Stem Cell Therapy For Infertility
Women in the late stage of reproductive age, introduce with the changes of hormonal levels include decreased of inhibin B, antimüllerian levels (AMH) and lower antral follicle count in the ovary with a progressive decrease in fertility rates. So far, therapeutic efforts to address this physiological problem, including repeated IVF cycles and the use of different methods to support the ovaries, have not yielded significant results. Several studies have shown that stem cells derived from different sources could have effect on the rescue of ovary functions such as recovering of ovary sex hormones, reducing apoptosis of germ cells and increasing the number of primordial follicles. Clinical trial with mesenchymal stem cells has been done with hUCMSC (human umbilical cord mesenchymal stem cell), hCBMNC (human cord blood-mononuclear cells), BMSC (bone marrow derived mesenchymal stem cells) and menstrual blood mesenchymal stem cells according to registry of the NIH clinical trial database (www.clinicaltrials.gov). Recent clinical results indicate that stem cell transplantation enhances ovarian function as evidenced by resumed menstruation, regulated hormone levels and enhance the ability of become pregnant. Within this context, cellular therapies have emerged from other medical fields as alternatives to recover ovarian function. There are several stem cell types that have been investigated in ovary dysfunctions treatment.
Stem cells (SCs) are an unspecialized population of cells that can be differentiated into other cells regardless of their sources. The two major characteristics of a stem cell are continuous self-renewal and the capacity to differentiate into a particular adult cell type. Stem cells are classifieds into two types based on their biologic possessions includingembryonic stem cells and somatic stem cells. Embryonic stem cells as pluripotent stem cells are obtained from the inner cell mass of the blastocyst that can develop any cell in the adult body, and somatic stem cells as multipotent stem cells are limited to charming a more limited population of cells. They have great potential for therapeutic uses in tissue regeneration and repair. Commonly, SCs procurement has been conducted by various protocols from diverse sources (e.g., bone marrow, peripheral blood, umbilical cord, adult body tissues). Source of SCs in stem cell therapy (SCT) can be patient’s own cells (autologous), another donor (allogenic). Allogeneic donor are primarily relative (familial-allogenic) or completely unrelated donor.
The most frequently used cell type for regenerative medicine is Mesenchymal stem cells (MSCs). MSCs are multipotential stromal cells that have the ability to self-renew and also exhibit multilineage differentiation. MSCs can be isolated from a variety of tissues, such as umbilical cord, endometrial tissue, menses blood, bone marrow, adipose tissue, etc. According to the International Society for Cellular Therapy (ISCT) they have characterized by plastic-adherence morphology, expression of the surface antigens CD73, CD90, and CD105 while lacking expression of CD45, CD34, and HLA-DR and differentiation into mesodermal cell types (i.e., adipocytes, chondrocytes, and osteoblasts) when cultured under specific conditions. MSCs are thought to mediate their regenerative effects primarily through delivering an anti-inflammatory effect, homing to injured tissues and employing other cells, such as endothelial progenitor cells, that are essential for tissue growth, backing up tissue restoration over scar creation, preventing apoptosis, and differentiating into bone, cartilage, tendon, and ligament, etc. tissue. Mesenchymal stem cells have also been shown to have a low immunogenicity due to the comparatively low quantity of MHC molecules set up on their surface. MSCs do not express MHC class II (HLA-DR ) and also they have been found to secrete chemokines that modify the immune response and promote patience of the new tissue. This allows for allogeneic treatments to be achieved without a high rejection risk. Mesenchymal stem cells have abundant benefits for clinical application including they can be harvested from multiple sources, are large-sale produced, differentiate into a different cell types and have pleiotropic effects. All these advantages make MSCs suitable for clinical application in various pathological situations.