Cortactin knockdown results in disruption of basal TBCs and alters turnover of Sertoli cell ESs in R. norvegicus

Biol Reprod. 2021 Aug 23:ioab161. doi: 10.1093/biolre/ioab161. Online ahead of print.ABSTRACTHere we explore the prediction that long-term knockdown of cortactin (CTTN), a component of tubulobulbar complexes (TBCs), disrupts TBCs in Sertoli cells and alters the turnover of basal ectoplasmic specializations (ESs). In rats, intratesticular injections of siRNA targeting CTTN (siCTTN) in one testis and non-targeting siRNA (siControl) in the contralateral testis were done on days 0, 2, 4, 6, and 8. The experiment was terminated on day 9 and testes were analyzed by either Western Blotting, or by stimulated emission depletion (STED), electron and/or conventional fluorescence microscopy. Levels of CTTN were successfully knocked down in experimental testes compared to controls. When cryo-sections were labeled for actin filaments, or CTTN, and oxysterol binding protein-related protein 9 (ORP9) and analyzed by STED microscopy, TBCs were "less distinct" than in tubules of the same stages from control testes. When analyzed by electron microscopy, redundant clumps of basal actin filament containing ESs were observed in experimental sections. Using labeling of actin filaments in ESs, thresholding techniques were used to calculate the number of pixels above threshold per unit length of tubule wall in seminiferous tubules at Stage VII. Median values were higher in experimental testes relative to controls in the four animals analyzed. Although we detected subtle differences in ES turnover, we ...
Source: Biology of Reproduction - Category: Reproduction Medicine Authors: Source Type: research