Heterotopic ossification after the use of recombinant human bone morphogenetic protein-7

AIM To present the incidence of heterotopic ossification after the use of recombinant human bone morphogenetic protein-7(rhB MP-7) for the treatment of nonunions.METHODS Bone morphogenetic proteins(BMPs) promote bone formation by auto-induction. Recombinant human BMP-7 in combination with bone grafts was used in 84 patients for the treatment of long bone nonunions. All patients were evaluated radiographicaly for the development of heterotopic ossification during the standard assessment for the nonunion healing. In all patients(80.9%) with radiographic signs of heterotopic ossification, a CT scan was performed. Nonunion site palpation and ROM evaluation of the adjacent jointswere also carried out. Factors related to the patient(age, gender), the nonunion(location, size, chronicity, number of previous procedures, infection, surrounding tissues condition) and the surgical procedure(graft and fixation type, amount of rhB MP-7) were correlated with the development of heterotopic ossification and statistical analysis with Pearsons χ~2 test was performed.RESULTS Eighty point nine percent of the nonunions treated with rh BMP-7, healed with no need for further procedures. Heterotopic bone formation occurred in 15 of 84 patients(17.8%) and it was apparent in the routine radiologi-cal evaluation of the nonunion site, in a mean time of 5.5 mo after the rh BMP-7 application(range 3-12). The heterotopic ossification was located at the femur in 8 cases, at the tibia in 6, and at the humerus in οne patient. In 4 patients a palpable mass was present and only in one patient, with a para-articular knee nonunion treated with rhB MP-7, the size of heterotopic ossification affected the knee range of motion. All the patients with heterotopic ossification were male. Statistical analysis proved that patient's gender was the only important factor for the development of heterotopic ossification(P = 0.007). CONCLUSION Heterotopic ossification after the use of rh BMP-7 in nonunions was common but it did not compromise the final clinical outcome in most cases, and affected only male patients.

Potential bone-inducing activity in vitro of recombinant human bone morphogenetic protein-7 from a CHO expression system

Objective: To express the recombinant human bone morphogenetic protein-7(rhBMP-7) in Chinese hamster ovary(CHO) cells, and to establish the in vitro biological activity assay of rhBMP-7.Methods: Human BMP-7 cDNA was subcloned into p114 mammalian expression vector and transfected to CHO cells by using the Lipofectamine 2000 transfection method. CHO cell supernatants were harvested and analyzed to identify the molecule mass of secreted rhBMP-7 and examine its biological activity in vitro to stimulate the synthesis of alkaline phophatase(ALP), a characteristic of osteoblast phenotypes. Results: rhBMP-7 was produced stably in CHO cells, as a processed mature disulfide-linked homodimer, with an apparent molecular mass of 36 000. Examination of the rhBMP-7 biological activity showed that rhBMP-7 specifically stimulated the production of ALP(4-fold increase at 100 ng of rhBMP-7/ml). Conclusion: The rhBMP-7 from CHO expression system has significant biological activity in induction of osteoblast phenotype, which demonstrates rhBMP-7 has the potential bone regeneration activity.

Exogenous bone morphogenetic protein-7 reduces hepatic fibrosis inSchistosoma japonicum-infected micevia transforming growth factor-β/Smad signaling

AIM: To investigate the antifibrotic effects of bone morphogenetic protein-7 (BMP-7) on Schistosoma japonicum (S. japonicum )-induced hepatic fibrosis in BALB/C mice. METHODS: Sixty BALB/C mice were randomly divided into three groups, including a control group (group A, n = 20), model group (group B, n = 20) and BMP-7 treated group (group C, n = 20). The mice in group B and group C were abdominally infected with S. japonicum cercariae to induce a schistosomal hepatic fibrosis model. The mice in group C were administered human recombinant BMP-7. Liver samples were extracted from mice sacrificed at 9 and 15 wk after modeling. Hepatic histopathological changes were assessed using Masson's staining. Transforming growth factor-beta 1 (TGF-β1), alpha-smooth muscle actin (α-SMA), phosphorylated Smad2/3 (pSmad2/3) and Smad7 protein levels and localization were measured by Western blotting and immunohistochemistry, respectively, and their mRNA expressions were detected by reverse transcriptionpolymerase chain reaction (RT-PCR). RESULTS: The schistosomal hepatic fibrosis mouse model was successfully established, as the livers of mice in group B and group C showed varying degrees of typical schistosomal hepatopathologic changes such as egg granuloma and collagen deposition. The degree of collagen deposition in group C was higher than that in group A (week 9: 22.95±6.66vs 2.02±0.76; week 15: 12.84±4.36 vs 1.74±0.80; P<0.05), but significantly lower than that in group B (week 9: 22.95±6.66 vs 34.43±6.96; week 15: 12.84±4.36 vs 18.90±5.07;P<0.05) at both time points. According to immunohistochemistry data, the expressions of α-SMA, TGF-β1 and pSmad2/3 protein in group C were higher than those in group A (α-SMA: week 9: 21.24±5.73 vs 0.33±0.20; week 15: 12.42±4.88 vs 0.34±0.27; TGF-β1: week 9: 37.00±13.74 vs 3.73±2.14; week 15: 16.71±9.80 vs 3.08±2.35; pSmad2/3: week 9: 12.92±4.81 vs 0.83±0.48; week 15: 7.87±4.09 vs 0.90±0.45; P<0.05), but significantly lower than those in group B (α-SMA: week 9: 21.24±5.73 vs 34.39±5.74; week 15: 12.42±4.88 vs 25.90±7.01; TGF-β1: week 9: 37.00±13.74 vs 55.66±14.88; week 15: 16.71±9.80 vs 37.10±12.51; pSmad2/3: week 9: 12.92±4.81 vs 19.41±6.87; week 15: 7.87±4.09vs 13.00±4.98;P<0.05) at both time points; the expression of Smad7 protein in group B was higher than that in group A and group C at week 9 (8.46±3.95 vs 1.00±0.40 and 8.46±3.95 vs 0.77±0.42; P<0.05), while there were no differences in Smad7 expression between the three groups at week 15 (1.09±0.38 vs 0.97±0.42 vs 0.89±0.39; P>0.05). Although minor discrepancies were observed, the results of RT-PCR and Western blotting were mainly consistentwith the immunohistochemical results. CONCLUSION: Exogenous BMP-7 significantly decreased the degree of hepatic fibrosis in both the acute and chronic stages of hepato-schistosomiasis, and the regulatory mechanism may involve the TGF-β/Smad signaling pathway.

Roles and regulation of bone morphogenetic protein-7 in kidney development and diseases

The gene encoding bone morphogenetic protein-7(BMP7) is expressed in the developing kidney in embryos and also in the mature organ in adults. During kidney development, expression of BMP7 is essential to determine the final number of nephrons in and proper size of the organ. The secreted BMP7 acts on the nephron progenitor cells to exert its dual functions: To maintain and expand the progenitor population and to provide them with competence to respond to differentiation cues, each relying on distinct signaling pathways. Intriguingly, in the adult organ, BMP7 has been implicated in protection against and regeneration from injury. Exogenous administration of recombinant BMP7 to animal models of kidney diseases has shown promising effects in counteracting inflammation, apoptosis and fibrosis evoked upon injury. Although the expression pattern of BMP7 has been well described, the mechanisms by which it is regulated have remained elusive and the processes by which the secretion sites of BMP7 impinge upon its functions in kidney development and diseases have not yet been assessed. Understanding the regulatory mechanisms will pave the way towards gaining better insight into the roles of BMP7, and to achieving desired control of the gene expression as a therapeutic strategy for kidney diseases.

Use of recombinant human bone morphogenetic protein-2 in spine surgery

Bone morphogenetic proteins are osteoinductive factors which have gained popularity in orthopaedicsurgery and especially in spine surgery. The use of recombinant human bone morphogenetic protein-2 has been officially approved by the United States Food and Drug Administration only for single level anterior lumbar interbody fusion, nevertheless it is widely used by many surgeons with off-label indications. Despite advantages in bone formation, its use still remains a controversial issue and several complications have been described by authors who oppose their wide use.

Construction of Adeno-associated Virus System for Human Bone Morphogenetic Protein 7 Gene

To construct the recombinant adeno-associated virus （rAAV） vector with human bone morphogenetic protein 7 （BMP7） and observe the BMP7 mRNA expression in vitro, BMP7 CDS sequence was cloned into expression plasmid pAAV-MCS of AAV Helper Free System. The recombinant plasmid was identified with enzyme digestion and sequencing. The recombinant plasmid, pAAV-RC, pHelper were co-transfected into AAV-293 cells according to the calcium phosphate-based protocol. The viral stock was collected by 4 rounds of freeze/thaw. After purified and concentrated, the recombinant virus titer was determined by dot-blot assay. HEK293 cells were transfected with the recombinant virus at different MOI, and the expression of BMP7 mRNA was detected by RT-PCR. The results showed rAAV-BMP7 was constructed and packaged successfully. The physical particle titer was 2.5×10^11 vector genomes/mL. There was different expression level of BMP7 mRNA after transfecton. These data suggested that recombinant AAV mediated a stable expression of hBMP7 mRNA in 293 cells. The AAV production method may pave the way of an effective strategy for the jaw bone defection around dental implants.

Bone morphogenetic protein-7 induced bone marrow stromal cells differentiate into neuron-like cells

Bone morphogenetic protein-7 is widely accepted as an inducer for bone marrow stem cells differentiating into osteoblasts and chondrocytes. Whether bone marrow stromal cells differentiate into neuron-like cells remains unclear. The current study examined the presence of positive cells for intermediate filament protein and microtubule associated protein-2 in the cytoplasm of bone marrow stromal cells induced by bone morphogenetic protein-7 under an inverted microscope, while no expression of glial fibrillary acidic protein was found. Reverse transcription PCR electrophoresis also revealed a positive target band for intermediate filament protein and microtubule-associated protein 2 mRNA. These results confirmed that bone morphogenetic protein-7 induces rat bone marrow stromal cells differentiating into neuron-like cells.

Implantation of xenogeneic bone combined with recombinant human bone morphogenetic protein-2 into bone defect—An scanning electron microscopic study

To determine the ability of a new type of composite xenogeneic bone grafting to repair bone defect. Methods: The new type of composite xenogeneic bone was obtained by combining the chemically treated cance1lous bone with recombinant human bone morphogenetic protein-2 (rhBMP-2). It was implanted on the bone defect of rabbit. Results: There was a large amount of new bone formation within the combined material and the amount was increasing as the time elapsed. In contrast, there was a lot of fibrous tissue with a little new bone formed on the area of the bone defect when the treated cancellous bone was implanted alone. Conclusion: The results imply that the rhBMP-2 plays a very important role in new bone formation and the composite xenogeneic bone appear to be an ideal material for repair of bone defect.

Molecular Cloning and Sequence Analysis of FullLength cDNA Encoding Human Bone Morphogenetic Protein—7

Objective:To clone the full-length human bane morphogenetic protein-7 (BMP-7 ) gene and analyse its sequence, to aid in investigation of its function and structure. Methods : Total RNA was isolated from Chinese fetal kidney by the acid gmnidinium thiocyanate phenol-chloroform method. Two overlapping segments of human BMP- 1 cDNA were obtained by reverse transcription (RT)-PCR. Following application, the two segments were ligated to each other and subcloned into POEM-T easy vector to form PEGM-T easy/hBMP-7 recombinant plasmid. Sanger dideoxy chain-termination method was used to sequence the cDNA. Results. There was 750 bp fragment obtained RT-PCR using #2 primer from 5' end of BMP-7 gene (PCR by using # 2 and # 1) ,and 540 bp fragment from 3' end was generated by KT-PCR using # 4 primer (PCR using # 3 and # 4). Full-length cDNA encoding BMP-7 was obtained by religation of two segments. When compared with hBMP-7 sequence in Gene bank (XM30619) ,our full-length BMP-7 cDNA has a G instead of a T at nucleotide 862. This change results in valine substituting for phenylalanine in the protein. Conclusion. This is the first time that BMP-7 cDNA was successfully cloned from Chinese fetal kidney. BMP-7 cDNA plays an important role in healing injuries of the osteo-articular system. This makes BMP-7 is an attractive target far various clinical applications.

Bone morphogenetic protein-4 affects both trophoblast and non-trophoblast lineage-associated gene expression in human embryonic stem cells

Human embryonic stem cells (hESC) can be induced to differentiate to trophoblast by bone morphogenetic proteins (BMPs) and by aggregation to form embryoid bodies (EB), but there are many differences and controversies regarding the nature of the differentiated cells. Our goals herein were to determine if BG02 cells form trophoblast-like cells (a) in the presence of BMP4-plus-basic fibroblast growth factor (FGF-2) and (b) upon EB formation, and (c) whether the BMP4 antagonist noggin elicits direct effects on gene expression and hormone production in the cells. Transcriptome profiling of hESC incubated with BMP4/FGF-2 showed a down-regulation of pluripotency-associated genes, an up-regulation of trophoblast-associated genes, and either a down-regulation or no change in gene expression for many markers of the three embryonic germ layers. Yet, there was up-regulation of several genes associated with mesoderm, ectoderm, and endoderm, strongly suggesting that differentiation to trophoblast-like cells under the conditions used does not yield a homogeneous cell type. Several genes, heretofore unreported, were identified that are altered in hESC in response to BMP4-mediated differentiation. The production of human chorionic gonadotropin (hCG), progesterone, and estradiol in the differentiated cells confirmed that trophoblast-like cells were obtained. Gene expression by EB was characterized by an up-regulation of a number of genes associated with trophoblast, ectoderm, endoderm, and mesoderm, and the production of hCG and progesterone confirmed that trophoblast-like cells were formed. These results suggest that, in the presence of FGF-2, BG02 cells respond to BMP4 to yield trophoblast-like cells, which are also obtained upon EB formation. Thus, BMP4-mediated differentiation of hESC represents a viable cell system for studying early developmental events post-implantation;however, up-regulation of non-trophoblast genes suggests a somewhat diverse response to BMP4/FGF-2. Noggin altered the transcription of a limited number of genes but, not surprisingly, did not lead to secretion of hormones.

The Use of Bone Morphogenetic Protein-7 and Resveratrol in Collagen Type II of Articular Cartilage

This study aimed to investigate the effects of resveratrol and bone morphogenetic protein 7 on type II collagen from superficial and middle zone of porcine articular chondrocytes. Articular cartilage was isolated from dissected porcine knee joint n = 12. Isolated cells were plated as monolayers at a density of 1 × 105 cells/well in 12-well culture plates and incubated at 37℃ in a humid atmosphere of 5% carbon dioxide and 95% air. Cell cultures were treated for four days with various concentrations of bone morphogenetic protein-7 and resveratroL Cells were then collected and analysed for collagen type II expression by real time polymerase chain reaction and protein level quantification by enzyme-linked immunosorbent assay. Cartilage tissue sections were localised for collagen type II by immunohistochemistry. Moreover, resveratrol and bone morphogenetic protein-7 effects on cartilage matrix contents were analysed by histology. Resveratrol and bone morphogenetic protein-7 stimulates expression of collagen type II mRNA and protein level accumulation in the surface zone and middle zone at 50μM ＋ 300 ng/ml （RSV ＋ BMP-7）. Immunohistochemistry results confirmed the presence of collagen type II on articular cartilage. Histological tissue sections confirmed that chondrocytes were obtained from different zones of articular cartilage. The study suggests that a combination of bone morphogenetic protein-7 and resveratrol up-regulate the expression and synthesis of collagen type II.

Expression of mature peptide of human bone morphogenetic protein-2 in Escherichia coli

To express die mature peptide of human bone morphogenetic protein-2 in Escherichia coil. Methods: TheDNA fragment encoding the mature peptide of human bone morphogenetic protein-2 (hBMP-2m) was inserted into expression vectorpDH in which foreign gene was controlled by PRPL promoters. E. coli DH5a transformed with recombinant plasmid pDHB2m wasinduced at 42℃to express the target protein. The expressed product was partially purified and refolded, and then implanted intorat thigh muscles to assay its bone inductive activity. Results: After induction, a protein band on SDS-PAGE gel with an apparentmol. wt. of 13kD was observed to anticipate in the strain carrying pDHB2m, but not in the control. The expressed hBMP-2m accounted for 45%-60% of the total bacterial protein. The expressed product existed in a form of inclusion body. After partially purified and refolded, rhBMP-2m could induce the formation of cartilage and bone tissue heterotopically. Conclusion: The maturepeptide of human bone morphogenetic protein-2 has ben successfully expressed in E. coli and the product has ectopic bone inductive activity.

Regulating the bioactivity of non-glycosylated recombinant human bone morphogenetic protein-2 to enhance bone regeneration

Recombinant human bone morphogenetic protein-2(rhBMP-2)is the predominant growth factor that effectively induces osteogenic differentiation in orthopedic procedures.However,the bioactivity and stability of rhBMP-2 are intrinsically associated with its sequence,structure,and storage conditions.In this study,we successfully determined the amino acid sequence and protein secondary structure model of non-glycosylated rhBMP-2 expressed by an E.coli expression system through X-ray crystal structure analysis.Furthermore,we observed that acidic storage conditions enhanced the proliferative and osteoinductive activity of rhBMP-2.Although the osteogenic activity of non-glycosylated rhBMP-2 is relatively weaker compared to glycosylated rhBMP-2;however,this discrepancy can be mitigated by incorporating exogenous chaperone molecules.Overall,such information is crucial for rationalizing the design of stabilization methods and enhancing the bioactivity of rhBMP-2,which may also be applicable to other growth factors.

人重组骨形态发生蛋白7通过下调半胱氨酸蛋白酶-1/焦孔素D信号通路抑制高糖诱导的近曲小管上皮细胞的焦亡

目的 观察人重组骨形态发生蛋白-7(recombinant human bone morphogenetic protein-7,rhBMP-7)对高糖诱导的人肾皮质近曲小管上皮细胞(human kidney-2,HK-2)的焦亡和炎症反应的作用。方法 体外培养高糖(high glucose,HG)刺激的HK-2细胞模拟糖尿病肾病模型。分为正常浓度葡萄糖对照组(Control)、高浓度葡萄糖组(HG)、Control+rhBMP-7组、HG+rhBMP-7组。采用免疫荧光方法检测HK-2细胞中E-钙黏蛋白(E-cadherin)、α平滑肌肌动蛋白(α-smooth muscle actin, α-SAM)、焦孔素D(gasderminD, GSDMD)蛋白和焦孔素E(gasderminE, GSDME)蛋白;TUNEL染色检测细胞死亡情况;蛋白质印迹法检测各组HK-2细胞中焦亡相关蛋白半胱氨酸蛋白酶-1(caspase-1)、半胱氨酸蛋白酶-4(caspase-4)、半胱氨酸蛋白酶-5(caspase-5)、 N-GSDMD和GAPDH的表达;酶联免疫吸附试验(enzyme linked immunosorbent assay,ELISA)检测各组HK-2细胞培养上清液中炎症因子白细胞介素-18(interleukin-18,IL-18)和白细胞介素-1β(interleukin-1β,IL-1β)的表达。结果 与Control组相比,高糖组HK-2细胞Tunel染色的阳性率明显增加,差异具有统计学意义(P<0.000 1),α-SMA蛋白和α-SMA mRNA表达量也显著增加(P<0.000 1),E-cadherin蛋白和Ecadherin mRNA表达量显著下降(P=0.000 6,P<0.000 1);HG组添加rhBMP-7后α-SMA蛋白和m RNA水平显著下降(P=0.011 7, P=0.002), E-cadherin蛋白和m RNA水平明显升高(P=0.001 5,P<0.000 1)。与对照组比较,HG组HK-2细胞GSDME/GSDMD蛋白的荧光信号明显增强。进而,HG组添加rhBMP-7后GSDME/GSDMD蛋白荧光信号显著减弱。同样,HG组HK-2细胞中焦亡相关蛋白caspase-1、caspase-4、caspase-5以及GSDMD的表达量显著高于对照组,差异明显(均P<0.001)。HG组添加rhBMP-7后焦亡相关蛋白的表达明显下降(分别P<0.001,P=0.002,P<0.001)。与对照组比较,HG组HK-2细胞培养上清液中IL-1β和IL-18蛋白浓度显著增加(均P<0.001)。进而导致rhBMP-7干预后HG组细胞上清液中IL-10和IL-1β蛋白浓度明显减少(P<0.001)。结论 rhBMP-7具有抑制HK-2细胞焦亡的作用,其通过调控caspase-1/GSDMD信号通路减缓高糖诱导的HK-2细胞焦亡。

Therapeutic effects of human umbilical cord-derived mesenchymal stem cells against acute tubular necrosis quantified through measures of iNOS, BMP-7 and Bcl-2

Introduction: Acute tubular necrosis (ATN) is the most prevalent cause of acute renal failure (ARF). Mesenchymal stem cell transplantation has been studied as a potential treatment for renal dysfunction due to ATN. Inducible nitric oxide synthase (iNOS), bone morphogenetic protein-7 (BMP-7) and B-cell lymphoma 2 (Bcl-2) are surrogate markers of renal tubular epithelial regeneration and subsequent recovery of renal function following ATN. Methods: Serum creatinine (Scr) and blood urea nitrogen (BUN), as well as expression of iNOS, BMP-7 and Bcl-2 in gentamycin-induced ATN rat kidneys was investigated after human umbilical cord-derived mesenchymal stem cell (HUC-MSC) transplantation. Immunohistochemical staining was performed in 3 groups of rats: gentamycin-induced ATN treated with HUC-MSC, gentamycin-induced ATN without HUC-MSC, and untreated rats not receiving any treatments. Results: HUC-MSC transplantation led to a reduction in Scr and BUN in the kidneys of rats with gentamycin-induced ATN. Expression of iNOS in the HUC-MSC treated group occurred later and the expression levels were much lower during gentamycin-induced ATN compared to rats with ATN that were not treated with HUC-MSC. The expression of BMP-7 and Bcl-2 in the MSC-transplanted group was significantly increased compared to both control groups of rats with injured and healthy renal tubules. Conclusions: HUC-MSCs induce renal protection in a rat model of gentamycin-induced ATN, which is associated with reduced iNOS expression and up-regulation of Bcl-2 and BMP-7.

Reconstruction of orbital defect in rabbits with composite of calcium phosphate cement and recombinant human bone morphogenetic protein-2

Background Calcium phosphate cement （CPC） is a biocompatible and osteoconductive bone substitute, and recombinant human bone morphogenetic protein-2 （rhBMP-2） has strong osteoinductibility, therefore we developed a composite bone substitute with CPC and rhBMP-2 and evaluate its reconstruction effect in rabbit orbital defect.Methods Thirty-six rabbits were randomly divided into two groups and a 5 mmx5 mmx2 mm bone defect in the infraorbital rim was induced by surgery in each orbit （72 orbits in all）. The orbital defects were treated with pure CPC or composite of CPC and rhBMP-2. The osteogenesis ability of different bone substitute was evaluated by gross observation, histological examination, histomorphometrical evaluation, compressive load-to-failure testing, and scanning electron microscope （SEM）.Results Gross observation showed that both bone substitutes were safe and effective for reconstruction of orbital defect. However, histological examination, histomorphometrical evaluation and SEM showed that CPC/rhBMP-2 group had faster speed in new bone formation and degradation of substitute material than CPC group. Compressive load-to-failure testing showed that CPC/rhBMP-2 group had stronger compressive strength than CPC group at every stage with significant difference （P ＜0.05）.Conclusion Composite of CPC/rhBMP-2 is an ideal bioactive material for repairing orbital defect, with good osteoconductibility and osteoinductibility.

The use of recombinant human bone morphogenetic protein-2 （rhBMP-2） in maxillofacial trauma

In recent years, recombinant human bone morphogenetic protein-2 （rhBMP-2） has been introduced as a therapeutic option in the treatment of several congenital and acquired craniofacial defects. Although there have been promising clinical results, the international literature still lacks complete guidelines, including limits and indications for the use of rhBMP-2. The possible indications for rhBMP-2 in patients undergoing facial trauma are discussed in this article.

芪蛭降糖胶囊对糖尿病肾病大鼠肾组织BMP-7及TGF-β_1/smads信号传导通路的影响

目的：观察芪蛭降糖胶囊对糖尿病肾病（diabetic nephropathy,DN）大鼠肾组织骨形成蛋白-7（bone morpho-genetic protein-7,BMP-7）及转化生长因子（transforming growth factor,TGF）-β1/Smads信号传导通路的影响。方法：48只清洁级雄性Wistar大鼠按体重随机抽取40只,采用切除右肾加腹腔注射链脲菌素（ streptozotocin,STZ）的方法制备DN模型,另外8只大鼠行右肾假切术。造模成功后按尿微量白蛋白（ microAlbumin,mAlb）高低,两头随机抽取分为模型组、缬沙坦对照组、芪蛭降糖胶囊低剂量组、芪蛭降糖胶囊高剂量组。成模2 d起各组给予相应浓度和剂量的药物,给药12周时观察DN大鼠尿mAlb、α1微球蛋白（α1-MG）和血清肌酐（ Scr）、尿素氮（ BUN）。然后,处死所有动物,肾组织行HE染色、PAS染色和Masson染色,观察肾组织病理变化并半定量计算肾小管损伤指数（tubulointerstitial injury index,TII）,免疫组化法检测BMP-7、TGF-β1、Smad2、Smad7在肾组织的表达。结果：给药12周后,模型组大鼠尿 mAlb、α1-MG较假手术组显著增多（ P 〈0.01）,3个治疗组DN大鼠尿mAlb、α1-MG较模型组明显减少（P〈0.01）,2个中药治疗组的上述4项指标亦较对照组降低（P〈0.05-0.01）,且呈剂量依赖性。模型组大鼠Scr、BUN亦较假手术组显著升高（P〈0.01）,对照组与模型组相比无明显变化（P〉0.05）,但2个中药治疗组较模型组明显降低（P〈0.05-0.01）。 HE染色显示,3个治疗组大鼠肾组织病理损害明显减轻,2个中药治疗组大鼠肾组织病理改善比对照组更明显；PAS染色进行TII评分发现,3个治疗组大鼠TII显著低于模型组（P〈0.01）,2个中药治疗组TII明显低于对照组（P〈0.05-0.01）；Masson染色观察发现,3个实验组大鼠肾小管间质病变明显轻于模型组,2个中药治疗组大鼠肾小管间质病变轻于对照组；免疫组化法染色并对其灰度值测定发现,3个治疗组大鼠TGF-β1、Smad2在肾组织的表达低于模型组（P〈0.01）,2个中药治疗组大鼠TGF-β1、Smad2在肾组织的表达低于对照组（P〈0.05-0.01）；3个治疗组大鼠BMP-7、Smad7在肾脏组织的表达高于模型组（P〈0.01）,2个中药治疗组大鼠BMP-7、Smad7在肾组织的表达高于对照组（P〈0.05-0.01）。结论：芪蛭降糖胶囊可能通过干预BMP-7/TGF-β1/Smads信号转导通路抑制了TGF-β1信号的细胞内转导,而对DN肾间质纤维化起到治疗作用。

人骨形态发生蛋白7(hBMP7)在毕赤酵母中的分泌表达

依据酵母密码子使用偏好性,利用重叠延伸PCR(OE-PCR)介导的定点突变方法,对人骨形态发生蛋白-7(human Bone Morphogenetic Protein-7,hBMP7)成熟肽编码序列进行改造,将毕赤酵母低频使用的精氨酸密码子CGG或CGA突变为高频使用的同义密码子AGA,明显提高了hBMP7成熟肽在毕赤酵母中的表达量摇瓶培养表达量为25.45mg/L,是改造前序列的4.6倍;TricineSDS-PAGE及Western-blotting结果表明,rhBMP7成熟肽分子量为18kD,以单体形式存在,具有良好的免疫原性;利用梯度浓度G418筛选到一株高拷贝整合的转化子,该转化子摇瓶表达量为45.45mg/L,约为单拷贝转化子的2倍。表达上清经阳离子交换介质SPSepharoseR○FastFlow纯化后,目的蛋白纯度达到90%。纯化后的样品与I型胶原混合冻干后埋植于小鼠股部肌袋内,能异位诱导间充质细胞分化形成软骨细胞。