Evaluating the Differential Effects of Valproic Acid on Wharton's Jelly Mesenchymal Stem Cells

Preconditioning of Human Umbilical Cord Mesenchymal Stem Cells with a Histone Deacetylase Inhibitor: Valproic Acid

Background

Mesenchymal stem cells (MSCs) play a key role in regenerative medicine due to their capacity to differentiate into multiple cell lines, regulate the immune system, and exert paracrine effects. The therapeutic impact of MSCs is primarily mediated through their secretome. The secretory and therapeutic potential of MSCs can be improved through preconditioning, which entails the application of hypoxic environments, 3-dimensional cell cultures, and pharmacological agents. Valproic acid (VPA) is a histone deacetylase inhibitor that is employed in medical practice for treating epilepsy and bipolar disorder. Hence, preconditioning MSCs with VPA is expected to induce histone acetylation, enhance gene expression, and beneficially modify the cells' secretomes.

Aims

To assess the effectiveness of VPA in enhancing and regulating the therapeutic potential of cells as well as its impact on MSC secretome profiles and ultrastructural morphologies.

Study Design

Expiremental study.

Methods

Human umbilical cord MSCs were preconditioned with 2 mM VPA for 24 and 48 hours; untreated MSCs served as controls. The secretome secreted by the cells was assessed for its total protein content. Subsequently, interferon-gamma (IFN-γ), interleukin-17 (IL-17), IL-10, vascular endothelial growth factor, nerve growth factor (NGF), glial cell line-derived neurotrophic factor, and brain-derived neurotrophic factor (BDNF) levels in the secretome were analyzed using the ELISA method. The ultrastructural properties of the cells were studied under transmission electron microscopy.

Results

Ultrastructural examinations revealed that the chromatin content of VPA-treated cells was reduced. VPA-preconditioned cells exhibited a higher density of rough endoplasmic reticulum, autophagic vesicles, and myelin figures on cytoplasmic structure analysis, which was indicative of increased secretion. Protein secretion was elevated in those cells, with notable increases in NGF and BDNF levels. Furthermore, the cytoskeletal rearrangement and elevated autophagic activity observed in the 48-hour preconditioned cells could indicate the initiation of neuronal differentiation. IL-10, IL-17, and IFN-γ were not detected in the secretome.

Conclusion

This study indicate that preconditioning with VPA enhances MSC activity and subsequently modifies the secretome content.

Autophagy enhances the differentiation of insulin-producing cells from Wharton's jelly-derived mesenchymal stem cells

Autophagy disruption suppresses insulin production and induces diabetes. The role of autophagy in the differentiation of Wharton's jelly (WJ)-derived mesenchymal stem cells (WJSCs) into insulin-producing cells (IPCs) was investigated in this experimental study. The WJSCs were incubated in a differentiation medium (DM) with or without an autophagy inhibitor (3-methyladenine: 3MA). The differentiation of IPCs was confirmed by flow cytometry analysis of PDX-1 and insulin-positive cells, insulin secretion, and the high expression of β cell-specific genes, Glucose transporter 2 (GLUT-2), and INSULIN. Autophagy has been assessed by calculating the percentage of Acridine orange (AO)-positive cells, expression of autophagy-related genes, and the LC3B/LC3A ratio. β cell-specific genes were up-regulated in the DM group, and 3MA decreased their expression. In the DM+3MA-treated cells, the expression of GLUT-2 and INSULIN genes and insulin secretion decreased compared to the DM group. In cells treated with 3MA, there was a significant decrease in the percentage of PDX-1 and insulin-positive cells compared to 3MA-untreated cells. Additionally, in the group receiving both DM and 3MA treatment, the expression of autophagy-related genes, the LC3B/LC3A protein ratio, and the percentage of AO-stained cells were significantly reduced compared to the group receiving only DM treatment. These findings suggest autophagy is essential for β cell differentiation and insulin secretion.

Human Wharton's jelly-derived mesenchymal stromal stem cells preconditioned with valproic acid promote cell migration and reduce renal inflammation in ischemia/reperfusion injury by activating the AKT/P13K and SDF1/CXCR4 pathways

OBJECTIVE

To determine whether WJ-MSCs pretreated with VPA would enhance their migration to improve functional recovery of renal IRI in rats.

METHODS

150 Sprague-Dawley rats were distributed into 5 groups; Sham, IRI, WJ-MSC, VPA, and WJ-MSCs + VPA. 10 rats were sacrificed after 3, 5, and 7 days. Role of WJ-MSCs pretreated with VPA was evaluated by assessment of renal function, antioxidant enzymes together with renal histopathological and immunohistopathological analyses and finally by molecular studies.

RESULTS

WJ-MSCs and VPA significantly improved renal function and increased antioxidants compared to IRI group. Regarding gene expression, WJ-MSCs and VPA decreased BAX and TGF-β1, up-regulated Akt, PI3K, BCL2, SDF1α, and CXCR4 related to IRI. Additionally, WJ-MSCs pretreated with VPA improved the measured parameters more than either treatment alone.

CONCLUSION

WJ-MSCs isolated from the umbilical cord and pretreated with VPA defended the kidney against IRI by more easily homing to the site of injury.

Epidrugs: novel epigenetic regulators that open a new window for targeting osteoblast differentiation

Efficient osteogenic differentiation of mesenchymal stem cells (MSCs) is a critical step in the treatment of bone defects and skeletal disorders, which present challenges for cell-based therapy and regenerative medicine. Thus, it is necessary to understand the regulatory agents involved in osteogenesis. Epigenetic mechanisms are considered to be the primary mediators that regulate gene expression during MSC differentiation. In recent years, epigenetic enzyme inhibitors have been used as epidrugs in cancer therapy. A number of studies mentioned the role of epigenetic inhibitors in the regulation of gene expression patterns related to osteogenic differentiation. This review attempts to provide an overview of the key regulatory agents of osteogenesis: transcription factors, signaling pathways, and, especially, epigenetic mechanisms. In addition, we propose to introduce epigenetic enzyme inhibitors (epidrugs) and their applications as future therapeutic approaches for bone defect regeneration.