IGF-1、IGF-1结合蛋白3在运动防治肥胖、糖尿病和心血管疾病中的作用

运动防治肥胖、糖尿病和心血管疾病,改善其紊乱的糖脂代谢,但其机制仍未完全阐明。胰岛素类生长因子1(IGF-1)和IGF-1结合蛋白3(IGFBP-3)的水平在肥胖及其相关疾病如2型糖尿病、心血管疾病等的发生、发展和严重程度上的重要作用受到越来越多的关注。运动防治肥胖及其相关疾病的机制,部分与运动增加血清IGF-1、降低IGFBP-3水平和提高IGF-1活性(IGF-1/IGFBP-3摩尔比)有关。本文综述了IGF-1、IGFBP-3与肥胖、糖尿病和心血管疾病的相关性,及其在运动防治上述疾病中的作用及可能机制。     

IGF-1、IGFBP-3在大鼠非酒精性脂肪性肝病进展中的变化

目的：观察非酒精性脂肪性肝病（NAFLD）大鼠血清胰岛素样生长因子1（IGF-1）、胰岛素样生长因子结合蛋白3（ IGFBP-3）的表达及多烯磷脂酰胆碱对其的影响。方法采用高脂饲料喂养建立大鼠NAFLD模型,以多烯磷脂酰胆碱进行干预。 HE染色动态观察大鼠4、8、12周时肝组织病理学变化,IRMA法动态监测血清IGF-1、IGFBP-3含量。结果正常组大鼠各时间点肝组织病理均无明显异常;模型组随高脂饮食时间延长,在4、8、12周3个时相点肝组织脂肪变、炎症程度、气球样变及NAFLD活动度积分逐渐增强,血清IGF-1、IGFBP-3逐渐明显下降,且模型组各时相点IGF-1、IGFBP-3的水平较正常组同一时相点明显降低;应用多烯磷脂酰胆碱干预后,大鼠肝组织炎症程度、NAFLD活动度积分较模型组显著降低,IGF-1、IGFBP-3的水平则较模型组明显增高。结论血清IGF-1、IGFBP-3水平随大鼠NAFLD进展而降低。     

补偿生长对异育银鲫IGF-1、IGFBP-1水平及IGF-1、IGF-1RmRNA表达的影响

该实验分析饥饿和恢复投喂对异育银鲫血液IGF-1和IGFBP-1水平和肝脏IGF-1、白肌IGF-1RmRNA表达量的影响。结果显示:饥饿期(14d)血液中IGF-1和IGFBP-1水平逐渐下降,在饥饿第14天均出现显著性降低(P<0.05);恢复投喂后第1天IGF-1迅速恢复到对照组水平,而IGFBP-1水平仍显著低于对照组(P<0.05),随后逐渐升高,直至于恢复投喂第14天后显著高于对照组水平(P<0.05);饥饿期肝脏IGF-1mRNA表达量呈下降趋势,但与对照组无显著性差异(P>0.05);恢复投喂初期(第1、3天),IGF-1mRNA表达量仍继续下降(P<0.05),对营养条件的变化反应滞后,至第7天,表达水平恢复到对照组水平。白肌IGF-1RmRNA表达水平在饥饿第3天出现显著性下降(P<0.05),继续饥饿其水平出现补偿性升高;恢复投喂后第14天IGF-1RmRNA表达量显著高于对照组水平(P<0.05)。该结果揭示恢复投喂期高水平的IGFBP-1含量和IGF-1RmRNA表达量可能通过提高IGF-1的促生长作用参与异育银鲫的补偿生长调节。     

有氧运动与饮食控制对2型糖尿病大鼠肝chemerin及其受体CMKLR1的影响

目的：研究4周有氧运动与饮食控制对2型糖尿病（DM）大鼠肝chemerin及其受体趋化因子样受体1（CMKLR1）的影响及其在改善糖脂代谢中的影响。方法：50只雄性SD大鼠随机分为正常对照组（Con,n=6）和糖尿病造模组（n=44）。采用高脂高糖饲料联合小剂量链脲佐菌素（STZ）（30 mg/kg）的方法制备2型糖尿病模型大鼠。造模成功的DM大鼠随机分为4组（n=6）：糖尿病对照组（DM）、糖尿病运动组（EDM）、改喂普通饲料的糖尿病饮食控制组（NDM）和糖尿病运动+饮食控制组（ENDM）。运动组大鼠进行为期4周中等强度跑台有氧运动,每周运动6 d。采用罗氏血糖仪检测大鼠空腹血糖（FBG）,全自动生化分析仪检测大鼠血清总胆固醇（TC）、甘油三酯（TG）和低密度脂蛋白（LDL）水平,real time PCR和Western blot分别检测大鼠肝chemerin、CMKLR1的mRNA和蛋白水平。结果：DM大鼠FBG和血清TC、TG、LDL水平显著升高的同时,肝chemerin和CMKLR1的mRNA和蛋白水平显著增加;4周有氧运动和/或饮食控制显著降低EDM、NDM和ENDM组FBG和血清TC、TG、LDL的同时,显著降低这3组大鼠的肝chemerin蛋白水平,其中ENDM组降低最显著（P<0.01）;NDM和ENDM组大鼠的肝CMKLR1蛋白水平升高（P<0.01）。结论：4周有氧运动和/或饮食控制降低2型糖尿病大鼠的肝chemerin蛋白水平、增加CMKLR1蛋白水平,这可能与其改善糖尿病大鼠的糖脂代谢有关。     

用酵母双杂交技术研究IGF-1与其结合蛋白3的相互作用

 为了探讨胰岛素样生长因子结合蛋白 3(IGFBP- 3)分子上的胰岛素样生长因子 1 (IGF- 1 )结合位点并找出其关键氨基酸残基组成 ,首先建立了研究 IGF- 1与 IGFBP- 3相互作用的酵母双杂交模型 ,可以定性和定量地分析两个蛋白质之间的相互作用大小 ;同时利用基因体外定点突变的方法 ,对推断出的 IGF- 1结合位点中的氨基酸突变 ,经 DNA序列分析 ,构建了 5种 IGFBP- 3突变体 .然后在酵母双杂交模型中通过对报告基因活性的定量分析 ,检测 IGF- 1与各种 IGFBP- 3突变体之间相互作用的大小 .结果表明 ,IGFBP- 3分子上的 Lys2 2 2 ,Gln2 2 3突变后 ,与 IGF- 1的结合力大大下降 ,而 Arg2 2 5,Pro2 2 6,Ser2 2 7突变后也导致与 IGF- 1结合力的部分下降 .从而初步确定了IGFBP- 3分子中第 2 2 2～ 2 2 7位的氨基酸区域为 IGF- 1的结合位点 ,并且 IGFBP- 3分子上 Lys2 2 2 ,Gln2 2 3在与 IGF- 1结合中起着重要作用 .     

特发性矮小症患儿治疗前后血清IGF-1、IGFBP-3、25（OH）D、皮质醇水平变化及其与体格发育和骨龄的相关性分析

摘要 目的：探究特发性矮小症（ISS）患儿治疗前后血清胰岛素样生长因子1（IGF-1）、胰岛素样生长因子结合蛋白3（IGFBP-3）、25羟维生素D[25（OH）D]、皮质醇水平变化及其与体格发育和骨龄的相关性。方法：选取安徽省儿童医院于2017年7月～2021年3月收治的88例ISS患儿作为研究组。另选取同期体检健康儿童88例作为对照组。比较两组血清IGF-1、IGFBP-3、25（OH）D及皮质醇水平。比较ISS患儿治疗前后血清IGF-1、IGFBP-3、25（OH）D及皮质醇水平,体格指标以及骨龄指标。通过Pearson相关性分析ISS患儿血清IGF-1、IGFBP-3、25（OH）D及皮质醇水平与体格指标、骨龄指标的相关性。结果：研究组患儿血清IGF-1、IGFBP-3、25（OH）D水平均低于对照组,而皮质醇水平高于对照组（均P＜0.05）。ISS患儿治疗后血清IGF-1、IGFBP-3、25（OH）D水平均高于治疗前,而皮质醇水平低于治疗前（均P＜0.05）。ISS患儿治疗后身高、体重、骨龄年龄差（BAD）、骨龄指数（BAI）以及体质指数（BMI）均高于治疗前（均P＜0.05）。经Pearson相关性分析发现：ISS患儿血清IGF-1、IGFBP-3、25（OH）D水平与身高、体重、BAD、BAI以及BMI均呈正相关;皮质醇与身高、体重、BAD、BAI以及BMI均呈负相关（均P＜0.05）。结论：ISS患儿血清IGF-1、IGFBP-3、25（OH）D水平异常降低,皮质醇水平升高,且上述四项指标均和身高、体重、BAD以及BAI有关。     

脓毒症患者血清HMGB1、IGF-1水平变化及与T淋巴细胞亚群、预后的关系研究

目的:探讨脓毒症患者血清高迁移率族蛋白1(HMGB1)、胰岛素样生长因子-1(IGF-1)水平变化及与T淋巴细胞亚群、预后的关系。方法:选取2016年2月～2018年12月期间我院收治的脓毒症患者139例,根据Sepsis 3.0定义,将脓毒症患者分成一般脓毒症组(n=73)及脓毒症休克组(n=66),根据患者进入重症监护室28d后的转归资料,将其分为存活组和死亡组。比较不同预后、不同病情严重程度的脓毒症患者血清IGF-1、HMGB1水平、急性病生理与慢性健康评价系统Ⅱ(APACHEⅡ)评分以及T淋巴细胞亚群;采用Pearson相关分析血清HMGB1、IGF-1水平与T淋巴细胞亚群、APACHEⅡ评分的关系。结果:一般脓毒症组CD3~+、CD4~+、CD4~+/CD8~+高于脓毒症休克组,CD8~+低于脓毒症休克组(P0.05)。脓毒症休克组血清HMGB1水平、APACHEⅡ评分均高于一般脓毒症组,血清IGF-1水平则低于一般脓毒症组(P0.05)。存活组CD8~+低于死亡组,CD3~+、CD4~+、CD4~+/CD8~+高于死亡组(P0.05)。存活组血清HMGB1水平、APACHEⅡ评分低于死亡组,血清IGF-1水平高于死亡组(P0.05)。Pearson相关分析显示,脓毒症患者血清HMGB1水平与CD8~+、APACHEⅡ评分呈正相关,与CD3~+、CD4~+、CD4~+/CD8~+呈负相关(P0.05);血清IGF-1水平与CD8~+、APACHEⅡ评分呈负相关,与CD3~+、CD4~+、CD4~+/CD8~+呈正相关(P0.05)。结论:脓毒症血清HMGB1、T淋巴细胞亚群、IGF-1均存在异常变化,可用于评估脓毒症患者的病情和预后。     

不同运动方式对肥胖青少年减肥效果的比较

目的：比较中等强度的有氧运动和高强度间歇性运动两种运动方式对肥胖青少年的减肥效果。方法：将40名受试者平均分成两组（n=20）：中等强度有氧运动组和高强度的间歇性运动组,分别进行9周的中等强度有氧运动和高强度的间歇性运动。试验前后分别对两组受试者身体形态指标、血液指标测试并进行比较。结果：试验后两组受试者身体形态指标明显下降（P < 0.05）,高强度间歇运动组在运动后腹部内脏脂肪面积、腹部皮下脂肪面积明显低于有氧运动组（P < 0.05）;中等强度有氧运动组胰岛素（FIN）、总胆固醇（TC）、低密度脂蛋白（LDL-C）与试验前相比显著下降（P < 0.05）,且有氧运动组TC明显低于高强度间歇性运动实验后值（P < 0.05）;高强度间歇性运动组FIN、LDL-C与试验前相比显著下降（P < 0.05）。结论：9周中等强度的有氧运动和高强度间歇性运动均能起到良好的减肥效果,高强度间歇性运动对内脏的减脂效果更好,但在胆固醇降低方面不如高强度间歇性运动组。     

IGF-Ⅱ、IGF-1R、IGFBP-3在结直肠癌中的表达及诊断价值研究

目的：探讨结直肠癌中IGF-Ⅱ、IGF-1R以及IGFBP-3等的阳性表达及诊断价值。方法：收集我院45例结直肠癌、33例炎性息肉、40例腺瘤以及35例正常肠粘膜组织予以免疫组织化学SP法进行IGF—Ⅱ、IGF—1R以及IGFBP-3检测,并统计结直肠腺瘤不同组织类型和结直肠癌不同Dukes分期的阳性表达差异。结果：结直肠癌组织中IGF—Ⅱ、IGF—1R以及IGFBP-3表达均呈高阳性率,并且显著高于其他3组（P〈0．05）。结直肠腺瘤管状、混合型、绒毛状等不同组织类型IGF-Ⅱ、IGF—1R以及IGFBP-3表达阳性率呈逐渐增高趋势,绒毛状腺瘤显著高于其他两型（P〈0．05）。45例结直肠癌中,Dukes分期A、B两期显著低于C期和D期,比较差异具有显著性（P〈0．05）。结论：IGF—Ⅱ、IGF-1R以及IGFBP-3可能在结直肠腺瘤发生、发展及进展为结直肠癌的过程中起一定作用,对结直肠癌早期诊断具有一定价值。     

6周有氧运动结合饮食控制对肥胖青少年身体形态及血液指标的影响

目的：通过对肥胖青少年进行为期6周的有氧运动结合饮食控制干预,探讨长期有氧运动结合饮食控制对肥胖青少年身体形态及血液指标的影响。方法：选取某减肥公司20名男性肥胖青少年为研究对象,对其进行为期6周（每周训练6 d,每天上下午各90 min,具体运动时间段分为上午：9：30-11：00,下午15：30-17：00）的有氧运动结合饮食控制干预,并在试验前后分别对受试者身体形态指标及血液指标进行检测、分析。结果：经过6周有氧运动结合饮食控制后,肥胖青少年的各身体形态指标（除身高）较干预前均有显著的变化（P < 0.05）;胰岛素、总胆固醇、低密度脂蛋白与试验前相比具有显著性差异（P < 0.01）,同时血糖、甘油三酯与试验前相比具有显著性差异（P < 0.05）,但高密度脂蛋白与试验前相比不具有显著性差异（P > 0.05）。结论：6周有氧运动结合饮食控制能明显的改善肥胖青少年的身体形态指标及血液指标,对提高肥胖青少年生命质量有着重要的意义,但对于更佳的运动方案的选择仍需进一步深入研究。     

Relationships between IGF-1 and IGFBP-1 and adiposity in obese African-American and Latino adolescents

The purpose of this study was to examine interrelationships between insulin-like growth factor 1 (IGF-1), IGF binding proteins (IGFBPs), and adiposity in 49 African-American and 77 Latino obese adolescents (15.3 ± 0.1 and 15.4 ± 0.2 years; BMI: 33.0 ± 0.7 and 35.0 ± 1.0 kg/m(2), respectively). Immunoradiometric assays were used to measure IGF-1, IGFBP-1, and IGFBP-3. Total fat and soft lean tissue were measured by dual-energy X-ray absorptiometry and visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAAT), and hepatic fat fraction (HFF) were measured by magnetic resonance imaging. IGF-1 levels were 23.1% higher and IGFBP-1 were 40.4% higher in African Americans compared to Latinos after adjustment for total lean and total fat mass. IGF-1 and IGFBP-1 were inversely correlated with BMI, total fat mass, VAT, and HFF (r = -0.20 to -0.33, P < 0.05) while IGFBP-1 was inversely correlated with SAAT (r = -0.22, P < 0.05). These relationships did not differ by ethnicity, however, the relationship between IGF-1 and SAAT, as well as IGFBP-1 and HFF, differed by ethnicity. Predicted mean IGF-1 levels were 30.7% higher for African Americans at the 75th compared to 25th percentile of SAAT and only 11.7% higher for Latinos. Predicted mean IGFBP-1 levels were 158% higher for African Americans at the 25th compared to the 75th percentile of HFF while IGFBP-1 levels were 1.7% higher for Latinos at the 75th compared to the 25th percentile. These results demonstrate that the relationship between IGF-1 and SAAT as well as IGFBP-1 and HFF are different in African-American and Latino adolescents and may contribute to the higher IGF-1 levels in African-Americans.     

Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans

Reduced function mutations in the insulin/IGF-I signaling pathway increase maximal lifespan and health span in many species. Calorie restriction (CR) decreases serum IGF-1 concentration by ~40%, protects against cancer and slows aging in rodents. However, the long-term effects of CR with adequate nutrition on circulating IGF-1 levels in humans are unknown. Here we report data from two long-term CR studies (1 and 6 years) showing that severe CR without malnutrition did not change IGF-1 and IGF-1 : IGFBP-3 ratio levels in humans. In contrast, total and free IGF-1 concentrations were significantly lower in moderately protein-restricted individuals. Reducing protein intake from an average of 1.67 g kg(-1) of body weight per day to 0.95 g kg(-1) of body weight per day for 3 weeks in six volunteers practicing CR resulted in a reduction in serum IGF-1 from 194 ng mL(-1) to 152 ng mL(-1). These findings demonstrate that, unlike in rodents, long-term severe CR does not reduce serum IGF-1 concentration and IGF-1 : IGFBP-3 ratio in humans. In addition, our data provide evidence that protein intake is a key determinant of circulating IGF-1 levels in humans, and suggest that reduced protein intake may become an important component of anticancer and anti-aging dietary interventions.     

低能量平衡膳食联合有氧运动对单纯性肥胖儿童体脂代谢、胰岛素抵抗及氧化应激反应的影响

摘要 目的：观察单纯性肥胖儿童经有氧运动、低能量平衡膳食联合干预后,机体体脂代谢、胰岛素抵抗及氧化应激反应的变化。方法：选择2019年8月~2021年7月期间新疆医科大学第一附属医院接收的单纯性肥胖儿童93例,将纳入的患儿根据随机数字表法分为对照组和研究组,各为46例和47例。对照组患儿接受低能量平衡膳食干预,研究组患儿接受低能量平衡膳食联合有氧运动干预。对比两组体脂代谢、胰岛素抵抗、血脂及氧化应激反应相关指标变化情况。结果：研究组干预12周后体质量指数（BMI）、甘油三酯（TG）、体脂含量、总胆固醇（TC）、体脂率、腰臀比、空腹胰岛素（FINS）、低密度脂蛋白（LDL-C）、空腹血糖（FPG）、蛋白质羰基（PC）、C肽、胰岛素抵抗指数（HONA-IR）、丙二醛（MDA）低于对照组（P<0.05）。研究组干预12周后高密度脂蛋白（HDL-C）、超氧化物歧化酶（SOD）高于对照组（P<0.05）。结论：低能量平衡膳食联合有氧运动可促进单纯性肥胖儿童体脂代谢改善,减轻胰岛素抵抗及氧化应激反应,效果确切。     

Relationships between serum IGF-1, IGFBP-2, interleukin-1beta and interleukin-6 in inflammatory bowel disease

AIMS: To study the relationships between serum IGF-1, IGFBP-3 and IGFBP-2 and interleukin (IL)-1beta and IL-6 in inflammatory bowel disease (IBD). METHODS: Thirty-seven patients (18 males, 19 females, aged 8.8-26.1 years) with IBD (Crohn's disease, CD, n = 17, and ulcerative colitis, UC, n = 20) were studied. Patients were in relapse or remission according to established criteria. Serum IGF-1, IGFBP-3, IGFBP-2, IL-1beta and IL-6 levels were determined in patients and 15 healthy controls (aged 8.2-19.0 years). RESULTS: IGF-1 levels were lower in patients with CD in relapse compared with controls (p < 0.05). IGFBP-2 levels were higher in CD in relapse compared with other groups (all p < 0.05). In CD and UC patients (n = 37), IGF-1 levels were inversely correlated with the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). IGFBP-2 levels correlated positively with ESR and IL-1beta. IL-6 levels correlated positively with ESR and CRP. IL-1beta levels were elevated in CD in relapse compared to controls (p < 0.05) and were higher in UC in relapse than in other groups (all p < 0.05). In combined CD/UC patients in relapse (n = 20), IL-1beta levels were higher (p < 0.05) in patients with recto-sigmoiditis (n = 5) than in other patients. CONCLUSIONS: IGF-1, IGFBP-2 levels were related to IL levels, disease activity and anatomical distribution, consistent with active inflammation modifying the IGF-IGFBP system, possibly relevant to disturbance of growth.     

Insulin-like growth factor-1 and its binding proteins, IGFBP-1 and IGFBP-3, in adolescents with type-1 diabetes mellitus and microalbuminuria

BACKGROUND/AIMS: Numerous clinical and experimental studies suggest that growth factors may contribute to the development of diabetic microvascular complications. The aim of the study was to test the hypothesis that in adolescents with type-1 diabetes mellitus and microalbuminuria (MA) there are specific disorders of serum insulin-like growth factor-1 (IGF-1) and concentrations of its binding proteins, IGFBP-1 and IGFBP-3, that could be of importance in the pathogenesis of microvascular diabetic complications. METHODS: 25 adolescents with MA, 24 adolescents with diabetes without complications, and 17 controls were examined. There were no differences with regard to age, puberty stage, HbA1c and body mass index between the groups examined. Two of the patients in the first group also had diabetic retinopathy. Serum fasting concentrations of IGF-1 and overnight urine albumin concentrations were measured by radioimmunoassay, IGFBP-1 and IGFBP-3 concentrations by immunoradiometric assay and HbA1c by high-performance liquid chromatography methods. Diabetic patients were examined by an experienced ophthalmologist and neurologist. The data were analyzed using Kruskal-Wallis ANOVA and multiple regression analysis. RESULTS: Significantly lower IGF-1 concentrations were found in adolescents with diabetes and MA compared to diabetic patients without complications and healthy contemporaries. IGFBP-1 concentrations were significantly higher and IGFBP-3 concentrations were statistically lower in diabetic patients with MA than in patients without complications. CONCLUSIONS: The IGF-IGFBP system is deranged in adolescents with type-1 diabetes mellitus and MA. Our results suggest the participation of circulating IGFBP-1 in the origin of diabetic complications. It could be also possible that IGFBP-3 takes part in the protection from them.     

Effects of Copper on Proliferation and Autocrine Secretion of Insulin-Like Growth Factor-1 (IGF-1) and IGF-Binding Protein-3 (IGFBP-3) in Chondrocytes from Newborn Pigs In Vitro

Chondrocytes from the lateral trochlear ridge of the distal femur taken from 1-day-old piglets were cultured in medium supplemented with 0, 7.8, 15.6, 31.2, and 62.5?μmol/L copper. Insulin-like growth factor-1 (IGF-1) and IGF-binding protein 3 (IGFBP-3) levels in culture medium were determined by radioimmunoassay. DNA synthesis in chondrocytes was measured by tritiated thymidine ((3)H-TdR) incorporation. Proliferation-promoting activity and incorporation of (3)H-TdR in chondrocytes were increased in all culture media supplemented with copper and 15% fetal calf serum (FCS). The contents of IGF-1 and IGFBP-3 were also enhanced significantly in culture media containing 15% FCS and supplemented with copper at 15.6, 31.2, and 62.5?μmol/L. The optimal copper concentration for promoting chondrocyte proliferation and autocrine secretion of IGF-1 and IGFBP-3 was 31.2?μmol/L.     

缺氧复氧对滑膜细胞IGF-IGFBP-3 以及线粒体的影响

目的:探讨氧波动环境对原代成纤维样滑膜细胞(fibroblast-like synoviocyte, FLS)胰岛素样生长因子-1(insulin growth factor-1,IGF-1)、胰岛素样生长因子结合蛋白-3(insulin-like growth factor binding protein-3, IGFBP-3)及线粒体的影响。方法:分离并鉴定正常人滑膜细胞,再对滑膜细胞进行分组:对照组、缺氧/再充氧(hypoxia/reoxygenation,H/R)干预组。采用实时定量PCR检测滑膜细胞中IGF-1、IGFBP-3的m RNA水平;Western blot检测滑膜细胞中IGF-1、IGFBP-3的蛋白水平;流式细胞仪检测线粒体膜电位(Mitochondrial membrane potential, MMP)以及线粒体通透性转换孔(Mitochondrial Permeability Transition Pore, MPTP)的变化。结果:与对照组比较,H/R干预组的相对IGF-1和IGFBP-3的m RNA水平和蛋白表达水平显著升高(P0.05),膜电位水平降低(P0.05),线粒体通透性转换孔开放。结论:氧波动环境可促进IGF-1和IGFBP-3的表达及细胞线粒体损伤,其可能是骨关节炎(OA)发病的重要机制之一。     

Mutual regulation between IGF-1R and IGFBP-3 in human corneal epithelial cells

The insulin-like growth factor type 1 receptor (IGF-1R) is part of the receptor tyrosine kinase superfamily. The activation of IGF-1R regulates several key signaling pathways responsible for maintaining cellular homeostasis, including survival, growth, and proliferation. In addition to mediating signal transduction at the plasma membrane, in serum-based models, IGF-1R undergoes SUMOylation by SUMO 1 and translocates to the nucleus in response to IGF-1. In corneal epithelial cells grown in serum-free culture, however, IGF-1R has been shown to accumulate in the nucleus independent of IGF-1. In this study, we report that the insulin-like growth factor binding protein-3 (IGFBP-3) mediates nuclear translocation of IGF-1R in response to growth factor withdrawal. This occurs via SUMOylation by SUMO 2/3. Further, IGF-1R and IGFBP-3 undergo reciprocal regulation independent of PI3k/Akt signaling. Thus, under healthy growth conditions, IGFBP-3 functions as a gatekeeper to arrest the cell cycle in G0/G1, but does not alter mitochondrial respiration in cultured cells. When stressed, IGFBP-3 functions as a caretaker to maintain levels of IGF-1R in the nucleus. These results demonstrate mutual regulation between IGF-1R and IGFBP-3 to maintain cell survival under stress. This is the first study to show a direct relationship between IGF-1R and IGFBP-3 in the maintenance of corneal epithelial homeostasis.