Exosome-transported IncRNA H19 regulates insulin-like growth factor-1 via the H19/let-7a/insulin-like growth factor-1 receptor axis in ischemic stroke

LncRNA(long non-coding RNA) H19 is a transcript of the H19 gene that is expressed during embryogenesis.We previously discove red a role for circular lncRNA H19 in the onset and prognosis of cerebral ischemic stroke.In this study,we used serum from patients with ischemic stroke,and mouse and cell culture models to elucidate the roles of plasma and neuronal exosomes in the regulatory effect of lncRNA H19 on insulin-like growth factor-1 and its mechanism in ischemic stroke,using western blotting,quantitative real-time polymerase chain reaction,and enzyme-linked immunosorbent assays.Plasma exosomal IncRNA H19 was negatively associated with blood levels of insulin-like growth factor-1 in samples from patients with cerebral ischemic stroke.In a mouse model,levels of exosomal IncRNA H19 were positively correlated with plasma and cerebral lncRNA H19.In a cell co-culture model,we confirmed that IncRNA H19 was transported from neuro ns to astrocytes by exosomes to induce downregulation of insulin-like growth factor-1 through the H19/let-7 a/insulin-like growth factor-1 receptor axis.This study provides the first evidence for the transpo rtation of IncRNA H19 by exosomes and the relationship between IncRNA H19 and insulinlike growth factor-1.

Insulin-like growth factor-1 mRNA isoforms and insulinlike growth factor-1 receptor mRNA expression in chronic hepatitis C

AIM: to evaluate the expression of different insulinlike growth factor(IGF)-1 mRNA isoforms and IGF-1 receptor(IGF-1R) mRNA in hepatitis C virus(HCV)-infected livers. METHODS: Thirty-four liver biopsy specimens from chronic hepatitis C(CH-C) patients were obtained before anti-viral therapy. Inflammatory activity(grading) and advancement of fibrosis(staging) were evaluated using a modified point scale of METAVIR. The samples were analyzed using quantitative real-time PCR technique. From fragments of liver biopsies and control liver that were divided and ground in liquid nitrogen, RNA was isolated using RNeasy Fibrous Tissue Mini Kit according to the manufacturer's instruction. Expression levels of IGF-1 mRNA isoforms(IGF-1A, IGF-1B, IGF-1C, P1, and P2) and IGF-1R mRNA were determined through normalization of copy numbers in samples as related to reference genes: glyceraldehyde-3-phosphate dehydrogenase and hydroxymethylbilane synthase. Results on liver expression of the IGF-1 mRNA isoforms and IGF-1R transcript were compared to histological alterations in liver biopsies and with selected clinical data in the patients. Statistical analysis was performed using Statistica PL v. 9 software. RESULTS: The study showed differences in quantitative expression of IGF-1 mRNA variants in HCV-infected livers, as compared to the control. Higher relative expression of total IGF-1 mRNA and of IGF-1 mRNAs isoforms(P1, A, and C) in HCV-infected livers as compared to the control were detected. Within both groups, expression of the IGF-1A mRNA isoform significantly prevailed over expressions of B and C isoforms. Expression of P1 mRNA was higher than that of P2 only in CH-C. Very high positive correlations were detected between reciprocal expressions of IGF-1 mRNA isoforms P1 and P2(r = 0.876). Expression of P1 and P2 mRNA correlated with IGF-1A mRNA(r = 0.891; r = 0.821, respectively), with IGF-1B mRNA(r = 0.854; r = 0.813, respectively), and with IGF-1C mRNA(r = 0.839; r = 0.741, respectively). Expression of IGF-1A mRNA significantly correlated with isoform B and C mRNA(r = 0.956; r = 0.869, respectively), and B with C isoforms(r = 0.868)(P < 0.05 in all cases). Lower expression of IGF-1A and B transcripts was noted in the more advanced liver grading(G2) as compared to G1. Multiple negative correlations were detected between expression of various IGF-1 transcripts and clinical data(e.g., alpha fetoprotein, HCV RNA, steatosis, grading, and staging). Expression of IGF-1R mRNA manifested positive correlation with grading and HCV-RNA. CONCLUSION: Differences in quantitative expression of IGF-1 mRNA isoforms in HCV-infected livers, as compared to the control, suggest that HCV may induce alteration of IGF-1 splicing profile.

A predictive score for retinopathy of prematurity by using clinical risk factors and serum insulin-like growth factor-1 levels

AIM：To detect the impact of insulin-like growth factor-1（IGF-1）and other risk factors for the early prediction of retinopathy of prematurity（ROP）and to establish a scoring system for ROP prediction by using clinical criteria and serum IGF-1 levels.METHODS：The study was conducted with 127 preterm infants.IGF-1 levels in the 1st day of life,1st,2nd,3rd and4th week of life was analyzed.The score was established after logistic regression analysis,considering the impact of each variable on the occurrences of any stage ROP.A validation cohort containing 107 preterm infants was included in the study and the predictive ability of ROP score was calculated.RESULTS：Birth weights（BW）,gestational weeks（GW）and the prevalence of breast milk consumption were lower,respiratory distress syndrome（RDS）,bronchopulmonarydysplasia（BPD）and necrotizing enterocolitis（NEC）were more frequent,the duration of mechanical ventilation and oxygen supplementation was longer in patients with ROP（P〈0.05）.Initial serum IGF-1 levels tended to be lower in newborns who developed ROP.Logistic regression analysis revealed that low BW（〈1250 g）,presence of intraventricular hemorrhage（IVH）and formula feeding increased the risk of ROP.Afterwards,the scoring system was validated on 107 infants.The negative predictive values of a score less than 4 were 84.3%,74.7%and 79.8%while positive predictive values were 76.3%,65.5%and71.6%respectively.CONCLUSION：In addition to BW〈1250 g and IVH,formula consumption was detected as a risk factor for the development of ROP.Breastfeeding is important for prevention of ROP in preterm infants.

Expression of insulin-like growth factor-1 in breast cancer tissues

Objective: We investigated the expression of insulin-like growth factor-1 (IGF-1) so as to explore its relationship with carcinogenesis and development of breast cancer. Methods: IGF-1 mRNA levels in tissues of breast cancer, adjacent breast cancer in 70 cases breast cancer patients were analyzed by RT-PCR with the normal breast tissues of paired breast as the control. Results: The level of IGF-1 mRNA expression in breast cancer tissues was significantly higher than that in the paired adjacent to breast cancer tissues, normal mammary gland tissues. The ration of IGF-1/β-actin were 0.679 ± 0.075, 0.463 ± 0.085, 0.305 ± 0.031, respectively. There was significant difference between different groups (P < 0.005). Expression of IGF-1 was associated with lymph node metastasis, pathological staging and estrogen receptor status of breast cancer and no significant relationship with tumor pathological grouping (P > 0.005). Conclusion: The high-level expression of IGF-1 in breast cancer tissues is correlated with carcinogenesis, development and metastasis of breast cancer.

Electroacupuncture-attenuated ischemic brain injury increases insulin-like growth factor-1 expression in a rat model of focal cerebral ischemia

Acupuncture has recently gained popularity in many countries as an alternative and complementary therapeutic intervention. Previous studies have shown that changes in genes, proteins, and their metabolites were measureable during acupuncture for treatment of cerebral ischemia. Through the use of in situ hybridization and immunohistochemistry, the present study confirmed that electroacupuncture increased insulin-like growth factor-1 mRNA and protein expression in the corpus stfiatum following cerebral ischemia, reduced brain edema following middle cerebral artery occlusion reperfusion, and decreased infarct volume. Results suggested that electroacupuncture is effective in the relief of cerebral ischemia by increasing endogenous insulin-like growth factor-1 expression.

Effects of targeted-edited oncogenic insulin-like growth factor-1 receptor with specific-sgRNA on biological behaviors of Hep G2 cells

BACKGROUND Insulin-like growth factor-1 receptor(IGF-1R)is over-expressed in hepatocellular carcinoma(HCC).However,the relationship between IGF-1R activation and HCC progression remains unidentified.AIM To investigate the effects of editing IGF-1R on the biological features of HCC cells.METHODS Immunohistochemistry analyzed the expressions of IGF-1R and P-glyco protein(P-gp)in HCC tissues and their distal non-cancerous tissues(non-Ca).IGF-1R was edited with Crispr/Cas9 system,screened specific sg RNAs,and then transfected into Hep G2 cells.CCK-8,scratch wound test detected cell proliferation,migration,invasion and transwell assays,respectively.Alterations of IGF-1R and P-gp were confirmed by Western blotting.Alterations of anti-cancer drug IC_(50)values were analyzed at the cell level.RESULTS The positive rates of IGF-1R(93.6%,χ~2=63.947)or P-gp(88.2%,χ~2=58.448)were significantly higher(P<0.001)in the HCC group than those(36.6%in IGF-1R or 26.9%in P-gp)in the non-Ca group.They were positively correlated between high IGF-1R and P-gp expression,and they were associated with hepatitis B virus infection and vascular invasion of HCC.Abnormal expressions of circulating IGF-1R and P-gp were confirmed and associated with HCC progression.Biological feature alterations of HCC cells transfected with specific sg RNA showed IGF-1R expression down-regulation,cell proliferation inhibition,cell invasion or migration potential decreasing,and enhancing susceptibility of Hep G2 cells to anti-cancer drugs.CONCLUSION Edited oncogenic IGF-1R was useful to inhibit biological behaviors of Hep G2 cells.

Expression of insulin-like growth factor-1 mRNA and protein level of corpora striata in ischemic side at the early stage of middle cerebral artery ischemia/reperfusion in rhesus monkeys

BACKGROUND： Insulin-like growth factor-I（IGF-1）, as one of the important members of growth factor family, participants in the regulation of many physiological functions and behaviors, having very strong neuroprotective effect. However, the expression of IGF-1 following cerebral ischemia/reperfusion is still disputed. OBJECTIVE： To observe the expression of IGF-1 and protein of corpora striata in ischemic side at the early stage of middle cerebral artery ischemia/reperfusion in rhesus monkey. DESIGN ： A completely randomized grouping design, controlled animal experiment SETTING ： Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University MATERIALS： ① Totally 17 rhesus monkeys , of either gender, aged 4 to 5 years, were enrolled . Seven rhesus monkeys observed with gene chip were randomly divided into 2 groups： sham operation group （n=3） and ischemia/reperfusion group 〈n=4〉. Ten rhesus monkeys observed with in situ hybridization and immunohistochemistry method were randomly divided into 2 groups： sham operation group 〈n=3 〉and ischemia/reperfusion group （n=7）. Rhesus monkeys observed under microscope were divided into 2 groups： sham operation group （n=6） and ischamia/reperfusion group （n=-11）.②Materials used in the experiment： cresyl violet （Sigma Company, America）; immunohistochemical reagent kit （ Huamei Bio-engineering Company）; In situ hybridization reagent kit （Boshide Bio-engineering Co.Ltd, Wuhan）; 12 800 dots chip （Boxing Company, Shanghai）. METHODS ： This experiment was carried out at the Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University from January 2001 to December 2003.① The onset area of middle cerebral artery was blocked for 2 hours, middle cerebral artery ischemia/reperfusion models were created.② After ischemia/reperfusion for 24 hours, cerebral tissue sections of rhesus monkeys were prepared and stained with cresyl violet. Image analysis was performed with 5001W image analysis software. Morphological change of corpora striata of operative side was observed in the rhesus monkeys between two groups. Total RNA was extracted from cerebral tissue. ③ Detection of gene chip： Cy3-duTP and Cy5-duTP were used to respectively perform reverse transcription labeling. The sample was reversely transcribed into cDNA, then hybridized with cDNA of cerebral tissue. Genes with the separate absolute value of cy3 and cy5〉800, cY3/cy5 〉 2（high expression） or 〈 0.5 （low expression） were found out. Those were genes with differential expression. ④ The expressions of IGF-1 mRNA and protein level of corpora striata in ischemic side of rhe- sus monkeys were detected between sham operation group and ischemia/reperfusion group at 9 and 24 hours after ischemia/reperfusion with in situ hybridization method and immunohistochemical method. Brown granules were IGF-1 protein positive cells. ⑤ Analysis of variance was used in the difference comparison of measurement data among groups. MAIN OUTCOME MEASURES ： ① Change of morphological structure of corpora striata at ischemic side in rhesus monkeys. ② Change of cerebral gene expression profiles at ischemia/reperfusion in rhesus monkeys between two groups.③ Expression of IGF-1 mRNA and protein level of corpora striata at ischemia/reperfu- sion in rhesus monkeys between two groups. RESULTS ： ① Pathological change ： Obvious pathological change of cerebral infarction appeared in the ischemia and reperfusion group, while there was no such pathological change in the sham operation group.② Change of gene expression profile ： There were 4480 genes with difference expression in the ischemia/reperfusion group and sham-operation group, in which, 260 genes had high expression and their absolute value was over 800, and 63 genes had low expression, cy3/cy5 of IGF-1 was 0.379, being relative low ex- pression. ③ IGF-1 mRNA and protein positive cell counts in corpora striata at cerebral ischemic side[IGF-1 mRNA： 〈9.72±1.18）,（9.11 ±0.76）,（14.77±0.60） counts/field：lGF-1 protein： （15.11 ±1.83）,（15.39±0.78）, （34.62±0.97）counts/field, P 〈 0.05-0.01]. CONCLUSION： IGF-1 mRNA and protein are lowly expressed in middle cerebral artery of rhesus monkeys at ischemia/reperfusion.

Insulin-like growth factor-1 induces lymphangiogenesis and facilitates lymphatic metastasis in colorectal cancer

AIM:To investigate the expression of insulin-like growth factor-1(IGF-1)/insulin-like growth factor-1 receptor(IGF-1R)in colorectal cancer(CRC)tissues and to analyze their correlation with lymphangiogenesis and lymphatic metastasis.METHODS:Immunohistochemistry was used to evaluate IGF-1 and IGF-1R expression and lymphatic vessel density(LVD)in 40 CRC specimens.The correlation between IGF-1/IGF-1R and LVD was investigated.Effects of IGF-1 on migration and invasion of CRC cells were examined using transwell chamber assays.A LoVo cell xenograft model was established to further detect the role of IGF-1 in CRC lymphangiogenesis in vivo. RESULTS:Elevated IGF-1 and IGF-1R expression in CRC tissues was correlated with lymph node metastasis(r=0.715 and 0.569,respectively,P<0.05)and tumor TNM stage(r=0.731 and 0.609,P<0.05).A higher LVD was also found in CRC tissues and was correlated with lymphatic metastasis(r=0.405,P<0.05).A positive correlation was found between LVD and IGF-1R expression(r=0.437,P<0.05).Transwell assays revealed that IGF-1 increased the migration and invasion of CRC cells.In vivo mouse studies showed that IGF-1 also increased LVD in LoVo cell xenografts.CONCLUSION:IGF-1/IGF-1R signaling induces tumorassociated lymphangiogenesis and contributes to lymphatic metastasis of CRC.

Improvement in erectile dysfunction after insulin-like growth factor-1 gene therapy in diabetic rats

Aim： To determine whether adenoviral gene transfer of insulin like growth factor-1 （IGF-1） to the penis of streptozotocin （STZ）-induced diabetic rats could improve erectile capacity. Methods： The STZ diabetic rats were transfected with AdCMV-βgal or AdCMV-IGF-1. These rats underwent cavernous nerve stimulation to assess erectile function and their responses were compared with those of age-matched control rats 1 to 2 days after transfection. In control and transfected STZ diabetic rats, IGF-1 expression were examined by reverse transcription polymerase chain reaction （RT-PCR）, Western blot and histology. The penis β-galactosidase activity and localization of the STZ diabetic rats were also determined. Results： One to two days after transfection, the β-galactosidase was found in the smooth muscle cells of the diabetic rat penis transfected with AdCMV-βgal. One to 2 days after administration of AdCMV- IGF-1, the cavernosal pressure, as determined by the ratio of maximal intracavernous pressure-to-mean arterial pressure （ICP/MAP） and total intracavernous pressure （ICP）, was increased in response to cavernous nerve stimulation. Transgene expression was confirmed by RT-PCR, Western blot and histology. Conclusion： Gene transfer of IGF-1 significantly increased erectile function in the STZ diabetic rats. These results suggest that in vivo gene transfer of IGF- 1 might be a new therapeutic intervention for the treatment of erectile dysfunction （ED） in the STZ diabetic rats.

Effects of Bifidobacterium infantis on cytokine-induced neutrophil chemoattractant and insulin-like growth factor-1 in the ileum of rats with endotoxin injury

BACKGROUND The digestive tract is the maximal immunizing tissue in the body, and mucosal integrity and functional status of the gut is very important to maintain a healthy organism. Severe infection is one of the most common causes of gastrointestinal dysfunction, and the pathogenesis is closely related to endotoxemia and intestinal barrier injury. Bifidobacterium is one of the main probiotics in the human body that is involved in digestion, absorption, metabolism, nutrition, and immunity.Bifidobacterium plays an important role in maintaining the intestinal mucosal barrier integrity. This study investigated the protective mechanism of Bifidobacterium during ileal injury in rats.AIM To investigate the effects of Bifidobacterium on cytokine-induced neutrophil chemoattractant(CINC) and insulin-like growth factor 1(IGF-1) in the ileum of rats with endotoxin injury.METHODS Preweaning rats were randomly divided into three groups: Control(group C),model(group E) and treatment(group T). Group E was intraperitoneally injected with lipopolysaccharide(LPS) to create an animal model of intestinal injury.Group T was intragastrically administered Bifidobacterium suspension 7 d before LPS. Group C was intraperitoneally injected with normal saline. The rats were killed at 2, 6 or 12 h after LPS or physiological saline injection to collect ilealtissue samples. The expression of ileal CINC mRNA was evaluated by reverse transcription-polymerase chain reaction(RT-PCR), and expression of ileal IGF-1 protein and mRNA was detected by immunohistochemistry and RT-PCR,respectively.RESULTS The ileum of rats in Group C did not express CINC mRNA, ileums from Group E expressed high levels, which was then significantly decreased in Group T(F =23.947, P < 0.05). There was no significant difference in CINC mRNA expression at different times(F = 0.665, P > 0.05). There was a high level of IGF-1 brown granules in ileal crypts and epithelial cells in Group C, sparse staining in Group E, and dark, dense brown staining in Group T. There was a significant difference between Groups C and E and Groups E and T(P < 0.05). There was no significant difference in IGF-1 protein expression at different times(F = 1.269, P > 0.05). IGF-1 mRNA expression was significantly different among the three groups(P < 0.05),though not at different times(F = 0.086, P > 0.05).CONCLUSION Expression of CINC mRNA increased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium reduced CINC m RNA expression. IGF-1 protein and mRNA expression decreased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium prevented the decrease in IGF-1 expression. Bifidobacterium may increase IGF-1 expression and enhance intestinal immune barrier function in rats with endotoxin injury.

Effect of Ganoderma lucidum spore on expression of insulin-like growth factor-1, nuclear factor-kappa B, and neuronal apoptosis in the epileptic rat brain

BACKGROUND：It has been reported that Ganoderma lucidum spore powder, a very well known Chinese traditional medicine, can affect immunoregulation, free radical scavenging, and anti-hypoxia responses. OBJECTIVE： To investigate the effect of Ganoderma lucidum spore powder on expression of insulin-like growth factor-1 （IGF-1）, nuclear factor-κB （NF-κB） and neuronal apoptosis in rats with pentylenetetrazol （PTZ）-induced epilepsy. DESIGN, TIME AND SETTING： A cellular and molecular biology experiment with randomized controlled study design was performed at the Central Laboratory of Basic Medical College of Jiamusi University from June to August 2005. MATERIALS： Thirty healthy, adult, male, Wistar rats were selected and randomly divided into 3 groups （10 rats per group）： control, epilepsy model, and Ganoderma lucidum spore powder. A sub-eclampsia PTZ dose （35 mg/kg） was intraperitoneally injected to induce epilepsy in the latter two groups. Wild Ganoderma lucidum spore powder （30 g/L） was provided by the wild Ganoderma lucidum plant nursery at Jiamusi, China. Immunohistochemical detection and terminal deoxynucleotidyl transferase-mediate dUTP nick end-labeling （TUNEL） kits were purchased from Wuhan Boster Biological Technology Co., Ltd., China. METHODS： Ganoderma lucidum spore powder was intragastrically administered at a dose of 10.0 mL/kg, once a day for 28 days. In the epilepsy and control groups, an equivalent volume of normal saline was intragastrically administered. MAIN OUTCOME MEASURES： Immunoreactivity for IGF-1 and NF-κB/P65 were detected by immunohistochemical staining. Neuronal apoptosis was detected using TUNEL methods. RESULTS： The hippocampus and cerebral cortex of rats with PTZ-induced epilepsy exhibited a higher number of apoptotic cells at high magnification （×400）, compared with the control group. Expression of IGF-1 and NF-κB were higher in the epilepsy group, compared with the control group （P 〈 0.01）. In Ganoderma lucidum spore-treated rats, fewer apoptotic cells were observed in the hippocampus and cerebral cortex, expression of NF-κB/P65 was lower, and immunoreactivity to IGF-1 increased more distinctly, compared with the epilepsy group. In addition, seizure latency was longer on 17, 21, and 25 days post-PTZ treatment in the Ganoderma lucidum spore powder group, compared with the epilepsy group （P 〈 0.05-0.01）. CONCLUSION： Ganoderma lucidum spore powder down-regulated expression of NF-κB in brain tissues of rats with PTZ-induced epilepsy, increased immunoreactivity to IGF-1, and inhibited neuronal apoptosis. These results indicated that Ganoderma lucidum spore powder has a neuroprotective effect.

RNA interference affects tumorigenicity and expression of insulin-like growth factor-1,insulin-like growth factor-1 receptor,and basic fibroblast growth factor-2 in rat C6 glioma cells

BACKGROUND： Human gliomas are more likely to express basic fibroblast growth factor-2 （FGF-2） insulin-like growth factor-1（IGF-1）, and IGF-1 receptor （IGF-1R） than normal brain tissue. These factors activate signal transduction systems of Ras/MAPK and PI3K/Akl, which promote glioma growth. OBJECTIVE： To utilize RNA interference （RNAi） technique to down-regulate FGF-2, IGF-1, and IGF-1R gene expression, and to investigate the effects of these genes on rat C6 glioma cells, as well as the feasibility of RNAi for treating glioma. DESIGN, TIME AND SETTING： This neurooncological, randomized, controlled, in vivo and in vitro experiment, which used RNAi methodology, was performed at the Laboratory of Molecular Biology, Institute of Biochemistry, Chinese Academy of Sciences between August 2005 and February 2008. MATERIALS： Rat C6 cell lines were purchased from Shanghai Institute of Cellular Biology Affiliated to Chinese Academy of Sciences. Small interfering RNA （siRNA） was synthesized by Shanghai GenePharma. Anti-IGF-1, anti-IGF-1R, anti-FGF-2, anti-mouse and anti-rabbit IgG G1-HRP antibodies were provided by Santa Cruz Biotechnology, USA. Four to six week-old BALB/c nude mice were purchased from the Laboratory Animal Center, Chinese Academy of Sciences. METHODS： C6 glioma cells were transfected with siRNA, which was chemically synthesized in vitro to correspond to endogenous FGF-2, IGF-1, and IGF-1R genes. The inhibition ratio of targeting mRNA expression was detected by semiquantitative RT-PCR, and protein expression was determined by Western blot analysis. C6 glioma cell proliferation was observed using a growth curve C6 glioma cell apoptosis rate and cell cycle were detected by flow cytometry. C6 glioma cell growth regression was observed by transwell migration assay. In addition, nude mouse subcutaneous tumor models were used in this study. For studying the anti-tumor effects of IGF-1 and IGF-1R siRNA, two blank control groups, with six mice each, were set up： A （2.5 μg siRNA was injected one week after C6 cells were inoculated, Le., when tumor volume reached 8 mm × 8 mm） and B （siRNA was injected at the same time with C6 cells were inoculated. To study the effects of FGF-2 siRNA, the groups consisted of a blank control group, negative control group, 2.6 μg siRNA group, 4 μg siRNA group, and 5.3 μg siRNA group, with six mice each. MAIN OUTCOME MEASURES： mRNA and protein inhibition ratio of FGF-2, IGF-1, and IGF-1 R; C6 glioma cell proliferation, apoptosis, and cycle growth arrest; C6 glioma cell growth regression and subcutaneous tumorigenicity rates. RESULTS： All siRNA constructs proved to be effective. After 48 hours, transfection of 200 nmol/L siRNA resulted in a FGF-2 or IGF-1R gene inhibition ratio 〉 80% and an IGF-1 gene inhibition ratio of approximately 70%. Protein expression levels for FGF-2, IGF-1, and IGF-1R decreased in a dose-dependent manner following siRNA transfection, with an inhibition rate 〉 85%, 60%, and 50%, respectively. C6 glioma cell proliferation and apoptosis rates increased in proportion to siRNA. The apoptosis rate of C6 glioma cells induced by FGF-2, IGF-1, and IGF-1R siRNA was 39.96%, 15.07% and 22.47%, respectively （P 〈 0.01）. Transfection of 200 nmol/L IGF or IGF-1R siRNA for 48 hours suppressed C6 glioma cell migration. At 30 days after intratumoral injection of 2.6, 4, and 5.3 tJg FGF-2 siRNA, tumor growth regression rate of FGF-2 siRNA was 56%, 67%, and 86%, respectively. The tumor growth regression rate was 71.88% and 45.71%, respectively, when IGF-1 or IGF-1R siRNA was intratumorally injected 1 week after C6 glioma cell transplantation. When IGF-1 or IGF-1 R siRNA was intratumorally injected during C6 glioma cell transplantation, the tumor growth regression rate was 78.13% and 74.29%, respectively. CONCLUSION： siRNA transfection downregulated gene expression of FGF-2, IGF-1, and IGF-1R In addition, siRNA treatment markedly suppressed glioma cell proliferation, growth, and migration, and concomitantly reduced subcutaneous tumorigenicity.

Associations between Placental Insulin-Like Growth Factor-1 Gene Expression, DNA Methylation and Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) is a common fetal development disorder which has great impact on neonatal health. Insulin-like growth factor-1 (IGF1) has an important role in regulating fetal growth. Whether IGF1 DNA methylation was associated with IUGR has not been studied. Placenta samples from IUGR (n = 27) and normal delivery (n = 29) were collected whereas basic information of mothers and infants were also collected. RT-PCR was performed to examine IGF1 transcriptions and bisulfite sequencing PCR was used for DNA methylation analysis. Gene expression analysis found IUGR had significantly lower IGF1 transcription compared to control group (IUGR: 0.330 ± 0.351;control group: 1.001 ± 0.800, t = 3.995, P IGF1 were all highly methylated and there is no difference on DNA methylation rate between IUGR and control group (IUGR: 75%;control group: 81%;P = 0.09). Interestingly, in both IUGR and control groups, male fetus had significantly higher methylation rate than female fetus (IUGR: male: 87%;female: 74%, P = 0.016;control: male: 82%;female: 69%, P = 0.012). There was no correlation between IGF1gene expression and DNA methylation rate (r = 0.095, P = 0.063). Intrauterine fetal growth restriction placenta had significantly lower IGF1gene expression;however, IGF1 DNA methylation level was similar. A potential fetus gender difference was also found in IGF1 DNA methylation rate.

Insulin-like growth factor 2 targets IGF1R signaling transduction to facilitate metastasis and imatinib resistance in gastrointestinal stromal tumors

BACKGROUND Gastrointestinal stromal tumors(GISTs)are typical gastrointestinal tract neoplasms.Imatinib is the first-line therapy for GIST patients.Drug resistance limits the long-term effectiveness of imatinib.The regulatory effect of insulin-like growth factor 2(IGF2)has been confirmed in various cancers and is related to resistance to chemotherapy and a worse prognosis.AIM To further investigate the mechanism of IGF2 specific to GISTs.METHODS IGF2 was screened and analyzed using Gene Expression Omnibus(GEO:GSE225819)data.After IGF2 knockdown or overexpression by transfection,the phenotypes(proliferation,migration,invasion,apoptosis)of GIST cells were characterized by cell counting kit 8,Transwell,and flow cytometry assays.We used western blotting to evaluate pathway-associated and epithelial-mesenchymal transition(EMT)-associated proteins.We injected transfected cells into nude mice to establish a tumor xenograft model and observed the occurrence and metastasis of GIST.RESULTS Data from the GEO indicated that IGF2 expression is high in GISTs,associated with liver metastasis,and closely related to drug resistance.GIST cells with high expression of IGF2 had increased proliferation and migration,invasiveness and EMT.Knockdown of IGF2 significantly inhibited those activities.In addition,OEIGF2 promoted GIST metastasis in vivo in nude mice.IGF2 activated IGF1R signaling in GIST cells,and IGF2/IGF1R-mediated glycolysis was required for GIST with liver metastasis.GIST cells with IGF2 knockdown were sensitive to imatinib treatment when IGF2 overexpression significantly raised imatinib resistance.Moreover,2-deoxy-D-glucose(a glycolysis inhibitor)treatment reversed IGF2 overexpressionmediated imatinib resistance in GISTs.CONCLUSION IGF2 targeting of IGF1R signaling inhibited metastasis and decreased imatinib resistance by driving glycolysis in GISTs.

Regulatory effects of insulin-like growth factor-1 on the expression of sensory neuropeptide mRNAs in cultured dorsal root ganglion neurons with excitotoxicity induced by glutamate

Objective To determine the effects of insulin-like growth factor-1 （IGF-1） on the expression of preprotachykinin （PPT） mRNA encoding substance P （SP） and calcitonin gene-related peptide （CGRP） mRNA in cultured dorsal root ganglion （DRG） neurons with excitotoxicity induced by glutamate （Glu）. Methods DRGs were dissected from embryonic day 15 Wistar rats. DRG neurons were dissociated and cultured for 48 h and then exposed to Glu （0.2 mmol/L） or Glu （0.2 mmol/L） plus IGF- 1 （5 nmol/L, 10 nmol/L and 20 nmol/L） for 12 h. The DRG neurons in control group were exposed to only growth media throughout the experiment. After that, the living DRG neurons were observed under inverted phase contrast microscope and microphotographs were taken. The expression levels of PPT and CGRP mRNAs were detected by reverse transcriptionpolymerase chain reaction （RT-PCR）. Results IGF-1 could inhibit Glu-induced shortening of neurite. Besides, IGF-1 could significantly increase the levels ofPPT mRNA and CGRP mRNA in primary cultured DRG neurons with Glu-induced excitotoxicity, in a dose-dependent manner. Conclusion IGF-1 may exert neuroprotective effects on DRG neurons against Glu-induced excitotoxicity, probably through regulating the expression levels of PPT and CGRP mRNAs.

Transforming growth factor-β1 and vascular endothelial growth factor levels in senile acute myeloid leukemia and correlation with prognosis

BACKGROUND Acute myeloid leukemia(AML)is a disease in which immature hematopoietic cells accumulate in the bone marrow and continuously expand,inhibiting hematopoiesis.The treatment and prognosis of this disease have always been unsatisfactory.AIM To investigate the correlation between vascular endothelial growth factor(VEGF)and transforming growth factor-β1(TGFβ1)expression and prognosis in older adults with AML.METHODS This study enrolled 80 patients with AML(AML group),including 36 with complete response(AML-CR),23 with partial response(AML-PR),and 21 with no response(AML-NR).The expression levels of VEGF and TGFβ1 were detected by reverse transcription polymerase chain reaction in bone marrow mononuclear cells isolated from 56 healthy controls.Kaplan-Meier analysis was performed to assess overall survival(OS)and progression-or disease-free survival(DFS).Prognostic risk factors were analyzed using a Cox proportional hazards model.RESULTS The AML group showed a VEGF level of 2.68±0.16.VEGF expression was lower in patients with AML-CR than those with AML-PR or AML-NR(P<0.05).TGFβ1 expression in the AML group was 0.33±0.05.Patients with AML-CR showed a higher TGFβ1 expression than those with AML-PR or AML-NR(P<0.05).VEGF and TGFβ1 expression in patients with AML was significantly correlated with the counts of leukocytes,platelets,hemoglobin,and peripheral blood immature cells(P<0.05);Kaplan-Meier survival analysis revealed that patients with high TGFβ1 expression had better OS and DFS than those with low TGFβ1 expression(P<0.05),whereas patients with low VEGF levels showed better OS and DFS than those with high VEGF levels(P<0.05).VEGF,TGFβ1,and platelet count were identified by the Cox proportional hazards model as independent risk factors for OS(P<0.05),while VEGF,TGFβ1,and white blood cell count were independent risk factors for DFS(P<0.05).CONCLUSION Decreased VEGF expression and increased TGFβ1 expression in patients with AML provide valuable references for determining and individualizing clinical treatment strategies.

Effects of insulin-like growth factor-1 on the properties of mesenchymal stem cells in vitro

Objective:To explore the effects of insulin-like growth factor-1(IGF-1) on migration,proliferation and differentiation of mesenchymal stem cells(MSCs).Methods:MSCs were obtained from Sprague-Dawley rats by a combination of gradient centrifugation and cell culture techniques and treated with IGF-1 at concentrations of 5-20 ng/ml.Proliferation of MSCs was determined as the mean doubling time.Expression of CXC chemokine receptor 4(CXCR4) and migration property were determined by flow cytometry and transwell migration essay,respectively.mRNA expression of GATA-4 and collagen II was determined by reverse transcription-polymerase chain reaction(RT-PCR).Results:The mean doubling time of MSC proliferation was decreased,and the expression of CXCR4 on MSCs and migration of MSCs were increased by IGF-1,all in a dose-dependent manner,while the optimal concentration of IGF-1 on proliferation and migration was different.IGF-1 did not affect the expression of GATA-4 or collagen II mRNA.Conclusions:IGF-1 dose-dependently stimulated the proliferation of MSCs,upregulated the expression of CXCR4,and accelerated migration.There was no apparent differentiation of MSCs to cardiomyocytes or chondrocytes after culturing with IGF-1 alone.

Expression of ghrelin and insulin-like growth factor-1 in immature piglet model of chronic cyanotic congenital heart defects with decreased pulmonary blood flow

Background Cyanotic patients have potential growth retardation and malnutrition due to hypoxemia and other reasons. Ghrelin is a novel endogenous growth hormone secretagogue that has effects on growth and cardiovascular activities. The aim of this study was to evaluate the plasma level and myocardial expression of ghrelin and insulin-like growth factor-1 （IGF-1） using an immature piglet model of chronic cyanotic congenital heart defects with decreased pulmonary blood flow. Methods Twelve weanling Chinese piglets underwent procedures of main pulmonary artery-left atrium shunt with pulmonary artery banding or sham operation as control. Four weeks later, hemodynamic parameters were measured. Enzyme-linked immunosorbent assay for plasma ghrelin and IGF-1 level measurement were performed. Ventricular ghrelin and IGF-1 mRNA expressions were measured by quantitative real-time polymerase chain reaction. Results Four weeks after surgical procedure, the cyanotic model produced lower arterial oxygen tension （（68.73±15.09） mmHg）, arterial oxygen saturation （（82.35±8.63）%）, and higher arterial carbon dioxide tension （（51.83±6.12） mmHg）, hematocrit （（42.67±3.83）%） and hemoglobin concentration （（138.17±16.73） g/L） than the control piglets （（194.08±98.79） mmHg, （96.43±7.91）%, （36.9±4.73） mmHg, （31.17±3.71）%, （109.83±13.75） g/L） （all P 〈0.05）. Plasma ghrelin level was significantly higher in the cyanotic model group in comparison to the control （P=0.004）, and the plasma IGF-1 level was significantly lower than control （P=0.030）. Compared with control animals, the expression of ghrelin mRNAs in the ventricular myocardium was significantly decreased in the cyanotic model group （P=0.000）, and the expression of IGF-1 mRNAs was elevated （P=0.001）. Conclusions Chronic cyanotic congenital heart defects model was successfully established. Plasma ghrelin level and myocardial IGF-1 mRNA expression were significantly up-regulated, while plasma iGF-1 level and myocardial ghrelin mRNA expression were down-regulated in the chronic cyanotic immature piglets. The ghrelin system may be an important part of the network regulating cardiac performance.

Neuroprotective effects of insulin-like growth factor-2 in 6-hydroxydopamine-induced cellular and mouse models of Parkinson’s disease

Skin-derived precursor Schwann cells have been reported to play a protective role in the central nervous system. The neuroprotective effects of skin-derived precursor Schwann cells may be attributable to the release of growth factors that nourish host cells. In this study, we first established a cellular model of Parkinson’s disease using 6-hydroxydopamine. When SH-SY5 Y cells were pretreated with conditioned medium from skin-derived precursor Schwann cells, their activity was greatly increased. The addition of insulin-like growth factor-2 neutralizing antibody markedly attenuated the neuroprotective effects of skin-derived precursor Schwann cells. We also found that insulin-like growth factor-2 levels in the peripheral blood were greatly increased in patients with Parkinson’s disease and in a mouse model of Parkinson’s disease. Next, we pretreated cell models of Parkinson’s disease with insulin-like growth factor-2 and administered insulin-like growth factor-2 intranasally to a mouse model of Parkinson’s disease induced by 6-hydroxydopamine and found that the level of tyrosine hydroxylase, a marker of dopamine neurons, was markedly restored, α-synuclein aggregation decreased, and insulin-like growth factor-2 receptor downregulation was alleviated. Finally, in vitro experiments showed that insulin-like growth factor-2 activated the phosphatidylinositol 3 kinase(PI3 K)/AKT pathway. These findings suggest that the neuroprotective effects of skin-derived precursor Schwann cells on the central nervous system were achieved through insulinlike growth factor-2, and that insulin-like growth factor-2 may play a neuroprotective role through the insulin-like growth factor-2 receptor/PI3 K/AKT pathway. Therefore, insulin-like growth factor-2 may be an useful target for Parkinson’s disease treatment.

Combination of insulin-like growth factor-1, IGF binding protein-3, chromogranin A and prostate specific antigen can improve the detection of prostate cancer

Aim:Prostate cancer(PCa)is the second most prevalent male cancer worldwide and designated the sixth most frequent male cancer in Arab countries.Although prostate specific antigen(PSA)has become the best and most valuable biomarker for screening of PCa,elevated levels of PSA can reflect the presence of malignant cells but can overlap with benign prostatic diseases.There is a necessity to develop and improve current tools for early detection and diagnosis of PCa.This study was done to evaluate the validation of serum insulin-like growth factor-1(IGF-1),IGF binding protein-3(IGFBP-3),chromogranin A(CgA)and combination with PSA in treatment of benign prostatic hyperplasia(BPH)and PCa patients.Methods:The study included 72 patients with PCa,70 BPH patients and 56 healthy male subjects of matched age.Full history and clinical data were recorded for all subjects.Results:Serum PSA attained sensitivity of 84%at 82%specificity with an accuracy of 83%,although IGF-1,IGFBP-3 and CgA did not recognize PCa patients.Conclusion:Combinations of IGF-1 and IGFBP-3 biomarkers with PSA were effectively differentiated between PCa and control groups as well as improving the overall value of sensitivity,specificity and diagnostic accuracy of PCa to 85%and 86%for IGF-1/PSA and IGFP-3/PSA respectively.