Mutations In Bone Morphogenetic Protein Research Articles

Genetic regulation of ovulation rate and multiple births.

Ovulation rate in many mammalian species is controlled to regulate the numbers of offspring and maximise reproductive success. Pathways that regulate ovulation rate still respond to genetic and environmental factors and show considerable variation within and between species. Genetic segregation, positional cloning, and association studies have discovered numerous mutations and genetic risk factors that contribute to this variation. Notable among the discoveries has been the role of mutations in bone morphogenetic protein 15 (BMP15 ), growth differentiation factor 9 (GDF9 ) and bone morphogenetic protein receptor type 1B (BMPR1B ) from the intra-ovarian signalling pathway contributing to the evidence that signalling from the oocyte is the key driver in follicle regulation rather than circulating gonadotrophin concentrations. Multiple variants in different domains of BMP15 and GDF9 result in partial or complete loss of function of the proteins providing insights into their functional roles and differential regulation contributing to species differences in ovulation rate. Early success encouraged many more studies in prolific strains of sheep, cattle and goats providing a valuable catalogue of genetic variants of large effect increasing ovulation rate and litter size. More recently, genetic association studies are beginning to identify genetic risk factors with smaller effects. Most genes implicated are from pathways with defined roles in regulation of the ovarian function. However, some genomic regions suggest regulation by novel genes. Continuing genetic and related functional studies will add further to our understanding of the detailed regulation of ovulation rate and litter size with implications for health and animal production systems.

Polymorphisms Analysis of BMP15, GDF9 and BMPR1B in Tibetan Cashmere Goat (Capra hircus).

The Tibetan cashmere goat is a prolific goat breed in China. In sheep breeds, natural mutations have demonstrated that the transforming growth factor beta (TGF-β) super family ligands, such as growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15) and their type I receptor (bone morphogenetic protein receptor (BMPR1B), are essential for ovulation and increasing litter size. In this study, 216 female Tibetan cashmere goats were sampled, and candidate genes with fecundity traits were detected via restriction fragment length polymorphism (RFLP) and sequenced. Four polymorphic loci were found in specific amplification fragments of BMP15 and GDF9. Two SNP sites of the BMP15 gene were discovered, namely G732A and C805G. The G732A mutation did not cause the change in amino acids, and the frequencies of each genotype were 0.695 for the GG type, 0.282 for the GA type and 0.023 for the AA type. The C805G mutation caused amino acids to change from glutamine to glutamate. The genotype frequencies were 0.620 for the CC type, 0.320 for the CG type and 0.320 for the CG type. For the GG type 0.060, the G3 and G4 mutations of the GDF9 gene were all homozygous mutations. Two known SNP sites, C719T and G1189A, were detected in the Tibetan cashmere goat GDF9 gene, of which the C719T mutation caused a change of alanine to valine, with a genotype frequency of 0.944 for the CC type and 0.056 for the CT type, whereas no TT type was found. The G1189A mutation caused valine to become isoleucine, and the frequencies of each genotype were 0.579 for the GG type, 0.305 for the GA type and 0.116 for the AA type; G1, B2, B3, B4, FecXH, FecXI, FecXL, G2, G5, G6, G7, G8, FecGE, FecTT and FecB mutations were not found in Tibetan cashmere goats. The results of this study provide a data basis for future studies of BMP15, GDF9 and BMPR1B gene mutations in goats.

Loss of bone morphogenetic protein signaling in fibroblasts results in CXCL12-driven serrated polyp development

Mutations in Bone Morphogenetic Protein (BMP) Receptor (BMPR)1A and SMAD4 are detected in 50% of juvenile polyposis syndrome (JPS) patients, who develop stroma-rich hamartomatous polyps. The established role of stromal cells in regulating BMP activity in the intestine implies a role for stromal cells in polyp development. We used conditional Cre-LoxP mice to investigate how specific loss of BMPR1A in endothelial cells, fibroblasts, or myofibroblasts/smooth muscle cells affects intestinal homeostasis. Selective loss of BMPR1A in fibroblasts causes severe histological changes in the intestines with a significant increase in stromal cell content and epithelial cell hyperproliferation, leading to numerous serrated polyps. This phenotype suggests that crucial changes occur in the fibroblast secretome that influences polyp development. Analyses of publicly available RNA expression databases identified CXCL12 as a potential candidate. RNAscope in situ hybridization showed an evident increase of Cxcl12-expressing fibroblasts. In vitro, stimulation of fibroblasts with BMPs resulted in downregulation of CXCL12, while inhibition of the BMP pathway resulted in gradual upregulation of CXCL12 over time. Moreover, neutralization of CXCL12 in vivo in the fibroblast-specific BMPR1A KO mice resulted in a significant decrease in polyp formation. Finally, in CRC patient specimens, mRNA-expression data showed that patients with high GREMLIN1 and CXCL12 expression had a significantly poorer overall survival. Significantly higher GREMLIN1, NOGGIN, and CXCL12 expression were detected in the Consensus Molecular Subtype 4 (CMS4) colorectal cancers, which are thought to arise from serrated polyps. Taken together, these data imply that fibroblast-specific BMP signaling–CXCL12 interaction could have a role in the etiology of serrated polyp formation.

A Case of Fibrodysplasia Ossificans Progressiva in Kenya

Fibrodysplasia Ossificans Progressiva (FOP) is an extremely rare and disabling disorder that affects 1 in 2 million individuals worldwide. It is caused by mutations in bone morphogenetic protein which leads to extra-skeletal ossification of soft tissues in a characteristic cranio-caudal pattern. Hallux valgus, episodic flares and progressive functional disability are characteristic features. The cause of death is often cardio-respiratory failure following thoracic insufficiency.

Abstract 10462: Increased Bone Morphogenetic Protein 10 Activity is Associated with Increased Right Atrial Wall Stress and Disease Severity in Pulmonary Hypertension

Background: Pulmonary Hypertension (PH) is characterized by increased right atrial (RA) stretch and pressure. The major predisposing risk factor for PH involves mutations in bone morphogenetic protein (BMP) receptor 2 (BMPR2), for which BMP9 and BMP10 are ligands. In adults, BMP10 is produced by RA cardiomyocytes, however, the mechanism to BMP10 release is unknown. We hypothesize that RA wall stress may be a trigger for BMP10 secretion. Methods: We determined BMP10 and BMP9 levels in plasma samples from PH-patients (22 idiopathic pulmonary arterial hypertension (iPAH), 14 hereditary PAH (hPAH) and 11 chronic thromboembolic PH (CTEPH)) and 16 controls by ELISA. To study BMP10 and BMP9 activity, we exposed endothelial cells to 10% serum and analyzed BMP-activity as read out of the BRE-luciferase reporter assay. Serum was incubated with trap antibodies: anti-BMP9 to inhibit BMP9 ligand, and ALK1-Fc to inhibit both BMP9 and BMP10 ligands. BMP9 and BMP10 activity were deducted from the difference vs baseline and BMP9-activity, respectively. Results: Circulating BMP10 levels were higher in PH-patients: 16.5 [9.5-69.7] pg/mL in iPAH, 17.1 [1.4-113.4] pg/mL in hPAH and 37.8 [10.7-87.1] pg/mL in CTEPH, vs 6.1 [0-8.7] pg/mL in controls (A). No differences were observed in BMP9 levels (B). BMP10 and BMP9 activity appeared lower in iPAH, only a trend was seen in BMP9-activity in iPAH vs hPAH (C,D). Next, we divided the PH cohort on median BMP10-activity. Higher active BMP10 in PH was associated with an increase in RA volume and pressure, and reduced RA compliance (E). Further, higher BMP10-activity in PH-patients was associated with worse disease status, shown by worse right ventricular function, lower stroke volume and increased NTproBNP (F). Conclusions: BMP10 circulating levels were increased in PH, whereas no difference in circulating BMP10-activity was observed. High BMP10-activity was associated with increased RA wall stress and disease severity in PH-patients.

P065 A case of fibrodysplasia ossificans progressiva in Kenya

Abstract Background Fibrodysplasia Ossificans Progressiva (FOP) is an extremely rare and disabling disorder affecting 1 in 2 million individuals worldwide. It is caused by mutations in bone morphogenetic protein which leads to extra-skeletal ossification of soft tissues in a characteristic cranio-caudal pattern. Hallux valgus, episodic flares and progressive functional disability are characteristic features. The cause of death is often cardio-respiratory failure following thoracic insufficiency. The objective of our case study is to describe a rare but interesting case of fibrodysplasia ossificans progressiva (FOP) in an African setting. Methods This was a retrospective case review Results Two-year-old boy presented with painful firm masses of bony consistency over the axilla, neck, occiput and the forehead for seven months. He developed progressive inability to lift the arms, flex his neck and had a characteristic stiff posture while walking. The masses had a waxing and waning nature lasting about 4–5 days but with no complete resolution. He was previously treated with antibiotics for lymphadenitis which was diagnosed by biopsy of the neck mass at a different health facility. On examinationhe had bony masses on the posterior aspect of the neck tender on palpation and attached to the underlying subcutaneous tissue. Similar masses were found on his anterior and posterior chest wall measuring 1 cm by 1 cm anteriorly and larger masses- measuring 5 cm by 5 cm posteriorly. He had bilateral hallux valgus and both elbows held in fixed flexion. His fingers had varying degrees of fixed flexion. The lower limbs were unaffected. Laboratory evaluation within normal ranges. extensive dystrophic soft tissue calcification around both elbows outlining the joint capsules. dystrophic soft tissue calcification in the bilateral axillae extensive “sheet like” soft tissue dystrophic calcifications overlying the posterior elements of the vertebral column separate from the vertebrae. Histology showed muscle replacement by hyaline cartilage and bone with intervening fibromyxoid stroma. Discussion & Conclusions This case is meant to raise awareness of this rare disease across Africa. The misdiagnosis of FOP approaches 90% of cases worldwide. Definitive genetic testing of FOP is now available and can now confirm a diagnosis before the appearance of heterotopic ossifications. Clinical suspicion of FOP early in life on the basis of malformed great toes can lead to early clinical diagnosis. Current management focuses on early diagnosis, avoidance of trauma and optimization of function. A short course of oral steroids is beneficial in prevention of flares.

A nonsense mutation of bone morphogenetic protein-15 (BMP15) causes both infertility and increased litter size in pigs

BackgroundAtypical external genitalia are often a sign of reproductive organ pathologies and infertility with both environmental or genetic causes, including karyotypic abnormalities. Genome-wide association studies (GWAS) provide a means for identifying chromosomal regions harboring deleterious DNA-variants causing such phenotypes. We performed a GWAS to unravel the causes of incidental cases of atypically small vulvae in German Landrace gilts.ResultsA case-control GWAS involving Illumina porcine SNP60 BeadChip-called genotypes of 17 gilts with atypically small vulvae and 1818 control animals (fertile German Landrace sows) identified a significantly associated region on the X-chromosome (P = 8.81 × 10− 43). Inspection of whole-genome sequencing data in the critical area allowed us to pinpoint a likely causal variant in the form of a nonsense mutation of bone morphogenetic protein-15 (BMP15; Sscrofa11.1_X:g.44618787C>T, BMP15:p.R212X). The mutant allele occurs at a frequency of 6.2% in the German Landrace breeding population. Homozygous gilts exhibit underdeveloped, most likely not functional ovaries and are not fertile. Male carriers do not seem to manifest defects. Heterozygous sows produce 0.41±0.02 (P=4.5 × 10-83) piglets more than wildtype animals. However, the mutant allele’s positive effect on litter size accompanies a negative impact on lean meat growth.ConclusionOur results provide an example for the power of GWAS in identifying the genetic causes of a fuzzy phenotype and add to the list of natural deleterious BMP15 mutations that affect fertility in a dosage-dependent manner, the first time in a poly-ovulatory species. We advise eradicating the mutant allele from the German Landrace breeding population since the adverse effects on the lean meat growth outweigh the larger litter size in heterozygous sows.

Vital Roles of Gremlin-1 in Pulmonary Arterial Hypertension Induced by Systemic-to-Pulmonary Shunts.

BackgroundHeterozygous mutation in BMP (bone morphogenetic protein) receptor 2 is rare, but BMP cascade suppression is common in congenital heart disease–associated pulmonary arterial hypertension (CHD‐PAH); however, the underling mechanism of BMP cascade suppression independent of BMP receptor 2 mutation is unknown.Methods and ResultsPulmonary hypertensive status observed in CHD‐PAH was surgically reproduced in rats. Gremlin‐1 expression was increased, but BMP cascade was suppressed, in lungs from CHD‐PAH patients and shunted rats, whereas shunt correction retarded these trends in rats. Immunostaining demonstrated increased gremlin‐1 was mainly in the endothelium and media of remodeled pulmonary arteries. However, mechanical stretch time‐ and amplitude‐dependently stimulated gremlin‐1 secretion and suppressed BMP cascade in distal pulmonary arterial smooth muscle cells from healthy rats. Under static condition, gremlin‐1 significantly promoted the proliferation and inhibited the apoptosis of distal pulmonary arterial smooth muscle cells from healthy rats via BMP cascade. Furthermore, plasma gremlin‐1 closely correlated with hemodynamic parameters in CHD‐PAH patients and shunted rats.ConclusionsServing as an endogenous antagonist of BMP cascade, the increase of gremlin‐1 in CHD‐PAH may present a reasonable mechanism explanation for BMP cascade suppression independent of BMP receptor 2 mutation.

Association between polymorphism in BMP15 and GDF9 genes and impairing female fecundity in diabetes type 2

BackgroundA shortened reproductive period and earlier menopause have been associated with type 2 diabetes. Growth differentiation factor 9(GDF9) and bone morphogenetic protein 15 (BMP15) gene mutations have been associated with earlier menopause. Therefore, this study aimed to evaluate the association between BMP15 and GDF9 mutations with impairing female fecundity in diabetic patients. The study subjects comprised 90 female diabetic patients and 60 female healthy controls. The physio-biochemical analysis was measured using enzymatic determination. A single-strand conformation polymorphism (SSCP) protocol was utilized to assess the pattern of genetic variations.ResultsGenotyping analysis of the BMP15 gene showed a heterogeneous pattern with the presence of two genotypes: AA and AC genotypes. Five novel missense single nucleotide polymorphisms (SNPs) were identified in the BMP15 gene: four SNPs detected in both genotypes, and Met4Leu, a specific SNP, was detected only in the AC genotype. Cumulative in silico tools indicated a highly deleterious effect for the Met4Leu on the mutant protein structure, function, and stability. Diabetes patients showed a significantly higher frequency of genotype AC. The physio-biochemical analysis of fasting plasma glucose (FBG), glycosylated hemoglobin (HbA1c), and luteinizing hormone (LH) were significantly higher (P < 0.05) in AC genotype than AA genotype.ConclusionsThe current research provides the first indication regarding the tight association of BMP15 polymorphism with the impairing female fecundity in the diabetic. A pivotal role is played by the novel (Met4Leu) SNP that can be used as a predictor for the impairing female fecundity of diabetes, while no polymorphism was found in exon 4 of the GDF9 gene.

Oocyte-derived growth factors and ovulation rate in sheep

The physiological mechanisms controlling ovulation rate in mammals involve a complex exchange of endocrine signals between the pituitary gland and the ovary, and a localized exchange of intraovarian hormones between the oocyte and its adjacent somatic cells. The discoveries in sheep of mutations in bone morphogenetic protein 15 (BMP15) and bone morphogenetic protein receptor type IB (BMPR-IB) together with recent findings on the physiological effects of growth differentiation factor 9 (GDF9) and BMP15 on follicular development and ovulation rate highlight some important differences in the way in which the oocyte may function in mammals with different ovulation rate phenotypes. In sheep, BMP15 and GDF9 have each been shown to be essential for the early and later stages of follicular development. In addition, ovulation rate is sensitive to changes in the dose of either of these two oocyte-derived growth factors. These findings are in contrast to those reported for mice in which GDF9, but not BMP15, is essential for follicular development. The evidence to date is consistent with the hypothesis that the oocyte plays a central role in regulating key events in the process of follicular development and hence, is important in determining ovulation rate. Moreover, it appears that the mechanisms that the oocyte uses to control these processes differ between species with low and high ovulation rate phenotypes.

Screening for Causative Mutations of Major Prolificacy Genes in Iranian Fat-Tailed Sheep.

BackgroundThe presence of different missense mutations in sheep breeds have shown that the bone morphogenetic protein receptor 1B (BMPR1B), bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) genes play a vital role in ovulation rate and prolificacy in ewes. Therefore, the present study aims to investigate BM- PR1B, BMP15 and GDF9 gene mutations in prolific ewes of Iranian fat-tailed Lori-Bakhtiari sheep.Materials and MethodsIn the present experimental study, genomic DNA was extracted from whole blood of 10 prolific Lori-Bakhtiari ewes with at least two twinning records in the first four parities to identify point mutations of the BMPR1B, BMP15 and GDF9 genes, using DNA sequencing.ResultsThe results obtained from DNA sequencing showed a new synonymous mutation (g.66496G>A) in exon 8 of the BMPR1B gene, without any amino acid change. Sequencing of the BMP15 gene revealed a deletion of 3 bp (g.656_658delTTC) in exon 1, leading to an amino acid deletion (p.Leu19del). Four single nucleotide polymorphisms (G1:g.2118G>A, G2:g.3451T>C, G3:g.3457A>G and G4:g.3701G>A), were detected in exons 1 and 2 of the GDF9 gene, two of which caused amino acid substitutions (G1: p.87Arg>His and G4: p.241Glu>Lys). These amino acid alterations are proposed to have a benign impact on structure and function of the GDF9 polypeptide sequence.ConclusionThree major prolificacy genes (BMPR1B, BMP15 and GDF9) were polymorphic in Lori-Bakhtiari sheep, although none of the major causative mutation was detected in this sheep type. Further studies using high throughput methods such as genome-wide association study (GWAS) and evaluation of other candidate genes are necessary in the future.

Tacrolimus rescues the signaling and gene expression signature of endothelial ALK1 loss-of-function and improves HHT vascular pathology.

Hereditary hemorrhagic telangiectasia (HHT) is a highly debilitating and life-threatening genetic vascular disorder arising from endothelial cell (EC) proliferation and hypervascularization, for which no cure exists. Because HHT is caused by loss-of-function mutations in bone morphogenetic protein 9 (BMP9)-ALK1-Smad1/5/8 signaling, interventions aimed at activating this pathway are of therapeutic value. We interrogated the whole-transcriptome in human umbilical vein ECs (HUVECs) and found that ALK1 signaling inhibition was associated with a specific pro-angiogenic gene expression signature, which included a significant elevation of DLL4 expression. By screening the NIH clinical collections of FDA-approved drugs, we identified tacrolimus (FK-506) as the most potent activator of ALK1 signaling in BMP9-challenged C2C12 reporter cells. In HUVECs, tacrolimus activated Smad1/5/8 and opposed the pro-angiogenic gene expression signature associated with ALK1 loss-of-function, by notably reducing Dll4 expression. In these cells, tacrolimus also inhibited Akt and p38 stimulation by vascular endothelial growth factor, a major driver of angiogenesis. In the BMP9/10-immunodepleted postnatal retina-a mouse model of HHT vascular pathology-tacrolimus activated endothelial Smad1/5/8 and prevented the Dll4 overexpression and hypervascularization associated with this model. Finally, tacrolimus stimulated Smad1/5/8 signaling in C2C12 cells expressing BMP9-unresponsive ALK1 HHT mutants and in HHT patient blood outgrowth ECs. Tacrolimus repurposing has therefore therapeutic potential in HHT.

BMP15 regulates the inhibin/activin system independently of ovulation rate control in sheep.

Polymorphisms in the gene encoding bone morphogenetic protein 15 (BMP15) have been associated with multiple ovulations in sheep. As BMP15 regulates inhibin expression in rodents, we assumed that the ovarian inhibin/activin system could mediate part of the effect of BMP15 mutations in the regulation of ovulation rate in sheep. To answer this question, we have studied the effects of two natural loss-of-function mutations of BMP15 on the expression of components of this system. The FecXR and the FecXGr mutations, when present respectively in Rasa Aragonesa ewes at the heterozygous state and in Grivette ewes at the homozygous state, were associated with a twofold increase in ovulation rate. There were only small differences between mutant and wild-type ewes for mRNA expression of INHA, INHBA, ACVR1B, ACVR2A, FST or TGFBR3 in granulosa cells and inhibin A or activin A concentrations in follicular fluid. Moreover, the effects of mutations differed between breeds. In cultures of granulosa cells from wild-type ewes, BMP15, acting alone or in synergy with GDF9, stimulated INHA, INHBA and FST expression, but inhibited the expression of TGFBR3 Activin A did not affect INHBA expression, but inhibited the expression of ACVR2A also. The complexity of the inhibin/activin system, including positive and antagonistic elements, and the differential regulation of these elements by BMP15 and activin can explain that the effects of BMP15 mutations differ when present in different genetic backgrounds. In conclusion, the ovarian inhibin/activin system is unlikely to participate in the increase of ovulation rate associated with BMP15 mutations in sheep.

BMP1 and TLL1 Are Required for Maintaining Periodontal Homeostasis

Mutations in bone morphogenetic protein 1 (BMP1) in humans or deletion of BMP1 and related protease tolloid like 1 (TLL1) in mice lead to osteogenesis imperfecta (OI). Here, we show progressive periodontal defects in mice in which both BMP1 and TLL1 have been conditionally ablated, including malformed periodontal ligament (PDL) (recently shown to play key roles in normal alveolar bone formation), significant loss in alveolar bone mass (P < 0.01), and a sharp reduction in cellular cementum. Molecular mechanism studies revealed a dramatic increase in the uncleaved precursor of type I collagen (procollagen I) and a reduction in dentin matrix protein 1 (DMP1), which is partially responsible for defects in extracellular matrix (ECM) formation and mineralization. We also showed a marked increase in the expression of matrix metallopeptidase 13 (MMP13) and tartrate-resistant acid phosphatase (TRAP), leading to an acceleration in periodontal breakdown. Finally, we demonstrated that systemic application of antibiotics significantly improved the alveolar bone and PDL damage of the knockdown phenotype, which are thus shown to be partially secondary to pathogen-induced inflammation. Together, identification of the novel roles of BMP1 and TLL1 in maintaining homeostasis of periodontal formation, partly via biosynthetic processing of procollagen I and DMP1, provides novel insights into key contributions of the extracellular matrix environment to periodontal homeostasis and contributes toward understanding of the pathology of periodontitis.

A new mutation in exon 2 of the bone morphogenetic protein 15 gene is associated with increase in prolificacy of Mehraban and Lori sheep.

Some mutations in bone morphogenetic protein 15 (BMP15) gene have been known to be associated with prolificacy in various breeds of sheep. Polymorphism of BMP15 gene exon 2 was studied in 100 Mehraban and 100 Lori ewes, using PCR-SSCP and DNA sequencing methods. A new point mutation (G → A) was found at position 57 of the amplified 312-b fragment of BMP15 gene exon 2. The frequencies of the AG and GG genotypes were 69.4 and 30.6% in Mehraban and 44.7 and 55.3% in Lori ewes, respectively. No individual carrying the AA genotype was found in the studied population. The allelic frequencies for A and G alleles were 34.7 and 65.3% in Mehraban and 22.4 and 77.6% in Lori ewes, respectively. Average litter size in the AG genotype (1.56) was significantly (P < 0.01) higher than the GG ewes (1.08). The results of the present study indicated the potential of the observed SNP in exon 2 of BMP15 for further exploitation in marker-assisted selection to improve reproduction efficiency of Mehraban and Lori sheep.

Screening for galway (FecXG), Inverdale (FecXI) and belclare (FecXB) mutations in BMP15 gene in Indian nilagiri sheep

Nilagiri sheep (n = 140) a prolific fine wool breed of India was screened for the presence of FecXG, FecXI and FecXB mutations in Bone Morphogenetic Protein 15 (BMP15)gene using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) technique. The study revealed absence of these mutations in Nilagiri sheep and suggested that these mutations are not responsible for prolificacy in Nilagiri sheep.

Identification of mutations in bone morphogenetic protein 2, 4 and 7 in congenital heart disease patients from Indian population

Background Congenital heart disease (CHD) is the most common congenital defect, affecting 1% of all livebirths. Initial cardiac development and the subsequent maturation of the heart are temporally and spatially regulated by several Bone Morphogenetic Proteins (BMPs). BMP signaling plays an important role in the specification and patterning of the early embryo. Animal model studies have established a strong link between BMPs and cardiac development. At least 6 BMPs (BMP2, BMP4, BMP5, BMP6, BMP7 & BMP10) are expressed in the heart where they have both independent and redundant functions. BMP2, 4 & 7 are expressed in the AtrioVentricular cushion and Out Flow Tract (OFT) and helps in their formation. However due to functional redundancy of BMP ligands, relatively little is known about the role of individual BMPs. The association of BMPs with CHD has not been studied so far in human subjects. Here we report the genetic variants in BMP2 (NM_001200.2), BMP4 (NM_001202.3) and BMP7 (NM_001719.2) in individuals with CHD.

Involvement of BMPR2 in the protective effect of fluoxetine against monocrotaline-induced endothelial apoptosis in rats

Mutations in bone morphogenetic protein (BMP) receptor II (BMPR2) are associated with the apoptosis of the pulmonary artery endothelial cells and the loss of the pulmonary small vessels. The present study was designed to investigate the involvement of BMPR2 in the protective effect of fluoxetine against monocrotaline (MCT)-induced endothelial apoptosis in rats. Models of pulmonary arterial hypertension in rats were established by a single intraperitoneal injection of MCT (60 mg/kg). Fluoxetine (2 and 10 mg/kg) was intragastrically administered once a day. After 21 days, MCT caused pulmonary hypertension, right ventricular hypertrophy, and pulmonary vascular remodeling and significantly reduced the BMPR2 expression in lungs and pulmonary arteries. Fluoxetine dose-dependently inhibited MCT-induced pulmonary arterial hypertension and effectively protected the lungs against MCT-induced endothelial apoptosis, reduction in the number of alveolar sacs, and loss of the pulmonary small vessels. Fluoxetine reversed the expression of cyclic guanosine 3',5'-monophosphate-dependent kinase І, BMPR2, phospho-Smad1, β-catenin, and reduced the expression of caspase 3 in rat lungs. These findings suggest that BMPR2 is probably involved in the protective effect of fluoxetine against MCT-induced endothelial apoptosis in rats.

Mutations in bone morphogenetic protein 15 and growth differentiation factor 9 genes are associated with increased litter size in fat-tailed sheep breeds

The objective of this study was to investigate association between GDF9 and BMP15 gene polymorphism and litter size in fat-tailed sheep, a total of 97 mature ewes from four breeds (Afshari=19; Baluchi=18; Makui=30 and Mehraban=30) were genotyped for the BMP15 HinfI and GDF9 HhaI polymorphisms by PCR-RFLP technique. The highest and lowest mutant allele frequencies were found in Makui (0.27) and Afshari (0.10) sheep for the BMP15 gene and in Afshari (0.24) and Mehraban (0.18) sheep for the GDF9 gene, respectively. Litter size was significantly influenced by genotype of the ewe for two genes (P < 0.01). Heterozygous genotypes for both loci showed higher litter size than homozygous genotypes (P < 0.01). None of the individuals carried homozygous genotype for both of the GDF9 and BMP15 variants in these breeds. The individuals carrying the mutant allele for one of the investigated candidate gene still showed fertile phenotype. Thus, existence of homozygosity at one of the BMP15 and GDF9 variant is not probably able to block normal hormonal pathway of reproduction in fat-tailed sheep.

Hypoxia inhibits hepcidin expression in HuH7 hepatoma cells via decreased SMAD4 signaling

Hepcidin negatively regulates systemic iron homeostasis in response to inflammation and elevated serum iron. Conversely, hepcidin expression is diminished in response to hypoxia, oxidative stress, and increased erythropoietic demand, though the molecular intermediates involved are incompletely understood. To address this, we have investigated hypoxic hepcidin regulation in HuH7 hepatoma cells either cultured alone or cocultured with activated THP-1 macrophages. HuH7 hepcidin mRNA expression was determined using quantitative polymerase chain reaction (Q-PCR). Hepcidin promoter activity was measured using luciferase reporter constructs containing a 0.9 kb fragment of the wild-type human hepcidin promoter, and constructs containing mutations in bone morphogenetic protein (BMP)/SMAD4, signal transducer and activator of transcription 3 (STAT3), CCAAT/enhancer-binding protein (C/EBP), and E-box-responsive elements. Hepatic expression of bone morphogenetic proteins BMP2 and BMP6 and the BMP inhibitor noggin was determined using Q-PCR, and the protein expression of hemojuvelin (HJV), pSMAD 1/5/8, and SMAD4 was determined by western blotting. Following exposure to hypoxia or H(2)O(2), hepcidin mRNA expression and promoter activity increased in HuH7 cells monocultures but were decreased in HuH7 cells cocultured with THP-1 macrophages. This repression was attenuated by mutation of the BMP/SMAD4-response element, suggesting that modulation of SMAD signaling mediated the response to hypoxia. No changes in hepatocyte BMP2, BMP6 or noggin mRNA, or protein expression of HJV or pSMAD 1/5/8 were detected. However, treatment with hypoxia caused a marked decrease in nuclear and cytosolic SMAD4 protein and SMAD4 mRNA expression in cocultured HuH7 cells. Together these data indicate that hypoxia represses hepcidin expression through inhibition of BMP/SMAD signaling.