Periostin/Bone Morphogenetic Protein 1 axis axis regulates proliferation and osteogenic differentiation of sutured mesenchymal stem cells and affects coronal suture closure in the TWIST1+/- mouse model of craniosynostosis.

BACKGROUND AND OBJECTIVE: The pathogenesis of coronal suture craniosynostosis is often attributed to the dysregulated cellular dynamics, particularly the excessive proliferation and abnormal osteogenic differentiation of suture cells. Despite its clinical significance, the molecular mechanims of this condition remain inadequately understood. This study is dedicated to exploring the influence of the Periostin/Bone Morphogenetic Protein 1 (BMP1) axis on the growth and osteogenic maturation of Suture Mesenchymal Stem Cells (SMSCs), which are pivotal in suture homeostasis. METHODS: Neonatal TWIST Basic Helix-Loop-Helix Transcription Factor 1 heterozygous (TWIST1+/-) mice, aged one day, were subjected to adenoviral vector-mediated Periostin upregulation. To modulate Periostin/BMP1 levels in SMSCs, we employed siRNA and pcDNA 3.1 vectors. Histological and molecular characterizations, including hematoxylin and eosin staining, Western blot, and immunohistochemistry were employed to study suture closure phenotypes and protein expression patterns. Cellular assays, encompassing colony formation, 5-ethynyl-2'deoxyuridine, and wound healing tests were conducted to analyze SMSC proliferation and migration. Osteogenic differentiation was quantified using Alkaline Phosphatase (ALP) and Alizarin Red S (ARS) staining, while protein markers of proliferation and differentiation were evaluated by Western blotting. The direct interaction between Periostin and BMP1 was validated through co-immunoprecipitation assays. RESULTS: In the TWIST1+/- model, an upregulation of Periostin coupled with a downregulation of BMP1 was observed. Augmenting Periostin expression mitigated craniosynostosis. In vitro, overexpression of Periostin or BMP1 knockdown suppressed SMSC proliferation, migration, and osteogenic differentiation. Periostin knockdown manifested an inverse biological impact. Notably, the suppressive influence of Periostin overexpression on SMSCs was effectively counteracted by upregulating BMP1. There was a direct interaction between Periostin and BMP1. CONCLUSION: These findings underscore the significance of the Periostin/BMP1 axis in regulating craniosynostosis and SMSC functions, providing new insights into the molecular mechanisms of craniosynostosis and potential targets for therapeutic intervention.

Activated hepatic stellate cell-derived Bmp-1 induces liver fibrosis via mediating hepatocyte epithelial-mesenchymal transition.

Liver fibrosis is a reparative response to injury that arises from various etiologies, characterized by activation of hepatic stellate cells (HSCs). Periostin, a secreted matricellular protein, has been reported to participate in tissue development and regeneration. However, its involvement in liver fibrosis remains unknown. This study investigated the roles and mechanisms of Periostin in phenotypic transition of HSCs and relevant abnormal cellular crosstalk during liver fibrosis. The fate of hepatic stellate cells (HSCs) during liver fibrogenesis was investigated using single-cell and bulk RNA sequencing profiles, which revealed a significant proliferation of activated HSCs (aHSCs) in fibrotic livers of both humans and mice. αSMA-TK mice were used to demonstrate that depletion of proliferative aHSCs attenuates liver fibrosis induced by carbon tetrachloride and 3,5-diethoxycarbonyl-1,4-dihydrocollidine. Through integrating data from single-cell and bulk sequencing, Periostin was identified as a distinctive hallmark of proliferative aHSC subpopulation. Elevated levels of Periostin were detected in fibrotic livers of both humans and mice, primarily within aHSCs. However, hepatic Periostin levels were decreased along with depletion of proliferative aHSCs. Deficiency of Periostin led to reduced liver fibrosis and suppressed hepatocyte epithelial-mesenchymal transition (EMT). Periostin-overexpressing HSCs, exhibiting a proliferative aHSC phenotype, release bone morphogenetic protein-1 (Bmp-1), which activates EGFR signaling, inducing hepatocyte EMT and contributing to liver fibrosis. In conclusion, Periostin in aHSCs drives their acquisition of a proliferative phenotype and the release of Bmp-1. Proliferative aHSC subpopulation-derived Bmp-1 induces hepatocyte EMT via EGFR signaling, promoting liver fibrogenesis. Bmp-1 and Periostin should be potential therapeutic targets for liver fibrosis.

Upregulation of BMP1 through ncRNAs correlates with adverse outcomes and immune infiltration in clear cell renal cell carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) accounts for approximately 2-3% of all adult malignancies. Clear cell renal cell carcinoma (ccRCC), which comprises 70-80% of all RCC cases, is the most common histological subtype. METHODS: ccRCC transcriptome data and clinical information were downloaded from the TCGA database. We used the TCGA and GEPIA databases to analyze relative expression of BMP1 in various types of human cancer. GEPIA was used to perform survival analysis for BMP1 in various cancer types. Upstream binding miRNAs of BMP1 were obtained through several important target gene prediction tools. StarBase was used to predict candidate miRNAs that may bind to BMP1 and candidate lncRNAs that may bind to hsa-miR-532-3p. We analyzed the association between expression of BMP1 and immune cell infiltration levels in ccRCC using the TIMER website. The relationship between BMP1 expression levels and immune checkpoint expression levels was also investigated. RESULTS: BMP1 was upregulated in GBM, HNSC, KIRC, KIRP and STAD and downregulated in KICH and PRAD. Combined with OS and DFS, BMP1 can be used as a biomarker for poor prognosis among patients with KIRC. Through expression analysis, survival analysis and correlation analysis, LINC00685, SLC16A1-AS1, PVT1, VPS9D1-AS1, SNHG15 and the CCDC18-AS1/hsa-miR-532-3p/BMP1 axis were established as the most potential upstream ncRNA-related pathways of BMP1 in ccRCC. Furthermore, we found that BMP1 levels correlated significantly positively with tumor immune cell infiltration, biomarkers of immune cells, and immune checkpoint expression. CONCLUSION: Our results demonstrate that ncRNA-mediated high expression of BMP1 is associated with poor prognosis and tumor immune infiltration in ccRCC.

O-Fucosylation of BMP1 promotes endometrial decidualization by activating BMP/Smad signaling pathway.

Endometrial decidualization is critical to successful uterine receptivity and embryo implantation. Dysfunction of decidualization is associated with some pregnancy-related disorders, including miscarriage. Protein glycosylation is involved in many physiological and pathological processes. Protein O-fucosyltransferase 1 (poFUT1) is a key enzyme responsible for O-fucosylation biosynthesis on glycoproteins. Bone morphogenetic protein 1 (BMP1) is an essential glycoprotein in reproduction. However, the role and molecular mechanism of fucosylated BMP1 in endometrial stromal cell decidualization are still unknown. In the current study, we found that BMP1 contains a potential O-fucosylation site. Moreover, poFUT1 and BMP1 levels in the secretory phase are higher than those in the proliferative phase, and the highest level was observed in the human uterine tissues of early pregnancy, while a decrease of poFUT1 and BMP1 in the decidua was observed in miscarriage patients. Using human endometrial stromal cells (hESCs), we demonstrated that O-fucosylation of BMP1 was elevated after induced decidualization. Moreover, the increase of BMP1 O-fucosylation by poFUT1 promoted BMP1 secretion to the extracellular matrix, and more actively binds to CHRD. The binding of BMP1 and CHRD further released BMP4 originally bound to CHRD, and activated BMP/Smad signaling pathway, thereby accelerating the decidualization of human endometrial stromal cells. In summary, these results suggest that BMP1 O-fucosylation by poFUT1 could be a potential diagnostic and therapeutic target to predict miscarriage in early pregnancy examinations.

Proteolysis of the low-density lipoprotein receptor in hepatocytes is mediated by BMP1 but not by other astacin proteases.

Bone morphogenetic protein 1 (BMP1), a member of the astacin family of zinc-metalloproteases, proteolytically cleaves the low-density lipoprotein receptor (LDLR) within its ligand-binding domain, reducing the binding and cellular uptake of LDL-cholesterol. Here, we aimed to determine whether astacin proteases other than BMP1 may also cleave LDLR. Although human hepatocytes express all six astacin proteases, including the meprins and mammalian tolloid, we found through pharmacological inhibition and genetic knockdown that only BMP1 contributed to the cleavage of LDLR in its ligand-binding domain. We also found that the minimum amino acid change required to render mouse LDLR susceptible to cleavage by BMP1 is mutation at the P1' and P2 positions of the cleavage site. When expressed in cells, the resulting humanised-mouse LDLR internalised LDL-cholesterol. This work provides insight into the biological mechanisms regulating LDLR function.

Functionally distinct BMP1 isoforms show an opposite pattern of abundance in plasma from non-small cell lung cancer subjects and controls.

Advancements in deep plasma proteomics are enabling high-resolution measurement of plasma proteoforms, which may reveal a rich source of novel biomarkers previously concealed by aggregated protein methods. Here, we analyze 188 plasma proteomes from non-small cell lung cancer subjects (NSCLC) and controls to identify NSCLC-associated protein isoforms by examining differentially abundant peptides as a proxy for isoform-specific exon usage. We find four proteins comprised of peptides with opposite patterns of abundance between cancer and control subjects. One of these proteins, BMP1, has known isoforms that can explain this differential pattern, for which the abundance of the NSCLC-associated isoform increases with stage of NSCLC progression. The presence of cancer and control-associated isoforms suggests differential regulation of BMP1 isoforms. The identified BMP1 isoforms have known functional differences, which may reveal insights into mechanisms impacting NSCLC disease progression.

Delayed inhibition of collagen deposition by targeting bone morphogenetic protein 1 promotes recovery after spinal cord injury.

Fibrotic scars appear after spinal cord injury (SCI) and are mainly composed of fibroblasts and excess extracellular matrix (ECM), including different types of collagen. The temporal and spatial distribution and role of excess collagens and ECM after SCI are not yet fully understood. Here, we identified that the procollagen type I C-terminal propeptide (PICP), a marker of collagen type I deposition, and bone morphogenetic protein 1 (BMP1), a secreted procollagen c-proteinase (PCP) for type I collagen maturation, were significantly elevatedin cerebrospinal fluid of patients with SCI compared with healthy controls, and were associated with spinal cord compression and neurological symptoms. We revealed the deposition of type I collagen in the area damaged by SCI in mice and confirmed that BMP1 was the only expressed PCP and induced collagen deposition. Furthermore, transforming growth factor-ß (TGF-ß), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) can activate the expression of BMP1. However, inhibition of BMP1 at the acute phase eliminated fibrotic scars in the damaged area and inhibited activation and enrichment of astrocytes, which made the damage difficult to repair and increased hematoma. Unexpectedly, knockdown of Bmp1 by adeno-associated virus or the inhibition of BMP1 biological function by specific inhibitors and monoclonal antibodies at different time points after injury led to distinct therapeutic effects. Only delayed inhibition of BMP1 improved axonal regeneration and myelin repair at the subacute stage post-injury, and led to the recovery of motor function, suggesting that scarring had a dual effect. Early inhibition of the scarring was not conducive to limiting inflammation, while excessive scar formation inhibited the growth of axons. After SCI, the collagen deposition indicators increased in both human cerebrospinal fluid and mouse spinal cord. Therefore, suppression of BMP1 during the subacute phase improves nerve function after SCI and is a potential target for scar reduction.

Macular Edema in Central Retinal Vein Occlusion Correlates With Aqueous Fibrinogen Alpha Chain.

Purpose: The global protein profile of the aqueous humor has been found to correlate with the severity of retinal vascular disease. Studying the aqueous humor in central retinal vein occlusion (CRVO) with proteomic techniques may bring insights to the molecular mechanisms underlying the condition. Methods: Aqueous humor samples from treatment naïve patients with CRVO complicated by macular edema (n = 28) and age-matched controls (n = 20) were analyzed by label-free quantification liquid chromatography - tandem mass spectrometry. Best corrected visual acuity (BCVA) was measured as logMAR, and the severity of macular edema was evaluated as central retinal thickness (CRT) with optical coherence tomography. Control samples were obtained prior to cataract surgery. Significantly changed proteins were identified by a permutation-based calculation with a false discovery rate of 0.05. Results: A total of 177 proteins were differentially expressed in CRVO. Regulated proteins were involved in complement activation, innate immune response, blood coagulation, and cell adhesion. Upregulated proteins that correlated with BCVA and CRT included fibrinogen alpha, beta, and gamma chains, fibronectin, Ig lambda-6 chain C region, Ig alpha-1 chain C region, and complement C7. Downregulated proteins that correlated negatively with BCVA, and CRT, included procollagen C-endopeptidase enhancer 1, clusterin, opticin, reelin, fibrillin-1, and cadherin-2. Monocyte differentiation antigen CD14 and lipopolysaccharide-binding protein were increased in CRVO. Conclusions: Fibrinogen chains, fibronectin, and immunoglobulin components correlated with BCVA and CRT, suggesting a multifactorial response. Protective anti-angiogenic proteins, including procollagen C-endopeptidase enhancer 1, clusterin, and opticin, were downregulated in CRVO and correlated negatively with BCVA and CRT.

An Analysis of BMP1 Associated with m6A Modification and Immune Infiltration in Pancancer.

Background: This research explores the underlying link between diagnosis and therapy between bone morphogenetic protein 1 (BMP1) and various cancers. Methods: Three immunotherapeutic cohorts, by the composition of IMvigor210, GSE35640, and GSE78220 were obtained from previously published articles and the Gene Expression Omnibus database. The different expressions of BMP1 in various clinical parameters were conducted, and prognostic analysis was executed utilizing Cox proportional hazard regression and Gene Expression Profiling Interactive Analysis. Moreover, the correlation between BMP1 and tumor microenvironment was analyzed using ESTIMATE and CIBERSORT algorithms. Tumor mutational burden and microsatellite instability were also included. The correlation between m6A modification and the gene expression level was analyzed using Tumor IMmune Estimation Resource, the University of Alabama at Birmingham Cancer data analysis portal. Gene Set Cancer Analysis analyzed the correlation of BMP1 expression level with copy number variations and methylation. Furthermore, the correlation between BMP1 and therapeutic response after antineoplastic drug use was illustrated for further discussion. Results: BMP1 expression had significant differences in 14 cancers. It presented an intimate relationship with immune-relevant biomarkers. A variation analysis indicated that BMP1 had a significant association with immunotherapeutic response. The expression level of BMP1 was closely associated with insulin-like growth factor binding protein 3, an m6A modification relative gene. Except for a few cancer types, methylation negatively correlated with BMP1, and copy number variations positively correlated with BMP1. Notably, low BMP1 expression was connected with immunotherapeutic response in the cohorts, and its expression was related to increased sectional sensitivity of drugs. Conclusion: BMP1 may serve as a potential biomarker for prognostic prediction and immunologic infiltration in diversified cancers, providing a new thought approach for oncotherapy.

Dynamics of the secreted frizzled related protein Sizzled and potential implications for binding to bone morphogenetic protein-1 (BMP-1).

Sizzled (Szl) is both a secreted frizzled related protein (sFRP) and a naturally occurring inhibitor of the zinc metalloproteinase bone morphogenetic protein-1 (BMP-1), a key regulator of extracellular matrix assembly and growth factor activation. Here we present a new crystal structure for Szl which differs from that previously reported by a large scale (90°) hinge rotation between its cysteine-rich and netrin-like domains. We also present results of a molecular docking analysis showing interactions likely to be involved in the inhibition of BMP-1 activity by Szl. When compared with known structures of BMP-1 in complex with small molecule inhibitors, this reveals features that may be helpful in the design of new inhibitors to prevent the excessive accumulation of extracellular matrix that is the hallmark of fibrotic diseases.

Procollagen C-proteinase enhancer-1 and renal failure in multiple myeloma.

BACKGROUND: Renal involvement is present in approximately 50% of multiple myeloma (MM) cases and is associated with a poor prognosis. Procollagen C-Proteinase Enhancer 1 (PCPE-1) is an extracellular matrix glycoprotein that has been shown to increase collagen production by enhancing the activity of Procollagen C-Proteinase (PCP) involved in collagen fibrillogenesis and contribute to the fibrotic process. This study investigates the relationship between PCPE-1 and renal function in myeloma patients. METHODS: Eighty-one adults, consisting of 61 patients diagnosed with MM and 20 healthy controls, were included in this cross-sectional study. The MM patients with renal injury (RI) were classified as "MM-RI( +)" and those with no RI as "MM-RI(-)". RESULTS: The median serum PCPE-1 level was 10.7 (5.0-39.4) ng/mL for the entire study population, 9.9 (5.0-13.6) ng/mL for the control group, 10.0 (6.4-22.5) ng/mL for the MM-RI(-) group, and 11.4 (8.1-39.4) ng/mL for the MM-RI( +) group. The difference between the control group and MM-RI( +) group was statistically significant (p < 0.013). PCPE-1 levels negatively correlated with estimated glomerular filtration rate (eGFR), serum albumin, and hemoglobin levels but positively correlated with serum creatinine and CRP levels in the entire study population. Among MM patients, only serum phosphorus and beta-2-microglobulin (ß2M) were positively correlated with PCPE-1. PCPE-1 levels was not affected by other parameters in the entire study population and in the MM group. CONCLUSIONS: Although serum PCPE-1 was higher in the MM-RI( +) group, it was thought to be associated with low GFR reflecting non-specific kidney injury rather than myeloma-related kidney injury.

Research on Mechanism of Nanometric Bone Pulp Activated with Double Gene as Bone Morphogenetic Protein 1 and Vascular Endothelial Growth Factor for Improving the Strength of Centrum in Osteoporosis.

The aim of this study was assessing the mechanism of nanometric bone pulp activated with double gene as bone morphogenetic protein 1 (BMP-1) and vascular endothelial growth factor (VEGF) in improving the strength of centrum in osteoporosis (OP). The model of nanometric bone pulp activated with BMP-1 and VEGF double gene was established and validated. Under maximum condition of load and collapsed fragments, the model was analyzed through biomechanical test. The conditions for ALP, BGP, MLL and BMD in the model were also analyzed, and three-dimensional structural transformation was analyzed. Western blot and qRT-PCR were used to detect the effect of adding or not adding dual gene activated nano-bone stickers on OC-specific protein and mRNA; ELISA kits were used to detect the changes of RANKL pathway RANKL, OPG and TRACP5b. The maximum conformed quality and condensed intensity were strengthened with the nanometric bone pulp activated with BMP-1 and VEGF double gene. The maximum load in centrum was extremely elevated in the model, and the condition of ALP and its effect on bone was partly improved in the model. The precision and efficiency in the quality of BMD were continuously decreased. The BMD and MLF were strengthened notably in the model, and their effect on the bone was extremely improved. There was tight displayed model of trabecular in centrum and porosity was also continuously reduced. After adding the double-gene activated nano-bone stickers, the results from qRTPCR and Western blot showed that the changes of osteoclast-related genes and protein expressions were significantly down-regulated. The nanometric bone pulp activated with BMP-1 and VEGF double gene was one of ideal filled criterion. The BMD and bone strength were also elevated.

BMP1 is not required for lung fibrosis in mice.

Bone morphogenetic protein 1 (BMP1) belongs to the astacin/BMP1/tolloid-like family of zinc metalloproteinases, which play a fundamental role in the development and formation of extracellular matrix (ECM). BMP1 mediates the cleavage of carboxyl terminal (C-term) propeptides from procollagens, a crucial step in fibrillar collagen fiber formation. Blocking BMP1 by small molecule or antibody inhibitors has been linked to anti-fibrotic activity in the preclinical models of skin, kidney and liver fibrosis. Therefore, we reason that BMP1 may be important for the pathogenesis of lung fibrosis and BMP1 could be a potential therapeutic target for progressive fibrotic disease such as idiopathic pulmonary fibrosis (IPF). Here, we observed the increased expression of BMP1 in both human IPF lungs and mouse fibrotic lungs induced by bleomycin. Furthermore, we developed an inducible Bmp1 conditional knockout (cKO) mouse strain. We found that Bmp1 deletion does not protect mice from lung fibrosis triggered by bleomycin. Moreover, we found no significant impact of BMP1 deficiency upon C-term propeptide of type I procollagen (CICP) production in the fibrotic mouse lungs. Based on these results, we propose that BMP1 is not required for lung fibrosis in mice and BMP1 may not be considered a candidate therapeutic target for IPF.

Cleavage of LOXL1 by BMP1 and ADAMTS14 Proteases Suggests a Role for Proteolytic Processing in the Regulation of LOXL1 Function.

Members of the lysyl oxidase (LOX) family catalyze the oxidative deamination of lysine and hydroxylysine residues in collagen and elastin in the initiation step of the formation of covalent cross-links, an essential process for connective tissue maturation. Proteolysis has emerged as an important level of regulation of LOX enzymes with the cleavage of the LOX isoform by metalloproteinases of the BMP1 (bone morphogenetic protein 1) and ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) families as a model example. Lysyl oxidase-like 1 (LOXL1), an isoform associated with pelvic organ prolapse and pseudoexfoliation (PEX) glaucoma, has also been reported to be proteolytically processed by these proteases. However, precise molecular information on these proteolytic events is not available. In this study, using genetic cellular models, along with proteomic analyses, we describe that LOXL1 is processed by BMP1 and ADAMTS14 and identify the processing sites in the LOXL1 protein sequence. Our data show that BMP1 cleaves LOXL1 in a unique location within the pro-peptide region, whereas ADAMTS14 processes LOXL1 in at least three different sites located within the pro-peptide and in the first residues of the catalytic domain. Taken together, these results suggest a complex regulation of LOXL1 function by BMP1- and ADAMTS14-mediated proteolysis where LOXL1 enzymes retaining variable fragments of N-terminal region may display different capabilities.

Bone morphogenetic protein 1.3 inhibition decreases scar formation and supports cardiomyocyte survival after myocardial infarction.

Despite the high prevalence of ischemic heart diseases worldwide, no antibody-based treatment currently exists. Starting from the evidence that a specific isoform of the Bone Morphogenetic Protein 1 (BMP1.3) is particularly elevated in both patients and animal models of myocardial infarction, here we assess whether its inhibition by a specific monoclonal antibody reduces cardiac fibrosis. We find that this treatment reduces collagen deposition and cross-linking, paralleled by enhanced cardiomyocyte survival, both in vivo and in primary cultures of cardiac cells. Mechanistically, we show that the anti-BMP1.3 monoclonal antibody inhibits Transforming Growth Factor ß pathway, thus reducing myofibroblast activation and inducing cardioprotection through BMP5. Collectively, these data support the therapeutic use of anti-BMP1.3 antibodies to prevent cardiomyocyte apoptosis, reduce collagen deposition and preserve cardiac function after ischemia.

A pan-cancer analysis of the oncogenic role of procollagen C-endopeptidase enhancer (PCOLCE) in human.

There is no evidence showing that the expression of procollagen C-endopeptidase enhancer (PCOLCE) is associated with human tumors, and pan-cancer analysis is not available. Based on public databases such as the cancer genome atlas, we investigated the potential role of PCOLCE expression in 33 different human tumors. PCOLCE expression in 11 tumors was significantly correlated with tumor prognosis and was a prognostic predictor for pancreatic adenocarcinoma, thymoma and CES. We also found that PCOLCE expression correlated with the immune microenvironment of tumors and the level of cancer-associated fibroblast infiltration. PCOLCE is a potential predictor of small molecule targeted drugs and immune checkpoint inhibitors. Finally, we found by enrichment analysis that PCOLCE localizes to extracellular structures and the extracellular matrix and exerts substantial effects on tumors through the PI3K-Akt and AGE-RAGE signaling pathways. We have a preliminary and relatively comprehensive understanding of the role of PCOLCE in various tumors.

Expression of GALNT8 and O-glycosylation of BMP receptor 1A suppress breast cancer cell proliferation by upregulating ERα levels.

BACKGROUND: Mucin-type O-glycosylation is one of the most abundant types of O-glycosylation and plays important roles in various human carcinomas, including breast cancer. A large family of polypeptide N-acetyl-α-galactosaminyltransferases (GALNTs) initiate and define sites of mucin-type O-glycosylation. However, the specific mechanisms underlying GALNT8 expression and its roles in tumorigenesis remain poorly characterized. METHODS: GALNT8 expression was assessed in 140 breast cancer patients. Immunofluorescence, immunoprecipitation, lectin blot and quantitative real-time PCR were used to investigate the expression of GALNT8 and its role in regulating estrogen receptor α (ERα) via bone morphogenetic protein (BMP) signaling. RESULTS: The expression of GALNT8 was associated with breast cancer patient survival. GALNT8 downregulation was associated with a reduction in ERα levels, while GALNT8 overexpression elevated the transcription and protein levels of ERα and suppressed colony formation, suggesting an important role of GALNT8 in cancer cell proliferation. Conversely, GALNT8 knockdown led to the inhibition of BMP/SMAD/RUNX2 axis, which decreased ERα transcription. Further analysis suggested that BMP receptor 1A (BMPR1A) was O-GalNAcylated. Sites mutation of BMPR1A indicated that Thr137 and Ser37/Ser39/Ser44/Thr49 of BMPR1A were the main O-glycosylation sites. Although we cannot exclude the indirect effect of GALNT8, our results demonstrated that the expression of GALNT8 and O-glycosylation of BMPR1A play key roles in regulating the activity of BMP/SMAD/RUNX2 signaling and ERα expression. CONCLUSION: These findings suggest that GALNT8 expression and abnormal O-GalNAcylation of BMPR1A increase ERα expression and suppress breast cancer cell proliferation by modulating the BMP signaling pathway. GENERAL SIGNIFICANCE: Our results identify the involvement of GALNT8 in regulating ERα expression.

Deficiency of Procollagen C-Proteinase Enhancer 1 in Mice has No Major Impact on Cardiac Collagen and Function Under Basal Conditions.

ABSTRACT: Maturation of fibrillar collagen is known to play a crucial role in the pathophysiology of myocardial fibrosis. Procollagen C-proteinase enhancer 1 (PCPE1) has a key role in procollagen maturation and collagen fibril formation. The phenotype of both male and female PCPE1 knock-out mice was investigated under basal conditions to explore the potential of PCPE1 as a therapeutic target in heart failure. Global constitutive PCPE1-/- mice were generated. Serum procollagen I C-terminal propeptide, organ histology, and cutaneous wound healing were assessed in both wild type (WT) and PCPE1-/- mice. In addition, the cardiac expression of genes involved in collagen metabolism was investigated and the total and insoluble cardiac collagen contents determined. Cardiac function was evaluated by echocardiography. No differences in survival, clinical chemistry, or organ histology were observed in PCPE1-/- mice compared with WT. Serum procollagen I C-terminal propeptide was lower in PCPE1-/- mice. Cardiac mRNA expression of Bmp1, Col1a1, Col3a1, and Loxl2 was similar, whereas Tgfb and Loxl1 mRNA levels were decreased in PCPE1-/- mice compared with sex-matched WT. No modification of total or insoluble cardiac collagen content was observed between the 2 strains. Ejection fraction was slightly decreased in PCPE1-/- male mice, but not in females. Finally, wound healing was not altered in PCPE1-/- mice. PCPE1 deficiency does not trigger any major liabilities and does not affect cardiac collagen content nor its function under basal conditions. Further studies are required to evaluate its role under stressed conditions and determine its suitability as a therapeutic target for heart failure.

A single cell characterisation of human embryogenesis identifies pluripotency transitions and putative anterior hypoblast centre.

Following implantation, the human embryo undergoes major morphogenetic transformations that establish the future body plan. While the molecular events underpinning this process are established in mice, they remain unknown in humans. Here we characterise key events of human embryo morphogenesis, in the period between implantation and gastrulation, using single-cell analyses and functional studies. First, the embryonic epiblast cells transition through different pluripotent states and act as a source of FGF signals that ensure proliferation of both embryonic and extra-embryonic tissues. In a subset of embryos, we identify a group of asymmetrically positioned extra-embryonic hypoblast cells expressing inhibitors of BMP, NODAL and WNT signalling pathways. We suggest that this group of cells can act as the anterior singalling centre to pattern the epiblast. These results provide insights into pluripotency state transitions, the role of FGF signalling and the specification of anterior-posterior axis during human embryo development.