Effects of Ethyl Pyruvate on Myocardial Apoptosis and Expression of Bcl-2 and Bax Proteins after Ischemia-reperfusion in Rats

In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion （I/R） in vitro and the expression of Bcl-2 and Bax proteins, isolated rat hearts were perfused in a Langendorff model. Twenty-four rats were randomly divided into 3 groups （n=8 in each group）： control group was perfused for 120 min. In the I/R group, after 30 min stabilization the injury was induced by 30 min global ischemia followed by 60 min reperfusion. Ethyl pyruvate （EP） group was set up with the same protocol as I/R group except that it was supplied with 2 mmol/L EP 15 rain before ischemia and throughout reperfusion. Myocardial malonaldehyde （MDA） content was measured. Myocardial apoptotic index （AI） was tested by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling （TUNEL） method. The expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in cardiac myocytes was detected by immunohistochemistry. As compared with control group, the content of MDA, myocardial AI and the expression of Bcl-2, Bax proteins were increased significantly in I/R group, but the content of MDA, myocardial AI and the expression of Bax protein were decreased obviously and the expression of Bcl-2 protein was up-regulated in EP group （P〈0.05）. These results demonstrate that EP could inhibit apoptosis of cardiac myocytes possibly via alleviating oxidative stress, up-regulating Bcl-2 and down-regulating Bax proteins.

Effect of Helicobacterpyloriinfection on Bax protein expression in patients with gastric precancerous lesions

AIM： To investigate the effect of Helicobacter pylori （H pylon） infection on Bax protein expression, and explore the role of Hpyloriin gastric carcinogenesis. METHODS： Hpyloriwas assessed by rapid urease test and Warthin-Starry method, and expression of Bax protein was examined immunohistochemically in 72 patients with pre-malignant lesions. RESULTS： Bax protein was differently expressed in intestinal metaplasia and gastric dysplasia, and showed 63.99% positivity. The positivity of Bax protein expression in Hpylori-positive gastric precancerous lesions （72.3%） was significantly higher than that in H pylori-negative gastric precancerous lesions （48.0%, x^2= 4.191, P〈0.05）. Hpyloriinfection was well correlated with the expression of Bax protein in gastric precancerous lesions （r= 0.978, P〈0.01）. After eradication of H pylori, the positivity of Bax protein expression significantly decreased in Hpylori-positive gastric precancerous lesions （x^2 = 5.506, P〈0.05）. In the persisting H pylori-infected patients, the positivity of Bax protein expression was not changed. CONCLUSION： H pyloriinfection may be involved in the upregulation of Bax gene, which might be one of the mechanisms of Hpyloriinfection-induced gastric epithelial cell apoptosis. Hpylorimight act as a tumor promoter in the genesis of gastric carcinoma and eradication of Hpylori could inhibit gastric carcinogenesis.

Total flavonoids of hawthorn leaves promote motor function recovery via inhibition of apoptosis after spinal cord injury

Flavonoids have been reported to have therapeutic potential for spinal cord injury.Hawthorn leaves have abundant content and species of total flavonoids,and studies of the effects of the total flavonoids of hawthorn leaves on spinal cord injury have not been published in or outside China.Therefore,Sprague-Dawley rats were used to establish a spinal cord injury model by Allen's method.Rats were intraperitoneally injected with 0.2 m L of different concentrations of total flavonoids of hawthorn leaves(5,10,and 20 mg/kg)after spinal cord injury.Injections were administered once every 6 hours,three times a day,for 14 days.After treatment with various concentrations of total flavonoids of hawthorn leaves,the Basso,Beattie,and Bresnahan scores and histological staining indicated decreases in the lesion cavity and number of apoptotic cells of the injured spinal cord tissue;the morphological arrangement of the myelin sheath and nerve cells tended to be regular;and the Nissl bodies in neurons increased.The Basso,Beattie,and Bresnahan scores of treated spinal cord injury rats were increased.Western blot assays showed that the expression levels of pro-apoptotic Bax and cleaved caspase-3 were decreased,but the expression level of the anti-apoptotic Bcl-2 protein was increased.The improvement of the above physiological indicators showed a dose-dependent relationship with the concentration of total flavonoids of hawthorn leaves.The above findings confirm that total flavonoids of hawthorn leaves can reduce apoptosis and exert neuroprotective effects to promote the recovery of the motor function of rats with spinal cord injury.This study was approved by the Ethics Committee of the Guangxi Medical University of China(approval No.201810042)in October 2018.

Relationship between expression of Bax and Bcl-2 proteins and apoptosis in radiation compound wound healing of rats

Objective: To study the relationship between the expression of Bax, Bcl 2 proteins, and apoptosis in radiation compound wound healing of rats. Methods: Apoptosis, Bax and Bcl 2 proteins were estimated by in situ terminal labeling (TUNEL) and immunohistochemical methods. Results: (1) Changes of the apoptosis in wound healing showed three typical characteristics: early occurrence, high frequency and delayed disappearance after radiation to rats when compared with those of simple wound group, which might be an important reason for radiation induced delayed wound healing. (2) The expression of Bax protein increased evidently with the increment of apoptosis and showed a good corresponding relationship with the apoptotic frequency in the process of wound healing. While the expression of Bcl 2 protein decreased obviously as the apoptosis reached a maximum and showed increasing tendency up to normal level when the apoptosis decreased distinctively. Conclusions: Bax and Bcl 2 proteins play an important role in the apoptotic regulation of radiation compound wound healing in rats.

Effects of ATRA, Acitretin and Tazarotene on Growth and Apoptosis of Tca8113 Cells

Summary：To investigate the effects of ATRA, acitretin and tazarotene on the growth and apoptosis of human tongue squamous cell carcinoma cell line Tca8113. The effect of retinoids on growth of Tca8113 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis with double staining with Annexin V-FITC and PI, and active caspase-3 analysis with the staining of FITC-conjugated monoclonal rabbit anli-active caspase-3 antibody were made by flow cytometer. Streptavidin-biotin complex （SABC） immunocytochemical assays were employed for the detections of Bax/Bcl-2 proteins expressions. Our results showed that the retinoids inhibited growth of Tca8113 cells in a dose-and time-dependent manner with maximal inhibition 24 h after treatment of 10 5 mol/L. 10^-5 mol/L retinoids altered cell cycle distribution of Tca8113 cells, revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. 10^-5 mol/L retinoids significantly induced apoptosis of Tca8113 cells （all P〈0.05）, elevated the cells population with detectable active caspase-3 （P〈 0.05 for all）, increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly （all P〈0.05）. Acitretin played a most prominent role among the retinoids. It is concluded that the inhibition of cell cycle progress of Tca8113 cells by ATRA, acitretin and tazarotene is one of the possible mechanisms for proliferation arrest of TcaS113 cells elicited by the retinoids. The retinoids mediate apoptosis in TcaS113 cells that may be caspase-dependent through mitochondria pathway. High concentration retinoids inhibit growth of Tca8113 cells in vitro by interfering with proliferation and inducing apoptosis of cells. Acitretin may be an alternative medicine for the prevention and treatment of tongue squamous cell carcinoma.

Insulin receptor substrate 1 may play divergent roles in human colorectal cancer development and progression

BACKGROUND Despite effective prevention and screening methods,the incidence and mortality rates associated with colorectal cancer(CRC)are still high.Insulin receptor substrate 1(IRS-1),a signaling molecule involved in cell proliferation,survival and metabolic responses has been implicated in carcinogenic processes in various cellular and animal models.However,the role of IRS-1 in CRC biology and its value as a clinical CRC biomarker has not been well defined.AIM To evaluate if and how IRS-1 expression and its associations with the apoptotic and proliferation tumor markers,Bax,Bcl-xL and Ki-67 are related to clinicopathological features in human CRC.METHODS The expression of IRS-1,Bax,Bcl-xL and Ki-67 proteins was assessed in tissue samples obtained from 127 patients with primary CRC using immunohistochemical methods.The assays were performed using specific antibodies against IRS-1,Bax,Bcl-xL,Ki-67.The associations between the expression of IRS-1,Bax,Bcl-xL,Ki-67 were analyzed in relation to clinicopathological parameters,i.e.,patient age,sex,primary localization of tumor,histopathological type,grading,staging and lymph node spread.Correlations between variables were examined by Spearman rank correlation test and Fisher exact test with a level of significance at P<0.05.RESULTS Immunohistochemical analysis of 127 CRC tissue samples revealed weak cytoplasmatic staining for IRS-1 in 66 CRC sections and strong cytoplasmatic staining in 61 cases.IRS-1 expression at any level in primary CRC was associated with tumor grade(69%in moderately differentiated tumors,G2 vs 31%in poorly differentiated tumors,G3)and with histological type(81.9%in adenocarcinoma vs 18.1%in adenocarcinoma with mucosal component cases).Strong IRS-1 positivity was observed more frequently in adenocarcinoma cases(95.1%)and in moderately differentiated tumors(85.2%).We also found statistically significant correlations between expression of IRS-1 and both Bax and Bcl-xL in all CRC cases examined.The relationships between studied proteins were related to clinicopathological parameters of CRC.No significant correlation between the expression of IRS-1 and proliferation marker Ki-67,excluding early stage tumors,where the correlation was positive and on a high level(P=0.043,r=0.723).CONCLUSION This study suggests that IRS-1 is co-expressed with both pro-and antiapoptotic markers and all these proteins are more prevalent in more differentiated CRC than in poorly differentiated CRC.

Effects of histamine on growth and apoptosis of human melanoma cells A375

Objective: To investigate the effects of histamine on growth and apoptosis of human melanoma cells A375. Methods: The effect of histamine on growth of A375 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis by double staining with Annexin V-FITC and PI, and active caspase-3 analysis by staining FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody were made by flow cytometer. StreptAvidin-Biotin Complex (SABC) immunocytochemical assays were adopted to detect Bax/Bcl-2 protein expressions.Results: Histamine inhibited proliferation of A375 cells in a dose- and time-dependent manner, and altered cell cycle distribution of A375 cells revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. Histamine induced apoptosis of A375 cells (P<0.05), elevated the cells population with detectable active caspase-3 (P<0.05), increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly (P<0.05). Conclusion: That histamine inhibits cell cycle progress of A375 cells is one of the possible mechanisms of proliferation arrest of A375 cells elicited by histamine. Histamine mediates apoptosis in A375 cells that may be caspase-dependent through mitochondria routine. Histamine with high concentration inhibits growth of A375 cells in vitro by interfering proliferation and inducing apoptosis of cells.

Comparison between synthetic retinoid CD437 and acitretin inhibiting melanoma A375 cell in vitro

Objective： To investigate the effects of synthetic retinoid CD437 and acitretin on cell proliferation, apoptosis, cycle arrest and Bax/ Bcl-2 protein expression of melanoma A375 cell, Methods：MTT assay was used to determine the anti-proliferative effects of CD437 and acitretin on melanoma A375 cell, Flow cytometry was performed to investigate the influence of CD437 and acitretin on cell cycle and cell apoptosis. SABC immunocytochemistry was employed for detection of Bax/bcl-2 protein expressions. Results：10^-5 mol/L CD437 was more effective than acitretin in inhibiting proliferation and inducing apoptosis of A375 cell after 24 h treatment, growth inhibiting ratio and apoptosis ratio（58.6%vs43.25% and 28.03%vs17.13%, P 〈 0.05 respectively）. CD437 promoted G0/G1 arrest in melanoma A375 cell, however acitretin could not. CD437 and acitretin could up-regulate the expression of Bax protein and downregulate the expression of bcl-2 protein（P 〈 0.05）. Conclusion：CD437 is more effective than acitretin in inhibiting proliferation and inducing apoptosis and cycle arrest on A375 cell, CD437 may have more potentialities than acitretin for subsidiary treatment of melanoma. Mitochondrial apoptosis pathway is partially involved in two drugs inducing apoptosis on A375 cell.

Directly targeting BAX for drug discovery:Therapeutic opportunities and challenges

For over two decades,the development of B-cell lymphoma-2(Bcl-2)family therapeutics has primarily focused on anti-apoptotic proteins,resulting in the first-in-class drugs called BH3 mimetics,especially for Bcl-2 inhibitor Venetoclax.The pro-apoptotic protein Bcl-2-associated X protein(BAX)plays a crucial role as the executioner protein of the mitochondrial regulated cell death,contributing to organismal development,tissue homeostasis,and immunity.The dysregulation of BAX is closely associated with the onset and progression of diseases characterized by pathologic cell survival or death,such as cancer,neurodegeneration,and heart failure.In addition to conducting thorough investigations into the physiological modulation of BAX,research on the regulatory mechanisms of small molecules identified through biochemical screening approaches has prompted the identification of functional and potentially druggable binding sites on BAX,as well as diverse all-molecule BAX modulators.This review presents recent advancements in elucidating the physiological and pharmacological modulation of BAX and in identifying potentially druggable binding sites on BAX.Furthermore,it highlights the structural and mechanistic insights into small-molecule modulators targeting diverse binding surfaces or conformations of BAX,offering a promising avenue for developing next-generation apoptosis modulators to treat a wide range of diseases associated with dysregulated cell death by directly targeting BAX.

白术多糖抗神经细胞缺氧性凋亡的机制研究

目的:探讨白术多糖抗神经细胞缺氧性凋亡的机制。方法:研究分为正常对照组、凋亡阳性组、白术多糖0.025g/L组、白术多糖0.05g/L组、白术多糖0.1g/L组、白术多糖0.25g/L组。采用"Neurobasal+B27"体外神经细胞无血清培养,免疫细胞化学鉴定神经细胞,MTT测定药物毒性,Rh-123染色流式细胞仪检测线粒体损伤,RT-PCR及免疫细胞化学测定Caspase-3、Bax、Bcl-2 mRNA及蛋白表达。结果:与凋亡阳性组比较,白术多糖在0.025g/L^0.1g/L降低缺氧的神经细胞线粒体损伤,0.025g/L^0.05g/L下调缺氧的神经细胞Caspase-3 mRNA的表达,0.05g/L下调缺氧的神经细胞Bax mRNA的表达,0.025g/L^0.25g/L下调缺氧的神经细胞Caspase-3和Bax蛋白表达,0.025g/L^0.25g/L上调缺氧的神经细胞Bcl-2蛋白表达,0.025g/L^0.05g/L提高Bcl-2/Bax mRNA及0.025g/L^0.1g/L提高Bcl-2/Bax蛋白的比例(P<0.05)。结论:白术多糖在一定发范围内能有效地抑制神经细胞缺氧性凋亡,其机理是降低凋亡基因及蛋白产生,上调抗凋亡蛋白产生,提高Bcl-2/Bax比例。

Effects of penehyclidine hydrochloride on apoptosis of lung tissues in rats with traumatic acute lung injury

Objective： To investigate the effects ofpenehyclidine hydrochloride on apoptosis of lung tissue cells and its mechanism in acute lung injury following blunt chest trauma in rats. Methods： Sprague Dawley （SD） rats （n=54） weighing （250-25） g were divided equally and randomly into three groups： normal control group （C group, n= 18）, trauma model group （T group, n= 18） and penehyclidine hydrochloride treatment group （P group, n=18）. Each group was further divided into three subgroups according to the time points of 3, 12 and 24 hours after experiment （at each time point, n=6 for each subgroup）. Rats of P group were intraperitoneally injected with penehyclidine hydrochloride for 2 mg/kg immediately after blunt chest trauma and rats in its 24 hours subgroup were once again injected with penehyclidine hy- drochloride in the same dose 12 hours after injury. Lung tissue samples were collected at every time point and cell apoptosis in lung tissues were measured by TUNEL. Apoptotic index （AI） was calculated, expressions of bax and bcl-2 were detected by immunohistochemical staining of SABC, and lung tissue sections were taken for light and electron microscopic observation. Results： As compared with C group, at every time point, AI and expressions ofbax and bcl-2 in T group were higher （P〈0.05）, and the ratio of bcl-2/bax markedly decreased （P〈0.05）, especially in the 24 hours subgroup. The ratio in T group （0.468±0.007） was lower than that in C group （1.382±0.058, t=12.5, P〈0.01）. Lung tissue injuries were significant under a light microscope, and the number of apoptotic cells increased obviously under a transmission electron microscope. As compared with T group at the same phase, AI and expression of bax decreased in P group （P〈0.05 and P〈0.01）, while the expression of bcl-2 increased significantly （P〈0.01）, and the ratio of bcl-2/bax markedly increased （P〈0.05）, especially in the 24 hours subgroup. The ratio in P group （1.012-0.070） was much higher than that in T group （0.468±0.007, t=-8.3, P〈0.01）. The injury of lung tissues was relieved, and apoptosis of cells decreased obviously under a transmission electron microscopic observation. Conclusions： Apoptosis and expressions ofbax and bcl-2 in lung tissues might be involved in the pathogenesis of lung injury induced by blunt chest trauma. Penehyclidine hydrochloride can alleviate lung injuries by inhibiting apoptosis of lung tissue cells, during which effects ofpenehyclidine hydrochloride on regulating expressions ofbax and bcl-2 may play an important role.

木犀草素对小鼠T淋巴细胞体外增殖及凋亡的作用

目的：研究木犀草素对小鼠T淋巴细胞体外增殖及凋亡作用的影响。方法：设置刀豆蛋白A（Con A）组和空白组,设置3个木犀草素药物组,终质量浓度分别为2.5,5,10 mg·L-1,细胞毒性活性检测-8（CCK-8）法检测各组细胞增殖情况,末端脱氧核苷酸转移酶介导的d UTP缺口末端标记测定法（TUNEL）和Annexin V-FITC/PI双染法检测各组细胞凋亡情况,蛋白免疫印迹法（Western blot）检测各组细胞凋亡通路蛋白B淋巴细胞瘤-2（B-cell lymphoma-2,Bcl-2）,Bcl-2相关X蛋白（Bcl-2-associated X protein,Bax）表达水平。结果：CCK-8实验结果显示3个木犀草素药物组细胞数明显低于Con A组和空白组（P〈0.01）,差异有统计学意义。TUNEL实验结果显示,Con A组的凋亡细胞数量显著低于3个木犀草素药物组（P〈0.01）,差异有统计学意义。流式细胞仪检测结果显示3个木犀草素药物组的细胞凋亡率显著高于Con A组和空白组（P〈0.01）,细胞凋亡率随着药物浓度增加而增高,呈明显的量-效关系。Western blot检测结果显示,2.5,5 mg·L-1木犀草素药物组中Bcl-2表达量高于对照组,Bax表达量低于对照组;10 mg·L-1药物组中Bcl-2表达量低于对照组,Bax表达量高于对照组。结论：2.5,5,10 mg·L-1木犀草素能够抑制T淋巴细胞增殖,能够诱导T淋巴细胞凋亡,10 mg·L-1木犀草素可能主要通过下调Bcl-2,上调Bax影响线粒体凋亡通路诱导细胞凋亡,2.5,5 mg·L-1木犀草素可能通过其他通路诱导细胞凋亡。

Synergistic impacts of rifampicin and doxorubicin against thioacetamide-induced hepatocellular carcinoma in rats

Background and aims:Combination therapy is a promising new strategy that has been proposed to increase the efficacy of cancer treatment.We aimed to investigate the anti-cancer activity of rifampicin monotherapy and its combination with doxorubicin against hepatocellular carcinoma(HCC).Materials and methods:The in vitro half maximal inhibitory concentration(IC50)and selectivity index(SI)of the drugs under investigation against HepG2 and human lung fibroblast(WI38)cell lines were determined.For the in vivo experiment,male Sprague-Dawley albino rats were injected with thioacetamide at 200 mg/kg twice a week for 90 days;HCC development was confirmed histopathologically.Following HCC induction,the rats were treated with intraperitoneal doxorubicin,rifampicin,or their combination for 45 or 90 days.After sacrifice,the livers were examined histopathologically.The levels of aminotransferases,albumin,bilirubin,malondialdehyde,superoxide dismutase(SOD),catalase(CAT),total antioxidant capacity(TAC),and nitric oxide were measured by spectrophotometry.Alphafetoprotein,cancer antigen 19-9,tumor necrosis factor-alpha,interleukin-6,Bcl-2-associated X protein,caspase 3,caspase 8,and p53 were estimated using ELISA.Results:In vitro,the combination of doxorubicin and rifampicin showed the highest SI of 3.43.In vivo,among the measured markers,the levels of TAC,CAT,SOD,and p53 decreased(P<0.001)and the rest of the measured marker levels increased(P<0.001)in the HCC-bearing rats;after treatment in all groups,all these changes improved toward normal in a time-dependent manner.The combination of doxorubicin and rifampicin optimized the effects of the two individual drugs and exerted the best antioxidant effects.Conclusions:In general,compared with rifampicin or doxorubicin alone,combination therapy has favorable outcomes.Based on our results,the combination of rifampicin and doxorubicin might be applicable for HCC chemotherapy.