Coronary reperfusion following ischemia: different expression of bcl-2 and bax proteins, and cardiomyocyte apoptosis

Bilobalide Prevents Apoptosis and Improves Cardiac Function in Myocardial Infarction

Myocardial infarction (MI) is an extremely severe cardiovascular disease, which ranks as the leading cause of sudden death worldwide. Studies have proved that cardiac injury following MI can cause cardiomyocyte apoptosis and myocardial fibrosis. Bilobalide (Bilo) from Ginkgo biloba leaves have been widely reported to possess excellent cardioprotective effects. However, concrete roles of Bilo in MI have not been investigated yet. We here designed both in vitro and in vivo experiments to explore the effects of Bilo on MI-induced cardiac injury and the underlying mechanisms of its action. We conducted in vitro experiments using oxygen-glucose deprivation (OGD)-treated H9c2 cells. Cell apoptosis in H9c2 cells was assessed by conducting flow cytometry assay and evaluating apoptosis-related proteins with western blotting. MI mouse model was established by performing left anterior descending artery (LAD) ligation. Cardiac function of MI mice was determined by assessing ejection fraction (EF), fractional shortening (FS), left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD). Histological changes were analyzed, infarct size and myocardial fibrosis were measured by hematoxylin and eosin (H&E) and Masson staining in cardiac tissues from the mice. The apoptosis of cardiomyocytes in MI mice was assessed by TUNEL staining. Western blotting was applied to detect the effect of Bilo on c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinases (p38 MAPK) signaling both in vitro and in vivo. Bilo inhibited OGD-induced cell apoptosis and lactate dehydrogenase (LDH) release in H9c2 cells. The protein levels of p-JNK and p-p38 were significantly downregulated by Bilo treatment. SB20358 (inhibitor of p38) and SP600125 (inhibitor of JNK) suppressed OGD-induced cell apoptosis as Bilo did. In MI mouse model, Bilo improved the cardiac function and significantly reduced the infarct size and myocardial fibrosis. Bilo inhibited MI-induced cardiomyocytes apoptosis in mice. Bilo suppressed the protein levels of p-JNK and p-p38 in cardiac tissues from MI mice. Bilo alleviated OGD-induced cell apoptosis in H9c2 cells and suppressed MI-induced cardiomyocyte apoptosis and myocardial fibrosis in mice via the inactivation of JNK/p38 MAPK signaling pathways. Thus, Bilo may be an effective anti-MI agent.

Effects of daidzein on rat ovary against ischemia-reperfusion

PURPOSE

Our aim was to investigate protective effects of daidzein treatment on ischemia-reperfusion (I/R) injury-induced ovarian tissue by immunohistochemical techniques.

METHODS

Thirty Sprague Dawley female rats were categorized into three groups as sham, I/R group, and I/R+daidzein groups. Bloods were analyzed for malondialdehyde (MDA), glutathione peroxidase (GSH), and myeloperoxidase (MPO), and ovaries were processed for histological tissue protocol.

RESULTS

Both MDA and MPO values were increased in I/R group compared to sham and I/R+daidzein groups. GSH content was increased in I/R+daidzein group compared to I/R groups. In I/R group, theca and follicular cells were degenerated with apoptosis and dilatation and congestion, edema. In I/R+daidzein group, daidzein improved pathologies. In the I/R group, Bax expression was positive with follicular cells, granulosa cells and inflammatory cells. In the I/R+daidzein group, positive Bax reaction was observed in the epithelial, antral, and inflammatory cells. In I/R group, Bcl-2 reaction was in germinative epithelial cells, cells of antral follicle. In the I/R+daidzein group, Bcl-2 expression level was reduced after daidzein treatment.

CONCLUSIONS

After the I/R procedure, ovarian cells and follicles were degenerated with apoptosis and inflammation. After daidzein treatment, Bax and Bcl-2 signal were decreased. It was observed that daidzein stopped the apoptotic process.

The Hematopoietic Function of Medicinal Wine Maoji Jiu Revealed in Blood Deficiency Model Rats

Maoji Jiu (MJ), a medicinal wine, has been used commonly by the Chinese to enrich and nourish the blood. In this study, the aim is to examine the hematopoietic function of MJ and investigate its hematopoietic regulation mechanism. Thirty-six female Sprague-Dawley rats (200 ± 20 g) were randomly divided into six groups with six rats in each group. The blood deficiency model was induced by injecting hypodermically with N-acetylphenylhydrazine (APH) and injecting intraperitoneally with cyclophosphamide (CTX), and treatment drugs were given by oral gavage twice a day for continuous 10 days from the start of the experiments. The administration of MJ improved the levels of white blood cells (WBCs), red blood cells (RBCs), hemoglobin (HGB), and hematocrit (HCT) in the blood deficiency model rats. Hematopoietic effect involves regulating the antioxidant activity in the liver and the levels of Bcl-2, Bax, erythropoietin (EPO), transforming growth factor-beta-1 (TGF-β1), and macrophage colony-stimulating factor (M-CSF) mRNA in spleen tissues to enhance extramedullary hematopoiesis. This study suggests that MJ has a beneficial effect on blood deficiency model rats.

Muscone Inhibits the Excessive Inflammatory Response in Myocardial Infarction by Targeting TREM-1

The inhibitory effect of muscone on the hyperinflammatory response after myocardial ischemia reperfusion injury (MIRI) was investigated, and the target and signal pathways of muscone were explored. The levels of inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor alpha were detected through qRT-PCR and ELISA. The expression levels of p38 and NF-κB signaling pathway-related proteins were detected through Western blot. TREM-1 siRNA was transfected into macrophages in vitro. The rat model of myocardial ischemia was established and used in studying the inhibitory effect of muscone on the inflammatory response and its protective effect muscone on myocardial apoptosis. The expression of TREM-1 was upregulated during myocardial ischemia. Knocking down TREM-1 decreased the increase in inflammatory cytokines in the supernatant of macrophages induced by rmHMGB1 (1 μg/mL) and rmHSP60 (1 mol/mL). In addition, knocking down TREM-1 decreased p38 and NF-κB signaling activation. Muscone can protect myocardial cells by inhibiting the expression of TREM-1 and the inflammatory response after myocardial infarction. Further study showed that muscone inhibited the production of DAM-triggered (damage-associated molecular pattern trigger) inflammatory cytokines. In addition, muscone inhibited the activation of p38 and NF-κB signals under DAM-induced conditions. Muscone and TREM-1 gene knockout reduced cell apoptosis and provided protection against MIRI by inhibiting p38 and NF-κB signaling activation. Mechanism studies showed that muscone inhibited the production and release of inflammatory cytokines by inhibiting TREM-1, and thereby reducing the inflammatory response and providing protection against MIRI.

Silencing UHRF1 Enhances Radiosensitivity of Esophageal Squamous Cell Carcinoma by Inhibiting the PI3K/Akt/mTOR Signaling Pathway

Purpose

Resistance to radiotherapy results in a high treatment failure rate for locally advanced esophageal squamous cell carcinoma (ESCC). Ubiquitin-like with plant homeodomain and ring-finger domains 1 (UHRF1), is associated with poor prognosis in ESCC. The present study aims to characterize the effect of UHRF1 silencing on the radiosensitivity of ESCC and its potential mechanism.

Methods

Both in vitro and in vivo experiments were conducted to observe the effects of UHRF1 silencing on the radiosensitivity of ESCC. The effects of UHRF1 silencing on the apoptosis of ESCC cells were assessed by flow cytometry. The expression of apoptosis-related factors (caspase-3 and Bcl-2), PI3K/Akt/mTOR signaling pathway-related factors (PTEN, p-Akt and Akt, p-mTOR and mTOR), and DNMT1 were measured via Western blot, and the status of PTEN methylation was detected by methylation-specific PCR. Immunohistochemistry was used to detect the expressions of PTEN, p-AKT, and p-mTOR in xenograft tumor tissues.

Results

In vitro and in vivo experiments showed that UHRF1 knock-down inhibited ESCC cell growth and enhanced their radiosensitivity. shUHRF1 combined with radiation significantly increased ESCC cell apoptosis. Meanwhile, it activated the expression of caspase-3 and inhibited the expression of Bcl-2. shUHRF1 inhibited the expression of DNMT1 and reduced the methylation of PTEN, and then upregulated the expression of PTEN to inhibit the PI3K/Akt/mTOR signaling pathway. On the contrary, the PI3K/Akt/mTOR signaling pathway can be activated by upregulation of UHRF1.

Conclusion

Our findings provide a theoretical basis for UHRF1 as a target to improve the radiosensitivity of ESCC.

MSC exosome-mediated cardioprotection in ischemic mouse heart comparative proteomics of infarct and peri-infarct areas

Mesenchymal stem cell (MSC) exosomes may limit cardiac injury, and even reverse cardiac damage in animal models of ischemia. To understand exosome-mediated improvement in cardiac function we examined the proteomic alternations in the MSC exosome-treated mice hearts subjected to left coronary artery (LCA) ligation, with particular emphasis on peri-infarct areas. At 7 days after LCA ligation, left ventricular end systolic thickness, infarct size and survival of mice were studied. Mass spectrometric analysis of infarct and peri-infarct areas was carried out. Expression of inflammatory markers (LOX-1 and NLRP3) and cell death markers (Bax, Bcl-2, Caspases 1 and 3 and GSDMD) were investigated by Western blots and immunofluorescence. Proteomic analysis of the infarct and peri-infarct areas in saline-treated hearts revealed differentially expressed proteins involved in inflammation and apoptotic cell death, while showing depletion of processes governing cell death. Exosome treatment significantly improved the proteomic profile in both infarct and peri-infarct areas, more so in the peri-infarct areas. The infarct size was smaller (9 ± 1%), and cardiac contractile function (fractional shortening) was preserved in the exosome-treated mice (28 ± 2%). Survival of exosome-treated mice was also better. White blood cell accumulation in and around the infarct area, expression of LOX-1 and NLRP3 inflammasome, and markers of cell death (cleaved Caspase-3, Caspase-1, GSDMD, Bcl-2 and Bax) were dramatically reduced by MSC exosome treatment (all p < 0.01). In cultured primary mouse cardiomyocytes, treatment with MSC exosomes essentially reversed inflammation-induced pro-apoptotic and inflammatory signals (p < 0.01). MSC exosomes exert their cardioprotective effects by suppressing inflammation and pro-apoptotic processes, particularly in the peri-infarct areas, resulting in preservation of cardiac function after LCA ligation.

Simvastatin protects high glucose-induced H9c2 cells from injury by inducing autophagy

CONTEXT

Simvastatin is the first line therapeutic drug for coronary heart disease and atherosclerosis. The protective effect mechanism of simvastatin on cardiomyocytes is unclear.

OBJECTIVE

This study explores the effect of simvastatin on high glucose induced cardiomyocyte injury and the role of autophagy during the process.

MATERIALS AND METHODS

H9c2 cells were incubated with different doses of glucose (0, 50, 100, 200 mM) for 24 h to verify the glucose induced injury. The H9c2 cells were pre-treated with simvastatin at different dosages (0, 0.1, 0.5, 1 μM) for 30 min to rescue the injury followed by the autophagy evaluation. 3-MA was used as an autophagy inhibitor to confirm the role of autophagy in simvastatin treated process. CCK-8 assay, FACS assay, confocal microscopy, western blotting and immunofluorescence analysis were conducted to evaluate the high glucose induced injury or protective effects of simvastatin in H9c2 cell line.

RESULTS

High glucose dramatically decreased H9c2 cell viability (0 mM, 0.58 ± 0.09%; vs. 50 mM, 8.67 ± 0.43%; 100 mM, 16.1 ± 3.56%; 200 mM, 32.9 ± 2.63%), induced significant cell apoptosis (0 mM, 0.96 ± 0.16%, vs. 50 mM, 7.00 ± 0.63%; 100 mM, 12.9 ± 0.78%; 200 mM, 21.8 ± 1.17%) and suppressed cell autophagy. Simvastatin decreased apoptosis and attenuate injury by decreasing cell apoptosis ratio, elevating Bcl-2 expression while decreasing Bax and caspase-3 protein expressions. Meanwhile, simvastatin restored the autophagy depicted by western blotting with increased ATG-5, Beclin1 and LC3II/LC3I protein expression and decreased p62 expression, as well as immunofluorescence with elevated LC3 fluorescence density.

DISCUSSION AND CONCLUSIONS

The myocardial protective effect mediated by autophagy activated by simvastatin to some extent elucidated the mechanism of the protective effect of simvastatin on H9c2 cell injury, which provided a certain theoretical basis for the clinical application of simvastatin in the treatment of cardiovascular diseases. In addition, we speculate that simvastatin may be used for diabetes associated cardiovascular diseases.

Adeno-associated Virus 9-mediated Small RNA Interference of TLR4 Alleviates Myocardial Ischemia and Reperfusion Injury by Inhibition of the NF-κB and MAPK Signaling Pathways in Rats

BACKGROUND

Despite intensive investigation, effective therapeutic procedures for myocardial I/R injury are still in demand.

OBJECTIVE

To explore the effect of adeno-associated virus 9 (AAV9)-mediated small interfering RNA targeting TLR4 in the treatment of myocardial ischemia and reperfusion (I/R) injury and its influence on the NF-κB and MAPK signaling pathways.

METHODS

Rats were divided into 3 groups, namely, the sham, AAV9-siRNA control, and AAV9-TLR4 siRNA groups. siRNA solution or normal saline was injected through the tail vain. The rat myocardial I/R injury model was then established. HE staining and TUNEL staining were applied to compare the pathological changes in cardiomyocytes in the three groups. Immunohistochemical staining and western blotting were utilized to detect TLR4 expression under siRNA interference. Serum inflammatory factor (IL-1β, TNF-α) expression was determined by an ELISA commercial kit. Key proteins in the MAPK (p38, JNK 1/2) and NF-κB (p65) signaling pathways were determined to identify the TLR4 siRNA functional mechanism.

RESULTS

Fluorescence microscopic images of the myocardium indicated that AAV9- mediated siRNA was efficiently transfected into the myocardium, and the infarcted size after I/R injury was decreased by AAV9-TLR4 siRNA when compared with negative control rats (P<0.05). TLR4 protein expression was significantly decreased by siRNA interference (P<0.001). Apoptosis-related factor BCL-2 expression was increased in the TLR4 gene silencing group, whereas Bax expression was decreased. The Bax/BCL-2 ratio was also decreased, demonstrating a protective effect for cardiomyocytes. Inflammatory factors were lower in the TLR4 gene silencing group than in the siRNA control group (P<0.001). The MAPK and NF-κB signaling pathways were activated in myocardial I/R injury; however, the primary proteins in these two signaling pathways were downregulated upon interference of TLR4 siRNA, with significant differences (P<0.05).

CONCLUSION

AAV9-TLR4 siRNA has a positive effect on myocardial I/R injury by inhibiting the MAPK and NF-κB signaling pathways and can be used as a potential therapeutic method for myocardial I/R injury.

Salvianolic acid B protects against myocardial ischaemia-reperfusion injury in rats via inhibiting high mobility group box 1 protein expression through the PI3K/Akt signalling pathway

Salvianolic acid B (Sal B) has a significant protective effect on myocardial ischaemia-reperfusion (I/R) injury. Therefore, the aims of this study were to determine the effects of Sal B on myocardial ischaemic-reperfusion (I/R) injury in rats and to explore whether its underlying mechanism of cardioprotection occurs through activating the expression of the phosphoinositide 3-kinase/protein, kinase B (PI3K/Akt) and inhibiting the expression of high mobility group protein 1 (HMGB1). Ninety Sprague-Dawley rats were randomized into five groups: group 1 (sham-operated), group 2 (myocardial I/R), group 3 (low dose of Sal B+I/R), group 4 (high dose of Sal B+I/R), and group 5 (high dose of Sal B+I/R+LY294002, which is a specific PI3k inhibitor). All I/R rats received 30 min myocardial ischaemia followed by 24-h reperfusion. Cardiac function, infarct size, myocardial injury marker levels, inflammatory response and cardiomyocyte apoptosis as well as Bcl-2, Bax, P-Akt, HMGB1 and TLR4 expression were measured. In the current study, Sal B significantly ameliorated myocardial I/R injury in a dose-dependent manner, ameliorated cardiac function, reduced myocardial infarction size, decreased myocardial injury marker expression, decreased inflammatory responses, reduced apoptosis, activated PI3K/Akt expression and inhibited HMGB1 expression. However, all effects of Sal B were significantly reversed by LY294002. Overall, the present study indicated that Sal B attenuated myocardial I/R injury by activating PI3K/Akt and inhibiting the release of HMGB1 in rats.

Stem Cell Therapies in Cardiovascular Disease

Despite considerable advances in medicine, cardiovascular disease is still rising, with ischemic heart disease being the leading cause of death and disability worldwide. Thus extensive efforts are continuing to establish effective therapeutic modalities that would improve both quality of life and survival in this patient population. Novel therapies are being investigated not only to protect the myocardium against ischemia-reperfusion injury but also to regenerate the heart. Stem cell therapy, such as potential use of human mesenchymal stem cells and induced pluripotent stem cells and their exosomes, will make it possible not only to address molecular mechanisms of cardiac conditioning, but also to develop new therapies for ischemic heart disease. Despite the studies and progress made over the last 15 years on the use of stem cell therapy for cardiovascular disease, the efforts are still in their infancy. Even though the expectations have been high, the findings indicate that most of the clinical trials generally have been small and the results inconclusive. Because of many negative findings, there is certain pessimism that cardiac cell therapy is likely to yield any meaningful results over the next decade or so. Similar to other new technologies, early failures are not unusual and they may be followed by impressive success. Nevertheless, there has been considerable attention to safety by the clinical investigators because the adverse events of stem cell therapy have been impressively rare. In summary, although regenerative biology might not help the cardiovascular patient in the near term, it is destined to do so over the next several decades.

Effects of procyanidin on cardiomyocyte apoptosis after myocardial ischemia reperfusion in rats

BACKGROUND

This study is aimed at investigating the effects of procyanidin on cardiomyocyte apoptosis of myocardial ischemia/reperfusion (I/R) injury in rats.

METHODS

Sprague-Dawley rats were randomly assigned into four groups: control group (normal saline), ischemic group (normal saline), procyanidin low-dose group (procyanidin 50 mg/kg/day) and procyanidin high-dose group (procyanidin 100 mg/kg/day) by intragastric administration for 2 weeks. After last administration, myocardial I/R model was induced by ligating left anterior descending artery for 30 min followed by 120 min of perfusion. The activity of serum creatine kinase mb isoenzyme (CK-MB) was detected after experiment. The content of reactive oxygen species (ROS) was determined by ROS fluorescent probe dihydroethidium; the expressions of p53, Caspase-9, Caspase-3, Bcl-2 and Bax were determined by western blotting; myocardial apoptosis was measured by the method of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling.

RESULTS

Compared with control group, the contents of serum CK-MB, ROS, the expressions of p53, Caspase-9, Caspase-3 and Bax increased significantly in ischemic group, the Bcl-2 expression, Bcl-2/Bax ratio decreased and the cardiomyocyte apoptosis index increased (p < 0.05); compared with ischemic group, the content of CK-MB, ROS, the expressions of p53, Caspase-9, Caspase-3 and Bax decreased, the Bcl-2 expression, Bcl-2/Bax ratio increased and the cardiomyocyte apoptosis index decreased in procyanidin group (p < 0.05).

CONCLUSIONS

Procyanidin can reduce cardiomyocyte apoptosis after I/R. This beneficial effect is partially dependant on decreased ROS, p53, Caspase-9, Caspase-3 and Bax, as well as increased Bcl-2 and Bcl-2/Bax ratio.

Effect of tanshinone IIA on oxidative stress and apoptosis in a rat model of fatty liver

Oxidative stress is a crucial factor associated with fatty liver disease, which raises the possibility of using antioxidants to improve liver steatosis. Tanshinone IIA (TSIIA) is a traditional Chinese medicine that has been reported to have antioxidant effects in vitro. The present study aimed to investigate whether TSIIA possesses antioxidant effects in vivo and whether TSIIA was able to improve liver steatosis. Hence, the ability of TSIIA to protect rats from liver disease was explored, particularly in regard to antioxidant activity. Rats were fed a high-lipid diet for 90 days, causing severe liver steatosis, both morphologically and biochemically. An increase in reactive oxygen species (ROS) in the liver was exhibited in addition to significantly elevated serum lipids and malondialdehyde (MDA). Furthermore, hepatocyte apoptosis was measured by Hoechst staining, reverse transcription-quantitative polymerase chain reaction and western blot analysis and an increase in hepatocyte apoptosis rate was indicated in mice on a high-fat diet. Following intraperitoneal injection of TSIIA (10 mg/kg/day), liver steatosis was significantly inhibited. In rats receiving TSIIA treatment, less ROS were indicated in the liver and significantly decreased levels of MDA (P<0.05) in serum were exhibited, whereas significantly increased activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX) were observed (P<0.05 and P<0.01, respectively). In addition, the rate of hepatocyte apoptosis was significantly decreased in the TSIIA group (P<0.01). However, TSIIA elicited no effect on serum lipid profiles. These results suggest that TSIIA attenuates oxidative stress by decreasing ROS and MDA production and enhancing the activity of T-SOD and GSH-PX, which may contribute to the inhibition of apoptosis and amelioration of liver steatosis.

Down-regulation of microRNA let-7d inhibits the proliferation and invasion of trophoblast cells in preeclampsia

Preeclampsia (PE) is a serious pregnancy complication that continues to adverse effects on mother and the fetus. The study investigated the effect of microRNA let-7d (miR-let-7d) on the proliferation and invasion of trophoblast cells (TC) in PE. In situ hybridization techniques were employed to evaluate the miR-let-7d expressions in the placental tissues from 63 PE patients as well as 65 normal placental tissues. Transfection of pre-let-7d, anti-let-7d, and their corresponding control sequences was performed in TCs obtained from PE. The blank group was composed of TCs no transfection and normal group consisted of normal TCs. Expressions of proliferation and invasion markers in TCs were detected by qRT-PCR. Proliferation, apoptosis, and the invasion ability of the TCs were determined using a CCK-8 assay, flow cytometry, and Transwell assay. In comparison to the normal placental tissues, PE placental tissues exhibited increased levels of let-7d expression. Following transfection of anti-let-7d, when compared with the blank group, the anti-let-7d group displayed increased levels of proliferation ability, expression of proliferation labeling proteins PCNA and Ki67, number of TCs as well as expressions of the invasion related proteins MMP-2, MMP-9, and TIMP-1. In contrast declines in cell apoptosis rate were observed. Compared with the blank group, the changes of the indexes were reversed in the pre-let-7d group. The study provided evidence suggesting that low expression levels of miR-let-7d plays a central role in suppressing apoptosis in addition to promoting the proliferation and invasion of PE TCs.

Total saponins from Aralia taibaiensis protect against myocardial ischemia/reperfusion injury through AMPK pathway

It was previously shown that total saponins extracted from Aralia taibaiensis (sAT) have potent antioxidant activities for treating diabetes mellitus and attenuate D-galactose-induced aging. Since diabetes mellitus and aging are closely associated with cardiac dysfunction, particularly ischemic heart disease, sAT may have potential protective activity against myocardial ischemia/reperfusion injury (MI/RI). However, the anti-MI/RI effects of sAT have yet to be examined, and the possible molecular mechanisms remain to be determined. The present study was undertaken to investigate the anti-MI/RI activities of sAT and to elucidate the mechanisms underlying these effects in rats using TUNEL and Hoechst 33258 staining. The results confirmed the cardioprotective effects in vivo and elucidated the potential molecular mechanisms of sAT in vitro. Pretreatment with sAT significantly reduced infarct size, decreased the levels of lactate dehydrogenase and creatine kinase in the serum and blocked apoptosis. In addition, sAT inhibited A/R-induced apoptosis by decreasing DNA strand breaks, caspase-3 activity and cytochrome c release in H9c2 cells. Furthermore, sAT markedly increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl CoA carboxylase and elevated the Bcl2/Bcl-2-associated X protein ratio. These effects were blocked by compound C. The results suggested that sAT pretreatment exerts protective effects on myocardial cells in vitro and in vivo against MI/RI-induced apoptosis by activating AMPK pathway.

A sphingosine kinase-1 inhibitor, SKI-II, induces growth inhibition and apoptosis in human gastric cancer cells

SKI-II has been reported as an inhibitor of sphingosine kinase 1 and has been extensively used to prove the involvement of sphingosine kinase and sphingosine-1-phosphate (Sphk1) in cellular processes. In the current study, we investigated the effects of SKI-II and its potential mechanisms in human gastric cancer SGC7901 cells. After treatment with SKI-II, cell growth, cell cycle distribution, apoptosis, expression of Sphk1, NF-κB, Bcl-2, Bax and p27 were assessed by MTT assay, flow cytometry, electron microscopy, immunocytochemistry and Western-blot assay, respectively. Our results showed that SKI-II markedly inhibited SGC7901 cell survival in a dose-dependent manner, reduced cell proliferation with accumulation of cells in the G0/G1 phase and induced apoptosis in the tumor cells. Furthermore, Western blotting and immunocytochemistry showed that the expression of p27 and Bax was increased significantly, but the expression of NF-κB, Bcl-2 and Sphk1 decreased by different degrees. These results indicate that SKI-II induced cell growth arrest and apoptosis. The increased apoptotic sensitivity of SGC7901 was correlated with NF-κB or Bcl-2/Bax activation.

Huangzhi Oral Liquid Prevents Arrhythmias by Upregulating Caspase-3 and Apoptosis Network Proteins in Myocardial Ischemia-Reperfusion Injury in Rats

To study the effect of Huangzhi oral liquid (HZOL) on I/R after 2 h and 4 h and determine its regulatory function on caspase-3 and protein networks. 70 SD male rats were randomly divided into seven groups and established myocardial I/R injury model by ligating the left anterior descending coronary artery. Myocardial infarction model was defined by TTC staining and color of the heart. The levels of CK-MB, CTnI, C-RPL, SOD, and MDA were tested at 2 h and 4 h after reperfusion. HE staining and ultramicrostructural were used to observe the pathological changes. The apoptotic index (AI) of cardiomyocyte was marked by TUNEL. The expression levels of caspase-3, p53, fas, Bcl-2, and Bax were tested by immunohistochemistry and western blot. HZOL corrected arrhythmia, improved the pathologic abnormalities, decreased CK-MB, CTnI, C-RPL, MDA, AI, caspase-3, p53, fas, and Bax, and increased SOD ans Bcl-2 with different times of myocardial reperfusion; this result was similar to the ISMOC (P > 0.05). HZOL could inhibit arrhythmia at 2 and 4 h after I/R and ameliorate cardiac function, which was more significant at 4 h after reperfusion. This result may be related to decreased expression of caspase-3, p53, and fas and increased Bcl-2/Bax ratio.

Protective effect of picroside II on myocardial ischemia reperfusion injury in rats

The aim of this study was to determine the effect of picroside II on myocardial ischemia reperfusion injury in rats and to explore its underlying mechanism. Isolated rat hearts underwent 30 minutes of global ischemia followed by 120 minutes of reperfusion. Different doses of picroside II (1 μM, 10 μM, and 100 μM) were given 20 minutes before ischemia. Phosphoinositide 3-kinase inhibitor (wortmannin) and nitric oxide synthase (NOS) inhibitor (L-N(G)-nitroarginine methyl ester) were given 10 minutes before picroside II treatment. The cardiac function, myocardial infarct size, apoptosis, myocardial nitric oxide content, the expressions of Bcl-2 and Bax, and the activation of the phosphoinositide 3-kinase/Akt/endothelial NOS pathway were evaluated. Treatment with 10 μM and 100 μM picroside II significantly improved postischemic myocardial function, reduced myocardial infarct size, inhibited apoptosis, increased myocardial NO content, upregulated Bcl-2, downregulated Bax, and increased the phosphorylation of Akt and endothelial NOS, but cardioprotection was not shown in the 1 μM picroside II treatment group and was abrogated by wortmannin and L-N(G)-nitroarginine methyl ester. Furthermore, cardioprotection in the 100 μM picroside II treatment group was superior to that in the 10 μM picroside II treatment group. In conclusion, the data reveals that picroside II has a significant protective effect on myocardial ischemia reperfusion injury in a dose-dependent manner, which was mediated by upregulating the phosphoinositide 3-kinase/Akt/endothelial NOS pathway to increase nitric oxide production and regulating the expressions of Bcl-2 and Bax to inhibit apoptosis.

CGRP inhibits norepinephrine induced apoptosis with restoration of Bcl-2/Bax in cultured cardiomyocytes of rat

Calcitonin gene related peptide (CGRP) and norepinephrine (NE) may interact in acute myocardial ischemia, protecting cardiomyocytes but the underlying mechanism is unclear. Here we investigated the correlation of the anti-apoptotic effect of CGRP with the change of Bcl-2/Bax. Cultured cardiomyocytes were divided into four groups: (1) control group (no treatment with any test agent), (2) NE group (treated with 10(-5)mol/L of NE), (3) CGRP+NE group (treated with 10(-8)mol/L of CGRP and NE at 10(-5)mol/L) and (4) CGRP8-37+CGRP+NE group (treated with 10(-7)mol/L of CGRP8-37, a specific antagonist of CGRP receptor, CGRP at 10(-8)mol/L and NE at 10(-5)mol/L). Apoptosis ratio was analyzed by flow cytometry. Bcl-2 and Bax and the coding mRNA were examined. It was found that the apoptosis ratio in NE group (29.4 ± 1.8%) was significantly greater (P<0.05) than that of the control group (10.1 ± 1.7%). The effect of NE was attenuated by CGRP (18.7 ± 2.1%), which was reversed by CGRP8-37 (24.9 ± 2.9%). NE treatment resulted in reductions in the ratio of Bcl-2/Bax (by 33%) and their mRNA (by 53%). CGRP restored the level of Bcl-2/Bax, which was abolished by CGRP8-37. Current study suggests that norepinephrine inhibits synthesis of Bcl-2 and increases Bax and apoptosis of cardiomyocytes. CGRP restores the ratio of Bcl-2/Bax and attenuates the apoptosis induced by NE, via specific CGRP receptor.

Reversion of multidrug resistance by SKI-II in SGC7901/DDP cells and exploration of underlying mechanisms

In order to investigate whether SKI-II could reverse drug resistance and its possible mechanisms, we treated SGC7901/DDP cells with SKI-II or SKI-II in combination with DDP. Then cell growth, apoptosis, micro- morphological changes, and expression of SphK1, P-gp, NF-kB, Bcl-2 and Bax were assessed by MTT assay, flow cytometry, electron microscopy, immunocytochemistry and Western blot assay respectively. SGC7901/DDP cells were insensitive to cisplatin 2.5 mg/L, but when pretreated with SKI-II, their proliferation was inhibited by cisplatin 2.5mg/L significantly, the inhibition rate increasing with time and dose. The apoptosis rate was also significantly elevated. Expression of SphK1 and P-gp was decreased significantly, Pearson correlation analysis showing significant correlation between the two (r=0.595, P<0.01). Expression of NF-kB and Bcl-2 was decreased significantly, while that of Bax was increased, compared to the control group. There were significant correlations between SphK1 and NF-kB(r=0.723, P<0.01), and NF-kB and Bcl-2(r=0.768, P<0.01). All these data indicated that SKI-II could reverse drug resistance of SGC7901/DDP to cisplatin by down-regulating expression of P-gp and up-regulating apoptosis through down-regulation of SphK1. The increased apoptotic sensitivity of SGC7901/ DDP to cisplatin was due to the decreasing proportion of Bcl-2/Bax via down-regulating NF-kB.

Improving outcome of transplanted mesenchymal stem cells for ischemic heart disease

Mesenchymal stem cells (MSCs) transplantation has been proposed as a promising means for the repair and regeneration of heart cells in ischemia heart disease. However, advancement in stem cell therapy is hindered by the poor survival of implanted cells. Recently, many kinds of methods have been developed to prevent stem cells apoptosis and improve their therapeutic potential in the ischemia heart, including genetically modifying, retaining viability in vitro, suitable transplantation means, and preconditioning. Despite the great promise of these methods, there are still many problems to be solved in this field, including limited kinds of experimental animals, few clinical trials, and cell differentiation.

In vitro and in vivo effects of bone marrow stem cells on cardiac structure and function

It is hypothesized that the protection of bone marrow stem cells (BMSCs) on ischemic myocardium might be related to the anti-apoptotic effect via paracrine mechanisms. In this study, a wide array of cytokines including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), stromal cell-derived factor-1 (SDF-1) and insulin growth factor-1 (IGF-1) were detected in the BMSCs cultured medium by ELISA. Myocyte apoptosis was assayed by DNA fragmentation and annexin-V staining. Myocardial infarction model was produced by ligation of mouse left anterior descending coronary artery (LAD). Before LAD ligation, mice were myoablated by irradiation and transplanted with bone marrow cells from transgenic mice expressing green fluorescent protein (GFP). After LAD ligation, animals were administered stem cell factor (SCF, 200 mug/day/kg, i.p.) or saline for 6 days. Animals were sacrificed at 4 weeks after SCF treatment. Apoptotic cardiomyocytes were analyzed by TUNEL. Myocardial function was analyzed by echocardiography and pressure-volume system. Bcl-2 protein was analyzed by Western blotting. Our results showed that cultured BMSCs released VEGF, bFGF, SDF-1 and IGF-1. Hypoxia-induced cell apoptosis was diminished in cardiomyocytes co-cultured with BMSCs. Smaller LV dimension and increased LV ejection fraction were seen in SCF-treated animals. SCF significantly reduced cardiomyocytes apoptosis within peri-infarct area and increased up-regulation expression of Bcl-2 in ischemic area. Moreover, conditioned medium from cultured BMSCs also induced up-regulation of Bcl-2 protein in cardiomyocytes. It is concluded that paracrine mediators secreted by BMSCs might be involved in early repair of ischemic heart by preventing cardiomyocytes apoptosis and improving cardiac function.

Temporal and spatial characteristics of apoptosis in the infarcted rat heart

Following myocardial infarction (MI), tissue repair/remodeling occurs in both the infarcted and noninfarcted myocardium. Apoptosis has been demonstrated to play an important role in these processes. In the present study, we sought to determine the temporal and spatial characteristics of apoptosis in the infarcted heart as well as to identify cells undergoing programmed cell death at different stages of repair/remodeling and their relationship to the expression of anti-/pro-apoptotic genes following MI. Our study has shown that apoptosis appears in both infarcted and noninfarcted myocardium, and cells undergoing apoptosis depend on the stage of healing. In the infarcted myocardium, apoptosis contributes to the loss of cardiomyocytes during the early stage of healing, elimination of inflammatory cells during the inflammatory phase of healing, and reduction of myofibroblasts with the fibrogenic phase of repair in the infarcted myocardium. In noninfarcted myocardium, cardiomyocyte apoptosis was observed from day 3 to 28 postMI. Cardiac apoptosis following MI is correlated with the increase of Bax expression.

Effects of carvedilol on cardiomyocyte apoptosis and gene expression in vivo after ischemia-reperfusion in rats

The effects of carvedilol on cardiomyocyte apoptosis and expression of bcl-2, bax genes following ischemia (0.5 h) and reperfusion (48 h) in vivo and the possible biological mechanism of carvedilol inhibiting cardiomyocyte apoptosis were studied. The left anterior descending artery in Wistar rats were ligated to establish ischemia-reperfusion (I/R) models. The model animals were divided into two groups: I/R group, the model rats not subject to other treatments except ischemia-reperfusion (n = 8); carvedilol-treated group (n = 8), I/R model rats treated with carvedilol. Eight rats in the sham-operated group were subjected to only experimental open operation. The number of apoptotic cardiomyocyte was determined by TUNEL staining. Immunohistochemistry and in situ hybridization histochemistry (ISHH) were used to detect the expression of bcl-2 and bax genes. Image processing system was used to quantitatively dispose the positive metric substances of both immunohistochemistry and ISHH through the average optical density (OD) value. The results showed that the number of the apoptotic cells were 36.18 +/- 9 (I/R group), 0-1 (sham-operated group) and 9.5 +/- 3 (carvedilol-treated group) in each visual field respectively with the difference being very significant among the groups (P < 0.001). The OD values of bcl-2 protein in sham-operated group, I/R group and carvedilol-treated group were 0.14 +/- 0.01, 0.08 +/- 0.02 and 0.15 +/- 0.03, respectively. The OD values of bcl-2 mRNA in sham-operated group, I/R group and carvedilol-treated group were 0.08 +/- 0.01, 0.06 +/- 0.01 and 0.09 +/- 0.01, respectively. There was no significant difference between carvedilol-treated group and I/R group (P > 0.05). The OD values of bax protein in I/R group, sham-operated and carvedilol-treated-treated group were 0.13 +/- 0.02, 0.07 +/- 0.01, 0.06 +/- 0.01, respectively. There was very significant difference between carvedilol-treated group and I/R group (P < 0.01). Bcl-2/bax ratio was 1.07 +/- 0.14 (I/R group), 1.28 +/- 0.16 (sham-operated group), 2.5 +/- 0.26 (carvedilol-treated group) respectively with the difference being very significant between carvedilol-treated group and I/R group (P < 0.05). It was indicated that carvedilol could inhibit cardiomyocyte apoptosis following ischemia and reperfusion, which was related to the increased bcl-2/bax ratio due to inhibition of bax gene expression.