scholarly journals Induction of MicroRNA-24 by HIF-1 Protects Against Ischemic Injury in Rat Cardiomyocytes

2012 ◽  
pp. 555-565 ◽  
Author(s):  
D.-F. LI ◽  
J. TIAN ◽  
X. GUO ◽  
L.-M. HUANG ◽  
Y. XU ◽  
...  

MicroRNAs are emerging as important regulators of cardiac function. This study investigated the role of microRNA-24 (miR-24) in ischemic cardiomyocytes, based on the observation that miR-24 expression was significantly enhanced in the ischemic myocardium of rats. Using primary cultured rat cardiomyocytes, cell injury was induced by ischemic conditions, and the cells were evaluated for changes in lactate dehydrogenase (LDH) release, cell viability, apoptosis and necrosis. The results showed that miR-24 was increased in myocytes exposed to ischemia. When miR-24 was further overexpressed in ischemic myocytes using the mimic RNA sequence, LDH release was reduced, cell viability was enhanced, and apoptosis and necrosis rates were both decreased. By contrast, a deficiency in miR-24 resulted in the largest LDH release, lowest cell viability and highest apoptosis and necrosis rates in normal and ischemic myocytes, with significant changes compared to that of non-transfected myocytes. Additionally, the mRNA and protein levels of the pro-apoptotic gene, BCL2L11, were down-regulated by miR-24 overexpression and up-regulated by miR-24 deficiency. The luciferase reporter assay confirmed BCL2L11 to be a target of miR-24. Overall, this study showed a protective role for miR-24 against myocardial ischemia by inhibiting BCL2L11, and may represent a potential novel treatment for ischemic heart disease.

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jianlei Zhang ◽  
Wei Liu ◽  
Yabo Wang ◽  
Shengnan Zhao ◽  
Na Chang

miR-135a-5p was reported to play a crucial role in the protective effects of hydrogen sulfide against Parkinson’s disease (PD) by targeting rho-associated protein kinase 2 (ROCK2). However, the role of another member of miR-135 family (miR-135b) and the underlying mechanism in PD are still unclear. qRT-PCR and western blot showed that miR-135 was downregulated and glycogen synthase kinase 3β (GSK3β) was upregulated at mRNA and protein levels in MPP+-intoxicated SH-SY5Y cells in a dose- and time-dependent manner. MTT, TUNEL, and ELISA assays revealed that miR-135b overexpression significantly promoted cell proliferation and inhibited apoptosis and production of TNF-α and IL-1β in SH-SY5Y cells in the presence of MPP+. Luciferase reporter assay demonstrated that GSK3β was a direct target of miR-135b. Moreover, sodium nitroprusside (SNP), a GSK3β activator, dramatically reversed the effects of miR-135b upregulation on cell proliferation, apoptosis, and inflammatory cytokine production in MPP+-intoxicated SH-SY5Y cells. Taken together, miR-135b exerts a protective role via promotion of proliferation and suppression of apoptosis and neuroinflammation by targeting GSK3β in MPP+-intoxicated SH-SY5Y cells, providing a potential therapeutic target for the treatment of PD.


2022 ◽  
Vol 12 (2) ◽  
pp. 335-345
Author(s):  
Xiaoyan Zhang ◽  
Wei Zhu ◽  
Junjie Lu

MicroRNAs (miRNAs/miRs) have been identified to serve a key role in the development of tumors. However, the role of miR-133b in colorectal cancer (CRC) remains largely unclear. This study will investigate the role and mechanism of miR-133b in CRC. Reverse transcription-quantitative polymerase chain reaction analysis was performed to detect the level of miR-133b in CRC cell lines. Bioinformatics software TargetScan predicted the potential target genes of miR-133b, and a dual luciferase reporter assay was used to confirm this. To investigate the role of miR-133b in CRC cells, miR-133b was upregulated or downregulated in CRC cell lines (SW620 and HT-29) by transfecting with a miR-133b mimic or inhibitor, respectively. Subsequently, cell viability was analyzed using MTT assay, whereas cell apoptosis and the cell cycle distribution were analyzed by flow cytometry. In addition, the associated protein levels were detected using western blot analysis. The results demonstrated that miR-133b was significantly downregulated in CRC cell lines when compared with the normal colonic epithelial NCM-460 cell line. Human antigen R (HuR; also termed ELAVL1) was demonstrated to be a direct target of miR-133b and was negatively regulated by miR-133b. HuR was also notably upregulated in the CRC cell lines when compared with the normal control. Transfection of SW620 and HT-29 cells with the miR-133b mimic significantly inhibited cell viability, and induced cell apoptosis and G1 phase arrest, while upregulation of HuR demonstrated the opposite effects. Furthermore, the present data demonstrated that the miR-133b mimic significantly enhanced the protein levels of p21 and p27, and downregulated cyclin D1 and cyclin A levels in SW620 and HT-29 cells; the opposite effects were observed following treatment with the miR-133b inhibitor. In conclusion, the data indicate that miR-133b suppressed CRC cell growth by targeting HuR.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jianwei Zhang ◽  
Lei Han ◽  
Feng Chen

Abstract Background Let-7a-5p is demonstrated to be a tumor inhibitor in nasopharyngeal carcinoma. However, the role of let-7a-5p in chronic rhinosinusitis with nasal polyps (CRSwNP) has not been reported. This study is designed to determine the pattern of expression and role of let-7a-5p in CRSwNP. Methods The expression level of let-7a-5p, TNF-α, IL-1β, and IL-6 in CRSwNP tissues and cells were detected by RT-qPCR. Western blot assay was carried out to measure the protein expression of the Ras-MAPK pathway. Dual luciferase reporter assay and RNA pull-down assay were used to explore the relationship between let-7a-5p and IL-6. Results Let-7a-5p was significantly downregulated in CRSwNP tissues and cells. Moreover, the mRNA expression of TNF-α, IL-1β and IL-6 was increased in CRSwNP tissues, while let-7a-5p mimic inhibited the expression of TNF-α, IL-1β and IL-6. Besides that, let-7a-5p was negatively correlated with TNF-α, IL-1β and IL-6 in CRSwNP tissues. In our study, IL-6 was found to be a target gene of let-7a-5p. Additionally, let-7-5p mimic obviously reduced the protein levels of Ras, p-Raf1, p-MEK1 and p-ERK1/2, while IL-6 overexpression destroyed the inhibitory effect of let-7a-5p on the Ras-MAPK pathway in CRSwNP. Conclusion We demonstrated that let-7a-5p/IL-6 interaction regulated the inflammatory response through the Ras-MAPK pathway in CRSwNP.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xu Zhou ◽  
Jingliang He ◽  
Jinbo Chen ◽  
Yu Cui ◽  
Zhenyu Ou ◽  
...  

Abstract Background Leydig cells reflect the activation of inflammation, decrease of androgen production, inhibition of cell growth and promotion of cell apoptosis under orchitis. Maternally expressed gene 3 (MEG3) exerts a crucial role in various human diseases, but under orchitis, the role and underlying molecular mechanism of MEG3 in Leydig cells remain unclear. Methods Lipofectamine 2000 was used for the cell transfections. qPCR and western blots assay were applied to assess the gene expression. ELISA assay was used to measure the TNFα, IL6 and testosterone secretion. CCK8 and EdU assay was employ to test the cell viability and proliferation respectively. Luciferase reporter and RIP assay were introduced to detect the binding of miR-93-5p with MEG3 and PTEN. Results Lipopolysaccharides (LPS) induced TNFα and IL6 secretion, lowered testosterone production, inhibited cell viability and proliferation, and induced cell apoptosis in Leydig cells. MEG3 was upregulated in Leydig cells treated with LPS and that knockdown of MEG3 inhibited the role of LPS in Leydig cells. MEG3 absorbed miR-93-5p and that suppression of miR-93-5p restored the role of silenced MEG3 in Leydig cells under LPS treatment. miR-93-5p inhibited PTEN expression and that over-expressed PTEN alleviated the effect of miR-93-5p in Leydig cells treated with LPS. LPS activated the MEG3/miR-93-5p/PTEN signalling pathway in Leydig cells. Conclusions This study revealed that MEG3 serves as a molecular sponge to absorb miR-93-5p, thus leading to elevation of PTEN expression in Leydig cells under LPS treatment, offering a theoretical basis on which to establish potential new treatment strategies for orchitis.


Author(s):  
Kang Zhou ◽  
Yan Xu ◽  
Qiong Wang ◽  
Lini Dong

Abstract Myocardial injury is still a serious condition damaging the public health. Clinically, myocardial injury often leads to cardiac dysfunction and, in severe cases, death. Reperfusion of the ischemic myocardial tissues can minimize acute myocardial infarction (AMI)-induced damage. MicroRNAs are commonly recognized in diverse diseases and are often involved in the development of myocardial ischemia/reperfusion injury. However, the role of miR-431 remains unclear in myocardial injury. In this study, we investigated the underlying mechanisms of miR-431 in the cell apoptosis and autophagy of human cardiomyocytes in hypoxia/reoxygenation (H/R). H/R treatment reduced cell viability, promoted cell apoptotic rate, and down-regulated the expression of miR-431 in human cardiomyocytes. The down-regulation of miR-431 by its inhibitor reduced cell viability and induced cell apoptosis in the human cardiomyocytes. Moreover, miR-431 down-regulated the expression of autophagy-related 3 (ATG3) via targeting the 3ʹ-untranslated region of ATG3. Up-regulated expression of ATG3 by pcDNA3.1-ATG3 reversed the protective role of the overexpression of miR-431 on cell viability and cell apoptosis in H/R-treated human cardiomyocytes. More importantly, H/R treatments promoted autophagy in the human cardiomyocytes, and this effect was greatly alleviated via miR-431-mimic transfection. Our results suggested that miR-431 overexpression attenuated the H/R-induced myocardial damage at least partly through regulating the expression of ATG3.


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Ming Liu ◽  
Zikun Xie ◽  
Guang Sun ◽  
Liujun Chen ◽  
Dake Qi ◽  
...  

Abstract Background Osteoarthritis (OA) is the most prevalent form of arthritis and the major cause of disability and overall diminution of quality of life in the elderly population. Currently there is no cure for OA, partly due to the large gaps in our understanding of its underlying molecular and cellular mechanisms. Macrophage migration inhibitory factor (MIF) is a procytokine that mediates pleiotropic inflammatory effects in inflammatory diseases such as rheumatoid arthritis (RA) and ankylosing spondylitis (AS). However, data on the role of MIF in OA is limited with conflicting results. We undertook this study to investigate the role of MIF in OA by examining MIF genotype, mRNA expression, and protein levels in the Newfoundland Osteoarthritis Study. Methods One hundred nineteen end-stage knee/hip OA patients, 16 RA patients, and 113 healthy controls were included in the study. Two polymorphisms in the MIF gene, rs755622, and -794 CATT5-8, were genotyped using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) and PCR followed by automated capillary electrophoresis, respectively. MIF mRNA levels in articular cartilage and subchondral bone were measured by quantitative polymerase chain reaction. Plasma concentrations of MIF, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) were measured by enzyme-linked immunosorbent assay. Results rs755622 and -794 CATT5-8 genotypes were not associated with MIF mRNA or protein levels or OA (all p ≥ 0.19). MIF mRNA level in cartilage was lower in OA patients than in controls (p = 0.028) and RA patients (p = 0.004), while the levels in bone were comparable between OA patients and controls (p = 0.165). MIF protein level in plasma was lower in OA patients than in controls (p = 3.01 × 10−10), while the levels of TNF-α, IL-6 and IL-1β in plasma were all significantly higher in OA patients than in controls (all p ≤ 0.0007). Multivariable logistic regression showed lower MIF and higher IL-1β protein levels in plasma were independently associated with OA (OR per SD increase = 0.10 and 8.08; 95% CI = 0.04–0.19 and 4.42–16.82, respectively), but TNF-α and IL-6 became non-significant. Conclusions Reduced MIF mRNA and protein expression in OA patients suggested MIF might have a protective role in OA and could serve as a biomarker to differentiate OA from other joint disorders.


2018 ◽  
Vol 127 (06) ◽  
pp. 387-395 ◽  
Author(s):  
Xu Han ◽  
Qiaobei Li ◽  
Chunyan Wang ◽  
Yinyan Li

Abstract Background Previous study has been reported that braykinin B2 receptor (Bdkrb2) involves in high glucose-induced renal and podocytes injuries. However, there have been some studies with contradictory results that Bdkrb2 has a protective effect on hyperglycemia-induced injuries in vivo and in vitro. The purpose of the present study was carried out to further investigate the post-transcriptional regulatory mechanism of microRNA (miR) in high glucose-treated podocytes by targeting Bdkrb2 signaling in vitro. Methods The CCK-8 and flow cytometry were performed to measure the cell viability and apoptosis. Gene and protein expression were assayed by RT-qPCR and western blotting, respectively. Results High glucose treatment decreased cell viability and induced membrane and DNA damage, as well as apoptosis in podocytes. High glucose treatment also increased the expression of Bdkrb2, which was blocked by miR-204-3p mimics transfection in podocytes. Bioinformatics and luciferase reporter activity showed that miR-204-3p was directly targeted to the 3′-untranslated region (3′-UTR) of Bdkrb2. High glucose-induced apoptosis and dysfunction in podocytes were reserved by miR-204-3p mimics transfection, while the effects of miR-204-3p mimics in high glucose-treated podocytes were neutralized by overexpressed Bdkrb2. Conclusions These findings suggested that miR-204-3p may play a protective role in high glucose-induced apoptosis and dysfunction in podocytes through down-regulation of Bdkrb2.


2004 ◽  
Vol 286 (1) ◽  
pp. G60-G67 ◽  
Author(s):  
Yoshiya Ito ◽  
Edward R. Abril ◽  
Nancy W. Bethea ◽  
Robert S. McCuskey

Nitric oxide (NO) is suggested to play a role in liver injury elicited by acetaminophen (APAP). Hepatic microcirculatory dysfunction also is reported to contribute to the development of the injury. As a result, the role of NO in hepatic microcirculatory alterations in response to APAP was examined in mice by in vivo microscopy. A selective inducible NO synthase (iNOS) inhibitor,l- N6-(1-iminoethyl)-lysine (l-NIL), or a nonselective NOS inhibitor, NG-nitro-l-arginine methyl ester (l-NAME), was intraperitoneally administered to animals 10 min before APAP gavage. l-NIL suppressed raised alanine aminotransferase (ALT) values 6 h after APAP, whereas l-NAME increased those 1.7-fold. Increased ALT levels were associated with hepatic expression of iNOS. l-NIL, but not l-NAME, reduced the expression. APAP caused a reduction (20%) in the numbers of perfused sinusoids. l-NIL restored the sinusoidal perfusion, but l-NAME was ineffective. APAP increased the area occupied by infiltrated erythrocytes into the extrasinusoidal space. l-NIL tended to minimize this infiltration, whereas l-NAME further enhanced it. APAP caused an increase (1.5-fold) in Kupffer cell phagocytic activity. This activity in response to APAP was blunted by l-NIL, whereas l-NAME further elevated it. l-NIL suppressed APAP-induced decreases in hepatic glutathione levels. These results suggest that NO derived from iNOS contributes to APAP-induced parenchymal cell injury and hepatic microcirculatory disturbances. l-NIL exerts preventive effects on the liver injury partly by inhibiting APAP bioactivation. In contrast, NO derived from constitutive isoforms of NOS exerts a protective role in liver microcirculation against APAP intoxication and thereby minimizes liver injury.


2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Guochao Sun ◽  
Ying Lu ◽  
Yingxia Li ◽  
Jun Mao ◽  
Jun Zhang ◽  
...  

miRNAs have been implicated in processing of cardiac hypoxia/reoxygenation (H/R)-induced injury. Recent studies demonstrated that miR-19a might provide a potential cardioprotective effect on myocardial disease. However, the effect of miR-19a in regulating myocardial ischemic injury has not been previously addressed. The present study was to investigate the effect of miR-19a on myocardial ischemic injury and identified the potential molecular mechanisms involved. Using the H/R model of rat cardiomyocytes H9C2 in vitro, we found that miR-19a was in low expression in H9C2 cells after H/R treatment and H/R dramatically decreased cardiomyocyte viability, and increased lactate dehydrogenase (LDH) release and cardiomyocyte apoptosis, which were attenuated by co-transfection with miR-19a mimic. Dual-luciferase reporter assay and Western blotting assay revealed that PTEN was a direct target gene of miR-19a, and miR-19a suppressed the expression of PTEN via binding to its 3′-UTR. We further identified that overexpression of miR-19a inhibited the expression of PTEN at the mRNA and protein levels. Moreover, PTEN was highly expressed in H/R H9C2 cells and the apoptosis induced by H/R was associated with the increase in PTEN expression. Importantly, miR-19a mimic significantly increased p-Akt levels under H/R. In conclusion, our findings indicate that miR-19a could protect against H/R-induced cardiomyocyte apoptosis by inhibiting PTEN /PI3K/p-Akt signaling pathway.


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