered alone, and IH magnifies the impairment in glucose disposal. These findings raise the possibility of potential deleterious effects of L-type calcium channel blockers in patients with obstructive sleep apnea (OSA).

Diabetes is characterized by variable loss of insulin-producing beta cells, and new regenerative approaches to increasing the functional beta cell mass of patients hold promise for reversing disease progression. In this Review, we summarize recent chemical biology breakthroughs advancing our knowledge of beta cell regeneration. We present current chemical-based tools, sensors and mechanistic insights into pathways that can be targeted to enhance beta cell regeneration in model organisms. We group the pathways according to the cellular processes they affect, that is, proliferation, conversion of other mature cell types to beta cells and beta cell differentiation from progenitor-like populations. We also suggest assays for assessing the functionality of the regenerated beta cells. Although regeneration processes differ between animal models, such as zebrafish, mice and pigs, regenerative mechanisms identified in any one animal model may be translatable to humans. Overall, chemical biology-based approaches in beta cell regeneration give hope that specific molecular pathways can be targeted to enhance beta cell regeneration.

Pancreatic islets maintain glucose homeostasis through coordinated action of their constituent endocrine and affiliate cell types and are central to type 2 diabetes (T2D) genetics and pathophysiology. Our understanding of robust human islet cell type-specific alterations in T2D remains limited. Here, we report comprehensive single cell transcriptome profiling of 245,878 human islet cells from a 48-donor cohort spanning non-diabetic (ND), pre-diabetic (PD), and T2D states, identifying 14 distinct cell types detected in every donor from each glycemic state. Cohort analysis reveals ~25-30% loss of functional beta cell mass in T2D vs. ND or PD donors resulting from (1) reduced total beta cell numbers/proportions and (2) reciprocal loss of 'high function' and gain of senescent β -cell subpopulations. We identify in T2D β -cells 511 differentially expressed genes (DEGs), including new (66.5%) and validated genes (e.g., FXYD2, SLC2A2, SYT1), and significant neuronal transmission and vitamin A metabolism pathway alterations. Importantly, we demonstrate newly identified DEG roles in human β -cell viability and/or insulin secretion and link 47 DEGs to diabetes-relevant phenotypes in knockout mice, implicating them as potential causal islet dysfunction genes. Additionally, we nominate as candidate T2D causal genes and therapeutic targets 27 DEGs for which T2D genetic risk variants (GWAS SNPs) and pathophysiology (T2D vs. ND) exert concordant expression effects. We provide this freely accessible atlas for data exploration, analysis, and hypothesis testing. Together, this study provides new genomic resources for and insights into T2D pathophysiology and human islet dysfunction.

Diabetes is a chronic metabolic disorder whose prevalence increases every year, affecting more than 530 million adults worldwide. Type 1 (T1D) and type 2 diabetes (T2D), the most common forms of diabetes, are characterized by the loss of functional pancreatic β-cells, mostly due to apoptosis. B-cell leukemia/lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xL), two anti-apoptotic proteins belonging to the Bcl-2 family, are crucial for regulating the intrinsic pathway of apoptosis. However, over the years, they have been implicated in many other cellular processes, including intracellular Ca2+ homeostasis and the regulation of mitochondrial metabolism. Thus, understanding the biological processes in which these proteins are involved may be crucial to designing new therapeutic targets. This review summarizes the roles of Bcl-2 and Bcl-xL in apoptosis and metabolic homeostasis. It focuses on how the dysregulation of Bcl-2 and Bcl-xL affects pancreatic β-cell function and survival, and the consequences for diabetes development.

Rationale: The current understanding on manipulating signaling pathways to generate mature human islet organoids with all major hormone-secreting endocrine cell types (i.e., α, β, δ, and γ cells) from induced pluripotent stem cells (iPSCs) is insufficient. However, donor islet shortage necessitates that we produce functional islets in vitro. In this study, we aimed to find decellularized pancreatic extracellular matrix (dpECM) proteins that leverage signaling pathways and promote functional iPSC islet organogenesis. Methods: We performed proteomic analysis to identify key islet promoting factors from porcine and rat dpECM. With this, we identified collagen type II (COL2) as a potential biomaterial cue that endorses islet development from iPSCs. Using global transcriptome profiling, gene set enrichment analysis, immunofluorescence microscopy, flow cytometry, Western blot, and glucose-stimulated hormonal secretion analysis, we examined COL2's role in regulating iPSC pancreatic lineage specification and signaling pathways, critical to islet organogenesis and morphogenesis. Results: We discovered COL2 acts as a functional biomaterial that augments islet development from iPSCs, similar to collagen type V (COL5) as reported in our earlier study. COL2 substantially stimulates the formation of endocrine progenitors and subsequent islet organoids with significantly elevated expressions of pancreatic signature genes and proteins. Furthermore, it enhances islets' glucose sensitivity for hormonal secretion. A cluster of gene expressions associated with various signaling pathways, including but not limited to oxidative phosphorylation, insulin secretion, cell cycle, the canonical WNT, hypoxia, and interferon-γ response, were considerably affected by COL2 and COL5 cues. Conclusion: We demonstrated dpECM's crucial role in refining stem cell differentiation microenvironments for organoid development and maturation. Our findings on biomaterial-stimulated signaling for stem cell specification, organogenesis, and maturation open up a new way to increase the differentiation efficacy of endocrine tissues that can contribute to the production of biologically functional islets.

Metabolic peptides can influence metabolic processes and contribute to both inflammatory and/or anti-inflammatory responses. Studies have shown that there are thousands of metabolic peptides, made up of short chains of amino acids, that the human body produces. These peptides are crucial for regulating many different processes like metabolism and cell signaling, as they bind to receptors on various cells. This review will cover the role of three specific metabolic peptides and their roles in hyperinsulinemia, diabetes, inflammation, and neurodegeneration, as well as their roles in type 3 diabetes and dementia. The metabolic peptides glucagon-like peptide 1 (GLP-1), gastric inhibitor polypeptide (GIP), and pancreatic peptide (PP) will be discussed, as dysregulation within their processes can lead to the development of various inflammatory and neurodegenerative diseases. Research has been able to closely investigate the connections between these metabolic peptides and their links to the gut-brain axis, highlighting changes made in the gut that can lead to dysfunction in processes in the brain, as well as changes made in the brain that can lead to dysregulation in the gut. The role of metabolic peptides in the development and potentially reversal of diseases such as obesity, hyperinsulinemia, and type 2 diabetes will also be discussed. Furthermore, we review the potential links between these conditions and neuroinflammation and the development of neurodegenerative diseases like dementia, specifically Parkinson's disease and Alzheimer's disease.

Type 2 diabetes (T2D), the most common form, is marked by insulin resistance and β-cell failure. β-cell dysfunction under high-glucose-high-lipid (HG-HL) conditions is a key contributor to the progression of T2D. This study evaluates the comparative effects of 10 nM semaglutide, 10 nM tirzepatide, and 1 mM metformin, both alone and in combination, on INS-1 β-cell maintenance and function under HG-HL conditions. INS-1 cells were pretreated for 2 h with single doses of metformin (1 mM), semaglutide (10 nM), tirzepatide (10 nM), or combinations of 1 mM metformin with either 10 nM semaglutide or 10 nM tirzepatide, followed by 48 h of HG-HL stimulation. The results indicate that combining 1 mM metformin with either 10 nM semaglutide or 10 nM tirzepatide significantly enhances the effects of 10 nM semaglutide and 10 nM tirzepatide on HG-HL-induced apoptosis and dysregulated cell cycle. Specifically, the combination treatments demonstrated superior restoration of glucose-stimulated insulin secretion (GSIS) functionality compared to 1 mM metformin, 10 nM semaglutide, and 10 nM tirzepatide.

The pituitary gland produces and secretes a variety of hormones that are essential to life, such as for the regulation of growth and development, metabolism, reproduction, and the stress response. This is achieved through an intricate signalling interplay between the brain and peripheral feedback signals that shape pituitary cell excitability by regulating the ion channel properties of these cells. In addition, endocrine anterior pituitary cells spontaneously fire action potentials to regulate the intracellular calcium ([Ca2+]i) level, an essential signalling conduit for hormonal secretion. To this end, pituitary cells must regulate their resting membrane potential (RMP) close to the firing threshold, but the molecular identity of the ionic mechanisms responsible for this remains largely unknown. Here, we revealed that the sodium leak channel NALCN, known to modulate neuronal excitability elsewhere in the brain, regulates excitability in the mouse anterior endocrine pituitary cells. Using viral transduction combined with powerful electrophysiology methods and calcium imaging, we show that NALCN forms the major Na+ leak conductance in these cells, appropriately tuning cellular RMP for sustaining spontaneous firing activity. Genetic depletion of NALCN channel activity drastically hyperpolarised these cells, suppressing their firing and [Ca2+]i oscillations. Remarkably, despite this profound function of NALCN conductance in controlling pituitary cell excitability, it represents a very small fraction of the total cell conductance. Because NALCN responds to hypothalamic hormones, our results also provide a plausible mechanism through which hormonal feedback signals from the brain and body could powerfully affect pituitary activity to influence hormonal function. KEY POINTS: Pituitary hormones are essential to life as they regulate important physiological processes, such as growth and development, metabolism, reproduction and the stress response. Pituitary hormonal secretion relies on the spontaneous electrical activity of pituitary cells and co-ordinated inputs from the brain and periphery. This appropriately regulates intracellular calcium signals in pituitary cells to trigger hormonal release. Using viral transduction in combination with electrophysiology and calcium imaging, we show that the activity of the background leak channel NALCN is a major controlling factor in eliciting spontaneous electrical activity and intracellular calcium signalling in pituitary cells. Remarkably, our results revealed that a minute change in NALCN activity could have a major influence on pituitary cell excitability. Our study provides a plausible mechanism through which the brain and body could intricately control pituitary activity to influence hormonal function.

Loss and functional failure of pancreatic β-cells results in disruption of glucose homeostasis and progression of diabetes. Although whole pancreas or pancreatic islet transplantation serves as a promising approach for β-cell replenishment and diabetes therapy, the severe scarcity of donor islets makes it unattainable for most diabetic patients. Stem cells, particularly induced pluripotent stem cells (iPSCs), are promising for the treatment of diabetes owing to their self-renewal capacity and ability to differentiate into functional β-cells. In this review, we first introduce the development of functional β-cells and their heterogeneity and then turn to highlight recent advances in the generation of β-cells from stem cells and their potential applications in disease modeling, drug discovery and clinical therapy. Finally, we have discussed the current challenges in developing stem cell-based therapeutic strategies for improving the treatment of diabetes. Although some significant technical hurdles remain, stem cells offer great hope for patients with diabetes and will certainly transform future clinical practice.

Modern bioelectronic tools are rapidly advancing to detect electric potentials within networks of electrogenic cells, such as cardiomyocytes, neurons, and pancreatic beta cells. However, it is becoming evident that electrical signaling is not limited to the animal kingdom but may be a universal form of cell-cell communication. In this review, we discuss the existing evidence of, and tools used to collect, subcellular, single-cell and network-level electrical signals across kingdoms, including bacteria, plants, fungi, and even viruses. We discuss how cellular networks employ altered electrical "circuitry" and intercellular mechanisms across kingdoms, and we assess the functionality and scalability of cutting-edge nanobioelectronics to collect electrical signatures regardless of cell size, shape, or function. Researchers today aim to design micro- and nano-topographic structures which harness mechanosensitive membrane and cytoskeletal pathways that enable tight electrical coupling to subcellular compartments within high-throughput recording systems. Finally, we identify gaps in current knowledge of inter-species and inter-kingdom electrical signaling and propose critical milestones needed to create a central theory of electrical signaling across kingdoms. Our discussion demonstrates the need for high resolution, high throughput tools which can probe multiple, diverse cell types at once in their native or experimentally-modeled environments. These advancements will not only reveal the underlying biophysical laws governing the universal language of electrical communication, but can enable bidirectional electrical communication and manipulation of biological systems.

Type 1 diabetes mellitus (T1DM) is a condition marked by elevated blood sugar levels and primarily recognized by the destruction of beta cells caused by an autoimmune attack, which is a significant characteristic of T1DM. Recent studies have demonstrated the regenerative potential of conditioned medium therapy. In light of this, the current research sought to assess the impact of Mesenchymal Stem Cell conditioned media (CM) and CM with resveratrol (CM+ Resveratrol) on the management of T1DM in Swiss albino mice. By leveraging and modifying existing conditioned medium therapy, this study aims to evaluate its effectiveness in treating T1DM.

Diabetes was induced in animals using the diabetes-inducing agent streptozotocin (STZ). The animals were then divided into five groups: Normal control, Disease Control, Resveratrol, Condition Media, and CM + Resveratrol. Treatments were given to the animals accordingly. The study period was 28 days. During this time, the animals were monitored for foodwater intake twice a week, blood glucose levels, and body weight. At the conclusion of the 28-day study period, biochemical estimations were performed for serum insulin levels, C-peptide levels, anti-inflammatory cytokines levels and pro-inflammatory cytokines levels. Additionally, histopathology of the pancreas was performed.

The test groups showed a significant decrease in blood glucose levels, an increase in Cpeptide levels, and a decrease in pro-inflammatory cytokine levels compared to the disease group. However, no statistically significant change within groups was observed in terms of serum insulin and anti-inflammatory cytokine levels. The improvement in diabetic symptoms, such as polyphagia, polydipsia, and weight loss, was observed in the treatment group, along with pancreatic regeneration, which indicated improved insulin secretion.

In the current investigation, we concluded that CM and CM+ Resveratrol, as natural immunomodulators, have the capacity to regenerate injured pancreatic beta cells and have antidiabetic action, together with immunomodulating impact. Nonetheless, future studies on this therapy appear to be promising.

Single cell Amperometry (SCA) is a powerful, sensitive, high temporal resolution electrochemical technique used to quantify secreted molecular messengers from individual cells and vesicles. This technique has been extensively applied to study the process of exocytosis, and it has also been applied, albeit less frequently, to investigate insulin exocytosis from single pancreatic beta cells. Insufficient insulin release can lead to diabetes, a chronic lifestyle disorder that affects millions of people worldwide. This review aims to summarize and highlight electrochemical measurements of insulin via monitoring its secretion from beta cells by SCA with micro- and nanoelectrodes since the 1990s and to explain how and why serotonin is used as a proxy for monitoring insulin during exocytosis from single beta cells. Finally, we describe how the combination of SCA measurements with the intracellular vesicle impact electrochemical cytometry (IVIEC) technique has led to important findings regarding fractional release types in beta cells. These findings, reported recently, have opened a new window in the study of pore formation, exocytosis from single vesicles, and the mechanisms of insulin secretion. This sensitive cellular electroanalysis approach should help in the development of novel therapeutic strategies targeting diabetes in the future.

Electrophysiology typically deals with the electrical properties of excitable cells like neurons and muscles. However, all other cells (non-excitable) also possess bioelectric membrane potentials for intracellular and extracellular communications. These membrane potentials are generated by different ions present in fluids available in and outside the cell, playing a vital role in communication and coordination between the cell and its organelles. Bioelectric membrane potential variations disturb cellular ionic homeostasis and are characteristic of many diseases, including cancers. A rapidly increasing interest has emerged in sorting out the electrophysiology of cancer cells. Compared to healthy cells, the distinct electrical properties exhibited by cancer cells offer a unique way of understanding cancer development, migration, and progression. Decoding the altered bioelectric signals influenced by fluctuating electric fields benefits understanding cancer more closely. While cancer research has predominantly focussed on genetic and molecular traits, the delicate area of electrophysiological characteristics has increasingly gained prominence. This review explores the historical exploration of electrophysiology in the context of cancer cells, shedding light on how alterations in bioelectric membrane potentials, mediated by ion channels and gap junctions, contribute to the pathophysiology of cancer.