Aldo Campana

Expression of extracellular matrix-degrading metalloproteinases by cultured human cytotrophoblast cells: Effects of cell adhesion and immunopurification

In vitro, invasion of basement membrane by human trophoblast can be blocked by metalloproteinase inhibitors. The purpose of our study was to characterize these enzymes by zymography, to define their cellular origin. First-trimester cytotrophoblast cells were prepared according to the method of Kliman et al. Half of the cell suspension was further purified with an antibody to leukocyte common antigen (CD45). Cytotrophoblast cells (immunopurified or not) were incubated in Dulbeccos modified Eagles medium on different matrices. Progesterone, total human chorionic gonadotropin, and free beta-human chorionic gonadotropin were measured in the supernatant by radioimmunoassay or enzyme immunoassays. Secreted (in the medium) and cell-bound proteases were characterized by zymography on sodium dodecyl sulfate-polyacrylamide gels containing gelatin. Cytotrophoblast cell preparations contained 12% to 34% leukocyte common antigen-positive cells before and 0% after immunopurification. Large zones of digested matrices were observed after 48 hours of culture on Matrigel or rat tail collagen but not on agarose. Cells secreted progesterone, human chorionic gonadotropin, and free beta-human chorionic gonadotropin in vitro, but no difference was observed among cells grown on different matrices or between immunopurified and nonimmunopurified cells. By zymography, seven gelatin-degrading enzymes were seen in culture supernatants and five of them were present in cell lysates. The molecular weights of these proteases ranged from 59 to 230 kd. Immunopurification eliminated three of these enzymes, so they were clearly produced by bone marrow-derived cells (leukocyte common antigen positive) contaminating the cytotrophoblast cell preparation. Cells grown on Matrigel express a unique 59 kd gelatinase that was not seen in the supernatants of cells grown on other matrices. Zymography in the presence of inhibitors showed that these enzymes were neutral metalloproteinases, which might be responsible for the observed extracellular matrix degradation.

Effect of Leukemia Inhibitory Factor on Human Cytotrophoblast Differentiation Along the Invasive Pathway

PROBLEM: Leukemia inhibitory factor (LIF) is a pleiotropic secreted cytokine that was shown to be essential for blastocyst implantation in mice. Since it is well documented that LIF is produced by the human endometrium, we wondered if this cytokine was capable of modulating the invasive behaviour of human cytotrophoblastic cells (CTB).

An Exploratory Pilot Study of Acupuncture on the Quality of Life and Reproductive Hormone Secretion in Menopausal Women

The majority of menopausal women suffer from climacteric symptoms. The purpose of this study was to assess the effects of acupuncture on the quality of life and reproductive hormones secretion in menopausal women. Eleven (11) menopausal women with climacteric symptoms entered this prospective study. The Menopause Specific Quality of life Questionnaire was filled out by the patients before the first acupuncture session, after the last one (5 weeks later), and 3 months after the last acupuncture session. Reproductive hormones including follicular-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, and prolactin were measured before and after treatment. Acupuncture significantly improved menopausal vasomotor symptoms (p = 0.001 and p = 0.003 for the end of treatment and 3 months later, respectively) and physical symptoms (p = 0.014 at the end of treatment and p = 0.046 3 months later). It did not change psychosocial or sexual symptoms, nor did it change the measured reproductive hormones. In conclusion, acupuncture is shown to be effective in relieving vasomotor and physical disturbances of menopausal women with effects lasting at least up to 3 months after termination of the treatment. Acupuncture may be a useful treatment alternative for women who are unable or do not want to receive hormone replacement therapy. A prospective study with larger sample sizes will be needed to define the role of acupuncture in the management of menopausal symptoms.

Comparison of results after in vitro fertilized human embryos are cultured in routine medium and in coculture on Vero cells: a randomized study.

OBJECTIVE To investigate whether coculture of human embryos on Vero cells improves embryo viability compared with a routine culture method. SETTING In vitro fertilization Clinic of the Hôpital Cantonal Universitaire de Genève, Geneva, Switzerland. PATIENT SELECTION Couples who had given informed consent, had undergone < 3 IVF cycles with ET and where the male had normal semen parameters were selected. Patients who had undergone > or = 3 IVF cycles with ET were allocated directly to coculture. DESIGN Patients were randomly allocated to have their embryos cultured in a routine embryo culture medium or in coculture with Vero cells. RESULTS There was no difference in pregnancy rates between the two culture groups. Coculture gave a high (> 50%) rate of blastocyst formation. In 16 cycles where patients had previously undergone > or = 3 IVF cycles 4 patients became pregnant. CONCLUSIONS Coculture provides no benefit for patients that are performing their initial treatment cycles in IVF.

Biochemistry and molecular biology of trophoblast invasion.

Cytotrophoblastic cells (CTBs) from first‐trimester placenta form columns of invasive CTBs. This invasive behavior is due to the ability of CTBs to secrete matrix metalloproteinases (MMPs), since tissue inhibitor of MMPs (TIMP) inhibits their invasiveness in the extracellular space. Although CTBs behave like metastic cells, in vivo they are only transiently invasive (first trimester), and their invasion is normally limited only to the endometrium and to the proximal third of the myometrium. This temporal and spatial regulation of trophoblast invasion is believed to be mediated in an autocrine way by trophoblastic factors and in a paracrine way by uterine factors. Several types of regulators have been investigated: hormones, extracellular matrix glycoproteins, and cytokines or growth factors. This review is not intended to be an exhaustive catalogue of potential regulators of trophoblast invasion but is aimed at summarizing the most important categories of factors affecting trophoblast‐endometrium interactions.

Localization of Tyrosine Phosphorylated Proteins in Human Sperm and Relation to Capacitation and Zona Pellucida Binding

Abstract Mammalian sperm must undergo a process known as capacitation before fertilization can take place. A key intracellular event that occurs during capacitation is protein tyrosine phosphorylation. The objective of this study was to investigate and visualize protein tyrosine phosphorylation patterns in human sperm during capacitation and interaction with the zona pellucida. The presence of specific patterns was also assessed in relation to the fertilizing capacity of the spermatozoa after in vitro fertilization. Protein tyrosine phosphorylation was investigated by immunofluorescence. Phosphorylation increased significantly with capacitation and was localized mainly to the principal piece of human sperm. Following binding to the zona pellucida, the percentage of sperm with phosphotyrosine residues localized to both the neck and the principal piece was significantly higher in bound sperm than in capacitated sperm in suspension. When the percentage of principal piece-positive sperm present after capacitation was <7%, fertilization rates after in vitro fertilization were reduced. Different compartments of human spermatozoa undergo a specific sequence of phosphorylation during both capacitation and upon binding to the zona pellucida. Tyrosine phosphorylation in the principal and neck piece may be considered a prerequisite for fertilization in humans.

Effects of leptin, interleukin-1α, interleukin-6, and transforming growth factor-β on markers of trophoblast invasive phenotype

Phenotypic changes of integrin and metalloproteinase secretion of the invasive human cytotrophoblast are regulated by cytokines and growth factors, but how this occurs is not completely understood. We used 24h cytotrophoblast cultures from first trimester pregnancies to investigate the effects of leptin and cytokines on the expression of the α2, α5, and α6 integrin subunits and on the activity of metalloproteinase-2 (gelatinase A) and metalloproteinase-9 (gelatinase B). The α2 subunit was marginally upregulated by leptin and interleukin-1α (IL-1α). All compounds tested upregulated, in some degree, the α5 expression. The α6 integrin subunit was massively upregulated, by leptin, interleukins, and transforming growth factor-β. None of the factors tested affected metalloproteinase-2 activity, but the activity of metalloproteinase-9 was upregulated by leptin and IL-1α. In conclusion, leptin and IL-1α actively induce some of the changes that cytotrophoblasts undergo to achieve a more invasive phenotype. A novel role for leptin is proposed during early pregnancy: leptin might be an autocrine/paracrine regulator of cytotrophoblast invasiveness during implantation and placentation.

Localization of alpha 2, alpha 5 and alpha 6 integrin subunits in human endometrium, decidua and trophoblast

Integrins are heterodimeric glycoproteins acting as membrane receptors for extracellular matrix components. The specificity of these receptors towards one particular matrix glycoprotein depends on the type of alpha and beta subunit combination. Since integrins are involved in the migratory behaviour of cells and since cytotrophoblastic cells are constitutively invasive, we undertook to immunolocalize the alpha 2, alpha 5 and alpha 6 integrin subunits in normal and hydatidiform molar trophoblast, in an implantation site as well as in decidualized and non-decidualized endometrium. alpha 6 positivity was confined to villous cytotrophoblast and was clearly polarized towards the basement membrane. Extravillous cytotrophoblastic cells were alpha 6-negative but became alpha 5-positive. In contrast to normal trophoblast, villous cytotrophoblast from hydatidiform molar tissue was alpha 5-positive. We conclude that the expression of a alpha 5 integrin subunit on cytotrophoblastic cell surfaces is correlated with the appearance of an invasive phenotype. alpha 6 and alpha 2 integrin subunits were both localized on the surface and glandular epithelium of the endometrium and their expression was increased during the secretory phase but became low or undetectable after decidualization. In contrast, alpha 5 subunit positivity was weak in the same epithelial during the first half of the cycle but disappeared after ovulation. Stromal cell alpha 5 positivity was present throughout the cycle but increased dramatically in decidualized endometria. We conclude that the alpha 5 integrin subunit which disappears from the epithelium at the end of the cycle might allow migration of the epithelial cells and repair of the endometrium after menses. We also wonder if alpha 5 positivity is part of a change in the stromal cell phenotype induced by decidualization.

Control of MMP-9 expression at the maternal–fetal interface

Cytotrophoblastic cells (CTB) from first trimester placenta form columns of invasive CTB. This invasive behaviour is due to the ability of CTB to secrete matrix metalloproteinases (MMPs) since tissue inhibitor of MMP (TIMP) inhibits their invasiveness. Although CTB behave like metastatic cells, in vivo they are only transiently invasive (first trimester) and their invasion is normally limited only to the endometrium and to the proximal third of the myometrium. This temporal and spatial regulation of trophoblast invasion is believed to be mediated in an autocrine way by trophoblastic factors and in a paracrine way by uterine factors. Several types of regulators have been investigated: hormones, extra-cellular matrix glycoproteins and cytokines or growth factors. This review is not intended to be an exhaustive catalogue of potential regulators of trophoblastic MMP-9 secretion but is aimed at summarising the most important signalling pathways involved in MMP-9 regulation.

Effects of decidua-conditioned medium and insulin-like growth factor binding protein-1 on trophoblastic matrix metalloproteinases and their inhibitors

The regulatory role of in vitro decidualized stromal cells (DESCM) and their main secretory product insulin-like growth factor binding protein-1 (IGFBP-1) was studied on the secretion of trophoblastic gelatinases and tissue inhibitor of metalloproteinase (TIMP-1). First trimester cytotrophoblastic cells (CTB) were obtained from abortions and cultured in vitro in presence or absence of DESCM or IGFBP-1. Secreted gelatinases were analysed in the culture supernatants by zymography and by measurements of the total gelatinolytic activity. TIMP-1, hCG, and fetal fibronectin (fFN) were measured by commercially available immunoassays. DESCM inhibited the total gelatinolytic activity of CTB but increased trophoblastic MMP-9, TIMP-1 and fFN. In contrast, IGFBP-1 increased the total gelatinolytic activity and TIMP-1, had no effect on MMP-2 , MMP-9 or fFN but inhibited hCG. It is concluded that a factor secreted by decidual cells inhibits the gelatinolytic property of trophoblast by increasing TIMP-1. Other decidual factors, as yet unidentified, increase MMP-2 and MMP-9 to an extent which does override the inhibitory effect of TIMP-1. Since in contrast to DESCM, IGFBP-1 increases the total gelatinolytic activity of CTB, it cannot be the primary active decidual factor regulating the proteolytic activity of CTB. The possibility of an integrin-mediated effect of IGFBP-1 on CTB is discussed.