Effect of bone morphogenetic protein signaling on development of the jaw skeleton

Bone morphogenetic proteins (BMPs) regulate many aspects of development including skeletogenesis. Here, we examined the response of neural crest‐derived cells to ectopic BMP signaling by infecting avian embryos with retroviruses encoding Bmp‐2 or Bmp‐4 at various times of development. Infection at stages 10 and 15 transformed large areas of the skull into cartilage by day 13. At this time cartilage condensations were still forming, which revealed the presence of uncommitted mesenchymal cells. By day 19, hypertrophic chondrocytes were present in the cartilage possibly due to changes in the perichondrium that relieved repression on hypertrophy. While these cells expressed Sox9, Collagen‐2, Runx2, Ihh, Noggin, and Collagen‐10, cartilage was not replaced by bone. Whether this is an intrinsic property of the skull cartilage, or results from sustained Bmp signaling is not known. Developmental Dynamics 237:3727–3737, 2008. © 2008 Wiley‐Liss, Inc.     

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.     

ADAMTS1 and MMP1 proteolytically engage EGF-like ligands in an osteolytic signaling cascade for bone metastasis

Bone metastasis is mediated by complex interactions between tumor cells and resident stromal cells in the bone microenvironment. The functions of metalloproteinases in organ-specific metastasis remain poorly defined despite their well-appreciated role in matrix degradation and tumor invasion. Here, we show a mechanism whereby two distinct metalloproteinases, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS1) and matrix metalloproteinase-1 (MMP1), orchestrate a paracrine signaling cascade to modulate the bone microenvironment in favor of osteoclastogenesis and bone metastasis. Proteolytic release of membrane-bound epidermal growth factor (EGF)-like growth factors, including Amphiregulin (AREG), heparin-binding EGF (HB-EGF), and transforming growth factor α (TGFα) from tumor cells suppress the expression of osteoprotegerin (OPG) in osteoblasts and subsequently potentiate osteoclast differentiation. EGF receptor (EGFR) inhibitors block osteolytic bone metastasis by targeting EGFR signaling in bone stromal cells. Furthermore, elevated MMP1 and ADAMTS1 expression is associated with increased risk of bone metastasis in breast cancer patients. This study established MMP1 and ADAMTS1 in tumor cells, as well as EGFR signaling in osteoblasts, as promising therapeutic targets for inhibiting bone metastasis of breast cancer.     

DNA sensing and associated type 1 interferon signaling contributes to progression of radiation-induced liver injury

Liver damage upon exposure to ionizing radiation (IR), whether accidental or therapeutic, can contribute to liver dysfunction. Currently, radiotherapy (RT) is used for various cancers including hepatocellular carcinoma (HCC); however, the treatment dose is limited by radiation-induced liver disease (RILD) with a high mortality rate. Furthermore, the precise molecular mechanisms of RILD remain poorly understood. Here, we investigated RILD pathogenesis using various knockout mouse strains subjected to whole-liver irradiation. We found that hepatocytes released a large quantity of double-stranded DNA (dsDNA) after irradiation. The cGAS-STING pathway in non-parenchymal cells (NPCs) was promptly activated by this dsDNA, causing interferon (IFN)-I production and release and concomitant hepatocyte damage. Genetic and pharmacological ablation of the IFN-I signaling pathway protected against RILD. Moreover, clinically irradiated human peri-HCC liver tissues exhibited substantially higher STING and IFNβ expression than non-irradiated tissues. Increased serum IFNβ concentrations post-radiation were associated with RILD development in patients. These results delineate cGAS-STING induced type 1 interferon release in NPCs as a key mediator of IR-induced liver damage and described a mechanism of innate-immunity-driven pathology, linking cGAS-STING activation with amplification of initial radiation-induced liver injury.     

软骨下骨局部注射常山酮抑制转化生长因子β1信号通路缓解犬骨关节炎

文题释义： Micro-CT：即微型计算机断层扫描,遵循的是与用于医疗的计算机断层扫描相同的原理,但可提供更高分辨率,Micro-CT和高分辨率外周定量计算机断层扫描系统是目前最有用的且拥有高分辨率的骨小梁和皮质骨超微结构成像,目前用于评估骨形态特征,作为传统组织学分析的补充替代方案。 X型胶原蛋白α1链(COL10A1)：为X型胶原蛋白的特异性裂解片段,X型胶原蛋白是软骨细胞肥大分化的典型标志,在骨关节炎进展过程中,软骨细胞肥大及其合成的促炎细胞因子助软骨破坏。 背景：研究表明随着破骨细胞骨吸收的增加,过度激活了的转化生长因子β1使骨吸收和骨形成解偶联,最终导致骨关节炎动物模型中软骨下骨的硬化表型,且可通过抑制转化生长因子β1信号传导减弱骨关节炎的进展。 目的：检测前十字韧带横切比格犬骨关节炎模型中局部注射常山酮是否可以延缓骨关节炎进展。 方法：将18只雄性比格犬分为假手术(对照组)、骨性关节炎组及治疗组,后两组通过前十字韧带横切构建骨关节炎模型,治疗组造模后于软骨下骨局部注射常山酮37.8 ng。在造模术后4,8,12,16周纵向测量血清Ⅱ型胶原C端肽(CTX-Ⅱ)和X型胶原蛋白α1链血清标志物的水平;术后16周Micro-CT扫描观察软骨下骨微结构;番红固绿染色及OARSI-Modified Manking评分评估关节软骨退变程度;免疫组织化学染色对比转化生长因子β1、基质金属蛋白酶13的表达情况。实验方案经新疆医科大学第一附属医院动物实验伦理委员会批准(批准号为IACUC20160304-07)。 结果与结论：①造模后8,12周,骨关节炎组X型胶原蛋白α1链水平高于治疗组和对照组(均P < 0.01);②造模后8,12,16周,骨关节炎组CTX-Ⅱ水平均高于对照组和治疗组(均P < 0.05);③骨关节炎组软骨下骨的骨体积分数较治疗组和对照组增加,骨小梁分离度降低,骨小梁模式因子减小(均P < 0.05);④骨关节炎组OARSI-Modified Manking评分较对照组和治疗组更高(均P < 0.01);⑤骨关节炎组基质金属蛋白酶13及转化生长因子β1的表达量较对照组和治疗组更高(均P < 0.01);⑥对照组与治疗组上述各指标比较差异均无显著性意义(均P > 0.05);⑦结果说明,局部注射常山酮可通过抑制软骨下骨中异常升高的转化生长因子β1,阻断异常骨重塑来减轻前十字韧带横切诱导的骨关节炎,表明这可能是骨关节炎的一种新的治疗选择。 ORCID: 0000-0003-1388-5541(任姜栋) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Facial surface analysis by 3D laser scanning and geometric morphometrics in relation to sexual dimorphism in cerebral--craniofacial morphogenesis and cognitive function

Over early fetal life the anterior brain, neuroepithelium, neural crest and facial ectoderm constitute a unitary, three-dimensional (3D) developmental process. This intimate embryological relationship between the face and brain means that facial dysmorphogenesis can serve as an accessible and informative index of brain dysmorphogenesis in neurological and psychiatric disorders of early developmental origin. There are three principal challenges in seeking to increase understanding of disorders of early brain dysmorphogenesis through craniofacial dysmorphogenesis: (i) the first, technical, challenge has been to digitize the facial surface in its inherent three-dimensionality; (ii) the second, analytical, challenge has been to develop methodologies for extracting biologically meaningful shape covariance from digitized samples, making statistical comparisons between groups and visualizing in 3D the resultant statistical models on a 'whole face' basis; (iii) the third, biological, challenge is to demonstrate a relationship between facial morphogenesis and brain morphogenesis not only in anatomical-embryological terms but also at the level of brain function. Here we consider each of these challenges in turn and then illustrate the issues by way of our own findings. These use human sexual dimorphism as an exemplar for 3D laser surface scanning of facial shape, analysis using geometric morphometrics and exploration of cognitive correlates of variation in shape of the 'whole face', in the context of studies relating to the early developmental origins of schizophrenia.     

High bone mass due to novel LRP5 and AMER1 mutations

WNT signaling is a key regulator of bone metabolism and its increased or decreased activity leads to skeletal disorders. Here we describe two patients with high bone mass (HBM) caused by novel mutations in two different WNT pathway components.The first patient is a 53-year-old male with HBM. He was diagnosed at adult age based on significantly increased bone mineral density (BMD). He has undergone several surgeries due to excessive bone in ear canals, bilateral jaw exostoses and mandibular tori. Radiographs show severe cortical thickening of cranial and long bones. Sanger sequencing identified a novel heterozygous mutation c.592A>T (p.N198Y) in LRP5 (Low-density lipoprotein receptor-related protein 5). The second patient, an adolescent female, was diagnosed with skeletal dysplasia in early childhood. She had macrocephaly (head circumference +6.0 SD), facial dysmorphism, delayed motor development, laryngomalasia and epilepsy. Radiographic findings were consistent with osteopathia striata with cranial sclerosis. A novel heterozygous frameshift mutation c.655del (p.E219Rfs*63) in AMER1 (APC Membrane Recruiting Protein 1) was identified. Although both mutations are predicted to lead to increased WNT signaling with a consequent increase in bone formation, the resulting phenotypes are different; cranial sclerosis versus macrocephaly, long bone cortical thickening versus vertical striations and discordant neurological development. This report underscores the diversity of genotypes and phenotypes of HBM and facilitates their differential diagnosis.     

Epidermal growth factor receptor signalling contributes to osteoblastic stromal cell proliferation, osteoclastogenesis and disease progression in giant cell tumour of bone

Balla P, Moskovszky L, Sapi Z, Forsyth R, Knowles H, Athanasou N A, Szendroi M, Kopper L, Rajnai H, Pinter F, Petak I, Benassi M S, Picci P, Conti A & Krenacs T
(2011) Histopathology 59 , 376–389 Epidermal growth factor receptor signalling contributes to osteoblastic stromal cell proliferation, osteoclastogenesis and disease progression in giant cell tumour of bone Aims: Epidermal growth factor receptor (EGFR) is implicated in bone remodelling. The aim was to determine whether EGFR protein expression contributes to the aggressiveness and recurrence potential of giant cell tumour of bone (GCTB), an osteolytic primary bone tumour that can exhibit markedly variable clinical behaviour. Methods and results: Immunohistochemical analysis on tissue microarrays (TMA) of 231 primary, 97 recurrent, 17 metastatic and 26 malignant GCTBs was performed using TMA analysis software and whole digital slides allowing validated scoring. EGFR expression was restricted to neoplastic stromal cells and was significantly more frequent in recurrent (71 of 92; 77%) than in non‐recurrent GCTBs (86 of 162; 53%) (P = 0.002); and in clinicoradiologically aggressive (31 of 43; 72%) than latent (27 of 54; 50%) cases (P = 0.034). Detecting phosphotyrosine epitopes pY1068 and ‐pY1173 indicated active EGFR signalling, and finding EGFR ligands EGF and transforming growth factor‐α restricted to cells of the monocytic lineage suggested paracrine EGFR activation in stromal cells. In functional studies EGF supported proliferation of GCTB stromal cells, and the addition of EGF and macrophage‐colony stimulating factor promoted osteoclastogenesis. Conclusion: In GCTB, EGFR signalling in neoplastic stromal cells may contribute to disease progression through promoting stromal cell proliferation and osteoclastogenesis.     

Beta-endorphin regulates interleukin 1 production and release by murine bone marrow macrophages

The role of the neuropeptide beta-endorphin on interleukin 1 (IL-1) production by murine bone marrow-derived macrophages was assessed. Beta-endorphin by itself did not induce IL-1 generation. However, over a wide range of concentrations (10(-6)-10(-14) M) beta-endorphin potentiated lipopolysaccharide (LPS)- or silica-induced production of intracellular and extracellular IL-1. This enhancement by beta-endorphin was most evident when using suboptimal doses of LPS. Naloxone, a competitive inhibitor of beta-endorphin opioid receptor interactions, abrogated the enhancing effects of beta-endorphin on LPS-induced IL-1 production. Furthermore, LPS-induced IL-1 production by macrophages (in the absence of added beta-endorphin) was also partially inhibited following treatment with naloxone, suggesting that opioids derived from activated macrophages may also modulate IL-1 generation and secretion. Thus, beta-endorphin-opioid receptor interactions result in enhanced production of immunomodulators such as IL-1.     

Ontogenetic changes to metacarpal trabecular bone structure in mountain and western lowland gorillas

The trabecular bone morphology of adult extant primates has been shown to reflect mechanical loading related to locomotion. However, ontogenetic studies of humans and other mammals suggest an adaptive lag between trabecular bone response and current mechanical loading patterns that could result in adult trabecular bone morphology reflecting juvenile behaviours. This study investigates ontogenetic changes in the trabecular bone structure of the third metacarpal of mountain gorillas (Gorilla beringei beringei; n = 26) and western lowland gorillas (Gorilla gorilla gorilla; n = 26) and its relationship to expected changes in locomotor loading patterns. Results show that trabecular bone reflects predicted mechanical loading throughout ontogeny. Bone volume fraction, trabecular thickness and trabecular number are low at birth and increase with age, although degree of anisotropy remains relatively stable throughout ontogeny. A high concentration of bone volume fraction can be observed in the distopalmar region of the third metacarpal epiphysis in early ontogeny, consistent with the high frequency of climbing, suspensory and other grasping behaviours in young gorillas. High trabecular bone concentration increases dorsally in the epiphysis during the juvenile period as terrestrial knuckle‐walking becomes the primary form of locomotion. However, fusion of the epiphysis does not take place until 10–11 years of age, and overall trabecular structure does not fully reflect the adult pattern until 12 years of age, indicating a lag between adult‐like behaviours and adult‐like trabecular morphology. We found minimal differences in trabecular ontogeny between mountain and western lowland gorillas, despite presumed variation in the frequencies of arboreal locomotor behaviours. Altogether, ontogenetic changes in Gorilla metacarpal trabecular structure reflect overall genus‐level changes in locomotor behaviours throughout development, but with some ontogenetic lag that should be considered when drawing functional conclusions from bone structure in extant or fossil adolescent specimens.     

Expression of parathyroid hormone-related peptide (PthrP) and its receptor (PTH1R) during the histogenesis of cartilage and bone in the chicken mandibular process

The purpose of this study was to examine the expression and actions of parathyroid hormone-related protein (PTHrP) when skeletal histogenesis occurs in the chicken mandible. Prior to the appearance of skeletal tissues, PTHrP and PTH1R were co-expressed by cells in the ectoderm, skeletal muscle, peripheral nerve and mesenchyme. Hyaline cartilage was first observed at HH stage 27 when many but not all chondroblasts expressed PTHrP and PTH1R. By stage 34, PTHrP and PTH1R were not detected in chondrocytes but were expressed in the perichondrium. Alkaline phosphatase (AP)-positive preosteoblasts and woven bone appeared at stages 31 and 34, respectively. Preosteoblasts, osteoblasts and osteocytes co-expressed PTHrP and PTH1R. Treatment with chicken PTHrP (1-36) increased cAMP in mesenchyme from stage 26 embryos. Continuous exposure to chicken PTHrP (1-36) for 14 days increased cartilage nodule number and decreased AP while intermittent exposure did not affect cartilage nodule number and increased AP in cultures of stage 26 mesenchymal cells. Adding a neutralizing anti-PTHrP antibody to the cultures reduced cartilage nodule number and did not affect AP. These findings show that PTHrP and PTH1R are co-expressed by extraskeletal and skeletal cells before and during skeletal tissue histogenesis, and that PTHrP may influence skeletal tissue histogenesis by affecting the differentiation of mandibular mesenchymal cells into chondroblasts and osteoblasts.     

胫骨髁塌陷裂骨折的手术治疗

目的探讨胫骨髁塌陷裂骨折的手术治疗方法。方法49例病人骨折按AO分类:44-B2型21例,44-B3型28例。其中合并韧带损伤19例,半月板损伤14例。均采用自体三面皮质髂骨块填充复位胫骨平台下方骨缺损以重建平台关节面,支撑钢板内固定治疗。合并韧带半月板损伤同期修复。在坚强内固定基础上,争取早期行CPM功能锻炼,8~10周后逐渐负重。结果随访2年以上,根据适用于一般膝关节损伤患者的功能评定方法标准,综合分析:优38例,良9例,尚可2例。结论利用三面皮质骨自体髂骨关节面下缺损处填充,既可充填骨缺损,又可构筑坚强的支持平台,保证了关节面的平整和高度;支撑钢板固定牢固,有利于早期功能锻炼,防止关节僵硬,使关节功能最大限度恢复,疗效显著。     

1, 25二羟基胆钙化醇诱导大鼠骨髓单核细胞向破骨细胞转化的机制

目的:探讨1,25二羟基胆钙化醇(1,25(OH)2D3)诱导大鼠骨髓单核细胞向破骨细胞转化时明胶酶表达及其参与骨陷窝形成机制。方法:分离乳鼠骨髓内细胞,诱导生成破骨样细胞。姬姆莎、抗酒石酸酸性磷酸酶(TRAP)染色鉴定。扫描电镜观察诱导出的细胞贴附于骨片上形成的骨陷窝,明胶酶谱检测细胞培养液中明胶酶表达水平。结果:单核细胞经1,25(OH)2D3诱导,第9日生成大量的破骨样细胞。姬姆莎染色显示出多核(≥3个),TRAP染色阳性,扫描电镜观察破骨细胞在骨片上培养时产生骨陷窝。1,25(OH)2D3组基质金属蛋白酶2(MMP-2)表达水平增加显著。结论:1,25(OH)2D3诱导单核细胞产生大量破骨细胞。参与骨陷窝形成的明胶酶是MMP-2。这可能是破骨细胞通过某些机制,促进其他非破骨细胞分泌有活性的MMP-2参与噬骨。     

Fcγ receptor‐mediated antigen uptake by lung DC contributes to allergic airway hyper‐responsiveness and inflammation

During asthma, lung DC capture and process antigens to initiate and maintain allergic Th2 cell responses to inhaled allergens. The aim of the study was to investigate whether allergen‐specific IgG, generated during sensitization, can potentiate the acute airway inflammation through Fcγ receptor (FcγR)‐mediated antigen uptake and enhance antigen presentation resulting in augmented T‐cell proliferation. We examined the impact of antigen presentation and T‐cell stimulation on allergic airway hyperresponsiveness and inflammation using transgenic and gene‐deficient mice. Both airway inflammation and eosinophilia in bronchoalveolar lavage fluid were markedly reduced in sensitized and challenged FcγR‐deficient mice. Lung DC of WT, but not FcγR‐deficient mice, induced increased antigen‐specific CD4⁺ T‐cell proliferation when pulsed with anti‐OVA IgG immune complexes. Intranasal application of anti‐OVA IgG immune complexes resulted in enhanced airway inflammation, eosinophilia and Th2 cytokine release, mediated through enhanced antigen‐specific T‐cell proliferation in vivo. Finally, antigen‐specific IgG in the serum of sensitized mice led to a significant increase of antigen‐specific CD4⁺ T‐cell proliferation induced by WT, but not FcγR‐deficient, lung DC. We conclude that FcγR‐mediated enhanced antigen presentation and T‐cell stimulation by lung DC has a significant impact on inflammatory responses following allergen challenge in asthma.     

Primary prostatic epithelial cell binding to human bone marrow stroma and the role of a2b1 integrin

Prostate cancer selectively metastasises to the bone. To investigate the importance of prostate epithelial cell adhesion to bone marrow cells in this process we examined the binding of human primary prostatic epithelial cells (PEC) to human bone marrow stromal cultures (BMS). We found that PEC derived from both malignant and benign tissue showed greater adhesion to BMS than to benign prostatic fibroblasts (median difference was 340% and 200% respectively), skin fibroblasts or plastic tissue culture plates. Adhesion to BMS grown from the bone marrow of patients with prostatic skeletal metastases was no different from those grown from normal bone marrow. The role of integrin molecules in these cell interactions was determined. Collagen type I and fibronectin were found to increase PEC adhesion whereas vitronectin and laminin did not. Inhibition studies demonstrated that although there was heterogeneity between samples, antibodies against the integrins a2 and b1 consistently inhibited PEC binding to BMS. This result was more marked for PEC derived from malignant tissue. However studies investigating the effects of disintegrins and anti-a3 and anti-a5 integrins indicated that for a percentage of patients these integrins and RGD (arginine, glycine, aspartamine)-dependent binding pathways were also involved. In summary, the results indicate that BMS are adherent to primary PEC derived from both malignant and benign tissue. The integrin a2b1 is a major contributor to this interaction.