Effect of arachidonic acid metabolic inhibitors on hypoxia/reoxygenation-induced renal cell injury

Renin gene rs1464816 polymorphism contributes to chronic kidney disease progression in ADPKD

Background

Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic disorder and is a common genetic cause of chronic renal failure in children and adults. The enzyme renin plays a key role in the RAAS cascade and an important role in the development of hypertension and progression of renal disease in ADPKD. The present study is aimed to investigate the potential modifier effect of REN gene polymorphisms on the progression of chronic kidney disease (CKD) in ADPKD.

Methods

We analyzed 102 ADPKD patients and 106 healthy controls from the same geographic area. FRET-based KASPar single-nucleotide polymorphism (SNP) genotyping assays for REN gene tag-SNPs (rs2887284, rs2368564, rs1464816, rs7521667, rs10900555, rs6693954, rs6676670 and rs11571078) were performed. Cochran-Armitage trend test was used to assess the potential associations between these polymorphisms and CKD stages. Haplotype frequencies and LD measures were estimated by using the software Haploview. Mantel-Haenszel stratified analysis was used to explore confounding and interaction effects of these polymorphisms.

Results

Of the eight tag-SNPs genotyped, the rs10900555 polymorphism deviated from the Hardy-Weinberg equilibrium in controls. The presence of ADPKD in general was not significantly associated with the REN tag-SNPs included in this study. Linkage disequilibrium analysis yielded three haplotype blocks and the haplotypes of the respective blocks are not statistically different between ADPKD and controls. In multivariate analysis, the rs1464816 TG genotype showed a significant association with the advancement of CKD in ADPKD (OR = 4.80; 95 % CI = 1.30–17.82; p = 0.019).

Conclusions

The present study provides evidence that the rs1464816 polymorphism in REN is associated with CKD progression in ADPKD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-015-0217-0) contains supplementary material, which is available to authorized users.

Effect of various oestrogens on cell injury and alteration of apical transporters induced by tert-butyl hydroperoxide in renal proximal tubule cells

1. The present study was undertaken in order to examine the effect of various oestrogens on tert-butyl hydroperoxide (t-BHP)-induced cell injury and changes in apical transporters in primary cultured rabbit renal proximal tubule cells. 2. Compared with control, t-BHP (0.5 mmol/L; 1 h) decreased cell viability (62%) and glutathione (GSH) content (60%) and increased lipid peroxide (LPO) formation (309%), arachidonic acid (AA) release (193%) and Ca(2+) influx (168%). 3. The protective potency of various oestrogens for these parameters is dependent on the precise oestrogenic structure, with 2-hydroxy-oestradiol-17 beta (2-OH-E(2)) and 4-OH-E(2), both catecholic oestrogens, or diethylstilbesterol (DES) being more potent than oestradiol (E(2)), oestriol or oestradiol-17 alpha, all phenolic oestrogens (P < 0.05). 4. These cytoprotective effects of oestrogens occur at concentrations above 10 micromol/L and are not dependent on classical oestrogen receptors and gene transcription and translation. In addition, various oestrogens have different preventative effects against t-BHP-induced inhibition of [(14)C]-alpha-methyl-D-glucopyranoside (alpha-MG), inorganic phosphate (Pi) and Na(+) uptake, consistent with the results of cell injury. In contrast, the potency against t-BHP-induced changes in cell viability, LPO, GSH content and transporter function of the anti-oxidants taurine and vitamin C is similar to that of phenolic oestrogens, whereas that of the iron chelators deferoxamine and phenanthroline is similar to that of catecholic oestrogens. 5. In conclusion, various oestrogens have differential cytoprotective potential against t-BHP-induced cell injury and decreases in alpha-MG, Na(+) and Pi uptake. These effects are due, in part, to both the basic chemical properties of the compounds and the maintenance of endogenous GSH or inhibition of AA release and Ca(2+) influx.