ischemic stroke is one of the leading causes of mortality and disability worldwide. However, there is a current lack of effective therapies available. as the resident macrophages of the brain, microglia can monitor the microenvironment and initiate immune responses. in response to various brain injuries, such as ischemic stroke, microglia are activated and polarized into the proinflammatory M1 phenotype or the anti-inflammatory M2 phenotype. The immunomodulatory molecules, such as cytokines and chemokines, generated by these microglia are closely associated with secondary brain damage or repair, respectively, following ischemic stroke. it has been shown that M1 microglia promote secondary brain damage, whilst M2 microglia facilitate recovery following stroke. in addition, autophagy is also reportedly involved in the pathology of ischemic stroke through regulating the activation and function of microglia. Therefore, this review aimed to provide a comprehensive overview of microglia activation, their functions and changes, and the modulators of these processes, including transcription factors, membrane receptors, ion channel proteins and genes, in ischemic stroke. The effects of autophagy on microglia polarization in ischemic stroke were also reviewed. Finally, future research areas of ischemic stroke and the implications of the current knowledge for the development of novel therapeutics for ischemic stroke were identified. Contents 1. introduction 2. Microglia 3. Modulatory mechanisms of microglia polarization 4. autophagy 5. conclusions
Mesenchymal stem cells (MSCs) have potential ability to differentiate into osteocytes in response to in vitro specific induction. However, the molecular basis underlying this biological process remains largely unclear. In this study, we identify lncRNA HOTAIRM1 as a critical regulator to promote osteogenesis of MSCs. Loss of HOTAIRM1 significantly inhibits the calcium deposition and alkaline phosphatase activity of MSCs. Mechanistically, we find that HOTAIRM1 positively modulates the activity of JNK and c‐Jun, both of which are widely accepted as crucial regulators of osteogenic differentiation. More importantly, c‐Jun is found to be functionally involved in the regulation of RUNX2 expression, a master transcription factor of osteogenesis. In detail, c‐Jun can help recruit the acetyltransferase p300 to RUNX2 promoter, facilitating acetylation of histone 3 at K27 site, therefore epigenetically activating RUNX2 gene transcription. In summary, this study highlights the functional importance of HOTAIRM1 in regulation of osteogenesis, and we characterize HOTAIRM1 as a promising molecular target for bone tissue repair and regeneration.
Objectives
The current study aimed to investigate the mechanism by which exosomes secreted by CHB patients with PNALT and liver inflammation grade (≥A2) affected the development of liver cancer.
Materials and methods
Gene expression was assessed by RT‐PCR, Western blotting and immunohistochemistry. CCK‐8, colony formation, transwell, scratch‐wound and flow cytometry assays were used to detect cell viability, proliferation, apoptosis and metastasis. The interaction of TCF21 and HHIP was assessed by co‐immunoprecipitation assay. Luciferase reporter was used to detect the combination of TCF21/HHIP and miR‐25‐3p. Xenograft studies in nude mice manifested tumour growth ability of miR‐25‐3p. Bioinformatics analyses were conducted using TargetScan, EVmiRNA, TCGA, GEO, DAVID
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COEXPEDIA
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UALCAN, UCSC and the Human Protein Atlas databases
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Results
CHB‐PNALT‐Exo (≥A2) promoted the proliferation and metastasis of HepG2.2.15 cells. miR‐25‐3p was upregulated in CHB‐PNALT‐Exo (≥A2). miR‐25‐3p overexpression promoted cell proliferation and metastasis and was related to poor survival in patients with CHB‐PNALT (≥A2). The cell proliferation‐ and metastasis‐promoting functions of CHB‐PNALT‐Exo (≥A2) were abolished by miR‐25‐3p inhibitors. TCF21 directly interacted with HHIP. Inhibition of TCF21 or HHIP promoted cell proliferation and metastasis. Knockdown of TCF21 or HHIP counteracted the effects of CHB‐PNALT‐Exo (≥A2) containing miR‐25‐3p inhibitor on cell proliferation, metastasis and the expression of Ki67, E‐cadherin and caspase‐3/‐9.
Conclusions
Transfer of miR‐25‐3p by CHB‐PNALT‐Exo promoted the development of liver cancer by inhibiting the co‐expression of TCF21 and HHIP.
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