Insulin-like Growth Factor-1 Receptor Expression Research Articles

#411 Magnesium deficiency abrogates the activation of Insulin-like growth factor-1 signaling pathway in the kidney induced by DPP4 inhibitor

Abstract Background and Aims Dipeptidyl peptidase-4 (DPP-4) inhibitor could attenuate cisplatin nephrotoxicity dependent on the glucagon-like peptide-1 (GLP-1) signaling pathway [1]. We had previously reported that the use of a DPP-4 inhibitor might also attenuate cisplatin nephrotoxicity in diabetic cancer patients [2], and its renoprotective effect was lost under magnesium (Mg) deficiency [3]. However, it remains to be investigated how the GLP-1 signaling pathway changes after the treatment of a DPP-4 inhibitor under Mg deficiency. The purpose of this study was to examine the changes in the downstream pathway of the GLP-1 signaling pathway after the treatment of DPP-4 inhibitor under Mg deficiency. Method Sprague Dawley rats received a Mg-deficient diet for 7 days to induce Mg deficiency (low Mg group). Control diet was given to the normal Mg group. Oral administration of a DPP-4 inhibitor was injected 1 day before sacrifice. The changes in serum active GLP-1, insulin, insulin-like growth factor (IGF-1), and the expression of their receptor in the kidney were examined. In addition, the phosphorylation of insulin/IGF-1 receptors in the kidney were investigated. Results Serum active GLP-1 increased equally in both groups with DPP-4 inhibitor administration. Renal GLP-1 receptor expression was not observed in the renal tubules. Serum IGF-1 did not change with DPP-4 inhibitor administration in the normal Mg group but increased in the low Mg group. In normal Mg group, renal IGF-1 receptor expression tended to increase with DPP-4 inhibitor administration, and its phosphorylation increased significantly. In contrast, the expression and phosphorylation of the IGF-1 receptor did not change with DPP-4 inhibitor administration in the low Mg group. The increase in serum insulin with the DPP-4 inhibitor was enhanced in the low Mg group, compared to the normal Mg group. The expression and phosphorylation of the insulin receptor did not change with DPP-4 inhibitor administration in both groups. Conclusion DPP-4 inhibitor activated the renal IGF-1 signaling pathway, but this effect disappeared under Mg deficiency. Further investigation is needed to determine whether the renal protective effect of DPP-4 inhibitor is dependent on the IGF-1 signaling pathway.

High salt diet induces cognitive impairment and is linked to the activation of IGF1R/mTOR/p70S6K signaling.

A high-salt diet (HSD) has been associated with various health issues, including hypertension and cardiovascular diseases. However, recent studies have revealed a potential link between high salt intake and cognitive impairment. This study aims to investigate the effects of high salt intake on autophagy, tau protein hyperphosphorylation, and synaptic function and their potential associations with cognitive impairment. To explore these mechanisms, 8-month-old male C57BL/6 mice were fed either a normal diet (0.4% NaCl) or an HSD (8% NaCl) for 3 months, and Neuro-2a cells were incubated with normal medium or NaCl medium (80 mM). Behavioral tests revealed learning and memory deficits in mice fed the HSD. We further discovered that the HSD decreased autophagy, as indicated by diminished levels of the autophagy-associated proteins Beclin-1 and LC3, along with an elevated p62 protein level. HSD feeding significantly decreased insulin-like growth factor-1 receptor (IGF1R) expression in the brain of C57BL/6 mice and activated mechanistic target of rapamycin (mTOR) signaling. In addition, the HSD reduced synaptophysin and postsynaptic density protein 95 (PSD95) expression in the hippocampus and caused synaptic loss in mice. We also found amyloid β accumulation and hyperphosphorylation of tau protein at different loci both in vivo and in vitro. Overall, this study highlights the clinical significance of understanding the impact of an HSD on cognitive function. By targeting the IGF1R/mTOR/p70S6K pathway or promoting autophagy, it may be possible to mitigate the negative effects of high salt intake on cognitive function.

PAPP-A as a Potential Target in Thyroid Eye Disease.

Proptosis in Thyroid Eye Disease (TED) can result in facial disfigurement and visual dysfunction. Treatment with Insulin-like growth factor I receptor (IGF-IR) inhibitors has been shown to be effective in reducing proptosis but with side effects. To test the hypothesis that inhibition of IGF-IR indirectly and more selectively with PAPP-A inhibitors attenuates IGF-IR signaling in TED. Informed consent was obtained from TED patients undergoing surgery, and retro-orbital tissue collected for fibroblast isolation and culture. Surgeries were performed in Mayo Clinic operating suites. Cell culture was performed in a sterile tissue culture facility. Retro-orbital tissue was collected from 19 TED patients. Treatment of TED fibroblasts with pro-inflammatory cytokines. Flow separation of CD34- and CD34+ orbital fibroblasts, the latter representing infiltrating fibrocytes into the orbit in TED. PAPP-A expression and proteolytic activity, IGF-I stimulation of phosphatidylinositol 3 kinase/Akt pathway and inhibition by immuno-neutralizing antibodies against PAPP-A, CD34+ status and associated PAPP-A and IGF-IR expression. Pro-inflammatory cytokines markedly increased PAPP-A expression in TED fibroblasts. IGF-IR expression was not affected by cytokine treatment. Inhibition of PAPP-A's proteolytic activity suppressed IGF-IR activation in orbital fibroblasts from TED patients. TED fibroblasts that were CD34+ represented ∼80% of the cells in culture and accounted for ∼70% of PAPP-A and IGF-IR expressing cells. These results support a role for PAPP-A in TED pathogenesis and indicate the potential for novel therapeutic targeting of the IGF axis.

Abstract 1918: LX-101, a novel, clinical stage, payload-bearing targeted therapy directed to the insulin-like growth factor receptor (IGF-1R), demonstrates potent preclinical anti-tumor activity against multiple cancer types with well-established ties to the IGF-1/IGF-1R pathway

Abstract Objective: LX-101 is a next-generation, targeted therapy directed to the insulin-like growth factor 1 receptor (IGF-1R). LX-101 consists of a proprietary IGF-1 variant coupled to a cytotoxic methotrexate payload. LX-101 was previously evaluated in Phase 1 trials of adult patients with advanced, pretreated cancers, where it was well-tolerated and demonstrated single agent activity. Neither a dose limiting toxicity, nor a maximum tolerated dose was reached, leaving potential room for additional dose escalation and schedule optimization. Multiple aggressive cancers of unmet need have genetic alterations affecting the IGF-1R pathway and/or high IGF-1R expression that correlates with poor outcomes, including certain cancers of the breast, head and neck, Ewing’s sarcoma, osteosarcoma, and others. Prior attempts at inhibiting IGF-1R with non-payload bearing naked monoclonal antibodies or small molecules produced a range of clinical outcomes including some partial and complete responses. None of these agents, however, were ultimately approved, potentially due to suboptimal potency that allowed for escape mechanisms, including redundant signaling pathways, and the lack of enrichment for select tumor types with strong ties to the IGF-1/IGF-1R pathway. Herein, we investigated the anti-tumor activity of the payload-bearing agent LX-101 against IGF-1R-involved cancer cell lines. Methods: Cell lines were incubated with LX-101 (~1.6 - 2500nM). Cell viability was assessed by CellTiter-Glo after 4 days. IC50s were calculated using GraphPad PRISM software. Results: LX-101 displayed potency against head and neck cancer (FaDu, IC50 = 9 nM), triple negative breast cancer (BT-20, IC50 = 17 nM), Ewing’s sarcoma, including EWSR1-FLI1 gene fusion-positive cell lines RD-ES (IC50 = 10 nM), A-673 (IC50 = 14 nM), and SK-ES-1 (IC50 = 29 nM) and EWSR1-ERG gene fusion-positive cell line CADO-ES1 (IC50 = 14 nM). LX-101 was also potent against PAX3-FOXO1 gene fusion positive alveolar rhabdomyosarcoma (SJCRH30, IC50 = 23 nM), osteosarcoma (143B, IC50 = 6 nM; HOS, IC50 = 7 nM; U2OS, IC50 = 32 nM), and neuroblastoma (SK-N-AS, IC50 = 16 nM; IMR-32, IC50 = 20 nM; SH-SY5Y, IC50 = 30 nM). Conclusion: These results demonstrate that LX-101 has potent preclinical anti-tumor activity against multiple cancer cell lines with well-established ties to the IGF-1/IGF-1R pathway, including with different genetic and epigenetic alterations. These data support further clinical development of LX-101 in IGF-1R-involved cancers. New clinical trials are planned. Citation Format: Matt Hoberman, Arkadiusz Z. Dudek. LX-101, a novel, clinical stage, payload-bearing targeted therapy directed to the insulin-like growth factor receptor (IGF-1R), demonstrates potent preclinical anti-tumor activity against multiple cancer types with well-established ties to the IGF-1/IGF-1R pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1918.

Growth indices and vitamin D content in children with idiopathic short stature depending on the variants of the Taql polymorphism genotype of the VDR gene

Background. The vitamin D receptor (VDR) gene is a key regulator of biological processes, including tissue and cell growth and differentiation, bone metabolism, and modulation of immune responses. Several studies have shown that 1,25(OH)2D increases circulating insulin-like growth factor-1 (IGF-1) levels in vivo and in bone cell cultures. It also increases the expression of IGF-1 receptors in growth plate chondrocytes and several IGF-binding proteins in osteoblasts and bone marrow stromal cell cultures. A vitamin D receptor gene polymorphism is associated with adult height and may affect the growth indicators in children with idiopathic short stature. The purpose was to study the growth indicators and vitamin D levels in children with idiopathic short stature depending on the variants of the Taql polymorphism genotype of the VDR gene. Materials and methods. Determination of the Taql polymorphism of the VDR gene (rs731236) was performed using polymerase chain reaction followed by an analysis of the length of the restriction fragments when detected by agarose gel electrophoresis in 35 children with idiopathic short stature. Results. Most children (68.57 %) were heterozygotes, 17.14 % were homozygotes for T/T alleles, and 14.29 % were homozygotes for C/C alleles. The highest growth retardation has been observed in homozygous T/T carriers. Children carrying homozygotes for C/C alleles had the least growth retardation. Growth hormone levels after clonidine stimulation test and IGF-1 levels in blood were within normal limits in all patients. Vitamin D deficiency was found in T/T homozygotes and vitamin D insufficiency in C/T heterozygotes and C/C homozygotes. Conclusions. Among children with idiopathic short stature, the prevalence of the T/C genotype was 68.57 %. The greatest growth retardation occurred in patients with homozygous T/T alleles (SDS = –2.61 ± 0.31). A decrease in serum vitamin D levels was detected in all children. Vitamin D deficiency (43.83 ± 6.47 nmol/l) was found in children homozygous for the T/T allele, and vitamin D insufficiency — in T/C heterozygotes (58.97 ± 11.78 nmol/l) and C/C homozygotes (56.93 ± 19.54 nmol/l).

Association between Expression of Insulin-like Growth Factor-1 (IGF-1), IGF-1 Receptor (IGF-1R), and Hypertension-Mediated Organ Damage (HMOD) Parameters in Leukocytes and Plasma of Children/Adolescents with Primary Hypertension.

A decrease in IGF-1 is often linked to inflammation. Low systemic and local IGF-1 production and downregulation of IGF-1R expression may precede and predict PH development in children/adolescents. Leukocyte mRNA expression of IGF-1 and its receptor (IGF-1R) and plasma IGF-1 were measured in a group of 39 PH children/adolescents (29 boys and 10 girls) and 35 age-matched normotensive children (19 boys and 16 girls) using the RT-PCR and ELISA tests. The expression of the IGF-1R protein was assessed by flow cytometry. Plasma IGF-1 concentration was evaluated with ELISA. The expression of IGF-1 and IGF-1R and plasma concentrations of IGF-1 did not differ between groups. However, the PH children had a decreased percentage in IGF-1R-bearing lymphocytes (p = 0.02) and monocytes (p = 0.0003), as well as a low density of IGF-R in monocytes (p = 0.02). The IGF-1 expression was negatively correlated with pulse-wave velocity (PWV) (r = -0.49), systolic blood pressure (SBP) (-0.44), and carotid intima-media thickness (cIMT) (-0.43). The IGF-1R expression was negatively correlated with PWV (r = -0.42) and SBP (r = -0.41). Our results suggest that early subclinical hypertensive arterial injury is associated with lower activity of IGF-1-IGF-1R expression and loss of protective actions.

IGF-1R mediates crosstalk between nasopharyngeal carcinoma cells and osteoclasts and promotes tumor bone metastasis

BackgroundNasopharyngeal carcinoma (NPC) poses a significant health burden in specific regions of Asia, and some of NPC patients have bone metastases at the time of initial diagnosis. Bone metastasis can cause pathologic fractures and pain, reducing patients' quality of life, and is associated with worse survival. This study aims to unravel the complex role of insulin-like growth factor 1 receptor (IGF-1R) in NPC bone metastasis, offering insights into potential therapeutic targets.MethodsWe assessed IGF-1R expression in NPC cells and explored its correlation with bone metastasis. Experiments investigated the impact of osteoclast-secreted IGF-1 on the IGF-1R/AKT/S6 pathway in promoting NPC cell proliferation within the bone marrow. Additionally, the reciprocal influence of tumor-secreted Granulocyte–macrophage colony-stimulating factor (GM-CSF) on osteoclast differentiation and bone resorption was examined. The effects of IGF-1 neutralizing antibody, IGF-1R specific inhibitor (NVP-AEW541) and mTORC inhibitor (rapamycin) on nasopharyngeal carcinoma bone metastasis were also explored in animal experiments.ResultsElevated IGF-1R expression in NPC cells correlated with an increased tendency for bone metastasis. IGF-1, secreted by osteoclasts, activated the IGF-1R/AKT/S6 pathway, promoting NPC cell proliferation in the bone marrow. Tumor-secreted GM-CSF further stimulated osteoclast differentiation, exacerbating bone resorption. The IGF-1 neutralizing antibody, NVP-AEW541 and rapamycin were respectively effective in slowing down the rate of bone metastasis and reducing bone destruction.ConclusionThe intricate interplay among IGF-1R, IGF-1, and GM-CSF highlights potential therapeutic targets for precise control of NPC bone metastasis, providing valuable insights for developing targeted interventions.

Estrogen Receptor Is Required for Metformin-Induced Apoptosis in Breast Cancer Cells Under Hyperglycemic Conditions.

About 25% to 30% of estrogen receptor (ER)-positive breast cancer patients develop resistance to endocrine therapy. Human epidermal growth factor receptor 2 (HER2) has been shown to cooperate with several growth factors that regulate cellular energy metabolism, including the insulin-like growth factor 1 receptor (IGF-1R). As the first-line therapy for type 2 diabetes mellitus (T2DM) patients, metformin is widely known to inhibit the metabolic reprogramming of cancer cells. This study aims to investigate metformin's efficacy in inhibiting endocrine resistance related to genes regulating energy metabolism in both ER-positive and ER-negative breast cancer cell lines under hyperglycemic conditions. MDA-MB-361 (ER-positive, HER2-positive) and SKBR3 (ER-negative, HER2-positive) cancer cell lines were used to represent ER status. Cell viability and cell survival rate were measured using the colorimetric assay of Cell Counting Kit-8. All mRNA levels were quantified using real-time quantitative polymerase chain reaction preceded by reverse transcription. A P value of <.05 was considered statistically significant. Unlike MDA-MB-361, SKBR3 were found to acquire resistance upon metformin treatment in hyperglycemic conditions. Moreover, the mRNA expression of IGF-1R and its downstream signaling, such as the mammalian target of rapamycin (mTOR), was not affected by metformin. Meanwhile, the mRNA expression level of ribosomal S6 kinase 1 (S6K1) was upregulated, whereas forkhead box O1 (FOXO1) was downregulated after metformin treatment in hyperglycemic conditions. This preliminary study suggests that an alternative pathway of metformin resistance may exist in the absence of ERα. Therefore, relying solely on metformin may be inadequate to inhibit the aggressiveness of breast cancer cells.

Targeted Degradation of Signal Transduction and Activator of Transcription 3 by Chaperone-Mediated Autophagy Targeting Chimeric Nanoplatform.

Chaperone-mediated autophagy (CMA) is a lysosomal-dependent proteolysis pathway for the degradation of cytosolic proteins. However, exploiting CMA-mediated proteolysis to degrade proteins of interest in cancer therapy has not been widely applied. In this study, we develop a CMA-targeting chimera (CMATAC) to efficiently and specifically degrade signal transduction and activator of transcription 3 (STAT3) in tumor cells. CMATAC consists of STAT3 and heat shock cognate 70 kDa protein (HSC70) targeting peptides connected by a linker. To efficiently deliver CMATACs into tumor cells, lipid nanoparticles (LNPs) are used to encapsulate CMATACs (nCMATACs) and decorated with an insulin-like growth factor 2 receptor (IGF2R) targeting peptide (InCMATACs) to achieve tumor targeting and precise delivery. The CMA pathway is activated in tumor cells by a fasting-mimicking diet (FMD). Furthermore, FMD treatment strongly enhances the cellular uptake and tumor accumulation of InCMATACs by upregulating the IGF2R expression. As a result, InCMATACs efficiently degrade STAT3 protein in both A549 and HCC827 tumor cells and inhibit tumor growths in vivo. This study demonstrates that InCMATACs can be used for selective proteolysis in cancer therapy.

Upregulation of Insulin-like Growth Factor-1 Receptor Expression in Pretibial Myxedema: Evidence for a Treatment Target.

Upregulation of Insulin-like Growth Factor-1 Receptor Expression in Pretibial Myxedema: Evidence for a Treatment Target.

Mechanism of adipose tissue-derived stromal cell-extracellular vesicles in treating oral submucous fibrosis by blocking the TGF-β1/Smad3 pathway via the miR-760-3p/IGF1R axis

Oral submucous fibrosis (OSF) is a prevalent chronic condition, and understanding its pathogenesis is crucial for developing effective therapeutic strategies. This study explores the potential of adipose tissue-derived stromal cell-extracellular vesicles (ADSC-EVs) in mitigating OSF and investigates the underlying molecular mechanisms. OSF was induced in mice by arecoline feeding. Adipose tissue-derived stromal cells (ADSCs), fibrotic buccal mucosal fibroblasts (fBMFs) isolated from OSF mice, and ADSC-EVs were comprehensively characterized. The treatment effects of extracellular vesicles (EVs) and pcDNA3.1-IGF1R on fBMF proliferation, migration, and invasion were assessed using Cell Counting Kit-8 (CCK-8) assay, transwell assay, and flow cytometry assay. The expression levels of alpha smooth muscle actin (α-SMA), collagen I, collagen III, and insulin-like growth factor 1 receptor (IGF1R) were evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot. The interaction between miR-760-3p and IGF1R was investigated. In fBMFs and OSF mice treated with a miR-760-3p inhibitor and/or EVs, the expression patterns of miR-760-3p, IGF1R, and proteins related to the TGF-β1/Smad3 pathway were determined. ADSC-EVs demonstrated the ability to upregulate miR-760-3p, impede cell proliferation, migration, and invasion, and reduce α-SMA, collagen I, and collagen III levels in fBMFs. The expression of miR-760-3p was diminished in ADSC-EVs treated with a miR-760-3p inhibitor. However, silencing miR-760-3p or overexpressing IGF1R partially counteracted the beneficial effects of ADSC-EVs on fBMF fibrosis. miR-760-3p directly targets IGF1R. Significantly, ADSC-EVs exert their suppressive effects on the TGF-β1/Smad3 pathway through the miR-760-3p/IGF1R axis. In summary, ADSC-EVs, by transferring miR-760-3p and inhibiting IGF1R expression, effectively block the TGF-β1/Smad3 pathway, thereby alleviating fibrosis in fBMFs and preventing the progression of OSF.

Actin cytoskeleton remodeling disrupts physical barriers to infection and presents entry receptors to respiratory syncytial virus.

RSV is the leading cause of infant hospitalizations and a significant cause of paediatric and geriatric morbidity worldwide. Recently, we reported that insulin-like growth factor 1 receptor (IGF1R) was a receptor for respiratory syncytial virus (RSV) in airway epithelial cells and that activation of IGF1R recruited the coreceptor, nucleolin (NCL), to the cell surface. Cilia and mucus that line the airways pose a significant barrier to viral and bacterial infection. The cortical actin cytoskeleton has been shown by others to mediate RSV entry, so we studied the roles of the RSV receptors and actin remodelling during virus entry. We found that IGF1R expression and phosphorylation were associated with the ability of RSV to infect cells. Confocal immunofluorescence imaging showed that actin projections, a hallmark of macropinocytosis, formed around viral particles 30 min after infection. Consistent with prior reports we also found that virus particles were internalized into early endosome antigen-1 positive endosomes within 90 min. Inhibiting actin polymerization significantly reduced viral titre by approximately ten-fold. Inhibiting PI3 kinase and PKCζ in stratified air-liquid interface (ALI) models of the airway epithelium had similar effects on reducing the actin remodelling observed during infection and attenuating viral entry. Actin projections were associated with NCL interacting with RSV particles resting on apical cilia of the ALIs. We conclude that macropinocytosis-like actin projections protrude through normally protective cilia and mucus layers of stratified airway epithelium that helps present the IGF1R receptor and the NCL coreceptor to RSV particles waiting at the surface.

Immunohistochemical Expression of Insulin-Like Growth Factor-1 Receptor and Its Association with Clinicopathological Parameters in Hepatocellular Carcinoma

Introduction: Hepatocellular carcinoma (HCC) carcinogenesis is not yet fully known. Insulin-like growth factor-1 receptor (IGF-1R) can translocate to the nucleus and modulate cellular growth, possibly participating in HCC development and aggressiveness. This study aimed to evaluate the immunoexpression of IGF-1R in HCC, the cellular compartment involved, and its association with clinicopathological parameters and clinical outcomes. Methods: Liver specimens from 111 HCC patients who underwent liver transplantation or partial surgical resections at a Brazilian referral hospital center were studied. IGF-1R expression was determined by immunohistochemistry, clinical data were collected from medical records, and pathological parameters were obtained from path review. Results: IGF-1R nuclear expression was higher in the tumor than in the adjacent cirrhosis (p p Conclusion: The data presented here suggest the role of IGF-1R in HCC progression and carcinogenesis as its expression increases in the nucleus relative to the membrane, from cirrhosis to tumor, and it was associated with a poorer differentiated tumor grade. Further research is awaited to fully understand the mechanisms underlying this association.

Lower muscle protein synthesis in humans with obesity concurrent with lower expression of muscle IGF1 splice variants.

This study tested the hypothesis that expression of insulin-like growth factor 1 (IGF-1) protein and mRNA splice variants is lower in skeletal muscle of humans with obesity who have a lower mixed-muscle protein fractional synthesis rate (MMP-FSR) when compared with individuals without obesity. The study included nine participants with obesity (OB, mean [SD], BMI = 35 [3] kg/m2 , MMP-FSR = 0.06%/h [0.02%/h]) and nine participants without obesity (W-OB, BMI = 24 [3] kg/m2 , MMP-FSR = 0.08%/h [0.02%/h]; for both BMI and MMP-FSR p < 0.05). MMP-FSR and mitochondrial protein FSR were measured following an overnight fast. Along with lower MMP-FSR, OB participants displayed lower mitochondrial protein FSR (p = 0.03) compared with W-OB participants. Expression of IGF-1 (p = 0.04) and IGF-1 receptor (p < 0.01) proteins was lower in muscle of OB participants. In addition, OB participantshad lower (p < 0.05) mRNA expression of IGF1 variants Eb and Ec. This study demonstrates that lower protein synthesis in muscle of humans with obesity occurs concurrently with lower expression of muscle IGF-1 and IGF-1 receptor proteins, as well as lower mRNA expression of the IGF1 splice variants. These findings indicate that lower protein synthesis observed in muscle of humans with obesity may result from diminished muscle IGF1 gene expression.

Insulin-Like Growth Factor 1 Receptor Deficiency Alleviates Angiotensin II-Induced Cardiac Fibrosis Through the Protein Kinase B/Extracellular Signal-Regulated Kinase/Nuclear Factor-κB Pathway.

Background The renin-angiotensin system plays a crucial role in the development of heart failure, and Ang II (angiotensin II) acts as the critical effector of the renin-angiotensin system in regulating cardiac fibrosis. However, the mechanisms of cardiac fibrosis are complex and still not fully understood. IGF1R (insulin-like growth factor 1 receptor) has multiple functions in maintaining cardiovascular homeostasis, and low-dose IGF1 treatment is effective in relieving Ang II-induced cardiac fibrosis. Here, we aimed to investigate the molecular mechanism of IGF1R in Ang II-induced cardiac fibrosis. Methods and Results Using primary mouse cardiac microvascular endothelial cells and fibroblasts, in vitro experiments were performed. Using C57BL/6J mice and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9)-mediated IGF1R heterozygous knockout (Igf1r+/-) mice, cardiac fibrosis mouse models were induced by Ang II for 2 weeks. The expression of IGF1R was examined by quantitative reverse transcription polymerase chain reaction, immunohistochemistry, and Western blot. Mice heart histologic changes were evaluated using Masson and picro sirius red staining. Fibrotic markers and signal molecules indicating the function of the Akt (protein kinase B)/ERK (extracellular signal-regulated kinase)/nuclear factor-κB pathway were detected using quantitative reverse transcription polymerase chain reaction and Western blot. RNA sequencing was used to explore IGF1R-mediated target genes in the hearts of mice, and the association of IGF1R and G-protein-coupled receptor kinase 5 was identified by coimmunoprecipitation. More important, blocking IGF1R signaling significantly suppressed endothelial-mesenchymal transition in primary mouse cardiac microvascular endothelial cells and mice in response to transforming growth factor-β1 or Ang II, respectively. Deficiency or inhibition of IGF1R signaling remarkably attenuated Ang II-induced cardiac fibrosis in primary mouse cardiac fibroblasts and mice. We further observed that the patients with heart failure exhibited higher blood levels of IGF1 and IGF1R than healthy individuals. Moreover, Ang II treatment significantly increased cardiac IGF1R in wild type mice but led to a slight downregulation in Igf1r+/- mice. Interestingly, IGF1R deficiency significantly alleviated cardiac fibrosis in Ang II-treated mice. Mechanistically, the phosphorylation level of Akt and ERK was upregulated in Ang II-treated mice, whereas blocking IGF1R signaling in mice inhibited these changes of Akt and ERK phosphorylation. Concurrently, phosphorylated p65 of nuclear factor-κB exhibited similar alterations in the corresponding group of mice. Intriguingly, IGF1R directly interacted with G-protein-coupled receptor kinase 5, and this association decreased ≈50% in Igf1r+/- mice. In addition, Grk5 deletion downregulated expression of the Akt/ERK/nuclear factor-κB signaling pathway in primary mouse cardiac fibroblasts. Conclusions IGF1R signaling deficiency alleviates Ang II-induced cardiac fibrosis, at least partially through inhibiting endothelial-mesenchymal transition via the Akt/ERK/nuclear factor-κB pathway. Interestingly, G-protein-coupled receptor kinase 5 associates with IGF1R signaling directly, and it concurrently acts as an IGF1R downstream effector. This study suggests the promising potential of IGF1R as a therapeutic target for cardiac fibrosis.

Clinico-pathological characteristics of IGFR1 and VEGF-A co-expression in early and locally advanced-stage lung adenocarcinoma.

Although targeted therapies and immunotherapy have achieved significant clinical benefits in patients with certain pathological types of lung cancer. However, prognosis for patients with lung adenocarcinoma still remains unsatisfactory. It is of extremely importance to find ideal prognostic indicators to predict the prognosis of lung adenocarcinoma patients, especially for patients with early and locally advanced-stage lung adenocarcinoma. The purpose of this study is to elucidate the significance of Insulin-like growth factor receptor 1 (IGFR1) and Vascular endothelial growth factor A (VEGF-A) expression in predicting progression-free survival (PFS) and overall survival (OS) in patients with early and locally advanced-stage lung adenocarcinoma. In this study, IGFR1 and VEGF-A expression on 119 specimens of patients early and locally advanced-stage lung adenocarcinoma were analyzed by immunohistochemistry with an H-score system. Both high IGFR1 expression and VEGF-A expression patients were resulted in 59 (49.6%) separately. The numbers and proportions of IGFR1-&VEGF-A- subgroup, IGFR1-&VEGF-A+ subgroup, IGFR1+&VEGF-A- subgroup and IGFR1+&VEGF-A+ subgroup are 23 (19.3%), 37 (31.1%), 37 (31.1%) and 22 (18.5%) respectively. High IGFR1 expression was significantly associated with both poor PFS and OS of all patients in a univariate analysis. Multivariable analysis showed that patients with IGFR1+&VEGF-A+ expression exhibited a worst PFS and OS in the subgroup of lung adenocarcinoma patients with EGFR mutation. These results suggest that IGFR1+&VEGF-A+ is expected to be a disadvantageous factor for prognosis in the subgroup of EGFR mutation in patients with early and locally advanced-stage lung adenocarcinoma. What's more, this study may provide the theoretical possibility to screen optimal population for a combination therapy with anti-VEGF and anti-IGFR1 in patients with early and locally advanced-stage lung adenocarcinoma.

Overexpression of miR-297b-5p in Mouse Insulin-Secreting Cells Promotes Metformin-Mediated Protection Against Stearic Acid-Induced Senescence by Targeting Igf1r.

A long-term consumption of saturated fat significantly increases the concentration of saturated fatty acids in serum, which accelerates the appearance of senescence markers in β-cells and leads to their dysfunction. An understanding of the mechanisms underlying β-cell senescence induced by stearic acid and the exploration of effective agents preventing it remains largely unclear. Here, we aimed to investigate the protective effect of metformin against stearic acid-treated β-cell senescence and to assess the involvement of miR-297b-5p in this process. To identify senescence, we measured senescence-associated β-galactosidase activity and the expression of senescence-related genes. Gain and loss of function approaches were applied to explore the role of miR-297b-5p in stearic acid-induced β-cell senescence. Bioinformatics analysis and a luciferase activity assay were used to predict the downstream targets of miR-297b-5p. Stearic acid markedly induced senescence and suppressed miR-297b-5p expression in mouse β-TC6 cells, which were significantly alleviated by metformin. After transfection of miR-297b-5p mimics, stearic acid-evoked β-cell senescence was remarkably prevented. Insulin-like growth factor-1 receptor was identified as a direct target of miR-297b-5p. Inhibition of the insulin-like growth factor-1 receptor prevented stearic acid-induced β-cell senescence and dysfunction. Moreover, metformin alleviates the impairment of the miR-297b-5p inhibitor in β-TC6 cells. Additionally, long-term consumption of a high-stearic-acid diet significantly increased senescence and reduced miR-297b-5p expression in mouse islets. These findings imply that metformin alleviates β-cell senescence by stearic acid through upregulating miR-297b-5p to suppress insulin-like growth factor-1 receptor expression, thereby providing a potential target to not only prevent high fat-diet-induced β-cell dysfunction but also for metformin therapy in type 2 diabetes.

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.

Association of IGF1R polymorphisms with kidney function-related traits.

Unimpaired kidney function is important for maintaining a healthy state of homeostasis in the body. A genome-wide association study (GWAS) conducted on kidney function-associated traits and novel loci of Japanese subjects found that insulin-like-growth factor 1 receptor (IGF1R) gene variants associated with replication were responsible for all three kinds of kidney functions and satisfied the Bonferroni significance level. This study aimed to investigate whether a comparable relationship exists in the Korean population. This study replicated three SNPs (rs28657002, rs10794486, and rs4966025) and conducted a linear regression analysis between 46 SNPs in the IGF1R gene and three kidney function-related traits, namely blood urea nitrogen (BUN), creatinine, and estimated glomerular filtration rate (eGFR) in Koreans. The IGF1R gene was found to be replicated with a significant correlation in Koreans and was extended to the entire gene region to confirm its association with kidney-related functions. Three SNPs in IGF1R were replicated (rs28657002, BUN, P = 3.39 × 10-4; rs10794486, creatinine, P = 5.79 × 10-6; rs4966025, eGFR, P = 1.57 × 10-5) and five SNPs (rs28657002, rs10794486, rs4966025, rs12439557, and rs11247372) showed common significance among the three traits. Additionally, two significant SNPs (rs11857366 and rs28657002) showed the potential to affect IGF1R expression. The results suggest that genetic polymorphisms in the IGF1R replicated previous studies and could affect kidney function. The results of this study will further enhance our understanding of how genetic differences in individuals affect kidney function-related traits.

P-543 Higher maternal age alters the insulin/IGF system and intracellular lipid metabolism of the endometrium and in the preimplantation embryo – insights from the rabbit model.

Abstract Study question Our aim was to analyse the embryo-maternal-interaction, focusing on the insulin/IGF-system and lipid metabolism on day 6 of pregnancy in reproductive young and old rabbits. Summary answer Advanced maternal age has a decisive effect on maternal and embryonic insulin/IGF-signalling and lipid metabolism, leading to higher embryo loss already during preimplantation period. What is known already The reproductive potential in women declines with age. Molecular and biochemical mechanisms involved in age-related infertility and their impact on embryo-maternal-interaction during early pregnancy are still not completely understood. However, establishment of a successful pregnancy depends on the physiological condition of the mother and a continuous dialogue with the developing embryo. The insulin/IGF-system plays a pivotal role in this embryo-maternal crosstalk, connecting maternal insulin/IGF with embryonic metabolism, cell proliferation and differentiation. Study design, size, duration We used the rabbit as reproductive model to investigate maternal age-related alterations in embryo-maternal-interaction during preimplantation period. Compared to humans, the rabbit shares high similarities in early embryo development, gastrulation and lipid metabolism (DOI: 10.1530/REP-12-0091 and DOI: 10.1093/ajcn/62.2.458S). A total of 50 young (16-20 weeks) and 31 old (&amp;lt;108 weeks) sexually mature, female rabbits were used for analysis at day 6 post coitum. Participants/materials, setting, methods We measured mRNA and protein levels of target genes of the insulin/IGF system and lipid metabolism by quantitative PCR, Western Blot and ELISA. Therefore, maternal blood, endometrium and blastocysts were analysed from reproductive young (16 to 20 weeks) and old (over 108 weeks) rabbits on day 6 of pregnancy. Blastocysts and ovulation points were counted and only blastocysts at the pre-gastrulating stage 1, separated in embryoblast (EB) and trophoblast (TB), were used for further analyses. Main results and the role of chance At day 6 of pregnancy, reproductive old rabbits had a lower amount of embryos. Maternal serum insulin and IGF levels were reduced in reproductive old rabbits, accompanied by a paracrine upregulation of IGF1 and its receptors in the endometrium. Preimplantation blastocysts adapted to hormonal changes by reducing IGF1 and IGF2 levels in both embryonic compartments, EB and TB, while the expression of embryonic IGF receptors was unchanged. Furthermore, an increase of fatty acids metabolism was observed in the ageing endometrium, indicated by the higher level of carnitine palmitoyltransferase I B (CPT1B) and elevated expression of fatty acid binding and transport proteins. These results are in line with lower level of fatty acid synthesis (FASN) in the endometrium from old, gravid rabbits, the key enzyme of fatty acid synthesis. Embryonic fatty acid uptake and b-oxidation were increased in EB and TB, too. The observed changes in embryonic and maternal lipid metabolism are caused by the alterations of the transcription factors cAMP-responsive element binding protein (CREB) and peroxisome proliferator-activated receptor (PPAR) α and γ in endometrium and embryos from reproductive old rabbits. Limitations, reasons for caution Rabbit embryogenesis reflects human development only during blastocysts formation. Therefore, statements are limited to the embryogenesis stages investigated. Wider implications of the findings The results of the current study are in accordance with the common literature, showing that advanced maternal age affects developmental competence of embryos. Our study points out that advanced maternal age alters lipid metabolism and insulin/IGF-signalling, which are two crucial components in embryo-maternal-interaction. Trial registration number not applicable