A common variant of RIP3 promoter region is associated with poor prognosis in heart failure patients by influencing SOX17 binding

Association between serum albumin to serum creatinine ratio and mortality risk in patients with heart failure

The aim of this study was to investigate the association between serum albumin to serum creatinine ratio (sACR) and the prognosis of heart failure (HF). In this single-center prospective cohort study, a total of 2625 patients with HF were enrolled between March 2012 and June 2017. All patients were divided into three groups according to the tertiles of sACR. Of 2625 patients, the mean age was 57.0 ± 14.3 years. During a median follow-up time of 23 months, 666 end point events occurred. Prognosis analysis indicated that the lowest sACR was significantly associated with higher mortality risk of HF (hazard ratio [HR] = 1.920, 95% confidence interval [CI] = 1.585-2.326, p < 0.001) when compared with the highest tertile. After adjusting for covariates including age, gender, diabetes, systolic blood pressure (SBP), diastolic blood pressure, heart rate, total cholesterol, triglycerides, HDL-C, LDL-C, white blood cell count, hemoglobin, glycosylated hemoglobin, and β-blocker use, the HRs for mortality risk of HF was 1.513 (95% CI = 1.070-2.139, p = 0.019). Subgroup analysis indicated that the mortality risk of HF statistically significantly reduced with the rise in sACR in patients with no β-blocker use, patients with serum creatine less than 97 μmol/L. However, stratification by age, sex, history of hypertension, diabetes, and smoking, level of glycosylated hemoglobin, and albumin have no obvious effect on the association between sACR and the prognosis of HF. Additionally, patients with lower sACR displayed reduced left ventricular ejection fraction and increased left ventricular end-diastolic diameter. The discriminant power of sACR alone and in combination with age, gender, SBP, heart rate, and glycosylated hemoglobin were excellent with C statistic of 0.655 and 0.889, respectively. Lower sACR was an independent risk factor for mortality risk of HF.

The pathophysiological role of receptor-interacting protein kinase 3 in cardiovascular disease

Recent studies have found that receptor interacting protein kinase 3 (RIPK3) can mediate CaMK Ⅱ phosphorylation and oxidation, open mitochondrial permeability transition pore (mPTP), and induce myocardial necroptosis. The increased expression or phosphorylation of RIPK3 is one of the important markers of necroptosis; Inhibition of CaMK Ⅱ phosphorylation or oxidation significantly reduces RIPK3 mediated myocardial necroptosis; Studies have shown that necroptosis plays an important role in the occurrence and development of cardiovascular diseases; Using the selective inhibitor GSK '872 of RIPK3 can effectively inhibit the occurrence and development of cardiovascular diseases, and can reverse cardiovascular and cardiac dysfunction caused by overexpression of RIPK3. In this review, we provide a brief overview of the current knowledge on RIPK3 in mediating necroptosis, inflammatory response, and oxidative stress, and discussed the role of RIPK3 in cardiovascular diseases such as atherosclerosis, myocardial ischaemia, myocardial infarction, and heart failure.

Association of rs35006907 Polymorphism with Risk of Dilated Cardiomyopathy in Han Chinese Population

Background

Several investigations have demonstrated the association of MTSS1 with left ventricular (LV) structure and function. A recently published study has even revealed that rs35006907 was associated with both MTSS1 expression and the risk of dilated cardiomyopathy (DCM).

Objective

Our study intended to investigate the relationship between rs35006907 and the risk of DCM in the Han Chinese population.

Methods

A total of 529 DCM and 600 healthy controls were recruited. We conducted genotyping for rs35006907 in all participants. Gene association studies were performed to assess the association between rs35006907 and the risk of DCM. A series of functional assays including western blot, realtime PCR and firefly luciferase reporter gene assays were conducted to illuminate the underlying mechanism.

Results

We found that rs35006907-A allele was significantly associated with reduced risk of DCM in additive (p= 0.004; OR=0.78; 95% CI=0.66-0.93) and recessive models (p= 0.0005; OR=0.56; 95%CI=0.41-0.78) when compared with the rs35006907-C allele. There were significant differences in the left ventricular end-diastolic diameter (LVEDD) and left ventricular ejection fraction (LVEF) between rs35006907-CC/AC and AA genotypes. Furthermore, the variant rs35006907-A allele presented lower reporter gene activity, reduced mRNA and protein expression levels when compared with the C allele.

Conclusions

Our findings demonstrated that rs35006907-C allele increased the risk of DCM in Han Chinese population. Besides, rs35006907-C displayed higher reporter gene activity and increased MTSS1 expression in human samples.

Ca2+/Calmodulin-Dependent Protein Kinase II Regulation by RIPK3 Alleviates Necroptosis in Transverse Arch Constriction-Induced Heart Failure

Some studies have reported that the activation of Ca²⁺/calmodulin dependent protein kinase (CaMKII) plays a vital role in the pathogenesis of cardiovascular disease. Moreover, receptor interacting protein kinase 3 (RIPK3)-mediated necroptosis is also involved in the pathological process of various heart diseases. In the present study, we aimed to investigate the effect of RIPK3-regulated CaMKII on necroptosis in heart failure (HF) and its underlying mechanism. Wild type (WT) and RIPK3-depleted (RIPK3^–/–) mice were treated with transverse arch constriction (TAC). After 6 weeks, echocardiography, myocardial injury, CaMKII activity, necroptosis, RIPK3 expression, mixed lineage kinase domain-like protein (MLKL) phosphorylation, and mitochondrial ultrastructure were measured. The results showed that TAC aggravated cardiac dysfunction, CaMKII activation, and necroptosis in WT mice. However, depletion of RIPK3 alleviated cardiac insufficiency, CaMKII activation, and necroptosis in TAC-treated mice. To verify the experimental results, WT mice were transfected with AAV-vector and AAV-RIPK3 shRNA, followed by TAC operation. The findings were consistent with the expected results. Collectively, our current data indicated that the activation of CaMKII, MLKL and necroptosis in HF mice were increased in a RIPK3-dependent manner, providing valuable insights into the pathogenesis and treatment strategy of HF.

RIP3 Contributes to Cardiac Hypertrophy by Influencing MLKL-Mediated Calcium Influx

Receptor-interacting protein 3(RIP3), a RIP family member, has been reported as a critical regulator of necroptosis and involves in the pathogenesis of various heart diseases. However, its role in the development of myocardial hypertrophy after pressure overload is unclear. We aimed to investigate the roles of RIP3 in pathological cardiac hypertrophy. A rat model of myocardial hypertrophy induced by the aortic banding method was used in this study. Neonatal rat cardiomyocytes (NRCMs) were stimulated with angiotensin II (Ang-II) or phenylephrine (PE) to induce neurohumoral stress. Our results showed that RIP3 level was significantly elevated in the hypertrophic myocardium tissues from patients, rats subjected to AB surgery, and NRCMs treated with Ang-II or PE. After downregulation of RIP3 expression in NRCMs, the phenotypes of myocardial hypertrophy were obviously alleviated. In mechanism, we demonstrated that RIP3 interacts with mixed lineage kinase domain-like protein (MLKL) and promotes its cell membrane localization to increase the influx of calcium within cells, thereby mediating the development of myocardial hypertrophy. More interestingly, we found the blockage of calcium influx by 2-aminoethoxydiphenyl borate, and lanthanum chloride efficiently reverses RIP3-induced cardiac remodeling in NRCMs. Taken together, our findings indicate a key role of the RIP3-MLKL signaling pathway in myocardial hypertrophy, which may be a novel promising treatment strategy for myocardial hypertrophy.

Shengmai Yin formula exerts cardioprotective effects on rats with chronic heart failure via regulating Linoleic Acid metabolism

The objective of this study was to investigate the protective effects of Shengmai Yin(SMY) on rats with chronic heart failure(CHF).Sprague-Dawley rats were used to establish a CHF animal model via ligation of the left anterior descending branch of the coronary artery and exhaustive swimming.Echocardiography, serum biochemical indicators and histopathology were used to evaluate the pharmacodynamics of SMY in CHF rats.UPLC-Q-TOF/MS analysis based on serum was performed to identify the potential metabolites in the pathological process of CHF. Metabolic pathway analysis was carried out to elucidate the metabolic network associated with SMY treatment of CHF.Moreover,quantitative real-time PCR (qRT-PCR), Western blotting (WB), and Enzyme-linked immunosorbent assay (ELISA) were used to measure the RNA and protein expression levels in related pathways. Results revealed that SMY significantly restored the cardiac function of CHF rats, reduced the serum biochemical indicators, and alleviated cardiac histological damage. Metabolomics analysis shows that the therapeutic effect of SMY for CHF involves 14 biomarkers and 8 metabolic pathways, especially linoleic acid pathway, to be influenced, which implied the potential mechanism of SMY in treating CHF. Two key indicators Lipoxygenase arachidonic acid 15 lipoxygenase (ALOX15) and Cytochrome P450 1A2(CYP1A2) of linoleic acid metabolism pathway were verified by RT-PCR, WB and ELISA. Verification result showed that compared with the model group, expression levels of ALOX15 and CYP1A2 in SMY group were lower. In conclusion, SMY has cardioprotective effect on chronic heart failure rats, and its mechanism may be related to linoleic acid metabolism pathway.

RIPK3 signaling and its role in the pathogenesis of cancers

RIPK3 (receptor-interacting protein kinase 3) is a serine/threonine-protein kinase. As a key component of necrosomes, RIPK3 is an essential mediator of inflammatory factors (such as TNFα-tumor necrosis factor α) and infection-induced necroptosis, a programmed necrosis. In addition, RIPK3 signaling is also involved in the regulation of apoptosis, cytokine/chemokine production, mitochondrial metabolism, autophagy, and cell proliferation by interacting with and/or phosphorylating the critical regulators of the corresponding signaling pathways. Similar to apoptosis, RIPK3-signaling-mediated necroptosis is inactivated in most types of cancers, suggesting RIPK3 might play a critical suppressive role in the pathogenesis of cancers. However, in some inflammatory types of cancers, such as pancreatic cancers and colorectal cancers, RIPK3 signaling might promote cancer development by stimulating proliferation signaling in tumor cells and inducing an immunosuppressive response in the tumor environment. In this review, we summarize recent research progress in the regulators of RIPK3 signaling, and discuss the function of this pathway in the regulation of mixed lineage kinase domain-like (MLKL)-mediated necroptosis and MLKL-independent cellular behaviors. In addition, we deliberate the potential roles of RIPK3 signaling in the pathogenesis of different types of cancers and discuss the potential strategies for targeting this pathway in cancer therapy.

Catecholamine Surges Cause Cardiomyocyte Necroptosis via a RIPK1-RIPK3-Dependent Pathway in Mice

Background: Catecholamine surges and resultant excessive β-adrenergic stimulation occur in a broad spectrum of diseases. Excessive β-adrenergic stimulation causes cardiomyocyte necrosis, but the underlying mechanism remains obscure. Necroptosis, a major form of regulated necrosis mediated by RIPK3-centered pathways, is implicated in heart failure; however, it remains unknown whether excessive β-adrenergic stimulation-induced cardiac injury involves necroptosis. Hence, we conducted the present study to address these critical gaps.

Methods and Results: Two consecutive daily injections of isoproterenol (ISO; 85 mg/kg, s.c.) or saline were administered to adult mixed-sex mice. At 24 h after the second ISO injection, cardiac area with Evans blue dye (EBD) uptake and myocardial protein levels of CD45, RIPK1, Ser166-phosphorylated RIPK1, RIPK3, and Ser345-phosphorylated MLKL (p-MLKL) were significantly greater, while Ser321-phosphorylated RIPK1 was significantly lower, in the ISO-treated than in saline-treated wild-type (WT) mice. The ISO-induced increase of EBD uptake was markedly less in RIPK3^−/− mice compared with WT mice (p = 0.016). Pretreatment with the RIPK1-selective inhibitor necrostatin-1 diminished ISO-induced increases in RIPK3 and p-MLKL in WT mice and significantly attenuated ISO-induced increases of EBD uptake in WT but not RIPK3^−/− mice.

Conclusions: A large proportion of cardiomyocyte necrosis induced by excessive β-adrenergic stimulation belongs to necroptosis and is mediated by a RIPK1–RIPK3-dependent pathway, identifying RIPK1 and RIPK3 as potential therapeutic targets for catecholamine surges.

Prediction of HF-Related Mortality Risk Using Genetic Risk Score Alone and in Combination With Traditional Risk Factors

Background: Common variants may contribute to the variation of prognosis of heart failure (HF) among individual patients, but no systematical analysis was conducted using transcriptomic and whole exome sequencing (WES) data. We aimed to construct a genetic risk score (GRS) and estimate its potential as a predictive tool for HF-related mortality risk alone and in combination with traditional risk factors (TRFs). Methods and Results: We reanalyzed the transcriptomic data of 177 failing hearts and 136 healthy donors. Differentially expressed genes (fold change >1.5 or <0.68 and adjusted P < 0.05) were selected for prognosis analysis using our whole exome sequencing and follow-up data with 998 HF patients. Statistically significant variants in these genes were prepared for GRS construction. Traditional risk variables were in combination with GRS for the construct of the composite risk score. Kaplan-Meier curves and receiver operating characteristic (ROC) analysis were used to assess the effect of GRS and the composite risk score on the prognosis of HF and discriminant power, respectively. We found 157 upregulated and 173 downregulated genes. In these genes, 31 variants that were associated with the prognosis of HF were finally identified to develop GRS. Compared with individuals with low risk score, patients with medium- and high-risk score showed 2.78 (95%CI = 1.82-4.24, P = 2 × 10^-6) and 6.54 (95%CI = 4.42-9.71, P = 6 × 10^-21) -fold mortality risk, respectively. The composite risk score combining GRS and TRF predicted mortality risk with an HR = 5.41 (95% CI = 2.72-10.64, P = 1 × 10^-6) for medium vs. low risk and HR = 22.72 (95% CI = 11.9-43.48, P = 5 × 10^-21) for high vs. low risk. The discriminant power of GRS is excellent with a C statistic of 0.739, which is comparable to that of TRF (C statistic = 0.791). The combination of GRS and TRF could significantly increase the predictive ability (C statistic = 0.853). Conclusions: The 31-SNP GRS could well distinguish those HF patients with poor prognosis from those with better prognosis and provide clinician with reference for the intensive therapy, especially when combined with TRF. Clinical Trial Registration: https://www.clinicaltrials.gov/, identifier: NCT03461107.

Targeting necroptosis as therapeutic potential in chronic myocardial infarction

Cardiovascular diseases (CVDs) are considered the predominant cause of morbidity and mortality globally. Of these, myocardial infarction (MI) is the most common cause of CVD mortality. MI is a life-threatening condition which occurs when coronary perfusion is interrupted leading to cardiomyocyte death. Subsequent to MI, consequences include adverse cardiac remodeling and cardiac dysfunction mainly contribute to the development of heart failure (HF). It has been shown that loss of functional cardiomyocytes in MI-induced HF are associated with several cell death pathways, in particular necroptosis. Although the entire mechanism underlying necroptosis in MI progression is still not widely recognized, some recent studies have reported beneficial effects of necroptosis inhibitors on cell viability and cardiac function in chronic MI models. Therefore, extensive investigation into the necroptosis signaling pathway is indicated for further study. This article comprehensively reviews the context of the underlying mechanisms of necroptosis in chronic MI-induced HF in in vitro, in vivo and clinical studies. These findings could inform ways of developing novel therapeutic strategies to improve the clinical outcomes in MI patients from this point forward.

A Common Missense Variant in OMA1 Associated with the Prognosis of Heart Failure

PURPOSE

Mitochondrial dysfunction plays a vital role in the pathophysiologic process of heart failure (HF). As a quality control system, mitochondrial fusion and fission are under control of mitochondrial fusion and fission-related proteins. The objective of this study was to investigate the effects of common variants in mitochondrial fusion and fission-related genes on the prognosis of HF.

METHODS

We performed whole exome sequencing (WES) with 1000 HF patients; the statistically significant variant was further genotyped in the replicated population with 2324 HF patients. A series of function analysis including western blot, cell proliferation assay, and in vitro OMA1 activity assay were conducted to illuminate the underlying mechanism.

RESULTS

We identified a missense variant rs17117699 associated with the prognosis of HF in group without β-blocker use rather than with β-blocker use in two-stage population: adjusted P = 0.79, HR = 0.88 (0.36-2.13) in group with β-blocker use and adjusted P = 0.016, HR = 1.43 (1.07-1.91) in group without β-blocker in first-stage population; adjusted P = 0.42, HR = 0.85 (0.56-1.28) in group with β-blocker use and adjusted P = 0.015, HR = 1.39 (1.06-1.82) in group without β-blocker in replicated stage. Functional analysis indicated that rs17117699-G allele increased the activity of OMA1 assessed by the ratio of S-OPA1 to L-OPA1 and suppressed cells proliferation under ISO treatment when compared with rs17117699-T allele. Furthermore, OMA1 functioned downstream of β-adrenergic receptor signaling and ISO-induced OPA1 cleavage is dependent on OMA1.

CONCLUSIONS

Our findings demonstrate that rs17117699T>G in OMA1 increases the risk of HF mortality via enhancing its OPA1 cleavage activity. It is a promising potential treatment target for HF.

CLINICAL TRIAL REGISTRATION

NCT03461107. https://www.clinicaltrials.gov/ct2/show/NCT03461107?term=03461107&cond=Heart+Failure&cntry=CN&rank=1.

Plasma concentration of receptor-interacting protein kinase-3 as a potential biomarker for diagnosis and prognosis in heart failure

BACKGROUND

Receptor-interacting serine-threonine kinase 3 (RIP3) is a key mediator of programmed necrosis (necroptosis), and is implicated in cardiac remodeling and heart failure (HF) triggered by ischemia-reperfusion or oxidative stress in animal study. However, its value in the diagnosis and prognosis of human HF remains unclear.

METHODS

Plasma RIP3 concentrations in 91 HF patients and 95 healthy volunteers were detected by enzyme-linked immunosorbent assay (ELISA). A receiver operating characteristic (ROC) curve was generated to evaluate the diagnostic value of RIP3. Follow-up was conducted, and the composite endpoint was defined as all-cause mortality/readmission due to decompensated HF/worse New York Heart Association (NYHA) functional class. The relationship between RIP3 and patient outcome was examined.

RESULTS

Plasma concentrations of RIP3 were significantly increased in patients with HF compared to controls (P < 0.001). ROC analysis supported plasma RIP3 as a good diagnostic marker for HF, with an optimal cutoff value of 357 pg/ml (AUC = 0.934, sensitivity = 0.846, specificity = 0.905). Kaplan-Meier survival analysis also supported increased plasma RIP3 as a predictor for a poor prognosis in HF (cutoff value = 622.2 pg/ml, P < 0.05). Additionally, binary logistic regression analysis revealed RIP3 to be an independent risk factor for all-cause mortality (OR = 11.844, P = 0.02), worse NYHA (OR = 9.013, P = 0.009) and a composite endpoint (OR = 5.065, P = 0.013).

CONCLUSIONS

Plasma concentration of RIP3 is significantly elevated in HF and associated with the prognosis. Plasma RIP3 possibly constitutes a valuable diagnostic and prognostic biomarker for HF.

COP9 Signalosome Suppresses RIPK1-RIPK3-Mediated Cardiomyocyte Necroptosis in Mice

BACKGROUND

Mechanisms governing the induction of heart failure by the impairment of autophagy and the ubiquitin-proteasome system and the molecular pathways to cardiomyocyte necrosis remain incompletely understood. COPS8 is an essential subunit of the COP9 (COnstitutive Photomorphogenesis 9) signalosome, a key regulator of ubiquitination. Mice with cardiomyocyte-restricted knockout of Cops8 (Cops8-cko) show autophagic and ubiquitin-proteasome system malfunction and massive cardiomyocyte necrosis followed by acute heart failure and premature death, providing an excellent animal model to address the mechanistic gaps specified above. This study was conducted to determine the nature and underlying mechanisms of the cardiomyocyte necrosis in Cops8-cko mice.

METHODS AND RESULTS

Compared with littermate control mice, myocardial protein levels of key factors in the necroptotic pathway (RIPK1 [receptor-interacting protein kinase 1], RIPK3, MLKL [mixed lineage kinase-like], the RIPK1-bound RIPK3), protein carbonyls, full-length Casp8 (caspase 8), and BCL2, as well as histochemical staining of superoxide anions were significantly higher but the cleaved Casp8 and the Casp8 activity were significantly lower in Cops8-cko mice. In vivo cardiomyocyte uptake of Evan's blue dye was used as an indicator of necrosis. Cops8-cko mice treated with a RIPK1 kinase inhibitor (Nec-1 [Necrostatin-1]) showed less Evans blue dye uptake (0.005% versus 0.20%; P<0.0001) and longer median lifespan (32.5 versus 27 days; P<0.01) than those treated with vehicle control. RIPK3 haploinsufficiency showed similar rescuing effects on Cops8-cko but Cyclophilin D deficiency did the opposite.

CONCLUSIONS

Cardiac Cops8/COP9 signalosome malfunction causes RIPK1-RIPK3 dependent, but mitochondrial permeability transition pore independent, cardiomyocyte necroptosis in mice and the COP9 signalosome plays an indispensable role in suppressing cardiomyocyte necroptosis.

Current translational potential and underlying molecular mechanisms of necroptosis

Cell death has a fundamental impact on the evolution of degenerative disorders, autoimmune processes, inflammatory diseases, tumor formation and immune surveillance. Over the past couple of decades extensive studies have uncovered novel cell death pathways, which are independent of apoptosis. Among these is necroptosis, a tightly regulated, inflammatory form of cell death. Necroptosis contribute to the pathogenesis of many diseases and in this review, we will focus exclusively on necroptosis in humans. Necroptosis is considered a backup mechanism of apoptosis, but the in vivo appearance of necroptosis indicates that both caspase-mediated and caspase-independent mechanisms control necroptosis. Necroptosis is regulated on multiple levels, from the transcription, to the stability and posttranslational modifications of the necrosome components, to the availability of molecular interaction partners and the localization of receptor-interacting serine/threonine-protein kinase 1 (RIPK1), receptor-interacting serine/threonine-protein kinase 3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL). Accordingly, we classified the role of more than seventy molecules in necroptotic signaling based on consistent in vitro or in vivo evidence to understand the molecular background of necroptosis and to find opportunities where regulating the intensity and the modality of cell death could be exploited in clinical interventions. Necroptosis specific inhibitors are under development, but >20 drugs, already used in the treatment of various diseases, have the potential to regulate necroptosis. By listing necroptosis-modulated human diseases and cataloging the currently available drug-repertoire to modify necroptosis intensity, we hope to kick-start approaches with immediate translational potential. We also indicate where necroptosis regulating capacity should be considered in the current applications of these drugs.

A common variant of RIP3 promoter region is associated with poor prognosis in heart failure patients by influencing SOX17 binding

Receptor‐interacting protein kinase 3 (RIP3) is a key determinant of necroptosis and participates in ischaemia—and oxidative stress‐induced necroptosis, myocardial remodelling and heart failure (HF). In this study, we tested the hypothesis that common variants in RIP3 gene were associated with the risk and prognosis of HF in the Chinese Han population. By re‐sequencing and luciferase assays, we identified a common functional variant in the RIP3 promoter region. The rs3212247‐T allele suppressed RIP3 promoter activity by facilitating transcription factor SOX17 binding, but not the C allele. We further recruited 2961 control participants and 3194 HF patients who underwent a mean follow‐up of 19 months (6‐31 months) for this study. Rs3212247 and another missense variant rs3212254 were genotyped. Although rs3212247 did not significantly associate with increased risk of HF (odds ratio = 1.00, 95% CI = 0.92‐1.08, P = 0.91), it raised the risk for cardiovascular death and cardiac transplantation (hazard ratio = 1.47, 95% CI = 1.13‐1.91, P = 0.004). Moreover, participants carrying the rs3212247 CC genotype had higher plasma levels of RIP3 than those carrying the TT or TC genotype (p for trend = 0.02) in New York Heart Association class III HF group. No association was found between the RIP3 missense variant rs3212254 and risk or prognosis of HF after adjustment for traditional risk factors. In conclusion, genetic variant in RIP3 promoter region is associated with increased RIP3 transcription, thus contributed to the poor prognosis of HF patients. Clinical Trial Registration: https://www.clinicaltrials.gov/ct2/show/NCT03461107?term=03461107&cond=Heart+Failure&cntry=CN&rank=1. Unique identifier: NCT03461107.