Bone morphogenetic protein (BMP) homodimers are of significant osteoinductivity. However, their clinical application is limited because of high effective dosage. Recently, BMP heterodimers are reported to address the issue. This is a review of the researches on BMP heterodimers, including existent evidences, types and synthetic methods, biological activities in comparison to BMP homodimers and possible mechanisms, further research direction and future expectations.
Animals ; Biopolymers ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Protein 7 ; Bone Morphogenetic Proteins ; genetics ; pharmacology ; Humans ; Protein Multimerization

OBJECTIVETo investigate the effect of salvianolic-acid B (SA-B) on epithelia-mesenchymal transition in human renal proximal tubular cells (HK2), induced by transforming growth factor beta1 (TGF-beta1).

METHODEpithelia-mesenchymal transition (EMT) was induced with TGF-beta1 in HK2 cultured in vitro. Different concentrations (2, 5, 10, 20 microg x L(-1)) and stimulant periods (12, 24, 48 h) were tried to find the perfect condition for EMT. At the same time bone morphogenetic protein-7 (BMP-7, positive control) and the SA-B intervention were given to observe their effect on EMT. Western blot and immunofluorescent microscopy were used to analyze the expression of E-cadherin and alpha-smooth muscle actin (alpha-SMA) in HK2.

RESULTBMP-7 significantly inhibited the down-regulation of E-cadherin and the up-regulation of alpha-SMA induced by TGF-beta1 (P < 0.05), and SA-B significantly inhibited the up-regulation of alpha-SMA expression induced by TGF-beta1 (P < 0.05), but not the down-regulation of E-cadherin induced by TGF-beta1.

CONCLUSIONSA-B and BMP-7 can inhibit TGF-beta1-induced EMT in HK2. Their common role is to inhibit the up-regulation of alpha-SMA, and the effect of SA-B on the regulation of E-cadherin needs further study to be confirmed.

Benzofurans ; pharmacology ; Bone Morphogenetic Protein 7 ; pharmacology ; Cadherins ; metabolism ; Cell Differentiation ; drug effects ; Cell Line ; Epithelial Cells ; pathology ; Humans ; Mesoderm ; pathology ; Transforming Growth Factor beta1 ; pharmacology

OBJECTIVEThis study explored the dynamic expression of the E3 ubiquitin-protein ligase gene, Arkadia, in response to carbon tetrachloride (CCl4)-induced liver fibrosis in a mouse model and investigated the differential expression that occurs following treatment with the anti-fibrotic bone morphogenetic protein-7 (BMP-7).

METHODSThirty healthy male imprinting control region (ICR) mice were randomly assigned to three groups: normal (control; n = 6), CCl4-induced model group (model; n = 18), and CCl4-induced model with BMP-7 treatment group (treatment; n = 6). The model group was further divided into three subgroups (n = 6 each) for analysis at 4, 8 and 12 weeks after fibrosis induction. Liver fibrosis was induced by hypodermic injections of 60% CCl4 /peanut oil (5 mL/kg) to the hind legs of mice two-times per week in alternating legs for a period of 12 weeks. At week 9, the treatment group of CCl4-induced mice were given an intraperitoneal injection of BMP-7 (300 pg/g) simultaneously with that day's hypodermic injection of 60% CCl4 /peanut oil, and then every other day for a period of four weeks. The pathological changes in liver tissues were observed after staining with hematoxylin-eosin (HE) and Masson's trichrome. Messenger RNA (mRNA) and protein expression of Arkadia in liver were evaluated using reverse transcription-polymerase chain reaction and immunohistochemistry and Western blotting, respectively.

RESULTSMouse models of liver fibrosis were successfully established by CCl4 exposure. Arkadia, Smad7 and TGF-beta1 mRNA levels were up-regulated in the model group in a time-dependent manner (vs. control group), and BMP-7 treatment led to significant down-regulation of the CCl4-induced expression of the three genes (vs. control group: F = 812.80, 451.46, and 998.96, respectively; P less than 0.01). At week 12, the mRNA levels of Arkadia, Smad7, and TGF-b1 were significantly lower in the BMP-7 treatment group than in the model group (t = 12.108, 18.737, and 16.364, respectively; P less than 0.01). Arkadia, Smad7, and TGF-b1 protein staining was weak in the portal area of control liver tissue. In contrast, the model group showed significantly stronger staining for all three proteins in the portal area and in the cytoplasm of liver cells. The staining of Arkadia, Smad7, and TGF-b1 proteins was significantly lower in the treatment group (vs. control group: F = 8.399, 609.690, and 900.561, respectively; P < 0.01). At week 12, the protein levels of Arkadia, Smad7, and TGF-b1 were significantly lower in the treatment group than in the model group (t = 23.438, 11.667, and 42.889, respectively; P < 0.01).

CONCLUSIONArkadia expression gradually increased along with the development of liver fibrosis but was suppressed by treatment with the anti-fibrotic factor, BMP-7.

Animals ; Bone Morphogenetic Protein 7 ; pharmacology ; Liver ; metabolism ; Liver Cirrhosis, Experimental ; metabolism ; prevention & control ; Male ; Mice ; Mice, Inbred ICR ; Ubiquitin-Protein Ligases ; metabolism ; Up-Regulation

Pulp loss is accompanied by the functional impairment of defense, sensory, and nutrition supply. The approach based on endogenous stem cells is a potential strategy for pulp regeneration. However, endogenous stem cell sources, exogenous regenerative signals, and neovascularization are major difficulties for pulp regeneration based on endogenous stem cells. Therefore, the purpose of our research is to seek an effective cytokines delivery strategy and bioactive materials to reestablish an ideal regenerative microenvironment for pulp regeneration. In in vitro study, we investigated the effects of Wnt3a, transforming growth factor-beta 1, and bone morphogenetic protein 7 (BMP7) on human dental pulp stem cells (h-DPSCs) and human umbilical vein endothelial cells. 2D and 3D culture systems based on collagen gel, matrigel, and gelatin methacryloyl were fabricated to evaluate the morphology and viability of h-DPSCs. In in vivo study, an ectopic nude mouse model and an in situ beagle dog model were established to investigate the possibility of pulp regeneration by implanting collagen gel loading BMP7. We concluded that BMP7 promoted the migration and odontogenic differentiation of h-DPSCs and vessel formation. Collagen gel maintained the cell adhesion, cell spreading, and cell viability of h-DPSCs in 2D or 3D culture. The transplantation of collagen gel loading BMP7 induced vascularized pulp-like tissue regeneration in vivo. The injectable approach based on collagen gel loading BMP7 might exert promising therapeutic application in endogenous pulp regeneration.
Animals ; Bone Morphogenetic Protein 7/pharmacology* ; Cell Differentiation ; Cells, Cultured ; Collagen/pharmacology* ; Dental Pulp ; Dogs ; Endothelial Cells ; Gelatin ; Humans ; Methacrylates ; Mice ; Regeneration ; Stem Cells

OBJECTIVETo observe the effect of bone morphogenetic protein-7 (BMP-7) on aristolchic acid induced renal tubular epithelial cell trans-differentiation to look for new therapeutic approach for aristolchic acid nephropathy (AAN).

METHODSIn vitro cultured human proximal renal tubular epithelial cell line HK-2 cells were treated with different concentrations of BMP-7 (75 ng/mL, 150 ng/mL and 300 ng/mL) after trans-differentiation of the cells was induced by AA (10 microg/mL). Levels of alpha-SMA mRNA and protein expressions were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting respectively.

RESULTSBMP-7 reversed the AA inducing alpha-SMA expressions in HK-2 cells in a dose-dependent manner.

CONCLUSIONBMP-7 can inhibit the trans-differentiation of human renal tubular epithelial cell induced by AA, thereby might be a new potential drug for AAN prevention and treatment.

Actins ; metabolism ; Aristolochic Acids ; adverse effects ; Bone Morphogenetic Protein 7 ; pharmacology ; Cell Line ; Cell Transdifferentiation ; drug effects ; Epithelial Cells ; cytology ; Humans ; Kidney Tubules, Proximal ; cytology

OBJECTIVETo explore the role of bone morphogenetic protein-7 (BMP-7) in strontium ranelate (Sr)-induced osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs).

METHODSBMSCs were isolated from 4-week-old rats and cultured in vitro. The third or fourth passages of BMSCs were examined using alkaline phosphatase kit for changes in ALP activity in response to treatment with different concentrations of Sr. Calcium nodules in the induced cells were detected using alizarin red staining, and the cellular BMP-7 expression was detected by Western blotting.

RESULTSWithin the concentration range of 0.1-3.0 mmol/L, Sr dose-dependently increased ALP activity in rat BMSCs. ALP activity reached the highest level after treatment with 3 mmol/L Sr, which also significantly promoted the formation of calcium nodules. Within the range of 0.1-3.0 mmol/L, Sr dose-dependently enhanced the expression of BMP-7, and its peak expression occurred following 3 mmol/L Sr treatment. Noggin (100 ng/ml), an inhibitor of BMP-7, obviously suppressed Sr-induced over-expression of BMP-7 and reduced ALP activity and calcium nodule formation in the BMSCs.

CONCLUSIONSr promotes osteogenic differentiation of rat BMSCs by increasing the expression of BMP-7.

Animals ; Bone Density Conservation Agents ; pharmacology ; Bone Marrow Cells ; cytology ; Bone Morphogenetic Protein 7 ; genetics ; metabolism ; Cell Differentiation ; drug effects ; Cells, Cultured ; Female ; Male ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Organometallic Compounds ; pharmacology ; Osteoblasts ; cytology ; Osteogenesis ; drug effects ; Rats ; Thiophenes ; pharmacology

OBJECTIVETo evaluate the effects of retinoic acid (RA) on expression of bone morphogenetic protein 7 (BMP-7) in rat fetus with cleft palate, and the effects of RA on proliferation and apoptosis of osteoblasts.

METHODSAll-trans RA (ATRA) was used to induce congenital cleft palate in Wistar rat BMP-7 mRNA expression in maxillary bone tissue of fetal rats was measured by Northern blotting analysis. Flow cytometry and MTT assay were used to measure the apoptosis and proliferation of ATRA-treated MC-3T3-E1 cells. BMP-7 mRNA and protein expressions in ATRA-treated MC-3T3-E1 cells were detected by RT-PCR and Western blotting analysis.

RESULTSATRA could induce cleft palate of rat fetus. The incidence rate of cleft palate induced by 100 mg/kg AT-RA (45.5%) was significantly higher than 50 mg/kg ATRA (12.5%, P < 0.05). BMP-7 mRNA expression decreased in maxillary bone tissue of rat fetus with cleft palate. MC-3T3-E1 cells proliferation treated with 1 x 10(-6) mol/L ATRA decreased by 60%, the cell apoptosis increased by 2 times. BMP-7 mRNA and protein levels in MC-3T3-E1 cells treated with 1 x 10(-6) mol/L ATRA decreased by 60% and 80%, respectively, compared with ATRA-untreated cells (P < 0.05).

CONCLUSIONSBMP-7 may play an important role in embryonic palate development RA may possess the ability to down-regulate cell proliferation through regulation of BMP-7 gene expression.

3T3 Cells ; Animals ; Apoptosis ; drug effects ; Base Sequence ; Blotting, Northern ; Bone Morphogenetic Protein 7 ; genetics ; Cell Proliferation ; drug effects ; Cleft Palate ; genetics ; DNA Primers ; Down-Regulation ; drug effects ; Female ; Mice ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Tretinoin ; pharmacology

OBJECTIVETo observe the effect of bone morphogenetic protein-7 (BMP-7) on the transdifferentiation of cultured human tubular epithelial cell (HKC) induced by TGF-beta1 and to elucidate its possible mechanism.

METHODSThe cultured HKC cells were divided into 5 groups: serum-free group (negative control); single TGF-beta1 treated group (positive control); single BMP-7 treated group; combined TGF-beta1 and BMP-7 treated group; and BMP-7 pre-treated group. Expression of keratin of HKC cells was assessed by indirect enzyme immunohistochemistry (IEI), expression of alpha-smooth muscle actin (alpha-SMA) and E-cadherin by immunohistological method, percentage of alpha-SMA positive HKC cells by flow cytometry, and mRNA expression of alpha-SMA, TGF-beta1, and TGF-beta type II receptor by reverse transcription PCR.

RESULTSThe expression of alpha-SMA and the percentage of alpha-SMA positive HKC cells markedly increased after having been treated by TGF-beta1 while the expression of E-cadherin and keratin decreased. In the group pre-treated with BMP-7 (50 ng/ml) and then added with TGF-beta1 (8 ng/ml), expression of alpha-SMA was significantly lower than in the positive control group, while expression of E-cadherin and keratin significantly higher than in the positive control group. Measurement of the percentage of alpha-SMA positive HKC found significant deference between the combined TGF-beta1 and BMP-7 treated group and the positive control group (9.7% vs 19.8%; 5.8% vs 19.8%; P < 0.05). Significant difference existed between the BMP-7 (50 ng/ml) pre-treated group and the positive control group (8.7% vs 19.8%, P < 0.05). mRNA expression of alpha-SMA was measured by RT-PCR and the results showed that it significantly decreased in the group treated or pre-treated with BMP-7 (50 ng/ml) (15% and 12% of the results in the positive control group, respectively). The mRNA expression levels of both TGF-beta1 and its type II receptor significantly decreased (28% and 19%; 47% and 36%, compared with the positive control group, respectively).

CONCLUSIONTransdifferentiation of cultured renal epithelial cell induced by TGF-beta1 can be inhibittd by certain levels of BMP-7, cultured together with TGF-beta1 or pretreated. BMP-7 can prevent and inhibit the mRNA expression of TGF-beta1 and its type II receptor, which may be an important mechanism by which BMP-7 inhibit the transdifferentiation of renal tubular epithelial cell.

Actins ; biosynthesis ; genetics ; Bone Morphogenetic Protein 7 ; Bone Morphogenetic Proteins ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Epithelial Cells ; cytology ; Humans ; Kidney Tubules ; cytology ; metabolism ; Polymerase Chain Reaction ; RNA, Messenger ; biosynthesis ; genetics ; Transforming Growth Factor beta ; pharmacology ; Transforming Growth Factor beta1

BACKGROUNDBone morphogenetic protein (BMP) is a member of the superfamily of transforming growth factor-beta. Recent studies show that it is an indispensable factor in hematopoiesis. To better characterize the effect of recombinant human BMP (rhBMP)-2 in hematopoiesis, we set out to determine whether rhBMP-2 could promote the proliferation of mesenchymal stem cells (MSCs) and increase the levels of hematopoietic cytokines in MSCs.

METHODS2, 3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino) carbonyl)-2H-tetrazolium hydroxide (XTT), real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the effects of rhBMP-2 on the proliferation and hematopoietic cytokine levels of MSCs. In addition, MSCs marked with Hoechst33342 were transplanted into BALB/c mice by the intravenous route or intra-bone marrow transplantation, and cluster numbers were counted.

RESULTSThe XTT test revealed that rhBMP-2 significantly induced proliferation of MSCs in doses ranging from 10 ng/ml to 0.1 mg/ml in a dose-dependent manner. The experiments in vivo showed that there were more clusters of donor cells in bone marrow, spleen, liver and lung of the BMP group than those in the control group after both intra-bone marrow transplantation (P < 0.001, P < 0.001, P < 0.001, and P = 0.001, respectively) and intravenous transplantation (P < 0.001, P < 0.001, and P < 0.001 respectively). The results of real-time PCR and ELISA revealed that rhBMP-2 significantly increased mRNA expressions and protein levels of IL-6, IL-7, IL-11, G-CSF, M-CSF and SCF.

CONCLUSIONSThe treatment with rhBMP-2 promotes the proliferation of MSCs in vivo and in vitro and increases the levels of hematopoietic cytokines in MSCs, which may contribute to the improvement of hematopoietic function.

Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Enzyme-Linked Immunosorbent Assay ; Granulocyte Colony-Stimulating Factor ; genetics ; Humans ; Interleukin-11 ; genetics ; Interleukin-6 ; genetics ; Interleukin-7 ; genetics ; Macrophage Colony-Stimulating Factor ; genetics ; Mesenchymal Stromal Cells ; cytology ; drug effects ; metabolism ; Mice ; Mice, Inbred BALB C ; Polymerase Chain Reaction ; Recombinant Proteins ; pharmacology ; Stem Cell Factor ; genetics ; Transforming Growth Factor beta ; pharmacology

OBJECTIVETo study the effects of core proteoglycan on the transdifferentiation of human renal tubular epithelial cell induced by transforming growth factor beta1 (TGF-beta1) in vitro.

METHODThe cultured HK-2 cells were divided into six groups: A. negative control group; B. 10 ng/ml TGF-beta1 group; C. 10 ng/ml core proteoglycan treated group; D. 100 ng/ml core proteoglycan treated group; E. 10 ng/ml TGF-beta1 + 10 ng/ml core proteoglycan group; F. 10 ng/ml TGF-beta1 + 100 ng/ml core proteoglycan group. The changes in configuration of HK-2 cells were inspected 48 hours after adding the stimulating factor. At the same time, changes in mRNA of keratin, alpha-smooth muscle actin, vimentin were analyzed.

RESULTSCompared with group A, group B showed great changes in the morphology of cells, most cells converted into spindle shape, like fibroblast; groups E and F, especially group F showed significantly reduced spindle shape cells. Compared with group A, groups C and D had no significant changes in morphology of cells Compared with 10 ng/ml TGF-beta1 group and negative control, the mRNA expression of alpha-smooth muscle actin and vimentin had significant increase, but that of keratin reduced (P < 0.05). However, after combined treatment with TGF-beta1 and core proteoglycan, alpha-smooth muscle actin and vimentin expression were reduced significantly, while expression of keratin was up-regulated. Single core proteoglycan treated group and negative control group had no dramatic differences (P > 0.05).

CONCLUSIONTGF-beta1 can induce the transdifferentiation of human renal tubular epithelial cell and core proteoglycan has some inhibitory effect on transdifferentiation of human renal tubular epithelial cell induced by TGF-beta1 in vitro.

Actins ; physiology ; Bone Morphogenetic Protein 7 ; metabolism ; Cadherins ; metabolism ; Cell Differentiation ; drug effects ; physiology ; Cell Line ; Cell Shape ; Cell Transdifferentiation ; Cells, Cultured ; Connective Tissue Growth Factor ; pharmacology ; Epithelial Cells ; cytology ; drug effects ; physiology ; Fibroblasts ; drug effects ; pathology ; Humans ; Kidney ; pathology ; Kidney Tubules ; pathology ; Kidney Tubules, Proximal ; pathology ; Proteoglycans ; chemistry ; pharmacology ; Transforming Growth Factor beta ; genetics ; pharmacology ; Transforming Growth Factor beta1 ; chemistry ; pharmacology ; Vimentin ; metabolism