Effect of nerve growth factor dimeric mimetic GK-2 on microcirculation in skeletal muscle on the hind limb ischemia model in rats

The purpose of the study. In experiments on a hind limb ischemia model in rats, the effect of the TrkA-receptor agonist of the NGF 4th loop dimeric dipeptide mimetic compound GK-2 has been studied on microcirculation in ischemic skeletal muscle.Methods. the Hind limb ischemia was caused in white male mongrel rats by the femoral artery resection. The compound GK-2 was administered intravenously (1 mg/kg/day during 14 days). Microcirculation parameters were recorded using a computer laser analyzer "LAKK-OP2". Registration was carried out simultaneously in the intact and operated limb before the operation, 1 and 14 days after it.Results. In the conditions of the hind limb ischemia model, it was shown that the compound GK-2 almost completely restored the perfusion index and its variation coefficient in the ischemic muscle to the intact contralateral limb level by the 14th day after surgery.Conclusion. It can be assumed that the anti-ischemic effect of the compound GK-2 is associated with the restoration of microcirculation as a result of increased neoangiogenesis.

miR-210 and GPD1L regulate EDN2 in primary and immortalized human granulosa-lutein cells

Endothelin-2 (EDN2), expressed at a narrow window during the periovulatory period, critically affects ovulation and corpus luteum (CL) formation. LH (acting mainly via cAMP) and hypoxia are implicated in CL formation; therefore, we aimed to elucidate how these signals regulate EDN2 using human primary (hGLCs) and immortalized (SVOG) granulosa-lutein cells. The hypoxiamiR, microRNA-210 (miR-210) was identified as a new essential player in EDN2 expression. Hypoxia (either mimetic compound-CoCl2, or low O2) elevated hypoxia-inducible factor 1A (HIF1A), miR-210 and EDN2. Hypoxia-induced miR-210 was suppressed in HIF1A-silenced SVOG cells, suggesting that miR-210 is HIF1A dependent. Elevated miR-210 levels in hypoxia or by miR-210 overexpression, increased EDN2. Conversely, miR-210 inhibition reduced EDN2 levels, even in the presence of CoCl2, indicating the importance of miR-210 in the hypoxic induction of EDN2. A molecule that destabilizes HIF1A protein, glycerol-3-phosphate dehydrogenase 1-like gene-GPD1L, was established as a miR-210 target in both cell types. It was decreased by miR-210-mimic and was increased by miR-inhibitor. Furthermore, reducing GPD1L by endogenously elevated miR-210 (in hypoxia), miR-210-mimic or by GPD1L siRNA resulted in elevated HIF1A protein and EDN2 levels, implying a vital role for GPD1L in the hypoxic induction of EDN2. Under normoxic conditions, forskolin (adenylyl cyclase activator) triggered changes typical of hypoxia. It elevated HIF1A, EDN2 and miR-210 while inhibiting GPD1L. Furthermore, HIF1A silencing greatly reduced forskolin’s ability to elevate EDN2 and miR-210. This study highlights the novel regulatory roles of miR-210 and its gene target, GPD1L, in hypoxia and cAMP-induced EDN2 by human granulosa-lutein cells.