Resistance exercise upregulates Irisin expression and suppresses myocardial fibrosis following myocardial infarction via activating AMPK-Sirt1 and inactivating TGFß1-Smad2/3.

AIM: To reveal the contribution of Irisin in the beneficial effects of resistance exercise on myocardial fibrosis (MF) and cardiac function in the mice with myocardial infarction (MI). METHODS: The MI model was built by ligating the left anterior descending coronary artery in Fndc5 knockout mice (Fndc5-/-). Resistance exercise was started one week after surgery and continued for four weeks. In addition, H2O2, AICAR, recombinant human Irisin protein (rhIRISIN), and Sirt1 shRNA lentivirus (LV-Sirt1 shRNA) were used to intervene primary isolated cardiac fibroblasts (CFs). MF was observed through Masson staining, and apoptosis was assessed using TUNEL staining. MDA and T-SOD contents were detected by biochemical kits. The expression of proteins and genes was detected by Western blotting and RT-qPCR. RESULTS: Resistance exercise increased Fndc5 mRNA level, inhibited the activation of TGFß1-TGFßR2-Smad2/3 pathway, activated AMPK-Sirt1 pathway, reduced the levels of oxidative stress, apoptosis, and MF in the infarcted heart, and promoted cardiac function. However, Fndc5 knockout attenuated the protective effects of resistance exercise on the MI heart. Results of the in vitro experiments showed that AICAR and rhIRISIN intervention activated the AMPK-Sirt1 pathway and inactivated the TGFß1-Smad2/3 pathway, and promoted apoptosis in H2O2-treated CFs. Notably, these effects of rhIRISIN intervention, except for the TGFßR2 expression, were attenuated by LV-Sirt1 shRNA. CONCLUSION: Resistance exercise upregulates Fndc5 expression, activates AMPK-Sirt1 pathway, inhibits the activation of TGFß1-Smad2/3 pathway, attenuates MF, and promotes cardiac function after MI.

Roxadustat and Oral Iron Absorption in Chinese Patients with Anemia of Chronic Kidney Disease: A Randomized, Open-Label, Phase 4 Study (ALTAI).

INTRODUCTION: Anemia of chronic kidney disease (CKD) has a high incidence and is associated with many disease conditions. Iron dysmetabolism is an important contributor to anemia in CKD patients. METHODS: ALTAI, a randomized, active-controlled, phase 4 trial, investigated the efficacy of roxadustat versus recombinant human erythropoietin (rHuEPO) on gastrointestinal iron absorption in patients with anemia of CKD (stage 4/5). The primary endpoint was change from baseline to day 15 in gastrointestinal iron absorption (serum iron area under the concentration-time curve; AUC0-3h) following single-dose oral iron. RESULTS: Twenty-five patients with a mean age of 55.1 years were randomized 1:1 to roxadustat (n = 13) or rHuEPO (n = 12). Baseline iron profiles were similar between treatment groups. Change from baseline to day 15 in serum iron AUC0-3h was not statistically significantly different between the roxadustat and rHuEPO groups. Mean (SD) change from baseline in serum iron AUC0-3h was 11.3 (28.2) g × 3 h/dl in the roxadustat group and - 0.3 (9.7) g × 3 h/dl in the rHuEPO group. Roxadustat treatment was associated with decreased hepcidin and also increased transferrin, soluble transferrin receptor, and total iron-binding capacity (TIBC), with nominal significance. The proportion of patients experiencing one or more adverse events was 38.5% when treated with roxadustat and 16.7% with rHuEPO. CONCLUSIONS: The study showed no significant difference between roxadustat and rHuEPO in iron absorption but was underpowered because of recruitment challenges. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT04655027.

Pegmolesatide for the treatment of anemia in patients undergoing dialysis: a randomized clinical trial.

Background: Pegmolesatide, a synthetic peptide-based erythropoietin (EPO) receptor agonist, is being evaluated as an alternative to epoetin alfa for treating anemia of chronic kidney disease (CKD) in Chinese dialysis patients. There is a critical need for a long-acting, cost-effective erythropoiesis-stimulating agent that does not produce EPO antibodies. Methods: A randomized, open-label, active-comparator, non-inferiority phase three trial was conducted at 43 dialysis centers in China between May 17th, 2019, and March 28th, 2022. Eligible patients aged 18-70 years were randomly assigned (2:1) to receive pegmolesatide once every four weeks or epoetin alfa one to three times per week, with doses adjusted to maintain a hemoglobin level between 10.0 and 12.0 g/dL. The primary efficacy endpoint was the mean change in hemoglobin level from baseline to the efficacy evaluation period in the per-protocol set (PPS) population. Non-inferiority of pegmolesatide to epoetin alfa was established if the lower limit of the two-sided 95% confidence interval for the between-group difference was ≥ -1.0 g/dL. Safety assessment included adverse events and potential anaphylaxis reactions. This trial is registered at ClinicalTrials.gov, NCT03902691. Findings: Three hundreds and seventy-two patients were randomly assigned to the pegmolesatide group (248 patients) or the epoetin alfa group (124 patients). A total of 347 patients (233 in the pegmolesatide group and 114 in the epoetin alfa group) were included in the PPS population. In the PPS, the mean change (standard deviation, SD) in hemoglobin level from baseline to the efficacy evaluation period was 0.07 (0.92) g/dL in the pegmolesatide group and -0.22 (0.97) g/dL in the epoetin alfa group. The between-group difference was 0.29 g/dL (95% confidence interval: 0.11-0.47), verifying non-inferiority of pegmolesatide to epoetin alfa. Adverse events occurred in 231 (94%) participants in the pegmolesatide group and in 110 (89%) in the epoetin alfa group. Hypertension was the most common treatment-related adverse event. No fatal cases of anaphylaxis or hypotension were reported. Interpretation: Monthly subcutaneously injection of pegmolesatide was as effective and safe as conventional epoetin alfa administrated one to three times a week in treating anemia in Chinese dialysis patients. Funding: The study was supported by Hansoh Medical Development Group.

Hyperkalaemia prevalence and dialysis patterns in Chinese patients on haemodialysis: an interim analysis of a prospective cohort study (PRECEDE-K).

BACKGROUND: Hyperkalaemia is a known risk factor for cardiac arrhythmia and mortality in patients on haemodialysis. Despite standard adequate haemodialysis, hyperkalaemia is common in patients with end-stage renal disease (ESRD) at interdialytic intervals. Data on hyperkalaemia burden and its effects on dialysis patterns and serum potassium (sK) fluctuations in patients on haemodialysis in China remain limited. The prospective, observational cohort study (PRECEDE-K; NCT04799067) investigated the prevalence, recurrence, and treatment patterns of hyperkalaemia in Chinese patients with ESRD on haemodialysis. METHODS: Six hundred adult patients were consecutively enrolled from 15 secondary and tertiary hospitals in China. In this interim analysis, we report the baseline characteristics of the cohort, the prevalence of predialysis hyperkalaemia (sK > 5.0 mmol/L), and the trends in serum-dialysate potassium gradient and intradialytic sK shift at Visit 1 (following a long interdialytic interval [LIDI]). RESULTS: At baseline, most patients (85.6%) received three-times weekly dialysis; mean duration was 4.0 h. Mean urea reduction ratio was 68.0% and Kt/V was 1.45; 60.0% of patients had prior hyperkalaemia (previous 6 months). At Visit 1, mean predialysis sK was 4.83 mmol/L, and 39.6% of patients had hyperkalaemia. Most patients (97.7%) received a dialysate potassium concentration of 2.0 mmol/L. The serum-dialysate potassium gradient was greater than 3 mmol/L for over 40% of the cohort (1- < 2, 2- < 3, 3- < 4, and ≥ 4 mmol/L in 13.6%, 45.1%, 35.7%, and 5.2% of patients, respectively; mean: 2.8 mmol/L). The intradialytic sK reduction was 1- < 3 mmol/L for most patients (0- < 1, 1- < 2, 2- < 3, and ≥ 3 mmol/L in 24.2%, 62.2%, 12.8%, and 0.9% of patients, respectively; mean: 1.4 mmol/L). CONCLUSIONS: Hyperkalaemia after a LIDI was common in this real-world cohort of Chinese patients despite standard adequate haemodialysis, and led to large serum-dialysate potassium gradients and intradialytic sK shifts. Previous studies have shown hyperkalaemia and sK fluctuations are highly correlated with poor prognosis. Effective potassium-lowering treatments should be evaluated for the improvement of long-term prognosis through the control of hyperkalaemia and sK fluctuations. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04799067.

A self-adjusting ant colony clustering algorithm for ECG arrhythmia classification based on a correction mechanism.

BACKGROUND AND OBJECTIVE: As a representative type of cardiovascular disease, persistent arrhythmias can often become life-threatening. In recent years, machine learning-based ECG arrhythmia classification aided methods have been effective in assisting physicians with their diagnosis, but these methods have problems such as complex model structures, poor feature perception ability, and low classification accuracy. METHODS: In this paper, a self-adjusting ant colony clustering algorithm for ECG arrhythmia classification based on a correction mechanism is proposed. This method does not distinguish between subjects when establishing the dataset in order to reduce the effect of differences in ECG signal features between individuals, thus improving the robustness of the model. When the classification is achieved, a correction mechanism is introduced to correct outliers caused by the accumulation of errors in the classification process in order to improve the classification accuracy of the model. According to the principle that the flow rate of gas can be increased under the convergence channel, a dynamically updated pheromone volatilization coefficient ρ, namely the increased flow rate ρ, is introduced to help the model converge more stably and faster. As the ants move, the next transfer target is selected by a truly self-adjusting transfer method, and the transfer probability is dynamically adjusted according to the pheromone concentration and the path distance. RESULTS: Based on the MIT-BIH arrhythmia dataset, the new algorithm achieved classification of five heart rhythm types, with an overall accuracy of 99.00%. Compared to other experimental models, the classification accuracy of the proposed method represents a 0.2% to 16.6% improvement, and compared to other current studies, the classification accuracy of the proposed method is 0.65% to 7.5% better. CONCLUSIONS: This paper addresses the shortcomings of ECG arrhythmia classification methods based on feature engineering, traditional machine learning and deep learning, and presents a self-adjusting ant colony clustering algorithm for ECG arrhythmia classification based on a correction mechanism. Experiments demonstrate the superiority of the proposed method compared to basic models as well as those with improved partial structures. Furthermore, the proposed method achieves very high classification accuracy with a simple structure and fewer iterations than other current methods.

FNDC5/Irisin Inhibits the Inflammatory Response and Mediates the Aerobic Exercise-Induced Improvement of Liver Injury after Myocardial Infarction.

Myocardial infarction (MI) causes peripheral organ injury, in addition to cardiac dysfunction, including in the liver, which is known as cardiac hepatopathy. Aerobic exercise (AE) can effectively improve liver injury, although the mechanism and targets are currently not well established. Irisin, mainly produced by cleavage of the fibronectin type III domain-containing protein 5 (FNDC5), is a responsible for the beneficial effects of exercise training. In this study, we detected the effect of AE on MI-induced liver injury and explored the role of irisin alongside the benefits of AE. Wildtype and Fndc5 knockout mice were used to establish an MI model and subjected to AE intervention. Primary mouse hepatocytes were treated with lipopolysaccharide (LPS), rhirisin, and a phosphoinositide 3-kinase (PI3K) inhibitor. The results showed that AE significantly promoted M2 polarization of macrophages and improved MI-induced inflammation, upregulated endogenous irisin protein expression and activated the PI3K/ protein kinase B (Akt) signaling pathway in the liver of MI mice, while knockout of Fndc5 attenuated the beneficial effects of AE. Exogenous rhirisin significantly inhibited the LPS-induced inflammatory response, which was attenuated by the PI3K inhibitor. These results suggest that AE could effectively activate the FNDC5/irisin-PI3K/Akt signaling pathway, promote the polarization of M2 macrophages, and inhibit the inflammatory response of the liver after MI.

Irisin is an Effector Molecule in Exercise Rehabilitation Following Myocardial Infarction (Review).

Background: Regular exercise is an effective non-pharmacological therapy for treatment and prevention of cardiovascular disease (CVD). The therapeutic benefits of exercise are mediated partly through improved vascular and increase in metabolic health. Release of exercise-responsive myokines, including irisin, is associated with beneficial effects of exercise in CVD patients. Observations: The present review provides an overview of the role of exercise in cardiac rehabilitation of patients with myocardial infarction (MI). Further, the role of irisin as a motion-responsive molecule in improving vascular and metabolic health is explored. Possible mechanism of cardioprotective effect of irisin-mediated exercise on myocardial infarction are also summarized in this review. Conclusion and significance of the review: Irisin is associated with reduced inflammation, antioxidant properties, and anti-apoptotic effect, implying that it is a potential key mediator of the beneficial effects of exercise on vascular and metabolic health. The findings show that irisin is a promising therapeutic target for treatment of patients with cardiovascular disease, particularly post-MI. Further research should be conducted to elucidate the potential mechanisms of cardioprotective effects of irisin and explored whether irisin induced by exercise exerts rehabilitation effects post-MI.

Hyperkalaemia prevalence, recurrence and treatment in patients on haemodialysis in China: protocol for a prospective multicentre cohort study (PRECEDE-K).

INTRODUCTION: Hyperkalaemia (HK) is a potentially life-threatening electrolyte imbalance associated with several adverse clinical outcomes and is common in patients with kidney failure. However, there is no evidence on the occurrence, recurrence and treatment of HK in patients on haemodialysis (HD) in China. METHODS AND ANALYSIS: The HK Prevalence, Recurrence, and Treatment in Haemodialysis Study is a prospective, multicentre, observational, cohort study being conducted across 15-18 sites in China. Approximately 600 patients with end-stage kidney disease on HD are anticipated to be enrolled and will be followed up for 24 weeks. Patients will be in the long interdialytic interval (LIDI) at enrolment and will receive follow-up care every 4 weeks in LIDI for pre-dialysis and post-dialysis (at enrolment only) serum potassium measurements. To obtain pre-dialysis serum potassium levels in the short interdialytic interval (SIDI), a follow-up visit will be performed in the SIDI during the first week. Information on concomitant medications, blood gas analysis and biochemistry measurements will be obtained at enrolment and at each follow-up visit. The primary endpoint will be the proportion of patients experiencing HK (defined as serum potassium level >5.0 mmol/L) at the study enrolment or during the 24-week follow-up. The key secondary endpoint will be the proportion of patients experiencing HK recurrence (defined as any HK event after the first HK event) within 1-6 months (if applicable) during the 24-week follow-up, including enrolment assessment. ETHICS AND DISSEMINATION: This study has been approved by Shanghai Jiaotong University School of Medicine, Renji Hospital Ethics Committee (2020-040). Other participating subcentres must also obtain ethics committee approval prior to the start of the study. The Good Clinical Practice regulations shall be strictly followed during the test implementation. Amendments to the protocol will be reviewed by the ethics committees. Written informed consent will be obtained from all participants before collection of any patient data and patient information. The findings of this study will be disseminated through peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT04799067).

Exercise Training Enhances Myocardial Mitophagy and Improves Cardiac Function via Irisin/FNDC5-PINK1/Parkin Pathway in MI Mice.

Myocardial infarction is the major cause of death in cardiovascular disease. In vitro and in vivo models are used to find the exercise mode which has the most significant effect on myocardial irisin/FNDC5 expression and illuminate the cardioprotective role and mechanisms of exercise-activated myocardial irisin/FNDC5-PINK1/Parkin-mediated mitophagy in myocardial infarction. The results indicated that expression of irisin/FNDC5 in myocardium could be up-regulated by different types of exercise and skeletal muscle electrical stimulation, which then promotes mitophagy and improves cardiac function and the effect of resistance exercise. Resistance exercise can improve cardiac function by activating the irisin/FNDC5-PINK1/Parkin-LC3/P62 pathway, regulating mitophagy and inhibiting oxidative stress. OPA1 may play an important role in the improvement of cardiac function and mitophagy pathway in myocardial infarction mice by irisin-mediated resistance exercise. Resistance exercise is expected to become an effective therapeutic way to promote myocardial infarction rehabilitation.

Endothelial dysfunction and vascular maladaptation in atrial fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia and is associated with worsened morbidity and mortality. The prevalence of AF is estimated to increase with an ageing population resulting in an ever-increasing burden on the healthcare system. Despite improvements in AF treatment, several questions remain unanswered in relation to the development and progression of AF. In this review, we discuss the evidence supporting the presence of vascular dysfunction in the development of AF, but also as a final common pathway explaining why AF constitutes a markedly increased risk of cardiovascular morbidity and mortality. Specifically, we summarise the work performed in humans related to the impact of AF on vascular structure and function, and whether measures of vascular function predict AF progression and the development of cardiovascular events. Subsequently, we discuss the potential mechanisms linking AF to the development of vascular dysfunction. Finally, we propose future perspectives of vascular health and AF, advocating a strong focus on regular exercise training as a safe and effective strategy to improve vascular function and, hence, reduce the risk for development and progression of AF and its associated risk for cardiovascular events.

Clinical Features and Risk Factors of ICU Admission for COVID-19 Patients with Diabetes.

INTRODUCTION: Previous studies of coronavirus disease 2019 (COVID-19) have focused on the general population. However, diabetes (DM) as one of the most common comorbidities is rarely studied in detail. This study is aimed at describing clinical characteristics and determining risk factors of ICU admission for COVID-19 patients with DM. METHODS: Data were extracted from 288 adult patients with laboratory-confirmed COVID-19 from Guangzhou Eighth People's Hospital. Demographic characteristics, laboratory results, radiographic findings, complications, and treatments were collected and compared between DM and non-DM groups. Binary logistic regression was used to identify the risk factors associated with ICU admission for COVID-19 patients with DM or non-DM. RESULTS: COVID-19 patients with DM showed as older ages, higher levels of C-reactive protein (CRP), myoglobin, alanine transaminase (ALT), and aspartate transaminase (AST). They were also more prone to transfer to the intensive care unit (ICU) for treatment. Multiple regression analysis showed that the following were the independent risk factors for COVID-19 patients with DM that received ICU admission: each 1-year increase in age (odds ratio (OR), 1.07; 95% CI, 1.02-1.13; P = 0.007), respiratory rate over 24 times per minute (OR, 5.22; 95% CI, 2.26-16.58; P = 0.016), HbA1c greater than 7% (OR, 4.58; 95% CI, 1.82-10.55; P = 0.012), and AST higher than 40 U/L (OR, 2.96; 95% CI, 1.58-8.85; P = 0.022). In addition, each 1-year increase in age (OR, 1.05; 95% CI, 1.01-1.10; P = 0.006), diarrhea (OR, 4.62; 95% CI, 2.01-9.36; P = 0.022), respiratory rate over 24 times per minute (OR, 5.13; 95% CI, 1.18-16.82; P = 0.035), CRP greater than 10 mg/L (OR, 5.19; 95% CI, 1.37-13.25, P = 0.009), and TnI higher than 0.03 µg/L (OR, 6.48; 95% CI, 1.17-21.38; P = 0.036) were risk factors for ICU admission of COVID-19 patients with non-DM. CONCLUSIONS: The older age, respiratory rate over 24 times per minute, HbA1c greater than 7%, and AST higher than 40 U/L were risk factors of ICU admission for COVID-19 patients with diabetes. Investigating and monitoring these factors could assist in the risk stratification of COVID-19 patients with DM at an early stage.

Clinical features and risk factors for ICU admission in COVID-19 patients with cardiovascular diseases.

Previous studies on coronavirus disease 2019 (COVID-19) have focused on the general population. However, cardiovascular disease (CVD) is a common comorbidity that has rarely been investigated in detail. This study aims to describe clinical characteristics and determine risk factors for intensive care unit (ICU) admission of COVID-19 patients with CVD. In this retrospective cohort study, we included 288 adult patients with COVID-19 in Guangzhou Eighth People's Hospital from January 15, 2020 to March 10, 2020. Demographic characteristics, laboratory results, radiographic findings, complications, and treatments were recorded and compared between CVD and non-CVD groups. A binary logistic regression model was used to identify risk factors associated with ICU admission for infected patients with underlying CVD. COVID-19 patients in the CVD group were older and had higher levels of troponin I (TnI), C-reactive protein (CRP), and creatinine. They were also more prone to develop into severe or critically severe cases, receive ICU admission, and require respiratory support treatment. Multivariate regression analysis showed that the following were risk factors for ICU admission in COVID-19 patients with CVD: each 1-year increase in age (odds ratio (OR), 1.08; 95% confidence interval (CI), 1.02-1.17; p = 0.018); respiratory rate over 24 times per min (OR, 25.52; 95% CI, 5.48-118.87; p < 0.0001); CRP higher than 10 mg/L (OR, 8.12; 95% CI, 1.63-40.49; p = 0.011); and TnI higher than 0.03 µg/L (OR, 9.14; 95% CI, 2.66-31.43; p < 0.0001). Older age, CRP greater than 10 mg/L, TnI higher than 0.03 µg/L, and respiratory rate over 24 times per minute were associated with increasing odds of ICU admission in COVID-19 patients with CVD. Investigating and monitoring these factors could assist in the risk stratification of COVID-19 patients with CVD at an early stage.

Risk factors for severe cases of COVID-19: a retrospective cohort study.

BACKGROUND: SARS-CoV-2 has raged around the world since March, 2020. We aim to describe the clinical characteristics and risk factors of severe patients with COVID-19 in Guangzhou. RESULTS: The severity and mortality of COVID-19 was 10.4% and 0.3% respectively. And each 1-year increase in age (OR, 1.057; 95% CI, 1.018-1.098; P=0.004), Wuhan exposure history greater than 2 weeks (OR, 2.765; 95% CI, 1.040-7.355; P=0.042), diarrhea (OR, 24.349; 95% CI, 3.580-165.609; P=0.001), chronic kidney disease (OR, 6.966; 95% CI, 1.310-37.058; P = 0.023), myoglobin higher than 106 µg/L (OR, 8.910; 95% CI, 1.225-64.816; P=0.031), white blood cell higher than 10×109/L (OR, 5.776; 95% CI, 1.052-31.722; P=0.044), and C-reactive protein higher than 10 mg/L (OR, 5.362; 95% CI, 1.631-17.626; P=0.006) were risk factors for severe cases. CONCLUSION: Older age, Wuhan exposure history, diarrhea, chronic kidney disease, elevated myoglobin, elevated white blood cell and C-reactive protein were independent risk factors for severe patients with COVID-19 in Guangzhou. METHODS: We included 288 adult patients with COVID-19 and compared the data between severe and non-severe group. We used univariate and multivariate logistic regression methods to explore risk factors of severe cases.

Successful recovery of recurrence of positive SARS-CoV-2 RNA in COVID-19 patient with systemic lupus erythematosus: a case report and review.

COVID-19 has become a global concern. A large number of reports have explained the clinical characteristics and treatment strategies of COVID-19, but the characteristics and treatment of COVID-19 patient with systemic lupus erythematosus (SLE) are still unclear. Here, we report the clinical features and treatment of the first SLE patient with confirmed COVID-19 pneumonia. This was a 39-year-old woman, diagnosed with SLE 15 years ago, whose overall clinical characteristics (symptoms, laboratory tests, and chest CTs) were similar to those of the general COVID-19 patients. She continued to take the previous SLE drugs (doses of glucocorticoids, hydroxychloroquine, and immunosuppressive agents were not reduced) and was treated with strict antiviral and infection prevention treatment. After the first discharge, she got a recurrence of COVID-19 during her home isolation, and then returned to hospital and continued the previous therapy. Finally, this long-term immune suppressive patient's COVID-19 was successfully cured. The successful recovery of this case has significant reference value for the future treatment of COVID-19 patients with SLE. Key Points • COVID-19 patients with SLE is advocated to continue the medical treatment for SLE. • Hydroxychloroquine may have potential benefits for COVID-19 patients with SLE. • COVID-19 patients with SLE is prone to relapse, and multiple follow-ups are necessary.

Vernakalant hydrochloride for the treatment of atrial fibrillation: evaluation of its place in clinical practice.

Vernakalant is an intravenous anti-arrhythmic drug available in Europe, Canada and some countries in Asia for the restoration of sinus rhythm in acute onset atrial fibrillation. Currently, it is not available in USA because the US FDA have ongoing concerns about its safety. Vernakalant has a unique pharmacological profile of multi-ion channel activity and atrial-specificity that distinguishes it from other anti-arrhythmic drugs. This is thought to enhance efficacy but there are concerns of adverse events stemming from its diverse pharmacology. This ambiguity has prompted a review of the available clinical evidence on efficacy and safety to help re-evaluate its place in clinical practice.

ERK1/2 communicates GPCR and EGFR signaling pathways to promote CTGF-mediated hypertrophic cardiomyopathy upon Ang-II stimulation.

BACKGROUND: Hypertrophic cardiomyopathy occurs along with pathological phenomena such as cardiac hypertrophy, myocardial fibrosis and cardiomyocyte activity. However, few of the specific molecular mechanisms underlying this pathological condition have been mentioned. METHODS: All target proteins and markers expression in the study was verified by PCR and western bloting. H9c2 cell morphology and behavior were analyzed using immunofluorescent and proliferation assays, respectively. And, the CTGF protein secreted in cell culture medium was detected by ELISA. RESULTS: We found that high expression of CTGF and low expression of EGFR were regulated by ERK1/2 signaling pathway during the cardiac hypertrophy induced by Ang-II stimulation. CTGF interacted with EGFR, and the interaction is reduced with the stimulation of Ang-II. ERK1/2 serves as the center of signal control during the cardiac hypertrophy. CONCLUSION: The ERK1/2 cooperates with GPCR and EGFR signaling, and promotes the occurrence and development of cardiac hypertrophy by regulating the expression and binding states of CTGF and EGFR. The study revealed a regulation model based on ERK1/2, suggesting that ERK1/2 signaling pathway may be an important control link for mitigation of hypertrophic cardiomyopathy treatment.

3-Bromo-4,5-Dihydroxybenzaldehyde Protects Against Myocardial Ischemia and Reperfusion Injury Through the Akt-PGC1α-Sirt3 Pathway.

Natural marine products are useful candidates for the treatment of oxidative and inflammatory diseases, including myocardial ischemia. 3-bromo-4,5 - dihydroxybenzaldehyde (BDB), a natural bromophenol isolated from marine red algae, has been shown to display anti-microbial, anti-oxidative, anti-cancer, anti-inflammatory, and free radical scavenging activities. In this study, the potential protective effects of BDB against myocardial ischemia and reperfusion (IR) injury was investigated in an in vitro model mimicked by oxygen and glucose deprivation (OGD) in cardiomyocytes and in an in vivo model induced by coronary artery ligation in rats. The results showed that BDB attenuated the OGD-induced cytotoxicity in a dose-dependent manner, with no toxic effect when treated alone. BDB significantly decreased apoptosis and the cleavage of caspase-3 after OGD. We found that OGD-induced oxidative stress, as evidenced by increases of reactive oxygen species (ROS) and lipid peroxidation, as well as mitochondrial dysfunction, as measured by mitochondrial reporter gene, cytochrome c release and ATP synthesis, were markedly attenuated by BDB treatment. In addition, BDB increased the enzymatic activities of mitochondrial antioxidant enzymes, including IDH2, GSH-Px and SOD2. Western blot analysis showed that BDB increased Akt phosphorylation and upregulated the expression of Sirt3 and PGC1α after OGD. Furthermore, BDB-induced protection in cardiomyocytes was partially reversed by the Akt inhibitor and downregulation of PGC1α. BDB also attenuated myocardial contractile dysfunction and activated the Akt-PGC1α-Sirt3 pathway in vivo. All these data suggest that BDB protects against myocardial IR injury through activating the Akt-PGC1α-Sirt3 pathway.

Assessment of creatinine and cystatin C-based eGFR equations in Chinese older adults with chronic kidney disease.

INTRODUCTION: Glomerular filtration rate (GFR) estimation equations using creatinine and Cystatin-C appear to be superior to those based on creatinine or Cystatin-C in older adults. We sought to compare the performances of those based on creatinine and Cystatin-C in Chinese older adults with chronic kidney disease (CKD). METHODS: A total of 368 Chinese elderly with CKD underwent the dynamic imaging with technetium-99m diethylene-triamine-pentaacetic acid (99mTc-DTPA), and serum creatinine and Cystatin-C were measured on the same day. The comparison of GFR equations which were creatinine and Cystatin-C-based including chronic kidney disease epidemiology collaboration (CKD-EPI) equation (CKD-EPI-Cr-Cys), Berlin Initiative Study (BIS) equation (BIS-Cr-Cys, also known as BIS-2), MA equation (MA-Cr-Cys), and FENG equation (FENG-Cr-Cys) was conducted. RESULTS: Four equations overestimated GFR except for BIS-2 equation in mGFR ≥ 60 ml/min/1.73 m2 (bias: - 1.40, p = 0.7) and CKD-EPI-Cr-Cys equation in mGFR < 30 ml/min/1.73 m2 (bias: - 1.82, p = 0.2) were unbiased. BIS-2 equation had the smallest interquartile range (IQR, ml/min/1.73 m2) from 12.73 in age < 75 years group to 16.05 in age ≥ 75 years group. BIS-2 equation achieved highest values of 79.1% in overall participants, and 80.77% in age ≥ 75 years group, respectively, and CKD-EPI-Cr-Cys equation 82.26% in age < 75 years group. Lowest values of root-mean-square error (RMSE, ml/min/1.73 m2) were seen in BIS-2 equation from 13.22 in age < 75 years group to 16.18 in age ≥ 75 years group. BIS-2 equation had the lowest misclassification rates of 41.76% in age ≥ 75 years group and 34.41% in age < 75 years group. CONCLUSIONS: BIS-2 equation may be optimal for Chinese older adults with CKD especially in older adults ≥ 75 years and with mGFR ≥ 30 ml/min/1.73 m2, while CKD-EPI-Cr-Cys equation could yield a better performance than BIS-2 equation, especially in those < 75 years and mGFR < 30 ml/min/1.73 m2.

Correlation between serum anti-C1q antibody levels and renal pathological characteristics and prognostic significance of anti-C1q antibody in lupus nephritis.

OBJECTIVE: To investigate the relationship between serum anti-C1q antibody levels and renal pathological characteristics in lupus nephritis as well as the prognostic significance of serum anti-C1q antibody. METHODS: Seventy-three patients with biopsy-proven lupus nephritis were enrolled. Anti-C1q antibody was measured in serum samples taken within 7 days before renal biopsy and remeasured at the end of the first and the third month after treatment. All patients were followed at least once a month for 3 months. A cross-sectional study analyzed the relationship between serum anti-C1q antibody levels and renal histopathology and nephritic activity, while a longitudinal study evaluated the prognostic significance of anti-C1q antibody levels in lupus nephritis. RESULTS: Fifty-eight of 73 patients (79.5%) were reported as having positive baseline serum anti-C1q antibody, with a mean level of 95.3 (+/- 55.2) U/ml. Significant differences were found in serum anti-C1q antibody levels between each World Health Organization (WHO) classification of lupus nephritis. The serum anti-C1q antibody level of WHO class IV was the highest. Serum anti-C1q antibody was positively correlated with the active and chronic indices in renal pathology. Patients with persistent high levels or increased titers of serum anti-C1q antibody tended to develop delayed remission in nephropathy. Serum anti-C1q antibody levels before and after treatment were relevant to renal remission, but serum anti-C1q antibody at the end of the third month after treatment was a stronger predictor for the prognosis after adjustment in the Cox's proportional hazards regression model. CONCLUSION: Serum anti-C1q antibody is a valuable noninvasive biological marker for evaluation of renal involvement and lupus prognosis.