Renalase rs10887800 polymorphism is associated with severe pre‐eclampsia in southeast Iranian women

The effect of RNLS gene polymorphisms on preeclampsia susceptibility: a meta-analysis study

Aim: The authors designed a meta-analysis to find a comprehensive result of the impact of RNLS polymorphisms on preeclampsia (PE) susceptibility. Methods: The online databases PubMed, Scopus, and Google Scholar were employed for the purpose of literature search. Data analysis was conducted using STATA (ver. 12.0) and MetaGenyo web tool. Results: The findings showed that the RNLS rs10887800 polymorphism could increase risk of PE in allelic, codominant heterozygous and dominant genetic models. In addition, the analysis indicated that the RNLS rs2576178 polymorphism was associated with higher risk of PE in allelic, codominant homozygous, dominant, and recessive models. Conclusion: The findings of meta-analysis showed that the RNLS rs10887800 and rs2576178 polymorphisms could increase risk of PE in several genetic models.

Cyclic-AMP response element binding protein (CREB) and microRNA miR-29b regulate renalase gene expression under catecholamine excess conditions

AIMS

Renalase, a key mediator of cross-talk between kidneys and sympathetic nervous system, exerts protective roles in various cardiovascular/renal disease states. However, molecular mechanisms underpinning renalase gene expression remain incompletely understood. Here, we sought to identify the key molecular regulators of renalase under basal/catecholamine-excess conditions.

MATERIALS AND METHODS

Identification of the core promoter domain of renalase was carried out by promoter-reporter assays in N2a/HEK-293/H9c2 cells. Computational analysis of the renalase core promoter domain, over-expression of cyclic-AMP-response-element-binding-protein (CREB)/dominant negative mutant of CREB, ChIP assays were performed to determine the role of CREB in transcription regulation. Role of the miR-29b-mediated-suppression of renalase was validated in-vivo by using locked-nucleic-acid-inhibitors of miR-29. qRT-PCR and Western-blot analyses measured the expression of renalase, CREB, miR-29b and normalization controls in cell lysates/ tissue samples under basal/epinephrine-treated conditions.

KEY FINDINGS

CREB, a downstream effector in epinephrine signaling, activated renalase expression via its binding to the renalase-promoter. Physiological doses of epinephrine and isoproteronol enhanced renalase-promoter activity and endogenous renalase protein level while propranolol diminished the promoter activity and endogenous renalase protein level indicating a potential role of beta-adrenergic receptor in renalase gene regulation. Multiple animal models (acute exercise, genetically hypertensive/stroke-prone mice/rat) displayed directionally-concordant expression of CREB and renalase. Administration of miR-29b inhibitor in mice upregulated endogenous renalase expression. Moreover, epinephrine treatment down-regulated miR-29b promoter-activity/transcript levels.

SIGNIFICANCE

This study provides evidence for renalase gene regulation by concomitant transcriptional activation via CREB and post-transcriptional attenuation via miR-29b under excess epinephrine conditions. These findings have implications for disease states with dysregulated catecholamines.

Renalase and its receptor, PMCA4b, are expressed in the placenta throughout the human gestation

Placental function requires organized growth, transmission of nutrients, and an anti-inflammatory milieu between the maternal and fetal interface, but placental factors important for its function remain unclear. Renalase is a pro-survival, anti-inflammatory flavoprotein found to be critical in other tissues. We examined the potential role of renalase in placental development. PCR, bulk RNA sequencing, immunohistochemistry, and immunofluorescence for renalase and its binding partners, PMCA4b and PZP, were performed on human placental tissue from second-trimester and full-term placentas separated into decidua, placental villi and chorionic plates. Quantification of immunohistochemistry was used to localize renalase across time course from 17 weeks to term. Endogenous production of renalase was examined in placental tissue and organoids. Renalase and its receptor PMCA4b transcripts and proteins were present in all layers of the placenta. Estimated RNLS protein levels did not change with gestation in the decidual samples. However, placental villi contained more renalase immunoreactive cells in fetal than full-term placental samples. RNLS co-labeled with markers for Hofbauer cells and trophoblasts within the placental villi. Endogenous production of RNLS, PMCA4b, and PZP by trophoblasts was validated in placental organoids. Renalase is endogenously expressed throughout placental tissue and specifically within Hofbauer cells and trophoblasts, suggesting a potential role for renalase in placental development and function. Future studies should assess renalase's role in normal and diseased human placenta.

Renalase gene polymorphisms and plasma levels are associated with preeclampsia: a hospital-based study in the Chinese cohort

Preeclampsia (PE) is one of the major contributors to maternal and fetal mortality worldwide. Many host-related biomolecules regulate the pathophysiology of PE. The current study aims to examine the role of the renalase in PE manifestations. A total of 384 Chinese women consisting of subjects with normotensive pregnancy (n = 105), women with PE (n = 121), and healthy women (n = 158) were included in the study. Serum renalase level was measured in all subjects by ELISA. Renalase gene polymorphisms (rs10887800, rs2576178, and rs2296545) were genotyped by PCR-RFLP. The pregnant women had elevated renalase levels compared to healthy controls and subjects with PE. Renalase level was negatively correlated with systolic and diastolic blood pressure. Interestingly, renalase was positively correlated with the glomerular filtration rate. Prevalence of homozygous mutant (GG) and minor allele (G) for rs10887800 and rs2576178 renalase gene polymorphisms were significantly higher in PE patients compared to normotensive pregnant women and healthy controls. Furthermore, an association of G-G-C haplotype with susceptibility to PE was also noticed. A low level of renalase may be associated with an increased risk of PE during pregnancy. Renalase gene polymorphisms (rs10887800 and rs2576178) are correlated with serum renalase and are associated with predisposition to PE development in the Chinese cohort.

The Effect of Renalase rs2576178 and rs10887800 Polymorphisms on Ischemic Stroke Susceptibility in Young Patients (<50 Years): A Case-Control Study and In Silico Analysis

Background

Ischemic stroke (IS) is the most common form of cerebrovascular accident which its precise etiology remains mysterious. Renalase is a catecholamine-degrading enzyme playing a major role in blood pressure control. Recent studies show the effect of renalase activity on various diseases like IS. In the current study, we examined the possible effects of renalase gene (RNLS) rs2576178 and rs10887800 variants at the 5′-flanking and intron 6 regions on IS, respectively.

Methods

One hundred and fifty-four IS patients younger than 50 years and 165 age- and sex-matched controls were recruited in the study. For genotyping of rs2576178 and rs10887800 variants, the PCR-RFLP method was used.

Results

The RNLS rs10887800 AG genotype was more repeated in IS patients, but the difference was marginally nonsignificant (P = 0.054). This variant was associated with IS in the overdominant model, and the AG genotype is associated with a1.6-fold increased risk of IS compared to AA+ GG genotypes (OR = 1.6, 95% CI: 1-2.5, P = 0.033). No relationship was observed between RNLS rs2576178 polymorphism and IS in all genetic models. The findings of the haplotype and combination effects of rs10887800 and rs2576178 variants on IS showed no significant association. The in silico analysis showed no effect of rs2576178 and rs10887800 polymorphisms in the RNA structure, but the alteration of RNA sequence in rs2576178 results in the lack of a MBNL1 protein binding site.

Conclusions

RNLS rs10887800 but not rs2576178 polymorphism was associated with IS susceptibility in the overdominant model (AG vs AA+ GG genotypes).

Renalase-A new understanding of its enzymatic and non-enzymatic activity and its implications for future research

Renalase was first described in 2005 and since then it became an object of scientific interest because of its proposed ability to catalyse circulating neurotransmitters and its promising antihypertensive effects. However, further research on the enzymatic activity of renalase did not confirm these initial findings and yielded that renalase serves to oxidize isomeric forms of β-NAD(P)H and recycle them by forming β-NAD(P)+. Moreover, in contrast to initial assumptions, it is indicated that renalase's enzymatic activity is confined to the cell and that extracellular renalase loses its enzymatic properties. These new reports led scientists to question as to whether renalase, as an enzyme, still has the potential to influence various systemic physiological responses (e.g. blood pressure). It was also put into question whether many physiological discoveries published based on the notion that renalase is secreted into the blood and acts by oxidation of catecholamines can still be considered valid. In this article, we attempt to review the literature to confront these doubts and find further possible directions of research on the importance of renalase. Our aim was to evaluate recent reports of non-enzymatic activity for renalase.

Association of renalase gene polymorphisms with the risk of hypertensive disorders of pregnancy in northeastern Han Chinese population

Renalase is a novel enzyme that can regulate blood pressure by degrading circulating catecholamines. We aimed to evaluate the possible effect of rs2296545, rs2576178 and rs10887800 polymorphisms of the renalase gene (RNLS) on the development of hypertensive disorders of pregnancy (HDP). This case-control study consisted of 185 patients with HDP and 380 normotensive pregnant women from the northeastern Chinese Han population. Association analyses were performed using PLINK, to compare allele and genotype frequencies in cases and controls. Adjustment for logistic regression analysis was performed by permutation testing. In the HDP patients compared with controls, we found that there was statistically significant difference in genotype distribution of rs2296545 (p = .037). Rs2296545 and rs2576178 polymorphisms have 1.91-fold (p = .004) and 1.73-fold (p = .015) increased risk of HDP in the dominant model, respectively. When compared preeclampsia (PE) to control, the RNLS rs2296545 polymorphism was significantly associated with PE risk in the dominant model (p = .021). We next analyzed the haplotypes of these SNPs and there was no difference between controls and HDP or PE. These findings suggest that rs2296545 was significantly associated with HDP and PE risk and the rs2576178 polymorphism may increase the susceptibility to HDP.

Roles and mechanisms of renalase in cardiovascular disease: A promising therapeutic target

Cardiovascular disease (CVD) is prevalent worldwide and remains a leading cause of death. Although substantial progress has been made in the diagnosis and treatment of CVD, the prognosis remains unsatisfactory. Renalase is a newly discovered cytokine that is synthesized by the kidney and then secreted into blood. Numerous studies have suggested the efficacy of renalase in treating CVD by metabolizing catecholamines in the circulatory system. As a new biomarker of heart disease, renalase is normally recognized as a signalling molecule that activates cytoprotective intracellular signals to lower blood pressure, protect ischaemic heart muscle and promote atherosclerotic plaque stability in CVD, which subsequently improves cardiac function. Due to its important regulatory role in the circulatory system, renalase has gradually become a potential target in the treatment of CVD. This review summarizes the structure, mechanism and function of renalase in CVD, thereby providing preclinical evidence for alternative approaches and new prospects in the development of renalase-related drugs against CVD.

Association of Serum Renalase Levels and Renalase rs10887800 Polymorphism with Unstable Angina Pectoris Patients Having Metabolic Syndrome

PURPOSE

An increased risk of cardiovascular mortality and morbidity has been linked with metabolic syndrome (MetS), described as the secondary risk reduction target. These patients are predisposed to high complication levels such as unstable angina-pectoris (USAP) by MetS. As with the role of renalase in the regulation of blood pressure (BP), the study was carried out to determine the levels of renalase circulation in patients with USAP and MetS (USAP+MetS), as well as the association of renalase gene (RNLS) rs10887800 polymorphism and USAP and MetS susceptibility.

PATIENTS AND METHODS

A total of 134 patients with USAP+MetS and 134 control subjects were recruited in this case-control study.

RESULTS

Renalase was found to have a significantly higher level in USAP+MetS patients (23.28 ± 4.09 µg/dL) than in healthy ones (20.81 ± 2.73 µg/dL) (P < 0.001). Also, it was shown that renalase sensitivity and specificity values for the early diagnosis of USAP and MetS seemed to be 53.7% and 76.9, respectively. Moreover, the value for renalase area under curve (AUC) was 0.654 (95% CI: 0.58-0.72). The frequency of rs10887800 AG and GG genotypes of RNLS gene was significantly higher in USAP+MetS patients than in control subjects, suggesting that this genotype might be a risk factor against USAP+MetS (OR = 2.114 [95% CI 1.113-4.016]; P = 0.022) and (OR = 2.057 [95% CI 1.011-4.186]; P = 0.047), respectively.

CONCLUSION

The present results showed that renalase serum levels increased in USAP and MetS patients. Moreover, the RNLS rs10887800 was reported to be associated with a higher risk of USAP+MetS.