Insulin-like Growth Factor-1 Levels Reflect Muscle and Bone Health and Determine Complications and Mortality in Decompensated Cirrhosis.

Background: The growth hormone-insulin-like growth factor (GH-IGF-1) axis and its impairment with sarcopenia, frailty, bone health, complications, and prognosis are not well characterized in cirrhosis. Methods: We investigated the adult decompensated cirrhosis out-patients at a tertiary care institute between 2021 and 2023 for serum GH and IGF-1 levels, and associated them with sarcopenia (CT-SMI in cm2/m2), liver frailty index (LFI), osteodystrophy (DEXA), clinical decompensations (overall, ascites, encephalopathy, infection, and bleed), and survival up to 180 days. Results: One-hundred-seventy-two patients, 95% males, aged 46.5 years (median). logIGF-1 levels were negatively associated with sarcopenia, osteodystrophy, LFI, CTP, and MELD-Na score (P < 0.05 each). Patients with low IGF-1 levels had a higher incidence of complications (overall, ascites and encephalopathy) than those with intermediate, and high IGF-1 levels (P < 0.05 each). Both logIGF-1 (AUC: 0.686) and MELD (AUC: 0.690) could predict 180-day mortality (P < 0.05, each). Adding logIGF-1 with MELDNa further improved discriminative accuracy of MELDNa (AUC: 0.729) P < 0.001. The increase in IGF-1 on follow-up was associated with better survival and fewer complications. Conclusion: Reduced IGF-1 levels reflect sarcopenia, frailty, and osteodystrophy in cirrhosis. Low IGF-1 are associated with severity, development of decompensations, and mortality.

The influence of genotype makeup on the effectiveness of growth hormone therapy in children with Prader-Willi syndrome.

BACKGROUND: Prader-Willi syndrome (PWS) is a rare multisystemic hereditary illness. Recombinant human growth hormone (rhGH) therapy is widely recognized as the primary treatment for PWS. This study aimed to examine how different PWS genotypes influence the outcome of rhGH treatment in children with PWS. METHODS: A review was conducted on 146 Chinese children with PWS, genetically classified and monitored from 2017 to 2022. Unaltered and modified generalized estimating equations (GEE) were employed to examine the long-term patterns in primary outcomes (growth metrics) and secondary outcomes (glucose metabolism metrics and insulin-like growth factor-1 (IGF-1)) during rhGH therapy. The study also evaluated the prevalence of hypothyroidism, hip dysplasia, and scoliosis before and after rhGH treatment. RESULTS: Children with PWS experienced an increase in height/length standard deviation scores (SDS) following rhGH administration. The impact of rhGH therapy on growth measurements was similar in both the deletion and maternal uniparental diploidy (mUPD) cohorts. Nevertheless, the deletion group was more prone to insulin resistance (IR) compared to the mUPD group. No significant variations in growth metrics were noted between the two groups (P > 0.05). At year 2.25, the mUPD group showed a reduction in fasting insulin (FINS) levels of 2.14 uIU/ml (95% CI, -4.26, -0.02; P = 0.048) and a decrease in homeostasis model assessment of insulin resistance (HOMA-IR) of 0.85 (95% CI, -1.52, -0.17; P = 0.014) compared to the deletion group. Furthermore, there was a decrease in the IGF standard deviation scores (SDS) by 2.84 (95% CI, -4.84, -0.84; P = 0.005) in the mUPD group during the second year. The frequency of hip dysplasia was higher in the mUPD group compared to the deletion group (P < 0.05). CONCLUSIONS: rhGH treatment effectively increased height/length SDS in children with PWS, with similar effects observed in both deletion and mUPD genotypes. Children with mUPD genetype receiving rhGH treatment may experience enhanced therapeutic effects in managing PWS.

Swimming training promotes angiogenesis of endothelial progenitor cells by upregulating IGF1 expression and activating the PI3K/AKT pathway in type 2 diabetic rats.

The present study aimed to investigate the effect of swimming training on the angiogenesis of endothelial progenitor cells (EPCs) in type 2 diabetes mellitus (T2DM) rats by upregulating the insulin­like growth factor 1 (IGF1) expression and to reveal its potential mechanism of action. Male Sprague­Dawley rats were divided into the Control, Model, Model train, Model train + short interfering (si)­NC and Model train + si­IGF1 groups. Serum glucose levels were measured using the oral glucose tolerance test. EPCs were isolated from the bone marrow cavity and identified through morphological observation and immunofluorescence staining. The expression of IGF­1 mRNA in rat serum and EPCs was analyzed by reverse transcription­quantitative PCR. The fasting insulin levels in serum were assessed by ELISA. Cell Counting Kit­8, scratch assay and tube formation assay were used to determine the cell viability, migration and tube formation of rat EPCs, and western blotting was employed to measure the expression levels of IGF1, phosphoinositide 3­kinase (PI3K), phosphorylated­PI3K, protein kinase B (AKT) and phosphorylated­AKT. The present study demonstrated that swimming training significantly decreased the glucose levels and homeostatic model assessment of insulin resistance scores, but increased the fasting insulin levels and IGF1 mRNA expression. Microscopic observation and immunofluorescence identification suggested that EPCs were successfully isolated. In addition, swimming training markedly elevated the levels of IGF1 and promoted cell viability, migration and tube formation in rat EPCs. Furthermore, IGF1 knockdown experiments indicated that swimming training might play a regulatory role by elevating the IGF1 expression to activate the PI3K/AKT pathway. Overall, swimming training promoted the angiogenesis of EPCs in T2DM rats and its potential mechanism may be related to the upregulation of IGF1 expression and the activation of the PI3K/AKT pathway.

Effect of ketogenic diets on insulin-like growth factor (IGF)-1 in humans: A systematic review and meta-analysis.

BACKGROUND: Insulin-like growth factor (IGF)-1 plays a role in aging and cancer biology, with fasting known to reduce serum IGF-1 levels in human adults. However, the impact of ad libitum ketogenic diets (KDs) on IGF-1 levels remains unclear. METHODS: Adhering to PRISMA guidelines, we conducted a meta-analysis of human trials by systematically searching Ovid, PubMed, Scopus, and CENTRAL Libraries until June 2023. Eligible studies prescribed KDs to adults of any health status, confirmed ketosis, and measured serum IGF-1. Protocols involving prescribed fasting or energy restriction were excluded. Mean differences (MD) and 95% confidence intervals (CIs) were calculated longitudinally between pre- and post-intervention measurements for the KD groups. RESULTS: Among twelve publications meeting the inclusion criteria, 522 individuals participated, with 236 assigned to KDs. The intervention duration ranged from 1-20 weeks. Pooled results from ten trials showed a significant reduction in serum IGF-1 levels post-intervention (MD: -24.9ng/mL [95% CI -31.7 to -18.1]; p<0.0001) with low heterogeneity across studies (I2=27%, p=0.19). KDs were also associated with significantly decreased fasting insulin (MD: -2.57 mU/L [95% CI -4.41 to -0.74], p=0.006) and glucose (MD: -7.30mg/dL [95% CI -11.62 to -2.98], p=0.0009), although heterogeneity was significant. Subgroup analyses on study design, gender, dietary duration, and oncological status revealed no significant differences. CONCLUSION: Ad libitum KDs (>55% fat) effectively induce ketosis and can lower serum IGF-1 by 20%, fasting glucose by 6% and insulin by 29%. This clinically notable reduction in IGF-1 can be attained without the need for a prescribed fasting or severe calorie restriction regimen. Further investigation is warranted to explore the impact of KDs on ageing biomarkers and cancer management.

Association between serum insulin-like growth factor-1 and bone mineral density in patients with type 2 diabetes.

Background: Secondary osteoporosis is associated with type 2 diabetes mellitus (T2DM), and there is conflicting evidence regarding the relationship between insulin-like growth factor-1 (IGF-1) and bone mineral density (BMD) in different populations. The objective of this study was to investigate the relationship between serum IGF-1 levels and BMD in patients with T2DM. Method: A retrospective cross-sectional study was performed on a cohort of 363 patients with T2DM, comprising men aged over 50 and women who are postmenopausal. Those with no significant medical history or medication affecting BMD or IGF-1 were considered. Data analyzed included IGF-1 levels, markers of bone metabolism, and measurements of BMD. To account for age and gender variations, we calculated IGF-1 standard deviation scores (IGF-1 SDS) for further investigation. Results: A significant increase in BMD at lumbar spine (LS), femoral neck (FN), and total hip (TH) was observed as IGF-1 SDS tertiles rose. We revealed a nonlinear correlation between IGF-1 SDS and BMD at these sites, with a common inflection point identified at an IGF-1 SDS level of -1.68. Additionally, our multivariate piecewise linear regression analysis highlighted a positive association between IGF-1 SDS and BMD at LS, FN, and TH when IGF-1 SDS exceeded the inflection point (ß 0.02, 95% CI 0.01, 0.04 for LS; ß 0.02, 95% CI 0.01, 0.03 for FN; ß 0.02, 95% CI 0.01, 0.03 for TH). Conversely, below the inflection point, this association was not significant (ß -0.04, 95% CI -0.10, 0.01 for LS; ß -0.04, 95% CI -0.08, 0.01 for FN; ß -0.03, 95% CI -0.08, 0.01 for TH). Conclusion: These findings reveal a nonlinear relationship between IGF-1 SDS and BMD in T2DM patients. Higher serum IGF-1 levels were connected to increased bone density only after surpassing a certain threshold.

The Effects of IGF1 and MGF on Neural Stem Cells in Hypoxic Conditions.

Introduction: Ischemic stroke has high morbidity and mortality rates worldwide. Low oxygen (O2) levels detected in such conditions create a vulnerable environment for neural stem cells (NSC), altering neuronal function, and leading to neuronal injury or death. There are still no effective treatments for such consequences. This study investigates the molecular and functional effects of growth factors, namely, insulin-like growth factor 1 (IGF-I) and mechano growth factor (MGF), in NSC exposed to low O2 levels. Methods: An in vitro ischemia model was created by rat hippocampal NSC grown in culture that was exposed to varying oxygen levels, including 0%, 3%, and 20 % for the representation of anoxic, hypoxic, and normoxic conditions, respectively, during 24 h. NSC has investigated IGF-I, MGF, and HIF1-Alpha (HIF-1α) gene expressions by real-time reverse transcription polymerase chain reaction. The effects of external administration of growth factors (IGF-I and MGF) on NSC proliferation in such conditions were explored. Results: Increased IGF-I and MGF gene expressions were detected in the samples exposed to low O2. Anoxia was the highest stimulant for IGF-I and MGF gene expressions. Meanwhile, HIF1-α that encodes hypoxia-inducible factor-1α revealed downregulation in relative gene expression fold change with IGF-I application in all conditions, whereas MGF application upregulated its change in an anoxic environment. Furthermore, MGF-induced NSC had more proliferationmigration rate in all oxygen conditions. IGF-I induced significant NSC proliferation in 0% and 20% O2. Conclusion: These findings suggest that IGF-I and MGF expressions were increased to reduce the damage in NSC exposed to low oxygen, and exogenous MGF and IGF-I application increased NSC proliferation at the time of injury. The results might imply the role of exogenous MGF and IGF-I in the treatment of ischemia for relieving the effect of neuronal damage due to their neuroprotective and proliferative effects.

Estetrol Inhibits the Prostate Cancer Tumor Stimulators FSH and IGF-1.

Background: The co-treatment of androgen deprivation therapy (ADT) for advanced prostate cancer (PCa) with the fetal estrogen estetrol (E4) may further inhibit endocrine PCa tumor stimulators. We previously reported the suppression of follicle-stimulating hormone (FSH), total and free testosterone, and prostate-specific antigen by ADT+E4. Here, we provide more detailed data on FSH suppression by E4 and present new findings on the effect of ADT+E4 on insulin-like growth factor-1 (IGF-1). Methods: A Phase II, double-blind, randomized, placebo-controlled study (the PCombi study) was conducted in advanced PCa patients treated with ADT. The study assessed the effect of E4 co-treatment with LHRH agonist ADT on tumor stimulators, including FSH and IGF-1. Patients starting ADT were randomized 2:1 to receive either 40 mg E4 (n = 41) or placebo (n = 21) for 24 weeks. Non-parametric analyses were performed on the per-protocol population (PP) and individual changes were visualized. Results: The PP included 57 patients (37 ADT+E4; 20 ADT+placebo). ADT+E4 almost completely suppressed FSH in all patients (98% versus 37%; p < 0.0001). IGF-1 levels decreased by 41% with ADT+E4 versus an increase of 10% with ADT+placebo (p < 0.0001). Conclusions: The almost complete suppression of the tumor stimulator FSH using ADT plus E4 observed in all individual patients in this study, along with the augmented suppression of IGF-1 versus an increase by ADT only, may be clinically relevant and suggest the enhanced anti-cancer treatment efficacy of E4 in addition to the previously reported additional suppression of total and free T and PSA.

Small molecule modulation of insulin receptor-insulin like growth factor-1 receptor heterodimers in human endothelial cells.

OBJECTIVES: The insulin receptor (IR) and insulin like growth factor-1 receptor (IGF-1R) are heterodimers consisting of two extracellular α-subunits and two transmembrane ß -subunits. Insulin αß and insulin like growth factor-1 αß hemi-receptors can heterodimerize to form hybrids composed of one IR αß and one IGF-1R αß. The function of hybrids in the endothelium is unclear. We sought insight by developing a small molecule capable of reducing hybrid formation in endothelial cells. METHODS: We performed a high-throughput small molecule screening, based on a homology model of the apo hybrid structure. Endothelial cells were studied using western blotting and qPCR to determine the effects of small molecules that reduced hybrid formation. RESULTS: Our studies unveil a first-in-class quinoline-containing heterocyclic small molecule that reduces hybrids by >50% in human umbilical vein endothelial cells (HUVECs) with no effects on IR or IGF-1R. This small molecule reduced expression of the negative regulatory p85α subunit of phosphatidylinositol 3-kinase, increased basal phosphorylation of the downstream target Akt and enhanced insulin/insulin-like growth factor-1 and shear stress-induced serine phosphorylation of Akt. In primary saphenous vein endothelial cells (SVEC) from patients with type 2 diabetes mellitus undergoing coronary artery bypass (CABG) surgery, hybrid receptor expression was greater than in patients without type 2 diabetes mellitus. The small molecule significantly reduced hybrid expression in SVEC from patients with type 2 diabetes mellitus. CONCLUSIONS: We identified a small molecule that decreases the formation of IR: IGF-1R hybrid receptors in human endothelial cells, without significant impact on the overall expression of IR or IGF-1R. In HUVECs, reduction of IR: IGF-1R hybrid receptors leads to an increase in insulin-induced serine phosphorylation of the critical downstream signalling kinase, Akt. The underpinning mechanism appears, at least in part to involve the attenuation of the inhibitory effect of IR: IGF-1R hybrid receptors on PI3-kinase signalling.

Masseter Muscle Volume and Its Association with Sarcopenia and Muscle Determinants in Older Japanese Adults: the Bunkyo Health Study.

AIM: Sarcopenia has been with a decrease in masseter muscle (MM) thickness in high-risk older populations. However, the relationship between sarcopenia and determinants of MM volume (MMV) in the general elderly population remains unclear. METHOD: In a cross-sectional study of 1,484 older adults in Tokyo, we evaluated MMV using 3D MRI scanning, appendicular skeletal muscle mass (ASMM), handgrip strength, dietary intake, smoking, insulin-like growth factor 1 (IGF-1) levels, and the ACTN3 R577X polymorphism. Participants were divided into quintiles based on MMV (Q1-5). RESULTS: Participants in our study had a mean age of 73.0 ± 5.3 years and their MMV (Men: 35.3 ± 7.8 mL, Women: 25.0 ± 5.1 mL) was significantly higher in men than in women. A significant association between MMV and sarcopenia was observed, with the lowest quintile (Q1) showing a higher risk compared to the highest quintile (Q5) in both sexes. Body mass index (BMI) and age were independent determinants of ASMM in both sexes, whereas BMI, but interestingly not age, was a determinant of MMV. Moreover, IGF-1 was positively correlated with MMV in both sexes; smoking was negatively correlated with MMV in women. The ACTN3 577XX genotype was only associated with smaller MMV in men. CONCLUSION: Low MMV increased the risk of sarcopenia, particularly in men. BMI and age strongly influenced ASMM, while MMV was only weakly associated with BMI and not with age. Notably, IGF-1 level was positively associated with MMV only, and ACTN3 genotype was associated to reduced MMV only in men.

The vasoprotective role of IGF-1 signaling in the cerebral microcirculation: prevention of cerebral microhemorrhages in aging.

Aging is closely associated with various cerebrovascular pathologies that significantly impact brain function, with cerebral small vessel disease (CSVD) being a major contributor to cognitive decline in the elderly. Consequences of CSVD include cerebral microhemorrhages (CMH), which are small intracerebral bleeds resulting from the rupture of microvessels. CMHs are prevalent in aging populations, affecting approximately 50% of individuals over 80, and are linked to increased risks of vascular cognitive impairment and dementia (VCID). Hypertension is a primary risk factor for CMHs. Vascular smooth muscle cells (VSMCs) adapt to hypertension by undergoing hypertrophy and producing extracellular matrix (ECM) components, which reinforce vessel walls. Myogenic autoregulation, which involves pressure-induced constriction, helps prevent excessive pressure from damaging the vulnerable microvasculature. However, aging impairs these adaptive mechanisms, weakening vessel walls and increasing susceptibility to damage. Insulin-like Growth Factor 1 (IGF-1) is crucial for vascular health, promoting VSMC hypertrophy, ECM production, and maintaining normal myogenic protection. IGF-1 also prevents microvascular senescence, reduces reactive oxygen species (ROS) production, and regulates matrix metalloproteinase (MMP) activity, which is vital for ECM remodeling and stabilization. IGF-1 deficiency, common in aging, compromises these protective mechanisms, increasing the risk of CMHs. This review explores the vasoprotective role of IGF-1 signaling in the cerebral microcirculation and its implications for preventing hypertension-induced CMHs in aging. Understanding and addressing the decline in IGF-1 signaling with age are crucial for maintaining cerebrovascular health and preventing hypertension-related vascular injuries in the aging population.

Deciphering the Dysregulating IGF-1-SP1-CD248 Pathway in Fibroblast Functionality during Diabetic Wound Healing.

Reduced fibroblast activity is a critical factor in the progression of diabetic ulcers. CD248, a transmembrane glycoprotein prominently expressed in activated fibroblasts, plays a pivotal role in wound healing. However, the role of CD248 in diabetic wound healing and the CD248 regulatory pathway remains largely unexplored. Our study shows that CD248 expression is significantly reduced in skin wounds from both diabetic patients and mice. Single-cell transcriptome data analyses reveal a marked reduction of CD248-enriched secretory-reticular fibroblasts in diabetic wounds. We identify insulin-like growth factor-1 (IGF-1) as a key regulator of CD248 expression through the Akt/mTOR signaling pathway and the Sp1 transcription factor. Overexpression of CD248 enhances fibroblast motility, elucidating the underrepresentation of CD248-enriched fibroblasts in diabetic wounds. Immunohistochemical staining of diabetic wound samples further confirm low SP1 expression and fewer CD248-positive secretory-reticular fibroblasts. Further investigation reveals that elevated tumor necrosis factor α (TNFα) levels in diabetic environment promotes IGF-1 resistance, and inhibiting IGF-1-induced CD248 expression. In summary, our findings underscore the critical role of the IGF1-SP1-CD248 axis in activating reticular fibroblasts during wound-healing processes. Targeting this axis in fibroblasts could help develop a therapeutic regimen for diabetic ulcers.

Correlation of tri-ponderal mass index with insulin-like growth factor-I and insulin-like growth factor binding protein-3 in children and adolescents.

PURPOSE: We aimed to investigate the relationship between the tri-ponderal mass index (TMI), a new indirect measure of fat mass, and insulin-like growth factor (IGF)-I/IGF binding protein (IGFBP)-3. METHODS: The study included 1,630 children and adolescents who visited Jeonbuk National University Children's Hospital. Each patient's medical record was retrospectively reviewed for age, sex, height, weight, body mass index (BMI), TMI, and IGF-1 and IGFBP-3 levels. Study participants were divided by sex and then categorized by age, BMI, and TMI. Finally, the correlations of TMI with IGF-1 level, IGF-1 standard deviation score (SDS), IGFBP-3 level, IGFBP-3 SDS, and IGF-1/IGFBP-3 ratio were investigated. RESULTS: All participants were <19 years of age. BMI correlated with IGF-1 and IGFBP-3 levels in both sexes; however, the relationship with TMI differed by sex. TMI correlated with IGF-1 and IGFBP-3 SDS in boys and with IGF-1, IGFBP-3, and IGFBP-3 SDS in girls across all ages. In boys, BMI and TMI significantly correlated with IGF-1, IGF-1 SDS, IGFBP-3, IGFBP-3 SDS, and the IGF-1/IGFBP-3 ratio in the normal-weight group. TMI also correlated with IGF-1, IGFBP-3, and IGFBP-3 SDS in the overweight group. In girls, BMI significantly correlated with IGF-1, IGF-1 SDS, IGFBP-3, IGFBP-3 SDS, and the IGF-1/IGFBP-3 ratio in the normal-weight group and with IGFBP-3 and IGFBP-3 SDS in the overweight group, while TMI correlated with IGF-1, IGF-1 SDS, and the IGF-1/IGFBP-3 ratio in the normal-weight group; with IGF-1, IGFBP-3, and IGFBP-3 SDS in the overweight group; and with IGFBP-3 SDS in the obese group. CONCLUSION: TMI may more strongly correlate with IGFBP-3 level than BMI in overweight boys and with IGFBP-3 SDS in overweight and obese girls. The correlation of IGFBP-3 SDS with TMI may be helpful for evaluating weight status in adolescent girls.

Overexpression of Igf2-derived Mir483 inhibits Igf1 expression and leads to developmental growth restriction and metabolic dysfunction in mice.

Mir483 is a conserved and highly expressed microRNA in placental mammals, embedded within the Igf2 gene. Its expression is dysregulated in a number of human diseases, including metabolic disorders and certain cancers. Here, we investigate the developmental regulation and function of Mir483 in vivo. We find that Mir483 expression is dependent on Igf2 transcription and the regulation of the Igf2/H19 imprinting control region. Transgenic Mir483 overexpression in utero causes fetal, but not placental, growth restriction through insulin-like growth factor 1 (IGF1) and IGF2 and also causes cardiovascular defects leading to fetal death. Overexpression of Mir483 post-natally results in growth stunting through IGF1 repression, increased hepatic lipid production, and excessive adiposity. IGF1 infusion rescues the post-natal growth restriction. Our findings provide insights into the function of Mir483 as a growth suppressor and metabolic regulator and suggest that it evolved within the INS-IGF2-H19 transcriptional region to limit excessive tissue growth through repression of IGF signaling.

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In recent years, growth hormone and insulin-like growth factors have become key regulators of bone metabolism and remodeling, crucial for maintaining healthy bone mass throughout life. Studies have shown that adult growth hormone deficiency leads to alterations in bone remodeling, significantly affecting bone microarchitecture and increasing fracture risk. Although recombinant human growth hormone replacement therapy can mitigate these adverse effects, improving bone density, and reduce fracture risk, its effectiveness in treating osteoporosis, especially in adults with established growth hormone deficiency, seems limited. Bisphosphonates inhibit bone resorption by targeting farnesyl pyrophosphate synthase in osteoclasts, and clinical trials have confirmed their efficacy in improving osteoporosis. Therefore, for adult growth hormone deficiency patients with osteoporosis, the use of bisphosphonates alongside growth hormone replacement therapy is recommended.

Murine neonatal cardiac regeneration depends on Insulin-like growth factor 1 receptor signaling.

Unlike adult mammals, the hearts of neonatal mice possess the ability to completely regenerate from myocardial infarction (MI). This observation has sparked vast interest in deciphering the potentially lifesaving and morbidity-reducing mechanisms involved in neonatal cardiac regeneration. In mice, the regenerative potential is lost within the first week of life and coincides with a reduction of Insulin-like growth factor 1 receptor (Igf1r) expression in the heart. Igf1r is a well-known regulator of cardiomyocyte maturation and proliferation in neonatal mice. To test the role of Igf1r as a pivotal factor in cardiac regeneration, we knocked down (KD) Igf1r specifically in cardiomyocytes using recombinant adeno-associated virus (rAAV) delivery and troponin T promotor driven shRNAmirs. Cardiomyocyte specific Igf1r KD versus control mice were subjected to experimental MI by permanent ligation of the left anterior descending artery (LAD). Cardiac functional and morphological data were analyzed over a 21-day period. Neonatal Igf1r KD mice showed reduced systolic cardiac function and increased fibrotic cardiac remodeling 21 days post injury. This cardiac phenotype was associated with reduced cardiomyocyte nuclei mitosis and decreased AKT and ERK phosphorylation in Igf1r KD, compared to control neonatal mouse hearts. Our in vivo murine data show that Igf1r KD shifts neonatal cardiac regeneration to a more adult-like scarring phenotype, identifying cardiomyocyte-specific Igf1r signaling as a crucial component of neonatal cardiac regeneration.

Association between insulin-like growth factor-1 and ocular surface parameters in obese prepubertal boys.

The study aimed to investigate the correlation between insulin-like growth factor 1 (IGF-1) and ocular surface parameters in obese prepubertal boys. Thirty obese prepubertal boys and 30 age- and gender-matched healthy controls underwent physical measurements, laboratory tests, and ocular surface assessments. The obese group showed lower IGF-1 levels (P = 0.001), reduced Schirmer I tear test (SIT) (P <0.001), and higher meibomian gland scores (meiboscore) compared to controls (P = 0.015). Bivariate analysis revealed a positive association between IGF-1 and SIT (r = 0.677, P < 0.001), and a negative association with between IGF-1 and meiboscore (r = - 0.487, P < 0.001). Multiple regression analysis indicated that IGF-1 (P < 0.001) and triglycerides (P = 0.028) independently influenced SIT. Logistic analysis showed a significant association between decreased IGF-1 and higher meiboscore values (OR 0.994, 95% confidence interval 0.988-1.000; P = 0.033). CONCLUSION: The findings suggest that reduced IGF-1 in obese prepubertal boys is independently linked to decreased SIT and increased meiboscore, irrespective of obesity and traditional cardiovascular risk factors. This implies that monitoring ocular surface parameters in obese children might provide a new perspective for clinical practice to focus on. WHAT IS KNOWN: • Obese children exhibit decreased levels of IGF-1, and this reduction in IGF-1 is associated with cardiovascular metabolic complications related to obesity. • Ocular surface tissues might act as targets for hormones, might experience local effects of these hormone. WHAT IS NEW: • In prepubertal obese boys, the decrease in IGF-1 is independently linked to decreased SIT and increased meiboscore, irrespective of obesity and traditional cardiovascular risk factors. • This finding implies that monitoring ocular surface parameters in obese children might provide a new perspective for clinical practice to focus on.

Cancer-associated fibroblasts promote the progression and chemoresistance of HCC by inducing IGF-1.

Crosstalk between cancer-associated fibroblasts (CAFs) and tumour cells plays a critical role in multiple cancers, including hepatocellular carcinoma (HCC). CAFs contribute to tumorigenesis by secreting growth factors, modifying the extracellular matrix, supporting angiogenesis, and suppressing antitumor immune responses. However, effect and mechanism of CAF-mediated promotion of hepatocellular carcinoma cells are still unclear. In study, we demonstrated CAFs promoted the proliferation and inhibited the apoptosis of HCC cells by secreting interleukin-6 (IL-6), which induced autocrine insulin-like growth factor-1 (IGF-1) in HCC. IGF-1 promoted the progression and chemoresistance of HCC. IGF-1 receptor (IGF-1R) inhibitor NT157 abrogated the effect of CAF-derived IL-6 and autocrine IGF-1 on HCC. Mechanistic studies revealed that NT157 decreased IL-6-induced IGF-1 expression by inhibiting STAT3 phosphorylation and led to IRS-1 degradation, which mediated the proliferation of tumour by activating AKT signalling in ERK-dependent manner. Inhibition of IGF-1R also enhanced the therapeutic effect of sorafenib on HCC, especially chemoresistant tumours. STATEMENT OF SIGNIFICANCE: Our study showed IL-6-IGF-1 axis played crucial roles in the crosstalk between HCC and CAFs, providing NT157 inhibited of STAT3 and IGF-1R as a new targeted therapy in combination with sorafenib.

Decoding the Role of Insulin-like Growth Factor 1 and Its Isoforms in Breast Cancer.

Insulin-like Growth Factor-1 (IGF-1) is a crucial mitogenic factor with important functions in the mammary gland, mainly through its interaction with the IGF-1 receptor (IGF-1R). This interaction activates a complex signaling network that promotes cell proliferation, epithelial to mesenchymal transition (EMT) and inhibits apoptosis. Despite extensive research, the precise molecular pathways and intracellular mechanisms activated by IGF-1, in cancer, remain poorly understood. Recent evidence highlights the essential roles of IGF-1 and its isoforms in breast cancer (BC) development, progression, and metastasis. The peptides that define the IGF-1 isoforms-IGF-1Ea, IGF-1Eb, and IGF-1Ec-act as key points of convergence for various signaling pathways that influence the growth, metastasis and survival of BC cells. The aim of this review is to provide a detailed exami-nation of the role of the mature IGF-1 and its isoforms in BC biology and their potential use as possible therapeutical targets.

Message Transmission Between Adipocyte and Macrophage in Obesity.

Obesity is characterized by the chronic low-grade activation of the innate immune system. In this respect, macrophage-elicited metabolic inflammation and adipocyte-macrophage interaction have primary importance in obesity. Large quantity of macrophages is accumulated by different mechanisms in obese adipose tissue. Hypertrophic adipocyte-derived chemotactic monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2) pathway promotes more macrophage accumulation into the obese adipose tissue. However, obesity-induced changes in adipose tissue macrophage density are mainly dependent on increases in the triple-positive cluster of differentiation (CD)11b+ F4/80+ CD11c+ adipose tissue macrophage subpopulation. As epigenetic regulators, microRNAs (miRNAs) are one of the most important mediators of obesity. miRNAs are expressed by adipocytes as well as macrophages and regulate inflammation with the expression of target genes. A paracrine loop involving free fatty acids and tumor necrosis factor-alpha (TNF-α) between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes in the adipose tissue. Adipocyte-specific caspase-1 and production of interleukin-1beta (IL-1ß) by macrophages; both adipocyte and macrophage induction by toll-like receptor-4 (TLR4) through nuclear factor-kappaB (NF-κB) activation; free fatty acid-induced and TLR-mediated activation of c-Jun N-terminal kinase (JNK)-related pro-inflammatory pathways in CD11c+ immune cells; are effective in mutual message transmission between adipocyte and macrophage and in the development of adipose tissue inflammation. Thus, the metabolic status of adipocytes and their released exosomes are important determinants of macrophage inflammatory output. However, old adipocytes are removed by macrophages through trogocytosis or sending an "eat me" signal. As a single miRNA can be able to regulate a variety of target genes and signaling pathways, reciprocal transfer of miRNAs between adipocytes and macrophages via miRNA-loaded exosomes reorganizes the different stages of obesity. Changes in the expression of circulating miRNAs because of obesity progression or anti-obesity treatment indicate that miRNAs could be used as potential biomarkers. Therefore, it is believed that targeting macrophage-associated miRNAs with anti-obesity miRNA-loaded nano-carriers may be successful in the attenuation of both obesity and adipose tissue inflammation in clinical practice. Moreover, miRNA-containing exosomes and transferable mitochondria between the adipocyte and macrophage are investigated as new therapeutic targets for obesity-related metabolic disorders.