PROGRAMMED CELL DEATH IN LONG TERM DIABETES MOUSE OVARY AND TESTICLE: AN ANALYSIS OF INTRINSIC AND EXTRINSEC PATHWAY OF APOPTOSIS

BARRIOS MARCELA; FRAUNHOFFER NICOLAS A.; MEILERMAN ABUELAFIA ANALIA.; ISOLABELLA MARCOS; KATAIFE EZEQUIEL; CURY AGUSTIN; RODRIGUEZ AGUSTIN; VITULLO ALFREDO D.

Chascomús

Jornada; XVI Jornadas Anuales de la Sociedad Argentina de Biología; 2014

Sociedad Argentina de Biología

Type I diabetes mellitus (T1D) accounts for about 10 -15% of all cases of diabetes. It is a multifactorial autoinmune disease for which susceptibility is determined by genetic, environmental and immunological factors. Recently, emerging evidence has shown that oocytes from diabetic mice experience delayed maturation, abnormal cellular metabolism, mitochondrial dysfunction and meiotic defects and cause infertility in man. These changes will be related with alteration in the follicular structure, masculine germ cells and an increase of apoptosis frequency in diabetic mice. The main objective of the present study was to analyze the balance between the apoptosis pathways in female and masculine gonads in diabetic mice. 50 BALB/c female and masculine mice (age 30 days; 15 diabetic and 10 controls) were used in this assay. To generate a T1D model, mice received five injections of streptozotocin at a dose of 60 mg/kg, during 5 consecutive days. Animals were selected as diabetic when glucose level was > 200 mg/dl. Weight and food intake was recorded weekly both in diabetic and control animals. Five diabetic and four control animals were sacrificed at day 15, 20, 40, 70 and 80 post-treatment. The ovaries and testicles were removed, weighed and fixed in 4% PFA for immunohistochemistry and immunofluorescence .The proteins studied were: BCL-2 family proteins: Bax, Bcl-2 and Bid cleaved, Fas/Fas-L system and Caspase family - active caspase 3. Bax and Bcl-2 expression was constant at all time-points, with no differences between control and diabetic mice. Extrinsic pathway markers (Fas, Fas-L and cleaved Bid) showed strong cytoplasmatic immunostaining in oocyte and granulosa cells and masculine germ cells of diabetic mice Active caspase 3 was positive in granulosa cells of atretic antral follicles and masculine germ cells. This study shows that during the earliest stages of streptozotocin - induced T1D, a switch from intrinsic to extrinsic apoptosis pathway takes place in mice ovaries and testicles. Clearly, apoptosis activity, both intrinsic and extrinsic, is enhanced in the ovary and testicle of diabetic-induced mice affecting follicular survival and compromising fertility.