Abstract 11972: Ivabradine Attenuates Hypoxia/Reoxygenation-Induced Excessive Autophagy in H9c2 Cardiomyocyte by Modulation of the PI3K/Akt/mTOR Pathway

Circulation ◽  
2021 ◽  
Vol 144 (Suppl_2) ◽  
Author(s):  
min yang ◽  
Hui Li ◽  
Wu Jiatian ◽  
Hua Tianfeng
Keyword(s):  
Cell Viability ◽  
Kinase Inhibitor ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Mtor Pathway ◽  
Beclin 1 ◽  
Western Blot Assay ◽  
Transmission Electron ◽  
H9c2 Cardiomyocytes ◽  
Hypoxia Reoxygenation

Introduction: Despite recent advances in resuscitation techniques, the mortality associated with survival from cardiac arrest (CA) still remains low. Cardiovascular ischemia/reperfusion injury (IRI) is one of the primary pathophysiology involved. Hypothesis: We assessed the hypothesis that ivabradine could attenuate hypoxia/reoxygenation injury of H9c2 cardiomyocytes by inhibiting excessive autophagy through PI3K/Akt/mTOR Pathway. Methods: Cultured H9c2 were randomly divided into 3 groups: CON (normoxia), H/R (hypoxia reoxygenation) and IVA. The IVA was divided into 4 subgroups, in which H9c2 were treated with or without ivabradine(20μM or 100μM) or PI3-kinase inhibitor LY294002(10μM) for 12 hours and then subjected to 12 hours of hypoxia and 24 hours of reoxygenation. Hypoxia was achieved by a hypoxia chamber filled with 5%CO 2 and 95% N 2 at 37°C. Cell viability were measured with CCK-8 assay kits. Cell autophagy was assessed by transmission electron microscopy (TEM). The expressions of autophagy marker protein (LC3, Beclin-1), PI3K, Akt and mTOR were determined by Western-blot assay. Results: A decrease of cell viability and an increase formulation of autophagosomes /autophagy lysozymes occurred after H/R. Significant improvement was noted in cells treated with ivabradine compared to H/R(Figure 1). Ivabradine promoted pmTOR/mTOR expression and lower expressions of LC3II/LC3I and Beclin 1. LY294002 antagonized the effects of ivabradine on antophagy (Figure 2). Conclusions: Ivabradine could protect H9c2 against H/R injury via inhibiting excessive autophagy through PI3K/Akt/mTOR pathway.

Overexpression of miR-431 attenuates hypoxia/reoxygenation-induced myocardial damage via autophagy-related 3

2020 ◽  
Author(s):  
Kang Zhou ◽  
Yan Xu ◽  
Qiong Wang ◽  
Lini Dong
Keyword(s):  
Cell Viability ◽  
Cell Apoptosis ◽  
Myocardial Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Myocardial Damage ◽  
Protective Role ◽  
Human Cardiomyocytes ◽  
Hypoxia Reoxygenation

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.

scholarly journals Cox-2 Negatively Affects the Protective Role of Propofol against Hypoxia/Reoxygenation Induced Cardiomyocytes Apoptosis through Suppressing Akt Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Kangmu Ma ◽  
Jiapei Qiu ◽  
Mi Zhou ◽  
Yang Yang ◽  
Xiaofeng Ye
Keyword(s):  
Protective Effect ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Protective Role ◽  
Akt Phosphorylation ◽  
Over Expression ◽  
H9c2 Cardiomyocytes ◽  
Cox 2 ◽  
Myocardial Ischemia Reperfusion ◽  
Hypoxia Reoxygenation

Nowadays, the prevention of severe myocardium injury resulting from myocardial ischemia/reperfusion injury (I/R) has been recognized as an important subject in the field of ischemic heart disease. In this study, H9c2 cardiomyocytes were exposed to cycles of hypoxia/reoxygenation (H/R) to mimic myocardial I/R injury. Western blot analysis and qRT-PCR were performed to detect the expression of Cox-2, Akt and p-Akt. Cell viability, LDH release and activity of Caspase-3 were assessed to determine the protective effect of propofol. The results proved that the protective effect of propofol for H/R challenged cardiomyocytes was associated with Akt phosphorylation. We also revealed that treatment of propofol suppressed the expression of Cox-2 in cardiomyocytes which was up-regulated after H/R treatment. Conversely, the over-expression of Cox-2 inhibited Akt phosphorylation while enhancing cardiomyocytes apoptosis. Interestingly, Akt activator exhibited similar protective effect with propofol and could diminish the influences brought by over-expression of Cox-2. Thus, it could be concluded that Cox-2 negatively affects the protective effect of propofol against hypoxia/reoxygenation induced cardiomyocyte apoptosis by suppressing Akt phosphorylation.

scholarly journals The Effect of Ginsenoside RB1, Diazoxide, and 5-Hydroxydecanoate on Hypoxia-Reoxygenation Injury of H9C2 Cardiomyocytes

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Heng Zhang ◽  
Xiao Wang ◽  
Yihua Ma ◽  
Yueping Shi
Keyword(s):  
Mitochondrial Permeability Transition ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Ginsenoside Rb1 ◽  
H9c2 Cardiomyocytes ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion ◽  
Hypoxia Reoxygenation

This study was aimed to investigate whether ginsenoside Rb1 (GS-Rb1) from the cardioprotective Chinese medicine ginseng can reduce hypoxia-reoxygenation (HR)-induced damage to cardiomyocytes by protecting the mitochondria. Mitochondria-mediated apoptosis plays a key role during myocardial ischemia-reperfusion injury (MIRI). When MIRI occurs, the continuous opening of the mitochondrial permeability transition pore (mPTP) causes mitochondrial damage and ultimately leads to apoptosis. We treated H9c2 cells, derived from rat embryonic cardiomyoblasts, with GS-Rb1, diazoxide, and 5-hydroxydecanoate (5-HD), using HR to simulate MIRI. We found that GS-Rb1 can reduce mPTP by stabilizing the mitochondrial membrane potential (MMP) and by reducing reactive oxygen species (ROS) during HR. This protects the mitochondria by reducing the release of cytochrome c and the expression of cleaved-caspase-3 in the cytoplasm, ultimately reducing apoptosis. During this process, GS-Rb1 and diazoxide showed similar effects. These findings provide some evidence for a protective effect of GS-Rb1 treatment on MIRI.

scholarly journals N-n-Butyl Haloperidol Iodide Ameliorates Cardiomyocytes Hypoxia/Reoxygenation Injury by Extracellular Calcium-Dependent and -Independent Mechanisms

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yanmei Zhang ◽  
Gaoyong Chen ◽  
Shuping Zhong ◽  
Fuchun Zheng ◽  
Fenfei Gao ◽  
...  
Keyword(s):  
Cell Viability ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Extracellular Calcium ◽  
Camp Content ◽  
Calcium Dependent ◽  
Reoxygenation Injury ◽  
Myocardial Ischemia Reperfusion ◽  
Pka Pathway ◽  
Hypoxia Reoxygenation

N-n-butyl haloperidol iodide (F2) has been shown to antagonize myocardial ischemia/reperfusion injury by blocking calcium channels. This study explores the biological functions of ERK pathway in cardiomyocytes hypoxia/reoxygenation injury and clarifies the mechanisms by which F2ameliorates cardiomyocytes hypoxia/reoxygenation injury through the extracellular-calcium-dependent and -independent ERK1/2-related pathways. In extracellularcalcium-containing hypoxia/reoxygenation cardiomyocytes, PKCαand ERK1/2 were activated, Egr-1 protein level and cTnI leakage increased, and cell viability decreased. The ERK1/2 inhibitors suppressed extracellular-calcium-containing-hypoxia/reoxygenation-induced Egr-1 overexpression and cardiomyocytes injury. PKCαinhibitor downregulated extracellularcalcium-containing-hypoxia/reoxygenation-induced increase in p-ERK1/2 and Egr-1 expression. F2downregulated hypoxia/reoxygenation-induced elevation of p-PKCα, p-ERK1/2, and Egr-1 expression and inhibited cardiomyocytes damage. The ERK1/2 and PKCαactivators antagonized F2’s effects. In extracellular-calcium-free-hypoxia/reoxygenation cardiomyocytes, ERK1/2 was activated, LDH and cTnI leakage increased, and cell viability decreased. F2and ERK1/2 inhibitors antagonized extracellular-calcium-free-hypoxia/reoxygenation-induced ERK1/2 activation and suppressed cardiomyocytes damage. The ERK1/2 activator antagonized F2’s above effects. F2had no effect on cardiomyocyte cAMP content or PKA and Egr-1 expression. Altogether, ERK activation in extracellular-calcium-containing and extracellular-calcium-free hypoxia/reoxygenation leads to cardiomyocytes damage. F2may ameliorate cardiomyocytes hypoxia/reoxygenation injury by regulating the extracellular-calcium-dependent PKCα/ERK1/2/Egr-1 pathway and through the extracellular-calcium-independent ERK1/2 activation independently of the cAMP/PKA pathway or Egr-1 overexpression.

scholarly journals Dexmedetomidine attenuates the injury of H9C2 cardiomyocytes under Hypoxia/reoxygenation condition partly through the inhibition of endoplasmic reticulum stress

2020 ◽  
Author(s):  
Zhipeng Zhu ◽  
Xiaoyan Ling ◽  
Hongmei Zhou ◽  
Caijun Zhang
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
Cell Function ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cell Counting ◽  
H9c2 Cells ◽  
Caspase 12 ◽  
Hypoxia Reoxygenation

BackgroundMyocardial ischemia-reperfusion injury (MIRI) has been confirmed to induce endoplasmic reticulum stress(ERS) during downstream cascade reaction when myocardial cell function keep deteriorating to a certain degree. The fact of matter is the clinical inconsistence with experimental outcomes still exist due to the mechanism has not been entirely clarified. Dexmedetomidine (DEX), a new generation anti-inflammatory and organ protector, has been testified can attenuate the IRI of heart. This study aimed to find out if DEX had the capacity to protect the injured cardiomyocytes under in vitro hypoxia/reoxygenation circumstance and if the ERS was totally or partly intervened.MethodsH9C2 cells were subjected to cytotoxicity detection for 24h with DEX normally cultivated in several different concentrations. The proper hypoxia/reoxygenation (H/R) model parameter were concluded by the cell viability and injuries by cell counting kit-8(CCK8) and lactate dehydrogenase (LDH) release, when undergoing hypoxic condition for 3 h and reoxygenated for 3h, 6h,12h, and 24h, respectively. Also, the above index was assessed for H/R cardiomyocytes cultivated by various concentrations of DEX. The apoptosis, expression of) Glucose-regulated protein 78(GRP78), C/EBP homologous protein (CHOP), and caspase-12 were also examined in all groups.Results1, 5 and 10 μM DEX in normal culture could significantly promote the proliferation of H9C2 (> 80%); the activity of H9c2 cells decreased to 62.67% (P < 0.05) at 3h of reoxygenation and to 36% at 6h of reoxygenation followed by 3h anoxic treatment; The cell viability of H9c2 cells in H/R groups incubated with 1 μM DEX increased 61.3%, and the LDH concentration in the supernatant was effectively lowered (−13.7, P < 0.05); H/R dramatically decreased the proportion of flow cytometry apoptosis and increased the expression of GRP78, CHOP and caspase-12, while both DEX and 4-phenyl butyric acid (4-PBA) could significantly reverse those above indicators. Additionally, DEX could induce deeper alterations than 4-PBA on the basis of H/R.Conclusion1 μM DEX can dramatically attended the cell injuries, apoptosis, the expression of GRP78, CHOP and caspase-12 of H9C2 induced by 3h’ hypoxia and 3h’s reoxygenation. moreover, the functions of DEX went beyond the inhibition of ERS under this situation.

scholarly journals Acacetin Protects Myocardial Cells against Hypoxia-Reoxygenation Injury through Activation of Autophagy

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Chong Liu ◽  
Minmin Zhang ◽  
Shenyi Ye ◽  
Chenliang Hong ◽  
Jiaxi Chen ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Dependent Manner ◽  
Myocardial Cells ◽  
Rat Cardiomyocytes ◽  
Mortality And Morbidity ◽  
Pi3k Inhibitor Ly294002 ◽  
H9c2 Cardiomyocytes ◽  
Hypoxia Reoxygenation

Ischemic heart disease is a leading cause of mortality and morbidity worldwide. We previously demonstrated that acacetin protects against myocardial ischemia reperfusion injury in rats, although the underlying mechanism remains to be elucidated. In the present study, we investigated the effects of acacetin on autophagy during hypoxia/reoxygenation (H/R) injury by exposing H9c2 myocardial cells to H/R with or without acacetin pretreatment during hypoxia. Our results show that acacetin significantly increased cell viability in a dose-dependent manner, enhanced antioxidant capacity, and suppressed protein apoptosis of rat cardiomyocytes H9c2 cells following H/R injury. In addition, lentiviral infection of H9c2 cardiomyocytes revealed that acacetin pretreatment significantly enhanced the fluorescence intensity of autophagy proteins Beclin 1, LC3-II, and p62. These results indicate that acacetin protected H9c2 cardiomyocytes from H/R damage by enhancing autophagy. Moreover, we found that application of acacetin increased activation of the PI3K/Akt signaling pathway, whereas cotreatment with the PI3K inhibitor LY294002 reversed the inhibition of apoptosis and autophagy induced by acacetin. In conclusion, acacetin mitigated H/R injury by promoting autophagy through activating the PI3K/Akt/mTOR signaling pathway.

scholarly journals Glycine Protects H9C2 Cardiomyocytes from High Glucose- and Hypoxia/Reoxygenation-Induced Injury via Inhibiting PKCβ2 Activation and Improving Mitochondrial Quality

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yuan Zhang ◽  
Wating Su ◽  
Qiongxia Zhang ◽  
Jinjin Xu ◽  
Huimin Liu ◽  
...  
Keyword(s):  
Cell Viability ◽  
High Glucose ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
H9c2 Cells ◽  
Sod Activity ◽  
Cyt C ◽  
Ldh Release ◽  
Myocardial Ischemia Reperfusion ◽  
Hypoxia Reoxygenation

Background. Patients with diabetes are more vulnerable to myocardial ischemia reperfusion injury (IRI), which is involved in PKCβ2 activation and mitochondrial dysfunction. Glycine has been documented as a cytoprotective agent to attenuate diabetes-related abnormalities and reduce myocardial IRI, but the underlying mechanisms are still unclear. We determined whether glycine could attenuate high glucose- (HG-) and hypoxia/reoxygenation- (H/R-) induced injury by inhibiting PKCβ2 activation and improving mitochondrial quality in cultured H9C2 cells. Methods. H9C2 cells were either exposed to low glucose (LG) or HG conditions with or without treatment of glycine or CGP53353 (a selective inhibitor of PKCβ2) for 48 h, then subjected to 4 h of hypoxia followed by 2 h of reoxygenation (H/R). Cell viability, lactate dehydrogenase (LDH) release, mitochondrial membrane potential (MMP), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) concentration were detected using corresponding commercial kits. Mitochondrial quality control-related proteins (LC-3II, Mfn-2, and Cyt-C) and PKCβ2 activation were detected by Western blot. Results. HG stimulation significantly decreased cell viability and SOD activity and increased LDH release, MDA production, and PKCβ2 activation as compared to LG group, all of which changes were further increased by H/R insult. Glycine or CGP53353 treatment significantly reduced the increase of LDH release, MDA production, PKCβ2 activation, and Cyt-C expression and the decrease of cell viability, SOD activity, MMP, Mfn-2 expression, and LC-3II/LC-3I ratio induced by HG and H/R stimulation. Conclusions. Supplementary glycine protects H9C2 cells from HG- and H/R-induced cellular injury by suppressing PKCβ2 activation and improving mitochondria quality.

scholarly journals Sappanone A alleviates hypoxia/reoxygenation-induced cardiomyocytes injury through inhibition of mitochondrial apoptosis and activation of PI3K–Akt–Gsk-3β pathway

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Xiaojing Shi ◽  
Guizhou Tao ◽  
Lili Ji ◽  
Ge Tian
Keyword(s):  
Cell Viability ◽  
Mitochondrial Permeability Transition ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Dependent Manner ◽  
Mitochondrial Apoptosis ◽  
Mptp Opening ◽  
Gsk 3Β ◽  
Potential Use ◽  
Hypoxia Reoxygenation

Abstract Myocardial ischemia reperfusion injury (MIRI) is a complex pathophysiological process involved with the activation of oxidative stress, inflammation and apoptosis. Sappanone A (SA), a homoisoflavanone isolated from the heartwood of Caesalpinia sappan L., could exhibit antioxidant, anti-inflammatory and anti-apoptotic activities. Therefore, we assumed that SA has a potential use for preventing against MIRI. The present study aimed to investigate the effect of SA treatment on MIRI and its mechanism. Cardiomyocytes (H9c2 cells) were treated with SA for 1 h, followed by 6 h of hypoxia/3 h of reoxygenation. Cell viability assay was detected by CCK-8 assay. Apoptosis was measured by flow cytometry and Hoechst staining. Mitochondrial permeability transition pore (mPTP) opening and mitochondrial transmembrane potential (ΔΨm) were measured by spectrophotometry and JC-1 staining. The changes of mitochondrial apoptosis-related proteins and PI3K–Akt–Gsk-3β signaling pathway were evaluated by Western blotting. The results showed that SA pretreatment enhanced the cell viability and decreased the activity of myocardial enzyme in a dose-dependent manner. Moreover, SA pretreatment significantly inhibited apoptosis, blocked mPTP opening, suppressed the release of ΔΨm, prevented the cytochrome c releasing from mitochondria into cytoplasm, and repressed the cleavage of caspase-9 and caspase-3. Furthermore, SA pretreatment increased the phosphorylation levels of Akt and Gsk-3β but not of Stat-3. Meanwhile, the protective effect of SA was abrogated by PI3K inhibitor (LY294002). In conclusion, our results demonstrate that SA could prevent hypoxia/reoxygenation-induced cardiomyocytes injury through inhibition of mitochondrial apoptosis and activation of PI3K–Akt–Gsk-3β pathway. Thus, SA may have a potential use for the prevention of MIRI.

scholarly journals ELAVL1 is transcriptionally activated by FOXC1 and promotes ferroptosis in myocardial ischemia/reperfusion injury by regulating autophagy

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Hui-Yong Chen ◽  
Ze-Zhou Xiao ◽  
Xiao Ling ◽  
Rong-Ning Xu ◽  
Peng Zhu ◽  
...  
Keyword(s):  
Myocardial Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Beclin 1 ◽  
Myocardial Cells ◽  
Myocardial Ischemia And Reperfusion ◽  
Functional Roles ◽  
Cellular Iron ◽  
Luciferase Activity Assay ◽  
Myocardial Ischemia Reperfusion

Abstract Aims Myocardial ischemia is the most common form of cardiovascular disease and the leading cause of morbidity and mortality. Understanding the mechanisms is very crucial for the development of effective therapy. Therefore, this study aimed to investigate the functional roles and mechanisms by which ELAVL1 regulates myocardial ischemia and reperfusion (I/R) injury. Methods Mouse myocardial I/R model and cultured myocardial cells exposed to hypoxia/reperfusion (H/R) were used in this study. Features of ferroptosis were evidenced by LDH activity, GPx4 activity, cellular iron, ROS, LPO, and GSH levels. The expression levels of autophagy markers (Beclin-1, p62, LC3), ELAVL1 and FOXC1 were measured by qRT-PCR, immunostaining and western blot. RIP assay, biotin-pull down, ChIP and dual luciferase activity assay were employed to examine the interactions of ELAVL1/Beclin-1 mRNA and FOXC1/ELAVL1 promoter. CCK-8 assay was used to examine viability of cells. TTC staining was performed to assess the myocardial I/R injury. Results Myocardial I/R surgery induced ferroptosis and up-regulated ELAVL1 level. Knockdown of ELAVL1 decreased ferroptosis and ameliorated I/R injury. Si-ELAVL1 repressed autophagy and inhibition of autophagy by inhibitor suppressed ferroptosis and I/R injury in myocardial cells. Increase of autophagy could reverse the effects of ELAVL1 knockdown on ferroptosis and I/R injury. ELAVL1 directly bound with and stabilized Beclin-1 mRNA. Furthermore, FOXC1 bound to ELAVL1 promoter region and activated its transcription upon H/R exposure. Conclusion FOXC1 transcriptionally activated ELAVL1 may promote ferroptosis during myocardial I/R by modulating autophagy, leading to myocardial injury. Inhibition of ELAVL1-mediated autophagic ferroptosis would be a new viewpoint in the treatment of myocardial I/R injury.

scholarly journals LncRNA LSINCT5/miR-222 regulates myocardial ischemia‑reperfusion injury through PI3K/AKT pathway

2021 ◽  
Author(s):  
Xueying Tong ◽  
Jiajuan Chen ◽  
Wei Liu ◽  
Hui Liang ◽  
Hezhong Zhu
Keyword(s):  
Myocardial Ischemia ◽  
Cell Viability ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Akt Signaling ◽  
Akt Pathway ◽  
Akt Signaling Pathway ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

AbstractCardiovascular diseases rank the top cause of morbidity and mortality worldwide and are usually associated with blood reperfusion after myocardial ischemia/reperfusion injury (MIRI), which often causes severe pathological damages and cardiomyocyte apoptosis. LSINCT5 expression in the plasma of MI patients (n = 53), healthy controls (n = 42) and hypoxia-reoxygenation (HR)-treated cardiomyocyte AC16 cells was examined using qRT-PCR. The effects of LSINCT5 on cell viability and apoptosis were detected by MTT and flow cytometry, respectively. The expression of apoptosis-related proteins Bcl2, Bax and caspase 3 were tested by Western blot. The interaction between LSINCT5 and miR-222 was predicted by bioinformatic analysis. Moreover, changes in viability and apoptosis of AC16 cells co-transfected with siLSINCT5 and miR-222 inhibitor after HR treatment were examined. At last, the expression of proteins in PI3K/AKT pathway, namely PTEN, PI3K and AKT, was examined to analyze the possible pathway participating in LSINCT5-mediated MI/RI. Our study showed that LSINCT5 expression was upregulated in the plasma of MI patients and HR-treated AC16 cells. LSINCT5 overexpression significantly decreased cell viability and apoptosis. Luciferase reporter gene assay and RNA pulldown assay showed that LSINCT5 was a molecular sponge of miR-222. MiR-222 silencing in AC16 cells simulated the phenotypes of MIRI patients and HR-treated cells, indicating that LSINCT5 functions via miR-222 to regulate proliferation and apoptosis of HR-treated AC16 cells. We also showed that proteins of PI3K/AKT signaling pathway were affected in HR-treated AC16 cells, and LSINTC5 knockdown rescued these effects. LncRNA LSINCT5 was upregulated during MI pathogenesis, and LSINCT5 regulated MIRI possibly via a potential LSINCT5/miR-222 axis and PI3K/AKT signaling pathway. Our findings may provide novel evidence for MIRI prevention.

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