• Hypoxic priming, 3D culture priming
• Mesenchymal stromal/stem cell paracrine effects
• Mesenchymal stromal/stem cell priming
• Mesenchymal stromal/stem cell therapeutic properties
• Mesenchymal stromal/stem cells
• Pro-inflammatory priming

• Cardiac regeneration
• Cardiac repair
• Mesenchymal stem cell
• Myocardial ischemia
• Paracrine
• Secreted

• Humans
• Mesenchymal Stem Cell Transplantation
• Paracrine Communication
• Cardiovascular Diseases/therapy
• Stroke Volume
• Myocardial Infarction/therapy
• Ventricular Function, Left

• Austrian Science Fund
• The University of Newcastle (Australia)

Aims: Hypoxic-ischaemic encephalopathy (HIE) is one of the most serious complications in neonates and infants. Mesenchymal stromal cell (MSC)-based therapy is emerging as a promising treatment avenue for HIE. However, despite its enormous potential, the clinical application of MSCs is limited by cell heterogeneity, low isolation efficiency and unpredictable effectiveness. In this study, we examined the therapeutic effects and underlying mechanisms of human pluripotent stem cell-derived ectomesenchymal stromal cells (hPSC-EMSCs) in a rat model of HIE.

Methods: hPSC-EMSCs were induced from either human embryonic stem cells or induced pluripotent stem cells. Stem cells or the conditioned medium (CM) derived from stem cells were delivered intracranially or intranasally to neonatal rats with HIE. Human umbilical cord-derived MSCs (hUC-MSCs) were used as the therapeutic comparison control and phosphate-buffered saline (PBS) was used as a negative control. Lesion size, apoptosis, neurogenesis, astrogliosis and microgliosis were evaluated. The rotarod test and Morris water maze were used to determine brain functional recovery. The PC-12 cell line, rat primary cortical neurons and neural progenitor cells were used to evaluate neurite outgrowth and the neuroprotective and neurogenesis effects of hPSC-EMSCs/hUC-MSCs. RNA-seq and enzyme-linked immunosorbent assays were used to determine the secretory factors that were differentially expressed between hPSC-EMSCs and hUC-MSCs. The activation and suppression of extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB) were characterised using western blotting and immunofluorescent staining.

Results: hPSC-EMSCs showed a higher neuroprotective potential than hUC-MSCs, as demonstrated by a more significant reduction in lesion size and apoptosis in the rat brain following hypoxia-ischaemia (HI). Compared with PBS treatment, hPSC-EMSCs promoted endogenous neurogenesis and alleviated astrogliosis and microgliosis. hPSC-EMSCs were more effective than hUC-MSCs. hPSC-EMSCs achieved a greater recovery of brain function than hUC-MSCs and PBS in rats with HIE. CM derived from hPSC-EMSCs had neuroprotective and neurorestorative effects in vitro through anti-apoptotic and neurite outgrowth- and neurogenesis-promoting effects. Direct comparisons between hPSC-EMSCs and hUC-MSCs revealed the significant enrichment of a group of secretory factors in hPSC-EMSCs, including nerve growth factor (NGF), platelet-derived growth factor-AA and transforming growth factor-β₂, which are involved in neurogenesis, synaptic transmission and neurotransmitter transport, respectively. Mechanistically, the CM derived from hPSC-EMSCs was found to potentiate NGF-induced neurite outgrowth and the neuronal differentiation of NPCs via the ERK/CREB pathway. Suppression of ERK or CREB abolished CM-potentiated neuritogenesis and neuronal differentiation. Finally, intranasal delivery of the CM derived from hPSC-EMSCs significantly reduced brain lesion size, promoted endogenous neurogenesis, mitigated inflammatory responses and improved functional recovery in rats with HIE.

Conclusion: hPSC-EMSCs promote functional recovery after HI through multifaceted neuromodulatory activities via paracrine/trophic mechanisms. We propose the use of hPSC-EMSCs for the treatment of HIE, as they offer an excellent unlimited cellular source of MSCs.

• ERK
• HIE
• brain damage
• ectomesenchymal stromal cells
• paracrine
• regeneration

Human umbilical cord mesenchymal stem cells (hUC-MSCs) and its conditioned medium (CM) promote wound healing. This study investigated the wound healing potential of hUC-MSC CM in vitro and in vivo using diabetic animal models.

The CM from hUC-MSC CM prepared under hypoxic conditions (hypoxic hUC-MSC) was evaluated for stimulating rat fibroblast growth, collagen production (in vitro), and wound healing in animal models (in vivo). An excision wound on the dorsal side of the diabetes-induced rats was established, and the rats were randomly divided into non-treatment, antibiotic, and hypoxic hUC-MSC CM groups. The cell number of fibroblasts and collagen secretion was evaluated and compared among the groups in an in vitro study. By contrast, wound size reduction, width of re-epithelialization, and the collagen formation area were assessed and compared among the groups in an in vivo study.

CM under hypoxic conditions contained a higher concentration of wound healing-related growth factors. Hypoxic hUC-MSC CM could facilitate fibroblast cell growth and collagen synthesis, although not significant compared with the control group. Re-epithelialization and collagen production were higher in the hUC-MSC CM group than in the antibiotic and non-treatment groups.

Hypoxic hUC-MSC CM possessed more positive effects on the wound healing process based on re-epithelialization and collagen formation than antibiotic treatment did.

• conditioned medium
• diabetic induced rat
• human umbilical cord mesenchymal stem cells
• wound healing

• Bovine follicles
• Granulosa cells
• Oxygen concentration
• Physiological hypoxia
• VEGF system

• angiogenesis
• dimethyloxalylglycine
• hypoxia
• mesenchymal stromal cells
• spheroids

• cell culture
• fibrinogen
• immunomodulation
• mesenchymal stem cells
• platelet lysate

• Animals
• Blood Platelets/metabolism
• Cell Culture Techniques/methods
• Cell Differentiation/drug effects
• Cell Extracts/chemistry
• Cell Extracts/pharmacology
• Cell Proliferation
• Cells, Cultured
• Culture Media/chemistry
• Culture Media/pharmacology
• Fibrinogen/metabolism
• Horses
• Humans
• Mesenchymal Stem Cells/cytology
• Mesenchymal Stem Cells/drug effects
• Monocytes/cytology
• Monocytes/drug effects

• Cryopreservation
• Human umbilical cord
• Long-term culture
• Mesenchymal stem cells
• Proteomic analysis

• National Natural Science Foundation of China

• HIF-1α/VEGF signaling
• constant oxygen therapy
• intermittent hyperoxia
• intermittent hypoxia
• preterm rat neonates

The toxic effects of particulate matter have been linked to polycyclic aromatic hydrocarbons (PAHs) such as benzopyrene. PAHs are potent inducers of the aryl hydrocarbon receptor (AhR), which is an expressed nuclear receptor that senses environmental stimuli and modulates gene expression. Even though several studies have shown that the benzopyrene (BP) of chemical pollutants significantly impaired stem cell activity, the exact molecular mechanisms were not clearly elucidated. In the present study, we aimed to investigate the effects of BP on placenta-derived mesenchymal stem cells (PD-MSCs) in vitro. We found that the AhR in PD-MSCs was expressed under the treatment of BP, and its activation markedly disrupted osteogenic differentiation through the alteration of stemness activity of PD-MSCs. Moreover, BP treatment significantly reduced the proliferation activity of PD-MSCs and expression of pluripotent markers through the induction of AhR. Treatment with StemRegenin 1 (SR1), a purine derivative that antagonizes the AhR, effectively prevented BP-induced reduction of the proliferation and differentiation activity of PD-MSCs. In this study, we found that BP treatment in PD-MSCs markedly obstructs PD-MSC stemness through AhR signaling. Noteworthy, SR1-mediated MSC application will contribute to new perspectives on MSC-based therapies for air pollution-related bone diseases.

• Dental stem cells
• Differentiation
• Inflammation
• Oligodendrocyte progenitor cells
• Spinal cord

• Activins/metabolism
• Adult
• Animals
• Cell Differentiation/physiology
• Cell Line
• Demyelinating Diseases/metabolism
• Demyelinating Diseases/prevention & control
• Dental Papilla/cytology
• Dental Papilla/metabolism
• Humans
• Inflammation/metabolism
• Inflammation/prevention & control
• Mice
• Neurons/metabolism
• Oligodendrocyte Precursor Cells/metabolism
• Oligodendroglia/metabolism
• Rats
• Rats, Wistar
• Spinal Cord/metabolism
• Spinal Cord Injuries/metabolism
• Spinal Cord Injuries/therapy
• Stem Cells/cytology
• Stem Cells/metabolism
• Tumor Necrosis Factor-alpha/metabolism

• MR/M020827/1 Medical Research Council
• MR/N022556/1 Medical Research Council
• Fonds De La Recherche Scientifique - FNRS
• Fonds De La Recherche Scientifique - FNRS (BE)
• Université Catholique de Louvain (BE)
• IRP

• cardiovascular disease
• cellular therapy
• mesenchymal stem cells
• mesenchymal stromal cells
• regenerative medicine

• Oct4
• alternative splicing
• differentiation
• internal ribosome entry site
• pluripotent stem cells

Human cancers are known to downregulate Major Histocompatibility Complex (MHC) class I expression thereby escaping recognition and rejection by anti-tumor T cells. Here we report that oxygen tension in the tumor microenvironment (TME) serves as an extrinsic cue that regulates antigen presentation by MHC class I molecules. In support of this view, hypoxia is shown to negatively regulate MHC expression in a HIF-dependent manner as evidenced by (i) lower MHC expression in the hypoxic TME in vivo and in hypoxic 3-dimensional (3D) but not 2-dimensional (2D) tumor cell cultures in vitro; (ii) decreased MHC in human renal cell carcinomas with constitutive expression of HIF due to genetic loss of von Hippel-Lindau (VHL) function as compared with isogenically paired cells with restored VHL function, and iii) increased MHC in tumor cells with siRNA-mediated knockdown of HIF. In addition, hypoxia downregulated antigen presenting proteins like TAP 1/2 and LMP7 that are known to have a dominant role in surface display of peptide-MHC complexes. Corroborating oxygen-dependent regulation of MHC antigen presentation, hyperoxia (60% oxygen) transcriptionally upregulated MHC expression and increased levels of TAP2, LMP2 and 7. In conclusion, this study reveals a novel mechanism by which intra-tumoral hypoxia and HIF can potentiate immune escape. It also suggests the use of hyperoxia to improve tumor cell-based cancer vaccines and for mining novel immune epitopes. Furthermore, this study highlights the advantage of 3D cell cultures in reproducing hypoxia-dependent changes observed in the TME.

To assess if in chronic venous insufficiency, there is a seasonal variation of cytokines levels which could explain the typical worsening of symptoms during Spring and Summer.

From 193 chronic venous insufficiency patients, we selected 32 patients in clinical stage C2–C3 of the Clinical–Etiology–Anatomy–Pathophysiology classification.

A prospective, comparative and blinded cytokines assessment in two different seasons.

We sorted patients by two homogenous groups, 17 Autumn Group and 15 Spring Group. A complete clinical and haemodynamic assessment and laboratory analysis of 22 circulating cytokines were performed on each patient.

Circulating cytokines levels assessment.

The two groups resulted homogenous for age, gender, clinical class, and haemodynamic parameters. Comparing cytokines expressions in Autumn Group vs. Spring Group, we found a significant difference of 11 out of 22 circulating cytokines (p < 0.05). Particularly Eotaxin, Interleukin-8, Monocyte Chemoattractant Protein-1, Tumour Necrosis Factor-α and Vascular Endothelial Growth Factor were increased in Autumn compared to the Control Group (p < 0.001); while significantly reduced in Spring, within the normal range (p, not significant).

Symptoms of chronic venous insufficiency are self-reported by patients more intense during warm seasons. Surprisingly, in our study, cytokines levels were significantly higher during Autumn and downregulated in Spring. These variations show for the first time the presence of a ‘Calendar of Cytokines’ in chronic venous insufficiency, which needs to be further investigated.

• Cytokines
• chronic venous insufficiency
• inflammation
• seasonality
• vitamin D

• Biosensing Techniques/instrumentation
• Cytological Techniques/instrumentation
• Cytological Techniques/methods
• HeLa Cells
• Humans
• Lab-On-A-Chip Devices
• Nanostructures/chemistry
• Nanotechnology
• Vascular Endothelial Growth Factor A/analysis
• Vascular Endothelial Growth Factor A/metabolism

• 3D scaffolds
• Cell culture media
• Cell source
• Culture conditions
• Differentiation
• Donor age
• Hypoxia
• MSCs
• Mechano-/electro-stimuli
• Self-renewal
• Supplementary factors

This study aimed at characterizing the impact of type 2 diabetes mellitus (T2DM) on the bone marrow mesenchymal stem cell (BMMSC) secretome and angiogenic properties. BMMSCs from Zucker diabetic fatty rats (ZDF) (a T2DM model) and Zucker LEAN littermates (control) were cultured. The supernatant conditioned media (CM) from BMMSCs of diabetic and control rats were collected and analysed. Compared to results obtained using CM from LEAN‐BMMSCs, the bioactive content of ZDF‐BMMSC CM (i) differently affects endothelial cell (HUVEC) functions in vitro by inducing increased (3.5‐fold; P < 0.01) formation of tubule‐like structures and migration of these cells (3‐fold; P < 0.001), as well as promotes improved vascular formation in vivo, and (ii) contains different levels of angiogenic factors (e.g. IGF1) and mediators, such as OSTP, CATD, FMOD LTBP1 and LTBP2, which are involved in angiogenesis and/or extracellular matrix composition. Addition of neutralizing antibodies against IGF‐1, LTBP1 or LTBP2 in the CM of BMMSCs from diabetic rats decreased its stimulatory effect on HUVEC migration by approximately 60%, 40% or 40%, respectively. These results demonstrate that BMMSCs from T2DM rats have a unique secretome with distinct angiogenic properties and provide new insights into the role of BMMSCs in aberrant angiogenesis in the diabetic milieu.

• MSCs
• angiogenesis
• diabetes type 2
• endothelial cells
• secretome

• graft-remodelling
• neuroinflammation
• neuroprotection
• stromal cells
• transplantation

Mesenchymal stem cells (MSCs) stabilise endothelial barrier function in acute lung injury via paracrine hepatocyte growth factor (HGF). Vascular endothelial growth factor (VEGF), which is secreted by MSCs, is another key regulator of endothelial permeability; however, its role in adjusting permeability remains controversial. In addition, whether an interaction occurs between HGF and VEGF, which are secreted by MSCs, is not completely understood.

We introduced a co-cultured model of human pulmonary microvascular endothelial cells (HPMECs) and MSC conditioned medium (CM) collected from MSCs after 24 h of hypoxic culture. The presence of VEGF and HGF in the MSC-CM was neutralised by anti-VEGF and anti-HGF antibodies, respectively. To determine the roles and mechanisms of MSC-secreted HGF and VEGF, we employed recombinant humanised HGF and recombinant humanised VEGF to co-culture with HPMECs. Additionally, we employed the RhoA inhibitor C3 transferase and the Rac1 inhibitor NSC23766 to inhibit the activities of RhoA and Rac1 in HPMECs treated with MSC-CM or VEGF/HGF with the same dosage as in the MSC-CM. Then, endothelial paracellular and transcellular permeability was detected. VE-cadherin, occludin and caveolin-1 protein expression in HPMECs was measured by western blot. Adherens junction proteins, including F-actin and VE-cadherin, were detected by immunofluorescence.

MSC-CM treatment significantly decreased lipopolysaccharide-induced endothelial paracellular and transcellular permeability, which was significantly inhibited by pretreatment with HGF antibody or with both VEGF and HGF antibodies. Furthermore, MSC-CM treatment increased the expression of the endothelial intercellular adherence junction proteins VE-cadherin and occludin and decreased the expression of caveolin-1 protein. MSC-CM treatment also decreased endothelial apoptosis and induced endothelial cell proliferation; however, the effects of MSC-CM treatment were inhibited by pretreatment with HGF antibody or with both HGF and VEGF antibodies. Additionally, the effects of MSC-CM and VEGF/HGF on reducing endothelial paracellular and transcellular permeability were weakened when HPMECs were pretreated with the Rac1 inhibitor NSC23766.

HGF secreted by MSCs protects the endothelial barrier function; however, VEGF secreted by MSCs may synergize with HGF to stabilise endothelial cell barrier function. Rac1 is the pathway by which MSC-secreted VEGF and HGF regulate endothelial permeability.

• cell-to-cell interaction
• human adipose tissue-derived stromal cells
• hypoxia
• interleukins
• mononuclear cells from human peripheral blood