Role Of Bone Morphogenetic Proteins Research Articles

BMP4 in Human Endometrial Stromal Cells Can Affect Decidualization by Regulating FOXO1 Expression.

Recurrent spontaneous abortion (RSA) is defined as the loss of 2 or more consecutive intrauterine pregnancies with the same sexual partner in the first trimester. Despite its significance, the etiology and underlying mechanisms of RSA remain elusive. Defective decidualization is proposed as one of the potential causes of RSA, with abnormal decidualization leading to disturbances in trophoblast invasion function. To assess the role of bone morphogenetic protein 4 (BMP4) in decidualization and RSA. Decidual samples were collected from both RSA patients and healthy controls to assess BMP4 expression. In vitro cell experiments utilized the hESC cell line to investigate the impact of BMP4 on decidualization and associated aging, as well as its role in the maternal-fetal interface communication. Subsequently, a spontaneous abortion mouse model was established to evaluate embryo resorption rates and BMP4 expression levels. Our study identified a significant downregulation of BMP4 expression in the decidua of RSA patients compared to the normal control group. In vitro, BMP4 knockdown resulted in inadequate decidualization and inhibited associated aging processes. Mechanistically, BMP4 was implicated in the regulation of FOXO1 expression, thereby influencing decidualization and aging. Furthermore, loss of BMP4 hindered trophoblast migration and invasion via FOXO1 modulation. Additionally, BMP4 downregulation was observed in RSA mice. Our findings highlighted the downregulation of BMP4 in both RSA patients and mice. BMP4 in human endometrial stromal cells was shown to modulate decidualization by regulating FOXO1 expression. Loss of BMP4 may contribute to the pathogenesis of RSA, suggesting potential avenues for abortion prevention strategies.

Novel role of bone morphogenetic protein 9 in innate host responses to HCMV infection

Herpesviruses modulate immune control to secure lifelong infection. The mechanisms Human Cytomegalovirus (HCMV) employs in this regard can reveal unanticipated aspects of cellular signaling involved in antiviral immunity. Here, we describe a novel relationship between the TGF-β family cytokine BMP9 and HCMV infection. We identify a cross-talk between BMP9-induced and IFN receptor-mediated signaling, showing that BMP9 boosts the transcriptional response to and antiviral activity of IFNβ, thereby enhancing viral restriction. We also show that BMP9 is secreted by human fibroblasts upon HCMV infection. However, HCMV infection impairs BMP9-induced enhancement of the IFNβ response, indicating that this signaling role of BMP9 is actively targeted by HCMV. Indeed, transmembrane proteins US18 and US20, which downregulate type I BMP receptors, are necessary and sufficient to cause inhibition of BMP9-mediated boosting of the antiviral response to IFNβ. HCMV lacking US18 and US20 is more sensitive to IFNβ. Thus, HCMV has a mutually antagonistic relationship with BMP9, which extends the growing body of evidence that BMP signaling is an underappreciated modulator of innate immunity in response to viral infection.

TGF-β signaling molecules in Hydra: role of BMP and BMP inhibitors during pattern formation.

Understanding the evolution of body plans has been one of the major areas of investigation in developmental and evolutionary biology. Cnidaria, the sister group to bilaterians, provides an opportunity to elucidate the origin and evolution of body axes. Hydra, a freshwater cnidarian, is a useful model to study signaling pathways governing pattern formation, which are conserved up to vertebrates including humans. The transforming growth factor β (TGF-β) signaling pathway is one of the fundamental pathways that regulate axis formation and organogenesis during embryonic development. In this article, we discuss the TGF-β pathway members identified in Hydra along with other cnidarians with an emphasis on bone morphogenetic proteins (BMPs) and their inhibitors. TGF-β members, especially those involved in BMP signaling pathway, are mainly involved in maintaining the Organizer region and patterning the body axis in Hydra. Identification of other members of this pathway in Hydra and fellow cnidarians would provide insights into the evolution of body axes and pattern formation in more complex metazoans.

Proteomics of CKD progression in the chronic renal insufficiency cohort

Progression of chronic kidney disease (CKD) portends myriad complications, including kidney failure. In this study, we analyze associations of 4638 plasma proteins among 3235 participants of the Chronic Renal Insufficiency Cohort Study with the primary outcome of 50% decline in estimated glomerular filtration rate or kidney failure over 10 years. We validate key findings in the Atherosclerosis Risk in the Communities study. We identify 100 circulating proteins that are associated with the primary outcome after multivariable adjustment, using a Bonferroni statistical threshold of significance. Individual protein associations and biological pathway analyses highlight the roles of bone morphogenetic proteins, ephrin signaling, and prothrombin activation. A 65-protein risk model for the primary outcome has excellent discrimination (C-statistic[95%CI] 0.862 [0.835, 0.889]), and 14/65 proteins are druggable targets. Potentially causal associations for five proteins, to our knowledge not previously reported, are supported by Mendelian randomization: EGFL9, LRP-11, MXRA7, IL-1 sRII and ILT-2. Modifiable protein risk markers can guide therapeutic drug development aimed at slowing CKD progression.

Bmp8a deletion leads to obesity through regulation of lipid metabolism and adipocyte differentiation

The role of bone morphogenetic proteins (BMPs) in regulating adipose has recently become a field of interest. However, the underlying mechanism of this effect has not been elucidated. Here we show that the anti-fat effect of Bmp8a is mediated by promoting fatty acid oxidation and inhibiting adipocyte differentiation. Knocking out the bmp8a gene in zebrafish results in weight gain, fatty liver, and increased fat production. The bmp8a-/- zebrafish exhibits decreased phosphorylation levels of AMPK and ACC in the liver and adipose tissues, indicating reduced fatty acid oxidation. Also, Bmp8a inhibits the differentiation of 3T3-L1 preadipocytes into mature adipocytes by activating the Smad2/3 signaling pathway, in which Smad2/3 binds to the central adipogenic factor PPARγ promoter to inhibit its transcription. In addition, lentivirus-mediated overexpression of Bmp8a in 3T3-L1 cells significantly increases NOD-like receptor, TNF, and NF-κB signaling pathways. Furthermore, NF-κB interacts with PPARγ, blocking PPARγ’s activation of its target gene Fabp4, thereby inhibiting adipocyte differentiation. These data bring a signal bridge between immune regulation and adipocyte differentiation. Collectively, our findings indicate that Bmp8a plays a critical role in regulating lipid metabolism and adipogenesis, potentially providing a therapeutic approach for obesity and its comorbidities.

Multiple roles of ALK3 in osteoarthritis.

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by progressive cartilage degradation, synovial membrane inflammation, osteophyte formation, and subchondral bone sclerosis. Pathological changes in cartilage and subchondral bone are the main processes in OA. In recent decades, many studies have demonstrated that activin-like kinase 3 (ALK3), a bone morphogenetic protein receptor, is essential for cartilage formation, osteogenesis, and postnatal skeletal development. Although the role of bone morphogenetic protein (BMP) signalling in articular cartilage and bone has been extensively studied, many new discoveries have been made in recent years around ALK3 targets in articular cartilage, subchondral bone, and the interaction between the two, broadening the original knowledge of the relationship between ALK3 and OA. In this review, we focus on the roles of ALK3 in OA, including cartilage and subchondral bone and related cells. It may be helpful to seek more efficient drugs or treatments for OA based on ALK3 signalling in future.

Bone Morphogenetic Protein-4 Impairs Retinal Endothelial Cell Barrier, a Potential Role in Diabetic Retinopathy.

Bone Morphogenetic Protein 4 (BMP4) is a secreted growth factor of the Transforming Growth Factor beta (TGFβ) superfamily. The goal of this study was to test whether BMP4 contributes to the pathogenesis of diabetic retinopathy (DR). Immunofluorescence of BMP4 and the vascular marker isolectin-B4 was conducted on retinal sections of diabetic and non-diabetic human and experimental mice. We used Akita mice as a model for type-1 diabetes. Proteins were extracted from the retina of postmortem human eyes and 6-month diabetic Akita mice and age-matched control. BMP4 levels were measured by Western blot (WB). Human retinal endothelial cells (HRECs) were used as an in vitro model. HRECs were treated with BMP4 (50 ng/mL) for 48 h. The levels of phospho-smad 1/5/9 and phospho-p38 were measured by WB. BMP4-treated and control HRECs were also immunostained with anti-Zo-1. We also used electric cell-substrate impedance sensing (ECIS) to calculate the transcellular electrical resistance (TER) under BMP4 treatment in the presence and absence of noggin (200 ng/mL), LDN193189 (200 nM), LDN212854 (200 nM) or inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2; SU5416, 10 μM), p38 (SB202190, 10 μM), ERK (U0126, 10 μM) and ER stress (Phenylbutyric acid or PBA, 30 μmol/L). The impact of BMP4 on matrix metalloproteinases (MMP2 and MMP9) was also evaluated using specific ELISA kits. Immunofluorescence of human and mouse eyes showed increased BMP4 immunoreactivity, mainly localized in the retinal vessels of diabetic humans and mice compared to the control. Western blots of retinal proteins showed a significant increase in BMP4 expression in diabetic humans and mice compared to the control groups (p < 0.05). HRECs treated with BMP4 showed a marked increase in phospho-smad 1/5/9 (p = 0.039) and phospho-p38 (p = 0.013). Immunofluorescence of Zo-1 showed that BMP4-treated cells exhibited significant barrier disruption. ECIS also showed a marked decrease in TER of HRECs by BMP4 treatment compared to vehicle-treated HRECs (p < 0.001). Noggin, LDN193189, LDN212854, and inhibitors of p38 and VEGFR2 significantly mitigated the effects of BMP4 on the TER of HRECs. Our finding provides important insights regarding the role of BMP4 as a potential player in retinal endothelial cell dysfunction in diabetic retinopathy and could be a novel target to preserve the blood-retinal barrier during diabetes.

BMP-7 Attenuates Sarcopenia and Adverse Muscle Remodeling in Diabetic Mice via Alleviation of Lipids, Inflammation, HMGB1, and Pyroptosis.

Diabetic myopathy involves hyperglycemia, oxidative stress, and inflammation. However, the role of hypercholesterolemia-induced inflammation-mediated pathological mechanisms leading to fibrosis, sarcopenia, deterioration of muscle, and muscle dysfunction in diabetes is not well understood. In this study, we investigated the novel role of bone morphogenetic protein-7 (BMP-7) in ameliorating metabolic alterations, inflammation, pyroptosis, TGF-β/SMAD cell signaling mechanisms, and progression of diabetic myopathy. C57BL/6J mice were treated with saline, streptozotocin (STZ), or STZ+BMP-7. Diabetes was confirmed by increased fasting glucose levels and a glucose tolerance test. Gastrocnemius muscle and blood samples were collected for lipid and tissue analysis using various methods. A significant increase in hyperglycemia resulted in an increase in lipid accumulation, monocyte infiltration, and inflammation, as well as an increase in pyroptotic markers and signaling markers in diabetic muscle myocytes. A structural analysis showed significant muscle loss, and increased muscle deterioration and fibrosis leading to muscle dysfunction. BMP-7 attenuated pathological processes that resulted in significantly improved muscle function. We report, for the first time, that increased hyperlipidemia aggravates inflammation-induced pyroptosis, resulting in significant muscle loss, sarcopenia, and adverse skeletal muscle remodeling in diabetic muscle myopathy. Interventional treatment with BMP-7 attenuates hypercholesterolemia-induced inflammation-mediated sarcopenia and adverse muscle remodeling, suggesting BMP-7 could be a potential treatment option for diabetic muscle myopathy.

The Impact of BMP-4 Tissue Expression on Progression and Survival in Breast Cancer.

Bone morphogenetic protein -4 (BMP-4) plays important role in many aspects of carcinogenesis but is also involved in progression and metastasis of breast cancer where its precise role is yet to be elucidated. Since the majority of studies related to BMP-4 expression in breast cancer were conducted on cell lines of mouse models, we aimed to investigate BMP-4 tissue expression in primary human breast cancer and to correlate it with standard pathological factors for breast cancer, progression and survival. We analyzed immunohistochemical expression of BMP-4 in primary breast cancer tissue of 97 patients, correlated it with standard pathological factors for breast cancer and investigated its impact on progression and survival. BMP-4 expression was positive in 74.23% breast cancer tissue specimens. We found that hormone positive breast tumors are more likely to show BMP-4 strong granular staining pattern (p<0.01; p=0.029, respectively). There was significant association between stage group and BMP-4 expression in order that stage III breast cancer group were predominantly BMP-4 positive tumors (p=0.046). Although the most common site of distant metastases in patients with BMP-4 positive tumors were bones, we found no significant association (p>0.05). Patients with BMP-4 positive breast cancer showed longer overall and progression-free survival, but the results did not reach statistical significance (p>0.05). The results of our study in some extent can confirm the current available data and suggest that the role of BMP-4 in breast cancer is ambiguous, acting both as tumor suppressor and tumor promoter in breast cancer. For final elucidation of its impact on survival and progression in breast cancer, multicentric studies on larger sample size are required.

Possible roles of bone morphogenetic protein 4 in regulating endometrial function in cows.

This study investigated the expression dynamics of bone morphogenetic protein 4 (BMP4) and its receptors (BMPR1A, BMPR1B, and BMPR2) in bovine endometrium and examined the physiological function and regulatory mechanism of BMP4 expression. The messenger RNA (mRNA) expression of BMP4 and its receptors was detected in bovine endometrium of both ipsilateral (corpus luteum [CL]-side) and contralateral (non-CL-side) uterine horns during the estrous cycle and early pregnancy. BMP4 protein levels were higher in the endometrial tissues obtained from those cows in early pregnancy than in the estrous cycle. Immunohistochemical analysis showed that BMP4 and its receptors were localized in endometrial epithelial cells. The addition of BMP4 to cultured endometrial epithelial cells did not affect caspase-3/-8 mRNA expression, whereas it significantly inhibited cell proliferation. Both prostaglandin (PG) E2 and PGF2α concentrations in the culture supernatant were decreased when stimulated by BMP4. Furthermore, BMP4 mRNA expression was increased by stimulation with tumor necrosis factor-α (TNF) and interferon-γ (IFNG). In conclusion, BMP4 is produced in bovine endometrial epithelial cells and may contribute to the regulation of cell proliferation and suppression of PG secretion through autocrine or paracrine mechanisms. BMP4 expression in the bovine endometrium may be regulated by TNF and IFNG.

Differentiation of rat bone marrow mesenchymal stem cells into neurons induced by bone morphogenetic protein 7 in vitro

ABSTRACT Objectives Spinal cord injury (SCI) is caused by external direct or indirect factors with high disability rate, which may even endanger the life of patients. To explore the role of bone morphogenetic protein 7 (BMP-7) in the differentiation of rat bone marrow mesenchymal stem cells (BMSCs) into neurons in vitro. Methods BMSCs were isolated and cultured by whole bone marrow adherence method. Adipogenic induction and osteogenic differentiation were used to test the multi⁃directional differentiation ability of BMSCs. Results After 28 days of adipogenic induction, BMSCs showed lipid droplets in the cytoplasm. After osteogenic induction, there were opaque lumps of mineral nodules in BMSCs. There were also orange-red or red mineral nodules in the extracellular matrix. The BMSCs in the 75 ng/ml BMP-7 group were morphologically similar to the neurons. After induction with BMP-7 for 2 h, the NF200 mRNA expression was higher, mRNA expression levels of SYN1, MAP2 and GFAP were higher. Positive rate of immunofluorescence staining in the BMP-7 group was notably increased. The positive rate of NSE immunofluorescence staining in the BMP-7 group was higher. Conclusion BMP-7 can induce rat BMSCs to differentiate into neurons in vitro.

Activin-like Kinase 2 (ALK2/ACVR1) Is a Resistance Factor and Therapeutic Vulnerability to FLT3 Inhibition in Acute Myeloid Leukemia

Background: FMS-like tyrosine kinase-3 (FLT3), a transmembrane receptor, is frequently mutated in acute myeloid leukemia (AML), and this is associated with poor prognosis. Although FLT3 inhibitors (FLT3i) have significantly improved overall survival, their clinical effectiveness is limited due to treatment resistance, and the molecular mechanism remains unknown. We previously reported that the bone morphogenetic protein (BMP) signaling pathway supports AML cell growth via osteogenic differentiation in mesenchymal stromal cells. However, the role of BMP in FLT3i resistance has not been studied. We hypothesized that BMP type-1 receptor (ALK2/ACVR1) is a resistance factor for FLT3i, and therefore targeting FLT3 and ACVR1 using a novel dual inhibitor, TP-0184, would overcome FLT3i resistance and sensitize AML cells to standard therapy. Methods: We assessed the association of ACVR1 expression with molecular mutations in AML by analyzing gene expression datasets (OHSU and TCGA). We also measured ACVR1 expression using qRT-PCR in FLT3-mutant AML cell lines (molm-13, molm-14, and MV4-11) treated with different doses of FLT3i (gilteritinib or midostaurin), as well as in peripheral blood mononuclear cells isolated from patients with FLT3-mutant AML treated with FLT3i. To determine the role of ACVR1 in FLT3i resistance, we knocked down ACVR1 in FLT3-mutant cells, treated them with various doses of FLT3i, and measured apoptosis using IncuCyte. We also measured the effect of TP-0184 on cell proliferation and the cell cycle in FLT3-wild-type (WT) and FLT3-mutant cells. To determine the mechanism of TP-0184-mediated cell cycle arrest, we measured the effect of TP-0184 on cell signaling pathways using Western blot analysis and RNA sequencing. We also performed human RTK kinase binding assay to understand the binding specificity of TP-0184 with 11 different FLT3 mutants. MTT assay was used to determine the synergistic effect of TP-0184 with cytarabine or venetoclax (BCL2 inhibitor). We investigated the effect of TP-0184 on AML growth in vivo using FLT3-mutant and FLT3-WT AML xenograft and patient-derived xenograft models. Results: Analysis of AML datasets showed that ACVR1 expression is upregulated in FLT3-mutant compared with FLT3-WT AML patient samples (p<0.01) and predicts poor overall survival (p=0.05). ACVR1 expression was also higher in FLT3-mutant than in FLT3-WT cell lines (p=0.039). Interestingly, ACVR1 expression was upregulated in patient samples of FLT3-mutant AML treated with gilteritinib (p=0.02) and FLT3-mutant cell lines treated with FLT3i in a dose- and time-dependent manner. Moreover, ACVR1 knockdown in FLT3-mutant cell lines sensitized AML cells to FLT3i 2- to 3-fold compared with scrambled control cells, suggesting that ACVR1 is a resistance factor in AML cells treated with FLT3i, and that targeting ACVR1 could sensitize AML cells to FLT3i. In FLT3-WT and FLT3-mutant AML cell lines treated with TP-0184, cell growth was significantly reduced in FLT3-mutant cells (IC50<25nM) but not in FLT3-WT cells. TP-0184 induced G1/G0 arrest in FLT3-mutant cells but had minimal or no effect in FLT3-WT cells, suggesting that TP-0184 overcomes ACVR1-mediated resistance in FLT3-mutant cells. Treatment with TP-0184 significantly inhibited multiple proteins downstream of FLT3, including STAT-5, ERK, PI3K, and mTOR pathways, and decreased in pSmad1/5 proteins downstream of ACVR1 in AML cells. These findings confirmed that TP-0184 inhibits both mutant FLT3 and ACVR1 in AML cells. Gene expression analysis revealed that TP-0184 significantly downregulated the serine biosynthesis pathway in FLT3-mutant cell lines. Moreover, molecular docking and kinase-binding studies confirmed that TP-0184 binds to FLT3 mutants with high affinity (KD=<5nM). Interestingly,TP-0184 with venetoclax or cytarabine showed a synergistic effect in FLT3-mutant cells (combination index 0.01; p<0.01). In vivo data also showed that TP-0184 inhibited AML growth and significantly prolonged survival in FLT3-mutant AML xenograft and patient-derived xenograft models (p<0.01). Conclusion: Our data indicate that ACVR1 causes resistance to FLT3 inhibitors. TP-0184, a dual inhibitor, targets mutant FLT3 and ACVR1 in AML cell lines. TP-0184 sensitizes AML cells with chemotherapy and venetoclax and inhibits AML growth in vivo.

OR13-5 Bone Morphogenetic Protein-4 (BMP4) Inhibits Adrenal Cell Cortisol Synthesis by Blocking CYP17A1 and CYP11B1 Expression.

Abstract Background Cytochrome P450c17 (17α-hydroxylase, encoded by CYP17A1) and cytochrome P450c11 (11β-hydroxylase, encoded by CYP11B1) are essential for production of adrenal cortisol. The expression of CYP17A1 and CYP11B1 in adrenocortical cells is stimulated by adrenocorticotropic hormone (ACTH) through the cAMP and protein kinase A signal transduction pathway. Several growth factors can act as autocrine/paracrine regulators for modulating the steroidogenesis in the adrenal cortex. Among these factors, bone morphogenetic protein-4 (BMP4), a member of the superfamily of transforming growth factor-beta (TGFβ) has been previously reported to have an inhibitory effect on adrenal cell CYP17A1 expression and dehydroepiandrosterone (DHEA) production [1]. The role of BMP4 within the adrenal and its mechanisms regulating steroidogenesis are still unclear. In the present study, we examined human adrenal expression of BMP4 and its chronic effects on the H295R adrenal cell line. Objective To define the autocrine/paracrine role of BMP4 in adrenocortical zonation and adrenal steroidogenesis. Methods BMP4 expression in normal human adrenal glands was studied using microarray analysis with laser-captured adrenal capsule and cortical zones. Adrenal BMP4 protein expression was examined following immunohistochemistry (IHC) with a rabbit polyclonal antibody against human BMP4. In vitro studies were performed using H295R and human adrenal cells treated with or without ACTH (10nM), forskolin (10 µM) and BMP4 (50 ng/mL). The experimental medium was collected every 24 h and analyzed for cortisol. Experiments were terminated at 96 h followed by isolation of RNA and qPCR analysis for PPIA (normalization transcript), cytochrome P450 cholesterol side-chain cleavage (CYP11A1), CYP17A1 and CYP11B1. Results Microarray analysis of adrenal zone RNA demonstrated a BMP4 expression gradient with zona glomerulosa (ZG) expressing 3 and 11-fold higher levels than the zona fasciculata (ZF) and zona reticularis (ZR), respectively. IHC confirmed that BMP4 expression was highest in the ZG and the outer ZF. Administration of BMP4 to cultures of H295R cells caused a significant decrease in basal and forskolin-stimulated cortisol production at 48 h. By 96 h, BMP4 inhibited forskolin-stimulated cortisol by 60%. Cortisol inhibition occurred in conjunction with an inhibition in forskolin-stimulated CYP17A1 (↓75%) and CYP11B1 (↓65%). However, CYP11A1 expression was unaffected. In primary cultures of human adrenal cells BMP4 inhibited the ability of ACTH to increase cortisol production (↓75%), as well as CYP11B1(↓65%) and CYP17A1 (↓57%) expression. Conclusion Our findings indicate that the human adrenal has outer cortex localized expression of BMP4 that could play a paracrine/autocrine role in zone-specific production of aldosterone vs. cortisol through BMP4 selective inhibition of CYP17A1 and CYP11B1. Bibliography: 1. Rege J, Nishimoto HK, Nishimoto K, Rodgers RJ, Auchus RJ, Rainey WE. Bone Morphogenetic Protein-4 (BMP4): A Paracrine Regulator of Human Adrenal C19 Steroid Synthesis. Endocrinology 2015; 156: 2530–2540. Presentation: Sunday, June 12, 2022 12:00 p.m. - 12:15 p.m.

The role of BMP4 in adipose-derived stem cell differentiation: A minireview.

Bone morphogenetic protein 4 (BMP4) is a member of the transforming growth factor beta (TGF-β) superfamily of cytokines responsible for stem cells' commitment to differentiation, proliferation, and maturation. To date, various studies have utilized BMP4 as a chemical inducer for in vitro differentiation of human mesenchymal stem cells (MSCs) based on its potential. BMP4 drives in vitro differentiation of ADSC via TGF-β signaling pathway by interactions with BMP receptors leading to the activation of smad-dependent and smad-independent pathways. The BMP4 signaling pathways are regulated by intracellular and extracellular BMP4 antagonists. Extracellular BMP4 antagonist prevents interaction between BMP4 ligand to its receptors, while intracellular BMP4 antagonist shutdowns the smad-dependent pathways through multiple mechanisms. BMP4 proved as one of the popular differentiation factors to induce ADSC differentiation into cell from mesodermal origin. However, addition of all-trans retinoic acid is also needed in trans-differentiation of ADSC into ectodermal lineage cells. Suggesting that both BMP4 and RA signaling pathways may be necessary to be activated for in vitro trans-differentiation of ADSC.

A brief insight into the etiology, genetics, and immunology of polycystic ovarian syndrome (PCOS).

Polycystic ovarian syndrome (PCOS) is a prevailing endocrine and metabolic disorder occurring in about 6-20% of females in reproductive age. Most symptoms of PCOS arise early during puberty. Since PCOS involves a combination of signs and symptoms, thus it is considered as a heterogeneous disorderliness. The most accepted diagnostic criteria is Rotterdam criteria which involves two of the latter three features: (a) hyperandrogenism, (b) oligo- or an-ovulation, and (c) polycystic ovaries. The persistent hormonal imbalance leads to multiple small antral follicles formation and irregular menstrual cycle, ultimately causing infertility among females. Insulin resistance, cardiovascular diseases, abdominal obesity, psychological disorders, infertility, and cancer are also related to PCOS. These pathophysiologies associated with PCOS are interrelated with each other. Hyperandrogenism causes insulin resistance and hyperglycemia, leading to ROS formation, oxidative stress, and abdominal adiposity. In consequence, inflammation, ROS production, insulin resistance, and hyperandrogenemia also increase. Elevation of AGEs in the body either produced endogenously or consumed from diet exaggerates PCOS symptoms and is also related to ovarian dysfunction. This review summarizes how AGE formation, inflammation, and oxidative stress are significantly essential in PCOS progression. Alterations during prenatal development like exposure to excess AMH, androgens, or toxins (bisphenol-A, endocrine disruptors, etc.) may also be the etiologic mechanism behind PCOS. Although the etiology of this disorder is unclear, environmental and genetic factors are primarily involved. Physical inactivity, as well as unhealthy eating habits, has a vital role in the progression of PCOS. This review outlines a collection of specific genes phenotypically linked with PCOS. Furthermore, beneficial effect of metformin in maintaining endocrine abnormalities and ovarian function is also mentioned. Kisspeptin is a protein which helps in onset of puberty and increases GnRH pulsatile release during ovulation as well as role of KNDy neurons in GnRH pulsatile signal required for reproduction are also elaborated. This review also focuses on the immunology related to PCOS involving chronic low-grade inflammation, and how the alterations within the follicular microenvironment are intricated in the development of infertility in PCOS patients. How PCOS develops following antiepileptic and psychiatric medication is also expanded in this review. Initiation of antiandrogen treatment in early age (≤ 25years) might be helpful in spontaneous conception in PCOS women. The role of BMP (bone morphogenetic proteins) in folliculogenesis and their expression in oocytes and granulosa cells are also explained. GDF8 and SERPINE1 expression in PCOS is given in detail.

The effect of BMP2/Smads pathway mediating platelet-rich fibrin on rat bone mesenchymal stem cells.

We explored the influences on platelet-rich fibrin (PRF) to rat Bone Mesenchymal Stem Cells (BMSCs), as well as the role of bone morphogenetic protein 2 (BMP2)/maternal signal protein homolog (Smads) pathway. The proposed research is approved by the ethics board of the Second Affiliated Hospital of Harbin Medical University. The BMSCs were isolated and purified. The BMSCs were assigned to a control group arbitrarily, PRF group, BMP activator group and BMP inhibitor group (hereinafter referred to as activator group and inhibitor group). Each group of BMSCs in the logarithmic growth phase was detected for the alkaline phosphatase (ALP) activity since 3 days and 14 days of culture; CCK-8 assay was conducted for detection of the proliferation of BMSCs; Real time PCR was conducted for detection of the osteogenic differentiation marker collagen I (COL-I), BMP2, Runt-related transcription factor 2(RUNX2), osteocalcin (OCN) mRNA relative expression levels; Western-Blot detection of BMP2, OCN, P-SMAD1/5/8, relative expression level of RUNX2 protein. In contrast to the control group, BMSCs' the ALP activity of the PRF group, activator group, as well as inhibitor group increased for 3 days and 14 days, and the activator group>PRF group>inhibitor group (p≤0.05). ALP activity in each group was elevated with the increase in culture time, the ALP activity of the control group, PRF group, activator group and inhibitor group increased (p≤0.05). In comparison to the control group, the relevant expression levels of COL-I, BMP-2, RUNX2 and OCN in the PRF group, activator group, and inhibitor group increased, and the activator group>PRF group>inhibitor group (p≤0.05). The relative expression levels of BMP2, OCN, p-SMAD1/5/8 and RUNX2 protein in each group were statistically different, the activator group>PRF group>control group>inhibitor group (p≤0.05). PRF can promote the proliferation and osteogenic differentiation of BMSCs by activating the BMP2/Smads signaling pathway.

Role of bone morphogenetic proteins in periodontal tissue engineering: Relatively unexplored horizon

Tissue engineering aims to reconstruct the natural target tissue by a combination of three key elements stem/progenitor cells (that will create the new tissue), signaling molecules (that instruct the cells to form the desired tissue) scaffold/extracellular matrix (to hold the cells). Regeneration of the periodontal tissues following destructive episodes of various forms of periodontitis is a formidable challenge to periodontologists. Bone morphogenic proteins have been considered as the most potent growth factors that can promote the bone regeneration. This review will emphasize on the unique nature of the tissue engineered bone morphogenic proteins molecules regarding their structure, classification, signaling mechanism, etc. which will further help in understanding their role and potential advances necessary to facilitate the process of regeneration in the field of periodontics.

Reversely immortalized mouse salivary gland cells presented a promising metabolic and fibrotic response upon BMP9/Gdf2 stimulation

The submandibular gland (SMG) and the sublingual gland (SLG) are two of the three major salivary glands in mammals. In mice, they are adjacent to each other and open into the oral cavity, producing saliva to lubricate the mouth and aid in food digestion. Though salivary gland dysfunction accompanied with fibrosis and metabolic disturbance is common in clinic, in-depth mechanistic research is lacking. Currently, research on how to rescue salivary function is challenging, as it must resort to using terminally differentiated acinar cells or precursor acinar cells with unknown differentiation. In this study, we established reversely immortalized mouse primary SMG cells (iSMGCs) and SLG cells (iSLGCs) on the first postnatal day (P0). The iSMGCs and iSLGCs grew well, exhibited many salivary gland characteristics, and retained the metabolism-related genes derived from the original tissue as demonstrated using transcriptome sequencing (RNA-seq) analysis. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of these two cell lines, which overlapped with those of the SMG and SLG, were enriched in cysteine and methionine metabolism. Furthermore, we investigated the role of bone morphogenetic protein 9 (BMP9), also known as growth differentiation factor 2(Gdf2), on metabolic and fibrotic functions in the SMG and SLG. We demonstrated that iSMGCs and iSLGCs presented promising adipogenic and fibrotic responses upon BMP9/Gdf2 stimulation. Thus, our findings indicate that iSMGCs and iSLGCs faithfully reproduce characteristics of SMG and SLG cells and present a promising prospect for use in future study of salivary gland metabolism and fibrosis upon BMP9/Gdf2 stimulation.

The Role of Bone Morphogenetic Protein 4 in Microglial Polarization in the Process of Neuropathic Pain.

BackgroundNeuropathic pain (NP) is known to be highly correlated with microglial polarization, of which the regulatory mechanism remains to be elucidated. Here, the aim of this study is to further investigate the relationship between bone morphogenetic protein 4 (BMP4) and microglial polarization in the process of NP.MethodsFirstly, normal adult rats received intrathecal BMP4 administration to assess BMP4ʹs effect on microglial polarization. Secondly, a BMP4 antagonist – Noggin – was applied to a rat NP model achieved by L5 spinal nerve ligation (SNL) to investigate whether antagonizing BMP4 signaling could alleviate allodynia by reversing the imbalance of the M1/M2 polarization ratio. In both experiments, Von-Frey filaments were used to test the changes in the paw withdrawal threshold (PWT), and Western blotting, immuno-fluorescence, PCR and flow cytometry were further performed to investigate microglial activity and the expression patterns of M1 and M2 markers, respectively.ResultsFirstly, BMP4 administration induced a significant PWT decrease and microglial activation in normal rats; Western blotting, PCR and flow cytometry further revealed that M1 markers including CD16, MHCII, and TNF-α showed a marked elevation after BMP4 application; while M2 markers, such as Arg-1, CD204 and IL-4, peaked at an early stage (P1 or P4) and then fell to the Sham level on P7, leading to a persistent imbalance of the M1/M2 ratio throughout the 1st week. Secondly, Noggin treatment significantly relieved allodynia and microglial activation in SNL rats. Moreover, Noggin persistently downregulated the M1 marker levels and simultaneously induced a late-stage elevation of M2 markers expressions, thereby reversing the imbalance of the M1/M2 polarization ratio.ConclusionOur results indicate that BMP4 has the ability to induce microglial polarization. Antagonizing BMP4 signaling can relieve pain behavior via mitigating microglial activation and reversing the imbalance of the M1/M2 polarization ratio in the process of NP.

A Novel Risk Score Model Based on Eleven Extracellular Matrix-Related Genes for Predicting Overall Survival of Glioma Patients.

Gliomas are the most common lethal primary brain tumors with variable survival outcomes for patients. The extracellular matrix (ECM) is linked with clinical prognosis of glioma patients, but it is not commonly used as a clinical indicator. Herein, we investigated changes in ECM-related genes (ECMRGs) via analyzing the transcriptional data of 938 gliomas from TCGA and CGGA datasets. Based on least absolute shrinkage and selection operator (LASSO) Cox regression analysis, a 11-ECMRG signature that is strongly linked with overall survival (OS) in glioma patients was identified. This signature was characterized by high-risk and low-risk score patterns. We found that the patients in the high-risk group are significantly linked with malignant molecular features and worse outcomes. Univariate and multivariate Cox regression analyses suggested that the signature is an independent indicator for glioma prognosis. The prediction accuracy of the signature was verified through time-dependent receiver operating characteristic (ROC) curves and calibration plots. Further bioinformatics analyses implied that the ECMRG signature is strongly associated with the activation of multiple oncogenic and metabolic pathways and immunosuppressive tumor microenvironment in gliomas. In addition, we confirmed that the high-risk score is an indicator for a therapy-resistant phenotype. In addition to bioinformatics analyses, we functionally verified the oncogenic role of bone morphogenetic protein 1 (BMP1) in gliomas in vitro.