MiR-19b-3p accelerates bone loss after spinal cord injury by suppressing osteogenesis via regulating PTEN/Akt/mTOR signalling

Rapid and extensive bone loss, one of the skeletal complications after spinal cord injury (SCI) occurrence, drastically sacrifices the life quality of SCI patients. It has been demonstrated that microRNA (miRNA) dysfunction plays an important role in the initiation and development of bone loss post-SCI. Nevertheless, the effect of miR-19b-3p on bone loss after SCI is unknown and the accurate mechanism is left to be elucidated. The present work was conducted to explore the role of miR-19b-3p/phosphatase and tensin homolog deleted on chromosome ten (PTEN) axis on osteogenesis after SCI and further investigates the underlying mechanisms. We found that miR-19b-3p level was increased in the femurs of SCI rats with decreased autophagy. The overexpression of miR-19b-3p in bone marrow mesenchymal stem cells (BMSCs) targeted down-regulation of PTEN expression, facilitated protein kinase B (Akt) and mammalian target of rapamycin (mTOR) phosphorylation, and thereby suppressing BMSCs osteogenic differentiation via autophagy. Besides, the inhibiting effects of miR-19b-3p on osteogenic differentiation of BMSCs could be diminished by autophagy inducer rapamycin. Meanwhile, bone loss after SCI in rats was also reversed by antagomir-19b-3p treatment, suggesting miR-19b-3p was an essential target for osteogenic differentiation via regulating autophagy. These results indicated that miR-19b-3p was involved in bone loss after SCI by inhibiting osteogenesis via PTEN/Akt/mTOR signalling pathway.     

MiR-29b-3p aggravates cardiac hypoxia/reoxygenation injury via targeting PTX3

Our current research aimed to decipher the role and underlying mechanism with regard to miR-29b-3p involving in myocardial ischemia/reperfusion (I/R) injury. In the present study, cardiomyocyte H9c2 cell was used, and hypoxia/reoxygenation (H/R) model was established to mimic the myocardial I/R injury. The expressions of miR-29b-3p and pentraxin 3 (PTX3) were quantified deploying qRT-PCR and Western blot, respectively. The levels of LDH, TNF-α, IL-1β and IL-6 were detected to evaluate cardiomyocyte apoptosis and inflammatory response. Cardiomyocyte viability and apoptosis were examined employing CCK-8 assay and flow cytometry, respectively. Verification of the targeting relationship between miR-29b-3p and PTX3 was conducted using a dual-luciferase reporter gene assay. It was found that miR-29b-3p expression in H9c2 cells was up-regulated by H/R, and a remarkable down-regulation of PTX3 expression was demonstrated. MiR-29b-3p significantly promoted of release of inflammatory cytokines of H9c2 cells, and it also constrained the proliferation and promoted the apoptosis of H9c2 cells. Additionally, PTX3 was inhibited by miR-29b-3p at both mRNA and protein levels, and it was identified as a direct target of miR-29b-3p. PTX3 overexpression could reduce the inflammatory response, increase the viability of H9c2 cells, and inhibit apoptosis. Additionally, PTX3 counteracted the function of miR-29b-3p during the injury of H9c2 cells induced by H/R. In summary, miR-29b-3p was capable of aggravating the H/R injury of H9c2 cells by repressing the expression of PTX3.     

Epidermal growth factor attenuates blood‐spinal cord barrier disruption via PI3K/Akt/Rac1 pathway after acute spinal cord injury

After spinal cord injury (SCI), disruption of blood–spinal cord barrier (BSCB) elicits blood cell infiltration such as neutrophils and macrophages, contributing to permanent neurological disability. Previous studies show that epidermal growth factor (EGF) produces potent neuroprotective effects in SCI models. However, little is known that whether EGF contributes to the integrity of BSCB. The present study is performed to explore the mechanism of BSCB permeability changes which are induced by EGF treatment after SCI in rats. In this study, we demonstrate that EGF administration inhibits the disruption of BSCB permeability and improves the locomotor activity in SCI model rats. Inhibition of the PI3K/Akt pathways by a specific inhibitor, LY294002, suppresses EGF‐induced Rac1 activation as well as tight junction (TJ) and adherens junction (AJ) expression. Furthermore, the protective effect of EGF on BSCB is related to the activation of Rac1 both in vivo and in vitro. Blockade of Rac1 activation with Rac1 siRNA downregulates EGF‐induced TJ and AJ proteins expression in endothelial cells. Taken together, our results indicate that EGF treatment preserves BSCB integrity and improves functional recovery after SCI via PI3K‐Akt‐Rac1 signalling pathway.     

miR-21 promotes proliferation and inhibits apoptosis of hepatic stellate cells through targeting PTEN/PI3K/AKT pathway

Abstract

To investigate the effect of microRNA 21 (miR-21) on hepatic stellate cells (HSCs) proliferation and apoptosis, and further to study its potential mechanisms. LX-2 cells were divided into miR-21 mimic group (Mimic), miR-21 mimic negative control group (NM), miR-21 inhibitor group (Inhibitor), miR-21 inhibitor negative control group (NC), and blank control group (Control). The cell proliferation was detected by CCK-8 assay and the cell migration and invasion were detected by scratch and transwell assay. Cell cycle and apoptosis were detected by flow cytometry. The levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β1 were detected by enzyme-linked immunosorbent assay (ELISA). Proliferation, apoptosis, and phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway related genes and proteins were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. The cells proliferation, migration, and invasion were promoted in Mimic group. The levels of IL-6, TNF-α, and TGF-β1 were increased after miR-21 administration. The expression of α-smooth muscle actin (SMA) and collagen 1 (Colla1) were increased, while Bax/B-cell lymphoma (Bcl)-2 ratio and programed cell death 4 (PDCD4) were reduced after miR?21 treatment. Meanwhile, the mRNA and protein expression of PTEN were reduced and PI3K/AKT pathway been promoted. Our study demonstrated that miR-21 could promote proliferation and inhibit apoptosis of HSCs, and its mechanism may be related to PTEN/PI3K/AKT pathway.     

DNA methylation and miR-92a-3p-mediated repression of HIP1R promotes pancreatic cancer progression by activating the PI3K/AKT pathway

Pancreatic cancer (PAAD) is a highly malignant tumour characterized of high mortality and poor prognosis. Huntingtin-interacting protein 1-related (HIP1R) has been recognized as a tumour suppressor in gastric cancer, while its biological function in PAAD remains to be elucidated. In this study, we reported the downregulation of HIP1R in PAAD tissues and cell lines, and the overexpression of HIP1R suppressed the proliferation, migration and invasion of PAAD cells, while silencing HIP1R showed the opposite effects. DNA methylation analysis revealed that the promoter region of HIP1R was heavily methylated in PAAD cell lines when compared to the normal pancreatic duct epithelial cells. A DNA methylation inhibitor 5-AZA increased the expression of HIP1R in PAAD cells. 5-AZA treatment also inhibited the proliferation, migration and invasion, and induced apoptosis in PAAD cell lines, which could be attenuated by HIP1R silencing. We further demonstrated that HIP1R was negatively regulated by miR-92a-3p, which modulates the malignant phenotype of PAAD cells in vitro and the tumorigenesis in vivo. The miR-92a-3p/HIP1R axis could regulate PI3K/AKT pathway in PAAD cells. Taken together, our data suggest that targeting DNA methylation and miR-92a-3p-mediated repression of HIP1R could serve as novel therapeutic strategies for PAAD treatment.     

miRNA-30-3p improves myocardial ischemia via the PTEN/PI3K/AKT signaling pathway

The aim of this study was to explain the effect and mechanisms of miRNA-30-3p in myocardial ischemia-induced cell apoptosis in vitro and in vivo studies. In the cell experiment, the H9C2 cells were divided into the normal control (NC), and the model, miRNA, and miRNA + phosphatidylinositol 3-kinase (PI3K) inhibitor groups. The cell survival rates of the different groups were measured with the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay kit; the lactate dehydrogenase (LDH), malondialdehyde (MDA) content, and superoxidedimutase (SOD) activity in the bathing medium were assayed for the evaluation of myocardial cell injury. The cell apoptosis rate of different groups was measured with flow cytometry analysis. The relative protein expressions of different cell groups were evaluated by Western blot analysis. In the vivo study, the Sprague-Dawley rats were divided into four groups: the NC group, the model group, miRNA group, and the (miRNA + PI3K inhibitor) group. The pathological observations, cell apoptosis, LDH, SOD, MDA, and relative protein expressions were evaluated with hematoxylin and eosin, enzyme-linked immunosorbent assay, terminal deoxynucleotide transferase dUTP nick-end labeling or immunohistochemical methods. The results show that miRNA-30-3p had the effect of improving cell apoptosis induced by myocardial ischemia in vitro and in vivo studies by the regulation of the PTEN/PI3K/AKT pathway.     

Enforced expression of miR-92b blunts E. coli lipopolysaccharide-mediated inflammatory injury by activating the PI3K/AKT/β-catenin pathway via targeting PTEN

Endometritis is a reproductive disorder characterized by an inflammatory response in the endometrium, which causes significant economic losses to the dairy farming industry. MicroRNAs (miRNAs) are implicated in the inflammatory response and immune regulation following infection by pathogenic bacteria. Recent miRNA microarray analysis showed an altered expression of miR-92b in cows with endometritis. In the present study, we set out to investigate the regulatory mechanism of miR-92b in endometritis. Here, qPCR results first validated that miR-92b was down-regulated during endometritis. And then, bovine endometrial epithelial cells (BEND cells) stimulated by high concentration of lipopolysaccharide (LPS) were employed as an in vitro inflammatory injury model. Our data showed that overexpression of miR-92b significantly suppressed the activation of Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF‐κB) in LPS-stimulated BEND cells, thereby reducing pro-inflammatory cytokines release and inhibiting cell apoptosis. Looking into the molecular mechanisms of regulation of inflammatory injury by miR-92b, we observed that overexpression of miR-92b restrained TLR4/NF‐κB by activating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT)/β-catenin pathway. Furthermore, the luciferase reporter assay suggested that miR-92b targeted inhibition of phosphatase and tensin homolog (PTEN), an inhibitor of the PI3K/AKT/β-catenin pathway. Importantly, in vivo experiments confirmed that up-regulation of miR-92b attenuated the pathological injury in an experimental murine model of LPS-induced endometritis. Collectively, these findings show that enforced expression of miR-92b alleviates LPS-induced inflammatory injury by activating the PI3K/AKT/β-catenin pathway via targeting PTEN, suggesting a potential application for miR-92b-based therapy to treat endometritis or other inflammatory diseases.     

LINC00963 targeting miR-128-3p promotes acute kidney injury process by activating JAK2/STAT1 pathway

The role of long non-coding RNAs (lncRNAs) in kidney diseases has been gradually discovered in recent years. LINC00963, as an lncRNA, was found to be involved in chronic renal failure. However, the role and molecular mechanisms of LINC00963 engaged in acute kidney injury (AKI) were still unclear. In this study, we established rat AKI models by ischaemia and reperfusion (I/R) treatment. Urea and creatinine levels were determined, and histological features of kidney tissues were examined following HE staining. CCK8 assay was chosen to assess the viability of hypoxia-induced HK-2 cells. Dual-luciferase reporter gene assays were performed to verify the target relationship between LINC00963 and microRNA. The mRNA and protein levels were assayed by RT-qPCR and Western blot, respectively. Annexin V-FITC/PI and TUNEL staining were used to evaluate apoptosis. LINC00963 was highly expressed in the cell and rat models, and miR-128-3p was predicted and then verified as a target gene of LINC00963. Knockdown of LINC00963 reduced acute renal injury both in vitro and in vivo. LINC00963 activated the JAK2/STAT1 pathway to aggravate renal I/R injury. LINC00963 could target miR-128-3p to reduce G1 arrest and apoptosis through JAK2/STAT1 pathway to promote the progression of AKI.     

Ginsenoside Rb3 alleviates smoke-induced lung injury via the H19/miR-29b-3p/HGMB1/TLR4 signalling pathway

The over-activation of inflammation is involved in the pathogenesis of smoke-induced lung injury (SILI), while Rb3 treatment may alleviate smoke-induced lung injury by down-regulating the expression of H19, a regulator of miR-29b expression. Moreover, HMGB1 is an important mediator of inflammation. Therefore, in this study, we set up an animal model of SILI and treated it with Rb3 to study the effect of Rb3 on the treatment of SILI and the involvement of H19/miR-29b/HMGB1/TLR4 signalling. SILI mice treated with Rb3 before H&E staining and TUNEL assay were conducted to observe the pathological damages and status of apoptosis in each group. Real-time PCR, Western blot, computational analysis and luciferase assays were utilized to establish the signalling pathway involved in the pathogenesis of SILI and the action of Rb3 treatment. Rb3 treatment alleviated pathological changes in the lungs while decreasing the levels of W/D ratio and cell apoptotic index. H19 was validated to sponge miR-29b-3p, while HMGB1 mRNA was validated to be a target gene of miR-29b-3. As a result, a signalling pathway of H19/miR-29b-3p/HMGB1 was established. Cell viability was evidently reduced after 72 hours of treatment with CSE, but the treatment of Rb3 elevated the expression of H19 and HMBG1 in the presence of CSE. Also, CSE-induced inhibition of miR-29b-3p expression was restored by Rb3. The findings of this study collectively demonstrated that Rb3 exhibited its therapeutic effect during the treatment of SILI via modulating the H19/miR-29b-3p/HMBG1 signalling pathway.     

宫颈癌组织miR-200b-5p、miR-424-5p表达与临床病理特征、PI3K/AKT/mTOR信号通路和预后的关系研究

摘要 目的：探讨宫颈癌组织微小核糖核酸（miRNA）-200b-5p、miR-424-5p表达与临床病理特征、磷脂酰肌醇3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白（PI3K/AKT/mTOR）信号通路和预后的关系。方法：选取2016年7月～2019年6月西安市中心医院收治的123例宫颈癌患者,采用定量聚合酶链式反应（qPCR）检测癌组织与癌旁组织中miR-200b-5p、miR-424-5p、PI3K信使RNA（mRNA）、AKT mRNA、mTOR mRNA表达。分析miR-200b-5p、miR-424-5p表达与PI3K mRNA、AKT mRNA、mTOR mRNA表达的相关性及与临床病理特征的关系。采用K-M法绘制不同miR-200b-5p、miR-424-5p表达宫颈癌患者生存曲线。结果：与癌旁组织比较,宫颈癌组织中miR-200b-5p、miR-424-5p表达降低,PI3K mRNA、AKT mRNA、mTOR mRNA表达升高（P＜0.05）。Pearson相关性分析显示,宫颈癌组织中miR-200b-5p、miR-424-5p表达与PI3K mRNA、AKT mRNA、mTOR mRNA表达均呈负相关,PI3K mRNA、AKT mRNA、mTOR mRNA表达呈两两相关（P＜0.05）。miR-200b-5p、miR-424-5p表达与宫颈癌分化程度、国际妇产科联盟（FIGO）分期和淋巴结转移有关（P＜0.05）。随访3年,123例宫颈癌患者累积生存率为62.60%（77/123）。K-M生存曲线分析显示,miR-200b-5p、miR-424-5p高表达组累积生存率分别高于miR-200b-5p、miR-424-5p低表达组（P＜0.05）。结论：宫颈癌组织中miR-200b-5p、miR-424-5p低表达,与分化程度、FIGO分期、淋巴结转移、PI3K/AKT/mTOR信号通路和预后有关。     

Homoharringtonine inhibited breast cancer cells growth via miR-18a-3p/AKT/mTOR signaling pathway

Homoharringtonine (HHT), a natural alkaloid derived from the cephalotaxus, exhibited its anti-cancer effects in hematological malignancies clinically. However, its pesticide effects and mechanisms in treating solid tumors remain unclear. In this study, we found that HHT was capable of inhibiting tumor growth after 5-days treatment of breast cancer cells, MCF-7, in vivo. Furthemore, HHT also significantly inhibited the cancer cell growth and induced cell apoptosis in vitro. miRNA sequencing proved miR-18a-3p was noticeably downregulated in the cells after HHT treatment. Moreover, downregulating miR-18a-3p increased HHT-induced cell apoptosis; our data supported that HHT suppressed miR-18a-3p expression and inhibited tumorigenesis might via AKT-mTOR signaling pathway. In conclusion: our study proved that HHT suppressed breast cancer cell growth and promoted apoptosis mediated by regulating of the miR-18a-3p-AKT-mTOR signaling pathway, HHT may be a promising antitumor agent in breast cancer treatment.     

miR-216b-5p靶向调控BTN3A2促进胶质瘤细胞LN-229的迁移以及侵袭能力

大量证据表明microRNA（miRNA）通过靶向调控靶基因的表达从而在肿瘤侵袭与转移中发挥重要作用。然而关于microRNA-216b-5p (miR-216b-5p )通过靶向嗜乳脂蛋白第3亚家族膜蛋白A2（butyrophilin subfamily 3 member A2,BTN3A2）促进胶质瘤侵袭与转移的机制尚不明确。本研究通过GSE15824与GSE4290差异表达分析筛选出同时在2个芯片中表达上调的BTN3A2（P＜0.05）。生存曲线结果显示,高表达BTN3A2病人总生存期明显下降（P＜0.001）。表达量分析结果显示,BTN3A2表达随WHO分级升高而升高（P＜0.05）,同时1p/19q未联合缺失与IDH突变型病人BTN3A2表达升高（P＜0.001）。基因集富集分析（gene set enrichment analysis,GSEA）结果显示,BTN3A2与众多癌症相关通路有关（P＜0.05）;Western印迹结果显示,BTN3A2在7例胶质瘤组织和胶质瘤细胞系U87、U251和LN-229中表达上调,过表达miR-216b-5p （miR-216b-5p mimics）后BTN3A2蛋白表达水平降低;Transwell结果显示,转染BTN3A2干扰质粒（si-BTN3A2）和miR-216b-5p mimics后可以抑制LN 229细胞体外迁移与侵袭能力（P＜0.05）;在线预测网站证实,miR-216b-5p 为BTN3A2潜在靶基因;生存曲线结果显示,与低表达miR-216b-5p 病人相比,高表达病人生存率明显上调（P=0.025）;荧光定量RT PCR结果显示,miR-216b-5p 在胶质瘤U87、U251和LN-229细胞中表达下降（P＜0.05）;双荧光素酶结果显示,BTN3A2存在与miR-216b-5p 的结合靶点(P<005);综上所述,BTN3A2可能通过结合miR-216b-5p 促进胶质瘤细胞LN 229的迁移以及侵袭。     

Long noncoding RNA PTENP1 affects the recovery of spinal cord injury by regulating the expression of miR-19b and miR-21

Exosomes derived from differentiated P12 cells and MSCs were proved to suppress apoptosis of neuron cells, and phosphatase and tensin homolog pseudogene 1 (PTENP1) was reported to inhibit cell proliferation. In this study, we aimed to investigate the role of PTENP1 in the process of post-spinal cord injury (SCI) recovery, so as to evaluate the therapeutic effects of exosomes derived from MSCs transfected with PTENP1 short hairpin RNA (shRNA), as a type of novel biomarkers in the treatment of SCI. Electron microscopy was used to observe the morphology of different exosomes. Real-time polymerase chain reaction and western blot, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, flow cytometry, Nissl staining, immunohistochemistry assay, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were conducted to investigate and validate the underlying molecular signaling pathway. PTENP1-shRNA downregulated PTENP1 and PTEN while upregulating miR-21 and miR-19b. PTENP1-shRNA also accelerated cell apoptosis and reduced cell viability. In addition, PTENP1 reduced the miR-21 and miR-19b expression by directly targeting miR-21 and miR-19b. Meanwhile, both miR-21 and miR-19b reduced the expression of PTEN by directly targeting the 3′-untranslated region of PTEN. Furthermore, PTEN level and apoptosis index of neuron cells was the highest in the SCI group, while the treatment with exosomes+PTENP1-shRNA reduced the PTEN expression to a level similar to that in the sham group. Finally, PTENP1 inhibited miR-21 and miR-19b expression but upregulated PTEN expression. The upregulation of miR-21/miR-19b also suppressed the apoptosis of neuron cells by downregulating the PTEN expression. PTENP1 is involved in the recovery of SCI by regulating the expression of miR-19b and miR-21, and exosomes from PTENP1-shRNA-transfected cells may be used as a novel biomarker in SCI treatment.