Sevoflurane preconditioning protects against acute MI/R injury via enhancing AdipoR1-Cav3 interaction and alleviating endoplasmic reticulum stress.

Whether and how sevoflurane preconditioning (SevoPre) exerts protection against acute myocardial ischemia/reperfusion (MI/R) injury remains elusive. We observed significant myocardial injury, as evidenced by infarct size, cardiomyocyte apoptosis, and circulating troponin-I, at 3 h of MI/R in both wildtype and adiponectin knockout mice. The injury was significantly ameliorated by SevoPre in wildtype mice, but not in adiponectin knockout mice. In wildtype mice, we found that MI/R could increase endoplasmic reticulum stress of cardiomyocytes, and impair association of adiponectin receptor 1 and ceveolin-3, both of which processes were largely restored by SevoPre. In summary, we demonstrated that significant injury had already took place at 3 h of MI/R, which could be ameliorated by SevoPre via promoting affinity of adiponectin receptor 1 and ceveolin-3, and then attenuating endoplasmic reticulum stress of cardiomyocytes.

Minocycline and Pyrrolidine Dithiocarbamate Attenuate Hypertension via Suppressing Activation of Microglia in the Hypothalamic Paraventricular Nucleus.

Proinflammatory cytokines, reactive oxygen species and imbalance of neurotransmitters are involved in the pathophysiology of angiotensin II-induced hypertension. The hypothalamic paraventricular nucleus (PVN) plays a vital role in hypertension. Evidences show that microglia are activated and release proinflammatory cytokines in angiocardiopathy. We hypothesized that angiotensin II induces PVN microglial activation, and the activated PVN microglia release proinflammatory cytokines and cause oxidative stress through nuclear factor-kappa B (NF-κB) pathway, which contributes to sympathetic overactivity and hypertension. Male Sprague-Dawley rats (weight 275-300 g) were infused with angiotensin II to induce hypertension. Then, rats were treated with bilateral PVN infusion of microglial activation inhibitor minocycline, NF-κB activation inhibitor pyrrolidine dithiocarbamate or vehicle for 4 weeks. When compared to control groups, angiotensin II-induced hypertensive rats had higher mean arterial pressure, PVN proinflammatory cytokines, and imbalance of neurotransmitters, accompanied with PVN activated microglia. These rats also had more PVN gp91phox (source of reactive oxygen species production), and NF-κB p65. Bilateral PVN infusion of minocycline or pyrrolidine dithiocarbamate partly or completely ameliorated these changes. This study indicates that angiotensin II-induced hypertensive rats have more activated microglia in PVN, and activated PVN microglia release proinflammatory cytokines and result in oxidative stress, which contributes to sympathoexcitation and hypertensive response. Suppression of activated PVN microglia by minocycline or pyrrolidine dithiocarbamate attenuates inflammation and oxidative stress, and improves angiotensin II-induced hypertension, which indicates that activated microglia promote hypertension through activated NF-κB. The findings may offer hypertension new strategies.

Beneficial effects of metformin supplementation in hypothalamic paraventricular nucleus and arcuate nucleus of type 2 diabetic rats.

Background Oxidative stress and inflammation play important roles in the development of diabetes. Metformin (MET) is considered as the first-line therapy for patients with type 2 diabetes (T2D). Hypothalamic paraventricular nucleus (PVN) and hypothalamic arcuate nucleus (ARC) are vital in obesity and diabetes. However, there have been few studies on the effects of MET on inflammatory reaction and oxidative stress in the PVN and ARC of T2D diabetic rats. Methods Male Sprague-Dawley (SD) rats were fed with high-fat diet (HFD), and intraperitoneally injected with low-dose streptozotocin (STZ, 30 mg/kg) at 6th week to induce T2D diabetes. After injection of STZ, they were fed with HFD continually. Starting from the 8th week of HFD feeding, T2D rats received intragastrical administration of MET (150 mg/kg/day) in addition to the HFD for another 8 weeks. At the end of the 15th week, the rats were anaesthetized to record the sympathetic nerve activity and collect blood and tissue samples. Results In comparison with control rats, T2D diabetic rats had higher levels of pro-inflammatory cytokines (PICs) and excessive oxidative stress in the PVN and ARC, accompanied with more activated astrocytes. The renal sympathetic nerve activity (RSNA) and the plasma norepinephrine (NE) increased in T2D diabetic rats. The expression of tyrosine hydroxylase (TH) increased and the expression of 67-kDa isoform of glutamate decarboxylase (GAD67) decreased in T2D diabetic rats. Supplementation of MET decreased blood glucose, suppressed RSNA, decreased PICs (TNF-α, IL-1ß and IL-6) in PVN and ARC, attenuated oxidative stress and activation of astrocytes in ARC and PVN of T2D diabetic rats, as well as restored the balance of neurotransmitter synthetase. The number of Fra-LI (chronic neuronal excitation marker) positive neurons in the ARC and PVN of T2D diabetic rats increased. Chronic supplementation of MET also decreased the number of Fra-LI positive neurons in the ARC and PVN of T2D diabetic rats. Conclusion These findings suggest that the PVN and ARC participate in the beneficial effects of MET in T2D diabetic rats, which is possibly mediated via down-regulating of inflammatory molecules, attenuating oxidative stress and restoring the balance of neurotransmitter synthetase by MET in the PVN and ARC.

GNRH1 and LTB4R might be novel immune-related prognostic biomarkers in clear cell renal cell carcinoma (ccRCC).

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) occupied most of renal cell carcinoma (RCC), which associated with poor prognosis. The purpose of this study is to screen novel and prognostic biomarkers for patients with ccRCC. METHODS AND RESULTS: Firstly, Gene Expression Omnibus database was used to collect microarray data for weighted gene co-expression network construction. Gene modules related to prognosis which interest us most were picked out. 90 hub genes were further chosen in the key modules, two of which including gonadotropin releasing hormone 1 (GNRH1) and leukotriene B4 receptor (LTB4R) were screened and validated as immune-related prognostic biomarkers. Based on several public databases and ccRCC tissues collected by ourselves, we performed survival analysis, spearman correlation analysis, receiver operating characteristic (ROC) analysis, quantitative real-time PCR (qRT-PCR), western blotting, immunofluorescence (IF) and immunohistochemistry (IHC) staining for the validation of immune-related prognostic biomarkers. We further explored the relationship between immune-related prognostic biomarker expressions and immunocytes. Finally, gene set enrichment analysis (GSEA) demonstrated that the two immune-related prognostic biomarkers were significantly correlated with cell cycle. CONCLUSIONS: Generally speaking, the present study has identified two novel prognostic biomarkers for patients with ccRCC, which showed strong correlation with prognosis of patients with ccRCC, could further be used as potential prognostic biomarkers in ccRCC.

Glucagon-Like Peptide-1 Analog Liraglutide Attenuates Pressure-Overload Induced Cardiac Hypertrophy and Apoptosis through Activating ATP Sensitive Potassium Channels.

PURPOSE: This study aimed to investigate whether inhibition of glucagon-like peptide-1 (GLP-1) on pressure overload induced cardiac hypertrophy and apoptosis is related to activation of ATP sensitive potassium (KATP) channels. METHODS: Male SD rats were randomly divided into five groups: sham, control (abdominal aortic constriction), GLP-1 analog liraglutide (0.3 mg/kg/twice day), KATP channel blocker glibenclamide (5 mg/kg/day), and liraglutide plus glibenclamide. RESULTS: Relative to the control on week 16, liraglutide upregulated protein and mRNA levels of KATP channel subunits Kir6.2/SUR2 and their expression in the myocardium, vascular smooth muscle, aortic endothelium, and cardiac microvasculature. Consistent with a reduction in aortic wall thickness (61.4 ± 7.6 vs. 75.0 ± 7.6 µm, p < 0.05), liraglutide enhanced maximal aortic endothelium-dependent relaxation in response to acetylcholine (71.9 ± 8.7 vs. 38.6 ± 4.8%, p < 0.05). Along with a reduction in heart to body weight ratio (2.6 ± 0.1 vs. 3.4 ± 0.4, mg/g, p < 0.05) by liraglutide, hypertrophied cardiomyocytes (371.0 ± 34.4 vs. 933.6 ± 156.6 µm2, p < 0.05) and apoptotic cells (17.5 ± 8.2 vs. 44.7 ± 7.9%, p < 0.05) were reduced. Expression of anti-apoptotic protein BCL-2 and contents of myocardial ATP were augmented, and expression of cleaved-caspase 3 and levels of serum Tn-I/-T were reduced. Echocardiography and hemodynamic measurement showed that cardiac systolic function was enhanced as evidenced by increased ejection fraction (88.4 ± 4.8 vs. 73.8 ± 5.1%, p < 0.05) and left ventricular systolic pressure (105.2 ± 10.8 vs. 82.7 ± 7.9 mmHg, p < 0.05), and diastolic function was preserved as shown by a reduction of ventricular end-diastolic pressure (-3.1 ± 2.9 vs. 6.7 ± 2.8 mmHg, p < 0.05). Furthermore, left ventricular internal diameter at end-diastole (5.8 ± 0.5 vs. 7.7 ± 0.6 mm, p < 0.05) and left ventricular internal diameter at end-systole (3.0 ± 0.6 vs. 4.7 ± 0.4 mm, p < 0.05) were improved. Dietary administration of glibenclamide alone did not alter all the parameters measured but significantly blocked liraglutide-exerted cardioprotection. CONCLUSION: Liraglutide ameliorates cardiac hypertrophy and apoptosis, potentially via activating KATP channel-mediated signaling pathway. These data suggest that liraglutide might be considered as an adjuvant therapy to treat patients with heart failure.

Construction and Validation of an Autophagy-Related Prognostic Signature and a Nomogram for Bladder Cancer.

OBJECTIVE: Bladder cancer (BC) is one of the top ten cancers endangering human health but we still lack accurate tools for BC patients' risk stratification. This study aimed to develop an autophagy-related signature that could predict the prognosis of BC. In order to provide clinical doctors with a visual tool that could precisely predict the survival probability of BC patients, we also attempted to establish a nomogram based on the risk signature. METHODS: We screened out autophagy-related genes (ARGs) combining weighted gene co-expression network analysis (WGCNA) and differentially expressed gene (DEG) in BC. Based on the screened ARGs, we performed survival analysis and Cox regression analysis to identify potential prognostic biomarkers. A risk signature based on the prognostic ARGs by multivariate Cox regression analysis was established, which was validated by using seven datasets. To provide clinical doctors with a useful tool for survival possibility prediction, a nomogram assessed by the ARG-based signature and clinicopathological features was constructed, verified using four independent datasets. RESULTS: Three prognostic biomarkers including BOC (P = 0.008, HR = 1.104), FGF7(P = 0.030, HR = 1.066), and MAP1A (P = 0.001, HR = 1.173) were identified and validated. An autophagy-related risk signature was established and validated. This signature could act as an independent prognostic feature in patients with BC (P = 0.047, HR = 1.419). We then constructed two nomograms with and without ARG-based signature and subsequent analysis indicated that the nomogram with ARG signature showed high accuracy for overall survival probability prediction of patients with BC (C-index = 0.732, AUC = 0.816). These results proved that the ARG signature improved the clinical net benefit of the standard model based on clinicopathological features (age, pathologic stage). CONCLUSIONS: Three ARGs were identified as prognosis biomarkers in BC. An ARG-based signature was established for the first time, showing strong potential for prognosis prediction in BC. This signature was proven to improve the clinical net benefit of the standard model. A nomogram was established using this signature, which could lead to more effective prognosis prediction for BC patients.

Identification of transforming growth factor beta induced (TGFBI) as an immune-related prognostic factor in clear cell renal cell carcinoma (ccRCC).

Clear cell renal cell carcinoma (ccRCC) is the most common subtype among kidney cancer, which has poor prognosis. The aim of this study was to screen out novel prognostic biomarkers and therapeutic targets for immunotherapy, and some novel molecule drugs for ccRCC treatment. Immune scores ranged from -1109.36 to 2920.81 and stromal scores ranged from -1530.11 to 1955.39 were firstly calculated by applying ESTIMATE algorithm. Then 17 DEGs associated with immune score and stromal score were further identified. 6 candidate hub genes were screened out by performing overall survival (OS) and disease-free survival analyses based on TCGA-KIRC data, one of which including TGFBI was further regarded as hub gene associated with prognosis by calculating the R2 (R2 = 0.011, P = 0.018) and AUC (AUC = 0.874). The prognostic value of TGFBI was validated by performing OS, CSS, and PFS analyses based on GSE29609 and E-MTAB-3267. CMap analysis suggested that 3 molecule drugs might be novel choice for ccRCC treatment. Further analysis demonstrated that CNVs of TGFBI was associated with OS of patients with ccRCC. TGFBI expression was also correlated with histologic grade, pathologic stage, and immune infiltration level, significantly. TGFBI was the most relevant gene with OS among the candidate hub genes, which might be novel DNA methylation biomarkers for ccRCC. In conclusion, our findings indicated that TGFBI was correlated with prognosis of patients with ccRCC, which might be novel prognostic biomarkers, and targets for immunotherapy in ccRCC. Three small molecule drugs were also identified, which showed strong potential for ccRCC treatment.

Complement C7 (C7), a Potential Tumor Suppressor, Is an Immune-Related Prognostic Biomarker in Prostate Cancer (PC).

Objectives: Prostate cancer (PC) is the second most frequent tumor in men, which has a high recurrence rate and poor prognosis. Therefore, this study aimed to identify novel prognostic biomarkers and therapeutic targets for immunotherapy and small molecule drugs for PC treatment. Materials and Methods: The Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) algorithm was applied to calculate immune scores and stromal scores of TCGA-PRAD data. Differentially expressed genes (DEGs) were identified using R package "limma." GO, KEGG, and DO analyses were performed to analyze DEGs. Overall survival and disease-free survival analyses were conducted for hub gene identification. To validate the hub gene at the mRNA and protein expression levels, genetic alterations were measured, and CCLE and Cox regression analyses were performed. Connectivity map (CMap) analysis and GSEA were performed for drug exploration and function analysis, respectively. Results: Immune scores ranged from -1795.98 to 2339.39, and stomal scores ranged from -1877.60 to 1659.96. In total, 45 tumor microenvironment (TME)-related DEGs were identified, of which Complement C7 (C7) was selected and validated as a hub gene. CMap analysis identified six small molecule drugs as potential agents for PC treatment. Further analysis demonstrated that C7 expression was significantly correlated with clinical T, pathological N, and immune infiltration level. Conclusions: In conclusion, of the 45 TME-related DEGs, C7 was shown to correlate with PC prognosis in patients, indicating it as a novel prognostic biomarker and immunotherapy target in PC. Additionally, six small molecule drugs showed strong therapeutic potential for PC treatment.

Exogenous supplement of glucagon like peptide-1 protects the heart against aortic banding induced myocardial fibrosis and dysfunction through inhibiting mTOR/p70S6K signaling and promoting autophagy.

Mammalian target of rapamycin (mTOR) and a ribosomal protein S6 kinase (p70S6K) mediate tissue fibrosis and negatively regulate autophagy. This study aims to investigate whether glucagon-like peptide-1 (GLP-1) analog liraglutide protects the heart against aortic banding-induced cardiac fibrosis and dysfunction through inhibiting mTOR/p70S6K signaling and promoting autophagy activity. Male SD rats were randomly divided into four groups (n = 6/each group): sham operated control; abdominal aortic constriction (AAC); liraglutide treatment during AAC (0.3 mg/kg, injected subcutaneously twice daily); rapamycin treatment during AAC (0.2 mg/kg/day, administered by gastric gavage). Relative to the animals with AAC on week 16, liraglutide treatment significantly reduced heart/body weight ratio, inhibited cardiomyocyte hypertrophy, and augmented plasma GLP-1 level and tissue GLP-1 receptor expression. Phosphorylation of mTOR/p70S6K, populations of myofibroblasts and synthesis of collagen I/III in the myocardium were simultaneously inhibited. Furthermore, autophagy regulating proteins: LC3-II/LC3-I ratio and Beclin-1 were upregulated, and p62 was downregulated by liraglutide. Compared with liraglutide group, treatment with rapamycin, a specific inhibitor of mTOR, compatibly augmented GLP-1 receptor level, inhibited phosphorylation of mTOR/p70S6K and expression of p62 as well as increased level of LC3-II/LC3-I ratio and Beclin-1, suggesting that there is an interaction between GLP-1 and mTOR/p70S6K signaling in the regulation of autophagy. In line with these modifications, treatment with liraglutide and rapamycin significantly reduced perivascular/interstitial fibrosis, and preserved systolic/diastolic function. These results suggest that the inhibitory effects of liraglutide on cardiac fibrosis and dysfunction are potentially mediated by inhibiting mTOR/p70S6K signaling and enhancing autophagy activity.

Liraglutide attenuates cardiac remodeling and improves heart function after abdominal aortic constriction through blocking angiotensin II type 1 receptor in rats.

OBJECTIVE: Angiotensin II (Ang II) is known to contribute to the pathogenesis of heart failure by eliciting cardiac remodeling and dysfunction. The glucagon-like peptide-1 (GLP-1) has been shown to exert cardioprotective effects in animals and patients. This study investigates whether GLP-1 receptor agonist liraglutide inhibits abdominal aortic constriction (AAC)-induced cardiac fibrosis and dysfunction through blocking Ang II type 1 receptor (AT1R) signaling. METHODS: Sprague-Dawley rats were subjected to sham operation and abdominal aortic banding procedure for 16 weeks. In treated rats, liraglutide (0.3 mg/kg) was subcutaneously injected twice daily or telmisartan (10 mg/kg/day), the AT1R blocker, was administered by gastric gavage. RESULTS: Relative to the animals with AAC, liraglutide reduced protein level of the AT1R and upregulated the AT2R, as evidenced by reduced ratio of AT1R/AT2R (0.59±0.04 vs. 0.91±0.06, p<0.05). Furthermore, the expression of angiotensin converting enzyme 2 was upregulated, tissue levels of malondialdehyde and B-type natriuretic peptide were reduced, and superoxide dismutase activity was increased. Along with a reduction in HW/BW ratio, cardiomyocyte hypertrophy was inhibited. In coincidence with these changes, liraglutide significantly decreased the populations of macrophages and myofibroblasts in the myocardium, which were accompanied by reduced protein levels of transforming growth factor beta1, Smad2/3/4, and upregulated smad7. The synthesis of collagen I and III was inhibited and collagen-rich fibrosis was attenuated. Consistent with these findings, cardiac systolic function was preserved, as shown by increased left ventricular systolic pressure (110±5 vs. 99±2 mmHg, p<0.05), ejection fraction (83%±2% vs. 69%±4%, p<0.05) and fraction shortening (49%±2% vs. 35%±3%, p<0.05). Treatment with telmisartan provided a comparable level of protection as compared with liraglutide in all the parameters measured. CONCLUSION: Taken together, liraglutide ameliorates cardiac fibrosis and dysfunction, potentially via suppressing the AT1R-mediated events. These data indicate that liraglutide might be selected as an add-on drug to prevent the progression of heart failure.

Curcumin inhibits cardiac hypertrophy and improves cardiovascular function via enhanced Na+/Ca2+ exchanger expression after transverse abdominal aortic constriction in rats.

BACKGROUND: This study tested the hypothesis that inhibition of cardiac hypertrophy and preservation of cardiac/endothelial function by the natural yellow pigment curcumin are associated with upregulated expression of Na+/Ca2+ exchanger (NCX) after transverse aortic constriction (TAC). METHODS: Male Wistar rats were subjected to TAC for 10 weeks and curcumin (50 mg/kg/day) was fed by gastric gavage during TAC. Expression of NCX and endothelial nitric oxide synthase (eNOS) was analyzed by Western blot and immunohistochemistry. RESULTS: Compared with the animals in the TAC group, curcumin significantly increased the survival rate and reduced the ratio of heart or left ventricle (LV) to body weight and the cross sectional area of cardiomyocytes. In coincidence with improved LV systolic pressure and reduced LV end-diastolic pressure, curcumin significantly reduced LV end-systolic and diastolic diameter/dimension, and enhanced LV ejection fraction and LV fractional shortening as measured by echocardiography. Furthermore, endothelium-dependent relaxation of aortic rings in response to acetylcholine was significantly improved by curcumin. Along with these modifications, the expression and localization of NCX and eNOS in the myocardium and vascular endothelium were significantly upregulated by curcumin. The protective effect of curcumin on endothelium-dependent relaxation was partly blocked by pretreatment with the NCX inhibitor, KB-R7943. CONCLUSIONS: These results demonstrate that inhibition of cardiac hypertrophy, improvement of cardiac systolic/diastolic function and preservation of vascular endothelium by curcumin might be associated with upregulated NCX expression level in response to increased afterload.

[Effects of E 4031 on isolated cardiac function and resting Ca2+ level of myocardial cells from rats with chronic heart failure].

OBJECTIVE: To investigate the effects of E 4031, a sodium calcium exchanger (NCX) agonist, on the isolated cardiac function and resting Ca2+ level in myocardial cells from rats with chronic heart failure. METHODS: Rats chronic heart failure model was established by abdominal aorta coarctation with; Isolated heart perfusion by Langendorff apparatus was used to detect heart function and the effects of E 4031 on haemodynamic indexes; Myocardial cells of rats in the model group were extracted quickly and co-incubated with calcium fluorescent indicator fluo3/AM and the impact of E 4031 on the fluorescence intensity in myocardial cells were evaluated by confocal microscopy. RESULTS: Heart function of rats in the model group detected by Langendorff perfusion was significantly reduced after 12 weeks, E 4031 at 10 micromol/L could improve their left ventricular developed pressure(LVDP) and systolic / diastolic maximum rate (+/- dp/dtmax). Compared with the control and sham operation groups, the resting Ca2+ fluorescence intensity of the myocardial cells of rats in model group was at a higher level and went through a process of transient rise and drop, then stably remaining at a low level after co-incubated with 10 micromol/L E 4031. CONCLUSION: E 4031 can improve the isolated heart function of rats with chronic heart failure, which may be associated with its enhancing the activity of NCX in the myocardial cell membrane and stabilizing intracellular Ca2+ level.