Conditioned Medium from Bone Marrow Mesenchymal Stem Cells Restored Oxidative Stress-Related Impaired Osteogenic Differentiation

TXNIP mediated by EZH2 regulated osteogenic differentiation in hBmscs and MC3T3-E1 cells through the modulation of oxidative stress and PI3K/AKT/Nrf2 pathway

BACKGROUND

Previous research has identified a significant role of Thioredoxin-interacting protein (TXNIP) in bone loss. The purpose of this investigation was to assess the role and the underlying molecular mechanisms of TXNIP in the osteogenic differentiation of human bone marrow stromal cells (hBMSCs) and pre-osteoblast MC3T3-E1 cells.

METHODS

Human bone marrow stem cells (hBMSCs) and MC3T3-E1 cells were used to induce osteogenic differentiation. The expression of genes and proteins was assessed using RT-qPCR and western blot, respectively. ChIP assay was used to validate the interaction between genes. The osteogenic differentiation ability of cells was reflected using ALP staining and detection of ALP activity. The mineralization ability of cells was assessed using ARS staining. DCFCA staining was employed to evaluate the intracellular ROS level.

RESULTS

Initially, downregulation of TXNIP and upregulation of EZH2 were observed during osteogenesis in hBMSCs and MC3T3-E1 cells. Additionally, it was discovered that EZH2 negatively regulates TXNIP expression in these cells. Furthermore, experiments indicated that the knockdown of TXNIP stimulated the activation of the PI3K/AKT/Nrf2 signaling pathway in hBMSCs and MC3T3- E1 cells, thus inhibiting the production of reactive oxygen species (ROS). Further functional experiments revealed that overexpression of TXNIP inhibited the osteogenic differentiation in hBMSCs and MC3T3-E1 cells by enhancing ROS produc-tion. On the other hand, knockdown of TXNIP promoted the osteogenic differentiation capacity of hBMSCs and MC3T3-E1 cells through the activation of the PI3K/AKT/Nrf2 pathway.

CONCLUSION

In conclusion, this study demonstrated that TXNIP expression, under the regulation of EZH2, plays a crucial role in the osteogenic differentiation of hBMSCs and MC3T3-E1 cells by regulating ROS production and the PI3K/AKT/Nrf2 pathway.

Conditioned medium of human mesenchymal stem cells affects stem cell senescence in osteoporosis

Systemic transplantation of mesenchymal stem cells (MSCs) and conditioned medium derived from MSCs have been reported to recover bone loss in animal models of osteoporosis; however, the underlying mechanisms remain unclear. We recently reported that extracellular vesicles released from human mesenchymal stem cells (hMSCs) prevent senescence of stem cells in bisphosphonate-related osteonecrosis of the jaw model. In this study, we aimed to compare the effects of conditioned medium (hMSCs-CM) from early and late passage hMSCs on cellular senescence and to verify the benefits of CM from early passage hMSCs in mitigating the progression of osteoporosis through the prevention of cellular senescence. We investigated the distinct endocrine effects of early (P5) and late (P17) passage hMSCs in vitro, as well as the preventive benefits of early passage hMSCs-CM in osteoporosis model triggered by ovariectomy. Our results indicate that long-term cultured hMSCs contributed to the progression of inflammatory transcriptional programs in P5 hMSCs, ultimately impairing their functionality and enhancing senescence-related characteristics. Conversely, early passage hMSCs reversed these alterations. Moreover, early passage hMSCs-CM infused intravenously in a postmenopausal osteoporosis mouse model suppressed bone degeneration and prevented osteoporosis by reducing ovariectomy-induced senescence in bone marrow MSCs and reducing the expression of senescence-associated secretory phenotype-related cytokines. Our findings highlight the high translational value of early passage hMSCs-CM in antiaging intervention and osteoporosis prevention.

The antiapoptotic effects of conditioned medium from bone marrow-derived mesenchymal stromal stem cells on cyclophosphamide-induced testicular damage in rat: An experimental study

Background

Cyclophosphamide (CP) has some negative effects on the reproductive system. Stem cells and their metabolites are being utilized to enhance fertility after chemotherapy.

Objective

This study aimed to investigate the impact of conditioned medium (CM) derived from bone marrow mesenchymal stromal stem cells (BM-MSCs) on the toxic effects of CP on testicles.

Materials and Methods

BM-MSCs were isolated, a CM was collected and 25-fold concentrated. 24 male Wistar rats (8 wk, 200-250 gr) were randomly divided into following groups: control, CP, CP+ Dulbecco's Modified Eagle Medium (DMEM), CP+CM. CP was given at a single dose of 100 mg/kg. 2 wk after the CP administration, CM was injected into the testicular efferent duct. Sperm parameters, testicular histopathology, and the level of testosterone were analyzed 2 months after treatment. The expression of B-cell lymphoma 2 (Bcl2) and Bcl2-associated X protein (Bax) genes were evaluated by real-time polymerase chain reaction.

Results

CP had a negative effect on testis histology (p < 0.001) and sperm quality (p < 0.001). It changed the expression of genes associated with apoptosis (p < 0.001). Treatment with CM reduced the expression of Bax (p < 0.001), while significantly increasing the expression of Bcl2 (p = 0.01). It improved sperm count (p = 0.03), viability (p < 0.001), motility (p < 0.001), spermatogonial count (p < 0.001), and epithelial thickness of testicular tubules (p = 0.02).

Conclusion

These findings suggest that CM produced from BM-MSCs may be valuable for therapeutic approaches in reproductive medicine and may lessen the side effects of CP.

A caffeine pre-treatment and sole effect of bone-marrow mesenchymal stem cells-derived conditioned media on hyperglycemia-suppressed fertilization

As a common metabolic disorder, hyperglycemia (HG) affects and disrupts the physiology of various systems in the body. Transplantation of mesenchymal stem cells (MSCs) has been used to control the complications of disease. Most of the therapeutic properties of MSCs are attributed to their secretome. This study aimed to investigate the effects of conditioned media extracted from sole or caffeine pre-treated bone-marrow-derived MSCs on hyperglycemia-induced detrimental impact on some aspects of reproduction. The HG was induced by intraperitoneally injection of streptozotocin (65 mg/kg) and nicotinamide (110 mg/kg). Twenty-four male Wistar rats (190 ± 20 g) were divided into control, HG, and the hyperglycemic groups receiving conditioned media of proliferated MSCs solely (CM) or MSCs pre-treated with caffeine (CCM). During the 49-day treatment, body weight and blood glucose were measured weekly. Finally, HbA1c, spermatogenesis development, sperm count, morphology, viability, motility, chromatin condensation, and DNA integrity were examined. Also, testicular total antioxidant capacity (TAC), malondialdehyde, sperm fertilization potential, and pre-implantation embryo development were evaluated. A one-way ANOVA and Tukey's post-hoc tests were used to analyze the quantitative data. The p < 0.05 was considered statistically significant. The CM and with a higher efficiency, the CCM remarkably (p < 0.05) improved body weight and HG-suppressed spermatogenesis, enhanced sperm parameters, chromatin condensation, DNA integrity, and TAC, reduced HbA1c, sperm abnormalities, and malondialdehyde, and significantly improved pre-implantation embryo development versus HG group. The conditioned media of MSCs solely (CM) and more effectively after pre-treatment of MSCs with caffeine (CCM) could improve spermatogenesis development, sperm quality, pre-implantation embryo development, and testicular global antioxidant potential during hyperglycemia.

Proteomic Analysis of Mesenchymal Stromal Cells Secretome in Comparison to Leukocyte- and Platelet-Rich Fibrin

Secretomes of mesenchymal stromal cells (MSCs) are emerging as a novel growth factor (GF)-based strategy for periodontal and bone regeneration. The objective of this study was to compare the secretome of human bone marrow MSC (BMSC) to that of leukocyte- and platelet-rich fibrin (L-PRF), an established GF-based therapy, in the context of wound healing and regeneration. Conditioned media from human BMSCs (BMSC-CM) and L-PRF (LPRF-CM) were subjected to quantitative proteomic analysis using liquid chromatography with tandem mass spectrometry. Global profiles, gene ontology (GO) categories, differentially expressed proteins (DEPs), and gene set enrichment (GSEA) were identified using bioinformatic methods. Concentrations of selected proteins were determined using a multiplex immunoassay. Among the proteins identified in BMSC-CM (2157 proteins) and LPRF-CM (1420 proteins), 1283 proteins were common. GO analysis revealed similarities between the groups in terms of biological processes (cellular organization, protein metabolism) and molecular functions (cellular/protein-binding). Notably, more DEPs were identified in BMSC-CM (n = 550) compared to LPRF-CM (n = 118); these included several key GF, cytokines, and extracellular matrix (ECM) proteins involved in wound healing. GSEA revealed enrichment of ECM (especially bone ECM)-related processes in BMSC-CM and immune-related processes in LPRF-CM. Similar trends for intergroup differences in protein detection were observed in the multiplex analysis. Thus, the secretome of BMSC is enriched for proteins/processes relevant for periodontal and bone regeneration. The in vivo efficacy of this therapy should be evaluated in future studies.

Functionalizing Collagen Membranes with MSC-Conditioned Media Promotes Guided Bone Regeneration in Rat Calvarial Defects

Functionalizing biomaterials with conditioned media (CM) from mesenchymal stromal cells (MSC) is a promising strategy for enhancing the outcomes of guided bone regeneration (GBR). This study aimed to evaluate the bone regenerative potential of collagen membranes (MEM) functionalized with CM from human bone marrow MSC (MEM-CM) in critical size rat calvarial defects. MEM-CM prepared via soaking (CM-SOAK) or soaking followed by lyophilization (CM-LYO) were applied to critical size rat calvarial defects. Control treatments included native MEM, MEM with rat MSC (CEL) and no treatment. New bone formation was analyzed via micro-CT (2 and 4 weeks) and histology (4 weeks). Greater radiographic new bone formation occurred at 2 weeks in the CM-LYO group vs. all other groups. After 4 weeks, only the CM-LYO group was superior to the untreated control group, whereas the CM-SOAK, CEL and native MEM groups were similar. Histologically, the regenerated tissues showed a combination of regular new bone and hybrid new bone, which formed within the membrane compartment and was characterized by the incorporation of mineralized MEM fibers. Areas of new bone formation and MEM mineralization were greatest in the CM-LYO group. Proteomic analysis of lyophilized CM revealed the enrichment of several proteins and biological processes related to bone formation. In summary, lyophilized MEM-CM enhanced new bone formation in rat calvarial defects, thus representing a novel 'off-the-shelf' strategy for GBR.

Thymoquinone-treated mouse mesenchymal stem cells-derived conditioned medium inhibits human breast cancer cells in vitro

Breast cancer is now the most prevalent cancer in females, therefore, it is essential to identify factors affecting its initiation and progression. Mesenchymal stem cells (MSCs) have received considerable attention in stem cell-based therapies and drug delivery applications. Because the therapeutic potential of MSCs is primarily achieved by their paracrine effects, thus identifying and employing bioactive molecules that promote the paracrine activity of MSCs is crucial for their efficient use in cancer treatment. Thymoquinone (TQ) has many biomedical properties, including anti-inflammatory, anti-diabetic, anti-aging, anti-cancer, etc. In addition, it has been found that TQ affects the self-renewal and immunomodulatory properties of MSCs. The present study aimed to investigate the effect of TQ-treated mouse bone marrow-derived MSCs conditioned medium (TQ-MSC-CM) on the biological characteristics of breast cancer cell line MCF7. MSCs were cultured and treated with TQ for 24 h. The TQ-MSC-CM and MSC-CM were collected, and their effects were investigated on ROS production, mitochondrial membrane potential (MMP), cell death, cell cycle, and migration of MCF7 cells by DCFDA-cellular ROS assay, Rhodamine-123 MMP assay, Annexin-PI staining and Caspase-3/7 activity assays, PI-staining and flow-cytometry, and in vitro wound healing assay, respectively. Moreover, the effects of TQ-MSC-CM and MSC-CM were studied on Cdk4, Sox2, c-Met, and Bcl2 gene expression by real-time PCR. Results demonstrated that MSC-CM and TQ-MSC-CM did not have a significant effect on the apoptosis induction in MCF7 cells; however, they significantly stimulated necrosis in the cells. Although TQ-MSC-CM promoted ROS production in MCF7 cells, it decreased the MMP of the cells. TQ-MSC-CM also induced Bcl2 anti-apoptosis gene expression and Casp-3/7 activity in cells. In addition, although MSC-CM induced MCF7 cells to enter the cell cycle, TQ-MSC-CM inhibited its progression. TQ-MSC-CM also downregulated the Cdk4 and Sox2 gene expression. Furthermore, TQ-MSC-CM induced the migration potential of MCF7 in a c-Met-independent manner. Altogether, we conclude that TQ may induce programmed necrosis and inhibits the proliferation and migration of the breast cancer cells by affecting the paracrine activity of MSCs.

Oxidative Stress Response in Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells

Reactive oxygen species (ROS) can irreversibly damage biological molecules, a process known as oxidative stress. Elevated ROS levels are associated with immune cell activation. Sustained immune system activation can affect many different cells in the environment. One cell type that has been detected in almost all tissues of the body is mesenchymal stem/stromal cells (MSC). MSC possess proliferation and differentiation potential, thus facilitating regeneration processes. However, the regenerative capacity of MSC might be impaired by oxidative stress, and the effects of long-term oxidative stress on MSC functions are sparsely described. The examination of oxidative stress is often performed by exposure to H2O2. Since H2O2 is rapidly degraded, we additionally exposed the cell cultures to glucose oxidase (GOx), resulting in sustained exposure to H2O2. Using these model systems, we have focused on the effects of short- and long-term oxidative stress on viability, migration, differentiation, and signaling. All cellular functions examined were affected by the applied oxidative stress. The differences that occur between pulsed and sustained oxidative stress indicated higher oxidative stress in MSC upon direct H2O2 exposure, whereas the GOx-induced prolonged exposure to H2O2 seems to allow for better cellular adaptation. The mechanisms underlying these different responses are currently unknown.

Brief communication: Effects of conditioned media from human platelet lysate cultured MSC on osteogenic cell differentiation in vitro

Culturing mesenchymal stromal cells (MSC) in human platelet lysate (HPL) supplemented media can enhance their osteogenic differentiation potential. The objective of this study was to test the hypothesis that conditioned media (CM) derived from HPL-cultured MSC also have pro-osteogenic effects. Pooled CM was prepared from HPL-cultured human bone marrow MSC (BMSC) of multiple donors and applied on BMSC of different donors (than those used for CM preparation), with or without additional supplementation [HPL, fetal bovine serum (FBS)] and osteogenic stimulation. At various time-points, cell proliferation, alkaline phosphatase (ALP) activity, osteogenic gene expression and in vitro mineralization were assessed. BMSC in standard unstimulated growth media served as controls. After 3–7 days, CM alone did not promote BMSC proliferation or ALP activity; supplementation of CM with HPL slightly improved these effects. After 2 and 7 days, CM alone, but not CM supplemented with HPL, promoted osteogenic gene expression. After 14 days, only CM supplemented with FBS and osteogenic stimulants supported in vitro BMSC mineralization; CM alone and CM supplemented with HPL did not support mineralization, regardless of osteogenic stimulation. In summary, CM from HPL-cultured BMSC promoted osteogenic gene expression but not in vitro mineralization in allogeneic BMSC even when supplemented with HPL and/or osteogenic stimulants. Future studies should investigate the role and relevance of supplementation and osteogenic induction in in vitro assays using CM from MSC.

Hypoxic condition induced H3K27me3 modification of the LncRNA Tmem235 promoter thus supporting apoptosis of BMSCs

Bone marrow mesenchymal stem cells (BMSCs) have strong regenerative potential and show good application prospects for treating clinical diseases. However, in the process of BMSC transplantation for treating ischemic and hypoxic diseases, BMSCs have high rates of apoptosis in the hypoxic microenvironment of transplantation, which significantly affects the transplantation efficacy. Our previous studies have confirmed the key role of long non-coding RNA Tmem235 (LncRNA Tmem235) in the process of hypoxia-induced BMSC apoptosis and its downstream regulatory mechanism, but the upstream mechanism by which hypoxia regulates LncRNA Tmem235 expression to induce BMSC apoptosis is still unclear. Under hypoxic conditions, we found that the level of LncRNA Tmem235 promoter histone H3 lysine 27 trimethylation modification (H3K27me3) was significantly increased by CHIP-qPCR. Moreover, H3K27me3 cooperated with LncRNA Tmem235 promoter DNA methylation to inhibit the expression of LncRNA Tmem235 and promote apoptosis of BMSCs. To study the mechanism of hypoxia-induced modification of LncRNA Tmem235 promoter H3K27me3 in the hypoxia model of BMSCs, we detected the expression of H3K27 methylase and histone demethylase and found that only histone methylase enhancer of zeste homolog 2 (EZH2) expression was significantly upregulated. Knockdown of EZH2 significantly decreased the level of H3K27me3 modification in the LncRNA Tmem235 promoter. The EZH2 promoter region contains a hypoxia-responsive element (HRE) that interacts with hypoxia-inducible factor-1alpha (HIF-1α), which is overexpressed under hypoxic conditions, thereby promoting its overexpression. In summary, hypoxia promotes the modification of the LncRNA Tmem235 promoter H3K27me3 through the HIF-1α/EZH2 signaling axis, inhibits the expression of LncRNA Tmem235, and leads to hypoxic apoptosis of BMSCs. Our findings improve the regulatory mechanism of LncRNA Tmem235 during hypoxic apoptosis of BMSCs and provide a more complete theoretical pathway for targeting LncRNA to inhibit hypoxic apoptosis of BMSCs.

Effect of Passage Number of Conditioned Medium Collected from Equine Amniotic Fluid Mesenchymal Stem Cells: Porcine Oocyte Maturation and Embryo Development

Oocyte in vitro maturation (IVM) is the most important first step in in vitro embryo production. One prerequisite for the success of IVM in oocytes is to provide a rich culture microenvironment that meets the nutritional needs of developing oocytes. We applied different equine amniotic fluid mesenchymal stem cell conditioned medium (eAFMSC-CM) from passages 7, 18, and 27 to porcine oocytes during IVM to determine its effects on oocyte development and subsequent embryo development, specifically. The eAFMSC-CM from passage 7 (eAFMSC-CMp7) has a considerable impact on 9 genes: BAX, BCL2, SOD2, NRF2, TNFAIP6, PTGS2, HAS2, Cx37, and Cx43, which are associated with cumulus cell mediated oocyte maturation. GSH levels and distribution of mitochondrial and cortical granules were significantly increased in oocytes incubated with eAFMSC-CMp7. In addition, catalase and superoxide dismutase activities were high after IVM 44 h with eAFMSC-CMp7. After in vitro fertilization, blastocyst quality was significantly increased in the eAFMSC-CMp7 group compared to control. Lastly, the antioxidant effect of eAFMSC-CMp7 substantially regulated the expression of apoptosis, pluripotency related genes and decreased autophagy activity in blastocysts. Taken together, this study demonstrated that the eAFMSC-CMp7 enhanced the cytoplasmic maturation of oocytes and subsequent embryonic development by generating high antioxidant activity.

MSC-ACE2 Ameliorates Streptococcus uberis-Induced Inflammatory Injury in Mammary Epithelial Cells by Upregulating the IL-10/STAT3/SOCS3 Pathway

In the dairy industry, Streptococcus uberis (S. uberis) is one of the most important pathogenic bacteria associated with mastitis in milk-producing cows, causing vast economic loss. To date, the only real effective method of treating and preventing streptococcal mastitis is antimicrobial therapy. In many inflammatory diseases, mesenchymal stem cells (MSCs) and angiotensin-converting enzyme 2 (ACE2) play an anti-inflammatory and anti-injurious role. Accordingly, we hypothesized that MSCs overexpressing ACE2 (MSC-ACE2) would ameliorate the inflammatory injury caused by S. uberis in mammary epithelial cells more efficiently than MSC alone. By activating the transcription 3/suppressor of cytokine signaling 3 (IL-10/STAT3/SOCS3) signaling pathway, MSC-ACE2 inhibited the NF-κB, MAPKs, apoptosis, and pyroptosis passways. Moreover, MSC-ACE2 overturned the downregulation of Occludin, Zonula occludens 1 (ZO-1), and Claudin-3 expression levels caused by S. uberis, suggesting that MSC-ACE2 promotes the repair of the blood-milk barrier. MSC-ACE2 demonstrated greater effectiveness than MSC alone, as expected. Based on these results, MSC-ACE2 effectively inhibits EpH4-Ev cell’s inflammatory responses induced by S. uberis, and would be an effective therapeutic tool for treating streptococcal mastitis.

Investigating the Effects of Conditioned Media from Stem Cells of Human Exfoliated Deciduous Teeth on Dental Pulp Stem Cells

Pulp regeneration has recently attracted interest in modern dentistry. However, the success ratio of pulp regeneration is low due to the compromising potential of stem cells, such as their survival, migration, and odontoblastic differentiation. Stem cells from human exfoliated deciduous teeth (SHED) have been considered a promising tool for regenerative therapy due to their ability to secrete multiple factors that are essential for tissue regeneration, which is achieved by minimally invasive procedures with fewer ethical or legal concerns than those of other procedures. The aim of this study is to investigate the potency of SHED-derived conditioned media (SHED CM) on dental pulp stem cells (DPSCs), a major type of mesenchymal stem cells for dental pulp regeneration. Our results show the promotive efficiency of SHED CM on the proliferation, survival rate, and migration of DPSCs in a dose-dependent manner. Upregulation of odontoblast/osteogenic-related marker genes, such as ALP, DSPP, DMP1, OCN, and RUNX2, and enhanced mineral deposition of impaired DPSCs are also observed in the presence of SHED CM. The analysis of SHED CM found that a variety of cytokines and growth factors have positive effects on cell proliferation, migration, anti-apoptosis, and odontoblast/osteogenic differentiation. These findings suggest that SHED CM could provide some benefits to DPSCs in pulp regeneration.