Cellular actions of the insulin-like growth factor binding proteins

IGFBP2/ITGA5 promotes gefitinib resistance via activating STAT3/CXCL1 axis in non-small cell lung cancer

There is a paucity of comprehensive knowledge pertaining to the underlying mechanisms leading to gefitinib resistance in individuals diagnosed NSCLC harboring EGFR-sensitive mutations who inevitably develop resistance to gefitinib treatment within six months to one year. In our preceding investigations, we have noted a marked upregulation of IGFBP2 in the neoplastic tissues of NSCLC, predominantly in the periphery of the tissue, implying its plausible significance in NSCLC. Consequently, in the current research, we delved into the matter and ascertained the molecular mechanisms that underlie the participation of IGFBP2 in the emergence of gefitinib resistance in NSCLC cells. Firstly, the expression of IGFBP2 in the bronchoalveolar lavage fluid and lung cancer tissues of 20 NSCLC patients with gefitinib tolerance was found to be significantly higher than that of non-tolerant patients. Furthermore, in vitro and in vivo experiments demonstrated that IGFBP2 plays a significant role in the acquisition of gefitinib resistance. Mechanistically, IGFBP2 can activate STAT3 to enhance the transcriptional activity of CXCL1, thereby increasing the intracellular expression level of CXCL1, which contributes to the survival of lung cancer cells in the gefitinib environment. Additionally, we identified ITGA5 as a key player in IGFBP2-mediated gefitinib resistance, but it does not function as a membrane receptor in the process of linking IGFBP2 to intracellular signaling transduction. In conclusion, this study demonstrates the promoting role and mechanism of IGFBP2 in acquired gefitinib resistance caused by non-EGFR secondary mutations, suggesting the potential of IGFBP2 as a biomarker for gefitinib resistance and a potential intervention target.

A Comprehensive Exploration of Novel Biomarkers for the Early Diagnosis of Aortic Dissection

Aortic dissection (AD) is a catastrophic life-threatening cardiovascular emergency with a 1-2% per hour mortality rate post-diagnosis, characterized physiologically by the separation of aortic wall layers. AD initially presents as intense pain that can then radiate to the back, arms, neck or jaw along with neurological deficits like difficulty in speaking, and unilateral weakness in some patients. This spectrum of clinical features associated with AD is often confused with acute myocardial infarction, hence leading to a delay in AD diagnosis. Cardiac and vascular biomarkers are structural proteins and microRNAs circulating in the bloodstream that correlate to tissue damage and their levels become detectable even before symptom onset. Timely diagnosis of AD using biomarkers, in combination with advanced imaging diagnostics, will significantly improve prognosis by allowing earlier vascular interventions. This comprehensive review aims to investigate emerging biomarkers in the diagnosis of AD, as well as provide future directives for creating advanced diagnostic tools and imaging techniques.

Serum IGFBP5 as a predictor of major adverse cardiac events in patients with acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI) is a serious condition with high mortality rates. Early risk stratification is of significant importance to assess the prognosis. Insulin-like growth factor-binding protein 5 (IGFBP5) levels in AMI patients and its potential as a prognosis biomarker were unclear.

OBJECTIVE

To investigate serum IGFBP5 levels in AMI and its prognostic value for short-term major adverse cardiovascular events (MACE).

METHODS

We collected serum IGFBP5 levels from 200 patients with new-onset AMI and 71 coronary heart disease (CAD) patients without AMI. Linear regression was used to analyze the relationship between IGFBP5 and baseline variables. AMI patients were followed up, and the risk of major adverse cardiovascular events (MACE) was assessed using Kaplan-Meier curve, multivariate Cox models and restricted cubic spline (RCS) analysis.

RESULTS

During a median follow-up of 217 days, 40 patients developed MACE. Serum IGFBP5 was associated with serum cardiac troponin T (cTnT) and C-reactive protein (CRP) (P = 0.013 and P = 0.013). In multivariable survival analyses, higher IGFBP5 was associated with an increased risk of MACE [HR = 1.183, 95%CI (1.104, 1.268), P < 0.001)]. There was a positive and linear association between IGFBP5 levels and the occurrence of MACE (P for nonlinearity = 0.283). The positive association between IGFBP5 and MACE risk consist across subgroups characterized by demographics and comorbidities.

CONCLUSION

Serum IGFBP5 was highly expressed in patients with AMI and positively associated with the short-term risk of MACE. Circulating IGFBP5 may be a diagnostic and prognostic indicator for AMI, and further studies with larger sample and longer follow-up are warranted.

IGF-1 and IGFBP-1 as Possible Predictors of Response to Lifestyle Intervention-Results from Randomized Controlled Trials

Lifestyle interventions can prevent type 2 diabetes (T2DM). However, some individuals do not experience anticipated improvements despite weight loss. Biomarkers to identify such individuals at early stages are lacking. Insulin-like growth factor 1 (IGF- 1) and Insulin-like growth factor binding protein 1(IGFBP-1) were shown to predict T2DM onset in prediabetes. We assessed whether these markers also predict the success of lifestyle interventions, thereby possibly guiding personalized strategies. We analyzed the fasting serum levels of IGF-1, IGFBP-1, and Insulin-like growth factor binding protein 2 (IGFBP-2) in relation to changes in metabolic and anthropometric parameters, including intrahepatic lipids (IHLs) and visceral adipose tissue (VAT) volume, measured by magnetic resonance imaging (MRI), in 345 participants with a high risk for prediabetes (54% female; aged 36-80 years). Participants were enrolled in three randomized dietary intervention trials and assessed both at baseline and one year post-intervention. Statistical analyses were performed using IBM SPSS Statistics (version 28), and significance was set at p < 0.05. Within the 1-year intervention, overall significant improvements were observed. Stratifying individuals by baseline IGF-1 and IGFBP-1 percentiles revealed significant differences: higher IGF-1 levels were associated with more favorable changes compared to lower levels, especially in VAT and IHL. Lower baseline IGFBP-1 levels were associated with greater improvements, especially in IHL and 2 h glucose. Higher bioactive IGF-1 levels might predict better metabolic outcomes following lifestyle interventions in prediabetes, potentially serving as biomarkers for personalized interventions.

The diverging roles of insulin-like growth factor binding proteins in pulmonary arterial hypertension

Pulmonary hypertension (PH) is a progressive, severe and to date not curable disease of the pulmonary vasculature. Alterations of the insulin-like growth factor 1 (IGF-1) system are known to play a role in vascular pathologies and IGF-binding proteins (IGFBPs) are important regulators of the bioavailability and function of IGFs. In this study, we show that circulating plasma levels of IGFBP-1, IGFBP-2 and IGFBP-3 are increased in idiopathic pulmonary arterial hypertension (IPAH) patients compared to healthy individuals. These binding proteins inhibit the IGF-1 induced IGF-1 receptor (IGF1R) phosphorylation and exhibit diverging effects on the IGF-1 induced signaling pathways in human pulmonary arterial cells (i.e. healthy as well as IPAH-hPASMCs, and healthy hPAECs). Furthermore, IGFBPs are differentially expressed in an experimental mouse model of PH. In hypoxic mouse lungs, IGFBP-1 mRNA expression is decreased whereas the mRNA for IGFBP-2 is increased. In contrast to IGFBP-1, IGFBP-2 shows vaso-constrictive properties in the murine pulmonary vasculature. Our analyses show that IGFBP-1 and IGFBP-2 exhibit diverging effects on IGF-1 signaling and display a unique IGF1R-independent kinase activation pattern in human pulmonary arterial smooth muscle cells (hPASMCs), which represent a major contributor of PAH pathobiology. Furthermore, we could show that IGFBP-2, in contrast to IGFBP-1, induces epidermal growth factor receptor (EGFR) signaling, Stat-3 activation and expression of Stat-3 target genes. Based on our results, we conclude that the IGFBP family, especially IGFBP-1, IGFBP-2 and IGFBP-3, are deregulated in PAH, that they affect IGF signaling and thereby regulate the cellular phenotype in PH.

Insulin-like growth factor family and prostate cancer: new insights and emerging opportunities

Prostate cancer is the second most commonly diagnosed cancer in men. The mammalian insulin-like growth factor (IGF) family is made up of three ligands (IGF-I, IGF-II, and insulin), three receptors (IGF-I receptor (IGF-1R), insulin receptor (IR), and IGF-II receptor (IGF-2R)), and six IGF-binding proteins (IGFBPs). IGF-I and IGF-II were identified as potent mitogens and were previously associated with an increased risk of cancer development including prostate cancer. Several reports showed controversy about the expression of the IGF family and their connection to prostate cancer risk due to the high degree of heterogeneity among prostate tumors, sampling bias, and evaluation techniques. Despite that, it is clear that several IGF family members play a role in prostate cancer development, metastasis, and androgen-independent progression. In this review, we aim to expand our understanding of prostate tumorigenesis and regulation through the IGF system. Further understanding of the role of IGF signaling in PCa shows promise and needs to be considered in the context of a comprehensive treatment strategy.

IGFBP2 induces podocyte apoptosis promoted by mitochondrial damage via integrin α5/FAK in diabetic kidney disease

Podocyte apoptosis or loss is the pivotal pathological characteristic of diabetic kidney disease (DKD). Insulin-like growth factor-binding protein 2 (IGFBP2) have a proinflammatory and proapoptotic effect on diseases. Previous studies have shown that serum IGFBP2 level significantly increased in DKD patients, but the precise mechanisms remain unclear. Here, we found that IGFBP2 levels obviously increased under a diabetic state and high glucose stimuli. Deficiency of IGFBP2 attenuated the urine protein, renal pathological injury and glomeruli hypertrophy of DKD mice induced by STZ, and knockdown or deletion of IGFBP2 alleviated podocytes apoptosis induced by high concentration of glucose or in DKD mouse. Furthermore, IGFBP2 facilitated apoptosis, which was characterized by increase in inflammation and oxidative stress, by binding with integrin α5 (ITGA5) of podocytes, and then activating the phosphorylation of focal adhesion kinase (FAK)-mediated mitochondrial injury, including membrane potential decreasing, ROS production increasing. Moreover, ITGA5 knockdown or FAK inhibition attenuated the podocyte apoptosis caused by high glucose or IGFBP2 overexpression. Taken together, these findings unveiled the insight mechanism that IGFBP2 increased podocyte apoptosis by mitochondrial injury via ITGA5/FAK phosphorylation pathway in DKD progression, and provided the potential therapeutic strategies for diabetic kidney disease.

The role of IGFBP-3 in tumor development and progression: enlightenment for diagnosis and treatment

IGFBP-3 is aberrantly expressed in many tumor types, and its serum and tumor tissue levels provide auxiliary information for assessing the degree of tumor malignancy and patient prognosis, making it a potential therapeutic target for human malignancies and conferring it remarkable clinical value for determining patient prognosis. In this review, we provide a comprehensive overview of the aberrant expression, diverse biological effects, and clinical implications of IGFBP-3 in tumors and its role as a potential prognostic marker and therapeutic target for tumors. In addition, we summarize the signaling pathways through which IGFBP-3 exerts its effects. IGFBP-3 comprises an N-terminal, an intermediate region, and a C-terminal structural domain, each exerting different biological effects in several tumor cell types in an IGF-dependent/non-independent manner. IGFBP-3 shares an intricate relationship with the tumor microenvironment, thereby affecting tumor growth. Overall, IGFBP-3 is an essential regulatory factor that mediates tumor occurrence and progression. Gaining deeper insights into the fundamental characteristics of IGFBP-3 and its role in various tumor types will provide new perspectives and allow for the development of novel strategies for cancer diagnosis, treatment, and prognostic evaluation.

Yak IGFBP3 promotes hepatocyte proliferation through PI3K-Akt signaling pathway

IGFBP3 (Insulin-like growth factor binding protein 3) constitutes a crucial constituent of the insulin-like growth factor (IGF), which are intimately associated with the organism's growth and development processes. Despite its significance, the precise function of IGFBP3 in yak liver development remains largely unexplored. In the present study, we systematically examined the expression profile of IGFBP3 in the liver tissues of yaks across various growth stages, elucidated its influence on the activity of yak hepatocytes, and probed its effects on murine liver development. A comparative analysis revealed that the expression of IGFBP3 was significantly higher in the liver tissue of 5-year-old yaks compared to their 15-month-old and 1-day-old counterparts (P < 0.01). To further validate its biological function, pET-28a-BgIGFBP3 prokaryotic expression vector was constructed. Upon exposing yak hepatocytes to varying concentrations of Bos grunniens (Bg) IGFBP3 protein, we observed augmented cellular activities and elevated colony formation rates. Moreover, our investigation revealed the upregulation of key genes within the PI3K-Akt signaling pathway, including ERBB2, IRS1, PIK3R1, AKT1, RAF1, MAP2K2, and MAPK3, in both yak hepatocyte cultures and murine models. These findings collectively indicate that BgIGFBP3 promotes the proliferation of yak hepatocytes and enhances murine liver development by modulating the PI3K-Akt signaling pathway. The functional relevance of BgIGFBP3 was substantiated through in vivo and in vitro experiments, thereby underscoring its potential as a regulatory factor in liver development processes.

Intramuscular injection of mesenchymal stem cells augments basal muscle protein synthesis after bouts of resistance exercise in male mice

Skeletal muscle mass is critical for activities of daily living. Resistance training maintains or increases muscle mass, and various strategies maximize the training adaptation. Mesenchymal stem cells (MSCs) are multipotent cells with differential potency in skeletal muscle cells and the capacity to secrete growth factors. However, little is known regarding the effect of intramuscular injection of MSCs on basal muscle protein synthesis and catabolic systems after resistance training. Here, we measured changes in basal muscle protein synthesis, the ubiquitin-proteasome system, and autophagy-lysosome system-related factors after bouts of resistance exercise by intramuscular injection of MSCs. Mice performed three bouts of resistance exercise (each consisting of 50 maximal isometric contractions elicited by electrical stimulation) on the right gastrocnemius muscle every 48 h, and immediately after the first bout, mice were intramuscularly injected with either MSCs (2.0 × 106 cells) labeled with green fluorescence protein (GFP) or vehicle only placebo. Seventy-two hours after the third exercise bout, GFP was detected only in the muscle injected with MSCs with concomitant elevation of muscle protein synthesis. The injection of MSCs also increased protein ubiquitination. These results suggest that the intramuscular injection of MSCs augmented muscle protein turnover at the basal state after consecutive resistance exercise.

The effect of SGLT2i on the GH/IGF1 axis in newly diagnosed male T2D patients - a prospective, randomized case-control study

PURPOSE

To investigate the effect of SGLT2i on the GH/IGF1 axis in male patients with newly diagnosed type 2 diabetes (T2D).

METHODS

Sixty male patients with newly diagnosed T2D were recruited, and randomly assigned to Metformin+SGLT2i group or Metformin group after baseline assessment. All patients received standard lifestyle interventions, and blood indices were obtained before and after 12 weeks of treatment.

RESULTS

After 12 weeks of treatment with Metformin+SGLT2i, there were noteworthy improvements in patients' FPG (Fasting plasma glucose), HBA1c, HOMA-IR, HOMA-β, TyG (Triglyceride-glucose) index and UACR (P < 0.05). Both IGF1 (P = 0.01) and the IGF1/IGFBP3 ratio (P < 0.01) considerably increased, while GH and IGFBP3 did not show significant changes. When comparing Metformin+SGLT2i group to Metformin group, SGLT2i significantly improved HOMA-IR [P = 0.04], and elevated IGF1/IGFBP3 ratio [P = 0.04], SGLT2i showed a tendency of increasing IGF1 (P = 0.10), but this was not statistically meaningful. There was no effect on GH and IGFBP3. Correlation analysis showed that blood IGF1 was negatively correlated with FPG, HBA1c, HOMA-IR, TyG index and positively correlated with IGFBP3. Regression analysis indicated that FPG and testosterone had a negative effect on blood IGF1 level, while HOMA-IR had no obvious effect.

CONCLUSION

In male patients with newly diagnosed T2D, SGLT2i can increase IGF1/IGFBP3 ratio, alleviate insulin resistance, but has no significant effect on GH and IGF1 levels. Additionally, our study showed that Metformin+SGLT2i treatment resulted in an increase in blood IGF1 levels and improved insulin resistance, suggesting a potentially beneficial role of IGF1 in newly diagnosed T2D.

Structural insight into CD93 recognition by IGFBP7

The CD93/IGFBP7 axis proteins are key factors expressed in endothelial cells (EC) that mediate EC angiogenesis and migration. Their upregulation contributes to tumor vascular abnormality and a blockade of this interaction promotes a favorable tumor microenvironment for therapeutic interventions. However, the interactions of these proteins with each other remain unclear. In this study, we determined a partial structure of the human CD93-IGFBP7 complex comprising the EGF1 domain of CD93 and the IB domain of IGFBP7. Mutagenesis studies confirmed interactions and specificities. Cellular and mouse tumor studies demonstrated the physiological relevance of the CD93-IGFBP7 interaction in EC angiogenesis. Our study provides leads for the development of therapeutic agents to precisely disrupt unwanted CD93-IGFBP7 signaling in the tumor microenvironment. Additionally, analysis of the CD93 full-length architecture provides insights into how CD93 protrudes on the cell surface and forms a flexible platform for binding to IGFBP7 and other ligands.

Effect of IGFBP-4 during In Vitro Maturation on Developmental Competence of Bovine Cumulus Oocyte Complexes

Insulin-like growth factors (IGFs) are essential for oocyte maturation. Their bioavailability is regulated by their respective binding proteins (IGFBPs) and proteases. IGFBP-4 blocks the biological effects of IGFs. High IGFBP-4 expression has been associated with follicle atresia. We hypothesized that IGFBP-4 affects oocyte developmental competence during maturation. Therefore, the aim of this study was to examine the effect of IGFBP-4 on the developmental rate of bovine cumulus-oocyte complexes (COCs) during in vitro embryo production. Abattoir-derived COCs were matured with rbIGFBP-4 (2000, 540, and 54 ng/mL) compared to a control. Cumulus expansion, oocyte maturation, cleavage, blastocyst, and hatching rates were evaluated. Furthermore, blastocyst gene expression of SOCS2, STAT3, SLC2A1, SLCA3, BAX, and POU5F1 transcripts were quantified using RT-qPCR. No statistical differences were detected among the groups for cumulus expansion, maturation, cleavage, blastocyst rates, or all gene transcripts analyzed. However, at day 8 and 9, the number of total hatching and successfully hatched blastocysts was lower in 2000 ng/mL rbIGFBP-4 compared to the control (day 8: total hatching: 17.1 ± 0.21 vs. 31.2 ± 0.11%, p = 0.02 and hatched blastocyst 6.7 ± 0.31 vs. 21.5 ± 0.14%, p = 0.004; day 9 total hatching 36.4 ± 0.18 vs. 57.7 ± 0.10%, p = 0.009 and hatched blastocyst 18.2 ± 0.21 vs. 38.1 ± 0.11%, p = 0.004). We concluded that high concentrations of rbIGFBP-4 might negatively affect the subsequent ability of the embryo to hatch and possibly compromise further elongation.

The Fascinating Interplay between Growth Hormone, Insulin-Like Growth Factor-1, and Insulin

This review intends to provide the reader with a practical overview of several (patho)physiological conditions in which knowledge of the interplay between growth hormone (GH), insulin-like growth factor-1 (IGF-1), and insulin is important. This might help treating physicians in making the right decisions on how to intervene and improve metabolism for the benefit of patients, and to understand why and how metabolism responds in their specific cases. We will specifically address the interplay between GH, IGF-1, and insulin in type 1 and 2 diabetes mellitus, liver cirrhosis, and acromegaly as examples in which this knowledge is truly necessary.

Role of increased IGFBP2 in trophoblast cell proliferation and recurrent spontaneous abortion development: A pilot study

Recurrent spontaneous abortion (RSA) is a serious condition that adversely affects women's health. Differentially expressed proteins (DEPs) in plasma of patients experiencing RSA is helpful to find new therapeutic targets and identified with mass spectrometry. In 57 DEPs, 21 were upregulated and 36 were downregulated in RSA. Gene ontology analyses indicated that identified DEPs were associated with cell proliferation, including significantly downregulated insulin-like growth factor binding protein 2 (IGFBP2). Immunohistochemical result using clinical decidual tissues also showed that IGFBP2 expression was significantly decreased in RSA trophoblasts. Cell proliferation assay indicated that IGFBP2 treatment increased the proliferation and mRNA expressions of PCNA and Ki67 in trophoblast cells. Transcriptome sequencing experiments and Kyoto Encyclopedia of Genes and Genomes analyses revealed that gene expression for components in PI3K-Akt pathway in trophoblasts was significantly upregulated following IGFBP2 treatment. To confirm bioinformatics findings, we did cell-based experiments and found that treatment of inhibitors for insulin-like growth factor (IGF)-1 receptor-PI3K-Akt pathway significantly reduced IGFBP2-induced trophoblast cell proliferation and mRNA expressions of PCNA and Ki67. Our findings suggest that IGFBP2 may increase trophoblast proliferation through the PI3K-Akt signaling pathway to affect pregnancy outcomes and that IGFBP2 may be a new target for future research and treatment of RSA.

Pregnancy associated plasma protein-A2 (PAPP-A2) and stanniocalcin-2 (STC2) but not PAPP-A are associated with circulating total IGF-1 in a human adult population

The pappalysins pregnancy associated plasma protein-A (PAPP-A) and -A2 (PAPP-A2) act as proteinases of insulin-like growth factor-1 (IGF-1) binding proteins, while stanniocalcin-2 (STC2) was identified as a pappalysin inhibitor. While there is some evidence from studies in children and adolescents, it is unclear whether these molecules are related to concentrations of IGF-1 and its binding proteins in adults. We investigated cross-sectionally the association of circulating PAPP-A, PAPP-A2 and STC2 with IGF-1 and its binding proteins (IGFBPs) in 394 adult pretest participants (20-69 years) of the German National Cohort Berlin North study center. Plasma PAPP-A, PAPP-A2, total and free IGF-1, IGFBP-1, IGFBP-2, IGFBP-3, IGFBP-5 and STC2 were measured by ELISAs. The associations of PAPP-A, PAPP-A2 and STC2 with IGF-1 or IGFBPs were investigated using multivariable linear regression analyses adjusting for age, sex, body mass index and pretest phase. We observed significant inverse associations of PAPP-A2 (difference in concentrations per 0.5 ng/mL higher PAPP-A2 levels) with total IGF-1 (- 4.3 ng/mL; 95% CI - 7.0; - 1.6), the IGF-1:IGFBP-3 molar ratio (- 0.34%; 95%-CI - 0.59; - 0.09), but not free IGF-1 and a positive association with IGFBP-2 (11.9 ng/mL; 95% CI 5.0; 18.8). PAPP-A was not related to total or free IGF-1, but positively associated with IGFBP-5. STC2 was inversely related to total IGF-1, IGFBP-2 and IGFBP-3 and positively to IGFBP-1. This first investigation of these associations in a general adult population supports the hypothesis that PAPP-A2 as well as STC2 play a role for IGF-1 and its binding proteins, especially for total IGF-1. The role of PAPP-A2 and STC2 for health and disease in adults warrants further investigation.

Food deprivation reduces sensitivity of liver Igf1 synthesis pathways to growth hormone in juvenile gopher rockfish (Sebastes carnatus)

Growth hormone (Gh) regulates growth in part by stimulating the liver to synthesize and release insulin-like growth factor-1 (Igf1), which then promotes somatic growth. However, for fish experiencing food limitation, elevated blood Gh can occur even with low circulating Igf1 and slow growth, suggesting that nutritional stress can alter the sensitivity of liver Igf1 synthesis pathways to Gh. Here, we examined how recent feeding experience affected Gh regulation of liver Igf1 synthesis pathways in juvenile gopher rockfish (Sebastes carnatus) to illuminate mechanisms underlying the nutritional modulation of Igf1 production. Juvenile gopher rockfish were maintained under conditions of feeding or complete food deprivation (fasting) for 14 d and then treated with recombinant sea bream (Sparus aurata) Gh or saline control. Gh upregulated hepatic igf1 mRNA levels in fed fish but not in fasted fish. The liver of fasted rockfish also showed a lower relative abundance of gene transcripts encoding teleost Gh receptors 1 (ghr1) and 2 (ghr2), as well as reduced protein levels of phosphorylated janus tyrosine kinase 2 (pJak2) and signal transducer and activator of transcription 5 (pStat5), which function to induce igf1 gene transcription following Gh binding to Gh receptors. Relative hepatic mRNA levels for suppressors of cytokine signaling (Socs) genes socs2, socs3a, and socs3b were also lower in fasted rockfish. Socs2 can suppress Gh activation of Jak2/Stat5, and fasting-related variation in socs expression may reflect modulated inhibitory control of igf1 gene transcription. Fasted rockfish also had elevated liver mRNA abundances for lipolytic hormone-sensitive lipase 1 (hsl1) and Igf binding proteins igfbp1a, -1b and -3a, reduced liver mRNAs encoding igfbp2b and an Igfbp acid labile subunit-like (igfals) gene, and higher transcript abundances for Igf1 receptors igf1ra and igf1rb in skeletal muscle. Together, these findings suggest that food deprivation impacts liver Igf1 responsiveness to Gh via multiple mechanisms that include a downregulation of hepatic Gh receptors, modulation of the intracellular Jak2/Stat5 transduction pathway, and possible shifts in Socs-inhibitory control of igf1 gene transcription, while also demonstrating that these changes occur in concert with shifts in liver Igfbp expression and muscle Gh/Igf1 signaling pathway components.

Plant homeodomain-finger protein 5A: A key player in cancer progression

PHF5A is a member of the zinc-finger proteins. To advance knowledge on their role in carcinogenesis, data from experimental studies, animal models and clinical studies in different tumorigenesis have been reviewed. Furthermore, PHF5A as an oncogenic function, is frequently high expressed in tumor cells and a potential prognostic marker for different cancers. PHF5A is implicated in the regulation of cancer cell proliferation, invasion, migration and metastasis. Knockdown of PHF5A prevented the invasion and metastasis of tumor cells. Here, the role of PHF5A in different cancers and their possible mechanism in relation to recent literature is reviewed and discussed. There is an open promising perspective to their therapeutic management for different cancer types.

Prognostic Value of Circulating Cytokines in Chemorefractory Colorectal Cancer

Circulating cytokines could be optimal biomarkers for prognostication and management decisions in colorectal cancer (CRC). Chemorefractory CRC patients with available plasma samples were included in this study. In the discovery cohort (n = 85), 182 circulating cytokines were tested with a semi-quantitative multiplex assay, and prognostic cytokines were analyzed in the validation cohort (n = 111) by ELISA. Overall survival (OS) was the primary outcome measure, with the false discovery rate (FDR) method (significance level of <0.01) being used to correct for multiple comparisons. Four cytokines were associated with OS in the discovery cohort: insulin-like growth factor-binding protein 1 (IGFBP-1) (HR 2.1 [95%CI: 1.58-2.79], FDR < 0.001), insulin-like growth factor-binding protein 2 (IGFBP-2) (HR 1.65 [95%CI: 1.28-2.13], FDR = 0.006), serum amyloid A (SAA) (HR 1.84 [95%CI: 1.39-2.43], FDR < 0.001), and angiotensin II (HR 1.65 [95%CI: 1.29-2.1], FDR = 0.006). Of these, IGFBP-1 (HR 2.70 [95%CI: 1.56-4.76], FDR = 0.007) and IGFBP-2 (HR 3.33 [95%CI: 1.64-6.67], FDR = 0.008) were confirmed to be independently associated with OS in the validation cohort. Patients with high concentrations of IGFBP-1 and/or IGFBP-2 had a median OS of 3.0 months as compared with 6.9 months for those with low concentrations of both cytokines (HR 2.44 [95%CI: 1.52-4.0], FDR = 0.002) Validation of circulating IGFBP-1 and IGFBP-2 as independent prognostic biomarkers for chemorefractory CRC in larger, independent series is warranted.

Molecular cloning and expression profiling of insulin-like growth factor 2 and IGF-binding protein 6 in Clarias magur (Hamilton 1822)

Growth is an important trait in aquaculture and the major genes that regulate it are Insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs). In this study, the full-length coding sequences of IGF2 and IGFBP6 genes in the Indian catfish Clarias magur were cloned and characterized. The full-length cDNA sequences of IGF2 and IGFBP6 were 885 bp (ORF 642 bp) and 928 bp (ORF 600 bp), encoding 213 and 199 amino acids, respectively. Bioinformatics analyses revealed that the magur IGF2 and IGFBP6 proteins are hydrophilic and secretory in nature. Sequence alignment with other teleosts and mammalian orthologues shows conservation of the functional domains. Gene expression analysis in 6 individuals each of high (298 ± 5.0 g) and low (210 ± 6.0 g) growth performing families showed significantly (p < 0.05) higher expression (2.5-3 fold) of IGF2, and lower expression (∼2.5 fold) of IGFBP6 in liver and muscle of fast-growing fish. This study suggests that IGF2 could be playing a major role in the growth regulation of magur. These genes and their expression patterns could be developed into growth-associated markers for magur and other catfishes.

Association Study of IGF-1 rs35767 and rs6214 Gene Polymorphisms with Cancer Susceptibility and Circulating Levels of IGF-1, IGFBP-2, and IGFBP-3 in Colorectal Cancer Patients

Early detection of colorectal cancer (CRC) increases the 5-year survival rate by 90%; therefore, non-invasive biomarkers such as measurable circulating proteins for early detection and prognosis are crucial. Insulin-like growth factor-1 (IGF-1) is involved in the regulation of cell proliferation and apoptosis. IGF binding proteins (IGFBPs) bind and inhibit the activity of IGF-1. It was inconsistently reported that high IGF-1 and IGFBP-2 and low IGFBP-3 circulating levels are associated with high cancer risk, poor prognosis, and tumor metastasis in several cancers. A total of 175 patients with CRC and 429 controls were enrolled in this study. We genotyped for IGF-1 rs35767 and rs6214 gene polymorphisms and assessed their association with circulating levels of IGF-1 and/or the risk for CRC. We also determined plasma levels of IGF-1, IGFBP-2, and IGFBP-3. Neither rs35767 nor rs2614 were associated with cancer risk or IGF-1 levels in our study cohort. IGF-1 and IGFBP-3 levels were higher in controls than in patients, whereas IGFBP-2 was higher in patients than in controls. Only IGFBP-2 was associated with increased tumor grade but not stage. Therefore, IGF-1, IGFBP-2, and IGFBP-3 may be useful as early detection and prognostic biomarkers in CRC.

Expression of insulin-like growth factor binding protein-3 in HELLP syndrome

OBJECTIVE

To investigate the expression of insulin-like growth factor binding protein-3(IGFBP-3) in HELLP syndrome and its possible role in the pathogenesis of this disease.

METHODS

1) 87 subjects were enrolled, including 29 patients with HELLP syndrome, 29 patients with pre-eclampsia (PE), and 29 healthy gravidae as control. The levels of IGFBP-3, IGF-1, TGF-β1, and VEGF in maternal and umbilical blood of them were detected using ELISA. Correlation analysis was used to observe the correlation between IGFBP-3 and IGF-1/TGF-β1/VEGF in maternal and umbilical blood, as well as that between maternal serum IGFBP-3 and clinical diagnostic indicators of HELLP syndrome. 2) Human hepatic sinusoid endothelial cells (HLSEC) and human umbilical vein endothelial cells (HUVEC) were cultured with different concentrations of IGFBP-3. After 72 h of culture, cell apoptosis and the normal living cells rate were detected and compared.

RESULTS

1) In both maternal and umbilical blood of HELLP group, levels of IGFBP-3 and TGF-β1 were higher than control and PE group, IGF-1was lower than control group, VEGF was lower than control and PE group. IGFBP-3 in maternal blood was correlated with IGF-1/TGF-β1/ VEGF, while IGFBP-3 in umbilical blood was linked to IGF-1/TGF-β1. In maternal blood, there was a negative correlation between PLT and IGFBP-3, and a positive correlation between ALT/AST/LDH and IGFBP-3. 2) After cultured with IGFBP-3, the total apoptosis rate of either HLSEC or HUVEC was considerably elevated, while the normal living rate was decreased.

CONCLUSION

The expression of IGFBP-3 is elevated in HELLP syndrome, which may subsequently promote cell apoptosis by affecting the expression and function of IGF-1, VEGF, and TGFβ1 in the IGF/PI3K/Akt, TGF-β1/Smad3, and VEGF/eNOS/NO pathways. IGFBP-3 aggravates inflammatory reactions of the vascular endothelium and liver under hypoxia, affects the normal function of cells, and plays a role in the pathogenesis of diseases.

A regulatory mechanism of mouse kallikrein 1 gene expression by estrogen

Tissue kallikrein 1 (Klk1) is a serine protease that degrades several proteins including insulin-like growth factor binding protein-3 and extracellular matrix molecules. Klk1 mRNA expression in the mouse uterus was increased by estradiol-17β (E2). The present study aimed to clarify the regulatory mechanism for Klk1 expression by estrogen. The promoter analysis of the 5'-flanking region of Klk1 showed that the minimal promoter of Klk1 existed in the -136/+24 region, and the estrogen-responsive region in the -433/-136 region. Tamoxifen increased Klk1 mRNA expression and the promoter activity, suggesting the involvement of AP-1 sites. Site-directed mutagenesis for the putative AP-1 sites in the -433/-136 region showed that the two putative AP-1 sites were involved in the regulation of Klk1 expression. Binding of estrogen receptor α (ERα) to the -433/-136 region was revealed by Chip assay. These results indicated that ERα bound the two putative AP-1 sites and transactivated Klk1 in the mouse uterus.

Mesenchymal stem cell-derived secretomes-enriched alginate/ extracellular matrix hydrogel patch accelerates skin wound healing

BACKGROUND

The secretomes of mesenchymal stem cells (MSCs) have great therapeutic potential and thereby their efficient delivery into the target site is of particular interest. Here, we propose a new strategy of hMSCs-derived secretomes delivery for advanced wound healing upon harnessing the working principle of extracellular matrix (ECM)-growth factors interaction in vivo.

METHODS

We prepared an alginate hydrogel based wound patch, where it contains both human MSC-derived secretomes and ECM. The ECM was obtained from the decellularization of in vitro cultured human lung fibroblasts. The alginate solution was blended with ECM suspension, crosslinked, air-dried, then rehydrated with the secretomes contained in the concentrated conditioned media (CCM) as a highly saturated form of conditioned media (CM). We tested four different groups, with or without the ECM to investigate not only the role of ECM but the therapeutic effect of secretomes.

RESULTS

The secretomes reserved many, diverse bioactive factors, such as VEGF, HGF, IGFBPs, IL-6, and IL-8. Alginate/ECM/CCM (AEC) patch could hold significantly larger amount of secretomes and release them longer than the other groups. Our AEC patch was the most effective in stimulating not only cell migration and proliferation but the collagen synthesis of dermal fibroblasts in vitro. Moreover, the AEC patch-treated full-thickness skin wounds disclosed significantly better wound healing indications: cell recruitment, neovascularization, epidermis thickness, keratinocyte migration, and mature collagen deposition, as assessed via histology (H&E, Herovici staining) and immunofluorescence, respectively. In particular, our AEC patch enabled a phenotype shift of myofibroblast into fibroblast over time and led to mature blood vessel formation at 14 day.

CONCLUSIONS

We believe that ECM certainly contributed to generate a secretomes-enriched milieu via ECM-secretomes interactions and thereby such secretomes could be delivered more efficiently, exerting significant therapeutic impact either individually or collectively during wound healing process.

Is There a Relationship Between First-Trimester Aneuploidy Screening Serum Biomarker Values and Nuchal Translucency Measurements and the Development of Retinopathy of Prematurity (ROP) in Premature Infants?

Purpose The purpose of this study is the evaluation of serum biomarker and nuchal translucency (NT) values measured during first-trimester aneuploidy screening in terms of the development of retinopathy of prematurity (ROP) in premature infants and investigation of whether the development of ROP is associated with these parameters. Methods In this retrospective cohort study, 3,750 premature infants who underwent ROP screening from 2016 to 2021 were identified from the hospital medical record system. Among 2,130 premature babies screened for first-trimester aneuploidy, 166 babies whose mothers had single pregnancies were screened by the same method and showed the same clinical course in both eyes were included in the study. The infants were divided into two groups according to the presence of ROP, and those with ROP were further evaluated in two groups according to the presence of proliferation. The groups were compared in terms of the serum values of human chorionic gonadotropin and pregnancy-associated plasma protein A, among aneuploidy screening biomarkers, and NT measurements. Results There was no significant difference in the evaluated serum biomarker values and NT measurements between the ROP and non-ROP groups or between the proliferative ROP, non-proliferative ROP, and non-ROP groups. Conclusion Our results showed that first-trimester aneuploidy screening serum biomarker values and NT measurements were not associated with the development of ROP in premature infants.

The Role of Adipokines in the Pathologies of the Central Nervous System

Adipokines are protein hormones secreted by adipose tissue in response to disruptions in physiological homeostasis within the body's systems. The regulatory functions of adipokines within the central nervous system (CNS) are multifaceted and intricate, and they have been identified in a number of pathologies. Therefore, specific adipokines have the potential to be used as biomarkers for screening purposes in neurological dysfunctions. The systematic review presented herein focuses on the analysis of the functions of various adipokines in the pathogenesis of CNS diseases. Thirteen proteins were selected for analysis through scientific databases. It was found that these proteins can be identified within the cerebrospinal fluid either by their ability to modify their molecular complex and cross the blood-brain barrier or by being endogenously produced within the CNS itself. As a result, this can correlate with their measurability during pathological processes, including Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, depression, or brain tumors.

Signaling Pathways of the Insulin-like Growth Factor Binding Proteins

The 6 high-affinity insulin-like growth factor binding proteins (IGFBPs) are multifunctional proteins that modulate cell signaling through multiple pathways. Their canonical function at the cellular level is to impede access of insulin-like growth factor (IGF)-1 and IGF-2 to their principal receptor IGF1R, but IGFBPs can also inhibit, or sometimes enhance, IGF1R signaling either through their own post-translational modifications, such as phosphorylation or limited proteolysis, or by their interactions with other regulatory proteins. Beyond the regulation of IGF1R activity, IGFBPs have been shown to modulate cell survival, migration, metabolism, and other functions through mechanisms that do not appear to involve the IGF-IGF1R system. This is achieved by interacting directly or functionally with integrins, transforming growth factor β family receptors, and other cell-surface proteins as well as intracellular ligands that are intermediates in a wide range of pathways. Within the nucleus, IGFBPs can regulate the diverse range of functions of class II nuclear hormone receptors and have roles in both cell senescence and DNA damage repair by the nonhomologous end-joining pathway, thus potentially modifying the efficacy of certain cancer therapeutics. They also modulate some immune functions and may have a role in autoimmune conditions such as rheumatoid arthritis. IGFBPs have been proposed as attractive therapeutic targets, but their ubiquity in the circulation and at the cellular level raises many challenges. By understanding the diversity of regulatory pathways with which IGFBPs interact, there may still be therapeutic opportunities based on modulation of IGFBP-dependent signaling.

Development of a time-resolved fluoroimmunoassay for salmonid insulin-like growth factor binding protein-2b

Insulin-like growth factor (IGF)-1 promotes the growth of vertebrates, and its binding proteins (IGFBPs) regulate the activity of circulating IGF-1. Three IGFBPs, IGFBP-2b, -1a, and -1b, were consistently detected in the circulatory system of salmonids. IGFBP-2b is thought to be the main carrier of IGFs and promoter of IGF-1-mediated growth in salmonids. Currently, there are no immunoassays for detecting IGFBP-2b. In this study, we developed a time-resolved fluoroimmunoassay (TR-FIA) for IGFBP-2b detection in salmonid fishes. To establish TR-FIA, we produced two recombinant trout (rt) IGFBP-2bs expressed, one with thioredoxin (Trx) and a histidine (His) tag, and the other with His-tag only. We labeled both recombinant proteins with europium (Eu). Only Eu-Trx.His.rtIGFBP-2b cross-reacted with anti-IGFBP-2b, and the addition of increasing amounts of Trx.His.rtIGFBP-2b replaced the binding, indicating its utility as a tracer and assay standard. The addition of unlabeled salmon IGF-1 did not affect the binding of the standard or sample. Serial dilution curves of sera from rainbow trout, Chinook salmon, and chum salmon were parallel to those of the standard. The assay range (ED80-ED20) of the TR-FIA was 60.4 to 251.3 ng/ml, and its minimum detection limit of this assay was 21 ng/ml. The intra- and inter-assay coefficients of variation were 5.68% and 5.65%, respectively. Circulating IGFBP-2b levels in fed rainbow trout were higher than those in fasted fish and were correlated with individual growth rates. This TR-FIA is useful for further exploring the physiological responses of circulating IGFBP-2b and evaluating the growth status of salmonids.

A Facile Strategy for the Fabrication of Cell-laden Porous Alginate Hydrogels Based on Two-phase Aqueous Emulsions

Porous alginate hydrogels possess many advantages as cell carriers. However, current pore generation methods require either complex or harsh fabrication processes, toxic components, or extra purification steps, limiting the feasibility and affecting the cellular survival and function. In this study, a simple and cell-friendly approach to generate highly porous cell-laden alginate hydrogels based on two-phase aqueous emulsions is reported. The pre-gel solutions, which contain two immiscible aqueous phases of alginate and caseinate, are crosslinked by calcium ions. The porous structure of the hydrogel construct is formed by subsequently removing the caseinate phase from the ion-crosslinked alginate hydrogel. Those porous alginate hydrogels possess heterogeneous pores around 100 μm and interconnected paths. Human white adipose progenitors (WAPs) encapsulated in these hydrogels self-organize into spheroids and show enhanced viability, proliferation, and adipogenic differentiation, compared to non-porous constructs. As a proof of concept, this porous alginate hydrogel platform is employed to prepare core-shell spheres for coculture of WAPs and colon cancer cells, with WAP clusters distributed around cancer cell aggregates, to investigate cellular crosstalk. This efficacious approach is believed to provide a robust and versatile platform for engineering porous-structured alginate hydrogels for applications as cell carriers and in disease modeling.

Circulating insulin-like growth factor-1 and brain health: Evidence from 369,711 participants in the UK Biobank

BACKGROUND

The effects of insulin-like growth factor-1 (IGF-1) deficiency on cognitive decline have been consistently reported in animal studies, but the relationship between IGF-1 and human brain health remains controversial. Our study aimed to investigate the associations of serum IGF-1 concentrations with some brain-related disorders and neuroimaging features.

METHODS

This prospective study included 369,711 participants (55.8 ± 8.1 years) from the UK biobank who had serum IGF-1 measured and were free from brain-related disorders of interest - dementia, stroke, and Parkinson's disease (PD) - at enrollment (2006-2010). Restricted cubic splines and Cox proportional hazards models were used to detect the associations between IGF-1 concentrations and brain-related diseases. In addition, general linear regressions were applied to explore the relationship between IGF-1 concentrations and neuroimaging features (volumes of white matter, grey matter, and hippocampus and white matter hyperintensity) among a sub-sample of 36,458 participants with magnetic resonance imaging data collected since 2014.

RESULTS

During a median follow-up of 12.6 years, a total of 4,857 dementia, 6,240 stroke, and 2,116 PD cases were documented. The dose-response analyses yielded U-shaped relationships between IGF-1 concentrations and risks of dementia and stroke (P < 0.001 for non-linearity), with the lowest risks at 18 nmol/L and 26 nmol/L, respectively. A positive linear relationship was observed between IGF-1 concentrations and risk of PD (P = 0.163 for non-linearity). Moreover, neuroimaging analyses showed that higher IGF-1 concentrations were associated with greater volumes of white matter (β = 2.98 × 10-4, P < 0.001) and hippocampus (β = 3.37 × 10-4, P = 0.002) and smaller white matter hyperintensity (β = -3.12 × 10-3, P < 0.001).

CONCLUSIONS

Apart from the diverse associations with neuroimaging features, both low and high IGF-1 concentrations are associated with increased risks of dementia and stroke and higher IGF-1 concentrations are linked to a higher risk of PD, highlighting the potential of IGF-1 as a biomarker for risk stratification of brain health.

The neurobiology of insulin-like growth factor I: From neuroprotection to modulation of brain states

After decades of research in the neurobiology of IGF-I, its role as a prototypical neurotrophic factor is undisputed. However, many of its actions in the adult brain indicate that this growth factor is not only involved in brain development or in the response to injury. Following a three-layer assessment of its role in the central nervous system, we consider that at the cellular level, IGF-I is indeed a bona fide neurotrophic factor, modulating along ontogeny the generation and function of all the major types of brain cells, contributing to sculpt brain architecture and adaptive responses to damage. At the circuit level, IGF-I modulates neuronal excitability and synaptic plasticity at multiple sites, whereas at the system level, IGF-I intervenes in energy allocation, proteostasis, circadian cycles, mood, and cognition. Local and peripheral sources of brain IGF-I input contribute to a spatially restricted, compartmentalized, and timed modulation of brain activity. To better define these variety of actions, we consider IGF-I a modulator of brain states. This definition aims to reconcile all aspects of IGF-I neurobiology, and may provide a new conceptual framework in the design of future research on the actions of this multitasking neuromodulator in the brain.

The Stanniocalcin-PAPP-A-IGFBP-IGF Axis

The pappalysin metalloproteinases, PAPP-A and PAPP-A2, have emerged as highly specific proteolytic enzymes involved in the regulation of insulin-like growth factor (IGF) signaling. The only known pappalysin substrates are a subset of the IGF binding proteins (IGFBPs), which bind IGF-I or IGF-II with high affinity to antagonize receptor binding. Thus, by cleaving IGFBPs, the pappalysins have the potential to increase IGF bioactivity and hence promote IGF signaling. This is relevant both in systemic and local IGF regulation, in normal and several pathophysiological conditions. Stanniocalcin-1 and -2 were recently found to be potent pappalysin inhibitors, thus comprising the missing components of a complete proteolytic system, the stanniocalcin-PAPP-A-IGFBP-IGF axis. Here, we provide the biological context necessary for understanding the properties of this molecular network, and we review biochemical data, animal experiments, clinical data, and genetic data supporting the physiological operation of this branch as an important part of the IGF system. However, although in vivo data clearly illustrate its power, it is a challenge to understand its subtle operation, for example, multiple equilibria and inhibitory kinetics may determine how, where, and when the IGF receptor is stimulated. In addition, literally all of the regulatory proteins have suspected or known activities that are not directly related to IGF signaling. How such activities may integrate with IGF signaling is also important to address in the future.

CA 19-9 but Not IGF-1/IGFBP-2 Is a Useful Biomarker for Pancreatic Ductal Adenocarcinoma (PDAC) and Chronic Pancreatitis (CP) Differentiation

INTRODUCTION

There are still no effective diagnostic and prognostic biomarkers in pancreatic ductal adenocarcinoma (PDAC). The differentiation between PDAC and chronic pancreatitis (CP) is often challenging. The inflammatory mass in the course of CP causes diagnostic difficulties in differentiating them from neoplastic lesions and, thus, delays the initiation of radical treatment. Insulin-like growth factor 1 (IGF-1) and insulin-like growth factor-binding protein 2 (IGFBP-2) form a network involved in PDAC development. The role of IGFs in promoting pancreatic cancer cell proliferation, survival, and migration is well established, and their ability to stimulate tumor growth and metastasis is well documented. The aim of the study was to evaluate the usability of IGF-1, IGFBP-2, and IGF-1/IGFBP-2 ratio in PDAC and CP differentiation.

MATERIAL AND METHODS

The study included 137 patients: 89 patients with PDAC and 48 patients with CP. All subjects were tested for the levels of IGF-1 and IGFBP-2 using the ELISA method (Corgenix UK Ltd. R&D Systems), along with the level of CA 19-9 in serum. Additionally, the IGF-1/IGFBP-2 ratio was calculated. Further analyses used logit and probit models with varying determinants in order to discern between PDAC and CP patients. The models served as a basis for AUROC calculation.

RESULTS

The mean IGF-1 serum level was equal to 52.12 ± 33.13 ng/mL in PDAC vs. 74.23 ± 48.98 ng/mL in CP (p = 0.0053). The mean level of IGFBP-2 was equal to 305.95 ± 194.58 ng/mL in PDAC vs. 485.43 ± 299 ng/mL in CP (p = 0.0002). The mean CA 19-9 serum concentration was 434.95 ± 419.98 U/mL in PDAC vs. 78.07 ± 182.36 U/mL in CP (p = 0.0000). The mean IGF-1/IGFBP-2 ratio was 0.213 ± 0.14 in PDAC vs. 0.277 ± 0.33 in CP (p = 0.1914). The diagnostic usefulness of indicators for the purpose of PDAC and CP differentiation was assessed by means of AUROC comparison. The AUROCs of IGF-1, IGFBP-2, and IGF-1/IGFBP-2 ratio ranged below 0.7, being lower than the AUROC of CA 19-9 (0.7953; 0.719 within 95% CI). Together, the CA 19-9 and IGFBP-2 AUROCs also ranged below 0.8. When age was included, the AUROC increased to 0.8632, and its 95% confidence interval held above the 0.8 limit. The sensitivity of the used markers was not correlated to the stage of pancreatic PDAC.

CONCLUSIONS

The presented results indicate that CA 19-9 is a marker demonstrating high potential for PDAC and CP differentiation. The inclusion of additional variables into the model, such as the serum level of IGF-1 or IGFBP-2, slightly increased the sensitivity in differentiating CP from PDAC. The IGF-1/IGFBP-2 ratio turned out to be a good marker of pancreatic diseases, but insufficient for the purpose of CP and PDAC differentiation.

IGFBP1 Sustains Cell Survival during Spatially-Confined Migration and Promotes Tumor Metastasis

Cell migration is a pivotal step in metastatic process, which requires cancer cells to navigate a complex spatially-confined environment, including tracks within blood vessels and in the vasculature of target organs. Here it is shown that during spatially-confined migration, the expression of insulin-like growth factor-binding protein 1 (IGFBP1) is upregulated in tumor cells. Secreted IGFBP1 inhibits AKT1-mediated phosphorylation of mitochondrial superoxide dismutase (SOD2) serine (S) 27 and enhances SOD2 activity. Enhanced SOD2 attenuates mitochondrial reactive oxygen species (ROS) accumulation in confined cells, which supports tumor cell survival in blood vessels of lung tissues, thereby accelerating tumor metastasis in mice. The levels of blood IGFBP1 correlate with metastatic recurrence of lung cancer patients. This finding reveals a unique mechanism by which IGFBP1 sustains cell survival during confined migration by enhancing mitochondrial ROS detoxification, thereby promoting tumor metastasis.

Role of Estrogen and Estrogen Receptor in GH-Secreting Adenomas

Acromegaly is a rare disease with several systemic complications that may lead to increased overall morbidity and mortality. Despite several available treatments, ranging from transsphenoidal resection of GH-producing adenomas to different medical therapies, complete hormonal control is not achieved in some cases. Some decades ago, estrogens were first used to treat acromegaly, resulting in a significant decrease in IGF1 levels. However, due to the consequent side effects of the high dose utilized, this treatment was later abandoned. The evidence that estrogens are able to blunt GH activity also derives from the evidence that women with GH deficiency taking oral estro-progestins pills need higher doses of GH replacement therapy. In recent years, the role of estrogens and Selective Estrogens Receptor Modulators (SERMs) in acromegaly treatment has been re-evaluated, especially considering poor control of the disease under first- and second-line medical treatment. In this review, we analyze the state of the art concerning the impact of estrogen and SERMs on the GH/IGF1 axis, focusing on molecular pathways and the possible implications for acromegaly treatment.

Structural insight into CD93 recognition by IGFBP7

The CD93/IGFBP7 axis are key factors expressed in endothelial cells (EC) that mediate EC angiogenesis and migration. Upregulation of them contributes to tumor vascular abnormality and blockade of this interaction promotes a favorable tumor microenvironment for therapeutic interventions. However, how these two proteins associated to each other remains unclear. In this study, we solved the human CD93-IGFBP7 complex structure to elucidate the interaction between the EGF 1 domain of CD93 and the IB domain of IGFBP7. Mutagenesis studies confirmed the binding interactions and specificities. Cellular and mouse tumor studies demonstrated the physiological relevance of the CD93-IGFBP7 interaction in EC angiogenesis. Our study provides hints for development of therapeutic agents to precisely disrupt unwanted CD93-IGFBP7 signaling in the tumor microenvironment. Additionally, analysis of the CD93 full-length architecture provides insights into how CD93 protrudes on the cell surface and forms a flexible platform for binding to IGFBP7 and other ligands.

Associations between changes of smartphone pedometer-assessed step counts and levels of obesity-related breast cancer biomarkers in non-cancer women: A population-based observational study

While a higher level of physical activity (PA) is inversely associated with a higher breast cancer (BC) risk, the health benefits of daily steps on obesity-related BC biomarkers remain unclear. We aimed to understand the associations of changes in step counts with levels of five obesity-related BC biomarkers during a two-year follow-up. In total, 144 non-cancer women (47.96 ± 5.72) were observed on both 2019 and 2021. A structured questionnaire, daily steps and fasting blood samples were collected before (t0, 2019) and after (t1, 2021). Levels of biomarkers (IGF-binding proteins 3, adiponectin, soluble leptin receptor, C-reactive protein, and resistin) were assayed by ELISA. Participants were divided into persistent low steps, decreasing steps, increasing steps, and persistent high steps. Associations of categories on proposed biomarkers were estimated using linear regression models, with persistent low steps as reference. Associations between time-varying step counts with biomarkers were quantified using mixed linear models. Compared with persistent low steps, increasing steps is associated with a reduction in C-reactive protein level (β=-0.74, 95%CI=-1.23--0.26, P-value = 2.98 × 10-3). An inverse association between time-varying step counts with C-reactive protein level was identified, consistent across different obesity types and baseline step level categories. No association with daily step counts was observed for other proteins.

Insulin-like growth factor binding protein-3 induces senescence by inhibiting telomerase activity in MCF-7 breast cancer cells

Insulin-like growth factor binding protein-3 (IGFBP-3) has been known to inhibit cell proliferation and exert tumor-suppressing effects depending on the cell type. In this study, we aimed to show that IGFBP-3 induces cellular senescence via suppression of the telomerase activity, thereby inhibiting MCF-7 breast cancer cell proliferation. We found that the induction of IGFBP-3 in MCF-7 cells enhanced the loss of cell viability. Flow cytometry revealed a higher percentage of non-cycling cells among IGFBP-3-expressing cells than among controls. IGFBP-3 induction also resulted in morphological alterations, such as a flattened cytoplasm and increased granularity, suggesting that IGFBP-3 induces a senescence-like phenotype. The percentage of IGFBP-3 expressing cells with senescence-associated β-galactosidase activity was 3.4 times higher than control cells. Telomeric repeat amplification and real-time PCR showed that IGFBP-3 decreased telomerase activity by reducing the levels of the RNA component (hTR) and catalytic protein component with reverse transcriptase activity (hTERT) of telomerase in a dose-dependent manner. These results suggest that IGFBP-3 is a negative regulator of MCF-7 breast cancer cell growth by inducing senescence through telomerase suppression.

Structural insights into regulation of CCN protein activities and functions

CCN proteins play important functions during development, in repair mechanisms following tissue injury, as well as in pathophysiologic mechanisms of metastasis of cancer. CCNs are secreted proteins that have a multimodular structure and are categorized as matricellular proteins. Although the prevailing view is that CCN proteins regulate biologic processes by interacting with a wide array of other proteins in the microenvironment of the extracellular matrix, the molecular mechanisms of action of CCN proteins are still poorly understood. Not dissuading the current view, however, the recent appreciation that these proteins are signaling proteins in their own right and may even be considered preproproteins controlled by endopeptidases to release a C-terminal bioactive peptide has opened new avenues of research. Also, the recent resolution of the crystal structure of two of the domains of CCN3 have provided new knowledge with implications for the entire CCN family. These resolved structures in combination with structural predictions based upon the AlphaFold artificial intelligence tool provide means to shed new light on CCN functions in context of the notable literature in the field. CCN proteins have emerged as important therapeutic targets in several disease conditions, and clinical trials are currently ongoing. Thus, a review that critically discusses structure - function relationship of CCN proteins, in particular as it relates to interactions with other proteins in the extracellular milieu and on the cell surface, as well as to cell signaling activities of these proteins, is very timely. Suggested mechanism for activation and inhibition of signaling by the CCN protein family (graphics generated with BioRender.com ).

Impact of Chorionic Somatomammotropin In Vivo RNA Interference Phenotype on Uteroplacental Expression of the IGF Axis

While fetal growth is dependent on many factors, optimal placental function is a prerequisite for a normal pregnancy outcome. The majority of fetal growth-restricted (FGR) pregnancies result from placental insufficiency (PI). The insulin-like growth factors (IGF1 and IGF2) stimulate fetal growth and placental development and function. Previously, we demonstrated that in vivo RNA interference (RNAi) of the placental hormone, chorionic somatomammotropin (CSH), resulted in two phenotypes. One phenotype exhibits significant placental and fetal growth restriction (PI-FGR), impaired placental nutrient transport, and significant reductions in umbilical insulin and IGF1. The other phenotype does not exhibit statistically significant changes in placental or fetal growth (non-FGR). It was our objective to further characterize these two phenotypes by determining the impact of CSH RNAi on the placental (maternal caruncle and fetal cotyledon) expression of the IGF axis. The trophectoderm of hatched blastocysts (9 days of gestation, dGA) were infected with a lentivirus expressing either a non-targeting sequence (NTS RNAi) control or CSH-specific shRNA (CSH RNAi) prior to embryo transfer into synchronized recipient ewes. At ≈125 dGA, pregnancies were fitted with vascular catheters to undergo steady-state metabolic studies. Nutrient uptakes were determined, and tissues were harvested at necropsy. In both CSH RNAi non-FGR and PI-FGR pregnancies, uterine blood flow was significantly reduced (p ≤ 0.05), while umbilical blood flow (p ≤ 0.01), both uterine and umbilical glucose and oxygen uptakes (p ≤ 0.05), and umbilical concentrations of insulin and IGF1 (p ≤ 0.05) were reduced in CSH RNAi PI-FGR pregnancies. Fetal cotyledon IGF1 mRNA concentration was reduced (p ≤ 0.05) in CSH RNAi PI-FGR pregnancies, whereas neither IGF1 nor IGF2 mRNA concentrations were impacted in the maternal caruncles, and either placental tissue in the non-FGR pregnancies. Fetal cotyledon IGF1R and IGF2R mRNA concentrations were not impacted for either phenotype, yet IGF2R was increased (p ≤ 0.01) in the maternal caruncles of CSH RNAi PI-FGR pregnancies. For the IGF binding proteins (IGFBP1, IGFBP2, IGFBP3), only IGFBP2 mRNA concentrations were impacted, with elevated IGFBP2 mRNA in both the fetal cotyledon (p ≤ 0.01) and maternal caruncle (p = 0.08) of CSH RNAi non-FGR pregnancies. These data support the importance of IGF1 in placental growth and function but may also implicate IGFBP2 in salvaging placental growth in non-FGR pregnancies.

Insulin-like growth factor-1 (Igf1) signaling responses to food consumption after fasting in the Pacific rockfish Sebastes carnatus

Fish adjust rates of somatic growth in the face of changing food consumption. As in other vertebrates, growth in fish is regulated by the growth hormone (Gh)/insulin-like growth factor-1 (Igf1) endocrine axis, and changes in food intake impact growth via alterations to Gh/Igf1 signaling. Understanding the time course by which the Gh/Igf1 axis responds to food consumption is crucial to predict how rapidly changes in food abundance might lead to altered growth dynamics. Here, we looked at the response times of plasma Igf1 and liver Igf1 signaling-associated gene expression to refeeding after food deprivation in juvenile gopher rockfish (Sebastes carnatus), one of several species of northern Pacific Ocean Sebastes rockfishes targeted by fisheries or utilized for aquaculture. Gopher rockfish were fasted for 30 d, after which a subset was fed to satiation for 2 h, while other rockfish continued to be fasted. Refed fish exhibited higher hepatosomatic index (HSI) values and increased Igf1 after food consumption. Gene transcripts for Gh receptor 1 (ghr1), but not ghr2, increased in the liver after eating. Transcripts encoding igf1 also increased in the liver of refed fish 2-4 d after feeding, only to return to levels similar as continually fasted rockfish by 9 d after feeding. Liver mRNA abundances for Igf binding protein (Igfbp) genes igfbp1a, igfbp1b, and igfbp3a declined within 2 d of feeding. These findings provide evidence that circulating Igf1 in rockfish reflects a fish's feeding experience within the previous few days, and suggest that feeding-induced increases in Igf1 are being mediated in part by altered liver sensitivity to Gh due to upregulated Gh receptor 1 expression.

Nutritional status affects Igf1 regulation of skeletal muscle myogenesis, myostatin, and myofibrillar protein degradation pathways in gopher rockfish (Sebastes carnatus)

Insulin-like growth factor-1 (Igf1) regulates skeletal muscle growth in fishes by increasing protein synthesis and promoting muscle hypertrophy. When fish experience periods of insufficient food intake, they undergo slower muscle growth or even muscle wasting, and those changes emerge in part from nutritional modulation of Igf1 signaling. Here, we examined how food deprivation (fasting) modulates Igf1 regulation of liver and skeletal muscle gene expression in gopher rockfish (Sebastes carnatus), a nearshore rockfish of importance for commercial and recreational fisheries in the northeastern Pacific Ocean, to understand how food limitation impacts Igf regulation of muscle growth pathways. Rockfish were either fed or fasted for 14 d, after which a subset of fish from each group was treated with recombinant Igf1 from sea bream (Sparus aurata). Fish that were fasted lost body mass and had lower body condition, reduced hepatosomatic index, and lower plasma Igf1 concentrations, as well as a decreased abundance of igf1 gene transcripts in the liver, increased hepatic mRNAs for Igf binding proteins igfbp1a, igfbp1b, and igfbp3a, and decreased mRNA abundances for igfbp2b and a putative Igf acid labile subunit (igfals) gene. In skeletal muscle, fasted fish showed a reduced abundance of intramuscular igf1 mRNAs but elevated gene transcripts encoding Igf1 receptors A (igf1ra) and B (igf1rb), which also showed downregulation by Igf1. Fasting increased skeletal muscle mRNAs for myogenin and myostatin1, as well as ubiquitin ligase F-box only protein 32 (fbxo32) and muscle RING-finger protein-1 (murf1) genes involved in muscle atrophy, while concurrently downregulating mRNAs for myoblast determination protein 2 (myod2), myostatin2, and myogenic factors 5 (myf5) and 6 (myf6 encoding Mrf4). Treatment with Igf1 downregulated muscle myostatin1 and fbxo32 under both feeding conditions, but showed feeding-dependent effects on murf1, myf5, and myf6/Mrf4 gene expression indicating that Igf1 effects on muscle growth and atrophy pathways is contingent on recent food consumption experience.

Expression characteristics and their functional role of IGFBP gene family in pan-cancer

BACKGROUND

Insulin-like growth factor binding proteins (IGFBPs) are critical regulators of the biological activities of insulin-like growth factors. The IGFBP family plays diverse roles in different types of cancer, which we still lack comprehensive and pleiotropic understandings so far.

METHODS

Multi-source and multi-dimensional data, extracted from The Cancer Genome Atlas (TCGA), Oncomine, Cancer Cell Line Encyclopedia (CCLE), and the Human Protein Atlas (HPA) was used for bioinformatics analysis by R language. Immunohistochemistry and qRT-PCR were performed to validate the results of the database analysis results. Bibliometrics and literature review were used for summarizing the research progress of IGFBPs in the field of tumor.

RESULTS

The members of IGFBP gene family are differentially expressed in various cancer types. IGFBPs expression can affect prognosis of different cancers. The expression of IGFBPs expression is associated with multiple signal transduction pathways. The expression of IGFBPs is significantly correlated with tumor mutational burden, microsatellite instability, tumor stemness and tumor immune microenvironment. The qRT-PCR experiments verified the lower expression of IGFBP2 and IGFBP6 in gastric cancer and the lower expression of IGFBP6 in colorectal cancer. Immunohistochemistry validated a marked downregulation of IGFBP2 protein in gastric cancer tissues. The keywords co-occurrence analysis of IGFBP related publications in cancer showed relative research have been more concentrating on the potential of IGFBPs as tumor diagnostic and prognostic markers and developing cancer therapies.

CONCLUSIONS

These findings provide frontier trend of IGFBPs related research and new clues for identifying novel therapeutic targets for various cancers.

System analysis based on the migration- and invasion-related gene sets identifies the infiltration-related genes of glioma

The current database has no information on the infiltration of glioma samples. Here, we assessed the glioma samples' infiltration in The Cancer Gene Atlas (TCGA) through the single-sample Gene Set Enrichment Analysis (ssGSEA) with migration and invasion gene sets. The Weighted Gene Co-expression Network Analysis (WGCNA) and the differentially expressed genes (DEGs) were used to identify the genes most associated with infiltration. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to analyze the major biological processes and pathways. Protein-protein interaction (PPI) network analysis and the least absolute shrinkage and selection operator (LASSO) were used to screen the key genes. Furthermore, the nomograms and receiver operating characteristic (ROC) curve were used to evaluate the prognostic and predictive accuracy of this clinical model in patients in TCGA and the Chinese Glioma Genome Atlas (CGGA). The results showed that turquoise was selected as the hub module, and with the intersection of DEGs, we screened 104 common genes. Through LASSO regression, TIMP1, EMP3, IGFBP2, and the other nine genes were screened mostly in correlation with infiltration and prognosis. EMP3 was selected to be verified in vitro. These findings could help researchers better understand the infiltration of gliomas and provide novel therapeutic targets for the treatment of gliomas.

Mechanisms of ageing: growth hormone, dietary restriction, and metformin

Tackling the mechanisms underlying ageing is desirable to help to extend the duration and improve the quality of life. Life extension has been achieved in animal models by suppressing the growth hormone-insulin-like growth factor 1 (IGF-1) axis and also via dietary restriction. Metformin has become the focus of increased interest as a possible anti-ageing drug. There is some overlap in the postulated mechanisms of how these three approaches could produce anti-ageing effects, with convergence on common downstream pathways. In this Review, we draw on evidence from both animal models and human studies to assess the effects of suppression of the growth hormone-IGF-1 axis, dietary restriction, and metformin on ageing.

Effects of the short-term fasting and refeeding on growth-related genes in Japanese eel (Anguilla japonica) larvae

The Japanese eel (Anguilla japonica) spends a long period as the leptocephalus larval form under current rearing conditions. The duration of the larval stage until metamorphosis is influenced by body size and growth; however, little knowledge exists of the regulatory mechanism of growth in eel larvae. The present study focused on growth hormone (GH), insulin-like growth factors (IGFs), and IGF binding protein (IGFBP) as the central regulators of growth in teleost fishes and transforming growth factor-beta 3 (TGF-β3) as a possible key modulator of muscle growth and body component synthesis. Japanese eel IGFBP-1a and TGF-β3, comprising 264 and 411 amino acids, respectively, were cloned. Short-term (5-day) fasting and refeeding experiments were performed to understand changes in growth-related genes affected by nutritional status. The relative expression of gh increased with fasting and subsequently decreased with refeeding to the basal levels of the fed control. Relative igf-1 and igf-2 expression levels were high in the fasted group. Relative igf-1 was reduced after 2-day refeeding, whereas igf-2 decreased to the basal level after 1-day refeeding, suggesting that IGF-1 and IGF-2 might be regulated independently and contribute to postnatal growth in eel larvae. Relative igfbp-1a expression was sharply increased by fasting, whereas tgf-β3 showed high and low values in the fed and fasted groups, respectively. Relative igfbp-1a and tgf-β3 levels were negatively and positively correlated with body size, respectively. These results suggest that igfbp-1a and tgf-β3 are potential indices of growth for exploring optimal rearing conditions to shorten the larval stage in Japanese eels.

Evaluation of SNPs from human IGFBP6 associated with gene expression: an in-silico study

In the bloodstream and in local tissues, most IGF molecules are associated with the one of the members of the IGF-binding protein (IGFBP) family, which are divided into six distinct types. IGF-binding proteins have been demonstrated to either decrease or increase the growth-promoting effects of IGFs on cell culture, by extending their half-life. They alter how IGFs interact with the receptors on their cell surfaces. IGFBP6 gene is associated with disease in-situ carcinoma. Upregulation or downregulation of IGFBP6 gene has been implicated in different types of cancer in humans. Nonsynonymous SNPs changes have the potential to affect the protein's structure and function. Potential functional SNPs can be assessed before undertaking studies in larger populations because validation of these functional SNPs can be a crucial problem. So, in this in-silico investigation, we used a variety of sequence- and structure-based bioinformatics methods to separate the potential nsSNPs of the IGFBP6 gene from the neutral ones. In total of 216 nsSNPs, 5 were found to have potential effects using 5 prediction tools. From which, 2 nsSNPs (R128G and R164H) were selected as potentially damaging due to their presence in highly conserved region and ability to decrease protein stability. Among these 2 nsSNPs, only R164H was found to be associated with Uterine corpus endometrial carcinoma. It was also found that both, upregulation or downregulation of IGFBP6 gene can lead to the different types of cancers. The findings of the present study will certainly be valuable in the future large population-based investigations as well as drug discovery, especially developing personalized medicine.Communicated by Ramaswamy H. Sarma.

The impact of circulating IGF-1 and IGFBP-2 on cardiovascular prognosis in patients with acute coronary syndrome

Background

While insulin-like growth factor 1 (IGF-1) exerts a cardioprotective effect in the setting of atherosclerosis, insulin-like growth factor binding protein 2 (IGFBP-2) is involved in metabolic syndrome. Although IGF-1 and IGFBP-2 are known to be predictors for mortality in patients with heart failure, their use in clinic as prognostic biomarkers for acute coronary syndrome (ACS) requires investigation. We evaluated the relationship between IGF-1 and IGFBP-2 levels at admission and the risk of major adverse cardiovascular events (MACEs) in patients with ACS.

Methods

A total of 277 ACS patients and 42 healthy controls were included in this prospective cohort study. Plasma samples were obtained and analyzed at admission. Patients were followed for MACEs after hospitalization.

Results

Among patients who suffered acute myocardial infarction, plasma levels of IGF-1 and IGFBP-2 were lower and higher, respectively, as compared to healthy controls (both p &lt; 0.05). The mean follow-up period was 5.22 (1.0–6.0) months and MACEs incidence was 22.4% (62 of 277 patients). Kaplan–Meier survival analysis revealed that patients with low IGFBP-2 levels had a greater event-free survival rate than patients with high IGFBP-2 levels (p &lt; 0.001). Multivariate Cox proportional hazards analysis revealed IGFBP-2, but not IGF-1, to be a positive predictor of MACEs (hazard ratio 2.412, 95% CI 1.360–4.277; p = 0.003).

Conclusion

Our findings suggest that high IGFBP-2 levels are associated with the development of MACEs following ACS. Moreover, IGFBP-2 is likely an independent predictive marker of clinical outcomes in ACS.

Insulin-like growth factor binding protein 4 loaded electrospun membrane ameliorating tendon injury by promoting retention of IGF-1

Tendon injury is one of the most common musculoskeletal disorders that impair joint mobility and lower quality of life. The limited regenerative capacity of tendon remains a clinical challenge. Local delivery of bioactive protein is a viable therapeutic approach for tendon healing. Insulin-like growth factor binding protein 4 (IGFBP-4) is a secreted protein capable of binding and stabilizing insulin-like growth factor 1 (IGF-1). Here, we applied an aqueous-aqueous freezing-induced phase separation technology to obtain the IGFBP4-encapsulated dextran particles. Then, we added the particles into poly (L-lactic acid) (PLLA) solution to fabricate IGFBP4-PLLA electrospun membrane for efficient IGFBP-4 delivery. The scaffold showed excellent cytocompatibility and a sustained release of IGFBP-4 for nearly 30 days. In cellular experiments, IGFBP-4 promoted tendon-related and proliferative markers expression. In a rat Achilles tendon injury model, immunohistochemistry and quantitative real-time polymerase chain reaction confirmed better outcomes by using the IGFBP4-PLLA electrospun membrane at the molecular level. Furthermore, the scaffold effectively promoted tendon healing in functional performance, ultrastructure and biomechanical properties. We found addition of IGFBP-4 promoted IGF-1 retention in tendon postoperatively and then facilitated protein synthesis via IGF-1/AKT signaling pathway. Overall, our IGFBP4-PLLA electrospun membrane provides a promising therapeutic strategy for tendon injury.

IGFBP-6 Network in Chronic Inflammatory Airway Diseases and Lung Tumor Progression

The lung is an accomplished organ for gas exchanges and directly faces the external environment, consequently exposing its large epithelial surface. It is also the putative determinant organ for inducing potent immune responses, holding both innate and adaptive immune cells. The maintenance of lung homeostasis requires a crucial balance between inflammation and anti-inflammation factors, and perturbations of this stability are frequently associated with progressive and fatal respiratory diseases. Several data demonstrate the involvement of the insulin-like growth factor (IGF) system and their binding proteins (IGFBPs) in pulmonary growth, as they are specifically expressed in different lung compartments. As we will discuss extensively in the text, IGFs and IGFBPs are implicated in normal pulmonary development but also in the pathogenesis of various airway diseases and lung tumors. Among the known IGFBPs, IGFBP-6 shows an emerging role as a mediator of airway inflammation and tumor-suppressing activity in different lung tumors. In this review, we assess the current state of IGFBP-6's multiple roles in respiratory diseases, focusing on its function in the inflammation and fibrosis in respiratory tissues, together with its role in controlling different types of lung cancer.