Estrogenized mouse model of polycystic ovary highlights mitochondrial pathway of apoptosis

Polycystic ovary syndrome, which is a major cause of anovulatory infertility in women, featured by an ovarian morphology that reflects arrested follicular growth and accumulation of cystic follicles. Alteration of apoptotic process may promote development and persistence of follicular cysts, which has not been explored in details. Female animals exposed to estrogenic compounds at specific growth stages show altered pubertal maturation, ovulatory dysfunction, accumulation of follicular cysts and infertility. Here, we developed a mouse model of cystic ovary by neonatal estrogenization and investigated apoptotic changes underlying cystogenesis across various time points. We compared pro- and anti-apoptotic markers along with ovarian morphology between control and estradiol treated mice using several techniques including flow cytometry, immunohistochemistry and electron microscopy. Treated mice presented with cystic follicles with degenerated oocyte and reduced granulosa cell layer, anovulation, along with persistent estrus cycle and infertility. Increased apoptosis was demonstrated in cystic follicles with significantly increased expression of JC-1, Bid, caspase-9 and caspase-3. Thus, our findings highlight the involvement of mitochondrial pathway of apoptosis in development of polycystic ovary in response to neonatal exposure to estrogen. This model may serve to delineate the effect of environmental estrogen exposure to altered ovarian physiology which is frequently observed in PCOS women

Nanovaccines: recent developments in vaccination.

In the past 100 years, vaccination has contributed immensely to public health by preventing a number of infectious diseases. Attenuated, killed or part of the microorganism is employed to stimulate the immune system against it. Progress in biotechnology has provided protective immunity through DNA vaccines. In recent years, nanovaccine is a novel approach to the methodology of vaccination. Nanomaterials are delivered in the form of microspheres, nanobeads or micro-nanoprojections. Painless, effective and safe needle-free routes such as the intranasal or the oral route, or patches of microprojections to the skin are some of the approaches which are in the experimental stage at present but may have a great future ahead in nanovaccination.

Effect of the human follicle-stimulating hormone-binding inhibitor and its N-terminal fragment on follicle-stimulating hormone-induced progesterone secretion by granulosa cells in vitro.

Intrafollicular factors play an important role in folliculogenesis. The follicle-stimulating hormone (FSH)-binding inhibitor (FSHBI), purified by our laboratory from human ovarian follicular fluid, has been shown to suppress ovulation and induce follicular atresia/apoptosis in mice as well as impair fertility in marmosets, the New World monkeys. The octapeptide, a peptide corresponding to the N-terminal region of human FSHBI (hFSHBI), has been synthesized and also shows FSHBI activity in vitro. In the present study, we have attempted to identify the mechanism of action of the peptide in granulosa cell cultures. Rat granulosa cell cultures were treated with varying concentrations of the octapeptide or partially purified hFSHBI (gel chromatography fraction hGF 2) in the presence or absence of human FSH (hFSH) and the amount of progesterone (P;4) secreted in the culture supernatants after 3 h/48 h was estimated. Both hGF2 and the octapeptide failed to alter basal levels as well as 8-bromo cAMP-induced P;4 production, while FSH-induced P 4 secretion was inhibited in a dose-dependent manner. These studies reveal that the octapeptide, a fragment of FSHBI, and the native protein have similar activity in vitro and both compounds alter FSH action at the receptor level upstream of cAMP formation.

Application of nanotechnology in biomedicine.

Nanotechnology is the development of engineered devices at the atomic, molecular and macromolecular level in nanometer range. Nanoparticles have potential application in medical field including diagnostics and therapeutics. Nanotechnology devices are being developed for diagnosis of cancer and infectious diseases which can help in early detection of the disease. Advances in nanotechnology also proved beneficial in therapeutic field such as drug discovery, drug delivery and gene/protein delivery. Nanoparticles can be constructed by various methodology so that effect can be targeted at desired site. In this review, some of the applications of nanoparticles in medicine as diagnostics and therapeutics which can be employed safely at the clinical level have been described. On other hand, as the particles become generally smaller their likehood of causing harm to the lung increases. Therefore, there is a need to study safety of nanoparticles.

Stem cell research: its relevance to reproductive biology.

Stem cells provide an excellent model system to understand the differentiation, development and functioning of gonads, and further use of these cells in transplantation or cell-based therapies. Embryonic germ cells present as a better source of pluripotent stem cells. The germ cells are specialized cells, which differentiate into sperm or oocytes. Spermatogonial stem cells are the only stem cells in the adult mammalian body that can be recognized and studied at cellular level with respect to proliferation and differentiation. In the present study, basic process of spermatogenesis, testicular niche and molecular regulation of spermatogenesis and density regulation has been discussed. Research on oogonial stem cells has recently been encouraged due to the demand for oocytes for various research purposes. Mechanism of regulation of follicle formation, oocyte attrition and follicle development and atresia are only partially understood. Hence, the stages of development, its interaction with the neighbouring somatic cells during each developmental stage and the molecular regulation underlying it has been reviewed. These studies will result in establishment of treatment of ovarian disorders, and in identifying cure for infertility that occurs due to ovarian pathophysiology. Indian scenario in terms of stem cell research and its benefits is also discussed.

Apoptosis in granulosa cells induced by intrafollicular peptide.

Ovarian follicular fluid peptide (OFFP) purified from sheep ovaries has been earlier shown to induce degeneration of ovarian follicles in mice. In the present study, whether the effect of OFFP on granulosa cells was similar to apoptosis was studied using three parameters. Immature mice injected with pregnant mare serum gonadotropin on day 0 were administered with 10 or 20 J.lg of OFFP on day 1 and autopsied on day 2. The granulosa cells were collected from the ovarian follicles. The presence of apoptotic bodies were observed by staining the cells with acridine orange. DNA profiles of DAPI-stained cells analysed by flow cytometry also revealed apoptotic response to OFFP. Furthermore, agarose gel electrophoresis of low molecular weight DNA fraction extracted from the cells of OFFP-treated animals confirmed ladder formation and induction of apoptosis and not necrosis in granulosa cells. In conclusion, all the three parameters indicated apoptotic changes in granulosa cells of ovarian follicles in .mice treated with OFFP. The effect of OFFP seems to be exerted directly on the granulosa cells showing its autocrine role in the process of follicular atresia. This is discussed in the light of other intra/extra ovarian factors.