Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs)-Exosome Carrying MiRNA-312 Inhibits Sevoflurane-Induced Cardiomyocyte Apoptosis Through Activation of Phosphatidylinositol 3-Kinase/Protein Kinase B (PI3K/AKT) Pathway

This study was to explore the mechanism by how exosomes (exo) derived from BMSCs affects cardiomyocyte apoptosis. BMSCs were isolated and incubated with cardiomyocytes while the cardiomyocytes were exposed to sevoflurane or DMSO treatment. Apoptotic cells were calculated and level of apoptosis related proteins was detected by Western blot. Through transfection with microRNA-(miRNA)-312 inhibitor, we evaluated the effect of BMSC-exo on the sevoflurane-induced apoptosis. Sevoflurane significantly inhibited the viability of cardiomyocytes and induced cardiomyocyte apoptosis. Besides, sevoflurane decreased the expression of miR-312 and enhanced Bax expression in cardiomyocytes through restraining the phosphorylation of MAPK/ERK. Treatment with BMSC-exo, however, activated MAPK/ERK signaling by up-regulating miR-312, thereby inhibiting cardiomyocyte apoptosis, promoting cardiomyocyte proliferation, and elevating the level of Bcl-2. In conclusion, BMSC-exo-derived miR-312 inhibits sevoflurane-induced cardiomyocyte apoptosis by activating PI3K/AKT signaling pathway.

Exosomal MicroRNA-204 Derived from Bone Marrow Mesenchymal Stem Cells (BMSCs) Inhibits Cell Proliferation and Induces Apoptosis Through NF-κB Signaling Pathway in Breast Cancer

Our study intends to assess the relationship between exosomes derived from bone marrow mesenchymal stem cells (BMSC-exo) and breast cancer. BMSC-exo were isolated and characterized by transmission electron microscopy. After transfection of BMSCs with miR-204 inhibitor, breast cancer cells were incubated with BMSC-exo followed by analysis of cell proliferation by CCK-8 assay, cell apoptosis by flow cytometry, and expression of apoptosis-related protein and NF-κB signaling by western blot. The co-culture of BMSC-exo with breast cancer cells enhanced miR-204 transcription, inhibited cell proliferation and induced apoptosis. Further, BMSC-exo accelerated apoptosis as demonstrated by the increased level of Bax and casepase-3 and decreased Bcl-2 expression, as well as reduced NF-κB signaling activity. But knockdown of miR-204 abolished the effect of BMSC-exo on apoptosis and proliferation with NF-κB signaling activation. In conclusion, miR-204 from BMSC-exo restrains growth of breast cancer cell and might be a novel target for treating breast cancer.

Exosomal MicroRNA-328 from Bone Marrow Mesenchymal Stem Cells (BMSCs) Alleviates Acute Lung Injury Through Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase (MAPK/ERK) Pathway

To elucidate the communication between exosomes (exo) derived from BMSCs and injured lung cells. BMSC-exo was isolated and characterized. Lung epithelial cells A549 were incubated with BMSC-exo, and treated by LPS to induce cell damage. CCK-8 assay was carried out to test cell proliferation, flow cytometry was adopted to analyze cell apoptosis, and RT-qPCR as well as Western blot analysis were selected to assess expression of apoptosis- and anti-apoptosis related proteins. Functional experiment was performed to identify the role of microRNA (miRNA)-328 in lung injury. LPS treatment significantly inhibited the viability of A549 cells, induced apoptosis of A549 cells by increasing Bax and casepase-3 levels and reducing Bcl-2 expression, whilst declined expression of miR-328 and suppressed the phosphorylation activation of the MAPK/ERK pathway. Meanwhile, the amount of IL-6, IL-1β and TNF-α were elevated in injured cells, but, the presence of BMSC-exo eliminated the elevation of the contents. Importantly, treatment with BMSC-exo increased miR-328 expression, activated MAPK MAPK/ERK pathway, inhibited apoptosis, and enhanced cell proliferation. However, the effect of BMSC-exo was attenuated when the cells were silenced for miR-328 expression. Collectively, BMSC-exo enriched miR-328 could relieve acute lung injury through MAPK/ERK pathway.

Apigenin Alleviates Intervertebral Disc Degeneration via Restoring Autophagy Flux in Nucleus Pulposus Cells

Oxidative stress–induced apoptosis and senescence of nucleus pulposus (NP) cells play a crucial role in the progression of intervertebral disc degeneration (IVDD). Accumulation of studies has shown that activated autophagy and enhanced autophagic flux can alleviate IVDD. In this study, we explored the effects of apigenin on IVDD in vitro and in vivo. Apigenin was found to inhibit tert-butyl hydroperoxide (TBHP)–induced apoptosis, senescence, and ECM degradation in NP cells. In addition, apigenin treatment can restore the autophagic flux blockage caused by TBHP. Mechanistically, we found that TBHP may induce autophagosome and lysosome fusion interruption and lysosomal dysfunction, while apigenin alleviates these phenomena by promoting the nuclear translocation of TFEB via the AMPK/mTOR signaling pathway. Furthermore, apigenin also exerts a protective effect against the progression of IVDD in the puncture-induced rat model. Taken together, these findings indicate that apigenin protects NP cells against TBHP-induced apoptosis, senescence, and ECM degradation via restoration of autophagic flux in vitro, and it also ameliorates IVDD progression in rats in vivo, demonstrating its potential for serving as an effective therapeutic agent for IVDD.

MicroRNA-625-3p improved proliferation and involved chemotherapy resistance via targeting PTEN in high grade ovarian serous carcinoma

Objective High-grade serous ovarian cancer (HGSOC) is an aggressive gynaecological malignancy and associated with poor prognosis. Here we examined the effects of miR-625-3p on proliferation, treatment, migration and invasion in HGSOC. Methods The proliferation of HGSOC cells was evaluated by MTT assay. Transwell assay was performed to examine migration and matrigel assay were used to assess invasion. The effect of miR-625-3p on cisplatin-induced apoptosis was investigated by Caspase-Glo3/7 assay. The dual-luciferase reporter assay was carried out to confirm the potential binding site. Results Overexpression of miR-625-3p promoted proliferation, and increased migration and invasion in HGSOC cells. MiR-625-3p significantly inhibited cisplatin sensitivity in HGSOC cells. Meanwhile, miR-625-3p decreased cisplatin-induced apoptosis by regulation of BAX and Bcl-2 expression. Furthermore, aberrant expression of miR-625-3p changed PTEN expression by directly binding to 3’UTR of PTEN. Further study showed miR-625-3p expression was higher in human HGSOC tissue than normal ovarian tissues and associated with higher clinical stage. Conclusions miR-625-3p promotes HGSOC growth, involves chemotherapy resistance and might serve as a potential biomarker to predict chemotherapy response and prognosis in HGSOC.

Expressing the pro-apoptotic Reaper protein via insertion into the structural open reading frame of Sindbis virus reduces the ability to infect Aedes aegypti mosquitoes

Arboviruses continue to threaten a significant portion of the human population, and a better understanding is needed of the determinants of successful arbovirus infection of arthropod vectors. Avoiding apoptosis has been shown to be one such determinant. Previous work showed that a Sindbis virus (SINV) construct called MRE/rpr that expresses the pro-apoptotic protein Reaper via a duplicated subgenomic promoter had a reduced ability to orally infect Aedes aegypti mosquitoes at 3 days post-blood meal (PBM), but this difference diminished over time as virus variants containing deletions in the inserted reaper gene rapidly predominated. The goal of this study was to generate a SINV construct that more stably expressed Reaper, in order to further clarify the effect of midgut apoptosis on disseminated infection in Ae. aegypti. We did this by inserting reaper as an in-frame fusion into the structural open reading frame (ORF) of SINV. This construct, MRE/rprORF, successfully expressed Reaper, replicated similarly to MRE/rpr in cell lines, and induced apoptosis in cultured cells and in mosquito midgut tissue. Mosquitoes that fed on blood containing MRE/rprORF developed less midgut and disseminated infection when compared to MRE/rpr or a control virus up to at least 7 days PBM, when less than 50% of mosquitoes that ingested MRE/rprORF had detectable disseminated infection, compared with around 80% or more of mosquitoes fed with MRE/rpr or control virus. However, virus titer in mosquitoes infected with MRE/rprORF was not significantly different from control virus, suggesting that induction of apoptosis by expression of Reaper by this method can reduce infection prevalence, but if infection is established then apoptosis induced by this method has limited ability to continue to suppress replication.