Receptor-mediated endocytosis of testicular transferrin by germinal cells of the rat testis

Petrie, Robert G.; Morales, Carlos R.

doi:10.1007/bf00318690

Cited by 34 publications

(21 citation statements)

References 47 publications

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“…Petrie and Morales (1992) demonstrated that spermatocytes and spermatids possess transferrin receptor binding sites . Transferrin [ID: T2-279] is internalized into endosomes where iron dissociates from transferrin which then recycles back to the cell surface, leaving iron to enter the cell.…”

Section: Microscopy Research and Techniquementioning

confidence: 98%

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 2: Changes in spermatid organelles associated with development of spermatozoa

Hermo

Pelletier

Cyr

et al. 2009

Microscopy Res & Technique

100

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Spermiogenesis is a long process whereby haploid spermatids derived from the meiotic divisions of spermatocytes undergo metamorphosis into spermatozoa. It is subdivided into distinct steps with 19 being identified in rats, 16 in mouse and 8 in humans. Spermiogenesis extends over 22.7 days in rats and 21.6 days in humans. In this part, we review several key events that take place during the development of spermatids from a structural and functional point of view. During early spermiogenesis, the Golgi apparatus forms the acrosome, a lysosome-like membrane bound organelle involved in fertilization. The endoplasmic reticulum undergoes several topographical and structural modifications including the formation of the radial body and annulate lamellae. The chromatoid body is fully developed and undergoes structural and functional modifications at this time. It is suspected to be involved in RNA storing and processing. The shape of the spermatid head undergoes extensive structural changes that are species-specific, and the nuclear chromatin becomes compacted to accommodate the stream-lined appearance of the sperm head. Microtubules become organized to form a curtain or manchette that associates with spermatids at specific steps of their development. It is involved in maintenance of the sperm head shape and trafficking of proteins in the spermatid cytoplasm. During spermiogenesis, many genes/proteins have been implicated in the diverse dynamic events occurring at this time of development of germ cells and the absence of some of these have been shown to result in subfertility or infertility.

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Section: Microscopy Research and Techniquementioning

confidence: 98%

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 2: Changes in spermatid organelles associated with development of spermatozoa

Hermo

Pelletier

Cyr

et al. 2009

Microscopy Res & Technique

100

View full text Add to dashboard Cite

show abstract

“…The germ cells were fractionated by velocity sedimentation according to Petrie and Morales (1992). The Northern blots were prepared as previously described .…”

Section: Northern Blot Analysismentioning

confidence: 99%

Role of sulfated glycoprotein‐1 (SGP‐1) in the disposal of residual bodies by sertoli cells of the rat

Igdoura

Morales

1995

Molecular Reproduction Devel

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Sulfated glycoprotein-1 (SGP-1) is a polypeptide secreted by Sertoli cells in the rat. Sequence analysis revealed a 76% sequence similarity with human prosaposin produced by various cell types. Human prosaposin is a 70 kDa protein which is cleaved in the lysosomes into four 10-15 kDa polypeptides termed saposins A, B, C, and D. The function of lysosomal saposins is to either solubilize certain membrane glycolipids or to form complexes with lysosomal enzymes and/or their glycolipid substrate to facilitate their hydrolysis. The present investigation dealt with the delivery of SGP-1 into the phagosomes of Sertoli cells; these phagosomes contain the residual bodies which detach from the late spermatids at the time of spermiation. Immunogold labeling with anti-SGP-1 antibody was found over Sertoli cell lysosomes, but was absent from phagosomes formed after phagocytosis of spermatid residual bodies in the apical Sertoli cell cytoplasm in stages VIII and early IX of the cycle of the seminiferous epithelium. The phagosomes found later in the basal Sertoli cell cytoplasm in stages IX and X of the cycle became labeled with the antibody as the components of the residual bodies rapidly underwent lysis and disappeared from the Sertoli cells. Sertoli cell lysosomes isolated by cell fractionation (estimated purity of 80%) were found to contain a 65 kDa form of SGP-1 or prosaposin, as well as the 15 kDa polypeptides or saposins. Thus, it appears that this unique lysosomal form of SGP-1 reached the Sertoli cell phagosomes and that their derived polypeptides, the saposins, must play a role in the hydrolysis of membrane glycolipids found in phagocytosed residual bodies.

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“…In addition, it is a reliable instrument of investigation of the function (Je´gou 1991;Foucault et al 1994;Migrenne et al 2003) and maturity of these cells, both in vitro and in vivo (Holmes et al 1983(Holmes et al , 1984. Tranferrin secreted by Sertoli cells is internalized by germ cell lineage through receptor-mediated endocytosis (Petrie and Morales 1992).…”

Section: Introductionmentioning

confidence: 99%

Sertoli cell function in albino rats treated with etoposide during prepubertal phase

Stumpp

Freymüller

Miraglia

2006

Histochem Cell Biol

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Sertoli cell plays a key role in spermatogenesis. Many studies refer that this cell is not harmed by the majority of anticancer treatments known to cause damage to the testis. However, in the previous study we observed that etoposide, an efficient chemotherapeutic drug, provokes an increase in numerical density of the Sertoli cells. This phenomenon suggests that this cell was harmed by etoposide. Thus, we decided to investigate a possible direct action of etoposide on Sertoli cells analyzing the function of this cell and relating it with the integrity and damage of the seminiferous epithelium. Prepubertal albino rats received 5 mg/kg of etoposide for eight consecutive days and were sacrificed in different ages. The control groups received 0.9% saline solution. The testes were fixed in Bouin's liquid for transferrin immunolabeling and testicular labeled tissue volume density measurement. Except for the younger rats, all the etoposide-treated rats showed diminution of transferrin immunolabeling in the seminiferous epithelium, and consequently, of total labeled testicular tissue volume density. We concluded that the diminution of transferrin labeling in the seminiferous epithelium was not associated with germ cell absence such as commonly reported. The results suggest etoposide impairs Sertoli cell function.

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Receptor-mediated endocytosis of testicular transferrin by germinal cells of the rat testis

Cited by 34 publications

References 47 publications

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 2: Changes in spermatid organelles associated with development of spermatozoa

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 2: Changes in spermatid organelles associated with development of spermatozoa

Role of sulfated glycoprotein‐1 (SGP‐1) in the disposal of residual bodies by sertoli cells of the rat

Sertoli cell function in albino rats treated with etoposide during prepubertal phase

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