IGFBP1a is a nutrient deficient response factor that can inhibit fish reproduction through the hypothalamus-pituitary-ovary axis†.

Reproduction is a high energy consuming process, so long-term malnutrition can significantly inhibit gonadal development. However, little is known about the molecular mechanism by which fasting inhibits reproduction. Our present study found that fasting could dramatically induce insulin-like growth factor binding protein 1 (IGFBP1) expression in the liver, hypothalamus, pituitary and ovaries of grass carp. In addition, IGFBP1a in the hypothalamus-pituitary-gonad axis could inhibit the development of gonads. These results indicated that fasting may participate in the regulation of fish gonadal development through the mediation of IGFBP1a. Further studies found that IGFBP1a could markedly inhibit gonadotropin-releasing hormone 3 expressions in hypothalamus cells. At the pituitary level, IGFBP1a could significantly reduce the gonadotropin hormones (LH and FSH) expression by blocking the action of pituitary insulin-like growth factor 1. Interestingly, IGFBP1a could also directly inhibit the expression of lhr, fshr, and sex steroid hormone synthase genes (cyp11a, cyp17a, and cyp19a1) in the ovary. These results indicated that IGFBP1a should be a nutrient deficient response factor that could inhibit fish reproduction through the hypothalamus-pituitary-ovary axis.

The 5:2 Diet Affects Markers of Insulin Secretion and Sensitivity in Subjects with and without Type 2 Diabetes-A Non-Randomized Controlled Trial.

This non-randomized controlled trial aimed to compare the effect of the 5:2 diet on insulin levels as a primary outcome and markers of insulin secretion (connecting peptide (C-peptide) and insulin-like growth factor binding protein-1 (IGFBP-1)) and sensitivity (Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)), as well as body composition as secondary outcomes in overweight/obese individuals with and without type 2 diabetes (T2D). Ninety-seven participants (62% women), 35 with T2D and 62 BMI- and waist-matched controls without T2D, followed the 5:2 diet (two days per week of fasting) for six months with a 12-month follow-up. At six months, there was no loss to follow-up in the T2D group, whereas four controls discontinued this study. Overall, 82% attended the 12-month follow-up. After the intervention, insulin levels decreased in the control group and glucose decreased in the T2D group, while C-peptide, HOMA-IR, waist circumference, BMI, trunk, and total fat% decreased in both groups. Furthermore, low IGFBP-1, indicating hyperinsulinemia, improved in the T2D group. The changes in fasting glucose and waist measurement were significantly more improved in the T2D group than in the controls. Persistent positive effects were observed at the 12-month follow-up. The 5:2 diet for six months was feasible and efficient to reduce markers of insulin secretion and resistance and therefore holds promise as management of overweight/obesity in subjects with and without T2D.

A Nonlinear Relation between Body Mass Index and Long-Term Poststroke Functional Outcome-The Importance of Insulin Resistance, Inflammation, and Insulin-like Growth Factor-Binding Protein-1.

Both high serum insulin-like growth factor-binding protein-1 (s-IGFBP-1) and insulin resistance (IR) are associated with poor functional outcome poststroke, whereas overweight body mass index (BMI; 25-30) is related to fewer deaths and favorable functional outcome in a phenomenon labeled "the obesity paradox". Furthermore, IGFBP-1 is inversely related to BMI, in contrast to the linear relation between IR and BMI. Here, we investigated s-IGFBP-1 and IR concerning BMI and 7-year poststroke functional outcome. We included 451 stroke patients from the Sahlgrenska Study on Ischemic Stroke (SAHLSIS) with baseline measurements of s-IGFBP1, homeostasis model assessment of IR (HOMA-IR), BMI (categories: normal-weight (8.5-25), overweight (25-30), and obesity (>30)), and high-sensitivity C-reactive protein (hs-CRP) as a measure of general inflammation. Associations with poor functional outcome (modified Rankin scale [mRS] score: 3-6) after 7 years were evaluated using multivariable binary logistic regression, with overweight as reference due to the nonlinear relationship. Both normal-weight (odds-ratio [OR] 2.32, 95% confidence interval [CI] 1.30-4.14) and obese (OR 2.25, 95% CI 1.08-4.71) patients had an increased risk of poor functional outcome, driven by deaths only in the normal-weight. In normal-weight, s-IGFBP-1 modestly attenuated (8.3%) this association. In the obese, the association was instead attenuated by HOMA-IR (22.4%) and hs-CRP (10.4%). Thus, a nonlinear relation between BMI and poor 7-year functional outcome was differently attenuated in the normal-weight and the obese.

Metformin enhances epithelial cell growth inhibition via the protein kinase-insulin-like growth factor binding protein-1 pathway.

BACKGROUND: Abnormal stromal-epithelial cell communication is a pathogenic mechanism in endometriosis, and metformin can modulate it. Insulin-like growth factor binding protein-1 (IGFBP1) plays a role in endometriosis, but the exact mechanism is unknown. IGFBP1 is reportedly a downstream target of metformin in some diseases. We aimed to investigate the role of IGFBP1 in endometriosis development, whether it is associated with abnormal communication, and whether metformin affects IGFBP1 expression. METHODS: Patients who underwent surgical treatment for endometriosis or other diseases were enrolled. Ten patients with ovarian-type endometriosis and eight patients each who underwent surgical treatment for other lesions with or without endometriosis were selected, and their tissues taken for cell proliferation, western blotting, polymerase chain reaction, and knockdown experiments. RESULTS: Ectopic and eutopic stromal cells (EcSCs and EuSCs) lost their ability to inhibit epithelial cell proliferation, and IGFBP1 expression was downregulated in both groups of stromal cells compared to that in normal stromal cells (NSCs; 1.09 vs. 0.25, p = .0002 1.09 vs. 0.57, p = .0029). In an EcSC IGFBP1 overexpression model, the ability of EcSCs to inhibit epithelial cell proliferation was enhanced (EdU positivity decreased from 38% to 25%, p = .0001). Furthermore, adenosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation was downregulated in EcSCs and EuSCs compared to that in NSCs (0.99 vs. 0.42, p = .0006/0.99 vs. 0.57, p = 0.0032). Treatment of EcSCs with metformin increased AMPK phosphorylation (0.47 vs. 1.04, p = .0107) while upregulating IGFBP1 expression (0.69 vs. 1.01, p = .0164), whereas pre-treatment with an AMPK phosphorylation inhibitor abrogated metformin-induced IGFBP1 upregulation. CONCLUSIONS: IGFBP1 mediates aberrant stromal-epithelial communication in endometriosis. Metformin can upregulate IGFBP1 expression in EcSCs by activating AMPK, and upregulated IGFBP1 enhances the inhibition of epithelial cell proliferation. IGFBP1 is expected to be a therapeutic target for endometriosis.

Insulin-like growth factor binding protein 1 (IGFBP1) is a protein that regulates cell growth and proliferation and is expressed at abnormal levels in patients with endometriosis. In some cases, metformin has been shown to modulate the expression of this protein. Here, we investigated the role of IGFBP1 in endometriosis development, whether it is associated with abnormal communication, and whether metformin affects IGFBP1 expression in endometrial cells. We found that downregulation of IGFBP1 in endometriosis diminished the ability of stromal cells to inhibit the proliferation of epithelial cells through inhibition of the protein kinase B and extracellular regulated protein kinase pathways. In addition, metformin upregulated IGFBP1 expression by activating adenosine 5'-monophosphate-activated protein kinase, suggesting that IGFBP1 may be one of the potential targets for drug therapy for endometriosis.

HMGA2 drives the IGFBP1/AKT pathway to counteract the increase in P27KIP1 protein levels in mtDNA/RNA-less cancer cells.

Recent comprehensive analyses of mtDNA and orthogonal RNA-sequencing data revealed that in numerous human cancers, mtDNA copy numbers and mtRNA amounts are significantly reduced, followed by low respiratory gene expression. Under such conditions (called mt-Low), cells encounter severe cell proliferation defects; therefore, they must acquire countermeasures against this fatal disadvantage during malignant transformation. This study elucidated a countermeasure against the mt-Low condition-induced antiproliferative effects in hepatocellular carcinoma (HCC) cells. The mechanism relied on the architectural transcriptional regulator HMGA2, which was preferably expressed in HCC cells of the mt-Low type in vitro and in vivo. Detailed in vitro analyses suggest that HMGA2 regulates insulin-like growth factor binding protein 1 (IGFBP1) expression, leading to AKT activation, which then phosphorylates the cyclin-dependent kinase inhibitor (CKI), P27KIP1, and facilitates its ubiquitin-mediated degradation. Accordingly, intervention in the HMGA2 function by RNAi resulted in an increase in P27KIP1 levels and an induction of senescence-like cell proliferation inhibition in mt-Low-type HCC cells. Conclusively, the HMGA2/IGFBP1/AKT axis has emerged as a countermeasure against P27KIP1 CKI upregulation under mt-Low conditions, thereby circumventing cell proliferation inhibition and supporting the tumorigenic state. Notably, similar to in vitro cell lines, HMGA2 was likely to regulate IGFBP1 expression in HCC in vivo, thereby contributing to poor patient prognosis. Considering the significant number of cases under mt-Low or the threat of CKI upregulation cancer-wide, the axis is noteworthy as a vulnerability of cancer cells or target for tumor-agnostic therapy inducing irreversible cell proliferation inhibition via CKI upregulation in a large population with cancer.

Exploring the role of insulin-like growth factor binding protein-1 in identifying idiopathic multicentric Castleman's disease types: Implications for the mTOR signaling pathway.

OBJECTIVE: To determine the molecular differences between iMCD-thrombocytopenia, anasarca, fevers, reticulin myelofibrosis, organomegaly (TAFRO), and iMCD-not otherwise specified (NOS). METHODS: CD4-positive T cells were isolated from two iMCD-TAFRO and two iMCD-NOS patients for RNA sequencing comparison. Serum proteins of two iMCD-TAFRO and four iMCD-NOS patients were comprehensively analyzed to identify pathogenesis-associated proteins. IGFBP-1 protein, extracted from serum analysis, was compared to healthy controls, iMCD, systemic lupus erythematosus, and rheumatoid arthritis patients. RESULTS: RNA sequencing of CD4-positive T cells revealed enhanced mTOR-related signaling in iMCD-TAFRO compared to iMCD-NOS. Comprehensive serum analysis found IGFBP-1 linked to iMCD pathogenesis, significantly higher in iMCD-TAFRO. This protein may be elevated in patients with iMCD caused by an enhanced mTOR pathway. CONCLUSION: The mTOR pathway is suggested to be activated in iMCD-TAFRO compared to iMCD-NOS, which may elevate the protein IGFBP-1. This protein may be a biomarker to distinguish iMCD-TAFRO from iMCD-NOS.

Further Evidence that an Episode of Premature Labor Is a Pathologic State: Involvement of the Insulin-Like Growth Factor System.

INTRODUCTION: Approximately 47% of women with an episode of preterm labor deliver at term; however, their infants are at greater risk of being small for gestational age and for neurodevelopmental disorders. In these cases, a pathologic insult may disrupt the homeostatic responses sustaining pregnancy. We tested the hypothesis of an involvement of components of the insulin-like growth factor (IGF) system. METHODS: This is a cross-sectional study in which maternal plasma concentrations of pregnancy-associated plasma protease (PAPP)-A, PAPP-A2, insulin-like growth factor-binding protein 1 (IGFBP-1), and IGFBP-4 were determined in the following groups of women: (1) no episodes of preterm labor, term delivery (controls, n = 100); (2) episode of preterm labor, term delivery (n = 50); (3) episode of preterm labor, preterm delivery (n = 100); (4) pregnant women at term not in labor (n = 61); and (5) pregnant women at term in labor (n = 61). Pairwise differences in maternal plasma concentrations of PAPP-A, PAPP-A2, IGFBP-1, and IGFBP-4 among study groups were assessed by fitting linear models on log-transformed data and included adjustment for relevant covariates. Significance of the group coefficient in the linear models was assessed via t-scores, with p < 0.05 deemed a significant result. RESULTS: Compared to controls, (1) women with an episode of premature labor, regardless of a preterm or a term delivery, had higher mean plasma concentrations of PAPP-A2 and IGFBP-1 (each p < 0.05); (2) women with an episode of premature labor who delivered at term also had a higher mean concentration of PAPP-A (p < 0.05); and (3) acute histologic chorioamnionitis and spontaneous labor at term were not associated with significant changes in these analytes. CONCLUSION: An episode of preterm labor involves the IGF system, supporting the view that the premature activation of parturition is a pathologic state, even in those women who delivered at term.

The Impact of Westernization on the Insulin/IGF-I Signaling Pathway and the Metabolic Syndrome: It Is Time for Change.

The metabolic syndrome is a cluster of overlapping conditions resulting in an increased incidence of type 2 diabetes, cardiovascular disease, and cancer. In the last few decades, prevalence of the metabolic syndrome in the Western world has reached epidemic proportions and this is likely due to alterations in diet and the environment as well as decreased physical activity. This review discusses how the Western diet and lifestyle (Westernization) has played an important etiological role in the pathogenesis of the metabolic syndrome and its consequences by exerting negative effects on activity of the insulin-insulin-like growth factor-I (insulin-IGF-I) system. It is further proposed that interventions that normalize/reduce activity of the insulin-IGF-I system may play a key role in the prevention and treatment of the metabolic syndrome. For successful prevention, limitation, and treatment of the metabolic syndrome, the focus should be primarily on changing our diets and lifestyle in accordance with our genetic make-up, formed in adaptation to Paleolithic diets and lifestyles during a period of several million years of human evolution. Translating this insight into clinical practice, however, requires not only individual changes in our food and lifestyle, starting in pediatric populations at a very young age, but also requires fundamental changes in our current health systems and food industry. Change is needed: primary prevention of the metabolic syndrome should be made a political priority. New strategies and policies should be developed to stimulate and implement behaviors encouraging the sustainable use of healthy diets and lifestyles to prevent the metabolic syndrome before it develops.

Serum IGFBP-1 Concentration as a Predictor of Outcome after Ischemic Stroke-A Prospective Observational Study.

Insulin-like growth factor-binding protein-1 (IGFBP-1) regulates insulin-like growth factor-I (IGF-I) bioactivity, and is a central player in normal growth, metabolism, and stroke recovery. However, the role of serum IGFBP-1 (s-IGFBP-1) after ischemic stroke is unclear. We determined whether s-IGFBP-1 is predictive of poststroke outcome. The study population comprised patients (n = 470) and controls (n = 471) from the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). Functional outcome was evaluated after 3 months, 2, and 7 years using the modified Rankin Scale (mRS). Survival was followed for a minimum of 7 years or until death. S-IGFBP-1 was increased after 3 months (p < 0.01), but not in the acute phase after stroke, compared with the controls. Higher acute s-IGFBP-1 was associated with poor functional outcome (mRS score > 2) after 7 years [fully adjusted odds ratio (OR) per log increase 2.9, 95% confidence interval (CI): 1.4-5.9]. Moreover, higher s-IGFBP-1 after 3 months was associated with a risk of poor functional outcome after 2 and 7 years (fully adjusted: OR 3.4, 95% CI: 1.4-8.5 and OR 5.7, 95% CI: 2.5-12.8, respectively) and with increased mortality risk (fully adjusted: HR 2.0, 95% CI: 1.1-3.7). Thus, high acute s-IGFBP-1 was only associated with poor functional outcome after 7 years, whereas s-IGFBP-1 after 3 months was an independent predictor of poor long-term functional outcome and poststroke mortality.

Protein Plasma Levels of the IGF Signalling System Are Altered in Major Depressive Disorder.

The Insulin-like growth factor 2 (IGF-2) has been recently proven to alleviate depressive-like behaviors in both rats and mice models. However, its potential role as a peripheral biomarker has not been evaluated in depression. To do this, we measured plasma IGF-2 and other members of the IGF family such as Binding Proteins (IGFBP-1, IGFBP-3, IGFBP-5 and IGFBP-7) in a depressed group of patients (n = 51) and in a healthy control group (n = 48). In some of these patients (n = 15), we measured these proteins after a period (19 ± 6 days) of treatment with antidepressants. The Hamilton Depressive Rating Scale (HDRS) and the Self-Assessment Anhedonia Scale (SAAS) were used to measure depression severity and anhedonia, respectively. The general cognition state was assessed by the Mini-Mental State Examination (MMSE) test and memory with the Free and Cued Selective Reminding Test (FCSRT). The levels of both IGF-2 and IGFBP-7 were found to be significantly increased in the depressed group; however, only IGF-2 remained significantly elevated after correction by age and sex. On the other hand, the levels of IGF-2, IGFBP-3 and IGFBP-5 were significantly decreased after treatment, whereas only IGFBP-7 was significantly increased. Therefore, peripheral changes in the IGF family and their response to antidepressants might represent alterations at the brain level in depression.

Starvation-induced transcription factor CREBH negatively governs body growth by controlling GH signaling.

cAMP responsive element-binding protein H (CREBH) is a hepatic transcription factor to be activated during fasting. We generated CREBH knock-in flox mice, and then generated liver-specific CREBH transgenic (CREBH L-Tg) mice in an active form. CREBH L-Tg mice showed a delay in growth in the postnatal stage. Plasma growth hormone (GH) levels were significantly increased in CREBH L-Tg mice, but plasma insulin-like growth factor 1 (IGF1) levels were significantly decreased, indicating GH resistance. In addition, CREBH overexpression significantly increased hepatic mRNA and plasma levels of FGF21, which is thought to be as one of the causes of growth delay. However, the additional ablation of FGF21 in CREBH L-Tg mice could not correct GH resistance at all. CREBH L-Tg mice sustained GH receptor (GHR) reduction and the increase of IGF binding protein 1 (IGFBP1) in the liver regardless of FGF21. As GHR is a first step in GH signaling, the reduction of GHR leads to impairment of GH signaling. These data suggest that CREBH negatively regulates growth in the postnatal growth stage via various pathways as an abundant energy response by antagonizing GH signaling.

IGFBP-1 expression is reduced in human type 2 diabetic glomeruli and modulates ß1-integrin/FAK signalling in human podocytes.

AIMS/HYPOTHESIS: Podocyte loss or injury is one of the earliest features observed in the pathogenesis of diabetic kidney disease (DKD), which is the leading cause of end-stage renal failure worldwide. Dysfunction in the IGF axis, including in IGF binding proteins (IGFBPs), is associated with DKD, particularly in the early stages of disease progression. The aim of this study was to investigate the potential roles of IGFBPs in the development of type 2 DKD, focusing on podocytes. METHODS: IGFBP expression was analysed in the Pima DKD cohort, alongside data from the Nephroseq database, and in ex vivo human glomeruli. Conditionally immortalised human podocytes and glomerular endothelial cells were studied in vitro, where IGFBP-1 expression was analysed using quantitative PCR and ELISAs. Cell responses to IGFBPs were investigated using migration, cell survival and adhesion assays; electrical cell-substrate impedance sensing; western blotting; and high-content automated imaging. RESULTS: Data from the Pima DKD cohort and from the Nephroseq database demonstrated a significant reduction in glomerular IGFBP-1 in the early stages of human type 2 DKD. In the glomerulus, IGFBP-1 was predominantly expressed in podocytes and controlled by phosphoinositide 3-kinase (PI3K)-forkhead box O1 (FoxO1) activity. In vitro, IGFBP-1 signalled to podocytes via ß1-integrins, resulting in increased phosphorylation of focal-adhesion kinase (FAK), increasing podocyte motility, adhesion, electrical resistance across the adhesive cell layer and cell viability. CONCLUSIONS/INTERPRETATION: This work identifies a novel role for IGFBP-1 in the regulation of podocyte function and that the glomerular expression of IGFBP-1 is reduced in the early stages of type 2 DKD, via reduced FoxO1 activity. Thus, we hypothesise that strategies to maintain glomerular IGFBP-1 levels may be beneficial in maintaining podocyte function early in DKD.

Metformin and insulin treatment of gestational diabetes: effects on inflammatory markers and IGF-binding protein-1 - secondary analysis of a randomized controlled trial.

BACKGROUND: Gestational diabetes mellitus (GDM) is characterized by disturbed glucose metabolism and activation of low-grade inflammation. We studied whether metformin treatment has favorable or unfavorable effects on inflammatory markers and insulin-like growth factor-binding protein 1 (IGFBP-1) in GDM patients compared with insulin, and whether these markers associate with major maternal or fetal clinical outcomes. METHODS: This is a secondary analysis of a previous randomized controlled trial comparing metformin (n = 110) and insulin (n = 107) treatment of GDM. Fasting serum samples were collected at the time of diagnosis (baseline, mean 30 gestational weeks [gw]) and at 36 gw. Inflammatory markers serum high-sensitivity CRP (hsCRP), interleukin-6 (IL-6), matrix metalloproteinase-8 (MMP-8) and glycoprotein acetylation (GlycA) as well as three IGFBP-1 phosphoisoform concentrations were determined. RESULTS: In the metformin and insulin groups combined, hsCRP decreased (p = 0.01), whereas IL-6 (p = 0.002), GlycA (p < 0.0001) and all IGFBP-1 phosphoisoforms (p < 0.0001) increased from baseline to 36 gw. GlycA (p = 0.02) and non-phosphorylated IGFBP-1 (p = 0.008) increased more in patients treated with metformin than those treated with insulin. Inflammatory markers did not clearly associate with pregnancy outcomes but non-phosphorylated IGFBP-1 was inversely associated with gestational weight gain. CONCLUSIONS: Metformin had beneficial effects on maternal serum IGFBP-1 concentrations compared to insulin, as increased IGFBP-1 related to lower total and late pregnancy maternal weight gain. GlycA increased more during metformin treatment compared to insulin. The significance of this observation needs to be more profoundly examined in further studies. There were no evident clinically relevant relations between inflammatory markers and pregnancy outcome measures. TRIAL REGISTRATION: The trial comparing metformin and insulin treatment was registered in ClinicalTrials.gov ( NCT01240785 ) November 3, 2010. Retrospectively registered.

Knockdown of Orphan Transporter SLC22A18 Impairs Lipid Metabolism and Increases Invasiveness of HepG2 Cells.

PURPOSE: The aim of this work is to investigate the roles of solute carrier family 22 member 18 (SLC22A18) in lipid metabolism and in establishing the tumor phenotype of HepG2 cells. METHODS: SLC22A18-knockdown HepG2 cells were established by stable transfection with shRNA. Protein expression levels were measured by quantitative proteomics and Western blot analysis. Cell growth was examined by cell counting kit. Accumulation of triglyceride-rich lipid droplets was measured by Oil-Red O staining. Cell migration and invasion were examined by Transwell assays. RESULTS: SLC22A18-knockdown HepG2 cells accumulated triglyceride-rich lipid droplets and showed decreased expression levels of lysosomal/autophagic proteins, suggesting that lipid degradation is suppressed. Growth of HepG2 cells was decreased by SLC22A18 knockdown, but was restored by free fatty acid supplementation. In addition, SLC22A18 knockdown decreased the expression of insulin-like growth factor-binding protein 1 (IGFBP-1) and increased the invasion ability of HepG2 cells. Exogenous IGFBP-1 blocked the increase of invasion activity induced by SLC22A18 knockdown. CONCLUSION: Our results suggest that suppression of SLC22A18 decreased the supply of intracellular free fatty acids from triglyceride-rich lipid droplets by impairing the lysosomal/autophagy degradation pathway and reduced the invasive activity of HepG2 cells by decreasing IGFBP-1 expression.

Hepatitis B virus suppresses the secretion of insulin-like growth factor binding protein 1 to facilitate anti-apoptotic IGF-1 effects in HepG2 cells.

Hepatitis B virus (HBV) infection is a major global health burden as chronic hepatitis B (CHB) is associated with the development of liver diseases including hepatocellular carcinoma (HCC). To gain insight into the mechanisms causing HBV-related HCC, we investigated the effects of HBV replication on global host cell gene expression using human HepG2 liver cells. By microarray analysis, we identified 54 differentially expressed genes in HBV-replicating HepG2 cells. One of the differentially-expressed genes was insulin-like growth factor binding protein 1 (IGFBP1) which was downregulated in HBV-replicating cells. Consistent with the gene expression data, IGFBP1 was suppressed at both the cellular and secreted protein levels in the presence of HBV replication. Transient transfection experiments with an inducible plasmid encoding the HBV X protein (HBx) revealed that HBx alone was sufficient to modulate IGFBP1 expression. Small interference RNA (siRNA)-mediated loss of function studies revealed that knockdown of IGFBP1 reduced apoptosis induced by either thapsigargin (TG) or staurosporine (STS). Treatment of cells with recombinant insulin-like growth factor 1 (IGF-1) decreased both TG- or STS-induced apoptosis. Interestingly, addition of recombinant IGFBP1 reversed the anti-apoptotic effect of IGF-1 on TG-induced, but not STS-induced, apoptosis. In conclusion, our results suggest an anti-apoptotic autocrine function of HBV-mediated downregulation of IGFBP1 in HepG2 cells. Such an effect may contribute to the development of HBV-mediated HCC by increasing pro-survival and anti-apoptotic IGF-1 effects.

Molecular identification of grouper Igfbp1 and its mRNA expression in primary hepatocytes under Gh and insulin.

The insulin-like growth factor (IGF) system plays a pivotal role in the regulation of growth, and IGF binding proteins (IGFBPs) are important regulatory factors in the IGF system. Generally, IGFBPs inhibit IGF actions by preventing its binding to receptors. Under some conditions, the IGFBPs can also enhance IGF actions. IGFBP1 is generally inhibitory to IGFI. In this study, the grouper (Epinephelus coioides) igfbp1 (MK621003) gene was cloned from the liver. The sequence of igfbp1 cDNA was 1055 bp and contained a 5'UTR of 127 bp and a 3'UTR of 247 bp, and the ORF of grouper igfbp1 was 741 bp, encoding 246 amino acids. The tissue distribution results showed that igfbp1 has a higher expression in the liver. In the nutritional status experiment, igfbp1 expression was significantly increased in the liver after 7 days of fasting and was markedly decreased after refeeding. In in vitro experiments, igfbp1 expression in grouper primary hepatocytes was significantly inhibited by recombinant grouper Gh (growth hormone) in a dose-dependent manner. Additionally, igfbp1 expression decreased in grouper primary hepatocytes upon incubation with insulin. This is the first report describing grouper igfbp1, and these findings contribute to understanding the roles of IGFBP1 in metabolism and growth in grouper.

Endometrial expression of receptivity markers subject to ovulation induction agents.

PURPOSE: Implantation rates differ according to ovulation induction agents in ART. This study investigates the different local endometrial effects of LH- versus hCG-induced ovulation. METHODS: Endometrial stromal cells from healthy patients were cultured with hCG or LH in different concentrations, supplemented with 250 ng/mL hCG and progesterone after 2 and 5 days. In addition after decidualization induction, cells were treated with hCG (50 or 250 ng/mL) or LH (10 or 50 ng/mL) for 3 days. Receptivity markers expression was evaluated by real-time quantitative PCR on day 3 and 6. RESULTS: On day 3, non-decidualized cells treated with LH showed an increased expression of IGFBP1, IL-8 and CXCL12 compared to hCG. The expression pattern changed on day 6, where cells treated with hCG showed higher expression of implantation markers compared to LH-treated cells. Furthermore, on day 3, decidualized cells treated with hCG250 showed an increased IL8 and CXCL12 expression compared to LH10. CONCLUSIONS: LH seems to modulate the local endometrial expression of receptivity markers earlier compared to hCG; however, the effect is not sustained over time in cells without prior decidualization. Though, in decidualized cells, pattern changed and an earlier positive effect of hCG was shown on IL-8 and CXCL12.

The levonorgestrel-releasing intrauterine device induces endometrial decidualisation in women on tamoxifen.

There is conflicting literature on whether the levonorgestrel-releasing intrauterine system (LNG-IUS; Mirena®) induces decidualisation in the tamoxifen-treated endometrium. The expression of the decidualisation marker IGFBP-1 was measured using immunohistochemistry in endometrial biopsies and in serum (using ELISA) of 20 postmenopausal women at the start of tamoxifen-treatment for breast cancer. Ten women were then fitted with LNG-IUS and the other ten received tamoxifen-treatment only and acted as controls. Samples were taken at baseline and after 12 months. At baseline, all endometrial samples were negative for IGFBP-1 and at 12 months, IGFBP-1 was only expressed in the endometria of women fitted with the LNG-IUS, confirming the observed histological features of decidualisation. By contrast, serum IGFBP-1 concentrations were increased by tamoxifen, but not in the group receiving LNG-IUS. In conclusion, tamoxifen induces a rise in serum IGFBP-1 suggesting a systemic, possibly hepatic effect, whilst LNG abrogates this in both the liver and endometrium. Impact statement What is already known on this subject? Previous reports of the use of LNG-IUS in women on tamoxifen have provided conflicting evidence as to whether the endometrium exhibited decidualisation or not. These reports were however based solely on histological examination and lacked supporting biochemical data. What do the results of this study add? After 12 months of treatment with LNG-IUS, the endometria of women on tamoxifen show histological features of decidualisation and the presence of the decidualisation marker IGFBP-1, suggesting that levonorgestrel protects the tamoxifen-treated uterus from additional pathology by causing decidualisation. Serum levels of IGFBP-1 were expected to be a reflection of uterine production, but contrary to expectations, higher levels were identified in women on tamoxifen alone. These data suggest that an inhibition of tamoxifen-induced serum IGFBP-1 production (possibly from a hepatic source) by LNG-IUS occurred and indicates independent systemic effects of both drugs in post menopausal breast cancer patients. What are the implications of these findings for clinical practice and/or further research? This research demonstrated a mechanism for endometrial protection in women on tamoxifen. It also alerts clinicians to the fact that both tamoxifen and LNG-IUS exert systemic effects in this patient group.

Inflammation-Associated Cytokines IGFBP1 and RANTES Impair the Megakaryocytic Potential of HSCs in PT Patients after Allo-HSCT.

Prolonged isolated thrombocytopenia (PT) is a severe complication in patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Whether the megakaryoctic potential of hematopoietic stem cells (HSCs) in bone marrow is intact and what factors drive the pathological process of PT remain elusive. A retrospective study in patients (n = 285) receiving HSCT revealed that the occurrence of PT was approximately 8% and the number of platelets and megakaryocytes in PT patients is much lower compared with control subjects. To test whether the deficiency of thrombopoiesis was caused by the activities of HSCs, the megakaryocytic differentiation potential of HSCs before or after transplantation was assessed. Interestingly, a substantial decrease of megakaryocytic differentiation was observed 2 weeks after transplantation of HSCs in all of the allo-HSCT recipients. However, 4 weeks after transplantation, the ability of HSCs to generate CD41+CD42b+ megakaryocytes in successful platelet engraftment patients recovered to the same level as those of HSCs before implantation. In contrast, HSCs derived from PT patients throughout the postimplantation period exhibited poor survival and failed to differentiate properly. A protein array analysis demonstrated that multiple inflammation-associated cytokines were elevated in allo-HSCT recipients with PT. Among them, insulin-like growth factor-binding protein 1 and regulated on activation, normal T cell expressed and secreted were found to significantly suppress the proliferation and megakaryocytic differentiation of HSCs in vitro. Our results suggested that the occurrence of PT may be attributed, at least partially, to the damage to HSC function caused by inflammation-associated cytokines after HSCT. These findings shed light on the mechanism underlying HSC megakaryocytic differentiation in PT patients and may provide potential new strategies for treating PT patients after HSCT.

TXNDC5 contributes to rheumatoid arthritis by down-regulating IGFBP1 expression.

The thioredoxin domain-containing 5 (TXNDC5) gene is associated with susceptibility to rheumatoid arthritis (RA) and exhibits increased expression in the synovial tissues. TXNDC5 is also associated strongly with diabetes, a metabolic disease characterized by interrupted insulin signalling. This study investigated whether TXNDC5 contributes to RA via the insulin signalling pathway. In this study, RA synovial fibroblast-like cells (RASFs) transfected with an anti-TXNDC5 small interfering RNA (siRNA) were analysed with an insulin signaling pathway RT2 profiler polymerase chain reaction (PCR) array and an insulin resistance RT2 profiler PCR array. The PCR arrays detected significantly increased expression of insulin-like growth factor binding protein 1 (IGFBP1) in RASFs with suppressed TXNDC5 expression. The result was verified using real-time PCR and Western blot analyses. Significantly elevated IGFBP1 expression and decreased interleukin (IL)-6 secretion were also detected in culture medium of transfected RASFs. Furthermore, decreased IGFBP1 mRNA and protein expression levels were detected in RA synovial tissues. Additionally, significantly increased apoptosis and decreased cell proliferation and cell migration were observed in RASFs transfected with the anti-TXNDC5 siRNA, whereas transfection with the anti-IGFBP1 siRNA or a mixture of the anti-IGFBP1 and anti-TXNDC5 siRNAs restored normal cell proliferation, migration and IL-6 level in RASFs. Insulin-like growth factor (IGF) has potent prosurvival and anti-apoptotic functions, and IGFBP1 can suppress IGF activity. Based on the results of the present study, we suggest that TXNDC5 contributes to abnormal RASF proliferation, migration and IL-6 production by inhibiting IGFBP1 expression.