Effects of nicorandil on PI3K/Akt signaling pathway and its anti-apoptotic mechanisms in coronary microembolization in rats

Therapeutic potential of nicorandil beyond anti-anginal drug: A review on current and future perspectives

Nicorandil (NIC) is a well-known anti-anginal agent, which has been recommended as one of the second-line treatments for chronic stable angina as justified by the European guidelines. It shows an efficacy equivalent to that of classic anti-anginal agents. NIC has also been used clinically in various cardiovascular diseases such as variant or unstable angina and reperfusion-induced damage following coronary angioplasty or thrombolysis. Different mechanisms have been involved in the protective effects of nicorandil in various diseases, including opening of adenosine triphosphate-sensitive potassium (KATP) channel and donation of nitric oxide (NO). In recent years, NIC has been found to show numerous pharmacological activities such as neuroprotective, nephroprotective, hepatoprotective, cardioprotective, and testicular protective effects, among other beneficial effects on the body. The present review dwells on the pharmacological potentials of NIC beyond its anti-anginal action.

Nicorandil attenuates cisplatin-induced acute kidney injury in rats via activation of PI3K/AKT/mTOR signaling cascade and inhibition of autophagy

Cisplatin is a highly effective antitumor agent, but its clinical use is limited due to critical adverse reactions including acute kidney injury (AKI). Nicorandil is an approved antianginal agent decreasing ischemia by potassium channel opening. The aim of this study was to investigate the nephroprotective effects of nicorandil and the possible role of activating PI3K/AKT/mTOR pathway in ameliorating cisplatin-induced AKI. Forty male Wistar rats were randomly allocated in 4 groups (n = 10). Group I: rats received the vehicle and served as control. Group II: rats received a single dose of cisplatin (7 mg/kg, i.p) on the 10th day of the experiment and served as AKI group. Group III: rats received cisplatin as in group II and nicorandil (3 mg/kg/day, p.o) for 14 days. Group IV: rats received cisplatin and nicorandil as in group III as well as wortmannin (15 μg/kg, i.v) for 14 days. Nicorandil exhibited obvious nephroprotective effects via the activation of PI3K/AKT/mTOR pathway. Moreover, nicorandil succeed to reduce the expression of the autophagy markers beclin-1 and LC-3II/I. In parallel, nicorandil showed anti-inflammatory and antiapoptotic effects via inhibition of NF-κB inflammatory pathway and depression of Bax/Bcl-2 ratio. Wortmannin, the PI3K inhibitor, was used to demonstrate the proposed pathway. Our study showed the nephroprotective effects of nicorandil in cisplatin-induced AKI in rats via activation of PI3K/AKT/mTOR signaling cascade, inhibition of autophagy, anti-inflammatory, anti-apoptotic, anti-oxidant activities. Thus, nicorandil could represent a promising renoprotective agent in cancer patients treated with cisplatin.

Effects of nicorandil on QT prolongation and myocardial damage caused by citalopram in rats

Citalopram is a selective serotonin re-uptake inhibitor (SSRI) antidepressant; it exhibits the greatest cardiotoxic effect among SSRIs. Citalopram can cause drug-induced long QT syndrome (LQTS) and ventricular arrhythmias. We investigated the protective effect of nicorandil, a selective mitochondrial KATP (mito-KATP) channel opener, on LQTS and myocardial damage caused by citalopram in male rats. In a preliminary study, we determined that the minimum citalopram dose that prolonged the QT interval was 102 mg/kg injected intraperitoneally. For the main study, rats were divided randomly into five experimental groups: untreated control, normal saline + citalopram, nicorandil + citalopram, 5-hydroxydecanoate (5-HD) + citalopram, 5-HD + nicorandil + citalopram. Biochemical and histologic data from blood and heart tissue samples from six untreated control rats were evaluated. Electrocardiographic parameters including QRS duration, QT interval, corrected QT interval (QTc) and heart rate (HR) were assessed, and biochemical parameters including malondialdehyde, reduced glutathione, glutathione peroxidase, superoxide dismutase were measured. We also performed histomorphologic and immunohistochemical examination of heart tissue. Citalopram prolonged QT-QTc intervals significantly and increased significantly the histomorphologic score and proportion of apoptotic cells, but produced no differences in the oxidant and antioxidant parameters. Nicorandil did not prevent citalopram induced QT-QTc interval prolongation and produced no significant changes in oxidant and antioxidant parameters; however, it did reduce histologic damage and apoptosis caused by citalopram.

Effect of the selective mitochondrial KATP channel opener nicorandil on the QT prolongation and myocardial damage induced by amitriptyline in rats

OBJECTIVES

The aim of this study is to evaluate the protective effect of nicorandil, a selective mitochondrial KATP channel opener, on QT prolongation and myocardial damage induced by amitriptyline.

METHODS

The dose of amitriptyline (intraperitoneal, i.p.) that prolong the QT interval was found 75 mg/kg. Rats were randomized into five groups the control group, amitriptyline group, nicorandil (selective mitochondrial KATP channel opener, 3 mg/kg i.p.) + amitriptyline group, 5-hdyroxydecanoate (5-HD, selective mitochondrial KATP channel blocker, 10 mg/kg i.p.) + amitriptyline group and 5-HD + nicorandil + amitriptyline group. Cardiac parameters, biochemical and histomorphological/immunohistochemical examinations were evaluated. p < 0.05 was accepted as statistically significant.

KEY FINDINGS

Amitriptyline caused statistically significant prolongation of QRS duration, QT interval and QTc interval (p < 0.05). It also caused changes in tissue oxidant (increase in malondialdehyde)/anti-oxidant (decrease in glutathione peroxidase) parameters (p < 0.05), myocardial damage and apoptosis (p < 0.01 and p < 0.001). While nicorandil administration prevented amitriptyline-induced QRS, QT, QTc prolongation (p < 0.05), myocardial damage and apoptosis (p < 0.05), it did not affect the changes in oxidative parameters (p > 0.05).

CONCLUSIONS

Our results suggest that nicorandil, a selective mitochondrial KATP channel opener, plays a protective role in amitriptyline-induced QT prolongation and myocardial damage. Mitochondrial KATP channel opening and anti-apoptotic effects may play a role in the cardioprotective effect of nicorandil.

Anti-apoptotic Effect of MiR-223-3p Suppressing PIK3C2A in Cardiomyocytes from Myocardial Infarction Rat Through Regulating PI3K/Akt Signaling Pathway

We aimed to explore the regulatory mechanism of the axis of miR-223-3p-PIK3C2A-PI3K/Akt on cardiomyocyte apoptosis in rats with myocardial infarction. Thirty 8-week-old healthy male SD rats were used for establishing the sham group and the model group, with HE staining, TUNEL staining, and TTC staining performed. After the identification of the targeting relationship between PIK3C2A and miR-223-3p, experimental rats were randomly divided into seven groups by plasmid transfection, including the Blank group, negative control (NC) group, miR-223-3p mimic group, miR-223-3p inhibitor group, siRNA-PIK3C2A group, oe-PIK3C2A group, and miR-223-3p inhibitor + oe-PIK3C2A group. Four weeks after transfection, the expression levels of miR-223-3p and PIK3C2A in tissues as well as PI3K, Akt, Bax, and bcl-2 mRNA in cells were detected by qRT-PCR and western blot, in combination with the detection of apoptosis rate by flow cytometry. Compared with the sham group, the model group showed typical myocardial injury and abnormal staining, higher apoptotic index, and larger myocardial infarction area (all P < 0.05). PIK3C2A was the target gene of miR-223-3p. The expression level of miR-223-3p in model group was significantly lower than that in sham group, while the mRNA and protein expression levels of PIK3C2A increased significantly (all P < 0.05). In cell tests, the expression level of miR-223-3p increased significantly in miR-223-3p mimic group (P < 0.05), which, however, showed no significant change in siRNA-PIK3C2A group (P > 0.05). MiR-223-3p inhibitor group and siRNA-PIK3C2A group had obviously increased PI3K, Akt, mTOR and Bcl-2 mRNA, and protein expression, while decreased mRNA and protein expression of PIK3C2A and Bax (all P < 0.05); miR-223-3p mimic groups had the opposite trends (all P < 0.05). siRNA-PIK3C2A + miR-223-3p mimic showed no obvious change relative to the control groups (all P > 0.05). Low expression of miR-223-3p may downregulate PIK3C2A expression, resulting in the inhibition of myocardial cell apoptosis in rats with myocardial infarction via the activation of PI3K/Akt signaling pathway.

MiR-32-3p Regulates Myocardial Injury Induced by Microembolism and Microvascular Obstruction by Targeting RNF13 to Regulate the Stability of Atherosclerotic Plaques

This study aimed to explore the molecular mechanism of myocardial protection. The effects of miR-32-3p and ring finger protein 13 (RNF13) on endoplasmic reticulum (ER) stress-induced apoptosis of A-10 cells and human umbilical vein endothelial cells (HUVEC) were detected using flow cytometry. The effects of miR-32-3p and phenylbutyric acid (PBA) on plaque instability and myocardial tissue injury in rats were investigated after establishment of arterial plaque model and embolization model and treatment with miR-32-3p-antagomir and PBA. RNF13, which was differentially expressed in myocardial infarction, was the direct target gene of miR-32-3p. MiR-32-3p inhibited RNF13 expression and targeted RNF13 to inhibit ER stress-induced cell apoptosis. Furthermore, inhibiting miR-32-3p expression induced arterial plaque instability by reducing survival, increasing pathological lesions in arterial tissue, up-regulating ER stress-related proteins, and regulating the expressions of apoptosis-related proteins in the model rats. However, PBA reversed the effects of miR-32-3p-antagomir on the model rats. MiR-32-3p regulates myocardial injury induced by micro-embolism and micro-vascular obstruction by targeting RNF13 to regulate the stability of atherosclerotic plaques.

Puerarin pretreatment attenuates cardiomyocyte apoptosis induced by coronary microembolization in rats by activating the PI3K/Akt/GSK-3β signaling pathway

Coronary microembolization (CME) is associated with cardiomyocyte apoptosis and cardiac dysfunction. Puerarin confers protection against multiple cardiovascular diseases, but its effects and specific mechanisms on CME are not fully known. Hence, our study investigated whether puerarin pretreatment could alleviate cardiomyocyte apoptosis and improve cardiac function following CME. The molecular mechanism associated was also explored. A total of 48 Sprague-Dawley rats were randomly divided into CME, CME + Puerarin (CME + Pue), sham, and sham + Puerarin (sham + Pue) groups (with 12 rats per group). A CME model was established in CME and CME + Pue groups by injecting 42 μm microspheres into the left ventricle of rats. Rats in the CME + Pue and sham + Pue groups were intraperitoneally injected with puerarin at 120 mg/kg daily for 7 days before operation. Cardiac function, myocardial histopathology, and cardiomyocyte apoptosis index were determined via cardiac ultrasound, hematoxylin-eosin (H&E) and hematoxylin-basic fuchsin-picric acid (HBFP) stainings, and TdT-mediated dUTP nick-end labeling (TUNEL) staining, respectively. Western blotting was used to measure protein expression related to the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway. We found that, puerarin significantly ameliorated cardiac dysfunction after CME, attenuated myocardial infarct size, and reduced myocardial apoptotic index. Besides, puerarin inhibited cardiomyocyte apoptosis, as revealed by decreased Bax and cleaved caspase-3, and up-regulated Bcl-2 and PI3K/Akt/GSK-3β pathway related proteins. Collectively, puerarin can inhibit cardiomyocyte apoptosis and thus attenuate myocardial injury caused by CME. Mechanistically, these effects may be achieved through activation of the PI3K/Akt/GSK-3β pathway.

Breviscapine Pretreatment Inhibits Myocardial Inflammation and Apoptosis in Rats After Coronary Microembolization by Activating the PI3K/Akt/GSK-3β Signaling Pathway

Purpose

Coronary microembolization (CME) can cause myocardial inflammation, apoptosis and progressive cardiac dysfunction. On the other hand, breviscapine exerts a significant cardioprotective effect in many cardiac diseases although its role and the potential mechanisms in CME remain unclear. Therefore, the present study aimed to ascertain whether pretreatment with breviscapine could improve CME-induced myocardial injury by alleviating myocardial inflammation and apoptosis. The possible underlying mechanisms were also explored.

Methods

In this study, 48 Sprague-Dawley (SD) rats were randomly assigned to the CME, CME + breviscapine (CME + BE), CME + breviscapine + LY294002 (CME + BE + LY) and sham groups (12 rats per group). In addition, the CME model was successfully established by injecting 42 μm inert plastic microspheres into the left ventricle of rats. Rats in the CME + BE and CME + BE + LY groups received 40 mg/kg/d of breviscapine for 7 days before inducing CME. Moreover, rats in the CME + BE + LY group were intraperitoneally injected with the phosphoinositide 3-kinase (PI3K) specific inhibitor, LY294002 (10 mg/kg) 30 minutes before CME modeling. 12 h after surgery, the study measured cardiac function, the serum levels of markers of myocardial injury, myocardial inflammation-associated mRNAs and proteins, myocardial apoptosis-associated mRNAs and proteins and conducted myocardial histopathology.

Results

The findings demonstrated that pretreatment with breviscapine alleviated myocardial injury following CME by improving cardiac dysfunction, decreasing the serum levels of markers of myocardial injury, reducing the size of myocardial microinfarct and lowering the cardiomyocyte apoptotic index. More importantly, pretreatment with breviscapine resulted to a decrease in the levels of inflammatory and pro-apoptotic mRNAs and proteins in myocardial tissues and there was an increase in the levels of anti-apoptotic mRNAs and proteins. However, these protective effects were eliminated when breviscapine was combined with LY294002.

Conclusion

The findings from this study indicated that breviscapine may inhibit myocardial inflammation and apoptosis by regulating the PI3K/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway, thereby ameliorating CME-induced cardiac dysfunction and reducing myocardial injury.

Ameliorative effect of nicorandil in ovarian ischemia-reperfusion-induced injury in rats: role of potassium channel

Ovarian torsion is a gynecological emergency that leads to serious outcomes. Nicorandil (NIC) is an ATP-sensitive potassium (K_ATP) channel activator that protects the heart from ischemia. The current study aimed to investigate the role and mechanism of action of NIC in ovarian ischemia-reperfusion (OIR) and possible K_ATP participation. Twenty-four female albino rats were classified into 4 groups: sham control, OIR, OIR + NIC, OIR + NIC+ glibenclamide (GLB) groups. Serum anti-Müllerian hormone (AMH), ovarian malondialdehyde (MDA), total nitrites (NO_x) contents, and superoxide dismutase (SOD) activity were evaluated. Bax and Bcl2 mRNA were also assessed. Histological and immunohistochemical (anti-COX-2 and anti CD68) studies were done. The OIR non-treated group showed histopathological ovarian injury with decreased AMH level. Ovarian MDA, NO_x, and Bax mRNA and the expression of COX-2 and CD68 were increased; however, SOD activity and Bcl2 mRNA level were decreased by OIR. NIC significantly ameliorated the histopathological ovarian injury with the restoration of AMH level. NIC significantly corrected oxidative stress and apoptotic biomarkers with decreased COX-2 and CD68 immunostaining. GLB co-administration significantly decreased the protection afforded by NIC. These results imply that NIC has a protective role against OIR via antioxidant, anti-inflammatory, and anti-apoptotic effects and such protection relies, at least partially, on the K_ATP channel.

Protective effect of nicorandil on collapse‑induced lung injury in rabbits by inhibiting apoptosis

The one‑lung ventilation (OLV) technique is vital in thoracic surgery. However, it can result in severe lung injury, which is difficult to manage. The main solution at present is the use of ventilation strategies, including continuous positive oxygen pressure, low tidal volume and high frequency ventilation, and the administering of drugs, including phenylephrine, dexmedetomidine and morphine. However, the protective effect of these methods on the lungs is not sufficient to improve the prognosis of patients. Therefore, how to develop a novel protective drug remains an open question. Nicorandil, a mitochondrial (mito)KATP‑specific opener, serves an important role in cardioprotection, although its effect on lung injury remains unclear. The present study examined the protective role of nicorandil against collapse‑induced lung injury in rabbits undergoing OLV. Changes in arterial oxygen saturation (SaO2), arterial partial pressure for oxygen (PaO2), wet/dry weight ratio, and the microstructure of tissues and cells were observed. Enzyme‑linked immunosorbent assays were used to determine the concentrations of malondialdehyde (MDA) and tumor necrosis factor (TNF)‑α, and the activity of superoxide dismutase (SOD) in rabbits treated with nicorandil. Terminal deoxynucleotidyl transferase transfer‑mediated dUTP nick end‑labeling was used to detect apoptosis and western blotting was used to analyze the relative proteins involved in apoptosis. Western blotting and reverse transcription‑quantitative polymerase chain reaction analysis were used to examine the expression of hypoxia inducible factor 1α (HIF‑1α), phosphatidylinositol‑3‑kinase (PI3K), protein kinase B (Akt) and nuclear factor (NF)‑κB in the lungs of rabbits treated with nicorandil. The SaO2 and PaO2 in the high‑dose group were significantly higher than those in the control group in the process of OLV. The wet/dry weight ratio, and the concentrations of MDA and TNF‑α in the collapsed lung of the high‑dose group were significantly lower than those in the control group. The activity of SOD in the high‑dose group was significantly higher than that in the control group. The lung had improved microstructure and less apoptosis, which was determined by the Bax/Bcl2 ratio in the high‑dose group. The expression levels of PI3K, phosphorylated Akt and HIF‑1α were upregulated, whereas the expression of NF‑κB was downregulated. In conclusion, nicorandil had a protective effect via inhibiting apoptosis in non‑ventilated lung collapsed and re‑expansion during OLV in the rabbit. It acted on mitoKATP through the PI3K/Akt signaling pathway.

Nicorandil alleviates apoptosis in diabetic cardiomyopathy through PI3K/Akt pathway

Nicorandil exerts myocardial protection through its antihypoxia and antioxidant effects. Here, we investigated whether it plays an anti‐apoptotic role in diabetic cardiomyopathy. Sprague‐Dawley rats were fed with high‐fat diet; then single intraperitoneal injection of streptozotocin was performed. Rats with fasting blood glucose (FBG) higher than 11.1 mmol/L were selected as models. Eight weeks after the models were built, rats were treated with nicorandil (7.5 mg/kg day and 15 mg/kg day respectively) for 4 weeks. H9c2 cardiomyocytes were treated with nicorandil and then stimulated with high glucose (33.3 mmol/L). TUNEL assay and level of bcl‐2, bax and caspase‐3 were measured. 5‐HD was used to inhibit nicorandil. Also, PI3K inhibitor (Miltefosine) and mTOR inhibitor (rapamycin) were used to inhibit PI3K/Akt pathway. The results revealed that nicorandil (both 7.5 mg/kg day and 15mg/kg day) treatment can increase the level of NO in the serum and eNOS in the heart of diabetic rats compared with the untreated diabetic group. Nicorandil can also improve relieve cardiac dysfunction and reduce the level of apoptosis. In vitro experiments, nicorandil (100 µmol) can attenuate the level of apoptosis stimulated by high glucose significantly in H9C2 cardiomyocyte compared with the untreated group. The effect of nicorandil on apoptosis was blocked by 5‐HD, and it was accompanied with inhibition of the phosphorylation of PI3K, Akt, eNOS, and mTOR. After inhibition of PI3K/Akt pathway, the protective effect of nicorandil is restrained. These results verified that as a NO donor, nicorandil can also inhibit apoptosis in diabetic cardiomyopathy which is mediated by PI3K/Akt pathway.

Ligustrazine Attenuates Myocardial Injury Induced by Coronary Microembolization in Rats by Activating the PI3K/Akt Pathway

Background/Aims

Coronary microembolization- (CME-) induced myocardial injury and progressive cardiac dysfunction are mainly caused due to CME-induced myocardial local inflammatory response and myocardial apoptosis. Ligustrazine plays an important protective role in multiple cardiovascular diseases, but its role and the protection mechanism in CME is unclear. This study hypothesized that ligustrazine attenuates CME-induced myocardial injury in rats. This study also explored the mechanism underlying this attenuation.

Methods

Forty SD rats were randomly divided into CME group, ligustrazine group, ligustrazine+LY294002 (ligustrazine+LY) group, and sham group (ten rats in each). In each group, the cardiac function, apoptotic index, serum c-troponin I (cTnI) level, inflammation [interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α)], and oxidative stress [nitric oxide (NO), superoxide dismutase (SOD), and malondialdehyde (MDA)] were determined. Western blotting was used to detect the proteins which are present in the PI3K/Akt pathway.

Results

Ligustrazine improved cardiac dysfunction induced by CME, increased serum NO and SOD activities, and decreased the serum level in IL-1β, MDA, cTnI, and TNF-α. Moreover, ligustrazine inhibited myocardial apoptosis, which is perhaps caused by the upregulated Bcl-2, the downregulated cleaved caspase-3 and Bax, and the increased protein level in endothelial nitric oxide synthase and phosphorylated Akt. These effects, however, were reduced if ligustrazine was coadministered with LY294002.

Conclusions

Ligustrazine attenuates CME-induced myocardial injury. The effects associated with this attenuation may be achieved by activating the myocardium PI3K/Akt signaling pathway.

Resveratrol Attenuates Cardiomyocyte Apoptosis in Rats Induced by Coronary Microembolization Through SIRT1-Mediated Deacetylation of p53

OBJECTIVE

Coronary microembolization (CME)-induced cardiomyocyte apoptosis is the primary factor in causing cardiac dysfunction. Resveratrol (RES) is known to play a protective role in a variety of cardiovascular diseases, yet it is not known whether RES has a protective role in CME. Therefore, the effect of RES on cardiomyocyte apoptosis and cardiac function damage which are induced by CME in rats was investigated in this study.

METHODS

Fifty Sprague-Dawley rats were separated into 5 groups randomly (10 rats were included in each): sham group, CME group, RES+CME group, RES+CME+Sirtuin-1 (SIRT-1) inhibitor EX527 (RES+CME+EX) group, and CME+EX group. Cardiac function, serum c-troponin I (cTnI) level, apoptotic index, and microinfarct were measured by cardiac ultrasound, myocardial enzyme assessment, TdT-mediated dUTP Nick-end labeling and hematoxylin-basic fuchsin-picric acid staining. The levels of p53, p53 acetylation, SIRT-1, Bax, Bcl-2, and cleaved caspase-3 were detected by Western blot.

RESULTS

Myocardial dysfunction, enhanced apoptotic index as well as cTnI were caused after the operation of CME. Coronary microembolization induced increased expression of p53 acetylation and cleaved caspase-3, while the SIRT-1 and Bcl-2/Bax ratio was reduced. The CME effect was reversed by RES while EX527 attenuated this protective effect.

CONCLUSIONS

Resveratrol can improve cardiac function, in the sense that it attenuates CME-induced cardiomyocyte apoptosis, which is perhaps associated with its inhibition pro-apoptotic pathway of p53 which is transcription-independent.

(-)-Epicatechin inhibits development of dilated cardiomyopathy in δ sarcoglycan null mouse

BACKGROUND AND AIMS

Several studies propose that (-)-epicatechin, a flavonol present in high concentration in the cocoa, has cardioprotective effects. This study aimed to evaluate the impact of (-)-epicatechin on the development of dilated cardiomyopathy in a δ sarcoglycan null mouse model.

METHODS AND RESULTS

δ Sarcoglycan null mice were treated for 15 days with (-)-epicatechin. Histological and morphometric analysis of the hearts treated mutant mice showed significant reduction of the vasoconstrictions in the coronary arteries as well as fewer areas with fibrosis and a reduction in the loss of the ventricular wall. On the contrary, it was observed a thickening of this region. By Western blot analysis, it was shown, and increment in the phosphorylation level of eNOS and PI3K/AKT/mTOR/p70S6K proteins in the heart of the (-)-epicatechin treated animals. On the other hand, we observed a significantly decreased level of the atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) heart failure markers.

CONCLUSION

All the results indicate that (-)-epicatechin has the potential to prevent the development of dilated cardiomyopathy of genetic origin and encourages the use of this flavonol as a pharmacological therapy for dilated cardiomyopathy and heart failure diseases.

Protective effects of PI3KCG gene on acute myocardial infarction

Background

To study the protective effects of recombinant phosphatidylinositol 3-kinase p110 gamma (rPLV-PI3KCG) lentiviral vector in Sprague-Dawley (SD) rats with acute myocardial infarction (AMI).

Method

The AMI rat models were established by ligaturing left anterior descending coronary artery. The rPLV-PI3KCG or empty lentiviral vectors were injected at the edge of the infarct zone. The experiment was divided randomly into four groups (n=8): (I) Sham group; (II) AMI group; (III) AMI + empty vector injection group (AMI + E group); and (IV) AMI + PLV-PI3KCG injection group (AMI + PLV-PI3KCG group). The ultrasonic cardiogram (UCG) was used to compare the structural or functional changes among the four groups after operation for 10 days. Meanwhile, the rats were sacrificed and HE staining was used to compare the myocardial tissue changes among the four groups. The immunofluorescence and western blots were performed to compare the angiogenesis in the infarct region and explore the mechanism of the protective effects of PI3KCG gene on AMI rats.

Results

Compared with AMI group and AMI + E group, in the AMI + PLV-PI3KCG group, left ventricular end diastolic diameter (LVEDd) was decreased, left ventricular ejection fraction (LVEF%) was significantly increased, and vascular endothelial growth factor (VEGF) expression was significantly increased in the infarct region (P<0.05); PI3KCG, pAkt/Akt, HIF-1a, and Bcl-2/Bax protein expressions were significantly increased (P<0.05).

Conclusions

The rPLV-PI3KCG injection could improve the cardiac function, relieve the cardiac injury after the AMI operation. PI3KCG gene could play the protection role in the AMI process possibly by activating PI3K/Akt signal pathway, inhibiting apoptosis and promoting angiogenesis.