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Co-immunolocalization of BMP-4 and fibrillins in wild type mouse tissues. A, P3 blood vessel, stained simultaneously with BMP-4 mAb (left panel) and pAb 9543 (specific for fibrillin-1) (middle panel), showed colocalization to fibrillar structures in the wall of the blood vessel. B, sections of dermis demonstrated colocalization of BMP-4 (left panel) and fibrillin-1 (middle panel) to fibrillar structures. C, fibrils in the dermis were also costained with BMP-4 (left panel) and fibrillin-2 pAb 0868 (middle panel). Arrows point to selected fibrils that are stained with both BMP-4 and fibrillin antibodies. Arrowheads indicate fibrils that are well stained with BMP-4 antibodies but not so well stained with fibrillin-2 antibodies. Panels on the right are merged images that also show 4,6-diamidino-2-phenylindole staining of nuclei. Scale bar 20 m.
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Both latent transforming growth factor-beta (TGF-beta)-binding proteins fibrillins are components of microfibril networks, and both interact with members of the TGF-beta family of growth factors. Interactions between latent TGF-beta-binding protein-1 and TGF-beta and between fibrillin-1 and bone morphogenetic protein-7 (BMP-7) are mediated by the p...
Citations
... It has been demonstrated that the growth differentiation factor GDF5 can form a complex with BMP10, and that the N-terminus of fibrillin-1 (a component of the microfibril network that interacts with TGFβ) is the high-affinity interaction site between the two. 72 Fibrillin is an extracellular microfibrillar protein produced by fibroblasts that regulates the physiological functions of connective tissue. The prodomain of BMP10 inhibits its own biological activity, and the BMP10-GDF5 complex is activated by breaking the prodomain and binding to the N-terminus of fibrillin, thereby influencing the downstream connective tissue pathways. ...
Early research suggested that bone morphogenetic protein 10 (BMP10) is primarily involved in cardiac development and congenital heart disease processes. BMP10 is a newly identified cardiac‐specific protein. In recent years, reports have emphasized the effects of BMP10 on myocardial apoptosis, fibrosis and immune response, as well as its synergistic effects with BMP9 in vascular endothelium and role in endothelial dysfunction. We believe that concentrating on this aspect of the study will enhance our knowledge of the pathogenesis of diabetes and the cardiovascular field. However, there have been no reports of any reviews discussing the role of BMP10 in diabetes and cardiovascular disease. In addition, the exact pathogenesis of diabetic cardiomyopathy is not fully understood, including myocardial energy metabolism disorders, microvascular changes, abnormal apoptosis of cardiomyocytes, collagen structural changes and myocardial fibrosis, all of which cause cardiac function impairment directly or indirectly and interact with one another. This review summarizes the research results of BMP10 in cardiac development, endothelial function and cardiovascular disease in an effort to generate new ideas for future research into diabetic cardiomyopathy.
... BMP antagonists directly inhibit BMP or interact with its receptors. 12,49) BMP receptors form a transmembrane receptor complex, with 2 types identified in mammals: type 1 and type 2. Generally, type 2 receptors are known to assist type 1 receptors. Upon binding of BMP dimers to receptors, 2 intracellular signaling pathways, the canonical Smad pathway and non-canonical pathways, are activated. ...
In Part II, we focus on an important aspect of spine fusion in patients with spine trauma: the pivotal role of recombinant human bone morphogenetic protein-2 (rhBMP-2). Despite the influx of diverse techniques facilitated by technological advancements in spinal surgery, spinal fusion surgery remains widely used globally. The persistent challenge of spinal pseudarthrosis has driven extensive efforts to achieve clinically favorable fusion outcomes, with particular emphasis on the evolution of bone graft substitutes. Part II of this review aims to build upon the foundation laid out in Part I by providing a comprehensive summary of commonly utilized bone graft substitutes for spinal fusion in patients with spinal trauma. Additionally, it will delve into the latest advancements and insights regarding the application of rhBMP-2, offering an updated perspective on its role in enhancing the success of spinal fusion procedures.
... Fibrillin contributes to the extracellular regulation of endogenous TGFB activity by providing a structural platform that controls the diffusion, storage, presentation, and release (Ramirez and Sakai, 2010). In addition, they also interact with the prodomains of bone morphogenic proteins (BMPs) and growth and differentiation factors (GDFs; Sengle et al., 2008), which are members of the TGFB superfamily and have been described as important for ovarian follicular development and function (Dong et al., 1996;McNatty et al., 2000;Yan et al., 2001;Knight and Glister, 2006). Taurine animals have been shown to have more preantral follicles than indicine animals. ...
The number of antral follicles is considered an important fertility trait because animals with a high follicle count (HFC) produce more oocytes and embryos per cycle. Identification of these animals by genetic markers such as single nucleotide polymorphisms (SNPs) can accelerate selection of future generations. The aim of this study was to perform a genome wide association study (GWAS) on Nelore and Angus heifers with HFC and low (LFC) antral follicle counts. The groups HFC and LFC for genotyping were formed based on the average of total follicles (≥ 3 mm) counted in each breed consistently ± standard deviation. A total of 72 Nelore heifers (32 HFC and 40 LFC) and 48 Angus heifers (21 HFC and 27 LFC) were selected and the DNA was extracted from blood and hair bulb. Genotyping was done using the Illumina Bovine HD 770K BeadChip. The GWAS analysis showed 181 and 201 SNPs with genotype/phenotype association (P ≤ 0.01) in Nelore and Angus heifers, respectively. Functional enrichment analysis was performed on candidate genes that were associated with SNPs. A total of 97 genes were associated to the 181 SNPs in the Nelore heifers and the functional analysis identified genes (ROBO1 and SLIT3) in the ROBO-SLIT pathway that can be involved in the control of germ cell migration in the ovary as it is involved in lutheal cell migration and fetal ovary development. In the Angus heifers, 57 genes were associated with the 201 SNPs, highlighting Fribilin 1 (FBN1) gene, involved in regulation of growth factors directly involved in follicle activation and development. In summary, GWAS for Nelore and Angus heifers showed SNPs associated with higher follicle count phenotype. Furthermore, these findings offer valuable insights for the further investigation of potential mechanism involved in follicle formation and development, important for breeding programs for both breeds.
... Studies show that FBN1 controls the bioavailability of extracellular TGF-β, modulates cell behaviors, and regulates cell survival and differentiation (Jensen et al., 2012). Furthermore, FBN1 also directly interacts with various bone morphogenetic proteins (BMPs) (Gregory et al., 2005;Sengle et al., 2008;Weinbaum et al., 2008;Sengle et al., 2011;Wohl et al., 2016) and activates other signal pathways, such as the mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription (STAT) signaling (Wang Z. et al., 2022). FBN1 is often found to be dysregulated in several human diseases such as cancer, cardiovascular and kidney diseases. ...
... It is worth noting that FBN1 itself has seven variable affinity heparin binding sites (Cain et al., 2005;Cain et al., 2008;Yadin et al., 2013;Sabatier et al., 2014), which have the ability to interact with heparan sulfate chains. In addition, previous studies have demonstrated that certain growth factors, such as BMP-2, BMP-4, BMP-5, BMP-7, BMP-10, and growth differentiation factor 5 (GDF-5), exhibit varying affinities when binding to recombinant segments of FBN1 in the N-terminal region (Sengle et al., 2008;Sengle et al., 2011;Sengle et al., 2012;Spanou et al., 2023). ...
... FBN1 also directly interacts with a variety of BMPs, such as BMP-2, -4, -7 and -10 (Sengle et al., 2008;Sengle et al., 2011;Wohl et al., 2016), and osteoclastogenic cytokine receptor activator of nuclear factor κB ligand (RANKL) across multiple cellular microenvironments (Tiedemann et al., 2013). FBN1 can also indirectly regulate TGF-β signaling through its binding partner MAGP1. ...
Fibrillin-1 (FBN1) is a large, cysteine-rich, calcium binding extracellular matrix glycoprotein encoded by FBN1 gene. It serves as a structural component of microfibrils and provides force-bearing mechanical support in elastic and nonelastic connective tissue. As such, mutations in the FBN1 gene can cause a wide variety of genetic diseases such as Marfan syndrome, an autosomal dominant disorder characterized by ocular, skeletal and cardiovascular abnormalities. FBN1 also interacts with numerous microfibril-associated proteins, growth factors and cell membrane receptors, thereby mediating a wide range of biological processes such as cell survival, proliferation, migration and differentiation. Dysregulation of FBN1 is involved in the pathogenesis of many human diseases, such as cancers, cardiovascular disorders and kidney diseases. Paradoxically, both depletion and overexpression of FBN1 upregulate the bioavailability and signal transduction of TGF-β via distinct mechanisms in different settings. In this review, we summarize the structure and expression of FBN1 and present our current understanding of the functional role of FBN1 in various human diseases. This knowledge will allow to develop better strategies for therapeutic intervention of FBN1 related diseases.
... While the results from this current study do not rule out the possibility that some promature BMP15 and GDF9 is secreted in a semi-processed non-covalently associated state, there is strong evidence that a significant portion is in an unprocessed form due to the presence of bands under reducing conditions. While secreted uncleaved promature forms are not common amongst the other TGFβ superfamily members, a number of studies using cell lines producing recombinant human, sheep or mouse BMP15 have observed uncleaved promature forms 18,28,29,42,43 . Therefore, the presence of uncleaved promature BMP15 and GDF9 may allow each species to have additional species-specific extracellular mechanisms for regulation of BMP15 signalling. ...
Bone morphogenetic protein (BMP15) and growth differentiation factor (GDF9) are critical for ovarian follicular development and fertility and are associated with litter size in mammals. These proteins initially exist as pre-pro-mature proteins, that are subsequently cleaved into biologically active forms. Thus, the molecular forms of GDF9 and BMP15 may provide the key to understanding the differences in litter size determination in mammals. Herein, we compared GDF9 and BMP15 forms in mammals with high (pigs) and low to moderate (sheep) and low (red deer) ovulation-rate. In all species, oocyte lysates and secretions contained both promature and mature forms of BMP15 and GDF9. Whilst promature and mature GDF9 levels were similar between species, deer produced more BMP15 and exhibited, together with sheep, a higher promature:mature BMP15 ratio. N-linked glycosylation was prominant in proregion and mature GDF9 and in proregion BMP15 of pigs, and present in proregion GDF9 of sheep. There was no evidence of secreted native homo- or hetero-dimers although a GDF9 dimer in red deer oocyte lysate was detected. In summary, GDF9 appeared to be equally important in all species regardless of litter size, whilst BMP15 levels were highest in strict monovulatory species.
... Furthermore, BMP signalling is also regulated through interaction of BMPs with the ECM, thereby restricting the local BMP bioavailability. BMPs interact, e.g., with fibronectin [27,28], collagens [29,30], fibrillin [31,32], and heparins [33]. Heparin binding of some BMPs (including BMP-2) was shown to have dual activity. ...
Disturbances in bone morphogenetic protein (BMP) signalling contribute to onset and development of a number of rare genetic diseases, including Fibrodysplasia ossificans progressiva (FOP), Pulmonary arterial hypertension (PAH), and Hereditary haemorrhagic telangiectasia (HHT). After decades of animal research to build a solid foundation in understanding the underlying molecular mechanisms, the progressive implementation of iPSC-based patient-derived models will improve drug development by addressing drug efficacy, specificity, and toxicity in a complex humanized environment. We will review the current state of literature on iPSC-derived model systems in this field, with special emphasis on the access to patient source material and the complications that may come with it. Given the essential role of BMPs during embryonic development and stem cell differentiation, gain- or loss-of-function mutations in the BMP signalling pathway may compromise iPSC generation, maintenance, and differentiation procedures. This review highlights the need for careful optimization of the protocols used. Finally, we will discuss recent developments towards complex in vitro culture models aiming to resemble specific tissue microenvironments with multi-faceted cellular inputs, such as cell mechanics and ECM together with organoids, organ-on-chip, and microfluidic technologies.
... In addition to their role in elastic fiber assembly, fibrillin microfibrils mediate tissue homeostasis, which when perturbed by fibrillin mutations causes a number of heritable connective tissue disorders, such as Marfan syndrome and Weill-Marchesani syndrome (WMS) 21 . This tissue homeostasis is mediated via fibrillin interactions with cell-surface receptors (such as integrins [22][23][24][25] and heparan sulfate proteoglycans 26 ) and with growth factors (including TGFβ and bone morphogenetic proteins (BMPs) [27][28][29]. Of the four LTBP isoforms, LTBP-1, -3 and -4 play important roles in the processing and secretion of TGFβ 30 , through covalent binding to the latency-associated peptide of TGFβ, producing the large latent complex (LLC) of TGFβ 31,32 . ...
Genetic mutations in fibrillin microfibrils cause serious inherited diseases, such as Marfan syndrome and Weill–Marchesani syndrome (WMS). These diseases typically show major dysregulation of tissue development and growth, particularly in skeletal long bones, but links between the mutations and the diseases are unknown. Here we describe a detailed structural analysis of native fibrillin microfibrils from mammalian tissue by cryogenic electron microscopy. The major bead region showed pseudo eightfold symmetry where the amino and carboxy termini reside. On the basis of this structure, we show that a WMS deletion mutation leads to the induction of a structural rearrangement that blocks interaction with latent TGFβ-binding protein-1 at a remote site. Separate deletion of this binding site resulted in the assembly of shorter fibrillin microfibrils with structural alterations. The integrin αvβ3-binding site was also mapped onto the microfibril structure. These results establish that in complex extracellular assemblies, such as fibrillin microfibrils, mutations may have long-range structural consequences leading to the disruption of growth factor signaling and the development of disease.
... [27][28][29][30][31] To better understand how targeting of BMPs by the ECM controls their bioavailability, the presence of BMPs as PD-GF CPLXs has to be considered. [32][33][34][35][36] Three modes have been proposed for how PDs may regulate GF BMP-10 GF and CPLX do not interact with heparin. Bioactivity assays on solid phase in combination with interaction studies showed that the BMP-7 PD protects the BMP-7 GF from inactivation by heparin. ...
... bone morphogenetic protein, complex, ELISA-style bioactivity assay, growth factor, heparan sulfate, heparan sulfate proteoglycans, heparin, heparin affinity chromatography, molecular modeling, negative-staining transmission electron microscopy, prodomain, surface plasmon resonance, vascular endothelial growth factor | 3 of 25 SPANOU et al. activity. 34 For BMP-2, it was shown that it does not form stable CPLXs with its cognate PD. 33 Therefore, studying BMP-2 GF bioactivity in absence of the PD may be still relevant for physiological processes. However, other TGF-β superfamily members form stable CPLXs with their PDs of which some are bioactive and some remain latent when soluble. ...
... For the generation of the human BMP-10/9 hybrid PD, the following specific amino acid stretches in BMP-10 PD were replaced by corresponding stretches in BMP-9 PD: All cDNA sequences were cloned via NdeI/BamHI sites into the pET11a expression vector as previously described. 33,34,41,42 N-terminal fibrillin-1 fragments rF90 (S 19 -V 1527 ), start_cbEGF4 (S 19 -E 571 ), rF87 (S 19 -Ile 329 ), as well as indicated N-terminal truncation variants of rF87 (A: G 55 -Ile 329 , B: R 62 -Ile 329 , C: G 70 -Ile 329 , D: G 77 -Ile 329 ) as well as BMP-7 CPLX were expressed and purified as previously described. [32][33][34]41 All fibrillin-1 protein fragments designed to start with S 19 commenced instead with R 45 as shown by N-terminal Edman degradation (Proteome Factory AG, Berlin, Germany). ...
Bone morphogenetic proteins (BMP) are powerful regulators of cellular processes such as proliferation, differentiation, and apoptosis. However, the specific molecular requirements controlling the bioavailability of BMPs in the extracellular matrix (ECM) are not yet fully understood. Our previous work showed that BMPs are targeted to the ECM as growth factor‐prodomain (GF‐PD) complexes (CPLXs) via specific interactions of their PDs. We showed that BMP‐7 PD binding to the extracellular microfibril component fibrillin‐1 renders the CPLXs from an open, bioactive V‐shape into a closed, latent ring shape. Here, we show that specific PD interactions with heparin/heparan sulfate glycosaminoglycans (GAGs) allow to target and spatially concentrate BMP‐7 and BMP‐9 CPLXs in bioactive V‐shape conformation. However, targeting to GAGs may be BMP specific, since BMP‐10 GF and CPLX do not interact with heparin. Bioactivity assays on solid phase in combination with interaction studies showed that the BMP‐7 PD protects the BMP‐7 GF from inactivation by heparin. By using transmission electron microscopy, molecular docking, and site‐directed mutagenesis, we determined the BMP‐7 PD‐binding site for heparin. Further, fine‐mapping of the fibrillin‐1‐binding site within the BMP‐7 PD and molecular modeling showed that both binding sites are mutually exclusive in the open V‐ versus closed ring‐shape conformation. Together, our data suggest that targeting exquisite BMP PD‐binding sites by extracellular protein and GAG scaffolds integrates BMP GF bioavailability in a contextual manner in development, postnatal life, and connective tissue disease.
... Studies in mouse models showed that aspects of the phenotype associated with Fbn1 and Fbn2 mutations could be ascribed to a failure to appropriately control the bioavailability of TFGβ [20,21]. Fibrillin-1 also sequesters bone morphogenetic proteins (BMPs) and the osteoclastogenic factor TNFSF11 (also known as RANKL; MIM 602642) [22][23][24][25]. These regulatory roles indicate the second probable function of fibrillins. ...
Fibrillin-1 is a major component of the extracellular microfibrils, where it interacts with other extracellular matrix proteins to provide elasticity to connective tissues, and regulates the bioavailability of TGFβ family members. A peptide consisting of the C-terminal 140 amino acids of fibrillin-1 has recently been identified as a glucogenic hormone, secreted from adipose tissue during fasting and targeting the liver to release glucose. This fragment, called asprosin, also signals in the hypothalamus to stimulate appetite. Asprosin levels are correlated with many of the pathologies indicative of metabolic syndrome, including insulin resistance and obesity. Previous studies and reviews have addressed the therapeutic potential of asprosin as a target in obesity, diabetes and related conditions without considering mechanisms underlying the relationship between generation of asprosin and expression of the much larger fibrillin-1 protein. Profibrillin-1 undergoes obligatory cleavage at the cell surface as part of its assembly into microfibrils, producing the asprosin peptide as well as mature fibrillin-1. Patterns of FBN1 mRNA expression are inconsistent with the necessity for regulated release of asprosin. The asprosin peptide may be protected from degradation in adipose tissue. We present evidence for an alternative possibility, that asprosin mRNA is generated independently from an internal promoter within the 3' end of the FBN1 gene, which would allow for regulation independent of fibrillin-synthesis and is more economical of cellular resources. The discovery of asprosin opened exciting possibilities for treatment of metabolic syndrome related conditions, but there is much to be understood before such therapies could be introduced into the clinic.
... Polyclonal rabbit anti-FBN1 antiserum (WB: 1:2,000, IF: 1:1,000) was raised against the recombinantly produced N-terminal half of human FBN1 (F90). 20 Polyclonal rabbit anti-EMILIN1 antiserum was raised against a recombinant fragment (Gly173-Gly815), 3 a rabbit monoclonal antibody detecting N-terminal residues of EMILIN1 was obtained from Abcam (#ab185953, WB: 1:500). Polyclonal rabbit antibodies recognizing mouse and human EFEMP2 (WB, IF: 1:1,000), as well as a monoclonal antibody recognizing human EFEMP2 used for immunogold labeling were generated as previously described. ...
EMILIN1 (elastin-microfibril-interface-located-protein-1) is a structural component of the elastic fiber network and localizes to the interface between the fibrillin microfibril scaffold and the elastin core. How EMILIN1 contributes to connective tissue integrity is not fully understood. Here, we report bi-allelic EMILIN1 loss-of-function variants causative for an entity combining cutis laxa, arterial tortuosity, aneurysm formation, and bone fragility, resembling autosomal-recessive cutis laxa type 1B, due to EFEMP2 (FBLN4) deficiency. In both humans and mice, absence of EMILIN1 impairs EFEMP2 extracellular matrix deposition and LOX activity resulting in impaired elastogenesis, reduced collagen crosslinking, and aberrant growth factor signaling. Collagen fiber ultrastructure and histopathology in EMILIN1- or EFEMP2-deficient skin and aorta corroborate these findings and murine Emilin1−/− femora show abnormal trabecular bone formation and strength. Altogether, EMILIN1 connects elastic fiber network with collagen fibril formation, relevant for both bone and vascular tissue homeostasis.
