SAT065 Developmental Programming: Sex-specific Programming Of Pancreas In A Sheep Model Of Polycystic Ovary Syndrome
Authors: Halloran Katherine M , Vyas Arpita K , Saadat Nadia , Padmanabhan Vasantha 
Published: October 2023

Disclosure: K.M. Halloran: None. A.K. Vyas: None. N. Saadat: None. V. Padmanabhan: None.

Prenatal testosterone (T) treatment from gestational days (GD) 30-90 (sexually dimorphic window of fetal development where male fetuses naturally see elevated T) leads to reproductive and metabolic disruptions in female sheep that includes dyslipidemia, insulin resistance, and compensatory hyperinsulinemia similar to that seen in women with PCOS. The effects of excess T are seen as decreased pancreatic/fetal weight in female fetuses as opposed to an increase in beta cell size and lipid/collagen accumulation in adult females. We addressed the prenatal T-induced gene expression changes contributing to pancreatic compromise to determine if 1) the programmed event persists after cessation of T treatment, 2) T females (TF) are similar to control males (CM), and 3) it is exacerbated in the T males (TM). Time-mated pregnant sheep were administered T propionate (100 mg in 2 ml corn oil) or vehicle between GD 30-90 to obtain control female (CF), TF, CM, and TM fetuses (n=6/group). On ∼GD 120 (term: 147), fetuses were weighed and pancreas was collected, weighed, and the tail portion stored at -80°C until next-generation sequencing for gene expression profiling to identify potential pathways influenced by T and fetal sex. After removal of outliers (determined by Principal Component Analysis-PCA using SIMCA), 3D PCA plots showed clear separation of the treatment groups after stratifying by fetal sex. DESeq2 R package was used to identify differentially expressed genes (DEGs) between the comparisons of interest (CF vs TF, TF vs CM, and CM vs TM). Overall, T fetuses weighed less (P&lt;0.05). Cohen’s effect size analysis found a large magnitude (Cohen’s d&gt;0.8) decrease in fetal weight for TF vs CF, TM vs CM, and TF vs CM and a medium magnitude (d=0.5) decrease in pancreas weight for TF vs CM. Pancreatic:fetal weight ratios did not differ by treatment or fetal sex. 16 DEGS (1 up, 15 down) were identified between TF and CF, 7 DEGs (2 up, 4 down) between TF and CM, and 2 DEGs (up) between TM and CM (Adj P&lt;0.1) with no overlap amongst them, suggesting that the effect of T in females is distinct from males and that TF are more similar to CM. Preliminary analysis indicates that the majority of the DEGs affected in TF are related to immune-signaling pathways, including c-type lectin domain family 4 member G (CLEC4G), cluster of differentiation 52 (CD52), and interleukin 21 receptor (IL21R); CD52, IL21R, and members of the CLEC4 family are implicated in autoimmune pathways linked to Type 1 diabetes. The 2 DEGs affected in TM are involved in plasma membrane dynamics: fer-1 like family member 6 (FER1L6) and chloride voltage gated channel 2 (CLCN2). These changes evident at the gene expression level a month after the cessation of T treatment is suggestive of sexually dimorphic reprogramming of fetal pancreas by exposure to excess T. Further, the endogenous increases in T seen in males may at least in part be responsible for sexually dimorphic programming.

Presentation: Saturday, June 17, 2023