The low levels of bone morphogenic protein-4 and its antagonist noggin in type 2 diabetes

OBJECTIVE

Bone morphogenic protein-4 (BMP-4) is a proinflammatory cytokine which is controlled by BMP-4 antagonists. Our aim was to investigate the levels of BMP-4 and its antagonists, noggin and matrix Gla protein (MGP), in prediabetes and diabetes.

DESIGN

One hundred and forty-two type 2 diabetic, 32 prediabetic, and 58 control subjects participated in this cross-sectional study. BMP-4, noggin, and MGP were measured with the ELISA method.

RESULTS

There was a significant difference between the three groups in relation to sex, hypertension, fasting plasma glucose, HbA1c, lipid profiles, and diastolic blood pressure (p < 0.05). BMP-4 levels were significantly lower in the diabetic group compared to the control group (108.5 and 127.5 ng/mL, respectively, p < 0.001 diabetes vs. control). Noggin levels were significantly lower in the diabetic group compared to the prediabetic and control groups (10.5, 11.5, and 12.0 ng/mL, as median, respectively, p < 0.001; diabetes vs. control, p = 0.002; diabetes vs. prediabetes). BMP-4 was associated significantly with noggin in the entire study population (ß coefficient = 0.796, p < 0.001). Receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve was 0.708 (95% CI 0.551-0.864, p = 0.011) for BMP-4 levels. The optimal cutoff value of BMP-4 for detecting albuminuria was 118.5 ng/mL for which sensitivity was 71.4% and specificity was 66.4%.

CONCLUSIONS

BMP-4 and noggin levels were lower in the diabetic group. High BMP-4 levels were significantly associated with albuminuria. Further studies are warranted to determine the role of BMP-4 in the pathogenic processes underlying albuminuria and hyperglycemia in patients with type 2 diabetes.

Bone Morphogenetic Proteins 2/4 Are Upregulated during the Early Development of Vascular Calcification in Chronic Kidney Disease

Vascular calcification is a main cause of increased cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients. This study aimed to investigate the role of the bone morphogenetic protein (BMP) signaling pathway in the early development of vascular calcification in CKD. A CKD vascular calcification rat model was established by providing rats with a 1.8% high-phosphorus diet and an intragastric administration of 2.5% adenine suspension. The kidney and aortic pathologies were analyzed. Blood biochemical indicators, serum BMP-2 and BMP-4 levels, and aortic calcium content were determined. The expression levels of BMP-2, BMP-4, bone morphogenetic protein receptor-IA (BMPR-IA), and matrix Gla protein (MGP) in aorta were examined by quantitative real-time polymerase chain reaction and immunohistochemistry. Compared with the normal control (Nor) rats, the CKD rats exhibited a significantly decreased body weight and an increased kidney weight as well as abnormal renal function and calcium-phosphorus metabolism. Aortic von Kossa and Alizarin red staining showed massive granular deposition and formation of calcified nodules in aorta at 8 weeks. The aortic calcium content was significantly increased, which was positively correlated with the serum BMP-2 (r = 0.929; P < 0.01) and serum BMP-4 (r = 0.702; P < 0.01) levels in CKD rats. The rat aortic BMP-2 mRNA level in the CKD rats was persistently increased, and the BMP-4 mRNA level was prominently increased at the 4th week, declining thereafter. Strong staining of BMP-2, BMP-4, BMPR-IA, and MGP proteins was observed in the tunica media of the aorta from the 4th week after model induction. In conclusion, activation of the BMP signaling pathway is involved in the early development of vascular calcification in CKD. Therefore, elevated serum BMP-2 and BMP-4 levels may serve as serum markers for CKD vascular calcification.

Enhanced serum levels of matrix Gla protein and bone morphogenetic protein in acute coronary syndrome patients

BACKGROUND

Vascular calcification has been found to be associated with increased risk of cardiovascular (CV) morbidity and mortality. Various bone-associated proteins have been suggested to be related with this process. In this study, we aimed to evaluate whether serum levels of bone morphogenic protein-4 (BMP-4) and matrix Gla protein (MGP) differed in patients who were found to have normal epicardial coronary arteries or a culprit lesion in the coronary angiography leading to acute coronary syndrome (ACS).

METHODS

Patients admitted to emergency department with the diagnosis of ACS who underwent primary percutaneous coronary intervention (PCI) between October 2015 and April 2016 were consecutively recruited as the patient group. Age and gender-matched subjects who underwent coronary angiography following non-invasive ischemia assessment made the control group.

RESULTS

A total of 90 subjects (63.00±14.02 years, 70% male) were included in this study. MGP (<0.001) and BMP-4 (<0.001) levels were significantly elevated when compared to subjects with normal coronary arteries. Fasting blood glucose (P=.024), HDL-cholesterol (P=.002), C-reactive protein (CRP) (P=.001) levels, and left ventricular ejection fraction (LVEF) (P=.021) were significantly correlated with serum MGP levels. HDL-cholesterol (P=.001) and CRP (P=.030) levels were also significantly correlated with serum BMP-4 levels. In the model including HDL-cholesterol, CRP, MGP, and BMP-4 levels, only MGP (odds ratio[OR]: 1.018, P=.019) and BMP-4 (OR: 1.313, P=.023) were found to be independently associated with ACS.

CONCLUSION

This study shows that serum BMP-4 and MGP are independently associated with ACS occurrence when adjusted for other CV risk factors. These biomarkers may have a diagnostic potential in ACS patients.

[Hypospadias induced by maternal exposure to di-n-butyl phthalate and its mechanisms in male rat offspring , , , , ,]

OBJECTIVE

To induce hypospadias in male rat offspring by maternal exposure to di-n-butyl phthalate (DBP) during late pregnancy and further investigate its mechanisms.

METHODS

We randomly divided 20 pregnant rats into a DBP exposure and a control group, the former treated intragastrically with DBP while the latter with soybean oil at 750 mg per kilogram of the body weight per day from gestation days (GD) 14 to 18. On postnatal day (PND) 1, we recorded the incidence rate of hypospadias and observed the histopathological changes in the genital tubercle of the hypospadiac rats. We also measured the level of serum testosterone (T) by radioimmunoassay and determined the mRNA and protein expressions of the androgen receptor (AR), sonic hedgehog (Shh), bone morphogenetic protein 4 (Bmp4) and fibroblast growth factor 8 (Fgf8) in the genital tubercle by real-time PCR and Western blot.

RESULTS

No hypospadiac male rats were found in the control group. The incidence rate of hypospadias in male offspring was 43.6% in the DBP-treatment group. Histological analysis confirmed hypospadiac malformation. The serum testosterone concentration was decreased in the hypospadiac male rats as compared with the controls (［0.49 ± 0.05］ vs ［1.12 ± 0.05］ ng/ml, P <0.05). The mRNA expressions of AR, Shh, Bmp4 and Fgf8 in the genital tubercle were significantly lower in the hypospadiac male rats than in the controls (AR: 0.50 ± 0.05 vs 1.00 ± 0.12, P <0.05; Shh: 0.65 ± 0.07 vs 1.00 ± 0.15, P <0.05; Bmp4: 0.42 ± 0.05 vs 1.00 ± 0.13, P <0.05; Fgf8: 0.46 ± 0.04 vs 1.00 ± 0.12, P <0.05), and so were their protein expressions (AR: 0.34 ± 0.05 vs 1.00 ± 0.09, P <0.05; Shh: 0.51 ± 0.07 vs 1.00 ± 0.12, P <0.05; Bmp4: 0.43 ± 0.05 vs 1.00 ± 0.11, P <0.05; Fgf8: 0.57 ± 0.04 vs 1.00 ± 0.13, P <0.05).

CONCLUSIONS

Maternal exposure to DBP during late pregnancy can induce hypospadias in the male rat offspring. DBP affects the development of the genital tubercle by reducing the serum T concentration and expressions of AR, Shh, Bmp4 and Fgf8 in the genital tubercle, which might underlie the mechanism of DBP inducing hypospadias.

The effect of parathyroid hormone (1-84) treatment on serum bone morphogenetic protein 4 and vascular endothelial growth factor in postmenopausal women with established osteoporosis

PURPOSE

To investigate the effect of 18 months' parathyroid hormone 1-84 (PTH 1-84) treatment on serum levels of bone morphogenetic protein 4 (BMP4) and vascular endothelial growth factor (VEGF), in postmenopausal women with established osteoporosis.

METHODS

Thirty-seven postmenopausal women with osteoporosis (mean age 72.9 ± 8.1 years old) and 23 healthy controls (mean age 68.9 ± 9.9 years old) were enrolled. Patients were treated with daily subcutaneous injections of PTH (1-84) 100 mcg for 18 months, plus calcium 1 gr and vitamin D 800 IU per os daily. Blood samples were taken every 6 months during the study.

RESULTS

At baseline, there were no differences considering anthropometric parameters, co-morbidities, current medications used between patients and controls. Mean serum VEGF levels were significantly higher in osteoporotic patients compared to controls (436.7 ± 259.7 vs. 260.3 ± 184.3 pg/ml, p = 0.006), while there were no differences in mean serum values of BMP4 (5.3 ± 1.7 vs. 5.7 ± 1.6 pg/ml, p = 0.40). Serum VEGF levels increased by approximately 20% after 12 months of PTH (1-84) treatment compared to baseline (p = 0.03) and by 22% after 18 months (p = 0.01). A significant increase of 10% in mean serum BMP4 levels was observed after 18 months of PTH (1-84) treatment compared to baseline (p = 0.02). In the control group we found no differences after 18 months compared to baseline in BMP4 (5.7 ± 1.6 vs. 6.0 ± 1.5 pg/ml, p = 0.53) and VEGF (260.3 ± 184.3 vs. 257.4 ± 107.1 pg/ml, p = 0.94).

CONCLUSIONS

PTH (1-84) treatment increased serum levels of VEGF and BMP4 in postmenopausal women with severe osteoporosis.

Bone morphogenetic protein-7 (BMP-7) augments insulin sensitivity in mice with type II diabetes mellitus by potentiating PI3K/AKT pathway

A direct link between development of insulin resistance and the presence of chronic inflammation, in case of obesity exists, with cytokines playing an important role in glucose metabolism. Members of TGF-β superfamily, including bone morphogenetic proteins (BMPs), have been shown to be involved in islet morphogenesis, establishment of β-cell mass and adipose cell fate determination. Here, we demonstrate a novel and direct role of BMP-4 and -7 in the regulation of glucose homeostasis and insulin resistance. An age-dependent increase in serum BMP-4 and decrease in serum BMP-7 levels was observed in animal models of type II diabetes. In this study, BMP-7 and -4 have been demonstrated to have antagonistic effects on insulin signaling and thereby on glucose homeostasis. BMP-7 augmented glucose uptake in the insulin sensitive tissues such as the adipose and muscle by increasing Glut4 translocation to the plasma membrane through phosphorylation and activation of PDK1 and Akt, and phosphorylation and translocation of FoxO1 to the cytoplasm in liver/HepG2 cells. Restoration of BMP-7 levels in serum of diabetic animals resulted in decreased blood glucose levels in contrast to age matched untreated control groups, opening up a new therapeutic avenue for diabetes. On the contrary, BMP-4 inhibited insulin signaling through activation of PKC-θ isoform, and resulted in insulin resistance through the attenuation of insulin signaling. BMP-7 therefore is an attractive candidate for tackling a multifaceted disease such as diabetes, since it not only reduces body fat, but also strengthens insulin signaling, causing improved glucose uptake and ameliorating peripheral insulin resistance. © 2017 BioFactors, 43(2):195-209, 2017.

Expression analysis of bone morphogenetic protein 4 between fat and lean birds in adipose tissue and serum

The objectives of the present study were to characterize the tissue expression of chicken (Gallus gallus) bone morphogenetic protein 4 (BMP4) and compare differences in its expression in abdominal fat tissue and serum between fat and lean birds and to determine a potential relationship between the expression of BMP4 and abdominal fat tissue growth and development. The results showed that chicken BMP4 messenger RNA (mRNA) and protein were expressed in various tissues, and the expression levels of BMP4 transcript and protein were relatively higher in adipose tissues. In addition, the mRNA and protein expression levels of BMP4 in abdominal fat tissue of fat males were lower than those of lean males at 1, 2, 5, and 7 wk of age (P < 0.05). Furthermore, the serum BMP4 content of fat males was lower than that of lean males at 7 wk of age (P < 0.05). BMP4 mRNA expression levels were significantly higher in preadipocytes than those in mature adipocytes (P < 0.05), and the expression level decreased during differentiation in vitro (P < 0.05). These results suggested that chicken BMP4 might affect abdominal fat deposition through differences in its expression level. The results of this study will provide basic molecular information for studying the role of BMP4 in the regulation of adipogenesis in avian species.

Serum Bone Morphogenic Protein-4 Contributes to Discriminating Coronary Artery Disease Severity

Bone morphogenic protein 4 (BMP-4) is a known pro-inflammatory and pro-atherogenic cytokine. Here, we investigated whether the serum BMP-4 level predicts coronary artery disease (CAD) severity in humans. We measured serum BMP-4 concentrations in 1044 consecutive patients who underwent elective coronary angiography and percutaneous coronary intervention. CAD severity was estimated by the number of diseased vessels showing ≥ 50% diameter stenosis. Among males, the serum BMP-4 level was significantly lower in patients with multivessel disease (MVD) compared with those with single-vessel disease (SVD) (16.3 ± 22.6 vs. 22.0 ± 28.4 pg/mL, P < 0.01). After adjustment for other cardiovascular risk factors, a high serum BMP-4 level was an independent predictor for a decreased risk of MVD (odds ratio, 0.992; 95% confidence interval [CI], 0.985-0.998; P =  .01) and patients in the lower tertile were 1.55-fold more likely to have MVD compared with upper tertile patients. Receiver-operating characteristic curve analysis demonstrated that the serum BMP-4 level had a 54% sensitivity and 54% specificity for predicting MVD (area under the curve [AUC], 56.5%; 95% CI, 51.9-61.0%; P < 0.01). Serum BMP-4 improved the predictive capability of risk factors for MVD (AUC with and without BMP-4: 64.9 and 63.6%, respectively). Considering the likelihood ratio and number of parameters, adding the serum BMP-4 level provided a better-fit model for predicting MVD compared with the model consisting of conventional risk factors (likelihood ratio χ2 = 6.20, P =  .01). However, an association between serum BMP-4 and CAD was not observed in females.Serum BMP-4 levels are independently associated with CAD severity and contribute to discriminating CAD severity in males.

Association of BMP4 polymorphisms with isolated tooth agenesis in a Chinese Han population: a case-control study

OBJECTIVE

Tooth agenesis is a common craniofacial anomaly in human beings. Mounting evidence has demonstrated that the bone morphogenetic protein 4 gene (BMP4) plays an important role in tooth development. This case-control study was designed to evaluate the association of the polymorphism rs17563 in BMP4 gene with susceptibility of isolated human tooth agenesis in a Chinese Han population.

PATIENTS AND METHODS

335 tooth agenesis cases and 444 healthy controls were included in this study.

RESULTS

Although no significant association was observed either in the overall or stratified analysis between the types and the severity of missing teeth. However, significant difference was observed between the anterior and posterior tooth agenesis (APTA) cases and the controls (p = 0.018 for allele distribution and OR = 0.39, 95% CI = 0.15-0.99). Furthermore, the heterozygote (TC) and dominant model (CC+TC) were associated with decreased risk of APTA compared with the control (phet = 0.018, ORhet = 0.39, 95% CIhet = 0.15-0.99 and pdom = 0.042, ORdom = 0.34, 95% CIdom = 0.13-0.87, respectively).

CONCLUSIONS

These results indicated that rs17563 in BMP4 gene was potentially associated with APTA in Chinese Han population and further independent studies are required to verify these findings.

The importance and the differences of bone morphogenetic proteins for osteoporotic hip fractures

Bone morphogenetic proteins (BMPs), major contributors to tissue repair, have become one of the most exciting fields in rheumatic and orthopaedic research. In our study we aimed to evaluate the relationship between osteoporotic hip fractures and the serum levels of BMPs to reveal their potential roles in the diagnosis of patients. The study group included 62 patients with osteoporotic hip fracture (Group 1; intertrochanteric fracture, Group 2; collum femoris fracture) and the control group. All fractures were due to low energy trauma, simple falls. For all subjects BMD measurements were in agreement for osteoporosis and no significant differences were observed between the two fracture groups. Biochemical markers; BMP-4 and BMP-7 (pg/mL) were determined by commercial Elisa kits from the serum samples. The mean and standard error values of serum samples for BMP-4 and BMP-7 in Group 1 (100.70 +/- 10.03, 74.41 +/- 6.31 respectively) and in Group 2 (112.34 +/- 11.52, 81.91 +/- 10.14 respectively) were not statistically different however for both groups only BMP-7 values increased statistically when compared to the control group. BMP-7 measurements may not only serve as potential biochemical markers for determining disease severity but also the increased levels, an osteogenic factor and bone stimulating agent in vivo, after trauma elevated levels are adaptive or protective and therefore may reduce the severity of the fracture.

Association of serum bone morphogenetic protein 4 levels with obesity and metabolic syndrome in non-diabetic individuals

Bone morphogenetic protein 4 (BMP-4) is involved in the earliest stages of adipocyte differentiation and is recognized as an adipogenic factor for white adipose tissue. The association of serum BMP-4 levels with anthropometric and metabolic parameters has not been previously studied. We aimed to explore the relationship of serum BMP-4 levels with obesity and metabolic syndrome. Serum BMP-4 levels were measured in 104 non-diabetic individuals from the Chungju Metabolic Disease Cohort Study. Anthropometric measurements and components of metabolic syndrome were assessed in all patients. Serum BMP-4 levels were significantly increased in individuals with obesity or metabolic syndrome. After adjusting for age and gender, serum BMP-4 levels were positively correlated with body mass index, waist circumference (WC), waist-to-hip ratio, fasting plasma insulin, homeostasis model assessment index, and triglycerides and were negatively correlated with high-density lipoprotein (HDL) cholesterol. Among these parameters, WC and HDL cholesterol were found to be independent contributing factors for serum BMP-4 levels. Serum BMP-4 levels were also significantly higher in subjects with positive diagnostic criteria for each component of metabolic syndrome. The area under the receiver operating characteristic curve for BMP-4 was 0.661 (P = 0.022, 95% CI = 0.528 to 0.794) and the cut-off value was 2.84 pg/mL. This is the first demonstration that serum BMP-4 levels are associated with adiposity, insulin resistance, and the presence of metabolic syndrome. Whether BMP-4 may be involved in the pathogenesis of obesity and metabolic syndrome deserves further investigation.