Activation of IK1 channel by zacopride attenuates left ventricular remodeling in rats with myocardial infarction.

Activating IK1 channels is considered to be a promising antiarrhythmic strategy. Zacopride has been identified as a selective IK1 channel agonist and can suppress triggered arrhythmias. Whether this drug also exerts a beneficial effect on cardiac remodeling is unknown, and the present study sought to address this question. Cardiac remodeling was induced through coronary ligation-induced myocardial infarction (MI) in male Sprague-Dawley rats. Zacopride (15 µg/kg) was administered (intraperitoneally) daily for 28 days after MI to determine whether it could attenuate MI-induced cardiac remodeling. A 4-week treatment with zacopride attenuated post-MI cardiac remodeling, as shown by the reduced left ventricular end-diastolic dimension and left ventricular end-systolic dimension and the increased ejection fraction and fractional shortening in zacopride-treated animals compared with animals treated with vehicle (all P < 0.05). Furthermore, zacopride significantly decreased myocardial collagen deposition, cardiomyocyte hypertrophy, the plasma level of brain natriuretic peptide, and cardiomyocyte ultrastructural injury. Zacopride also upregulated the expression of the IK1 channel protein and downregulated the expression of phosphorylated p70S6 kinase (p-p70S6K) and mTOR. These beneficial effects of zacopride were partially abolished by the IK1 channel blocker chloroquine. We conclude that the activation of IK1 channel by zacopride attenuates post-MI cardiac remodeling by suppressing mTOR-p70S6 kinase signaling.

Differential molecular genetic analysis in glioblastoma multiforme of long- and short-term survivors: a clinical study in Chinese patients.

This study was designed to find whether long-term survivors (LTSs) exhibit molecular genetic differences compared with short-term survivors (STSs) in patients with GBM. Tumors from 12 patients initially diagnosed with GBM and survived longer than 36 months (LTSs) were compared with 30 patients with GBM and STSs (survival <18 months) for detecting of MGMT promoter methylation, 1p/19q LOH and IDH1 mutation. IDH1 mutation and MGMT promoter methylation were significantly more frequent in the LTSs group (P = 0.039 and 0.017, respectively). The incidence of 1p/19q co-deletion was not significantly different (P = 1.0). IDH1 mutation and MGMT promoter methylation might be independent, significant, and favorable factors for LTSs with GBM.

[Feature analysis of IDH1 mutation in oligodendroglial tumors].

OBJECTIVE: To analyze the features of isocitrate dehydrogenase 1 (IDH 1) mutation in 165 oligodendroglial tumors. METHODS: IDH1 was detected in a series of 165 oligodendroglial paraffin specimens from 2009 to 2011. And their features were analyzed. RESULTS: Mutant IDH1 was detected in 111 (67.3%) tumors including 109 (98.2%) CGT→CAT mutations, 1 (0.9%) CGT→AGT mutation and 1 (0.9%) CGT→TGT mutation. The frequencies of IDH mutation in AO, O and OA were 13/15, 83.3% and 72.9% respectively. They were significantly higher than that in AOA (27.0%, P < 0.001). CONCLUSION: The different frequencies of IDH1 mutation in different subsets of oligodendroglial tumors may imply varied tumorigenic pathways between subsets.

[Effects of resveratrol on inhibiting pyroptosis of intestinal cancer cells].

Objective: To study the effects of resveratrol (Res) on pyroptosis of colorectal cancer cells . Methods: ①The experiment of dextran sodium sulfate (DSS) induced colon cancer (CRC) in mice: 30 C57BL/6 mice were randomly divided into control group, Azoxymethane (AOM) group, AOM/DSS group, AOM/DSS+Res group and Res group, with 6 mice in each group, the modeling cycle was 70 days in total. Mice in AOM group, AOM/DSS group and AOM/DSS+Res group, at the first day of the first week, were intraperitoneally injected with AOM (10 mg/kg) once, and the ordinary chaw was replaced with high iron feed, and sterile water was given, 1% DSS water was given to AOM/DSS group and AOM/DSS+Res group. The mice in AOM/DSS+Res and Res groups were given resveratrol (50 mg/kg) by oral gavage, When the mold was finished, colon tissue of mice was fixed, embedded and sectionalized. The expressions of NLRP3, Caspase-1 and IL-18 in colon tissues of mice were detected by IHC and Western blot. ②In vitro experiment: HCT 116 cells were given Res (2.4 µg/L) and transfected with miR-31. The Res was divided into 4 groups and labeled with 0 h, 12 h, 24 h and 48 h respectively. The transfected cells were divided into 5 groups: Control group, miR-31 mimic group, miR-31 mimic + Res group, miR-31 inhibitor group, miR-31 inhibitor + Res group. The protein expressions of NLRP3, Caspase-1, GSDMD-N, IL-18 and IL-1ß were detected by Western blot. Results: Animal experiments: Compared with control group, the protein expressions of NLRP3, Caspase-1 and IL-18 in AOM/DSS group were increased significantly (P<0.01). The protein expression levels of NLRP3, Caspase-1 and IL-18 in AOM/DSS+Res group were significantly lower than those in AOM/DSS group (P<0.01). Cell experiments: Compared with the control group, the protein expressions of NLRP3 (P<0.01), GSDMD-N (P<0.05) and IL-18 (P< 0.01) in miR-31 mimic group were increased significantly. The protein expressions of NLRP3, GSDMD-N and IL-18 in miR-31 inhibitor group were decreased significantly (P<0.05). Conclusion: Res inhibited the pyroptosis of colorectal cancer cells through pyroptosis.

Effect of Carbapenem-Resistant Klebsiella pneumoniae Infection on the Clinical Outcomes of Kidney Transplant Recipients.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection has proven to be difficult to control and typically presents with devastating effects. Methods: This retrospective study was conducted on the renal recipients at our institution between January 2021 to January 2022. Clinical data was collected to identify factors associated with CRKP infection and clinical outcomes. Results: There were 104 cases out of 186 total renal recipients who presented with at least one infection within 3 months after KT, and 14 cases developed unfavorable clinical outcomes. We identified 16 confirmed CRKP infected cases with the incidence of 8.60%. Possible donor derived infection (DDI) (OR = 6.743; 95% CI: 1.477-30.786; P = 0.014) were independent risk factors for the occurrence of CRKP infection of renal recipients in our analysis, CRKP infection (OR = 20.723; 95% CI: 3.448-124.547; P = 0.001) and pneumonia (OR = 28.458; 95% CI: 1.956-413.984 P = 0.014) were independent risk factors for the occurrence of unfavorable clinical outcomes following KT, and the occurrence of unfavorable clinical outcomes following KT were significantly associated with CRKP infection (r = 0.535; P < 0.001) and antibiotic regimen containing ceftazidime/avibactam (CZA) (r = -0.655; P = 0.006). The use of CZA was significantly different in the comparison of antibiotic regimens between the CRKP infected renal recipients with unfavorable outcomes and CRKP infected patients with favorable outcomes. Conclusion: It is possible that DDI can lead to CRKP infection, and CRKP infection and pneumonia were closely correlated with poor prognosis. The use of CZA may play a role in avoiding the unfavorable outcomes of CRKP infected recipients.

Toxicity spectrum of immunotherapy in advanced lung cancer: A safety analysis from clinical trials and a pharmacovigilance system.

Background: With the increased use of immune checkpoint inhibitors (ICIs) in advanced lung cancer, adverse events (AEs), particularly immune-related AEs (irAEs), have garnered considerable interest. We conducted a comprehensive assessment of the toxicity profile in advanced lung cancer using multi-source medical data. Methods: First, we systematically searched the PubMed, Embase, and Cochrane Library databases (from inception to 10 August 2021) for relevant randomised controlled trials (RCTs) involving ICI-based treatments for advanced lung cancer. The primary outcomes were treatment-related AEs and irAEs, including events that were assigned grade 1-5 and 3-5. The secondary outcomes were grade 5 AEs and irAEs (grade 1-5 and grade 3-5) in specific organs. Network comparisons were conducted for 11 treatments, including chemotherapy (CT), ICI monotherapy (three regimens: programmed death-1 receptor [PD-1] inhibitors, programmed death ligand-1 [PD-L1] inhibitors, and cytotoxic T lymphocyte-associated antigen [CTLA-4] inhibitors), dual-ICI combination therapy (two regimens), and treatment using one or two ICI drugs administered in combination with CT (five regimens). We also conducted a disproportionality analysis by extracting reports of various irAEs associated with ICIs from the FDA Adverse Event Reporting System (FAERS) database. The reporting odds ratios and fatality proportions of different irAEs were calculated and compared. PROSPERO: CRD42021268650. Findings: Overall, 41 RCTs involving 23,121 patients with advanced lung cancer were included. Treatments containing chemotherapy increased the risk of treatment-related AEs compared to ICI-based regimens without chemotherapy. Concerning irAEs, PD-L1 + CTLA-4 + CT was associated with the highest risk of grade 1-5 irAEs, followed by two regimens of dual ICI combination, three regimens of ICI monotherapy, and three regimens of one ICI combined with CT. For 3-5 irAEs, CTLA-4 accounted for most AEs. Detailed comparisons of ICI-based treatment options provided irAE profiles based on specific organs/systems and AE severity. Insights from the FAERS database revealed that signals corresponding to pneumonitis, colitis, thyroiditis, and hypophysitis were observed across all ICI regimens. Further analyses of the outcomes indicated that myocarditis (163 of 367, 44.4%), pneumonitis (1610 of 4497, 35.8%), and hepatitis (290 of 931, 31.1%) had high fatality rates. Interpretation: Included RCTs showed heterogeneity in a few clinical factors, and reports derived from the FAERS database might have involved inaccurate data. Our results can be used as a basis for improving clinical treatment strategies and designing preventive methods for ICI treatment in advanced lung cancer. Funding: This study was supported by the Research Project of Drug Clinical Comprehensive Evaluation and Drug Treatment Pathway (SHYXH-ZP-2021-001, SHYXH-ZP-2021-006), Clinical Research Innovation and Cultivation Fund of Ren Ji Hospital (RJPY-LX-008), Ren Ji Boost Project of National Natural Science Foundation of China (RJTJ-JX-001), and Shanghai "Rising Stars of Medical Talent" Youth Development Program - Youth Medical Talents - Clinical Pharmacist Program (SHWJRS (2019) 072).

Inhibitory effects of purified antibody against α-1 repeat (117-137) on Na(+)-Ca(2+) exchange and L-type Ca(2+) currents in rat cardiomyocytes.

Considering that α-1 repeat region may be involved in the ion binding and translocation of Na(+)-Ca(2+) exchanger (NCX), it is possible that the antibodies against NCX α-1 repeat may have a crucial action on NCX activity. The aim of the present study is to investigate the effect of antibody against α-1 repeat (117-137), designated as α-1(117-137), on NCX activity. The antibody against the synthesized α-1(117-137) was prepared and affinity-purified. Whole-cell patch clamp technique was used to study the change of Na(+)-Ca(2+) exchange current (I(Na/Ca)) in adult rat cardiomyocytes. To evaluate the functional specificity of this antibody, its effects on L-type Ca(2+) current (I(Ca,L)), voltage-gated Na(+) current (I(Na)) and delayed rectifier K(+) current (I(K)) were also observed. The amino acid sequences of α-1(117-137) in NCX and residues 1 076-1 096 within L-type Ca(2+) channel were compared using EMBOSS Pairwise Alignment Algorithms. The results showed that outward and inward I(Na/Ca) were decreased by the antibody against α-1(117-137) dose-dependently in the concentration range from 10 to 160 nmol/L, with IC(50) values of 18.9 nmol/L and 22.4 nmol/L, respectively. Meanwhile, the antibody also decreased I(Ca,L) in a concentration-dependent manner with IC(50) of 22.7 nmol/L. No obvious effects of the antibody on I(Na) and I(K) were observed. Moreover, comparison of the amino acid sequences showed there was 23.8% sequence similarity between NCX α-1(117-137) and residues 1 076-1 096 within L-type Ca(2+) channel. These results suggest that antibody against α-1(117-137) is a blocking antibody to NCX and can also decrease I(Ca,L) in a concentration-dependent manner, while it does not have obvious effects on I(Na) and I(K).

[The correlation between combining 1p/19q LOH and pathology in gliomas].

OBJECTIVE: To investigate the frequencies of combining loss of heterozygosity (LOH) of chromosome 1p/19q in gliomas of different pathologies and analyze the clinical factors correlated with combining LOH by logistic regression. METHODS: Tumor samples from 127 glioma patients were collected. The status of 1p and 19q was evaluated by fluorescence in situ hybridization (FISH) and the frequencies of combining 1p/19q LOH in gliomas of different pathologies were analyzed. RESULTS: The frequencies of combining 1p/19q LOH in astrocytic, oligoastrocytic and oligodendroglial tumors were 19.30%, 50.00% and 80.77% respectively. The frequencies of combining 1p/19q LOH in oligoastrocytic and oligodendroglial tumors were higher than those in astrocytic tumors (P < 0.01) and the frequencies of combining 1p/19q LOH in oligodendroglial tumors was higher than those in oligoastrocytic tumors (P < 0.05). The frequencies of 1p/19q LOH in astrocytic, oligoastrocytic and oligodendroglial tumors were 12.28%, 11.36 and 0 respectively. There was no significant correlation between combining 1p/19q LOH and age, gender and grade by logistic regression. CONCLUSION: In gliomas, combining 1p/19q LOH is proved to be the most common pattern of chromosome deletion involving 1p or 19q. It is significantly correlated with oligodendroglial component. Combining 1p/19q LOH may be valuable in the diagnosis, treatment and prognostic prediction for glioma with oligodendroglial component.

[Characteristics of combining loss of heterozygosity of 1p/19q in glioma].

OBJECTIVES: To find possible factors correlated with combined loss of heterozygosity (LOH) of 1p and 19q. METHODS: The status of 1p and 19q of 138 glioma specimen from January 2009 to December 2009 was evaluated by Fluorescence in situ hybridization (FISH) method, and the frequencies of combining LOH of 1p/19q were compared between different pathologies, brain sub-regions, genders and ages. RESULTS: The frequencies of combined LOH of 1p and 19q of oligodendroglial (81.3%) and oligo astrocytic tumors (55.8%) were significantly higher than that of astrocytic tumor (22.2%) (P < 0.01), and the frequency of oligodendroglial tumor was significantly higher than that of oligo astrocytic tumor (P < 0.05). The frequency of combining LOH of 1p and 19q in frontal lobe (61.8%) was higher than that in temporal (31.8%) and insular lobes (34.6%) (P < 0.05). CONCLUSION: Combining LOH of 1p and 19q has significant correlation with the pathologies and brain sub-regions.

[Overexpression of miR-31 regulates TLR4/NF-κB signaling pathway and apoptotic protein in colitis model mice].

Objective: To investigate the effects of miR-31 on TLR4/NF-κB signaling pathway and apoptosis-related proteins in dextran sulfate sodium (DSS) induced mouse colon colitis. Methods: ① Mouse model of colon colitis: 1% DSS was used to induce mouse ulcerative colitis (UC). Fourteen FVB non-transgenic mice were randomly divided into control group (n= 6), DSS group (n= 8), and 16 FVB miR-31 transgenic mice were randomly divided into miR-31 overexpression group (n= 8), miR-31 overexpression +DSS group (n= 8). DSS was dissolved in water and administered to mice by drinking water. The DSS group and miR-31+DSS group drank 1% DSS water in the first week, normal sterilized water in the second week, and 1% DSS water in the third week, after 5 weeks, the modeling was completed, then the colon tissues of the mice were collected. Western blot and IHC were used to detect the expressions of NF-κB p65, TLR4, Bax and Bcl-2 proteins in mouse colon tissue, TUNEL was used to detect apoptosis of mouse colon tissues. ② Cell culture experiments: Transfection of miR-31mimic and inhibitor by lipofectamine resulted in overexpression or knockdown of miR-31 in human colon epithelial cell line HCT 116 cells, each group was repeated three times and cells were collected 48 h later, Western blot was used to detect the expressions of NF-κB p65 and TLR4 protein. Results: ① In animal experiments, compared with the control group, the expression levels of NF-κB p65, TLR4 protein and apoptotic cell index in the DSS group and miR-31 overexpression group in mouse colon tissue were significantly increased (P＜0.05 or P＜0.01), and the Bcl-2 / Bax ratio was significantly reduced (P＜0.05 or P＜0.01); and compared with the DSS group, the expression levels of NF-κB p65, TLR4 protein and apoptotic cell index in the miR-31+DSS group were significantly increased (P＜0.01), while the Bcl-2/Bax ratio was significantly decreased (P＜0.01). ② In cell experiments, compared with the control group, the expression levels of NF-κB p65 and TLR4 protein in the over-expressed miR-31 group of HCT 116 cells were significantly increased (P＜0.05 or P＜0.01), the expressions of NF-κB p65 and TLR4 protein in miR-31 knockdown group were decreased (P＜0.05). Conclusion: miR-31 promotes the development of colitis by promoting TLR4/NF-κB signaling pathway and mediating apoptosis of intestinal epithelial cells.

Effects of nitidine chloride on ulcerative colitis in mice and its mechanism

OBJECTIVE: To investigate the protective effects of nitidine chloride (NC) on dextran sodium sulfate (DSS) - induced ulcerative colitis (UC) in mice by targeting miR-31 and its underlying mechanisms. METHODS: DSS at the concentration of 1% was used to induce UC in mice. Thirty C57BL/6 male mice were randomly divided into four groups: normal control group (n=7), DSS group (n=8), DSS + NC group (7.27 mg/kg) (n=8) and NC group (n=7). DSS was added in drinking water, and NC was administrated by gavage. The period of modeling lasted for 3 weeks. The control group and NC group drank sterile water every day, DSS group and DSS + NC group drank 1% DSS water in the first week, normal water in the second week and 1% DSS water in the third week. In the last week of modeling, mice in control group and DSS group were given 0.5% CMC-Na by gavage, while mice in DSS + NC group and NC group were given NC by gavage. After the establishment of the model, the disease activity index (DAI) related to colitis was observed, the pathological score of colon tissue was evaluated by HE staining, the expression level of miR-31 in colon tissue was detected by qPCR, and the protein expressions of NF -κ B and COX-2 in colon tissue were detected by Western blot. RESULTS: ① Compared with DSS group, the DAI in the DSS + NC group was decreased (P＜0.01). The colonic pathological injury was obviously ameliorated after treated by NC. ② Compared with normal control group, the expression of miR-31 in colonic tissue of DSS group was increased significantly(P＜0.01), compared with DSS group, the expression of miR-31 was decreased after treatment with NC(P＜ 0.05). ③ Compared with DSS group, the levels of inflammatory protein NF-κB and COX-2 in DSS + NC group was decreased significantly (P＜0.05). CONCLUSION: Nitidine chloride has obvious therapeutic effects on DSS induced mouse colitis, and its anti-inflammatory mechanism is related to the down-regulation of miR-31 expression.

[Effects of resveratrol on ulcerative colitis in mice and its mechanism].

OBJECTIVE: To investigate the anti-ulcerative colitis mechanism of resveratrol through regulation of Wnt/ß-catenin signaling pathway. METHODS: ①The experiment of ulcerative colitis induced by dextran sulfate sodium salt (DSS): 28 C57BL/6 mice were randomly divided into four groups including control group(n=7), DSS group(n=7), DSS+Resveratrol (DSS+Res) group(n=7) and Res group(n=7). The experiment lasted for 3 weeks. Ulcerative colitis of mice was induced by drinking DSS water and treated with resveratrol by intragastric administration. The mice were weighed daily and their activities and state of feces were recorded. After that, the mice were euthanized, the spleens were weighed, and the colonic length was measured.Hematoxylin-eosin staining (HE) was used to observe the pathological changes of the colon, and the expression of miR-31 in colonic tissue was detected by quantitative real-time PCR (qPCR). The expressions of ß-catenin and Cyclin D1 were measured by Western blot. ②In vitro experiment: HCT 116 cells were treated with resveratrol at 10 mg/ml, the expressions of ß-catenin, LDL receptor related protein-6 (LRP-6), frizzled-3 (FZD3) and c-Myc were detected. The expression of ß-catenin was also detected in HCT 116 cells transfected with miRNA-31 mimic and miRNA-31 inhibitor. RESULTS: ① The body weight was decreased in DSS group, the activity was decreased and blood stool appeared. The colonic length of mice was shortened, the spleen was enlarged and the tissue was damaged seriously in DSS group. While the above symptoms were improved after resveratrol treatment. ② Resveratrol inhibited the expressions of miRNA-31, ß-catenin and CyclinD1 in ulcerative colitis mice, and also down-regulated the expressions of ß-catenin, LRP-6, FZD3 and c-Myc in HCT 116 cells. After transfection of miRNA-31 inhibitor, the expression of ß-catenin was decreased in HCT 116 cells. CONCLUSION: Resveratrol suppresses DSS induced colitis by down-regulation of Wnt signal pathway. The down-regulation of Wnt signal may be related to miRNA-31.

Stimulation of Na+-Ca2+ exchange by purified antibody against alpha-2 repeat of Na+-Ca2+ exchanger in rat cardiomyocytes.

AIM: The aim of the present study was to investigate the effect of the antibody against alpha-2 repeat on Na+-Ca2+ exchanger (NCX) current (I(Na/Ca)). To evaluate the functional specificity of this antibody, its effects on L-type Ca2+ current (I(Ca,L)), voltage-gated Na+ current (I(Na)) and delayed rectifier K+ current (I(K)) were also observed. METHODS: The whole-cell patch-clamp technique was used in this study. RESULTS: The antibody against alpha-2 repeat augmented both the outward and inward Na+-Ca2+ exchanger current concentration-dependently, with EC(50) values of 27.9 nmol/L and 24.7 nmol/L, respectively. Meanwhile, the antibody could also increase I(Ca,L) in a concentration-dependent manner with the EC(50) of 33.6 nmol/L. Effects of the antibody on I(Na) and I(K) were not observed in the present study. CONCLUSION: The present results suggest that antibody against alpha-2 repeat is a stimulating antibody to NCX and could also increase I(Ca,L) in a concentration-dependent manner, but did not have an obvious effect on I(Na) and I(K).

Puerarin attenuates angiotensin II-induced cardiac fibroblast proliferation via the promotion of catalase activity and the inhibition of hydrogen peroxide-dependent Rac-1 activation.

The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of H2O2 in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular H2O2. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of H2O2-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and H2O2-dependent Rac1 activation.

Heparin-induced thrombocytopenia: A critical appraisal of clinical practice guidelines with the AGREE II instrument.

BACKGROUND: Despite the availability of clinical practice guidelines (CPGs), the risk of death or thromboembolic complication associated with heparin-induced thrombocytopenia (HIT) remains high. Our aim was to systematically review the quality of CPGs for HIT and summarize the recommendations. METHODS: CPGs for HIT were systematically searched on PubMed, Embase, guidelines' websites, and Google up to August 6, 2017. Independently, three appraisers assessed the quality of CPGs using the Appraisal of Guidelines for Research & Evaluation II (AGREE II) instrument and extracted the data. Recommendations were summarized, and a comparative study was conducted to analyze the consistency among guidelines. RESULTS: A total of 11 CPGs were evaluated. The quality assessed by AGREE II varied widely, not only between domains within guidelines, but also between guidelines across domains. The domain of scope and purpose and clarity of presentation obtained the highest median scores, while the domain of rigor of development and editorial independence obtained the lowest median scores. The ACCP guideline and BSH guideline were recommended for use in dealing with HIT, achieving a score of at least 50% in all six AGREE II domains. Recommendations across guidelines were inconsistent, especially in the choice of non-heparin anticoagulant for HIT. CONCLUSIONS: Future HIT guidelines should place more emphasis on methodological quality and improve efforts to include cost and local availability of drugs when providing recommendations.

[Simvastatin prevented myocardium of diabetes rats from apoptosis through inhibition of oxidative stress].

OBJECTIVE: To investigate the protective effects and the possible mechanisms of simvastatin on myocardial injury induced by diabetes. METHODS: Twenty-four SD rats (180~220)g were randomly divided into control group (control, n=8) and modeled groups(n=16), the modeled groups were injected with streptozotocin intraperitoneally to induce diabetes. Then the modeled rats were randomly divided into diabetes mellitus group (DM group, n=8) and diabetes mellitus + simvastatin group (DM+S group, n=8). Rats in DM+S group were treated with simvastatin at the dose of 40 mg/(kg·d)by gavage for 4 weeks, and the other two groups were treated with the same amount of saline. At the end of experiments, the heart tissues were collected for further observation. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in heart tissues were measured by spectrophotometry; HE staining of rat heart slides was used to observe the pathological changes; TUNEL assay was used to determine the apoptosis index of myocardial cells in each groups; The distribution of p53 in the heart tissues was evaluated by immunohistochemistry; Western blot was used to detect the expressions of p53, p53-phospho-serine 15, Bax and Bcl-2 in the heart tissues. RESULTS: ①Compared with control group, the content of malondialdehyde (MDA) was increased while the activity of superoxide dismutase (SOD) was decreased significantly in DM group (P<0.01). After simvastatin administration, the activity of SOD was increased and the content of MDA was decreased significantly (P<0.01). ② HE staining results showed that the myocardial cells in the DM group were disorganized, with unclear morphological structure and a large number of inflammatory cells infiltration. Compared with DM group, the myocardial morphology in DM+S group was improved significantly. ③TUNEL staining results showed that the apoptosis index of myocardial cells in DM group was increased significantly compared with that of control group, and the apoptosis index was decreased significantly after the treatment of simvastatin (P<0.01).④ Immunohistochemistry showed that compared with control group,the expression of p53 in DM group was increased significantly, and was expressed in both cytoplasm and nucleus, while the expression of p53 in DM+S group was decreased and the expression of p53 in nucleus was decreased significantly (P<0.01). ⑤ The results of Western blot showed that the expression levels of p53, p53-phospho-serine15 and Bax were higher than those in control group, and the expression of Bcl-2 was lower than that in control group (P<0.01). After simvastatin administration, the expression levels of p53,p53-phospho-serine 15 (P<0.01) and Bax were decreased significantly (P<0.05) and the expression of Bcl-2 was increased (P<0.05). CONCLUSIONS: Simvastatin exerted protective effects on myocardial injury caused by diabetes through improving the abnormal morphological changes of diabetic myocardium, alleviating oxidative stress and inhibiting apoptosis of myocardial cells. The mechanism is related to the regulation of apoptosis pathway mediated by p53.

[Protective effect of simvastatin on kidney of rats with diabetes mellitus and the possible mechanism].

OBJECTIVE: To observe the protective effect of simvastatin on renal injury in diabetic rats and to explore the possible molecular mechanism. METHODS: Twenty-four SD rats were randomly divided into normal control (NC) group (n=8) and modeling group (n=16).The rats in modeling group were injected with streptozotocin intraperitoneally at a dose of 55 mg/kg to establishing diabetic rat model. After diabetic ratmodel established successfully, the diabetic rats were randomly subdivided into diabetes mellitus (DM) group and diabetes mellitus + simvastatin (DM+Sim) group (n=8).Rats in DM+Sim group were given simvastatin at a dose of 40 mg/kg by oral gavages, once a day for 4 weeks. Morphological changes and interstitial fibrosis of kidney were observed by histopathological method. The expressions of relative protein in endoplasmic reticulum stress, inflammatory molecules in renal tissues and cells apoptosis were detected by molecular biology method. RESULTS: ① Compared with NC group, the pathological changes of glomerulus and tubulointerstitium were obvious, and the collagen fibers were obviously erythrophilous and unevenly distributed in DM group. Compared with DM group, the morphological changes and fibrosis were significantly improved in DM+Sim group. ② The expressions of GRP78, p-IRE1α, NF-κB p65 and MCP-1 in DM group were significantly higher than those in NC group (P<0.05), while the expressions of GRP78, p-IRE1α, NF-κB p65 and MCP-1in DM + Sim group were decreased (P<0.05). ③ There were a small number of apoptotic nuclei in the glomeruli and adjunctive renal tubules in NC group detected by TUNEL assay, while there were a large number of apoptotic nuclei in DM group (P<0.01). The number of apoptotic nuclei was decreased significantly in DM+Sim group (P<0.01). CONCLUSIONS: Morphologicalchanges and fibrosis of renal tissue are improved obviously, and the number of apoptotic cells is decreased significantly after administration of simvastatin in diabetic rats. Simvastatin exertsthe protective effect on diabetic nephropathy by inhibiting endoplasmic reticulum stress and NF-κB inflammatory signaling pathway, and reducing renal cell apoptosis.

Carbachol exhibited positive inotropic effect on rat ventricular myocytes via M2 muscarinic receptors.

The present study was aimed to investigate the positive inotropic mechanism of carbachol (CCh) on rat ventricular myocytes. The effects of CCh on L-type calcium current (I(Ca,L)) and Na(+)/Ca(2+) exchange current (I(Na/Ca)) were investigated in isolated rat ventricular myocytes. After loading myocytes with Fura-2/AM, electrically triggered Ca(2+) transient and cell shortening in single myocyte were measured simultaneously using ion imaging system with charge-coupled device (CCD) camera. CCh (100 mumol/L) increased I(Na/Ca) in forward mode from (1.18 +/- 0.57) pA/pF in the control group to (1.65 +/- 0.52) pA/pF (P<0.01) and that in reverse mode from (1.11 +/- 0.49) pA/pF in the control group to (1.53 +/- 0.52) pA/pF (P<0.01), respectively. CCh had no effect on I(Ca,L). The stimulatory effect of CCh on I(Na/Ca) was blocked by application of atropine, a non-selective M muscarinic receptor antagonist, and methoctramine, a selective M(2) muscarinic receptor antagonist. CCh (100 mumol/L) increased cell shortening from (3.00 +/- 0.67) mum in the control group to (3.55 +/- 1.21) mum. Ca(2+) transient was also increased from 203.8 +/- 50.0 in the control group to 234.8 +/- 64.3 in 100 mumol/L CCh group. KB-R7943, a selective inhibitor of reverse mode Na(+)/Ca(2+) exchange, did not change the baseline level of cell shortening and Ca(2+) transient, while completely abolished CCh-induced increments of both Ca(2+) transient and cell shortening. CCh increased cell shortening and Ca(2+) transient in the presence of nicardipine, indicating that the positive inotropic effect of CCh was through activation of Na(+)/Ca(2+) exchange. Calcium sensitivity was not changed by CCh. Both atropine and methoctramine abolished the positive inotropic effects of CCh, demonstrating that CCh induced positive inotropism via the M(2) muscarinic receptor. The results suggest that CCh increases cell contraction and Ca(2+) transient in rat ventricular myocytes. This positive inotropic effect of CCh is through activation of reverse mode Na(+)/Ca(2+) exchange, and M(2) receptors are involved in mediating CCh-induced contraction.

[SR 59230A on the expression of MicroRNAs in myocardium of heart failure rats].

OBJECTIVE: To investigate the effects of ß3-adrenoceptors(ß3-AR) inhibitor SR 59230A on MicroRNAs expression in rat myocardium with chronic heart failure and the related mechanisms. METHODS: One hundred male SD rats were randomly divided into sham operated group(40)and chronic heart failure(CHF)group(60). Coronary artery ligation was used to induce CHF. Then the rats in CHF group were further randomly divided into CHF control group and CHF+SR 59230A group (CHF+SR). Rats in the sham group were divided into sham control group and sham+SR 59230A group (Sham+SR). The rats in Sham+SR group and CHF+SR group were treated with 1 ml SR 59230A(85 mmoL/L in 0.9% saline)twice a day for seven weeks by intraperitoneal injection, while the rats in control groups were injected with the same amount of saline for seven weeks separately. miScript miRNA PCR Arrays were used to determine the expression profile of MicroRNAs. Immunohistochemistry was used to evaluate the distribution of the related proteins in the heart tissue sections. Western blot was used to detect the expressions of nuclear factor-kappaB(NF-κB),p53 and p53-Phospho-Serine 15 in the heart. RESULTS: ①After in vivo blockade of ß3-AR by SR 59230A, there were 18MicroRNAs down-regulated in sham control group and CHF control group. Within them, 6 MicroRNAs were related to NF-κB signaling pathway, they were miR-125b-5p,miR-143-3p,miR-145-5p,miR-26a-5p,miR-30a-5p and miR-320-5p. ②Slides from the heart tissue showed that NF-κB was distributed both in nucleus and cytoplasm, while p53 in cytoplasm was more than that in nucleus in heart tissue sections. The expressions of NF-κB and p53 were higher in the CHF control group than those in the sham control group(P<0.05), but were lower in CHF+SR group than those in CHF control group(P<0.05),while they were elevated in Sham+SR group compared to the sham control group(P<0.05). ③ Compared with the sham control group, the protein expression of NF-κB p65 was increased significantly in the CHF control group (P<0.05). After treated with SR59230A in vivo,the protein expressions of NF-κB and p53-Phospho-Serine 15 were decreased significantly in CHF rats(P<0.05),while the protein expressions of NF-κB, p53 and p53-Phospho-Serine 15 proteins were increased in the sham rats (P<0.05). CONCLUSIONS: Blocking of ß3-AR improved the damaged heart in CHF rats; ß3-AR caused the change of MicroRNAs expression, and it related to NF-κB signal pathway.