Federica Tiberi

Effects of Nicotine on Human Luteal Cells In Vitro: A Possible Role on Reproductive Outcome for Smoking Women

Abstract We investigated the effect of nicotine and its methylated metabolite, N-methyl-nicotine (M-nicotine), on human luteal cells by measuring release of progesterone and prostaglandins (PGs) from cultured cells and by testing gene expression of vascular endothelial growth factor (VEGF), an angiogenic factor strictly involved in luteal pathophysiology. Primary cultures of human luteal cells were treated for 24 h with nicotine and M-nicotine (from 10−6 to 10−11 M) either alone or combined with hCG (25 ng/ml); progesterone and PGs were assayed in the culture medium. In another group of experiments, luteal cells were treated for 24 h with nicotine and M-nicotine (10−7 M) to perform reverse transcriptase-polymerase chain reaction on VEGF mRNA. Nicotine and M-nicotine negatively affected basal luteal steroidogenesis at all tested concentrations, but neither was able to affect hCG-induced progesterone release. Both substances were able to significantly increase PGF2α release from luteal cells, with a dose-related efficacy for M-nicotine. On the contrary, PGE2 release was significantly inhibited by both nicotine and its metabolite. Finally, nicotine was able to increase VEGF mRNA expression significantly, whereas M-nicotine was not. In conclusion, nicotine and M-nicotine can induce a sort of luteal insufficiency by inhibiting progesterone release, probably through modulation of the PG system.

Paracrine regulation of endometriotic tissue

Endometriosis is a chronic estrogen-dependent gynecological disease, characterized by pelvic pain and infertility, defined as the presence of endometrial glands and stroma within the pelvic peritoneum and other extrauterine sites. In the peritoneal cavity endometrial cells adhere, proliferate and induce an inflammatory response. Despite a long history of clinical and experimental research, the pathogenesis of endometriosis is still controversial. Abnormal immunological activation, the endocrine milieu and the peritoneal environment all dramatically affect endometriotic tissue function. Recent studies suggest that the peritoneal fluid of women with endometriosis contains an increased number of activated macrophages and other immune cells that secrete various local products, such as growth factors and cytokines, which exert a paracrine action on endometriotic cells. Since the peculiar biological characteristics of eutopic endometrium from women with endometriosis differ from endometrium of normal subjects, an important role in the pathogenesis of this complex disease has been suggested. All of these factors contribute to enhanced proliferative and angiogenic activity and a number of functional and structural changes, resulting in the particular behavior of this tissue.

Nicotine and cotinine affect the release of vasoactive factors by trophoblast cells and human umbilical vein endothelial cells.

OBJECTIVE To examine nicotine (N) and cotinine (C) effects on trophoblast cells (TCs) and human umbilical vein endothelial cells (HUVEC) secretion of soluble fms-like tyrosine kinase (sFlt-1), soluble endoglin (sENG), placental growth factor (PlGF), transforming growth factor-beta (TGF-beta) and vascular endothelial growth factor (VEGF). STUDY DESIGN Human placentas and umbilical cords were collected from uncomplicated pregnancies at term from a total of 24 non-smoking women with a history of normal blood pressure. TCs and HUVEC were cultured for 24 h with C or N (from 10(-12) to 10(-7) M). MAIN OUTCOME MEASURES sFlt-1, sENG, PlGF, TGF-beta and VEGF release and messenger RNA (mRNA) expression were evaluated by ELISA and real-time polymerase chain reaction (PCR), respectively. RESULTS N and C reduced sFlt-1, sENG and PlGF release by TCs and TGF-beta release by HUVEC. Conversely, N and C increased PlGF secretion, while N alone increased sFlt-1 release by HUVEC. N and C were able to modulate VEGF mRNA expression in HUVEC. CONCLUSIONS Our results suggest that N and C affect the balance of some important vasoactive factors released by TCs and HUVEC. This might be one of the possible mechanism through which smoke reduces the risk of hypertensive disorders during pregnancy as well as contributes to the well known detrimental effects of smoking on fetal development.

Prokineticin 1 mRNA expression in the endometrium of healthy women and in the eutopic endometrium of women with endometriosis

OBJECTIVE To examine prokineticin 1 (PROK1) mRNA expression in eutopic endometrial glands obtained from patients with or without endometriosis, to investigate the presence of additional endometrial abnormalities in women with endometriosis. DESIGN Prospective laboratory study. SETTING University hospital. PATIENTS Twelve control women and 12 patients affected by endometriosis in the secretory phase of the menstrual cycle. INTERVENTION(S) Endometrial specimens were obtained from women affected (cases) or not (control group) by endometriosis. Endometrial glands were freshly isolated from endometrial biopsies. MAIN OUTCOME MEASURE(S) PROK1 mRNA expression levels by real-time polymerase chain reaction analysis. RESULTS PROK1 mRNA was detectable in 4 of 12 (33%) samples obtained from women affected by endometriosis, whereas 10 of 12 (83%) samples obtained from normal women were positive for PROK1 detection by real-time polymerase chain reaction. Moreover, detectable PROK1 mRNA levels were 10 times lower in samples obtained from women with endometriosis than in samples obtained from control women. CONCLUSION(S) PROK1 is a newly discovered angiogenic factor implicated in the vascular function of peri-implantation endometrium and early pregnancy. An altered expression of PROK1 could be one of the several biochemical abnormalities characterizing eutopic endometrium in endometriosis.

Prokineticin 1, homeobox A10, and progesterone receptor messenger ribonucleic acid expression in primary cultures of endometrial stromal cells isolated from endometrium of healthy women and from eutopic endometrium of women with endometriosis.

OBJECTIVE To examine prokineticin 1 (PROK1), homeobox (HOX) A10, and P receptor (PR) messenger ribonucleic acid (mRNA) expression in primary cultures of endometrial stromal cells (ESC) obtained from eutopic endometrial samples of patients with endometriosis and to clarify whether in vitro steroid hormone dependence of PROK1 gene expression is altered in endometriosis. DESIGN Prospective laboratory study. SETTING Tertiary university hospital. PATIENT(S) Twelve normal women (controls) and 12 patients affected by moderate to severe endometriosis in the midsecretory phase of the menstrual cycle. INTERVENTION(S) Endometrial specimens were obtained from control women and from women affected by endometriosis; ESC were isolated from endometrial biopsies, and primary cultures were established. MAIN OUTCOME MEASURE(S) Real-time polymerase chain reaction analysis of PROK1, HOXA10, and PR mRNA expression in ESC after 1-4 days of steroid hormone treatment and after decidual differentiation. RESULT(S) Contrary to ESC from control women, in ESC obtained from women affected by endometriosis PROK1 and PR mRNA expression was not induced by 1-4 days of treatment with steroid hormones. Nevertheless, when ESC from both groups of women were differentiated to decidual phenotype, PROK1 mRNA was up-regulated and PR and HOXA10 mRNA were down-regulated to the same extent. CONCLUSION(S) Our results provide additional evidence for P resistance in endometriosis.

Estrogens and androgens affect human luteal cell function

OBJECTIVE To evaluate estrogens (Es)--E2, estrone (E1), and estriol--and androgens--T and androstendione (A)-effect on P, prostaglandin (PG) F2α, PGE2, and vascular endothelial growth factor (VEGF) release and on VEGF expression in human luteal cells. To elucidate whether androgens effects were direct or mediated by their conversion in Es, an aromatase inhibitor was used. Finally, the luteal effect of the non-aromatizable dihydrotestosterone was evaluated. DESIGN Prospective laboratory study. SETTING University hospital. PATIENT(S) Corpora lutea (CLs) were obtained from 36 normally menstruating patients in the midluteal phase of the menstrual cycle. INTERVENTION(S) The human luteal cells were isolated from CLs and primary cultures were established. MAIN OUTCOME MEASURE(S) P and PG release were assayed by enzyme immunoassay; VEGF secretion by ELISA; VEGF messenger RNA (mRNA) expression by real-time polymerase chain reaction (PCR). RESULT(S) P and PGF2α secretion were decreased by Es and androgens. The VEGF release was increased by Es and androgens, whereas VEGF mRNA expression was not. The aromatase inhibitor counteracted T and A luteal effects. CONCLUSION(S) Both Es and androgens could participate in the regulation of human luteal function. The effect of T and A seems to be mediated by their conversion to Es, whereas for dihydrotestosterone, both direct androgenic and indirect estrogenic luteal effects could coexist.