Enhanced yield of neuroepithelial precursors and midbrain-like dopaminergic neurons from human embryonic stem cells using the bone morphogenic protein antagonist noggin.

It is currently not known whether dopamine (DA) neurons derived from human embryonic stem cells (hESCs) can survive in vivo and alleviate symptoms in models of Parkinson disease (PD). Here, we report the use of Noggin (a bone morphogenic protein antagonist) to induce neuroectodermal cell development and increase the yield of DA neurons from hESCs. A combination of stromal-derived inducing activity and Noggin markedly enhanced the generation of neuroepithelial progenitors that could give rise to DA neurons. In addition, Noggin diminished the occurrence of a fibroblast-like Nestin-positive precursor population that differentiated into myocytes. After transplantation of differentiated hESCs to a rodent model of PD, some grafts contained human midbrain-like DA neurons. This protocol demonstrates hESC derivation and survival of human DA neurons appropriate for cell therapy in PD.     

自体骨、同种异体骨及骨形态发生蛋白重组骨治疗腰椎骨折

背景：骨形态发生蛋白重组骨是一种新型植骨材料,已逐步应用于临床,但在腰椎骨折植骨融合中效果仍少见报道。 目的：比较自体骨、同种异体骨及骨形态发生蛋白重组骨治疗腰椎骨折的疗效差异。 方法：选择2005年3月至2009年3月南阳医学高等专科学校附属第一医院收治的腰椎骨折患者78例,根据植骨材料不同随机分为3组,分别植入自体骨、同种异体骨、骨形态发生蛋白重组骨。 结果与结论：78例腰椎骨折患者均获24个月的随访。植骨后24个月JOA评分改善率骨形态发生蛋白植入组90%>自体骨植入组85%>同种异体骨植入组70%(P < 0.05);植骨后12,24个月,同种异体骨植入组Cobb角较其他2组和植骨后6个月增大(P < 0.05),较植骨前减小(P < 0.05);自体骨植入组与骨形态发生蛋白植入组相比,差异无统计学意义(P > 0.05);同种异体骨植入组植骨后各时间点骨融合率均低于其他2组(P < 0.05)。提示骨形态发生蛋白重组骨与自体骨应用于脊椎腰椎骨折近期疗效相似,均优于同种异体骨移植,骨形态发生蛋白重组骨在腰椎骨折脊柱融合快,效果更好,临床应用更有优势。     

Modulation of bone morphogenic protein signaling in T-cells for cancer immunotherapy

Abstract

Immunotherapy is becoming an increasingly attractive therapeutic alternative for conventional cancer therapy. In recent years Foxp3⁺ regulatory T-cells (T_R) were identified as the major obstacle to effective cancer immunotherapy. The abundance of these cells in peripheral blood is increased in patients with multiple types of cancer and their prevalence among tumor-infiltrating lymphocytes correlated with poor clinical prognosis. In contrast, removal or inactivation of T_R cells led to enhanced anti-tumor immune response and better efficacy of cancer vaccines. This study reports that Bone Morphogenic Protein Receptor 1α (BMPR1α, Alk-3) is expressed by activated effector CD4⁺ and T_R cells and modulates functions of both cell types. Bone Morphogenic Proteins (BMPs) belong to the transforming growth factor (TGF)-β family of cytokines that also include TGFβ and activins. BMPs play crucial roles in embryonic development, tissue differentiation and homeostasis, and development of cancer. It was demonstrated that BMPs and activins synergize with TGFβ to regulate thymic T-cell development, maintain T_R cells, and control peripheral tolerance. Inactivation of BMPR1α in T-cells results in impaired thymic and peripheral generation of T_R cells. BMPR1α-deficient activated T-cells produced a higher level of interferon (IFN)-γ than BMPR1α-sufficient T-cells. Moreover, transplanted B16 melanoma tumors grew smaller in mice lacking expression of BMPR1α in T-cells and tumors had few infiltrating T_R cells and a higher proportion of CD8⁺ T-cells than wild-type mice.     

The JAK/STAT pathway regulates proximo-distal patterning in Drosophila.

JAK/STAT signaling is thought to control growth and proliferation. However, here we show a novel role for this pathway in the patterning of Drosophila appendages. Loss of Stat92E function results mainly in ventralizations and multiplications of the proximo-distal axis in leg and antenna, primarily through the ectopic misexpression of wingless. We also show that the pathway ligand Unpaired is expressed in two domains in leg and antenna that abuts those of wingless and decapentaplegic. We report that JAK/STAT signaling represses both wingless and decapentaplegic, restricting them to their respective domains in leg and antenna. In a reciprocal manner, we show that wingless and decapentaplegic restrict unpaired to its two domains. Thus, a main function of the JAK/STAT pathway in leg and antennal development is to promote the formation of a single proximo-distal axis per disc by constraining the intersection of wingless and decapentaplegic to the center of the disc.     

Activin A maintains self-renewal and regulates fibroblast growth factor, Wnt, and bone morphogenic protein pathways in human embryonic stem cells

Human embryonic stem cells (hESCs) self-renew indefinitely while maintaining pluripotency. The molecular mechanism underlying hESCs self-renewal and pluripotency is poorly understood. To identify the signaling pathway molecules that maintain the proliferation of hESCs, we performed a microarray analysis comparing an aneuploid H1 hESC line (named H1T) versus euploid H1 hESC line because the H1T hESC line demonstrates a self-renewal advantage while maintaining pluripotency. We find differential gene expression for the Nodal/Activin, fibroblast growth factor (FGF), Wnt, and Hedgehog (Hh) signaling pathways in the H1T line, which implicates each of these molecules in maintaining the undifferentiated state, whereas the bone morphogenic protein (BMP) and Notch pathways could promote hESCs differentiation. Experimentally, we find that Activin A is necessary and sufficient for the maintenance of self-renewal and pluripotency of hESCs and supports long-term feeder and serum-free growth of hESCs. We show that Activin A induces the expression of Oct4, Nanog, Nodal, Wnt3, basic FGF, and FGF8 and suppresses the BMP signal. Our data indicates Activin A as a key regulator in maintenance of the stemness in hESCs. This finding will help elucidate the complex signaling network that maintains the hESC phenotype and function.     

Fgfr1 regulates patterning of the pharyngeal region

Development of the pharyngeal region depends on the interaction and integration of different cell populations, including surface ectoderm, foregut endoderm, paraxial mesoderm, and neural crest. Mice homozygous for a hypomorphic allele of Fgfr1 have craniofacial defects, some of which appeared to result from a failure in the early development of the second branchial arch. A stream of neural crest cells was found to originate from the rhombomere 4 region and migrate toward the second branchial arch in the mutants. Neural crest cells mostly failed to enter the second arch, however, but accumulated in a region proximal to it. Both rescue of the hypomorphic Fgfr1 allele and inactivation of a conditional Fgfr1 allele specifically in neural crest cells indicated that Fgfr1 regulates the entry of neural crest cells into the second branchial arch non-cell-autonomously. Gene expression in the pharyngeal ectoderm overlying the developing second branchial arch was affected in the hypomorphic Fgfr1 mutants at a stage prior to neural crest entry. Our results indicate that Fgfr1 patterns the pharyngeal region to create a permissive environment for neural crest cell migration.     

中国人胃癌骨形态发生蛋白3基因遗传的不稳定和甲基化

目的 探讨骨形态发生蛋白3(BMP3)基因遗传不稳定性及异常甲基化与胃癌进展的关系,为揭示BMP3基因作用机制和胃癌发生发展机制提供实验依据. 方法 采用聚合酶链反应-单链构象多态(PCR-SSCP)技术分析中国人胃癌BMP3基因D4S2922、 D4S2964位点微卫星不稳定性(MSI)和杂合性缺失(LOH);使用甲基化特异PCR法检测BMP3基因启动子的甲基化状况. 结果 在本实验中,50例胃癌标本BMP3基因微卫星位点MSI、 LOH的阳性率分别为16.00%和20.00%,并且LOH检出率在胃癌的TNM Ⅲ+Ⅳ期高于Ⅰ+Ⅱ期(P<0.01),并随淋巴转移的发生而增高(P<0.01).45例胃癌标本中BMP3基因启动子区域甲基化阳性率为64.44%,其检出率与胃癌分化程度、浆膜浸润、淋巴转移及TNM分期均无关.此外,MSI阴性组的甲基化阳性率为71.05%, 显著高于MSI阴性组的28.58%(P<0.05). 结论 BMP3基因遗传不稳定和启动子甲基化存在于胃癌的发生发展中.LOH多发生于胃癌的晚期阶段并赋予胃癌高侵袭、预后差的表型.BMP3基因启动子高甲基化可能是胃癌发生因素之一.     

Augmented autocrine bone morphogenic protein (BMP) 7 signaling increases the metastatic potential of mouse breast cancer cells

As malignant breast cancers progress, they acquire the ability to spread to other regions of the body, including bone and lung, but the molecular mechanism underlying the increase in metastatic potential is not fully understood. Here we studied murine 4T1E/M3 highly bone marrow metastatic breast cancer cells, which we established previously. These cells show upregulated expression of bone morphogenetic protein (BMP) 7 and BMP receptors, as well as augmented phosphorylation of Smad1/5/8. Both anchorage-independent cell growth measured in colony forming assays and cell migration measured in wound healing assays were suppressed in 4T1E/M3 cells following treatment with a neutralizing anti-BMP7 antibody or knockdown of BMP7 gene expression. In addition, metastasis of 4T1E/M3 cells to the spine and lung and intracellular levels of phosphorylated Smad1/5/8 were suppressed by knocking down BMP7. Conversely, overexpression of BMP7 in the weakly metastatic parental 4T1E cells augmented their anchorage-independent growth, migration and metastasis to spine and lung. Taken together, our results strongly suggest that augmented autocrine BMP7 signaling leads to increases in the anchorage-independent cell growth, migration and metastatic potential in our bone marrow metastatic breast cancer model.     

Activation of the mitogen-activated protein kinase pathway by bone sialoprotein regulates osteoblast differentiation

Bone sialoprotein (BSP) is an abundant protein in the extracellular matrix of bone that has been suggested to have several different physiological functions, including the nucleation of hydroxyapatite (HA), promotion of cell attachment and binding of collagen. Studies in our lab have demonstrated that increased expression of BSP in osteoblast cells can increase expression of the osteoblast-related genes Runx2 and Osx as well as alkaline phosphatase and osteocalcin and increase matrix mineralization. To determine the molecular mechanisms responsible for the BSP-mediated increase in osteoblastic differentiation, several functional domain mutants of BSP were expressed in primary rat bone osteoblastic cells, including the contiguous glutamic acid sequences (polyGlu) and the arginine-glycine-aspartic acid (RGD) motif. Markers of osteoblast differentiation, including matrix mineralization and alkaline phosphatase staining, were increased in cells expressing BSP mutants of the polyGlu sequences but not in cells expressing RGD-mutated BSP. We also determined the dependence on integrin-associated pathways in promoting BSP-mediated differentiation responses in osteoblasts by demonstrating the activation of focal adhesion kinase, MAP kinase-associated proteins ERK1/2, ribosomal s6 kinase 2 and the AP-1 protein cFos. Thus, the mechanism regulating osteoblast differentiation by BSP was determined to be dependent on integrin-mediated intracellular signaling pathways.     

Somatic frameshift mutations of bone morphogenic protein receptor 2 gene in gastric and colorectal cancers with microsatellite instability

Mounting evidence exists that perturbation of bone morphogenic protein (BMP) signaling is involved in cancer development, especially in gastrointestinal cancers. However, somatic mutations of the genes encoding BMP and BMP receptors have not yet been discovered in human cancer tissues. By analyzing a public database, we found that BMP receptor 2 (BMPR2) and BMP1 genes had mononucleotide repeats in their coding sequences that could be mutation targets in cancers with microsatellite instability (MSI). In this study, we analyzed the mutation of BMPR2 and BMP1 genes in gastric (GC) and colorectal cancers (CRC) with MSI [31 GC with high MSI (MSI-H), 13 GC with low MSI (MSI-L), 38 CRC with MSI-H and 15 CRC with MSI-L] by single-strand conformation polymorphism analysis and DNA sequencing. Overall, we found seven frameshift mutations in the BMPR2 gene, but not in the BMP1 gene. The mutations were an identical deletion mutation of one base in the repeats (c.1748delA) that would result in premature stops of the amino acid synthesis (p.Asn583ThrfsX44). The BMPR2 mutations were detected in 6.5% of GC and 13.2% of CRC with MSI-H. All the cancers with the BMPR2 mutation showed loss of BMPR2 expression. Our data indicate that frameshift mutation of BMPR2 gene occurs in GC and CRC with MSI-H, and suggest that the BMPR2 mutation might contribute to cancer pathogenesis by inactivating BMPR2-mediated BMP signaling.     

Loss of the Tg737 protein results in skeletal patterning defects.

Tg737 mutant mice exhibit pathologic conditions in numerous tissues along with skeletal patterning defects. Herein, we characterize the skeletal pathologic conditions and confirm a role for Tg737 in skeletal patterning through transgenic rescue. Analyses were conducted in both the hypomorphic Tg737(orpk) allele that results in duplication of digit one and in the null Tg737(delta2-3betaGal) allele that is an embryonic lethal mutation exhibiting eight digits per limb. In early limb buds, Tg737 expression is detected throughout the mesenchyme becoming concentrated in precartilage condensations at later stages. In situ analyses indicate that the Tg737(orpk) mutant limb defects are not associated with changes in expression of Shh, Ihh, HoxD11-13, Patched, BMPs, or Glis. Likewise, in Tg737(delta2-3betaGal) mutant embryos, there was no change in Shh expression. However, in both alleles, Fgf4 was ectopically expressed on the anterior apical ectodermal ridge. Collectively, the data argue for a dosage effect of Tg737 on the limb phenotypes and that the polydactyly is independent of Shh misexpression.     

Developmental patterning in chondrocytic cultures by morphogenic gradients: BMP induces expression of Indian hedgehog and Noggin

BACKGROUND: The maturation of chondrocytes is essential for endochondral bone formation. The Indian Hedgehog (Ihh) gene is expressed in prehypertropic chondrocytes and has been proposed to regulate chondrocyte maturation. While such secretary factors as PTHrP and BMP are thought to be involved in Ihh expression, the mechanism of the restricted expression of Ihh is not clear. RESULTS: Using primary chondrocytes, we have developed here a modified micromass culture (MM-C) system that allows the formation of concentration gradients of secreted factors, expressed either endogenously or retrovirally, from each of plural micromass cultures on a single plate. Using this system, we determined that chondrocytes create the inhibitory micro-environment, partly dependent on PTHrP secretion, for the Ihh expression. We also showed that retrovirally induced BMP-2 induces the expression of both Ihh and Noggin (encoding the BMP-inactivating protein), and we further present evidence that a negative-feedback loop involving Noggin might account for the precise localization of BMP signalling for Ihh induction. CONCLUSION: These results suggest that the expression of the Ihh gene in cartilage is regulated by several mechanisms that include the secretion of inhibitory factors (including PTHrP) and the negative-feed back loop formed by BMPs and Noggin.     

Role of Sonic hedgehog in patterning of tracheal-bronchial cartilage and the peripheral lung.

Sonic hedgehog (Shh) was conditionally deleted in respiratory epithelial cells of the embryonic lung in vivo. Deletion of Shh before embryonic day (E) 13.5 resulted in respiratory failure at birth. While lobulation was not perturbed, the lungs were hypoplastic, with reduced branching of peripheral lung tubules, evident from E13.5. Smooth muscle and endothelial cells were absent or reduced, the latter in relationship to the loss of peripheral lung parenchyma. Tracheal-bronchial ring abnormalities occurred when Shh was deleted between E8.5 and E12.5. Deletion of Shh later in gestation (after E13.5) caused mild abrogation of peripheral branching morphogenesis but did not disrupt tracheal-bronchial development. Defects in branching morphogenesis and vascularization seen in Shh null mutant (Shh(-/-)) mice were substantially corrected when SHH was ectopically expressed in the respiratory epithelium; however, peripheral expression of SHH failed to correct cartilage abnormalities in the trachea and bronchi, indicating a spatial requirement for SHH expression near sites of cartilage formation. Expression of SHH by the respiratory epithelium plays an important role in the patterning of tracheal-bronchial mesenchyme required for formation of cartilage rings in conducting airways. SHH regulates branching morphogenesis and influences differentiation of the peripheral lung mesenchyme required for formation of bronchial and vascular smooth muscle.     

骨形态发生蛋白9调控干细胞分化与骨再生

背景:骨形态发生蛋白9(bone morphogenetic protein 9,BMP9)具有很强的促进干细胞成骨分化的潜能.大量研究表明,BMP9可在动物体内促进骨缺损的修复.目的:探究BM P9调控干细胞分化的机制,讨论影响BMP9促进干细胞成骨分化的潜在因素以及BMP9在骨组织工程中的应用前景.方法:在PubM...     

Temporal and spatial regulation of bone morphogenetic protein signaling in late lung development.

Bone morphogenetic proteins (BMPs) play important roles in early lung development. No study to date has addressed a role for BMP signaling in late lung development. We describe changes in the expression and localization of BMP receptors (Bmpr1a, Bmpr1b, and Bmpr2) and Smad (Smad1, Smad4, Smad5, and Smad8) intracellular signaling proteins during the saccular and alveolarization stages of late lung development. BMP signaling, assessed by Smad1/5 phosphorylation, nuclear translocation, and induction of id1, id2, and id3 gene expression, was evident throughout late lung development. Our data indicate that BMP signaling is active during late lung development, and points to roles for the BMP system in septal and vascular development, and in the homeostasis of the epithelial layer of large conducting airways in the mature lung.