Role of mesenchymal stem cell-derived soluble factors and folic acid in wound healing

Advances in the applications of mesenchymal stem cell-conditioned medium in ocular diseases

Mesenchymal stem cell-conditioned medium (MSC-CM), also known as secretome, is secreted by MSC and contains a variety of bioactive factors with anti-inflammatory, anti-apoptotic, neuroprotection, and proliferation effects. Increasing evidence proved that MSC-CM plays an important role in various diseases, including skin, bone, muscle, and dental diseases. However, the role of MSC-CM in ocular diseases is not quite clear, Therefore, this article reviewed the composition, biological functions, preparation, and characterization of MSC-CM and summarized current research advances in different sources of MSC-CM in corneal and retinal diseases, including dry eye, corneal epithelial damage, chemical corneal injury, retinitis pigmentosa (RP), anterior ischemic optic neuropathy (AION), diabetic retinopathy (DR), and other retinal degenerative changes. For these diseases, MSC-CM can promote cell proliferation, reduce inflammation and vascular leakage, inhibit retinal cell degeneration and apoptosis, protect corneal and retinal structures, and further improves visual function. Hence, we summarize the production, composition and biological functions of MSC-CM and focus on describing its mechanisms in the treatment of ocular diseases. Furthermore, we look at the unexplored mechanisms and further research directions for MSC-CM based therapy in ocular diseases.

In Vitro Toxicological Profile of Labetalol-Folic Acid/Folate Co-Administration in H9c2(2-1) and HepaRG Cells

Background and Objectives: The consumption of dietary supplements has increased over the last decades among pregnant women, becoming an efficient resource of micronutrients able to satisfy their nutritional needs during pregnancy. Furthermore, gestational drug administration might be necessary to treat several pregnancy complications such as hypertension. Folic acid (FA) and folate (FT) supplementation is highly recommended by clinicians during pregnancy, especially for preventing neural tube birth defects, while labetalol (LB) is a β-blocker commonly administered as a safe option for the treatment of pregnancy-related hypertension. Currently, the possible toxicity resulting from the co-administration of FA/FT and LB has not been fully evaluated. In light of these considerations, the current study was aimed at investigating the possible in vitro cardio- and hepato-toxicity of LB-FA and LB-FT associations. Materials and Methods: Five different concentrations of LB, FA, FT, and their combination were used in myoblasts and hepatocytes in order to assess cell viability, cell morphology, and wound regeneration. Results: The results indicate no significant alterations in terms of cell viability and morphology in myoblasts (H9c2(2-1)) and hepatocytes (HepaRG) following a 72-h treatment, apart from a decrease in the percentage of viable H9c2(2-1) cells (~67%) treated with LB 150 nM−FT 50 nM. Additionally, LB (50 and 150 nM)−FA (0.2 nM) exerted an efficient wound regenerating potential in H9c2(2-1) myoblasts (wound healing rates were >80%, compared to the control at 66%), while LB-FT (at all tested concentrations) induced no significant impairment to their migration. Conclusions: Overall, our findings indicate that LB-FA and LB-FT combinations lack cytotoxicity in vitro. Moreover, beneficial effects were noticed on H9c2(2-1) cell viability and migration from LB-FA/FT administration, which should be further explored.

Fabrication and Characterization of Electrospun Folic Acid/Hybrid Fibers: In Vitro Controlled Release Study and Cytocompatibility Assays

The fabrication of skin-care products with therapeutic properties has been significant for human health trends. In this study, we developed efficient hydrophilic composite nanofibers (NFs) loaded with the folic acid (FA) by electrospinning and electrospraying processes for tissue engineering or wound healing cosmetic applications. The morphological, chemical and thermal characteristics, in vitro release properties, and cytocompatibility of the resulting composite fibers with the same amount of folic acid were analyzed. The SEM micrographs indicate that the obtained nanofibers were in the nanometer range, with an average fiber diameter of 75-270 nm and a good porosity ratio (34-55%). The TGA curves show that FA inhibits the degradation of the polymer and acts as an antioxidant at high temperatures. More physical interaction between FA and matrices has been shown to occur in the electrospray process than in the electrospinning process. A UV-Vis in vitro study of FA-loaded electrospun fibers for 8 h in artificial acidic (pH 5.44) and alkaline (pH 8.04) sweat solutions exhibited a rapid release of FA-loaded electrospun fibers, showing the effect of polymer matrix-FA interactions and fabrication processes on their release from the nanofibers. PVA-CHi/FA webs have the highest release value, with 95.2% in alkaline media. In acidic media, the highest release (92%) occurred on the PVA-Gel-CHi/sFA sample, and this followed first-order and Korsmeyer-Peppas kinetic models. Further, the L929 cytocompatibility assay results pointed out that all NFs (with/without FA) generated had no cell toxicity; on the contrary, the FA in the fibers facilitates cell growth. Therefore, the nanofibers are a potential candidate material in skin-care and tissue engineering applications.

Leptin promotes proliferation of neonatal mouse stem/progenitor spermatogonia

PURPOSE

To keep and increase spermatogonial stem cell number (SSC) is the only available option for pediatric cancer survivors to maintain fertility. Leptin is secreted by the epididymal white adipose tissue and has receptors on stem/progenitor spermatogonia. The purpose of this study is to demonstrate dose- and time-dependent proliferative effect of leptin on stem/progenitor spermatogonia cultures from prepubertal mice testes.

METHODS

CD90.2 (+) stem/progenitor spermatogonia were isolated from the C57BL/6 mouse testis on postnatal day 6 and placed in culture. The proliferative effect of leptin supplementation was assessed by colony formation (diameter and number), WST proliferation assays, and xCELLigence real-time cell analysis (RTCA) on days 3, 5, and 7 of culture. Expressions of p-ERK1/2, p-STAT3, total STAT3, and p-SHP2 levels were determined by western blot analysis.

RESULTS

Leptin supplementation of 100 ng/ml increased the diameter (p = 0.001) and number (p = 0.01) of colonies in stem/progenitor spermatogonial cultures and caused higher proliferation by WST-1 (p = 0.009) compared with the control on day 7. The EC50 was calculated as 114 ng/ml for leptin by RTCA. Proliferative dose of leptin induced increased expression of p-ERK1/2 (p = 0.009) and p-STAT3 (p = 0.023) on stem/progenitor spermatogonia when compared with the untreated group.

CONCLUSION

The results indicated that leptin supplementation exhibited a dose- and time-dependent proliferative effect on stem/progenitor spermatogonia that was associated with increased expression of ERK1/2 and STAT3 pathways while maintaining their undifferentiated state. This output presents a new agent that may help to expand the stem/progenitor spermatogonia pool from the neonatal testis in order to autotransplant after cancer treatment.