Exogenous Metabolic Modulators Improve Response to Carboplatin in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) lacks targeted therapies, leaving cytotoxic chemotherapy as the current standard treatment. However, chemotherapy resistance remains a major clinical challenge. Increased insulin-like growth factor 1 signaling can potently blunt chemotherapy response, and lysosomal processes including the nutrient scavenging pathway autophagy can enable cancer cells to evade chemotherapy-mediated cell death. Thus, we tested whether inhibition of insulin receptor/insulin-like growth factor 1 receptor with the drug BMS-754807 and/or lysosomal disruption with hydroxychloroquine (HCQ) could sensitize TNBC cells to the chemotherapy drug carboplatin. Using in vitro studies in multiple TNBC cell lines, in concert with in vivo studies employing a murine syngeneic orthotopic transplant model of TNBC, we show that BMS-754807 and HCQ each sensitized TNBC cells and tumors to carboplatin and reveal that exogenous metabolic modulators may work synergistically with carboplatin as indicated by Bliss analysis. Additionally, we demonstrate the lack of overt in vivo toxicity with our combination regimens and, therefore, propose that metabolic targeting of TNBC may be a safe and effective strategy to increase sensitivity to chemotherapy. Thus, we conclude that the use of exogenous metabolic modulators, such as BMS-754807 or HCQ, in combination with chemotherapy warrants additional study as a strategy to improve therapeutic responses in women with TNBC.

Donohue syndrome caused by mutation of insulin receptor gene: a case report / 中华围产医学杂志

This article reported the comprehensive management and short-term follow-up of a neonate diagnosed with Donohue syndrome. The affected male neonate presented with obvious insulin resistance (uncontrollable hyperglycemia) and unusual facies (more hair and dense, wide eye distance, large ears, etc.). Whole exome sequencing revealed a compound heterozygous variant in the insulin receptor gene [c.3258+4A>G in intron 17 and c.1321T>A (p.W441R) in exon 6], and Sanger sequencing confirmed that the mutation was inherited from both parents, which is likely pathogenic mutation. Based on the genetic test results and clinical manifestation, the neonate had a high probability of being diagnosed with Donohue syndrome. During a follow-up of nine months, the baby showed growth and development retardation, intermittent low-grade fever, and the fasting glucose was around 18 mmol/L.

Downregulation of the let-7 family of microRNAs may promote insulin receptor/insulin-like growth factor signalling pathways in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer type characterized by dysregulated cell signalling pathways and resistance to treatment. The insulin-like growth factor (IGF) signalling pathway has been identified to have a role in tumour progression and therapy resistance. However, its regulatory roles in PDAC have remained to be fully elucidated. In the present study, dysregulated microRNAs (miRNAs) in PDAC were explored with a focus on those that may be involved in regulating the insulin/IGF signalling pathway. A total of 208 patients were recruited, comprising 112 patients with PDAC, 50 patients with chronic pancreatitis (CP) and 46 subjects as a control group (CG). miRNA-specific quantitative PCR assays were used to measure 300 candidate miRNAs. The Student's t-test was applied to compare miRNA regulation between cancer patients and controls with a false discovery rate correction using Bonferroni-type comparison procedures. The DIANA-mirPath v.3 tool and HMDD v3.0 were used to identify miRNA-mRNA interactions within specific pathways. In patients with PDAC, 42 miRNAs were significantly upregulated and 42 were downregulated compared to the CG (P<0.01). In the PDAC vs. CP analysis, 16 significantly (P<0.01) upregulated and 16 downregulated miRNAs were identified. Of note, members of the let-7 family of miRNAs were downregulated and were indicated to target several components of the insulin receptor (INSR)/IGF pathway, including receptors and binding proteins, for upregulation and thus, may enable the activation of the pathway. Downregulation of the let-7 family may help promote the INSR/IGF pathway in PDAC. It may thus be an effective target for the development of INSR/IGF pathway-specific treatment strategies.

Glucose-Sensitive Myokine/Cardiokine MG53 Regulates Systemic Insulin Response and Metabolic Homeostasis.

BACKGROUND: Mitsugumin 53 (MG53 or TRIM72), a striated muscle-specific E3 ligase, promotes ubiquitin-dependent degradation of the insulin receptor and insulin receptor substrate-1 and subsequently induces insulin resistance, resulting in metabolic syndrome and type 2 diabetes mellitus (T2DM). However, it is unknown how MG53 from muscle regulates systemic insulin response and energy metabolism. Increasing evidence demonstrates that muscle secretes proteins as myokines or cardiokines that regulate systemic metabolic processes. We hypothesize that MG53 may act as a myokine/cardiokine, contributing to interorgan regulation of insulin sensitivity and metabolic homeostasis. METHODS: Using perfused rodent hearts or skeletal muscle, we investigated whether high glucose, high insulin, or their combination (conditions mimicking metabolic syndrome or T2DM) alters MG53 protein concentration in the perfusate. We also measured serum MG53 levels in rodents and humans in the presence or absence of metabolic diseases, particularly T2DM. The effects of circulating MG53 on multiorgan insulin response were evaluated by systemic delivery of recombinant MG53 protein to mice. Furthermore, the potential involvement of circulating MG53 in the pathogenesis of T2DM was assessed by neutralizing blood MG53 with monoclonal antibodies in diabetic db/db mice. Finally, to delineate the mechanism underlying the action of extracellular MG53 on insulin signaling, we analyzed the potential interaction of MG53 with extracellular domain of insulin receptor using coimmunoprecipitation and surface plasmon resonance assays. RESULTS: Here, we demonstrate that MG53 is a glucose-sensitive myokine/cardiokine that governs the interorgan regulation of insulin sensitivity. First, high glucose or high insulin induces MG53 secretion from isolated rodent hearts and skeletal muscle. Second, hyperglycemia is accompanied by increased circulating MG53 in humans and rodents with diabetes mellitus. Third, systemic delivery of recombinant MG53 or cardiac-specific overexpression of MG53 causes systemic insulin resistance and metabolic syndrome in mice, whereas neutralizing circulating MG53 with monoclonal antibodies has therapeutic effects in T2DM db/db mice. Mechanistically, MG53 binds to the extracellular domain of the insulin receptor and acts as an allosteric blocker. CONCLUSIONS: Thus, MG53 has dual actions as a myokine/cardiokine and an E3 ligase, synergistically inhibiting the insulin signaling pathway. Targeting circulating MG53 opens a new therapeutic avenue for T2DM and its complications.

Combined and individual tumor-specific expression of insulin-like growth factor-I receptor, insulin receptor and phospho-insulin-like growth factor-I receptor/insulin receptor in primary breast cancer: Implications for prognosis in different treatment groups.

Clinical trials examining insulin-like growth factor-I receptor (IGF1R)-targeting strategies have emphasized that better predictive biomarkers are required to improve patient selection.Immunohistochemical tumor-specific protein expression of IGF1R, insulin receptor (InsR), and phosphorylated IGF1R/InsR (pIGF1R/InsR) individually and combined in relation to breast cancer prognosis was evaluated in a population-based cohort of 1,026 primary invasive breast cancer patients without preoperative treatment diagnosed in Sweden. IGF1R (n = 923), InsR (n = 900), and pIGF1R/InsR (n = 904) combined cytoplasmic and membrane staining was dichotomized. IGF1Rstrong/InsRmod/strong/pIGF1R/InsRpos tumors were borderline associated with 2-fold risk for events, HRadj (2.00; 95%CI 0.96-4.18). Combined IGF1R and pIGF1R/InsR status only impacted prognosis in patients with InsRmod/strong expressing tumors (Pinteraction = 0.041). IGF1Rstrong expression impacted endocrine treatment response differently depending on patients' age and type of endocrine therapy. Phospho-IGF1R/InsRpos was associated with lower risk for events among non-endocrine-treated patients irrespective of ER status, HRadj (0.32; 95%CI 0.16-0.63), but not among endocrine-treated patients (Pinteraction = 0.024). In non-endocrine-treated patients, pIGF1R/InsRpos was associated with lower risk for events after radiotherapy, HRadj (0.31; 95%CI 0.12-0.80), and chemotherapy, HRadj (0.29; 95%CI 0.09-0.99). This study highlights the complexity of IGF hetero-and homodimer signaling network and its interplay with endocrine treatment, suggesting that combinations of involved factors may improve patient selection for IGF1R-targeted therapy.

Promoting effects of insulin-like growth factor-1 on proliferation of orbital fibroblasts derived from thyroid associated ophthalmopathy / 中华实验眼科杂志

Background Thyroid associated ophthalmopathy (TAO) is an autoimmune disease.Current research on the pathogenesis focuses on common autoantigen.Insulin-like growth factor-1 receptor (IGF-1R) is necessary for the function of IGF-1,also IGF-1 plays an important role in signaling pathway of thyroid stimulating hormone receptor (TSHR).Objective This study was to investigate the effects of IGF-1 on the proliferation,expression of IGF-1R and TSHR on cultured orbital fibroblasts (OFs) derived from TAO.Methods Human orbital tissue was obtained from 17 TAO patients who received orbital adipectomy and 4 normal controls who received cosmetic surgery in West China Hospital from March 2016 to June 2016.OFs were cultured by explant culture with DMEM/F12 containing 5％ fetal bovine serum and identified by immunochemistry.The OFs were treated with different concentrations of IGF-1.IGF-1 at different concentrations (0,50,100,125 μg/L) was added into the medium,respectively,and the proliferation of the cells (absorbancy) was detected by MTS.The percentages of IGF-1R and TSHR expressions in the cells were assayed by flow cytometry.Results Cultured cells appeared to be spindle-like in shape and grew well with abundant cytoplasm.The characteristics of the cells derived from TAO patients were consistant with normal ones.The cells showed the positive response for vimentin and absent respose for desmin,S-100,myoglobin and cytokeratin.The proliferative values of OFs were gradually elevated with the increase of IGF-I dose in both TAO group and normal group (Fgroup =219.639,P＜0.001;F ion =17.752,P＜0.001) with the optimal effects in 100 μg/L IGF-1.The expression levels of IGF-1R in the OFs were (0.009 1 ±0.008 7)％,(0.095 3±0.023 3) ％,(0.083 7±0.022 7) ％ and (0.070 9 ± 0.024 1) ％ in the TAO group,and those in the normal group were (0.0023± 0.0006)％,(0.0093±0.0012)％,(0.0073±0.0015)％ and (0.0083±0.0012)％ after treatment of 50,100,125 μg/L IGF-1.The expression levels of IGF-1 R were significantly higher after treatment of 50,100 and 125 μtg/L IGF-1 than those treatment of 0 μg/L IGF-1 in both TAO group and normal group,and the expression levels of IGF-1R in the OFs were significantly increased in the TAO group compared with the normal group (all at P＜0.05).No statistical difference was seen in the TSHR expression between the TAO group and normal group after treatment of 0,50,100 and 125 μg/L IGF-1 (Fgroup =0.133,P ＞ 0.05;F ion =0.004,P ＞ 0.05).Conclusions IGF-1 can promote the proliferation of OFs and up-regulate the expression of IGF-1R in OFs.However,IGF-1 dose not play a regulating effect on the expression of TSHR in OFs.

miR-126-mediated activation of IGF2/IGF1R/IRS1 signaling promotes the Herceptin resistance in ErbB2 positive breast cancer cells / 中国医师杂志

Objective To explore the role of insulin-like growth factor-2/insulin-like growth factor1 receptor/insulin receptor substrate-1 (IGF2/IGF1R/IRS1) signal pathway inducing the chemoresistance of epidermal growth factor receptor 2 (ErbB2) positive breast cancer cells to Herceptin.Methods Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assay were used to determine the expression levels of IGF2,IGF1 R,and IRS1.The direct targets of miR-126 were validated by dual-luciferase reporter gene assay.In SKBR3/pool2 cells,IGF1 R activity was reduced by an inhibitor of IGF1 R,and IRS1 was knocked-down by shRNAs.Furthermore,3-(4,5-dimenthylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was performed to evaluate the sensitivity of these treated cells to Herceptin.Results IGF2,IGF1 R,and IRS1 were significantly higher expressed in SKBR3/pool2 cell compared to that in SKBR3 cell.Western blot assay showed that IGF2/IGF1R/IRS1 was activated in SKBR3/pool2 cells.Bioinformatics analysis combined with luciferase activity suggested that miR-126 directly targeted IRS1.MTS results demonstrated that the chemosensitivity to Herceptin of SKBR3/ pool2 cells with inhibitor of IGF1R or shRNAs targeting IRS1 or overexpressing miR-126 was significantly reduced.Conclusions IGF2/IGF1R/IRS1 signal pathway confers to the chemoresistance of ErbB2 positive breast cancer cells to Herceptin.

Ridaforolimus (MK-8669) synergizes with Dalotuzumab (MK-0646) in hormone-sensitive breast cancer.

BACKGROUND: Mammalian target of rapamycin (mTOR) represents a key downstream intermediate for a myriad of oncogenic receptor tyrosine kinases. In the case of the insulin-like growth factor (IGF) pathway, the mTOR complex (mTORC1) mediates IGF-1 receptor (IGF-1R)-induced estrogen receptor alpha (ERα) phosphorylation/activation and leads to increased proliferation and growth in breast cancer cells. As a result, the prevalence of mTOR inhibitors combined with hormonal therapy has increased in recent years. Conversely, activated mTORC1 provides negative feedback regulation of IGF signaling via insulin receptor substrate (IRS)-1/2 serine phosphorylation and subsequent proteasomal degradation. Thus, the IGF pathway may provide escape (e.g. de novo or acquired resistance) from mTORC1 inhibitors. It is therefore plausible that combined inhibition of mTORC1 and IGF-1R for select subsets of ER-positive breast cancer patients presents as a viable therapeutic option. METHODS: Using hormone-sensitive breast cancer cells stably transfected with the aromatase gene (MCF-7/AC-1), works presented herein describe the in vitro and in vivo antitumor efficacy of the following compounds: dalotuzumab (DALO; "MK-0646"; anti-IGF-1R antibody), ridaforolimus (RIDA; "MK-8669"; mTORC1 small molecule inhibitor) and letrozole ("LET", aromatase inhibitor). RESULTS: With the exception of MK-0646, all single agent and combination treatment arms effectively inhibited xenograft tumor growth, albeit to varying degrees. Correlative tissue analyses revealed MK-0646 alone and in combination with LET induced insulin receptor alpha A (InsR-A) isoform upregulation (both mRNA and protein expression), thereby further supporting a triple therapy approach. CONCLUSION: These data provide preclinical rationalization towards the combined triple therapy of LET plus MK-0646 plus MK-8669 as an efficacious anti-tumor strategy for ER-positive breast tumors.

Potential targets prediction of apigenin via virtual screening / 重庆医学

Objective To predict the potential targets of apigenin by virtual screening .Methods The targets preliminarily forecast by PharmMapper ,were validated by associating data mining and Autodock Vina in PyRx 0 .8 .Subsequently ,receptor‐ligand interactions were analyzed by Discovery Studio 3 .5 .Results The virtual screening by PharmMapper indicated that apigenin coupled well with the disease‐related targets including insulin receptor ,estradiol 17‐beta‐dehydrogenase 1 ,and cathepsin K .According to the data mining ,insulin receptor was found in related experimental researches ,while the other two had few reports previously .And then ,the interactions between apigenin and the target proteins were analyzed by Autodock Vina and Discovery Studio Visualizer 3 .5 ,involving hydrogen bonds ,electrostatic forces ,van der Waals forces etc .Conclusion The most potential targets of apigenin were insulin receptor ,while 17‐beta‐dehydrogenase 1 and cathepsin K were also possible .

GSK1838705A, an insulin-like growth factor-1 receptor/insulin receptor inhibitor, induces apoptosis and reduces viability of docetaxel-resistant prostate cancer cells both in vitro and in vivo.

Prostate cancer is the leading malignancy and the second most common cause of cancer-related death in men. Despite high cure rates with surgery and/or radiation, 30%-40% of patients eventually develop advanced cancer. Docetaxel is one of the most effective and well established chemotherapeutic agents for prostate cancer. However, docetaxel resistance often develops within months. Combination therapies have been proposed to improve the therapeutic efficacy of docetaxel in prostate cancer, and there is an urgent need to identify agents that are effective for treatment of the disease, especially docetaxel-resistant prostate cancer. In this work, we investigated the activity of GSK1838705A, a potent insulin-like growth factor-1 receptor (IGF1R)/insulin receptor (IR) inhibitor, in prostate cancer, especially docetaxel-resistant prostate cancer. We found that GSK1838705A could effectively reduce the viability of both docetaxel-sensitive and docetaxel-resistant prostate cancer cells. GSK1838705A induced marked apoptosis in docetaxel-resistant cells, and also dramatically inhibited migration of these cells. Further, GSK1838705A significantly inhibited phosphorylation of IGF1R/IR. Importantly, GSK1838705A significantly suppressed docetaxel-resistant PC-3R tumor growth in vivo. This is the first study of GSK1838705A in prostate cancer. Our results indicate that GSK1838705A is a promising compound for the treatment of prostate cancer, especially for those who develop resistance to docetaxel, and might shed new light on treatment for prostate cancer.

Asociación entre periodontitis crónica y altos niveles de glicemia en pacientes no diabético / Association between chronic periodontitis and high blood glucose levels in non-diabetic patients

Fundamento: los mediadores inflamatorios originados por la periodontitis interfieren con la acción de los receptores de la insulina. Objetivo: evaluar la asociación entre periodontitis y niveles de glicemia en sangre en pacientes no diabéticos. Métodos: en el presente estudio de corte transversal, el universo estuvo constituido por 94 pacientes, 80 con periodontitis crónica y 14 controles sin periodontitis. Se realizó un examen periodontal completo que evaluó los parámetros periodontales más importantes. De cada paciente se obtuvo una muestra de sangre en ayunas a través de punción venosa en el brazo derecho, procesada posteriormente para obtener los niveles de glucosa. Resultados: no se observaron individuos con niveles elevados de glicemia en ayunas en el grupo de pacientes sin periodontitis, mientras que en el grupo de pacientes con periodontitis crónica un total de 22 (23 %) individuos presentaron niveles elevados de glicemia (p<0.05). Se observó mayor profundidad al sondaje y mayor pérdida de inserción clínica en los pacientes con periodontitis y glicemia alterada comparados con el grupo de pacientes con periodontitis y glicemia normal. El análisis de regresión logística crudo mostró una asociación estadísticamente significativa entre periodontitis crónica y niveles de glicemia elevados (OR= 1,087; intervalo de confianza del 95 % 1,010-1,168). Esta asociación se conservó después de ajustar por las variables de confusión. Conclusiones: los niveles elevados de glicemia son un factor de riesgo para periodontitis crónica en pacientes no diabéticos en la población estudiada; igualmente estos hallazgos indican la necesidad de implementar exámenes médicos y sanguíneos de rutina en pacientes con periodontitis crónica, con el fin de evaluar signos y síntomas que permitan identificar un metabolismo anormal de la glucosa.

ABSTRACT Background: inflammatory mediators originated by periodontitis interfere with the action of insulin receptors. Objective: to evaluate the association between periodontitis and the blood glucose levels in non-diabetic patients. Method: a cross-sectional study was conducted; the universe was composed of 94 patients: 80 with chronic periodontitis and 14 controls without periodontitis. A complete periodontal exam that evaluated the most important periodontal parameters was made. A fasting blood sample was taken from each patient through a venous puncture in the right arm and subsequently processed to obtain the glucose levels. Results: none of the individuals from the group of patients without periodontitis presented high fasting blood glucose levels; on the other hand, in the group of patients with chronic periodontitis a total of 22 individuals (23 %) presented high blood glucose levels (p<0.05). A greatest depth at probing and a greatest loss of clinical insertion were observed in patients with periodontitis and impaired glucose compared with the group of patients with periodontitis and normal blood glucose levels. The raw logistic regression analysis showed a statistically significant association between chronic periodontitis and high blood glucose levels (OR= 1,087; an interval of trust of 95 % 1,010-1,168). This association was maintained after adjusting by means of the variables of confusion. Conclusions: high blood glucose levels are a risk factor for chronic periodontitis in non-diabetic patients in the studied population. This finds show as well the need of implementing routine medical and blood exams in patients with chronic periodontitis with the aim of evaluating signs and symptoms that allow identifying an abnormal metabolism of the glucose.

Safety, tolerability, pharmacokinetics and antitumor activity of ganitumab, an investigational fully human monoclonal antibody to insulin-like growth factor type 1 receptor, combined with gemcitabine as first-line therapy in patients with metastatic pancreatic cancer: a phase 1b study.

OBJECTIVE: Previous Phase 1 studies have shown the acceptable safety profile of ganitumab-a fully human monoclonal antibody to insulin-like growth factor Type 1 receptor-in patients with advanced solid tumors. However, ganitumab 20 mg/kg in combination with gemcitabine had not been administered to patients with metastatic pancreatic cancer. To evaluate the safety, tolerability, pharmacokinetics and antitumor activity of ganitumab 20 mg/kg combined with gemcitabine 1000 mg/m(2) as first-line therapy in patients with metastatic pancreatic cancer, we conducted a Phase 1b study. METHODS: Eligible patients were adults with previously untreated metastatic adenocarcinoma of the pancreas. Patients received gemcitabine 1000 mg/m(2) on Days 1, 8 and 15 plus ganitumab 20 mg/kg on Days 1 and 15 of each 28-day cycle. Gemcitabine was administered intravenously over 30-60 min. Ganitumab was administered intravenously over 60 min after completing gemcitabine infusion. RESULTS: Six patients were enrolled and received the study treatment. All patients had thrombocytopenia and leukopenia. Other most common adverse events were neutropenia and nausea. One patient had a dose-limiting toxicity defined as Grade 3 neutropenia with fever. Exposure to ganitumab 20 mg/kg was not affected by the administration of gemcitabine. No apparent pharmacokinetic drug-drug interaction was observed. No anti-ganitumab antibodies were detected. Five patients had a measurable tumor region at baseline. Of these, four patients had a best response of stable disease. CONCLUSIONS: Ganitumab 20 mg/kg combined with gemcitabine 1000 mg/m(2) was tolerable and showed an acceptable safety profile in patients with untreated metastatic pancreatic cancer.

Association between single nucleotide polymorphism of rs2252673 of INSR gene and polycystic ovarian syndrome / 中华妇产科杂志

Objective This study is designed to determine whether an association exists between single nucleotide polymorphism (SNP) variant rs2252673 of insulin receptor(INSR) gene and polycystic ovarian syndrome (PCOS) in Han Chinese in order to identify INSR as a genetic susceptibility factor for PCOS.Methods A total of 224 women with PCOS,192 controls and 672 participants consisting of 224 trios (mother,father and offspring with PCOS) were recruited from the Hospital for Reproductive Medicine Affiliated to Shandong University,from July 2007 to April 2013.Genomic DNA was extracted according to the manufacturer' s protocol.SNP rs2252673 of INSR gene was amplified by PCR and then sequenced on an automated sequencer.Moreover,clinical and metabolic features of the patients with PCOS were compared according to the genotypes.The subjects were divided into twot groups according to body mass index (BMI),and then the results were compared between two groups.And the transmitted disequilibrium test (TDT) was applied for data analysis.Results (1) There were three kinds of genotype of CC,CG and GG.Genotype frequencies of rs2252673 were 8.0％,38.8％,53.1％ and 14.6％,42.2％,43.2％ in the PCOS group and the control group,respectively.The allele frequencies of C and G were 27.5％,72.5％ and 35.7％,64.3％ in the PCOS group and the control group,respectively.There were statistical differences in genotype frequencies and allele frequencies between two groups (all P＜0.05).(2)No significant differences were observed in the different genotype according to clinical and metabolic characteristics of women with PCOS (P＞0.05).But when merging the genotype CG and GG,carriers of the CG and GG genotypes in women with PCOS were slightly associated with total cholesterol (TC) levels (t=2.072,P=0.048) and lower high-density lipoprotein (HDL) levels (t=2.274,P=0.026).Although statistical significance was not achieved,there was an increased tendency in fasting blood glucose (FBG) and fasting insulin (FINS) levels in CG and GG genotypes in PCOS cases.(3)Between the obesity and the non-obesity with PCOS,there was no statistical significance in the genotype and allele frequencies (x2=0.054,P=0.974; x2=0.022,P=0.883).(4)The results of families based analysis shown that genotype distribution of the SNP rs2252673 was in Hardy-Weinberg equilibrium (P＞0.05).After the TDT,the G allele in SNP rs2252673 was over transmitted in families (transmitted∶ non-transmitted=120∶ 88; x2=4.923,P=0.027).There was a transmitted disequilibrium in rs2252673,which implies the association of INSR and PCOS were independent of population stratification.Conclusions There were a association between the SNP variant rs2252673 of INSR gene and the susceptibility to PCOS in Han Chinese women,which was independently of body mass index.The carrier of G allele frequency of rs2252673 may have higher risk of PCOS.

Effects of acute knockdown of hepatic insulin receptor on secretion of apolipoprotein B and triglyceride in mice / 中华老年医学杂志

Objective To analyze the effects of acute depletion of liver-specific insulin signaling on secretion of apolipoprotein B (apoB) and triglyceride (TG).Methods Based on Cre-LoxP principle,a promoter of hepatic tissue specific albumin gene was inserted into upstream of the cre recombinase gene.Albumin-Cre adenovirus (Ad-CRE) and GFP adenovirus (Ad-GFP) were amplified in 293A cells and purified before intravenous administration to mice.After adenovirus infection for 2 days,4 days and 6 days,blood samples from mice were collected and hepatic tissues were frozen.The secretion rates of hepatic newly synthesized apoB and very low density lipoprotein (VLDL)-TG were determined by injection of Triton WR-1339.The levels of plasma cholesterol (TC) and TG were measured.The expressions of insulin receptor and other lipoprotein metabolism related proteins in hepatic tissues were analyzed by Western blot.Results After 2 d,4 d and 6 d of the Ad-CRE injection into mice,insulin receptor expression was reduced by 30.50％ (P＜0.05),60.12％ (P＜ 0.01) and 99.54％ (P＜0.001),and VLDL-TG secretion rate was decreased by 20.43％ (P＜0.05),33.63％ (P＜0.05) and 44.21％ (P＜0.01),respectively.Expressions of sterol regulatory binding proteins 1,fatty acid synthase,and the related proteins of VLDL-formation were decreased,but there were no changes in hepatic secretion of apoB100 and hepatic lipids.The hepatic secretion of apoB48 was increased by 35.07％ (P＜0.05) 6 d after Ad-CRE injection.Conclusions Acute depletion of hepatic insulin receptor might reduce VLDL-TG secretion in manner of time-dependent,and increase the assembly and secretion of smaller apoB-containing lipoproteins in mice liver,which is probably associated with decreased lipogenesis.

The role of gut-liver axis in the restriction of intrauterine growth in a model of experimental gastroschisis / O papel do eixo intestino-fígado na restrição de crescimento intra-uterino em um modelo de gastrosquise experimental

PURPOSE: To evaluate the intrauterine growth restriction (IUGR) by the expression of IR-β, IRS-1, IRS-2, IGF-IRβ and Ikappaβ in experimental model of gastroschisis. METHODS: Pregnant rats at 18.5 days of gestation were submitted to surgery to create experimental fetal gastroschisis (term = 22 days) were divided in three groups: gastroschisis (G), control (C) and sham (S). Fetuses were evaluated for body weight (BW), intestinal (IW), liver (LW) and their relations IW/BW and LW/BW. IR-β and IGF-IRβ receptors, IRS-1 and IRS-2 substrates and Ikappaβ protein were analyzed by western blotting. RESULTS: BW was lower in G, the IW and IW / BW were greater than C and S (p<0.05) groups. The liver showed no differences between groups. In fetuses with gastroschisis, compared with control fetuses, the expression of IGF-IRβ (p<0.001) and Ikappaβ (p<0.001) increased in the liver and intestine, as well as IR-β (p<0.001) which decreased in both. In contrast to the intestine, IRS-1 (p<0.001) increased in the liver and IRS-2 decreased (p<0.01). CONCLUSION: The axis of the intestine liver has an important role in inflammation, with consequent changes in the metabolic pathway of glucose can contribute to the IUGR in fetuses with gastroschisis.

OBJETIVO: Avaliar a restrição de crescimento intra-uterino (RCIU) pela expressão de IR-β, IRS-1, IRS-2, IGF-IRβ e a via inflamatória do Ikappaβ no modelo de gastrosquise experimental. MÉTODOS: Ratas grávidas com 18,5 dias de gestação foram submetidas a cirurgia experimental para criar gastrosquise fetal (termo = 22 dias) e os fetos foram divididos em três grupos: gastrosquise (G), controle (C) e sham (S). Os fetos foram avaliados quanto ao peso corporal (BW), intestinal (IW), fígado (LW) e suas relações IW/BW e LW/BW. Os receptores IR-β e IGF-IRβ, os substratos IRS-1 e IRS-2 e a proteína Ikappaβ foram analisados por western blotting. RESULTADOS: O BW de G foi menor, o IW e IW/BW foram superiores a C e S (p < 0.05). O fígado não apresentou diferenças entre os grupos. Nos fetos com gastrosquise, quando comparados com fetos controles, a expressão de IGF-IRβ (p<0.001) e Ikappaβ (p<0.001) aumentou no fígado e intestino, assim como IR-β (p<0.001) que diminuiu em ambos. Inversamente ao intestino, IRS-1 (p<0.001) aumentou no fígado e IRS-2 diminuiu (p<0.01). CONCLUSÃO: O eixo do intestino fígado tem um papel importante na inflamação, com consequentes alterações na via metabólica de glicose que pode contribuir para a RCIU em fetos com gastrosquise.

Two novel insulin receptor gene mutations in a patient with Rabson-Mendenhall syndrome: the first Korean case confirmed by biochemical, and molecular evidence.

Rabson-Mendenhall syndrome (RMS) is a rare syndrome manifested by extreme insulin resistance with hyperinsulinemia, acanthosis nigricans, tooth dysplasia and growth retardation. Our patient was first noted at the age of 8 months due to pigmentations on skin-folded areas. Initial laboratory tests showed normal fasting glucose (69 mg/dL). Fasting insulin level was severely elevated, up to 554.6 µIU/mL, and c-peptide level was increased, up to 13.81 ng/mL. However, hemoglobin A1c was within normal range (4.8%). He is now 11 yr old. His growth development followed the 5-10th percentile and oral hypoglycemic agents are being administered. The last laboratory results showed insulin 364.1 µIU/mL, C-peptide 4.30 ng/mL, and hemoglobin A1c 7.6%. The boy was a compound heterozygote for the c.90C > A and c.712G > A mutations of the insulin receptor gene, INSR, which are nonsense and missense mutations. In summary, we report the first Korean case of RMS, which was confirmed by two novel mutations of the INSR.

Two Novel Insulin Receptor Gene Mutations in a Patient with Rabson-Mendenhall Syndrome: The First Korean Case Confirmed by Biochemical, and Molecular Evidence

Rabson-Mendenhall syndrome (RMS) is a rare syndrome manifested by extreme insulin resistance with hyperinsulinemia, acanthosis nigricans, tooth dysplasia and growth retardation. Our patient was first noted at the age of 8 months due to pigmentations on skin-folded areas. Initial laboratory tests showed normal fasting glucose (69 mg/dL). Fasting insulin level was severely elevated, up to 554.6 microIU/mL, and c-peptide level was increased, up to 13.81 ng/mL. However, hemoglobin A1c was within normal range (4.8%). He is now 11 yr old. His growth development followed the 5-10th percentile and oral hypoglycemic agents are being administered. The last laboratory results showed insulin 364.1 microIU/mL, C-peptide 4.30 ng/mL, and hemoglobin A1c 7.6%. The boy was a compound heterozygote for the c.90C > A and c.712G > A mutations of the insulin receptor gene, INSR, which are nonsense and missense mutations. In summary, we report the first Korean case of RMS, which was confirmed by two novel mutations of the INSR.

Preliminary investigation of the expression and functions of insulin receptor isoforms in endometrial carcinoma / 中华妇产科杂志

Objective To investigate the expression of insulin receptor isoforms(IR,including IR-A and IR-B)in endometrial carcinoma(EC),and explore the role of IR-A in the growth of endometrial carcinoma cells.Methods The expression of IR isoforms were detected by reverse transcription(RT)-PCR and real-time PCR in 4 different endometrial cancer cell lines(HEC-1-A,Ishikawa,RL95-2 and KLE),with human breast cancer cell line MCF-7 cells and hepatocellular carcinoma cell line Hep-G2 as positive control and in the endometrial cancer tissue specimens of 42 cases,admitted in Peking University People's Hospital from November 2007 to July 2009,with normal endometrial tissues from 15 cases of ovarian neoplasms at the same period as controls.The relationships among the expression of IR,IR-A isoforms and the clinicopathological parameters of EC tissues were analyzed by Spearman rank correlation analysis.An eukaryotic IR-A expression plasmid was constructed and transfected into RL95-2 cells[RL95-2(IR-A)]for overexpression of IR-A in RL95-2 cells,in which the expression of IR-A originally was low.Non radioactive cell proliferation assay—MTS was used to determine the proliferation curves in the four EC cells listed above and in RL95-2 or RL95-2(IR-A).Results(1)There were two isoforms of IR-A and IR-B coexpressed were detected in EC cells and EC tissues.Among four kinds of EC cell lines,the expression level of IR mRNA in RL95-2 cells was the highest,followed by Ishikawa,KLE and HEC-1-A cells,in which the relative IR mRNA expression levels were(26.54 ± 1.82)× 10-4,(15.44 ± 3.29)× 10-4,(10.14 ±0.10)× 10-4 and(2.63 ±0.23)× 10-4,respectively(P ＜0.01).The expression level of IR-A mRNA was the highest in Ishikawa cells,followed by KLE,RL95-2 and HEC-1-A cells,with the relative expression levels were(12.07 ±3.31)× 10-4,(4.68 ±0.63)× 10-4,(3.03 ±0.22)× 10 4 and(1.46 ±0.03)×10-4,respectively(P ＜0.01).The relative expression level of IR and IR-A mRNA were 0.017 ±0.013 and 0.011 ±0.010 in the EC tissues,respectively,compared with 0.015 ± 0.014 and 0.010 ± 0.012 in the controls,in which there were no significant differences in the expression level of IR or IR-A mRNA between EC tissues and the control(P =0.662,P =0.780).The expression of IR and IR-A in EC tissues had no significant relevance with International Federation of Gynecology and Obstetrics(FIGO)stage,cell differentiation,depth of myometrial invasion,invasion of lymph-vascular space,lymph nodes metastasis,the expression status of estrogen receptor,human progesterone receptor,and PTEN gene(all P ＞ 0.05).The expression of IR-A mRNA in EC patients with type 2 diabetes mellitus(DM)was significantly higher than that in patients without type 2 DM(P =0.031),while there were no statistical correlation between the expression of IR mRNA and type 2 DM(P =0.438).(2)The proliferation rates of the four kinds of EC cells was positively related with the IR-A expression ratio,with the most growth potential in Ishikawa,followed by HEC-1-A,KLE and RL95-2 cells.The overexpression of IR-A in RL95-2(IR-A)cells showed a significant proliferation-promoting effect than that in control RL95-2 cells(P ＜ 0.01).Conclusion There are two isoforms of IR-A and IR-B co-expressed in EC.The overexpression of IR-A may promote the proliferation of EC cells.

Changes in expression of insulin receptor, insulin receptor substrate- Ⅰ and protein kinase B in Alzheimer's disease model rats / 中华神经科杂志

ObjectiveTo investigate the effect of soluble β-amyloid protein (Aβ) oligomers on the expression levels of insulin signaling transduction cascades-associated proteins including insulin receptor ( InsR),insulin receptor substrate-Ⅰ( IRS-Ⅰ) and protein kinase B (PKB) of rat hippocampal neurons,and the pathogenesis of Alzheimer's disease (AD) in depth.MethodsSoluble Aβ oligomers (5 μl) were injected into the lateral ventriculus of the AD group by a microinjector under the stereotaxic apparatus.Normal saline solution ( NS,5 μl) was injected into the NS group in the same way,and the control group received the puncture without injection. It was repeated after 1 week and the behavior of all rats was evaluatedbyY-mazetestafter2weeks.Thenhippocampuswasremovedandunderwent immunohistochemical staining to detect the expression of proteins associated.ResultsCompared with the other groups,learning and memory ability of the Aβ-treated rats were impaired.To be specific,the times of learning were increased and the times of memory were decreased. However,there was no significant difference between the NS group and the control group.Besides,the expression levels of InsR,IRS-Ⅰ,and PKB were decreased in AD group showing that a mean optical density of staining on these proteins ( InsR:0.12 ± 0.0l ; IRS-Ⅰ:0.14 ± 0.02; PKB:0.12 ± 0.03 ) was reduced in contrast with that in the NS group and the control group.Whereas there was no significant difference between the NS group (0.40 ± 0.02,0.39 ± 0.06,0.38 ± 0.03,mean difference:- 0.13,- 0.13,- 0.17,all P ＜ 0.05 ) and the control group (0.38 ± 0.07,0.35 ± 0.03,0.35 ± 0.06,mean difference:- 0.15,- 0.07,- 0.73,all P ＜ 0.05 ).ConclusionsSoluble Aβ1-42 induced learning and memory disability of the rats.The mechanism might be that Aβ can lead to disorders of the insulin signaling transduction pathway of hippocampal neurons and decrease the expression levels of the proteins in the pathway.

Insulin stimulation of Akt/PKB phosphorylation in the placenta of preeclampsia patients / Estimulação com insulina da fosforilação da Akt/PKB em placenta de pacientes com pré-eclâmpsia

CONTEXT AND OBJECTIVE: Preeclampsia is a multi-systemic disease and one of the most frequent severe health problems during pregnancy. Binding of insulin triggers phosphorylation and activates cytoplasmic substrates such as phosphatidylinositol 3 kinase (PI3K). Phosphorylation of membrane phosphoinositide 2 (PIP2) to phosphoinositide 3 (PIP3) by PI3K starts Akt/PKB activation. Defects in phosphorylation of the insulin receptor and its substrates have an important role in insulin resistance. Studies have shown that insulin resistance is associated with preeclampsia and its pathophysiology. The aim here was to investigate insulin stimulation of the Akt/PKB pathway in the placenta, in normal and preeclampsia parturients. DESIGN AND SETTING: Cross-sectional study in a tertiary public university hospital. METHODS: Placentas were collected from 12 normal and 12 preeclampsia patients. These were stimulated and analyzed using Western blot to quantify the Akt/PKB phosphorylation. RESULTS: The insulin stimulation was confirmed through comparing the stimulated group (1.14 ± 0.10) with the non-stimulated group (0.91 ± 0.08; P < 0.001). The phosphorylation of Akt/PKB did not differ between the placenta of the normal patients (1.26 ± 0.16) and those of the preeclampsia patients (1.01 ± 0.11; P = 0.237). CONCLUSIONS: In vitro insulin stimulation of the human placenta has been well established. There was no difference in Akt/PKB phosphorylation, after stimulation with insulin, between placentas of normal and preeclampsia patients. Nevertheless, it cannot be ruled out that the Akt/PKB signaling pathway may have a role in the pathophysiology of preeclampsia, since the substrates of Akt/PKB still need to be investigated.

CONTEXTO E OBJETIVO: Pré-eclâmpsia (PE) é uma doença multissistêmica das mais frequentes e graves durante a gestação. A ligação da insulina inicia a fosforilação e ativação de substratos citoplasmáticos, tais como fosfatidil-inositol 3 quinase (PI3K). A fosforilação do fosfoinositol 2 (PIP2) da membrana em fosfoinosiltol 3 (PIP3) pela PI3K inicia a ativação da Akt/PKB. Defeitos na fosforilação do receptor de insulina e seus substratos têm papel importante na resistência à insulina. Estudos demonstraram que resistência à insulina está associada com pré-eclâmpsia e sua patofisiologia. O objetivo foi investigar a via de estimulação com insulina da Akt/PKB em placenta de parturientes normais e com pré-eclampsia. TIPO DE ESTUDO E LOCAL: Estudo do tipo transversal em um hospital universitário público de nível terciário. MÉTODOS: Vinte e quatro placentas (12 normais, 12 com PE) foram coletadas, estimuladas e analisadas por Western blot para quantificar a fosforilação da Akt/PKB. RESULTADOS: A estimulação com insulina foi confirmada comparando os grupos estimulados (1,14 ± 0,10) e não estimulados (0.91 ± 0.08; P < 0.001). A fosforilação de Akt/PKB não foi diferente na placenta de pacientes normais (1,26 ± 0,16) e com PE (1,01 ± 0,11; P = 0,237). CONCLUSÕES: A estimulação in vitro da placenta humana com insulina foi bem estabelecida. Não houve diferença na fosforilação da Akt/PKB após estimulação em placentas de pacientes normais e PE. Contudo, não é possível descartar a participação desta via de sinalização na patofisiologia da PE, uma vez que os substratos da Akt/PKB ainda precisam ser investigados.