LncRNA XIST Promoted OGD-Induced Neuronal Injury Through Modulating/miR-455-3p/TIPARP Axis

In recent years, the incidence of ischemic stroke has gradually increased, but its pathogenesis has not been fully elucidated. lncRNAs played an important role in the occurrence and regulation of disease, but the research on ischemic stroke is very limited. Therefore, the role of lncRNA in ischemic stroke needs further exploration. The mice model was built to obtain OGD-induced neuronal cells for the following experiments. The protein expression of TCDD inducible poly [ADP-ribose] polymerase (TIPARP), B-cell lymphoma-2 (Bcl-2) and Cleaved Caspase-3 (Cleaved-cas3) were detected with western blot. qRT-PCR was used to analyze expression of XIST, miR-455-3p and TIPARP. CCK-8 assay indicated the capacity of cell proliferation. Flow cytometry was applied to assess cell apoptosis rate. Moreover, dual-luciferase reporter assay and RIP assay were used to determine that the relationship among XIST, miR-455-3p and TIPARP. In this study, we found that oxygen–glucose deprivation (OGD) induced XIST expression, inhibited miR-455-3p expression and promoted TIPARP mRNA and protein expression in neurons. Furthermore, XIST could affect cell growth of OGD-induced neuronal cells. Further analysis showed that XIST could regulate TIPARP by binding to miR-455-3p, and overexpression of miR-455-3p or inhibition of TIPARP could reverse the effects of high XIST expression on OGD-induced neuronal cells. On the contrary, suppression of miR-455-3p or promotion of TIPARP could reverse the effects of low XIST expression on OGD-induced neuronal cells. XIST could affect cell proliferation and apoptosis through miR-455-3p/TIPARP axis in OGD-induced neuronal cells, providing a new regulatory network to understand the pathogenesis of hypoxia-induced neuronal injury.

     

Downregulation of XIST ameliorates acute kidney injury by sponging miR-142-5p and targeting PDCD4

Acute kidney injury (AKI) is a common kidney disease that markedly affects public health. To date, the roles of long noncoding RNA XIST in AKI are poorly understood. Here, we investigated the biological functions of XIST in AKI. We observed that XIST expression increased in patients with AKI and HK-2 cells stimulated by CoCl₂. In addition, a rat AKI model induced by ischemia–reperfusion was established. Tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2 messenger RNA expression were induced in vivo; moreover, XIST expression was upregulated. Knockdown of XIST significantly repressed CoCl₂-triggered injury in HK-2 cells. However, microRNA (miR)-142-5p, a downstream target of XIST, was downregulated in AKI. miR-142-5p was repressed by XIST and miR-142-5p could inhibit CoCl₂-induced injury in HK-2 cells. Moreover, PDCD4 expression was significantly increased in AKI. PDCD4 was predicted to be the target of miR-142-5p. Subsequently, loss of PDCD4 was able to retard injury in HK-2 cells exposed to CoCl_2. Thus, we suggest that XIST regulates miR-142-5p and PDCD4, and it has the potential to function as a biomarker in therapeutic strategies for AKI.     

Atractylenolide II reverses the influence of lncRNA XIST/miR‐30a‐5p/ROR1 axis on chemo‐resistance of colorectal cancer cells

This investigation was conducted to elucidate whether atractylenolide II could reverse the role of lncRNA XIST/miR‐30a‐5p/ROR1 axis in modulating chemosensitivity of colorectal cancer cells. We totally collected 294 pairs of colorectal cancer tissues and adjacent normal tissues and also purchased colorectal cancer cell lines and human embryonic kidney cell line. 5‐fluorouracil, cisplatin, mitomycin and adriamycin were designated as the chemotherapies for colorectal cell lines, and atractylenolides were arranged as the Chinese drug. The expressions of XIST, miR‐30a‐5p and ROR1 were quantified with aid of qRT‐PCR or Western blot, and luciferase reporter gene assay was implemented to determine the relationships among XIST, miR‐30a‐5p and ROR1. Our results demonstrated that XIST and ROR1 expressions were dramatically up‐regulated, yet miR‐30a‐5p expression was down‐regulated within colorectal cancer tissues (P < 0.05). The overexpressed XIST and ROR1, as well as under‐expressed miR‐30a‐5p, were inclined to promote viability and proliferation of colorectal cells under the influence of chemo drugs (P < 0.05). In addition, XIST could directly target miR‐30a‐5p, and ROR1 acted as the targeted molecule of miR‐30a‐5p. Interestingly, atractylenolides not only switched the expressions of XIST, miR‐30a‐5p and ROR1 within colorectal cancer cells but also significantly intensified the chemosensitivity of colorectal cancer cells (P < 0.05). Finally, atractylenolide II was discovered to slow down the viability and proliferation of colorectal cancer cells (P < 0.05). In conclusion, the XIST/miR‐30a‐5p/ROR1 axis could be deemed as pivotal markers underlying colorectal cancer, and administration of atractylenolide II might improve the chemotherapeutic efficacy for colorectal cancer.     

LncRNA OIP5-AS1 facilitates ox-LDL-induced endothelial cell injury through the miR-98-5p/HMGB1 axis

Cerebrovascular diseases have a high mortality and disability rate in developed countries. Endothelial cell injury is the main cause of atherosclerosis and cerebrovascular disease. Long non-coding RNA (lncRNA) has been proved to participate in the progression of endothelial cell. Our study aimed to develop the function of lncRNA opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) in oxidative low-density lipoprotein (ox-LDL)-induced endothelial cell injury. The expression of OIP5-AS1, miR-98-5p and High-mobility group protein box-1 (HMGB1) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry were used to detect the cell proliferation and apoptosis. The levels of cyclinD1, Bcl-2 Associated X Protein (Bax), Cleaved-caspase-3, Toll like receptors 4 (TLR4), phosphorylation of p65 (p-P65), phosphorylation of nuclear factor-kappa B inhibitor α (p-IκB-α) and HMGB1 were measured by Western blot. The concentrations of Interleukin-6 (IL-6), Interleukin-1β (IL-1β) and Tumor necrosis factor-α (TNF-α) were detected by Enzyme-linked immunosorbent assay (ELISA). The production of Reactive oxygen species (ROS), Superoxide Dismutase (SOD) and malondialdehyde (MDA) was detected by the corresponding kit. The targets of OIP5-AS and miR-98-5p were predicted by starBase 3.0 and TargetScan and confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The expression of OIP5-AS1 was upregulated, while miR-98-5p was downregulated in ox-LDL-induced human umbilical vein endothelial cells (HUVECs). Functionally, knockdown of OIP5-AS1 induced proliferation and inhibited apoptosis, inflammatory injury and oxidative stress injury in ox-LDL-induced HUVEC cells. Interestingly, miR-98-5p was a target of OIP5-AS1 and miR-98-5p inhibition abolished the effects of OIP5-AS1 downregulation on ox-LDL-induced HUVECs injury. More importantly, miR-98-5p directly targeted HMGB1, and OIP5-AS1 regulated the expression of HMGB1 by sponging miR-98-5p. Finally, OIP5-AS1 regulated the TLR4/nuclear factor-kappa B (NF-κB) signaling pathway through miR-98-5p/HMGB1 axis. LncRNA OIP5-AS1 accelerates ox-LDL-induced endothelial cell injury through regulating HMGB1 mediated by miR-98-5p via the TLR4/NF-κB signaling pathway.

     

Inhibition of lncRNA MEG3 protects renal tubular from hypoxia-induced kidney injury in acute renal allografts by regulating miR-181b/TNF-α signaling pathway

Early damage to transplanted organs initiates excess inflammation that deteriorates existing injury, which is a leading cause of graft loss. Long noncoding RNAs (lncRNAs) are recently thought to play a significant role in cellular homeostasis during pathological process of kidney diseases. The aim of this study was to assess the function and mechanism of lncRNA, maternally expressed gene 3 (MEG3), on early renal allografts pathogenesis. Real-time polymerase chain reaction (RT-PCR) analysis found that the levels of MEG3 and miR-181b-5p were increased and decreased respectively in grafted kidney. The Western blot assay showed that TNF-alpha was upregulated in the kidney and in HK-2 cells. Administering MEG3-specific small interfering RNA (siRNA) in mice silenced MEG3 expression and protected kidney renal allograft from injury. Bioinformatical analysis and luciferase assay indicated that MEG3 is a target of miR-181b-5p. MEG3 inhibition and overexpression promoted and suppressed miR-181b-5p levels respectively. In addition, Western blot and immunohistochemical staining suggested that decreased TNF-alpha expression was observed in the kidney. In contrary to MEG3, miR181b overexpression attenuated hypoxia-induced HK-2 cell apoptosis, as well as suppressed hypoxia-induced TNF-alpha upregulation. In luciferase reporter assay, we confirmed that miR-181b directly bound to the 3′-untranslated region (3′-UTR) of TNF-alpha, thereby negatively regulating the TNF-alpha expression. Our data suggested that MEG3 functions as a competing endogenous RNA for miR-181b to regulate the TNF-alpha expression in hypoxia-induced kidney injury in acute renal allografts.