The blood-testis barrier and its formation relative to spermatocyte maturation in the adult rat: A lanthanum tracer study

1978 ◽  
Vol 190 (1) ◽  
pp. 99-111 ◽  
Author(s):  
Lonnie D. Russell
Keyword(s):  
Tracer Study ◽  
Adult Rat ◽  
Lanthanum Tracer ◽  
Blood Testis Barrier

BLOOD–TESTIS BARRIER: EVIDENCE FOR INTACT INTER-SERTOLI CELL JUNCTIONS AFTER HYPOPHYSECTOMY IN THE ADULT RAT

1978 ◽  
Vol 76 (1) ◽  
pp. 87-91 ◽  
Author(s):  
L. HAGENÄS ◽  
L. PLÖEN ◽  
H. EKWALL
Keyword(s):  
Sertoli Cell ◽  
Structural Integrity ◽  
Cell Junctions ◽  
Junctional Complex ◽  
Tracer Technique ◽  
Adult Rats ◽  
Adult Rat ◽  
Hormonal Dependence ◽  
Lanthanum Tracer ◽  
Blood Testis Barrier

SUMMARY To study the hormonal dependence of the blood–testis barrier, adult rats were hypophysectomized and the ultrastructural integrity of the inter-Sertoli cell junctional complex was examined at various times with a lanthanum tracer technique. It was found that the structural integrity of the inter-Sertoli cell junctions and their capacity to exclude lanthanum from the adluminal compartment were preserved up to 35 days after hypophysectomy. Furthermore, transport of newly formed spermatocytes through the inter-Sertoli cell junctions still occurred 20 days after hypophysectomy. It is therefore concluded that the function of the inter-Sertoli cell junctional complex is not directly dependent on gonadotrophic or androgenic hormones, but is regulated by other mechanisms.

scholarly journals mTORC1/rpS6 regulates blood-testis barrier dynamics and spermatogenetic function in the testis in vivo

2018 ◽  
Vol 314 (2) ◽  
pp. E174-E190 ◽  
Author(s):  
Stephen Y. T. Li ◽  
Ming Yan ◽  
Haiqi Chen ◽  
Tito Jesus ◽  
Will M. Lee ◽  
...  
Keyword(s):  
Mammalian Target Of Rapamycin ◽  
Downstream Signaling ◽  
Signaling Complex ◽  
Adult Rat ◽  
Mammalian Expression ◽  
Ribosomal Protein S6 ◽  
Spatiotemporal Expression ◽  
Blood Testis Barrier

The blood-testis barrier (BTB), conferred by Sertoli cells in the mammalian testis, is an important ultrastructure that supports spermatogenesis. Studies using animal models have shown that a disruption of the BTB leads to meiotic arrest, causing defects in spermatogenesis and male infertility. To better understand the regulation of BTB dynamics, we report findings herein to understand the role of ribosomal protein S6 (rpS6), a downstream signaling protein of mammalian target of rapamycin complex 1 (mTORC1), in promoting BTB disruption in the testis in vivo, making the barrier “leaky.” Overexpression of wild-type rpS6 (rpS6-WT, the full-length cDNA cloned into the mammalian expression vector pCI-neo) and a constitutively active quadruple phosphomimetic mutant cloned into pCI-neo (p-rpS6-MT) vs. control (empty pCI-neo vector) was achieved by transfecting adult rat testes with the corresponding plasmid DNA using a Polyplus in vivo-jetPEI transfection reagent. On the basis of an in vivo functional BTB integrity assay, p-rpS6-MT was found to induce BTB disruption better than rpS6-WT did (and no effects in empty vector control), leading to defects in spermatogenesis, including loss of spermatid polarity and failure in the transport of cells (e.g., spermatids) and organelles (e.g., phagosomes), to be followed by germ exfoliation. More important, rpS6-WT and p-rpS6-MT exert their disruptive effects through changes in the organization of actin- and microtubule (MT)-based cytoskeletons, which are mediated by changes in the spatiotemporal expression of actin- and MT-based binding and regulatory proteins. In short, mTORC1/rpS6 signaling complex is a regulator of spermatogenesis and BTB by modulating the organization of the actin- and MT-based cytoskeletons.

scholarly journals Dynamin II interacts with the cadherin- and occludin-based protein complexes at the blood–testis barrier in adult rat testes

2006 ◽  
Vol 191 (3) ◽  
pp. 571-586 ◽  
Author(s):  
Pearl P Y Lie ◽  
Weiliang Xia ◽  
Claire Q F Wang ◽  
Dolores D Mruk ◽  
Helen H N Yan ◽  
...  
Keyword(s):  
Germ Cell ◽  
Protein Complexes ◽  
Adherens Junction ◽  
Cell Movement ◽  
Cell Loss ◽  
Adult Rat ◽  
Ectoplasmic Specialization ◽  
Stage Viii ◽  
Blood Testis Barrier

In adult rat testes, blood–testis barrier (BTB) restructuring facilitates the migration of preleptotene spermatocytes from the basal to the adluminal compartment that occurs at stage VIII of the epithelial cycle. Structural proteins at the BTB must utilize an efficient mechanism (e.g. endocytosis) to facilitate its transient ‘opening’. Dynamin II, a large GTPase known to be involved in endocytosis, was shown to be a product of Sertoli and germ cells in the testis. It was also localized to the BTB, as well as the apical ectoplasmic specialization (apical ES), during virtually all stages of the epithelial cycle. By co-immunoprecipitation, dynamin II was shown to associate with occludin, N-cadherin, zonula occludens-1 (ZO-1), β-catenin, junctional adhesion molecule-A, and p130Cas, but not nectin-3. An in vivo model in rats previously characterized for studying adherens junction (AJ) dynamics in the testes by adjudin (formerly called AF-2364, 1-(2,4-dichlorobenzyl)-1H-indazole-3-car-hohydrizide) treatment was used in our studies. At the time of germ cell loss from the seminiferous epithelium as a result of adjudin-induced AJ restructuring without disrupting the BTB integrity, a significant decline in the steady-state dynamin II protein level was detected. This change was associated with a concomitant increase in the levels of two protein complexes at the BTB, namely occludin/ZO-1 and N-cadherin/β-catenin. Interestingly, these changes were also accompanied by a significant increase in the structural interaction of dynamin II with β-catenin and ZO-1. β-Catenin and ZO-1 are adaptors that structurally link the cadherin- and occludin-based protein complexes together at the BTB in an ‘engaged’state to reinforce the barrier function in normal testes. However, β-catenin and ZO-1 were ‘disengaged’ from each other but bound to dynamin II during adjudin-induced AJ restructuring in the testis. The data reported herein suggest that dynamin II may assist the ‘disengagement’ of β-catenin from ZO-1 during BTB restructuring. Thus, this may permit the occludin/ZO-1 complexes to maintain the BTB integrity when the cadherin/catenin complexes are dissociated to facilitate germ cell movement.

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