Involvement of EphB1 receptor/ephrinB1 ligand in bone cancer pain

In prior studies, Eph/ephrin system was demonstrated to be involved in inflammatory and neuropathic pain modulation. The present study was to investigate whether the spinal Eph/ephrin signaling was involved in modulation of spinal inflammatory cytokines in bone cancer pain (BCP) of rats. BCP was induced by intra-tibial inoculation of Walker 256 mammary gland carcinoma cells. The expressions of EphB1/ephrinB1 in spinal cord (SC) and dorsal root ganglia (DRG) were determined. At 16 days post inoculation, the pain relieving effect and the mRNA levels of inflammatory cytokines were detected after intrathecal administration of EphB1-Fc (blocker of EphB1 receptor, 10μg). The results showed that the EphB1/ephrinB1 expression was significantly increased in SC, but ephrinB1 was decreased in DRG after Walker 256 inoculation. The mechanical allodynia induced by bone cancer was significantly alleviated by intrathecal administration of EphB1-Fc. Furthermore, the RT-PCR analysis showed that the mRNA levels of IL-1β, IL-6 and TNF-α were significantly increased at 16 days post Walker 256 inoculation and were significantly suppressed by intrathecal administration of EphB1-Fc in SC. We concluded that Eph/ephrin might be involved in the maintenance of mechanical allodynia, via modulating the expression of spinal inflammatory cytokines, in the present rat model of BCP. This study suggested that Eph/ephrin signaling would be a potential target for the treatment of BCP.     

4,5,7-三羟基异黄酮对绒癌耐药细胞株JAR/MTX增殖、凋亡和侵袭的影响及相关机制

目的：研究4,5,7-三羟基异黄酮（genistein）对绒癌耐药细胞株JAR/MTX增殖、凋亡和侵袭能力的影响，并探讨其影响侵袭的相关机制。方法： 分别采用MTT法、Annexin-Ⅴ和PI双染法、transwell 小室法，检测不同浓度genistein 作用于JAR/MTX细胞72 h后细胞增殖、凋亡和侵袭能力的变化。采用RT-PCR技术检测雌激素受体（ER）以及与侵袭有关的MTA3、Snail基因mRNA的表达，采用蛋白印迹法和明胶酶谱法检测E-钙黏附蛋白（E-cadherin）和基质金属蛋白酶2（MMP-2）和9(MMP-9)蛋白的表达。结果： Genistein能抑制JAR/MTX细胞的增殖和侵袭能力，并呈剂量依赖关系。小剂量genistein（10 μmol/L）仅能引起少部分JAR/MTX细胞凋亡，而25、50、100 μmol/L genistein则引起大量细胞凋亡和坏死。JAR/MTX细胞经genistein作用后，ERβ和MTA3的mRNA表达量多于对照组，Snail基因的mRNA表达量少于对照组。E-cadherin的蛋白表达大于对照组，MMP-2和MMP-9的蛋白表达量少于对照组。结论： Genistein能抑制JAR/MTX细胞的增殖，诱导细胞凋亡和坏死，通过上调E-cadherin和下调MMP-2以及MMP-9的表达、抑制JAR/MTX细胞的侵袭能力，MTA3→Snail→E-cadherin通路可能是genistein抑制JAR/MTX细胞侵袭的信号通路之一。     

Eph/ephrin signaling: networks

Bidirectional signaling has emerged as an important signature by which Ephs and ephrins control biological functions. Eph/ephrin signaling participates in a wide spectrum of developmental processes, and cross-regulation with other communication pathways lies at the heart of the complexity underlying their function in vivo. Here, we review in vitro and in vivo data describing molecular, functional, and genetic interactions between Eph/ephrin and other cell surface signaling pathways. The complexity of Eph/ephrin function is discussed in terms of the pathways that regulate Eph/ephrin signaling and also the pathways that are regulated by Eph/ephrin signaling.     

大豆异黄酮诱导裸鼠人胃癌移植瘤凋亡（英文）

目的：探讨大豆异黄酮诱导人胃癌原代细胞裸鼠移植瘤凋亡的机制。方法： 建立人胃癌原代细胞裸鼠移植瘤模型并测定移植瘤的生长曲线；25只BALB/C裸鼠接种胃癌原代细胞悬液生成移植瘤后，不同剂量的大豆异黄酮进行瘤旁注射，透射电镜和TUNEL法检测肿瘤组织细胞凋亡情况，免疫组化法和RT-PCR法检测肿瘤组织的凋亡相关基因bcl-2和bax的表达情况。结果： 大豆异黄酮对胃癌原代细胞移植瘤有明显的抑制作用，在剂量为0.5 mg/kg、1 mg/kg、1.5 mg/kg时，其抑制率分别为10.6%、29.7%和39.1%；透射电镜发现大豆异黄酮导致移植瘤内大量细胞发生调亡；TUNEL染色法发现大豆异黄酮注射组瘤细胞的凋亡指数是随剂量递增（28.7%±1.1%、33.4%±1.4%和37.1%±1.0%）。免疫组织化学法发现大豆异黄酮注射组的Bcl-2蛋白阳性细胞率随剂量递减（11.8%±0.9%、5.7%±0.8%和4.0%±0.8%），而Bax蛋白阳性细胞率随剂量递增（20.0％±±1.2%、24.7％±0.9%和29.3%±1.6%）；RT-PCR法发现,大豆异黄酮注射组的〖STBX〗bcl-2〖STBZ〗 mRNA条带强度随剂量的增大而递减，并明显低于对照组P<0.05）；而bax mRNA条带强度递增，并明显低于对照组（P<0.05），而2对照组bcl-2，bax之间差异无统计学意义（P>0.05）。结论： 大豆异黄酮对胃癌原代细胞移植瘤有明显的抑制作用，通过下调bcl-2的表达和上调bax的表达而诱导胃癌裸鼠移植瘤细胞发生凋亡，是其抗胃癌作用的机制之一。     

Laminar Expression of Ephrin‐A2 in Primary Somatosensory Cortex of Postnatal Rats

Several Eph receptors, prominently EphA4 and EphA7, and their corresponding ligands are known to influence neocortical development, including topographic sorting of thalamocortical axons within primary somatosensory cortex (SI). This study investigated postnatal expression of a ligand that can bind to these receptors, ephrin‐A2. Quantitative methods revealed that expression of ephrin‐A2 mRNA in SI reached maximum levels on postnatal day (P) 4 and dropped thereafter to background by P18. Ephrin‐A2 mRNA expression assessed by in situ hybridization qualitatively revealed a similar time course and localized the expression pattern primarily in two broad laminae in SI, comprising the supragranular and infragranular layers, and with additional expression in the subplate. This expression pattern was investigated in greater detail using immunohistochemistry for ephrin‐A2 protein. Immunoreactivity generally showed the same laminar distribution as seen with in situ hybridization, except that it persisted longer, lasting to approximately P14. Expression in the cortical plate was low or absent within presumptive layer IV, and it remained so as cortical lamination progressed. Double‐labeling immunohistochemistry with confocal microscopy revealed that cortical neurons were the principal elements expressing ephrin‐A2 protein. These findings are consistent with possible involvement of ephrin‐A2, in concert with one or more Eph receptors, in influencing arbor development of thalamocortical axons at cortical layer IV boundaries. Anat Rec, 2012. © 2011 Wiley Periodicals, Inc.     

Ephrin A receptors and ligands in lesions and normal-appearing white matter in multiple sclerosis

Complexes of the tyrosine kinase ephrin ligands (ephrins) and their receptors (Ephs) provide critical cell recognition signals in CNS development. Complementary ephrin/Eph expression gradients present topographic guidance cues that may either stimulate or repulse axon growth. Some ephrin/Ephs are upregulated in adult CNS injury models. To assess their involvement in multiple sclerosis (MS), ephrin A1-5 and Eph A1-8 expression was analyzed in CNS tissues using immunohistochemistry. Control samples showed distinct expression patterns for each ephrin/Eph on different cell types. Perivascular mononuclear inflammatory cells, reactive astrocytes and macrophages expressed ephrin A1-4, Eph A1, -A3, -A4, -A6 and -A7 in active MS lesions. Axonal ephrin A1 and Eph A3, -A4, and -A7 expression was increased in active lesions and was greater in normal-appearing white matter (NAWM) adjacent to active lesions than within or adjacent to chronic MS lesions, in contralateral NAWM, or in control samples. As in development, therefore, there are temporally dynamic, lesion-associated axonal ephrin/Eph A expression gradients in the CNS of MS patients. These results indicate that ephrin/Eph As are useful cell markers in human CNS tissue samples; they likely are involved in the immunopathogenesis of active lesions and in neurodegeneration in MS NAWM; and they represent potential therapeutic targets in MS.     

伊班膦酸钠干预骨关节炎模型大鼠丝裂原活化蛋白激酶信号通路的变化

背景:丝裂原活化蛋白激酶信号通路参与成骨细胞与破骨细胞的分化,与软骨下骨重建过程密切相关,在骨关节炎的发生发展中起重要作用。双膦酸盐作为骨吸收抑制剂,主要用于骨质疏松的治疗。目的:探讨伊班膦酸钠对大鼠骨关节炎的治疗效果,以及其对丝裂原活化蛋白激酶信号通路的影响。方法:实验方案经南华大学附属第一医院动物实验伦理委员会批准。30只雌性SD大鼠随机分为假手术组、模型组、治疗组。模型组和治疗组行双侧去卵巢及前交叉韧带切断术,假手术组大鼠只切除卵巢周围与卵巢大小相仿的脂肪组织,切开双侧膝关节腔,但不切断前交叉韧带。术后1周,治疗组予以腹腔注射伊班膦酸钠10μg/kg,模型组予以腹腔注射等量生理盐水,假手术组不作干预。12周以后,处死实验动物,进行关节软骨的组织形态学观察及Mankin评分,软骨下骨的Micro-CT扫描及骨组织显微结构定量分析,检测丝裂原活化蛋白激酶信号通路中细胞外信号调节蛋白激酶(ERK1)和c-Jun氨基酸末端激酶(JNK)的mRNA表达量及蛋白表达水平。结果与结论:①模型组软骨结构明显破坏,Mankin评分较假手术组明显增高,而治疗组的Mankin评分较模型组显著降低(P<0.01);②与假手术组比较,模型组中的骨密度、骨体积分数、骨小梁数量降低,骨小梁分离度显著增高(P<0.01);与模型组相比,治疗组的骨密度、骨体积分数、骨小梁数量增加,骨小梁分离度明显下降(P<0.01);③模型组中的ERK1、JNK mRNA表达和蛋白表达较假手术组明显增加(P<0.05,P<0.01);与模型组相比,治疗组中的ERK1、JNK mRNA表达和蛋白表达显著降低(P<0.05);④结果说明,伊班膦酸钠可能通过抑制ERK1、JNK丝裂原活化蛋白激酶信号通路的表达改善膝骨关节炎大鼠的软骨下骨的微结构,抑制软骨的退变。     

Connecting thalamus and cortex: the role of ephrins

The complex task of wiring up the brain during embryonic development is achieved by a multitude of guidance signals acting in complex combinations to drive growing axons to their proper targets. The somatosensory system provides an extensively studied model system featuring many universal mechanisms of neural development. In rodents, it constitutes an important model to study how precise topographic connections are achieved. Recent evidence suggests that the Eph/ephrin family of guidance molecules is of pivotal importance for the development of the somatosensory system. Members of Eph/ephrin family are thought to be involved in the global presorting of thalamic axons projecting to the cortex, in labeling specific cortical areas for innervation, in providing topographic cues within the target area, and in distinguishing cortical layers for intracortical wiring. The Eph/ephrin system also seems to contribute to the formation of specific corticothalamic feedback projections. So far, the functions of only a few members of the Eph/ephrin family have been examined, but expression analysis indicates complex combinatorial effects of these signaling molecules. Understanding the Eph/ephrin wiring code is expected to yield new insights into the development and plasticity of brain circuits involved in higher functions.     

Eph/ephrin molecules--a hub for signaling and endocytosis

The development, homeostasis, and regeneration of complex organ systems require extensive cell-cell communication to ensure that different cells proliferate, migrate, differentiate, assemble, and function in a coordinated and timely fashion. Eph receptor tyrosine kinases and their ephrin ligands are critical regulators of cell contact-dependent signaling and patterning. Eph/ephrin binding can lead to very diverse biological readouts such as adhesion versus repulsion, or increased versus decreased motility. Accordingly, depending on cell type and context, a limited and conserved set of receptor-ligand interactions is translated into a large variety of downstream signaling processes. Recent evidence indicates that the endocytosis of Eph/ephrin molecules, together with the internalization of various associated tissue-specific effectors, might be one of the key principles responsible for such highly diverse and adaptable biological roles. Here, we summarize recent insights into Eph/ephrin signaling and endocytosis in three biological systems; i.e., the brain, intestine, and vasculature.     

genistein对人卵巢癌细胞系SKOV3及其裸鼠移植瘤中表皮生长因子受体介导的信号转导通路的影响

目的　通过 genistein对人卵巢癌细胞系SKOV3 及其裸鼠移植瘤中表皮生长因子受体(EGFR)介导的肿瘤信号转导系统的影响 ,探讨其抑制增殖作用的机制。方法　应用免疫细胞化学链霉素抗生物素蛋白过氧化物酶 (SP)法检测c erbB 2蛋白的表达 ;Western印迹检测细胞c jun和c fos蛋白的表达 ;逆转录 聚合酶链反应 (RT PCR)检测c erbB 2 ,c raf 1,c jun和c fosmRNA的表达。结果　 2 0 μmol/Lgenistein处理组c erbB 2、c raf 1及其下游基因c jun、c fosmRNA表达减弱。2 0 μmol/Lgenistein处理SKOV3 细胞 4 8h后 ,c erbB 2蛋白表达减弱 ,平均吸光度 (A)值减低 ,为0 4 2± 0 0 2 (P <0 0 5 )。Western印迹检测结果表明 :2 0 μmol/Lgenistein处理SKOV3 细胞 12～ 72h后 ,c jun、c fos蛋白表达水平逐渐减弱。结论　genistein下调SKOV3 中EGFR介导的肿瘤信号转导通路中两个关键基因c erbB 2和c raf 1之mRNA及蛋白及其下游核转录因子c jun和c fos的mRNA及蛋白的表达水平 ,提示genistein干预EGFR介导的肿瘤信号转导系统中主要信号分子的表达可能是其抑制卵巢癌增殖的分子基础。     

Genistein induces growth arrest and suppresses telomerase activity in brain tumor cells

Genistein, a soy isoflavone, has been reported to exhibit multiple effects, such as inducing cell cycle arrest, triggering apoptosis, inhibiting the activation of NF_KB and inactivating several signaling cascades in human cancer cells. In vivo studies demonstrating antiangiogenesis and antimetastatic effects of genistein have also been reported. Here, we demonstrate that genistein inhibits the growth of glioblastoma multiforme and medulloblastoma cells with different TP53 mutations and radio‐responses by arresting the cells at G2/M phase of the cell cycle. The cell cycle arrest was found to be independent of DNA damage and such an arrest was sustainable for at least 10 days even after drug removal. Annexin V staining revealed absence of apoptotic or necrotic cell populations after genistein treatment. This supports the observation that genistein induces insignificant DNA damage and indicates that the cell cycle arrest triggered does not lead to cell death. Gene and protein expression studies reveal similar changes in the same pathways following treatment in the cell types tested. Genistein was also able to inhibit telomerase activity resulting in telomere shortening. Thus, we demonstrate, for the first time, that genistein induces growth arrest in association with telomerase inhibition in brain tumor cells via the suppression of TR‐ and TERT mRNA. By elucidating the mechanisms of anticancer effects after genistein treatment in brain tumor cells, there will be a premise for the incorporation of genistein dietary sources to complement radiotherapy in brain tumor patients. © 2012 Wiley Periodicals, Inc.     

bcl-2基因表达在genistein抑制裸鼠肝癌生长中的作用

目的：探讨bcl-2基因表达变化在genistein治疗裸鼠移植人肝癌中的作用。方法:以裸鼠移植人肝癌为对照, 对照组腹腔注入含0.04%DMSO RPMI-1640培养基0.05 L/kg，genistein治疗组腹腔注入genistein 1 mg kg-1·d-1，3周后观察肝癌增长情况，并应用同位素试剂盒检测肝癌组织IP3 含量,RT-PCR分析癌组织bcl-2 mRNA表达，Western blotting 分析肝癌组织Bcl-2蛋白表达。结果:治疗组肝癌体积和重量均显著低于对照组［体积:（42.7±27.8)mm3 vs (52.3±26.5)mm3;重量:(42.7±27.8)mg vs (91.3±31.4)mg］，IP3含量显著低于对照组［(13.4±1.4)nmol/g protein vs （35.3±6.6）nmol/g protein］，bcl-2 mRNA表达显著低于对照组［RI（灰度与面积之积的相对强度）0.48±0.02 vs 0.56±0.15］, P<0.01，Bcl-2蛋白表达显著低于对照组［RI（灰度与面积之积的相对强度）1.69±0.52 vs 1.37±0.48］。结论:Genistein能减少IP3 生成,下调肝癌组织bcl-2基因表达,抑制裸鼠移植肝癌的生长。     

Ursolic acid derivative ameliorates streptozotocin-induced diabestic bone deleterious effects in mice

Objective: This study was performed to investigate bone deteriorations of diabetic mice in response to the treatment of ursolic acid derivative (UAD). Methods: The biomarkers in serum and urine were measured, tibias were taken for the measurement on gene and protein expression and histomorphology analysis, and femurs were taken for the measurement on bone Ca and three-dimensional architecture of trabecular bone. Results: UAD showed a greater increase in bone Ca, BMD and significantly increased FGF-23 and OCN, reduced PTH and CTX in diabetic mice. UAD reversed STZ-induced trabecular deleterious effects and stimulated bone remodeling. The treatment of STZ group with UAD significantly elevated the ratio of OPG/RANKL. Moreover, insulin and IGF-1 showed a negative correlation with both FBG and Hb1Ac in STZ group. We attributed down-regulating the level of Hb1Ac in diabetic mice to that ursolic acid derivative could primely control blood sugar levels. After analyzing of two adipocyte markers, PPARγ and aP2, increased expression in the tibias of diabetic mice, and UAD could improve STZ-induced adipocyte dysfunction. Conclusions: These results demonstrated that UAD could ameliorate STZ-induced bone deterioration through improving adipocyte dysfunction and enhancing new bone formation and inhibiting absorptive function of osteoclast in the bone of diabetic mice.     

Local bone interaction between renin-angiotensin system and kallikrein-kinin system in diabetic rat

Objective: This study was performed to investigate bone deteriorations and the involvement of skeletal renin-angiotensin system (RAS) and kallikrein-kinin system (KKS) of male rat in response to the hyperglycemia. Methods: The biomarkers in serum and urine were measured by ELISA kit, and tibias were taken for the measurement on gene, protein expression and histological analysis, feumrs were taken for the measurement on biomechanical parameters and micro-CT. Results: The DM1 showed the decreased level of osteocalcin, testosterone and FGF-23, and the increased level of serum CTX as compared to those of vehicle group. The H&E staining showed remarkable bone deteriorations, including increased disconnections and separation of trabecular bone among growth plate and joint cartilage in DM1 group. Biomechanically, the maximum load, maximum stress, and strain parameter of DM1 group was significantly lower than control group. Type 1 diabetic mice displayed bone loss shown the reduction of bone volume/total volume, trabecular number, trabecular thickness and bone mineral density. The STZ injection significantly up-regulated mRNA expression of AT1R, AGT, renin, renin-receptor, and ACE, and the expression of AT2R, B1R and B2R were down-regulated in tibia of rat in hyperglycemia group. The protein expression of renin, ACE and Ang II were significantly up-regulated, and AT2R, B1R and B2R were down-regulated in DM1 group. Conclusions: The treatment of hyperglycemia was detrimental to bone as compared to the vehicle group, and the underlying mechanism was mediated, at least partially, through down-regulation of KSS activity and up-regulation of RAS activity in local bone.     

Ephs and ephrins during early stages of chick embryogenesis.

The Eph family of receptor tyrosine kinases and their ligands, the ephrins, are membrane-bound proteins that mediate bidirectional signals between adjacent cells. By modulating cytoskeleton dynamics affecting cell motility and adhesion, Ephs and ephrins orchestrate cell movements during multiple morphogenetic processes, including gastrulation, segmentation, angiogenesis, axonal pathfinding, and neural crest cell migration. The full repertoire of developmental Eph/ephrin functions remains uncertain, however, because coexpression of multiple receptor and ligand family members, and promiscuous interactions between them, can result in functional redundancy. A complete understanding of expression patterns, therefore, is a necessary prerequisite to understanding function. Here, we present a comprehensive expression overview for 10 Eph and ephrin genes during the first 48 hr of chick embryo development. First, dynamic expression domains are described for each gene between Hamburger and Hamilton stages 4 and 12; second, comparative analyses are presented of Eph/ephrin expression patterns in the primitive streak, the somites, the vasculature, and the brain. Complex spatially and temporally dynamic expression patterns are revealed that suggest novel functions for Eph and ephrin family members in both known and previously unrecognized processes. This study will provide a valuable resource for further experimental investigations of Eph and ephrin functions during early embryonic development.     

Eph signaling is required for segmentation and differentiation of the somites

Somitogenesis involves the segmentation of the paraxial mesoderm into units along the anteroposterior axis. Here we show a role for Eph and ephrin signaling in the patterning of presomitic mesoderm and formation of the somites. Ephrin-A-L1 and ephrin-B2 are expressed in an iterative manner in the developing somites and presomitic mesoderm, as is the Eph receptor EphA4. We have examined the role of these proteins by injection of RNA, encoding dominant negative forms of Eph receptors and ephrins. Interruption of Eph signaling leads to abnormal somite boundary formation and reduced or disturbed myoD expression in the myotome. Disruption of Eph family signaling delays the normal down-regulation of her1 and Delta D expression in the anterior presomitic mesoderm and disrupts myogenic differentiation. We suggest that Eph signaling has a key role in the translation of the patterning of presomitic mesoderm into somites.     

EphB/ephrin-B interaction mediates adult stem cell attachment, spreading, and migration: implications for dental tissue repair

Human adult dental pulp stem cells (DPSCs) reside predominantly within the perivascular niche of dental pulp and are thought to originate from migrating neural crest cells during development. The Eph family of receptor tyrosine kinases and their ligands, the ephrin molecules, play an essential role in the migration of neural crest cells during development and stem cell niche maintenance. The present study examined the expression and function of the B-subclass Eph/ephrin molecules on DPSCs. Multiple receptors were primarily identified on DPSCs within the perivascular niche, whereas ephrin-B1 and ephrin-B3 were expressed by the surrounding pulp tissue. EphB/ephrin-B bidirectional signaling inhibited cell attachment and spreading, predominately via the mitogen-activated protein kinase (MAPK) pathway for forward signaling and phosphorylation of Src family tyrosine kinases via reverse ephrin-B signaling. DPSC migration was restricted through unidirectional ephrin-B1-activated EphB forward signaling, primarily signaling through the MAPK pathway. Furthermore, we observed that ephrin-B1 was downregulated in diseased adult teeth compared with paired uninjured controls. Collectively, these studies suggest that EphB/ephrin-B molecules play a role in restricting DPSC attachment and migration to maintain DPSCs within their stem cell niche under steady-state conditions. These results may have implications for dental pulp development and regeneration.     

Phosphorylation of ephrin-B1 regulates dissemination of gastric scirrhous carcinoma

Interaction of the Eph family of receptor protein tyrosine kinase and its ligand ephrin family induces bidirectional signaling via cell-cell contacts. High expression of B-type ephrin is frequently found in various cancer cells, and their expression levels are associated with high invasion of tumors and poor prognosis. However, whether ephrin-B1 actually promotes invasion of cancer cells in vivo has not been shown. We investigated the involvement of ephrin-B1 in regulating the invasiveness of scirrhous gastric cancer, which is a diffusely infiltrative carcinoma with high invasion potential. Reduction of ephrin-B1 expression by short inter-fering RNA or overexpression of phosphorylation-defective mutant suppressed migration and invasion of scirrhous gastric cancer cells in vitro without affecting tumor cell proliferation and apoptosis. Blocking of tyrosine phosphorylation of ephrin-B1 attenuates not only dissemination of cancer cells injected intraperitoneally but also local invasion and dissemination of orthotopically implanted cancer cells in the gastric wall of nude mice. Furthermore, blocking of ephrin-B1 phosphorylation attenuated the activation of Rac1 GTPase in these invasive gastric cancer cells. Our results suggest that tyrosine phosphorylation of ephrin-B1 promotes invasion of cancer cells in vivo and is a potential therapeutic target in some types of gastrointestinal cancers.