Mobilization of human mesenchymal stem cells through different cytokines and growth factors after their immobilization by sulfur mustard

Paracrine interleukin-8 affects mesenchymal stem cells through the Akt pathway and enhances human umbilical vein endothelial cell proliferation and migration

Interleukin-8 (IL-8) promotes cell homing and angiogenesis, but its effects on activating human bone marrow mesenchymal stem cells (BMSCs) and promoting angiogenesis are unclear. We used bioinformatics to predict these processes. In vitro, BMSCs were stimulated in a high-glucose (HG) environment with 50 or 100 μg/ml IL-8 was used as the IL-8 group. A total of 5 μmol/l Triciribine was added to the two IL-8 groups as the Akt inhibitor group. Cultured human umbilical vein endothelial cells (HUVECs) were cultured in BMSCs conditioned medium (CM). The changes in proliferation, apoptosis, migration ability and levels of VEGF and IL-6 in HUVECs were observed in each group. Seventy processes and 26 pathways were involved in vascular development, through which IL-8 affected BMSCs. Compared with the HG control group, HUVEC proliferation absorbance value (A value), Gap closure rate, and Transwell cell migration rate in the IL-8 50 and IL-8 100 CM groups were significantly increased (P<0.01, n=30). However, HUVEC apoptosis was significantly decreased (P<0.01, n=30). Akt and phospho-Akt (P-Akt) protein contents in lysates of BMSCs treated with IL-8, as well as VEGF and IL-6 protein contents in the supernatant of BMSCs treated with IL-8, were all highly expressed (P<0.01, n=15). These analyses confirmed that IL-8 promoted the expression of 41 core proteins in BMSCs through the PI3K Akt pathway, which could promote the proliferation and migration of vascular endothelial cells. Therefore, in an HG environment, IL-8 activated the Akt signaling pathway, promoted paracrine mechanisms of BMSCs, and improved the proliferation and migration of HUVECs.

Current Advanced Therapies Based on Human Mesenchymal Stem Cells for Skin Diseases

Skin disease may be related with immunological disorders, external aggressions, or genetic conditions. Injuries or cutaneous diseases such as wounds, burns, psoriasis, and scleroderma among others are common pathologies in dermatology, and in some cases, conventional treatments are ineffective. In recent years, advanced therapies using human mesenchymal stem cells (hMSCs) from different sources has emerged as a promising strategy for the treatment of many pathologies. Due to their properties; regenerative, immunomodulatory and differentiation capacities, they could be applied for the treatment of cutaneous diseases. In this review, a total of thirteen types of hMSCs used as advanced therapy have been analyzed, considering the last 5 years (2015-2020). The most investigated types were those isolated from umbilical cord blood (hUCB-MSCs), adipose tissue (hAT-MSCs) and bone marrow (hBM-MSCs). The most studied diseases were wounds and ulcers, burns and psoriasis. At preclinical level, in vivo studies with mice and rats were the main animal models used, and a wide range of types of hMSCs were used. Clinical studies analyzed revealed that cell therapy by intravenous administration was the advanced therapy preferred except in the case of wounds and burns where tissue engineering was also reported. Although in most of the clinical trials reviewed results have not been posted yet, safety was high and only local slight adverse events (mild nausea or abdominal pain) were reported. In terms of effectiveness, it was difficult to compare the results due to the different doses administered and variables measured, but in general, percentage of wound's size reduction was higher than 80% in wounds, Psoriasis Area and Severity Index and Severity Scoring for Atopic Dermatitis were significantly reduced, for scleroderma, parameters such as Modified Rodnan skin score (MRSC) or European Scleroderma Study Group activity index reported an improvement of the disease and for hypertrophic scars, Vancouver Scar Scale (VSS) score was decreased after applying these therapies. On balance, hMSCs used for the treatment of cutaneous diseases is a promising strategy, however, the different experimental designs and endpoints stablished in each study, makes necessary more research to find the best way to treat each patient and disease.

Chronic senescent human mesenchymal stem cells as possible contributor to the wound healing disorder after exposure to the alkylating agent sulfur mustard

Wound healing is a complex process, and disturbance of even a single mechanism can result in chronic ulcers developing after exposure to the alkylating agent sulfur mustard (SM). A possible contributor may be SM-induced chronic senescent mesenchymal stem cells (MSCs), unable to fulfil their regenerative role, by persisting over long time periods and creating a proinflammatory microenvironment. Here we show that senescence induction in human bone marrow derived MSCs was time- and concentration-dependent, and chronic senescence could be verified 3 weeks after exposure to between 10 and 40 µM SM. Morphological changes, reduced clonogenic and migration potential, longer scratch closure times, differences in senescence, motility and DNA damage response associated genes as well as increased levels of proinflammatory cytokines were revealed. Selective removal of these cells by senolytic drugs, in which ABT-263 showed initial potential in vitro, opens the possibility for an innovative treatment strategy for chronic wounds, but also tumors and age-related diseases.

Nutraceuticals as potential therapeutics for vesicant-induced pulmonary fibrosis

Exposure to vesicants, including sulfur mustard and nitrogen mustard, causes damage to the epithelia of the respiratory tract and the lung. With time, this progresses to chronic disease, most notably, pulmonary fibrosis. The pathogenic process involves persistent inflammation and the release of cytotoxic oxidants, cytokines, chemokines, and profibrotic growth factors, which leads to the collapse of lung architecture, with fibrotic involution of the lung parenchyma. At present, there are no effective treatments available to combat this pathological process. Recently, much interest has focused on nutraceuticals, substances derived from plants, herbs, and fruits, that exert pleiotropic effects on inflammatory cells and parenchymal cells that may be useful in reducing fibrogenesis. Some promising results have been obtained with nutraceuticals in experimental animal models of inflammation-driven fibrosis. This review summarizes the current knowledge on the putative preventive/therapeutic efficacy of nutraceuticals in progressive pulmonary fibrosis, with a focus on their activity against inflammatory reactions and profibrotic cell differentiation.

Circulating mesenchymal stem cells in sulfur mustard-exposed patients with long-term pulmonary complications

Sulfur mustard (SM) is a toxic agent that causes acute and long-term pulmonary complications. Recent evidence has shown the impact of SM on mesenchymal stem cells (MSCs). These cells have a critical role in repairing the damaged tissues. In this study, we evaluated the mobilization of MSCs in SM-exposed patients with long-term pulmonary complications. Fifty-nine SM-injured patients with prolonged pulmonary complications and 20 healthy individuals were included. Patients were classified based on taking drugs, having comorbidities, and severity of respiratory consequence. MSCs with phenotype of CD45-CD44⁺CD29⁺CD105⁺ were evaluated in peripheral blood using flow cytometry. Circulating MSCs were lower in SM-exposed patients compared to the control group (0.93 vs. 2.72 respectively, P = 0.005). No significant difference was observed in the MSC count between patients taking corticosteroids or antibiotics and those patients not taking them. Comorbidities like liver and kidney diseases had changed the count of MSCs in SM-exposed subjects. In addition, the frequency of MSCs did not show any association with the severity of long-term pulmonary complications. In conclusion, SM-exposure causes a decline in the frequency of circulating MSCs in survivors. The lower number of the peripheral MSC population in SM-exposed patients was not affected by taking corticosteroids or antibiotics, but comorbidities are probably involved in MSC frequency. The decreases observed in the number of circulating MSCs was not associated with the severity of the pulmonary complications; however, further studies in mustard lung models are required to demonstrate the therapeutic or pathologic role of MSCs in SM injuries.