Impact of interstitial cells of Cajal on slow wave and gallbladder contractility in a guinea pig model of acute cholecystitis

BACKGROUND Impaired interstitial cells of Cajal(ICCs)are central to the pathophysiology of acute cholecystitis(AC).Common bile duct ligation is a common model of AC,producing acute inflammatory changes and decrease in gallbladder contractility.AIM To investigate the origin of slow wave(SW)in the gallbladder and the effect of ICCs on gallbladder contractions during the process of AC.METHODS Methylene blue(MB)with light was used to establish selective impaired ICCs gallbladder tissue.Gallbladder motility was assessed using the frequency of SW and gallbladder muscle contractility in vitro in normal control(NC),AC12h,AC24h,and AC48h groups of guinea pigs.Hematoxylin and eosin and Massonstained gallbladder tissues were scored for inflammatory changes.ICCs pathological changes alterations were estimated using immunohistochemistry and transmission electron microscopy.The alterations of c-Kit,α-SMA,cholecystokinin A receptor(CCKAR),and connexin 43(CX43)were assessed using Western blot.RESULTS Impaired ICCs muscle strips resulted in the decrease in gallbladder SW frequency and contractility.The frequency of SW and gallbladder contractility were significantly lower in the AC12h group.Compared with the NC group,the density and ultrastructure of ICCs were remarkably impaired in the AC groups,especially in the AC12h group.The protein expression levels of c-Kit were significantly decreased in the AC12h group,while CCKAR and CX43 protein expression levels were significantly decreased in the AC48h group.CONCLUSION Loss ICCs could lead to a decrease in gallbladder SW frequency and contractility.The density and ultrastructure of ICCs were clearly impaired in the early stage of AC,while CCKAR and CX43 were significantly reduced at end stage.

近5年中医药调控Cajal间质细胞增殖治疗慢性传输型便秘的研究进展

慢性传输型便秘(STC)是由于肠道蠕动减慢、粪便传输迟缓所致的便秘,主要表现为排便困难、排便次数减少、排便不尽感,同时伴有腹胀、腹痛等症状,是一种较为普遍的便秘类型,其发病机制尚未被完全阐述。Cajal间质细胞(ICC)作为消化道传导慢波信号的基础,与STC密切相关,是近年来研究的热点。ICC的数量、分布、功能、结构的改变均会影响胃肠道运动,其中ICC的减少是引起STC发病的主要原因。中医药通过辨证论治干预与ICC增殖有关的信号通路,调节ICC数目,调控自噬,抗凋亡,促进胃肠道蠕动,缓解便秘症状。文章对实验研究的信号通路与单味中药、中药复方及针灸推拿方面的治疗机制进行综述,以望为临床治疗STC提供思路。

基于Cajal间质细胞治疗慢传输型便秘患者的研究进展

慢传输型便秘(slow transit constipation,STC)是功能性便秘的一种常见类型,以结肠蠕动缓慢、肠道内容物排出延迟为特点,常伴有排便次数少、排便困难等症状。研究表明,STC的发生与Cajal间质细胞(interstitial cells of Cajal,ICCs)的异常改变有关。本文通过总结ICCs的分类、标志物、功能及其与STC的关系发现ICCs的数量和功能异常可影响STC患者的症状。此外,本文还总结了STC的不同治疗措施如微生态制剂、中医药、物理疗法和分子治疗对ICCs的潜在影响,并提供了STC患者治疗的新思路。笔者认为,ICCs可作为STC患者治疗的潜在靶标,未来研究应当关注ICCs在STC发病机制中的作用,开发特异性治疗手段,并评估干细胞疗法和基因疗法等新兴策略在临床中应用的可能性,为STC患者提供新的治疗选择。

Interstitial cells of Cajal in the gut-A gastroenterologist’s point of view

Alterations of normal function of interstitial cells of Cajal (ICC) are reported in many intestinal disorders. Diagnosis of their involvement is rare (infrequent), but necessary to propose a specifi c treatment. This article reviews the place of ICC in the pathogenesis of achalasia, gastroesophageal reflux disease, infantile hypertrophic pyloric stenosis, chronic intestinal pseudoobstruction and slow transit constipation. Moreover we discuss the role of the Cajal cells in the development of stromal tumors of the gastrointestinal tract.

白术七物颗粒调控PI3K/AKT/mTOR通路抑制Cajal间质细胞凋亡治疗慢传输型便秘机制研究

目的探讨白术七物颗粒抑制Cajal间质细胞(ICC)凋亡治疗慢传输型便秘(STC)的作用机制。方法利用洛哌丁胺复制STC小鼠模型,将其随机分成对照组,模型组,白术七物颗粒低、中、高剂量组和普芦卡必利组,另设对照组。白术七物颗粒低、中、高剂量组分别灌以不同浓度白术七物颗粒,普芦卡必利组灌以普芦卡必利,对照组与模型组灌胃等体积蒸馏水。HE染色观察结肠组织病理变化,IHC法检测结肠c-kit表达,TUNEL法检测结肠ICC凋亡,WB法检测结肠PI3K、AKT、mTOR蛋白表达。结果与对照组相比,模型组结肠组织结构破坏,c-kit表达显著降低,ICC凋亡显著升高,p-PI3K/PI3K、p-AKT/AKT、p-mTOR/mTOR水平显著升高(P<0.01)。与模型组相比,白术七物颗粒各剂量组及普芦卡必利组结肠组织结构改善,白术七物颗粒高剂量组及普芦卡必利组c-kit表达显著升高,白术七物颗粒各剂量组及普芦卡必利组ICC凋亡显著降低,白术七物颗粒低剂量组p-PI3K/PI3K、p-AKT/AKT水平降低,白术七物颗粒中、高剂量组及普芦卡必利组p-PI3K/PI3K、p-AKT/AKT、p-mTOR/mTOR水平显著降低(P<0.05,P<0.01)。与白术七物颗粒高剂量组相比,白术七物颗粒低剂量组c-kit表达降低,白术七物颗粒低、中剂量组p-PI3K/PI3K水平显著升高,普芦卡必利组p-AKT/AKT水平降低(P<0.05,P<0.01)。结论白术七物颗粒可有效改善STC小鼠结肠组织损伤,促进c-kit表达,抑制ICC凋亡,其作用机制可能与PI3K/Akt/mTOR信号通路有关。

Interstitial cells of Cajal, the Maestro in health and disease

Interstitial cells of Cajal (ICC) are important players in the symphony of gut motility. They have a very signif icant physiological role orchestrating the normal peristaltic activity of the digestive system. They are the pacemaker cells in gastrointestinal (GI) muscles. Absence, reduction in number or altered integrity of the ICC network may have a dramatic effect on GI system motility. More understanding of ICC physiology will foster advances in physiology of gut motility which will help in a future breakthrough in the pharmacological interventions to restore normal motor function of GI tract. This mini review describes what is known about the physiologic function and role of ICCs in GI system motility and in a variety of GI system motility disorders.

Jianpi Qingchang decoction regulates intestinal motility of dextran sulfate sodium-induced colitis through reducing autophagy of interstitial cells of Cajal

AIM To investigate the underlying effect of Jianpi Qingchang decoction(JQD) regulating intestinal motility of dextran sulfate sodium(DSS)-induced colitis in mice. METHODS C57BL/6 mice were randomly divided into four groups: the control group, the DSS group, the JQD group, and the 5-aminosalicylic acid group. Except for the control group, colitis was induced in other groups by giving distilled water containing 5% DSS. Seven days after modeling, the mice were administered corresponding drugs intragastrically. The mice were sacrificed on the 15^(th) day. The disease activity index, macroscopic and histopathologic lesions, and ultrastructure of colon interstitial cells of Cajal(ICC) were observed. The levels of tumor necrosis factor-alpha(TNF-α), interleukin(IL)-1β, IL-10 and interferon gamma(IFN-γ), the expression of nuclear factor-kappa B(NF-κB) p65, c-kit, microtubule-associated protein 1 light chain 3(LC3-Ⅱ) and Beclin-l m RNA, and the colonic smooth muscle tension were assessed. RESULTS Acute inflammation occurred in the mice administered DSS. Compared with the control group, the levels of IL-1β, TNF-α, IL-10 and IFN-γ, the expression of LC3-Ⅱ, Beclin-1 and NF-κB p65 m RNA, and the contractile frequency increased(P < 0.05), the expression of c-kit m RNA and the colonic smooth muscle contractile amplitude decreased in the DSS group(P < 0.05). Compared with the DSS group, the levels of IL-10 and IFN-γ, the expression of c-kit m RNA, and the colonic smooth muscle contractile amplitude increased(P < 0.05), the levels of TNF-α and IL-1β, the expression of LC3-Ⅱ, Beclin-1 and NF-κB p65 m RNA, and the contractile frequency decreased in the JQD group(P < 0.05).CONCLUSION JQD can regulate the intestinal motility of DSS-induced colitis in mice through suppressing intestinal inflammatory cascade reaction, reducing autophagy of ICC, and regulating the network path of ICC/smooth muscle cells.

Control of gallbladder contractions by cholecystokinin through cholecystokinin-A receptors on gallbladder interstitial cells of cajal

AIM: To identify the cholecystokinin (CCK)-A receptors (CCK-AR) on the guniea pig gallbladder interstitial cells of cajal (ICC) and to study CCK-8 induced gallbladder muscle strip contractions through the CCK-AR. METHODS: The existence of CCK-AR was examined by immunohistofluorescence on sectioned tissue and cultured cells. In vitro contractile response of guinea pig gallbladder muscle strips and the strips with ICC removed were also studied with CCK-8 receptors added. RESULTS: In tissue sections, intensely CCKAR- immunoreactive interstitial cells were found mainly in the muscular layers. In cultured cell sections, distinctive double staining of C-kit and CCK-AR ICCs were found. When we removed the ICC of the gallbladder, CCK-8 induced muscle strip contraction dose response curve significantly shifted to the right. CONCLUSION: We proved that both the existence of CCK-AR on the guinea pig gallbladder ICC and CCK evoked contraction are mediated through direct action on CCK-AR on the gallbladder ICC.

Loss of interstitial cells of Cajal network in severe idiopathic gastroparesis

AIM: To report a case of severe idiopathic gastroparesis in complete absence of Kit-positive gastric interstitial cells of Cajal (ICC). METHODS: Gastric tissue from a patient with severe idiopathic gastroparesis unresponsive to medical treatment and requiring surgery was analyzed by conventional histology and immunohistochemistry. RESULTS: Gastric pacemaker cells expressing Kit receptor had completely disappeared while the local level of stem cell factor, the essential ligand for its development and maintenance, was increased. No signs of cell death were observed in the pacemaker region. CONCLUSION: These results are consistent with the hypothesis that a lack of Kit expression may lead to impaired functioning of ICC. Total gastrectomy proves to be curative.

白术七物颗粒对慢传输型便秘小鼠肠道运动、Cajal间质细胞、c-Kit表达及肠道菌群的影响

目的观察白术七物颗粒对慢传输型便秘(STC)小鼠肠道运动、Cajal间质细胞(ICC)、酪氨酸激酶受体c-Kit及肠道菌群的影响,探讨其治疗STC的作用机制。方法42只ICR小鼠随机分为对照组、模型组、普芦卡必利组和白术七物颗粒低、中、高剂量组,采用盐酸洛哌丁胺灌胃建立STC小鼠模型,各给药组分别予相应药物灌胃14 d。观察小鼠一般体征变化,测定粪便干湿重及肠道推进率,HE染色观察结肠组织形态,免疫组化染色检测结肠组织c-Kit表达,TUNEL染色检测结肠组织ICC凋亡情况,16S rRNA测序检测肠道菌群变化。结果与对照组比较,模型组小鼠精神不振,皮毛粗糙、光泽度差,大便干结、呈团块状,粪便干湿重显著减少,肠道推进率显著降低(P<0.01),结肠黏膜有明显糜烂,腺体被破坏,结肠组织c-Kit表达显著降低(P<0.01),ICC凋亡有所增加;与模型组比较,白术七物颗粒中、高剂量组和普芦卡必利组小鼠一般体征显著改善,粪便干湿重显著增加,肠道推进率显著升高(P<0.01),结肠黏膜结构改善,结肠组织c-Kit表达显著升高(P<0.01),ICC凋亡减少。16S rRNA测序结果显示,白术七物颗粒可调节模型小鼠粪便绒毛杆菌属、乳杆菌属、拟杆菌属、副拟杆菌属和阿克曼菌属等菌群丰度,尤以白术七物颗粒高剂量组效果最明显。结论白术七物颗粒可改善STC小鼠症状和结肠损伤,促进肠道运动,其机制可能与上调结肠组织c-Kit表达、抑制ICC凋亡、改善肠道菌群失调有关。

Dissociation, culture and morphologic changes of interstitial cells of Cajal in vitro

AIM: To study the method of dissociation, culture and investigate its morphologic changes in vitro of interstitial cells of Cajal (ICC).METHODS: Enzymatic digestion and Ficoll density centrifugation were used to dissociate ICC from the ileal segment of mice. Factors including contamination, Ca2+, Mg2+ and collagenase, and stem cell factor, etc., were investigated.ACK2, the antibody of c-kit, was used to identify the cultured ICC. Both light microscope and fluorescence microscope were used to observe the changes of ICC in vitro.RESULTS: The method for dissociation and culture of ICC in vitro was successfully established. After 24 h, cultured ICC exhibited a few axis-cylinders, and longer axis-cylinders were observed to form synapse of each other after 3 d. More widespread connections formed within 7 d in vitro. The changes of its morphologic character were obvious within 7 d; however, there were no obvious morphologic changes after 30 d.CONCLUSION: Many factors can influence the dissociation and culture of ICC.

Hwangryunhaedok-tang induces the depolarization of pacemaker potentials through 5-HT3 and 5-HT4 receptors in cultured murine small intestine interstitial cells of Cajal

AIM To investigate the effects of a water extract of Hwangryunhaedok-tang(HHTE) on the pacemaker potentials of mouse interstitial cells of Cajal(ICCs).METHODS We dissociated ICCs from small intestines and cultured. ICCs were immunologically identified using an antic-kit antibody. We used the whole-cell patch-clamp configuration to record the pacemaker potentials generated by cultured ICCs under the current clamp mode(I = 0). All experiments were performed at 30 ℃-32 ℃RESULTS HHTE dose-dependently depolarized ICC pacemaker potentials. Pretreatment with a 5-HT_3 receptor anta-gonist(Y25130) or a 5-HT_4 receptor antagonist(RS39604) blocked HHTE-induced pacemaker potential depolarizations, whereas pretreatment with a 5-HT7 receptor antagonist(SB269970) did not. Intracellular GDPβS inhibited HHTE-induced pacemaker potential depolarization and pretreatment with a Ca^(2+)-free solution or thapsigargin abolished the pacemaker potentials. In the presence of a Ca^(2+)-free solution or thapsigargin, HHTE did not depolarize ICC pacemaker potentials. In addition, HHTE-induced pacemaker potential depolarization was unaffected by a PKC inhibitor(calphostin C) or a Rho kinase inhibitor(Y27632). Of the four ingredients of HHT, Coptidis Rhizoma and Gardeniae Fructus more effectively inhibited pacemaker potential depolarization.CONCLUSION These results suggest that HHTE dose-dependently depolarizes ICC pacemaker potentials through 5-HT_3 and 5-HT_4 receptors via external and internal Ca^(2+) regulation and via G protein-, PKC-and Rho kinase-independent pathways.

Characterization of smooth muscle, enteric nerve, interstitial cells of Cajal, and fibroblast-like cells in the gastric musculature of patients with diabetes mellitus

AIM To investigate histologic abnormalities in the gastric smooth muscle of patients with diabetes mellitus(DM).METHODS Full-thickness gastric specimens were obtained from patients undergoing surgery for gastric cancer. H&E stain and Masson's Trichrome stain were performed to assess the degree of fibrosis. Immunohistochemical staining using various antibodies was also performed [antibodies against protein gene product 9.5(PGP9.5), neuronal nitric oxide synthase(n NOS), vasoactive intestinal peptide(VIP), neurokinin-1(NK1) receptor, c-Kit, and platelet-derived growth factor receptor-alpha,(PDGFRα)]. Immunofluorescent staining and evaluation with confocal microscopy were also conducted.RESULTS Twenty-six controls and 35 diabetic patients(21 shortduration patients and 14 long-duration patients) were included. There were no significant differences in basic demographics between the two groups except in mean body mass index(BMI)(higher in the DM group). Proportions of moderate-to-severe intercellular fibrosis in the muscle layer were significantly higher in the DM group than in the control group(P < 0.01). On immunohistochemical staining, c-Kit- and PDGFRα-positive immunoreactivity were significantly decreased in the DM group compared with the control group(P < 0.05). There were no statistically significant differences in PGP9.5, n NOS, VIP, and neurokinin 1 expression. On immunofluorescent staining, cellularity of interstitial cells of Cajal(ICC) was observed to decrease with increasing duration of DM.CONCLUSION Our study suggests that increased intercellular fibrosis, loss of ICC, and loss of fibroblast-like cells are found in the smooth muscle of DM patients. These abnormalities may contribute to changes in gastric motor activity in patients with DM.

Long-pulse gastric electrical stimulation protects interstitial cells of Cajal in diabetic rats via IGF-1 signaling pathway

AIM: To investigate the effects of different parameters of gastric electrical stimulation (GES) on interstitial cells of Cajal (ICCs) and changes in the insulin-like growth factor 1 (IGF-1) signal pathway in streptozotocin-induced diabetic rats. METHODS: Male rats were randomized into control, diabetic (DM), diabetic with sham GES (DM + SGES), diabetic with GES1 (5.5 cpm, 100 ms, 4 mA) (DM + GES1), diabetic with GES2 (5.5 cpm, 300 ms, 4 mA) (DM + GES2) and diabetic with GES3 (5.5 cpm, 550 ms, 2 mA) (DM + GES3) groups. The expression levels of c-kit, M-SCF and IGF-1 receptors were evaluated in the gastric antrum using Western blot analysis. The distribution of ICCs was observed using immunolabeling for c-kit, while smooth muscle cells and IGF-1 receptors were identified using alpha-SMA and IGF-1R antibodies. Serum level of IGF-1 was tested using enzyme-linked immunosorbent assay. RESULTS: Gastric emptying was delayed in the DM group but improved in all GES groups, especially in the GES2 group. The expression levels of c-kit, M-SCF and IGF-1R were decreased in the DM group but increased in all GES groups. More ICCs (c-kit(+)) and smooth muscle cells (alpha-SMA(+)/IGF-1R(+)) were observed in all GES groups than in the DM group. The average level of IGF-1 in the DM group was markedly decreased, but it was up-regulated in all GES groups, especially in the GES2 group. CONCLUSION: The results suggest that long-pulse GES promotes the regeneration of ICCs. The IGF-1 signaling pathway might be involved in the mechanism underlying this process, which results in improved gastric emptying.

Morphological changes in interstitial cells of Cajal in the deep muscular plexus and enteric motor neurons of the intestine in rats with multiple organ dysfunction syndrome

BACKGROUND：Gastrointestinal motility dysfunction in multiple organ dysfunction syndrome （MODS） has been reported to be related to damage to interstitial cells of Cajal （ICC）. In the entedc nervous system, ICC and smooth muscle cells are connected in a network to form a special functional unit. Many gastrointestinal motility dysfunction diseases are associated with damage to this network.OBJECTIVE：To investigate the morphological changes of intestinal ICC, and to explore the mechanisms underlying gastrointestinal motility dysfunction in rats with MODS.DESIGN, TIME AND SE＇I-FING：The randomized, controlled, experiment was performed at the Central Laboratory of the First Affiliated Hospital of Dalian Medical University of China between June 2007 and March 2009.MATERIALS：Escherichia coli （E. colistrain O127 H6） and bovine serum albumin were purchased from Sigma, USA.METHODS：A total of 40 Wistar rats were equally and randomly divided into MODS group and control group. Suspension of E. coil strain O127 H6 containing BaSO4 and saline were sterilely injected into the abdominal cavity of rats in the MODS and control groups, respectively.MAIN OUTCOME MEASURES：Immunohistochemical double-staining and confocal laser scanning microscopy were used to observe the morphological changes in intestinal cholinergic nerves and ICC in the deep muscular plexus network. Electron microscopy was employed to evaluate the ultrastructural features of ICC in the deep muscular plexus of rats with MODS.RESULTS：Compared with the control group, the distributions and densities of cholinergic/nitrergic newes and ICC in the deep muscular plexus were significantly decreased in the MODS group （P 〈 0.01）. The enteric nerve-ICC network were disrupted.CONCLUSION：There is ultrastructural injury in the ICC in the deep muscular plexus and enteric nerves of the intestine in rats with MODS, which may be associated with the dysmotility of the gastrointestinal tract in MODS.

Different distributions of interstitial cells of Cajal and platelet-derived growth factor receptor-α positive cells in colonic smooth muscle cell/interstitial cell of Cajal/plateletderived growth factor receptor-α positive cell syncytium in mice

AIM To investigate the distribution and function of interstitialcells of Cajal(ICCs) and platelet-derived growth factor receptor-α positive(PDGFRα+) cells in the proximal and distal colon.METHODS The comparison of colonic transit in the proximal and distal ends was performed by colonic migrating motor complexes(CMMCs). The tension of the colonic smooth muscle was examined by smooth muscle spontaneous contractile experiments with both ends of the smooth muscle strip tied with a silk thread. Intracellular recordings were used to assess electrical field stimulation(EFS)-induced inhibitory junction potentials(IJP) on the colonic smooth muscle. Western blot analysis was used to examine the expression levels of ICCs and PDGFRα in the colonic smooth muscle.RESULTS Treatment with NG-nitro-L-arginine methyl ester hydrochloride(L-NAME) significantly increased the CMMC frequency and spontaneous contractions, especially in the proximal colon, while treatment with MRS2500 increased only distal CMMC activity and smooth muscle contractions. Both CMMCs and spontaneous contractions were markedly inhibited by NPPB, especially in the proximal colon. Accordingly, CyPPA sharply inhibited the distal contraction of both CMMCs and spontaneous contractions. Additionally, the amplitude of stimulationinduced nitric oxide(NO)/ICC-dependent slow IJPs(sIJPs) by intracellular recordings from the smooth muscles in the proximal colon was larger than that in the distal colon, while the amplitude of electric field stimulationinduced purinergic/PDGFRα-dependent fast IJPs(fIJPs) in the distal colon was larger than that in the proximal colon. Consistently, protein expression levels of c-Kit and anoctamin-1(ANO1) in the proximal colon were much higher, while protein expression levels of PDGFRα and small conductance calcium-activated potassium channel 3(SK3) in the distal colon were much higher.CONCLUSION The ICCs are mainly distributed in the proximal colon and there are more PDGFRα+ cells are in the distal colon, which generates a pressure gradient between the two ends of the colon to propel the feces to the anus.

电针对糖尿病胃轻瘫大鼠胃Cajal间质细胞自噬信号通路的影响

目的:探讨电针对糖尿病胃轻瘫大鼠胃窦Cajal间质细胞自噬信号通路及胃动力的影响。方法:42只SD大鼠随机分为对照组(15只)和建模组(27只)。采用腹腔注射链脲佐菌素联合高脂高糖饮食不规则喂养8周建立糖尿病胃轻瘫模型,将建模成功的大鼠随机分为模型组和电针组,每组12只。电针组采用电针“足三里”“三阴交”“梁门”穴治疗;对照组与模型组不予以任何治疗。干预结束后,检测各组大鼠血糖水平、尿糖水平、胃排空率和小肠推进率;激光共聚焦检测Cajal间质细胞自噬流;透射电镜观察Cajal间质细胞自噬状态及超微结构;Western blot法检测Cajal间质细胞中微管相关蛋白1轻链3(LC3)、p62、磷酯酰肌醇3-激酶(PI3K)、三磷酸磷脂酰肌醇(PIP3)、蛋白激酶B(PKB/AKT)、腺苷酸活化蛋白激酶(AMPK)、哺乳动物雷帕霉素靶蛋白(mTOR)及磷酸化mTOR(p-mTOR)蛋白表达量。结果:与对照组比较,模型组大鼠胃排空率和小肠推进率显著下降(P<0.01),血糖和尿糖水平显著升高(P<0.01),AMPK表达下降(P<0.05),LC3-II/LC3-I、p62、PI3K、PIP3、AKT、mTOR和p-mTOR蛋白水平显著升高(P<0.05或P<0.01),绿色荧光蛋白(GFP)和红色荧光蛋白(RFP)的荧光强度均增强(P<0.01),Cajal间质细胞内可见1个自噬小体且胞内破损严重;与模型组比较,电针组大鼠胃排空率和小肠推进率显著上升(P<0.01),血糖和尿糖水平降低(P<0.05或P<0.01),AMPK表达上调(P<0.05),LC3-II/LC3-I、p62、PI3K、PIP3、AKT、mTOR和p-mTOR蛋白水平显著降低(P<0.05或P<0.01),GFP和RFP荧光强度均减弱(P<0.01),Cajal间质细胞内受损状况明显减轻。结论:电针能够提高糖尿病胃轻瘫大鼠胃肠动力,其作用机制可能与调节mTOR介导的信号通路而激活Cajal间质细胞自噬有关。

Differential changes in intrinsic innervation and interstitial cells of Cajal in small bowel atresia in newborns

AIM: To investigate morphological changes of the enteric nervous system (ENS) and the interstitial cells of Cajal (ICCs) in small bowel atresia.METHODS: Resected small bowel specimens from affected patients (n = 7) were divided into three parts (proximal, atretic, distal). Standard histology and enzyme immunohistochemistry anti-S100, anti-protein gene product (PGP) 9.5, anti-neurofilament (NF), antic-kit-receptor (CD117) was carried out on conventional paraffin sections of the proximal and distal part. RESULTS: The neuronal and glial markers (PGP 9.5, NF, S-100) were expressed in hypertrophied ganglia and nerve fibres within the myenteric and submucosal plexuses. Furthermore, the submucous plexus contained typical giant ganglia. The innervation pattern of the proximal bowel resembled intestinal neuronal dysplasia. The density of myenteric ICCs was clearly reduced in the proximal bowel, whereas a moderate number of muscular ICCs were found. The anti-CD117 immunore- action revealed additional numerous mast cells. The distal bowel demonstrated normal morphology and density of the ENS, the ICCs and the mast cells.CONCLUSION: The proximal and distal bowel in small bowel atresia revealed clear changes in morphology and density of the ENS and ICCs.

Identification of TRPM7 channels in human intestinal interstitial cells of Cajal

AIM： To investigate the characteristics of slow electrical waves and the presence of transient receptor potential melastatin-type 7 （TRPM7） in the human gastrointestinal （GI） tract. METHODS： Conventional microelectrode techniques were used to record intracellular electrical responses from human GI smooth muscle tissue. Immunohistochemistry was used to identify TRPM7 channels in interstitial cells of Cajat （ICCs）. RESULTS： The human GI tract generated slow electrical waves and had ICCs which functioned as pacemak er cells. Flufenamic acid, a nonselective cation channel blocker, and 2-APB （2-aminoethoxydiphenyl borate） and La3＋, TRPM7 channel blockers, inhibited the slowwaves. Also, TRPM7 channels were expressed in ICCs in human tissue. CONCLUSION： These results suggest that the human GI tract generates slow waves and that TRPM7 channels expressed in the ICCs may be involved in the gen- eration of the slow waves.

Inhibition of pacemaker activity in interstitial cells of Cajal by LPS via NF-κB and MAP kinase

AIM:To investigate lipopolysaccharide(LPS) related signal transduction in interstitial cells of Cajal(ICCs) from mouse small intestine.METHODS:For this study,primary culture of ICCs was prepared from the small intestine of the mouse.LPS was treated to the cells prior to measurement of the membrane currents by using whole-cell patch clamp technique.Immunocytochemistry was used to examine the expression of the proteins in ICCs.RESULTS:LPS suppressed the pacemaker currents of ICCs and this could be blocked by AH6809,a prostaglandin E2-EP2 receptor antagonist or NG-Nitro-Larginine Methyl Ester,an inhibitor of nitric oxide(NO) synthase.Toll-like receptor 4,inducible NO synthase or cyclooxygenase-2 immunoreactivity by specific antibodies was detected on ICCs.Catalase(antioxidant agent) had no action on LPS-induced action in ICCs.LPS actions were blocked by nuclear factor kB(NF-kB) inhibitor,actinomycin D(a gene transcription inhibitor),PD 98059(a p42/44 mitogen-activated protein kinases inhibitor) or SB 203580 [a p38 mitogen-activated protein kinases(MAPK) inhibitor].SB 203580 also blocked the prostaglandin E2-induced action on pacemaker currents in ICCs but not NO.CONCLUSION:LPS inhibit the pacemaker currents in ICCs via prostaglandin E2-and NO-dependent mechanism through toll-like receptor 4 and suggest that MAPK and NF-kB are implicated in these actions.