[The role of Pax2 in regulation of kidney development and kidney disease]

A genome-wide association and replication study of blood pressure in Ugandan early adolescents

BACKGROUND

Genetic association studies of blood pressure (BP) have mostly been conducted in non-African populations. Using the Entebbe Mother and Baby Study (EMaBS), we aimed to identify genetic variants associated with BP among Ugandan adolescents.

METHODS

Systolic and diastolic BP were measured among 10- and 11-year olds. Whole-genome genotype data were generated using Illumina omni 2.5M arrays and untyped variants were imputed. Genome-wide association study (GWAS) was conducted using linear mixed model regression to account for population structure. Linear regression analysis was used to assess whether variants previously associated with BP (p < 5.0 × 10-8 ) in published BP GWASs were replicated in our study.

RESULTS

Of the 14 million variants analyzed among 815 adolescents, none reached genome-wide significance (p < 5.0×10-8 ) for association with systolic or diastolic BP. The most strongly associated variants were rs181430167 (p = 6.8 × 10-7 ) for systolic BP and rs12991132 (p = 4.0 × 10-7 ) for diastolic BP. Thirty-three (17 single nucleotide polymorphisms (SNPs) for systolic BP, 15 SNPs for diastolic BP and one SNP for both) of 330 variants previously identified as associated with BP were replicated in this study, but none remained significant after accounting for multiple testing.

CONCLUSION

Variants showing suggestive associations are worthy of future investigation. Replication results suggest that variants influencing adolescent BP may overlap somewhat with those already established in previous studies, largely based on adults in Western settings.

Omega-3 attenuates high fat diet-induced kidney injury of female rats and renal programming of their offsprings

Context: Maternal diet composition could influence fetal organogenesis. Objective: We investigated effects of high fat diet (HFD) intake alone or combined with omega 3 during pregnancy, lactation and early days of weaning on nephrogenesis of pups and maternal renal function and morphology. Material and methods: Mothers and their pups included in each group were supplied with the same diet composition. Rats were divided into group I, II and III supplied with chow of either 10 kcal%, 45 kcal% or 45 kcal% from fat together with omega-3 respectively. Results: Group II showed increased serum urea and creatinine, renal TNF-α, IL1β. Structural injury was observed in mothers and their pups as Bowman's capsule and tubular dilatation and increased expression of PCNA that were decreased following omega-3 supplementation added to down regulation of Wnt4, Pax2 gene and podocin expression. Discussion and conclusion: Omega-3 supplementation improves lipid nephrotoxicity observed in mothers and their pups.

Molecular characterization of nephron progenitors and their early epithelial derivative structures in the nephrogenic zone of the canine fetal kidney

Nephron progenitors (NPs) and nephrogenesis have been extensively studied in mice and humans and have provided insights into the mechanisms of renal development, disease and possibility of NP-based therapies. However, molecular features of NPs and their derivatives in the canine fetal kidney (CFK) remain unknown. This study was focused to characterize the expression of potential markers of canine NPs and their derivatives by immuno-fluorescence and western blot analysis. Transcription factors (TFs) SIX1 and SIX2, well-characterized human NP markers, were expressed in NPs surrounding the ureteric bud in the CFK. Canine NPs also expressed ITGA8 and NCAM1, surface markers previously used to isolate NPs from the mouse and human fetal kidneys. TF, PAX2 was detected in the ureteric bud, NPs and their derivative structures such as renal vesicle and S-shaped body. This study highlights the similarities in dog, mouse and human renal development and characterizes markers to identify canine NPs and their derivatives. These results will facilitate the isolation of canine NPs and their functional characterization to develop NP-based therapies for canine renal diseases.