Therapeutic Potential of Mesenchymal Stem Cell‐Derived Conditioned Medium for Diabetes Mellitus and Related Complications

Dynamic analysis of metabolic and ultrastructural changes in mesenchymal stem cells at hypoxic preconditioning and post-preconditioning stages: Cobalt chloride on the spotlight

Mesenchymal stem cells (MSCs) have come up as a potential remedy for treatment of various diseases thanks to their regenerative abilities. However, MSC-based therapies face challenges like reduced cell survival and functionality after transplantation. Preconditioning, particularly with hypoxia-mimicking agents like cobalt chloride (CoCl2), has been explored to enhance MSCs' effectiveness. This study aims to evaluate MSC survival, migration, and therapeutic outcomes at the CoCI2-preconditioning and post-preconditioning stages. Human umbilical cord-MSCs were treated with 100 µM CoCI2 with/out serum for 24-hours, and then passaged and planted in corresponding culture conditions without CoCI2, these two consecutive passages were named as the preconditioning and post-preconditioning stages, respectively. In each stage, total protein concentrations, total antioxidant and total oxidant status (TAS/TOS) of the conditioned media derived from the cells were investigated with bicinchoninic acid assay and TAS/TOS kits, respectively. The proliferation rates, migratory capacities, cellular senescence, expression levels of hypoxia-inducible factor1-α (HIF1-α), Ki-67, active caspase-3 and beclin-1 proteins and ultrastructures of the cells were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide test, wound healing assay, β-galactosidase-activity assessment, immunocytochemistry and transmission electron microscopy, respectively. Our results indicated that preconditioning MSCs with CoCl2 did not significantly enhance their proliferation, migration, or secretory abilities. However, it increased antioxidant capacity and along with normalization of senescence-status post-preconditioning, possibly by shifting energy metabolism from oxidative-phosphorylation to glycolysis through the upregulation of the HIF1-α signalling pathway. These findings indicate that CoCl2 preconditioning could be an effective approach to boost the therapeutic potential of MSCs, especially in enhancing their survival and functionality after transplantation.

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.

Preconditioning of human umbilical cord mesenchymal stem cells with deferoxamine potentiates the capacity of the secretome released from the cells and promotes immunomodulation and beta cell regeneration in a rat model of type 1 diabetes

This study aimed to examine the effects of the secretome released by human umbilical cord-mesenchymal stem cells (MSC) as a result of preconditioning with deferoxamine (DFX), a hypoxia mimetic agent, on type 1 diabetes (T1D), by comparing it with the secretome produced by untreated MSCs. Initially, the levels of total protein, IL4, IL10, IL17, and IFNγ in the conditioned medium (CM) obtained from MSCs subjected to preconditioning with 150 µM DFX (DFX-CM) were analyzed in comparison to CM derived from untreated MSCs (N-CM). Subsequently, the CMs were administered to rats with T1D within a specific treatment plan. Following the sacrification, immunomodulation was evaluated by measuring serum cytokine levels and assessing the regulatory T cell (Treg) ratio in spleen mononuclear cells. Additionally, β-cell mass was determined in the islets by immunohistochemical labeling of NK6 Homeobox 1 (Nkx6.1), Pancreatic duodenal homeobox-1 (Pdx1), and insulin antibodies in pancreatic sections. In vitro findings indicated that the secretome levels of MSCs were enhanced by preconditioning with DFX. In vivo, the use of DFX-CM significantly increased the Treg population, and accordingly, the level of inflammatory cytokines decreased. In β-cell marker labeling, D + DFX-CM showed significantly increased PDX1 and insulin immunoreactivity. In conclusion, while the factors released by MSCs without external stimulation had limited therapeutic effects, substantial improvements in immunomodulation and β-cell regeneration were seen with DFX-preconditioned cell-derived CM.