Insulin-like Growth Factor Binding Protein-3 Research Articles

P-411 CD55 deficiency hinders decidualization in unexplained early miscarriage through the Src/ERK signaling pathway

Abstract Study question What is the role of CD55 in the process of human endometrial stromal cells (HESCs) decidualization in unexplained early miscarriage? Summary answer CD55, responsive to cAMP signaling, is deficient in decidua of patients with unexplained early miscarriage, which hinders decidualization in vitro through perturbing Src/ERK signaling pathway. What is known already Decidualization is a process where HESCs differentiate into decidual stromal cells and present morphological changes and acquisition of secretory function, which is essential for embryo implantation and maintenance of pregnancy while abnormal decidualization contributed to several pregnancy disorders like a miscarriage. Reprogramming of several signaling pathways and transcription factors are involved in this process and cAMP is a critical mediator. Our previous bioinformatic analysis revealed that CD55 was upregulated over five times in the window of implantation, responding to estrogen and progesterone. We speculated that CD55, regulated by cAMP signaling pathway, might play an important role in decidualization. Study design, size, duration Decidua tissues were collected from 8 patients with unexplained early miscarriage and 10 control women with normal early pregnancy undergoing artificial abortion between June 2020 and September 2020. Immortalized HESCs line T-hESCs (ATCC CRL-4003) were cultured for up to 6 days to establish in-vitro decidualization model. Each experiment was conducted in triplicate and replicated at least three times independently. Participants/materials, setting, methods CD55 expression in control and miscarriage decidua was compared by immunohistochemistry and RT-qPCR. T-hESCs were induced into decidualization by medroxyprogesterone acetate (MPA) and 8-Br-cAMP, with prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) as decidualization biomarkers. The changes of genes and signaling pathways were detected by RT-qPCR and western blot during decidualization after CD55 knockdown by lentivirus-mediated RNA interference. Signaling pathway disruptors were added to verify the involvement of signaling pathways. Main results and the role of chance The decidua of women with unexplained early miscarriage exhibited decreased expression of CD55, accompanied by a compromised level of decidualization. During in-vitro decidualization, CD55 was significantly upregulated by cAMP in a time- and dose-dependent manner, which was attenuated by a PKA inhibitor H89. Knocking down CD55 expression diminished the expression of decidualization markers PRL and IGFBP1 through inhibition of Src, aberrant activation of ERK and frustrated expression of decidualization-related genes like FOXO1, EGFR, and STAT3. Limitations, reasons for caution The mechanisms revealed in this study were based on in-vitro cell models. It is necessary to verify the significance of CD55 in decidualization with in-vivo models to directly explain the link between CD55, decidualization, and pregnancy loss. Wider implications of the findings CD55 deficiency hinders decidualization through perturbing Src/ERK signaling pathway and expression of decidualization-related genes, potentially contributing to the pathogenesis of spontaneous miscarriage. Progestin supplementation or other factors stimulating cAMP accumulation can restore CD55 expression and improve decidualization, providing a basis for the therapy of spontaneous miscarriage. Trial registration number not applicable

Relationship between Serum Sirtuin 1 and Growth Hormone/Insulin-like Growth Factor 1 Concentrations in Children with Growth Hormone Deficiency and Idiopathic Short Stature.

Sirtuin 1 (SIRT1) inhibits growth hormone (GH) intracellular signaling for the insulin-like growth factor 1 (IGF-1) synthesis via the janus kinase (JAK)/signal transducer and activator of transcription proteins (STATs) pathway. The aim of this study was to compare SIRT1 concentrations in children with GH deficiency (GHD) and so-called idiopathic short stature (ISS, non-GH deficient), in order to determine the possible impact of changes in serum SIRT1 concentrations on the GH-IGF-1 axis. The study group included 100 short-stature children: 38 with GHD and 62 with ISS (maxGH in two stimulation tests <10 and ≥10 ng/mL, respectively). The control group consisted of 47 healthy, normal-height children. For each child, the concentrations of SIRT1, IGF-1 and insulin-like growth factor-binding protein 3 (IGFBP-3) were determined and the IGF-1/IGFBP-3 molar ratio was calculated. The level of SIRT1 was significantly higher in both groups of short children than in the controls (p < 0.0001), but there were no differences between GHD and ISS (mean ± SD: 0.89 ± 0.45 for ISS; 1.24 ± 0, 86 for GHD; and 0.29 ± 0.21 for controls). A significant negative correlation was found between SIRT1 and height standard deviation score (SDS), IGF-1 and IGF-1/IGFBP-3, but not between SIRT1 and maxGH. Elevated SIRT1 levels may serve as one of the mechanisms through which the secretion of IGF-1 is reduced in children with short stature; however, further research is required to confirm this issue.

Evaluation of Serum Cytokeratines, Thymidine Kinase, and Growth Factors as Cancer Biomarkers in Colorectal Cancer.

Classical serum cancer biomarkers, such as carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA 19-9), remain important tools in colorectal cancer (CRC) management for disease follow up. However, their sensitivity and specificity are low for diagnostic and prognostic evaluation. The aim of this study was to evaluate the potential of biomarkers reflecting biological activity of tumors - tissue polypeptide specific antigen (TPS), cytokeratin fragment 19 (CYFRA 21-1), thymidine kinase (TK), insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGF-BP3) - together with the CEA and CA 19-9 in CRC diagnosis and prognosis. This is a retrospective study including 148 CRC patients and 68 age-matched healthy subjects. Serum biomarkers were measured in pre-operative serum samples using immunoanalytical methods. The end-point for the diagnostic evaluation was the area under the receiving operating characteristic curve (AUC ROC) of the biomarkers. The end-point for the prognostic evaluation was overall survival. Serum levels of CEA, CA 19-9, TPS, and TK were significantly increased in CRC early-stage patients compared with healthy controls. Each of the studied biomarkers had AUC between 0.6 and 0.7. Analysis of survival demonstrated that the patients with CEA, CA 19-9, cytokeratin, and TK above optimal cut offs had significantly shorter survival. A multivariate analysis performed on all the study biomarkers resulted in the selection of CYFRA 21-1 as the best performing biomarker with hazard ratio 10.413. The combination of cytokeratins and thymidine kinase with classical cancer biomarkers enables the prediction of tumor aggressiveness and long-term prognosis.

Tissue Inhibitor of Metalloproteinases-2 (TIMP-2) as a Prognostic Biomarker in Acute Kidney Injury: A Narrative Review.

Acute kidney damage (AKI) is a serious and common consequence among critically unwell individuals. Traditional biomarkers, such as serum creatinine, frequently fail to detect AKI in its early stages, necessitating the development of new accurate early biomarkers. Tissue inhibitor of metalloproteinases 2 (TIMP-2) has emerged as a promising biomarker for predicting early AKI. The present narrative review investigates the role of TIMP-2 in AKI prediction in a variety of clinical scenarios. In the NephroCheck® test, TIMP-2 exceeds established biomarkers for the early identification of AKI in terms of sensitivity and specificity when combined with insulin-like growth factor-binding protein 7 (IGFBP-7). Elevated levels of these biomarkers can provide a warning signal for AKI two to three days before clinical symptoms appear. TIMP-2 and IGFBP-7 have high predictive values, with an area under the curve (AUC) typically above 0.8, indicating good predictive capacity. For example, the [TIMP-2] × [IGFBP-7] product produced an AUC of 0.85 in surgical patients at high risk. In critically ill patients, a threshold of 0.3 (ng/mL)2/1000 demonstrated 92% sensitivity and 72% specificity. Elevated TIMP-2 levels have been correlated with higher mortality rates and the need for renal replacement therapy (RRT). In sepsis-associated AKI (SA-AKI), TIMP-2 levels combined with clinical prognostic models improved predictive accuracy (AUC: 0.822). Furthermore, elevated urine TIMP-2 levels were good predictors of AKI in pediatric patients after cardiac surgery, with AUC-ROC values of up to 0.848. Urine output and the presence of concomitant disorders may influence the prognostic accuracy of these biomarkers; therefore, more research is needed to fully understand their utility. The predictive value of TIMP-2 could be strengthened by combining it with other clinical parameters, reinforcing its role in the early detection and treatment of AKI.

N6-methyladenosine methylation regulates the tumor microenvironment of Epstein-Barr virus-associated gastric cancer.

N6-methyladenosine (m6A) methylation modification exists in Epstein-Barr virus (EBV) primary infection, latency, and lytic reactivation. It also modifies EBV latent genes and lytic genes. EBV-associated gastric cancer (EBVaGC) is a distinctive molecular subtype of GC. We hypothesized EBV and m6A methylation regulators interact with each other in EBVaGC to differentiate it from other types of GC. To investigate the mechanisms of m6A methylation regulators in EBVaGC to determine the differentiating factors from other types of GC. First, The Cancer Gene Atlas and Gene Expression Omnibus databases were used to analyze the expression pattern of m6A methylation regulators between EBVaGC and EBV-negative GC (EBVnGC). Second, we identified Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment of m6A-related differentially expressed genes. We quantified the relative abundance of immune cells and inflammatory factors in the tumor microenvironment (TME). Finally, cell counting kit-8 cell proliferation test, transwell test, and flow cytometry were used to verify the effect of insulin-like growth factor binding protein 1 (IGFBP1) in EBVaGC cell lines. m6A methylation regulators were involved in the occurrence and development of EBVaGC. Compared with EBVnGC, the expression levels of m6A methylation regulators Wilms tumor 1-associated protein, RNA binding motif protein 15B, CBL proto-oncogene like 1, leucine rich pentatricopeptide repeat containing, heterogeneous nuclear ribonucleoprotein A2B1, IGFBP1, and insulin-like growth factor 2 binding protein 1 were significantly downregulated in EBVaGC (P < 0.05). The overall survival rate of EBVaGC patients with a lower expression level of IGFBP1 was significantly higher (P = 0.046). GO and KEGG functional enrichment analyses showed that the immunity pathways were significantly activated and rich in immune cell infiltration in EBVaGC. Compared with EBVnGC, the infiltration of activated CD4+ T cells, activated CD8+ T cells, monocytes, activated dendritic cells, and plasmacytoid dendritic cells were significantly upregulated in EBVaGC (P < 0.001). In EBVaGC, the expression level of proinflammatory factors interleukin (IL)-17, IL-21, and interferon-γ and immunosuppressive factor IL-10 were significantly increased (P < 0.05). In vitro experiments demonstrated that the expression level of IGFBP1 was significantly lower in an EBVaGC cell line (SNU719) than in an EBVnGC cell line (AGS) (P < 0.05). IGFBP1 overexpression significantly attenuated proliferation and migration and promoted the apoptosis levels in SNU719. Interfering IGFBP1 significantly promoted proliferation and migration and attenuated the apoptosis levels in AGS. m6A regulators could remodel the TME of EBVaGC, which is classified as an immune-inflamed phenotype and referred to as a "hot" tumor. Among these regulators, we demonstrated that IGFBP1 affected proliferation, migration, and apoptosis.

Serum IGFBP5 as a predictor of major adverse cardiac events in patients with acute myocardial infarction

BackgroundAcute myocardial infarction (AMI) is a serious condition with high mortality rates. Early risk stratification is of significant importance to assess the prognosis. Insulin-like growth factor-binding protein 5 (IGFBP5) levels in AMI patients and its potential as a prognosis biomarker were unclear. ObjectiveTo investigate serum IGFBP5 levels in AMI and its prognostic value for short-term major adverse cardiovascular events (MACE). MethodsWe collected serum IGFBP5 levels from 200 patients with new-onset AMI and 71 coronary heart disease (CAD) patients without AMI. Linear regression was used to analyze the relationship between IGFBP5 and baseline variables. AMI patients were followed up, and the risk of major adverse cardiovascular events (MACE) was assessed using Kaplan-Meier curve, multivariate Cox models and restricted cubic spline (RCS) analysis. ResultsDuring a median follow-up of 217 days, 40 patients developed MACE. Serum IGFBP5 was associated with serum cardiac troponin T (cTnT) and C-reactive protein (CRP) (P = 0.013 and P = 0.013). In multivariable survival analyses, higher IGFBP5 was associated with an increased risk of MACE [HR = 1.183, 95%CI (1.104, 1.268), P < 0.001)]. There was a positive and linear association between IGFBP5 levels and the occurrence of MACE (P for nonlinearity = 0.283). The positive association between IGFBP5 and MACE risk consist across subgroups characterized by demographics and comorbidities. ConclusionSerum IGFBP5 was highly expressed in patients with AMI and positively associated with the short-term risk of MACE. Circulating IGFBP5 may be a diagnostic and prognostic indicator for AMI, and further studies with larger sample and longer follow-up are warranted.

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.

Urinary beta-2 microglobulin increases whereas TIMP-2 and IGFBP7 decline after unilateral nephrectomy in healthy kidney donors

Early kidney injury may be detected by urinary markers, such as beta-2 microglobulin (B2M), tissue inhibitor of metalloproteinases-2 (TIMP-2), insulin-like growth factor-binding protein 7 (IGFBP7), kidney injury molecule-1 (KIM-1) and/or neutrophil gelatinase-associated lipocalin (NGAL). Of these biomarkers information on pathophysiology and reference ranges in both healthy and diseased populations are scarce. Differences in urinary levels of B2M, TIMP-2, IGFBP7, KIM-1 and NGAL were compared 24 h before and after nephrectomy in 38 living kidney donors from the REnal Protection Against Ischaemia–Reperfusion in transplantation study. Linear regression was used to assess the relation between baseline biomarker concentration and kidney function 1 year after nephrectomy. Median levels of urinary creatinine and creatinine standardized B2M, TIMP-2, IGFBP7, KIM-1, NGAL, and albumin 24 h before nephrectomy in donors were 9.4 mmol/L, 14 μg/mmol, 16 pmol/mmol, 99 pmol/mmol, 63 ng/mmol, 1390 ng/mmol and 0.7 mg/mmol, with median differences 24 h after nephrectomy of − 0.9, + 1906, − 7.1, − 38.3, − 6.9, + 2378 and + 1.2, respectively. The change of donor eGFR after 12 months per SD increment at baseline of B2M, TIMP-2, IGFBP7, KIM-1 and NGAL was: − 1.1, − 2.3, − 0.7, − 1.6 and − 2.8, respectively. Urinary TIMP-2 and IGFBP7 excretion halved after nephrectomy, similar to urinary creatinine, suggesting these markers predominantly reflect glomerular filtration. B2M and NGAL excretion increased significantly, similar to albumin, indicating decreased proximal tubular reabsorption following nephrectomy. KIM-1 did not change considerably after nephrectomy. Even though none of these biomarkers showed a strong relation with long-term donor eGFR, these results provide valuable insight into the pathophysiology of these urinary biomarkers.

The role of biomarkers in early identification of acute kidney injury among non-critically ill patients.

Prediction and/or early identification of acute kidney injury (AKI) and individuals at greater risk remains of great interest in clinical medicine. Acute kidney injury continues to be a common complication among hospitalized patients, with an incidence ranging from 6 to 58%, depending on the setting.Aim of this study was to determine the performance of Insulin-like growth factor binding protein-7 (IGFBP7), tissue metallopeptidase inhibitor 2 (TIMP2), and urinary neutrophil gelatinase-associated lipocalin (uNGAL) in early detection of AKI among non-critically ill patients. In this prospective observational study at Mayo Clinic Hospitals in Rochester, Minnesota, USA, non-critically ill patients admitted from the emergency department between October 31st, 2016 and May 1st, 2018, who had an acute kidney injury (AKI) probability of 5% or higher were included. Biomarkers were measured in residual urine samples collected in the emergency department. The primary outcome was biomarker performance in predicting AKI development within the first 72h. Among 368 included patients, the mean age was 79 ± 12years, and 160 (43%) were male. Acute kidney injury occurred in 62 (17%) patients; 11.5% stage 1, 2.5% stage 2, and 3% stage 3. Twelve patients (3%) died during hospitalization and 102 (28%) within nine months after admission. The median uNGAL and IGFBP7-TIMP2 were 57 [20-236ng/ml], and 0.3 [0.1-0.8], respectively. The C-statistic of uNGAL and IGFBP7-TIMP2 of > 0.3 and > 2.0 for AKI prediction were 0.56, 0.54, and 0.53, respectively. In a model where one point is assigned to each marker of AKI (elevated serum creatinine, IGFBP7-TIMP2 > 0.3, and uNGAL), a higher score correlated with higher nine-month mortality [OR of 1.32 per point (95% CI 1.02-1.71)]. Among non-critically ill hospitalized patients, the performance of uNGAL and IGFBP7-TIMP2 for AKI prediction within 72h of admission was modest. This suggests a limited role for these biomarkers in AKI risk stratification among non-critically ill patients. Key learning points What was known Acute kidney injury (AKI) is a common complication among hospitalized patients. It is associated with increased morbidity and mortality. Various clinical prediction models and biomarkers have been developed to identify patients in special populations (such as ICU and cardiac surgery) who are at risk of AKI and diagnose AKI early. This study adds The performance of the biomarkers uNGAL, TIMP-2, and IGFBP-7 in predicting AKI within 72h of admission in non-critically ill patients was modest. However, these biomarkers were found to have a prognostic value for predicting 9-month mortality. One potential application of these biomarkers is identifying patients at higher AKI risk before exposing them to nephrotoxic agents. Potential impact This study provides evidence regarding the real-world performance of current FDA-approved biomarkers (uNGAL, TIMP-2, and IGFBP-7) for predicting acute kidney injury (AKI) within 72h of hospital admission among noncritically ill patients. While the performance of these biomarkers for predicting short-term AKI was modest, they may have a prognostic value for predicting 9-month mortality.

Deletion of endothelial IGFBP5 protects against ischaemic hindlimb injury by promoting angiogenesis.

Angiogenesis is critical for forming new blood vessels from antedating vascular vessels. The endothelium is essential for angiogenesis, vascular remodelling and minimisation of functional deficits following ischaemia. The insulin-like growth factor (IGF) family is crucial for angiogenesis. Insulin-like growth factor-binding protein 5 (IGFBP5), a binding protein of the IGF family, may have places in angiogenesis, but the mechanisms are not yet completely understood. We sought to probe whether IGFBP5 is involved in pathological angiogenesis and uncover the molecular mechanisms behind it. IGFBP5 expression was elevated in the vascular endothelium of gastrocnemius muscle from critical limb ischaemia patients and hindlimb ischaemic (HLI) mice and hypoxic human umbilical vein endothelial cells (HUVECs). In vivo, loss of endothelial IGFBP5 (IGFBP5EKO) facilitated the recovery of blood vessel function and limb necrosis in HLI mice. Moreover, skin damage healing and aortic ring sprouting were faster in IGFBP5EKO mice than in control mice. In vitro, the genetic inhibition of IGFBP5 in HUVECs significantly promoted tube formation, cell proliferation and migration by mediating the phosphorylation of IGF1R, Erk1/2 and Akt. Intriguingly, pharmacological treatment of HUVECs with recombinant human IGFBP5 ensued a contrasting effect on angiogenesis by inhibiting the IGF1 or IGF2 function. Genetic inhibition of IGFBP5 promoted cellular oxygen consumption and extracellular acidification rates via IGF1R-mediated glycolytic adenosine triphosphate (ATP) metabolism. Mechanistically, IGFBP5 exerted its role via E3 ubiquitin ligase Von Hippel-Lindau (VHL)-regulated HIF1α stability. Furthermore, the knockdown of the endothelial IGF1R partially abolished the reformative effect of IGFBP5EKO mice post-HLI. Our findings demonstrate that IGFBP5 ablation enhances angiogenesis by promoting ATP metabolism and stabilising HIF1α, implying IGFBP5 is a novel therapeutic target for treating abnormal angiogenesis-related conditions.

The Role of Insulin-like Growth Factor Binding Protein (IGFBP)-2 in DNA Repair and Chemoresistance in Breast Cancer Cells.

The role if insulin-like growth factor binding protein-2 (IGFBP-2) in mediating chemoresistance in breast cancer cells has been demonstrated, but the mechanism of action is unclear. This study aimed to further investigate the role of IGFBP-2 in the DNA damage response induced by etoposide in MCF-7, T47D (ER+ve), and MDA-MB-231 (ER-ve) breast cancer cell lines. In the presence or absence of etoposide, IGFBP-2 was silenced using siRNA in the ER-positive cell lines, or exogenous IGFBP-2 was added to the ER-negative MDA-MB-231 cells. Cell number and death were assessed using trypan blue dye exclusion assay, changes in abundance of proteins were monitored using Western blotting of whole cell lysates, and localization and abundance were determined using immunofluorescence and cell fractionation. Results from ER-positive cell lines demonstrated that upon exposure to etoposide, loss of IGFBP-2 enhanced cell death, and this was associated with a reduction in P-DNA-PKcs and an increase in γH2AX. Conversely, with ER-negative cells, the addition of IGFBP-2 in the presence of etoposide resulted in cell survival, an increase in P-DNA-PKcs, and a reduction in γH2AX. In summary, IGFBP-2 is a survival factor for breast cancer cells that is associated with enhancement of the DNA repair mechanism.

Targeted proteomic profiling of cardiogenic shock in the cardiac intensive care unit.

We sought to characterize circulating protein biomarkers associated with cardiogenic shock (CS) using highly multiplex proteomic profiling. This analysis employed a cross-sectional case-control study design using a biorepository of patients admitted to a cardiac intensive care unit between 2017 and 2020. Cases were patients adjudicated to have CS, and controls were those presenting for cardiac critical care without shock, including subsets of patients with isolated hypotension or heart failure (HF). The Olink platform was used to analyse 359 biomarkers with Bonferroni correction. The analysis included 239 patients presenting for cardiac critical care (69 cases with CS, 170 non-shock controls). A total of 63 biomarkers (17.7%) were significantly associated with CS after Bonferroni correction compared with all controls. Of these, nine biomarkers remained significantly associated with CS when separately cross-validated in subsets of controls presenting with isolated hypotension and HF: cathepsin D, fibroblast growth factor (FGF)-21 and -23, growth differentiation factor (GDF)-15, insulin-like growth factor-binding protein-1, N-terminal pro-B-type natriuretic peptide, osteopontin, oncostatin-M-specific receptor subunit beta (OSMR), and soluble ST2 protein (sST2). Four biomarkers were identified as providing complementary information for CS diagnosis with development of a multi-marker model: sST2, FGF-23, CTSD, and GDF-15. In this pilot study of targeted proteomic profiling in CS, we identified nine biomarkers significantly associated with CS when cross-validated against non-shock controls including those with HF or isolated hypotension, illustrating the potential application of a targeted proteomic approach to identify novel candidates that may support the diagnosis of CS.

Plasma proteome association with coronary heart disease and carotid intima media thickness: results from the KORA F4 study

Background and aimsAtherosclerosis is the main cause of stroke and coronary heart disease (CHD), both leading mortality causes worldwide. Proteomics, as a high-throughput method, could provide helpful insights into the pathological mechanisms underlying atherosclerosis. In this study, we characterized the associations of plasma protein levels with CHD and with carotid intima-media thickness (CIMT), as a surrogate measure of atherosclerosis.MethodsThe discovery phase included 1000 participants from the KORA F4 study, whose plasma protein levels were quantified using the aptamer-based SOMAscan proteomics platform. We evaluated the associations of plasma protein levels with CHD using logistic regression, and with CIMT using linear regression. For both outcomes we applied two models: an age-sex adjusted model, and a model additionally adjusted for body mass index, smoking status, physical activity, diabetes status, hypertension status, low density lipoprotein, high density lipoprotein, and triglyceride levels (fully-adjusted model). The replication phase included a matched case-control sample from the independent KORA F3 study, using ELISA-based measurements of galectin-4. Pathway analysis was performed with nominally associated proteins (p-value < 0.05) from the fully-adjusted model.ResultsIn the KORA F4 sample, after Bonferroni correction, we found CHD to be associated with five proteins using the age-sex adjusted model: galectin-4 (LGALS4), renin (REN), cathepsin H (CTSH), and coagulation factors X and Xa (F10). The fully-adjusted model yielded only the positive association of galectin-4 (OR = 1.58, 95% CI = 1.30–1.93), which was successfully replicated in the KORA F3 sample (OR = 1.40, 95% CI = 1.09–1.88). For CIMT, we found four proteins to be associated using the age-sex adjusted model namely: cytoplasmic protein NCK1 (NCK1), insulin-like growth factor-binding protein 2 (IGFBP2), growth hormone receptor (GHR), and GDNF family receptor alpha-1 (GFRA1). After assessing the fully-adjusted model, only NCK1 remained significant (β = 0.017, p-value = 1.39e-06). Upstream regulators of galectin-4 and NCK1 identified from pathway analysis were predicted to be involved in inflammation pathways.ConclusionsOur proteome-wide association study identified galectin-4 to be associated with CHD and NCK1 to be associated with CIMT. Inflammatory pathways underlying the identified associations highlight the importance of inflammation in the development and progression of CHD.

Exosomal Serum Biomarkers as Predictors for Laryngeal Carcinoma.

The lack of screening methods for LSCC is a critical issue, as treatment options and the treatment outcome greatly depend on the stage of LSCC at initial diagnosis. Therefore, the objective of this study was to identify potential exosomal serum biomarkers that can diagnose LSCC and distinguish between early- and late-stage disease. A multiplexed proteomic array was used to identify differentially expressed proteins in exosomes isolated from the serum samples of LSCC patients compared to the control group (septorhinoplasty, SRP). The most promising proteins for diagnosis and differentiation were calculated using biostatistical methods and were validated by immunohistochemistry (IHC), Western blots (WB), and ELISA. Exosomal insulin-like growth factor binding protein 7 (IGFBP7) and Annexin A1 (ANXA1) were the most promising exosomal biomarkers for distinguishing between control and LSCC patients and also between different stages of LSCC (fold change up to 15.9, p < 0.001 for all). The identified proteins represent potentially novel non-invasive biomarkers. However, these results need to be validated in larger cohorts with a long-term follow-up. Exosomal biomarkers show a superior signal-to-noise ratio compared to whole serum and may therefore be an important tool for non-invasive biomarker profiling for laryngeal carcinoma in the future.

IGFBP2 induces podocyte apoptosis promoted by mitochondrial damage via integrin α5/FAK in diabetic kidney disease.

Podocyte apoptosis or loss is the pivotal pathological characteristic of diabetic kidney disease (DKD). Insulin-like growth factor-binding protein 2 (IGFBP2) have a proinflammatory and proapoptotic effect on diseases. Previous studies have shown that serum IGFBP2 level significantly increased in DKD patients, but the precise mechanisms remain unclear. Here, we found that IGFBP2 levels obviously increased under a diabetic state and high glucose stimuli. Deficiency of IGFBP2 attenuated the urine protein, renal pathological injury and glomeruli hypertrophy of DKD mice induced by STZ, and knockdown or deletion of IGFBP2 alleviated podocytes apoptosis induced by high concentration of glucose or in DKD mouse. Furthermore, IGFBP2 facilitated apoptosis, which was characterized by increase in inflammation and oxidative stress, by binding with integrin α5 (ITGA5) of podocytes, and then activating the phosphorylation of focal adhesion kinase (FAK)-mediated mitochondrial injury, including membrane potential decreasing, ROS production increasing. Moreover, ITGA5 knockdown or FAK inhibition attenuated the podocyte apoptosis caused by high glucose or IGFBP2 overexpression. Taken together, these findings unveiled the insight mechanism that IGFBP2 increased podocyte apoptosis by mitochondrial injury via ITGA5/FAK phosphorylation pathway in DKD progression, and provided the potential therapeutic strategies for diabetic kidney disease.

Mechanism and clinical role of TIMP-2 and IGFBP-7 in cardiac surgery-associated acute kidney injury: A review.

Acute kidney injury (AKI) is a common postoperative complication, but there is still a lack of accurate biomarkers. Cardiac surgery-associated AKI is the most common cause of major-surgery-related AKI, and patients requiring renal replacement therapy have high mortality rates. Early diagnosis, intervention, and management are crucial for improving patient prognosis. However, diagnosing AKI based solely on changes in serum creatinine level and urine output is insufficient, as these changes often lag behind actual kidney damage, making early detection challenging. Biomarkers such as tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein-7 (IGFBP-7) have been found to be significant predictors of moderate-to-severe AKI when combined with urine content analysis. This article reviews the mechanism of biomarkers TIMP-2 and IGFBP-7 in AKI and provides a comprehensive overview of the clinical effects of TIMP-2 and IGFBP-7 in cardiac surgery-associated AKI, including prediction, diagnosis, and progression.

Clinical determinants of blood biomarkers of atrial cardiomyopathy: results from the ISOLATION AF ablation cohort study

Abstract Background In patients with atrial fibrillation (AF), significant advances have been made in identifying biomarkers representing diverse pathophysiological pathways, such as inflammation, myocyte injury, collagen deposition, and fatty-fibrotic infiltration. Data on clinical determinants of biomarkers in patients with AF, however, are lacking. Objective Our primary aim was to explore the relationships between clinical determinants and biomarker levels in AF patients scheduled for catheter ablation. Methods A cross-sectional analysis was conducted in AF patients undergoing catheter ablation included in the prospective multicenter ISOLATION study between July 2020 and May 2022. Clinical characteristics, routine tests and blood samples were collected before ablation. Blood samples were analyzed for known and novel cardiovascular biomarkers, including Bone morphogenetic protein 10 (BMP10), Angiopoietin-2 (Ang-2), Fibroblast growth factor 23 (FGF-23), Dickkopf-related protein 3 (DKK-3), Endocan (ESM-1), Insulin-like growth factor-binding protein 7 (IGFBP-7), B-type natriuretic peptides (proBNP, NTproBNP), High sensitive Troponin-T (hsTnT)&amp;lt; Growth differentiation factor 15 (GDF-15), interleukin 6 (IL-6), Fatty acid binding protein 3 (FABP3), Cancer antigen-125 (Ca-125) (Table 1). For each biomarker we trained a lasso regression model to identify the most important clinical determinants out of all the 60 available determinants (including anthropometry, ECG, comorbidities). The strongest associations are summarized in figure 1. Results Blood samples of 508 patients were analyzed. The mean age was 63 ±9 years, and 31.1% were female. 354 patients (69.7%) had paroxysmal AF and 154 patients (30.3%) had persistent AF. Heart failure was reported in 77 patients (15.2%). 355 (72.3%) patients were in sinus rhythm during sample collection. The following clinical determinants of biomarker levels were frequently identified as important: rhythm during blood phlebotomy, age, heart failure, decreased kidney function and female sex (Figure 1). Most notably, rhythm at the time of sampling was strongly associated with various biomarker levels. Female sex was positively associated with BMP10 and FGF23 (atrial fibrosis), but negatively associated with hsTNT (cardiac injury). Conclusion In patients with AF scheduled for catheter ablation, we identified several clinical determinants of biomarker levels with potential implications for disease mechanisms. In women, pro-fibrotic biomarkers were frequently higher, while male patients more often showed signs of myocardial injury. Importantly, rhythm during blood draw is a very strong determinant of many biomarkers and should be taken into account in future biomarker studies.Figure 1.Table 1.

#1211 IGFBP-5/TGF-β1-mediated cell crosstalk between endothelia and tubular epithelia promotes renal fibrosis

Abstract Background and Aims Renal fibrosis is a common pathophysiological characteristic of chronic kidney disease (CKD) for which there is no effective treatment. The mechanism of renal fibrosis is complicated and remains unclear. Our previous study revealed that Insulin-like growth factor binding protein 5 (IGFBP-5) induces glycolytic activation in ECs and ultimately aggravates renal inflammation in diabetic kidney disease (DKD). This study aims to discover the relationship between IGFBP-5 and renal fibrosis. Method HK-2 and HUVEC cells were included in this study. UUO and ANN model were obstructed by Wild-type, IGFBP-5−/− and IGFBP-5flox/flox, cre mice. IGFBP-5, TGF-β and fibrosis makers were detected to explore the mechanism of IGFBP-5 in fibrosis. Results We found that the serum IGFBP-5 levels were significantly increased in CKD, that IGFBP-5 was dominantly localized in vascular endothelial cells (ECs) of kidney tissue, and that IGFBP-5 deficiency relieved renal fibrosis in CKD model mice. In vitro experiments indicated that IGFBP-5 exacerbated the fibrosis phenotypic alteration of tubular epithelial cells (TECs) by the TGF-β1/p-Smad3 signaling pathway. In turn, TGF-β1 could facilitate the synthesis of IGFBP-5 in ECs. The crosstalk between TECs and ECs mediated by IGFBP-5 and TGF-β1 was confirmed in a coculture system and endothelial-specific IGFBP-5-deficient mice. Conclusion Renal fibrosis is exacerbated by TEC-EC cellular crosstalk through the feedback loop consisting of IGFBP-5 and TGF-β1. These findings suggest that IGFBP-5 may be a new pathogenic factor in renal fibrosis and a potential new therapeutic target in CKD.

Biological Variation Data in Triathletes for Metabolism and Growth-Related Biomarkers Included in the Athlete Biological Passport.

When using biological variation (BV) data, BV estimates need to be robust and representative. High-endurance athletes represent a population under special physiological conditions, which could influence BV estimates. Our study aimed to estimate BV in athletes for metabolism and growth-related biomarkers involved in the Athlete Biological Passport (ABP), by 2 different statistical models. Thirty triathletes were sampled monthly for 11 months. The samples were analyzed for human growth hormone (hGH), insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), insulin, and N-terminal propeptide of type III procollagen (P-III-NP) by immunoassay. Bayesian and ANOVA methods were applied to estimate within-subject (CVI) and between-subject BV. CVI estimates ranged from 7.8% for IGFBP-3 to 27.0% for insulin, when derived by the Bayesian method. The 2 models gave similar results, except for P-III-NP. Data were heterogeneously distributed for P-III-NP for the overall population and in females for IGF-1 and IGFBP-3. BV components were not estimated for hGH due to lack of steady state. The index of individuality was below 0.6 for all measurands, except for insulin. In an athlete population, to apply a common CVI for insulin would be appropriate, but for IGF-1 and IGFBP-3 gender-specific estimates should be applied. P-III-NP data were heterogeneously distributed and using a mean CVI may not be representative for the population. The high degree of individuality for IGF-1, IGFBP-3, and P-III-NP makes them good candidates to be interpreted through reference change values and the ABP.

#2508 Urinary [TIMP-2]*[IGFBP7] as the ultimate potential biomarker of subclinical Acute Kidney Injury after kidney surgery: a multicentric study

Abstract Background and Aims Nephron-sparing surgery (NSS) represents the preferred technique to treat localized renal lesions and better preserve kidney function. Still it is not exempted from the risk of postoperative acute kidney injury (AKI) to happen, with a reported incidence ranging from 5.5% to 34%. Patients experiencing postoperative AKI, either clinical or subclinical, are more susceptible to chronic kidney disease (CKD). The latter represents a difficult-to-identify subpopulation characterized by tubular damage biomarker's rising without changes in serum creatinine (scr), that after surgery is less likely to be included among the ones deserving a closer follow-up, but actually needing one, as this subpopulation's long term outcomes slightly differ from individuals recovered from clinical postoperative AKI. This is the reason why a standardized tool for early identification of patients suffering from subclinical AKI is required, to allow a customized postoperative surveillance, promote strategies of nephroprotection and reduce the incidence of CKD and end-stage kidney disease. Recent evidences show that by exclusively following outdated consensus criteria for AKI (changes in scr, urine output), 15-20% of patients undergoing through acute tubular injury and suffering from its adverse outcomes are likely to be missed. Only recently, FDA approved NephroCheck® biomarker, which combines two urinary markers, tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7). It represents the first effective test for AKI's risk assessment. In a previous monocentric study [1], our group presented NephroCheck® as a biomarker able to efficiently identify subclinical AKI and predict long-term eGFR decline after robotic NSS. In order to confirm our previous results, we recruited a larger cohort and performed a multicentric study. Method We prospectively observed all patients scheduled for robotic NSS in suspected localized renal cell carcinoma in two different Centers from 2016 to 2018. Samples were collected preoperatively and postoperatively (4 h, 10 h, 24 h, 48 h), while kidney function was re-assessed up to 24 months. A multivariate logistic analysis was performed to evaluate the association between different parameters and eGFR decline at 24 months. Results A total number of 131 patients were included; 55/131 (42%) developed clinical AKI. A significant association between NephroCheck® at 4 h and clinical AKI, as stated by KDIGO Guidelines, is confirmed (p = 0.0055). In the overall cohort, the multivariate analysis shows that only clinical AKI appears as an independent factor for predicting eGFR decline at 24 months (p &amp;lt; 0.0003), while postoperative NephroCheck® alone did not (p = 0.92). Based on NephroCheck® measured 4 h after surgery and clinical AKI, patients can be divided in four groups with significantly different eGFR at 24 months (p = 0.0003) (Fig. 1). Not considering patients who experienced clinical AKI, the independent role of different parameters in predicting severe eGFR decline at 24 months was evaluated by multivariate logistic analysis; in this subgroup of patients, NephroCheck® evaluated at 4 h postoperatively appears as an independent factor able to predict a severe eGFR decline at 24 months (OR 3.76, p = 0.02) (Fig. 2). Conclusion NephroCheck®, in combination with scr, represents an accurate and easy-to-use test, likely able to early identify long-term eGFR decline in patients undergoing NSS surgery that don't develop a clinically evident postoperative AKI (subclinical AKI), making it possible to identify those in need of closer-up surveillance, reducing the incidence and progression of CKD. Still, clinical postoperative AKI is confirmed as the most important prognostic parameter and predictive factor for eGFR decline in the long-term. Further studies are needed, particularly focusing on application of NephroCheck® in setting other than NSS.