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The document discusses the impact of loss-of-function mutations in Bone Morphogenetic Protein Receptor 2 (BMPR2) on the pulmonary vasculature in pulmonary arterial hypertension (PAH). The study focuses on identifying which cell lineages in and around pulmonary arteries are affected by derangements in BMPR2 signaling in PAH vascular lesions. Through high-resolution imaging and spatial mRNA profiling, the researchers found that specific subsets of endothelial and mesenchymal cells within vascular lesions express Bone Morphogenetic Protein-responsive transcription factors ID1 and ID3 at significantly higher levels compared to other cells in the lung. The study suggests that the role of BMPR2 signaling in PAH pathogenesis is more complex than previously thought, potentially implicating extravascular cells in disease development. [Extracted from the article]

Rationale: Although sex differences in right heart phenotypes have been observed, the molecular drivers remain unknown. Objectives: To provide biological insights into sex differences in the structure and function of the right ventricle (RV) using common genetic variation. Methods: RV phenotypes were obtained from cardiac magnetic resonance imaging in 18,156 women and 16,171 men from the UK Biobank. Observational analyses and sex-stratified genome-wide association studies were performed. Candidate female-specific loci were evaluated against invasively measured cardiac performance in 479 female patients with idiopathic or heritable pulmonary arterial hypertension (PAH), recruited to the UK National Institute for Health Research BioResource Rare Diseases study. Measurements and Main Results: Sex was associated with differences in RV volumes and ejection fraction in models adjusting for left heart counterparts, blood pressure, lung function, and sex hormone concentrations. Six genome-wide significant loci (13%) revealed heterogeneity of allelic effects between women and men and significant sex-by-genotype interaction. These included two sex-specific candidate loci present in women only: a locus for RV ejection fraction in BMPR1A (bone morphogenetic protein receptor type 1A) and a locus for RV end-systolic volume near DMRT2 (doublesex and mab-3 related transcription factor 2). Epigenetic data in RV tissue indicate that variation at the BMPR1A locus likely alters transcriptional regulation. In female patients with PAH, a variant located in the promoter of BMPR1A was significantly associated with cardiac index (effect size, 0.16 L/min/m2), despite similar RV afterload. Conclusions:BMPR1A has emerged as a biologically plausible candidate gene for female-specific genetic determination of RV function, showing associations with cardiac performance under chronically increased afterload in female patients with PAH. [ABSTRACT FROM AUTHOR]

Introduction: Idiopathic pulmonary arterial hypertension (IPAH) is a progressive and fatal disease. The aim of this study was to evaluate the association of polymorphism of the type 2 bone morphogenetic protein receptor gene (BMPR2) with the risk of IPAH development in an ethnic group of Kazakhs. We also describe the clinical and hemodynamic characteristics and outcomes of patients with and without carriers of BMPR2 gene mutations in IPAH. No available research highlights this problem in an ethnic group of Kazakhs. Materials and methods: A total of 53 patients of only Kazakh nationality with IPAH participated in the study. Clinical, functional, and hemodynamic characteristics, as well as the outcome of the disease, were compared among carriers and non-carriers of the BMPR2 mutation. Results: When receiving IPAH diagnosis, the average age of patients was 40.0 (32.0–48.0) years. Women predominated among the patients (86.8%). Of these, 17 (32.0%) were carriers of the gene mutation, and 36 (68.0%) did not have this mutation. The results of our research demonstrate that the Rs17199249 variant in BMPR2 contributed to increased susceptibility to IPAH. The T allele was associated with an increased risk of IPAH, with T = 75 (70.75%), G = 31 (29.24%), MAF—0.2925, x2—0.001, and HWE p—0.975. Carriers of the BMPR2 mutation were predominantly women (80.0%), and they had higher pulmonary vascular resistance (8.7–14.9 vs. 5.9–12.6 WU; p = 0.038), a low cardiac index (1.9–2.6 vs. 2.3–3.1 L/min per m2; p = 0.027), and a shorter time to death (p = 0.022). Conclusions: This is the first study of the genetic causes of IPAH that demonstrates the genetic polymorphism of BMPR2 is associated with an increased risk of IPAH developing with worse hemodynamic parameters and clinical outcomes. [ABSTRACT FROM AUTHOR]

Background: Lumbar disc degeneration (LDD) is a ubiquitous finding in low back pain. Many different etiology factors may explain the LDD process, such as bone morphogenetic proteins (BMPs), DNA methylation, and gut microbiota. Until recently the mechanisms underlying the LDD process have been elusive. Methods: BMP‐related genes were extracted from the GeneCards database. The LDD transcriptome dataset was obtained from the Gene Expression Omnibus. We used linear regression and meta‐analysis to screen and integrate the differentially expressed genes associated with BMPs in LDD. Genome‐wide association studies (GWASs) of LDD were from FinnGen and UKBB. The expression quantitative trait loci (eQTLs) and DNA methylation quantitative trait loci from the blood were identified via the summary data‐based Mendelian randomization (SMR) method, and the possible blood BMP genes and their regulatory elements associated with the risk of LDD were prioritized. Intestinal eQTLs and fecal microbial QTLs (mbQTLs) were integrated, and the potential interactions between BMP gene expression in host intestinal tissue and the gut microbiota were revealed through SMR and colocalization analysis. The GWAS catalog (GCST90246169) was used to validate SMR results. Results: A meta‐analysis of five datasets revealed that 113 BMP genes were differentially expressed between LDD and control tissues. Seven genes were selected as candidate pathogenic genes of LDD via the three‐step SMR method: CREB1, BMP6, PTCH1, GLI1, MEG3, GALNS, and NF1. SMR analysis also revealed five possible gut genes: HFE, MET, MAPK3, NPC1, and GDF5. The correlation between the gut microbiota and BMP gene expression in intestinal tissues was verified by eQTL‐mbQTL colocalization. Conclusion: This multi‐omics study revealed that the BMP genes associated with LDD are regulated by DNA methylation. There are genetic differences between gut gene expression and the gut microbiota. These findings provide evidence for new therapeutic targets in the future. [ABSTRACT FROM AUTHOR]

Exercise hemodynamics are recommended for early detection of pulmonary arterial hypertension (PAH) and have been suggested to be predictive of future development of PAH in high-risk populations such as BMPR2 mutation carriers. However, the optimal exercise hemodynamic screening parameter remains to be determined. Recent data suggest that pulmonary vascular distensibility (α) may serve as a useful parameter for early detection of PAH. What is the value of exercise hemodynamics, including α, for predicting the occurrence of PAH during long-term follow-up in BMPR2 mutation carriers? Fifty-two asymptomatic BMPR2 mutation carriers who underwent symptom-limited exercise hemodynamic assessment were followed up for a median of 10 years. The impact of hemodynamics at rest and exercise, presence of exercise pulmonary hypertension, and α on occurrence of PAH during long-term follow-up were assessed. During long-term follow-up, five patients developed PAH. Patients who developed PAH showed a significantly lower α (0.8 ± 0.4%/mm Hg) than patients without PAH (1.8 ± 0.8%/mm Hg; P =.008). The only hemodynamic parameter that predicted the occurrence of PAH during long-term follow-up at regression analysis was α. Receiver operating characteristic analysis showed that α ≤ 1.5%/mm Hg predicted PAH occurrence with a specificity of 75% and sensitivity of 100%. The results of this study indicate that before development of PAH in BMPR2 mutation carriers, α is reduced markedly and may serve as a useful parameter in the setting of early disease detection. Given the low event rate, caution is warranted in interpreting these results, highlighting the need for validation studies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Eucommia ulmoides has a certain osteogenic effect, which can promote the proliferation and differentiation of osteoblasts. However, it is unclear whether Eucommia ulmoides has effects on alveolar bone formation and Wnt/β-Catenin signaling pathway. OBJECTIVE: To investigate the mechanism by which Eucommia ulmoides promotes alveolar bone formation in ovariectomized rats based on the Wnt/β-Catenin signaling pathway. METHODS: Sixty female Sprague-Dawley rats were selected and randomly divided into five groups: blank control group, sham-operation group, model group, low-dose group Eucommia ulmoides group, and high-dose Eucommia ulmoides group, with twelve rats in each group. Osteoporosis animal models were constructed by bilateral oophorectomy in the model group and the low-dose and high-dose Eucommia ulmoides groups. The sham-operation group underwent the same method to remove adipose tissue of equal mass around the bilateral ovaries. Three months after surgery, the low- and high-dose Eucommia ulmoides groups were given 2.1 g/kg/d and 4.2 g/kg/d Eucommia ulmoides by gavage, respectively. The sham-operation group and model group were given the same amount of physiological saline by gavage. After 12 weeks of drug intervention, the changes in alveolar bone mass of rats in each group were observed through Micro-CT; hematoxylin-eosin staining was used to observe the pathological structural changes of alveolar bone in rats; enzyme linked immunosorbent assay was used to detect the expression levels of alkaline phosphatase and osteocalcin in the serum of rats; western blot was used to detect the expression levels of β-Catenin and Frizzled9 receptor proteins in the alveolar bone of rats; and real-time fluorescence quantitative PCR was used to detect the expression of osteocalcin, Runt-related transcription factor 2 (Runx2), alkaline phosphatase, β-catenin, and frizzled9 mRNAs in alveolar bone tissues of rats. RESULTS AND CONCLUSION: Compared with the blank control group, bone volume fraction, trabecular number, trabecular thickness, and bone mineral density were reduced in the model group (P < 0.05), and trabecular separation was elevated (P < 0.05). Pathological observation showed that the arrangement of trabeculae was disordered and irregular, the trabeculae were thinned or broken, and the marrow cavity was enlarged in the model group, with a significant reduction in bone volume; the level of alkaline phosphatase in the serum was increased (P < 0.05), and the level of osteocalcin was decreased (P < 0.05); mRNA expression of alkaline phosphatase, osteocalcin, Runx2, β-catenin, and frizzled9 were decreased (P < 0.05); protein expression of β-Catenin and Frizzled9 was decreased (P < 0.05). Compared with the model group, the low- and high-dose Eucommia ulmoides groups showed an increase in bone volume fraction, trabecular number, trabecular thickness, and bone mineral density (P < 0.05) and a decrease in trabecular separation (P < 0.05). In the low- and high-dose Eucommia ulmoides groups, bone trabeculae were slightly aligned and thickened, with a significant increase in bone mass. Compared with the model group, the serum level of alkaline phosphatase was reduced (P < 0.05) and the serum level of osteocalcin was elevated (P < 0.05) in the low- and high-dose Eucommia ulmoides groups. Compared with the model group, the mRNA expression of alkaline phosphatase, osteocalcin, Runx2, β-catenin, and frizzled9 were increased in the low- and high-dose Eucommia ulmoides groups (P < 0.05). Compared with the model group, the protein expression of Frizzled9 was increased in the lowdose Eucommia ulmoides group (P < 0.05), while the protein expression of β-Catenin and Frizzled9 was increased in the high-dose Eucommia ulmoides group (P < 0.05). Compared with the low-dose Eucommia ulmoides group, the high-dose Eucommia ulmoides group had a more significant improvement in the above indexes. To conclude, Eucommia ulmoides can effectively promote the alveolar bone formation, and its mechanism of action might be related to the activation of the Wnt/β-catenin signaling pathway [ABSTRACT FROM AUTHOR]

BACKGROUND: Polylactic acid (PLA) has good biocompatibility and a controllable degradation rate and is currently widely used in biomedical engineering. However, PLA has shortcomings such as low mechanical strength and insufficient biological activity, which limits its further application in bone tissue engineering. OBJECTIVE: To construct polylactic acid/polydopamine/tantalum (PLA/PDA/Ta) bone tissue engineering scaffolds, and explore their biosafety and in vitro osteogenesis. METHODS: A PLA scaffold with a porous structure was prepared through liquid crystal display light-curing technology. PLA/PDA scaffolds and PLA/PDA/Ta scaffolds were prepared by soaking PLA scaffolds in dopamine solution and dopamine-tantalum nanoparticle solution, respectively. The microstructure and water contact angle of scaffolds were characterized. MC3T3-E1 cells were co-cultured with PLA, PLA/PDA, and PLA/PDA/Ta scaffolds, respectively, and CCK-8 assay and live/dead cell staining were performed. After osteogenic differentiation, alkaline phosphatase, alizarin red staining, and osteogenic gene detection were performed. RESULTS AND CONCLUSION: (1) The scanning electron microscope results exhibited that the three kinds of prepared scaffolds had an interconnected porous three-dimensional structure, and the average pore diameter was 200 μm. The water contact angle of PLA/PDA/Ta scaffolds was lower than that of PLA and PLA/ PDA scaffolds (P < 0.05). (2) CCK-8 assay showed that compared with PLA and PLA/PDA scaffolds, PLA/PDA/Ta scaffolds could promote cell proliferation (P < 0.05). Live/dead cell staining showed good cell proliferation in the three groups. (3) Alkaline phosphatase and alizarin red staining showed that compared with PLA and PLA/PDA scaffolds, PLA/PDA/Ta scaffolds could promote the expression of alkaline phosphatase and the formation of mineralized nodules. RT-qPCR showed that compared with PLA and PLA/PDA scaffolds, PLA/PDA/Ta scaffolds could enhance the mRNA expression of cell bone morphogenetic protein, Runx- 2, and type I collagen (P < 0.05, P < 0.01). (4) The results showed that the PLA/PDA/Ta scaffold had excellent osteogenic activity and the ability to promote cell proliferation. [ABSTRACT FROM AUTHOR]

Background: Pulmonary arterial hypertension is a life-threatening progressive disorder characterised by high blood pressure (hypertension) in the arteries of the lungs (pulmonary artery). Although treatable, there is no known cure for this rare disorder, and its exact cause is unknown. Mutations in the bone morphogenetic protein receptor type-2 (BMPR2) are the most common genetic cause of familial pulmonary arterial hypertension. This study represents the first-ever trial of treatments aimed at directly rescuing the BMPR2 pathway, repurposing two drugs that have shown promise at restoring levels of BMPR2 signalling: hydroxychloroquine and phenylbutyrate. Methods: This three-armed phase II precision medicine study will investigate BMPR2 target engagement and explore the efficacy of two repurposed therapies in pulmonary arterial hypertension patients with BMPR2 mutations. Patients will be stratified based on two BMPR2 mutation classes: missense and haploinsufficient mutations. Eligible subjects will be randomised to one of the three arms (two active therapy arms and a placebo arm, all plus standard of care) following a Bayesian response-adaptive design implemented independently in each stratum and updated in response to a novel panel of primary biomarkers designed to assess biological modification of the disease. Discussion: The results of this trial will provide the first randomised evidence of the efficacy of these therapies to rescue BMPR2 function and will efficiently explore the potential for a differential response of these therapies per mutation class to address causes rather than consequences of this rare disease. Trial registration: The study has been registered with ISRCTN (ISRCTN10304915, 22/09/2023). [ABSTRACT FROM AUTHOR]

Background: Acromesomelic chondrodysplasias are a rare subgroup of the clinically and genetically heterogeneous osteochondrodysplasias that are characterised by abnormalities in the limb development and short stature. Here, we report a 2‐year‐old boy, offspring of consanguineous parents, with acromesomelic dysplasia and postaxial polydactyly in which exome sequencing identified a novel homozygous missense variant in BMPR1B. The patient showed skeletal malformation of both hands and feet that included complex brachydactyly with the thumbs most severely affected, postaxial polydactyly of both hands, shortened toes as well as a bilateral hypoplasia of the fibula. Methods: Whole trio exome sequencing was conducted to identify potential genetic variants in the patient. Results: The analysis identified the biallelic variant NM_001203.3:c.821A > G;p.(Gln274Arg) in BMPR1B, a gene encoding bone morphogenetic protein receptor 1B. Conclusion: The skeletal phenotype can be brought in line with the phenotypes of previously reported cases of BMPR1B‐associated chondrodysplasias. However, the postaxial polydactyly described here is a novel clinical finding in a BMPR1B‐related case; notably, it has previously been reported in other acromesomelic dysplasia cases caused by homozygous pathogenic variants in GDF5—a gene which encodes for growth differentiation factor 5, a high‐affinity ligand to BMPR1B. [ABSTRACT FROM AUTHOR]

Fragile X mental retardation protein (FMRP) is a translational repressor encoded by FMR1. It targets bone morphogenetic protein receptor type II (BMPR2), which regulates granulosa cell (GC) function and follicle development. However, whether this interaction affects folliculogenesis remains unclear. Therefore, this study investigated the potential effect of FMRP-BMPR2 dysregulation in ovarian reserves and infertility. COV434 cells and patient-derived GCs were used to evaluate FMRP and BMPR2 expression. Similarly, FMR1, BMPR2, LIMK1, and SMAD expression were evaluated in GCs with normal (NOR) and poor (POR) ovarian responses. FMRP and BMPR2 were expressed in both cell types. They were co-localized to the nuclear membrane of COV434 cells and cytoplasm of primary GCs. FMR1 silencing increased the mRNA and protein levels of BMPR2. However, the mRNA levels of FMR1 and BMPR2 were significantly lower in the POR group. FMR1 and BMPR2 levels were strongly positively correlated in the NOR group but weakly correlated in the POR group. Additionally, SMAD9 expression was significantly reduced in the POR group. This study highlights the crucial role of FMR1/FMRP in the regulation of BMPR2 expression and its impact on ovarian function. These findings indicate that the disruption of FMRP-BMPR2 interactions may cause poor ovarian responses and infertility. [ABSTRACT FROM AUTHOR]

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. Genetic studies have discovered multiple mutations and genetic risk factors that have helped to understand how ovulation rate is controlled in low ovulating species to regulate the numbers of offspring and maximise reproductive success. Most genes identified are from pathways with defined roles in regulation of the ovarian follicle development. Continued genetic studies can continue to improve detailed understanding of the regulation of ovulation rate and litter size with implications for health and animal production systems. Image by G. W. Montgomery. This article belongs to the Collection The biology of the ovary – Honouring the contributions of Ken P McNatty and Rex J Scaramuzzi. [ABSTRACT FROM AUTHOR]

[Display omitted] • The immune response and inflammation in pulmonary hypertension (PH) have been systematically summarized based on recent studies. • The relationship between CC chemokines and the pathogenesis of pH is summarized in clinical and animal models. • We found that although the immune response serves as an important potential factor in the pathogenesis of PH, less attention has been paid to CC chemokines and their receptors. • We believe that a greater understanding of the relationship between PH and CC chemokines and their receptors is a pressing issue. • We believe that we need to further clarify the pathogenesis of pH and provide basis for the clinical treatment of PH. Pulmonary hypertension (PH) represents a progressive condition characterized by the remodeling of pulmonary arteries, ultimately culminating in right heart failure and increased mortality rates. Substantial evidence has elucidated the pivotal role of perivascular inflammatory factors and immune dysregulation in the pathogenesis of PH. Chemokines, a class of small secreted proteins, exert precise control over immune cell recruitment and functionality, particularly with respect to their migration to sites of inflammation. Consequently, chemokines emerge as critical drivers facilitating immune cell infiltration into the pulmonary tissue during inflammatory responses. This review comprehensively examines the significant contributions of CC chemokines in the maintenance of immune cell homeostasis and their pivotal role in regulating inflammatory responses. The central focus of this discussion is directed towards elucidating the precise immunoregulatory actions of CC chemokines concerning various immune cell types, including neutrophils, monocytes, macrophages, lymphocytes, dendritic cells, mast cells, eosinophils, and basophils, particularly in the context of pH processes. Furthermore, this paper delves into an exploration of the underlying pathogenic mechanisms that underpin the development of PH. Specifically, it investigates processes such as cellular pyroptosis, examines the intricate crosstalk between bone morphogenetic protein receptor type 2 (BMPR2) mutations and the immune response, and sheds light on key signaling pathways involved in the inflammatory response. These aspects are deemed critical in enhancing our understanding of the complex pathophysiology of PH. Moreover, this review provides a comprehensive synthesis of findings from experimental investigations targeting immune cells and CC chemokines. Aim of review : In summary, the inquiry into the inflammatory responses mediated by CC chemokines and their corresponding receptors, and their potential in modulating immune reactions, holds promise as a prospective avenue for addressing PH. The potential inhibition of CC chemokines and their receptors stands as a viable strategy to attenuate the inflammatory cascade and ameliorate the pathological manifestations of PH. Nonetheless, it is essential to acknowledge the current state of clinical trials and the ensuing progress, which regrettably appears to be less than encouraging. Substantial hurdles exist in the successful translation of research findings into clinical applications. The intention is that such emphasis could potentially foster the advancement of potent therapeutic agents presently in the process of clinical evaluation. This, in turn, may further bolster the potential for effective management of PH. [ABSTRACT FROM AUTHOR]

Objective: The present study aimed to investigate the involvement of aberrant BMP8A expression in TNBC and bone metastasis. Methods: Aberrant expression of BMP8A in breast cancer was first determined by analyzing The Cancer Genome Atlas breast cancer cohort (TCGA-BRCA) and an immunohistochemical (IHC) staining of BMP8A in a breast cancer tissue microarray (TMA). Clinical relevance of deregulated BMP8A in breast cancer was assessed using Kaplan-Meier online analysis. The influence of BMP8A on cellular functions of two TNBC cell lines was assessed using in vitro assays. Conditional medium (CM) collected from the supernatant of hFOB cells and bone matrix extract (BME) was applied to mimic the bone micro-environment to evaluate the role played by BMP8A in bone metastasis. Correlations with both osteolytic and osteoblastic markers were evaluated in the TCGA-BRCA cohort. Expression of certain responsive genes was quantified in the BMP8A overexpression cell lines. Additionally, signal transduction through both Smad-dependent and independent pathways was evaluated using Western blot assay. Results: Compared to the adjacent normal tissues, BMP8A expression was significantly increased in primary tumors (p < 0.05) which was associated with shorter distant metastasis free survival (DMFS) in TNBC (p < 0.05). BMP8A was observed to enhance cell invasion and migration within TNBC cells. In the simulated bone milieu, both MDA-MB-231BMP8Aexp and BT549BMP8Aexp cells presented enhanced invasiveness. BMP8A level was strongly correlated with most osteolytic and osteoblastic markers, suggesting the potential involvement of BMP8A in bone metastasis in TNBC. Receptor activator of nuclear factor kappa-B ligand (RANKL) expression was significantly increased in BMP8A overexpressed triple-negative cell lines (MDA-MB-231 and BT549 Furthermore, enhanced phosphorylation of Smad3 and increased expression of epidermal growth factor receptor (EGFR) were observed in MDA-MB-231 cells overexpressing BMP8A. Conclusion: BMP8A was upregulated in TNBC which was associated with poorer DMFS. BMP8A overexpression enhanced the invasion and migration of TNBC cells. With a putative role in osteolytic bone metastasis in TNBC, BMP8A represents a promising candidate for further investigation into its therapeutic potential. [ABSTRACT FROM AUTHOR]

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterized by the development of arteriovenous malformations (AVMs) that can result in significant morbidity and mortality. HHT is caused primarily by mutations in bone morphogenetic protein receptors ACVRL1/ALK1, a signaling receptor, or endoglin (ENG), an accessory receptor. Because overexpression of Acvrl1 prevents AVM development in both Acvrl1 and Eng null mice, enhancing ACVRL1 expression may be a promising approach to development of targeted therapies for HHT. Therefore, we sought to understand the molecular mechanism of ACVRL1 regulation. We previously demonstrated in zebrafish embryos that acvrl1 is predominantly expressed in arterial endothelial cells and that expression requires blood flow. Here, we document that flow dependence exhibits regional heterogeneity and that acvrl1 expression is rapidly restored after reinitiation of flow. Furthermore, we find that acvrl1 expression is significantly decreased in mutants that lack the circulating Alk1 ligand, Bmp10, and that, in the absence of flow, intravascular injection of BMP10 or the related ligand, BMP9, restores acvrl1 expression in an Alk1-dependent manner. Using a transgenic acvrl1:egfp reporter line, we find that flow and Bmp10 regulate acvrl1 at the level of transcription. Finally, we observe similar ALK1 ligand-dependent increases in ACVRL1 in human endothelial cells subjected to shear stress. These data suggest that ligand-dependent Alk1 activity acts downstream of blood flow to maintain or enhance acvrl1 expression via a positive feedback mechanism, and that ALK1 activating therapeutics may have dual functionality by increasing both ALK1 signaling flux and ACVRL1 expression. [ABSTRACT FROM AUTHOR]

Background: The significant role of embryonic cerebrospinal fluid (eCSF) in the initial stages of brain development has been thoroughly studied. This fluid contains crucial molecules for proper brain development such as members of the Wnt and FGF families, apolipoproteins, and retinol binding protein. Nevertheless, the source of these molecules remains uncertain since they are present before the formation of the choroid plexus, which is conventionally known as the primary producer of cerebrospinal fluid. The subcommissural organ (SCO) is a highly conserved gland located in the diencephalon and is one of the earliest differentiating brain structures. The SCO secretes molecules into the eCSF, prior to the differentiation of the choroid plexus, playing a pivotal role in the homeostasis and dynamics of this fluid. One of the key molecules secreted by the SCO is SCO-spondin, a protein involved in maintenance of the normal ventricle size, straight spinal axis, neurogenesis, and axonal guidance. Furthermore, SCO secretes transthyretin and basic fibroblast growth factor 2, while other identified molecules in the eCSF could potentially be secreted by the SCO. Additionally, various transcription factors have been identified in the SCO. However, the precise mechanisms involved in the early SCO development are not fully understood. Results: To uncover key molecular players and signaling pathways involved in the role of the SCO during brain development, we conducted a transcriptomic analysis comparing the embryonic chick SCO at HH23 and HH30 stages (4 and 7 days respectively). Additionally, a public transcriptomic data from HH30 entire chick brain was used to compare expression levels between SCO and whole brain transcriptome. These analyses revealed that, at both stages, the SCO differentially expresses several members of bone morphogenic proteins, Wnt and fibroblast growth factors families, diverse proteins involved in axonal guidance, neurogenic and differentiative molecules, cell receptors and transcription factors. The secretory pathway is particularly upregulated at stage HH30 while the proliferative pathway is increased at stage HH23. Conclusion: The results suggest that the SCO has the capacity to secrete several morphogenic molecules to the eCSF prior to the development of other structures, such as the choroid plexus. [ABSTRACT FROM AUTHOR]

BACKGROUND: The research of dental stem cells in the fields of regenerative medicine and tissue engineering has been deepening, bringing hope for the repair of tooth-related tissues and the treatment of systemic diseases. However, there is a lack of systematic research and analysis on the biological characteristics of dental stem cells in different age groups. OBJECTIVE: To explore the biological characteristics of the human deciduous tooth and permanent tooth pulp stem cells cultured in umbilical cord blood platelet lysate to provide a reliable basis for human platelet lysates to replace fetal bovine serum. METHODS: The pulp tissues of deciduous teeth, juvenile permanent teeth and adult permanent teeth were taken out and cultured in DMEM/F-12 medium supplemented with 10% fetal bovine serum or different concentrations (5%, 10% and 15%) of human platelet lysates. Cell proliferation in the four groups was detected by cytometry. The optimal concentration of human platelet lysates was selected for subsequent experiments. Under the optimal concentration of human platelet lysates, human deciduous tooth and juvenile and adult permanent tooth pulp stem cells were cultured in vitro. The cell growth status was observed under the microscope. The specific antigen on the cell surface was detected by flow cytometry. The cell proliferation ability was tested by the cell counting method and CCK-8 assay. The cell differentiation ability in vitro was observed by a three-line differentiation assay. RESULTS AND CONCLUSION: (1) The cell proliferation rate of the 10% human platelet lysate group was the highest. (2) In all three groups, fusiform fibrous cells grew and expanded from around the tissue block. There was no significant difference between deciduous teeth and juvenile permanent tooth cells, but the adult permanent tooth cells were larger than the deciduous and juvenile permanent tooth cells of the same generation. (3) The results of flow cytometry showed that deciduous teeth, juvenile permanent teeth and adult permanent teeth conformed to the phenotypic characteristics of mesenchymal stem cells. (4) The proliferative capacity of adult permanent dental pulp stem cells was significantly lower than those of deciduous teeth and juvenile permanent dental pulp stem cells (P < 0.01). (5) mRNA expressions of osteoblast-related genes alkaline phosphatase and bone morphogenetic protein 2, lipoprotein lipase and peroxisome proliferator-activated receptor γ2, mRNA expressions of chondroblast related gene type II collagen α1 and cartilage oligomeric matrix protein in adult pulp stem cells of permanent teeth were significantly lower than those of deciduous teeth and juvenile permanent teeth pulp stem cells (P < 0.01). (6) Compared with adult dental pulp stem cells, human deciduous teeth and juvenile permanent teeth dental pulp stem cells have the stronger proliferative capacity and multidirectional differentiation potential, and are more suitable for clinical research and disease treatment. [ABSTRACT FROM AUTHOR]

Pulmonary arterial hypertension (PAH) is a poorly understood disease of the small pulmonary arteries. Pulmonary vascular remodeling and progressively rising pulmonary vascular resistance are hallmarks of the disease that ultimately result in right heart failure. Several genetic mutations, most notably in bone morphogenetic protein receptor type 2, have a causal association with heritable forms of PAH. Mutations in neurogenic locus notch homolog protein 3 (NOTCH3) have been reported in adults and children with PAH, but whether NOTCH3 is causally associated with PAH is debated. With this case report, we describe the clinical characteristics, comorbidities, and exposure history of an adult patient with PAH and multiple sclerosis who was found to have a NOTCH3 missense mutation and exposure to leflunomide. [ABSTRACT FROM AUTHOR]

Low-density lipoprotein receptor-related protein 5 (LRP5) is a constitutively expressed receptor with observed roles in bone homeostasis, retinal development, and cardiac metabolism. However, the function of LRP5 in the brain remains unexplored. This study investigates LRP5's role in the central nervous system by conducting an extensive analysis using RNA-seq tools and in silico assessments. Two protein-coding Lrp5 transcripts are expressed in mice: full-length Lrp5-201 and a truncated form encoded by Lrp5-202. Wt mice express Lrp5-201 in the liver and brain and do not express the truncated form. Lrp5−/− mice express Lrp5-202 in the liver and brain and do not express Lrp5-201 in the liver. Interestingly, Lrp5−/− mouse brains show full-length Lrp5-201 expression, suggesting that LRP5 has a role in preserving brain function during development. Functional gene enrichment analysis on RNA-seq unveils dysregulated expression of genes associated with neuronal differentiation and synapse formation in the brains of Lrp5−/− mice compared to Wt mice. Furthermore, Gene Set Enrichment Analysis highlights downregulated expression of genes involved in retinol and linoleic acid metabolism in Lrp5−/− mouse brains. Tissue-specific alternative splicing of Lrp5 in Lrp5−/− mice supports that the expression of LRP5 in the brain is needed for the correct synthesis of vitamins and fatty acids, and it is indispensable for correct brain development. [ABSTRACT FROM AUTHOR]

The stemness loss-associated dysregeneration of impaired alveolar type 2 epithelial (AT2) cells abolishes the reversible therapy of idiopathic pulmonary fibrosis (IPF). We here report an inhalable mucus-penetrating lipid nanoparticle (LNP) for codelivering dual mRNAs, promoting realveolarization via restoring AT2 stemness for IPF treatment. Inhalable LNPs were first formulated with dipalmitoylphosphatidylcholine and our in-house-made ionizable lipids for high-efficiency pulmonary mucus penetration and codelivery of dual messenger RNAs (mRNAs), encoding cytochrome b5 reductase 3 and bone morphogenetic protein 4, respectively. After being inhaled in a bleomycin model, LNPs reverses the mitochondrial dysfunction through ameliorating nicotinamide adenine dinucleotide biosynthesis, which inhibits the accelerated senescence of AT2 cells. Concurrently, pathological epithelial remodeling and fibroblast activation induced by impaired AT2 cells are terminated, ultimately prompting alveolar regeneration. Our data demonstrated that the mRNA-LNP system exhibited high protein expression in lung epithelial cells, which markedly extricated the alveolar collapse and prolonged the survival of fibrosis mice, providing a clinically viable strategy against IPF. [ABSTRACT FROM AUTHOR]

Background: In the context of increasing exposure to silica nanoparticles (SiNPs) and ensuing respiratory health risks, emerging evidence has suggested that SiNPs can cause a series of pathological lung injuries, including fibrotic lesions. However, the underlying mediators in the lung fibrogenesis caused by SiNPs have not yet been elucidated. Results: The in vivo investigation verified that long-term inhalation exposure to SiNPs induced fibroblast activation and collagen deposition in the rat lungs. In vitro, the uptake of exosomes derived from SiNPs-stimulated lung epithelial cells (BEAS-2B) by fibroblasts (MRC-5) enhanced its proliferation, adhesion, and activation. In particular, the mechanistic investigation revealed SiNPs stimulated an increase of epithelium-secreted exosomal miR-494-3p and thereby disrupted the TGF-β/BMPR2/Smad pathway in fibroblasts via targeting bone morphogenetic protein receptor 2 (BMPR2), ultimately resulting in fibroblast activation and collagen deposition. Conversely, the inhibitor of exosomes, GW4869, can abolish the induction of upregulated miR-494-3p and fibroblast activation in MRC-5 cells by the SiNPs-treated supernatants of BEAS-2B. Besides, inhibiting miR-494-3p or overexpression of BMPR2 could ameliorate fibroblast activation by interfering with the TGF-β/BMPR2/Smad pathway. Conclusions: Our data suggested pulmonary epithelium-derived exosomes serve an essential role in fibroblast activation and collagen deposition in the lungs upon SiNPs stimuli, in particular, attributing to exosomal miR-494-3p targeting BMPR2 to modulate TGF-β/BMPR2/Smad pathway. Hence, strategies targeting exosomes could be a new avenue in developing therapeutics against lung injury elicited by SiNPs. [ABSTRACT FROM AUTHOR]

Pericyte dysfunction, with excessive migration, hyperproliferation, and differentiation into smooth muscle-like cells contributes to vascular remodeling in Pulmonary Arterial Hypertension (PAH). Augmented expression and action of growth factors trigger these pathological changes. Endogenous factors opposing such alterations are barely known. Here, we examine whether and how the endothelial hormone C-type natriuretic peptide (CNP), signaling through the cyclic guanosine monophosphate (cGMP) -producing guanylyl cyclase B (GC-B) receptor, attenuates the pericyte dysfunction observed in PAH. The results demonstrate that CNP/GC-B/cGMP signaling is preserved in lung pericytes from patients with PAH and prevents their growth factor-induced proliferation, migration, and transdifferentiation. The anti-proliferative effect of CNP is mediated by cGMP-dependent protein kinase I and inhibition of the Phosphoinositide 3-kinase (PI3K)/AKT pathway, ultimately leading to the nuclear stabilization and activation of the Forkhead Box O 3 (FoxO3) transcription factor. Augmentation of the CNP/GC-B/cGMP/FoxO3 signaling pathway might be a target for novel therapeutics in the field of PAH. This study reveals that exogenous CNP counteracts growth factor-induced pericyte alterations by preserving FoxO3 activity. Thus, impaired signaling of endogenous, paracrine-acting CNP might contribute to vascular remodeling in patients with PAH. [ABSTRACT FROM AUTHOR]

Pulmonary arterial hypertension (PAH) is a rare and life-threatening vascular disorder, characterised by abnormal remodelling of the pulmonary vessels and elevated pulmonary artery pressure, leading to right ventricular hypertrophy and right-sided heart failure. The importance of bone morphogenetic protein (BMP) signalling in the pathogenesis of PAH is demonstrated by human genetic studies. Many PAH risk genes are involved in the BMP signalling pathway and are highly expressed or preferentially act on vascular endothelial cells. Endothelial dysfunction is recognised as an initial trigger for PAH, and endothelial BMP signalling plays a crucial role in the maintenance of endothelial integrity. BMPR2 is the most prevalent PAH gene, found in over 80% of heritable cases. As BMPRII protein is the major type II receptor for a large family of BMP ligands and expressed ubiquitously in many tissues, dysregulated BMP signalling in other cells may also contribute to PAH pathobiology. Sotatercept, which contains the extracellular domain of another transforming growth factor-β family type II receptor ActRIIA fused to immunoglobin Fc domain, was recently approved by the FDA as a treatment for PAH. Neither its target cells nor its mechanism of action is fully understood. This review will revisit BMPRII function and its extracellular regulation, summarise how dysregulated BMP signalling in endothelial cells and smooth muscle cells may contribute to PAH pathogenesis, and discuss how novel therapeutics targeting the extracellular regulation of BMP signalling, such as BMP9 and Sotatercept, can be related to restoring BMPRII function. [ABSTRACT FROM AUTHOR]

Both tissue and blood lead levels are elevated in renal cell carcinoma (RCC) patients. These studies assessed the impact of the subchronic lead challenge on the progression of RCC in vitro and in vivo. Lead challenge of Renca cells with 0.5 μM lead acetate for 10 consecutive passages decreased E-cadherin expression and cell aggregation. Proliferation, colony formation, and wound healing were increased. When lead-challenged cells were injected into mice, tumor size at day 21 was increased; interestingly, this increase was seen in male but not female mice. When mice were challenged with 32 ppm lead in drinking water for 20 weeks prior to tumor cell injection, there was an increase in tumor size in male, but not female, mice at day 21. To investigate the mechanism underlying the sex differences, the expression of sex hormone receptors in Renca cells was examined. Control Renca cells expressed estrogen receptor (ER) alpha but not ER beta or androgen receptor (AR), as assessed by qPCR, and the expression of ERα was increased in tumors in both sexes. In tumor samples harvested from lead-challenged cells, both ERα and AR were detected by qPCR, yet there was a significant decrease in AR seen in lead-challenged tumor cells from male mice only. This was paralleled by a plate-based array demonstrating the same sex difference in BMP-7 gene expression, which was also significantly decreased in tumors harvested from male but not female mice; this finding was validated by immunohistochemistry. A similar expression pattern was seen in tumors harvested from the mice challenged with lead in the drinking water. These data suggest that lead promotes RCC progression in a sex-dependent via a mechanism that may involve sex-divergent changes in BMP-7 expression. [ABSTRACT FROM AUTHOR]

The presence of feathers is a vital characteristic among birds, yet most modern birds had no feather on their feet. The discoveries of feathers on the hind limbs of basal birds and dinosaurs have sparked an interest in the evolutionary origin and genetic mechanism of feathered feet. However, the majority of studies investigating the genes associated with this trait focused on domestic populations. Understanding the genetic mechanism underpinned feathered-foot development in wild birds is still in its infancy. Here, we assembled a chromosome-level genome of the Asian house martin (Delichon dasypus) using the long-read High Fidelity sequencing approach to initiate the search for genes associated with its feathered feet. We employed the whole-genome alignment of D. dasypus with other swallow species to identify high-SNP regions and chromosomal inversions in the D. dasypus genome. After filtering out variations unrelated to D. dasypus evolution, we found six genes related to feather development near the high-SNP regions. We also detected three feather development genes in chromosomal inversions between the Asian house martin and the barn swallow genomes. We discussed their association with the wingless/integrated (WNT), bone morphogenetic protein, and fibroblast growth factor pathways and their potential roles in feathered-foot development. Future studies are encouraged to utilize the D. dasypus genome to explore the evolutionary process of the feathered-foot trait in avian species. This endeavor will shed light on the evolutionary path of feathers in birds. [ABSTRACT FROM AUTHOR]

Objectives: Bee pollen (BP) contains isoflavonoids and minerals that can be effective in bone repair, stimulation of osteoprogenitors, differentiation of osteoblasts, and inhibition of osteoclasts. For this purpose, in the present study, BP was used to stimulate osteogenesis in an animal model of a femur fracture. Materials and Methods: After induction of the femur fracture model, 80 Wistar rats in eight groups (n = 10) were studied as follows. Normal control group (0.5 cc of distilled water, DW/gavage/90 days), BP group (200 mg/kg BP/daily/gavage/90 days), fracture (FX-0.5 cc of distilled water/gavage/90 days), FX group treated with 100 and 200 mg/kg BP (100 and 200 mg/kg BP/daily/gavage/90 days), FX group treated with osteocare (OC) syrup (1 mL/day/gavage/90 days) and combinatorial FX groups treated with BP and OC syrup (100 and 200 mg/kg BP plus 1 mL OC/daily/gavage/90 days). On the 30th, 60th, and 90th days, radiography of the lesion was done. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry during the mentioned days. At the end of the study, blood calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP), along with the activity of glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) enzymes, and nitric oxide levels, were measured. Calcitonin and parathyroid hormone levels were measured with enzyme-linked immunosorbent assay (ELISA) kits. In order to evaluate the stimulation of osteoprogenitors, the expression of osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B (RANK), receptor activator of nuclear factor kappa-B ligand (RANKL), and bone morphogenetic protein-2 (BMP-2) genes and proteins in bone tissue was measured. Results: The evaluations of this study showed that BP could improve BMD parameters through stimulation of the OPG/RANK/BMP-2 pathway. BP also improved serum levels of biochemical factors (Ca, P, and ALP) and hormones related to osteogenesis. Conclusion: BP can be used for bone fractures and disorders related to osteoporosis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Natural bone morphogenetic protein 2 disperses and degrades rapidly in vivo, reducing local concentration and therapeutic efficacy. Simply combining bone morphogenetic protein 2 with tissue engineering scaffolds could not stay in vivo for a long time, making it difficult to achieve good sustained and controlled release effects. OBJECTIVE: To prepare and test the biological properties and chondrogenic induction effect of collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold. METHODS: SD rat tail collagen was extracted and a collagen cartilage scaffold was prepared using a vacuum freeze-drying machine chemical crosslinking method. The plasmid expressing collagen-binding domain-bone morphogenetic protein 2 was constructed by rapid cloning C112 homologous recombination, constructed by genetic engineering, and introduced into E. coli, and then collagen-binding domain-bone morphogenetic protein 2 was isolated and purified. Natural bone morphogenetic protein 2 and collagen-binding domain-bone morphogenetic protein 2 were combined with collagen cartilage scaffolds, respectively, to detect the release level of bone morphogenetic protein 2 in the scaffolds. The biocompatibility of collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold was detected by CCK-8 assay and F-Actin staining. Bone marrow mesenchymal stem cells were implanted on two kinds of collagen cartilage scaffolds for chondrogenic induction, and their chondrogenic induction activity was tested. RESULTS AND CONCLUSION: (1) The binding rate of collagen-binding domain-bone morphogenetic protein 2 to collagen cartilage scaffolds was higher than that of natural bone morphogenetic protein 2 (P < 0.05). After being immersed in PBS for 7 days in vitro, the release of bone morphogenetic protein 2 in the collagen-binding domain bone morphogenetic protein 2-collagen cartilage scaffold was smaller than that in the natural bone morphogenetic protein 2-collagen cartilage scaffold (P < 0.05). The results of the CCK-8 assay and F-Actin staining showed that the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold had no obvious cytotoxicity and had good biocompatibility. (2) After 14 days of chondrogenic induction, ELISA detection demonstrated that the expressions of agglutincan and type II collagen A1 in the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold group were higher than those in the natural bone morphogenetic protein 2-collagen cartilage scaffold group (P < 0.05). Under scanning electron microscopy, more bone marrow mesenchymal stem cells were observed on the inner wall of the pores of the two groups of scaffolds, and the cell morphology and size were the same, and the cells were closely arranged, without cell fragmentation or abnormal morphology. (3) The results indicate that the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold has good biological properties and chondrogenic induction activity. [ABSTRACT FROM AUTHOR]

Background: We aimed to determine whether serum levels of proteins related to changes in cardiac extracellular matrix (ECM) were associated with ischemic injury assessed by cardiac magnetic resonance (CMR) and mortality in patients with ST-elevation myocardial infarction (STEMI). Methods: The concentrations of six ECM-related proteins (periostin, osteopontin, syndecan-1, syndecan-4, bone morphogenetic protein 7, and growth differentiation factor (GDF)-15) were measured in serum samples from patients on Day 1 and Month 4 after STEMI (n = 239). Ischemic injury was assessed by myocardial salvage index, microvascular obstruction, infarct size, and left ventricular function measured by CMR conducted during the initial admission (median 2 days after admission) and after 4 months. All-cause mortality was recorded after a median follow-up time of 70 months. Results: Levels of periostin increased from Day 1 to Month 4 after hospitalization, while the levels of GDF-15, osteopontin, syndecan-1, and syndecan-4 declined. At both time points, high levels of syndecan-1 were associated with microvascular obstruction, large infarct size, and reduced left ventricular ejection fraction, whereas high levels of syndecan-4 at Month 4 were associated with a higher myocardial salvage index and less dilatation of the left ventricle. Higher mortality rates were associated with periostin levels at both time points, low syndecan-4 levels at Month 4, or high GDF-15 levels at Month 4. Conclusions: In patients with STEMI, we found an association between serum levels of ECM biomarkers and ischemic injury and mortality. The results provide new insight into the role ECM components play in ischemic injury following STEMI and suggests a potential for these biomarkers in prognostication after STEMI. [ABSTRACT FROM AUTHOR]

Hyperthyroidism is a well-known trigger of high bone turnover that can lead to the development of secondary osteoporosis. Previously, we have shown that blocking bone morphogenetic protein (BMP) signaling systemically with BMPR1A-Fc can prevent bone loss in hyperthyroid mice. To distinguish between bone cell type-specific effects, conditional knockout mice lacking Bmpr1a in either osteoclast precursors (LysM-Cre) or osteoprogenitors (Osx-Cre) were rendered hyperthyroid and their bone microarchitecture, strength and turnover were analyzed. While hyperthyroidism in osteoclast precursor-specific Bmpr1a knockout mice accelerated bone resorption leading to bone loss just as in wildtype mice, osteoprogenitor-specific Bmpr1a deletion prevented an increase of bone resorption and thus osteoporosis with hyperthyroidism. In vitro, wildtype but not Bmpr1a-deficient osteoblasts responded to thyroid hormone (TH) treatment with increased differentiation and activity. Furthermore, we found an elevated Rankl/Opg ratio with TH excess in osteoblasts and bone tissue from wildtype mice, but not in Bmpr1a knockouts. In line, expression of osteoclast marker genes increased when osteoclasts were treated with supernatants from TH-stimulated wildtype osteoblasts, in contrast to Bmpr1a-deficient cells. In conclusion, we identified the osteoblastic BMP receptor BMPR1A as a main driver of osteoporosis in hyperthyroid mice promoting TH-induced osteoblast activity and potentially its coupling to high osteoclastic resorption. Comparison of the bone phenotypes of hyperthyroid versus euthyroid bone cell-specific conditional knockout mice suggests that the osteoblastic, but not osteoclast, BMP receptor BMPR1A is a main driver of hyperthyroidism-associated bone disease. [ABSTRACT FROM AUTHOR]

This review examines how single-cell omics technologies, particularly single-cell RNA sequencing (scRNAseq), enhance our understanding of pulmonary arterial hypertension (PAH). PAH is a multifaceted disorder marked by pulmonary vascular remodeling, leading to high morbidity and mortality. The cellular pathobiology of this heterogeneous disease, involving various vascular and non-vascular cell types, is not fully understood. Traditional PAH studies have struggled to resolve the complexity of pathogenic cell populations. scRNAseq offers a refined perspective by detailing cellular diversity within PAH, identifying unique cell subsets, gene networks, and molecular pathways that drive the disease. We discuss significant findings from recent literature, summarizing how scRNAseq has shifted our understanding of PAH in human, rat, and mouse models. This review highlights the insights gained into cellular phenotypes, gene expression patterns, and novel molecular targets, and contemplates the challenges and prospective paths for research. We propose ways in which single-cell omics could inform future research and translational efforts to combat PAH. [ABSTRACT FROM AUTHOR]

The vitamin D receptor (VDR) signalling has been implicated in vertebrate limb or fin formation. However, the involvement of VDR signalling in the early stages of limb/fin development remains to be elucidated. In this study, the role of VDR signalling in pectoral fin development was investigated in zebrafish embryos. Knockdown of vdr induced the severe impairment of pectoral fin development. The zebrafish larvae lacking vdr exhibited reduced pectoral fins with no skeletal elements. In situ hybridization revealed depletion of vdr downregulated fibroblast growth factor 24 (fgf24), a marker of early pectoral fin bud mesenchyme, in the presumptive fin field even before fin buds were visible. Moreover, a perturbed expression pattern of bone morphogenetic protein 4 (bmp4), a marker of the pectoral fin fold, was observed in the developing fin buds of zebrafish embryos that lost the vdr function. These findings suggest that VDR signalling is crucial in the early stages of fin development, potentially influencing the process by regulating other signalling molecules such as Fgf24 and Bmp4. [ABSTRACT FROM AUTHOR]

This article reviews the role of fibroblast growth factor 23 (FGF23) protein in phosphate metabolism, highlighting its regulation of vitamin D, parathyroid hormone, and bone metabolism. Although it was traditionally thought that phosphate–calcium homeostasis was controlled exclusively by parathyroid hormone (PTH) and calcitriol, pathophysiological studies revealed the influence of FGF23. This protein, expressed mainly in bone, inhibits the renal reabsorption of phosphate and calcitriol formation, mediated by the α-klotho co-receptor. In addition to its role in phosphate metabolism, FGF23 exhibits pleiotropic effects in non-renal systems such as the cardiovascular, immune, and metabolic systems, including the regulation of gene expression and cardiac fibrosis. Although it has been proposed as a biomarker and therapeutic target, the inhibition of FGF23 poses challenges due to its potential side effects. However, the approval of drugs such as burosumab represents a milestone in the treatment of FGF23-related diseases. [ABSTRACT FROM AUTHOR]

Macrophages in the endometrium promote receptivity and implantation by secreting proinflammatory cytokines and other factors like fractalkine (FKN). Macrophages are closely linked to regulating iron homeostasis and can modulate iron availability in the tissue microenvironment. It has been revealed that the iron metabolism of the mother is crucial in fertility. Iron metabolism is strictly controlled by hepcidin, the principal iron regulatory protein. The inflammatory cytokines can modulate hepcidin synthesis and, therefore, the iron metabolism of the endometrium. It was proven recently that FKN, a unique chemokine, is implicated in maternal–fetal communication and may contribute to endometrial receptivity and implantation. In the present study, we investigated the effect of activated THP‐1 macrophages and FKN on the iron metabolism of the HEC‐1A endometrial cells. We established a noncontact coculture with or without recombinant human FKN supplementation to study the impact of the macrophage‐derived factors and FKN on the regulation of hepcidin synthesis and iron release and storage of endometrial cells. Based on our findings, the conditioned medium of the activated macrophages could modify hepcidin synthesis via the nuclear factor kappa‐light‐chain‐enhancer of activated B cells, the signal transducer and activator of transcription 3, and the transferrin receptor 2/bone morphogenetic protein 6/suppressor of mothers against decapentaplegic 1/5/8 signaling pathways, and FKN could alter this effect on the endometrial cells. It was also revealed that the conditioned macrophage medium and FKN modulated the iron release and storage of HEC‐1A cells. FKN signaling may be involved in the management of iron trafficking of the endometrium by the regulation of hepcidin. It can contribute to the iron supply for fetal development at the early stage of the pregnancy. [ABSTRACT FROM AUTHOR]

A common flame-retardant and plasticizer, triphenyl phosphate (TPhP) is an aryl phosphate ester found in many aquatic environments at nM concentrations. Yet, most studies interrogating its toxicity have used µM concentrations. In this study, we used the model organism zebrafish (Danio rerio) to uncover the developmental impact of nM exposures to TPhP at the phenotypic and molecular levels. At concentrations of 1.5–15 nM (0.5 µg/L–5 µg/L), chronically dosed 5dpf larvae were shorter in length and had pericardial edema phenotypes that had been previously reported for exposures in the µM range. Cardiotoxicity was observed but did not present as cardiac looping defects as previously reported for µM concentrations. The RXR pathway does not seem to be involved at nM concentrations, but the tbx5a transcription factor cascade including natriuretic peptides (nppa and nppb) and bone morphogenetic protein 4 (bmp4) were dysregulated and could be contributing to the cardiac phenotypes. We also demonstrate that TPhP is a weak pro-oxidant, as it increases the oxidative stress response within hours of exposure. Overall, our data indicate that TPhP can affect animal development at environmentally relevant concentrations and its mode of action involves multiple pathways. [ABSTRACT FROM AUTHOR]

The article discusses the limitations of using rat models to study human pulmonary veno-occlusive disease (PVOD) mechanisms. While rat models have shown promising results in targeting the PKR-ISR axis to manage PVOD, human cases may not exhibit the same activation of this pathway. The study highlights the importance of considering species-specific differences in disease mechanisms and suggests that alternative pathways, such as GCN2 and the BMPR2-SMAD axis, may be more critical in human PVOD. The findings underscore the need for improved in vivo models that better mimic human disease to develop effective therapeutic interventions. [Extracted from the article]

Background: Extrachromosomal circular DNAs (eccDNAs) have been reported to play a key role in the occurrence and development of various diseases. However, the characterization and role of eccDNAs in pulmonary arterial hypertension (PAH) remain unclear. Methods: In the discovery cohort, we first explored eccDNA expression profiles by Circle-sequencing analysis. The candidate eccDNAs were validated by routine polymerase chain reaction (PCR), TOPO-TA cloning and Sanger sequencing. In the validation cohort, 30 patients with PAH and 10 healthy controls were recruited for qPCR amplification to detect the candidate eccDNAs. Datas at the baseline were collected, including clinical background, biochemical variables, echocardiography and hemodynamic factors. Receiver operating characteristic curve was used to investigate the diagnostic effect of the eccDNA. Results: We identified a total of 21,741 eccDNAs in plasma samples of 3 IPAH patients and 3 individuals in good health, and the expression frequency, GC content, length distribution, and genome distribution of the eccDNAs were thoroughly characterized and analyzed. In the validation cohort, 687 eccDNAs were differentially expressed in patients with IPAH compared with healthy controls (screening threshold: |FC|≥2 and P < 0.05). Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the specific eccDNAs in IPAH were significantly enriched in calcium channel activity, the mitogen-activated protein kinase pathway, and the wnt signaling pathway. Verification queue found that the expression of eccDNA-chr2:131208878–131,424,362 in PAH was considerably higher than that in healthy controls and exhibited a high level of accuracy in predicting PAH with a sensitivity of 86.67% and a specificity of 90%. Furthermore, correlation analysis disclosed a significant association between serum eccDNA-chr2:131208878–131,424,362 and mean pulmonary artery pressure (mPAP) (r = 0.396, P = 0.03), 6 min walking distance (6MWD) (r = -0.399, P = 0.029), N-terminal pro-B-type natriuretic peptide (NT-proBNP) (r = 0.685, P < 0.001) and cardiac index (CI) (r = − 0.419, P = 0.021). Conclusions: This is the first study to identify and characterize eccDNAs in patients with PAH. We revealed that serum eccDNA-chr2:131208878–131,424,362 is significantly overexpressed and can be used in the diagnosis of PAH, indicating its potential as a novel non-invasive biomarker. [ABSTRACT FROM AUTHOR]

Background: In vitro chondrogenesis of mesenchymal stromal cells (MSCs) driven by the essential chondro-inducer transforming growth factor (TGF)-β is instable and yields undesired hypertrophic cartilage predisposed to bone formation in vivo. TGF-β can non-canonically activate bone morphogenetic protein-associated ALK1/2/3 receptors. These have been accused of driving hypertrophic MSC misdifferentiation, but data remained conflicting. We here tested the antihypertrophic capacity of two highly specific ALK1/2/3 inhibitors – compound A (CompA) and LDN-212854 (LDN21) – in order to reveal potential prohypertrophic contributions of these BMP/non-canonical TGF-β receptors during MSC in vitro chondrogenesis. Methods: Standard chondrogenic pellet cultures of human bone marrow-derived MSCs were treated with TGF-β and CompA (500 nM) or LDN21 (500 nM). Daily 6-hour pulses of parathyroid hormone-related peptide (PTHrP[1–34], 2.5 nM, from day 7) served as potent antihypertrophic control treatment. Day 28 samples were subcutaneously implanted into immunodeficient mice. Results: All groups underwent strong chondrogenesis, but GAG/DNA deposition and ACAN expression were slightly but significantly reduced by ALK inhibition compared to solvent controls along with a mild decrease of the hypertrophy markers IHH-, SPP1-mRNA, and Alkaline phosphatase (ALP) activity. When corrected for the degree of chondrogenesis (COL2A1 expression), only pulsed PTHrP but not ALK1/2/3 inhibition qualified as antihypertrophic treatment. In vivo, all subcutaneous cartilaginous implants mineralized within 8 weeks, but PTHrP pretreated samples formed less bone and attracted significantly less haematopoietic marrow than ALK1/2/3 inhibitor groups. Conclusions: Overall, our data show that BMP-ALK1/2/3 inhibition cannot program mesenchymal stromal cells toward stable chondrogenesis. BMP-ALK1/2/3 signalling is no driver of hypertrophic MSC misdifferentiation and BMP receptor induction is not an adverse prohypertrophic side effect of TGF-β that leads to endochondral MSC misdifferentiation. Instead, the prohypertrophic network comprises misregulated PTHrP/hedgehog signalling and WNT activity, and a potential contribution of TGF-β-ALK4/5-mediated SMAD1/5/9 signalling should be further investigated to decide about its postulated prohypertrophic activity. This will help to successfully engineer cartilage replacement tissues from MSCs in vitro and translate these into clinical cartilage regenerative therapies. [ABSTRACT FROM AUTHOR]

The leading cause of mortality in patients with breast cancer is metastasis, and bone morphogenetic protein (BMP) signaling activation regulates metastasis in breast cancer. This study explored the genetic and epigenetic modification of BMP receptor genes associated with metastatic breast cancer cells using bioinformatics. The genetic and epigenetic alterations of BMP receptors (BMPR1A, BMPR1B, BMPR2, ACVR2A, ACVR1, ACVR2B, ACVR1B, HJV, and ENG) were examined using cBioportal and methSurv, respectively. mRNA expression was analyzed using TNM plot and bcgenex, and protein expression was studied using Human Protein Atlas. Prognostic value and ROC were investigated using Kaplan–Meier (KM) and ROC plot, respectively. Finally, mutant function was predicted using several databases, including PolyPhen-2, FATHMM, Mutation Assessor, and PredictSNP. Oncoprint analysis showed genetic alterations in BMPR1A (39%), BMPR1B (13%), BMPR2 (34%), ACVR2A (14%), ACVR1 (7%), ACVR2B (13), ACVR1B (35%), HJV (40%), and ENG (33%) across the patients with breast cancer in The Metastatic Breast Cancer Project. The mRNA and protein levels of BMPR2 were increased in metastatic breast tumor tissues compared with those in normal and breast tumor tissues. BMPR1A and BMPR2 showed the highest and lowest levels of epigenetic alterations among the BMP receptors, respectively. The patients with breast cancer who had low levels of BMPR2 had a better overall survival (OS) than those with high levels of BMPR2. Functional mutation prediction showed that mutants in BMPR2 (R272L, E274K, and L685F), ACVR2A (S127L), and ACVR1B (R484H), are deleterious, probably damaging, and possess a cancer phenotype. ROC plot revealed no BMP receptors correlated with endocrine therapy sensitivity. BMPR1B, BMPR2, and ACVR2A levels were significantly linked as moderate prediction of anti-HER2, BMPR2, and ACVR1B demonstrated moderate predictive potential for chemotherapy sensitivity. This study contributed in fully comprehending the significance of genetic and epigenetic alterations in BMP receptors and BMP signaling in metastatic breast cancer cells for the development of breast cancer treatment plans. [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PH) is a fatal disorder characterized by pulmonary vascular remodeling and obstruction. The phosphodiesterase 4 (PDE4) family hydrolyzes cyclic AMP (cAMP) and is comprised of four subtypes (PDE4A–D). Previous studies have shown the beneficial effects of pan-PDE4 inhibitors in rodent PH; however, this class of drugs is associated with side effects owing to the broad inhibition of all four PDE4 isozymes. Here, we demonstrate that PDE4B is the predominant PDE isozyme in lungs and that it was upregulated in rodent and human PH lung tissues. We also confirmed that PDE4B is mainly expressed in the lung endothelial cells (ECs). Evaluation of PH in Pde4b wild type and knockout mice confirmed that Pde4b is important for the vascular remodeling associated with PH. In vivo EC lineage tracing demonstrated that Pde4b induces PH development by driving endothelial-to-mesenchymal transition (EndMT), and mechanistic studies showed that Pde4b regulates EndMT by antagonizing the cAMP-dependent PKA–CREB–BMPRII axis. Finally, treating PH rats with a PDE4B-specific inhibitor validated that PDE4B inhibition has a significant pharmacological effect in the alleviation of PH. Collectively, our findings indicate a critical role for PDE4B in EndMT and PH, prompting further studies of PDE4B-specific inhibitors as a therapeutic strategy for PH. Pan-PDE4 inhibitors attenuate rat pulmonary hypertension (PH), while its applications show serious gastrointestinal side-effects. PDE4B-specific inhibitor may be an advisable therapeutic strategy that can alleviate PH by suppressing EndMT with less side-effects. [Display omitted] [ABSTRACT FROM AUTHOR]

Pulmonary hypertension (PH) is a malignant disease with progressive increase of pulmonary vascular pressure, which eventually leads to right heart failure. More and more evidences show that immune cells and inflammation play an important role in the occurrence and development of PH. In the context of pulmonary vascular diseases, immune cells migrate into the walls of the pulmonary vascular system. This leads to an increase in the levels of cytokines and chemokines in both the bloodstream and the surrounding tissues of the pulmonary vessels. As a result, new approaches such as immunotherapy and anti-inflammatory treatments are being considered as potential strategies to halt or potentially reverse the progression of PH. We reviewed the potential mechanisms of immune cells, cytokines and chemokines in PH development. The potential relationship of vascular cells or bone morphogenetic protein receptor 2 (BMPR2) in immune regulation was also expounded. The clinical application and future prospect of immunotherapy were further discussed. [ABSTRACT FROM AUTHOR]

The BMP pathway is one of the major signaling pathways in embryonic development, ontogeny and homeostasis, identified many years ago by pioneers in developmental biology. Evidence of the deregulation of its activity has also emerged in many cancers, with complex and sometimes opposing effects. Recently, its role has been suspected in Diffuse Midline Gliomas (DMG), among which Diffuse Intrinsic Pontine Gliomas (DIPG) are one of the most complex challenges in pediatric oncology. Genomic sequencing has led to understanding part of their molecular etiology, with the identification of histone H3 mutations in a large proportion of patients. The epigenetic remodeling associated with these genetic alterations has also been precisely described, creating a permissive context for oncogenic transcriptional program activation. This review aims to describe the new findings about the involvement of BMP pathway activation in these tumors, placing their appearance in a developmental context. Targeting the oncogenic synergy resulting from this pathway activation in an H3K27M context could offer new therapeutic perspectives based on targeting treatment-resistant cell states. [ABSTRACT FROM AUTHOR]

Simple Summary: Both FecB and FecGE mutations were first identified in sheep in Thailand. These two gene mutations have been reported to be associated with multiple births in sheep. To improve crossbred sheep prolificacy, selecting sheep containing the FecB allele was one of the better options. In addition, the coexistence of the FecB and FecGE allele mutations was found in sheep, and this requires further study with respect to its effects on ovulation rates and prolificacy. This study aimed to investigate the appearance and frequencies of the Booroola polymorphism of the bone morphogenetic protein receptor 1b (BMPR1B) gene (FecB) and the Embrapa polymorphism of the growth differentiation factor 9 (GDF9) gene (FecGE) in sheep in Thailand. A total of 454 crossbred sheep blood samples were collected from four provinces in Thailand during August 2022 to July 2023. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to identify the FecB and FecGE genotypes. The history of ewe birth types was collected from the owners to analyze the association between fecundity (Fec) genotypes and the history of birth types. The genotypic frequencies of FecB for homozygous genotype (B/B), heterozygous genotype (+/B), and wildtype (+/+) were 0.22%, 1.54%, and 98.24%, respectively. Meanwhile, the genotypic frequencies of FecGE for homozygous genotype (E/E), heterozygous genotype (+/E), and wildtype (+/+) were 0.00%, 2.42%, and 97.58%, respectively. Furthermore, three ewes exhibited both FecB and FecGE genotypes. Fisher's exact test revealed that possession of the FecB genotype was associated with multiple births (p < 0.01). Both FecB and FecGE mutations were identified in crossbred sheep in Thailand. Sheep containing FecB allele could be alternative candidates to be selected to improve the prolificacy of crossbred sheep in Thailand. [ABSTRACT FROM AUTHOR]

Primary pulmonary hyalinizing clear cell carcinoma (HCCC) is a very rare lung tumor that accounts for less than 0.09% of all primary lung tumors and has no specific epidemiology. The correct diagnosis requires imaging, laboratory, pathological, immunohistochemical, and molecular examination. The most typical feature of pulmonary HCCC is the clear cell component with clear stroma. In addition, the fusion gene EWSR1::ATF1 due to t(12;22)(q13;q12) is essential for the pathological diagnosis of pulmonary HCCC. The main treatment for pulmonary HCCC is surgery. This review focus on the pathological features, immunohistochemical examination, mutation analysis and treatment of pulmonary HCCC. [ABSTRACT FROM AUTHOR]

Numerous biological systems contain vesicle‐like biomolecular compartments without membranes, which contribute to diverse functions including gene regulation, stress response, signaling, and skin barrier formation. Coacervation, as a form of liquid–liquid phase separation (LLPS), is recognized as a representative precursor to the formation and assembly of membrane‐less vesicle‐like structures, although their formation mechanism remains unclear. In this study, a coacervation‐driven membrane‐less vesicle‐like structure is constructed using two proteins, GG1234 (an anionic intrinsically disordered protein) and bhBMP‐2 (a bioengineered human bone morphogenetic protein 2). GG1234 formed both simple coacervates by itself and complex coacervates with the relatively cationic bhBMP‐2 under acidic conditions. Upon addition of dissolved bhBMP‐2 to the simple coacervates of GG1234, a phase transition from spherical simple coacervates to vesicular condensates occurred via the interactions between GG1234 and bhBMP‐2 on the surface of the highly viscoelastic GG1234 simple coacervates. Furthermore, the shell structure in the outer region of the GG1234/bhBMP‐2 vesicular condensates exhibited gel‐like properties, leading to the formation of multiphasic vesicle‐like compartments. A potential mechanism is proposed for the formation of the membrane‐less GG1234/bhBMP‐2 vesicle‐like compartments. This study provides a dynamic process underlying the formation of biomolecular multiphasic condensates, thereby enhancing the understanding of these biomolecular structures. [ABSTRACT FROM AUTHOR]

Over the past decades, an unimaginably large number of attempts have been made to restore the structure of mammalian organs after injury by introducing stem cells into them. However, this procedure does not lead to full recovery. At the same time, it is known that complete regeneration (restitution without fibrosis) is possible in organs with proliferating parenchymal cells. An analysis of such models allows to conclude that the most important condition for the repair of histological structures of an organ (in the presence of stem cells) is preservation of the collagen frame structures in it, which serve as "guide rails" for proliferating and differentiating cells. An alternative condition for complete reconstruction of organ structures is the presence of a free "morphogenetic space" containing a gel-like matrix of the embryonic-type connective tissue, which exists during embryonal development of organs in mammals or during complete regeneration in amphibians. Approaches aimed at preserving frame structures or creating a "morphogenetic space" could radically improve the results of organ regeneration using both local and exogenous stem cells. [ABSTRACT FROM AUTHOR]

Marked sexual dimorphism is displayed in the onset and progression of pulmonary hypertension (PH). Females more commonly develop pulmonary arterial hypertension, yet females with pulmonary arterial hypertension and other types of PH have better survival than males. Pulmonary microvascular endothelial cells play a crucial role in pulmonary vascular remodeling and increased pulmonary vascular resistance in PH. Given this background, we hypothesized that there are sex differences in the pulmonary microvascular endothelium basally and in response to hypoxia that are independent of the sex hormone environment. Human pulmonary microvascular endothelial cells (HPMECs) from healthy male and female donors, cultured under physiological shear stress, were analyzed using RNA sequencing and label-free quantitative proteomics. Gene set enrichment analysis identified a number of sex-different pathways in both normoxia and hypoxia, including pathways that regulate cell proliferation. In vitro, the rate of proliferation in female HPMECs was lower than in male HPMECs, a finding that supports the omics results. Interestingly, thrombospondin-1, an inhibitor of proliferation, was more highly expressed in female cells than in male cells. These results demonstrate, for the first time, important differences between female and male HPMECs that persist in the absence of sex hormone differences and identify novel pathways for further investigation that may contribute to sexual dimorphism in pulmonary hypertensive diseases. NEW & NOTEWORTHY There is marked sexual dimorphism in the development and progression of pulmonary hypertension. We show differences in RNA and protein expression between female and male human pulmonary microvascular endothelial cells grown under conditions of physiological shear stress, which identify sex-different cellular pathways both in normoxia and hypoxia. Importantly, these differences were detected in the absence of sex hormone differences. The pathways identified may provide novel targets for the development of sex-specific therapies. [ABSTRACT FROM AUTHOR]

This article is an editorial published in Frontiers in Physiology titled "Pulmonary hypertension: from bench to bedside." The editorial discusses the challenge of translating research findings on pulmonary hypertension (PH) from the laboratory to clinical practice. It highlights the importance of multidisciplinary approaches in understanding the physiology and pathophysiology of PH. The editorial also mentions recent guidelines on the diagnosis and treatment of PH, as well as the potential role of exercise-induced hemodynamic changes and metabolic changes in PH. Additionally, it discusses the identification of biomarkers and the role of genetic factors in PH. The authors emphasize the value of interdisciplinary collaboration and knowledge sharing in advancing the field of PH research. [Extracted from the article]

BACKGROUND: As a member of bone morphogenetic proteins, growth differentiation factor-5 shows promising potential in the application of cartilage and bone repair. The affinity of growth differentiation factor-5 onto bone tissue determines protein use efficiency, so it is of great significance to prepare growth differentiation factor-5 with bone targeting capability. OBJECTIVE: To modify growth differentiation factor-5 using bisphosphonates and investigate the effects of modified protein on the growth of preosteoblasts in mice. METHODS: Pamidronate disodium/growth differentiation factor-5 complex was prepared using chemical crosslinking to couple growth differentiation factor-5 with pamidronate disodium. The functional groups and structures of the complex were characterized using Fourier transform infrared spectroscopy and circular dichromatography. To determine the bone targeting in vitro, the binding of the modified growth differentiation factor-5 with calcium phosphate and in vitro release amount of growth differentiation factor-5 were measured with an ELISA kit. Growth differentiation factor-5 (control group) and the pamidronate disodium/growth differentiation factor-5 complex (experimental group) were co-cultured with preosteoblasts MC3T3-E1. Individually cultured cells were blank controls. The effect of the complex on cell proliferation and differentiation was evaluated. RESULTS AND CONCLUSION: (1) The infrared spectroscopy and circular dichromatography results indicated that the bisphosphonate/growth differentiation factor-5 complex was successfully prepared without significant changes in the protein secondary structure. In vitro protein adsorption results showed that growth differentiation factor-5 adsorption on calcium phosphate was increased by about one time after coupling with a bisphosphonate. In the presence of cysteine, growth differentiation factor-5 could be released from the bisphosphonate/growth differentiation factor-5 complex. (2) CCK-8 assay results showed that the absorbance value of the experimental group cultured for 4 and 7 days was higher than that of the control group and blank control group (P < 0.000 1). After 7 days of culture, the expression of alkaline phosphatase in the experimental group was significantly higher than that in the control group and blank control group (P < 0.000 1). After 13 days of culture, the content of calcium nodules in the experimental group was significantly higher than that in the control group and the blank control group (P < 0.000 1). The results of qRT-PCR showed that the mRNA expression of alkaline phosphatase, osteocalcin and Runx2 in the experimental group was higher than that in the control group and the blank control group after 7 days of culture (P < 0.01, P < 0.001, P < 0.000 1). (3) These findings exhibit that bisphosphonate modification can enhance the binding capacity of growth differentiation factor-5 to calcium phosphate as well as improve its biological activity. [ABSTRACT FROM AUTHOR]