Biomedical subjects

Riitta Koistinen

Publications and source records attributed to Riitta Koistinen.

At least 19 recordsLinked to original sources

PubMed2006

Cumulus oophorus-associated glycodelin-C displaces sperm-bound glycodelin-A and -F and stimulates spermatozoa-zona pellucida binding.

Spermatozoa have to swim through the oviduct and the cumulus oophorus before fertilization in vivo. In the oviduct, spermatozoa are exposed to glycodelin-A and -F that inhibit spermatozoa-zona pellucida binding. In this study, we determined whether these glycodelins would inhibit fertilization. The data showed that the spermatozoa without previous exposure to glycodelin-A and -F acquired glycodelin immunoreactivity during their passage through the cumulus oophorus. On the other hand, when glycodelin-A or -F-pretreated spermatozoa were exposed to the cumulus oophorus, the zona pellucida binding inhibitory activity of glycodelin-A and -F was not only removed, but the spermatozoa acquired enhanced zona pellucida binding ability. These actions of the cumulus oophorus were due to the presence of a cumulus isoform of glycodelin, designated as glycodelin-C. The cumulus cells could convert exogenous glycodelin-A and -F to glycodelin-C, which was then released into the surrounding medium. The protein core of glycodelin-C was identical to that in other glycodelin isoforms, as demonstrated by mass spectrum, peptide mapping, and affinity to anti-glycodelin antibody recognizing the protein core of glycodelin. In addition to having a smaller size and a higher isoelectric point, glycodelin-C also had lectin binding properties different from other isoforms. Glycodelin-C stimulated spermatozoazona pellucida binding in a dose-dependent manner, and it effectively displaced sperm-bound glycodelin-A and -F. In conclusion, the cumulus cells transform glycodelin-A and -F to glycodelin-C, which in turn removes the spermatozoazona binding inhibitory glycodelin isoforms and enhances the zona binding capacity of spermatozoa passing through the cumulus oophorus.

Female↗

PubMed2006

Glycodelin-A interacts with fucosyltransferase on human sperm plasma membrane to inhibit spermatozoa-zona pellucida binding.

Fertilization depends on successful binding of the spermatozoa to the zona pellucida of the oocyte. Glycodelin-A inhibits spermatozoa-zona pellucida binding. Previous data showed that glycodelin-A receptor(s) and zona pellucida protein receptor(s) on human spermatozoa are closely related. Using a chemical cross-linking approach, the glycodelin-A-sperm receptor complex was isolated. The receptor was identified to be fucosyltransferase-5 (FUT5) by mass spectrometry and confirmed with the use of anti-FUT5 antibodies. Sperm FUT5 was an externally oriented integral membrane protein in the acrosomal region of human spermatozoa. Biologically active FUT5 was purified from spermatozoa. Co-immunoprecipitation confirmed the interaction between glycodelin-A and sperm FUT5. Solubilized zona pellucida reduced the binding of glycodelin-A to sperm FUT5. An anti-FUT5 antibody and FUT5 acceptor blocked the binding of glycodelin-A to spermatozoa and the zona binding inhibitory activity of glycodelin-A. Sperm FUT5 bound strongly to intact and solubilized human zona pellucida. The equilibrium dissociation constant of sperm FUT5 binding to solubilized zona pellucida was 42.82 pmol/ml. These observations suggest that human sperm FUT5 is a receptor of glycodelin-A and zona pellucida proteins, and that glycodelin-A inhibits spermatozoa-zona binding by blocking the binding of sperm FUT5 to the zona pellucida.

Antibodies↗

PubMed2006

Extracellular matrix-induced changes in expression of cell cycle-related proteins and proteasome components in endometrial adenocarcinoma cells.

OBJECTIVE: Extracellular matrix (ECM) components regulate growth and differentiation of epithelial cells, and impaired cell-ECM interaction may lead to increased cell proliferation and tumorigenesis. Whereas ECM has been shown to alter cellular morphology and reduce proliferation of HEC-1B endometrial adenocarcinoma cells, little is known about the underlying changes in gene expression. The purpose of this study was to investigate these changes. METHODS: We studied by cDNA array the effects of ECM components, as present in Matrigel basement membrane cell culture matrix, on gene expression in HEC-1B endometrial adenocarcinoma cells in respect of the same cells cultured on conventional plastic surface. Some of the changes were confirmed by protein analyses. RESULTS: As expected, several growth-promoting genes were downregulated, while many genes associated with growth restriction were upregulated in Matrigel-grown carcinoma cells. Also, the expression of many 20S proteasome components was downregulated. The observed changes point to a less malignant phenotype of Matrigel-grown tumor cells, supported by reduced growth characteristics and morphology. CONCLUSION: The study provides further insight into the mechanisms whereby ECM components may participate in the regulation of cell growth--by reducing expression of growth-promoting genes and increasing expression of the genes associated with growth restriction.

Adenocarcinoma↗

PubMed2006

Roles of glycodelin in modulating sperm function.

Glycodelin is a glycoprotein with three well-defined isoforms. They are named as glycodelin-S, glycodelin-A and glycodelin-F. The three isoforms have similar protein core but different carbohydrate moieties. Glycodelin-S is abundant in the human seminal plasma. It suppresses sperm capacitation and in doing so, it maintains the spermatozoa in an uncapacitated state before they enter into the uterine cavity. Glycodelin-A is abundant in the amniotic fluid. It is also secreted from endometrial glands into uterine fluid and is produced by the fallopian tube. Glycodelin-A is the first endogenous glycoprotein that was found to inhibit the binding of spermatozoa to the zona pellucida. The immunosuppressive properties of glycodelin-A suggest that the molecule may protect the spermatozoa from immune attack in the maternal reproductive tract. Glycodelin-F was first found in the follicular fluid, hence its name. It also inhibits spermatozoa-zona pellucida binding. In addition, glycodelin-F suppresses progesterone-induced acrosome reaction, and may serve to prevent premature acrosome reaction. Preliminary findings suggest possible presence of yet another glycodelin isoform in the extracellular matrix of cumulus oophorus. Unlike glycodelin-A and -F, it stimulates spermatozoa-zona pellucida binding. In summary, different isoforms of glycodelin have different biological roles on sperm function, and they act in succession to contribute to the success of fertilization.

Female↗

PubMed2006

Glycodelin is present in pinopodes of receptive-phase human endometrium and is associated with down-regulation of progesterone receptor B.

OBJECTIVE: To test the hypothesis that glycodelin is localized on pinopodes and correlates with temporal immunostaining of leukemia inhibitory factor (LIF), LIF receptor (LIFR), and progesterone receptor B (PRB). DESIGN: Prospective clinical study. SETTING: Hospital-based reproductive health unit and research laboratories. PATIENT(S): Twenty-five healthy fertile women with normal menstrual cycles. INTERVENTION(S): Endometrial biopsy specimens were obtained from healthy fertile women in the luteal phase of the menstrual cycle. MAIN OUTCOME MEASURE(S): Immunohistochemical staining of glycodelin, ultrastructural immunostaining of glycodelin, and double staining of glycodelin and PRB. RESULT(S): Glycodelin is present in the glands when pinopodes appear. Glycodelin is localized on pinopodes but is also secreted from luminal epithelial cells regardless of pinopode formation. There was a negative correlation between glycodelin secretion from the glands and PRB staining. A weak correlation between the presence of LIFR (but not LIF) and glycodelin was found. CONCLUSION(S): Pinopode appearance, intense staining of LIFR in pinopodes and glycodelin staining in the glands are synchronized events. Down-regulation of PRB in the endometrium is concomitant with the presence of glycodelin in the endometrium, suggesting interaction.

Adult↗

PubMed2006

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Journal Article↗

PubMed2005

Mutations in two short noncoding mononucleotide repeats in most microsatellite-unstable colorectal cancers.

DNA mismatch repair (MMR)-deficient cells typically accumulate mutations in short repetitive DNA tracts. This microsatellite instability (MSI) facilitates malignant transformation when affecting genes with growth-related and caretaker functions. To date, several putative MSI target genes have been proposed mainly based on high mutation frequency within their coding regions. However, some intronic repeat mutations have also been suggested to associate with MSI tumorigenesis, indicating the need for additional analyses on noncoding repeats. Here we have analyzed an intronic T9 repeat of semenogelin I (SEMG1) and report mutation frequencies of 51% (75 of 146) and 62% (8 of 13) in MMR-deficient primary colorectal cancers and cell lines, respectively. The putative effect of the SEMG1 mutations was assessed by RNA and protein level analyses, but no differences were detected between colorectal cancer cell lines with different SEMG1 status. Subsequently, the general background mutation frequency of MSI colorectal cancers was assessed by screening for intergenic T9 repeat alterations. One of 10 examined repeats was mutated in 70% (102 of 145) of the colorectal cancers evaluated. The frequencies observed here are notably higher than previously published in noncoding repeats shorter than 10 bp in MMR-deficient primary tumors. Our results indicate that high mutation frequencies, similar or higher than those observed in proposed and approved target genes, can be detected in repeat tracts of MSI tumors without any apparent selection pressure. These data call for urgent and thorough large-scale evaluation of mutation frequencies in neutral short repetitive sequences in MMR-deficient tumors.

Alleles↗

PubMed2005

Glycodelin-S in human seminal plasma reduces cholesterol efflux and inhibits capacitation of spermatozoa.

Tight control of sperm capacitation is important for successful fertilization. Glycodelin-S is one of the most abundant glycoproteins in the human seminal plasma. However, its function is unclear. We investigated the role of glycodelin-S on capacitation of human spermatozoa. Binding kinetics experiments demonstrated the presence of two saturable and reversible binding sites of glycodelin-S on human spermatozoa. Differently glycosylated other isoforms of glycodelin, glycodelin-A and -F, did not compete with glycodelin-S for these binding sites, suggesting that the glycodelin-S binding sites are different from those of the other isoforms. Indirect immunofluorescent staining revealed specific binding of glycodelin-S around the sperm head. This immunoreactivity was greatly reduced in spermatozoa that had migrated through the cervical mucus surrogates. Glycodelin-S at physiological concentrations significantly reduced the bovine serum albumin and cyclodextrin-induced cholesterol efflux and down-regulated the adenylyl cyclase/protein kinase A/tyrosine kinase signaling pathway, resulting in suppression of capacitation. Deglycosylation abolished glycodelin-S binding and the effect of glycodelin-S on bovine serum albumin-induced capacitation. This indicates that the carbohydrate moiety of glycodelin-S is critical for the function of the molecule. It is concluded that glycodelin-S in seminal plasma maintains the uncapacitated state of human spermatozoa.

Acrosome↗

PubMed2005

Glycodelin reduces carcinoma-associated gene expression in endometrial adenocarcinoma cells.

OBJECTIVE: Glycodelin is a major secretory glycoprotein of differentiated endometrial epithelium, rarely expressed in proliferative endometrium or endometrial cancer. We aimed to elucidate its role in growth and gene expression of endometrial adenocarcinoma cells, and hypothesized that glycodelin affects cell growth and tumor-associated gene expression. STUDY DESIGN: Endometrial adenocarcinoma HEC-1B cells were transfected with glycodelin cDNA in both antisense and sense orientations. Cellular morphology, cell proliferation, and gene expression were compared between native and transfected cells. RESULTS: Compared with native and antisense-transfected carcinoma cells, sense-transfected, glycodelin-producing carcinoma cells showed reduced proliferation, morphologic changes, and altered expression of cancer-related genes. Notably, anti-apoptotic Bcl-XL and MUC1 genes were down-regulated. CONCLUSION: Reduction by glycodelin transfection of carcinoma cell proliferation and expression of MUC1 and Bcl-XL is significant because these genes are often overexpressed in human cancers--MUC1 is linked to invasive growth and metastases, and both confer resistance to chemotherapy. These results suggest a novel mechanism whereby malignant growth of endometrial adenocarcinoma cells is regulated.

Adenocarcinoma↗

PubMed2005

Late follicular phase administration of levonorgestrel as an emergency contraceptive changes the secretory pattern of glycodelin in serum and endometrium during the luteal phase of the menstrual cycle.

This study examined serum glycodelin concentrations and endometrial expression during the luteal phase following oral administration of levonorgestrel (LNG) at different stages of the ovarian cycle. Thirty women were recruited and allocated into three groups. All groups were studied during two consecutive cycles, a control cycle and the treatment cycle. In the treatment cycle, each woman received two doses of 0.75 mg LNG taken 12 h apart on days 3-4 before the luteinizing hormone (LH) surge (Group 1), at the time of LH rise (Group 2) and 48 h after the rise in LH was detected (Group 3). Serum progesterone (P) and glycodelin were measured daily during the luteal phase, and an endometrial biopsy was taken at day LH +9 for immunohistochemical glycodelin-A staining. In Group 1, serum P levels were significantly lower, serum glycodelin levels rose earlier and endometrial glycodelin-A expression was weaker than in Groups 2 and 3, in which no differences were found between control and treatment cycles. Levonorgestrel taken for emergency contraception (EC) prior to the LH surge alters the luteal phase secretory pattern of glycodelin in serum and endometrium. Based on the potent gamete adhesion inhibitory activity of glycodelin-A, the results may account for the action of LNG in EC in those women who take LNG before the LH surge.

Adult↗

PubMed2005

Glycodelin responses to hyperinsulinaemic clamp vary according to basal serum glycodelin concentration.

OBJECTIVE: Treatment with metformin, an insulin-lowering agent, increases serum glycodelin, a progesterone-regulated lipocalin protein of the reproductive axis that may play a role in foeto-maternal defence mechanisms. This finding led to the hypothesis that insulin might decrease serum glycodelin concentration. DESIGN, PATIENTS AND MEASUREMENTS: Euglycaemic hyperinsulinaemic clamp experiments (n = 50) were carried out on 28 women of reproductive age (range 25-47 years; mean +/- SEM 39 +/- 1.0 years), and the results were analysed with respect to their baseline serum progesterone (< 10 or > or = 10 nmol/l) and glycodelin (< 10 or > or = 10 microg/l, equivalent to < 357 or > or = 357 pmol/l) concentrations at the onset of the clamp. Ten clamp experiments were performed on five women wearing a levonorgestrel-releasing intrauterine device (IUD), and these were analysed as a separate group. RESULTS: Contrary to the hypothesis, no acute glycodelin-lowering effect of insulin was found in any of the groups studied. All the small rises in glycodelin levels detected during acute hyperinsulinaemia occurred in the comparisons of medians and not means, and all such changes took place within the limits seen in the women with no progesterone exposure. In the group with low progesterone/low glycodelin (n = 21), glycodelin showed a small but significant increase at 30 and 90 min of the clamp (P < 0.01). In the group with elevated progesterone/low glycodelin (n = 11), there was a slight glycodelin increase at 30 min (P < 0.05), whereas no increase was found in the group with elevated glycodelin levels (n = 8). In the clamp experiments on women with levonorgestrel-releasing IUD, the basal glycodelin level was low in all cases and, as in the other women with low glycodelin levels, glycodelin was slightly increased at 30, 60 and 90 min of hyperinsulinaemia (P < 0.01). CONCLUSIONS: The results rule out any acute glycodelin-reducing effects of insulin, although indirect long-term effects mediated by insulin on glycodelin secretion cannot be excluded.

Adult↗

PubMed2004

Sex hormone-binding globulin and insulin-like growth factor-binding protein-1 as indicators of metabolic syndrome, cardiovascular risk, and mortality in elderly men.

Two binding proteins, SHBG and IGF-binding protein-1 (IGFBP-1), are both down-regulated by insulin and therefore could serve as potential indicators of the metabolic syndrome and hyperinsulinemia-related cardiovascular risk. We compared serum SHBG and IGFBP-1 as potential markers of abnormal glucose tolerance, the metabolic syndrome, diabetes mellitus, cardiovascular risk factors, and total, cardiovascular, and coronary heart disease mortality in elderly men. Of the original cohort of 1711 men, 524 were alive on January 1, 1989, and 413 participated in the 30-yr examination, of whom 335 men, aged 70-89 yr, formed the study group for the present analysis. Low SHBG and IGFBP-1 were both associated with an increased prevalence of abnormal glucose tolerance and the metabolic syndrome, but only SHBG was associated with diabetes mellitus. SHBG was less influenced by body mass index than IGFBP-1. Low SHBG indicated increased cardiovascular and coronary disease mortality; the association remained after adjustment for abnormal glucose tolerance, but not after adjustment for prevalent cardiovascular disease. IGFBP-1 had no association with mortality. It is concluded that low SHBG is a better indicator of increased cardiovascular mortality than low or high IGFBP-1.

Aged↗

PubMed2004

Reduced serum glycodelin and insulin-like growth factor-binding protein-1 in women with polycystic ovary syndrome during first trimester of pregnancy.

The polycystic ovary syndrome (PCOS) is associated with an increased rate of early pregnancy loss (EPL). Hyperinsulinemia is an independent risk factor for EPL and has been found to decrease levels of glycodelin and IGF binding protein-1 (IGFBP-1), two major endometrial proteins. We hypothesized that serum glycodelin IGFBP-1 concentrations would be reduced in women with PCOS during the first trimester of pregnancy. Fasting serum insulin, glycodelin, and IGFBP-1 were measured, and oral glucose tolerance tests were performed in 72 women with PCOS and 62 normal women. Each woman was seen once and assigned to one of three gestational groups: wk 3-5, 6-8, and 9-11. The insulin sensitivity index during oral glucose tolerance test was lower in women with PCOS compared with normal women throughout the first trimester (P < 0.0001). Both serum glycodelin and IGFBP-1 were markedly lower in women with PCOS (for glycodelin: wk 3-5, P < 0.0001; wk 6-8, P = 0.03; wk 9-11, P = 0.19; and for IGFBP-1: wk 3-5 and 6-8, P < 0.0001; wk 9-11, P = 0.0003). Comparing women with PCOS who experienced EPL with those who did not, serum glycodelin was significantly lower during wk 3-8 (P < 0.02) and serum IGFBP-1 during wk 9-11 (P = 0.003). During the first trimester, serum glycodelin and IGFBP-1 concentrations are markedly decreased in PCOS, implicating endometrial epithelial and stromal dysfunction during periimplantation and early pregnancy as a possible mechanism for EPL in PCOS. These decreases are likely to be secondary to hyperinsulinemia and reduced insulin sensitivity.

Abortion, Spontaneous↗

PubMed2003

Glycodelin in ovarian serous carcinoma: association with differentiation and survival.

Ovarian cancer consists of many subtypes, serous carcinoma being the most common of them. In addition to the histopathological subtype, grading, clinical staging, and the amount of residual tumor, a great number of putative prognostic markers have been introduced. This study addresses in ovarian serous carcinoma the role of glycodelin, the major progesterone-regulated lipocalin protein of the reproductive axis with diverse actions in cell recognition and differentiation. Glycodelin expression was determined by immunohistochemistry of tissue microarrays in ovarian serous carcinomas from 460 patients, and the results were analyzed with respect to progesterone receptor subtype A (PRA) and progesterone receptor subtype B (PRB), clinical parameters, and survival. Glycodelin was localized to the cytoplasm of tumor cells, whereas vascular endothelium in tumor tissue was glycodelin-negative. Glycodelin expression was more frequent in well-differentiated (grade I, 79%) than in poorly differentiated carcinomas (grade III, 51%; P < 0.0001), and it was also more frequent in early-stage compared with advanced-stage carcinomas (P = 0.002). Nuclear PRA and PRB were often coexpressed with cytoplasmic glycodelin. Although this was not consistent in all tumors, there was a positive correlation between the presence of glycodelin and PRs in the tumor (P < 0.02), but not between the presence of, or the absence of, glycodelin in tumor and the CA-125 serum concentration. Although in multivariate analysis glycodelin was not an independent variable, the patients with glycodelin-expressing tumors showed a higher 5-year overall survival compared with those with glycodelin-negative tumors (55 versus 39%; P < 0.0001; hazard ratio in univariate analysis, 0.57; confidence interval, 0.44-0.74). This difference was notable in patients with grade I tumors and stage III disease. In the latter group, the 10-year survival probability of patients with glycodelin-positive tumors was more than twice as high as that in women with glycodelin-negative tumors. This was also found within well-defined clinical categories, e.g., stage III/grade II and stage III/grade III carcinomas, in which patients with glycodelin-positive tumors carried significantly better 10-year overall survival compared with those with glycodelin-negative tumors. It is concluded that, in ovarian serous carcinoma, glycodelin expression portends better prognosis, probably because of its differentiation-related disposition.

Adolescent↗

PubMed2003

Cord serum glycodelin concentrations in normal pregnancies and pregnancies complicated by diabetes.

OBJECTIVE: Glycodelin is a glycoprotein released by secretory/decidualized endometrial glands. Its synthesis increases during pregnancy. Hormonal factors whose levels have been shown to change in diabetes (vascular endothelial growth factor, relaxin) may mediate the actions or regulate the synthesis of glycodelin. Cord serum glycodelin levels have not been studied in pregnancies complicated by diabetes. METHODS: Cord serum glycodelin concentrations were measured at birth by an immunofluorometric assay in 62 normal pregnancies, in 67 pregnancies complicated by type 1 diabetes, and in 28 pregnancies complicated by insulin-treated gestational diabetes. RESULTS: The mean glycodelin concentration in cord serum was 2.7 ng/ml (standard error of the mean 0.6) in normal pregnancies. The concentration was not altered in pregnancies complicated by diabetes. Cord serum glycodelin concentrations were also unaltered in diabetic pregnancies with hypertensive disorders (chronic hypertension, pregnancy-induced hypertension or pre-eclampsia) or fetal macrosomia. There was a negative borderline correlation between cord serum glycodelin concentrations and the birth weight in pregnancies complicated by diabetes (r=-0.21, p=0.049). CONCLUSIONS: Decidual function, as assessed by cord serum glycodelin levels, is not markedly altered in diabetic pregnancies. The negative correlation between cord serum glycodelin and the birth weight of the newborns in diabetic pregnancies may be due to the decline in glycodelin levels with advancing pregnancy in the third trimester.

Adult↗

PubMed2003

Differences in glycosylation and sperm-egg binding inhibition of pregnancy-related glycodelin.

Glycodelin is a glycoprotein produced in many glands, particularly those of reproductive tissues. It appears as different glycoforms in amniotic fluid (glycodelin-A) and seminal plasma (glycodelin-S), but only glycodelin-A inhibits gamete adhesion. In the present study, glycodelin from secretory-phase endometrium, first-trimester pregnancy decidua, and midtrimester amniotic fluid was studied with respect to physicochemical properties, including glycosylation patterns and inhibitory activity of sperm-egg binding. Purified glycodelins from all these sources were similar in isoelectric focusing and in lectin immunoassays using lectins from Wisteria floribunda and Sambucus nigra. Likewise, the glycodelins inhibited sperm-egg binding in a dose-dependent manner, as measured by hemizona-binding assay. However, subtle quantitative physicochemical and biological differences were found between glycodelins from different sources as well as within the same tissue/fluid between different individuals. Differences were most pronounced between endometrial glycodelins from nonpregnancy and first-trimester pregnancy. The glycan structures studied by fast-atom bombardment mass spectrometry of individual amniotic fluid glycodelin-A samples also showed interindividual quantitative differences. In conclusion, glycodelins from different female reproductive tract tissues and amniotic fluid share substantial similarity, allowing all of them to be called glycodelin-A. However, these glycodelins exhibit quantitative physicochemical and functional differences between different sources and individuals.

Adult↗

PubMed2003

Binding of zona binding inhibitory factor-1 (ZIF-1) from human follicular fluid on spermatozoa.

Previous studies showed that zona binding inhibitory factor-1 (ZIF-1) was the glycoprotein mainly responsible for the spermatozoa zona binding inhibitory activity of human follicular fluid. ZIF-1 has a number of properties similar to glycodelin-A. A binding kinetics experiment in the present study demonstrated the presence of two binding sites of ZIF-1 on human spermatozoa. These binding sites were saturable, reversible, and bound to (125)I-ZIF-1 in a time-, concentration-, and temperature-dependent manner. Glycodelin-A shared one common binding site with ZIF-1 on spermatozoa, and it could displace only 70% of the (125)I-ZIF-1 bound on human spermatozoa. ZIF-1 and glycodelin-A formed complexes with the soluble extract of human spermatozoa. Coincubation of solubilized zona pellucida proteins reduced the binding of ZIF-1 to two complexes of the extract, suggesting that the ZIF-1 binding sites and zona pellucida protein receptors on human spermatozoa were closely related. ZIF-1, but not glycodelin-A, significantly suppressed progesterone-induced acrosome reaction of human spermatozoa. The carbohydrate moieties derived from ZIF-1 reduced the binding of native ZIF-1 on human spermatozoa as well as the zona binding inhibitory activity of the glycoprotein, although the intensity of the effects are lower when compared with the native protein. These effects are not due to the action of the molecules on the motility, viability, and acrosomal status of the treated spermatozoa. Deglycosylated ZIF-1 had no inhibitory effect on both ZIF-1 binding and zona binding capacity of spermatozoa. We concluded that the carbohydrate part of ZIF-1 was critical for the functioning of the glycoprotein.

Acrosome Reaction↗

PubMed2003

Serum insulin-like growth factor (IGF)-I and IGF-binding protein-1 in elderly people: relationships with cardiovascular risk factors, body composition, size at birth, and childhood growth.

The IGF system is important in regulation of fetal and childhood growth. In later life, IGF-I and IGF-binding protein-1 (IGFBP-1) have been implicated in the pathogenesis of arteriosclerosis. They are, thus, potential candidates in explaining the link between early growth and adult cardiovascular disease. We measured fasting serum IGF-I and IGFBP-1 concentrations in 394 men and women from a cohort of 7086 individuals, born between 1924 and 1933 in Helsinki, Finland, whose weight and height were recorded at birth and from 7 to 15 yr of age. They also underwent clinical examination, including measurement of body fat using bioimpedance, blood pressure, glucose tolerance, and plasma insulin and fibrinogen concentrations. Serum IGF-I was positively correlated with fasting glucose (r = 0.10, P = 0.06) and fibrinogen (r = 0.19, P = 0.0001) concentrations and blood pressure (systolic and diastolic r = 0.10, P </= 0.05) and inversely with percentage body fat (r = -0.13, P = 0.01) and waist circumference (r = -0.11, P = 0.03). IGFBP-1 was inversely correlated with adult body mass index (BMI) (r = -0.46, P < 0.0001), fasting glucose and insulin concentrations, and blood pressure. There were correlations between the adult level of IGFBP-1 and birth weight (r = 0.11, P = 0.03) and ponderal index (weight/length(3)) at birth (r = 0.13, P = 0.01), but IGF-I was not related to birth measurements. There were interactive effects between childhood height or BMI and adult BMI on IGF-I and IGFBP-1 in adulthood. Tall height and high BMI at 7 yr were associated with low IGF-I (P = 0.03 for height and P = 0.003 for BMI) and high IGFBP-1 (P = 0.02 and P = 0.06) in adulthood but only in those subjects whose current BMI was below median. On further analysis these interactive effects were particularly strong for height in childhood and adult lean BMI (lean body mass/height(2)). Among men and women of below-average lean BMI, tall height at 7 yr was associated with low adult IGF-I (P = 0.007) and high IGFBP-1 (P = 0.0004) concentrations [interaction (7-yr height x adult lean BMI); P = 0.008 for IGF-I and 0.001 for IGFBP-1]. There is no evidence that reduced fetal growth programs IGF-I concentrations in old age. An association between small size at birth and low IGFBP-1 concentrations may in part reflect fetal programming effects on insulin resistance. Given the anabolic effects of the GH-IGF-I axis, subjects with tall height in childhood but low adult lean body mass may be at risk of late-life GH-IGF-I axis dysfunction. Prospective studies should address whether this group is susceptible to type 2 diabetes, coronary heart disease, and osteoporosis.

Adolescent↗