Dependence of mitochondrial function on the filamentous actin cytoskeleton in cultured mesenchymal stem cells treated with cytochalasin B

Abstract Background: Mesenchymal stem cells (MSCs) have a limited self-renewal ability, impaired multi-differentiation potential, and undetermined cell senescence during in vitro series expansion. To address this concern, we investigated the effects of the microenvironment provided by stem cells from human exfoliated deciduous teeth (SHED) in maintaining the stemness of human bone marrow mesenchymal stem cells (hBMSCs) and identified the key factors and possible mechanisms responsible for maintaining the stemness of MSCs during long-term expansion in vitro.Methods: The passage 3 (P3) to passage 8 (P8) hBMSCs were cultured in the conditioned medium from SHED (SHED-CM). The percentage of senescent cells was evaluated by β-galactosidase staining. In addition, the osteogenic differentiation potential was analyzed by reverse transcription quantitative PCR (RT-qPCR), Western blot, alizarin red and alkaline phosphatase (ALP) staining. Furthermore, RT-qPCR results identified hepatocyte growth factor (HGF) and stem cell factor (SCF) as key factors. Thus, the effects of HGF and SCF on mitochondrial function were assessed by measuring the ROS and mitochondrial membrane potential levels. Finally, selected mitochondrial-related proteins associated with the PI3K/AKT, ERK1/2, and STAT3 signaling pathways were investigated to determine the effects of HGF and SCF in preserving the mitochondrial function of hBMSCs during long-term expansion.Results: SHED-CM had significantly enhanced the cell viability, reduced the senescent cells, and maintained the osteogenesis and pro-angiogenic capacity in P8 hBMSCs during long-term expansion. In addition, hBMSCs treated with 100 ng/ml HGF and 10 ng/ml SCF had reduced ROS levels, and preserved mitochondrial membrane potential compared with P8 hBMSCs during long-term expansion. Furthermore, HGF and SCF upregulated the expression of mitochondrial-related proteins associated with the PI3K/AKT, ERK1/2, and STAT3 signaling pathways, possibly contributing to the maintenance of hBMSCs stemness by preserving mitochondrial function.Conclusion: Both HGF and SCF are key factors in maintaining the stemness of hBMSCs by preserving mitochondrial function through the expression of proteins associated with the PI3K/AKT, ERK1/2, and STAT3 signaling pathways. This study provides new insights into the anti-senescence capability of HGF and SCF, as well as new evidence for their potential application in optimizing the long-term culture of MSCs.

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Biomimetic Membrane Vesicles: Evaluation of Inflammatory Response In Vivo

Blood ◽

10.1182/blood-2020-135826 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 1-1

Author(s):

Olga Vasileva ◽

Ekaterina E Garanina ◽

Albert A Rizvanov ◽

Marina Gomzikova

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Russian Federation ◽

Cytochalasin B ◽

Membrane Vesicles ◽

Host Cells ◽

Vector System ◽

Gm Csf ◽

Biomimetic Membrane ◽

The Russian Federation

Introduction: Biomimetic membrane vesicles are produced from live cells using cytochalasin B which disrupts the structure of the cytoskeleton and facilitate generation of membrane vesicles under subsequent vortexing. Membrane vesicles are pinched off from the cell surface, surrounded by a cytoplasmic membrane and contain the cytoplasm of parental cell. It is known that mesenchymal stem cells (MSCs) are immunoprivileged. The aim of our study was to determine whether Cytochalasin B-induced membrane vesicles (CIMVs) derived from mesenchymal stem cells retain the immunoprivileged properties of parental cells. Method: All experiments were carried out in compliance with the procedure protocols approved by Kazan Federal University and local ethics committee (protocol #5, date 27.05.2014). To analyze the immunogenicity, murine MSCs (7.5x104 cells) either CIMVs-MSCs (15µg) were injected i.v. in 8 week old mice (Mus musculus, C57Bl/6). CIMVs were used at a concentration equivalent to 7.5×104 MSCs based on total protein concentration. Serum isolation was performed after 2 hours post-administration. Secretion of inflammatory cytokines was evaluated using multiplex analysis BioPlex Pro Mouse 23 Plex kit. (BioRad, USA). Results: We detected all investigated cytokines in serum of control and experimental mice: Eotaxin, G-CSF, GM-CSF, IFN-g, IL-10, IL-13, IL-17A, IL-1a, IL-1b, IL-2, IL-3, IL-4, IL-5, IL-6, IL-9, IL12p40, KC, MCP-1, MIP-1a, MIP-1b, RANTES, TNFa. Allogenic MSCs but not CIMVs increased concentration of Eotaxin, G-CSF, IL-17A and IL-9. The level of GM-CSF, IFN-g, IL-10, IL-1a, IL-1b, IL-2, IL-3, IL-4, IL-5, IL-6, IL12p40, KC, MCP-1, MIP-1a, MIP-1b, RANTES, TNFa in mice serum were not affected by murine MSCs injection. Injection of CIMVs did not induce any statistically significant changes in cytokines level. Conclusion: Elevated levels of Eotaxin, G-CSF, IL-17A and IL-9 cytokines after the i.v.injection of murine MSCs suggest that moderate allergy inflammation was developed after the MSCs allotransplantation. CIMVs injection did not induced increase of cytokines level in mice serum indicating absence of immunogenicity. Taken together our results demonstrate that CIMVs show less/no immunogenicity compared to parental MSCs. We believe that small diameter, better biodistribution and fusion with host cells lead to the non-immunogenicity of CIMVs. Thus, CIMVs are confirmed to be a perspective, new biomimetic vector system. This study was funded by the grant of the President of the Russian Federation for state support of the leading scientific schools of the Russian Federation НШ-2603.2020.4. Kazan Federal University was supported by the Russian Government Program of Competitive Growth. Disclosures No relevant conflicts of interest to declare.

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Melatonin suppresses ER stress-dependent proapoptotic effects via AMPK in bone mesenchymal stem cells during mitochondrial oxidative damage

Stem Cell Research & Therapy ◽

10.1186/s13287-020-01948-5 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Chongxi Fan ◽

Jianyu Feng ◽

Chi Tang ◽

Zhengbin Zhang ◽

Yingtong Feng ◽

...

Keyword(s):

Oxidative Stress ◽

Stem Cells ◽

Mesenchymal Stem Cells ◽

Oxidative Damage ◽

Er Stress ◽

Mitochondrial Function ◽

Antioxidant Effect ◽

Ampk Activation ◽

Stress Injury ◽

Oxidative Stress Injury

Abstract Background Bone marrow mesenchymal stem cells (BMSCs) have been used as important cell-based tools for clinical applications. Oxidative stress-induced apoptosis causes a low survival rate after transplantation, and the underlying mechanisms remain unknown. The endoplasmic reticulum (ER) and mitochondria are vital organelles regulated by adenosine monophosphate (AMP)-activated protein kinase (AMPK), especially during oxidative stress injury. Melatonin exerts an antioxidant effect by scavenging free radicals. Here, we aimed to explore whether cytoprotective melatonin relieves ER stress-mediated mitochondrial dysfunction through AMPK in BMSCs after oxidative stress injury. Methods Mouse BMSCs were isolated and exposed to H2O2 in the absence or presence of melatonin. Thereafter, cell damage, oxidative stress levels, mitochondrial function, AMPK activity, ER stress-related proteins, and apoptotic markers were measured. Additionally, the involvement of AMPK and ER stress in the melatonin-mediated protection of BMSCs against H2O2-induced injury was investigated using pharmacologic agonists and inhibitors. Results Melatonin improved cell survival and restored mitochondrial function. Moreover, melatonin intimately regulated the phosphorylation of AMPK and molecules associated with ER stress pathways. AMPK activation and ER stress inhibition following melatonin administration improved the mitochondrial membrane potential (MMP), reduced mitochondria-initiated oxidative damage, and ultimately suppressed apoptotic signaling pathways in BMSCs. Cotreatment with N-acetyl-l-cysteine (NAC) significantly enhanced the antioxidant effect of melatonin. Importantly, pharmacological AMPK activation/ER stress inhibition promoted melatonin-induced cytoprotection, while pharmacological AMPK inactivation/ER stress induction conferred resistance to the effect of melatonin against H2O2 insult. Conclusions Our data also reveal a new, potentially therapeutic mechanism by which melatonin protects BMSCs from oxidative stress-mediated mitochondrial apoptosis, possibly by regulating the AMPK-ER stress pathway.

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