Regulation Of Bone Morphogenetic Protein Research Articles

Prognostic Significance of Proteomics-Discovered Circulating Inflammatory Biomarkers in Patients With Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) ultimately leads to right ventricular failure and premature death. The identification of circulating biomarkers with prognostic utility is considered a priority. As chronic inflammation is recognized as key pathogenic driver, we sought to identify inflammation-related circulating proteins that add incremental value to current risk stratification models for long-term survival in patients with PAH. Plasma levels of 384 inflammatory proteins were measured with the proximity extension assay technology in patients with PAH (n=60) and controls with normal hemodynamics (n=28). Among these, 51 analytes were significantly overexpressed in the plasma of patients with PAH compared with controls. Cox proportional hazard analyses and C-statistics were performed to assess the prognostic value and the incremental prognostic value of differentially expressed proteins. A panel of 6 proteins (CRIM1 [cysteine rich transmembrane bone morphogenetic protein regulator 1], HGF [hepatocyte growth factor], FSTL3 [follistatin-like 3], PLAUR [plasminogen activator, urokinase receptor], CLSTN2 [calsyntenin 2], SPON1 [spondin 1]) were independently associated with death/lung transplantation at the time of PAH diagnosis after adjustment for the 2015 European Society of Cardiology/European Respiratory Society guidelines, the REVEAL (Registry to Evaluate Early and Long-Term PAH Disease Management) 2.0 risk scores, and the refined 4-strata risk assessment. CRIM1, PLAUR, FSTL3, and SPON1 showed incremental prognostic value on top of the predictive models. As determined by Western blot, FSTL3 and SPON1 were significantly upregulated in the right ventricle of patients with PAH and animal models (monocrotaline-injected and pulmonary artery banding-subjected rats). In addition to revealing new actors likely involved in cardiopulmonary remodeling in PAH, our screening identified promising circulating biomarkers to improve risk prediction in PAH, which should be externally confirmed.

Deciphering aging-associated molecular mechanisms in bone marrow derived hematopoietic stem cells in the elderly using NGS data

Aging is a complex process that is not yet fully understood. Despite advancements in research, a deeper understanding of the underlying biological mechanisms is necessary to develop interventions that promote healthy longevity. The aim of this study was to elucidate the complex mechanisms associated with healthy aging and longevity in healthy elderly individuals. The RNA sequencing (RNA-seq) data used in this study was obtained from the Gene Expression Omnibus (GEO) database (accession number GSE104406), which was collected from Fluorescent Activated Cell Sorting (FACS) of human bone marrow derived human hematopoietic stem cells (BM-HSCs) (Lineage-, CD34+, CD38-) young (18-30 years old) and aged (65-75 years old) donors who had no known hematological malignancy, with 10 biological replicates per group. The GEO RNA-seq Experiments Interactive Navigator (GREIN) software was used to obtain raw gene-level counts and filtered metadata for this dataset. Next generation knowledge discovery (NGKD) tools provided by BioJupies were used to obtain differentially regulated pathways, gene ontologies (GO), and gene signatures in the HSCs. Finally, theL1000 Characteristic Direction Signature Search Engine (L1000CDS2) tool was used to identify specific drugs that reverse aging-associated gene signatures in old but healthy individuals. The down-regulation of signaling pathways such as longevity regulation, proteasome, notch, apoptosis, nuclear factor kappa B (NFkB), and peroxisome proliferator-activated receptors (PPAR) signaling pathways in the HSCs of healthy elderly. GO functions related to negative regulation of bone morphogenetic protein (BMP), telomeric DNA binding, nucleoside binding, calcium -dependent protein binding, chromatin-DNA binding, SMAD binding, and demethylase activity were significantly downregulated in the BM-HSCs of the elderly compared to the healthy young group. Importantly, we identified potential drugs such as salermide, celestrol, cercosporin, dorsomorphin dihydrochloride, and LDN-193189 monohydrochloride that can reverse the aging-associated signatures in HSCs from healthy elderly. The analysis of RNA-seq data based on NGKD techniques revealed a plethora of differentially regulated pathways, gene ontologies, and drugs with anti-aging potential to promote healthspan in the elderly.

Role of HFSCARC in hair follicle stem cell proliferation and differentiation in cashmere goat

AbstractAs a model of regenerative medicine, hair follicle stem cell (HFSC) plays a determining role in the hair cycle. Emerging evidences showed that long noncoding RNAs regulated the biological function of HFSC. In this current study, we found that lncRNA‐000552, standing for “goat secondary HFSC Associated SYNE3 Regulator of HF Cycle” (HFSCARC) expressed higher in anagen than that in telogen of cashmere goat. Through experiments involving nucleocytoplasmic separation and RNA‐FISH, we determined that HFSCARC was primarily located in the nucleus of HFSC. To understand the function of HFSCARC, the study performed various assays, including crystal violet staining, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, EdU, and flow cytometry analysis, which collectively revealed that HFSCARC inhibited HFSC proliferation. Additionally, HFSCARC promoted the differentiation of HFSC by investigating the expression of marker genes specific to stem cells and keratinocytes. RNA sequencing analysis was conducted to investigate the global gene expression changes associated with HFSCARC expression. The results showed that HFSCARC altered the expression of genes involved in cell proliferation, hair follicle development, and regulation of bone morphogenetic proteins (BMP) signaling. Furthermore, the study revealed that HFSCARC activated the BMP signaling pathway. Intriguingly, the study found a decreased expression of SYNE3, which was a neighboring gene of HFSCARC. The altered expression of genes associated with transmethylase and demethylase further suggested that HFSCARC might play an important role in regulating the SYNE3 expression. Overall, this study provides valuable insights into the regulatory role of HFSCARC in the biological function of HFSC. These findings contribute to a better understanding of the involvement of noncoding RNAs in the regulation of hair cycle.

Deciphering aging-associated molecular mechanisms in bone marrow derived hematopoietic stem cells in the elderly using NGS data.

Aging is a complex process that is not yet fully understood. Despite advancements in research, a deeper understanding of the underlying biological mechanisms is necessary to develop interventions that promote healthy longevity. The aim of this study was to elucidate the complex mechanisms associated with healthy aging and longevity in healthy elderly individuals. The RNA sequencing (RNA-seq) data used in this study was obtained from the Gene Expression Omnibus (GEO) database (accession number GSE104406), which was collected from Fluorescent Activated Cell Sorting (FACS) of human bone marrow derived human hematopoietic stem cells (BM-HSCs) (Lineage-, CD34+, CD38-) young (18-30 years old) and aged (65-75 years old) donors who had no known hematological malignancy, with 10 biological replicates per group. The GEO RNA-seq Experiments Interactive Navigator (GREIN) software was used to obtain raw gene-level counts and filtered metadata for this dataset. Next generation knowledge discovery (NGKD) tools provided by BioJupies were used to obtain differentially regulated pathways, gene ontologies (GO), and gene signatures in the BM-HSCs. Finally, the L1000 Characteristic Direction Signature Search Engine (L1000CDS2) tool was used to identify specific drugs that reverse aging-associated gene signatures in old but healthy individuals. The down-regulation of signaling pathways such as longevity regulation, proteasome, Notch, apoptosis, nuclear factor kappa B (NFkB), and peroxisome proliferator-activated receptors (PPAR) signaling pathways in the BM-HSCs of healthy elderly. GO functions related to negative regulation of bone morphogenetic protein (BMP), telomeric DNA binding, nucleoside binding, calcium -dependent protein binding, chromatin-DNA binding, SMAD binding, and demethylase activity were significantly downregulated in the BM-HSCs of the elderly compared to the healthy young group. Importantly, potential drugs such as salermide, celestrol, cercosporin, dorsomorphin dihydrochloride, and LDN-193189 monohydrochloride that can reverse the aging-associated signatures in HSCs from healthy elderly were identified. The analysis of RNA-seq data based on NGKD techniques revealed a plethora of differentially regulated pathways, gene ontologies, and drugs with anti-aging potential to promote healthspan in the elderly.

A Functional Variant Alters the Binding of Bone morphogenetic protein 2 to the Transcription Factor NF-κB to Regulate Bone morphogenetic protein 2 Gene Expression and Chicken Abdominal Fat Deposition

In this study, we employed a dual-luciferase reporter assay and electrophoretic mobility shift analysis (EMSA) in vitro to explore whether a 12-base pair (bp) insertion/deletion (InDel) variant (namely g.14798187_14798188insTCCCTGCCCCCT) within intron 2 of the chicken BMP2 gene, which was significantly associated with chicken abdominal fat weight and abdominal fat percentage, is a functional marker and its potential regulatory mechanism. The reporter analysis demonstrated that the luciferase activity of the deletion allele was extremely significantly higher than that of the insertion allele (p < 0.01). A bioinformatics analysis revealed that compared to the deletion allele, the insertion allele created a transcription factor binding site of nuclear factor-kappa B (NF-κB), which exhibited an inhibitory effect on fat deposition. A dual-luciferase reporter assay demonstrated that the inhibitory effect of NF-κB on the deletion allele was stronger than that on the insertion allele. EMSA indicated that the binding affinity of NF-κB for the insertion allele was stronger than that for the deletion allele. In conclusion, the 12-bp InDel chicken BMP2 gene variant is a functional variant affecting fat deposition in chickens, which may partially regulate BMP2 gene expression by affecting the binding of transcription factor NF-κB to the BMP2 gene.

Determination of the Expression of Bone Morphogen Protein 15 and its Receptors in Laying Hens’ Ovary

Abstract The objective of the current research was to determine expression, function and regulation of bone morphogenetic protein 15 (BMP15) during follicular development in laying hens. A trial was conducted with 40 layers from Lohman Klassik Brown breed (40 weeks old). At the end of the study fifteen layers were humanely killed and their ovaries were then dissected. Ribonucleic acid (RNA) expression of BMP15 was analyzed in the ooplasm and in granulosa cells. It was significantly higher in the ooplasm (p<0.01). BPM15 expression was not found in the granulosa cells from 6-8 mm and >9 mm follicles. The expression for bone morphogenetic protein 15 receptors (BMPR1B and BMPR2) in the granulosa cells was in significant positive correlation with the follicle size (p<0.05). The results obtained in this study demonstrate the possible role of BMP15 in developing oocytes. BMP15 expression is important for the growth regulation and signaling in the follicular cells in the preovulatory phase.

Acupotomy ameliorates subchondral bone absorption and mechanical properties in rabbits with knee osteoarthritis by regulating bone morphogenetic protein 2-Smad1 pathway.

To investigate the effects of acupotomy on the subchondral bone absorption and mechanical properties in rabbits with knee osteoarthritis (KOA). The rabbits were divided into blank control, model, acupotomy and electroacupuncture (EA) groups, with 12 rabbits in each. Modified Videman's method was used to prepare KOA model. The acupotomy and EA group were given indicated intervention for 3 weeks. The behavior of rabbits in each group was recorded. Subsequently, cartilage-subchondral bone units were obtained and morphological changes were observed by optical microscope and micro computed tomography. Compression test was used to detect the mechanical properties of subchondral bone, Western blot and real-time polymerase chain reaction (RT-PCR) were applied to detect the expression of bone morphogenetic protein 2-Smad1 (BMP2-Smad1) pathway in subchondral bone. Compared with the control group, rabbits in the KOA group showed lameness, knee pain, and cartilage degradation; the subchondral bone showed active resorption, the mechanical properties decreased significantly and the BMP2-Smad1 pathway downregulated significantly. Both acupotomy and EA intervention could increase the thickness of trabecular bone (Tb. Th), the bone volume fraction (BV/TV) and the thickness of subchondral bone plate, reduce the separation of trabecular bone (Tb. Sp), improve the maximum load and elastic modulus of subchondral bone, and effectively delay cartilage degeneration in KOA rabbits. This process may be achieved through upregulation the related proteins of BMP2-Smad1 pathway. The maximum load and elastic modulus of subchondral bone in the acupotomy group were slightly better than those in the EA group. Acupotomy could effectively protect cartilage by inhibiting abnormal bone resorption and improving mechanical properties of subchondral bone thorough the related proteins of BMP2-Smad1 pathway in KOA rabbits.

Chronic Electroacupuncture With High-Frequency at ST-36 Promotes Gastrointestinal Motility by Regulating Bone Morphogenetic Protein 2 Secretion of Muscularis Macrophages

BackgroundElectroacupuncture (EA) at Zusanli (ST36) is an alternative treatment for several gastrointestinal motility disorders; however, the exact mechanism is unconfirmed. We aimed to show the potential effects of EA on muscularis macrophages (MMφ), the bone morphogenetic protein (BMP)/BMP receptor (BMPR)-Smad signal pathway, and enteric neurons in diabetic mice. This may provide fresh insight into ways EA affects gastrointestinal motility. Materials and MethodsC57BL/6J healthy adult male mice were randomly divided into five groups: regular control group, diabetes group, diabetes with sham EA group (acupuncture only), diabetes with low-frequency EA group (10 Hz), diabetes with high-frequency EA group (HEA) (100 Hz). The stimulation lasted eight weeks. Gastrointestinal motility was assessed. We identified M2-like MMφ in the layer of colonic muscle by flow cytometry. Western Blot, real-time polymerase chain reaction, and immunofluorescent staining were also used to determine the MMφ, molecules in the BMP2/BMPR-Smad pathway, and PGP9.5, neuronal nitric oxide synthase (nNOS) expression of enteric neurons in the colon of each group. Results1) HEA improved the gastrointestinal motility (gastrointestinal transit time, defecation frequency) of diabetic mice. 2) HEA reversed the decreased proportion of M2-like MMφ and expression of the CD206 in the colon of diabetic mice. 3) HEA restored the downregulations of BMP2, BMPR1b, and Smad1 in the BMP2/BMPR-Smad pathway and increased downstream enteric neurons marked by PGP9.5, nNOS in the colon of diabetes mice. ConclusionsHEA might promote gut dynamics by upregulating M2-like MMφ in the colon of diabetic mice, which in turn leads to the accumulation of molecules in the BMP2/BMPR-Smad signaling pathway and downstream enteric neurons.

Lack of evidence that fibrillin1 regulates bone morphogenetic protein 4 activity in kidney or lung.

The Bone morphogenetic protein 4 (BMP4) precursor protein is cleaved at two sites to generate an active ligand and inactive prodomain. The ligand and prodomain form a noncovalent complex following the first cleavage, but dissociate after the second cleavage. Transient formation of this complex is essential to generate a stable ligand. Fibrillins (FBNs) bind to the prodomains of BMPs, and can regulate the activity of some ligands. Whether FBNs regulate BMP4 activity is unknown. Mice heterozygous for a null allele of Bmp4 showed incompletely penetrant kidney defects and females showed increased mortality between postnatal day 6 and 8. Removal of one copy of Fbn1 did not rescue or enhance kidney defects or lethality. The lungs of Fbn1+/- females had enlarged airspaces that were unchanged in Bmp4+/- ;Fbn1+/- mice. Additionally, removal of one or both alleles of Fbn1 had no effect on steady state levels of BMP4 ligand or on BMP activity in postnatal lungs. These findings do not support the hypothesis that FBN1 plays a role in promoting BMP4 ligand stability or signaling, nor do they support the alternative hypothesis that FBN1 sequesters BMP4 in a latent form, as is the case for other BMP family members.

Identification of the Time Period during Which BMP Signaling Regulates Proliferation of Neural Progenitor Cells in Zebrafish.

Bone morphogenetic protein (BMP) signaling regulates neural induction, neuronal specification, and neuronal differentiation. However, the role of BMP signaling in neural progenitors remains unclear. This is because interruption of BMP signaling before or during neural induction causes severe effects on subsequent neural developmental processes. To examine the role of BMP signaling in the development of neural progenitors in zebrafish, we bypassed the effect of BMP signaling on neural induction and suppressed BMP signaling at different time points during gastrulation using a temporally controlled transgenic line carrying a dominant-negative form of Bmp receptor type 1aa and a chemical inhibitor of BMP signaling, DMH1. Inhibiting BMP signaling from 8 hpf could bypass BMP regulation on neural induction, induce the number of proliferating neural progenitors, and reduce the number of neuronal precursors. Inhibiting BMP signaling upregulates the expression of the Notch downstream gene hairy/E(spl)-related 2 (her2). Inhibiting Notch signaling or knocking down the Her2 function reduced neural progenitor proliferation, whereas inactivating BMP signaling in Notch-Her2 deficient background restored the number of proliferating neural progenitors. These results reveal the time window for the proliferation of neural progenitors during zebrafish development and a fine balance between BMP and Notch signaling in regulating the proliferation of neural progenitor cells.

A p53-TLR3 axis ameliorates pulmonary hypertension by inducing BMPR2 via IRF3

Pulmonary arterial hypertension (PAH) features pathogenic and abnormal endothelial cells (ECs), and one potential origin is clonal selection. We studied the role of p53 and toll-like receptor 3 (TLR3) in clonal expansion and pulmonary hypertension (PH) via regulation of bone morphogenetic protein (BMPR2) signaling. ECs of PAH patients had reduced p53 expression. EC-specific p53 knockout exaggerated PH, and clonal expansion reduced p53 and TLR3 expression in rat lung CD117+ ECs. Reduced p53 degradation (Nutlin 3a) abolished clonal EC expansion, induced TLR3 and BMPR2, and ameliorated PH. Polyinosinic/polycytidylic acid [Poly(I:C)] increased BMPR2 signaling in ECs via enhanced binding of interferon regulatory factor-3 (IRF3) to the BMPR2 promoter and reduced PH in p53-/- mice but not in mice with impaired TLR3 downstream signaling. Our data show that a p53/TLR3/IRF3 axis regulates BMPR2 expression and signaling in ECs. This link can be exploited for therapy of PH.

Upregulation of miR-664a-3p Ameliorates Calcific Aortic Valve Disease by Inhibiting the BMP2 Signaling Pathway.

The development of calcific aortic valve disease (CAVD) is a complex process of ectopic calcification involving various factors that lead to aortic valve stenosis, hemodynamic changes, and, in severe cases, even sudden death. Currently, aortic valve replacement is the only effective method. The osteogenic differentiation of aortic valve interstitial cells (AVICs) is one of the key factors of valve calcification. Emerging evidence suggests that bone morphogenetic protein 2 (BMP2) can induce the proosteogenic activation of AVICs. However, the regulatory mechanism underlying this activation in AVICs is unclear. In the present study, we elucidated through high-throughput RNA sequencing and RT-qPCR that miR-664a-3p was evidently downregulated in the calcific aortic valve. We also proved that miR-664a-3p was involved in regulating osteogenic differentiation in AVICs. Target prediction analysis and dual-luciferase reporter gene assay confirmed that miR-664a-3p is preferentially bound to BMP2. Furthermore, the effect of the miR-664a-3p/BMP2 axis on osteogenic differentiation in AVICs was examined using the gain- and loss-of-function approach. Finally, we constructed a mouse CAVD model and verified the effect of the miR-664a-3p/BMP2 axis on the aortic valve calcification leaflets in vivo. In conclusion, miR-664a-3p regulates osteogenic differentiation in AVICs through negative regulation of BMP2, highlighting that miR-664a-3p may be a potential therapeutic target for CAVD.

Crim1 inhibits angiotensin II-induced hypertrophy and preserves Kv4.2 expression in cardiomyocytes.

Objective(s):Angiotensin II (Ang II) plays a key role in the regulation of myocardial hypertrophy via downstream cysteine-rich transmembrane bone morphogenetic protein regulator 1 (Crim1). However, it is still unclear whether Crim1 is involved in ionic channel remodeling. The study aimed to explore the effects of Crim1 on transient outward potassium current (Ito) and Kv4.2 (the main subunit of Ito channel) expression in hypertrophic ventricular cardiomyocytes. Materials and Methods:The ventricular cardiomyocytes were isolated from the neonatal rats. Hypertrophy was induced by Ang II. Crim1 expression was modulated by using adenovirus transfection. The expression of myosin heavy chain beta (β-MHC), Crim1, and Kv4.2 was determined by RT-qPCR and western blot. The cellular surface area was assessed using Image J software. Ito was recorded by the whole-cell patch clamp technique. Results:Ang II-induced hypertrophy in cardiomyocytes was identified by their larger cellular surface area and higher mRNA expression of β-MHC. Ang II significantly decreased the expression of Crim1 and Kv4.2 and reduced Ito current density. However, Crim1 overexpression abolished the Ang II-induced hypertrophy and preserved the expression of Kv4.2 and Ito current density. Conclusion:Crim1 overexpression inhibits Ang II-induced hypertrophy and preserves Ito current density via up-regulating Kv4.2 in ventricular cardiomyocytes from neonatal rats. Crim1 could have a role in the development of ventricular arrhythmia in hypertrophic hearts.

GREM1 is a novel serum diagnostic marker and potential therapeutic target for pancreatic ductal adenocarcinoma.

ObjectivePancreatic ductal adenocarcinoma (PDAC) is a highly malignant neoplasm with rising incidence worldwide. Gremlin 1 (GREM1), a regulator of bone morphogenetic protein (BMP) signaling, fine-tunes extensive biological processes, including organ morphology, cellular metabolism, and multiple pathological developments. The roles of GREM1 in PDAC remain unknown.MethodsVarieties of public databases and online software were employed to analyze the expressions at transcription and protein levels of GREM1 in multiple malignant neoplasms including PDAC, and in addition, its potential pro-tumoral functions in PDAC were further evaluated. A total of 340 serum samples of pancreatic disease, including PDAC, low-grade malignant pancreatic neoplasm, benign pancreatic neoplasm, pancreatitis, and 132 healthy controls, were collected to detect GREM1. The roles of serum GREM1 in the diagnosis and prediction of survival of PDAC after radical resection were also analyzed.ResultsBioinformatics analyses revealed that GREM1 was overexpressed in PDAC and predicted a poorer survival in PDAC. A higher protein level of GREM1 in PDAC correlated with stroma formation and immunosuppression by recruiting varieties of immunosuppressive cells, including T regulatory cells (Tregs), M2 macrophages, myeloid-derived suppressor cells (MDSCs), and exhaustion T cells into the tumor microenvironment. A higher level of serum GREM1 was observed in PDAC patients, compared to healthy control (p < 0.001). Serum GREM1 had a good diagnostic value (area under the curve (AUC) = 0.718, p < 0.001), and its combination with carbohydrate antigen 199 (CA199) achieved a better diagnostic efficacy (AUC = 0.914, p < 0.001), compared to CA199 alone. The cutoff value was calculated by receiver operating characteristic (ROC) analysis, and PDAC patients were divided into two groups of low and high GREM1. Logistic analyses showed serum GREM1 positively correlated with tumor size (hazard ratio (HR) = 7.097, p = 0.032) and histopathological grades (HR = 2.898, p = 0.014). High-level serum GREM1 (1,117.8 pg/ml) showed a shorter postoperative survival (p = 0.0394).ConclusionHigher intra-tumoral expression of GREM1 in PDAC contributes to tumor stroma and immunosuppressive tumor microenvironment, presenting its therapeutic potential. High-level serum GREM1 predicts poorer survival after resection. A combination of serum CA199 and GREM1 shows a stronger diagnostic efficacy in PDAC.

RUNX2 Regulates Osteoblast Differentiation via the BMP4 Signaling Pathway

RUNX2 is a master osteogenic transcription factor, and mutations in RUNX2 cause the inherited skeletal disorder cleidocranial dysplasia (CCD). Studies have revealed that RUNX2 is not only a downstream target of the bone morphogenetic protein (BMP) pathway but can also regulate the expression of BMPs. However, the underlying mechanism of the regulation of BMPs by RUNX2 remains unknown. In this project, we diagnosed a CCD patient with a 7.86-Mb heterozygous deletion on chromosome 6 containing all exons of RUNX2 by multiplex ligation-dependent probe amplification (MLPA) and whole-genome sequencing (WGS). Bone marrow mesenchymal stem cells (BMSCs) were further extracted from patient alveolar bone fragments (CCD-BMSCs), an excellent natural model to explore the possible mechanism. The osteogenic differentiation ability of CCD-BMSCs was severely affected by RUNX2 heterozygous deletion. Also, BMP4 decreased most in BMP ligands, and CHRDL1, a BMP antagonist, was abnormally elevated in CCD-BMSCs. Furthermore, BMP4 treatment essentially rescued the osteogenic capacity of CCD-BMSCs, and RUNX2 overexpression reversed the abnormal expression of BMP4 and CHRDL1. Notably, we constructed CRISPR/Cas9 Runx2+/m MC3T3-E1 cells, which simulated a variant in CCD-BMSCs, to exclude the interference of other gene deletions and the heterogeneity of the genetic background of primary cells, and verified all findings from the CCD-BMSCs. Moreover, the luciferase reporter experiment showed that RUNX2 could inhibit the transcription of CHRDL1. Through immunofluorescence, the inhibitory effect of CHRDL1 on BMP4/Smad signaling was confirmed in MC3T3-E1 cells. These results revealed that RUNX2 regulated the BMP4 pathway by inhibiting CHRDL1 transcription. We collectively identified a novel RUNX2/CHRDL1/BMP4 axis to regulate osteogenic differentiation and noted that BMP4 might be a valuable therapeutic option for treating bone diseases.

Effects of hypoxia on bone metabolism and anemia in patients with chronic kidney disease.

BACKGROUNDAbnormal bone metabolism and renal anemia seriously affect the prognosis of patients with chronic kidney disease (CKD). Existing studies have mostly addressed the pathogenesis and treatment of bone metabolism abnormality and anemia in patients with CKD, but few have evaluated their mutual connection. Administration of exogenous erythropoietin to CKD patients with anemia used to be the mainstay of therapeutic approaches; however, with the availability of hypoxia-inducible factor (HIF) stabilizers such as roxadustat, more therapeutic choices for renal anemia are expected in the future. However, the effects posed by the hypoxic environment on both CKD complications remain incompletely understood.AIMTo summarize the relationship between renal anemia and abnormal bone metabolism, and to discuss the influence of hypoxia on bone metabolism.METHODSCNKI and PubMed searches were performed using the key words “chronic kidney disease,” “abnormal bone metabolism,” “anemia,” “hypoxia,” and “HIF” to identify relevant articles published in multiple languages and fields. Reference lists from identified articles were reviewed to extract additional pertinent articles. Then we retrieved the and Introduction and searched the results from the literature, classified the extracted information, and summarized important information. Finally, we made our own conclusions.RESULTSThere is a bidirectional relationship between renal anemia and abnormal bone metabolism. Abnormal vitamin D metabolism and hyperparathyroidism can affect bone metabolism, blood cell production, and survival rates through multiple pathways. Anemia will further attenuate the normal bone growth. The hypoxic environment regulates bone morphogenetic protein, vascular endothelial growth factor, and neuropilin-1, and affects osteoblast/osteoclast maturation and differentiation through bone metabolic changes. Hypoxia preconditioning of mesenchymal stem cells (MSCs) can enhance their paracrine effects and promote fracture healing. Concurrently, hypoxia reduces the inhibitory effect on osteocyte differentiation by inhibiting the expression of fibroblast growth factor 23. Hypoxia potentially improves bone metabolism, but it still carries potential risks. The optimal concentration and duration of hypoxia remain unclear. CONCLUSIONThere is a bidirectional relationship between renal anemia and abnormal bone metabolism. Hypoxia may improve bone metabolism but the concentration and duration of hypoxia remain unclear and need further study.

MiR-181a Targets RSPO2 and Regulates Bone Morphogenetic Protein - WNT Signaling Crosstalk During Chondrogenic Differentiation of Mesenchymal Stromal Cells.

Mechanisms of WNT and bone morphogenetic protein (BMP) signaling crosstalk is in the focus of multiple biological studies, and it also has been discovered to play important roles in human mesenchymal stromal cells (MSC) that are of great interest for neocartilage engineering due to their high chondrogenic differentiation potential. However, MSC-derived chondrocytes undergo hypertrophic degeneration that impedes their clinical application for cartilage regeneration. In our previous study, we established that several microRNAs (miRs) are differentially expressed between articular chondrocytes (AC) – and MSC-derived neocartilage, with miR-181a being the most prominent candidate as key microRNA involved in the regulation of a balance between chondral and endochondral differentiation. The aim of this study was the identification of precise mRNA targets and signaling pathways regulated by miR-181a in MSC during chondrogenesis. MiR-181a was upregulated during chondrogenesis of MSC, along with an increase of the hypertrophic phenotype in resulting cartilaginous tissue. By in silico analysis combined with miR reporter assay, the WNT signaling activator and BMP signaling repressor RSPO2 was suggested as a target of miR-181a. Further validation experiments confirmed that miR-181a targets RSPO2 mRNA in MSC. It was found that in human MSC miR-181a activated BMP signaling manifested by the accumulation of SOX9 protein and increased phosphorylation of SMAD1/5/9. These effects, together with the concomitant reduction of canonical WNT signaling induced by miR-181a mimic, were in accordance with the effects expected by the loss of RSPO2, thus indicating the causative link between miR-181a and RSPO2. Moreover, we observed that a tight correlation between miR-181a and miR-218 expression levels in healthy human cartilage tissue was disrupted in osteoarthritis (OA) highlighting the importance of the WNT-BMP signaling crosstalk for preventing OA.

ILF3 is responsible for hyperlipidemia-induced arteriosclerotic calcification by mediating BMP2 and STAT1 transcription

Calcification is common in atherosclerotic plaque and can induce vulnerability, which further leads to myocardial infarction, plaque rupture and stroke. The mechanisms of atherosclerotic calcification are poorly characterized. Interleukin enhancer binding factor 3 (ILF3) has been identified as a novel factor affecting dyslipidemia and stroke subtypes. However, the precise role of ILF3 in atherosclerotic calcification remains unclear. In this study, we used smooth muscle-conditional ILF3 knockout (ILF3SM-KO) and transgenic mice (ILF3SM-Tg) and macrophage-conditional ILF3 knockout (ILF3M-KO) and transgenic (ILF3M-Tg) mice respectively. Here we showed that ILF3 expression is increased in calcified human aortic vascular smooth muscle cells (HAVSMCs) and calcified atherosclerotic plaque in humans and mice. We then found that hyperlipidemia increases ILF3 expression and exacerbates calcification of VSMCs and macrophages by regulating bone morphogenetic protein 2 (BMP2) and signal transducer and activator of transcription 1 (STAT1) transcription. We further explored the molecular mechanisms of ILF3 in atherosclerotic calcification and revealed that ILF3 acts on the promoter regions of BMP2 and STAT1 and mediates BMP2 upregulation and STAT1 downregulation, which promotes atherosclerotic calcification. Our results demonstrate the effect of ILF3 in atherosclerotic calcification. Inhibition of ILF3 may be a useful therapy for preventing and even reversing atherosclerotic calcification.

Experimental Study on the Effect of miR-200b Regulation of Bone Morphogenetic Protein (BMP)-2 Expression on the Proliferation and Invasion of Nasopharyngeal Carcinoma Cells

BMP is an important member of the skeletal junction proteins associated with cell invasion, metastasis, and migration. MiR-200b is associated with the progression of several tumors. This study investigated whether miR-200b plays a role in regulating BMP-2 expression and affecting the proliferation and invasion of nasopharyngeal carcinoma cells. The nasopharyngeal carcinoma tissues with different TNM stages were collected and the proliferative nasal tissues alone were used as controls to detect the expression of miR-200b and BMP by RT-PCR. The nasopharyngeal carcinoma cell line CNE1 cells were divided into miR-NC group, miR-200b mimic group, siRNA-NC group, and siRNA-BMP-2 group, to detect BMP-2 level, cell invasion and proliferation ability by transwell. The BMP-2 mRNA expressed in nasopharyngeal carcinoma tissues was significantly elevated compared to controls and correlated with TNM stage. BMP-2 was higher in tumor tissues than in controls, however, the expression profile of miR-200b was opposite to BMP-2. Transfection with miR-200b mimic or siRNA-BMP-2 significantly down-regulated BMP-2 in CNE1 cells and attenuated cell invasive and proliferative capacity. Reduced expression of miR-200b is associated with elevated BMP-2 expression and increased invasive capacity of nasopharyngeal cancer cells. Overexpression of miR-200b reduces the invasive and proliferative capacity of nasopharyngeal cancer cells by targeting and inhibiting BMP-2 expression.

The Wnt Effector TCF7l2 Promotes Oligodendroglial Differentiation by Repressing Autocrine BMP4-Mediated Signaling.

Promoting oligodendrocyte (OL) differentiation represents a promising option for remyelination therapy for treating the demyelinating disease multiple sclerosis (MS). The Wnt effector transcription factor 7-like 2 (TCF7l2) was upregulated in MS lesions and had been proposed to inhibit OL differentiation. Recent data suggest the opposite yet underlying mechanisms remain elusive. Here, we unravel a previously unappreciated function of TCF7l2 in controlling autocrine bone morphogenetic protein (BMP)4-mediated signaling. Disrupting TCF7l2 in mice of both sexes results in oligodendroglial-specific BMP4 upregulation and canonical BMP4 signaling activation in vivo Mechanistically, TCF7l2 binds to Bmp4 gene regulatory element and directly represses its transcriptional activity. Functionally, enforced TCF7l2 expression promotes OL differentiation by reducing autocrine BMP4 secretion and dampening BMP4 signaling. Importantly, compound genetic disruption demonstrates that oligodendroglial-specific BMP4 deletion rescues arrested OL differentiation elicited by TCF7l2 disruption in vivo Collectively, our study reveals a novel connection between TCF7l2 and BMP4 in oligodendroglial lineage and provides new insights into augmenting TCF7l2 for promoting remyelination in demyelinating disorders such as MS.SIGNIFICANCE STATEMENT Incomplete or failed myelin repairs, primarily resulting from the arrested differentiation of myelin-forming oligodendrocytes (OLs) from oligodendroglial progenitor cells, is one of the major reasons for neurologic progression in people affected by multiple sclerosis (MS). Using in vitro culture systems and in vivo animal models, this study unraveled a previously unrecognized autocrine regulation of bone morphogenetic protein (BMP)4-mediated signaling by the Wnt effector transcription factor 7-like 2 (TCF7l2). We showed for the first time that TCF7l2 promotes oligodendroglial differentiation by repressing BMP4-mediated activity, which is dysregulated in MS lesions. Our study suggests that elevating TCF7l2 expression may be possible in overcoming arrested oligodendroglial differentiation as observed in MS patients.