Circadian variation of cell proliferation in HTR-8/SVneo cell line.

Circadian clock controls several physiological processes such as cell proliferation. Extravillous trophoblast proliferation is a tightly regulated function playing a fundamental role in maternal vessel remodeling. We recently demonstrated that clock genes Per2 and Dec1 as well as the clock-controlled genes Dbp and Vegf are rhythmically expressed in human extravillous trophoblast-derived HTR-8/SVneo cells.

Evidence for circadian rhythms in human trophoblast cell line that persist in hypoxia.

Circadian clock governs daily rhythmicity of a number of physiological processes such as reproductive functions. The existence of circadian clocks in the placenta is not clearly established. In order to investigate whether human placenta may function as circadian oscillator, we utilized HTR-8/SVneo cells derived from human first-trimester trophoblast.

Adenylyl cyclase/cAMP system involvement in the antiangiogenic effect of somatostatin in the retina. Results from transgenic mice.

Neoangiogenesis is a response to retinal hypoxia that is inhibited by somatostatin (SRIF) through its subtype 2 receptor (sst2). Using a mouse model of hypoxia-induced retinopathy, we investigated whether inhibition of adenylyl cyclase (AC) is involved in SRIF anti-angiogenic actions. Hypoxia increased AC responsiveness in wild type (WT) retinas and in retinas lacking sst2, but not in sst2-overexpressing retinas.

Interactions between the nitric oxide and prostaglandin E2 biosynthetic pathways in human amnion-like WISH cells.

The aim of this study was to investigate the possible relationship between prostaglandin (PG) and nitric oxide (NO) biosynthetic pathways in human amnion-like WISH cells. Our results indicate that: (1) sodium nitroprusside (SNP), a NO donor, dose-dependently increases spontaneous prostaglandin E2 (PGE2) release while it inhibits the prostanoid output induced by the inflammatory cytokine, interleukin-1beta (IL-1beta); (2) L-arginine, the substrate of nitric oxide synthase (NOS), is ineffective in both conditions; (3) IL-1beta, which greatly enhances mRNA expression for cyclooxygenase (COX)-inducible isoform (COX-2), does not modify the mRNA expression for the NOS-inducible (iNOS) isoform; (4) indomethacin, which as expected inhibits both basal and IL-1beta-induced PGE2 release, permits the expression of iNOS mRNA in the presence of the cytokine; (5) a similar permissive action on IL-1beta action is exerted by the synthetic steroid betamethasone, which is able to inhibit both mRNA COX-2 expression and IL-1beta-induced PGE2 output in WISH cells; (6) exogenous PGE2 inhibits iNOS mRNA expression induced by indomethacin plus IL-1beta treatment; and (7) PGE2 significantly increases intracellular adenosine 3',5'-cyclic monophosphate (cAMP). The results reported here suggest the existence of a relationship between the prostaglandinergic and nitridergic pathways in WISH cells.