Superior mesenteric ganglion neural modulation of ovarian angiogenesis, apoptosis and proliferation by the neuroactive steroid allopregnanolone

Abstract

Allopregnanolone (ALLO), a potent neuroactive steroid, is synthesized and active in the peripheral nervous system. Previous studies have shown that ALLO participates in the central regulation of reproduction with effects on ovarian physiology, although there is little evidence for its ability to modulate peripheral tissues. The present study aimed to determine whether ALLO, administered to an ex vivo system that comprises the superior mesenteric ganglion (SMG), the ovarian nervous plexus (ONP) and the ovary (O), or to the denervated ovary (DO), was able to modify ovarian apoptosis, proliferation and angiogenesis. For this purpose, the SMG‐ONP‐O system and DO were incubated during 120 min at 37°C, in the presence of two ALLO doses (0.06 µm and 6 µm). The intrinsic and extrinsic pathways of apoptosis were analyzed. Incubation of the SMG‐ONP‐O system with ALLO 0.06 µm led to an increase in the BAX/BCL‐2 ratio and a reduction of FAS‐L mRNA levels. ALLO 6 µm induced a decrease of FAS‐L levels. Incubation of DO with ALLO 0.06 µm reduced FAS‐L, whereas ALLO 6 µm significantly increased it. Cyclin D1 mRNA was measured to evaluate proliferation. Treatment with ALLO 6 µm increased proliferation in both SMG‐ONP‐O and DO. ALLO 0.06 µm produced an increase of Cyclin D1 in DO only. Administration of either ALLO dose led to a higher ovarian expression of vascular endothelial growth factor in the SMG‐ONP‐O system, but a lower one in the DO system. ALLO 6 µm induced ovarian sensitization to GABA by increasing GABAA receptor expression. In conclusion, ALLO participates in the peripheral neural modulation of ovarian physiology. It can also interact directly with the ovarian tissue, modulating key mechanisms involved in normal and pathological processes in a dose‐dependent manner.

Local effect of allopregnanolone in rat ovarian steroidogenesis, follicular and corpora lutea development

“…RNA integrity was verified by electrophoresis in a 1% agarose gel stained with SYBR Gold (Thermofisher Scientific Technologies, Buenos Aires, Argentina). Five micrograms of total RNA were retrotranscribed at 37 °C using random hexamer primers (Random Hexamers, Thermofisher) and murine leukemia virus retrotranscriptase enzyme (M-MLV, Thermofisher) in a reaction mixture with a final volume of 20 µl, according to previously published steps 21 .…”

Neuroactive steroids: From basic research to clinical use

“…These potential treatments are reviewed by Reddy, 8 summarizing two decades of research, during neurosteroid replacement therapy was proposed and championed as a rational strategy for treating disorders such as catamenial epilepsy and other related ovarian or menstrual disorders. The research paper by Caceres et al 9 reports an investigation aiming to determine whether allopregnanolone, administered to an ex vivo system that comprises the superior mesenteric ganglion, the ovarian nervous plexus and the ovary, or to the denervated ovary, could modify ovarian apoptosis, proliferation and angiogenesis. In their experimental model, this neuroactive steroid induced ovarian sensitization to GABA by increasing GABA A receptor expression.…”