Enamel protects teeth from external irritation and its formation involves sequential differentiation of ameloblasts, a dental epithelial cell. Keratinocyte differentiation factor 1 (KDF1) is important in the development of epithelial tissues and organs. However, the specific role of KDF1 in enamel formation and corresponding regulatory mechanisms are unclear. This study demonstrated that KDF1 was persistently expressed in all stages of ameloblast differentiation, through RNAscope in situ hybridization. KDF1 expression in the mouse ameloblast cell line LS8 was demonstrated via immunofluorescence assay. KDF1 was knocked out in LS8 cells using the CRISPR/Cas-9 system or overexpressed in LS8 cells through lentiviral infection. In vitro ameloblast differentiation induction, quantitative reverse transcription PCR, western blot analysis, and alkaline phosphatase (ALP) assay indicated that knockout or overexpression of KDF1 in LS8 cells decreased or increased the mRNA and protein levels of several key amelogenesis markers, as well as ALP activity. Furthermore, liquid chromatography-mass spectrometry and co-immunoprecipitation analyses revealed that KDF1 can interact with the IKK complex, thereby inhibiting the NF-κB pathway. Suppressing NF-κB activity partially recovered the decreased ameloblast differentiation in LS8 cells induced by KDF1-knockout. This study demonstrated that KDF1 can promote ameloblast differentiation of LS8 cells by inhibiting the IKK/IκB/NF-κB axis, and is a potential target for functional enamel regeneration.

Children with neurodevelopmental disorders (NDDs) often have poor oral health and dental abnormalities. An increasing number of genes have been associated with neurodevelopmental conditions affecting the oral cavity, but the specific dental features associated with many genes remain unknown.

To report the types and frequencies of dental manifestations in children with neurodevelopmental conditions of known genetic cause.

A 30-question survey assesing ectodermal and dental features was administered through Simons Searchlight, with which formed a recontactable cohort of individuals with genetic NDDs often associated with autism spectrum disorder (ASD).

Data were collected from a largely paediatric population with 620 affected individuals across 39 genetic conditions and 145 unaffected siblings without NDDs for comparison. Drooling, difficulty accessing dental care, late primary teeth eruption, abnormal primary and permanent teeth formation, misshapen nails, and hair loss were more frequent in individuals with NDDs. Additionally, we evidenced an association between three new pathogenic gene variant/oral manifestation pairs: CSNK2A1/unusual primary teeth, DYRK1A/late primary teeth eruption, and PPP2R5D/sialorrhea.

Our results demonstrate that genetic NDDs caused by mutations in CSNK2A1, DYRK1A, and PP2R5D are associated with unique dental manifestations, and knowledge of these features can be helpful to personalize dental care.

The increasing life expectancy has led to a higher incidence of age-related neurodegenerative conditions. Within this framework, neuroinflammation emerges as a significant contributing factor. It involves the activation of microglia and astrocytes, leading to the release of pro-inflammatory cytokines and chemokines and the infiltration of peripheral leukocytes into the central nervous system (CNS). These instances result in neuronal damage and neurodegeneration through activated nucleotide-binding domain and leucine-rich repeat containing (NLR) family pyrin domain containing protein 3 (NLRP3) and nuclear factor kappa B (NF-kB) pathways and decreased nuclear factor erythroid 2-related factor 2 (Nrf2) activity. Due to limited effectiveness regarding the inhibition of neuroinflammatory targets using conventional drugs, there is challenging growth in the search for innovative therapies for alleviating neuroinflammation in CNS diseases or even before their onset. Our results indicate that interventions focusing on Interleukin-Driven Immunomodulation, Chemokine (CXC) Receptor Signaling and Expression, Cold Exposure, and Fibrin-Targeted strategies significantly promise to mitigate neuroinflammatory processes. These approaches demonstrate potential anti-neuroinflammatory effects, addressing conditions such as Multiple Sclerosis, Experimental autoimmune encephalomyelitis, Parkinson's Disease, and Alzheimer's Disease. While the findings are promising, immunomodulatory therapies often face limitations due to Immune-Related Adverse Events. Therefore, the conduction of randomized clinical trials in this matter is mandatory, and will pave the way for a promising future in the development of new medicines with specific therapeutic targets.

Glucosamine (GlcN) is a glycosaminoglycan (GAGs) constituent in connective tissues. It is naturally produced by our body or consumed from diets. In the last decade, in vitro and in vivo trials have demonstrated that the administration of GlcN or its derivates has a protective effect on cartilage when the balance between catabolic and anabolic processes is disrupted and cells are no longer able to fully compensate for the loss of collagen and proteoglycans. To date, these benefits are still controversial because the mechanism of action of GlcN is not yet well clarified. In this study, we have characterized the biological activities of an amino acid (AA) derivate of GlcN, called DCF001, in the growth and chondrogenic induction of circulating multipotent stem cells (CMCs) after priming with tumor necrosis factor-alpha (TNFα), a pleiotropic cytokine commonly expressed in chronic inflammatory joint diseases. In the present work, stem cells were isolated from the human peripheral blood of healthy donors. After priming with TNFα (10 ng/mL) for 3 h, cultures were treated for 24 h with DCF001 (1 μg/mL) dissolved in a proliferative (PM) or chondrogenic (CM) medium. Cell proliferation was analyzed using a Corning^® Cell Counter and trypan blue exclusion technique. To evaluate the potentialities of DCF001 in counteracting the inflammatory response to TNFα, we measured the amount of extracellular ATP (eATP) and the expression of adenosine-generating enzymes CD39/CD73, TNFα receptors, and NF-κB inhibitor IκBα using flow cytometry. Finally, total RNA was extracted to perform a gene expression study of some chondrogenic differentiation markers (COL2A1, RUNX2, and MMP13). Our analysis has shed light on the ability of DCF001 to (a) regulate the expression of CD39, CD73, and TNF receptors; (b) modulate eATP under differentiative induction; (c) enhance the inhibitory activity of IκBα, reducing its phosphorylation after TNFα stimulation; and (d) preserve the chondrogenic potentialities of stem cells. Although preliminary, these results suggest that DCF001 could be a valuable supplement for ameliorating the outcome of cartilage repair interventions, enhancing the efficacy of endogenous stem cells under inflammatory stimuli.

Transforming growth factor (TGFβ) is known to play a major role in establishment and maintenance of endometriosis as reported by our group earlier, the underlying mechanism remains to be explored. We deciphered the involvement of TAK1 in TGFβ1- induced cellular responses and delineated the signaling mechanism in human endometriotic cells. The endometriotic cells showed elevated expression of TGFβ1 signaling-effector molecules. TGFβ1 exposure to endometriotic cells induced the expression of the downstream target molecules indicating that TGFβ1 is implicated in the commencement ofTAK1/NFκB-p65/Smad7 cascade. The silencing of TAK1 in endometriotic cells attenuated the TGFβ1 -induced NFκB transcriptional activation and nuclear translocation of NFκB-p65 subunit. The pharmacological inhibition of NFκB by QNZ or knockdown of TAK1 reduced the expression of Smad7 and Cox2. The knockdown of TAK1 in endometriotic cells showed G1 phase cell-cycle arrest and showed low BrdU-incorporation in the presence of TGFβ1. The inhibition of TAK1 attenuated the TGFβ1 signaling activation indicating that TAK1 is a crucial mediator for TGFβ1 action in endometriotic cells. The exposure of endometriotic cells to TAK1 inhibitor, celastrol caused activation of caspase-3 and -9 that led to PARP cleavage and induced apoptosis. Simultaneously, autophagy occurred in celastrol-treated and TAK1-silenced cells as was evidenced by the formation of autophagosome and the increased expression of autophagic markers. Thus, TAK1 activation appears to protect the growth of endometriotic cells by suppressing the cell death process. Overall, our study provided the evidence that of TAK1 significant in the endometriotic cell regulation and mediates a functional cross-talk between TGFβ1 and NFκB-p65 that promotes the growth and inflammatory response in endometriotic cells.

Although safflower seed extract exhibits pharmacological activity against various diseases, the effects of its individual compounds on osteoarthritis (OA) have not been elucidated. Here, we evaluated the effects of these extracts and their single compounds on OA. N-(p-Coumaroyl) serotonin and N-feruloyl serotonin, main components of safflower seed extract, were isolated by high-performance liquid chromatography. Under in vitro OA mimic conditions, the expression of the matrix metalloproteinases (MMPs) MMP3/13 and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) ADAMTS5 were reduced in mouse chondrocytes treated with safflower seed extract. Furthermore, the oral administration of safflower seed extract attenuated cartilage destruction in a mouse OA model induced by destabilization of the medial meniscus. N-(p-Coumaroyl) serotonin and N-feruloyl serotonin, but not serotonin, reduced MMP3, MMP13, and ADAMTS5 expression in IL-1β-treated chondrocytes. Additionally, they significantly blocked the nuclear factor-κB (NF-κB) pathway by inhibiting IκB degradation and p65 phosphorylation. Our results suggest that safflower seed extract and its single compounds can attenuate cartilage destruction by suppressing MMP and ADMATS5 expression. The anti-arthritic effects are mediated by NF-κB signaling and involve the inhibition of IκB degradation and p65 phosphorylation. These results indicate that safflower seed extract may serve as a novel therapeutic agent against OA.

Hypohidrotic ectodermal dysplasia (HED) is a hereditary disorder characterized by abnormal structures and functions of the ectoderm-derived organs, including teeth. HED patients exhibit a variety of dental symptoms, such as hypodontia. Although disruption of the EDA/EDAR/EDARADD/NF-κB pathway is known to be responsible for HED, it remains unclear whether this pathway is involved in the process of enamel formation.

To address this question, we examined the mice overexpressing Ikkβ (an essential component required for the activation of NF-κB pathway) under the keratin 5 promoter (K5-Ikkβ).

Upregulation of the NF-κB pathway was confirmed in the ameloblasts of K5-Ikkβ mice. Premature abrasion was observed in the molars of K5-Ikkβ mice, which was accompanied by less mineralized enamel. However, no significant changes were observed in the enamel thickness and the pattern of enamel rods in K5-Ikkβ mice. Klk4 expression was significantly upregulated in the ameloblasts of K5-Ikkβ mice at the maturation stage, and the expression of its substrate, amelogenin, was remarkably reduced. This suggests that abnormal enamel observed in K5-Ikkβ mice was likely due to the compromised degradation of enamel protein at the maturation stage.

Therefore, we could conclude that the overactivation of the NF-κB pathway impairs the process of amelogenesis.