Down-regulation of PFL expression activates the AMPK-α signaling pathway to improve MF induced by pressure load.

Berberine attenuates mitochondrial dysfunction by inducing autophagic flux in myocardial hypoxia/reoxygenation injury.

Berberine (BBR) is routinely prescribed in many Asian countries to treat diarrhea. Evidence from both animal and clinical investigations suggests that BBR exerts diverse pharmacological activities, including antidiabetic, antineoplastic, antihypertensive, and antiatherosclerotic effects. This study aimed to explore the cardioprotective mechanisms of BBR and to elucidate the modulations between autophagy and mitochondrial function during hypoxia/reoxygenation (H/R) in H9c2 cells. The degree of autophagic flux was assessed by pretreating H9c2 cells with BBR prior to H/R exposure and measuring the expression levels of Beclin-1 and green fluorescent protein (GFP)-labeled LC3B fusion proteins as well as the LC3II/LC3I ratio. The mitochondrial membrane potential (△Ψm) in H9c2 cells was evaluated by detecting rhodamine-123 fluorescence using flow cytometry. The results revealed that pretreatment with BBR upregulated autophagic flux and protected against the loss of the △Ψm in H9c2 cells subjected to H/R. We conclude that BBR attenuates mitochondrial dysfunction by inducing autophagic flux.

Berberine Protects Against Simulated Ischemia/Reperfusion Injury-Induced H9C2 Cardiomyocytes Apoptosis In Vitro and Myocardial Ischemia/Reperfusion-Induced Apoptosis In Vivo by Regulating the Mitophagy-Mediated HIF-1α/BNIP3 Pathway.

Berberine (BBR) has a variety of pharmacological activities and is widely used in Asian countries. However, the clinical application of BBR still lacks scientific basis, what protective mechanism of BBR against myocardial ischemia-reperfusion injury (MIRI). In vitro experiments, BBR pretreatment regulated autophagy-related protein expression, induced cell proliferation and autophagosome formation, and reduced the mitochondrial membrane potential (ΔΨm) increase in H9C2 cells. In vivo experiments, BBR reduced the myocardial infarct size, decreased cardiomyocyte apoptosis, and markedly decreased myocardial enzyme (CK-MB, LDH, and AST) activity-induced I/R. In addition, upon BNIP3 knockdown, the regulatory effects of BBR on the above indicators were weakened both in H9C2 cells and in vivo. Luciferase reporter and ChIP assays indicated that BBR mediated BNIP3 expression by enhancing the binding of HIF-1α to the BNIP3 promoter. BBR protects against myocardial I/R injury by inducing cardiomyocytes proliferation, inhibiting cardiomyocytes apoptosis, and inducing the mitophagy-mediated HIF-1α/BNIP3 pathway. Thus, BBR may serve as a novel therapeutic drug for myocardial I/R injury.

Y-box protein 1 promotes hypoxia/reoxygenation- or ischemia/reperfusion-induced cardiomyocyte apoptosis via SHP-1-dependent STAT3 inactivation.

Cardiomyocyte apoptosis induced by hypoxia and ischemia plays important roles in heart dysfunction after acute myocardial infarction (AMI). However, the mechanism of apoptosis induction remains unclear. A previous study reported that Y-box protein 1 (YB1) is upregulated after myocardial hypoxia/reoxygenation or ischemia/reperfusion (H/R or I/R, respectively) injury; however, whether YB1 is associated with H/R-induced cardiomyocyte apoptosis is completely unknown. In the present study, we investigated the roles of YB1 in H/R-induced cardiomyocyte apoptosis and the possible underlying molecular mechanisms. In vitro, H/R treatment upregulated the YB1 expression in H9C2 cells, whereas YB1 knockdown inhibited H/R-induced cardiomyocyte apoptosis and induced H9C2 cell proliferation via Src homology region 2 domain-containing phosphatase 1 (SHP-1)-mediated activation of signal transducer and activator of transcription 3 (STAT3). In vivo, YB1 knockdown ameliorated AMI, reducing infarct size, cardiomyocyte apoptosis, and oxidative stress, via SHP-1-mediated inactivation of STAT3. Additionally, YB1 knockdown inhibited H/R- or I/R-induced oxidative stress in vitro and in vivo. H/R and I/R increase YB1 expression, and YB1 knockdown ameliorates AMI injury via SHP-1-dependent STAT3 inactivation.

Effects of miR-181a targeting XIAP gene on apoptosis of cardiomyocytes induced by hypoxia/reoxygenation and its mechanism.

To investigate the effect of miR-181a targeting XIAP gene on the apoptosis of cardiomyocytes induced by hypoxia/reoxygenation (H/R) and its mechanism. The primary cultured cardiomyocytes were treated with hypoxia for 3 hours and reoxygenation for 4 hours to construct H/R cell model. The expression of miR-181a and XIAP messenger RNA in cardiomyocytes was detected by reverse-transcription polymerase chain reaction, and the expression of XIAP protein in cardiomyocytes was detected by Western blot analysis. H/R cardiomyocytes with low expression of miR-181a and overexpression of XIAP were constructed, and the effects of low expression of miR-181a and upregulation of XIAP on cardiomyocyte apoptosis were detected by flow cytometry. A dual luciferase reporter assay was used to detect the target relationship between miR-181a and XIAP. Further, H/R myocardial cells with low XIAP expression were constructed to observe the effect of downregulation of XIAP expression on apoptosis of myocardial cells with low expression of microarray-181a. The expression of apoptosis-related proteins Bax and Bcl-2 in myocardial cells was detected by Western blot analysis. After H/R treatment, the expression of microRNAs-181a was high but that of XIAP was low. The apoptosis of cardiomyocytes could be inhibited by both the low expression of miR-181a and the upregulation of XIAP. The results of dual luciferase reporter gene showed that XIAP was a potential target gene for miR-181a. The inhibitory effect of low expression of miR-181a on myocardial apoptosis could be reversed and the inhibitory effect of low expression of miR-181a on Bax protein expression and the promotion of Bcl-2 protein expression could be reversed by the downregulation of XIAP. MiR-181a can inhibit the apoptosis of hypoxic-reoxygenated cardiomyocytes by targeting XIAP to downregulate Bax and upregulate Bcl expression.

Down-regulation of PFL expression activates the AMPK-α signaling pathway to improve MF induced by pressure load.

Berberine attenuates mitochondrial dysfunction by inducing autophagic flux in myocardial hypoxia/reoxygenation injury.

Berberine (BBR) is routinely prescribed in many Asian countries to treat diarrhea. Evidence from both animal and clinical investigations suggests that BBR exerts diverse pharmacological activities, including antidiabetic, antineoplastic, antihypertensive, and antiatherosclerotic effects. This study aimed to explore the cardioprotective mechanisms of BBR and to elucidate the modulations between autophagy and mitochondrial function during hypoxia/reoxygenation (H/R) in H9c2 cells. The degree of autophagic flux was assessed by pretreating H9c2 cells with BBR prior to H/R exposure and measuring the expression levels of Beclin-1 and green fluorescent protein (GFP)-labeled LC3B fusion proteins as well as the LC3II/LC3I ratio. The mitochondrial membrane potential (△Ψm) in H9c2 cells was evaluated by detecting rhodamine-123 fluorescence using flow cytometry. The results revealed that pretreatment with BBR upregulated autophagic flux and protected against the loss of the △Ψm in H9c2 cells subjected to H/R. We conclude that BBR attenuates mitochondrial dysfunction by inducing autophagic flux.

Berberine Protects Against Simulated Ischemia/Reperfusion Injury-Induced H9C2 Cardiomyocytes Apoptosis In Vitro and Myocardial Ischemia/Reperfusion-Induced Apoptosis In Vivo by Regulating the Mitophagy-Mediated HIF-1α/BNIP3 Pathway.

Berberine (BBR) has a variety of pharmacological activities and is widely used in Asian countries. However, the clinical application of BBR still lacks scientific basis, what protective mechanism of BBR against myocardial ischemia-reperfusion injury (MIRI). In vitro experiments, BBR pretreatment regulated autophagy-related protein expression, induced cell proliferation and autophagosome formation, and reduced the mitochondrial membrane potential (ΔΨm) increase in H9C2 cells. In vivo experiments, BBR reduced the myocardial infarct size, decreased cardiomyocyte apoptosis, and markedly decreased myocardial enzyme (CK-MB, LDH, and AST) activity-induced I/R. In addition, upon BNIP3 knockdown, the regulatory effects of BBR on the above indicators were weakened both in H9C2 cells and in vivo. Luciferase reporter and ChIP assays indicated that BBR mediated BNIP3 expression by enhancing the binding of HIF-1α to the BNIP3 promoter. BBR protects against myocardial I/R injury by inducing cardiomyocytes proliferation, inhibiting cardiomyocytes apoptosis, and inducing the mitophagy-mediated HIF-1α/BNIP3 pathway. Thus, BBR may serve as a novel therapeutic drug for myocardial I/R injury.

Y-box protein 1 promotes hypoxia/reoxygenation- or ischemia/reperfusion-induced cardiomyocyte apoptosis via SHP-1-dependent STAT3 inactivation.

Cardiomyocyte apoptosis induced by hypoxia and ischemia plays important roles in heart dysfunction after acute myocardial infarction (AMI). However, the mechanism of apoptosis induction remains unclear. A previous study reported that Y-box protein 1 (YB1) is upregulated after myocardial hypoxia/reoxygenation or ischemia/reperfusion (H/R or I/R, respectively) injury; however, whether YB1 is associated with H/R-induced cardiomyocyte apoptosis is completely unknown. In the present study, we investigated the roles of YB1 in H/R-induced cardiomyocyte apoptosis and the possible underlying molecular mechanisms. In vitro, H/R treatment upregulated the YB1 expression in H9C2 cells, whereas YB1 knockdown inhibited H/R-induced cardiomyocyte apoptosis and induced H9C2 cell proliferation via Src homology region 2 domain-containing phosphatase 1 (SHP-1)-mediated activation of signal transducer and activator of transcription 3 (STAT3). In vivo, YB1 knockdown ameliorated AMI, reducing infarct size, cardiomyocyte apoptosis, and oxidative stress, via SHP-1-mediated inactivation of STAT3. Additionally, YB1 knockdown inhibited H/R- or I/R-induced oxidative stress in vitro and in vivo. H/R and I/R increase YB1 expression, and YB1 knockdown ameliorates AMI injury via SHP-1-dependent STAT3 inactivation.

Effects of miR-181a targeting XIAP gene on apoptosis of cardiomyocytes induced by hypoxia/reoxygenation and its mechanism.

To investigate the effect of miR-181a targeting XIAP gene on the apoptosis of cardiomyocytes induced by hypoxia/reoxygenation (H/R) and its mechanism. The primary cultured cardiomyocytes were treated with hypoxia for 3 hours and reoxygenation for 4 hours to construct H/R cell model. The expression of miR-181a and XIAP messenger RNA in cardiomyocytes was detected by reverse-transcription polymerase chain reaction, and the expression of XIAP protein in cardiomyocytes was detected by Western blot analysis. H/R cardiomyocytes with low expression of miR-181a and overexpression of XIAP were constructed, and the effects of low expression of miR-181a and upregulation of XIAP on cardiomyocyte apoptosis were detected by flow cytometry. A dual luciferase reporter assay was used to detect the target relationship between miR-181a and XIAP. Further, H/R myocardial cells with low XIAP expression were constructed to observe the effect of downregulation of XIAP expression on apoptosis of myocardial cells with low expression of microarray-181a. The expression of apoptosis-related proteins Bax and Bcl-2 in myocardial cells was detected by Western blot analysis. After H/R treatment, the expression of microRNAs-181a was high but that of XIAP was low. The apoptosis of cardiomyocytes could be inhibited by both the low expression of miR-181a and the upregulation of XIAP. The results of dual luciferase reporter gene showed that XIAP was a potential target gene for miR-181a. The inhibitory effect of low expression of miR-181a on myocardial apoptosis could be reversed and the inhibitory effect of low expression of miR-181a on Bax protein expression and the promotion of Bcl-2 protein expression could be reversed by the downregulation of XIAP. MiR-181a can inhibit the apoptosis of hypoxic-reoxygenated cardiomyocytes by targeting XIAP to downregulate Bax and upregulate Bcl expression.