Bone Morphogenetic Protein Research Articles

Abstract 4136316: BMP10 as novel marker for right atrial dilatation and pressure in precapillary pulmonary hypertension

Introduction: Precapillary pulmonary hypertension (precPH) leads to increased right atrial (RA) stretch and pressure. The right atrium is the major source of bone morphogenetic protein 10 (BMP10) in adults. Aim: This study aims to investigate BMP10 in relation to RA dilatation and pressure overload. Methods: We studied BMP10 mRNA in fresh RA tissue of N=5 Chronic Thromboembolic Pulmonary Hypertension (CTEPH) patients and N=9 controls and protein expression in paraffin-embedded RA tissue of N=4 Pulmonary Arterial Hypertension (PAH) patients and N=6 controls. We prospectively included 48 precPH patients (N=22 idiopathic PAH, N=14 hereditary PAH and N=12 CTEPH, and N=16 controls. To study BMP10-induced transcriptional activity, we assayed serum samples in human microvascular endothelial cells (HMEC) with a BMP-responsive transcriptional luciferase assay. BMP10 activity was calculated by subtracting BMP activity after incubation with antibodies for Alk1Fc and bone morphogenetic protein 9 (BMP9). We assessed correlations between BMP10 activity and RA dilatation (RA max volume>79 ml/m 2 for male or >69 ml/m 2 for female) and right ventricular (RV) dilatation (RV end-diastolic volume>108 ml/m 2 for male and >96 ml/m 2 for female). In a cohort of CTEPH patients that underwent pulmonary endarterectomy (PEA) we assessed the effect of pressure unloading on BMP10 activity. Normality of data was checked and statistical differences between groups were tested using an independent sample t-test or Wilcoxon rank-sum test. Results: BMP10 mRNA, protein and downstream activity were higher in the precPH RA tissue (Figure 1A-F). High systemic BMP10 activity was associated with RA dilatation and high RA pressure, but not RV dilatation in precPH (Figure 2A-C). Finally, pressure unloading after PEA in CTEPH patients results in a reduction in BMP10 activity (figure 2D). Conclusions: Local RA BMP10 expression and activity is increased in precPH. Increased systemic BMP10 activity was related to RA dilatation and pressure. Pressure unloading of the right heart leads to a reduction of systemic BMP10 activity. Future studies are needed to determine whether increased BMP10 release is an adaptative mechanism or can be used as therapeutic target.

Abstract 4138348: Mechanical stress-mediated nuclear envelope damage promotes Aortic Valve Calcification through the ZBP1-RIPK3-NF-κB signaling axis

Methods and Results: We describe a comprehensive characterization of the AVICs nucleus landscape as determined by transmission electron microscopy (TEM) of samples obtained from CAVD patients. Turbulence led to nuclear envelope integrity lose in AVICs cultured in shear stress experiments, with three different fluid conditions [static (ST), laminar stress (LS), and oscillatory stress (OS)], indicated by Western blot and immunofluorescence (IF). Silencing lamin A/C (LMNA) through small interfering RNA (siRNA), accelerated nuclear envelope damage , as indicated by Western blot, qPCR, and immunofluorescence (IF). The formation of Z-DNA and its co-localization with Z-DNA binding protein (ZBP1) was observed due to the nuclear envelope damage by IF. Western blot, qPCR, IHC and IF confirmed Z-DNA-induced inflammation in AVICs through the ZBP1-RIPK3-NF-κB signaling pathway. ZBP1 and RIPK3 knockdown with siRNA markedly reduced the protein level of osteogenic markers alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), and bone morphogenetic protein 2 (BMP2) in VICs. In vivo, aortic valve disease was constructed by direct wire injury (DWI), and we showed that overexpression of LMNA by adeno-associated virus significantly decelerated the progression of aortic valve lesion induced by DWI in mice. Conclusion: Excessive mechanical stress can induce damage to the nuclear envelope of AVICs by causing cytoskeletal remodeling, initiating the formation of Z-DNA, and hastening the calcification process in AVICs and CAVD.

Heterotopic Ossification with Intrathyroidal Extramedullary Hematopoiesis in Multifocal Papillary Thyroid Carcinoma: Histopathological Findings and Literature Review

In recent decades, there has been an increase in the identification of thyroid nodules, both benign and malignant, due to the rise in imaging studies and complementary tests. Among thyroid gland tumors, papillary thyroid carcinoma (PTC) stands out as the most prevalent. Degenerative changes, mainly in the form of nodular goiter, have been recorded, occasionally including areas of calcification and, more rarely, ossification; although the latter seldom progresses to calcinosis. Ectopic bone formation, known as osseous metaplasia, is a rare phenomenon in the thyroid gland, even more so when associated with extramedullary hematopoiesis (EMH), characterized by the presence of hematopoietic elements outside the bone marrow. We present the first documented instance in our country of a patient diagnosed with malignant thyroid nodule, specifically PTC, exhibiting areas of heterotopic ossification with EMH on histopathological examination of the surgical specimen. A possible relationship between heterotopic ossification, EMH, and PTC is suggested. Various growth factors such as bone morphogenetic proteins (BMPs), specific BMP subtypes, and associated receptors could play a crucial role in initiating and developing ectopic bone formation in the context of PTC. However, further research is needed to fully elucidate its clinical significance and impact on the therapeutic management of these patients.

Abstract 4136605: Effect Of A Bone Morphogenetic Protein Receptor Type 2 Mutation On The Cardiomyocyte Response To Pressure Overload

Introduction: A mutation in the Bone Morphogenetic Protein Receptor Type 2 ( BMPR2 ) gene is in 70% of hereditary pulmonary arterial hypertension (hPAH) patients the causative mutation of the disease. Previous work demonstrated that right ventricular function is more impaired in hPAH patients with a BMPR2 mutation. However, the underlying mechanism remains elusive. Moreover, natriuretic peptides, such as N-terminal Brain Natriuretic Peptides (NTproBNP) and Mid Regional proAtrial Natriuretic Peptides (MRproANP), are secreted from cardiomyocytes upon stretch as adaptation to increased pressure overload. We hypothesize that the BMPR2 mutation impairs the response to increased pressure overload. For this purpose, we make use of ventricular induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) of hPAH patients carrying a BMPR2 mutation and their isogenic controls in which the mutation was corrected. Aim: To study the effect of a BMPR2 mutation on the response to pressure overload in vitro . Methods: iPSCs from 2 hPAH patients and its isogenic controls were used. iPSCs were differentiated into ventricular iPSC-CMs and stretched 10% equiaxially for 24h at 1Hz on the Flexcell FX-6000 system. Natriuretic peptides gene expressions were quantified via RT-PCR. NTproBNP and MRproANP release were measured on cell supernatants throughout specific immunoassays. Normality of the data was checked, and statistics were performed accordingly. Results: No differences were observed on natriuretic peptides gene expression on static and stretched iPSC-CMs. There is a clear correlation between NTproBNP and MRproANP release (R 2 =0.83, p<0.0001, Figure 1A). Interestingly, hPAH iPSC-CMs showed higher baseline values for NTproBNP release compared to isogenic iPSC-CMs (p<0.01, Figure 1B). Furthermore, stretching resulted in increased NTproBNP and MRproANP secretion in both hPAH and isogenic iPSC-CMs (Figure 1B-C). Conclusions: Secretion of NTproBNP and MRproANP was closely correlated in iPSC-CMs. iPSC-CMs of hPAH patients with a BMPR2 mutation showed higher baseline values of NTproBNP. Increased secretion of NTproBNP and MRproANP upon mechanical stimulation was similar between hPAH and isogenic iPSC-CMs. Experiments in atrial iPSC-CMs are currently ongoing to test potential differences in natriuretic peptide secretion between ventricular and atrial cardiomyocytes as the right atrium is also under stretch in PAH.

Excess Weight Impairs Oocyte Quality, as Reflected by mtDNA and BMP-15

This prospective, case-control study evaluated the impact of obesity on oocyte quality based on mtDNA expression in cumulus cells (CC), and on bone morphogenetic protein 15 (BMP-15) and heparan sulfate proteoglycan 2 (HSPG2) in follicular fluid (FF). It included women 18 to <40 years of age, divided according to BMI < 24.9 (Group 1, n = 28) and BMI > 25 (Group 2, n = 22). Demographics, treatment, and pregnancy outcomes were compared. The mtDNA in CC, BMP-15, HSPG2, the lipid profile, the hormonal profile, and C-reactive protein were evaluated in FF and in blood samples. The BMP-15 levels in FF and the mitochondrial DNA in CC were higher in Group 1 (38.8 ± 32.5 vs. 14.3 ± 10.8 ng/mL; p = 0.001 and 1.10 ± 0.3 vs. 0.87 ± 0.18-fold change; p = 0.016, respectively) than in Group 2. High-density lipoprotein levels in blood and FF were higher in Group 1 (62 ± 18 vs. 50 ± 12 mg/dL; p = 0.015 and 34 ± 26 vs. 20.9 ± 7.2 mg/dL; p = 0.05, respectively). Group 2 had higher blood C-reactive protein (7.1 ± 5.4 vs. 3.4 ± 4.3 mg/L; p = 0.015), FF (5.2 ± 3.8 vs. 1.5 ± 1.6 mg/L; p = 0.002) and low-density lipoprotein levels (91 ± 27 vs. 71 ± 22 mg/dL; p = 0.008) vs. Group 1. Group 1 demonstrated a trend toward a better clinical pregnancy rate (47.8% vs. 28.6%: p = 0.31) and frozen embryo transfer rate (69.2% vs. 53.8; p = 0.69). Higher BMI resulted in lower BMP-15 levels and reduced mtDNA expression, which reflect decreased oocyte quality in overweight women.

Hedgehog Signalling Pathway and Its Role in Shaping the Architecture of Intestinal Epithelium

The hedgehog (Hh) signalling pathway plays a key role in both embryonic and postnatal development of the intestine and is responsible for gut homeostasis. It regulates stem cell renewal, formation of the villous–crypt axis, differentiation of goblet and Paneth cells, the cell cycle, apoptosis, development of gut innervation, and lipid metabolism. Ligands of the Hh pathway, i.e., Indian hedgehog (Ihh) and Sonic hedgehog (Shh), are expressed by superficial enterocytes but act in the mesenchyme, where they are bound by a Patched receptor localised on myofibroblasts and smooth muscle cells. This activates a cascade leading to the transcription of target genes, including those encoding G1/S-specific cyclin-D2 and -E1, B-cell lymphoma 2, fibroblast growth factor 4, and bone morphogenetic protein 4. The Hh pathway is tightly connected to Wnt signalling. Ihh is the major ligand in the Hh pathway. Its activation inhibits proliferation, while its blocking induces hyperproliferation and triggers a wound-healing response. Thus, Ihh is a negative feedback regulator of cell proliferation. There are data indicating that diet composition may affect the expression of the Hh pathway genes and proteins, which in turn, induces changes in mucosal architecture. This was shown for fat, vitamin A, haem, berberine, and ovotransferrin. The Hh signalling is also affected by the intestinal microbiota, which affects the intestinal barrier integrity. This review highlights the critical importance of the Hh pathway in shaping the intestinal mucosa and summarises the results obtained so far in research on the effect of dietary constituents on the activity of this pathway.

Naringenin can Inhibit the Pyroptosis of Osteoblasts by Activating the Nrf2/HO-1 Signaling Pathway and Alleviate the Differentiation Disorder of Osteoblasts Caused by Microgravity.

Naringenin (4,5,7-trihydroxyflavone, NAR) is an effective active ingredient in Rhizoma Drynariae, which has many biological functions, encompassing anti-inflammatory and -oxidant functions. Prior research has shown that NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasomes possessed a significant contribution to osteoporosis. However, the NAR impact on bone loss caused by microgravity remains unclear. Classical microgravity simulation methods were used to induce simulated microgravity (SMG) in mice and cells. Microcomputed tomography, immunohistochemical examination, and hematoxylin and eosin staining were implemented to ascertain alterations in bone microstructure and morphology in mice subsequent to NAR gavage. Cellular investigations were implemented encompassing quantitative real-time polymerase chain reaction, Western blotting, and immunofluorescence labeling to investigate the molecular mechanism behind NAR resistance to microgravity-induced bone loss. Our research has shown that NAR can significantly enhance the SMG-stimulated alterations in bone microstructure and morphology in mice, mainly by increasing the trabecular thickness, bone volume fraction, and trabecular number while increasing the bone trabecula number. Cell experiments also showed that SMG caused the activation of inflammatory corpuscles of NLRP3 and induced pyroptosis simultaneously, which can be confirmed by the upregulation of protein and mRNA expression levels such as those of NLRP3, cleaved caspase-1, gasdermin D, and apoptosis-associated speck-like protein. The occurrence of pyroptosis further led to the disorder of osteogenic differentiation, which showed that the osteopontin, Runt-related transcription factor 2, bone morphogenetic protein 2, and alkaline phosphatase expression levels were decreased. The intervention of NAR can activate the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) pathway, reverse this phenomenon via controlling the reactive oxygen species generation in cells and correcting mitochondrial malfunction, weaken the pyroptosis of osteoblasts (OBs), and promote osteogenic differentiation. In summary, NAR could hinder the pyroptosis of OBs caused by SMG and promote osteogenic differentiation via activating the Nrf2/HO-1 pathway. This provides a unique view for inhibiting bone loss under weightlessness and confirms the NAR capacity in treating microgravity-stimulated bone loss, giving new ideas and methods for future space medicine development.

Nanoclay gels attenuate BMP2-associated inflammation and promote chondrogenesis to enhance BMP2-spinal fusion

Bone morphogenetic protein 2 (BMP2) is clinically applied for treating intractable fractures and promoting spinal fusion because of its osteogenic potency. However, adverse effects following the release of supraphysiological doses of BMP2 from collagen carriers are widely reported. Nanoclay gel (NC) is attracting attention as a biomaterial, given the potential for localized efficacy of administered agents. However, the efficacy and mechanism of action of NC/BMP2 remain unclear. This study explored the efficacy of NC as a BMP2 carrier in bone regeneration and the enhancement mechanism. Subfascial implantation of NC containing BMP2 elicited superior bone formation compared with collagen sponge (CS). Cartilage was uniformly formed inside the NC, whereas CS formed cartilage only on the perimeter. Additionally, CS induced a dose-dependent inflammatory response around the implantation site, whereas NC induced a minor response, and inflammatory cells were observed inside the NC. In a rat spinal fusion model, NC promoted high-quality bony fusion compared to CS. In vitro, NC enhanced chondrogenic and osteogenic differentiation of hBMSCs and ATDC5 cells while inhibiting osteoclastogenesis. Overall, NC/BMP2 facilitates spatially controlled, high-quality endochondral bone formation without BMP2-induced inflammation and promotes high-density new bone, functioning as a next-generation BMP2 carrier.

Upregulation of ACSL, ND75, Vha26 and sesB genes by antiepileptic drugs resulted in genotoxicity in drosophila.

Clobazam (CLB) and Vigabatrin (VGB) are commonly used antiepileptic drugs (AEDs) in the treatment of epilepsy. Here, we have examined the genotoxic effect of these AEDs in Drosophila melanogaster. The Drosophila larvae were exposed to different concentrations of CLB and VGB containing food media. The assessment encompassed oxidative stress, DNA damage, protein levels, and gene expression profiles. In the CLB-treated group, a reduction in reactive oxygen species (ROS) and lipid peroxidation (LPO) levels was observed, alongside increased levels of superoxide dismutase (SOD), catalase (CAT), and nitric oxide (NO). Conversely, the VGB-treated group displayed contrasting results, with increased ROS and LPO and decreased SOD, CAT, and NO levels. However, both CLB and VGB induced DNA damage in Drosophila. Proteomic analysis (SDS-PAGE and OHRLCMS) in the CLB and VGB groups identified numerous proteins, including Acyl-CoA synthetase long-chain, NADH-ubiquinone oxidoreductase 75kDa subunit, V-type proton ATPase subunit E, ADP/ATP carrier protein, malic enzyme, and DNA-binding protein modulo. These proteins were found to be associated with pathways like growth promotion, notch signaling, Wnt signaling, neuromuscular junction (NMJ) signaling, bone morphogenetic protein (BMP) signaling, and other GABAergic mechanisms. Furthermore, mRNA levels of ACSL, ND75, Vha26, sesB, and Men genes were upregulated in both CLB and VGB-treated groups. These findings suggest that CLB and VGB could have the potential to induce genotoxicity and post-transcriptional modifications in humans, highlighting the importance of monitoring their effects when used as AEDs.

Enhanced BMP Signaling Alters Human β-Cell Identity and Function.

Inflammation contributes to the pathophysiology of diabetes. Identifying signaling pathways involved in pancreatic β-cell failure and identity loss can give insight into novel potential treatment strategies to prevent the loss of functional β-cell mass in diabetes. It is reported earlier that the immunosuppressive drug tacrolimus has a detrimental effect on human β-cell identity and function by activating bone morphogenetic protein (BMP) signaling. Here it is hypothesized that enhanced BMP signaling plays a role in inflammation-induced β-cell failure. Single-cell transcriptomics analyses of primary human islets reveal that IL-1β+IFNγ and IFNα treatment activated BMP signaling in β-cells. These findings are validated by qPCR. Furthermore, enhanced BMP signaling with recombinant BMP2 or 4 triggers a reduced expression of key β-cell maturity genes, associated with increased ER stress, and impaired β-cell function. Altogether, these results indicate that inflammation-activated BMP signaling is detrimental to pancreatic β-cells and that BMP-signaling can be a target to preserve β-cell identity and function in a pro-inflammatory environment.

Exploring Metabolic Mechanisms in Calcific Tendinopathy and Shoulder Arthrofibrosis: Insights and Therapeutic Implications

Rotator cuff calcific tendinopathy and arthrofibrosis of the shoulder (adhesive capsulitis) are debilitating musculoskeletal disorders that significantly impact joint function and impair quality of life. Despite its high prevalence and common clinical presentation, the metabolic mechanisms underlying these conditions characterized by pain, and reduced mobility, remain poorly understood. This review aims to elucidate the role of metabolic processes implicated in the pathogenesis of calcific tendinopathy and shoulder arthrofibrosis. We will be focusing on the mechanistic role of how these processes contribute to disease progression and can direct potential therapeutic targets. Calcific tendinopathy is marked by aberrant calcium deposition within tendons, influenced by disrupted calcium and phosphate homeostasis, and altered cellular responses. Key molecular pathways, including bone morphogenetic proteins (BMPs), Wnt signaling, and transforming growth factor-beta (TGF-β), play crucial roles in the pathophysiology of calcification, calcium imbalance, and muscle fibrosis. In contrast, shoulder arthrofibrosis involves excessive collagen deposition and fibrosis within the shoulder joint capsule, driven by metabolic dysregulation and inflammation. The TGF-β signaling pathway and inflammatory cytokines, such as interleukin-6 (IL-6), are central to the fibrotic response. A comparative analysis reveals both shared and distinct metabolic pathways between these conditions, highlighting the interplay between inflammation, cellular metabolism, extracellular matrix remodeling, calcific deposition, and calcium migration to the glenohumeral joints, resulting in adhesive capsulitis, thereby providing insights into their pathophysiology. This review discusses current therapeutic approaches and their limitations, advocating for the development of targeted therapies that address specific metabolic dysregulations. Future therapeutic strategies focus on developing targeted interventions that address the underlying metabolic dysregulation, aiming to improve patient outcomes and advance clinical management. This review offers a comprehensive overview of the metabolic mechanisms involved in calcific tendinopathy and shoulder arthrofibrosis, providing a foundation for future research and therapeutic development.

Efficacy of Stand-Alone Anterior Lumbar Interbody Fusion With PEEK Cages, BMP-2, and Allografts for Treating Discogenic Low Back Pain: Assessing Clinical and Radiographic Outcomes.

Chronic low back pain secondary to degenerative disc disease is a significant public health issue worldwide, contributing to substantial health care burdens and patient disability. Anterior lumbar interbody fusion (ALIF) has emerged as a promising surgical solution, offering benefits such as disc height restoration, reduced neural compression, and improved spinal alignment. This study evaluates the efficacy of stand-alone ALIF using polyetheretherketone (PEEK) cages, structural femoral head allografts, and recombinant human bone morphogenetic protein-2 (rhBMP-2) in treating discogenic low back pain caused by degenerative disc disease. This prospective case series study included 1335 patients who underwent stand-alone ALIF by a single surgeon. The surgical construct involved PEEK cages with structural femoral allograft dowels and rhBMP-2, supplemented by anterior fixation. Patient-reported outcome measures, including the visual analog scale for back and leg pain, the Oswestry Disability Index, the Roland-Morris Disability Questionnaire, and patient satisfaction, were monitored over 12 months. The overall fusion rate was 99.6%, with pseudoarthrosis occurring in 0.2% of patients. Lower fusion rates were observed in patients older than 65 years and those using the Brantigan cage. Significant improvements were seen in visual analog scale for back and leg pain, Oswestry Disability Index, and Roland-Morris Disability Questionnaire scores from baseline, with most scores exceeding the substantial clinical benefit thresholds. More than 85% of patients reported "Excellent" or "Good" outcomes. Stand-alone ALIF, augmented with rhBMP-2 and structural femoral head allografts, can enhance mechanical stability, fusion rates, and radiographic assessment. This integrated approach achieves successful spinal fusion and positive clinical outcomes for patients with refractory discogenic low back pain. Stand-alone ALIF with PEEK cages, structural femoral head allografts, and rhBMP-2 demonstrates high fusion rates and significant clinical improvements in patients with discogenic low back pain. This approach enhances spinal stability and promotes biological healing, making it a reliable and effective surgical option.

Hybrid 3D microfluidic bioprinting for the engineering of cancer models and tissue substitutes

ABSTRACT 3D bioprinting is at the forefront of tissue engineering to fabricate complex constructs resembling functional tissues. However, the inability to produce heterogeneous tissues and the lack of spatio-temporal control over the release of bioactive factors are greatly limiting clinical translation. Herein, the combination of 3D bioprinting with high-throughput dispensing using a custom microfluidic system and nanoclay-based inks is presented. This approach was found to enhance printability, retention, and controlled release of bioactive factors. Advanced tissue models were developed to resemble cancer and skeletal tissue, while studying the effect of anti-cancer (Doxorubicin) and pro-osteogenic growth factors (bone morphogenetic protein-2, BMP-2), respectively. The engineering of a new nanoclay ink allowed the sustained release, making it suitable for long-term applications. These findings suggest that by combining 3D bioprinting and high-throughput delivery of nanoclay-based inks a new platform for the engineering of functional tissue constructs can be assembled, offering significant advancements in regenerative medicine.

Revision of Hip Luxation in a Canine Total Hip Replacement Caused by a Greater Trochanteric Fracture Secondary to an Inflammatory Granuloma.

A hip luxation 3 years following a cementless total hip replacement was diagnosed in a 4.7-year-old neutered male Lagotto Romagnolo that presented with a non-weight-bearing left pelvic limb lameness. Orthogonal radiographs revealed a left hip luxation and an osteolytic fracture of the greater trochanter. A mass consistent with an inflammatory granuloma was identified on preoperative computed tomography scan. Surgical revision consisted of granuloma excision, replacement of the loose acetabular cup, and repair of the femoral fracture with a locking plate. Fracture biology was augmented with the use of recombinant human bone morphogenetic protein 2 (rhBMP2) impregnated collagen sponge applied around the acetabulum and femoral fracture site. Osteointegration of the prosthetics and fracture healing were documented within 3 months of revision. Long-term follow-up at 3 years postrevision showed normal limb usage and no further evidence of total hip replacement complication.

Incorporating Hydrogel (with Low Polymeric Content) into 3D-Printed PLGA Scaffolds for Local and Sustained Release of BMP2 in Repairing Large Segmental Bone Defects.

Treating large bone defects remains a considerable challenge for clinicians: bone repair requires scaffolds with mechanical properties and bioactivities. Herein, based on crosslinking o-phthalaldehyde (OPA) with amine groups, 4-arm polyethylene glycol (4armPEG)-OPA/Gelatin hydrogel loaded with bone morphogenetic protein 2 (BMP2) is prepared and a three dimensional (3D)-printed poly (lactic-co-glycolic acid) (PLGA) porous scaffold is filled with the hydrogel solution. The composite scaffold, with a compression modulus of 0.68 ±0.097GPa similar to the cancellous bone, has a porosity of 56.67 ± 4.72% and a pore size of about 380µm, promoting bone growth. The hydrogel forms a porous network at low concentrations, aiding protein release and cell migration. The hydrogel degrades in approximately three weeks, and the scaffold takes five months, matching bone repair timelines. BMP2 release experiment shows a sustained BMP2 release with a 72.4 ± 0.53% release ratio. The ALP activity test and alizarin red staining shows effective osteogenic promotion, while RT-PCR confirms BMP2@Gel enhanced COL-1 and OPN expression. Animal experiments further validate the composite scaffold's bone repair efficacy. This study demonstrates the effectiveness of the hydrogel in releasing BMP2 and the mechanical support of the 3D-printed PLGA porous scaffold, providing a new treatment for bone defects.

BMP5 promotes trophoblast functions upon N-glycosylation via the BMP5-SMAD1/5 signaling pathway in preeclampsia

IntroductionPreeclampsia (PE) is one of the most common pregnancy-related complications worldwide and currently lacks an effective treatment. While trophoblast cell dysfunction has been identified as the fundamental cause of PE, the underlying mechanisms remain unclear. Bone morphogenetic protein 5 (BMP5) is a secreted glycoprotein highly expressed in the placenta that is involved in cell proliferation, migration, and invasion. However, the role and mechanism of BMP5 glycosylation of trophoblast cell function remain unclear. MethodsThe expression of BMP5 and N-glycosylation in preeclamptic placental tissues was investigated. We predicted and validated the N-glycosylation sites of BMP5. Additionally, we evaluated the effect of BMP5 N-glycosylation on the proliferation, migration, invasion, and angiogenesis of human immortalized trophoblastic HTR-8/SVneo cells. Furthermore, the role of N-glycosylated BMP5 in activating the BMP5-SMAD1/5 signaling pathway and regulating trophoblastic cell functions was explored. ResultsOur study reveals that PHA-E+L (recognizing branching N-glycans) reactive N-glycans and BMP5 expression levels are lower in preeclamptic villous tissues compared to normal placental tissues. Additionally, we demonstrated that BMP5 is an N-glycosylation-modified protein. Furthermore, N-glycosylated BMP5 promoted the functional trophoblastic cells (HTR-8/SVneo). We also revealed that N-glycosylation of BMP5 regulates multiple cell functions through the BMP5-SMAD1/5 signaling pathway. ConclusionN-glycosylated BMP5 promotes trophoblast cell proliferation, migration, invasion, and angiogenesis. This study provides mechanistic insight as to how N-glycosylation of BMP5 in trophoblast cells can contribute to the pathogenesis of preeclampsia and provides a new basis for its diagnosis and treatment.

Recapitulating the adenoma-carcinoma sequence by selection of four spontaneous oncogenic mutations in mismatch-repair-deficient human colon organoids.

Carcinogenesis results from the sequential acquisition of oncogenic mutations that convert normal cells into invasive, metastasizing cancer cells. Colorectal cancer exemplifies this process through its well-described adenoma-carcinoma sequence, modeled previously using clustered regularly interspaced short palindromic repeats (CRISPR) to induce four consecutive mutations in wild-type human gut organoids. Here, we demonstrate that long-term culture of mismatch-repair-deficient organoids allows the selection of spontaneous oncogenic mutations through the sequential withdrawal of Wnt agonists, epidermal growth factor (EGF) agonists and the bone morphogenetic protein (BMP) antagonist Noggin, while TP53 mutations were selected through the addition of Nutlin-3. Thus, organoids sequentially acquired mutations in AXIN1 and AXIN2 (Wnt pathway), TP53, ACVR2A and BMPR2 (BMP pathway) and NRAS (EGF pathway), gaining complete independence from stem cell niche factors. Quadruple-pathway (Wnt, EGF receptor, p53 and BMP) mutant organoids formed solid tumors upon xenotransplantation. This demonstrates that carcinogenesis can be recapitulated in a DNA repair-mutant background through in vitro selection that targets four consecutive cancer pathways.

Hepatoprotective and neuroprotective effects of quinacrine against bile duct ligation-induced hepatic encephalopathy in rats: Role of bone morphogenetic proteins signaling

AimsThis study aimed to assess the potential protective effect of quinacrine, an FDA approved antimalarial drug with reported anti-inflammatory effects, on hepatic encephalopathy (HE) in a bile duct ligation (BDL) experimental model and to investigate the mechanisms responsible for this effect, namely those associated with the liver-brain axis, particularly, bone morphogenetic protein 2 (BMP2) signaling. Materials and methodsFive groups of rats were selected at random: sham, BDL, (BDL+ quinacrine 5), (BDL+ quinacrine 10), and (quinacrine 10 + sham). Daily Intraperitoneal (I.P.) administration of quinacrine was initiated on the surgery day and continued for 28 days. Key findingsResults showed that rats that underwent BDL exhibited marked elevation of serum liver enzymes, ammonia, total bilirubin, together with oxidative stress, inflammation, dysregulated farnesoid x receptor (FXR), dysregulated BMP2 signaling and escalated fibrotic markers indicating hepatotoxicity, cholestasis and fibrosis. Besides, neurotoxicity was detected as manifested by cognitive deficits and dysregulation of hippocampal FXR, BMP2 signaling, WNT3A signaling, brain derived neurotrophic factor (BDNF), phospholipase A2 (PLA2) and glial fibrillary acidic protein (GFAP). In contrast, co-treatment with quinacrine mitigated BDL-induced hepatotoxicity, cholestasis, fibrosis, and neurotoxicity. Notably, quinacrine improved learning and memory and restored FXR, BMP2 signaling in the liver and hippocampus. In addition, quinacrine restored hippocampal WNT3A signaling, BDNF, whereas it downregulated expression of hippocampal PLA2 and GFAP. SignificanceThese findings demonstrated implication of BMP2 signaling in the molecular process of BDL-induced HE and proposed that quinacrine has potential hepatoprotective and neuroprotective properties against HE.

Zhuangyao Jianshen Wan ameliorates senile osteoporosis in SAMP6 mice through Modulation of the GCN5L1-mediated PI3K/Akt/wnt signaling pathway

BackgroundSenile osteoporosis (SOP) is a systemic bone disease characterized by increased susceptibility to fractures. However, there is currently no effective treatment for SOP. The Zhuangyao Jianshen Wan (ZYJSW) pill is traditionally believed to possess kidney-nourishing and bone-strengthening effects, demonstrating efficacy in treating fractures. Despite this, its effectiveness and mechanism in SOP remain unclear. This study aims to investigate the therapeutic potential of ZYJSW in treating SOP in senescence accelerated mouse prone 6 (SAMP6, P6) mice, and elucidate the underlying mechanisms. MethodsFour-month-old SAMP6 mice were categorized into six groups: the model group (SAMP6), low, medium, and high-dose ZYJSW treatment groups, calcitriol treatment (positive control 1) group, and metformin treatment (positive control 2) group. Gastric administration was carried out for 15 weeks, and a normal control group comprising four-month-old Senescence-Accelerated Mouse Resistant 1 (SAMR1) mice. Changes in body weight, liver and kidney function, bone protective effects, and muscle quality were evaluated using various assays, including H&E staining, Goldner staining, bone tissue morphology analysis, Micro-CT imaging, and biomechanical testing. Qualitative analysis and quality control of ZYJSW were performed via LC-MS/MS analysis. To explore mechanisms, network pharmacology and proteomics were employed, and the identified proteins were validated by Western blotting. ResultsOral administration of ZYJSW to P6 mice exerted preventive efficacy against osteopenia, impaired bone microstructure, and poor bone and muscle quality. ZYJSW attenuated the imbalance in bone metabolism by promoting bone formation, as evidenced by the upregulation of key factors such as Runt-related transcription factor 2 (RUNX2), Bone Morphogenetic Protein (BMP2), Osteoprotegerin (OPG) and Osteocalcin (OCN), while simultaneously inhibiting bone resorption through the downregulation of TNF receptor associated factor 6 (TRAF6), Tartrate resistant acid phosphatase (TRAP), Receptor activator for nuclear factor-κB ligand (RANKL) and Cathepsin K (CTSK). Additionally, ZYJSW enhanced muscle structure and function by counteracting the elevation of Ubiquitin (Ub), Muscle RING-finger protein-1 (Murf-1), F-Box Protein 32 (FBOX32), and Myogenin (Myog). Network pharmacology predictions, proteomics analysis corroborated by published literature demonstrated the role of ZYJSW involving in safeguarding mitochondrial biogenesis. This was achieved by suppressing GCN5L1 expression, contributing to the heightened expression of TFAM, PGC-1α, and nuclear respiratory factor-1 (NRF-1) proteins. ZYJSW also positively modulated Wnt signaling pathways responsible for bone formation, due to regulating expressions of key components like β-catenin, GSK-3β, and LRP5. In addition, ZYJSW causes the downregulation of the PI3K/Akt pathway by inhibiting the phosphorylation of both PI3K and Akt. ConclusionsThe study highlights the significance of ZYJSW in preserving the health of both bone and muscle in P6 mice, potentially through the regulation of the GCN5L1-mediated PI3K/Akt/Wnt signaling pathway. The translational potential of this articleOur research provides evidence and a mechanistic rationale for ZYJSW as a candidate for SOP treatment, offering insights for further exploration and strategy development.

The MCP-3/Ccr3 axis contributes to increased bone mass by affecting osteoblast and osteoclast differentiation.

Several CC subfamily chemokines have been reported to regulate bone metabolism by affecting osteoblast or osteoclast differentiation. However, the role of monocyte chemotactic protein 3 (MCP-3), a CC chemokine, in bone remodeling is not well understood. Here, we show that MCP-3 regulates bone remodeling by promoting osteoblast differentiation and inhibiting osteoclast differentiation. In a Ccr3-dependent manner, MCP-3 promoted osteoblast differentiation by stimulating p38 phosphorylation and suppressed osteoclast differentiation by upregulating interferon beta. MCP-3 increased bone morphogenetic protein 2-induced ectopic bone formation, and mice with MCP-3-overexpressing osteoblast precursor cells presented increased bone mass. Moreover, MCP-3 exhibited therapeutic effects by abrogating receptor activator of nuclear factor kappa-B ligand-induced bone loss. Therefore, MCP-3 has therapeutic potential for diseases involving bone loss due to its positive role in osteoblast differentiation and negative role in osteoclast differentiation.