Association of calcitonin receptor gene ( CALCR ) polymorphism with kidney stone disease in the population of West Bengal, India

Genetic mutation of SLC6A20 (c.1072T > C) in a family with nephrolithiasis: A case report

Nephrolithiasis is a highly prevalent disease worldwide that is associated with significant suffering, renal failure, and cost for the healthcare system. A patient with nephrolithiasis was found to have SLC6A20 variation. SLC6A20 gene in human is located on chromosome 3p21.3, which is a member of SLC6 family of membrane transporters and the product of this gene expression is transporter protein of sub-amino acid transporter system. The previous studies have reported that the mutation of SLC6A20 may cause hyperglycinuria or iminoglycinuria which may lead to nephrolithiasis. The object was to investigate the relationship between nephrolithiasis and SLC6A20 through pedigree genetic analysis. To explore whether the SLC6A20 mutation can cause hereditary nephrolithiasis, and provide evidence for further research. The urine and blood were collected from the patients for compositional analysis. DNA sequencing was applied to analyze the gene mutation. Labial gland and kidney biopsy were conducted for pathological analysis. As a result we reported a rare family case of nephrolithiasis accompanied by primary Sjogren's syndrome and investigated it by examining the family members with whole exome gene sequencing technology and detecting 20 different amino acids and 132 kinds of organic acids in the urine with gas chromatography-mass spectrometry. We discovered that the proband and her mother had hyperglycinuria and the proband (Ⅱ₂), her sister (Ⅱ₃), and mother (Ⅰ₁) were found to carry the SLC6A20 gene exon NM_020208.3 sequence c.1072T > C heterozygous mutation, and the other family members (Ⅰ₂, Ⅱ₁, Ⅱ₄, Ⅲ₁, Ⅲ₂) did not carry the genetic mutation. As a conclusion, the heterozygous mutation of SLC6A20 (c.1072T > C) might be contributed to hyperglycinuria and the formation of nephrolithiasis.

Homozygous GRHPR C.494G>A mutation is deleterious that causes early onset of nephrolithiasis in West Bengal, India

Pediatric nephrolithiasis (NL) or Kidney stone disease (KSD) is an untethered topic in Asian population. In Western countries, the annual incidence of paediatric NL is around 6-10%. Here, we present data from West Bengal, India, on lower age (LA, 0-20 years) NL and its prevalence for the first time. To discover the mutations associated with KSD, twenty-four (18 + 6) rare LA-NL patients were selected for Whole Exome Sequencing (WES) and Sanger sequencing, respectively. It was found that GRHPR c. 494G>A mutation (MZ826703) is predominant in our study cohort. This specific homozygous mutation is functionally studied for the first time directly from human peripheral mononuclear cell (PBMC) samples. Using expression study with biochemical activity and computational analysis we assumed that the mutation is pathogenic with loss of function. Moreover, three genes, AGXT, HOGA1 and GRHPR with Novel variants known to cause hyperoxaluria were found frequently in the study cohort. Our study analyses the genes and variations that cause LA-NL, as well as the molecular function of the GRHPR mutation, which may serve as a clinical marker in the population of West Bengal, Eastern India.

Association of TRPV5, CASR, and CALCR genetic variants with kidney stone disease susceptibility in Egyptians through main effects and gene–gene interactions

Kidney stone disease (KSD) represents an urgent medical problem because of increasing its prevalence. Several functional polymorphisms in genes involved in the renal handling of calcium were associated with KSD pathogenesis. Among those, the rs4236480 of transient receptor potential vanilloid member 5 (TRPV5) gene, the rs1801725 of calcium-sensing receptor (CASR) gene, and the rs1801197 of calcitonin receptor (CALCR) gene appear to be of great importance. Due to the scarce data on the Egyptians, this study aimed to evaluate the association of these candidate genetic variants with the risk of developing KSD in an Egyptian population. To do so, the biochemical parameters were measured along with the genotyping of the three polymorphisms using allelic discrimination assay in 134 KSD patients and 86 age and sex-matched healthy subjects. The results showed that the genotypic distributions and allelic frequencies of the studied variants were significantly different between cases and controls. The three polymorphisms increased the risk of KSD significantly under all the tested genetic models (OR ranges from 2.152 to 5.994), except for the recessive model of the CALCR rs1801197 polymorphism after Bonferroni correction. The gene–gene interaction analyzed by multifactor dimensionality reduction selected the three-locus combination as the best model associated with the susceptibility to KSD with OR 9.706. Further, synergistic interactions were identified between TRPV5 rs4236480 and CALCR rs1801197 variants and CASR rs1801725 and CALCR rs1801197 variants. In conclusion, the TRPV5 rs4236480, CASR rs1801725, and CALCR rs1801197 polymorphisms showed a significant association with the risk of KSD in the Egyptian population. Furthermore, their complex interactions might have an impact on the genetic susceptibility to develop KSD.

CALCR knockdown inhibits the development and progression of non-small-cell lung cancer

G-protein-coupled receptors (GPCRs) have been reported to participate in the occurrence and development of a variety of human cancers. CALCR is one of the hundreds of GPCRs, but its expression level and functional importance have never been investigated in non-small-cell lung cancer (NSCLC). In the present study, the protein expression level of CALCR was detected by immunohistochemical staining and western blot analysis. The Celigo cell counting assay was used to assess cell proliferation. Both the wound-healing assay and the transwell assay were performed to evaluate cell migration. Flow cytometric analysis was utilized to detect cell apoptosis and cell cycle. A mouse xenograft model was constructed to conduct the in vivo experiments. The results indicated that the CALCR expression was abundantly up-regulated in NSCLC and positively related to tumor infiltrate. Besides, CALCR knockdown could significantly suppress cell proliferation, migration, enhance apoptosis and arrest cell cycle. The in vivo study verified the inhibitory effects of CALCR knockdown on NSCLC tumorigenesis. The abovementioned results provided a reference for the treatment of NSCLC, that was, CALCR knockdown might be a considerable therapeutic strategy.

Association between calcitonin receptor gene polymorphisms and calcium stone urolithiasis: A meta-analysis

PURPOSE

It has been reported that calcitonin receptor (CALCR) gene polymorphisms might be associated with calcium stone urolithiasis. Owing to mixed and inconclusive results, we conducted a meta-analysis to summarize and clarify this association.

MATERIALS AND METHODS

A systematic search of studies on the association between CALCR gene polymorphisms and calcium stone urolithiasis susceptibility was conducted in databases.

RESULTS

Odds ratios and 95% confi dence intervals were used to pool the effect size. Five articles were included in our meta-analysis.

CONCLUSIONS

CALCR rs1801197 might be associated with increased risk of calcium stone urolithiasis. There is insufficient data to fully confirm the association between CALCR rs1042138 and calcium stone urolithiasis susceptibility. Well-designed studies with larger sample size and more subgroups are required to validate the risk identified in the current meta-analysis.

Association of TRPV5 gene polymorphism with calcium urolithiasis: a case-control study from West Bengal, India

PURPOSE

Present study was intended to investigate the potential contribution of TRPV5 gene polymorphisms with calcium urolithiasis in the population of West Bengal, India.

METHODS

A case-control study was performed with 152 calcium urolithiasis patients and 144 corresponding healthy controls. Epidemiological and clinical parameters were documented as well as peripheral blood sample was collected from each individual, followed by genomic DNA isolation. Then to identify genetic variants of TRPV5, the entire coding region and exon-intron boundaries of the gene were amplified by polymerase chain reaction using specific oligonucleotide primers and then genotypes were determined by bi-directional DNA sequencing and sequence alignment between case and control individuals.

RESULTS

Urinary calcium excretion was found to be significantly high (p value < 0.0001) in urolithiasis patients as compared to controls. A total of 14 SNPs were obtained of which one non-synonymous (rs4236480; p.Arg154His; CGT > CAT), one synonymous (rs4252417; p.Tyr278Tyr; TAC > TAT) and three intronic (rs4252400, rs4252402, rs4236481) SNPs were found to be significantly associated with increased risk of urolithiasis. For non-synonymous SNP rs4236480, 'A' was found to be the risk allele (OR 1.77, 95% CI 1.24-2.51; p value 0.001) and genotype frequency analysis revealed that individuals carrying variant genotype AA were more prone to the disease than individuals with wild genotype GG (OR 3.09, 95% CI 1.26-7.59; p value 0.0136), indicating AA as the risk genotype.

CONCLUSIONS

The non-synonymous SNP rs4236480 showed significant association with urolithiasis risk in West Bengal population of India. Future translational and larger population-based studies are required to validate our finding.

Association of sirtuin 1 gene polymorphisms with nephrolithiasis in Eastern chinese population

Sirtuin 1 (SIRT1), an NAD⁺-dependent deacylase, has been identified to be associated with renal tubular inflammatory conditions and metabolic disorders, which are risk factors of nephrolithiasis. To further confirm the role of the SIRT1 in kidney stone formation, the expression of SIRT1 was analyzed based on a mouse model and the genetic polymorphisms of SIRT1 gene was compared between patients with kidney stones and controls. The calcium oxalate (CaOx) crystal-induced renal injury model was established to analyzed the expression of SIRT1 in the kidney tissue of both wild-type and ApoE(−/−) mice. And a total of 430 Eastern Chinese subjects (215 patients with nephrolithiasis and 215 age- and gender-matched controls) were recruited for the present study to investigate the associations between 6 common single nucleotide polymorphisms (SNPs) (i.e., rs10509291, rs3740051, rs932658, rs33957861, rs3818292 and rs1467568) in the SIRT1 gene and the incidence of kidney stones. Pairwise linkage disequilibrium and the haplotypes of the 6 SNPs were also analyzed. The genotypes of SIRT1 gene polymorphisms were analyzed by a Snapshot assay. Reduced expression of SIRT1 was observed in the kidney of the mice in the crystal group, revealing the potential role of SIRT1 in the nephrolithiasis. However, we did not find a significant association between the 6 SNPs of the SIRT1 gene and kidney stone formation in the Eastern Chinese population.

Polymorphisms of PTH (Parathyroid Hormone) Gene and Risk of Kidney Stone Disease: A Case-Control Study from West Bengal, India

OBJECTIVE

To investigate the potential contribution of parathyroid hormone (PTH) gene polymorphisms in kidney stone disease (KSD), a global clinical problem impacting major burden on public health care system worldwide.

METHODS

A case-control study was performed in West Bengal (India) with 152 patients reported with calcium-rich stone in kidney and 144 corresponding normal healthy individuals as controls. To identify genetic variants of PTH, the entire coding region, exon-intron boundaries and a few hundred nucleotides downstream the exon 3 (3' UTR region) was bi-directionally sequenced for all the study participants.

RESULTS

Two intronic (rs694 and rs6254) and one synonymous (rs6256, located in exon 3) variant were identified along with 2 single nucleotide polymorphisms (SNPs) (rs307247 and rs307248) in the 3' UTR of the PTH gene. Allele and genotype frequency analysis of these SNPs revealed that rs6254 and rs6256 had moderate association with increased risk of KSD. The 2 SNPs (rs307247 and rs307248) of the 3' UTR, which were in strong linkage disequilibrium, were found to be significantly associated with kidney stone risk in the population of West Bengal, India.

CONCLUSION

This is the first time report in the world, regarding association of PTH gene polymorphisms with KSD. Our finding suggests that PTH gene polymorphisms can be used as potential genetic markers for early detection of KSD and for preventing its occurrence. Additional studies with larger sample size are essential to validate our result.

Does quality of drinking water matter in kidney stone disease: A study in West Bengal, India

Purpose

The combined interaction of epidemiology, environmental exposure, dietary habits, and genetic factors causes kidney stone disease (KSD), a common public health problem worldwide. Because a high water intake (>3 L daily) is widely recommended by physicians to prevent KSD, the present study evaluated whether the quantity of water that people consume daily is associated with KSD and whether the quality of drinking water has any effect on disease prevalence.

Materials and Methods

Information regarding residential address, daily volume of water consumption, and source of drinking water was collected from 1,266 patients with kidney stones in West Bengal, India. Drinking water was collected by use of proper methods from case (high stone prevalence) and control (zero stone prevalence) areas thrice yearly. Water samples were analyzed for pH, alkalinity, hardness, total dissolved solutes, electrical conductivity, and salinity. Average values of the studied parameters were compared to determine if there were any statistically significant differences between the case and control areas.

Results

We observed that as many as 53.6% of the patients consumed <3 L of water daily. Analysis of drinking water samples from case and control areas, however, did not show any statistically significant alterations in the studied parameters. All water samples were found to be suitable for consumption.

Conclusions

It is not the quality of water, rather the quantity of water consumed that matters most in the occurrence of KSD.

Characterization of signalling and regulation of common calcitonin receptor splice variants and polymorphisms

The calcitonin receptor (CTR) is a class B G protein-coupled receptor that is a therapeutic target for the treatment of hypercalcaemia of malignancy, Paget's disease and osteoporosis. In primates, the CTR is subject to alternative splicing, with a unique, primate-specific splice variant being preferentially expressed in reproductive organs, lung and kidney. In addition, humans possess a common non-synonymous single-nucleotide polymorphism (SNP) encoding a proline/leucine substitution in the C-terminal tail. In low power studies, the leucine polymorphism has been associated with increased risk of osteoporosis in East Asian populations and, independently, with increased risk of kidney stone disease in a central Asian population. The CTR is pleiotropically coupled, though the relative physiological importance of these pathways is poorly understood. Using both COS-7 and HEK293 cells recombinantly expressing human CTR, we have characterized both splice variant and polymorphism dependent response to CTs from several species in key signalling pathways and competition binding assays. These data indicate that the naturally occurring changes to the intracellular face of CTR alter ligand affinity and signalling, in a pathway and agonist dependent manner. These results further support the potential for these primate-specific CTR variants to engender different physiological responses. In addition, we report that the CTR exhibits constitutive internalization, independent of splice variant and polymorphism and this profile is unaltered by peptide binding.