IGFBP-2 and aging: a 20-year longitudinal study on IGFBP-2, IGF-I, BMI, insulin sensitivity and mortality in an aging population

A human omentum-specific mesothelial-like stromal population inhibits adipogenesis through IGFBP2 secretion

Adipose tissue plasticity is orchestrated by molecularly and functionally diverse cells within the stromal vascular fraction (SVF). Although several mouse and human adipose SVF cellular subpopulations have by now been identified, we still lack an understanding of the cellular and functional variability of adipose stem and progenitor cell (ASPC) populations across human fat depots. To address this, we performed single-cell and bulk RNA sequencing (RNA-seq) analyses of >30 SVF/Lin- samples across four human adipose depots, revealing two ubiquitous human ASPC (hASPC) subpopulations with distinct proliferative and adipogenic properties but also depot- and BMI-dependent proportions. Furthermore, we identified an omental-specific, high IGFBP2-expressing stromal population that transitions between mesothelial and mesenchymal cell states and inhibits hASPC adipogenesis through IGFBP2 secretion. Our analyses highlight the molecular and cellular uniqueness of different adipose niches, while our discovery of an anti-adipogenic IGFBP2+ omental-specific population provides a new rationale for the biomedically relevant, limited adipogenic capacity of omental hASPCs.

Proteomic Analysis of the Senescence-Associated Secretory Phenotype: GDF-15, IGFBP-2, and Cystatin-C Are Associated With Multiple Aging Traits

Cellular senescence, a hallmark of aging, results in a senescence-associated secretory phenotype (SASP) with an increased production of proinflammatory cytokines, growth factors, and proteases. Evidence from nonhuman models demonstrates that SASP contributes to tissue dysfunction and pathological effects of aging. However, there are relatively few human studies on the relationship between SASP and aging-related health outcomes. Proteins from the SASP Atlas were measured in plasma using aptamer-based proteomics (SomaLogic). Regression models were used to identify SASP protein associations with aging-related traits representing multiple aspects of physiology in 1 201 participants from 2 human cohort studies (BLSA/GESTALT and InCHIANTI). Traits examined were fasting glucose, C-reactive protein, interleukin-6, alkaline phosphatase, blood urea nitrogen, albumin, red blood cell distribution width, waist circumference, systolic and diastolic blood pressure, gait speed, and grip strength. Study results were combined with a fixed-effect inverse-variance weighted meta-analysis. In the meta-analysis, 28 of 77 SASP proteins were significantly associated with age. Of the 28 age-associated SASP proteins, 18 were significantly associated with 1 or more clinical traits, and 7 SASP proteins were significantly associated with 3 or more traits. Growth/differentiation factor 15, Insulin-like growth factor-binding protein 2, and Cystatin-C showed significant associations with inflammatory markers and measures of physical function (grip strength or gait speed). These results support the relevance of SASP proteins to human aging, identify specific traits that are potentially affected by SASP, and prioritize specific SASP proteins for their utility as biomarkers of human aging.

Serum Insulin-like Growth Factor-Binding Protein-2 as a Prognostic Factor for COVID-19 Severity

Insulin-like growth factor-binding protein (IGFBP)-2 is a regulator of anabolic pathways, which become inactivated in severe illness. Here, we measured the serum IGFBP-2 levels of COVID-19 patients with moderate and severe disease as well as healthy controls to identify the associations of serum IGFBP-2 levels with disease severity. Patients with severe COVID-19 had higher serum IGFBP-2 levels than those with moderate disease and healthy controls, who had similar levels. Non-survivors of COVID-19 tended to have elevated serum IGFBP-2 levels compared to survivors. Increased serum IGFBP-2 levels were observed in patients requiring dialysis and vasopressor therapy. Serum IGFBP-2 was positively correlated with procalcitonin in both patient groups. Bacterial co-infection in severe COVID-19 patients did not influence serum IGFBP-2 levels. Patients with liver cirrhosis and obesity, showing increased and decreased serum IGFBP-2 levels, respectively, were excluded from the study. The present analysis showed that higher serum IGFBP-2 levels are associated with increased disease severity in COVID-19 patients. The similarity in serum IGFBP-2 levels between patients with moderate COVID-19 and healthy controls suggests that elevated IGFBP-2 is associated with critical illness rather than SARS-CoV-2 infection itself.

Plasma Insulin-like Growth Factor-Binding Protein-2 of Critically Ill Patients Is Related to Disease Severity and Survival

Insulin-like growth factor-binding protein (IGFBP)-2 regulates the bioactivity of the anabolic hormone's insulin-like growth factors, which are decreased in sepsis and contribute to the catabolic status of severely ill patients. The circulating levels of IGFBP-2 in critical illness have been rarely studied; therefore, we evaluated IGFBP-2 plasma levels in patients with systemic inflammatory response syndrome (SIRS) or sepsis as well as healthy controls. Our analysis of 157 SIRS/sepsis patients revealed higher plasma IGFBP-2 levels compared to 22 healthy controls. Plasma IGFBP-2 levels correlated positively with procalcitonin but not with C-reactive protein, interleukin-6, or the leukocyte count. Septic shock patients exhibited higher IGFBP-2 levels than those with SIRS. Bacterial or SARS-CoV-2 infection did not influence plasma IGFBP-2 levels. There was no difference in the IGFBP-2 levels between ventilated and non-ventilated SIRS/sepsis patients, and vasopressor therapy did not alter these levels. Dialysis patients had elevated plasma IGFBP-2 levels. Survivors had lower plasma IGFBP-2 levels than non-survivors. In conclusion, our study indicates that plasma IGFBP-2 levels are associated with disease severity, renal failure, and mortality in SIRS/sepsis patients.

Associations between insulin-like growth factor binding protein-2 and insulin sensitivity, metformin, and mortality in persons with T2D

AIMS

Serum insulin-like growth factor binding protein-2 (IGFBP-2) is low in persons with type 2 diabetes mellitus (T2D) and possibly regulated by metformin. Counter-intuitively, high IGFBP-2 associates with mortality. We investigated the association between IGFBP-2, metformin-treatment, and indices of insulin sensitivity, and assessed IGFBP-2 in relation to prior comorbidity and mortality during five-year follow-up.

METHODS

The study included 859 treatment-naive and 558 metformin-treated persons enrolled in the Danish Centre for Strategic Research in T2D and followed for 4.9 (3.9-5.9) years through national health registries. All proteins were determined in serum collected at enrollment.

RESULTS

Following adjustment for age, metformin-treated and treatment-naive persons has similar IGFBP-2 levels. Low IGFBP-2 level was associated with increased BMI, fasting glucose, and C-peptide. IGFBP-2 was higher in the 437 persons who had comorbidities at enrollment than in those with T2D only (343 (213;528) vs. 242 (169;378) ng/mL). During follow-up, 87 persons died, and IGFBP-2 predicted mortality with an unadjusted HR (95% CI) per doubling in IGFBP-2 concentration of 2.62 (2.04;3.37) and a HR of 2.21 (1.61;3.01) following full adjustment.

CONCLUSIONS

In T2D, high IGFBP-2 associates with low glucose and insulin secretion, is unaffected by metformin treatment, and associates with risk of prior comorbidity and mortality.

Circulating IGF-1 and IGFBP-2 may be biomarkers for risk stratification in patients with acute coronary syndrome: A prospective cohort study

BACKGROUND AND AIM

The involvement of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-2 (IGFBP-2) following acute coronary syndrome (ACS) is rarely studied in clinical practice. Therefore, we sought to evaluate the relationship between IGF-1 and IGFBP-2 concentrations at admission and risk stratification based on the Thrombolysis in Myocardial Infarction (TIMI) risk score in patients with ACS.

METHODS AND RESULTS

In all, 304 patients diagnosed with ACS were included in this study. Plasma IGF-1 and IGFBP-2 were measured using commercially available ELISA kits. The TIMI risk score was calculated and the study population was stratified into high (n = 65), medium (n = 138), and low (n = 101) risk groups. Levels of IGF-1 and IGFBP-2 were analyzed for their predictive ability of risk stratification based on the TIMI risk scores. Correlation analysis showed that IGF-1 levels were negatively correlated with TIMI risk levels (r = -0.144, p = 0.012), while IGFBP-2 levels were significantly and positively correlated with TIMI risk levels (r = 0.309, p < 0.001). In multivariate logistic regression analysis, IGF-1 (odds ratio [OR]: 0.995; 95% confidence interval [CI]: 0.990-1.000; p = 0.043) and IGFBP-2 (OR: 1.002; 95%CI: 1.001-1.003; p < 0.001) were independent predictors of high TIMI risk levels. In receiver operating characteristic curves, the area under the curve values for IGF-1 and IGFBP-2 in the prediction of high TIMI risk levels were 0.605 and 0.723, respectively.

CONCLUSIONS

IGF-1 and IGFBP-2 levels are excellent biomarkers for risk stratification in patients with ACS, which provides further guidance for clinicians to identify patients at high risk and to lower their risk.

Age-related increases in IGFBP2 increase melanoma cell invasion and lipid synthesis

Aged melanoma patients (>65 years old) have more aggressive disease relative to young patients (<55 years old) for reasons that are not completely understood. Analysis of the young and aged secretome from human dermal fibroblasts identified >5-fold levels of insulin-like growth factor binding protein 2 (IGFBP2) in the aged fibroblast secretome. IGFBP2 functionally triggers upregulation of the PI3K-dependent fatty acid biosynthesis program in melanoma cells through increases in FASN. Melanoma cells co-cultured with aged dermal fibroblasts have higher levels of lipids relative to young dermal fibroblasts, which can be lowered by silencing IGFBP2 expression in fibroblasts, prior to treating with conditioned media. Conversely, ectopically treating melanoma cells with recombinant IGFBP2 in the presence of conditioned media from young fibroblasts, promoted lipid synthesis and accumulation in the melanoma cells. Neutralizing IGFBP2 in vitro reduces migration and invasion in melanoma cells, and in vivo studies demonstrate that neutralizing IGFBP2 in syngeneic aged mice, ablates tumor growth as well as metastasis. Conversely, ectopic treatment of young mice with IGFBP2 in young mice increases tumor growth and metastasis. Our data reveal that aged dermal fibroblasts increase melanoma cell aggressiveness through increased secretion of IGFBP2, stressing the importance of considering age when designing studies and treatment.

Significance

The aged microenvironment drives metastasis in melanoma cells. This study reports that IGFBP2 secretion by aged fibroblasts induces FASN in melanoma cells and drives metastasis. Neutralizing IGFBP2 decreases melanoma tumor growth and metastasis.

FGF1 ameliorates obesity-associated hepatic steatosis by reversing IGFBP2 hypermethylation

Obesity is a major contributing factor for metabolic-associated fatty liver disease (MAFLD). Fibroblast growth factor (FGF) 1 is the first paracrine FGF family member identified to exhibit promising metabolic regulatory properties capable of conferring glucose-lowering and insulin-sensitizing effect. This study explores the role and molecular underpinnings of FGF1 in obesity-associated hepatic steatosis. In a mouse high-fat diet (HFD)-induced MAFLD model, chronic treatment with recombinant FGF1(rFGF1) was found to effectively reduce the severity of insulin resistance, hyperlipidemia, and inflammation. FGF1 treatment decreased lipid accumulation in the mouse liver and palmitic acid-treated AML12 cells. These effects were associated with decreased mature form SREBF1 expression and its target genes FASN and SCD1. Interestingly, we uncovered that rFGF1 significantly induced IGFBP2 expression at both mRNA and protein levels in HFD-fed mouse livers and cultured hepatocytes treated with palmitic acid. Adeno-associated virus-mediated IGFBP2 suppression significantly diminished the therapeutic benefit of rFGF1 on MAFLD-associated phenotypes, indicating that IGFBP2 plays a crucial role in the FGF1-mediated reduction of hepatic steatosis. Further analysis revealed that rFGF1 treatment reduces the recruitment of DNA methyltransferase 3 alpha to the IGFBP2 genomic locus, leading to decreased IGFBP2 gene methylation and increased mRNA and protein expression. Collectively, our findings reveal FGF1 modulation of lipid metabolism via epigenetic regulation of IGFBP2 expression, and unravel the therapeutic potential of the FGF1-IGFBP2 axis in metabolic diseases associated with obesity.

Biological age models based on a healthy Han Chinese population

BACKGROUND

Biological age (BA) may reflect the actual aging state in humans better than chronological age (CA). The study aimed to construct BA models suitable for the Chinese Han population by selecting appropriate aging markers and evaluation methods.

METHODS

A total of 1207 individuals (21∼91 years) from the Han Chinese population in Beijing were examined for essential organ functions, and 156 cardiovascular, pulmonary function, and atherosclerotic indices and clinical and genetic factors were used as candidate markers of aging. BA models were constructed using multiple linear regression (MLR), principal component analysis (PCA), and the Klemera and Doubal method (KDM). Models were internally and externally validated using cross-validation and disease populations.

RESULTS

Nine aging markers were selected. Two MLR, three PCA, and three KDM models were successfully constructed. External validation showed that the difference between CA and BA was most significant in the PCA3 and KDM2 models, while there was no significant difference in the MLR1 and MLR2 models; the fitted lines for BA in the disease population were higher than those in the healthy population in the MLR1, MLR2, KDM1, and KDM2 models, while the other models showed the opposite.

CONCLUSIONS

Based on a healthy population in Beijing, nine markers representing multiple organ/system functions were screened from the candidate markers, eight methods were successfully used to construct BA models, and the KDM2 model was found to potentially be more appropriate for assessing BA in the Chinese Han population.

The impact of circulating IGF-1 and IGFBP-2 on cardiovascular prognosis in patients with acute coronary syndrome

Background

While insulin-like growth factor 1 (IGF-1) exerts a cardioprotective effect in the setting of atherosclerosis, insulin-like growth factor binding protein 2 (IGFBP-2) is involved in metabolic syndrome. Although IGF-1 and IGFBP-2 are known to be predictors for mortality in patients with heart failure, their use in clinic as prognostic biomarkers for acute coronary syndrome (ACS) requires investigation. We evaluated the relationship between IGF-1 and IGFBP-2 levels at admission and the risk of major adverse cardiovascular events (MACEs) in patients with ACS.

Methods

A total of 277 ACS patients and 42 healthy controls were included in this prospective cohort study. Plasma samples were obtained and analyzed at admission. Patients were followed for MACEs after hospitalization.

Results

Among patients who suffered acute myocardial infarction, plasma levels of IGF-1 and IGFBP-2 were lower and higher, respectively, as compared to healthy controls (both p &lt; 0.05). The mean follow-up period was 5.22 (1.0–6.0) months and MACEs incidence was 22.4% (62 of 277 patients). Kaplan–Meier survival analysis revealed that patients with low IGFBP-2 levels had a greater event-free survival rate than patients with high IGFBP-2 levels (p &lt; 0.001). Multivariate Cox proportional hazards analysis revealed IGFBP-2, but not IGF-1, to be a positive predictor of MACEs (hazard ratio 2.412, 95% CI 1.360–4.277; p = 0.003).

Conclusion

Our findings suggest that high IGFBP-2 levels are associated with the development of MACEs following ACS. Moreover, IGFBP-2 is likely an independent predictive marker of clinical outcomes in ACS.

Cell non-autonomous regulation of cerebrovascular aging processes by the somatotropic axis

Age-related cerebrovascular pathologies, ranging from cerebromicrovascular functional and structural alterations to large vessel atherosclerosis, promote the genesis of vascular cognitive impairment and dementia (VCID) and exacerbate Alzheimer's disease. Recent advances in geroscience, including results from studies on heterochronic parabiosis models, reinforce the hypothesis that cell non-autonomous mechanisms play a key role in regulating cerebrovascular aging processes. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) exert multifaceted vasoprotective effects and production of both hormones is significantly reduced in aging. This brief overview focuses on the role of age-related GH/IGF-1 deficiency in the development of cerebrovascular pathologies and VCID. It explores the mechanistic links among alterations in the somatotropic axis, specific macrovascular and microvascular pathologies (including capillary rarefaction, microhemorrhages, impaired endothelial regulation of cerebral blood flow, disruption of the blood brain barrier, decreased neurovascular coupling, and atherogenesis) and cognitive impairment. Improved understanding of cell non-autonomous mechanisms of vascular aging is crucial to identify targets for intervention to promote cerebrovascular and brain health in older adults.

Diets with higher insulinaemic potential are associated with increased risk of overall and cardiovascular disease-specific mortality

Hyperinsulinaemia and insulin resistance have been proposed to be associated with mortality risk, and diet can modulate insulin response. However, whether dietary patterns with high insulinaemic potential are associated with mortality remains unknown. We prospectively examined the associations between hyperinsulinaemic diets and the risk of total and cause-specific mortality in a large nationally representative population. Dietary factors were assessed by 24-h recalls. Two empirical dietary indices for hyperinsulinaemia (EDIH) and insulin resistance (EDIR) were developed to identify food groups most predictive of biomarkers for hyperinsulinaemia (C-peptide and insulin) and insulin resistance (homoeostatic model assessment for insulin resistance), respectively. Deaths from date of the first dietary interview until 31 December 2015 were identified by the National Death Index. Multivariable hazard ratios (HR) and 95 % CI were calculated using Cox regression models. During a median follow-up of 7·8 years, 4904 deaths were documented among 40 074 participants. For EDIH, the multivariable-adjusted HR (comparing extreme quintiles) were 1·20 (95 % CI 1·09, 1·32, P-trend<0·001) for overall mortality and 1·41 (95 % CI 1·15, 1·74, P-trend = 0·002) for CVD mortality. Similar associations were observed for EDIR with HR of 1·18 (95 % CI 1·07, 1·29, P-trend < 0·001) for total and 1·35 (95 % CI 1·09, 1·67, P-trend = 0·005) for CVD mortality. After further adjustments for BMI and diabetes, these positive associations were somewhat attenuated. Our findings suggested that diets with higher insulinaemic potential are associated with increased risk of overall and CVD-specific mortality.

The single-cell atlas of cultured human endometrial stromal cells

OBJECTIVE

To systematically analyze the cell composition and transcriptome of primary human endometrial stromal cells (HESCs) and transformed human endometrial stromal cells (THESCs).

DESIGN

The primary HESCs from 3 different donors and 1 immortalized THESC were collected from the human endometrium at the midsecretory phase and cultured in vitro.

SETTING

Academic research laboratory.

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Single-cell ribonucleic acid sequencing analysis.

RESULT(S)

We found the individual differences among the primary HESCs and bigger changes between the primary HESCs and THESCs. Cell clustering with or without integration identified cell clusters belonging to mature, proliferative, and active fibroblasts that were conserved across all samples at different stages of the cell cycles with intensive cell communication signals. All primary HESCs and THESCs can be correlated with some subpopulations of fibroblasts in the human endometrium.

CONCLUSION(S)

Our study indicated that the primary HESCs and THESCs displayed conserved cell characters and distinct cell clusters. Mature, proliferative, and active fibroblasts at different stages or cell cycles were detected across all samples and presented with a complex cell communication network. The cultured HESCs and THESCs retained the features of some subpopulations within the human endometrium.

Progeria and Aging-Omics Based Comparative Analysis

Since ancient times aging has also been regarded as a disease, and humankind has always strived to extend the natural lifespan. Analyzing the genes involved in aging and disease allows for finding important indicators and biological markers for pathologies and possible therapeutic targets. An example of the use of omics technologies is the research regarding aging and the rare and fatal premature aging syndrome progeria (Hutchinson-Gilford progeria syndrome, HGPS). In our study, we focused on the in silico analysis of differentially expressed genes (DEGs) in progeria and aging, using a publicly available RNA-Seq dataset (GEO dataset GSE113957) and a variety of bioinformatics tools. Despite the GSE113957 RNA-Seq dataset being well-known and frequently analyzed, the RNA-Seq data shared by Fleischer et al. is far from exhausted and reusing and repurposing the data still reveals new insights. By analyzing the literature citing the use of the dataset and subsequently conducting a comparative analysis comparing the RNA-Seq data analyses of different subsets of the dataset (healthy children, nonagenarians and progeria patients), we identified several genes involved in both natural aging and progeria (KRT8, KRT18, ACKR4, CCL2, UCP2, ADAMTS15, ACTN4P1, WNT16, IGFBP2). Further analyzing these genes and the pathways involved indicated their possible roles in aging, suggesting the need for further in vitro and in vivo research. In this paper, we (1) compare "normal aging" (nonagenarians vs. healthy children) and progeria (HGPS patients vs. healthy children), (2) enlist genes possibly involved in both the natural aging process and progeria, including the first mention of IGFBP2 in progeria, (3) predict miRNAs and interactomes for WNT16 (hsa-mir-181a-5p), UCP2 (hsa-mir-26a-5p and hsa-mir-124-3p), and IGFBP2 (hsa-mir-124-3p, hsa-mir-126-3p, and hsa-mir-27b-3p), (4) demonstrate the compatibility of well-established R packages for RNA-Seq analysis for researchers interested but not yet familiar with this kind of analysis, and (5) present comparative proteomics analyses to show an association between our RNA-Seq data analyses and corresponding changes in protein expression.

Old blood from heterochronic parabionts accelerates vascular aging in young mice: transcriptomic signature of pathologic smooth muscle remodeling

Vascular aging has a central role in the pathogenesis of cardiovascular diseases contributing to increased mortality of older adults. There is increasing evidence that, in addition to the documented role of cell-autonomous mechanisms of aging, cell-nonautonomous mechanisms also play a critical role in the regulation of vascular aging processes. Our recent transcriptomic studies (Kiss T. et al. Geroscience. 2020;42(2):727-748) demonstrated that circulating anti-geronic factors from young blood promote vascular rejuvenation in aged mice. The present study was designed to expand upon the results of this study by testing the hypothesis that circulating pro-geronic factors also contribute to the genesis of vascular aging phenotypes. To test this hypothesis, through heterochronic parabiosis, we determined the extent to which shifts in the vascular transcriptome (RNA-seq) are modulated by the old systemic environment. We reanalyzed existing RNA-seq data, comparing the transcriptome in the aorta arch samples isolated from isochronic parabiont aged (20-month-old) C57BL/6 mice [A-(A); parabiosis for 8 weeks] and young isochronic parabiont (6-month-old) mice [Y-(Y)] and also assessing transcriptomic changes in the aortic arch in young (6-month-old) parabiont mice [Y-(A); heterochronic parabiosis for 8 weeks] induced by the presence of old blood derived from aged (20-month-old) parabionts. We identified 528 concordant genes whose expression levels differed in the aged phenotype and were shifted towards the aged phenotype by the presence of old blood in young Y-(A) animals. Among them, the expression of 221 concordant genes was unaffected by the presence of young blood in A-(Y) mice. GO enrichment analysis suggests that old blood-regulated genes may contribute to pathologic vascular remodeling. IPA Upstream Regulator analysis (performed to identify upstream transcriptional regulators that may contribute to the observed transcriptomic changes) suggests that the mechanism of action of pro-geronic factors present in old blood may include inhibition of pathways mediated by SRF (serum response factor), insulin-like growth factor-1 (IGF-1) and VEGF-A. In conclusion, relatively short-term exposure to old blood can accelerate vascular aging processes. Our findings provide additional evidence supporting the significant plasticity of vascular aging and the existence of circulating pro-geronic factors mediating pathological remodeling of the vascular smooth muscle cells and the extracellular matrix.

Proteins in the pathway from high red blood cell width distribution to all-cause mortality

Background

The pathophysiological mechanisms underlying the association between red blood cell distribution width (RDW) and all-cause mortality are unknown. We conducted a data-driven discovery investigation to identify plasma proteins that mediate the association between RDW and time to death in community-dwelling adults.

Methods

At baseline, 962 adults (women, 54·4%; age range, 21–98 years) participated in the InCHIANTI, “Aging in the Chianti Area” study, and proteomics data were generated from their plasma specimens. Of these, 623 participants had proteomics data available at the 9-year follow-up. For each visit, a total of 1301 plasma proteins were measured using SOMAscan technology. Complete data on vital status were available up to the 15-year follow-up period. Protein-specific exponential distribution accelerated failure time, and linear regression analyses adjusted for possible covariates were used for mortality and mediation analyses, respectively (survival data analysis).

Findings

Baseline values of EGFR, GHR, NTRK3, SOD2, KLRF1, THBS2, TIMP1, IGFBP2, C9, APOB, and LRP1B mediated the association between baseline RDW and all-cause mortality. Changes in IGFBP2 and C7 over 9 years mediated the association between changes in RDW and 6-year all-cause mortality.

Interpretation

Cellular senescence may contribute to the association between RDW and mortality.

Funding

This study was funded by grants from the National Institutes of Health (NIH) and the National Institute on Aging (NIA) contract and was supported by the Intramural Research Program of the NIA, NIH. The InCHIANTI study was supported as a ‘targeted project’ by the Italian Ministry of Health and in part by the U.S. NIA.

Four groups of type 2 diabetes contribute to the etiological and clinical heterogeneity in newly diagnosed individuals: An IMI DIRECT study

The presentation and underlying pathophysiology of type 2 diabetes (T2D) is complex and heterogeneous. Recent studies attempted to stratify T2D into distinct subgroups using data-driven approaches, but their clinical utility may be limited if categorical representations of complex phenotypes are suboptimal. We apply a soft-clustering (archetype) method to characterize newly diagnosed T2D based on 32 clinical variables. We assign quantitative clustering scores for individuals and investigate the associations with glycemic deterioration, genetic risk scores, circulating omics biomarkers, and phenotypic stability over 36 months. Four archetype profiles represent dysfunction patterns across combinations of T2D etiological processes and correlate with multiple circulating biomarkers. One archetype associated with obesity, insulin resistance, dyslipidemia, and impaired β cell glucose sensitivity corresponds with the fastest disease progression and highest demand for anti-diabetic treatment. We demonstrate that clinical heterogeneity in T2D can be mapped to heterogeneity in individual etiological processes, providing a potential route to personalized treatments.

Multifactorial Mechanism of Sarcopenia and Sarcopenic Obesity. Role of Physical Exercise, Microbiota and Myokines

Obesity and ageing place a tremendous strain on the global healthcare system. Age-related sarcopenia is characterized by decreased muscular strength, decreased muscle quantity, quality, and decreased functional performance. Sarcopenic obesity (SO) is a condition that combines sarcopenia and obesity and has a substantial influence on the older adults’ health. Because of the complicated pathophysiology, there are disagreements and challenges in identifying and diagnosing SO. Recently, it has become clear that dysbiosis may play a role in the onset and progression of sarcopenia and SO. Skeletal muscle secretes myokines during contraction, which play an important role in controlling muscle growth, function, and metabolic balance. Myokine dysfunction can cause and aggravate obesity, sarcopenia, and SO. The only ways to prevent and slow the progression of sarcopenia, particularly sarcopenic obesity, are physical activity and correct nutritional support. While exercise cannot completely prevent sarcopenia and age-related loss in muscular function, it can certainly delay development and slow down the rate of sarcopenia. The purpose of this review was to discuss potential pathways to muscle deterioration in obese individuals. We also want to present the current understanding of the role of various factors, including microbiota and myokines, in the process of sarcopenia and SO.

The potential role of mesenchymal stem cells in modulating antiageing process

Ageing and age-related diseases share some basic origin that largely converges on inflammation. Precisely, it boils down to a common pathway characterised by the appearance of a fair amount of proinflammatory cytokines known as inflammageing. Among the proposed treatment for antiageing, MSCs gained attention in recent years. Since mesenchymal stem cells (MSCs) can differentiate itself into a myriad of terminal cells, previously it was believed that these cells migrate to the site of injury and perform their therapeutic effect. However, with the more recent discovery of huge amounts of paracrine factors secreted by MSCs, it is now widely accepted that these cells do not engraft upon transplantation but rather unveil their benefits through excretion of bioactive molecules namely those involved in inflammatory and immunomodulatory activities. Conversely, the true function of these paracrine changes has not been thoroughly investigated all these years. Hence, this review will describe in detail on ways MSCs may capitalize its paracrine properties in modulating antiageing process. Through a comprehensive literature search various elements in the antiageing process, we aim to provide a novel treatment perspective of MSCs in antiageing related clinical conditions.

Aging-related genes are potential prognostic biomarkers for patients with gliomas

Aging has a significant role in the proliferation and development of cancers. This study explored the expression profiles, prognostic value, and potential roles of aging-related genes in gliomas. We designed risk score and cluster models based on aging-related genes and glioma cases using LASSO Cox regression analysis, consensus clustering analysis and univariate cox regression analyses. High risk score was related to malignant clinical features and poor prognosis based on 10 datasets, 2953 cases altogether. Genetic alterations analysis revealed that high risk scores were associated with genomic aberrations of aging-related oncogenes. GSVA analysis exhibited the potential function of the aging-related genes. More immune cell infiltration was found in high-risk group cases, and glioma patients in high-risk group may be more responsive to immunotherapy. Knock-down of CTSC, an aging-related gene, can inhibit cell cycle progression, colony formation, cell proliferation and increase cell senescence in glioma cell lines in vitro. Indeed, high expression of CTSC was associated with poor prognosis in glioma cases. In conclusion, this study revealed that aging-related genes have prognostic potential for glioma patients and further identified potential mechanisms for aging-related genes in tumorigenesis and progression in gliomas.

The Roles of Insulin-Like Growth Factor Binding Protein Family in Development and Diseases

The insulin-like growth factor (IGF) system comprises ligands of IGF-I/II, IGF receptors (IGFR), IGF binding proteins (IGFBPs), and IGFBP hydrolases. The IGF system plays multiple roles during various disease development as IGFs are widely involved in cell proliferation and differentiation through regulating DNA transcription. Meanwhile, IGFBPs, which are mainly synthesized in the liver, can bind to IGFs and perform two different functions: either inhibition of IGFs by forming inactive compounds with IGF or enhancement of the function of IGFs by strengthening the IGF-IGFR interaction. Interestingly, IGFBPs may have wider functions through IGF-independent mechanisms. Studies have shown that IGFBPs play important roles in cardiovascular disease, tumor progression, fetal growth, and neuro-nutrition. In this review, we emphasize that different IGFBP family members have common or unique functions in numerous diseases; moreover, IGFBPs may serve as biomarkers for disease diagnosis and prediction.

Potential Role of Insulin Growth-Factor-Binding Protein 2 as Therapeutic Target for Obesity-Related Insulin Resistance

Evidence from observational and in vitro studies suggests that insulin growth-factor-binding protein type 2 (IGFBP2) is a promising protein in non-communicable diseases, such as obesity, insulin resistance, metabolic syndrome, or type 2 diabetes. Accordingly, great efforts have been carried out to explore the role of IGFBP2 in obesity state and insulin-related diseases, which it is typically found decreased. However, the physiological pathways have not been explored yet, and the relevance of IGFBP2 as an important pathway integrator of metabolic disorders is still unknown. Here, we review and discuss the molecular structure of IGFBP2 as the first element of regulating the expression of IGFBP2. We highlight an update of the association between low serum IGFBP2 and an increased risk of obesity, type 2 diabetes, metabolic syndrome, and low insulin sensitivity. We hypothesize mechanisms of IGFBP2 on the development of obesity and insulin resistance in an insulin-independent manner, which meant that could be evaluated as a therapeutic target. Finally, we cover the most interesting lifestyle modifications that regulate IGFBP2, since lifestyle factors (diet and/or physical activity) are associated with important variations in serum IGFBP2.

Circulating IGFBP-2 levels are inversely associated with the incidence of nonalcoholic fatty liver disease: A cohort study

Objective

The insulin-like growth factor (IGF) axis is essential for the body’s metabolism. The hepatokine, insulin-like growth factor-binding protein 2 (IGFBP-2), acts as a major regulator of this metabolism. We aimed to evaluate the role of serum IGFBP-2 in the incidence of nonalcoholic fatty liver disease (NAFLD).

Methods

This hospital-based prospective cohort study recruited residents from a health program from January to November 2013, and re-invited them for follow-up in 2016. The occurrence of NAFLD was noted and IGFBP-2 levels were evaluated by enzyme-linked immunosorbent assay at both visits.

Results

Of 763 participants at baseline, 296 completed the re-evaluation. Baseline serum IGFBP-2 levels were significantly lower in subjects with NAFLD compared with those without NAFLD. Circulating IGFBP-2 levels were negatively correlated with body mass index, waist-to-hip ratio, alanine transaminase, triglycerides, fasting glucose, and insulin. IGFBP-2 levels at follow-up decreased in subjects who developed NAFLD compared with those who did not. Higher circulating levels of IGFBP-2 at baseline were negatively associated with the incidence of NAFLD.

Conclusion

These results indicate that IGFBP-2 levels are inversely associated with the risk of NAFLD. This offers new insights into the role of circulating IGFBP-2, as an IGF-axis hepatokine, in the pathogenesis of hepatic steatosis.

Effects of gastric sleeve surgery on the serum levels of GH, IGF-1 and IGF-binding protein 2 in healthy obese patients

Background

Bariatric surgery is an effective treatment for severe obesity. It also ameliorates diabetes independently of weight loss through mechanisms that are not fully understood. In this study, we investigated the levels of GH, IGF-1 and IGF-binding protein 2 (IGFBP-2) after gastric sleeve surgery in healthy obese individuals.

Method

This study was conducted in 33 obese (BMI > 38.3) healthy male subjects aged 25 to 50 years undergoing sleeve gastrectomy. GH, IGF-1 and IGFBP-2 levels were evaluated by ELISA at baseline and 6–12 months after surgery. Other parameters, such as glucose, BMI, insulin, HOMA-IR and lipid profile, were also investigated.

Results

Systemic GH (12.32 vs. 50.97 pg/mL, p < 0.001) and IGFBP-2 levels (51.86 vs. 68.81 pg/mL, p < 0.001) were elevated after bariatric surgery. There was no change in IGF-1 level from before to after surgery. BMI (52.18 vs. 40.11, p = 0.001), insulin (19.35 vs. 8.80 mIU/L, p < 0.001) and HOMA-IR index (6.48 to 2.52, p < 0.001) were reduced after surgery. Lipid profile analysis revealed that total cholesterol (4.26 vs. 5.12 mmol/L, p < 0.001) and high-density lipoprotein (HDL) (0.90 to 1.55 mmol/L, p < 0.001) were increased, while triglycerides were decreased, after surgery (1.62 vs. 1.05 mmol/L p < 0.001). GH, IGF-1, and IGFBP-2 were not correlated with insulin or lipid parameters.

Conclusions

Our study suggests that improved circulating GH and IGFBP-2 levels may mediate the beneficial effects of gastric sleeve surgery in improving insulin sensitivity and reducing insulin demand.

Overlap of Peak Growth Activity and Peak IGF-1 to IGFBP Ratio: Delayed Increase of IGFBPs versus IGF-1 in Serum as a Mechanism to Speed up and down Postnatal Weight Gain in Mice

Forced expression of insulin-like growth factor binding proteins (IGFBPs) in transgenic mice has clearly revealed inhibitory effects on somatic growth. However, by this approach, it cannot be solved if or how IGFBPs rule insulin-like growth factor (IGF)-dependent growth under normal conditions. In order to address this question, we have used growth-selected mouse models (obese and lean) and studied IGF-1 and IGFBPs in serum with respect to longitudinal growth activity in males and females compared with unselected controls. In mice of both genders, body weights were recorded and daily weight gains were calculated. Between 2 and 54 weeks of age, serum IGF-1 was determined by ELISA and intact IGFBP-2, -3 and -4 were quantified by Western ligand blotting. The molar ratio of IGF-1 to the sum of IGFBP-2 to -4 was calculated for all groups and plotted against the daily weight gain curve. Growth-selected mice are characterized by higher daily weight gains and extended periods of elevated growth activity if compared to matched unselected controls. Therefore, adult mice from the obese and lean groups can achieve more than twofold increased body weight in both genders (p < 0.001). Between 2 and 11 weeks of age, in obese and lean mice of both genders, serum IGF-1 concentrations are increased more prominently if compared to unselected controls (p < 0.001). Instead, substantial decreases of IGFBPs, particularly of IGFBP-2, are observed in males and females of all groups at the age of 2 to 4 weeks (p < 0.001). Due to the strong increase of IGF-1 but not of IGFBPs between two and four weeks of age, the ratio of IGF-1 to IGFBP-2 to -4 in serum significantly increased in all groups and genders (p < 0.05). Notably, the IGF-1 to IGFBP ratio was higher in male and female obese mice if compared to unselected controls (p < 0.05).

Proteome-wide assessment of diabetes mellitus in Qatari identifies IGFBP-2 as a risk factor already with early glycaemic disturbances

BACKGROUND

Proteomics is expected to provide novel insights in the underlying pathophysiology of type 2 diabetes mellitus. In the present study, we aimed to identify and biochemically characterize proteins associated with diabetes mellitus in a Qatari population.

METHODS

In a diabetes case-control study (175 cases, 164 controls; Arab, South Asian and Philippine ethnicities), we conducted a discovery study to screen 1141 blood protein levels for associations with diabetes mellitus. Additional analyses were done in controls in relation to Hb1Ac, and biochemical characterization of the main findings was performed with metabolomics (501 metabolites). We performed two-sample Mendelian Randomization to provide evidence of potential causality using data from European descent of the DIAGRAM consortium (74,124 cases of diabetes mellitus and 824,006 controls) for the identified proteins for T2D and Hb1Ac.

RESULTS

After accounting for multiple testing, 30 protein levels were different (p-values<8.6e^-5) between cases and controls. Of these, a higher Hb1Ac in controls was associated with a lower IGFBP-2 level (p-value = 4.1e^-6). IGFBP-2 protein level was found lower among cases compared with controls across all ethnicities. In controls, IGFBP-2 was associated with 21 metabolite levels, but specifically connected to the metabolite citrulline in network analyses. We observed no evidence, however, that the association between IGFBP-2 and diabetes mellitus was causal.

CONCLUSIONS

We specifically identified IGFBP-2 to be associated with diabetes mellitus, although with no evidence for causality, which was specifically connected to citrulline metabolism.

Physiological Disturbance in Fatty Liver Energy Metabolism Converges on IGFBP2 Abundance and Regulation in Mice and Men

Fatty liver occurs from simple steatosis with accumulated hepatic lipids and hepatic insulin resistance to severe steatohepatitis, with aggravated lipid accumulation and systemic insulin resistance, but this progression is still poorly understood. Analyses of hepatic gene expression patterns from alb-SREBP-1c mice with moderate, or aP2-SREBP-1c mice with aggravated, hepatic lipid accumulation revealed IGFBP2 as key nodal molecule differing between moderate and aggravated fatty liver. Reduced IGFBP2 expression in aggravated fatty liver was paralleled with promoter hypermethylation, reduced hepatic IGFBP2 secretion and IGFBP2 circulating in plasma. Physiologically, the decrease of IGFBP2 was accompanied with reduced fatty acid oxidation and increased de novo lipogenesis potentially mediated by IGF1 in primary hepatocytes. Furthermore, methyltransferase and sirtuin activities were enhanced. In humans, IGFBP2 serum concentration was lower in obese men with non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) compared to non-obese controls, and liver fat reduction by weight-loss intervention correlated with an increase of IGFBP2 serum levels. In conclusion, hepatic IGFBP2 abundance correlates to its circulating level and is related to hepatic energy metabolism and de novo lipogenesis. This designates IGFBP2 as non-invasive biomarker for fatty liver disease progression and might further provide an additional variable for risk prediction for pathogenesis of fatty liver in diabetes subtype clusters.

Biomarker-defined pathways for incident type 2 diabetes and coronary heart disease-a comparison in the MONICA/KORA study

Background

Biomarkers may contribute to our understanding of the pathophysiology of various diseases. Type 2 diabetes (T2D) and coronary heart disease (CHD) share many clinical and lifestyle risk factors and several biomarkers are associated with both diseases. The current analysis aims to assess the relevance of biomarkers combined to pathway groups for the development of T2D and CHD in the same cohort.

Methods

Forty-seven serum biomarkers were measured in the MONICA/KORA case-cohort study using clinical chemistry assays and ultrasensitive molecular counting technology. The T2D (CHD) analyses included 689 (568) incident cases and 1850 (2004) non-cases from three population-based surveys. At baseline, the study participants were 35–74 years old. The median follow-up was 14 years. We computed Cox regression models for each biomarker, adjusted for age, sex, and survey. Additionally, we assigned the biomarkers to 19 etiological pathways based on information from literature. One age-, sex-, and survey-controlled average variable was built for each pathway. We used the R²_PM coefficient of determination to assess the explained disease risk.

Results

The associations of many biomarkers, such as several cytokines or the iron marker soluble transferrin receptor (sTfR), were similar in strength for T2D and CHD, but we also observed important differences. Lipoprotein (a) (Lp(a)) and N-terminal pro B-type natriuretic peptide (NT-proBNP) even demonstrated opposite effect directions. All pathway variables together explained 49% of the T2D risk and 21% of the CHD risk. The insulin-like growth factor binding protein 2 (IGFBP-2, IGF/IGFBP system pathway) best explained the T2D risk (about 9% explained risk, independent of all other pathway variables). For CHD, the myocardial-injury- and lipid-related-pathways were most important and both explained about 4% of the CHD risk.

Conclusions

The biomarker-derived pathway variables explained a higher proportion of the T2D risk compared to CHD. The ranking of the pathways differed between the two diseases, with the IGF/IGFBP-system-pathway being most strongly associated with T2D and the myocardial-injury- and lipid-related-pathways with CHD. Our results help to better understand the pathophysiology of the two diseases, with the ultimate goal of pointing out targets for lifestyle intervention and drug development to ideally prevent both T2D and CHD development.

The Concept of Growth Hormone Deficiency Affecting Clinical Prognosis in IVF

The current understanding of human growth hormone (hGH; here GH) action is that the molecule is a 191-amino acid, single-chain polypeptide that is synthesized, stored and secreted by the somatotroph cells within the lateral wings of the anterior pituitary gland. It can be classified as a protein (comprising more than 50 amino acids) but true proteins have tertiary and quaternary chains creating a more complex structure, hence GH is usually classified as a polypeptide. GH is normally secreted at night during sleep and promotes skeletal, visceral and general body growth through the action of somatomedins or IGFs, notably IGF-1. In some tissues, GH action is directed via specific receptors GHRs; these are most abundant in liver, adipose and muscle tissues but have also been shown in granulosa cells, testicular tissues and on the oocyte, as well as in glandular cells of the luteal phase endometrium and decidua; such findings being recent and minimally researched to now. Following engagement with its receptor, the transduction process activates multiple signaling proteins. These all lead to extensive metabolic and mitogenic (growth promoting) responses. Clinically, GH is known to have an important role in pubertal development and is a key hormone for the vigor associated with adolescence and early adult life stages but has a faded presence and role for later adulthood, beyond age 30 years, and is minimally detected in advanced age, beyond 40 years. In association with the rapidly increasing trend for delaying reproduction beyond age 35 years, GH is being widely researched now as a potential adjuvant for infertility treatment in this group who, studies consistently show, have a poorer prognosis than younger females when relying on autologous oocytes. The idea that the age-related reduction in fertility prognosis is a feature of growth hormone deficiency is supported by our studies showing an elevated binding protein IGFBP-3/IGF-1 ratio and this can be reduced to a normal range (matching younger, good prognosis women) by the administration of GH as an adjuvant.