Alterations of materno-placento-fetal glucose homeostasis after a single course of antenatal betamethasone

INTRODUCTION

Intrauterine growth impairment is associated with long-term metabolic changes (perinatal programming). We recently demonstrated that antenatal betamethasone (BET) decreased head circumference in term born females. Since glucose is the main energy source for fetal growth, BET-induced changes in maternal glucose homeostasis, a reduced transplacental glucose transfer or an altered fetal glucose utilization may be linked with the observed growth impairment.

METHODS

86 pregnant women exposed to BET (single course, <34 + 0 weeks of gestation (wks)) were compared to 92 gestational-age/sex-matched controls. Glucose, insulin, leptin, insulin-like growth factors (IGF-1, IGF-2) and their binding proteins (IGFBP-1, IGFBP-3) were measured in maternal and umbilical cord blood samples. Homeostasis Model Assessment (HOMA-IR) was calculated. Placental glucose transporter 1 and 3 (GLUT1, GLUT3) protein levels were determined. Statistics were performed for overall and subgroup analysis (gestational age, sex).

RESULTS

After BET maternal HOMA-IR was elevated, IGFBP-1 reduced. In female pregnancies, glucose levels ≥37 + 0 wks and IGF-1 levels <37 + 0 wks were tendentially increased. Placental GLUT1 and GLUT3 protein levels were not significantly altered. Fetal umbilical venous glucose levels ≥37 + 0 wks were increased. HOMA-IR tended to be elevated in females.

DISCUSSION

Growth impairment after BET appears neither caused by maternal nor fetal hypoglycemia nor changes of GLUT1 and GLUT3 total protein levels. Nonetheless, glucose homeostasis of mothers and daughters was altered even beyond the BET time frame (hyperglycemia, enhanced insulin resistance). Despite glucose supply was sufficient, an anabolic effect was apparently absent. Overall, our results highlight the relevance of adequate glucose management after BET and peripartum.

Maternal obesity and acute lymphoblastic leukemia risk in offspring: A summary of trends, epidemiological evidence, and possible biological mechanisms

Acute lymphoblastic leukemia, a heterogenous malignancy characterized by uncontrolled proliferation of lymphoid progenitors and generally initiated in utero, is the most common pediatric cancer. Although incidence of ALL has been steadily increasing in recent decades, no clear reason for this trend has been identified. Rising concurrently with ALL incidence, increasing maternal obesity rates may be partially contributing to increasing ALL prevelance. Epidemiological studies, including a recent meta-analysis, have found an association between maternal obesity and leukemogenesis in offspring, although mechanisms underlying this association remain unknown. Therefore, the purpose of this review is to propose possible mechanisms connecting maternal obesity to ALL risk in offspring, including changes to fetal/neonatal epigenetics, altered insulin-like growth factor profiles and insulin resistance, modified adipokine production and secretion, changes to immune cell populations, and impacts on birthweight and childhood obesity/adiposity. We describe how each proposed mechanism is biologically plausible due to their connection with maternal obesity, presence in neonatal and/or fetal tissue, observation in pediatric ALL patients at diagnosis, and association with leukemogenesis, A description of ALL and maternal obesity trends, a summary of epidemiological evidence, a discussion of the pathway from intrauterine environment to subsequent malignancy, and propositions for future directions are also presented.

Components of IGF-axis in growth disorders: a systematic review and patent landscape report

PURPOSE

In this review, epi/genetic mutations of IGF-axis components associated with growth disorders have been summarized alongwith assessment of relevant diagnostic and therapeutic technology through patent literature.

METHODOLOGY

PROSPERO protocol registration CRD42021279468. For scientific literature search Literature databases (PubMed, EMBASE, ScienceDirect, and Google Scholar) were queried using the appropriate syntax. Various filters were applied based on inclusion and exclusion criteria. Search results were further refined by two authors for finalizing studies to be included in this synthesis. For patent documents search Patent databases (Patentscope and Espacenet) were queried using keywords: IGF or IGFBP. Filters were applied according to International Patent Classification (IPC) and Cooperative Patent Classification (CPC). Search results were reviewed by two authors for inclusion in the patent landscape report.

RESULTS

For scientific literature analysis, out of 545 search results, 196 were selected for review based on the inclusion criteria. For Patent literature search, out of 485 results, 37 were selected for this synthesis.

CONCLUSION

Dysregulation of IGF-axis components leads to various abnormalities and their key role in growth and development suggests epi/mutations or structural defects among IGF-axis genes can be associated with growth disorders and may explain some of the idiopathic short stature cases. Trend of patent filings indicate advent of recombinant technology for therapeutics.

Altered gene expression of VEGF, IGFs and H19 lncRNA and epigenetic profile of H19-DMR region in endometrial tissues of women with endometriosis

Background

Endometriosis, as chronic estrogen-dependent disease, is defined by the presence of endometrial-like tissue outside the uterus. Proliferation of endometrial tissue and neoangiogenesis are critical factors in development of endometriosis. Hence, vascular endothelial growth factor (VEGF) as well as insulin‐like growth factor 1 and 2 (IGF1, 2) may be involved as inducers of cellular proliferation or neoangiogenesis. Imprinted long noncoding RNA H19 (lncRNA H19) has been suggested to be involved in pathogenesis of endometriosis via regulation of cellular proliferation and differentiation. Epigenetic aberrations appear to play an important role in its pathogenesis. The present study was designed to elucidate VEGF, IGF1, IGF2 and H19 lncRNA genes expression and epigenetic alterations of differentially methylated region (DMR) of H19 (H19-DMR) regulatory region in endometrial tissues of patients with endometriosis, in comparison with control women.

Methods

In this case–control study, 24 women with and without endometriosis were studied for the relative expression of VEGF, IGF1, IGF2 and H19 lncRNA genes using real-time polymerase chain reaction (PCR) technique. Occupancy of the MeCP2 on DMR region of H19 gene was assessed using chromatin immunoprecipitation (ChIP), followed by real-time PCR.

Results

Genes expression profile of H19, IGF1 and IGF2 was decreased in eutopic and ectopic endometrial tissues of endometriosis group, compared to the control tissues. Decreased expression of H19 in ectopic samples was significant in comparison with the controls (P < 0.05). Gene expression of VEGF was increased in eutopic tissues of endometriosis group, compared to control group. Whereas its expression level was lower in ectopic lesions versus eutopic and control endometrial samples. ChIP analysis revealed significant and nearly significant hypomethylation of H19-DMR region II in eutopic and ectopic samples, compared to the control group respectively. This epigenetic change was aligned with expression of IGF2. While methylation of H19-DMR region I was not significantly different between the eutopic, ectopic and control endometrial samples.

Conclusion

These data showed that VEGF, IGF1, IGF2 and H19 lncRNA genes expression and epigenetic alterations of H19 lncRNA have dynamic role in the pathogenesis of endometriosis, specifically in the way that hypomethylation of H19-DMR region II can be involved in IGF2 dysregulation in endometriosis.

IGF1R is a mediator of sex-specific metabolism in mice: Effects of age and high-fat diet

OBJECTIVE

We aimed to investigate the short and long-term metabolic consequences of IGF1R systemic gene deficiency in mice.

METHODS

UBC-CreERT2, Igf1r^fl/fl mutant mice were used to suppress IGF1R signaling in adult tissues by inducing postnatal generalized Igf1r deletion with tamoxifen. Animals were analyzed at two different ages: i) 13-weeks old young mice, and ii) 12-months old middle-aged mice. In addition, the effects of 10 weeks-long high-fat diet (HFD) were investigated in middle-aged mice.

RESULTS

Young IGF1R-deficient mice were insulin-resistant, with high IGF1, growth hormone (GH) and IGFBP3, as well as low IGFBP2 circulating levels. Males also presented increased triglycerides in liver. In contrast, middle-aged mice did not clearly show all of these alterations, suggesting possible compensatory effects. Middle-aged IGF1R-deficient male mice were able to counteract the negative effects induced by aging and HFD in adiposity, inflammation and glucose metabolism. A metabolic sexual dimorphism dependent on IGF1R was observed, especially in middle-aged mice.

CONCLUSIONS

These results demonstrate that IGF1R is involved in metabolic homeostasis, with effects modulated by diet-induced obesity and aging in a sex dependent manner. Thus, IGF1R deficiency in mice is proposed as a useful tool to understand metabolic alterations observed in patients with IGF1R gene deletions.

Association of decreased sperm motility and increased seminal plasma IGF-I, IGF-II, IGFBP-2, and PSA levels in infertile men

PURPOSE

Previous studies have suggested the involvement of serum insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) in the regulation of the female reproductive system. Little is known of these peptides in the seminal plasma (SP) of men and their potential effects on fertility. We assessed SP levels of these peptides in infertile men with low sperm motility (asthenozoospermic; AZ) and low sperm counts (oligozoospermic; OZ), its effects on in vivo sperm motility, and whether there is a correlation with aging.

METHODS

Twenty-eight infertile men (AZ; n = 18 and OZ; n = 10) and 20 fertile normozoospermic (NZ) men were studied. Seminal plasma IGF-I, IGF-II, IGFBP-2, IGFBP-3, and prostate-specific antigen (PSA) levels were measured, and spermatozoa mRNA transcript patterns were examined.

RESULTS

Asthenozoospermic men had higher SP IGF-I, IGF-II, IGFBP-2, and PSA levels than NZ and OZ men, whereas SP IGFBP-3 levels were similar between the three groups. Sperm count positively correlated with SP IGF-I, IGF-II, and IGFBP-2; sperm motility negatively correlated with SP IGF-II and IGFBP-2; and age correlated positively with SP IGF-II. The expression of IGF-I and IGF-II mRNA and mRNA receptors was detectable, but no variations in transcript levels were noted.

CONCLUSION

Decreased sperm motility, but not sperm count, in infertile AZ men is associated with increased SP IGF-I, IGF-II, IGFBP-2, and PSA levels. Changes in SP IGFs and their interactions with IGFBPs and IGF receptors, and PSA levels suggest a role of these SP peptides in modulating sperm motility and possibly prostate disease development in aging men.

Environmental estrogens inhibit the expression of insulin-like growth factor mRNAs in rainbow trout in vitro by altering activation of the JAK-STAT, AKT-PI3K, and ERK signaling pathways

Environmental estrogens (EE) have been found to disrupt a host of developmental, reproductive, metabolic, and osmoregulatory process in a wide-range of animals, particularly those in aquatic ecosystems where such compounds concentrate. Previously, we showed that EE inhibited post-embryonic organismal growth of rainbow trout in vivo, but the precise mechanism(s) through which EE exert their growth inhibiting effects remain unknown. In this study, we used rainbow trout (Oncorhynchus mykiss) as a model to investigate the direct effects of 17β-estradiol (E2), β-sitosterol (βS), and 4-n-nonylphenol (NP) on the synthesis of insulin-like growth factors (IGFs) and to elucidate the mechanism(s) by which EEs exert such effects. E2, βS, and NP significantly inhibited the expression of both IGF-1 and IGF-2 mRNAs in liver and gill in a time- and concentration-related manner. Although the response evoked by each EEs on the expression of IGF mRNAs was similar, the potency and efficacy varied with EE; the rank order potency/efficacy was as follows: E2 > NP > βS. The effects of EEs on the expression of IGF mRNAs was blocked by the estrogen receptor (ER) antagonist, ICI 182780. The mechanism(s) through which EEs inhibit IGF mRNA expression were investigated in isolated liver cells in vitro. EE treatment deactivated JAK, STAT, ERK, and AKT. Moreover, blockade of growth hormone (GH)-stimulated IGF expression by EE was accompanied by deactivation of JAK, STAT, ERK, and AKT. EEs also increased the expression of suppressor of cytokine signaling 2 (SOCS-2), a known inhibitor of JAK-2--an action that also was blocked by ICI 182780. These results indicate that EEs directly inhibit the expression of IGF mRNAs by disrupting GH post-receptor signaling pathways (e.g., JAK, STAT, ERK, and AKT) in an ER-dependent manner.

Insulin-like growth factors: Ligands, binding proteins, and receptors

BACKGROUND

The insulin-like growth factor family of ligands (IGF-I, IGF-II, and insulin), receptors (IGF-IR, M6P/IGF-IIR, and insulin receptor [IR]), and IGF-binding proteins (IGFBP-1-6) play critical roles in normal human physiology and disease states.

SCOPE OF REVIEW

Insulin and insulin receptors are the focus of other chapters in this series and will therefore not be discussed further. Here we review the basic components of the IGF system, their role in normal physiology and in critical pathology's. While this review concentrates on the role of IGFs in human physiology, animal models have been essential in providing understanding of the IGF system, and its regulation, and are briefly described.

MAJOR CONCLUSIONS

IGF-I has effects via the circulation and locally within tissues to regulate cellular growth, differentiation, and survival, thereby controlling overall body growth. IGF-II levels are highest prenatally when it has important effects on growth. In adults, IGF-II plays important tissue-specific roles, including the maintenance of stem cell populations. Although the IGF-IR is closely related to the IR it has distinct physiological roles both on the cell surface and in the nucleus. The M6P/IGF-IIR, in contrast, is distinct and acts as a scavenger by mediating internalization and degradation of IGF-II. The IGFBPs bind IGF-I and IGF-II in the circulation to prolong their half-lives and modulate tissue access, thereby controlling IGF function. IGFBPs also have IGF ligand-independent cell effects.

The Roles of Insulin-Like Growth Factor Binding Protein Family in Development and Diseases

The insulin-like growth factor (IGF) system comprises ligands of IGF-I/II, IGF receptors (IGFR), IGF binding proteins (IGFBPs), and IGFBP hydrolases. The IGF system plays multiple roles during various disease development as IGFs are widely involved in cell proliferation and differentiation through regulating DNA transcription. Meanwhile, IGFBPs, which are mainly synthesized in the liver, can bind to IGFs and perform two different functions: either inhibition of IGFs by forming inactive compounds with IGF or enhancement of the function of IGFs by strengthening the IGF-IGFR interaction. Interestingly, IGFBPs may have wider functions through IGF-independent mechanisms. Studies have shown that IGFBPs play important roles in cardiovascular disease, tumor progression, fetal growth, and neuro-nutrition. In this review, we emphasize that different IGFBP family members have common or unique functions in numerous diseases; moreover, IGFBPs may serve as biomarkers for disease diagnosis and prediction.

IGF Bioregulation System in Benign and Malignant Thyroid Nodular Disease: A Systematic Review

BACKGROUND/AIM

The insulin-like growth factor bioregulation system is implicated in cancer biology. Herein, we aim to review the evidence on the expression of the insulin-like growth factor 1 and 2 (IGF1 and IGF2), their receptors (IGF-Rs) and IGF-binding proteins (IGFBPs) in thyroid tissue and their possible association with benign and malignant thyroid nodular diseases.

MATERIALS AND METHODS

We systematically reviewed Pubmed and Scopus databases up to May 2020. A total of 375 articles were retrieved and analyzed.

RESULTS

Among 375 articles, 45 were included in this systematic review study. IGF1 was investigated in 31 studies, IGF2 in 1, IGF1 receptor in 15 and IGF-binding proteins in 13 articles. IGF1 expression in humans was dependent on the number and compound of benign nodules as well as the method of measurement. In differentiated thyroid carcinoma, a positive correlation between IGF1 and immunohistological stage was documented in some studies while in others only a positive trend was observed. IGF-1R and IGFBPs expression was higher in malignant rather than benign lesions. There was only a positive trend for increased IGF2 expression in malignancy, while IGFBPs were in most studies statistically increased in various cancer types compared to benign nodular disease.

CONCLUSION

The present data demonstrate that in most studies there is statistically positive expression of IGF-1 and less of IGF-2 in thyroid cancer compared to normal thyroid tissue.

Identification of a Prognostic Signature Based on the Expression of Genes Related to the Insulin Pathway in Early Breast Cancer

Introduction

Insulin and the insulin-like growth factor (IGF) family play a key role in breast cancer (BC).

Objective

In this study, we evaluated on a genomic scale the potential prognostic value of insulin signaling in early BC.

Methods

Candidate genes were selected from the published literature and gene expression profiling experiments. Three publicly available BC datasets, containing gene expression data on 502 cases, were used to test the prognostic ability of the score. The gene signature was developed on GSE1456, containing microarray data from 159 patients, split into a training set (102 breast tumors) and a validation set (n = 57). GSE3494 and GSE2990 (350 patients) were used for external validation. Univariate Mann-Whitney test was used to identify genes differentially expressed between relapsed and nonrelapsed patients. Expression of genes significantly correlated with relapse was combined in a linear score. Patients were classified as low or high risk with respect to the median value.

Results

On the training set, 15 genes turned out to be differentially expressed: 8-year disease-free survival (DFS) was 51 and 91% in the high- and low-risk group (p < 0.001), respectively. In the validation set, DFS was 97 and 54% (p = 0.009), respectively. External validation: 8-year DFS was 72 and 61%, respectively, in GSE3494 (p = 0.03) and 74 and 55% in GSE2990 (p = 0.03). By multivariate analyses, the insulin signature was significantly associated with DFS, independently of age, hormone receptor status, nodal status, and grade.

Conclusions

Our findings indicate that the insulin pathway is involved in BC prognosis at a genomic level and provide a window of selectivity for preventive and treatment strategies targeting the insulin/IGF pathway in BC patients.

Normal Growth despite Combined Pituitary Hormone Deficiency

BACKGROUND

The paradox of normal growth despite a lack of growth hormone (GH) is an unexplained phenomenon described in some pathological (sellar, suprasellar, and hypothalamic disorders) and overgrowth syndromes. It has been suggested that the paradoxical growth is due to other GH variants, GH-like moieties, prolactin, insulin, insulin-like growth factors (IGFs), and unidentified serum factors or growth mechanisms. The objective of this study was to determine the mechanism underlying this normal growth without GH.

CASE DESCRIPTION

We describe here growth, hormonal, and genetic analyses for an adolescent boy with panhypopituitarism who achieved an adult height above his genetic potential.

RESULTS

Normal growth was observed despite low serum GH, IGF-I, IGF-II, IGF binding protein 3 (IGFBP-3) and acid labile subunit (ALS) concentrations, but the IGF-II/IGFBP-3 molar ratio was slightly high. Panhypopituitarism was associated with a heterozygous missense mutation of HESX1, with variable penetrance in heterozygous relatives. Exome analysis detected heterozygous missense mutations of various genes involved in intracellular signaling pathways. The growth-promoting activity of the patient's serum was unable to induce AKT phosphorylation in the MCF-7 cell line.

CONCLUSION

The high IGF-II/IGFBP-3 molar ratio was not the cause of the sustained high growth velocity, due to the low affinity of IGF-II for IGF type 1 receptor. The key finding was the HESX1 mutation, as similar cases have been described before, suggesting a common mechanism for growth without GH. However, the variable penetrance of this variant in heterozygous relatives suggests that modifier genes or mechanisms involving combinations with mutations of other genes involved in intracellular signaling pathways might be responsible.

Dynamics of gene expression of hormones involved in the growth of broiler chickens in response to the dietary protein and energy changes

The synergy between the genetic potential and the nutrient intake determines the growth performance of meat-type chicken and nutrigenomics approach helps us understand the response of candidate genes of growth in chicken to dietary manipulations. The current study aimed to assess the growth performance and expression of hepatic growth related genes in the naked neck broiler chicken in response to different dietary energy and protein levels with a hypothesis that high plane of nutrition enhances both of these positively. The results revealed that birds have shown significantly better growth performance under high protein (HP) and high energy (HE) dietary regime. The expression profiles of the genes studied revealed upregulation of IGF-1, IGF-2, and GH under dietary HP and HE regime relative to other protein and energy levels with greater upregulation at 3rd week than the 1st and 5th week of age of birds. The IGFR and GHR mRNA expression was significantly higher under HP and HE dietary regimen with an increasing and decreasing trend from 1st to 5th week of age, respectively. A consistent and significant downregulation of IGFBP-2 was observed under HP and HE regime throughout the feeding trial. The myostatin expression was higher at 3rd week of age followed by 1st week expression. The HP and HE as well as LP (Low protein) and HE diet resulted in significant upregulation of myostatin gene expression in liver. In support to the set hypothesis of this study the high protein and high energy diet resulted in better growth performance of broiler chickens with corresponding upregulation of IGF-1, IGF-2, IGFR, GH, GHR, and Myostatin gene expression and downregulation of IGFBP-2 in liver.

Unravelling the insulin-like growth factor I-mediated photoprotection of the skin

Chronic exposure of human skin to solar ultraviolet radiation (UVR) induces a range of biological reactions which may directly or indirectly lead to the development of skin cancer. In order to overcome these damaging effects of UVR and to reduce photodamage, the skin's endogenous defence system functions in concert with the various exogenous photoprotectors. Growth factors, particularly insulin-like growth factor-I (IGF-I), produced within the body as a result of cellular interaction in response to UVR demonstrates photoprotective properties in human skin. This review summarises the impact of UVR-induced photolesions on human skin, discusses various endogenous as well as exogenous approaches of photoprotection described to date and explains how IGF-I mediates UVR photoprotective responses at the cellular and mitochondrial level. Further, we describe the current interventions using growth factors and propose how the knowledge of the IGF-I photoprotection signalling cascades may direct the development of improved UVR protection and remedial strategies.

Tcf7l1 Acts as a Suppressor for the Self-Renewal of Liver Cancer Stem Cells and Is Regulated by IGF/MEK/ERK Signaling Independent of β-Catenin

Tcf7l1, which is a key effector molecule of the Wnt/β-catenin signaling pathway, is highly expressed in various cancers, and it promotes tumor growth. In this study, we demonstrated that unlike its tumor-promoting effects in several other types of cancers, Tcf7l1 expression is downregulated in hepatocarcinoma compared with their adjacent nontumor counterparts. Underexpression of Tcf7l1 is correlated with poorer survival. In liver cancer stem cell (CSC) populations, Tcf7l1 expression is downregulated. Ectopic expression of Tcf7l1 attenuates the self-renewal abilities of liver CSCs. Mechanistically, Tcf7l1 regulates the self-renewal abilities of liver CSCs through transcriptional repression of the Nanog gene, and the effect is independent of β-catenin. Moreover, we found that Tcf7l1 expression is controlled by extracellular insulin-like growth factor (IGF) signaling, and we demonstrated for the first time that IGF signaling stimulates Tcf7l1 phosphorylation and degradation through the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway. Overall, our results provide some new insights into how extracellular signals modulate the self-renewal of liver CSCs and highlight the inhibitory roles of Tcf7l1 in cancer. Stem Cells 2019;37:1389-1400.

Involvement and expression of growth hormone/insulin-like growth factor member mRNAs in the ovarian development of turbot (Scophthalmus maximus)

Accumulating evidence suggests that the growth hormone (GH)/insulin-like growth factor (IGF) system participates in fish reproduction. To understand the physiological functions of the GH/IGF system, the mRNA expression profiles of all known members of the GH/IGF system, including hepatic and ovarian gh, GH receptor (ghr), IGFs (igf-i, igf-ii), IGF-I receptor (igf-ir) and IGF binding protein (igfbp1, igfbp2), pituitary gh, and hepatic vitellogenin (vtg) were investigated during ovarian development in turbot Scophthalmus maximus. Results showed that ghr, igf-i, igf-ii, igf-ir, and igfbp2 were expressed in the liver and ovary, whereas igfbp1 and gh were undetected. The hepatosomatic index (HSI) and gonadosomatic index (GSI) gradually increased and peaked during the late vitellogenesis (Latvtg) and migratory nucleus (Mig-nucl) stages, respectively. The mRNA expression profiles of ovarian ghr, igf-ii, hepatic igf-ir, vtg, and pituitary gh were similar to the HSI; ovarian igf-i and igf-ir expression was close to the GSI. However, the hepatic mRNA levels of ghr, igf-i, and igf-ii peaked at the early vitellogenesis (Evtg) stage, and then drastically declined during ovarian development. The mRNA expression of hepatic igfbp2 decreased and reached the lowest at the atresia (Atre) stage, whereas that of ovarian igfbp2 increased and peaked at Latvtg stage. Furthermore, significant correlations between pituitary gh, ovarian ghr, igf-i, and igf-ii, and hepatic ghr, igf-i, igf-ir, and igf-ii were observed, respectively. These results suggest that GH/IGF members appear to play distinct roles in the regulation of ovarian development in turbot and will be valuable for fish reproduction and broodstock management of aqua-cultured fish species.

Deregulated microRNAs and Adiponectin in Postmenopausal Women with Breast Cancer

BACKGROUND

Obesity is a risk factor for breast cancer (BC). Some mechanisms through which obesity can lead to cancer development are insulin-like growth factors (IGFs), adipokines, and microRNAs (miRs). The objective of the study was to determine whether miR-17-5p, miR-195-5p, and miR-221-3p expressions were deregulated in serum samples of obese and nonobese postmenopausal women with BC. In addition, insulin, adiponectin, leptin and IGFs were analyzed.

METHODS

Fifty postmenopausal women with newly diagnosed BC and 50 postmenopausal healthy women were evaluated. Differences in miRs between BC and healthy cases and between obese and lean participants were analyzed. Receiver operating characteristic curves for miRs for discriminating patients with or without BC were established, and relationships between the miRs, adipokines, and breast tumor characteristics were also investigated.

RESULTS

miR-17-5p and miR-195-5p were higher in patients with BC in comparison to the controls, while miR-221-3p and adiponectin were significantly lower. Increased levels of miR-195-5p allowed the differentiation of BC from controls with a sensitivity of 83.3 and a specificity of 78.3%, and were associated with lobular and poorly differentiated cancer. There was no difference in miRs levels between obese and lean groups.

CONCLUSIONS

Circulating miRs and adiponectin were deregulated in postmenopausal women with BC.

Modeling gene-environment interactions in longitudinal family studies: a comparison of methods and their application to the association between the IGF pathway and childhood obesity

BACKGROUND

The interactive effect of the IGF pathway genes with the environment may contribute to childhood obesity. Such gene-environment interactions can take on complex forms. Detecting those relationships using longitudinal family studies requires simultaneously accounting for correlations within individuals and families.

METHODS

We studied three methods for detecting interaction effects in longitudinal family studies. The twin model and the nonparametric partition-based score test utilized individual outcome averages, whereas the linear mixed model used all available longitudinal data points. Simulation experiments were performed to evaluate the methods' power to detect different gene-environment interaction relationships. These methods were applied to the Quebec Newborn Twin Study data to test for interaction effects between the IGF pathway genes (IGF-1, IGFALS) and environmental factors (physical activity, daycare attendance and sleep duration) on body mass index outcomes.

RESULTS

For the simulated data, the twin model with the mean time summary statistic yielded good performance overall. Modelling an interaction as linear when the true model had a different relationship influenced power; for certain non-linear interactions, none of the three methods were effective. Our analysis of the IGF pathway genes showed suggestive association for the joint effect of IGF-1 variant at position 102,791,894 of chromosome 12 and physical activity. However, this association was not statistically significant after multiple testing correction.

CONCLUSIONS

The analytical approaches considered in this study were not robust to different gene-environment interactions. Methodological innovations are needed to improve the current methods' performances for detecting non-linear interactions. More studies are needed in order to better understand the IGF pathway's role in childhood obesity development.

Multiplex PCR for the rapid detection of insulin-like growth factor in the Pacific oyster, Crassostrea gigas: a useful indicator for growth assessment

Insulin-like growth factor (IGF) expression plays a critical role in the endocrine regulation of proliferation, differentiation, and growth in shellfish as well as in fish. The Pacific oyster, Crassostrea gigas, is a significant aquaculture species that comprises a large percentage of the Korean shellfish industry; moreover, its growth is economically important in aquaculture. However, when measuring the growth rate in shellfish, the soft tissue weight is difficult to determine because of the shell weight. In the present study, we describe an indirect method of measuring the growth rate using multiplex polymerase chain reaction (PCR) and analyzing levels of molluscan insulin-related peptide (MIP), the acid labile subunit of the IGF-binding protein complex (IGFBP ALS), and insulin-related peptide receptor (CIR) in Pacific oysters. The predicted sizes of amplicons were 776, 537, 380, and 198 bp, and the detection limit of the annealing temperatures was confirmed to be 65 °C. The annual expression of MIP and IGFBP ALS in tissues reached high levels in the winter following the condition index (CI). MIP and IGFBP ALS in male gonads and CIR in female gonads were related to the CI. This newly improved multiplex PCR provides an indirect measure of the growth rate; thus, it can be used to rapidly assess the growth rate. In addition, this method can supplement traditional growth data from oyster farms.

Concise Review: Heart-Derived Cell Therapy 2.0: Paracrine Strategies to Increase Therapeutic Repair of Injured Myocardium

Despite progress in cardiovascular medicine, the incidence of heart failure is rising and represents a growing challenge. To address this, ex vivo proliferated heart-derived cell products have emerged as a promising investigational cell-treatment option. Despite being originally proposed as a straightforward myocyte replacement strategy, emerging evidence has shown that cell-mediated gains in cardiac function are leveraged on paracrine stimulation of endogenous repair and tissue salvage. In this concise review, we focus on the paracrine repertoire of heart-derived cells and outline strategies used to boost cell potency by targeting cytokines, metabolic preconditioning and supportive biomaterials. Mechanistic insights from these studies will shape future efforts to use defined factors and/or synthetic cell approaches to help the millions of patients worldwide suffering from heart failure. Stem Cells 2018;36:1794-10.

Characterization of igf1 and igf2 genes during maraena whitefish (Coregonus maraena) ontogeny and the effect of temperature on embryogenesis and igf expression

The insulin-like growth factors IGF-1 and IGF-2 play important roles in the growth, development, and metabolism of teleost fish. We isolated cDNA sequences of igf1, and igf2 genes from maraena whitefish. We quantified the mRNA and protein expressions of IGFs in different tissues of marketable juvenile maraena whitefish. Moreover, we analyzed the gene expression profiles during maraena whitefish development from unfertilized egg to fingerling and examined the effect of incubation temperature on igf1, and igf2 gene expression during embryonic and early larval development. Transcripts encoding IGF-1 or IGF-2 were detected in all tested tissues, with the greatest abundance in the liver. We measured higher igf2 than igf1 copy numbers in all tissues and at all developmental stages examined, even at advanced juvenile stages. Using the Western blot technique, we demonstrated that several isoforms of IGF-1 are expressed in the liver and gills but not in muscle tissue, indicating tissue-specific protein expression of IGF-1. We observed an accelerated embryonic development with increasing temperature, resulting in shortened hatching periods. Out of the three tested temperatures, we observed the highest hatching rate, larval hatching size, and larval growth at 6 °C. At 9 °C, hatching rate, larval hatching size and larval growth were reduced compared to the values we observed at 4 °C and 6 °C, since incubation temperature might have exceeded the optimum. To our knowledge, our data show for the first time that both igf1 and igf2 expression were upregulated due to elevated incubation temperature within embryonic development of fish. Further, we found significantly higher igf expression for the best-developing larvae (6 °C group) at specific life stages of maraena whitefish.

Insulin-Like Growth Factors and Metabolic Syndrome in Obese Children

BACKGROUND/AIMS

Insulin-like growth factor (IGF)-I is related to cardiometabolic risk in adults, whereas the metabolic role of IGF-II is unclear. The aim of this study was to assess IGFs in obese children and correlate them with metabolic syndrome (MetS) components.

METHODS

This is a retrospective study including 574 obese children (11.34 ± 3.16 years). All subjects underwent complete anthropometry and biochemical assessment. In a subgroup of 136 subjects, body composition was evaluated. IGF-I was measured in 300 obese subjects and IGF-II in 77 obese and 15 lean children. 177 subjects were divided according to the presence of 1 or more MetS criteria: group 1, subjects with 1 MetS criterion; group 2, subjects with 2 components; and group 3, subjects with MetS diagnosis.

RESULTS

IGF-I, IGF-II, and IGF-I/insulin-like growth factor-binding protein-3 ratio were not different among subjects with an increasing number of MetS criteria and were not associated with single components of MetS as well as with body composition parameters. In children younger than 10 years, IGF-I directly correlated with high-density lipoprotein cholesterol (p < 0.005) even after controlling for confounders. IGF-II was significantly higher in obese children and correlated with parameters of insulin sensitivity (p < 0.05).

CONCLUSION

IGFs were neither related to MetS nor to body composition parameters in obese children. Further studies are needed to clarify the mechanisms underlying the relationship between IGF-II and insulin sensitivity.

Effects of dietary advice on insulin-like growth factors among healthy newborns

OBJECTIVES

In fetal life, insulin, insulin-like growth factor (IGF) 1, IGF 2 and IGF-binding protein (IGFBP) 3 are essential growth factors. The purpose of this study is to investigate the effects of dietary intervention on insulin-like growth factors in the cord blood of neonates.

METHODS

The study involved 52 pregnant women who were followed up in Gazi University Medical School Hospital at Ankara, Turkey. They were randomly divided into two groups: The experimental group was involved in nutrition education. We measured IGF 1, IGF 2 and IGFBP 3 concentrations in cord blood from 52 neonates.

RESULTS

In the experimental group, cord serum levels of IGF 1, IGF 2 were observed to be higher than that of control group.

CONCLUSION

Dietary advice had positive effects on the cord serum IGF 1 and IGF 2 concentrations. Dietary advice during pregnancy proved to be effective in fetal development.

A journey through growth plates: tracking differences in morphology and regulation between the spine and the long bones in a pig model

BACKGROUND CONTEXT

The process of linear growth is driven by axial elongation of both long bones and vertebral bodies and is accomplished by enchondral ossification. Differences in regulation between the two skeletal sites are mirrored clinically by the age course in body proportions. Whereas long bone growth plates (GPs) can easily be discriminated, vertebral GPs are part of the cartilaginous end plate, which typically shows important species differences.

PURPOSE

The objective of this study was to describe and compare histologic, histomorphometric, and regulatory characteristics in the GPs of the spine and the long bones in a porcine model.

MATERIALS AND METHODS

Two- and six-week-old piglet GPs of three vertebral segments (cervical, thoracic, and lumbar) and eight long bones (proximal and distal radius, humerus, tibia, and femur) were analyzed morphometrically. Further, estrogen receptors, proliferation markers, and growth factor expressions were examined by immunohistochemistry.

RESULTS

Individual vertebral GPs were smaller in width and contained fewer chondrocytes than long bone GPs, although their proliferation activity was similar. Whereas the expression pattern of growth hormone-associated factors such as insulin-like growth factor (IGF)-1 and IGF-1 receptor (IGF-1R) was similar, estrogen receptor (ER)-ß and IGF-2 were distinctly expressed in the vertebral samples.

CONCLUSIONS

Vertebral GPs display differential growth, with measurements similar to the slowest-growing GPs of long bones. Further investigation is needed to decipher the molecular basis of the differential growth of the spine and the long bones. Knowledge on the distinct mechanism will ultimately improve the assessment of clinically essential characteristics of spinal growth, such as vertebral elongation potential and GP fusion.

Post-diagnosis serum insulin-like growth factors in relation to dietary and lifestyle changes in the Prostate testing for cancer and Treatment (ProtecT) trial

PURPOSE

The insulin-like growth factor (IGF) system is modifiable by diet and lifestyle, and has been linked to prostate cancer development and progression.

METHODS

We conducted a prospective cohort study of 621 men diagnosed with localized prostate cancer to investigate the associations of dietary and lifestyle changes with post-diagnosis circulating levels of IGF-I and IGFBP-3. We used analysis of covariance to estimate the associations, controlling for baseline IGF-I or IGFBP-3, respectively.

RESULTS

Mean IGF-I levels were 6.5% (95% CI -12.8, -0.3%, p = 0.04) lower in men who decreased their protein intake after diagnosis compared to men who did not change. Men who changed their fruit and vegetable intake had lower IGF-I levels compared to non-changers [Decreased intake: -10.1%, 95% CI -18.4, -1.8%, p = 0.02; Increased intake: -12.0%, 95% CI -18.4, -1.8%, p = 0.002]. IGFBP-3 was 14.6% (95% CI -24.5, -4.8%, p = 0.004) lower in men who achieved a healthy body mass index after diagnosis. Men who became inactive had 9.5% higher average IGF-I levels (95% CI 0.1, 18.9%, p = 0.05).

CONCLUSIONS

Decreased protein intake and body mass index, and increased physical activity and fruit and vegetable intake, following a prostate cancer diagnosis were associated with reduced post-diagnosis serum IGF-I and IGFBP-3. Counterintuitively, reduced fruit and vegetable intake was also associated with reduced IGF-I, but with weak statistical support, possibly implicating chance. If confirmed in other studies, our findings may inform potential lifestyle interventions in prostate cancer. ProtecT was registered at International Standard Randomised Controlled Trial Registry, http://isrctn.org as ISRCTN20141297.

Does milk intake promote prostate cancer initiation or progression via effects on insulin-like growth factors (IGFs)? A systematic review and meta-analysis

PURPOSE

To establish whether the association between milk intake and prostate cancer operates via the insulin-like growth factor (IGF) pathway (including IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3).

METHODS

Systematic review, collating data from all relevant studies examining associations of milk with IGF, and those examining associations of IGF with prostate cancer risk and progression. Data were extracted from experimental and observational studies conducted in either humans or animals, and analyzed using meta-analysis where possible, with summary data presented otherwise.

RESULTS

One hundred and seventy-two studies met the inclusion criteria: 31 examining the milk-IGF relationship; 132 examining the IGF-prostate cancer relationship in humans; and 10 animal studies examining the IGF-prostate cancer relationship. There was moderate evidence that circulating IGF-I and IGFBP-3 increase with milk (and dairy protein) intake (an estimated standardized effect size of 0.10 SD increase in IGF-I and 0.05 SD in IGFBP-3 per 1 SD increase in milk intake). There was moderate evidence that prostate cancer risk increased with IGF-I (Random effects meta-analysis OR per SD increase in IGF-I 1.09; 95% CI 1.03, 1.16; n = 51 studies) and decreased with IGFBP-3 (OR 0.90; 0.83, 0.98; n = 39 studies), but not with other growth factors. The IGFBP-3 -202A/C single nucleotide polymorphism was positively associated with prostate cancer (pooled OR for A/C vs. AA = 1.22; 95% CI 0.84, 1.79; OR for C/C vs. AA = 1.51; 1.03, 2.21, n = 8 studies). No strong associations were observed for IGF-II, IGFBP-1 or IGFBP-2 with either milk intake or prostate cancer risk. There was little consistency within the data extracted from the small number of animal studies. There was additional evidence to suggest that the suppression of IGF-II can reduce tumor size, and contradictory evidence with regards to the effect of IGFBP-3 suppression on tumor progression.

CONCLUSION

IGF-I is a potential mechanism underlying the observed associations between milk intake and prostate cancer risk.

Control of leptin by metabolic state and its regulatory interactions with pituitary growth hormone and hepatic growth hormone receptors and insulin like growth factors in the tilapia (Oreochromis mossambicus)

Leptin is an important cytokine for regulating energy homeostasis, however, relatively little is known about its function and control in teleost fishes or other ectotherms, particularly with regard to interactions with the growth hormone (GH)/insulin-like growth factors (IGFs) growth regulatory axis. Here we assessed the regulation of LepA, the dominant paralog in tilapia (Oreochromis mossambicus) and other teleosts under altered nutritional state, and evaluated how LepA might alter pituitary growth hormone (GH) and hepatic insulin-like growth factors (IGFs) that are known to be disparately regulated by metabolic state. Circulating LepA, and lepa and lepr gene expression increased after 3-weeks fasting and declined to control levels 10days following refeeding. This pattern of leptin regulation by metabolic state is similar to that previously observed for pituitary GH and opposite that of hepatic GHR and/or IGF dynamics in tilapia and other fishes. We therefore evaluated if LepA might differentially regulate pituitary GH, and hepatic GH receptors (GHRs) and IGFs. Recombinant tilapia LepA (rtLepA) increased hepatic gene expression of igf-1, igf-2, ghr-1, and ghr-2 from isolated hepatocytes following 24h incubation. Intraperitoneal rtLepA injection, on the other hand, stimulated hepatic igf-1, but had little effect on hepatic igf-2, ghr1, or ghr2 mRNA abundance. LepA suppressed GH accumulation and gh mRNA in pituitaries in vitro, but had no effect on GH release. We next sought to test if abolition of pituitary GH via hypophysectomy (Hx) affects the expression of hepatic lepa and lepr. Hypophysectomy significantly increases hepatic lepa mRNA abundance, while GH replacement in Hx fish restores lepa mRNA levels to that of sham controls. Leptin receptor (lepr) mRNA was unchanged by Hx. In in vitro hepatocyte incubations, GH inhibits lepa and lepr mRNA expression at low concentrations, while higher concentration stimulates lepa expression. Taken together, these findings indicate LepA gene expression and secretion increases with fasting, consistent with the hormones function in promoting energy expenditure during catabolic stress. It would also appear that LepA might play an important role in stimulating GHR and IGFs to potentially spare declines in these factors during catabolism. Evidence also suggests for the first time in teleosts that GH may exert important regulatory effects on hepatic LepA production, insofar as physiological levels (0.05-1 nM) suppresse lepa mRNA accumulation. Leptin A, may in turn exert negative feedback effects on basal GH mRNA abundance, but not secretion.

Insulin-Like Growth Factors and Their Binding Proteins in Tumors and Ascites of Ovarian Cancer Patients: Association With Response To Neoadjuvant Chemotherapy

Purpose: Tumor cell growth and sensitivity to chemotherapy depend on many factors, among which insulin-like growth factors (IGFs) may play important roles. The aim of the present study was to evaluate the levels of insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) in primary tumors and ascites as predictors of response to neoadjuvant chemotherapy in ovarian cancer (OC) patients. Materials and Methods: Tumor tissue samples and ascitic fluid were obtained from 59 patients with advanced OC. The levels of IGF-I, IGF-II, IGFBP-3, IGFBP-4 and PAPP-A were determined using ELISA kits. Taking into account the data on expression of these IGF-related proteins and outcome, logistic regression was performed to identify predictors of response to neoajuvant chemotherapy. Results: Human ovarian tumors expressed IGFs, IGFBP-3, IGFBP-4 and PAPP-A and these proteins were also present in ascites fluid and associated with its volume. IGFs and IGFBPs in ascites and soluble PAPP-A might play a key role in ovarian cancer progression . However, levels of proteins of the IGF system in tumors were not significant predictors of objective clinical response (oCR). Univariate analysis showed that the level of IGF-I in ascites was the only independent predictor for oCR. Conclusion: The level of IGF-I in ascites was shown to be an independent predictor of objective clinical response to chemotherapy for OC patients treated with neoadjuvant chemotherapy and debulking surgery.

Protective potential of epigallocatechin-3-gallate against benign prostatic hyperplasia in metabolic syndrome rats

Epigallocatechin-3-gallate (EGCG) is a major catechin in green tea with functions of antioxidant, anti-proliferative, anti-inflammatory and attenuating metabolic syndrome. In this study, rat model of benign prostatic hyperplasia (BPH) accompanied with metabolic syndrome was induced by fed on high-fat diet for 12 weeks combined with testosterone injection (10mg/kg/d) from 9th to 12th weeks. EGCG was orally given from 9th to 12th weeks. Finally, the levels of glucose, total cholesterol, triglyceride, prostate weight, insulin-like growth factors (IGFs), inflammatory cytokines, antioxidant enzymes, and prostatic expression of IGF binding protein-3 (IGFBP-3) and peroxisome proliferator activated receptors (PPARs) were evaluated. It was found that EGCG significantly decreased the levels of glucose, total cholesterol, triglyceride, IGFs, and inflammatory cytokines, normalized the activities of antioxidant enzymes, as well as increased the prostatic expression of IGFBP-3 and PPARs. These results indicated that EGCG was able to exert anti-BPH activities in metabolic syndrome rats.

IGF-I and IGF-II effects on local IGF system and signaling pathways in gilthead sea bream (Sparus aurata) cultured myocytes

The insulin-like growth factors (IGFs) have a fundamental role in a vast range of functions acting through a tyrosine-kinase receptor (IGF-IR). IGFs in muscle can affect the expression of components of the local IGF system, myogenic regulatory factors (MRFs), proliferating (proliferating cell nuclear antigen, PCNA) or differentiating molecules (myosin heavy chain, MHC) and, lead to the activation of different signaling pathways. The response of all these genes to IGFs incubation at two different times in day 4 cultured myocytes of gilthead sea bream was analyzed. Both IGFs increased the expression of IGF-I and IGFBP-5, but showed different effects on the receptors, with IGF-I suppressing the expression of both isoforms (IGF-IRa and IGF-IRb) and IGF-II up-regulating only IGF-IRb. Moreover, the protein levels of PCNA and target of rapamycin (TOR) increased after IGF-II incubation, although a decline in Myf5 and a rise in MHC gene expression was caused by IGF-I. Taken together, these results provide evidence for the importance of IGFs on controlling muscle development and growth in gilthead sea bream and suggest that each IGF may be preferentially acting through a specific IGF-IR. Moreover, the data support the hypothesis that IGF-II has a more important role during proliferation, whereas IGF-I seems to be relevant for the differentiation phase of myogenesis.

Epigenetic regulation of insulin-like growth factor axis in hepatocellular carcinoma

The insulin-like growth factor (IGF) signaling pathway is an important pathway in the process of hepatocarcinogenesis, and the IGF network is clearly dysregulated in many cancers and developmental abnormalities. In hepatocellular carcinoma (HCC), only a minority of patients are eligible for curative treatments, such as tumor resection or liver transplant. Unfortunately, there is a high recurrence of HCC after surgical tumor removal. Recent research efforts have focused on targeting IGF axis members in an attempt to find therapeutic options for many health problems. In this review, we shed lights on the regulation of members of the IGF axis, mainly by microRNAs in HCC. MicroRNAs in HCC attempt to halt the aberrant expression of the IGF network, and a single microRNA can have multiple downstream targets in one or more signaling pathways. Targeting microRNAs is a relatively new approach for identifying an efficient radical cure for HCC.

IGF/STAT3/NANOG/Slug Signaling Axis Simultaneously Controls Epithelial-Mesenchymal Transition and Stemness Maintenance in Colorectal Cancer

Discovery of epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs) are two milestones in people exploring the nature of malignant tumor in recent decades. Although some studies have presented the potential connections between them, the link details, underneath their superficial correlation, are largely unknown. In this study, we identified a small subpopulation of NANOG-positive colorectal cancer (CRC) cells, and demonstrated that they exhibited characteristics of CSCs and EMT traits simultaneously. Furthermore, we found that NANOG was a core factor in regulating both of EMT and stemness in CRC cells, NANOG modulate EMT and metastasis by binding to Slug promoter and transcriptionally regulate Slug expression. For the first time, we demonstrated that NANOG was regulated by extracellular IGF signaling pathway via STAT3 phosphorylation in CRC. This coincides with that IGF receptor IGF-1R is often increasing expressed in malignant metastasis colon cancer. Taken together, our data define the crucial functions of IGF/STAT3/NANOG/Slug signaling axis in the progression of CRC by operating EMT and CSCs properties, which make them served as potential therapeutic targets for treatment of CRC.

Insulin/IGF signaling in Drosophila and other insects: factors that regulate production, release and post-release action of the insulin-like peptides

Insulin, insulin-like growth factors (IGFs) and insulin-like peptides (ILPs) are important regulators of metabolism, growth, reproduction and lifespan, and mechanisms of insulin/IGF signaling (IIS) have been well conserved over evolution. In insects, between one and 38 ILPs have been identified in each species. Relatively few insect species have been investigated in depth with respect to ILP functions, and therefore we focus mainly on the well-studied fruitfly Drosophila melanogaster. In Drosophila eight ILPs (DILP1-8), but only two receptors (dInR and Lgr3) are known. DILP2, 3 and 5 are produced by a set of neurosecretory cells (IPCs) in the brain and their biosynthesis and release are controlled by a number of mechanisms differing between larvae and adults. Adult IPCs display cell-autonomous sensing of circulating glucose, coupled to evolutionarily conserved mechanisms for DILP release. The glucose-mediated DILP secretion is modulated by neurotransmitters and neuropeptides, as well as by factors released from the intestine and adipocytes. Larval IPCs, however, are indirectly regulated by glucose-sensing endocrine cells producing adipokinetic hormone, or by circulating factors from the intestine and fat body. Furthermore, IIS is situated within a complex physiological regulatory network that also encompasses the lipophilic hormones, 20-hydroxyecdysone and juvenile hormone. After release from IPCs, the ILP action can be modulated by circulating proteins that act either as protective carriers (binding proteins), or competitive inhibitors. Some of these proteins appear to have additional functions that are independent of ILPs. Taken together, the signaling with multiple ILPs is under complex control, ensuring tightly regulated IIS in the organism.

Molecular characterization and transcriptional regulation by GH and GnRH of insulin-like growth factors I and II in white seabream (Diplodus sargus)

Insulin-like growth factors (IGF) I and II are key regulators of development, growth and reproduction in fish. In the present study we have cloned and characterized the cDNA and genomic sequences of IGF-I and IGF-II in the white seabream (Diplodus sargus). The igf1 and igf2 genes were encoded putatively by five and four exons, respectively. Moreover, the 5'-flanking upstream region of the igf1 gene contained highly conserved regulatory elements including HNF-1α, HNF-3β, CCAAT/enhancer binding protein (C/EBP) and the TATA box. The full-length cDNAs were 1225 and 1666 nucleotides long for igf1 and igf2, respectively. Sequence analysis identified the A-E domains as well as three spliced forms involving the E domain in exons 3-5. ORF identities were higher than 83% with respect to other fish orthologs. Expression analysis demonstrated that igf1 and its spliced forms were mostly expressed in liver, whereas the igf2 was expressed ubiquitously not detecting significant differences among the ten tissues analyzed. Hormonal treatments using the porcine GH demonstrated a sharply increase of both igf1 and igf2 mRNA levels in liver and gills at 30 min and 1h after injection. In the gonads, igf1 mRNA levels increased steadily with testis and ovary maturation. In contrast, igf2 transcript amounts were higher in immature stages (S1-S2). Hormonal treatments using GH and GnRH demonstrated that igf1 and igf2 expression were upregulated in the gonads. Overall, these data demonstrate that IGF-I and IGF-II are locally expressed in several tissues and regulated by key hormones of the somatotropic and gonadotropic axes.

Glomerulocystic Kidney Disease and Hepatoblastoma in an Infant: A Rare Presentation

Glomerulocystic kidney disease (GCKD) is a rare condition comprising heritable and non-heritable types [Oh et al.: Nephron 1986;43:299–302]. Hepatoblastoma is a sporadically occurring tumor of embryonal origin that is associated with overgrowth syndrome and renal cysts. A concurrent presentation of GCKD with hepatoblastoma was first described in 1989 [Rao et al.: Jpn J Surg 1989;19:583–585]. We report the simultaneous presentation of hepatoblastoma and GCKD in a 5-month-old child and explore the probability of insulin-like growth factors, insulin-like growth factor-binding protein and Beckwith-Wiedemann gene mutation as a putative cause.

Socioeconomic conditions across life related to multiple measures of the endocrine system in older adults: Longitudinal findings from a British birth cohort study

Background

Little is known about how socioeconomic position (SEP) across life impacts on different axes of the endocrine system which are thought to underlie the ageing process and its adverse consequences. We examined how indicators of SEP across life related to multiple markers of the endocrine system in late midlife, and hypothesized that lower SEP across life would be associated with an adverse hormone profile across multiple axes.

Methods

Data were from a British cohort study of 875 men and 905 women followed since their birth in March 1946 with circulating free testosterone and insulin-like growth factor-I (IGF-I) measured at both 53 and 60–64 years, and evening cortisol at 60–64 years. Indicators of SEP were ascertained prospectively across life—paternal occupational class at 4, highest educational attainment at 26, household occupational class at 53, and household income at 60–64 years. Associations between SEP and hormones were investigated using multiple regression and logistic regression models.

Results

Lower SEP was associated with lower free testosterone among men, higher free testosterone among women, and lower IGF-I and higher evening cortisol in both sexes. For example, the mean standardised difference in IGF-I comparing the lowest with the highest educational attainment at 26 years (slope index of inequality) was −0.4 in men (95% CI -0.7 to −0.2) and −0.4 in women (−0.6 to −0.2). Associations with each hormone differed by SEP indicator used and sex, and were particularly pronounced when using a composite adverse hormone score. For example, the odds of having 1 additional adverse hormone concentration in the lowest compared with highest education level were 3.7 (95% CI: 2.1, 6.3) among men, and 1.6 (1.0, 2.7) among women (P (sex interaction) = 0.02). We found no evidence that SEP was related to apparent age-related declines in free testosterone or IGF-I.

Conclusions

Lower SEP was associated with an adverse hormone profile across multiple endocrine axes. SEP differences in endocrine function may partly underlie inequalities in health and function in later life, and may reflect variations in biological rates of ageing. Further studies are required to assess the likely functional relevance of these associations.

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Socioeconomic position (SEP) across life was related to multiple hormone measures.

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Lower SEP was related to lower testosterone in men, higher testosterone in women.

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Lower SEP was related to lower IGF-I and higher evening cortisol in both sexes.

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SEP differences in multiple hormone axes may underlie later life health inequality.

Maternal insulin-like growth factor 1 and 2 differentially affect the renin-angiotensin system during pregnancy in the guinea pig

OBJECTIVE

Insulin-like growth factors (IGFs) are known to interact with the renin-angiotensin system (RAS). We previously demonstrated that administration of IGF1 to guinea pigs in early to mid pregnancy promotes placental function and fetal growth in mid to late gestation. Early administration of IGF2 had sustained, but not acute, effects on these parameters and also on placental structural differentiation. Here, we aimed to determine whether the IGFs interact with the placental RAS in early to mid gestation to modulate placental development and increase fetal growth and survival, and if IGF2 binding the IGF2R is implicated in the sustained effects of IGF2 treatment.

DESIGN

At day 20 of pregnancy, guinea pigs were infused with 1m g/kg/day of IGF1, IGF2, (Leu27)IGF2 or vehicle for 18days and sacrificed on either day 62 (late pregnancy) or during the infusion period on day 35 (early-mid pregnancy). Placental structure at day 35 was analyzed using morphometric technique and expression of RAS genes in the placenta and placental and plasma renin activity were measured at both time points.

RESULTS

Compared with vehicle at day 35 of gestation, IGF1 infusion reduced the total midsagittal cross-sectional area of the placenta (-17%, p = 0.02) and the labyrinth area (-22%, p = 0.014) but did not alter the labyrinth volume nor labyrinth:interlobium ratios. IGF2 treatment did not affect placental structure. IGF1 did not alter placental mRNA for any of the RAS genes quantified at day 35 (AGTR1, ACE, AGT, TGFB1) but increased TGFB1 expression by more than 16-fold (p = 0.005) at day 62. IGF2 increased placental expression of AGTR1 (+88%, p = 0.03) and decreased AGT (-73%, p = 0.01) compared with the vehicle-treated group at day 35, and both IGF2 and (Leu27)IGF2 increased expression of TGFB1 at day 62 by 9-fold (p = 0.016) and 6-fold (p = 0.019) respectively. Both IGFs increased the ratio of active:total placental renin protein (+22% p = 0.026 p = 0.038) compared to vehicle compared to vehicle at day 35 but not 62. At day 62, IGF2-treated mothers showed a marked increase in total plasma renin (+495%) and active renin (+359%) compared to vehicle but decreased the ratio of active to total renin by 41% (p = 0.042). (Leu27)IGF2-treated animals had higher levels of placental active renin (+73%, p = 0.001) and total renin (+71%, p = 0.001) compared with the vehicle control.

CONCLUSIONS

The data obtained in the current study suggest the potential for alternate roles for the induction of the RAS after IGF treatment. IGF1 and 2 treatments increase the activation of prorenin to renin in the placenta, possibly due to increased protease activity. In addition, IGF2 treatment in early pregnancy may enhance the maternal adaptation to pregnancy through stimulation of renin in the kidney. The sustained effects on placental differentiation and function after IGF2 treatment suggest therapeutic potential for exogenous administration of IGFs in improving pregnancy outcomes.

Influence of polymorphisms in insulin-like growth factor-1 on the risk of osteoporosis in a Chinese postmenopausal female population

We conducted a case-control study in a Chinese postmenopausal population, and explore the potential role of the promoter region variation of the IGF-1 gene in bone mineral density and osteoporosis risk. 485 postmenopausal women with a primary diagnosis of osteoporosis and 485 age-matched controls were selected between 2012 and 2014. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) was used for rs35767, rs2288377 and rs5742612 of IGF-1 genotyping. By conditional regression analysis, individuals carrying TT genotype and CT+TT genotype of rs35767 were found to be correlated with an elevated risk of osteoporosis, with adjusted ORs (95% CI) of 1.90 (1.23-2.93) and 1.35 (1.04-1.76), respectively. Our study found that CT+TT genotype of rs35767 was significantly associated with moderate increased risk of osteoporosis in smokers and drinkers, and the ORs (95% CI) were 2.11 (1.06-4.20) and 2.36 (1.29-4.32), respectively. We found that those carrying CT+TT genotype of rs35767 had a significant lower BMD levels at L1-L4 vertebrae, femoral neck, total hip and trochanter compared to those with CC genotype. Our study suggests that TT genotype and CT+TT genotype of IGF-I rs35767 were associated with risk of osteoporosis and BMD levels.

Alteration in pancreatic islet function in human immunodeficiency virus

Molecular mechanisms behind the defects in insulin production and secretion associated with antihuman immunodeficiency virus (anti-HIV) therapy and the development of HIV-associated lipodystrophy syndrome (HALS) are discussed in this article. Data suggesting insulin resistance on the beta cell and defects in first-phase insulin release of HALS patients are presented. Hepatic extraction of insulin, nonglucose insulin secretagogues and insulin-like growth factor release may exert influence on the demand of circulating insulin and on insulin secretion in HIV-infected patients. Finally, the paucity in understanding the incretin effects in HIV and HIV therapy in relation to insulin secretion is highlighted.

Oestrogen and insulin-like growth factors during the reproduction and growth of the tilapia Oreochromis niloticus and their interactions

Oestrogens and insulin-like growth factors (Igfs) play both a central role in the regulation of reproduction and growth and can interact especially in species showing a clear-cut sex-linked growth dimorphism (SGD) like in tilapia. Aromatase is essential in ovarian differentiation and oogenesis since it controls oestrogen synthesis. During tilapia sex differentiation, aromatase cyp19a1a expression increases from 9 days post-fertilization (dpf), resulting in high oestradiol level. High temperature, exogenous androgens or aromatase inhibitors override genetic sex differentiation inducing testes development through the suppression of cyp19a1a gene expression and aromatase activity. Supplementation with 17ß-oestradiol (E2) of gonadectomized juveniles induced a sustained and higher E2 plasma level than in intact or gonadectomized controls and both sexes showed reduced growth. Juvenile and mature females treated with the aromatase inhibitor 1,4,6-androstatriene-3,17-dione had 19% lower E2 plasma level compared to controls and they showed a 32% increased growth after 28 days of treatment. Altogether, these data suggest that E2 inhibits female growth leading to the SGD. Regarding Igf-1, mRNA and peptide appeared in liver at ∼ 4 dpf and then in organs involved in growth and metabolism, indicating a role in early growth, metabolism and organogenesis. Gonad igf-1 showed an early expression and the peptide could be detected at ∼ 7 dpf in somatic cells. It appeared in germ cells at the onset of ovarian (29 dpf) and testicular (52 dpf) meiosis. In testis, Igf-1 together with steroids may regulate spermatogenesis whereas in ovary it participates in steroidogenesis regulation. Igf-1 and Igf-2 promote proliferation of follicular cells and oocyte maturation. Igf-3 expression is gonad specific and localized in the ovarian granulosa or testicular interstitial cells. In developing gonads igf-3 is up-regulated in males but down-regulated in females. In contrast, bream Gh injections increased igf-1 mRNA in male and female liver and ovaries but gonadal igf-3 was not affected. Thus, local Igf-1 and Igf-2 may play crucial roles in the formation, development and function of gonads while Igf-3 depending on the species is involved in male and female reproduction. Furthermore, precocious ethynylestradiol (EE) exposure induced lasting effects on growth, through pituitary gh inhibition, local suppression of igf-1 expression and in testis only down-regulation of igf-3 mRNA. In conclusion, SGD in tilapia may be driven through an inhibitory effect due to E2 synthesis in female and involving Igfs regulation.

Role of IGF-I, IGF-II and IGFBP-3 in lung function of males: the Caerphilly Prospective Study

Insulin-like growth factors are peptide hormones that have an endocrine role in the development, growth and repair of human tissues including the respiratory tract. To date, only one population study exists which found positive cross-sectional associations with IGF-I and higher lung volumes. We hypothesised that higher IGF-I, IGF-II, IGFBP-3 and IGF molar ratio would be associated with better cross-sectional and longitudinal lung function. We examined cross-sectional (n=843) and prospective associations (n=717) between IGF-I, IGF-II, IGFBP-3 and IGF molar ratio with lung function in the Caerphilly Prospective Study (CaPS) from blood samples obtained around 1986, with spirometry (forced expiratory volume in one second (FEV1) and forced vital capacity (FVC)) performed in the same year and around 2003. Higher IGF molar ratio was associated with improved FEV1/FEV ratio cross-sectionally in both simple (0.007, 95% CI 0.001-0.013, P=0.02) and fully adjusted (0.001, 95% CI 0.001-0.012, P=0.03) models. With the exception of IGFBP-3 and FEV1/FVC in the simple model (0.009, 95% CI 0.001-0.018, P=0.04) all prospective associations between IGF and spirometric measures were consistent with chance. In this study of men, higher IGF molar ratio was associated with improved cross-sectional lung function, although these findings were not replicated prospectively. Further work is required with repeat IGF sampling during follow up to see if IGF levels play any role in predicting future lung function through the life course.

Administration of growth hormone and nandrolone decanoate alters mRNA expression of the GABAB receptor subunits as well as of the GH receptor, IGF-1, and IGF-2 in rat brain

OBJECTIVE

The illicit use of anabolic androgenic steroids (AAS), especially among young adults, is of major concern. Among AAS users it is common to combine the AAS nandrolone decanoate (ND), with intake of growth hormone (GH) and a connection between gonadal steroids and the GH system has been suggested. Both AAS and GH affect functions in the brain, for example those associated with the hypothalamus and pituitary, and several GH actions are mediated by growth factors such as insulin-like growth factor 1 (IGF-1) and insulin-like growth factor 2 (IGF-2). The GABAergic system is implicated in actions induced by AAS and previous studies have provided evidence for a link between GH and GABAB receptors in the brain. Our aim was to examine the impact of AAS administration and a subsequent administration of GH, on the expression of GABAB receptors and important GH mediators in rat brain.

DESIGN

The aim was to investigate the CNS effects of a high-dose ND, and to study if a low, but physiological relevant, dose of GH could reverse the ND-induced effects. In the present study, male rats were administered a high dose of ND every third day during three weeks, and subsequently the rats were given recombinant human GH (rhGH) during ten days. Quantitative PCR (qPCR) was used to analyze gene expression in hypothalamus, anterior pituitary, caudate putamen, nucleus accumbens, and amygdala.

RESULTS

In the pituitary gland, the expression of GABAB receptor subunits was affected differently by the steroid treatment; the GABAB1 mRNA expression was decreased whereas a distinct elevation of the GABAB2 expression was found. Administration of ND also caused a decrease of GHR, IGF-1, and IGF-2 mRNA expression in the pituitary while the corresponding expression in the hypothalamus, caudate putamen, nucleus accumbens, and amygdala was unaffected. The rhGH administration did not alter the GABAB2 expression but increased the GABAB1 gene expression in the hypothalamus as compared to the AAS treated group.

CONCLUSIONS

These results provide new insights on the impact of ND and GH on the brain and highlight the interaction of these hormones with systems influencing GABAB receptor expression. The physiological significance of the observed effects of these hormones is discussed.

Sleep and insulin-like growth factors in the Cardiovascular Health Study

STUDY OBJECTIVES

Sleep and sleep disordered breathing (obstructive sleep apnea [OSA]) are known to affect the growth hormone/insulin-like growth factor (GH/IGF) axis. There are few relevant population studies in this area, particularly in the elderly. We conducted this study to investigate the relationship between sleep (architecture and OSA) and circulating IGF-I (insulin-like growth factor-1), IGFBP-1 (insulin-like growth factor binding protein-1), and IGFBP-3 (insulin-like growth factor binding protein-3) levels in an elderly population.

DESIGN SETTING

Cross-sectional analysis of participants from the year 9 visit of the Cardiovascular Health Study (CHS) who were enrolled in the Sleep Heart Health Study (SHHS).

PATIENTS OR PARTICIPANTS

1,233 elderly participants from the CHS and SHHS.

MEASUREMENTS AND RESULTS

The mean age of males (n = 526) and females (n = 697) was 77 years. The mean value of IGF-I (ng/mL) in males was 112.4 vs. 97.1 in females (p < 0.01). Mean IGFBP-1 and IGFBP-3 levels were higher in females than males (p < 0.01). As expected, slow wave sleep was better preserved in females compared to males (22% total sleep time vs. 9% total sleep time, p < 0.01). Furthermore, as expected, OSA (apneahypopnea index [AHI] ≥ 5/h) was more prevalent in males compared to females (60% vs. 46%, p < 0.01). Multivariable linear regression was used to determine the relationship between objective sleep parameters and circulating IGF-I, IGFBP-1, and IGFBP-3 levels, with adjustment for age, sex, race, BMI, diabetes, estrogen use, progestin use, and physical activity. We did not detect a significant association between slow wave sleep (SWS) (per 5 min) and IGF-I, IGFBP-1, and IGFBP-3 levels (ng/mL). We found no significant linear association between OSA (AHI ≥ 5/h) and IGF-I, IGFBP-1, and IGFBP-3 levels. Gender-stratification of the entire cohort did not alter these findings. Sensitivity analyses excluding diabetics revealed that moderate OSA (AHI ≥ 5 and < 15) is inversely associated with IGFBP-3 levels in women. Conclusions The relationship between SWS and GH/IGF system is not significant in the elderly. Furthermore, OSA does not appear to adversely influence the GH/IGF axis, as reported in younger individuals. Whether our study findings are due to diminished GH/IGF-I axis activity in elderly needs further investigation by replication in other large population based elderly cohorts.

Metabolic endocrine factors involved in spawning recovery and rematuration of iteroparous female rainbow trout (Oncorhynchus mykiss)

To determine how energy balance affects metabolic hormones hypothesized to play a role in the onset of a new reproductive cycle in iteroparous salmonids, food availability after spawning was restricted in female rainbow trout. These fish were compared with a control group that was fed a standard brood stock ration. Bodyweight, length, and muscle lipid content were determined, and blood was collected from fish at regular intervals; a subset of fish from each group was sacrificed at each sampling time for the collection of liver and ovary tissue, and to calculate hepatosomatic index (HSI) and gonadosomatic index (GSI). Plasma hormone levels were quantified by radioimmunoassay, and tissue gene expression levels were analyzed using q-RT-PCR. The experiment was conducted twice, using two-year-old and three-year-old post-spawned fish. Food-restriction arrested ovarian growth and development within 15-20 weeks, as evidenced by lower GSI in restricted-ration fish. Food restriction also reduced Fulton's condition factor, muscle lipid content, and specific growth rate from one month onward, and reduced HSI after 3 months. In the liver, insulin-like growth factor (igf1 and igf2) gene expression was reduced in three-year-old food-restricted fish within 2 months; however, no effect of ration on igf1 or igf2 expression was detected in two-year-old fish. In both years, IGF binding protein-1 (igfbp1) gene expression decreased over time in both treatment groups. Liver leptin (slepA1) gene expression was lower in two-year-old food-restricted fish at 4 months. These results show that this feed restriction regime arrested reproductive development and affected factors associated with energy balance purported to play a role in initiating reproductive development within 2-4months after spawning.

Detection and identification of oxidized insulin-like growth factor-binding proteins and receptors in patients with colorectal carcinoma

Colorectal cancer (CRC) is one of the most prevalent cancers worldwide and also the one with the highest mortality rate. Tumor growth is assisted by various growth factors, and insulin-like growth factors (IGFs) are among the most important. A majority of the IGFs are bound to IGF-binding proteins (IGFBPs) and their release is dependent on the rate of IGFBP proteolysis. The action of free IGFs is exerted and controlled by binding to cell membrane receptors (IGF-Rs). The objective of this work was to connect two determinants of the CRC pathology: oxidation as a process that underlies tumor development and the members of the IGF system that control it. Carbonyl groups (CO) on IGFBP-2, IGFBP-3, IGF-1R, and IGF-2R were determined in samples obtained from patients with CRC, and IGF-binding properties of these proteins were analyzed. According to our results, IGFBP-2 and IGFBP-3 in serum had increased content of CO groups due to CRC. Oxidation of IGFBP-2 increased its affinity for IGF molecules, whereas oxidation of IGFBP-3 reduced it. As for receptors, only intact CO-IGF-2R was detected on solubilized colon membranes, whereas CO-IGF-1R was degraded into fragments. Oxidative changes in the IGF axis may be regarded as part of the mechanism of its action. IGFs bound to IGFBP-3 remain in the circulation, whereas those bound to IGFBP-2 freely reach target tissues. Therefore, oxidation supports IGF distribution toward tissues and, consequently, promotes tumor growth.

Insulin-like growth factors and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most malignant types of cancer. It has a rapid course and carries a poor prognosis. Hepatocarcinogenesis is a complex multi-step and multi-factorial process. Recent studies have discovered the association between the dysregulation of insulin-like growth factor (IGF)-related signaling pathways and pathogenesis of liver cancer. IGFs are multifunctional cell proliferation regulatory factors and play an important role in fetal development, central nervous system development and cancer cell proliferation. The biological activity of IGFs is regulated by a complex regulatory network which consists of different types of receptors, IGF-binding proteins and IGF binding-related proteins. This review focuses on the changes in the IGF axis and IGF-related signaling pathways in liver tumorigenesis and their application in targeted therapy for liver cancer.