Mesenchymal Stem Cell-Conditioned Medium Protects Hippocampal Neurons From Radiation Damage by Suppressing Oxidative Stress and Apoptosis

Apoptotic effects of mesenchymal stem cells' conditioned medium on colorectal cancer cell lines

Multipotent Mesenchymal stem cells (MSCs) have vigorous immunomodulatory activity, apoptotic effects, and the capacity to migrate to inflammatory and tumor sites. This study focuses on the apoptotic effects of MSCs conditioned medium (CM) on colorectal cancer cell lines. MSCs were preconditioned with lipopolysaccharide (LPS) to induce apoptosis in colorectal cancer cells. The conditioned medium (LPS-CM) from the preconditioned cells was isolated and used to treat colorectal cancer cells (HT29 and SW48). The survival and proliferation of cancer cells were assessed using Trypan blue staining and MTT assay. The apoptosis rate was evaluated through flow cytometry analysis and caspase-3 activity. Additionally, Real-Time PCR was used to measure the mRNA level of apoptotic and anti-apoptotic factors, including bcl2, bax, and p53 genes. The results showed that LPS-CM significantly increased (p < 0.001) the percentage of apoptosis in the SW48 and HT29 cell lines. Caspase-3 activity significantly increased (p < 0.001) in these cell lines after treatment with LPS-CM. The mRNA level of bcl2 was significantly decreased (p < 0.001), while bax and p53 genes were significantly overexpressed (p < 0.001) in the LPS-CM treated cell lines. Notably, the mRNA level of bcl2 and bax genes was significantly altered at a higher concentration of LPS-CM. In conclusion, the conditioned medium from LPS-preconditioned MSCs can effectively induce apoptosis in colorectal cancer cells. This finding suggests that LPS-CM could be a potential strategy for inhibiting the proliferation and progression of colorectal cancer cells.

Hair follicle mesenchymal stem cell exosomal lncRNA H19 inhibited NLRP3 pyroptosis to promote diabetic mouse skin wound healing

Skin wounds caused by diabetes are a major medical problem. Mesenchymal stem cell-derived exosomes hold promise to quicken wound healing due to their ability to transfer certain molecules to target cells, including mRNAs, microRNAs, lncRNAs, and proteins. Nonetheless, the specific mechanisms underlying this impact are not elucidated. Therefore, this research aimed to investigate the effect of MSC-derived exosomes comprising long non-coding RNA (lncRNA) H19 on diabetic skin wound healing. Hair follicle mesenchymal stem cells (HF-MSCs) were effectively isolated and detected, and exosomes (Exo) were also isolated smoothly. Pretreatment with 30 mM glucose for 24 h (HG) could efficiently induce pyroptosis in HaCaT cells. Exosomal H19 enhanced HaCaT proliferation and migration and inhibited pyroptosis by reversing the stimulation of the NLRP3 inflammasome. Injection of exosomes overexpressing lncRNA H19 to diabetic skin wound promoted sustained skin wound healing, whereas sh-H19 exosomes did not have this effect. In conclusion, Exosomes overexpressing H19 promoted HaCaT proliferation, migration and suppressed pyroptosis both in vitro and in vivo. Therefore, HFMSC-derived exosomes that overexpress H19 may be included in strategies for healing diabetic skin wounds.

MiR-29c Inhibits TNF-α-Induced ROS Production and Apoptosis in Mouse Hippocampal HT22 Cell Line

Recent reports have suggested that abnormal miR-29c expression in hippocampus have been implicated in the pathophysiology of some neurodegenerative and neuropsychiatric diseases. However, the underlying effect of miR-29c in regulating hippocampal neuronal function is not clear. In this study, HT22 cells were infected with lentivirus containing miR-29c or miR-29c sponge. Cell counting kit-8 (CCK8) and lactate dehydrogenase (LDH) assay kit were applied to evaluate cell viability and toxicity before and after TNF-α administration. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Hoechst 33258 staining and TUNEL assay were used to evaluate cell apoptosis. The expression of key mRNA/proteins (TNFR1, Bcl-2, Bax, TRADD, FADD, caspase-3, -8 and -9) in the apoptosis pathway was detected by PCR or WB. In addition, the protein expression of microtubule-associated protein-2 (MAP-2), nerve growth-associated protein 43 (GAP-43) and synapsin-1 (SYN-1) was detected by WB. As a result, we found that miR-29c overexpression could improve cell viability, attenuate LDH release, reduce ROS production and inhibit MMP depolarization in TNF-α-treated HT22 cells. Furthermore, miR-29c overexpression was found to decrease apoptotic rate, along with decreased expression of Bax, cleaved caspase-3, cleaved caspase-9, and increased expression of Bcl-2 in TNF-α-treated HT22 cells. However, miR-29c sponge exhibited an opposite effects. In addition, in TNF-α-treated HT22 cells, miR-29c overexpression could decrease the expressions of TNFR1, TRADD, FADD and cleaved caspase-8. However, in HT22 cells transfected with miR-29c sponge, TNF-α-induced the expressions of TNFR1, TRADD, FADD and cleaved caspase-8 was significantly exacerbated. At last, TNF-α-induced the decreased expression of MAP-2, GAP-43 and SYN-1 was reversed by miR-29c but exacerbated by miR-29c sponge. Overall, our study demonstrated that miR-29c protects against TNF-α-induced HT22 cells injury through alleviating ROS production and reduce neuronal apoptosis. Therefore, miR-29c might be a potential therapeutic agent for TNF-α accumulation and toxicity-related brain diseases.

Neuroprotective Effect of Wharton's Jelly-Derived Mesenchymal Stem Cell-Conditioned Medium (WJMSC-CM) on Diabetes-Associated Cognitive Impairment by Improving Oxidative Stress, Neuroinflammation, and Apoptosis

According to strong evidence, diabetes mellitus increases the risk of cognitive impairment. Mesenchymal stem cells have been shown to be potential therapeutic agents for neurological disorders. In the current study, we aimed to examine the effects of Wharton's jelly-derived mesenchymal stem cell-conditioned medium (WJMSC-CM) on learning and memory, oxidative stress, apoptosis, and histological changes in the hippocampus of diabetic rats. Randomly, 35 male Sprague Dawley rats weighing 260-300 g were allocated into five groups: control, diabetes, and three diabetic groups treated with insulin, WJMSC-CM, and DMEM. The injections of insulin (3 U/day, S.C.) and WJMSC-CM (10 mg/week, I.P.) were done for 60 days. The Morris water maze and open field were used to measure cognition and anxiety-like behaviors. Colorimetric assays were used to determine hippocampus glutathione (GSH), malondialdehyde (MDA) levels, and antioxidant enzyme activity. The histopathological evaluation of the hippocampus was performed by Nissl staining. The expression levels of Bax, Bcl-2, BDNF, and TNF-α were detected by real-time polymerase chain reaction (RT-PCR). According to our findings, WJMSC-CM significantly reduced and increased blood glucose and insulin levels, respectively. Enhanced cognition and improved anxiety-like behavior were also found in WJMSC-CM-treated diabetic rats. In addition, WJMSC-CM treatment reduced oxidative stress by lowering MDA and elevating GSH and antioxidant enzyme activity. Reduced TNF-α and enhanced Bcl-2 gene expression levels and elevated neuronal and nonneuronal (astrocytes and oligodendrocytes) cells were detected in the hippocampus of WJMSC-CM-treated diabetic rats. In conclusion, WJMSC-CM alleviated diabetes-related cognitive impairment by reducing oxidative stress, neuroinflammation, and apoptosis in diabetic rats.

Mesenchymal stromal cells-derived secretome protects Neuro-2a cells from oxidative stress-induced loss of neurogenesis

Neurodegenerative diseases (ND) are characterized by debilitating medical conditions that principally affect the neuronal cells in the human brain. One of the major reasons that there are no effective drugs for the treatment of ND is because researchers face technical challenges while conducting studies to understand the molecular mechanism behind ND. Although various studies have established in vitro neurodegenerative model systems, we feel that these model systems are not physiologically relevant, as they do not mimic the in vivo situation of chronic insult. Therefore, the primary aim of this study was to establish an in vitro neurodegenerative model system by inducing oxidative stress in such a way that the neuronal cells remain viable, but lose their structural and functional characteristics. Using a murine neuroblastoma cell line, Neuro-2a, we demonstrate that induction of oxidative stress significantly affects various neurite outgrowth parameters and reduces the expression of neuronal and autophagy markers without causing apoptosis in them. Previously, we have discussed the possible therapeutic applications of mesenchymal stromal cells (MSCs) and their secretome in the treatment of ND. Here, using two distinct approaches, we show that when Neuro-2a cells subjected to oxidative stress are exposed to MSC-derived conditioned medium (secretome), they exhibit a significant improvement in various neuronal parameters and in the expression of neuronal markers. Overall, our findings support the salutary role of MSC-derived secretome in rescuing the oxidative stress-induced loss of neurogenesis using a physiologically relevant in vitro model system. Our data underscore the propensity of the MSC-secretome in reversing ND.