2 research outputs found
Comparative evaluation of glomerular morphometric techniques reveals differential technical artifacts between focal segmental glomerulosclerosis and normal glomeruli
Abstract Morphometric estimates of mean or individual glomerular volume (MGV, IGV) have biological implications, over and above qualitative histologic data. However, morphometry is timeâconsuming and requires expertise limiting its utility in clinical cases. We evaluated MGV and IGV using plasticâ and paraffinâembedded tissue from 10 control and 10 focal segmental glomerulosclerosis (FSGS) mice (aging and 5/6th nephrectomy models) using the gold standard Cavalieri (Cav) method versus the 2âprofile and WeibelâGomez (WG) methods and a novel 3âprofile method. We compared accuracy, bias and precision, and quantified results obtained when sampling differing numbers of glomeruli. In both FSGS and controls, we identified an acceptable precision for MGV of 10âglomerular sampling versus 20âglomerular sampling using the Cav method, while 5âglomerular sampling was less precise. In plastic tissue, 2â or 3âprofile MGVs showed greater concordance with MGV when using Cav, versus MGV with WG. IGV comparisons using the same glomeruli reported a consistent underestimation bias with both 2â or 3âprofile methods versus the Cav method. FSGS glomeruli showed wider variations in bias estimation than controls. Our 3âprofile method offered incremental benefit to the 2âprofile method in both IGV and MGV estimation (improved correlation coefficient, Lin's concordance and reduced bias). In our control animals, we quantified a shrinkage artifact of 52% from tissue processed for paraffinâembedded versus plasticâembedded tissue. FSGS glomeruli showed overall reduced shrinkage albeit with variable artifact signifying periglomerular/glomerular fibrosis. A novel 3âprofile method offers slightly improved concordance with reduced bias versus 2âprofile. Our findings have implications for future studies using glomerular morphometry
Multiscale genetic architecture of donor-recipient differences reveals intronic LIMS1 mismatches associated with kidney transplant survival
Donor-recipient (D-R) mismatches outside of human leukocyte antigens (HLA) contribute to kidney allograft loss, but mechanisms remain unclear, specifically for intronic mismatches. We quantified non-HLA mismatches at variant-, gene-, and genome-wide scales from SNP data of D- Rs from two well-phenotyped transplant cohorts: Genomics of Chronic Allograft Rejection (GoCAR; n=385) and Clinical Trials in Organ Transplantation-01/17 (CTOT-01/17; n=146). Unbiased gene-level screening in GoCAR uncovered the LIMS1 locus as the top-ranked gene where D-R mismatches associated with death-censored graft loss (DCGL). A previously unreported, intronic, LIMS1 haplotype of 30 SNPs independently associated with DCGL in both cohorts. Haplotype mismatches showed a dosage effect, and minor-allele introduction to major- allele-carrying recipients showed greater hazard of DCGL. The LIMS1 haplotype and the previously reported LIMS1 SNP rs893403 are expression quantitative trait loci (eQTL) in immune cells for GCC2 (not LIMS1), which encodes a protein involved in mannose-6-phosphase receptor (M6PR) recycling. Peripheral blood and T-cell transcriptome analyses associated GCC2 gene and LIMS1 SNPs with the TGFB1-SMAD pathway, suggesting a regulatory effect. In vitro GCC2 modulation impacted M6PR-dependent regulation of active TGFB1 and downstream signaling in T-cells. Together, our data link LIMS1 locus D-R mismatches to DCGL via GCC2 eQTLs that modulate TGFB1-dependent effects on T-cells