Influence of male human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection on the reproductive outcomes in serodiscordant couples: a case-control study

BACKGROUND

Nowadays, serodiscordant couples (SDCs) with human immunodeficiency virus (HIV) or hepatitis C virus (HCV)-infected men have the chance to conceive safely, giving birth with a minimum risk of cross-infection.

OBJECTIVE

To assess the impact of male HIV and HCV infection on the assisted reproductive technologies (ART) outcomes in SDCs, with HIV or HCV seropositive men and negative partners.

MATERIALS AND METHODS

Of 153 couples: 24 in Group 1 (HIV-seropositive men), 60 in Group 2 (HCV-seropositive men) and 69 in Group 3 (controls). Sperm-washing procedure was performed using a three-step system. Fresh ICSI cycles were carried out in HIV SDCs, HCV SDCs and controls. Seminal parameters, fertilization rate (FR), cleavage rate (CR), pregnancy rate per cycle (PR/C), miscarriage rate, implantation rate (IR) and live birth rate were evaluated.

RESULTS

All the seropositive men have undetectable viral loads at the time of insemination, and both partners were free from co-morbid infections. The median number of embryos transferred was 2.0 (IQR 1.0-3.0), with no differences among groups. FR was significantly reduced in HIV and HCV SDCs compared to the controls (66%, 61% and 75%, respectively; p < 0.01). CR was similar between groups (p = 0.3). IR was 12.1%, 11.1% and 14.1%, respectively, in the three groups (p = 0.30). PR/C was 21.7%, 17.6% and 20.2% in HIV, HCV and controls, respectively. Live birth rate per cycle was 17.4%, 15.7% and 15.9%, respectively. There were no significant differences in clinical pregnancies per cycle, as well as miscarriages and live births (p = 0.30; 0.30; 0.60, respectively).

CONCLUSIONS

The sperm-washing technique with ICSI may generate a promising way to improve pregnancy outcomes and to reduce the risk of viral transmission in these couples. In this setting, we can correctly counsel HIV- and HCV-infected men of SDCs with regard to the likelihood of father their own biological child.

Identification of Arg-12 in the active site of Escherichia coli K1 CMP-sialic acid synthetase

Escherichia coli K1 CMP-sialic acid synthetase catalyses the synthesis of CMP-sialic acid from CTP and sialic acid. The active site of the 418 amino acid E. coli enzyme was localized to its N-terminal half. The bacterial CMP-sialic acid synthetase enzymes have a conserved motif, IAIIPARXXSKGLXXKN, at their N-termini. Several basic residues have been identified at or near the active site of the E. coli enzyme by chemical modification and site-directed mutagenesis. Only one of the lysines in the N-terminal motif, Lys-21, appears to be essential for activity. Mutation of Lys-21 in the N-terminal motif results in an inactive enzyme. Furthermore, Arg-12 of the N-terminal motif appears to be an active-site residue, based on the following evidence. Substituting Arg-12 with glycine or alanine resulted in inactive enzymes, indicating that this residue is required for enzymic activity. The Arg-12-->Lys mutant was partially active, demonstrating that a positive charge is required at this site. Steady-state kinetic analysis reveals changes in k(cat), K(m) and K(s) for CTP, which implicates Arg-12 in catalysis and substrate binding.

Haptoglobin transport into human ovarian follicles and its binding to apolipoprotein A-1

Controlled ovarian stimulation was induced in 19 women for in vitro fertilisation/embryo transfer. After ovum pick-up, haptoglobin titres were determined by ELISA in sera and homologous follicular fluids. The haptoglobin phenotype of each subject was assessed and the penetration of the protein forms through the blood-follicle barrier was predicted on the basis of their molecular weight. The penetration threshold compatible with the barrier integrity was calculated as 92%, 73% and 57% of the blood level of phenotypes Hpt 1-1, Hpt 1-2 and Hpt 2-2 respectively. Penetration values comparable/lower or higher than threshold were found associated with 46 of 49 and 3 of 49 fertilised oocytes, respectively. Complexes of haptoglobin with apolipoprotein A-1 were isolated from follicular fluids by affinity chromatography with haemoglobin. The haptoglobin beta chain, after Western blotting and incubation with apolipoprotein A-1, was found to be involved in the protein-protein interaction as detected by anti-apolipoprotein A-1 antibodies. Complexes from separate fluids were analysed by electrophoresis and densitometry: the plain beta chain/apolipoprotein A-1 stoichiometric ratio was 0.75 and 1.40 in fluids associated with fertilised and unfertilised oocytes respectively. The results suggest that haptoglobin transport in the follicle depends on the integrity of the blood-follicle barrier and might be associated with oocyte quality, possibly by interfering with the role of apoliprotein A-1 in cholesterol or vitamin E exchange between high-density lipoproteins and granulosa cells.

In the thyroid cells proliferation, differentiated and metabolic functions are under the control of different steps of the cyclic AMP cascade

In the course of studies to elucidate the complex network of interactions controlling FRTL5 cell proliferation, thyroid stimulating hormone (TSH)-independent mutants (M cells), have been obtained from FRTL5 cells by chemical mutagenesis. In the present studies, the role of TSH on the proliferation and on differentiated and metabolic functions in these mutant cells have been investigated and compared to their response to insulin-like growth factor I (IGF-I). The addition of IGF-I to M cells leads to normal stimulation of DNA synthesis. However, inspite of the fact that mutant cells display normal TSH receptors, TSH is unable to stimulate the proliferation of the M cells. Nevertheless, TSH is able to increase intracellular levels of cAMP leading to regulation of TSH function in the M cells. On the other hand, TSH does not influence iodide transport and actin filaments depolimerization in these cells. However, aminoacid transport, stimulated in wild-type FRTL5 cells by both TSH and IGFs, is under the control of IGFs but not of TSH in the mutant cells. Neither TSH or IGF-I modified the expression of c-fos proto-oncogene in the M cells, probably because of high constitutive expression. These data suggest that a crucial signalling step(s) required for TSH induced mitogenesis is impaired in the M cells, and that this signalling step is not required for IGF-I induced mitogenesis.

Regulation of urokinase receptors in monocytelike U937 cells by phorbol ester phorbol myristate acetate

A specific surface receptor for urokinase plasminogen activator (uPA) recognizes the amino-terminal growth factor-like sequence of uPA, a region independent from and not required for the catalytic activity of this enzyme. The properties of the uPA receptor (uPAR) and the localization and distribution of uPA in tumor cells and tissues suggest that the uPA/uPAR interaction may be important in regulating extracellular proteolysis-dependent processes (e.g., invasion, tissue destruction). Phorbol myristate acetate (PMA), an inducer of U937 cell differentiation to macrophage-like cells, elicits a time- and concentration-dependent increase in the number of uPAR molecules as shown by binding, cross-linking, and immunoprecipitation studies. The effect of PMA is blocked by cycloheximide. Overall, the data indicate that PMA increases the synthesis of uPA. PMA treatment also causes a decrease in the affinity of the uPAR for uPA, thus uncovering another way of regulating the interaction between uPA and uPAR. In addition, the PMA treatment causes a modification of migration of the cross-linked receptor in mono- and bidimensional gel electrophoresis.

A 55,000-60,000 Mr receptor protein for urokinase-type plasminogen activator. Identification in human tumor cell lines and partial purification

The iodinated Mr approximately equal to 15,000 amino-terminal fragment (ATF) of the urokinase-type plasminogen activator (u-PA) molecule bound specifically to the cell surface of all of seven cultured human tumor cell lines studied. Cross-linking of iodinated ATF to the cell surface using a bifunctional amino-reactive reagent followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography revealed with the four cell lines studied the occurrence of a single band migrating with an Mr of 70,000-75,000, indicating complex formation with an Mr of 55,000-60,000 u-PA receptor protein (u-PA-R). In the human monocyte cell line U937 cultivated in the presence of phorbol ester, the amount of complex was strongly increased, and a fraction of the complex had a slower electrophoretic mobility. Comparison between autoradiograms of reduced and unreduced samples suggests that u-PA-R consists of one polypeptide chain. Two forms of u-PA-R, which differed with respect to affinity to concanavalin A, were identified. u-PA-R retained its ability to bind to ATF after cell lysis, and it was purified approximately 2,200-fold from biosynthetically labeled U937 cells by affinity chromatography with proenzyme u-PA coupled to Sepharose. The purified Mr 55,000-60,000 protein was specifically bound and cross-linked to u-PA, proenzyme u-PA, and ATF, but not to tissue-type plasminogen activator or other unrelated proteins.

Characterization and regulations of the receptor for insulin-like growth factor-I in the FRTL-5 rat thyroid follicular cell line

In previous studies we have shown that insulin-like growth factor I (IGF-I) has a mitogenic effect in a line of rat thyroid follicular cells, the FRTL-5. In view of this effect, we undertook studies to identify and characterize some physicochemical and binding properties of the receptor for IGF-I in these cells and to determine what role it plays in the mitogenic activity of insulin and insulin-like growth factors in the FRTL-5 cell. Binding of 125I-labeled IGF-I (biosynthetic Thr59-IGF-I) to FRTL-5 was a function of time, temperature, and pH and was completely inhibited by high concentrations of unlabeled IGF-I. Scatchard plots of four saturation studies revealed a single apparent binding site with an average Ka of 4.2 +/- 0.6 X 10(9) M-1 (mean +/- SD) and an average maximum binding capacity of 20 +/- 2 pm/100 micrograms cellular protein. Rat IGF-II (rIGF-II) and insulin were far less potent that IGF-I in inhibiting the binding of [125I] IGF-I, and bovine TSH was without effect. 125I-Labeled IGF-II also bound to FRTL-5 cells. Binding was completely inhibited by unlabeled rIGF-II and, with lesser potency, by IGF-I. Even at high concentrations, insulin failed to inhibit the binding of [125I]IGF-II. Disuccinimidyl suberate cross-linked [125I]IGF-I to a moiety in FRTL-5 that had an apparent mol wt of approximately 135,000, as judged from sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. Cross-linking of [125I]IGF-I was inhibited in a dose-dependent manner by unlabeled IGF-I and, with far lower potency, by rIGF-II and insulin. All three peptides stimulated the incorporation of [3H]thymidine into the DNA of FRTL-5 cells, IGF-I being the most potent, followed in decreasing order of potency of rIGF-II and insulin. The mitogenic activities of these polypeptides correlated well with their abilities to inhibit the binding of [125I]IGF-I. These data indicate that the FRTL-5 cell possesses a receptor for IGF-I that resembles in its binding and physicochemical properties the receptor for IGF-I in other tissues (type I IGF receptor) and that mediates the mitogenic response to IGF-I and insulin in these cells. FRTL-5 cells also contain a receptor for IGF-II (type II IGF receptor), but its role vis-à-vis that of the type I IGF receptor in relation to the mitogenic effect of IGF-II in these cells is uncertain.