T-cell cytokine gene polymorphisms and vitamin D pathway gene polymorphisms in end-stage renal disease due to type 2 diabetes mellitus nephropathy: comparisons with health status and other main causes of end-stage renal disease

Long non-coding RNA MALAT1 and microRNA-499a expression profiles in diabetic ESRD patients undergoing dialysis: a preliminary cross-sectional analysis

Background: Circulating non-coding RNAs (ncRNAs) have been implicated in health and disease. This study aimed to evaluate the serum expression profile of microRNA-499a (miR-499a) and its selected bioinformatically predicted partner long-ncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) in diabetes-related end-stage renal disease (ESRD) patients and to correlate the expressions with the patients' clinicolaboratory data.Subjects and methods: Real-time quantitative polymerase chain reaction was applied in diabetics with and without ESRD (n = 90 for each).Results: Serum MALAT1 expression levels were increased in the ESRD group relative to diabetics without ESRD with median (quartile) values of 10.5 (1.41-126.7) (p < .001). However, miR-499a levels were decreased in more than half of ESRD patients with a median of 0.96 (0.13-3.14). Both MALAT1 and miR-499a expression levels were inversely correlated in the ESRD patient-group.Conclusions: MALAT1 up-regulation and miR-499 down-regulation might be involved in diabetic nephropathy-related ESRD pathogenesis. Functional validation studies are warranted to confirm the MALAT1/miR-499a partnership.

Association between Monocyte Chemoattractant Protein-1 -2518 (A/G) Single Nucleotide Polymorphism and Chronic Periodontitis in End-stage Renal Disease Patients - A Case-control Study

Monocyte chemoattractant protein 1 (MCP-1) plays an important role in the development of periodontitis. The purpose of this investigation was to evaluate association of the  MCP-1 gene polymorphism with chronic periodontitis in patients with end-stage renal disease (ESRD). One hundred fifty ESRD patients with chronic periodontitis (CP), 100 without CP and 190 healthy controls were included in this study. Genomic DNA from all participants was genotyped for the -2518 (A/G) polymorphism by a polymerase chain reaction - restriction fragment length polymorphism (PCR--RFLP) assay. Significant differences were observed in the genotype and allele frequencies between patients with ESRD and CP and controls.  The G allele frequency was significantly higher in patients than in control subjects, with odds ratio 1.77 (95 % CI 1.2-2.5), p = 0.0014. For the GG genotype the OR was 3.63 (95 % CI 1.5-8.76), p = 0.041.  No significant differences in the polymorphism distribution were observed between ESRD patients  without CP and control subjects. Comparison of the MCP-1 gene polymorphism distribution in ESRD patients with various primary diseases leading to ESRD did not show any significant differences. The mean MCP-1 serum levels were compared between subgroups. They were significantly higher in ESRD patients with CP (582 ± 112 pg/ml) than in patients without CP (309 ± 103 pg/ml) and controls (265 ± 85 pg/ml). Our results suggest that the MCP-1-2518 A/G  polymorphism might be a novel risk factor for developing chronic periodontitis in patients with ESRD.

IL4 gene VNTR polymorphism in chronic periodontitis in end-stage renal disease patients

OBJECTIVE

Interleukin-4 gene polymorphisms were found to be associated with periodontitis. The purpose of this case-control study was to evaluate association of IL4 VNTR polymorphism with periodontitis in patients with end-stage renal disease (ESRD).

SUBJECTS AND METHODS

We examined 180 ESRD patients with chronic periodontitis, 82 without CP and 180 healthy controls. Genomic DNA from all subjects was genotyped for the IL4 VNTR polymorphism by polymerase chain reaction (PCR).

RESULTS

Genotype distribution in all groups followed Hardy-Weinberg equilibrium. Significant differences in genotype and allele frequencies were observed between groups. The patient group had higher frequency of P1 allele than controls, with odds ratio for P1 allele 1.6 (95% CI 1.1-2.3) and P1P1 genotype 2.73 (95% CI 1.06-7.5). There were no differences in polymorphism distribution between ESRD patients without CP and controls. Periodontal disease was more severe in older patients (≥50 years). Similarly, patients with T2DM had more severe manifestation of CP than patients without diabetes (p = 0.01 for plaque index, p = 0.004 for bleeding index and p = 0.03 for gingival index).

CONCLUSION

Our findings suggest that VNTR polymorphism in IL4 gene might be a risk factor for chronic periodontitis in patients with ESRD.

Associations of the calcium-sensing receptor gene CASR rs7652589 SNP with nephrolithiasis and secondary hyperparathyroidism in haemodialysis patients

Nephrolithiasis, secondary hyperparathyroidism (sHPT), and cardiovascular complications are associated with disturbances in Ca handling and contribute to morbidity/mortality during haemodialysis (HD). Calcimimetics, activators of the calcium-sensing receptor (CaSR), provide an effective means of reducing parathyroid hormone (PTH) secretion in sHPT. Polymorphism in CaSR gene (CASR) influences Ca-related parameters, however it was not shown in HD patients for CASR rs7652589. The minor allele at this polymorphism modifies the binding sites of transcription factors and CaSR expression. We hypothesized that CASR rs7652589 variants may also influence CaSR in end stage renal disease (ESRD). We aimed to determine the associations of rs7652589 with nephrolithiasis-related ESRD, Ca, P, ALP, PTH, response to treatment with cinacalcet, prevalence of coronary artery disease, and all-cause/cardiovascular mortality in HD patients (n = 1162). Healthy individuals (n = 918) were controls. This study shows that the A allele of rs7652589 is a risk allele for nephrolithiasis-related ESRD. The AA genotype is associated with more severe sHPT (higher Ca and PTH concentrations). The A allele is associated with reduced CaSR transcript level in peripheral blood mononuclear cells. According to computational analysis, potential binding sites for GLI3, AHR and TP53 are removed by the A allele, whereas binding sites for SOX18 and TP63 are created.

Polymorphisms of Vitamin D Signaling Pathway Genes and Calcium-Sensing Receptor Gene in respect to Survival of Hemodialysis Patients: A Prospective Observational Study

We evaluated in the 7-year prospective study whether variants in vitamin D pathway genes and calcium-sensing receptor gene (CASR) are determinants of mortality in hemodialysis (HD) patients (n = 532). HRM analysis was used for GC rs2298849, GC rs1155563, RXRA rs10776909, RXRA rs10881578, and CASR rs7652589 genotyping. GC rs7041, RXRA rs749759, VDR rs2228570, and VDR rs1544410 were genotyped using PCR-RFLP analysis. The minor allele in GC rs2298849 was associated with all-cause mortality in univariate analysis (HR 1.330, 95% CI 1.046-1.692, P = 0.020). Bearers of the minor allele in GC rs2298849 demonstrated higher infection/neoplasm mortality than major allele homozygotes also in multivariate analysis (HR 2.116, 95% CI 1.096-4.087, P = 0.026). Cardiovascular mortality was associated with major homozygosity (CC) in VDR rs2228570 (HR 1.896, 95% CI 1.163-3.091, P = 0.010). CC genotype patients were more often dyslipidemic than TT genotype subjects (46.1% versus 31.9%, P = 0.047). Dyslipidemics showed higher frequency of rs1544410_rs2228570 haplotype AC than nondyslipidemics (26 versus 18%, P corr = 0.005), whereas TT genotype patients were at lower risk of dyslipidemia compared with CC/CT genotype patients (HR 0.59, 95% CI 0.37-0.96, P = 0.04). In conclusion, GC rs2298849 and VDR rs2228570 SNPs are associated with survival on HD. VDR-related cardiovascular mortality may occur due to connections of rs2228570 with dyslipidemia.

Association of Retinoid X Receptor Alpha Gene Polymorphism with Clinical Course of Chronic Glomerulonephritis

Background

Vitamin D (VD), VD binding protein, VD receptor (VDR), and retinoids are involved in pathogenesis of chronic glomerulonephritis (ChGN). We aimed to compare distribution of VD pathway gene polymorphisms in ChGN patients showing glomerular filtration rate (GFR) category 1–3, GFR category 5D, and healthy controls in order to elucidate the role of VD-related polymorphisms in the course of ChGN.

Material/Methods

GFR category 1–3 ChGN patients (n=195), GFR category 5D ChGN patients (n=178), and controls (n=751) underwent testing for polymorphisms of genes encoding VD binding protein (GC, rs2298849, rs7041, rs1155563), VDR (VDR, rs2228570, rs1544410), and retinoid X receptor alpha (RXRA, rs10776909, rs10881578, rs749759).

Results

Among GFR 1–3 subjects possessing TT genotype of RXRA rs10776909, 75% of patients had nephrotic syndrome, and 37.5% had glomerular hyperfiltration defined as GFR >140 ml/min/1.73 m², and, consequently, serum creatinine was lower in these patients compared to the remaining subjects (0.67±0.26 vs. 0.94±0.34, P=0.014). In GFR category 5D ChGN patients, frequencies of RXRA rs10776909 allele T (25% vs. 19%) and CT+TT (46% vs. 34%) were higher compared to frequencies of respective variants in controls (P_trend=0.004, P_genotype=0.008).

Conclusions

RXRA rs10776909 allele T is specifically involved in the pathogenesis of ChGN. This risk allele may be also associated with worse clinical course of ChGN.

Vitamin D-Binding Protein in Health and Chronic Kidney Disease

Vitamin D-binding protein (DBP) is a multifunctional protein that has attracted increasing interest in recent years, largely because of its potential role in modulating the activity of vitamin D. Nearly all circulating vitamin D (~85-90%) circulates bound to DBP, with a smaller proportion bound to albumin, leaving <5% circulating freely. DBP may also play roles beyond vitamin D binding, with potential roles in the immune system and elsewhere. Numerous polymorphisms of DBP exist around the world, and recent studies have identified relevance of different DBP phenotypes in determining DBP concentration and vitamin D affinity. This review focuses on the known roles of DBP in health and kidney disease, and current views on the relevance of DBP polymorphisms.