Categories
Uncategorized

Sertoli cells

2495

2554

A Sertoli cell is part of a seminiferous tubule of the testicle and helps in the process of spermatogenesis, the production of sperm.

 

Sertoli cells are activated by follicle-stimulating hormone (FSH) secreted by the pituitary, and has FSH receptor on its membranes. 

 

Sertoli cells are located in the convoluted seminiferous tubules.

 

Seminiferous tubules is the only place in the testes where the spermatozoa are produced.

 

The most distinctive feature of the Sertoli cell histologically is its dark nucleolus.

 

They are required for male sexual development. 

 

During male development, the gene SRY activates SOX9 gene transforming factor which then activates and forms a feedforward loop with FGF9. 

 

Sertoli cell proliferation and differentiation is mainly activated by FGF9 gene activating factor.

 

In the absence of FGF9 tends to cause a female to develop.

 

The  Sertoli cell is considered to be terminally differentiated, and is unable to proliferate, so once spermatogenesis has begun, no more Sertoli cells are created.

 

Sertoli cell’s main function is to nourish the developing sperm cells through the stages of spermatogenesis.

 

The Sertoli cell acts as a nurse cell.

 

Phagocytosis  by  Sertoli cells occurs with consuming the residual cytoplasm during spermatogenesis. 

 

Sertoli cells translocate from the base to the lumen of the seminiferous tubules occurs by conformational changes in their lateral margins.

 

 

Sertoli cells secrete:

 

anti-Müllerian hormone (AMH) — secreted during the early stages of fetal life.

 

Inhibin and activins  — secreted after puberty, and work together to regulate FSH secretion:

 

androgen binding protein-increases testosterone concentration in the seminiferous tubules to stimulate spermatogenesis.

 

estradiol-aromatase from Sertoli cells convert testosterone to 17 beta estradiol to direct spermatogenesis.

 

ETS Related Molecule needed for maintenance of the spermatogonial stem cell in the adult testis.

 

transferrin

 

Testicular ceruloplasmin

 

The Sertoli cell junctions create a blood-testis barrier that partitions the interstitial blood compartment of the testis from the compartment of the seminiferous tubules. 

Inhibin B is a marker of Sertoli cell number.

Sperm stem cells, the spermatogia, are allowed to cross through the blood-testis barrier so they can become immunologically unique. 

 

Sertoli cells control the entry and exit of nutrients, hormones and other chemicals into the tubules of the testis.

 

 Sertoli cells make the adluminal compartment an immune-privileged site.

 

They are responsible for establishing and maintaining the spermatogonial stem cell line.

 

They ensure the renewal of stem cells and the differentiation of spermatogonia into mature germ that progress stepwise through spermatogenesis.

 

They release of spermatozoa in a process known as spermiation.

 

Sertoli cells bind to spermatogonial cells, and consume the unneeded portions of the spermatozoa.

 

By using XRCC1 and PARP1 proteins.

 

Sertoli cells are capable of repairing DNA damage.

 

Sertoli cells have a higher mutation frequency than germ cell spermatogenic cells, about  5 to 10-fold higher.

 

Suggesting a greater efficiency of DNA repair and mutation avoidance in the germ line than in Sertoli somatic cells.

 

Sertoli cells  express factors required for sperm cell maturation.

 

Sertoli cells also produce molecules, either on their surface or soluble, that are able to modify the Immune system.

 

The ability of Sertoli cells to alter the immune response in the testicle 

 

 tubule is needed for successful sperm cell maturation. 

 

Sperm cells express neoepitopes on their surface as they progress through different stages of maturation, and can trigger a strong immune response if placed in a different site of the body.

 

Sertoli cells produce molecules that are associated with immunosuppression or immunoregulation, and are able to inhibit the migration of immune cells.

 

Sertoli cells can lower immune cells infiltration to the site of inflammation.

 

Sertoli-Leydig cell tumor is part of the sex cord-stromal tumor group of ovarian neoplasms. 

 

These tumors produce both sertoli and leydig cells and lead to an increased secretion of testosterone in ovaries and testicles.

 

Sertoli cell tumors account for only 1% of all testicular tumors.

 

Sertoli cell tumors may be associated with Peutz-Jeghers syndrome and  Carney complex.

 

Testicle sparing  surgery is indicated as there is less than 1% local recurrence rate following this procedure.

 

Orchiectomy may be required if there is local recurrence.

 

Leave a Reply

Your email address will not be published. Required fields are marked *