Blood BMP6 Associated with Cognitive Performance and Alzheimer's Disease Diagnosis: A Longitudinal Study of Elders.

BACKGROUND: Bone morphogenetic protein (BMP) plays important roles in the pathology of Alzheimer's disease (AD). OBJECTIVE: We sought blood BMP6 involved in the processes underlying cognitive decline and detected them in association with AD. METHODS: A total of 309 participants in Shanghai Mental Health Center (SMHC) and 547 participants in Alzheimer's disease Neuroimaging Initiative (ADNI) cohort were included. Blood BMP6 and cognitive functions were measured in all subjects of both cohorts at baseline, and in 482 subjects of ADNI cohort after one year. A total of 300 subjects in ADNI cohort were detected cerebrospinal fluid (CSF) tau biomarker, and 244 received 1-year follow-up. RESULTS: AD patients had lower levels of blood BMP6 compared to normal controls, and BMP6 was positively associated with cognitive functions. Longitudinal BMP6 combing with APOE genotype could distinguish probable AD from normal controls. The influence of blood BMP6 on cognition was modulated by tau pathology. CONCLUSION: Blood BMP6 was associated with cognitive performance and identified as a potential predictor for probable AD.

Erythropoietin and a hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHDi) lowers FGF23 in a model of chronic kidney disease (CKD).

Iron-deficiency anemia is a potent stimulator of the phosphaturic hormone Fibroblast growth factor-23 (FGF23). Anemia, elevated FGF23, and elevated serum phosphate are significant mortality risk factors for patients with chronic kidney disease (CKD). However, the contribution of anemia to overall circulating FGF23 levels in CKD is not understood. Our goal was to investigate the normalization of iron handling in a CKD model using the erythropoiesis stimulating agents (ESAs) Erythropoietin (EPO) and the hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHDi) FG-4592, on the production of, and outcomes associated with, changes in bioactive, intact FGF23 ("iFGF23"). Our hypothesis was that rescuing the prevailing anemia in a model of CKD would reduce circulating FGF23. Wild-type mice were fed an adenine-containing diet to induce CKD, then injected with EPO or FG-4592. The mice with CKD were anemic, and EPO improved red blood cell indices, whereas FG-4592 increased serum EPO and bone marrow erythroferrone (Erfe), and decreased liver ferritin, bone morphogenic protein-6 (Bmp-6), and hepcidin mRNAs. In the mice with CKD, iFGF23 was markedly elevated in control mice but was attenuated by >70% after delivery of either ESA, with no changes in serum phosphate. ESA treatment also reduced renal fibrosis markers, as well as increased Cyp27b1 and reduced Cyp24a1 mRNA expression. Thus, improvement of iron utilization in a CKD model using EPO and a HIF-PHDi significantly reduced iFGF23, demonstrating that anemia is a primary driver of FGF23, and that management of iron utilization in patients with CKD may translate to modifiable outcomes in mineral metabolism.

Usefulness of Certain Protein Biomarkers for Prediction of Coronary Heart Disease.

Identification of biomarkers can help monitor and prevent cardiovascular disease (CVD) risk. We performed an exploratory analysis to identify potential biomarkers for coronary heart disease (CHD) in participants from the Life Conditions, Stress, and Health study. A total of 1,007 participants (50% women), randomly selected from the general population, were followed for incident CHD at 8 and 13 years of follow-up. Plasma levels of 184 CVD-related biomarkers were measured in samples collected at baseline in 86 cases with CHD and 184 age- and sex-matched controls by proximity extension assay. Biomarker levels were presented as normalized protein expression values (log 2 scale). After adjusting for confounding factors, 6 biomarkers showed significant association with incident CHD at 13 years. In a sensitivity analysis, this association remained significant at 8 years for 3 biomarkers; collagen α-1(I) chain (COL1A1), bone morphogenetic protein-6 (BMP-6), and interleukin-6 receptor α chain (IL-6Rα). When entering these biomarkers in the full adjustment model simultaneously, their association with incident CHD at 13 years remained significant, hazards ratio being 0.671, 0.335, and 2.854, respectively per unit increase in normalized protein expression values. Subjects with low COL1A1, low BMP-6, and high IL-6Rα levels had a hazards ratio of 5.097 for incident CHD risk (p = 0.019), compared with those without. In conclusion, we identified COL1A1, BMP-6 and IL-6Rα as biomarkers for incident CHD over a long-term follow-up in this exploratory analysis. For COL1A1 and BMP-6 this has not been previously reported. Further studies are needed to confirm our findings and establish their clinical relevance.

Exploring the Benefit of 2-Methylbutyric Acid in Patients Undergoing Hemodialysis Using a Cardiovascular Proteomics Approach.

Short-chain fatty acids (SCFAs) can reduce pro-inflammatory parameters and oxidative stress, providing potential cardiovascular (CV) benefits. Although some evidence links SCFAs with host metabolic health via several biological mechanisms, the role of SCFA on CV disease in patients with kidney disease remains unclear. Herein, we investigate the association between a SCFA, 2-methylbutyric acid, and target CV proteomics to explore the potential pathophysiology of SCFA-related CV benefit in patients with kidney disease. Circulating 2-methylbutyric acid was quantified by high-performance liquid chromatography and 181 CV proteins by a proximity extension assay in 163 patients undergoing hemodialysis (HD). The associations between 2-methylbutyric acid and CV proteins were evaluated using linear regression analysis with age and gender, and multiple testing adjustment. The selected CV protein in the discovery phase was further confirmed in multivariable-adjusted models and evaluated by continuous scale association. The mean value of circulating 2-methylbutyric acid was 0.22 ± 0.02 µM, which was negatively associated with bone morphogenetic protein 6 (BMP-6) according to the false discovery rate (FDR) multiple testing adjustment method. The 2-methylbutyric acid level remained negatively associated with BMP-6 (ß coefficient -1.00, 95% confidence interval -1.45 to -0.55, p < 0.001) after controlling for other CV risk factors in multivariable models. The cubic spline curve demonstrated a linear relationship. In conclusion, circulating 2-methylbutyric acid level was negatively associated with BMP-6, suggesting that this pathway maybe involved in vascular health in patients undergoing HD. However, further in vitro work is still needed to validate the translation of the mechanistic pathways.

The Clinical Value of Hepcidin in Breast Cancer and Its Bone Metastasis.

PURPOSE: We explored the role of hepcidin in the progression of breast cancer. METHODS: A retrospective analysis of 25 breast cancer patients with bone metastases, 30 breast cancer patients without bone metastases, and 30 patients with breast hyperplasia was conducted to compare the differences in Hb, hepcidin, BMP6, IL-6, and sTfR among the three groups and explore the correlation of Hepcidin with BMP6 IL-6, Hb and sTfR. In addition, ROC analysis was performed to evaluate the diagnostic value of hepcidin, BMP6 and IL-6 in breast cancer and its bone metastasis, while multivariate Logistic regression analysis was conducted to compare various indicators in breast cancer and its bone metastasis. RESULTS: The incidence of anemia was significantly different among three groups; hepcidin, BMP6, IL-6, sTfR, and Hb were also significantly different. Hepcidin level has a significant correlation with IL-6 and Hb levels in breast cancer patients with bone metastasis. Hepcidin had a higher diagnostic value for both breast cancer and breast cancer with bone metastasis than both BMP6 and IL-6. Hepcidin was an independent risk factor for breast cancer and its bone metastasis. CONCLUSION: Hepcidin can very well be utilized as a potential prognostic marker to follow patients with breast cancer metastatic to bone.

Bone morphogenetic protein-binding endothelial regulator of liver sinusoidal endothelial cells induces iron overload in a fatty liver mouse model.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is frequently accompanied by iron overload. However, because of the complex hepcidin-regulating molecules, the molecular mechanism underlying iron overload remains unknown. To identify the key molecule involved in NAFLD-associated iron dysregulation, we performed whole-RNA sequencing on the livers of obese mice. METHODS: Male C57BL/6 mice were fed a regular or high-fat diet for 16 or 48 weeks. Internal iron was evaluated by plasma iron, ferritin or hepatic iron content. Whole-RNA sequencing was performed by transcriptome analysis using semiconductor high-throughput sequencer. Mouse liver tissues or isolated hepatocytes and sinusoidal endothelial cells were used to assess the expression of iron-regulating molecules. RESULTS: Mice fed a high-fat diet for 16 weeks showed excess iron accumulation. Longer exposure to a high-fat diet increased hepatic fibrosis and intrahepatic iron accumulation. A pathway analysis of the sequencing data showed that several inflammatory pathways, including bone morphogenetic protein (BMP)-SMAD signaling, were significantly affected. Sequencing analysis showed 2314 altered genes, including decreased mRNA expression of the hepcidin-coding gene Hamp. Hepcidin protein expression and SMAD phosphorylation, which induces Hamp, were found to be reduced. The expression of BMP-binding endothelial regulator (BMPER), which inhibits BMP-SMAD signaling by binding BMP extracellularly, was up-regulated in fatty livers. In addition, immunohistochemical and cell isolation analyses showed that BMPER was primarily expressed in the liver sinusoidal endothelial cells (LSECs) rather than hepatocytes. CONCLUSIONS: BMPER secretion by LSECs inhibits BMP-SMAD signaling in hepatocytes and further reduces hepcidin protein expression. These intrahepatic molecular interactions suggest a novel molecular basis of iron overload in NAFLD.

Bone morphogenetic protein 6-a possible new player in pathophysiology of heart failure.

Derangement of bone morphogenetic protein (BMP) signalling was observed in cardiovascular disorders. The present study assesses the diagnostic and prognostic value of BMP6 plasma concentration in chronic heart failure (CHF). 130 CHF patients and 32 controls participated in the study. BMP6 plasma level was measured at baseline. During 12-month follow-up death and hospitalisation with CHF exacerbation were recorded. BMP6 was significantly increased in CHF patients with highest concentration in most advanced disease. Individuals with pulmonary congestion or peripheral oedema had higher levels of BMP6 than isovolemic patients. BMP6 was not a predictor of all-cause mortality or CHF hospitalisation. BMP6 may be involved in pathophysiology of systolic CHF. BMP6 plasma level is related to the disease severity and signs of exacerbation.

[Expression of serum FSTL-1 in bone metastasis of prostate cancer and its clinical implication].

OBJECTIVE: To investigate the expression of follistatin-like protein 1 (FSTL-1) in bone metastasis of prostate cancer (BMPC), the correlation of serum FSTL-1 with the chronic inflammatory factor interleukin-6 (IL-6) and bone morphogenetic protein 6 (BMP6) , and the clinical application value of serum FSTL-1 in BMPC. METHODS: Using ELISA, we measured the expression levels of serum FSTL-1, IL-6, and BMP6 in 35 patients with BMPC and another 30 with benign prostatic hyperplasia (BPH) and performed correlation analysis on the data obtained. RESULTS: Compared with the BPH controls, the BMPC patients showed a significantly decreased expression of serum FSTL-1 ([34.45 ± 12.35] µg/L vs [20.23 ± 8.69] µg/L, P < 0.01) and increased levels of IL-6 ([11.21 ± 8.62] µg/L vs [23.56 ± 20.12] µg/L, P < 0.05) and BMP6 ([293.50 ± 39.72] µg/L vs [428.30 ± 178.40] µg/L, P < 0.05). There was a significant negative correlation between the level of serum FSTL-1 and those of IL-6 and BMP6 in the BMPC patients, with correlation coefficients of -0.971 and -0.972, respectively (P < 0.05). CONCLUSION: The expression of serum FSTL-1 decreases in patients with bone metastasis of prostate cancer, and it is correlated with the levels of inflammatory factor and cell transformation factor. This finding offers a novel biological marker for the development and progression of prostate cancer as well as a new biological target factor for its intervention.

Post-treatment circulating plasma BMP6 mRNA and H3K27 methylation levels discriminate metastatic prostate cancer from localized disease.

BACKGROUND: We evaluated the utility of post-treatment plasma levels of the circulating bone-morphogenetic protein-6-specific mRNA (cBMP6 mRNA), cell-free DNA (cf-DNA), apoptotic nucleosomes and Histone H3 lysine 27 trimethylation (H3K27me3), in discriminating metastatic prostate cancer (PCa) from organ confined, locally controlled disease. METHODS: Peripheral blood was taken from the patients at the end of therapy, and quantitative PCR was performed to amplify cBMP6 mRNA or cf-DNA from plasma while apoptotic nucleosomes and H3K27me3 were determined by ELISA-based approaches. Following blinded measurements, the markers were compared between the patients with local (n=22), local advanced (n=11) or metastatic disease (n=28). RESULTS: Of the four markers investigated, the cBMP6 mRNA and H3K27me3 levels revealed significant differences between the three subgroups. We found higher levels of cBMP6 mRNA in the patients with metastases than in those with localized (p=0.001) or local advanced disease (p=0.05). When compared to cBMP6, H3K27me3 displayed an inverse distribution and was significantly lower in the patients with metastatic disease than in those with localized (p=0.05) or local advanced disease (p=0.024). There was no correlation between the different markers and total PSA levels or Gleason score at diagnosis. CONCLUSION: Our study provides evidence that post-treatment analysis of cBMP6 mRNA and H3K27me3 may be used to distinguish metastatic PCa from organ confined, locally controlled disease.

A rapid and sensitive bioassay for the simultaneous measurement of multiple bone morphogenetic proteins. Identification and quantification of BMP4, BMP6 and BMP9 in bovine and human serum.

BACKGROUND: Bone morphogenetic proteins (BMPs) are pleiotropic members of the TGF-beta superfamily which regulate many biological processes during development and adult tissue homeostasis and are implicated in the pathogenesis of a number of human diseases. Their involvement in both normal and aberrant physiology creates a need for rapid, sensitive and methodologically simple assays to evaluate their activity from a variety of biological samples. Previously alkaline phosphatase based assays, ELISA and luciferase based bioassays have been developed to evaluate either individual or total BMP activity. In this paper, we describe a highly sensitive, rapid and specific cell based assay for the simultaneous quantification of total and isoform specific BMP activity from biological samples. RESULTS: A C2C12 cell line stably transfected with a reporter plasmid consisting of the BMP response element (BRE) from the Id1 promoter fused to a luciferase reporter gene was generated. Exposure of this cell line to human recombinant BMP2, BMP4, BMP6, BMP7, BMP9 and BMP10 induced the expression of luciferase which was quantified using a luminometer. This assay was specific for BMP activity as the other TGF-beta superfamily members TGF-beta 1, Nodal and Mullerian Inhibiting Substance (MIS) did not induce the reporter. Pretreatment of samples with isoform specific BMP blocking antibodies coupled with isoform specific titration analysis allowed the simultaneous identification and quantification of BMP4, BMP6 and BMP9 in serum samples. CONCLUSION: The assay is rapid (<48 hours) and can be used to simultaneously measure isoform specific and total BMP activity in complex solutions.