Familial correlations in postmenopausal serum concentrations of sex steroid hormones and other mitogens: a twins and sisters study.

BACKGROUND: Serum concentrations of some hormones are risk factors for certain cancers, but little is known about their familial associations especially for females. METHODS: We measured serum concentrations of estradiol (E(2)), testosterone (T), SHBG, prolactin, and IGF-I for 645 Australian female postmenopausal twins and their sisters [182 monozygotic (MZ) and 107 dizygotic (DZ) pairs and 67 nontwin sisters] using well-established immunoassays. After suitable transformation and adjusting for age, body mass index (BMI), and time since menopause, familial correlations and proportions of variance attributed to genetic (h(2)) and nongenetic factors common to sisterships (c(2)) were estimated under the classic twin multivariate normal model using FISHER. RESULTS: For all serum concentrations except prolactin, MZ, DZ, and sister pairs were correlated (P < 0.001). MZ correlations were in the range 0.5-0.7, and for all serum concentrations, there were no differences between DZ and sister correlations. MZ correlations were greater than DZ and sister correlations for log SHBG (P = 0.0001), IGF-I (P = 0.0002), and square-root T (P = 0.007) but not log E(2) (P = 0.3), and the respective h(2) estimates were 0.56 (SE = 0.14), 0.53 (0.17), 0.39 (0.14), and 0.14 (0.16). For log E(2) and square-root T, c(2) estimates were 0.39 (0.14) and 0.22 (0.12). CONCLUSION: There are strong familial correlations in postmenopausal SHBG, IGF-I, and to a lesser extent T, which are consistent with a genetic etiology. For E(2), and to a lesser extent T, correlations are consistent with substantial nongenetic familial factors. The latter might include maternal effects.

Hepatocyte growth factor (HGF) in patients with hepatitis B and meningitis.

OBJECTIVES: The present study investigates serum hepatocyte growth factor (HGF) levels in patients with acute and chronic hepatitis B and the relation between these levels and intrahepatic inflammatory markers of the liver and fibrosis, as well as the cerebrospinal fluid (CSF) HGF levels in patients with meningitis and the relation between these levels and CSF findings. To our knowledge this is the first study regarding CSF HGF levels in tuberculous meningitis. PATIENTS AND METHODS: The study consisted of 35 patients with chronic hepatitis B (HbeAg and HBV-DNA positive), 20 with acute hepatitis B, 20 with acute bacterial meningitis and 15 having tuberculous meningitis. HGF levels in the serum and CSF samples were measured by using the ELISA method. RESULTS: The mean serum HGF levels in acute hepatitis B group were found statistically significantly higher than those in the control group and chronic hepatitis B group (p<0.0001). It was established that serum HGF levels in patients with chronic hepatitis B were significantly correlated with serum alanine aminotransferase (ALT) and HBV-DNA levels (r: 0.816, 0.951; p<0.05, respectively). Similarly, serum HGF levels of patients with chronic hepatitis B were correlated with fibrosis score and hepatic activity index of the liver histopathology (r: 0.750, 0.459; p<0.05, respectively). The mean CSF HGF levels of patients with acute bacterial meningitis and tuberculous meningitis were higher than those in the control group (p<0.05). In addition, it was observed that mean CSF HGF levels in patients suffered from tuberculous meningitis were statistically significantly higher than those in acute bacterial meningitis (p<0.05). CONCLUSIONS: We suggest that serum HGF level in patients with chronic hepatitis B might reflect viral load, necro-inflammatory activity in the liver and the degree of structural progression. Our findings have demonstrated that tuberculous meningitis cause increased HGF concentrations in CSF. It is, therefore, suggested that examination of HGF levels in CSF may provide additional information in the differential diagnosis.

Insulin-like growth factor I is a comitogen for hepatocyte growth factor in a rat model of hepatocellular carcinoma.

Hepatocyte growth factor-scatter factor (HGF-SF) is a potent hepatic mitogen yet inhibits hepatocellular carcinoma (HCC) cell growth in vitro. Insulin-like growth factor I (IGF-I) is a pleiotropic growth factor shown to be important in cell growth and differentiation in other tumors. We hypothesized that IGF-I may play a role in regulating HGF-SF activity and HCC progression. Using an in vivo model of HCC, we showed elevated IGF-I messenger RNA (mRNA) expression in normal liver from tumor-burdened animals in the absence of changes in circulating IGF-I levels. Analysis of IGF-I receptor (IGF-IR) and HGF-SF (c-met) receptor expression showed significantly higher expression of both receptors in normal liver compared with an HCC specimen. Using cultured HCC cells from this model, we next showed that treatment with IGF-I led to significant increases in mitogen-activated protein kinase (MAPK) activity. Furthermore, we observed significant time-dependent increases in the expression of the c-fos and c-jun proto-oncogenes after addition of IGF-I (n = 5 per group, P <.05). Despite activation of a MAPK pathway and increased proto-oncogene expression, IGF-I failed to significantly affect cell mitogenesis. In contrast, HGF significantly inhibited cell mitogenesis in HCC lines (68.4% +/- 9.4% vs. control, n = 4, P <.05). Pretreatment of HCC cells with IGF-I (60 minutes) led to significant HGF-SF stimulation of total cell mitogenesis dependent on both IGF-I and HGF-SF dose (194% +/- 8% increase vs. control, n = 4, P <.05). In conclusion, tumor burden is important in altering intrahepatic growth factor synthesis. Signal cooperation between multiple cytokine pathways is an important factor in the progression of HCC.

Immunity in adolescents with major depression.

OBJECTIVE: The association between major depression (MD) and altered immunity appears to be age-related, with differing immune changes found in prepubertal children, young adults, and older adults. There is limited information concerning immunity in adolescents with MD. METHOD: Thirty-six otherwise healthy medication-free adolescents (aged 14-20; 23 female) from a community sample, meeting Diagnostic Interview Schedule for Children DSM-III-R criteria for unipolar MD, were compared with 36 nondepressed adolescents matched by gender, age, and racial background. A battery of quantitative and functional immune measures was obtained. RESULTS: MD adolescents had increased (p < .05) circulating lymphocytes and lymphocyte subsets; however, altered distribution of lymphocyte subsets was found only for activated T (HLA-DR+) cells (p < .004) and, possibly, natural killer (NK) (CD56+) cells (p < .06), each showing lower percentages in the MD adolescents. Concanavalin A (but not phytohemagglutinin or pokeweed mitogen) mitogen response was lower in the MD adolescents (p < .02). NK cell activity was elevated at higher effector-target ratios (p < .001), an effect not associated with the number of circulating CD56+ (NK) cells. CONCLUSIONS: Depressed adolescents showed changes in immune measures that have been found to be altered in other MD groups, although the pattern of effects differs.

Comparison of severity scoring of atopic dermatitis values and serum levels of eosinophil cationic protein and mast cell tryptase for routine evaluation of atopic dermatitis.

In this study the routine use of different parameters for evaluation of the overall therapeutic outcome in atopic dermatitis was investigated. The disease activity of 117 randomly selected hospitalized patients suffering from atopic dermatitis was routinely assessed using the Severity Scoring of Atopic Dermatitis (SCORAD) index on admission and at discharge. Serum levels of eosinophil cationic protein and mast cell tryptase were determined in parallel both on admission and at discharge. After a mean treatment period of 24+/-12 days a decrease in the SCORAD index from 47.6+/-19.5 to 7.7+/-8.2 was achieved (p<0.001). Serum levels of eosinophil cationic protein decreased from 22.8+/-19.7 microg/l to 15.4+/-17.5 microg/l, whereas serum tryptase levels did not change. However, there was no significant correlation between the changes in SCORAD, eosinophil cationic protein and tryptase in our cohort. Thus, routine determination of serum eosinophil cationic protein or tryptase levels, in addition to evaluation of disease activity using the SCORAD index, is not recommended in unselected patients with atopic dermatitis.

Truncated thioredoxin is a mitogenic cytokine for resting human peripheral blood mononuclear cells and is present in human plasma.

Human thioredoxin (Trx) catalyzes intracellular disulfide reductions but has also co-cytokine activity with interleukins after leaderless secretion. A recombinant truncated form of thioredoxin with the 80 N-terminal residues (Trx80) was purified to homogeneity. We discovered that Trx80 by itself is a potent mitogenic cytokine stimulating growth of resting human peripheral blood mononuclear cells. No effect was seen by Trx, but Trx80 at 50-100 nm induced cell proliferation of human peripheral blood mononuclear cells in serum-free synthetic medium, measured as [(3)H]thymidine incorporation after 72 h, with a maximum effect being comparable with that of 5 units/ml of interleukin-2. Trx80 lacked redox activity, but CD spectra suggested a secondary structure similar to Trx. Reduced Trx80 had an M(r) of 25,000, indicating that it is a dimer in solution. We also developed two different sandwich enzyme-linked immunosorbent assays that distinguish between full-length Trx and Trx80 and determined plasma levels of Trx and Trx80 in blood donors. The levels of Trx80 varied from 2 to 175 ng/ml; in comparison levels of Trx varied from 16 to 55 ng/ml without correlation to Trx80. In conclusion, the naturally occurring Trx80 is a novel mitogenic cytokine for normal resting human blood mononuclear cells.

Anti-MAM antibodies in rheumatic disease: evidence for a MAM-like superantigen in rheumatoid arthritis?

OBJECTIVE: Superantigens (SAg) are potent immunomodulatory microbial proteins that can activate T cells, B cells, natural killer cells, and monocytes and are known to trigger experimental autoimmune disease. We investigated whether sera from patients with rheumatic diseases contained elevated antibodies to Mycoplasma arthritidis mitogen (MAM) or staphylococcal enterotoxins A and B (SEA and SEB). METHODS: Standard ELISA were used to measure IgG responses to SAg and IgM and IgG rheumatoid factors and total IgM and IgG levels. Modifications of standard lymphocyte proliferation assays were used to determine functional consequences of the observed antibodies. RESULTS: Antibodies to MAM were elevated in sera from patients with rheumatoid arthritis (RA) compared to sera from patients with systemic lupus erythematosus, ankylosing spondylitis, psoriatic arthritis, Reiter's syndrome, or healthy controls. Responses to other SAg were also elevated in rheumatic disease sera, but the levels were not specific for a given rheumatic disease. Anti-superantigen antibody levels did not correlate with the presence of rheumatoid factor. CONCLUSION: The selected elevation of antibodies to MAM in RA sera suggests that MAM or a MAM-like molecule might be associated with RA, whereas elevation of antibodies to SEA and SEB in sera from patients with rheumatic diseases was less specific.

Serum levels of connective tissue growth factor are elevated in patients with systemic sclerosis: association with extent of skin sclerosis and severity of pulmonary fibrosis.

OBJECTIVE: To determine the serum levels and clinical correlation of connective tissue growth factors (CTGF) in patients with systemic sclerosis (SSc). METHODS: Serum samples from patients with limited cutaneous SSc (lSSc, n = 32), diffuse cutaneous SSc (dSSc, n = 28), systemic lupus erythematosus (SLE, n = 30), polymyositis/dermatomyositis (PM/DM, n = 20), and healthy control subjects (n = 30) were examined by ELISA for detection of CTGF. RESULTS: Serum CTGF levels in patients with SSc were significantly higher than those in patients with SLE or PM/DM, and in controls. CTGF levels in patients with dSSc were significantly higher than those in patients with lSSc. As for clinical correlation of CTGF, SSc patients with elevated CTGF had pulmonary fibrosis, decreased DLCO, and decreased vital capacity more frequently than those with normal CTGF levels. Further, DLCO and vital capacity were inversely and directly correlated with serum CTGF levels in patients with SSc. The dSSc patients with disease duration of 1-3 years had significantly elevated levels of CTGF compared with dSSc patients with duration < 1 year or more than 3 years. CONCLUSION: Serum CTGF levels were increased in patients with SSc, and correlated with the extent of skin sclerosis and the severity of pulmonary fibrosis. In addition, it appears that production of CTGF is involved in the development or maintenance of fibrosis rather than in initiation of fibrosis in SSc. These data suggest that CTGF plays a critical role in the development of fibrosis in SSc.

In vivo regulation of the insulin-like growth factor system of mitogens by human chorionic gonadotropin.

Human chorionic gonadotropin (hCG) is a differentiating agent and chemopreventive in rat DMBA-induced breast carcinogenesis. Insulin-like growth factors (IGFs) are potent mitogens for breast cancer cells. We report that the administration of hCG to female rats resulted in a significant increase in serum IGFBP-3 levels at doses greater than 10 UI and a significant decrease in serum IGF-I levels. Northern blot analysis revealed that hCG inhibited hepatic and mammary IGF-I gene expression at doses greater than 10 UI. Mammary IGFBP-5 and IGFBP-2 gene expression significantly increased at high doses of hCG while IGFBP-4 slightly decreased. Treatments greater than 10 UI of hCG resulted in a significant suppression of mammary IGFBP-3 and IGF-I receptor expression. Since IGFs are potent mitogens and antiapoptotic agents for breast cancer, this newly described activity of hCG may contribute to its antiproliferative properties, particularly with regard to the differentiation and inhibition of mammary tumours seen in animal models.

Serum mitogenic activity on in vitro glial cells in Neurofibromatosis type 1.

Glial mitogenic effect was investigated in sera from the following groups of subjects: group (1) 31 patients clinically and genetically affected by Neurofibromatosis type 1 (NF1) belonging to different families; group (2) 42 patients without family history of NF1 affected by sporadic neoplasms of the same histogenetic origin as the proliferative lesions that are present in NF1; group (3) 51 healthy volunteers without family history of NF1 nor of neoplastic disease; group (4) 54 clinically healthy relatives of the NF1 patients included in the first group. All NF1 patients and 3/54 healthy relatives had alterations of exons 31 or 32 of NF1 gene. Glial proliferation, measured by [3H]thymidine incorporation, was significantly increased by sera from all NF1 patients and from 23/54 of clinically healthy relatives, as compared to sera from healthy volunteers. This serum mitogenic activity strongly suggests the existence of soluble glial proliferating molecules in NF1 families. The molecular weight (3-30 kDa), the heat- and freeze-stability and the specificity for glial cells, suggest that the molecules responsible for this mitogenic effect are different from the growth factors previously described in NF1-associated tumor extracts and from lymphokines. Within each NF1 family, the maximal serum dilution stimulating glial proliferation was similar both in affected members and in their clinically healthy relatives. Since none of the clinically healthy relatives showing serum mitogenic activity was positive for the NF1 mutation analysis and, conversely, those having altered exons 31 or 32 of NF1 gene did not show any mitogenic activity; these results suggest that the phenotype expression of NF1 might depend not only on the NF1 mutations per se, but also on other genetic or epigenetic factors, such as serum glial proliferating molecules.

Serum tryptase measured with B12 and G5 antibody-based immunoassays in mastocytosis patients and its relation to histamine turnover.

Serum tryptase was measured with the B12 and G5 antibody-based immunoassays in 25 adult patients with mastocytosis and in 18 controls. Twelve patients had uncomplicated cutaneous mastocytosis (urticaria pigmentosa) and 13 had urticaria pigmentosa with systemic symptoms. Tryptase levels were compared with histamine turnover estimated as urinary excretion of the main histamine metabolite tele-methylimidazoleacetic acid. Elevated B12 tryptase levels (> 20 microg/L) were found in most mastocytosis patients, including five of eight patients with only cutaneous manifestations who had a low urinary histamine metabolite excretion. This indicated a higher sensitivity for diagnosing mild mastocytosis on the basis of levels of serum tryptase as opposed to urinary methylimidazoleacetic acid. However, the serum B12 tryptase assay could not differentiate between urticaria pigmentosa patients with and without systemic disease: the measurement of histamine metabolite excretion probably reflects the mast cell burden more accurately. Serum G5 tryptase levels were generally low in both controls and mastocytosis patients.

Mitogenic effect of naturally occurring elevated plasma prolactin on ring dove lymphocytes.

3H-thymidine incorporation into isolated ring dove lymphocytes in vitro was used as a measure of lymphocyte proliferation. Lymphocytes taken from doves with increased plasma concentrations of prolactin demonstrated significantly increased 3H-thymidine incorporation. In vitro incubation with mitogens significantly increased incorporation of 3H-thymidine into lymphocytes from non-breeding doves. However, similar treatment of lymphocytes taken from doves which had elevated levels of plasma prolactin failed to induce any further increase in the stimulation index. Antigen caused a significant increase in 3H-thymidine incorporation in non-breeding doves. Antigen administration also led to the production of specific antibodies. The titre of specific anti-human red blood cell (HRBC) agglutinins was greatest in those birds which also had elevated levels of plasma prolactin, reaching significance in the group of incubating doves with naturally occurring increased concentrations of plasma prolactin. The results presented here may be relevant to our understanding of the role of hormones such as prolactin on lymphocyte activation.

Involvement of intact inositol-1,4,5-trisphosphate-sensitive Ca2+ stores in cell cycle progression at the G1/S boundary in serum-stimulated human fibroblasts.

Thapsigargin, a selective inhibitor of the endoplasmic reticulum Ca2+ pump, has been shown to deplete inositol-1,4,5-trisphosphate-sensitive Ca2+ stores. Here we report that when thapsigargin was introduced to serum-stimulated human fibroblasts at a time point just before the G1/S boundary, it completely inhibited expression of cyclin A, activation of p33CDK2 cyclin-dependent kinase and initiation of DNA synthesis. In contrast, the Ca2+ mobilizing ionophore ionomycin was without effect. These findings indicate that Ca2+ inside the inositol-1,4,5-trisphosphate-sensitive Ca2+ stores plays a pivotal role for traverse across the G1/S transition point.

Mitogenic effects of platelet-derived growth factor, fibroblast growth factor, transforming growth factor-beta, and heparin-binding serum factor for adult mouse Schwann cells.

Mitogenic effects of fetal calf serum (FCS), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), transforming growth factor-beta (TGF-beta), and forskolin to adult mouse Schwann cells were examined by bromodeoxyuridine (BrdU) incorporation and double immunofluorescence for S100 and BrdU. PDGF-BB, basic FGF, and TGF-beta 1 and beta 2 were all mitogenic for Schwann cells in media containing FCS. Forskolin suppressed the mitogenic activity of these factors. In serum-free media, PDGF-BB and bFGF were also mitogenic, but TGF-beta 1 and beta 2 were not. Heparin-binding fractions of FCS obtained by heparin-Sepharose chromatography synergized with TGF-beta 1 and beta 2 to produce a mitogenic response. Since PDGF-BB, acidic FGF, and basic FGF were not detected in these fractions by immunoabsorption and immunoblot assays, the presence of unidentified heparin-binding molecules in FCS bioactive for adult mouse Schwann cells is suggested.

A microplate-based bioassay system for measuring porcine serum mitogenic activity.

A bioassay system was developed to measure porcine serum mitogenic activity, which is an indicator of growth factor activity. A MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide++ +] cell proliferation assay was used to monitor cell growth. In comparison with electronic cell counting, this bioassay system is sensitive, economical, and semi-automatic. A non-fusing myoblast cell line, BC3H1, was used, making it possible to increase seeding density and thus improve precision. The assay was carried out in 96-well microplates with automatic reading and data processing by a computer-controlled ELISA reader. Results were highly correlated with Kotts' method. This assay system is of potential value in studying growth regulation in pigs.

Age-related changes in the mitogenic activity of heparin-binding growth factors in rat sera.

Sera from rats of either sex and different ages were examined for their ability to stimulate DNA synthesis in BALB/c 3T3 cells. The activity levels of sera from male and female rats were almost the same, with age-related changes in activity also being quite similar. Activity was considerably higher in infant rats (1-month-old), but then, at a young age (6-7 months), decreased drastically for male rats, but not significantly for female rats. It increased again in middle-aged rats (12-13 months old) and was maintained at the same level toward old age (24-26 months old) for both sexes. In order to determine what kinds of growth factors were responsible for these changes, we carried out heparin affinity chromatography on the sera of male rats. Four peaks were obtained for all sera, with individual peaks exhibiting specific age-related changes in activity. Among them a peak which was eluted at 1.1 M NaCl had very high activity. It showed a similar age-related change to that of the whole sera, except for a significant increase at old age, and the factor(s) included in the peak was found to be derived from platelets. These results suggested that the factor(s) in the peak was responsible for maintaining serum mitogenic activity at an old age. The experiments undertaken to characterize this factor suggested that it is a novel one.

Relationship between functional Na+ pumps and mitogenesis in cultured coronary artery smooth muscle cells.

An increase in functional sarcolemmal Na(+)-K(+)-ATPase (Na+ pump) precedes proliferation in vascular smooth muscle cells (VSMCs) seeded in 10% fetal bovine serum (FBS), but its role in mitogenesis is unresolved. Enzymatically dispersed canine coronary artery VSMCs were seeded in FBS and studied through confluence. Before a shift in cell cycle (G1-->S, G2 + M) and appearance of the nonmuscle isoform of myosin (MHCnm), intracellular Na+ content (Na+i) and cell volume (CV) increased (day 0 through day 3). Na+ pump number ([3H]-ouabain binding) increased at day 4 followed by a decrease in Na+i and CV. When Na+ pumps were inhibited by the addition of ouabain to FBS, VSMCs were arrested in G1, and MHCnm was not upregulated. Na+i increased similarly to that in FBS but failed to correct to day 0 levels. Withdrawal of ouabain at day 4 in culture led to an increase in Na+ pump number, a decrease in Na+i, entry of cells into S and G2 + M, and upregulation of MHCnm. These data suggest that Na+i, phenotypic modulation, and entry of cells into the cell cycle are temporally related, with Na+ pump-mediated correction of increased Na+i as a key event in the VSMC mitogenic process.

[Expression of surface antigens on lymphocytes stimulated by non- specific mitogens in multiple sclerosis patients]. / Badanie ekspresji powierzchniowych antygenów limfocytów stymulowanych nieswoistymi mitogenami u chorych na stwardnienie rozsiane.

In studies performed on 30 MS cases, as compared to 16 healthy individuals, significantly higher expression of HLA class II antigens, interleukin 2 receptor and antigens specific for lymphocytes B was observed. In MS patients after stimulation by non specific mitogens increased expression of HLA class II antigens and increased proliferation induced by PMA was found. The obtained results suggest absence of any greater modulation of surface antigens on the lymphocytes stimulated by non-specific mitogens. Our observations indicate that the number of activated T cells, as assessed by expression of Il-2 receptor, is in MS patients relatively low.