Gremlin-1 Levels Research Articles

Unveiling the significance of Gremlin-1 as a novel biomarker for enhanced severity prediction in COVID-19 patients.

Gremlin-1 is associated with lung disease and plays a role in the initiation and progression of pulmonary fibrosis. This suggests that Gremlin-1 may be associated with lung involvement in COVID-19 and poor clinical outcomes and warrants further investigation. This prospective, cross-sectional, single-blind study was the first to investigate Gremlin-1 levels in COVID-19 patients and whether Gremlin-1 levels could be used to predict and guide clinical follow-up in outpatients and inpatients. In this context, serum Gremlin-1 levels were measured and compared in 2 groups of patients who were diagnosed as positive for COVID-19 by RT-PCR and were followed up as outpatients (n = 28) or required hospitalization (n = 30). The median Gremlin-1 values were statistically significantly different between outpatients and intensive care unit patients (0.367 ng/mL [IQR = 0.377], 1.858 ng/mL [IQR = 2.245], respectively) (P < .0001). The area under the ROC curve value to determine the discriminative power of Gremlin-1 was found to be 0.772 (95% CI: 0.672-0.871; P < .0001), and the cutoff value of Gremlin-1 to discriminate between outpatients and hospitalized patients was found to be 1.242 ng/mL with 66.7% sensitivity and 67.2% specificity. Serum Gremlin-1 level is an important biomarker that can be used as a clinical decision-making tool for COVID-19 positive patients.

Retinal microvascular changes with OCT angiography and serum gremlin-1 levels in acromegaly: a case-control study

Retinal microvascular changes with OCT angiography and serum gremlin-1 levels in acromegaly: a case-control study

Gremlin-1 in pregnancy and postpartum: relation to the fatty liver index, markers of bone health, glucose metabolism and gestational diabetes mellitus status

IntroductionGremlin-1 is a peptide that functions as an antagonist to bone morphogenic proteins and is overexpressed in obesity and type 2 diabetes mellitus. Gremlin-1 has not yet been investigated in pregnancy, pregnancy-related insulin resistance or gestational diabetes mellitus (GDM).Patients and methodsGremlin-1 levels were measured throughout the pregnancy of 58 women at high risk for GDM at the Medical University of Vienna. Furthermore, an oral glucose tolerance test, fasting insulin, fasting glucose, sex hormones, blood lipids, liver and renal parameters, and markers of bone development were evaluated at two points during pregnancy (< 20 weeks of gestation (GW), GW 24–28) and 12–14 weeks postpartum.ResultsGremlin-1 levels decreased from < 20 GW (mean = 9.2 pg/ml, SD = 8.4 pg/ml) to GW 24–28 (mean = 6.7 pg/ml, SD = 5.7 pg/ml, p = 0.033) and increased again postpartum, albeit not significantly (mean = 10.7 pg/ml, SD = 13.1 pg/ml, p = 0.339). During pregnancy, Gremlin-1 levels correlated negatively with osteocalcin and procollagen type I aminoterminal propeptide (P1NP), markers of bone health. Concerning glucose metabolism, Gremlin-1 levels were inversely related to the Insulinogenic Index at GW < 20. However, Gremlin-1 levels were not significantly different between women with normal glucose tolerance and GDM during pregnancy. Postpartum, Gremlin-1 was associated with the fatty liver index, osteocalcin levels, diastolic blood pressure and weight.ConclusionGremlin-1 levels decreased significantly during pregnancy. The biomarker is not related to GDM status, but correlates negatively with the Insulinogenic Index, an index related to beta cell function.Trial Registry Number ACTRN12616000924459.

Metabolic memory in diabetic foot syndrome (DFS): MICRO-RNAS, single nucleotide polymorphisms (SNPs) frequency and their relationship with indices of endothelial function and adipo-inflammatory dysfunction

BackgroundDiabetic foot is a significant cause of morbidity in diabetic patients, with a rate that is approximately twice that of patients without foot ulcers. “Metabolic memory” represents the epigenetic changes induced by chronic hyperglycaemia, despite the correction of the glucose levels themselves. These epigenetic modifications appear to perpetuate the damage caused by persistently elevated glucose levels even in their absence, acting at various levels, mostly affecting the molecular processes of diabetic ulcer healing.MethodsThe aim of our cross-sectional study was to analyse a cohort of patients with diabetes with and without lower limb ulcers.We examined the effects of epigenetic changes on miRNA 126, 305, and 217 expression and the frequency of the SNPs of genes encoding inflammatory molecules (e.g., IL-6 and TNF-alpha) and their correlations with serum levels of proangiogenic molecules (e.g., ENOS, VEGF and HIF-1alpha) and several adipokines as well as with endothelial dysfunction, assessed noninvasively by reactive hyperaemia peripheral artery tonometry.Between March 2021 and June 2022, 110 patients were enrolled into the study: 50 diabetic patients with diabetic foot injuries, 40 diabetic patients without ulcerative complications and 20 nondiabetic patients as the control group.ResultsDiabetic subjects with lower limb ulcerative lesions exhibited higher levels of inflammatory cytokines, such as VEGF (191.40 ± 200 pg/mL vs. 98.27 ± 56.92 pg/mL vs. 71.01 ± 52.96 pg/mL; p = 0.22), HIF-1alpha (40.18 ± 10.80 ng/mL vs. 33.50 ± 6.16 ng/mL vs. 33.85 ± 6.84 ng/mL; p = 0.10), and Gremlin-1 (1.72 ± 0.512 ng/mL vs. 1.31 ± 0.21 ng/mL vs. 1.11 ± 0.19 ng/mL; p < 0.0005), than those without lower limb ulcers and healthy controls. Furthermore, we observed that miR-217-5p and miR-503-5p were 2.19-fold (p < 0.05) and 6.21-fold (p = 0.001) more highly expressed in diabetic foot patients than in healthy controls, respectively. Additionally, diabetic patients without lower limb ulcerative complications showed 2.41-fold (p = 0) and 2.24-fold (p = 0.029) higher expression of miR-217-5p and miR-503-5p, respectively, than healthy controls. Finally, diabetic patients with and without ulcerative complications of the lower limbs showed higher expression of the VEGFC2578A CC polymorphism (p = 0.001) and lower expression of the VEGFC2578A AC polymorphism (p < 0.005) than the healthy control population. We observed a significant increase in Gremlin-1 levels in patients with diabetic foot, suggesting that this inflammatory adipokine may serve as a predictive marker for the diagnosis of diabetic foot.ConclusionsOur results highlighted that patients with diabetic foot showed predominant expression of the VEGF C2578A CC polymorphism and reduced expression of the AC allele. Additionally, we found an overexpression of miR-217-5p and miR-503-5p in diabetic patients with and without diabetic foot syndrome compared with healthy controls.These results align with those reported in the literature, in which the overexpression of miR-217-5p and miR-503-5p in the context of diabetic foot is reported. The identification of these epigenetic modifications could therefore be helpful in the early diagnosis of diabetic foot and the treatment of risk factors. However, further studies are necessary to confirm this hypothesis.

Gremlin-1 Level In Polycystic Ovary Syndrome And Its Clinical Correlations; A Case Control Study.

To evaluate the involvement of the level of Gremlin-1 in serum and follicular fluid in the diagnosis of polycystic ovary syndrome. The case-controlstudy was conducted at the Kafrelsheikh University Hospital, Egypt, from September 2021 to February 2022, and comprised women with polycystic ovary syndrome and healthy controls. All participants were subjected to a detailed clinical assessment, complete clinical examination and hormonal profile assessment. Gremlin1 concentrationsin plasma and follicular fluid samples were assessed by a double-antibody sandwich enzyme-linked immunosorbent assay kit. Data was analysed using SPSS 20. Of the 90 subjects, 45(50%) were patients with a mean age of 29.53±4.82 years, and 45(50%) were controls with a mean age of 30.89±6.08 (p>0.05). Mean weight, body massindex, waist circumference and waist-hip ratio were significantly higher in patients compared to controls (p<0.05). Serum and follicular fluid Gremlin-1 levels were significantly higher in the patient group (p<0.05). The best cutoff of serum Gremlin-1 in the diagnosis of polycystic ovary syndrome was ≥1.325ng/ml with area under curve 0.857,sensitivity 93.3%,specificity 68.9%, positive predictive value 75%, negative predictive value 91.2% and overall accuracy 81.1%. The best cutoff of follicular fluid Gremlin-1 in the diagnosis of polycystic ovary syndrome was ≥1.725ng/ml with area under curve 0.789,sensitivity 73.3%,specificity 68.9%, positive predictive value 70.2%, negative predictive value 72.1% and overall accuracy 71.1%. There was a strong correlation between serum and follicular Gremlin-1 levelsin polycystic ovary syndrome patients.

Saikosaponin D Inhibits Peritoneal Fibrosis in Rats With Renal Failure by Regulation of TGFβ1/ BMP7 / Gremlin1/ Smad Pathway.

Peritoneal dialysis (PD) can improve the quality of life of patients with kidney disease and prolong survival. However, peritoneal fibrosis can often occur and lead to PD withdrawal. Therefore, it is imperative to better understand how to inhibit and slow down progression of peritoneal fibrosis. This study aimed to investigate the regulatory effect of Saikosaponin d (SSD), a monomer extracted from the plant Bupleurum, on peritoneal fibrosis and the contribution of TGFβ1/BMP7/Gremlin1 pathway cross-talk in this process. To this aim, we used a model 5/6 nephrectomy and peritoneal fibrosis in rats. Rats were divided into four groups, namely a control group (saline administration); a model group (dialysate administration; group M); a SSD group (dialysate and SSD administration); and a positive drug group (dialysate and Benazepril Hydrochloride administration; group M + A). Histological analysis indicated that peritoneal fibrosis occurred in all groups. WB, ELISA, and PCR essays suggested that TGFβ1 and Gremlin1 levels in group M were significantly higher than those in group C, whereas BMP7 expression was significantly lower. TGFβ1, Gremlin1 and BMP7 levels were significantly lower in the group where SSD was administered than in the other groups. The expression of BMP7 in SSD group was significantly increased. In addition, levels of Smad1/5/8 as assessed by PCR, and levels of p-Smad1/5/8 expression as assessed by WB were also significantly higher in the SSD group than in the M group. Expression of vimentin and α-SMA, two important markers of fibrosis, was also significantly decreased. Our study suggests a role for the TGFβ1/BMP7/Gremlin1/Smad pathway in peritoneal fibrosis with potential therapeutic implications. Finally, our results also suggest that the monomer SSD may be able to reverse peritoneal fibrosis via regulation of the TGFβ1/BMP7/Gremlin1/Smad pathway.

Circulating Gremlin-1 is elevated in systemic sclerosis patients.

Introduction:Systemic sclerosis is an autoimmune connective tissue disease in which there is activation of the immune system, vascular disease and fibrosis. Activation of quiescent fibroblasts to myofibroblasts is key to disease pathogenesis. Gremlin-1 is a bone morphogenetic protein antagonist which is important in development and we recently reported in skin fibrosis. The aim of this study was to determine the serum circulating levels of Gremlin-1 in early diffuse systemic sclerosis.Methods:Twenty-one early diffuse systemic sclerosis patients (less than 2 years from first non-Raynaud’s symptom) were included and age and sex-matched healthy controls. Serum was isolated from blood and measured with a specific enzyme-linked immunoassay for Gremlin-1. Clinical variables were also measured.Results:Significantly elevated Gremlin-1 was found in sera of early diffuse systemic sclerosis patients (p < 0.001). In patients with interstitial lung disease, this compared to systemic sclerosis without evidence of interstitial lung disease, Gremlin-1 was significantly elevated (p < 0.0007). A correlation was found between circulating Gremlin-1 and modified Rodnan Skin Score, albeit weak.Discussion:In early diffuse systemic sclerosis patients, elevated Gremlin-1 is found in serum. This is particularly prominent in systemic sclerosis–associated interstitial lung disease. This suggests that Gremlin-1 may be a biomarker for systemic sclerosis interstitial lung disease.

Gremlin-1 and gremlin-2 levels in polycystic ovary syndrome and their clinical correlations

Objective: Gremlin 1 and 2 regulate oocyte primordial follicle transition in animal models. The main objective of this study is to measure the blood levels of Gremlin 1 and 2 in the women with Polycystic Ovary Syndrome (PCOS). We also aimed to evaluate the association of these markers with hormonal and biochemical parameters of PCOS as interrupted folliculogenesis in those women is related to metabolic dysfunction.Material and methods: Fifty women with PCOS were diagnosed according to Rotterdam criteria, and thirty age-matched female controls were included in this prospective study. Gremlin 1 and 2 levels along with hormonal and metabolic parameters were compared between PCOS and control groups.Results: Serum Gremlin 1 levels were significantly higher in the PCOS group than in the control group (p = .001). Gremlin 2 levels were similar between the groups. Besides, there was a significant positive correlation between Gremlin 1 and insulin levels, Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) and waist to hip ratio (WHR) (r = 0.305; r = 0.297; r = 0.303, respectively).Conclusion: Our data suggest that Gremlin 1 may be the key regulator in the pathogenesis of PCOS. In future, Gremlin 1 may be a novel therapeutic target for the treatment of PCOS.

Relation between serum levels of chemotaxis-related factors and the presence of coronary artery calcification as expression of subclinical atherosclerosis

BackgroundAtherosclerotic plaque formation is characterized by recruitment of monocytes/macrophages, which contributes to its calcification by releasing pro-osteogenic cytokines. Chemotaxis-related proteins, including netrin-1, gremlin-1 and macrophage inflammatory protein-1β (MIP-1β), regulate immune cell migration. However, their relation with the presence of subclinical atherosclerosis, assessed by measures of coronary artery calcifications (CAC) in patients without known coronary artery disease (CAD), remains unclear. AimsTo examine whether these chemoattractant-related proteins are associated with the presence of CAC in patients without known CAD. MethodsA retrospective case-control observational study was conducted in 120 outpatients without CAD, undergoing a CAC evaluation by computed tomography with the Agatston Calcium score, categorized as CAC− (none) and CAC+ (≥1). Serum biomarkers were quantified by ELISA. ResultsLpa, dyslipidaemia and smoking were significantly higher (p=0.006, p≤0.0001 and p=0.001, respectively) in CAC+ patients. Serum netrin-1 levels were lower in CAC+ than in CAC− patients (196.8±127.8pg/ml versus 748.3±103.2pg/ml, p≤0.0001), and a similar pattern was found for gremlin-1 (1.14±0.39ng/ml versus 4.33±1.20ng/ml, p≤0.0001). However, TNFα and MIP-1β were strongly upregulated in CAC+ patients (447.56±74pg/ml versus 1104±144pg/ml and 402.00±94pg/ml versus 905.0±101.6pg/ml, respectively, p≤0.001). Multivariate analyses revealed that low netrin-1 and gremlin-1 levels and high TNFα and MIP-1β amounts were associated with CAC presence, after adjustment for clinical and biochemical variables. ConclusionsWe found a netrin-1 and gremlin-1 deficiency and a TNFα and MIP-1β overproduction in CAC+ patients' serum. These proteins may be used to identify individuals with subclinical atherosclerosis. Further research is warranted in a larger cohort of patients to establish these chemotactic-related proteins as biomarkers that improve CAD risk stratification.

Platelets as a novel source of Gremlin-1: Implications for thromboinflammation.

Platelets mediating haemostasis-thrombosis are central players in coronary artery disease (CAD). We characterised platelets as a novel source of Gremlin-1. Platelets express Gremlin-1 like inflammatory and endothelial cells. Gremlin-1 co-localised with P-selectin containing randomly distributed α-granules under resting state, which were peripheralised following platelet activation or adhesion over fibrinogen-coated surface. Gremlin-1 release upon activation with ADP, CRP, and TRAP was detected as enhanced surface expression; also in activated platelet supernatant as detected by Western Blot following CRP activation and by ELISA upon activation with ADP, CRP, PAR-1, and PAR4 agonist. Recombinant (rh)Gremlin-1 synergistically enhanced CRP-triggered intracellular calcium mobilisation, ADP-TRAP induced platelet activation, aggregation, and thrombin-activation triggered apoptosis; also thrombus formation ex vivo. Intracellular localisation of macrophage migration inhibitory factor (MIF) and Gremlin-1 a high-affinity binding partner and functional antagonist of MIF were found in intracoronary thrombus sections from acute coronary syndrome (ACS) patients and showed moderate overlap in α-granules of platelets. Intra-platelet Gremlin-1 levels were significantly decreased in ACS patients as compared to stable CAD (n=235). rhGremlin-1 also counteracted the anti-apoptotic and anti-thrombotic effects of rhMIF on platelets. Platelet-derived-Gremlin-1 prompted monocyte migration, facilitated adhesion under static and dynamic arterial flow conditions to collagen-adherent activated platelets; supported monocyte survival against BH-3-mimetic-induced apoptosis and macrophage differentiation in monocyte-platelet co-culture system, which were counteracted upon Gremlin-1 neutralisation. Thus platelet derived Gremlin-1 might contribute to the elevated circulating levels of Gremlin-1 in ACS and serve as a thrombo-inflammatory mediator in cardiovascular pathophysiologies.

Bone Morphogenic Protein Type 2 Receptor Mutation-Independent Mechanisms of Disrupted Bone Morphogenetic Protein Signaling in Idiopathic Pulmonary Arterial Hypertension.

Altered bone morphogenic protein (BMP) signaling, independent of BMPR2 mutations, can result in idiopathic pulmonary arterial hypertension (IPAH). Glucose dysregulation can regulate multiple processes in IPAH. However, the role of glucose in BMP antagonist expression in IPAH has not been characterized. We hypothesized that glucose uptake regulates BMP signaling through stimulation of BMP antagonist expression in IPAH. Using human plasma, lung tissue, and primary pulmonary arterial smooth muscle cells (PASMCs), we examined the protein expression of BMP2, BMP-regulated Smads, and Smurf-1 in patients with IPAH and control subjects. Gremlin-1 levels were elevated in patients with IPAH compared with control subjects, whereas expression of BMP2 was not different. We demonstrate increased Smad polyubiquitination in IPAH lung tissue and PASMCs that was further enhanced with proteasomal inhibition. Examination of the Smad ubiquitin-ligase, Smurf-1, showed increased protein expression in IPAH lung tissue and localization in the smooth muscle of the pulmonary artery. Glucose dose dependently increased Smurf-1 protein expression in control PASMCs, whereas Smurf-1 in IPAH PASMCs was increased and sustained. Conversely, phospho-Smad1/5/8 levels were reduced in IPAH compared with control PASMCs at physiological glucose concentrations. Interestingly, high glucose concentrations decreased phosphorylation of Smad1/5/8 in control PASMCs. Blocking glucose uptake had opposing effects in IPAH PASMCs, and inhibition of Smurf-1 activity resulted in partial rescue of Smad1/5/8 activation and cell migration rates. Collectively, these data suggest that BMP signaling can be regulated through BMPR2 mutation-independent mechanisms. Gremlin-1 (synonym: induced-in-high-glucose-2 protein) and Smurf-1 may function to inhibit BMP signaling as a consequence of the glucose dysregulation described in IPAH.

Gremlin-1 Overexpression in Mouse Lung Reduces Silica-Induced Lymphocyte Recruitment - A Link to Idiopathic Pulmonary Fibrosis through Negative Correlation with CXCL10 Chemokine.

Idiopathic pulmonary fibrosis (IPF) is characterized by activation and injury of epithelial cells, the accumulation of connective tissue and changes in the inflammatory microenvironment. The bone morphogenetic protein (BMP) inhibitor protein gremlin-1 is associated with the progression of fibrosis both in human and mouse lung. We generated a transgenic mouse model expressing gremlin-1 in type II lung epithelial cells using the surfactant protein C (SPC) promoter and the Cre-LoxP system. Gremlin-1 protein expression was detected specifically in the lung after birth and did not result in any signs of respiratory insufficiency. Exposure to silicon dioxide resulted in reduced amounts of lymphocyte aggregates in transgenic lungs while no alteration in the fibrotic response was observed. Microarray gene expression profiling and analyses of bronchoalveolar lavage fluid cytokines indicated a reduced lymphocytic response and a downregulation of interferon-induced gene program. Consistent with reduced Th1 response, there was a downregulation of the mRNA and protein expression of the anti-fibrotic chemokine CXCL10, which has been linked to IPF. In human IPF patient samples we also established a strong negative correlation in the mRNA expression levels of gremlin-1 and CXCL10. Our results suggest that in addition to regulation of epithelial-mesenchymal crosstalk during tissue injury, gremlin-1 modulates inflammatory cell recruitment and anti-fibrotic chemokine production in the lung.

High Plasma Levels of Gremlin-1 and Macrophage Migration Inhibitory Factor, but Not Their Ratio, Indicate an Increased Risk for Acute Coronary Syndrome in Patients With Type 2 Diabetes Mellitus.

Chronic inflammation promotes atherosclerosis and is a prognostic factor in coronary artery disease (CAD). Patients with type 2 diabetes mellitus (DM2) are at risk for progressive atherosclerosis. Macrophage migration inhibitory factor (MIF) is a key player in atherosclerosis, mediating pro-inflammatory responses. Its endogenous antagonist Gremlin-1 inhibits foam-cell formation and atheroprogression by binding MIF, neutralizing its proatherosclerotic functions. Plasma levels of MIF and Gremlin-1 correlate with the stability of CAD in patients with DM2. We assessed plasma levels of Gremlin-1 and MIF in 198 nondiabetic and 88 diabetic patients with symptomatic CAD using enzyme-linked immunosorbent assays. Plasma levels of Gremlin-1 were higher DM2 patients (278.8 ± 16.6 vs 224.7 ± 6.7 ng/mL; P = 0.001). MIF levels were elevated but not significantly increased in DM2 (P = 0.098). Interestingly, we found that Gremlin-1 plasma levels were significantly higher in diabetic patients with stable angina pectoris (SAP; n = 53) or acute coronary syndrome (ACS; n = 35) compared with nondiabetic patients with SAP (P = 0.008 and P = 0.011, respectively). MIF levels were significantly higher in diabetic patients with ACS compared with SAP (P < 0.001). Although the single plasma parameters showed an association with DM2 and CAD status, we could not confirm that the Gremlin-1/MIF ratio is significantly different in patients stratified by DM2 and CAD (P = 0.072). Hence, Gremlin-1/MIF ratio was significantly lower in patients with ACS compared with SAP (1.1 ± 0.1 vs 4.4 ± 1.1; P = 0.003). Diabetic patients with ACS show increased levels of Gremlin-1 and MIF, leading to unfavorable Gremlin-1/MIF ratios. However, DM2 alone is not associated with low Gremlin-1/MIF ratios.

Intrinsic BMP Antagonist Gremlin-1 as a Novel Circulating Marker in Pulmonary Arterial Hypertension.

Gremlin-1, an intrinsic antagonist of bone morphogenetic protein (BMP) signaling, has been implicated in the pathophysiology of pulmonary arterial hypertension (PAH). However, it is unknown whether gremlin-1 can be detected in the circulation of PAH patients and whether it is associated with patients' functional status and outcome. With a mean level of 242 ± 24 ng/ml, gremlin-1 levels of 31 PAH patients were significantly elevated compared to 151 ± 18 ng/ml in 15 age- and gender-matched healthy subject (p = 0.016). In PAH patients, increasing gremlin-1 levels correlated with N-terminal prohormone of brain natriuretic peptide levels (r = 0.608, p < 0.001) and inversely with the 6-minute walking distance (r = -0.412, p = 0.029). Furthermore, gremlin-1 significantly stratified survival in PAH patients (p = 0.015). Gremlin-1 may represent a new biomarker for PAH which can be linked directly to the underlying pathomechanism. Elevated levels of gremlin-1 are associated with patients' functional status and survival, thus gremlin-1 neutralization could represent a potential therapeutic strategy to increase BMPR2 signaling.

Abstract 18743: Diagnostic and Prognostic Value of Gremlin-1 In Patients With Acute Congestive Heart Failure

PURPOSE: Gremlin-1 is an inhibitor of bone morphogenetic proteins regulating cardiomyocyte formation. Gremlin-1 is involved in fibrotic and inflammatory processes and correlates with the degree of cardiac fibrosis. Congestive heart failure is characterized by an adverse structural remodelling of the myocardium. This study evaluates serum levels of Gremlin-1 in patients being suspected of acute congestive heart failure (aCHF) in the emergency department. PATIENTS AND METHODS: 401 patients presenting with symptoms of acute dyspnea and/or peripheral edema in the emergency department were evaluated. Patients were followed up to five years after presentation in the emergency department. Blood samples for measurement of Gremlin-1 (Human Grem1 ELISA®, USCN Life Science Inc.), Osteopontin (OPN) (R&amp;D Systems, Inc.) and NT-proBNP (Dimension System, Siemens AG) were collected at the initial clinical presentation. RESULTS: Median Gremlin-1 levels were significantly higher in patients with aCHF (291 ng/ml, n=122) as compared to patients without aCHF (205 ng/ml, n=279) (p=0.0001). Median Gremlin-1 correlated significantly with OPN (r=0.16, p=0.002) and NT-proBNP (r=0.24, p=0.001). Median Gremlin-1 levels were higher in patients with a left ventricular (LV) dysfunction (258 ng/ml, n=91) compared to patients with a normal LV function (221 ng/ml, n=135) (p=0.05). Median Gremlin-1 levels were higher in ACC/AHA class C/D patients (246 ng/ml, n=215) compared to class A/B patients (208 ng/ml, n=133) (p=0.02). Median Gremlin-1 levels were significantly higher in patients being rehospitalized because of aCHF (1 year: 477 ng/ml (n=34) vs. 215 ng/ml (n=367), p=0.0001; 5 years: 301 ng/ml (n=73) vs. 212 ng/ml (n=328); p=0.001) and in patients who died during follow-up (1 year: 255 ng/ml (n=57) vs. 218 ng/ml (n=344), p=0.04; 5 years: 229 ng/ml (n=129) vs. 210 ng/ml (n=272); p=0.08). CONCLUSIONS: Gremlin-1 serum levels were increased in patients suffering from aCHF. Gremlin-1 correlated with OPN, NT-proBNP, functional NYHA and structural AHA/ACC classification. Increased Gremlin-1 levels were associated with long-term aCHF related rehospitalization and all-cause mortality after 5 years.

Gremlin-1 associates with fibrillin microfibrils in vivo and regulates mesothelioma cell survival through transcription factor slug

Malignant mesothelioma is a form of cancer that is highly resistant to conventional cancer therapy for which no major therapeutic advances have been introduced. Here, we identify gremlin-1, a known bone morphogenetic protein inhibitor crucial for embryonic development, as a potential therapeutic target for mesothelioma. We found high expression levels of gremlin-1 in the mesothelioma tumor tissue, as well as in primary mesothelioma cells cultured from pleural effusion samples. Downregulation of gremlin-1 expression by siRNA-mediated silencing in a mesothelioma cell line inhibited cell proliferation. This was associated with downregulation of the transcription factor slug as well as mesenchymal proteins linked to cancer epithelial-to-mesenchymal transition. Further, resistance to paclitaxel-induced cell death was associated with high gremlin-1 and slug expression. Treatment of gremlin-1-silenced mesothelioma cells with paclitaxel or pemetrexed resulted in efficient loss of cell survival. Finally, our data suggest that concomitant upregulation of fibrillin-2 in mesothelioma provides a mechanism for extracellular localization of gremlin-1 to the tumor microenvironment. This was supported by the demonstration of interactions between gremlin-1, and fibrillin-1 and -2 peptides as well as by colocalization of gremlin-1 to fibrillin microfibrils in cells and tumor tissue samples. Our data suggest that gremlin-1 is also a potential target for overcoming drug resistance in mesothelioma.

Circulating Plasma Levels of Bone Morphogenic Protein Antagonist Gremlin-1 Are Increased in Patients with Pulmonary Arterial Hypertension

AbstractAbstract 5189 Background:Pulmonary arterial hypertension (PAH) is a severe and life-threatening disease. It is characterized by excessive growth of pulmonary artery endothelial and smooth muscle cells leading to a profound pulmonary artery remodeling and consequently increased pulmonary artery pressure and vascular resistance. Most patients with the heritable form of PAH harbor a mutation in the bone morphogenic protein (BMP) receptor 2 (BMPR2) resulting in dysregulated BMP signaling. In addition, aberrant BMP signaling was also observed in the idiopathic form of PAH although the underlying molecular mechanisms have not been elucidated. Recently, it was shown that BMP antagonist Gremlin-1 was elevated in pulmonary vessels of mice during development of hypoxic pulmonary hypertension (Cahill et al, Circulation. 2012;125(7):920–30). Methods and Results:The aim of this prospective study was to investigate the plasma levels of Gremlin-1 in PAH patients (Dana point classification group I) and to correlate Gremlin-1 levels to clinical and hemodynamic parameters. Thirty subjects were included in the study (19 patients with PAH treated at the PH clinics of the University Medical Center Hamburg-Eppendorf, Germany and 11 healthy volunteers) after giving informed consent.The mean Gremlin-1 plasma level was 2. 6-fold increased with 333 ± 160 ng/ml, in patients with pulmonary arterial hypertension compared to those of healthy control subjects with a mean Gremlin-1 plasma level of 118 ± 115 ng/ml (p=0. 001 in t-test).Gremlin-1 plasma levels of PAH patients were correlated to demographic, clinical and hemodynamic parameters including age, sex, 6-minute walk distance, systemic and pulmonary blood pressure & vascular resistance, lung function testing, NT-proBNP (N terminal pro-brain natriuretic peptide) and NYHA/WHO functional classification.A positive correlation between Gremlin-1 plasma levels and NT-proBNP plasma levels was observed (Spearman Rho 0. 809 with p<0. 001). Furthermore, a negative correlation was observed between the Gremlin-1 levels and the 6-minute walk distance (Spearman Rho −0. 522 with p=0. 032). Conclusion:The plasma levels of BMP antagonist Gremlin-1 are significantly elevated in patients with pulmonary arterial hypertension and may serve as new serological marker. Gremlin-1 might mirror the state of BMP dysregulation and represent a potential follow up marker under a future targeted therapy. Furthermore, since Gremlin-1 was shown to induce proliferative effects on both endothelial as well as smooth muscle cells, it might also contribute directly to the aberrant vessel growth observed in PAH. [Display omitted] Gremlin-1 plasma levels of patients with pulmonary hypertension (n=19) were analyzed in an enzyme-linked immunosorbent assay. Compared to healthy subjects (n=11), mean plasma levels of Gremlin-1 were 2. 6-fold increased in PH patients (t-test p=0. 001). Box plots show the median (center horizontal line), the 25th to the 75th percentile (box) and the range (whiskers).** indicates p<0. 01. Disclosures:Hennigs:Bayer: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Actelion: Research Funding; GlaxoSmithKline: Honoraria; Novartis: Honoraria. Fiedler:Pfizer Inc. : Consultancy, Research Funding; Novartis: Consultancy, Research Funding.

Elevated levels of gremlin-1 in eutopic endometrium and peripheral serum in patients with endometriosis

To examine the expression of gremlin-1 (GREM1) on the levels of messenger RNA (mRNA) and protein in eutopic endometrium and its serum level in patients with endometriosis. Prospective, experimental study using reverse-transcription polymerase chain reaction, Western blot, immunofluorescence, and ELISA. Gynecological oncology laboratory in a department of obstetrics and gynecology in a medical college in China. Thirty-five patients with endometriosis and 23 healthy control women. During surgery, the eutopic endometria and peripheral serum were obtained from the patients with endometriosis and the control women. The cellular compartment location of GREM1 expression was examined by using immunofluorescent double staining. The expression levels of mRNA and protein for GREM1 were determined by reverse-transcription polymerase chain reaction and Western blot, respectively. The serum level of GREM1 was measured by indirect ELISA. The expression of GREM1 was defined within endometrial blood vessel endothelium exclusively, with the concomitant expressions of GREM1 and CD146. The expression of GREM1 on the levels of mRNA and protein was significantly higher in eutopic endometria of patients with endometriosis than in those from healthy control women. According to the ELISA established in our laboratory, the concentration of GREM1 in peripheral serum that was collected during the follicular menstrual phase of patients with endometriosis was significantly higher than that in serum from healthy control women. Gremlin-1 plays a role to some extent in the aberrant angiogenesis of eutopic endometrium in patients with endometriosis. It is possible that the peripheral serum level of GREM1 is a prospective serum biomarker of endometriosis.

Association between human oocyte developmental competence and expression levels of some cumulus genes

At present, oocyte selection is mainly based upon morphological criteria but it is generally acknowledged that its reliability requires further improvement. The aim of this study was to determine whether transcript levels in cumulus cells can provide a useful marker of oocyte developmental competence in vitro. A retrospective study was performed on cumulus cells isolated from 90 oocytes retrieved from 45 patients. Upon fertilization, 35 oocytes originated good-quality embryos and 36 developed into poor-quality embryos, whereas 19 failed to be fertilized. Semi-quantitative measurement of hyaluronic acid synthase 2 (HAS2), gremlin1 (GREM1), and pentraxin 3 (PTX3) mRNAs was performed and data for all genes were obtained from all the samples. Cumulus cells isolated from oocytes that originated high-quality embryos on day 3 of culture had HAS2 and GREM1 transcript levels higher than those detected in cells from oocytes that did not fertilize or developed into poor-quality embryos. No differences were observed in PTX3 levels. Results indicate that the measurement of HAS2 and GREM1 levels in cumulus cells would reliably complement the morphological evaluation providing a useful tool for selecting oocytes with greater chances to be fertilized and develop in vitro.