Cytoskeletal proteins associate with specific cell adhesion complexes and membrane proteins and influence the structural and functional organization of polarized epithelial cells in the kidney. Among such proteins that have been studied in cultured cell lines and in animals are the tight junction complex (ZO-1 and occludin), the adherens cell-cell adhesion complex (alpha-, beta-catenin and plakoglobin), and Na+,K+-ATPase, with its associated membrane skeleton proteins ankyrin and fodrin. Although abnormal distribution of these proteins has been implicated in the pathogenesis of various renal diseases, the relevance of these findings to corresponding disease of the human kidney remains to be established. As a first step towards elucidating a role for such proteins in human kidney disease, we undertook a histochemical analysis of the distribution of these proteins in biopsy specimens of human kidney taken from healthy kidney transplant donors. We found each protein to have a characteristic subcellular localization and an intensity of staining that varied among different segments of the nephron in a manner that is consistent with discrete, segmental nephron function.
We studied glomerular function longitudinally for 36-120 mo in 21 patients undergoing treatment for diffuse, proliferative lupus nephritis. We determined glomerular filtration rate (GFR) and glomerular oncotic pressure (IIGC) and computed the two-kidney ultrafiltration coefficient (Kf) at 6- to 12-mo intervals. The relationships and cross talk among the three variables over time were then analyzed by eigenfunction regression and canonical correlations. We also performed a morphometric analysis of serial biopsies and computed single-nephron Kf in patent glomeruli at baseline and after 36-94 mo of follow-up. Patients were divisible into progressors (n = 12) or nonprogressors (n = 9) according to the presence or absence, respectively, of an irrevocable decline in GFR over time. Examination of longitudinal variables revealed GFR to be strongly related to Kf in all patients and inversely related to IIGC in progressors. By serial morphometric analysis we observed a threefold increase in the prevalence of global sclerosis in progressors but unchanged prevalence in nonprogressors. Whereas single-nephron Kf of remnant glomeruli increased to supernormal levels in nonprogressors, the absence of this compensatory phenomenon in progressors permitted GFR and Kf to decline in parallel with the declining number of functional glomeruli.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.