Upregulation Of Insulin-like Growth Factor Research Articles

Insulin promotes growth in breast cancer cells through the type I IGF receptor in insulin receptor deficient cells

Breast cancer is the most common cancer in women. The upregulation of insulin-like growth factor (IGF) system observed in certain types of breast cancers was linked to growth, metastasis, and survival resulting in multiple strategies designed to target the type I IGF receptor (IGF-1R) in breast cancer. These attempts failed to prove beneficial and it has been suggested that insulin receptor (IR) could also play an important role in breast cancer biology. To better understand the IR's role in breast cancer cells, the receptor was deleted from MCF-7L cells using CRISPR technology, and fluorescence-assisted cell sorting was used to obtain clone 35 (CL35). It was found that CL35 activated signaling pathways upon insulin stimulation despite the absence of IR expression. We hypothesized that CL35 used a surrogate receptor for sustained growth and development. IGF-1R was able to activate insulin signaling and growth in CL35. Thus, insulin may play a central role in regulating breast cancer growth due to its ability to activate all the receptors of the IGF family. These findings argue that dual targeting of IR and IGF-IR may be required to inhibit breast cancer growth.

Effect of Swimming Training on Cardiac Morphological Factors, Apelin and Insulin like Growth Factor-1 in Male Wistar Rats

Introduction: Different training methods have cardioprotective effects. The aim of this study was to examine the potential protective impact of continuous and interval swimming training with weights on cardiac morphological factors and serum levels of Apelin and Insulin-like Growth Factor-1 in male Wistar rats.
 Methods: In this experimental study, 27 male rats divided randomly into the control (n=6), sham (n=5), interval (n=8) and endurance (n=8) groups. The endurance group swam for 12 weeks/5 days while swimming time increased incrementally. During the 12-week/4-day period, the interval group engaged in swimming exercises while gradually increasing the load and reducing the duration of rest. Apelin and Insulin like Growth Factor-1 concentration, heart weight and left ventricle weight were measured. One-way ANOVA was utilized and Tuckey-HSD test was used to point out the place of significance (α ≤ 0.05).
 Results: Findings showed that total heart weight in interval and endurance training compared to the control (P= 0.02 and P= 0.02 respectively) and sham (P= 0.02 and P= 0.02, respectively) significantly increased. Furthermore, the weight of the left ventricle showed a significant increase following endurance training in comparison to both the control (P= 0.02) and the sham groups (P= 0.02). Additionally, it was found to be significantly higher than the sham group following interval training. (P= 0.01). Apelin significantly increased in interval and endurance training compared to the control (P= 0.00 and P= 002 respectively) and sham groups (P= 0.02 and P= 0.04, respectively). Moreover, insulin like growth factor-1 significantly increased in interval and endurance training compared to the control (P= 0.01 and P= 0.01, respectively).
 Conclusion: It appears that a 12-week swimming training program, particularly in an interval format, can induce physiological hypertrophy in cardiac tissue and provide cardiac protective benefits through the upregulation of Insulin-like Growth Factor-1 and Apelin.

Insulin-like growth factor 1 receptor inhibits the proliferation of acute myeloid leukaemia cells via NK cell activation.

Acute myeloid leukaemia (AML) denotes a heterogeneous category of cancers occurring within the bone marrow that are initiated by the unrestricted proliferation of haematopoietic stem cells. Various factors effectuate the dysregulation of AML cell proliferation; for instance, the upregulation of insulin-like growth factor 1 receptor (IGF1R) within AML cells influences their proliferation. However, there is a current dearth of research assessing the association between IGF1R and prognostic risk as well as its potential as an AML immunotherapeutic. This study aims to elucidate the role of IGF1R in AML progression and evaluate its prognostic value. To this end, RNA-sequencing (RNA-seq) data from The Cancer Genome Atlas (TCGA) database was analysed to compare IGF1R expression between AML and normal tissues. Moreover, a Kaplan-Meier survival analysis was performed to determine whether IGF1R expression correlates with patient overall survival (OS). TCGA data revealed upregulated IGF1R expression in the peripheral blood of AML patients compared to that in healthy individuals. Meanwhile, IGF1R expression positively correlates with patient OS. Additionally, elevated IGF1R expression promotes NK cell expansion and enhances its functional activation, thereby inhibiting AML cell proliferation. Collectively, these findings highlight the clinical potential of IGF1R in the effective treatment of AML through the activation of NK cell proliferation and function and suggest that it may represent a potential predictive marker of AML prognosis.

Nano-Curcumin/Chitosan Modulates Growth, Biochemical, Immune, and Antioxidative Profiles, and the Expression of Related Genes in Nile tilapia, Oreochromis niloticus

This study aimed to evaluate the effects of dietary supplementation with nano-curcumin (NCur) and a nano-curcumin/chitosan blend (NCur/Ch) on growth performance, digestibility, immune response, antioxidant status, intestinal morphometric characters, and gene regulation in Nile tilapia. Fish (n = 180, initial body weight = 12.0 ± 0.53 g) received supplementary NCur at rates of 0 (control), 0.00625, and 0.0125, and NCur/Ch at rates of 0.00625 + 0.5 g/kg diet for 4 weeks. Growth performance parameters (final weight and length, body mass gain, specific growth, and length gain rates) were markedly increased, and the feed conversion ratio was significantly decreased in the NCur- and NCur/Ch-supplemented groups. Digestive enzyme (amylase), immune response markers (immunoglobulin M, nitrous oxide, and lysozyme activity), plasma albumin, and total protein were increased significantly, mainly with a diet supplemented with 0.00625 g NCur/kg. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), glucose, and cortisol levels decreased in the supplemented groups compared to the control. Significantly increased glutathione peroxidase (GPx) and decreased malondialdehyde (MDA) levels were observed in the NCur/Ch group. Superoxide dismutase (SOD) activity was improved in the 0.0125 NCur group. Intestinal morphometric characters, including villus length, width, interspace, and goblet cell abundance, were increased to cope with improved growth performance and were associated with upregulation of insulin-like growth factor 1 (igf-1) and complement C-5 (cc5) compared to the control group. Therefore, NCur and an NCur/Ch blend could be supplemented in the Nile tilapia diets as a natural alternative to promote growth, digestion, immune status, liver function, antioxidant status, and related gene expression in O. niloticus.

Hyperbaric Oxygen Therapy Promotes Hearing Gain with Increases in Serum IGF-1 and HSP70 in Patients with Idiopathic Sudden Sensorineural Hearing Loss.

Hyperbaric oxygen therapy (HBOT) has been recommended for the initial and salvage treatment of patients with idiopathic sudden sensorineural hearing loss (ISSHL), but its underlying mechanisms remain unclear. In this study, we investigated whether HBOT alters serum levels of insulin-like growth factor 1 (IGF-1) and heat shock protein 70 (HSP70) in patients with ISSHL. Then, we identified the relationship between hearing recovery and changes in serum IGF-1 and HSP70 levels. Moderately severe to profound unilateral ISSHL patients (n = 70) and healthy control participants (n = 30) were enrolled. The ISSHL patients were randomly assigned to receive medical therapy alone (MT group, n = 35) or both HBOT and medical therapy (HBOT + MT group, n = 35). Audiometric testing was performed before and after treatment. Serum IGF-1 and HSP70 levels were assessed by ELISA in ISSHL patients pre-and posttreatment and healthy controls. Before treatment, compared with the healthy controls, serum IGF-1 and HSP70 were lower in ISSHL patients. After treatment, serum IGF-1 and HSP70 increased in both the HBOT + MT and MT groups, although they were significantly higher in the HBOT + MT group (p < 0.01). In the HBOT + MT group, these increases were associated with hearing gains. In addition, IGF-1 was strongly associated with HSP70 (r = 0.621, p = 0.001). No such association was found in the MT group (p = 0.757). Administering HBOT in addition to medical therapy can improve the hearing of patients with moderately severe to profound unilateral ISSHL. The improvement is related to the upregulation of IGF-1 and HSP70.

Hyperbaric Oxygen Therapy Alleviates Social Behavior Dysfunction and Neuroinflammation in a Mouse Model for Autism Spectrum Disorders.

Autism spectrum disorder (ASD) is a multifactorial neurodevelopmental disorder (NDD) characterized by impaired social communication and repetitive behavior, among other symptoms. ASD is highly heritable, with SHANK3 being one of the high-risk genes for ASD. In recent years, knowledge has been growing regarding the neuroplasticity effect induced by hyperbaric oxygen therapy (HBOT) and its potential use for ASD. Here, we characterized the effect of HBOT on a mouse model for ASD with the human genetic condition of InsG3680 mutation in the Shank3 gene. As compared to placebo, HBOT improved social behavior and reduced neuroinflammation in the cortex of the InsG3680(+/+) mice. Specifically, HBOT induced upregulation of Insulin-like growth factor 1 (Igf1) expression levels and reduced the number of Iba1-positive cells in the mouse model for ASD compared to placebo control. Together, our research suggests that HBOT has the potential to improve the clinical outcome of ASD by ameliorating some of the core pathophysiological processes responsible for the development of the disorder.

The efficacy of salivary Histatin-1 protein in wound closure of nicotine treated human periodontal ligament fibroblast cells – In vitro study

ObjectivesThe aims of this study were to investigate the efficacy of Histatin-1 in wound closure as well as effects on gene expression of nicotine-treated human Periodontal Ligament Fibroblast cells (HPDL) in vitro. DesignHPDL grown in 2.5% culture medium treated with 10 ng/ml Histatin − 1 in the presence/absence of 0.5 µM nicotine were subjected to wound assay and migration was studied at 0 h, 6 h, 12 h and 24 h. Cells grown in 2.5% medium served as control. Cell migration was studied by wound gap and transwell migration assays. The effect of Histatin-1 on expression of matrix metalloproteinase 8 (MMP-8), insulin-like growth factor 1 (IGF-1), transforming growth factor beta (TGF-β), collagen type I (COL1) and plasminogen activator inhibitor 1 (PAI-1) were studied. ResultsHistatin-1 treatment significantly decreased percentage wound gap at 12 h (62.96 ± 3.22 vs 79.23 ± 1.73; p < 0.05) and at 24 h (38.78 ± 7.59 vs 75.21 ± 4.94; p < 0.001) compared with controls. In nicotine+Histatin-1 treated cells, wound gap decreased to 70.2 ± 2.9% (p < 0.01) at 24 h compared to nicotine alone in which 82 ± 1.64% of wound gap was retained. Transwell migration assays showed significant migration of HPDL with Histatin-1 (p < 0.05). Gene expression demonstrated significant upregulation for IGF-1, TGF β, COL1 and PAI-1 with Histatin-1. ConclusionHistatin-1 significantly mitigated the effect of nicotine in wound healing assay involving HPDL fibroblast cells at 24 h. Histatin-1 aided wound closure is attributed to the upregulation of IGF-1, TGF β, COL1, and PAI-1 genes.

Atractylodes chinensis volatile oil up-regulated IGF-1 to improve diabetic gastroparesis in rats.

Objective(s):Diabetic gastroparesis (DGP) is one of the main complications of diabetes, and more than half of diabetes cases are accompanied by gastroparesis. This study aims to explore the effect of Atractylodes chinensis volatile oil (ACVO) on DGP rats.Materials and Methods:The rats were injected with STZ combined with a high-sugar and high-fat diet in an irregular manner to establish the DGP model. ACVO at different doses (9.11 mg/kg, 18.23 mg/kg, and 36.45 mg/kg) were given by intragastric administration. A mixture of cisapride and metformin was used as the positive control. At the end of the experiment, gastric emptying and intestinal propulsion were determined. Then the tissue samples and blood were taken from each group for serum analysis, western blot and immunopathological examination. Results:After treatment with ACVO, body weight increased and blood glucose decreased when compared with rats in the DGP group. Gastric emptying and intestinal propulsion were accelerated, and gastric acid secretion increased. The serum insulin-like growth factor-1 (IGF-1) level was increased. Protein expressions and positive cells of IGF-1 receptor (IGF-1R), acetylcholine transferase (CHAT), and stem cell factors (SCF) in the stomach were significantly increased determined by western blot and immunofluorescence staining. The morphology and the number of interstitial cells of Cajal (ICCs) in the stomach were restored, determined by hematoxylin and eosin staining and immunohistochemical staining, respectively. Conclusion:ACVO effectively alleviated DGP in rats, and its mechanism may be related to the up-regulation of IGF-1/IGF-1R signaling.

Collagen type I enhances cell growth and insulin biosynthesis in rat pancreatic cells.

Type I collagen (collagen I) is the most abundant component of the extracellular matrix (ECM) in the pancreas. We previously reported that collagen I-coated culture dishes enhanced proliferation of rat pancreatic β cell line, INS-1 cells, via up-regulation of β-catenin nuclear translocation. In this study, we further investigated the effects of collagen I on insulin production of INS-1 cells. The results indicate that insulin synthesis as well as cell proliferation is increased in the INS-1 cells cultured on the dishes coated with collagen I. Up-regulation of insulin-like growth factor 1 receptor (IGF-1R) on the INS-1 cells cultured on the collagen-coated dishes is involved in up-regulation of cell proliferation and increase of insulin biosynthesis; however, up-regulation of insulin secretion in the INS-1 cells on collagen I-coated dishes was further enhanced by inhibition of IGF-1R. Autophagy of INS-1 cells on collagen I-coated dishes was repressed via IGF-1R upregulation, and inhibition of autophagy with 3MA further enhanced cell proliferation and insulin biosynthesis but did not affect insulin secretion. E-cadherin/β-catenin adherent junction complexes are stabilized by autophagy. That is, autophagy negatively regulates the nuclear translocation of β-catenin that leads to insulin biosynthesis and cell proliferation. In conclusion, IGF-1R/downregulation of autophagy/nuclear translocation of β-catenin is involved in collagen I-induced INS-1 cell proliferation and insulin synthesis.

Promising Role of Growth Hormone-Boosting Peptide in Regulating the Expression of Muscle-Specific Genes and Related MicroRNAs in Broiler Chickens.

Simple SummaryIn chickens, breast muscle is a key contributor to meat yield. Skeletal muscle development is a complex process regulated by many genes, transcription factors, and miRNA through different muscle signaling pathways. The latter are activated by synthetic growth hormone-boosting peptides (GHBP) that mimic the effects of endogenous growth factors, mainly insulin-like growth factor-1 (IGF-1)/mammalian target of rapamycin (mTOR), and modulate myostatin gene expression. The molecular mechanisms underlying chicken breast muscle development in relation to GHBP are still unclear. In the current study, the role of GHBP in a chicken’s growth rate, skeletal muscle development-related genes and myomiRs, serum bio-chemical parameters, and myofiber characteristics post-hatching was evaluated. Using of GHBP at a level of 200 μg/kg positively regulated gene expression related to muscle growth and muscle-specific myomiRs. This was evidenced by upregulation of IGF-1, mTOR, myoD and myogenin genes, and miR-27b and miR-499 and downregulation of myostatin, Pax-3 and -7 genes and miR-1a, miR-133a, miR-133b, and miR-206 compared to the control group. Therefore, administration of GHBP at the level of 200 μg/kg to broiler chicks can accelerate their growth by enhancing skeletal muscle development via controlling the transcription of breast muscle-related genes and associated myomiRs.Appropriate skeletal muscle development in poultry is positively related to increasing its meat production. Synthetic peptides with growth hormone-boosting properties can intensify the effects of endogenous growth hormones. However, their effects on the mRNA and miRNA expression profiles that control muscle development post-hatching in broiler chicks is unclear. Thus, we evaluated the possible effects of synthetic growth hormone-boosting peptide (GHBP) inclusion on a chicken’s growth rate, skeletal muscle development-related genes and myomiRs, serum biochemical parameters, and myofiber characteristics. A total of 400 one-day-old broiler chicks were divided into four groups supplied with GHBP at the levels of 0, 100, 200 and 300 μg/kg for 7 days post-hatching. The results showed that the highest levels of serum IGF-1 and GH at d 20 and d 38 post-hatching were found in the 200 μg/kg GHBP group. Targeted gene expression analysis in skeletal muscle revealed that the GHBP effect was more prominent at d 20 post-hatching. The maximum muscle development in the 200 μg/kg GHBP group was fostered by the upregulation of IGF-1, mTOR, myoD, and myogenin and the downregulation of myostatin and the Pax-3 and -7 genes compared to the control group. In parallel, muscle-specific myomiR analysis described upregulation of miR-27b and miR-499 and down-regulation of miR-1a, miR-133a, miR-133b, and miR-206 in both the 200 and 300 μg/kg GHBP groups. This was reflected in the weight gain of birds, which was increased by 17.3 and 11.2% in the 200 and 300 μg/kg GHBP groups, respectively, when compared with the control group. Moreover, the maximum improvement in the feed conversion ratio was achieved in the 200 μg/kg GHBP group. The myogenic effects of GHBP were also confirmed via studying myofiber characteristics, wherein the largest myofiber sizes and areas were achieved in the 200 μg/kg GHBP group. Overall, our findings indicated that administration of 200 μg/kg GHBP for broiler chicks could accelerate their muscle development by positively regulating muscle-specific mRNA and myomiR expression and reinforcing myofiber growth.

MicroRNA-185 activates PI3K/AKT signalling pathway to alleviate dopaminergic neuron damage via targeting IGF1 in Parkinson’s disease

Objectives Studies have extensively explored the role of microRNAs (miRs) in Parkinson’s disease (PD) and miR-185 is related to autophagy and apoptosis of dopaminergic neurons in PD. However, the role of miR-185 mediating insulin-like growth factor 1 (IGF1)/phosphatidylinositol-3-kinase/protein kinase B signalling pathway (PI3K/AKT) in PD still needs in-depth exploration. Methods Rat PD models were established by injection of 6-hydroxydopamine. PD rats were injected with miR-185 or insulin-like growth factor 1 (IGF1)-related sequences. Behaviour tests were performed, oxidative stress-related factors, tyrosine hydroxylase (TH)-, glial fibrillary acidic protein (GFAP)-, ionised calcium-binding adaptor molecule-1 (Iba-1)- and TUNEL-positive cells in the substantia nigra were determined. Levels of miR-185, IGF1 and phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signalling pathway-related factors were also detected. Results miR-185 level was reduced in rats with PD. Restoring miR-185 promoted behaviour functions, ameliorated pathological damages and oxidative stress, increased TH-positive dopaminergic neurons, decreased GFAP- and Iba-1-positive cells and restrained neuronal apoptosis in the substantia nigra in PD rats. miR-185 targeted IGF1 to activate PI3K/AKT signalling pathway. Up-regulation of IGF1 mitigated restored miR-185-mediated effects on PD rats. Conclusion This study illustrates that miR-185 ameliorates dopaminergic neuron damage via targeting IGF1 and activating PI3K/AKT signalling pathway in PD, which renews the therapy for PD.

Effect of Insulin-Like Growth Factor-1 on Bone Formation of Bone Marrow Mesenchymal Stem Cells Under High Glucose Environment by Regulating Insulin Like Growth Factor Binding Protein 2(IGFBP-2)/p38 Pathway

Diabetes easily affects the biological properties of bone marrow mesenchymal stem cells (BMSCs). Insulin-like growth factor-1 (IGF-1) promotes bone healing during osteoporotic fractures. However, IGF-1's effect on BMSCs high glucose is unclear. Rat BMSCs were assigned into control group, high glucose group, and IGF-1 group in which BMSCs were transfected with pc-DNA 3.1-IGF-1 plasmid on the basis of high glucose followed by analysis of IGF-1, RUNX2 and OPN mRNA level by real time PCR, cell proliferation by MTT assay, alkaline phosphatase (ALP) activity, IGFBP-2 level by ELISA, and p38 phosphorylation by Western blot. High glucose group showed significantly decreased IGF-1, RUNX2 and OPN mRNA level, reduced ALP activity, IGFBP-2 expression and p38 phosphorylation compared to control group (P &lt; 0 05). Transfection of IGF-1 plasmid under high-glucose environment significantly upregulated IGF-1, RUNX2 and OPN mRNA, increased ALP activity, IGFBP-2 expression and p38 phosphorylation compared to high-glucose group (P &lt; 0 05). IGF-1 expression is reduced in high glucose environment. Up-regulation of IGF-1 can promote BMSCs osteogenic differentiation through the IGFBP-2/p38 pathway.

Downregulation of lncRNA H19 sensitizes melanoma cells to cisplatin by regulating the miR-18b/IGF1 axis.

Long noncoding RNAs (LncRNAs) lncRNA H19 has been shown to be involved in the chemotherapy resistance of cancer cells. However, the role of lncRNA H19 in chemotherapy resistance of melanoma cells remains unknown. Here, we determined lncRNA H19, miR-18b, and insulin-like growth factor 1 (IGF1) expression by utilizing quantitative real-time PCR. Cell proliferation ability and chemosensitivity were assessed by colony formation assay and MTT assay. Flow cytometry assay was applied to detect cell apoptosis. We discovered that lncRNA H19 was upregulated, but miR-18b was downregulated in melanoma tissues and cisplatin (DDP)-resistant melanoma cells. The overall survival for the group with lower lncRNA H19 was significantly better than the group with higher H19. IGF1 mRNA level was higher in melanoma tissues than that in normal tissues. miR-18b expression level A negative correlation was observed between the expression levels of miR-18b, lncRNA H19, and IGF1 mRNA. Functionally, knockdown of lncRNA H19 sensitized resistant A375/DDP and M8/DDP cells to DDP. Silencing lncRNA H19 inhibited colony formation ability and promoted apoptosis of DDP-resistant melanoma cells, which was abrogated by miR-18b inhibition and IGF1 upregulation. Mechanistically, lncRNA H19 directly interacted with miR-18b to regulate its expression. IGF1 was identified as a target of miR-18b. These findings highlight the fact that lncRNA H19 could influence DDP-resistance by modulating the miR-18b/IGF axis in melanoma cells, suggesting a new potential therapeutic target for melanoma patient treatment.

IPF pathogenesis is dependent upon TGFβ induction of IGF-1.

Pathogenic fibrotic diseases, including idiopathic pulmonary fibrosis (IPF), have some of the worst prognoses and affect millions of people worldwide. With unclear etiology and minimally effective therapies, two-thirds of IPF patients die within 2-5years from this progressive interstitial lung disease. Transforming Growth Factor Beta (TGFβ) and insulin-like growth factor-1 (IGF-1) are known to promote fibrosis; however, myofibroblast specific upregulation of IGF-1 in the initiation and progression of TGFβ-induced fibrogenesis and IPF have remained unexplored. To address this, the current study (1) documents the upregulation of IGF-1 via TGFβ in myofibroblasts and fibrotic lung tissue, as well as its correlation with decreased pulmonary function in advanced IPF; (2) identifies IGF-1's C1 promoter as mediating the increase in IGF-1 transcription by TGFβ in pulmonary fibroblasts; (3) determines that SMAD2 and mTOR signaling are required for TGFβ-dependent Igf-1 expression in myofibroblasts; (4) demonstrates IGF-1R activation is essential to support TGFβ-driven profibrotic myofibroblast functions and excessive wound healing; and (5) establishes the effectiveness of slowing the progression of murine lung fibrosis with the IGF-1R inhibitor OSI-906. These findings expand our knowledge of IGF-1's role as a novel fibrotic-switch, bringing us one step closer to understanding the complex biological mechanisms responsible for fibrotic diseases and developing effective therapies.

Ketamine Increases Proliferation of Human iPSC-Derived Neuronal Progenitor Cells via Insulin-Like Growth Factor 2 and Independent of the NMDA Receptor.

The N-methyl-D-aspartate (NMDA) receptor antagonist ketamine offers promising perspectives for the treatment of major depressive disorder. Although ketamine demonstrates rapid and long-lasting effects, even in treatment-resistant patients, to date, the underlying mode of action remains elusive. Thus, the aim of our study was to investigate the molecular mechanism of ketamine at clinically relevant concentrations by establishing an in vitro model based on human induced pluripotent stem cells (iPSCs)-derived neural progenitor cells (NPCs). Notably, ketamine increased the proliferation of NPCs independent of the NMDA receptor, while transcriptome analysis revealed significant upregulation of insulin-like growth factor 2 (IGF2) and p11, a member of the S100 EF-hand protein family, which are both implicated in the pathophysiology of depression, 24 h after ketamine treatment. Ketamine (1 µM) was able to increase cyclic adenosine monophosphate (cAMP) signaling in NPCs within 15 min and cell proliferation, while ketamine-induced IGF2 expression was reduced after PKA inhibition with cAMPS-Rp. Furthermore, 24 h post-administration of ketamine (15 mg/kg) in vivo confirmed phosphorylation of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in the subgranular zone (SGZ) of the hippocampus in C57BL/6 mice. In conclusion, ketamine promotes the proliferation of NPCs presumably by involving cAMP-IGF2 signaling.

Long Noncoding RNA-Maternally Expressed Gene 3 Contributes to Hypoxic Pulmonary Hypertension.

The expression and function of long noncoding RNAs (lncRNAs) in the development of hypoxic pulmonary hypertension (HPH), especially in the proliferation of pulmonary artery smooth muscle cells (PASMCs), are largely unknown. Herein, we examined the expression and role of lncRNA-maternally expressed gene 3 (lncRNA-MEG3) in HPH. lncRNA-MEG3 was significantly increased and primarily localized in the cytoplasm of hypoxic PASMCs. lncRNA-MEG3 knockdown by lung-specific delivery of small interfering RNAs (siRNAs) significantly inhibited the development of HPH invivo. Silencing of lncRNA-MEG3 by siRNAs and gapmers attenuated proliferation and cell-cycle progression in both PASMCs from idiopathic pulmonary arterial hypertension (iPAH) patients (iPAH-PASMCs) and hypoxia-exposed PASMCs invitro. Mechanistically, we found that lncRNA-MEG3 interacts with and leads to the degradation of microRNA-328-3p (miR-328-3p), leading to upregulation of insulin-like growth factor 1 receptor (IGF1R). Additionally, higher expression of lncRNA-MEG3 and IGF1R and lower expression of miR-328-3p were observed in iPAH-PASMCs and relevant HPH models. These data provide insights into the contribution of lncRNA-MEG3 to HPH. Upregulation of lncRNA-MEG3 sequesters cytoplasmic miR-328-3p, eventually leading to expression of IGF1R, revealing a regulatory mechanism by lncRNAs in hypoxia-induced PASMC proliferation.

Role of insulin-like growth factor-1 in skin tags: a clinical, genetic and immunohistochemical study in a sample of Egyptian patients.

Background: Skin tags (STs) are benign connective tissue neoplasms, in which insulin-like growth factor −1 (IGF-1) has a mitogenic and antiapoptotic activity.Purpose: We aimed to study for the first time, the possible role of IGF-1 (CA) 19 and rs6214 gene polymorphisms, and its tissue immunoreactivity in the pathogenesis of STs.Patients and methods: This case–control study included 40 ST patients and 20 controls. We searched for (CA) 19 single-nucleotide polymorphism (SNP) using conversional PCR and for rs6214 gene polymorphism using real-time PCR. IGF-1 tissue immunoreactivity was investigated using polyclonal IGF-1 antibody.Results: IGF-1 immunoreactivity showed significantly strong upregulation in epidermis (p=0.002) and dermal components (endothelial cells [p=0.038] and fibroblasts [p=0.004]) of excised STs than control skin. TT and CT rs6214 genotypes and its T allele were significantly associated with STs (p=0.006 and P=0.002, respectively). Also (<192 bp) and 192–194 bp (CA) 19 genotypes were significantly predominant in ST patients than controls (p=0.013). These 4 genotypes were significantly associated with development of multiple STs and epidermal IGF-1 tissue immunoreactivity in studied patients.Conclusions: IGF-1 (CA) 19 and rs6214 gene polymorphisms may contribute to a predisposition of STs in Egyptian patients, the role of which could be mediated through local upregulation of IGF-1 in cutaneous tissues.

Mir‐1976 Downregulation and Phosphorylation of LARP6 are Associated with Insulin‐like Growth Factor‐1 (IGF1)‐induced Collagen Upregulation in Vascular Smooth Muscle Cells

Collagen content in atherosclerotic plaque is a hallmark of plaque stability. We have shown that insulin‐like growth factor‐1 (IGF1) increased collagen content in atherosclerotic plaques of Apoe−/− mice. We have identified LARP6 (La Ribonucleoprotein Domain Family, Member 6), a collagen mRNA binding protein, as a mediator of IGF1‐dependent collagen I upregulation and increased mature fibril formation in smooth muscle cells (SMCs), however specific mechanisms have not been elucidated yet. A total of six micro RNAs (miRs), including miR‐1976, have been shown to bind to LARP6 mRNA. In fact, miR‐1976 mimic (20 nM) decreased LARP6 by 67% and reduced procollagen I by 85% (both are P&lt;0.05), indicating that miR‐1976 negatively regulates LARP6 expression. We found that IGF1 significantly downregulated miR‐1976 by 41±5% in SMCs after 3h of exposure. Moreover, miR‐1976 mimic inhibited IGF1‐induced LARP6 upregulation, suggesting that the downregulation of miR‐1976 mediates IGF1 upregulation of LARP6.It has been reported that LARP6 phosphorylation is critical for regulating translation of collagen polypeptides. To investigate whether IGF1 induces LARP6 phosphorylation, we assessed LARP6 electrophoretic mobility shift by SDS‐PAGE and immunoblotting. SMCs were serum‐starved and treated for 0–48h either with 10 ng/ml IGF1, or 2 ng/ml IFNy, or 2 ng/ml IL‐1b, or 2 ng/ml TNFa, or 10 ng/ml IL‐6. LARP6 protein was detected on immunoblots as a single 65kDa band in untreated SMCs. However, additional 67kDa LARP6 band was evident after 6h of cell treatment with IGF1 or with IL‐6. The density of 67kDa LARP6 band was gradually increased up to 18h of treatment. IGF1 and IL‐6 also increased expression levels of procollagen I and collagen I in a time‐dependent manner, with a peak at 18h. IFNy, IL‐1b, and TNFa did not induce 67kDa LARP6 band or increase in expression level of collagen in SMCs.Taken together, our data suggest that IGF1 promotes collagen expression by upregulating LARP6 levels via a downregulation of miR‐1976 and also by inducing phosphorylation of LARP6. Suggested mechanisms by which IGF1 induces collagen expression in vascular SMCs and thus potentially in atherosclerotic plaques would provide novel insights for a therapeutic approach increasing plaque stability.Support or Funding InformationNIH/NHLBI R01HL070241 (PD)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

MiR-148a regulates bone marrow mesenchymal stem cells-mediated fracture healing by targeting insulin-like growth factor 1.

The purpose of this study was to investigate the underlying molecular mechanisms of fracture healing mediated by bone marrow mesenchymal stem cells. Differentially expressed microRNAs in acutely injured subjects and healthy volunteers were screened by microarray analysis. The dual luciferase reporter system was used to verify whether insulin-like growth factor 1 (IGF1) was the direct target gene regulated by miR-148a. The expression level of miR-148a and IGF1 after osteogenic differentiation was detected by quantitative real-time polymerase chain reaction. Western blot was used to determine the protein expression of bone markers, including IGF1, runt-related transcription factor 2 (Runx2), osteocalcin, and osteopontin inrat bone marrow-derived mesenchymal stem cells. Alkaline phosphatase and alizarin redstaining was used to detect alkaline phosphatase activity and calcium deposition. An animal fracture model was used for in vivo experiments. MiR-148a was highly expressed in acutely injured subjects compared with healthy volunteers, and IGF1 was a target of miR-148a. Moreover, compared with the negative control group, IGF1 messenger RNA expression was significantly increased in the miR-148a antagomir group. Duringosteogenic differentiation, the expression of IGF1, Runx2, osteocalcin, and osteopontin was higher in the miR-148a antagomir group than other groups. In vivo experiments further confirmed that upregulation of IGF1 enhanced fracture healing efficiently by decreasing callus width and area and improving bone mineral density, maximum load, stiffness, and energy absorption. It was proved that IGF1 was the direct target gene of miR-148a, and the use of rat bone marrow-derived mesenchymal stem cells with low expression of miR-148a could improve fracture healing by upregulating IGF1.

Upregulation of insulin-like growth factor II mRNA-binding protein 3 (IMP3) has negative prognostic impact on early invasive (pT1) adenocarcinoma of the esophagus.

Therapeutic decisions in esophageal adenocarcinomas (EAC) restricted to mucosa (pT1a) or submucosa (pT1b) depend mainly on classic histomorphology-based criteria like tumor grading or lymphovascular invasion with limited success. There is a strong need for reliable pre-therapeutical biomarker-based evaluation also applicable on endoscopically obtained biopsies. Patients who underwent esophagectomy due to EAC in a high volume center between 1999 and 2016 were included. Tissue microarrays (TMA) were retrospectively established from the formalin-fixed and paraffin-embedded material of the resected specimens and immunohistochemically stained using a monoclonal primary antibody specific for IMP3. IMP3 staining intensity was scored manually according to a 3-tier-scoring system (negative, weak and strong). 371 EACs were interpretable for analysis. 109 patients (29%) had early invasive (pT1a/pT1b) and 262 patients (71%) locally advanced EAC (> pT2). 259 EACs (70%) revealed positive immunostaining for IMP3 including 167 strongly and 92 weakly positive. Early EAC had significantly lower IMP3 expression compared to advanced tumor stages (p < 0.0001). IMP3 positive pT1 EAC revealed higher levels of lymph node metastases (LNM) (p = 0.0001) and pT1b tumors showed higher rates of IMP3 positivity compared to pT1a (p = 0.007). Subdividing the submucosa in thirds, there was a significant trend for higher IMP3 expression with deeper tumor infiltration from pT1a to pT1b (sm3) (p = 0.0001). There was an association between IMP3 expression and shortened survival in pT1 EAC (p = 0.038). IMP3 expression correlates with depth of tumor infiltration, rate of LNM and is associated with worse outcome. Thus, IMP3 might be useful for therapeutic decisions in early-invasive EAC.