BMP-2 mRNA Research Articles

Brd4 Inactivation Increases Adenoviral Delivery of BMP2 for Paracrine Stimulation of Osteogenic Differentiation as a Gene Therapeutic Concept to Enhance Bone Healing.

ABSTRACTBromodomain (BRD) proteins are histone code interpreters that recognize acetylated lysines and link the dynamic state of chromatin with the transcriptional machinery. Here, we demonstrate that ablation of the Brd4 gene in primary mouse bone marrow–derived mesenchymal stem cells via a conditional Brd4fl/fl allele suppresses osteogenic lineage commitment. Remarkably, loss of Brd4 function also enhances expression of genes in engineered adenoviral vectors, including Cre recombinase and green fluorescent protein (GFP). Similarly, vector‐based expression of BMP2 mRNA and protein levels are enhanced upon Brd4 depletion in cells transduced with an adenoviral vector that expresses BMP2 (Ad‐BMP2). Importantly, Brd4 depletion in MC3T3‐E1 and human adipose‐derived mesenchymal stem cells (AMSCs) transduced with Ad‐BMP2 enhances osteogenic differentiation of naïve MC3T3‐E1 cells via paracrine mechanisms based on transwell and conditioned medium studies. Our studies indicate that Brd4 depletion enhances adenoviral transgene expression in mammalian cells, which can be leveraged as a therapeutic strategy to improve viral vector‐based gene therapies. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Effect of Inducible BMP-7 Expression on the Osteogenic Differentiation of Human Dental Pulp Stem Cells.

BMP-7 has shown inductive potential for in vitro osteogenic differentiation of mesenchymal stem cells, which are an ideal resource for regenerative medicine. Externally applied, recombinant BMP-7 was able to induce the osteogenic differentiation of DPSCs but based on our previous results with BMP-2, we aimed to study the effect of the tetracyclin-inducible BMP-7 expression on these cells. DPSC, mock, and DPSC-BMP-7 cell lines were cultured in the presence or absence of doxycycline, then alkaline phosphatase (ALP) activity, mineralization, and mRNA levels of different osteogenic marker genes were measured. In the DPSC-BMP-7 cell line, the level of BMP-7 mRNA significantly increased in the media supplemented with doxycycline, however, the expression of Runx2 and noggin genes was upregulated only after 21 days of incubation in the osteogenic medium with doxycycline. Moreover, while the examination of ALP activity showed reduced activity in the control medium containing doxycycline, the accumulation of minerals remained unchanged in the cultures. We have found that the induced BMP-7 expression failed to induce osteogenic differentiation of DPSCs. We propose three different mechanisms that may worth investigating for the engineering of expression systems that can be used for the induction of differentiation of mesenchymal stem cells.

Effects of WNT1 c.110\u2009T>C and c.505G>T mutations on osteoblast differentiation via the WNT1/\u03b2-catenin signaling pathway

BackgroundWNT1 c.110 T>C and c.505G>T missense mutations have been identified in patients with osteogenesis imperfecta (OI). Whether these mutations affect osteoblast differentiation remains to be determined. This study aimed to investigate the effects of WNT1 c.110 T>C and c.505G>T mutations on osteoblast function, gene expression, and pathways involved in OI.MethodsEmpty vector (negative control), wild-type WNT1, WNT1 c.110 T>C, WNT1 c.505G>T, and WNT1 c.884C>A (positive control) mutant plasmids were constructed and transfected into preosteoblast (MC3T3-E1) cells to investigate their effect on osteoblast differentiation. The expressions of osteoblast markers, including BMP2, RANKL, osteocalcin, and alkaline phosphatase (ALP), were determined using quantitative real-time polymerase chain reaction (RT-qPCR), western blotting (WB), enzyme-linked immunosorbent assay, and ALP staining assay, respectively. The mRNA and protein expression levels of WNT1 or the expression levels of the relevant proteins involved in the WNT1/β-catenin signaling pathway were also determined using RT-qPCR, WB, and immunofluorescence (IF) assays after the different plasmids were transfected into MC3T3-E1 cells.ResultsCompared with those in the wild-type group, in the mutation groups, the mRNA and protein expression levels of BMP2 were suppressed, the expressions of osteocalcin and ALP were inhibited, and the mRNA and protein expression levels of RANKL were enhanced in MC3T3-E1 cells. WB and IF assays revealed that the protein expression levels of WNT1 in MC3T3-E1 cells were downregulated in the mutation groups compared with those in the wild-type WNT1 group. Furthermore, the expression levels of nonphosphorylated β-catenin (non-p-β-catenin) and phosphorylated GSK-3β (p-GSK-3β) were downregulated in the mutation groups compared with those in the wild-type group. However, no significant changes in the expression level of non-p-β-catenin or p-GSK-3β were observed in the mutation groups.ConclusionsWNT1 c.110 T>C and c.505G>T mutations may alter the proliferation and osteogenic phenotype of MC3T3-E1 linked to the progression of OI via the inhibition of the WNT1/β-catenin signaling pathway. This is the first study to confirm the effect of WNT1 c.110 T>C and c.505G>T missense mutations on osteoblast differentiation and propose a new molecular mechanism for OI development.

BMP6 Mediates BMP2-Increased Human Trophoblast Invasion

TGF-β superfamily proteins play divergent roles in regulating human extravillous trophoblast (EVT) invasion and their coordinated effects are essential for adequate placentation during pregnancy 1. Bone morphogenetic protein 2 (BMP2), which belongs to the BMP subfamily of TGF-β superfamily, has been shown to promote human EVT invasion and the acquisition of endothelial-like phenotype 2,3. It has been reported that BMP2 promotes EVT invasion by up-regulating Activin A, a growth factor which also belongs to TGF-β superfamily. However, whether BMP6 mediates the pro-invasive effect of BMP2 has yet to be determined. Herein, we firstly treated immortalized trophoblast cells (HTR8/SVneo) with recombinant BMP2 protein for 6 and 24 hrs, and our bulk-RNA sequencing results demonstrated significantly increased BMP6 mRNA levels after BMP2 treatment. Furthermore, we confirmed the up-regulatory effects of BMP2 on BMP6 mRNA and protein levels in both HTR8/SVneo and primary EVTs isolated from first-trimester villi. Notably, siRNA-mediated down-regulation of BMP6 significantly attenuated both basal and BMP2-induced cell invasion in HTR8/SVneo cells as measured by Matrigel-coated transwell invasion assay. In summary, our results firstly demonstrated the up-regulatory effect of BMP2 on BMP6 expression in human trophoblasts and identified the mediation role of BMP6 in BMP2-promoted EVT invasion, suggesting the interplay between BMP subfamily members during EVT invasion regulation. Our ongoing research focusing the underlying molecular mechanisms and signaling pathways could further benefit the advancement of diagnostic and therapeutic strategies for EVT invasion dysregulation-related pregnancy disorders, e.g., pre-eclampsia. Reference: (1) Li Yan et al., Trends Endocrinol Metab 2021 18: S1043-2760(20)30266-6. (2) Hong-Jin Zhao et al., FASEB J 2020;34(2):3151-3164. (3) Hong-Jin Zhao et al., Cell Death Dis 2018;9(2):174.

In Vivo bone tissue induction by freeze-dried collagen-nanohydroxyapatite matrix loaded with BMP2/NS1 mRNAs lipopolyplexes

Messenger RNA (mRNA) activated matrices (RAMs) are interesting to orchestrate tissue and organ regeneration due to the in-situ and sustained production of functional proteins. However, the immunogenicity of in vitro transcribed mRNA and the paucity of proper in vivo mRNA delivery vector need to be overcome to exert the therapeutic potential of RAM. We developed a dual mRNAs system for in vitro osteogenesis by co-delivering NS1 mRNA with BMP2 mRNA to inhibit RNA sensors and enhance BMP-2 expression. Next, we evaluated a lipopolyplex (LPR) formulation platform for in vivo mRNA delivery and adapted the LPRs for RAM preparation. The LPR formulated BMP2/NS1 mRNAs were incorporated into an optimized collagen-nanohydroxyapatite scaffold and freeze-dried to prepare ready-to-use RAMs. The loaded BMP2/NS1 mRNAs lipopolyplexes maintained their spherical morphology in the RAM, thanks to the core-shell structure of LPR. The mRNAs release from RAMs lasted for 16 days resulting in an enhanced prolonged transgene expression period compared to direct cell transfection. Once subcutaneously implanted in mice, the BMP2/NS1 mRNAs LPRs containing RAMs (RAM-BMP2/NS1) induced significant new bone tissue than those without NS1 mRNA, eight weeks post implantation. Overall, our results demonstrate that the BMP2/NS1 dual mRNAs system is suitable for osteogenic engagement, and the freeze-dried RAM-BMP2/NS1 could be promising off-the-shelf products for clinical orthopedic practice.

αA-Crystallin inhibits optic nerve astrocyte activation induced by oxygen-glucose deprivation in vitro

AimsA previous study reported that intravitreal injection of αA-crystallin inhibits glial scar formation after optic nerve traumatic injury. The purpose of this study was to investigate the effect of αA-crystallin on optic nerve astrocytes induced by oxygen glucose deprivation (OGD) in vitro. Materials and methodsOptic nerve astrocytes from newborn Long Evans rats were cultured with αA-crystallin (10−4 g/l) to detect the effects of αA-crystallin on astrocytes. Using a scratch assay, the effect of αA-crystallin treatment on astrocyte migration was assessed. Astrocytes were exposed to OGD and glucose reintroduction/reoxygenation culture for 24 h and 48 h. The expression of glial fibrillary acidic protein (GFAP) and neurocan were subsequently evaluated via immunocytochemistry and western blot. BMP2/4, BMPRIa/Ib and Smad1/5/8 mRNA expression levels were detected by RT-PCR. Key findingsThe results showed that αA-crystallin slowed the migration of astrocytes in filling the scratch gaps. GFAP and neurocan expression in astrocytes was increased after OGD. However, after treatment with αA-crystallin, GFAP and neurocan expression levels clearly decreased. Furthermore, RT-PCR showed that BMP2 and BMP4 mRNA expression levels decreased significantly. SignificanceThese results suggest that αA-crystallin inhibits the activation of astrocytes after OGD injury in vitro. Inhibition of the BMP/Smad signaling pathway might be the mechanism underlying this effect.

MiR-105 enhances osteogenic differentiation of hADSCs via the targeted regulation of SOX9

ObjectiveTo investigate whether miR-105 can regulate the osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADSCs) by targeting SOX9. MethodsThe hADSCs were grouped for subsequent transfection and induction of osteogenic differentiation as follows: control, miR-NC, miR-105 mimics, miR-105 inhibitors, SOX9, SOX9 siRNA, miR-105 mimics + SOX9 and miR-105 inhibitors + SOX9 siRNA groups. Next, hADSCs were stained for alkaline phosphatase (ALP), and Alizarin Red S staining (ARS) was performed. Osteogenic differentiation-related genes and miR-105 expression were assessed by qRT-PCR, while SOX9 protein expression was determined by Western blotting. ResultsMiR-105 expression was increased and SOX9 protein expression was decreased during the osteogenic differentiation of hADSCs. A dual-luciferase reporter assay confirmed SOX9 to be a target gene of miR-105. Compared with the control group, the miR-105 mimics and SOX9 siRNA groups had elevated BMP2, OPN, OCN, BSP, Osx and Runx2 mRNA expression with reduced SOX9 expression, as well as increased ARS intensity and ALP activity. After transfection of miR-105 inhibitors/SOX9 into hADSCs, the results were the opposite. Overexpressing SOX9 reversed the effect of miR-105 in promoting the osteogenic differentiation of hADSCs. ConclusionMiR-105 could target SOX9 to improve the expression of osteogenic differentiation genes and thus enhance the osteogenic differentiation of hADSCs.

Co-transfection with BMP2 and FGF2 via chitosan nanoparticles potentiates osteogenesis in human adipose-derived stromal cells in vitro.

ObjectiveTo investigate if co-transfection of human bone morphogenetic protein 2 (BMP-2, BMP2) and human fibroblast growth factor 2 (FGF2, FGF2) via chitosan nanoparticles promotes osteogenesis in human adipose tissue-derived stem cells (ADSCs) in vitro.Materials and MethodsRecombinant BMP2 and/or FGF2 expression vectors were constructed and packaged into chitosan nanoparticles. The chitosan nanoparticles were characterized by atomic force microscopy. Gene and protein expression levels of BMP-2 and FGF2 in ADSCs in vitro were evaluated by real-time polymerase chain reaction (PCR), western blot, and enzyme-linked immunosorbent assay. Osteocalcin (OCN) and bone sialoprotein (BSP) gene expression were also evaluated by real-time PCR to assess osteogenesis.ResultsThe prepared chitosan nanoparticles were spherical with a relatively homogenous size distribution. The BMP2 and FGF2 vectors were successfully transfected into ADSCs. BMP-2 and FGF2 mRNA and protein levels were significantly up-regulated in the co-transfection group compared with the control group. OCN and BSP mRNA levels were also significantly increased in the co-transfection group compared with cells transfected with BMP2 or FGF2 alone, suggesting that co-transfection significantly enhanced osteogenesis.ConclusionsCo-transfection of human ADSCs with BMP2/FGF2 via chitosan nanoparticles efficiently promotes the osteogenic properties of ADSCs in vitro.

The differentiation of prehypertrophic into hypertrophic chondrocytes drives an OA-remodeling program and IL-34 expression

We hypothesize that chondrocytes from the deepest articular cartilage layer are pivotal in maintaining cartilage integrity and that the modification of their prehypertrophic phenotype to a hypertrophic phenotype will drive cartilage degradation in osteoarthritis. Murine immature articular chondrocytes (iMACs) were successively cultured into three different culture media to induce a progressive hypertrophic differentiation. Chondrocyte were phenotypically characterized by whole-genome microarray analysis. The expression of IL-34 and its receptors PTPRZ1 and CSF1R in chondrocytes and in human osteoarthritis tissues was assessed by RT-qPCR, ELISA and immunohistochemistry. The expression of bone remodeling and angiogenesis factors and the cell response to IL-1β and IL-34 were investigated by RT-qPCR and ELISA. Whole-genome microarray analysis showed that iMACs, prehypertrophic and hypertrophic chondrocytes each displayed a specific phenotype. IL-1β induced a stronger catabolic effect in prehypertrophic chondrocytes than in iMACs. Hypertrophic differentiation of prehypertrophic chondrocytes increased Bmp-2 (95%CI [0.78; 1.98]), Bmp-4 (95%CI [0.89; 1.59]), Cxcl12 (95%CI [2.19; 5.41]), CCL2 (95%CI [3.59; 11.86]), Mmp 3 (95%CI [10.29; 32.14]) and Vegf mRNA expression (95%CI [0.20; 1.74]). Microarray analysis identified IL-34, PTPRZ1 and CSFR1 as being strongly overexpressed in hypertrophic chondrocytes. IL-34 was released by human osteoarthritis cartilage; its receptors were expressed in human osteoarthritis tissues. IL-34 stimulated CCL2 and MMP13 in osteoblasts and hypertrophic chondrocytes but not in iMACs or prehypertrophic chondrocytes. Our results identify prehypertrophic chondrocytes as being potentially pivotal in the control of cartilage and subchondral bone integrity. Their differentiation into hypertrophic chondrocytes initiates a remodeling program in which IL-34 may be involved.

Studies on the therapeutic effects of three TCM methods on steroid-induced osteonecrosis of femoral head

Purpose: To determine the therapeutic effects of kidney yang-tonifying, blood-activating and phlegmeliminating methods on steroid-induced osteonecrosis of femoral head (SONFH), and their mechanisms of action.Methods: A rabbit model of SONFH was established. Six rabbit groups were used: control, SONFH (given normal saline); tongluo shenggu group, kidney-tonifying group, blood-activating group, and phlegm--eliminating group, which received tongluo shenggu capsule (0.28 g/kg/day), yougui yin (YGY, 2.52 g/kg/day), taohong siwu decoction (TSD, 2.38 g/kg/day) and linggui zhugan decoction (LZD,1.54 g/kg/day), respectively, for 8 weeks. The following serum indices were assayed on the 2nd, 4th and 8th weeks: total cholesterol, triglycerides, thromboxane B2 (TXB2), 6-keto-PGF1α, osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-Β ligand (RANKL). At the end of the 8th week, mRNA levels of OPG, BMP-2 and VEGF were assayed using real-time fluorescent quantitative polymerase chain reaction (RTF-qPCR).Results: Serum OPG in the kidney-tonifying group was increased, while its RANKL was decreased on the 2nd week, but these parameters, along with mRNA of OPG and BMP-2, reached normal levels at the 8th week (p <0.05). The TXB2 of blood-activating group was decreased, while its 6-keto-PGF1 level was increased at the 2nd week, but both of them attained normal levels at the 8th week, along with VEGF mRNA. Serum total cholesterol, triglycerides and TXB2 in the phlegm-eliminating group were decreased, while its 6-keto-PGF1α was increased at the 2nd week, but the levels of serum total cholesterol and triglycerides were normalized at the 8th week (p <0.05). Histological examination showed increases in bone trabeculae and bone marrow cells, while the proliferation of fat cells was decreased in kidney-tonifying, blood-activating and phlegm-eliminating groups.Conclusion: These findings suggest that the therapeutic effects of the three different TCM methods on SONFH involve different mechanisms.
 Keywords: Steroid-induced osteonecrosis, Femoral head, Yougui yin, Taohong siwu, Linggui zhugan decoction, Kidney-tonifying yang, Phlegm

Effect of pinocembrin isolated from Alpinia zerumbet on osteoblast differentiation.

Bone mass is regulated by osteoblast-mediated bone formation and osteoclast-mediated bone resorption. Osteoporosis is a bone metabolism disorder in which bone mass decreases due to increased bone resorption rather than bone formation. We focused on the traditional plant Alpinia zerumbet in Okinawa, Japan, and searched for promising compounds for the prevention and treatment of osteoporosis. Pinocembrin isolated from the leaves of A. zerumbet showed enhanced alkaline phosphatase (ALP) activity and mineralization and increased mRNA expression of osteoblast-related genes Alp and Osteocalcin (Ocn) in MC3T3-E1 cells. Pinocembrin increased the mRNA expression of Runx2 and Osterix, which are important transcription factors in osteoblast differentiation, and the mRNA expression of Dlx5 and Msx2, which are enhancers of these transcription factors. The bone morphogenetic protein (BMP) antagonist noggin, its receptor kinase inhibitor LDN-193189 and p38 MAPK inhibitor SB203580 attenuated pinocembrin-promoted ALP activity. Pinocembrin increased the mRNA of Bmp-2 and its target gene Id1. In addition, the estrogen receptor (ER) inhibitor ICI182780 suppressed pinocembrin-stimulated ALP activity. Pinocembrin may increase BMP-2 expression via ER. Then, the BMP-2 promotes osteoblast specific genes expression and mineralization through both Smad-dependent and independent pathway following Runx2 and Osterix induction. Our findings suggest that pinocembrin has bone anabolic effects and may be useful for the prevention and treatment of bone metabolic diseases such as osteoporosis.

Abstract 2614: Elucidation of the molecular mechanisms mediating sorafenib-resistance in Hepatocellular carcinoma

Abstract Sorafenib is the only first line and FDA-approved drug available for the treatment of advanced hepatocellular carcinoma (HCC). Despite an increased overall patient survival of about 3-5 months with sorafenib, majority of the HCC patients acquire sorafenib-resistance, thus making sorafenib treatment ineffective in long-term. Therefore, there is an urgent need to explore the mechanisms underlying sorafenib-resistance to develop better treatment strategies to combat this deadly disease. To achieve this goal, we first established sorafenib-resistant cells by repeated treatment of different HCC cell lines (Huh7, Hep3B and HepG2) with increasing concentrations of sorafenib up to 6µM. MTT assays confirmed that all three cell types treated with sorafenib achieved resistance and were termed soraR to distinguish them from their sorafenib-sensitive (soraS) counterparts. Further characterization of the soraR cells showed increased expression of mesenchymal markers including Slug, Snail, Zeb2, vimentin, and reduced expression of epithelial marker (E-cadherin), indicative of Epithelial-Mesenchymal Transition (EMT). Moreover soraR cells were found to have high migratory potential in wound healing assay and higher sphere-forming capability compared to the soraS cells. To find out the signaling pathways which could be responsible for promoting sorafenib-resistance, RT2-profiler PCR Array analysis for cytokine and chemokines (PAHS-150Z from Qiagen) were performed, which revealed an increase in the expression of BMP6 and BMP7 mRNA levels in the soraR cells. The results were validated by qPCR. In addition, western blot analyses showed an increase in pSmad1, 5, 9 levels in the soraR cells, suggesting a potential activation of BMP6, 7 axis in sorafenib-resistance. Effect of inhibition of BMP6 and BMP7 signaling in re-sensitizing the SoraR cells towards sorafenib was determined next. Flow cytometric analysis of Hep3B-SoraR cells treated with DMH1, a small molecule inhibitor of BMP receptors in combination with sorafenib showed increased cell death which was accompanied with increased expression of cleaved PARP and cleaved caspase 3 in western blot. BMP6 and BMP7 inhibition also reduced migration capacity of soraR cell types as examined by wound healing assay. The results were further confirmed by treating soraR cells with recombinant BMP6 and BMP7 and examining their effect on migration and sorafenib-mediated apoptosis. Interestingly, exogenous BMP6 and BMP7 treatment was found to enhance migration capacity and rescue the soraS cells from sorafenib-mediated cell death. These findings indicated an important role of BMP6 and BMP7 pathways in mediating sorafenib-resistance in HCC and suggested that pharmacological targeting of BMP6 and BMP7 signaling could be an effective strategy to ameliorate sorafenib-resistance in advanced HCC. Citation Format: Kanchan Vishnoi, Rong Ke, Randhir Kumar, Navin Viswakarma, Ajay Rana, Basabi Rana. Elucidation of the molecular mechanisms mediating sorafenib-resistance in Hepatocellular carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2614.

Remodeling process in bone of aged rats in response to resistance training

AimsWe investigate the effects of RT on the mechanical function, gene, and protein expression of key factors involved in bone remodeling during aging. Main methodsMale rats of 3 and 21 months of age were randomly allocated into four groups (8 per group): young sedentary (YS), young trained (YT), old sedentary (OS), and old trained (OT). RT was performed three times per week (12 weeks). Bone tenacity and stiffness were measured by biomechanical tests and mRNA levels of COL1A1, MEPE, SOST, OPG, BMP-2, PPAR-y, MMP-2-9-13, and TIMP-1 were evaluated by quantitative PCR. COL1A1 protein and MMP-2 activity were detected by western blotting and zymography assays. Key findingsAging increased stiffness, while BMP-2, OPG, COL1A1 and MMP-2 mRNA levels reduced (OS vs YS; p ≤ 0.05). RT increased the tenacity of the femur and reduced PPAR-γ regardless of age (YT vs. YS; OT vs. OS; p ≤ 0.05). RT downregulated SOST mRNA levels only in the OT group (vs. OS group, p ≤ 0.05). RT mitigated the age-associated increase in MMP-9 mRNA levels (p ≤ 0.05). In young animals, upregulation in MEPE, MMP-13, TIMP-1 were observed after RT, as well an increase in COL1A1 protein and MMP-2 activity (p ≤ 0.05). SignificanceRT improved bone tenacity independent of aging, which is relevant for mechanical function, while, at protein levels, RT upregulated MMP-2 activity and collagen 1 only in young rats. This study highlights the importance of exercise on bone health and identifies specific molecular changes in response to RT. Our findings provide insights into the mechanisms involved in age-related changes.

The Action of JAK/STAT3 and BMP/HJV/SMAD Signaling Pathways on Hepcidin Suppression by Tucum-do-Cerrado in a Normal and Iron-Enriched Diets.

The Brazilian savanna fruit, tucum-do-cerrado (Bactris setosa Mart.) reduces hepatic hepcidin levels. Therefore, we investigated the effect of tucum-do-cerrado on the TfR/HFE and/or BMP/HJV/SMAD and JAK/STAT pathways, in normal and excess iron conditions. Rats were treated with: control diet (CT); control diet +15% tucum-do-cerrado (Tuc); iron-enriched diet (+Fe); or iron-enriched diet +15% tucum-do-cerrado (Tuc+Fe). Tucum-do-cerrado (Tuc) decreased hepatic Hamp and Hjv mRNA levels but did not alter Bmp6, Smad7, Tfr1, and Hfe mRNA levels; pSMAD1/5/8 and pSTAT3 protein levels; labile iron pool (LIP); and inflammatory biomarkers, compared to the CT group. The iron-enriched diet increased Hamp mRNA levels, as well as pSMAD1/5/8 and pSTAT3 protein levels, while no difference was observed in Hjv, Bmp6, Smad7, Tfr1, and Hfe mRNA levels and LIP compared to the CT group. The association of tucum-do-cerrado with the iron-enriched diet (Tuc+Fe) decreased Hamp, Hjv, Bmp6, and Hfe mRNA levels and pSTAT3 protein content compared to the +Fe group, while increased Hamp and decreased Hfe mRNA levels compared to the Tuc group. Therefore, the inhibition of hepatic hepcidin by tucum-do-cerrado consumption may involve the downregulation of intestinal Dmt1 and hepatic Hjv expression and deacetylation mediated by SIRT1 by a mechanism that is independent of tissue iron content. However, in excess iron conditions, the modulation of hepatic hepcidin expression by tucum-do-cerrado seems to be partially mediated by the inflammatory signaling pathway, as well as involves the chelating activity of tucum-do-cerrado.

Up-regulation of miR-135b expression induced by oxidative stress promotes the apoptosis of renal tubular epithelial cells under high glucose condition.

This study aimed to investigate the role and underlying mechanism of miR-135b in high glucose-induced oxidative stress of renal tubular epithelial cells. Here, in vivo experiments found that compared to the control group, miR-135b expression was significantly up-regulated in the diabetes group, whereas BMP7 mRNA and protein levels were down-regulated. In high glucose-treated renal tubular epithelial cells (HK-2) in vitro, oxidative stress was induced, which up-regulated miR-135b expression. In addition, the regulation of miR-135b on BMP7 expression was confirmed in HK-2 cells. Under high glucose conditions, oxidative stress promoted the apoptosis of HK-2 cells through the up-regulation of miR-135b expression. In vivo experiments indicated that interference with miR-135b improved renal function in mice with diabetic nephropathy. In conclusion, these results indicated that the up-regulation of miR-135b expression induced by oxidative stress promotes the apoptosis of HK-2 cells under high glucose conditions.

Co-delivery of NS1 and BMP2 mRNAs to murine pluripotent stem cells leads to enhanced BMP-2 expression and osteogenic differentiation

Application of messenger RNA (mRNA) for bone regeneration is a promising alternative to DNA, recombinant proteins and peptides. However, exogenous in vitro transcribed mRNA (IVT mRNA) triggers innate immune response resulting in mRNA degradation and translation inhibition. Inspired by the ability of viral immune evasion proteins to inhibit host cell responses against viral RNA, we applied non-structural protein-1 (NS1) from Influenza A virus (A/Texas/36/1991) as an IVT mRNA enhancer. We evidenced a dose-dependent blocking of RNA sensors by NS1 expression. The co-delivery of NS1 mRNA with mRNA of reporter genes significantly increased the translation efficiency. Interestingly, unlike the use of nucleosides modification, NS1-mediated mRNA translation enhancement does not dependent to cell type. Dual delivery of NS1 mRNA and BMP-2 mRNA to murine pluripotent stem cells (C3H10T1/2), promoted osteogenic differentiation evidenced by enhanced expression of osteoblastic markers (e.g. alkaline phosphatase, type I collagen, osteopontin, and osteocalcin), and extracellular mineralization. Overall, these results support the adjuvant potentiality of NS1 for mRNA-based regenerative therapies. Statement of SignificancemRNA therapy has the potential to improve the efficiency of nucleic acid based regenerative medicine. Up to now, the incorporation of expensive modified nucleotides is a common way to avoid IVT mRNA-induced detrimental immunogenicity. We here introduce co-delivery of Influenza virus immune evasion protein-NS1 coding mRNA as a strategy to suppress RNA sensors for maximizing IVT mRNA expression. An increased osteogenic commitment of pluripotent stem cells was observed after BMP2 mRNA and NS1 mRNA delivery. This study revealed how applying non-modified mRNA with NS1 could be a promising alternative as a therapeutic in bone regeneration.

The Interplay of Wnt‐ and PPARγ‐signaling in macrophages & vascular smooth muscle cells during vascular calcification

BackgroundMolecular mechanisms and structural changes of the vessel wall including inflammation and vascular calcification (VC) are linked to atherosclerosis, and various cell types such as macrophages and vascular smooth muscle cells (VSMC) are involved. Importantly, VC enhances the risk of acute cardiovascular events by 4‐fold. Hence, it is of great importance to reveal underlying molecular mechanisms to prevent this outcome. The environmental shifts in atherosclerotic plaques stimulate the expression of Wnt5a and BMP‐2. Both factors are secreted by M1‐macrophages and induce an osteo‐chondrogenic phenotype of VSMC by enhancing SOX9 and RUNX2 mRNA expression while modulating the Wnt‐signaling pathway. Subsequently, we observed a 2‐fold upregulation of Wnt5a expression in human macrophages treated with serum from patients with acute myocardial infarction. However, PPARγ‐signaling drives the secretion of Wnt‐inhibitors (Dkk1, sFRPs) in multiple cell types. This raises the question if PPARγ‐stimulation can limit the deleterious effects of pathologically activated Wnt‐signaling in VC by attenuating the osteogenic differentiation of VSMC. Thus, identification of the molecular pathways linking PPARγ‐and Wnt‐signaling may be of major clinical importance for the treatment of VC. Additionally, the existence of already registered PPARγ‐agonists could receive new clinical indications.MethodsHuman VSMC from abdominal aorta were differentiated to synthetic VSMC (PDGF‐BB 10 ng/ml, FCS 20%, 3 d) and calcified for 12 d (Pi, 2 mM; Cai, 3 mM, FCS 5%). THP‐1 cells derived M0‐macrophages (PMA, 150 nM, 24 h) were activated to M1‐macrophages (IFN‐γ, 20 ng/ml; LPS 10 ng/ml; 24 h). Cells were treated with a PPARγ‐agonist (Rosiglitazone, 10 μM) or PPARγ‐antagonist (GW9662, 10 μM) for 12 d (VSMC) or 24 h (macrophages).ResultsPPARγ‐stimulation decreased the expression of osteo‐chondrogenic genes (SOX9 −50%; RUNX2 −37%, P<0.01), WNT5A (−31%, P<0.05) and nuclear translocation of active β‐catenin (−20%, P<0.01), but not calcium‐deposition in calcifying, synthetic VSMC. The Wnt/β‐catenin‐Inhibitor DKK1 was increased (+46%, P<0.05) and blocking PPARγ increased calcium‐deposition (+78%, P<0.05). In M1‐macrophages, PPARγ was decreased (−73%, P<0.0001) and WNT5A increased (+424%, P<0.0001) while BMP2 was not affected. However, PPARγ‐stimulation reduced BMP2 mRNA expression (−29%, P<0.01).ConclusionsPPARó‐stimulation decreases mRNA expression of BMP2 in M1‐macrophages, which may prevent secretion while possibly reducing osteogenic differentiation of VSMC. Moreover, PPARγ‐stimulation attenuated Wnt5a‐ and Wnt/β‐catenin‐signaling by modulating DKK1 expression and translocation of active β‐catenin in synthetic, calcifying VSMC. Hence, these effects may attenuate the osteogenic differentiation of VSMC and subsequent calcification of atherosclerotic plaques.Support or Funding InformationThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No 722609.

A Wnt-BMP4 Signaling Axis Induces MSX and NOTCH Proteins and Promotes Growth Suppression and Differentiation in Neuroblastoma.

The Wnt and bone morphogenetic protein (BMP) signaling pathways are known to be crucial in the development of neural crest lineages, including the sympathetic nervous system. Surprisingly, their role in paediatric neuroblastoma, the prototypic tumor arising from this lineage, remains relatively uncharacterised. We previously demonstrated that Wnt/β-catenin signaling can have cell-type-specific effects on neuroblastoma phenotypes, including growth inhibition and differentiation, and that BMP4 mRNA and protein were induced by Wnt3a/Rspo2. In this study, we characterised the phenotypic effects of BMP4 on neuroblastoma cells, demonstrating convergent induction of MSX homeobox transcription factors by Wnt and BMP4 signaling and BMP4-induced growth suppression and differentiation. An immunohistochemical analysis of BMP4 expression in primary neuroblastomas confirms a striking absence of BMP4 in poorly differentiated tumors, in contrast to a high expression in ganglion cells. These results are consistent with a tumor suppressive role for BMP4 in neuroblastoma. RNA sequencing following BMP4 treatment revealed induction of Notch signaling, verified by increases of Notch3 and Hes1 proteins. Together, our data demonstrate, for the first time, Wnt-BMP-Notch signaling crosstalk associated with growth suppression of neuroblastoma.

The Regulation of Bone Morphogenetic Protein/Smads Signaling Pathway in Spinal Cord Injury

The incidence of spinal cord injury (SCI) increases year by year. SCI is characterized as high disability rate and poor prognosis. BMP/Smads signaling participates in the formation of osteoblasts and renal failure. This article will explore the regulation of BMP/Smads signaling pathway in SCI. Wistar rats were divided into control group; SCI group; and BMP-2 treatment group that were treated by tail vein injection of BMP-2 antisense oligonucleotide BMP-2 phosphorothioate AODN at 30 min after modeling. Real-time PCR and Western blot were used to detect BMP-2, Smad1, and Smad5 expressions. Hematoxylin-eosin (HE) staining was applied to analyze the change of SCI in each group. Immunohistochemistry (IHC) was selected to test BMPR Ia expression. Basso, Beattie Bresnahan-cocomotor rating scale (BBB) scale and Reuter score were compared. Enzyme-linked immunosorbent assay (ELISA) was adopted to detect TNF-α and Interleukin-2 (IL-2) expressions. Compared with the control group, BMP-2, Smad1, and Smad5 mRNA and protein expressions increased, BBB score declined, Reuter score elevated, and TNF-α and IL-2 secretion enhanced in the SCI group (P < 0.05). HE staining showed spinal cord injury, and IHC exhibited increased expression of BMPR Ia. The TGF-β treatment group significantly reduced the expressions of BMP-2, Smad1, and Smad5 mRNA and protein, increased BBB score, reduced Reuter score, and weakened the secretions of TNF-α and IL-2 (P < 0.05). HE staining demonstrated decreased reduction of spinal cord tissue and declined expression of BMPR Ia. SCI activated BMP/Smads signaling pathway, up-regulated BMPR Ia expression, and promoted inflammation. Regulation of BMP/Smads signaling pathway can downregulate BMPR Ia expression and inhibit inflammation to effectively relieve SCI.

Regenerative Effect of Resorbable Scaffold Embedded Boron-Nitride/Hydroxyapatite Nanoparticles in Rat Parietal Bone.

BN has important roles in several physiological events, including bone growth and immune system. New infection-free cranioplasty and has an osteogenic activities material that are compatible with tissue are being developed. We aimed in our study to examine whether different combinations of Boron-nitride/Hydroxyapatite are embedded into the scaffold in the treatment of calvarial defects. 200 adult female Sprague-Dawley rats divided into 10 equal groups. Osteotomy was made by trepan drill in 8 mm diameter. The scaffolds were placed in the rats and were left to recovery for 2 months. During the experiment, CT scans were taken from the calvarial areas of the rats in the 2nd, 4th and 8th weeks. Significant healing was observed in defect diameters in 2.5% BN+10% HA, 2.5% BN and 5% BN+10% HA, respectively. After 8 weeks, it was seen that the amounts of OPN, BMP-2, RunX2 and ALP mRNA expression significantly decreased in 2.5% BN+10% HA, 2.5% BN, 5% BN+10% HA and 5% BN groups. It was shown that bone recovery was at the best grade in the groups, which contained 2.5% BN and 2.5% BN+10% HA when compared to the other groups. BN is a very promising agent that will be used in reconstructive surgery for the treatment of calvarial bone defects.