MEK-MAPK信号通路在P2Y嘌呤受体活化对人前列腺癌细胞效应中的作用

目的 探讨细胞外信号调节激酶(ERK1／2)及p38通路在P2Y嘌呤受体活化对前列腺癌细胞产生的生物学效应中所起的作用。方法 脂质体法将负显性MAPK激酶1(KA—MEK1)转染高转移性前列腺癌1E8细胞;Western印迹法检测ERK1／2活化水平;应用细胞计数、软琼脂集落形成实验、体外侵袭实验检测ERK1／2及p38通路在P2Y嘌呤受体活化对前列腺癌细胞生长、集落形成、体外侵袭效应中的作用;用流式细胞术检测ATP对凋亡的影响。结果 转染KA—MEK1抑制了细胞的ERK1／2活性。常规培养6d时,KA—MEK1细胞的活细胞数比对照组细胞减少了约71％;以100μmol／L ATP连续刺激6d,KA—MEK1细胞的生长被进一步抑制17.2％;用10μmol／L p38抑制剂SB203580预处理细胞,可以封闭ATP所诱导的额外生长抑制效应。说明持续P2Y受体活化可抑制前列腺癌细胞生长,ERK1／2和p38通路均在其中起作用。细胞凋亡并非ATP生长抑制作用的主要机制。在软琼脂集落形成实验中,KA—MEK1细胞比对照组细胞形成的集落小,而且数目减少了约75％;在抑制了ERK1／2活性后,以ATP预处理并不显著改变细胞的集落形成能力;进一步在抑制了：ERK1／2活性的基础上,以SB203580处理细胞,对细胞集落形成能力也无明显影响。说明在影响癌细胞集落形成方面,主要是ERK1／2通路起作用。在体外侵袭实验中,KA—MEK1细胞的穿膜细胞数比对照组细胞减少了41％;以ATP刺激12h可以促进前列腺癌细胞体外侵袭,其中KA—MEK1细胞的穿膜细胞增加率低于对照组细胞;进一步以SB203580处理细胞,可以抑制ATP诱导的促侵袭效应。说明ERK1／2和p38通路在ATP促侵袭效应中均发挥主要作用。结论P2Y嘌呤受体激活程度的差异可导致不同效应,并涉及不同信号传导通路。持续P2Y嘌呤受体活化抑制前列腺癌细胞生长,其中有ERK1／2及p38通路的参与;短暂P2Y嘌呤受体活化抑制前列腺癌细胞集落形成但促进前列腺癌细胞体外侵袭,在前者ERK1／2起重要的作用,后者有ERK1／2和p38通路的参与。     

P2Y_6受体及其在神经系统疾病研究中的进展

<正>1978年Burnstock等发现了介导ATP神经递质信号转导的嘌呤受体,将其分为P2X1-7和P2Y1,2,4,6,11,12,13,14受体两类,其中P2X受体是离子通道受体,P2Y受体是G蛋白偶联受体。不同亚型P2Y受体通过不同G蛋白激活不同的细胞内信号转导通路,从而产生特定的生理功能。近年研究表明,P2Y6受体不仅参与了神经病理性疼痛的发生与维持,而且     

μ阿片受体在大鼠结肠肠肌丛的神经化学特性

目的:探索μ阿片受体(MOR)在大鼠结肠肠肌丛的分布及化学神经解剖学特性。方法:取大鼠结肠右曲和左曲之间肠管行全层铺片,剥离粘膜层、粘膜下层和环形肌层,保留纵行肌层。运用免疫荧光组织化学双重标记技术染色,共聚焦显微镜下观察MOR在大鼠结肠肠肌丛的分布及与一氧化氮合酶(NOS)、肠血管活血肽(VIP)、P物质(SP)或降钙素基因相关蛋白(CGRP)等在肠神经细胞的共存关系。结果:免疫荧光组织化学染色显示:在大鼠结肠肠肌层,MOR阳性细胞聚集形成神经节,其阳性突起穿行于神经节之间形成网格状神经丛。在肠肌丛神经细胞内,可见MOR分别与NOS、VIP、SP、CGRP共存。MOR阳性神经纤维和终末分布于NOS阳性神经细胞周围,也可见部分NOS、VIP阳性神经纤维和终末分布于MOR阳性神经细胞表面。有大量SP和CGRP阳性神经纤维穿行于MOR阳性神经细胞之间并包绕于MOR阳性神经细胞的胞体周围。结论:在结肠的肠肌丛,MOR与抑制性和感觉性神经递质在肠神经细胞有共存,且相互之间有纤维联系,推测MOR可能介导了阿片类调节肠神经细胞内抑制性神经递质的释放,并可能对肠感觉信息的传递有调节作用。     

SHP2和MKP5在P2Y嘌呤受体介导的人前列腺癌细胞侵袭中的调控机制研究

目的　探讨蛋白质酪氨酸磷酸酶(SHP2)及丝裂原活化蛋白激酶磷酸酶5 (MKP5 )在P2Y嘌呤受体激活人不同转移潜能的前列腺癌细胞系MAPKs信号通路中的调节机制及其与细胞侵袭能力的相关性。方法　构建野生型和突变型SHP2及野生型MKP5表达质粒并分别稳定转染入1E8(高转移)和(或)2B4(不转移)细胞。应用免疫沉淀法检测细胞SHP2的酪氨酸磷酸化的程度,免疫印迹法检测ERK1 /2、p38的磷酸化,用Matrigel穿膜实验检测细胞的体外侵袭能力。结果　ATP可刺激细胞的SHP2发生磷酸化,且在1E8中的激活程度高于2B4。野生型SHP2转染可使2B4细胞中ATP对ERK1 /2的激活时效明显延长;而突变型SHP2延迟并降低1E8细胞中ATP对ERK1 /2的激活水平;两者对细胞p38的活性均无明显影响。ATP刺激可使不转移2B4细胞穿膜数明显增多(比对照组增加72 2% ±14 0% ),野生型SHP2转染可使经ATP刺激的细胞穿膜数进一步增加18 7%。ATP刺激可使高转移1E8细胞穿膜数进一步增加(112 8% ±32 0% ),而转染突变型SHP2可部分(40 9% )抑制ATP的促细胞侵袭作用。转染野生型MKP5在明显抑制p38磷酸化的同时,也能部分抑制ATP的促侵袭作用(抑制率在1E8和2B4分别为22 4%和28 7% )。结论　SHP2正性调节P2Y嘌呤受体介导的ERK活化,并可促进前列腺癌细胞的侵袭能力。而MKP5     

胰岛素受体与胰岛素样生长因子受体1在阿尔茨海默病中的作用机制

近年来,越来越多的研究岁示阿尔茨海默病（Alzheimer’s disease,AD）与2型糖尿病（Type 2 diabetes mellitus,T2DM）相关,进一步研究表明,胰岛素受体（insulinreceptor,IR）和胰岛素样生长因子受体1（Insulin-like growth factor I receptor,IGF-1R）在AD的发生发展中占有很重要的地位。本文通过对眼和IGF-1R在阿尔茨海默病中的作用机制进行综述,为阿尔茨海默病的研究和治疗提供新的方向。     

先天性巨结肠的易感基因及表观遗传调控的研究进展

先天性巨结肠(HSCR)是一种由神经嵴细胞衍生的肠神经系统发育障碍性疾病,相关基因异常编码会影响神经嵴细胞在消化道中的迁移、增殖、分化或存活,导致远端肠无神经节细胞症。神经嵴细胞和周围环境的调节涉及各种基因、信号通路、转录因子和表观遗传机制。因此,肠神经系统发育过程中相关基因的突变或基因表达的变化可能参与先天性巨结肠的发病过程。本文综述了参与肠神经系统发育的相关机制,总结了主要的先天性巨结肠相关基因和表观遗传模式,如RET、EDNRB、DNA甲基化等促进神经嵴病变的发展。本文总结了至今为止先天性巨结肠发病原因的主要机制,为先天性巨结肠相关的研究提供了理论依据,为先天性巨结肠疾病的防治提供了新策略。     

NO合酶阳性神经元在便秘型肠易激综合征大鼠结肠的表达

目的:探索一氧化氮合酶(NOS)阳性神经元在便秘型肠易激综合征(C-IBS)大鼠结肠的分布特点及变化。方法:冷水持续灌胃15 d制作C-IBS大鼠模型。通过对大鼠大便性状和结肠内膨胀刺激后腹肌反应的观察及结肠HE染色对模型进行评价。免疫荧光组织化学和Western Blot观察NOS阳性神经元在结肠肠肌丛的分布及改变。结果:造模15 d后,模型组大鼠大便呈腊肠状的碎块,结肠的腹肌反应阈值明显降低,HE染色显示结肠粘膜层完整。免疫荧光组织化学显示,C-IBS大鼠结肠肠肌从神经元NOS表达较对照组明显增高。Western Blot结果显示,C-IBS大鼠结肠NOS的表达明显增加。结论:NO在C-IBS大鼠结肠神经元内表达增加,此异常可能与C-IBS大鼠结肠运动功能紊乱相关。     

ATP及其P2X受体在疼痛机制中的作用

<正>目前,ATP已被认为是中枢和外周神经系统的协同递质或调质。其受体根据分子结构和信号传导机制分为两类:离子通道型P2X受体和代谢型P2Y受体。近年来的研究显示,ATP及其P2X受体(主要是P2X3)可能在伤害性信息传递上具有重要作用。本文将首先介绍P2X受体在神经系统中的研究近况,然后讨论ATP及其受体P2X(主要是P2X3)在疼痛发生机制中的作用。     

Reelin在阿尔茨海默病小鼠发病中的作用

目的探讨阿尔茨海默病(AD)小鼠病理改变、Reelin和Notch1的表达变化及DNA甲基化状态的改变,为深入了解阿尔茨海默病的发病机制提供理论依据。方法以淀粉样蛋白前体(APP)/早老素-1(PS1)双转基因小鼠为AD模型、同窝野生型小鼠为对照组,两组小鼠共计184只,利用高尔基染色、透射电子显微镜、免疫荧光染色、免疫印迹等技术检测AD模型鼠病理改变、Reelin和Notch1的表达变化及DNA甲基化状态的改变。结果AD小鼠在约6个月时开始出现淀粉样斑沉积、神经元纤维出现缠结等病理改变;AD小鼠发病后,星形胶质细胞和小胶质细胞在淀粉样斑周围聚集增多,随病情加重逐渐增加;Reelin在淀粉样斑周围聚积形成斑块,随病情加重逐渐增多;全长Notch1受体和其活性Notch细胞内片段(NICD)在AD鼠脑部表达减少;AD小鼠脑部甲基化状态减弱,淀粉样斑中有DNA片段,但甲基化状态消失,DNA甲基转移酶1(Dnmt1)和Dnmt3a在AD小鼠中表达减少。结论 AD小鼠脑内淀粉样斑沉积,促使胶质细胞聚集、Reelin聚积形成斑块、Notch1受体表达下降及甲基化状态减弱,进一步加剧AD神经功能紊乱。     

去甲肾上腺素在阿尔茨海默病中的作用

<正>阿尔茨海默病(Alzheimer’s disease,AD)神经病理学改变包括[1]:(1)神经细胞间的β-淀粉样蛋白(β-amyloid,Aβ)沉积并聚集形成老年斑(senile plauqus,SP),SP以Aβ为核心,加上小胶质细胞、星形胶质细胞和少量其他成分组成;     

Targeting renal purinergic signalling for the treatment of lithium‐induced nephrogenic diabetes insipidus

Lithium still retains its critical position in the treatment of bipolar disorder by virtue of its ability to prevent suicidal tendencies. However, chronic use of lithium is often limited by the development of nephrogenic diabetes insipidus (NDI), a debilitating condition. Lithium‐induced NDI is due to resistance of the kidney to arginine vasopressin (AVP), leading to polyuria, natriuresis and kaliuresis. Purinergic signalling mediated by extracellular nucleotides (ATP/UTP), acting via P2Y receptors, opposes the action of AVP on renal collecting duct (CD) by decreasing the cellular cAMP and thus AQP2 protein levels. Taking a cue from this phenomenon, we discovered the potential involvement of ATP/UTP‐activated P2Y₂ receptor in lithium‐induced NDI in rats and showed that P2Y₂ receptor knockout mice are significantly resistant to Li‐induced polyuria, natriuresis and kaliuresis. Extension of these studies revealed that ADP‐activated P2Y₁₂ receptor is expressed in the kidney, and its irreversible blockade by the administration of clopidogrel bisulphate (Plavix^®) ameliorates Li‐induced NDI in rodents. Parallel in vitro studies showed that P2Y₁₂ receptor blockade by the reversible antagonist PSB‐0739 sensitizes CD to the action of AVP. Thus, our studies unravelled the potential beneficial effects of targeting P2Y₂ or P2Y₁₂ receptors to counter AVP resistance in lithium‐induced NDI. If established in further studies, our findings may pave the way for the development of better and safer methods for the treatment of NDI by bringing a paradigm shift in the approach from the current therapies that predominantly counter the anti‐AVP effects to those that enhance the sensitivity of the kidney to AVP action.     

Antagonistic changes of gastric and colonic motility during selective thermal stimulation of thoracic and lumbosacral cords in anesthetized dogs

Changes in gastric and distal colonic motility evoked by thermal stimulation of the thoracic and lumbosacral cords, either individually or simultaneously, were investigated in spinal-intact dogs and in dogs spinalized at the cervical level.Simultaneous cooling of the thoracic and lumbosacral cords increased both gastric and colonic motility before and after spinalization. The direction of the responses evoked by simultaneous heating was the opposite, but only the decrease in gastric activity in the spinal-intact dog was significant.Selective cooling of the thoracic cord increased gastric motility, but decreased colonic motility before and after spinalization. Selective heating decreased gastric motility before and after spinalization, and increased colonic motility before spinalization.Selective cooling of the lumbosacral cord decreased gastric motility and increased colonic motility in spinal-intact dogs. No significant responses could be observed during selective heating in spinal-intact dogs. However, in spinalized dogs, the selective cooling and heating increased and decreased colonic motility respectively, while no significant change was observed in gastric motility during the cooling and the heating.It is concluded from the results that thermal stimulation of the spinal cord directly affects spinal functions which control gastrointestinal motility, and that there exists a mutual inhibitory interaction between the thoracic and lumbosacral innervation of the gastrointestinal tract.     

孕酮减轻ATP诱导的SH-SY5Y细胞损伤

目的:探讨孕酮对抗腺苷三磷酸(ATP)诱导的人神经母细胞瘤SH-SY5Y细胞损伤的神经保护作用和机制。方法:取对数生长期的SH-SY5Y细胞按照孕酮或ATP浓度的不同进行分组,CCK-8法检测细胞存活率,YO-PRO-1染色检测细胞膜通透性,Fluo-3染色检测细胞内Ca~(2+)浓度的变化,Western blot法检测嘌呤能P2X_7受体表达的变化。结果:与对照组相比,不同浓度(1、3、5和7 mmol/L)ATP作用2 h,SH-SY5Y细胞存活率显著降低(P0.05),细胞摄入YO-PRO-1的荧光强度明显增加(P0.05),且呈剂量依赖性。浓度为3、10和30 nmol/L的孕酮预孵育30 min可减轻ATP损伤作用,细胞存活率较单纯ATP组明显升高(P0.05或P0.01)。孕酮(30nmol/L)或P2X_7受体拮抗剂KN-62(500 nmol/L)预孵育30 min均可显著抑制ATP诱导的胞内YO-PRO-1的荧光增强(P0.01),而孕酮和KN-62两者之间没有明显差异。正常组细胞内钙离子含量少,ATP组细胞内钙离子荧光强度较对照组明显增高(P0.05),孕酮(30 nmol/L)或KN-62(500 nmol/L)预孵育30 min可明显降低(P0.05)ATP诱导的胞内钙荧光增强,而孕酮和KN-62两者之间的作用无明显差异。ATP组SH-SY5Y细胞P2X_7受体表达较对照组明显增加(P0.05),而孕酮(30 nmol/L)预孵育30 min则可显著降低ATP诱导的P2X_7受体表达(P0.05)。结论:孕酮可抑制ATP诱导的P2X_7受体表达、膜孔形成和胞内Ca~(2+)升高,降低细胞死亡率,明显减轻高浓度ATP对SH-SY5Y细胞的损伤作用。     

H_2S抑制高浓度ATP诱导的SH-SY5Y细胞凋亡与P2X_7受体的相关性研究

目的:研究H_2S对高浓度ATP诱导的SH-SY5Y细胞凋亡的保护作用和可能的机制。方法:人神经母细胞瘤SH-SY5Y细胞、HEK 293和HEK 293-hP2X_7R细胞,分为对照组,Na HS组,KN-62组,ATP组,ATP+Na HS组和ATP+KN-62组。倒置显微镜观察细胞形态变化,CCK-8法检测细胞活力,Hoechst 33258核染色分析细胞凋亡,流式细胞术检测细胞凋亡率,Western Blot和RT-PCR法分别检测Caspase-3、Bcl-2在蛋白和mRNA水平的表达。结果:与对照组比较,6 mmol/L ATP处理3 h后SH-SY5Y细胞损伤明显,活力降低至62.7%±3.8%(P0.01),而凋亡率升高至30.75%±5.1%(P0.01)。与ATP组比较,用200μmol/L Na HS和500 nmol/L KN-62预处理30 min,SH-SY5Y细胞活力分别升高至90.1%±3.8%和84.6%±3.1%(P0.05),凋亡率则分别降低至14.73%±3.4%和18.32%±3.1%(P0.01)。ATP组SH-SY5Y细胞内Caspase-3表达上调,Bcl-2表达下调,但Na HS和KN-62可抑制Caspase-3表达,促进Bcl-2表达。与对照组和HEK293细胞比较,用2 mmol/L ATP分别处理HEK 293、HEK 293-h P2X7R细胞3 h,可见HEK 293-h P2X7R细胞内Caspase-3表达上调(P0.01)。与ATP组比较,200μmol/L Na HS预处理30 min,HEK 293-h P2X7R细胞内Caspase-3表达明显下调(P0.01)。HEK 293细胞Caspase-3表达在各组无差异(P0.05)。结论:H2S对高浓度ATP诱导的SH-SY5Y细胞凋亡具有抑制作用,且呈浓度依赖性,其作用机制可能与P2X7R相关。     

W/W c-Kit mutant mice possess interstitial cells of Cajal in the deep muscular plexus layer of the small intestine

The c-Kit receptor tyrosine kinase regulates the development and differentiation of various progenitor cells. W mutant mice with spontaneous mutations in the c-kit gene show various phenotypes such as anemia, infertility, loss of coat color and mast cells. c-Kit also regulates the development of the interstitial cells of Cajal (ICC) that are responsible for the motility regulation of the gastrointestinal musculature. W^sh/W^sh mice possess an inversion mutation upstream of the c-kit promoter region; this mutation is responsible for reducing c-Kit activity, leading to a decrease in the number of mast cells, melanocytes, and ICC. We extensively examined the small intestine of W^sh/W^sh mice by using immunohistochemistry and electron microscopy. Although the musculature of the W^sh/W^sh mice did not show any c-Kit immunoreactivity, there were neurokinin 1 receptor (NK1R)-immunopositive cells that were associated with the nerve fibers in the deep muscular plexus (DMP) region. These NK1R-immunopositive cells showed a bipolar shape with long processes and were identified as ICC in the DMP layer (ICC-DMP). Electron microscopic analysis revealed that ICC-DMP had numerous mitochondria, caveolae, and gap junctions and were closely associated with nerve terminals. In contrast, ICC were not observed at the myenteric layer. In the small intestine of the W^sh/W^sh mice, we detected ICC-DMP that showed NK1R immunoreactivity and ultrastructural characters. This type of ICC may develop and maturate structurally without c-Kit expression and regulate gastrointestinal motility.     

No association of Tachykinin receptor 2 (TACR2) polymorphisms with Alzheimer's disease

The Tachykinin Receptor 2 (TACR2) located at chromosome 10q21.3 belongs to a class of receptors that bind members of the tachykinin neurotransmitter family. The TACR2 binds neurokinin A, also known as substance K, and is expressed in distinct parts of the human brain. Functionally, the TACR2 has been implicated in stress induced hippocampal acetylcholine release and the gene TACR2 is located within a previously identified linkage region for Alzheimer's disease (AD) on chromosome 10q21. Together, both facts make the TACR2 a reasonable positional and functional candidate gene for AD. Genotyping of 13 single nucleotide polymorphisms (SNPs) covering the entire gene and haplotypic analysis revealed no association with AD. Thus, we conclude that TACR2 can be excluded as a major susceptibility gene conferring risk to AD.     

Regulation of ion transport via apical purinergic receptors in intact rabbit airway epithelium

We investigated purinergic receptors involved in ion transport regulation in the intact rabbit nasal airway epithelium. Stimulation of apical membrane P2Y receptors with ATP or UTP (200 M) induced transient increases in short-circuit current (I_sc) of 13 and 6% followed by sustained inhibitions to 8 and 17% below control level, respectively. Serosal application of nucleotides had no effect. The ATP-induced response appeared to involve additional activation of apical adenosine (P1) and P2X receptors. The inhibitory effect of ATP and UTP on I_sc was eliminated by pretreatment with amiloride (100 M), while the stimulatory effect was potentiated, indicating that ATP and UTP inhibit Na⁺ and stimulate Cl^– current. Ionomycin (1 M) induced responses similar to UTP and ATP and desensitized the epithelium to the nucleotides, indicating involvement of intracellular Ca²⁺ (Ca²⁺_i). Furthermore, ATP, UTP and ionomycin induced 21, 24, and 21% decreases, respectively, in transepithelial conductance. Measurements of unidirectional isotope fluxes showed a 39% decrease in the dominant net Na⁺ absorption in response to ATP, while the smaller net Cl^– secretion increased only insignificantly and unidirectional Cl^– fluxes decreased significantly. The results suggest that nucleotides released to the airway surface liquid exert an autocrine regulation of epithelial NaCl absorption mainly by inhibiting the amiloride-sensitive epithelial Na⁺ channel (ENaC) and paracellular anion conductance via a P2Y receptor-dependent increase in Ca²⁺_i, while stimulation of Cl^– secretion is of minor importance.     

Neurochemical coding and projection patterns of gastrin-releasing peptide-immunoreactive myenteric neurone subpopulations in the guinea-pig gastric fundus

The aim of this study was to characterise the projection and neurochemical coding patterns of gastrin-releasing peptide (GRP)-containing subpopulations of myenteric neurones in the guinea-pig gastric fundus. For this purpose, we used retrograde tracing with the dye DiI and immunohistochemistry against GRP, choline acetyltransferase (ChAT), enkephalin (ENK), substance P (SP) and neuropeptide Y (NPY). Cell counts revealed that 44% of the myenteric neurones were GRP-positive. Of the GRP-positive neurones, 92% were ChAT-positive and, hence, 8% were presumptively nitric oxide synthase positive (NOS). The GRP-positive subpopulations were ChAT/GRP (40% of all GRP neurones), ChAT/NPY/GRP (25%), ChAT/SP/GRP/±ENK (20%), ChAT/ENK/GRP (8%), NOS/NPY/GRP/±ENK (5%) and NOS/GRP (3%). The tracing experiments revealed the relative contributions of the various GRP-positive subpopulations to the innervation of the circular muscle and the mucosa. GRP immunoreactivity was detected in 46 and 38% of the DiI-labelled muscle and mucosa neurones, respectively. GRP was almost exclusively found in ascending ChAT-positive mucosa and muscle neurones. The populations encoded ChAT/SP/GRP/±ENK and ChAT/ENK/GRP projected predominantly to the circular muscle, whereas the ChAT/NPY/GRP and ChAT/GRP populations had primarily projections to the mucosa. GRP was colocalised with ChAT, ENK and/or SP in varicose nerve fibres innervating the circular muscle and the muscularis mucosae, whereas in the mucosal epithelium GRP was mainly present in nerve fibres containing ChAT and NPY. The data suggest that in the guinea-pig gastric fundus, the ChAT/SP/GRP/±ENK and ChAT/ENK/GRP neurones are ascending excitatory muscle motor neurones, whereas the ChAT/NPY/GRP and ChAT/GRP neurones are very likely involved in the regulation of mucosal functions.