Association between polymorphisms in connexin 40 gene (Cx40) and risk of atrial fibrillation: a meta-analysis based on 3,452 subjects.

INTRODUCTION: Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with heart failure and stroke, leading sometimes to death. But the pathogenesis of AF remains unclear. Numerous studies have investigated whether the connexin 40 (Cx40) polymorphisms influences the risk of AF, but the results are controversial. METHODS: We searched English and Chinese databases and calculated the odds ratio (OR) and 95% confidence interval (CI) to examine the existence of genetic associations between the Cx40 polymorphisms and the risk of AF. All relevant studies were screened and meta-analyzed using Review Manager 5.0. RESULTS: A total of 12 studies, including 10 studies for -44 polymorphism (rs35594137) and 4 studies for -26 polymorphism (rs10465885), were identified for the meta-analysis. For -44 polymorphism, the results showed a significantly increased risk of AF in the five genetic models in the overall analysis. Furthermore, in subgroup analysis, increased AF risks were also observed in Asian and non-Asian populations. For -26 polymorphism, the overall OR revealed an increased risk of AF in dominant model. In subgroup analysis, increased AF risk was only found in recessive genetic model of the Asian population. CONCLUSIONS: The Cx40 polymorphisms were positively associated with AF in both populations, especially on -44 polymorphism.

Xinfuli granule alleviates metabolic remodeling through inhibition of endoplasmic reticulum stress and mitochondrial injury in heart failure.

ETHNOPHARMACOLOGICAL RELEVANCE: "Qi deficiency-blood stasis-water retention syndrome" was the most frequent syndrome among heart failure(HF) patients according to Traditional Chinese Medicine (TCM) theory. Xinfuli Granule (XG) was constructed on the basis of classical formula "Baoyuan decoction" to enhance the function of nourishing Qi, activating blood and removing water retention. XG treatment has obtained clinical effect on HF patients. AIM OF THE STUDY: The regulation of XG on energy metabolism of HF was investigated with special focus on endoplasmic reticulum stress (ERS) and mitochondrial function. MATERIALS AND METHODS: Components of XG was acquired by UPLC/Q-TOF-MS Analysis, left anterior descending ligation(LAD)-induced HF rats model and hypoxia-ischemia(H-I)-induced H9c2 cells model were constructed to evaluate the effect of XG treatment. Cardiac function was evaluated by echocardiographic parameters, energy metabolism was evaluated by metabolites and ATP/ADP/AMP levels in blood samples, cardiomyocyte morphology and myocardial fibrosis were assessed by HE staining and Masson staining, mitochondrial ultrastructure was observed under Transmission Electron Microscope, viability and apoptosis rate of H9c2 cells was detected by cell counting kit-8 reaction and flow cytometry analysis, respectively. Mitochondrial membrane potential (MMP) of H9c2 cells was observed by JC-1 kit under fluorescent microscope, expression of peroxisome-proliferator-activated receptor (PPAR)-coactivator (PGC1α), ERS-related genes and RHOA/ROCK pathway were analysed by Quantitative Real-time PCR (RT-qPCR) and Western Blot. RESULTS: Here, we showed that XG alleviated cardiac metabolic remodeling and stimulated ATP production through elevated expression of PGC1α in HF rats. XG also helped recover mitochondrial deformation and decrease apoptosis rate accompanied by an increase of the Bcl2/Bax ratio and the mitochondrial membrane potential in hypoxia-ischemia (H-I) H9c2 cells. In addition, we found that XG downregulated ERS-related proteins ATF4, CHOP, Phospho-eIF2α, and Phospho-PERK, and suppressed the RHOA/ROCK pathway, which served as a potential mediator of ERS. CONCLUSIONS: we found that XG improved energy production by alleviating mitochondrial injury and inhibiting ERS in heart failures mediated by the RHOA/ROCK pathway.

Complement use of Chinese herbal medicine after percutaneous coronary intervention: a prospective observational study.

BACKGROUND: Chinese herbal medicine is widely used as a complement or alternative treatment in coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI) in China. We compared the incidence of the major adverse cardiovascular event (MACE) of CAD patients with or without the complement use of Chinese herbal medicine after PCI. METHODS: In this prospective, observational study that was conducted from September 2016 to August 2019 in Fuwai Hospital (China), we followed up consecutive patients who received PCI treatment for two years. MACE was defined as the composite all-cause mortality, revascularization, and myocardial infarction (MI) and was compared between those using (integrative medicine group) or those not using Chinese herbal medicine as an additional treatment to standard Western medicine, with unadjusted (Kaplan-Meier curves) and risk-adjusted (multivariable Cox regression) analyses. RESULTS: A total of 5942 patients after PCI were enrolled in this study, and 5453 patients were included in the final analysis (4189 [76.8%] male; mean age: 61.9 ± 9.9% years). During the follow-ups, 2932 (53.8%) patients used only Western medicine while 2521(46.2%) patients had used Chinese herbal medicine as an additional treatment to standard Western medicine. Patients in the integrative medicine group (IM group) were older than the Western medicine group (WM group), had more females and less previous MI. The incidence of MACE was 15.3% (449/2932) in WM group and 11.54% (291/2521) in IM group. Cox regression analysis showed that cumulative incidence of MACE was 27% lower in patients of the IM group than those in WM group (hazard ratio = 0.73; 95% CI: 0.63-0.85; P < 0.0001). CONCLUSIONS: For CAD patients after PCI treatment, complement use of Chinese herbal medicine is associated with a lower 2-year MACE incidence. Randomized prospective studies are warranted to provide higher levels of benefit evidence in these patients.

MiR-199a-5p promotes ferroptosis-induced cardiomyocyte death responding to oxygen-glucose deprivation/reperfusion injury via inhibiting Akt/eNOS signaling pathway.

Myocardial ischemia/reperfusion (I/R) injury is associated with the poor outcome and higher mortality after myocardial infarction. Recent studies have revealed that miR-199a-5p participates in the process of myocardial I/R injury, but the precise roles and molecular mechanisms of miR-199a-5p in myocardial I/R injury remain not well-studied. Ferroptosis has been proposed to promote cardiomyocyte death, closely associated with myocardial I/R injury. Herein, the present study aimed to explore the function and mechanisms by which miR-199a-5p regulates whether miR-199a-5p contributes to ferroptosis-induced cardiomyocyte death responding to oxygen-glucose deprivation/reoxygenation (OGD/R) injury, an in vitro model of myocardial I/R injury focusing on Akt/eNOS signaling pathway. The results found that ferroptosis-induced cardiomyocyte death occurs and is accompanied by an increase in miR-199a-5p level in OGD/R-treated H9c2 cells. MiR-199a-5p inhibitor ameliorated ferroptosis-induced cardiomyocyte death as evidenced by the increased cell viability, the reduced reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) activity, malondialdehyde (MDA) and Fe2+ contents, and the up-regulated glutathione (GSH)/glutathione disulphide (GSSG) ratio as well as glutathione peroxidase 4 (Gpx4) protein expression in H9c2 cells-exposed to OGD/R, while miR-199a-5p mimic had the opposite effects. In addition, OGD/R led to the inhibition of Akt/eNOS signaling pathway, which was also blocked by miR-199a-5p inhibitor and aggravated by miR-199a-5p mimic. Furthermore, LY294002, an inhibitor of Akt/eNOS signaling pathway, abrogated miR-199a-5p inhibitor-induced the reduction of ferroptosis-induced cardiomyocyte death. In summary, our findings demonstrated that miR-199a-5p plays a central role in stimulating ferroptosis-induced cardiomyocyte death during ischemic/hypoxic injury via inhibiting Akt/eNOS signaling pathway.

Essen score in the prediction of cerebrovascular events compared with cardiovascular events after ischaemic stroke or transient ischaemic attack: a nationwide registry analysis.

BACKGROUND: The Essen risk score improves stratification of patients with acute ischemic stroke by early stroke recurrence. Recent study showed it could also predict myocardial infarction (MI). This study aimed to compare the Essen score's ability to predict cerebrovascular events with compared cardiovascular events. METHODS: We included patients with acute ischaemic stroke or transient ischaemic attack within seven days from the Third China National Stroke Registry. One-year cumulative event rates of combined vascular events (a composite of MI, stroke recurrence or vascular death) and cardiac events (a composite of MI, heart failure or cardiac death) was estimated using the Kaplan-Meier method. The predictive value of the Essen score was assessed with C-statistics. In multivariate Cox regression analyses, we assessed whether Essen score, etiological subtype and imaging parameters were associated with outcomes. RESULTS: Of 13,012 patients were included, the cumulative one-year event rates were 10.03% for combined vascular events and 0.77% for cardiac events, respectively. Compared with those with an Essen score < 3, patients with an Essen score ≥ 3 were more likely to have a subsequent combined vascular event [hazard ratio (HR) = 1.39, 95% CI: 1.24-1.55] and cardiac events (HR = 2.30, 95% CI: 1.53-3.44). The score tended to be more predictive of the risk of MI (C-statistic = 0.63, 95% CI: 0.55-0.71) and cardiac events (C-statistic = 0.62, 95% CI: 0.56-0.67) than stroke recurrence (C-statistic = 0.55, 95% CI: 0.54-0.57) and combined vascular events (C-statistic = 0.56, 95% CI: 0.54-0.57). In multivariable analysis after adjusted Essen score, patients with multiple acute infarctions or single acute infarctions and large artery atherosclerosis subtype were independently associated with an increased risk of combined vascular events. While the cardioembolism subtype was associated with an increased risk of cardiac events. CONCLUSIONS: The Essen score is potentially more suitable for risk stratification of cardiovascular events than cerebrovascular events. Moreover, future predictive tools should take brain imaging findings and cause of stroke into consideration.

Qishen capsule safely boosts cardiac function and angiogenesis via the MEK/ERK pathway in a rat myocardial infarction model.

BACKGROUND: Qishen (QS) capsules, a Traditional Chinese Medicine, has been widely used to treat coronary heart disease in China. However, evidence of its effectiveness remains unclear. METHODS: To explore whether QS has cardioprotective efficacy and/or promotes angiogenesis after myocardial infarction (MI), we performed experiments in a preclinical rat MI model. One month after left anterior descending coronary artery ligation, the rats received either QS solution (0.4 g/kg/day) or the same volume of saline by intragastric injection for four weeks. RESULTS: Echocardiographic and hemodynamic analyses demonstrated relatively preserved cardiac function in MI rats administered QS. Indeed, QS treatment was associated with reduced infarct scar size and heart weight index, and these beneficial effects were responsible for enhancing angiogenesis. Mechanistically, QS treatment increased phosphorylation of protein kinase B (Akt) and downregulated phosphorylation of mitogen-activated protein kinase/extracellular-regulated kinase (MEK/ERK). CONCLUSIONS: QS therapy can improve the cardiac function of rats after MI by an underlying mechanism involving increased angiogenesis, at least partially via activation of the Akt signaling pathway and inhibition of MEK/ERK phosphorylation.

[RAD51 regulates REV1 recruitment to DNA double-strand break sites].

REV1 is one of the major Y-family DNA polymerases. It not only functions as a scaffold protein to mediate other specialized DNA polymerases to sites of lesions, but also inserts deoxycytidine across the lesion strand during translesion DNA synthesis (TLS). Meanwhile, REV1 has been reported to be involved in homologous recombination (HR) repair. Here we further explore the roles of REV1-interacting proteins RAD51 and RAD51C in REV1-mediated DNA double-strand break (DSB) repair. We found that RAD51 but not RAD51C regulates REV1 recruitment to DSB sites via pulsed laser microirradiation. Interestingly, immunofluorescence staining exhibits that REV1 also regulates RAD51 focus formation in response to CPT treatment. These results suggest that REV1 and RAD51 might be mutually dependent on each other in the REV1-related HR pathway.

Xinfuli Granule improves post-myocardial infarction ventricular remodeling and myocardial fibrosis in rats by regulating TGF-ß/Smads signaling pathway.

BACKGROUND: Recent clinical and experimental studies have confirmed the effects of Xinfuli Granule (XG), a compound Chinese medicine in the prevention and treatment of heart failure (HF). This study aimed to investigate the effects and the mechanisms of XG on ventricular reconstruction in rats with acute myocardial infarction (AMI). METHODS: Sprague-Dawley rats were subjected to left anterior descending branch ligation. The rats that survived 24 h were randomly assigned to five groups: medium-dose of XG group (MI+XGM), high-dose of XG group (MI+XGH), carvedilol group (MI+C), medium-dose of XG + carvedilol group (MI+C+XGM). Fourteen rats underwent identical surgical procedures without artery ligation, serving as sham controls. At 28 days, left ventricular weight to body weight (LVW/BW) and heart weight to body weight (HW/BW) were calculated; left ventricular ejection fraction (LVEF), left ventricular shortening fraction (LVFS), left ventricular internal diameter at systole (LVIDS) were measured by ultrasound; HE staining, Masson staining, and Sirius red staining were used to assess the myocardial pathological and physiological changes as well as myocardial fibrosis area and non-infarct zone I/III collagen ratio. Expression of Smad3 were detected and analyzed by Western blot, immunohistochemistry and immunofluorescence. P-Smad3, Smad2 and Smad7 in the TGF-ß/Smads signaling pathway were also analyzed by Western blot. RESULTS: The LVIDS (P < 0.01), HW/BW (P < 0.05), type I/III collagen ratio (P < 0.01) and myocardial collagen (P < 0.01) decreased significantly while the LVW/BW, LVFS (P < 0.05) increased significantly in MI+XGM group as compared with those in other groups. The expression of key signal molecules of the TGF-ß/Smads signaling pathway, including Smad3, P-Smad3 and Smad2 protein were decreased, while the expression of Smad7 increased in both XG and carvedilol treatment groups as compared to those of the MI group (all P < 0.01). Immunohistochemistry and immunofluorescence further confirmed the down-regulated Smad3 expression. CONCLUSION: XG can improve ventricular reconstruction and inhibit myocardial fibrosis in rats with AMI by regulating TGF-ß/Smads signaling pathway.

A network meta-analysis of eight chemotherapy regimens for treatment of advanced ovarian cancer.

This study compared the short-term efficacies of different chemotherapy regimens in the treatment of advanced ovarian cancer (AOC) through pair-wise and network meta-analyses (NMA). Randomized controlled trials (RCTs) identified in a comprehensive online literature search met our inclusion criteria. Direct and indirect evidence was combined to compare odds ratios (OR) and surfaces under the cumulative ranking curves (SUCRA) across the different treatment regimens. Twelve eligible RCTs were finally included, involving eight regimens (Paclitaxel + Carboplatin [PC], Gemcitabine + Carboplatin [GC], Carboplatin, Pegylated Liposomal Doxorubicin + Carboplatin [PLD + Carboplatin], Paclitaxel, Paclitaxel + Carboplatin + Topotecan [PC + Topotecan], Paclitaxel + Carboplatin + Epirubicin [PC + Epirubicin] and Docetaxel + Carboplatin [DC]). The NMA results revealed that in terms of overall response rate (ORR) and disease control rate (DCR), PC (ORR: OR=2.59, 95%CI=1.20-6.22; DCR: OR=2.58, 95%CI=1.05-6.82) and GC (ORR: OR=2.08, 95%CI=1.08-4.37; DCR: OR=2.43, 95%CI=1.07-5.80) were more effective against AOC than Carboplatin alone. Similarly, PC (OR=0.21, 95%CI=0.05-0.69), GC (OR=0.31, 95%CI=0.09-0.90) and PLD + Carboplatin (OR=0.22, 95%CI=0.04-0.92) slowed disease progression better than Carboplatin alone. We also found that PC was more efficacious against AOC than Carboplatin or Paclitaxel single-agent chemotherapy. Combination chemotherapy is thus recommended for AOC, and should guide subsequent drug development and treatment strategies.

[Temporal and spatial variability of livestock and poultry productions and manure nutrients in Shanxi Province, China].

China's livestock and poultry productions have changed significantly in the last three decades, from mainly traditional and small-scale systems in early 1980s towards more intensive and industrialized ones in recent years, due to the booming economy and the changes in people' diet. There is an urgent need to increase the understanding of the changes in the livestock and poultry productions and the impact of manure recycle on the environment. Here, we reported on a systematic and quantitative analysis on the temporal and spatial variability of livestock and poultry productions and manure nutrients in Shanxi Province, China, using a large database and a coupled food chain nutrient flow model (NUFER) with GIS. In the period of 1978 to 2012, total animal manure production increased from 1.61 x 107 t to 2.75 x 107 t by 171%. The manure N increased from 7.74 x 104 t to 17.32 x 104 t, and the manure P from 1.09x104 t to 3.39x104 t. Besides the huge increase in total animal manure production, the distribution of animal manure was much uneven among regions, with high amounts of manure N and P per unit land in the north, middle and southeastern regions and low values in the north-central and southwestern regions, based on the results of 2012. The uneven distribution of manure was the combined effect of regional specializations in livestock and poultry productions and related policies. Our findings suggested that optimizing the structure of livestock and poultry productions and enhancing interregional collaborations on nutrient management could be two effective measures for reducing pollution and environmental risks, while achieving efficient and sustainable use of manure nutrient in the long term.

Soluble receptor for advanced glycation end-products protects against ischemia/reperfusion-induced myocardial apoptosis via regulating the ubiquitin proteasome system.

AIM: Apoptosis participated in the pathological process of myocardial ischemia/reperfusion (I/R) injury. Previous studies have reported that endogenous substance sRAGE protect against I/R injury through inhibiting myocardial apoptosis. But the mechanisms are currently unknown. Prior work has demonstrated that ubiquitin proteasome system (UPS) dysfunction is closely related to apoptosis. We explored the potential role of UPS in the effect of sRAGE inhibition on I/R-induced myocardial apoptosis. METHODS AND RESULTS: Adult male C57BL mice treated with sRAGE (100µg/day, i.p.) or saline were performed to ligate left anterior descending coronary artery (LAD) as an in vivo model. As an in vitro model, primary murine cardiomyocytes pretreated with sRAGE or sRAGE-containing adenovirus were simulated I/R by "ischemia buffer". The TUNEL and caspase-3 activity were assessed. Also the activity and expression of proteasome were detected. sRAGE decreased the number of TUNEL-positive cardiomyocytes and caspase-3 activity, however, the inhibition of sRAGE on I/R-induced apoptosis was abolished by proteasome inhibitor Bortezimb (BTZ). sRAGE inhibited the decreased proteasome activity, also the reduction in protein and gene levels of ß1i and ß5i following I/R. Suppression of STAT3 blocked the inhibition of sRAGE on apoptosis induced by I/R. The chromatin immunoprecipitation (CHIP) results confirmed that sRAGE promoted activating STAT3 binding to ß1i and ß5i promoter. CONCLUSIONS: Our data suggest that the inhibition of sRAGE on I/R-induced apoptosis is associated with activation and expression of proteasome, including improved proteasome activity and elevated ß1i and ß5i expression mediated by STAT3 activation. We predict that sRAGE is a novel intervention to target UPS activation for preventing and treating myocardial apoptosis.

Xinfuli improves cardiac function, histopathological changes and attenuate cardiomyocyte apoptosis in rats with doxorubicin-induced cardiotoxicity.

BACKGROUND: Xinfuli Granule (XG), a compound Chinese herbal medicine, has been effectively used in China for the treatment of heart failure for more than fifty years. This study aimed to investigate the effects and the underlying mechanisms of Xinfuli in rats with doxorubicin-induced cardiotoxicity. METHODS: Sprague-Dawley rats were treated with intraperitoneal injection of Doxorubicin (DOX, 2.5 mg/kg per week) for six weeks, and then randomly divided into four groups which received intragastrically administration of normal saline (control group) or different dosage of XG (0.675 g/kg per day, 1.35 g/kg per day, and 2.7g/kg per day, respectively) for six weeks. Transthoracic echocardiography was performed to evaluate the left ventricular fractional shortening (LVFS) and left ventricular ejection fraction (LVEF) before and after the XG treatment and histopathologic changes were also examined. Myocardial cell apoptosis was detected by TUNEL staining. The expression of related genes and proteins were analyzed using immunohistochemical staining. RESULTS: Compared to those in the control group, rats in XG treated groups showed significantly improved cardiac function and milder cardiac histopathological changes, lower cardiomyocyte apoptosis index, higher expression of Bcl-2 and lower expression of Bax. CONCLUSIONS: Administration of XG improves cardiac function and histopathological changes in rats with doxorubicin-induced cardiotoxicity. These effects are associated with inhibition of cardiomyocyte apoptosis, perhaps via regulation of Bcl-2 and Bax protein expression.

A soluble receptor for advanced glycation end-products inhibits myocardial apoptosis induced by ischemia/reperfusion via the JAK2/STAT3 pathway.

sRAGE can protect cardiomyocytes from apoptosis induced by ischemia/reperfusion (I/R). However, the signaling mechanisms in cardioprotection by sRAGE are currently unknown. We investigated the cardioprotective effect and potential molecular mechanisms of sRAGE inhibition on apoptosis in the mouse myocardial I/R as an in vivo model and neonatal rat cardiomyocyte subjected to ischemic buffer as an in vitro model. Cardiac function and myocardial infarct size following by I/R were evaluated with echocardiography and Evans blue/2,3,5-triphenyltetrazolium chloride. Apoptosis was detected by TUNEL staining and caspase-3 activity. Expression of the apoptosis-related proteins p53, Bax, Bcl-2, JAK2/p-JAK2, STAT3/p-STAT3, AKT/p-AKT, ERK/p-ERK, STAT5A/p-STAT5A and STAT6/p-STAT6 were detected by western blot analysis in the presence and absence of the JAK2 inhibitor AG 490. sRAGE (100 µg/day) improved the heart function in mice with I/R: the left ventricular ejection fraction and fractional shortening were increased by 42 and 57%, respectively; the infarct size was decreased by 52%, the TUNEL-positive myocytes by 66%, and activity of caspase-3 by 24%, the protein expression of p53 and ratio of Bax to Bcl-2 by 29 and 88%, respectively; protein expression of the p-JAK2, p-STAT3 and p-AKT were increased by 92, 280 and 31%, respectively. sRAGE have no effect on protein expression of p-ERK1/2, p-STAT5A and p-STAT6 following by I/R. sRAGE (900 nmol/L) exhibited anti-apoptotic effects in cardiomyocytes by decreasing TUNEL-positive myocytes by 67% and caspase-3 activity by 20%, p53 protein level and the Bax/Bcl-2 ratio by 58 and 86%, respectively; increasing protein expression of the p-JAK2 and p-STAT3 by 26 and 156%, respectively, p-AKT protein level by 33%. The anti-apoptotic effects of sRAGE following I/R were blocked by JAK2 inhibitor AG 490. The effect of sRAGE reduction on TUNEL-positive myocytes and caspase-3 activity were abolished by PI3K inhibitor LY294002, but not ERK 1/2 inhibitor PD98059. These results suggest that sRAGE protects cardiomyocytes from apoptosis induced by I/R in vitro and in vivo by activating the JAK2/STAT3 signaling pathway.

Circulating E3 ligases are novel and sensitive biomarkers for diagnosis of acute myocardial infarction.

Ubiquitin ligase (E3) is a decisive element of the ubiquitin-proteasome system (UPS), which is the main pathway for intracellular protein turnover. Recently, circulating E3 ligases have been increasingly considered as cancer biomarkers. In the present study, we aimed to determine if cardiac-specific E3 ligases in circulation can serve as novel predictors for early diagnosis of acute myocardial infarction (AMI). By screening and verifying their tissue expression patterns with microarray and real-time PCR analysis, six of 261 E3 ligases, including cardiac-specific Rnf207 and cardiac- and muscle-enriched Fbxo32/atrogin-1, Trim54/MuRF3, Trim63/MuRF1, Kbtbd10/KLHL41, Asb11 and Asb2 in mouse heart, were selected for the present study. In the AMI rats, the levels of five E3 ligases including Rnf207, Fbxo32, Trim54, Trim63 and Kbtbd10 in the plasma were significantly increased compared with control animals. Especially, the plasma levels of Rnf207 was markedly increased at 1 h, peaked at 3 h and decreased at 6-24 h after ligation. Further evaluation of E3 ligases in AMI patients confirmed that plasma Rnf207 level increased significantly compared with that in healthy people and patients without AMI, and showed a similar time course to that in AMI rats. Simultaneously, plasma level of cardiac troponin I (cTnI) was measured by ELISA assays. Finally, receiver operating characteristic (ROC) curve analysis indicated that Rnf207 showed a similar sensitivity and specificity to the classic biomarker troponin I for diagnosis of AMI. Increased cardiac-specific E3 ligase Rnf207 in plasma may be a novel and sensitive biomarkers for AMI in humans.

An HIV-1 envelope immunogen with W427S mutation in CD4 binding site induced more T follicular helper memory cells and reduced non-specific antibody responses.

The CD4 binding site (CD4BS) of the HIV-1 envelope glycoprotein (Env) contains epitopes for broadly neutralizing antibody (nAb) and is the target for the vaccine development. However, the CD4BS core including residues 425-430 overlaps the B cell superantigen site and may be related to B cell exhaustion in HIV-1 infection. Furthermore, production of nAb and high-affinity plasma cells needs germinal center reaction and the help of T follicular helper (Tfh) cells. We believe that strengthening the ability of Env CD4BS in inducing Tfh response and decreasing the effects of the superantigen are the strategies for eliciting nAb and development of HIV-1 vaccine. We constructed a gp120 mutant W427S of an HIV-1 primary R5 strain and examined its ability in the elicitation of Ab and the production of Tfh by immunization of BALB/c mice. We found that the trimeric wild-type gp120 can induce more non-specific antibody-secreting plasma cells, higher serum IgG secretion, and more Tfh cells by splenocyte. The modified W427S gp120 elicits higher levels of specific binding antibodies as well as nAbs though it produces less Tfh cells. Furthermore, higher Tfh cell frequency does not correlate to the specific binding Abs or nAbs indicating that the wild-type gp120 induced some non-specific Tfh that did not contribute to the production of specific Abs. This gp120 mutant led to more memory Tfh production, especially, the effector memory Tfh cells. Taken together, W427S gp120 could induce higher level of specific binding and neutralizing Ab production that may be associated with the reduction of non-specific Tfh but strengthening of the memory Tfh.

Effects of endosulfan on the immune function of erythrocytes, and potential protection by testosterone propionate.

While the immunotoxicity of endosulfan has been studied, little is known about its influence on immune function associated with erythrocytes (RBC). The aim of this study was to investigate the possible effects of endosulfan, and any possible mitigation by testosterone propionate (TP), on erythrocyte immune function in a mouse model. To this end, rosette formation [as erythrocyte C3b receptor(E-C3bR) and erythrocyte immune complexes (E-IC)], as well as measures of the erythrocyte C3b receptor rosette-forming enhancing rate (RFER; reflecting immunoenhancing factor activity) and C3b receptor rosette-forming inhibitory rate (RFIR; reflecting immunosuppressive factor activity) were performed. The effects of RBC on regulating NK cell function or T-cell adherence were also analyzed. Lastly, to begin to assess potential mechanisms by which endosulfan could impact on the measured endpoints, CD35, CD58, and CD59 expression on RBC was evaluated; expression/mRNA levels of complement receptor I-related gene/protein y (Crry) on cells/splenic tissues was also assessed. The data show that E-C3bR rosette ratios decreased, and those of E-IC increased, due to endosulfan treatment. In these hosts, RFER (i.e., immunoenhancing factor in plasma) was decreased, but RFIR (i.e., immunosuppressive factor) was unchanged.There were no clear effects from endosulfan on RBC regulatory function against NK or T-cells. Lastly, Crry mRNA levels in tissues/cells from these mice were significantly decreased; however, CD59 and CD58 expression levels were unaffected. The data also show that TP co-treatment reversed or mitigated effects of endosulfan on each endpoint, in part, by two possible mechanisms; the TP may be increasing the activity of the innate immune enhancing factor, or, an anti-oxidant effect of TP might help to protect membrane structures and increase Crry stability on the RBC.

Ago2 facilitates Rad51 recruitment and DNA double-strand break repair by homologous recombination.

DNA double-strand breaks (DSBs) are highly cytotoxic lesions and pose a major threat to genome stability if not properly repaired. We and others have previously shown that a class of DSB-induced small RNAs (diRNAs) is produced from sequences around DSB sites. DiRNAs are associated with Argonaute (Ago) proteins and play an important role in DSB repair, though the mechanism through which they act remains unclear. Here, we report that the role of diRNAs in DSB repair is restricted to repair by homologous recombination (HR) and that it specifically relies on the effector protein Ago2 in mammalian cells. Interestingly, we show that Ago2 forms a complex with Rad51 and that the interaction is enhanced in cells treated with ionizing radiation. We demonstrate that Rad51 accumulation at DSB sites and HR repair depend on catalytic activity and small RNA-binding capability of Ago2. In contrast, DSB resection as well as RPA and Mre11 loading is unaffected by Ago2 or Dicer depletion, suggesting that Ago2 very likely functions directly in mediating Rad51 accumulation at DSBs. Taken together, our findings suggest that guided by diRNAs, Ago2 can promote Rad51 recruitment and/or retention at DSBs to facilitate repair by HR.

Cardioprotective effects of adipokine apelin on myocardial infarction.

Angiogenesis plays an important role in myocardial infarction. Apelin and its natural receptor (angiotensin II receptor-like 1, AGTRL-1 or APLNR) induce sprouting of endothelial cells in an autocrine or paracrine manner. The aim of this study is to investigate whether apelin can improve the cardiac function after myocardial infarction by increasing angiogenesis in infarcted myocardium. Left ventricular end-diastolic pressure (LVEDP), left ventricular end systolic pressure (LVESP), left ventricular developed pressure (LVDP), maximal left ventricular pressure development (±LVdp/dtmax), infarct size, and angiogenesis were evaluated to analyze the cardioprotective effects of apelin on ischemic myocardium. Assays of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, 5-bromo-2'-deoxyuridine incorporation, wound healing, transwells, and tube formation were used to detect the effects of apelin on proliferation, migration, and chemotaxis of cardiac microvascular endothelial cells. Fluorescein isothiocyanate-labeled bovine serum albumin penetrating through monolayered cardiac microvascular endothelial cells was measured to evaluate the effects of apelin on permeability of microvascular endothelial cells. In vivo results showed that apelin increased ±LV dp/dtmax and LVESP values, decreased LVEDP values (all p < 0.05), and promoted angiogenesis in rat heart after ligation of the left anterior descending coronary artery. In vitro results showed that apelin dose-dependently enhanced proliferation, migration, chemotaxis, and tube formation, but not permeability of cardiac microvascular endothelial cells. Apelin also increased the expression of vascular endothelial growth factor receptors-2 (VEGFR2) and the endothelium-specific receptor tyrosine kinase (Tie-2) in cardiac microvascular endothelial cells. These results indicated that apelin played a protective role in myocardial infarction through promoting angiogenesis and decreasing permeability of microvascular endothelial cells via upregulating the expression of VEGFR2 and Tie-2 in cardiac microvascular endothelial cells.

Involvement of endoplasmic reticulum stress in apoptosis of testicular cells induced by low-dose radiation.

The study examined the role of endoplasmic reticulum stress (ERS) and signaling pathways of inositol-requiring enzyme-1 (IRE1), RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor-6 (ATF6) in apoptosis of mouse testicular cells treated with low-dose radiation (LDR). In the dose-dependent experiment, the mice were treated with whole-body X-ray irradiation at different doses (25, 50, 75, 100 or 200 mGy) and sacrificed 12 h later. In the time-dependent experiment, the mice were exposed to 75 mGy X-ray irradiation and killed at different time points (3, 6, 12, 18 or 24 h). Testicular cells were harvested for experiments. H(2)O(2) and NO concentrations, and Ca(2+)-ATPase activity were detected by biochemical assays, the calcium ion concentration ([Ca(2+)]i) by flow cytometry using fluo-3 probe, and GRP78 mRNA and protein expressions by quantitative real-time RT-PCR (qRT-PCR) and Western blotting, respectively. The mRNA expressions of S-XBP1, JNK, caspase-12 and CHOP were measured by qRT-PCR, and the protein expressions of IRE1α, S-XBP1, p-PERK, p-eIF2α, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP by Western blotting. The results showed that the concentrations of H2O2 and NO, the mRNA expressions of GRP78, S-XBP1, JNK, caspase-12 and CHOP, and the protein expressions of GRP78, S-XBP1, IRE1α, p-PERK, p-eIF2α, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP were significantly increased in a time- and dose-dependent manner after LDR. But the [Ca(2+)]i and Ca(2+)-ATPase activities were significantly decreased in a time- and dose-dependent manner. It was concluded that the ERS, regulated by IRE1, PERK and ATF6 pathways, is involved in the apoptosis of testicular cells in LDR mice, which is associated with ERS-apoptotic signaling molecules of JNK, caspase-12 and CHOP.

[Study on mechanism of inactivated cider yeast adsorbing patulin by Fourier transform infrared spectroscopy].

The mechanism of patulin adsorption by inactivated cider yeast was studied by chemical modification and FTIR The results of patulin removal by various modified yeast biomass showed that the ability of patulin biosorption by acetone-treated yeast and NaOH-treated yeast increased siginificantly, while the methylation of amino group and esterification of carboxylate functionalities of yeast cell surface caused a decrease in patulin binding, which indicated that amino group and carboxyl group presented in the cell walls of yeast might be involved in the binding of patulin to the yeast. The FTIR analysis indicated that the main functional groups were amino group, carboxyl group and hydroxy group which are associated with protein and polysaccharides.