Sertoli cell

Because its main function is to nourish the developing sperm cells through the stages of spermatogenesis, the Sertoli cell has also been called the "mother" or "nurse" cell.[1] Sertoli cells also act as phagocytes, consuming the residual cytoplasm during spermatogenesis. Translocation of cells from the base to the lumen of the seminiferous tubules occurs by conformational changes in the lateral margins of the Sertoli cells.

Besides expressing factors that are crucial for sperm cell maturation, Sertoli cells are producing a wide range of molecules (either on their surface or soluble) that are able to modify the Immune system (IS). The ability of Sertoli cells to change the immune response in the tubule is needed for successful sperm cell maturation. Sperm cells are expressing neoepitopes on their surface as they progress through different stages of maturation. They can trigger a strong immune response if placed in a different site of the body.

Sertoli cells are required for male sexual development. During male development, the gene SRY activates SOX9, which then activates and forms a feedforward loop with FGF9. Sertoli cell proliferation and differentiation is mainly activated by FGF9.[12] The absence of FGF9 tends to cause a female to develop.[13]

Once fully differentiated, the Sertoli cell has been considered to be terminally differentiated, and is unable to proliferate.[14] Therefore, once spermatogenesis has begun, no more Sertoli cells are created.

Recently however, some scientists have found a way to induce Sertoli cells to a juvenile proliferative phenotype outside of the body.[15] This gives rise to the possibility of repairing some defects that cause male infertility.

It has been suggested that Sertoli cells may derive from the fetal mesonephros.[16]

Sertoli cells are called so because of their eponym Enrico Sertoli, an Italian physiologist who discovered them while studying medicine in the University of Pavia, Italy.[17]

He published a description of this cell in 1865. The cell was discovered by Sertoli with a Belthle microscope purchased in 1862, which he used while studying medicine.

In the 1865 publication, his first description used the terms "tree-like cell" or "stringy cell" and most importantly he referred to these as "mother cells". It was other scientists who used Enrico's family name, Sertoli, to label these cell in publications, starting in 1888. As of 2006, two textbooks that are devoted specifically to the Sertoli cell have been published.

On slides, using standard staining, Sertoli cells can easily be confused with the other cells of the germinal epithelium. The most distinctive feature of the Sertoli cell is the dark nucleolus.[18]

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

• 
  section of a tubule of the testis of a rat. X 250.

Recently, experimental models of autoimmune inflammatory disorders, including diabetes, have prompted the implication of Sertoli cells into cell therapy transplantation thanks to their immunoregulatory and anti-inflammatory properties.[19]

Research adopting Sertoli cells in Diabetes type I. treatment is in the deepest stage by now. The strategy is to cotransplant β cells together with Sertoli cells into recipient organism. In case of mice, rats and also human presence of these cells restored glucose homeostasis together with lower requirement of external insulin. In all cases no immunosuppression was used, the role of this medication was taken and provided by SC.[20][21][22]

By treating spontaneously diabetic and obese mice with the transplantation of microencapsulated Sertoli cells in the subcutaneous abdominal fat depot, Giovanni et al.[19] have demonstrated that more than the half of the treated mice showed improved glucose homeostasis. This recent scientific work promises a future better treatment to patients with type 2 diabetes mellitus through the use of cell therapy.

Sertoli cells promote skin graft acceptation by recipient organism[23] and also their presence helps to increase numbers of motor neurons in spinal cord of SOD1 mice (mouse model of Amyotrofic lateral sclerosis)[24]

Function of Sertoli cells in amniota and anamniota is the same, but they have a slightly different properties when compared to each other. Anamnionts (fish and amphibians) are employing cystic spermatogenesis in order to produce sperm cells.[25] In case of amniota Sertoli cells are considered to be terminally differentiated cells not able to proliferate. In anamniota Sertoli cells go through two proliferative phases. First phase of proliferation occurs during cyst establishment promoting also migration of germ cells into it.[26][27] second one is to enlarge the cyst and produce a space for priliferating germ cells.[28]

Commonly accepted fact that Sertol cells are terminally differentiated in amniota was recently changed. After xenogeneic transplantation Sertoli cells were able to proliferate.[29]

• Sertoli cell only syndrome
• Sertoli cell nodule
• List of human cell types derived from the germ layers

Wikimedia Commons has media related to Sertoli cells.

• Histology image: 17805loa – Histology Learning System at Boston University
• Histology image: 17806loa – Histology Learning System at Boston University