Higher IGF-I Levels Research Articles

6667 IGF1 Induces The Expression of CYR61 In Metastatic Prostate Cancer

Abstract Disclosure: G.L. Ortiz Hernández: None. M. Walker: None. L. Woods-Burnham: None. R.A. Kittles: None. C.A. Casiano: None. S.L. Neuhausen: None. The cysteine-rich angiogenic inducer 61 (CYR61) is a member of the cellular communication network (CCN) protein family that can be induced by growth factors. CYR61-specific functions are dependent on cellular context. In prostate cancer (PCa), CYR61 contributes to cell growth and survival through its interactions with extracellular ligands, such as integrins avb3 and a6b4, in the extracellular matrix space. CYR61 contains an insulin-like growth factor-binding protein domain suggesting that it may interact with insulin-like growth factor-I (IGF1). High serum levels of IGF1 are directly linked to PCa development and recently have been studied as a predictor of metastatic disease. Given the important roles that IGF1 and CYR61 play in PCa and their potential interaction, it is critical to investigate their molecular interplay. The correlation between PCa aggressiveness and circulating levels of CYR61 and IGF1 is poorly studied. Our goal was to assess the contribution of the interaction of CYR61-IGF1 to PCa cell proliferation. Their combined role may explain a proportion of aggressive PCa. This study was designed to characterize the role of IGF1-induced expression of CYR61 in metastatic PCa cellular models and to determine if this interaction contributes to aggressive tumor properties (e.g., proliferation, migration, tumorsphere formation). Using immunoblotting, we demonstrated that CYR61 is upregulated in the metastatic cell line PC3. Furthermore, optimized knockdown of CYR61 using siRNA significantly reduced PC3 cell proliferation, viability, and prostasphere formation. To examine the underlying mechanisms associated with IGF1 signaling, we assessed the activation of either the PI3/Akt and MAPK pathways in PC3 cells with CYR61 silencing. CYR61 siRNA-mediated knockdown decreased activation of the PI3/Akt pathway but did not affect the MAPK pathway. In addition, we found that IGF1 induces protein expression of CYR61 in a time-dependent manner, validated by both immunoblotting and confocal microscopy. PC3 cell lines are androgen receptor negative (AR-) and glucocorticoid receptor positive (GR+), which is characteristic of aggressive, advanced metastatic castration-resistant prostate cancer (mCRPC). Currently, we are conducting the same experiments in LNCaP cells, which are AR+/GR-, to determine if the CYR61-IGF1 interplay also occurs in PCa cells capable of AR signaling. In conclusion, we found that CYR61 expression is induced by IGF1 and its inhibition decreased the capacity of metastatic PCa cells to proliferate. Our results suggest that CYR61 inhibition may have the potential for treating metastatic PCa. Presentation: 6/1/2024

6667 IGF1 Induces the Expression of CYR61 in Metastatic Prostate Cancer

Abstract Disclosure: G.L. Ortiz Hernández: None. M. Walker: None. L. Woods-Burnham: None. R.A. Kittles: None. C.A. Casiano: None. S.L. Neuhausen: None. The cysteine-rich angiogenic inducer 61 (CYR61) is a member of the cellular communication network (CCN) protein family that can be induced by growth factors. CYR61-specific functions are dependent on cellular context. In prostate cancer (PCa), CYR61 contributes to cell growth and survival through its interactions with extracellular ligands, such as integrins avb3 and a6b4, in the extracellular matrix space. CYR61 contains an insulin-like growth factor-binding protein domain suggesting that it may interact with insulin-like growth factor-I (IGF1). High serum levels of IGF1 are directly linked to PCa development and recently have been studied as a predictor of metastatic disease. Given the important roles that IGF1 and CYR61 play in PCa and their potential interaction, it is critical to investigate their molecular interplay. The correlation between PCa aggressiveness and circulating levels of CYR61 and IGF1 is poorly studied. Our goal was to assess the contribution of the interaction of CYR61-IGF1 to PCa cell proliferation. Their combined role may explain a proportion of aggressive PCa. This study was designed to characterize the role of IGF1-induced expression of CYR61 in metastatic PCa cellular models and to determine if this interaction contributes to aggressive tumor properties (e.g., proliferation, migration, tumorsphere formation). Using immunoblotting, we demonstrated that CYR61 is upregulated in the metastatic cell line PC3. Furthermore, optimized knockdown of CYR61 using siRNA significantly reduced PC3 cell proliferation, viability, and prostasphere formation. To examine the underlying mechanisms associated with IGF1 signaling, we assessed the activation of either the PI3/Akt and MAPK pathways in PC3 cells with CYR61 silencing. CYR61 siRNA-mediated knockdown decreased activation of the PI3/Akt pathway but did not affect the MAPK pathway. In addition, we found that IGF1 induces protein expression of CYR61 in a time-dependent manner, validated by both immunoblotting and confocal microscopy. PC3 cell lines are androgen receptor negative (AR-) and glucocorticoid receptor positive (GR+), which is characteristic of aggressive, advanced metastatic castration-resistant prostate cancer (mCRPC). Currently, we are conducting the same experiments in LNCaP cells, which are AR+/GR-, to determine if the CYR61-IGF1 interplay also occurs in PCa cells capable of AR signaling. In conclusion, we found that CYR61 expression is induced by IGF1 and its inhibition decreased the capacity of metastatic PCa cells to proliferate. Our results suggest that CYR61 inhibition may have the potential for treating metastatic PCa. Presentation: 6/1/2024

Insulin-like Growth Factor-1 Levels Reflect Muscle and Bone Health and Determine Complications and Mortality in Decompensated Cirrhosis

The growth hormone-insulin-like growth factor (GH-IGF-1) axis and its impairment with sarcopenia, frailty, bone health, complications, and prognosis are not well characterized in cirrhosis. We investigated the adult decompensated cirrhosis out-patients at a tertiary care institute between 2021 and 2023 for serum GH and IGF-1 levels, and associated them with sarcopenia (CT-SMI in cm2/m2), liver frailty index (LFI), osteodystrophy (DEXA), clinical decompensations (overall, ascites, encephalopathy, infection, and bleed), and survival up to 180 days. One-hundred-seventy-two patients, 95% males, aged 46.5 years (median). logIGF-1 levels were negatively associated with sarcopenia, osteodystrophy, LFI, CTP, and MELD-Na score (P<0.05 each). Patients with low IGF-1 levels had a higher incidence of complications (overall, ascites and encephalopathy) than those with intermediate, and high IGF-1 levels (P<0.05 each). Both logIGF-1 (AUC: 0.686) and MELD (AUC: 0.690) could predict 180-day mortality (P<0.05, each). Adding logIGF-1 with MELDNa further improved discriminative accuracy of MELDNa (AUC: 0.729) P<0.001. The increase in IGF-1 on follow-up was associated with better survival and fewer complications. Reduced IGF-1 levels reflect sarcopenia, frailty, and osteodystrophy in cirrhosis. Low IGF-1 are associated with severity, development of decompensations, and mortality.

Prospective Analysis of Circulating Biomarkers and Ovarian Cancer Risk in the UK Biobank.

Risk factors have a limited ability to predict individuals at high risk of developing ovarian cancer among average-risk women, highlighting the need for discovery of novel biomarkers. In the UK Biobank, we investigated serum biomarkers commonly measured in clinical laboratory tests and ovarian cancer risk. We conducted a prospective analysis of 20 serum biomarkers and ovarian cancer risk in 232,037 female UK Biobank participants (including 1,122 incident ovarian cancer cases diagnosed from 2006 to 2020). Multivariable adjusted Cox proportional hazards models were used to examine associations between biomarkers and ovarian cancer risk overall and by histotype. FDR was used to account for multiple testing. Overall, higher levels of insulin-like growth factor (IGF)-1 [RRquartile 4 vs. 1 = 0.73; 95% confidence interval (CI), 0.60-0.87; P-trend = 0.002/FDR = 0.04], HbA1c (RRquartile 4 vs. 1 = 0.74; 95% CI, 0.62-0.89; P-trend = 0.002/FDR = 0.04), and alanine aminotransferase (RRquartile 4 vs. 1 = 0.76; 95% CI, 0.63-0.91; P-trend = 0.002/FDR = 0.04) were significantly associated with lower ovarian cancer risk. When stratified by histotype, higher IGF1 levels were associated with lower risk of serous (RRquartile 4 vs. 1 = 0.73; 95% CI, 0.58-0.91; P-trend = 0.01/FDR = 0.20) and clear cell tumors (RRquartile 4 vs. 1 = 0.18; 95% CI, 0.07-0.49; P-trend = 0.001/FDR = 0.02), and higher HbA1c levels were associated with lower risk of serous tumors (RRquartile 4 vs. 1 = 0.73; 95% CI, 0.59-0.90; P-trend = 0.004/FDR = 0.08). We observed that higher levels of circulating IGF1, HbA1c, and alanine aminotransferase were associated with lower ovarian cancer risk. These results suggest metabolism of glucose/amino acid and insulin/IGF1 signaling pathway may be contributing to ovarian carcinogenesis. Further research is needed to replicate our findings and elucidate how systemic changes in metabolism impact ovarian carcinogenesis.

Glucose metabolism outcomes after pituitary surgery in patients with acromegaly.

To investigate the impact of pituitary surgery on glucose metabolism and to identify predictors of remission of diabetes after pituitary surgery in patients with acromegaly. A national multicenter retrospective study of patients with acromegaly undergoing transsphenoidal surgery for the first time at 33 tertiary Spanish hospitals (ACRO-SPAIN study) was performed. Surgical remission of acromegaly was evaluated according to the 2000 and 2010 criteria. A total of 604 acromegaly patients were included in the study with a total median follow up of 91 months (interquartile range [IQR] 45-163). At the acromegaly diagnosis, 23.8% of the patients had diabetes mellitus (DM) with a median glycated hemoglobin (HbA1c) of 6.9% (IQR 6.4-7.9) [51.9 mmol/mol (IQR 46.4-62.8)]. In the multivariate analysis, older age (odds ratio [OR] 1.02, 95% CI 1.00-1.05), dyslipidemia (OR 5.25, 95% CI 2.81 to 9.79), arthropathy (OR 1.39, 95% CI 2.82 to 9.79), and higher IGF-I levels (OR 1.30, 95% CI 1.05 to 1.60) were associated with a greater prevalence of DM. At the last follow-up visit after surgery, 21.1% of the DM patients (56.7% of them with surgical remission of acromegaly) experienced diabetes remission. The cure rate of DM was more common in older patients (hazard ratio [HR] 1.77, 95% CI 1.31 to 2.43), when surgical cure was achieved (HR 2.10, 95% CI 1.01 to 4.37) and when anterior pituitary function was not affected after surgery (HR 3.38, 95% CI 1.17 to 9.75). Glucose metabolism improved in patients with acromegaly after surgery and 21% of the diabetic patients experienced diabetes remission; being more frequent in patients of older age, and those who experienced surgical cure and those with preserved anterior pituitary function after surgery.

IGF-1 and IGFBP-1 as Possible Predictors of Response to Lifestyle Intervention-Results from Randomized Controlled Trials.

Lifestyle interventions can prevent type 2 diabetes (T2DM). However, some individuals do not experience anticipated improvements despite weight loss. Biomarkers to identify such individuals at early stages are lacking. Insulin-like growth factor 1 (IGF- 1) and Insulin-like growth factor binding protein 1(IGFBP-1) were shown to predict T2DM onset in prediabetes. We assessed whether these markers also predict the success of lifestyle interventions, thereby possibly guiding personalized strategies. We analyzed the fasting serum levels of IGF-1, IGFBP-1, and Insulin-like growth factor binding protein 2 (IGFBP-2) in relation to changes in metabolic and anthropometric parameters, including intrahepatic lipids (IHLs) and visceral adipose tissue (VAT) volume, measured by magnetic resonance imaging (MRI), in 345 participants with a high risk for prediabetes (54% female; aged 36-80 years). Participants were enrolled in three randomized dietary intervention trials and assessed both at baseline and one year post-intervention. Statistical analyses were performed using IBM SPSS Statistics (version 28), and significance was set at p < 0.05. Within the 1-year intervention, overall significant improvements were observed. Stratifying individuals by baseline IGF-1 and IGFBP-1 percentiles revealed significant differences: higher IGF-1 levels were associated with more favorable changes compared to lower levels, especially in VAT and IHL. Lower baseline IGFBP-1 levels were associated with greater improvements, especially in IHL and 2 h glucose. Higher bioactive IGF-1 levels might predict better metabolic outcomes following lifestyle interventions in prediabetes, potentially serving as biomarkers for personalized interventions.

Integrative clinical, hormonal, and molecular data associate with invasiveness in acromegaly: REMAH study.

Growth hormone (GH)-secreting pituitary tumors (GHomas) are the most common acromegaly cause. At diagnosis, most of them are macroadenomas, and up to 56% display cavernous sinus invasion. Biomarker assessment associated with tumor growth and invasion is important to optimize their management. The study aims to identify clinical/hormonal/molecular biomarkers associated with tumor size and invasiveness in GHomas and to analyze the influence of pre-treatment with somatostatin analogs (SSAs) or dopamine agonists (DAs) in key molecular biomarker expression. Clinical/analytical/radiological variables were evaluated in 192 patients from the REMAH study (ambispective multicenter post-surgery study of the Spanish Society of Endocrinology and Nutrition). The expression of somatostatin/ghrelin/dopamine system components and key pituitary/proliferation markers was evaluated in GHomas after the first surgery. Univariate/multivariate regression studies were performed to identify association between variables. Eighty percent of patients harbor macroadenomas (63.8% with extrasellar growth). Associations between larger and more invasive GHomas with younger age, visual abnormalities, higher IGF1 levels, extrasellar/suprasellar growth, and/or cavernous sinus invasion were found. Higher GH1 and lower PRL/POMC/CGA/AVPR1B/DRD2T/DRD2L expression levels (P < .05) were associated with tumor invasiveness. Least Absolute Shrinkage and Selection Operator's penalized regression identified combinations of clinical and molecular features with areas under the curve between 0.67 and 0.82. Pre-operative therapy with DA or SSAs did not alter the expression of any of the markers analyzed except for DRD1/AVPR1B (up-regulated with DA) and FSHB/CRHR1 (down-regulated with SSAs). A specific combination of clinical/analytical/molecular variables was found to be associated with tumor invasiveness and growth capacity in GHomas. Pre-treatment with first-line drugs for acromegaly did not significantly modify the expression of the most relevant biomarkers in our association model. These findings provide valuable insights for risk stratification and personalized management of GHomas.

Prepubertal children with obesity have high free IGF-1 levels and accelerated growth despite reduced pappalysin levels.

Prepubertal children with obesity frequently have enhanced growth, accelerated skeletal maturation and changes in the GH-IGF axis. However, the involvement of pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC1, STC2) as regulators of IGF bioavailability has not been studied in obesity. We aimed to determine the effects of childhood obesity and weight reduction on serum levels of PAPP-A, PAPP-A2, STC1 and STC2 and their relationship with IGF bioavailability, growth, and other components of the GH-IGF system. Prepubertal children with severe obesity (150, 50% males/females, age: 7.72 ± 2.05 years, BMI z-score: 4.95 ± 1.70, height z-score: 1.28 ± 1.04) were studied at diagnosis and after a minimum of 0.5 BMI z-score reduction. Two hundred and six healthy age- and sex-matched children were used as controls. Children with obesity had decreased serum concentrations of PAPP-A, PAPP-A2 and STC2, but increased total and free IGF-I (fIGF-I), intact IGFBP-3, ALS, IGF-II and insulin levels, with no difference in the free/total IGF-I ratio. Neither the standardized BMI nor height correlated with any biochemical parameter analyzed. A decrease in IGF-II, insulin, and ALS with an increase in IGFBP-2 and -5, STC2 and PAPP-A were observed after weight loss. Increased circulating total and free IGF-I, insulin and IGF-II may all contribute to the increased rate of prepubertal growth and bone maturation observed in children with obesity, with STC2 possibly being involved.

Abstract 560: IGF1 induces the expression of CYR61 in metastatic prostate cancer

Abstract The cysteine-rich angiogenic inducer 61 (CYR61) is a member of the cellular communication network (CCN) protein family that can be induced by growth factors. CYR61-specific functions are dependent on cellular context. In prostate cancer (PCa), CYR61 contributes to cell growth and survival through its interactions with extracellular ligands, such as integrins avb3 and a6b4, in the extracellular matrix space. Interestingly, CYR61 contains an insulin-like growth factor-binding protein domain suggesting that it may interact with insulin-like growth factor-I (IGF1). High serum levels of IGF1 are directly linked to PCa development and recently have been studied as a predictor of metastatic disease. Given the important roles that IGF1 and CYR61 play in PCa and their potential interaction, it is critical to investigate their molecular interplay. The correlation between PCa aggressiveness and circulating levels of CYR61 and IGF1 is poorly studied. Our goal was to assess the contribution of CYR61-IGF1 interaction to PCa cell proliferation. Their combined role may explain a proportion of aggressive PCa. This study was designed to characterize the role of IGF1-induced expression of CYR61 in metastatic PCa cellular models and to determine if this interaction contributes to aggressive tumor properties (e.g., proliferation, migration, tumorsphere formation). Using immunoblotting, we demonstrated that CYR61 is upregulated in the metastatic cell line PC3. Furthermore, optimized knockdown of CYR61 using siRNA significantly reduced PC3 cell proliferation, viability, and prostasphere formation. To examine the underlying mechanisms associated with IGF1 signaling, we assessed the activation of either the PI3/Akt and MAPK pathways in PC3 cells with CYR61 silencing. CYR61 siRNA-mediated knockdown decreased activation of the PI3/Akt pathway but did not affect the MAPK pathway. In addition, we found that IGF1 induces protein expression of CYR61 in a time-dependent manner, validated by both immunoblotting and confocal microscopy. In conclusion, these data provided evidence that CYR61 expression is induced by IGF1, and its inhibition decreased the capacity of metastatic PCa cells to proliferate, indicating a potential utilization of CYR61 inhibition in the therapy of metastatic PCa. Citation Format: Greisha L. Ortiz Hernandez, Mya Walker, Leanne Woods-Burnham, Rick A. Kittles, Carlos A. Casiano, Susan Neuhausen. IGF1 induces the expression of CYR61 in metastatic prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 560.

Abstract P512: Associations of Serum Insulin-Like Growth Factor (IGF)-1 Levels With Cognitive Function and Atherosclerosis in a Japanese General Population: The Tanushimaru Study

Background: Insulin-like growth factor (IGF)-1 is a peptide hormone implicated in insulin sensitivity and anti-inflammatory. However, there is limited exploration of the association of serum IGF-1 levels with cognitive function and atherosclerosis. This study aimed to investigate the association between serum IGF-1 levels and cognitive function, as well as carotid atherosclerosis in a general population. Methods: In 1,345 participants (544 men; mean age, 68.7 (11.3) years) recruited from the Tanushimaru cohort, we measured their serum IGF-1 levels and evaluated cognitive function using mini-mental state examination (MMSE) and atherosclerosis through carotid intima-media thickness (IMT). Linear regression models were utilized to analyze the association between quartiles of serum IGF-1 levels and MMSE scores, as well as IMT, continuous dependent variables. We also visualized the continuous associations using restricted cubic spline models. Two-sided statistical significance was defined as p &lt;0.05. All statistical analyses were performed using the SAS system (Release 9.4, SAS Institute, Cary, NC, USA). Results: The mean serum IGF-1 level was 96.6 (30.2) ng/ml. Multiple linear regression analysis revealed that the highest quartile of serum IGF-1 levels showed a statistically significant association with higher MMSE scores (p=0.0019), and the third quartile also reached statistical significance (p=0.0006) compared to the lowest. We observed a positive association between serum IGF-1 levels and MMSE scores, even when exploring the full spectrum of serum IGF-1 levels with their spline terms (Figure). In contrast, serum IGF-1 levels did not exhibit a significant association with IMT measurements. Conclusion: High serum IGF-1 levels were associated with higher cognitive function, while no significant association was observed with carotid atherosclerosis. Our findings suggest that IGF-1 levels may play a role in preserving cognitive function, potentially distinct from its role in atherosclerosis.

The IGF-PAPP-A-Stanniocalcin Axis in Serum and Ascites Associates with Prognosis in Patients with Ovarian Cancer.

Pregnancy-associated plasma protein-A (PAPP-A) and PAPP-A2 modulate insulin-like growth factor (IGF) action and are inhibited by the stanniocalcins (STC1 and STC2). We previously demonstrated increased PAPP-A and IGF activity in ascites from women with ovarian carcinomas. In this prospective, longitudinal study of 107 women with ovarian cancer and ascites accumulation, we determined corresponding serum and ascites levels of IGF-1, IGF-2, PAPP-A, PAPP-A2, STC1, and STC2 and assessed their relationship with mortality. As compared to serum, we found highly increased ascites levels of PAPP-A (51-fold) and PAPP-A2 (4-fold). Elevated levels were also observed for IGF-1 (12%), STC1 (90%) and STC2 (68%). In contrast, IGF-2 was reduced by 29% in ascites. Patients were followed for a median of 38.4 months (range: 45 days to 8.9 years), during which 73 patients (68.2%) died. Overall survival was longer for patients with high serum IGF-1 (hazard ratio (HR) per doubling in protein concentration: 0.60, 95% CI: 0.40-0.90). However, patients with high ascites levels of IGF-1 showed a poorer prognosis (HR: 2.00 (1.26-3.27)). High serum and ascites IGF-2 levels were associated with increased risk of mortality (HR: 2.01 (1.22-3.30) and HR: 1.78 (1.24-2.54), respectively). Similarly, serum PAPP-A2 was associated with mortality (HR: 1.26 (1.08-1.48)). Our findings demonstrate the presence and activity of the IGF system in the local tumor ecosystem, which is likely a characteristic feature of malignant disease and plays a role in its peritoneal dissemination. The potential clinical implications are supported by our finding that serum levels of the proteins are associated with patient prognosis.

CD200Rhigh neutrophils with dysfunctional autophagy establish systemic immunosuppression by increasing regulatory T cells.

Distinct neutrophil populations arise during certain pathological conditions. The generation of dysfunctional neutrophils during sepsis and their contribution to septicemia-related systemic immune suppression remain unclear. In this study, using an experimental sepsis model that features immunosuppression, we identified a novel population of pathogenic CD200Rhigh neutrophils that are generated during the initial stages of sepsis and contribute to systemic immune suppression by enhancing regulatory T (Treg) cells. Compared to their CD200Rlow counterparts, sepsis-generated CD200Rhigh neutrophils exhibit impaired autophagy and dysfunction, with reduced chemotactic migration, superoxide anion production, and TNF-α production. Increased soluble CD200 blocks autophagy and neutrophil maturation in the bone marrow during experimental sepsis, and recombinant CD200 treatment in vitro can induce neutrophil dysfunction similar to that observed in CD200Rhigh neutrophils. The administration of an α-CD200R antibody effectively reversed neutrophil dysfunction by enhancing autophagy and protecting against a secondary infection challenge, leading to increased survival. Transcriptome analysis revealed that CD200Rhigh neutrophils expressed high levels of Igf1, which elicits the generation of Treg cells, while the administration of an α-CD200R antibody inhibited Treg cell generation in a secondary infection model. Taken together, our findings revealed a novel CD200Rhigh neutrophil population that mediates the pathogenesis of sepsis-induced systemic immunosuppression by generating Treg cells.

Effect of kefir and soy yogurt consumption on serum IGF-1 levels in young healthy women

Background:Milk and dairy product intake are associated with higher IGF-1 concentrations, a well-known factor promoting adverse events such as carcinogenesis. Different associations with high levels of IGF-I were found for dairy protein such as milk and derivatives, and soy protein. In this contest, fermented milk product (kefir)exhibits a growing number of health-promoting effects including stimulation of the immune system, and antimutagenic and anticarcinogenic activity, but there is a lack of data on healthy humans. Objectives: We aimed to determine the serum IGF-1 profiles of young healthy volunteers of the female sex after kefir or soy yogurt consumption during a Mediterranean diet.Materials and Methods: The study was conducted by monitoring the serum IGF-1 levels of female participants, following a normocaloric and normoproteic Mediterranean Diet, at the baseline (T0) and after 40 days of which the first 20 days (T1) consuming 125g of kefir, and the last 20 days (T2) consuming 125g of soy yogurt. Results: A total of 10 female participants were enrolled in the study (age=26.1± 2.9). The IGF-1 level was in the range of normality for all the participants except for one participant (T0=245 ± 61, T1=227 ± 58, T2= 239 ± 55). The mixed-model analysis revealed statistically significant differences in IGF-1 levels by diet (p=0.014; η2p=0.49). In particular, post-hoc analysis revealed a lower value after 20 days of kefir diet compared to both baseline (p= 0.014) and 40 days of diet (p=0.163). Conclusion: Caloric and protein intake have been suggested to influence circulating IGF-I, promoting carcinogenesis. Kefir consumption could improve the IGF-1 levels. Our data suggest that the inclusion of whole milk kefir in a normocaloric and normoprotein diet promotes blood IGF-1 levels in healthy young women as compared to soy yogurt consumption, reinforcing the beneficial effect of fermented milk on metabolic disorders. The interpretation of this result will need to be better investigated in further studies on large sample sizes.Keywords: IGF-1, Kefir, normocaloric diet, soy yogurt

Confirming the association between low serum 25OHD levels in girls with central precocious puberty and its severity

BackgroundTo assess the differences in vitamin D levels in girls with rapidly progressive (RP) or slowly progressive (SP) central precocious puberty (CPP) and to compare whether the factors related to RP-CPP influenced the vitamin D status. A cross-sectional study was performed among girls with CPP classified as RP-CPP or SP-CPP.MethodsThe baseline data, gonadotropin-releasing hormone (GnRH) stimulation test results, serum 25-hydroxyvitamin D (25OHD) levels, and season of sample collection were analyzed.ResultsThe mean 25OHD level in 340 girls was 15.89 ± 6.87 ng/mL, of whom only 10 (2.9%) had normal levels (≥ 30 ng/mL). A total of 114 girls in the SP-CPP group and 226 in the RP-CPP group had similar chronological age, disease course, height SDS, bone mineral density, baseline follicle-stimulating hormone (FSH), peak FSH, and 25OHD levels. Developmental age, body mass index (BMI), BMI SDS, peak luteinizing hormone (LH)/FSH, insulin-like growth factor 1 (IGF-1), and IGF-1 SDS were independent risk factors for RP-CPP. Significant differences were observed among the different serum 25OHD levels in terms of season, disease course, IGF1 level, and BMI SDS (P < 0.05). Moreover, the sampling season was strongly correlated with serum 25OHD levels (r = 0.402, P < 0.001).ConclusionThe vitamin D levels were generally deficient or insufficient in girls with CPP, but were not related to the different types of CPP. High BMI levels, IGF1 levels, or peak LH/FSH ratio, but not vitamin D levels, could promote the progression of RP-CPP. Seasonal factors mainly influenced the vitamin D levels.

Reduction in Pappalysin-2 Levels and Lower IGF-I Bioavailability in Female Adolescents With Anorexia Nervosa.

Anorexia nervosa (AN) can cause severe undernutrition associated with alterations in the IGF axis. Pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC-1, STC-2) modulate IGF binding-protein (IGFBP) cleavage and IGF bioavailability, but their implications in AN are unknown. We determined serum levels of PAPP-As and STCs in relationship with classical IGF axis parameters in female adolescents with AN and their association with nutritional status and secondary amenorrhea. Parameters of the IGF axis were determined in fasting serum samples of 68 female adolescents with AN at diagnosis and 62 sex- and age-matched controls. Standardized body mass index (BMI) and bone mineral density (BMD) were calculated. Patients with AN had lower concentrations of total and free IGF-I, total IGFBP-3, acid-labile subunit (ALS), insulin, PAPP-A2, STC-1, and STC-2 and higher levels of IGF-II and IGFBP-2. Their free/total IGF-I ratio was decreased and the intact/total IGFBP-3 and -4 ratios increased. BMI was directly related to total IGF-I and intact IGFBP-3 and inversely with IGFBP-2 and intact IGFBP-4. Weight loss was directly correlated with intact IGFBP-4 and negatively with intact IGFBP-3, ALS, STC-2, and PAPP-A2 concentrations. BMD was directly related to intact IGFBP-3 and inversely with intact IGFBP-4 and PAPP-A2 levels. Patients with amenorrhea had lower levels of total IGF-I and IGFBP-3 than those with menses. The reduction of PAPP-A2 in patients with AN may be involved in a decline in IGFBP cleavage, which could underlie the decrease in IGF-I bioavailability that is influenced by nutritional status and amenorrhea.

Causal Association of Cytokines and Growth Factors with Stroke and Its Subtypes: a Mendelian Randomization Study.

Cytokines and growth factors contribute to nerve growth and angiogenesis and are associated with the development of vascular disease. This Mendelian randomization (MR) study was designed to examine the causal relationship between factors associated with stem cell paracrine mechanisms and with stroke and its subtypes. We used pooled statistics on cytokine levels from three studies (INTERIAL, Olink Proseek CVD array, and KORA) encompassing 7795 participants in Europe. Data for stroke and its subtypes were pooled from these European populations (40,585 cases and 406,111 controls) in a multiprogenitor genome-wide association study (GWAS). MR was performed using established analytical methods, including inverse variance weighting (IVW), weighted median (WM), and MR-Egger. Genetically determined high IGF-1 levels were found to associate negatively with risk of stroke, ischemic stroke (large-artery atherosclerosis), and ischemic stroke (cardiogenic embolism). Meanwhile, high IL-13 levels had a positive causal relationship with ischemic stroke (large-artery atherosclerosis). An additional 27 cytokines were found to have a causal association with stroke or its subtypes. However, these results should be interpreted with caution given that the power efficacy was <80%. This MR study supports the concept of a causal relationship of 29 cytokines with stroke or its subtypes. Our genetic analysis provides new insights into stroke prevention and treatment by demonstrating an association of stem cell paracrine-related cytokines with stroke risk.

SAT033 Disruption Of GHR In “Middle Aged” Mice Enhances Insulin Sensitivity And Extends Male Lifespan

Abstract Disclosure: S. Duran-Ortiz: None. E.O. List: None. J.A. Young: None. S.C. Mathes: None. R. Basu: None. Y.B. Slama: None. D.E. Berryman: None. Reduced growth hormone (GH) action has been shown to extend healthspan and lifespan in several organisms. In fact, mice and humans with a congenital disruption in the GH receptor (R) gene (GHRKO mice and patients with Laron Syndrome, respectively) have improved insulin sensitivity and are resistant to diabetes, cancer and age-associated cognitive decline. Importantly, the GHRKO mice hold the record for the longest-lived laboratory mice, with a lifespan one week shy of five years of age. GHRKO mice also show reduced markers of aging such as adipose tissue senescence and mTORC1 signaling in liver, kidney, heart and muscle. However, as GH action is required for normal growth and development, we and others have hypothesized that targeted inhibition of GH action at an adult age could be a potent method to extend healthy lifespan. To test this hypothesis and to elucidate how far in development would disruption of GHR extend healthy lifespan, our laboratory recently reported on two mouse lines with post-natal ablation of the GHR at a pubertal age (1.5 months - 1.5mGHRKO mice) and at mature-adult age (6 months - 6mGHRKO mice). We found that ablation of the GHR gene at both 1.5- and 6-months of age extends maximal and mean lifespan preferentially in females. Furthermore, 6mGHRKO mice showed improved oxidative stress resistance while males had improved insulin sensitivity and reduced cancer incidence. With these promising results, we believe that interventions to extend aging should be effective when administered later in life. In the current study, we disrupted the GHR in middle aged mice (12 months - 12mGHRKO mice) using the Cre-Lox system. We found that 12mGHRKO mice exhibit GH insensitivity (high serum GH and low IGF-1 levels), increased adipose tissue mass, reduced lean mass, minimal impact on body weight and length, improved insulin sensitivity and reduced glucose levels in males as well as decreased adipose tissue fibrosis in females compared to males. Moreover, despite the increased fat mass, motor coordination and strength as measured by rotarod and grip strength tests show no deficit in 12mGHRKO mice compared to the controls. Importantly, the male 12mGHRKO mice showed a preferential and significant lifespan extension compared to control mice. Collectively, our results indicate that not only does post-natal GHR disruption does not affect growth and development, but it also confers several crucial healthspan and lifespan advantages. Acknowledgements: This work is supported by the State of Ohio's Eminent Scholar Program, by NIH grant AG059779, by the American Federation for Aging Research (AFAR) and by the Diabetes Institute and by the AMVETS. Presentation: Saturday, June 17, 2023

Loss of Dact2 alleviates cisplatin-induced nephrotoxicity through regulation of the Igfl-MAPK pathway axis.

Wnt signaling is a principal pathway regulating the essential activities of cell proliferation. Here, we investigated the effect of Wnt/β-catenin signaling on in vivo drug-induced renal injury through the deletion of Dact2, a Wnt antagonist, and deciphered the underlying mechanism. Wild-type (WT) and Dact2 knockout (KO) mice were administered a single intraperitoneal injection of cisplatin to induce renal injury. The injury was alleviated in Dact2 KO mice, which showed lower levels of blood urea nitrogen and creatinine. RNA sequencing revealed 194 differentially expressed genes (DEGs) between WT and Dact2 KO mouse kidney before cisplatin treatment. Among them, higher levels of Igf1, one of the Wnt target genes responsible for "Positive regulation of cell proliferation" in KO mice, were confirmed along with the induction of Ki67 expression. In RNA-seq analysis comparing WT and Dact2 KO mice after cisplatin treatment, genes related to "Apoptosis" and "Activation of mitogen-activated protein kinase (MAPK) activity" were among the downregulated DEGs in KO mice. These results were corroborated in western blotting of proteins related to apoptosis and proapoptotic MAPK pathway; the expression of which was found to be lower in cisplatin-treated KO mice. Importantly, β-catenin was found to directly bind to and regulate the transcription of Igf1, leading to the alleviation of cisplatin-induced cytotoxicity by the Wnt agonist, CHIR-99021. In addition, Igf1 knockdown accelerated cisplatin-induced cytotoxicity, accompanied by the MAPK upregulation. Our findings suggest that Dact2 knockout could protect cisplatin-induced nephrotoxicity by inhibiting apoptosis, possibly through the regulation of the Igf1-MAPK axis associated with Wnt/β-catenin signaling.

Comparison of Bevacizumab and Aflibercept for Suppression of Angiogenesis in Human Retinal Microvascular Endothelial Cells.

Bevacizumab (Avastin) is a vascular endothelial growth factor (VEGF) inhibitor that is widely used for aggressive posterior retinopathy of prematurity (APROP). Its use is associated with multiple adverse effects. Aflibercept (Eylea) is a VEGFR-1 analogue that is approved for ocular use, but its efficacy for APROP is less studied. We tested the hypothesis that Eylea is as effective as Avastin for suppression of intermittent hypoxia (IH)-induced angiogenesis. Human retinal microvascular endothelial cells (HRECs) were treated with Avastin and low- or high-dose Eylea and exposed to normoxia, hyperoxia (50% O2), or neonatal IH for 24, 48, or 72 h. Cells were assessed for migration and tube formation capacities, as well as biomarkers of angiogenesis and oxidative stress. Both doses of Eylea suppressed migration and tube formation in all oxygen environments, although the effect was not as robust as Avastin. Furthermore, the lower dose of Eylea appeared to be more effective than the higher dose. Eylea induced soluble VEGFR-1 (sVEGFR-1) coincident with high IGF-I levels and decreased Notch/Jagged-1, demonstrating a functional association. Given the role of VEGFR-1 and Notch as guidance cues for vascular sprouting, these data suggest that Eylea may promote normal vascular patterning in a dose-dependent manner.

Paradoxical GH increase after oral glucose load in subjects with and without acromegaly

ObjectiveA paradoxical GH rise after the glucose load (GH-Par) is described in about one-third of acromegalic patients. Here, we evaluated the GH profile in subjects with and without acromegaly aiming to refine the definition of GH-Par.DesignObservational case–control study.MethodsOur cohort consisted of 60 acromegalic patients, and two groups of subjects presenting suppressed GH (< 0.4 µg/L) and high (non-acro↑IGF−1, n = 116) or normal IGF-1 levels (non-acro, n = 55). The distribution of GH peaks ≥ 120% from baseline, insulin, and glucose levels were evaluated over a 180-min time interval after glucose intake.ResultsA similar proportion of subjects in all three groups shows a GH ratio of ≥ 120% starting from 120 min. Re-considering the definition of paradoxical increase of GH within 90 min, we observed that the prevalence of GH peaks ≥ 120% was higher in acromegaly than in non-acro↑IGF−1 and non-acro (respectively 42%, 16%, and 7%, both p < 0.001). In patients without GH-Par, a late GH rebound was observed in the second part of the curve. Higher glucose peak (p = 0.038), slower decline after load, 20% higher glucose exposure (p = 0.015), and a higher prevalence of diabetes (p = 0.003) characterized acromegalic patients with GH-Par (with respect to those without).ConclusionsGH-Par response may be defined as a 20% increase in the first 90 min after glucose challenge. GH-Par, common in acromegaly and associated with an increased prevalence of glucose metabolism abnormalities, is found also in a subset of non-acromegalic subjects with high IGF-1 levels, suggesting its possible involvement in the early phase of the disease.