Copy number variation analysis identifies MIR9-3 and MIR1299 as novel miRNA candidate genes for CAKUT.

BACKGROUND: Congenital anomalies of the kidney and urinary tract (CAKUT) represent a frequent cause of pediatric kidney failure. CNVs, as a major class of genomic variations, can also affect miRNA regions. Common CNV corresponding miRNAs (cCNV-miRNAs) are functional variants regulating crucial processes which could affect urinary system development. Thus, we hypothesize that cCNV-miRNAs are associated with CAKUT occurrence and its expressivity. METHODS: The extraction and filtering of common CNVs, identified in control samples deposited in publicly available databases gnomAD v2.1 and dbVar, were coupled with mapping of miRNA sequences using UCSC Genome Browser. After verification of the mapped miRNAs using referent miRBase V22.1, prioritization of cCNV-miRNA candidates has been performed using bioinformatic annotation and literature research. Genotyping of miRNA gene copy numbers for MIR9-3, MIR511, and MIR1299, was conducted on 221 CAKUT patients and 192 controls using TaqMan™ technology. RESULTS: We observed significantly different MIR9-3 and MIR1299 gene copy number distribution between CAKUT patients and controls (Chi-square, P = 0.006 and P = 0.0002, respectively), while difference of MIR511 copy number distribution showed nominal significance (Chi-square, P = 0.027). The counts of less and more than two of MIR1299 copy numbers were more frequent within CAKUT patients compared to controls (P = 0.01 and P = 0.008, respectively) and also in cohort of patients with anomalies of the urinary tract compared to controls (P = 0.016 and P = 0.003, respectively). CONCLUSIONS: Copy number variations of miRNA genes represent a novel avenue in clarification of the inheritance complexity in CAKUT and provide potential evidence about the association of common genetic variation with CAKUT phenotypes.

A preliminary study of the miRNA restitution effect on CNV-induced miRNA downregulation in CAKUT.

BACKGROUND: The majority of CAKUT-associated CNVs overlap at least one miRNA gene, thus affecting the cellular levels of the corresponding miRNA. We aimed to investigate the potency of restitution of CNV-affected miRNA levels to remediate the dysregulated expression of target genes involved in kidney physiology and development in vitro. METHODS: Heterozygous MIR484 knockout HEK293 and homozygous MIR185 knockout HEK293 cell lines were used as models depicting the deletion of the frequently affected miRNA genes by CAKUT-associated CNVs. After treatment with the corresponding miRNA mimics, the levels of the target genes have been compared to the non-targeting control treatment. For both investigated miRNAs, MDM2 and PKD1 were evaluated as common targets, while additional 3 genes were investigated as targets of each individual miRNA (NOTCH3, FIS1 and APAF1 as hsa-miR-484 targets and RHOA, ATF6 and CDC42 as hsa-miR-185-5p targets). RESULTS: Restitution of the corresponding miRNA levels in both knockout cell lines has induced a change in the mRNA levels of certain candidate target genes, thus confirming the potential to alleviate the CNV effect on miRNA expression. Intriguingly, HEK293 WT treatment with investigated miRNA mimics has triggered a more pronounced effect, thus suggesting the importance of miRNA interplay in different genomic contexts. CONCLUSIONS: Dysregulation of multiple mRNA targets mediated by CNV-affected miRNAs could represent the underlying mechanism behind the unresolved CAKUT occurrence and phenotypic variability observed in CAKUT patients. Characterizing miRNAs located in CNVs and their potential to become molecular targets could eventually help in understanding and improving the management of CAKUT.

Expression levels of GSDMB and ORMDL3 are associated with relapsing-remitting multiple sclerosis and IKZF3 rs12946510 variant.

Multiple sclerosis (MS), a noncurable autoimmune neurodegenerative disease, requires constant research that could improve understanding of both environmental and genetic factors that lead to its occurrence and/or progression. Recognition of the genetic basis of MS further leads to an investigation of the regulatory role of genetic variants on gene expression. Among risk variants for MS, Ikaros zinc finger 3 (IKZF3) gene variant rs12946510 was identified as one of the top-ranked and the expression quantitative trait loci (eQTL) for genes residing in chromosomal locus 17q12-21. The study aimed to investigate the association of gene expression of the immunologically relevant genes, which map to indicated locus, ORMDL3, GSDMB, and IKZF3, with MS and rs12946510 genotype, taking into account disease phase, clinical parameters of disease progression, and severity and immunomodulatory therapy. We used TaqMan® technology for both allelic discrimination and gene expression determination in 67 relapsing MS patients and 50 healthy controls. Decreased ORMDL3 and GSDMB mRNA levels had significant associations with MS and rs12946510 TT rare homozygote among patients. Significant positive correlations between ORMDL3 and GSDMB mRNA expression were observed in both patients and controls. We detected the significant between-effect of sex and rs12946510 on the expression of ORMDL3 in the patient group and interferon ß therapy and rs12946510 on GSDMB expression. Our results show the association of ORMDL3 and GSDMB mRNA expression with the clinical manifestation of MS and confirm that IKZF3 rs12946510 exerts the eQTL effect on both genes in multiple sclerosis. Besides providing novel insight related to MS phases and interferon ß therapy, the study results confirm previous studies on regulatory genetic variants, autoimmunity, and MS.

Identification and functional interpretation of miRNAs affected by rare CNVs in CAKUT.

Rare copy number variants (CNVs) are among the most common genomic disorders underlying CAKUT. miRNAs located in rare CNVs represent well-founded functional variants for human CAKUT research. The study aimed to identify and functionally interpret miRNAs most frequently affected by rare CNVs in CAKUT and to estimate the overall burden of rare CNVs on miRNA genes in CAKUT. The additional aim of this study was to experimentally confirm the effect of a rare CNV in CAKUT on candidate miRNA's expression and the subsequent change in mRNA levels of selected target genes. A database of CAKUT-associated rare CNV regions, created by literature mining, was used for mapping of the miRNA precursors. miRNAs and miRNA families, most frequently affected by rare CAKUT-associated CNVs, have been subjected to bioinformatic analysis. CNV burden analysis was performed to identify chromosomes with over/underrepresentation of miRNA genes in rare CNVs associated with CAKUT. A functional study was performed on HEK293 MIR484+/- KO and HEK293 WT cell lines, followed by the analysis of relative miRNA and mRNA target gene levels. 80% of CAKUT patients with underlying rare CNV had at least one miRNA gene overlapping the identified CNV. Network analysis of the most frequently affected miRNAs has revealed the dominant regulation of the two miRNAs, hsa-miR-484 and hsa-miR-185-5p. Additionally, miR-548 family members have shown substantial enrichment in rare CNVs in CAKUT. An over/underrepresentation of miRNA genes in rare CNVs associated with CAKUT was observed in multiple chromosomes, such as chr16, chr20, and chr21. A significant 0.37 fold downregulation of hsa-miR-484, followed by a notable upregulation of MDM2 and APAF1 and downregulation of NOTCH3 was detected in HEK293 MIR484+/- KO compared to HEK293 WT cell lines, supporting the study hypothesis. miRNA genes are frequently affected by rare CNVs in CAKUT patients. Understanding the potential of CNV-affected miRNAs to participate in CAKUT as genetic drivers represent a crucial implication for the development of novel therapeutic approaches.

The association of genetic variants IL2RA rs2104286, IFI30 rs11554159 and IKZF3 rs12946510 with multiple sclerosis onset and severity in patients from Serbia.

An algorithm Probabilistic Identification of Causal SNPs, identified 434 causal variants for multiple sclerosis (MS) including IL2RA rs2104286, IFI30 rs11554159 and IKZF3 rs12946510. Analysis of individual and combined effects of these variants in the Serbian population identified that Il2RA rs2104286 G allele carriers had a lower risk for developing MS (gender adjusted OR = 0.63, p = .003). With regard to the IFI30 rs11554159 recessive genetic model, among HLA-DRB1*15:01 positive patients, the AA homozygote had a significantly higher MSSS compared to the G allele carriers (p = .003). This study confirms role of IL2RA rs2104286 in MS and suggest the role of IFI30 rs11554159 in disease severity, which needs validation.

The Effects of Aronia melanocarpa Juice Consumption on the mRNA Expression Profile in Peripheral Blood Mononuclear Cells in Subjects at Cardiovascular Risk.

Foods and food products that contain polyphenols are proposed to modulate risk of cardiovascular disease. The aim of this three-arm, crossover, randomized, double-blind, placebo-controlled intervention study was to examine the impact of Aronia melanocarpa juice (AMJ), high-polyphenol (AMJ treatment, 1.17 g/100 mL polyphenols) and low-polyphenol (dAMJ treatment, 0.29 g/100 mL polyphenols) dose, on the transcriptome in peripheral blood mononuclear cells (PBMC) of 19 subjects at cardiovascular risk. Transcriptome data were obtained by microarray. Bioinformatic functional annotation analysis was performed on both the whole transcriptome datasets and the differentially expressed genes (DEGs). Expression of selected DEGs was validated by RT-qPCR. Administration of AMJ and dAMJ treatments during the two consecutive four-week treatment periods had additive effects on PBMC transcriptome profiles, with the most pronounced and specific effect noticed for AMJ in the last treatment period (TP3) of the trial. Between the high-dose and low-dose treatments in TP3, there was a multitude of overlapping DEGs and DEG-enriched biological processes and pathways, which primarily included immunomodulation and regulation of cell proliferation/death. Increased expression of TNF, IL1B, IL8, RGS1, OSM, and DUSP2 in TP3 was confirmed by RT-qPCR. The results suggest the immunomodulatory effects of prolonged habitual consumption of polyphenol-rich aronia juice in individuals at cardiovascular risk.

CDKN2B gene expression is affected by 9p21.3 rs10757278 in CAD patients, six months after the MI.

BACKGROUND: Chromosomal region 9p21.3 is most robustly associated with coronary artery disease (CAD) in western European populations. However, heterogeneity in CAD phenotypes leads to uncertainty whether 9p21.3 is associated with stable and/or acute clinical presentations of CAD. 9p21.3 is rich in regulatory elements, but the underlying mechanisms of its actions in CAD remain unclear. We investigate the association of 9p21.3 two haplotype blocks lead variants (rs10757278 and rs518394) with first-ever non-fatal myocardial infarction (MI) in CAD patients and their association with CDKN2B mRNA expression in peripheral blood mononuclear cells 6 months after the event. METHODS: We included CAD patients with sustained first MI (n = 523) and controls (n = 583). Gene expression was assessed in 72 patients 6 months after MI and 43 healthy controls. TaqMan® technology was used for the gene expression and genotyping analysis. RESULTS: CDKN2B mRNA was significantly lower in MI patients compared with the controls (p = 0.002) and in patients carrying the rs10757278 G risk allele versus AA homozygotes (p = 0.012) 6 months after the event. While we confirmed the association of rs10757278 with CDKN2B expression in MI patients, we failed to find an association between the investigated variants and MI or disease burden. CONCLUSIONS: We suggest a dysregulation of gene expression in the 9p21.3 region six months after acute MI, which is affected by a genetic variant in patients. The rs10757278 rare allele is one factor that might lead to prolonged risk for proatherogenic complications.

The HACD4 haplotype as a risk factor for atherosclerosis in males.

The 9p21.3 region is rich in regulatory elements and the variants in this region had been robustly associated with carotid plaque (CP) and coronary artery disease (CAD). Recently, the HACD4 was detected as one of the six 9p21.3 differentially expressed genes associated with accelerated atherosclerosis and greater mean lesion area in the Athsq1 congenic mice. We aimed to investigate association of two potentially regulatory HACD4 variants (rs36212560 I/D, rs2275888 T/C) and their haplotypes with CP occurrence and the level of HACD4 and FOCAD mRNA in human CP tissue. Association study was replicated in CAD patients who suffered the first myocardial infarction. Study included 477 CP patients, 303 healthy controls and replication sample of 224 CAD males from the population of Serbia. Genotypes were determined by polymerase chain reaction (PCR) and real-time PCR using TaqMan® technology. The gene expression was detected with TaqMan® technology. We have found significant and independent association of DT haplotype with CP presence in men (adjusted OR=1.64 CI=1.12-2.42, p=0.011). The result was replicated in CAD males (adjusted OR=1.84 CI=1.21-2.80, p=0.004). We have found significant effect of the HACD4 rs2275888 on FOCAD mRNA level in human CP tissue. Correction for multiple testing was performed. Independent association of HACD4 haplotypes with atherosclerotic phenotypes connotes a further validation and replication in larger cohorts as well as functional studies to enlighten the potential mechanism of its action in pathophysiology of atherosclerosis.

Genetic Variants in the Vicinity of LGALS-3 Gene and LGALS-3 mRNA Expression in Advanced Carotid Atherosclerosis: An Exploratory Study.

BACKGROUND: Previous research has shown that there is an association between galectin-3 (gal-3) protein and cardiovascular pathology. The aim of this study was to investigate the effects of rs2274273 and rs17128183 on genetic susceptibility to advanced carotid atherosclerosis (CA) and its complications. The rs2274273 has been singled out as the lead SNP of the haplotype block containing LGALS-3 (gal-3 gene) associated with gal-3 circulating levels, while rs17128183 constitutes a potentially functional SNP of the same hap-block. We further sought to determine whether these genetic variants have an impact on the expression of LGALS-3 mRNA in human carotid atherosclerotic plaque tissue. METHODS: The study encompassed 300 control subjects and 485 patients with advanced CA who had undergone carotid endarterectomy. Rs2274273, rs17128183, and LGALS-3 relative mRNA expression was detected by means of real-time PCR (TaqMan® technology). RESULTS: There were no statistically significant associations of the investigated genetic variants with susceptibility to advanced CA, nor did we find any associations in terms of ultrasonographically defined plaque phenotypes. The relative expression of LGALS-3 mRNA proved to be significantly higher in carriers of the rare alleles (P = 0.039) for both genetic variants. CONCLUSION: Our exploratory results suggest that while rs2274273 and rs17128183 bear no association with the risk of advanced CA or CA-related complications, these genetic variants are likely to affect LGALS-3 expression levels. In order to reach a definitive conclusion on the role played by rs2274273 and rs17128183 in advanced CA, our results should be further validated.

9p21 locus rs10757278 is associated with advanced carotid atherosclerosis in a gender-specific manner.

Single nucleotide polymorphisms from the chromosome locus 9p21 are reported to carry a risk for various cardiovascular diseases. One of the lead single nucleotide polymorphisms, rs10757278, was mostly investigated in association with coronary artery disease but rarely with carotid atherosclerosis. In this study, we aimed to analyze the association of rs10757278 A/G polymorphism with carotid plaque presence in advanced carotid atherosclerosis. The study included 803 participants, 486 patients with high-grade stenosis (>70%) who were undergoing carotid endarterectomy and 317 controls from Serbian population. Genotypes were determined using the real-time polymerase chain reaction. According to the recessive model of inheritance, GG genotype was significantly and independently associated with carotid plaque in females only (odds ratio 2.42, CI = 1.20-4.90, P = 0.013). Odds ratio was adjusted for age, body mass index, hypertension, TC, LDLC, HDLC and TG, and P value was corrected for multiple comparisons. Our preliminary findings suggest a gender-specific association of rs10757278 polymorphism with carotid plaque. Further studies on larger sample and in genetically and environmentally similar populations are needed.

The glutathione S-transferase T1 deletion is associated with susceptibility to multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) occurs as a result of interaction between genetic and environmental factors. Recent data support the view that oxidative damage is one of an early event in MS tissue injury. The safe elimination of reactive oxygen species and toxins via glutathione S-transferase (GST) pathways is required in order to protect cells against reactive oxygen-induced damage. The aim of our study was to analyze the possible association of GSTM1 and GSTT1 gene polymorphisms with the susceptibility and clinical parameters of MS, in 455 consecutive patients and 366 controls. METHODS: A multiplex polymerase chain reaction (PCR) was used to detect the deletions in GSTM1 and GSTT1 genes. RESULTS: Patients with MS had significantly higher frequency of GSTT1 null genotype compared to controls (37.36% vs. 21.86%, respectively, p<0.0001, adjusted OR 2.13 (1.56-2.90)), as well as double deletions (15.38% vs. 10.38%, respectively, p<0.05). The carriers of GSTM1 deletion had significantly earlier onset of MS compared to the wild-type carriers (28.31 ± 8.45 vs. 30.64 ± 9.30 years, respectively, p = 0.03). CONCLUSION: This study suggests the potential pathogenic role of GSTT1 deletion on MS susceptibility. There are no similar data published so far, yet this study should be replicated in other populations.