The expression of neurogenic markers after neuronal induction of chorion-derived mesenchymal stromal cells

Fucoxanthin diminishes oxidative stress damage in human placenta-derived mesenchymal stem cells through the PI3K/Akt/Nrf-2 pathway

Placenta-derived mesenchymal stem cells (PL-MSCs) have therapeutic potential in various clinical contexts due to their regenerative and immunomodulatory properties. However, with increasing age or extensive in vitro culture, their viability and function are gradually lost, thus restricting their therapeutic application. The primary cause of this deterioration is oxidative injury from free radicals. Therefore, enhancing cell viability and restoring cellular repair mechanisms of PL-MSCs in an oxidative stress environment are crucial in this context. Fucoxanthin, a carotenoid derived from brown seaweed, demonstrates antioxidant activity by increasing the production of antioxidant enzymes and lowering the levels of reactive oxygen species (ROS). This study aimed to determine whether fucoxanthin protects PL-MSCs from hydrogen peroxide (H2O2)-induced oxidative stress. After characterization, PL-MSCs were co-treated with fucoxanthin and H2O2 for 24 h (co-treatment) or pre-treated with fucoxanthin for 24 h followed by H2O2 for 24 h (pre-treatment). The effects of fucoxanthin on cell viability and proliferation were examined using an MTT assay. The expression of antioxidant enzymes, PI3K/Akt/Nrf-2 and intracellular ROS production were investigated in fucoxanthin-treated PL-MSCs compared to the untreated group. The gene expression and involvement of specific pathways in the cytoprotective effect of fucoxanthin were investigated by high-throughput NanoString nCounter analysis. The results demonstrated that co-treatment and pre-treatment with fucoxanthin restored the viability and proliferative capacity of PL-MSCs. Fucoxanthin treatment increased the expression of antioxidant enzymes in PL-MSCs cultured under oxidative stress conditions and decreased intracellular ROS accumulation. Markedly, fucoxanthin treatment could restore PI3K/Akt/Nrf-2 expression in H2O2-treated PL-MSCs. High-throughput analysis revealed up-regulation of genes involved in cell survival pathways, including cell cycle and proliferation, DNA damage repair pathways, and down-regulation of genes in apoptosis and autophagy pathways. This study demonstrated that fucoxanthin protects and rescues PL-MSCs from oxidative stress damage through the PI3K/Akt/Nrf-2 pathway. Our data provide the supporting evidence for the use of fucoxanthin as an antioxidant cytoprotective agent to improve the viability and proliferation capacity of PL-MSCs both in vitro and in vivo required to increase the effectiveness of MSC expansion for therapeutic applications.

Role of YAP as a Mechanosensing Molecule in Stem Cells and Stem Cell-Derived Hematopoietic Cells

Yes-associated protein (YAP) and WW domain-containing transcription regulator protein 1 (WWTR1, also known as TAZ) are transcriptional coactivators in the Hippo signaling pathway. Both are well-known regulators of cell proliferation and organ size control, and they have significant roles in promoting cell proliferation and differentiation. The roles of YAP and TAZ in stem cell pluripotency and differentiation have been extensively studied. However, the upstream mediators of YAP and TAZ are not well understood. Recently, a novel role of YAP in mechanosensing and mechanotransduction has been reported. The present review updates information on the regulation of YAP by mechanical cues such as extracellular matrix stiffness, fluid shear stress, and actin cytoskeleton tension in stem cell behaviors and differentiation. The review explores mesenchymal stem cell fate decisions, pluripotent stem cells (PSCs), self-renewal, pluripotency, and differentiation to blood products. Understanding how cells sense their microenvironment or niche and mimic those microenvironments in vitro could improve the efficiency of producing stem cell products and the efficacy of the products.

Fisetin Inhibits Osteogenic Differentiation of Mesenchymal Stem Cells via the Inhibition of YAP

Mesenchymal stem cells (MSCs) are self-renewal and capable of differentiating to various functional cell types, including osteocytes, adipocytes, myoblasts, and chondrocytes. They are, therefore, regarded as a potential source for stem cell therapy. Fisetin is a bioactive flavonoid known as an active antioxidant molecule that has been reported to inhibit cell growth in various cell types. Fisetin was shown to play a role in regulating osteogenic differentiation in animal-derived MSCs; however, its molecular mechanism is not well understood. We, therefore, studied the effect of fisetin on the biological properties of human MSCs derived from chorion tissue and its role in human osteogenesis using MSCs and osteoblast-like cells (SaOs-2) as a model. We found that fisetin inhibited proliferation, migration, and osteogenic differentiation of MSCs as well as human SaOs-2 cells. Fisetin could reduce Yes-associated protein (YAP) activity, which results in downregulation of osteogenic genes and upregulation of fibroblast genes. Further analysis using molecular docking and molecular dynamics simulations suggests that fisetin occupied the hydrophobic TEAD pocket preventing YAP from associating with TEA domain (TEAD). This finding supports the potential application of flavonoids like fisetin as a protein–protein interaction disruptor and also suggesting an implication of fisetin in regulating human osteogenesis.

MicroRNA treatment modulates osteogenic differentiation potential of mesenchymal stem cells derived from human chorion and placenta

Mesenchymal stem cells (MSCs) are important in regenerative medicine because of their potential for multi-differentiation. Bone marrow, chorion and placenta have all been suggested as potential sources for clinical application. However, the osteogenic differentiation potential of MSCs derived from chorion or placenta is not very efficient. Bone morphogenetic protein-2 (BMP-2) plays an important role in bone development. Its effect on osteogenic augmentation has been addressed in several studies. Recent studies have also shown a relationship between miRNAs and osteogenesis. We hypothesized that miRNAs targeted to Runt-related transcription factor 2 (Runx-2), a major transcription factor of osteogenesis, are responsible for regulating the differentiation of MSCs into osteoblasts. This study examines the effect of BMP-2 on the osteogenic differentiation of MSCs isolated from chorion and placenta in comparison to bone marrow-derived MSCs and investigates the role of miRNAs in the osteogenic differentiation of MSCs from these sources. MSCs were isolated from human bone marrow, chorion and placenta. The osteogenic differentiation potential after BMP-2 treatment was examined using ALP staining, ALP activity assay, and osteogenic gene expression. Candidate miRNAs were selected and their expression levels during osteoblastic differentiation were examined using real-time RT-PCR. The role of these miRNAs in osteogenesis was investigated by transfection with specific miRNA inhibitors. The level of osteogenic differentiation was monitored after anti-miRNA treatment. MSCs isolated from chorion and placenta exhibited self-renewal capacity and multi-lineage differentiation potential similar to MSCs isolated from bone marrow. BMP-2 treated MSCs showed higher ALP levels and osteogenic gene expression compared to untreated MSCs. All investigated miRNAs (miR-31, miR-106a and miR148) were consistently downregulated during the process of osteogenic differentiation. After treatment with miRNA inhibitors, ALP activity and osteogenic gene expression increased over the time of osteogenic differentiation. BMP-2 has a positive effect on osteogenic differentiation of chorion- and placenta-derived MSCs. The inhibition of specific miRNAs enhanced the osteogenic differentiation capacity of various MSCs in culture and this strategy might be used to promote bone regeneration. However, further in vivo experiments are required to assess the validity of this approach.

Grafted human chorionic stem cells restore motor function and preclude cerebellar neurodegeneration in rat model of cerebellar ataxia

Cerebellar ataxia (CA) is a form of ataxia that adversely affects the cerebellum. Cell replacement therapy (CRT) has been considered as a potential treatment for neurological disorders. In this report, we investigated the neuro-restorative effects of human chorionic stem cells (HCSCs) transplantation on rat model of CA induced by 3-acetylpyridine (3-AP). In this regard, HCSCs were isolated and phenotypically determined. Next, a single injection of 3-AP was administered for ataxia induction, and bilateral HCSCs implantation was conducted 3 days after 3-AP injection, followed by expression analysis of a number of apoptotic, autophagic and inflammatory genes as well as vascular endothelial growth factor (VEGF) level, along with assessment of cerebellar neurodegeneration, motor coordination and muscle activity. The findings revealed that grafting of HCSCs in 3-AP model of ataxia decreased the expression levels of several inflammatory, autophagic and apoptotic genes and provoked the up-regulation of VEGF in the cerebellar region, prevented the degeneration of Purkinje cells caused by 3-AP toxicity and ameliorated motor coordination and muscle function. In conclusion, these data indicate in vivo efficacy of HCSCs in the reestablishment of motor skills and reversal of CA.

Mesenchymal stromal cells' role in tumor microenvironment: involvement of signaling pathways

Mesenchymal stromal cells (MSCs) are adult multipotent stem cells residing as pericytes in various tissues and organs where they can differentiate into specialized cells to replace dying cells and damaged tissues. These cells are commonly found at injury sites and in tumors that are known to behave like " wounds that do not heal." In this article, we discuss the mechanisms of MSCs in migrating, homing, and repairing injured tissues. We also review a number of reports showing that tumor microenvironment triggers plasticity mechanisms in MSCs to induce malignant neoplastic tissue formation, maintenance, and chemoresistance, as well as tumor growth. The antitumor properties and therapeutic potential of MSCs are also discussed.