Enteric nerves and interstitial cells of Cajal are altered in patients with slow-transit constipation and megacolon

BACKGROUND & AIMS: A variety of gastrointestinal motility disorders have been attributed to alterations of interstitial cells of Cajal and malformations of the enteric nervous system. This study evaluates both the distribution of interstitial cells of Cajal and the pathohistology of the enteric nervous system in 2 severe human colorectal motility disorders. METHODS: Colonic specimens obtained from patients with slow-transit constipation (n = 11), patients with megacolon (n = 6), and a control group (n = 13, nonobstructing neoplasia) were stained with antibodies against c-kit (marker for interstitial cells of Cajal) and protein gene product 9.5 (neuronal marker). The morphometric analysis of interstitial cells of Cajal included the separate registration of the number and process length within the different regions of the muscularis propria. The structural architecture of the enteric nervous system was assessed on microdissected whole-mount preparations. RESULTS: In patients with slow-transit constipation, the number of interstitial cells of Cajal was significantly decreased in all layers except the outer longitudinal muscle layer. The myenteric plexus showed a reduced ganglionic density and size (moderate hypoganglionosis) compared with the control group. Patients with megacolon were characterized by a substantial decrease in both the number and the process length of interstitial cells of Cajal. The myenteric plexus exhibited either complete aganglionosis or severe hypoganglionosis. CONCLUSIONS: The enteric nervous system and interstitial cells of Cajal are altered concomitantly in slow-transit constipation and megacolon and may play a crucial role in the pathophysiology of colorectal motility disorders.     

Development of interstitial cells of Cajal in a full-term infant without an enteric nervous system

The relationship between the development of the enteric nervous system and interstitial cells of Cajal (ICC) in the human small intestine was investigated in a full-term infant who presented with intestinal pseudo-obstruction. Immunohistochemistry revealed absence of enteric nerves and ganglia but abundant c-Kit immunoreactivity associated with Auerbach's plexus (ICC-AP). However, c-Kit immunoreactivity associated with the deep muscular plexus (ICC-DMP) and intermuscular ICC was absent. Electron microscopy showed ICC-AP with a normal ultrastructure; ICC-DMP were seen but were severely injured, suggesting degeneration. In vitro recording of intestinal muscle showed slow wave activity as well as response to cholinergic stimulation. Fluoroscopic examination of the small bowel showed a variety of motor patterns, including rhythmic, propagating contractions. In conclusion, total absence of enteric nerves was associated with absence of normal ICC-DMP. However, a normal musculature, including a network of ICC-AP, allowed for generation of rhythmic, propagating contractile activity, suggesting the presence of functional motor activity.     

Intestinale Innervationsstörungen: Anatomische Grundlagen und Diagnostik

Histopathological insights into intestinal innervation disorders require the knowledge of the anatomical topography and structure of the enteric nervous system (ENS). The ENS of the human colon is composed of intramural nerve meshes located in different layers of the intestinal wall (plexus musculares, plexus myentericus, plexus submucosi, plexus mucosi). A differentiated visualization of the components of the ENS is achieved-by enzyme- and immunohistochemical methods. In comparison to cross-sections, wholemount preparations of the intestinal wall allow a two dimensional demonstration of the network-character of the nerve plexus and preserve the anatomical in-situ conditions. A complete histopathological diagnosis of the ENS requires full-thickness biopsies or resected specimens, as an assessment of the entire plexus layers is achieved only by this procedure. The establishment of reference values by means of morphometrical studies of ENS contributes to an objective and standardized histopathological diagnosis. Aganglionosis, hypoganglionosis, intestinal neuronal dysplasia and heterotopias are considered to be the most acknowledged forms of intestinal innervation disorders. In addition, degenerative changes of enteric nerve plexus, visceral neuropathies and a disturbed homeostasis of enteric neurotransmitters are described. Recently, a pathogenetical significance for functional intestinal motility disorders has been attributed to interstitial cells of Cajal (ICC). The ENS and ICC play a major role in mediating and coordinating gastrointestinal motility and therefore shoud be taken into account in clinical disorders of the intestinal motor function.     

Evolving concepts in the cellular control of gastrointestinal motility: neurogastroenterology and enteric sciences

The enteric nervous system is an independent nervous system with a complexity comparable with the central nervous system. This complex system is integrated into several other complex systems, such as interstitial cells of Cajal networks and immune cells. The result of these interactions is effective coordination of motility, secretion, and blood flow in the gastrointestinal tract. Loss of subsets of enteric nerves, of interstitial cells of Cajal, malfunction of smooth muscle, and alteration in immune cells have been identified as the basis of many motility disorders. The initial factors triggering these changes and how to intervene to prevent, halt, and reverse them needs to be understood.     

Deficiency of interstitial cells of Cajal in the small intestine of patients with Crohn''s disease

OBJECTIVE: Interstitial cells of Cajal are critical for the generation of electrical slow waves that regulate the phasic contractile activity of the tunica muscularis of the GI tract. Under certain pathophysiological conditions loss of interstitial cells of Cajal may play a role in the generation of certain motility disorders. The aim of the present study was to determine if there is an abnormality in the density or distribution of interstitial cells of Cajal from patients with Crohn's disease. METHODS: Small intestines from control subjects and patients with Crohn's disease were examined using immunohistochemistry and antibodies against the Kit receptor, which is expressed in interstitial cells of Cajal within the tunica muscularis of the GI tract. The density and distribution of interstitial cells of Cajal were assessed in the longitudinal and circular muscle layers and in the myenteric and deep muscular plexus regions of Crohn's and control tissues. RESULTS: Tissues from Crohn's disease patients showed an almost complete abolition of interstitial cells of Cajal within the longitudinal and circular muscle layers and a significant reduction in numbers at the level of the myenteric and deep muscular plexuses. CONCLUSIONS: In tissues from Crohn's disease patients, the density of interstitial cells of Cajal was reduced throughout the tunica muscularis in comparison to control small intestines. The disturbance of intestinal motility that occurs in patients with Crohn's disease may be a consequence of the loss of or defects in specific populations of interstitial cells of Cajal within the tunica muscularis.     

Understanding and controlling the enteric nervous system

The enteric nervous system or the 'Little Brain' of the gut controls gastrointestinal motility and secretion, and is involved in visceral sensation. In this chapter, new developments in understanding the function of the enteric nervous system are described. In particular, the interaction of this system with the interstitial cells of Cajal, the pacemaker cells of the gut, is highlighted. The importance of the interaction between the enteric nervous system and the immune system is discussed, especially in relation to functional bowel disorders and post-operative ileus. Evidence is also provided that neurones can change their function and phenotype, a phenomenon called neuronal plasticity, which contributes to the pathogenesis of visceral hypersensitivity. Finally, new developments in stem cell transplantation are described. All these new insights should lead to a better understanding of the enteric nervous system and hopefully to better ways of controlling it.     

肠道炎症和恢复期Cajal间质细胞变化的相关机制

摘要炎症性肠病（IBD）患者常出现肠道动力紊乱，动力紊乱与肠道炎症密切相关。Cajal间质细胞（ICC）作为起搏细胞和肠道神经支配的调节者对控制胃肠道动力起关键作用。越来越多的证据显示在健康状态下或动力疾病中存在大量ICC的修复或再生。因此，明确ICC在肠道炎症中的病理生理机制，并阐明炎症恢复阶段促进ICC生长发育的因素具有重要意义。     

慢传输型便秘发病机制的研究

慢传输型便秘(STC)的发病机制主要与肠神经系统(ENS)、Cajal间质细胞(ICC)、平滑肌、神经递质等有关。研究发现STC结肠组织中ENS出现退行性变化,肌间神经丛空泡变性,ICC数量减少,形态改变,平滑肌退行性变,多种神经递质发生改变。本文就STC发病机制的研究作一综述。     

肠神经系统在功能性胃肠病发病中的作用

肠神经系统对胃肠道运动、分泌和血液供应具有独立的调节作用,功能性胃肠病（FGIDs）的慢性症状如腹泻、便秘和疼痛与肠神经调控的胃肠道功能异常有关。某些FGIDs存在肠神经递质表达异常,甚至神经元退行性改变;肠神经系统与肠道Cajal间质细胞、胶质细胞和免疫细胞连接和功能的异常亦可能参与了FGIDs的发病;脑-肠轴功能紊乱是应激和感染后肠易激综合征的发病机制之一。肠神经系统在FGIDs的发病中具有重要作用,以肠神经为靶点为开发治疗FGIDs的有效药物开辟了广阔的前景。     

Loss of interstitial cells of cajal and inhibitory innervation in insulin-dependent diabetes

BACKGROUND & AIMS: Gastrointestinal complications of long-standing diabetes include nausea, vomiting, abdominal pain, diarrhea, and constipation. The pathophysiology underlying these symptoms is poorly understood. Recent evidence suggests an important role for interstitial cells of Cajal in controlling gastrointestinal motility. The aim of this study was to determine changes in interstitial cells of Cajal and enteric innervation in a patient with insulin-dependent diabetes. METHODS: A full thickness jejunal biopsy was obtained from a 38-year-old insulin-dependent diabetic with evidence for diabetic gastroenteropathy. Immunohistochemistry, confocal microscopy, and 3-dimensional reconstruction techniques were used to quantify changes in the volume of interstitial cells of Cajal and enteric innervation. RESULTS: Interstitial cells of Cajal were markedly decreased throughout the entire thickness of the jejunum. A decrease in neuronal nitric oxide synthase, vasoactive intestinal peptide, PACAP, and tyrosine hydroxylase immunopositive nerve fibers was observed in circular muscle layer while substance P immunoreactivity was increased. CONCLUSIONS: The data suggest that long-standing diabetes is associated with a decrease in interstitial cells of Cajal volume and a decrease in inhibitory innervation, associated with an increase in excitatory innervation. The changes in interstitial cells of Cajal volume and enteric nerves may underlie the pathophysiology of gastrointestinal complications associated with diabetes and suggest future therapeutic targets.     

Decreased interstitial cell of cajal volume in patients with slow-transit constipation

BACKGROUND & AIMS: The cause of slow-transit constipation is incompletely understood. Recent observations suggest a central role for interstitial cells of Cajal in the control of intestinal motility. The aim of this study was to determine the volume of interstitial cells of Cajal in the normal sigmoid colon and in the sigmoid colon from patients with slow transit constipation. METHODS: Sigmoid colonic samples were stained with antibodies to protein gene product 9.5, c-Kit, and alpha-smooth muscle actin. Three-dimensional reconstruction of regions of interest was performed using consecutive images collected on a laser scanning confocal microscope and ANALYZE software. RESULTS: Volume of interstitial cells of Cajal was significantly decreased in all layers of sigmoid colonic specimens from patients with slow-transit constipation compared with normal controls. Neuronal structures within the colonic circular smooth muscle layer were also decreased. CONCLUSIONS: A decrease in the volume of interstitial cells of Cajal may play an important role in the pathophysiology of slow-transit constipation.     

针刺对功能性便秘ENS-ICC调节机制的研究进展

功能性便秘(functional constipation,FC)是临床常见病和多发病,其病因和发病机制尚不十分清楚,存在多种学说.实验研究表明,"泻药性结肠"动物模型结肠表现为肠神经系统神经丛超微结构、多种受体与ICC表达的异常.我们通过检索和分析近年来针刺治疗FC的实验研究文献,发现目前针刺对FC的调节机制的研究偏于单一化,多种机制之间的调控关系没有进行深入研究.今后的研究应侧重针刺对各机制之间相互关系的阐释以及对其关键机制的探讨,使针刺作用机制的研究进一步深入,从而更好地服务于临床.     

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.     

实验性脂肪肝大鼠肠道Cajal间质细胞的研究

背景：随着社会经济的飞速发展，脂肪肝的发病率呈逐年增高的趋势。目前关于脂肪肝对胃肠动力影响的研究仍较少，尤其是对并发症的影响因素及其相关机制。目的：观察实验性脂肪肝大鼠空肠Cajal间质细胞数量的变化，探讨其与胃肠动力的相关性。方法：35只Sprague—Dawley（SD）大鼠分为脂肪肝模型组和对照组，其中脂肪肝模型组25只，对照组10只。以高脂饲料喂养大鼠制备脂肪肝模型。造模12周后，以蓝色葡聚糖-2000灌胃，通过检测大鼠小肠推进率评估肠道动力。免疫组化染色检测空肠c—kit阳性Cajal间质细胞的变化。结果：脂肪肝模型制备成功。与对照组相比。脂肪肝模型组肠道动力显著减弱（P〈0．05）。空肠c—kit阳性Cajal间质细胞显著减少（P〈0．05）。结论：脂肪肝大鼠肠道动力减弱可能与空肠CaM间质细胞减少有关。     

Intestinal pseudo-obstruction as the presenting manifestation of small-cell carcinoma of the lung. A paraneoplastic neuropathy of the gastrointestinal tract

A 58-year-old woman who had presented with intestinal pseudo-obstruction died 9 months later from rapidly progressive neurologic symptoms and autonomic insufficiency. Her gastric emptying had been markedly delayed and transit of markers had been slowed throughout the small bowel. A 5-hour manometric recording of the antrum and duodenum had shown absence of the normal interdigestive motor complex, which was replaced by irregular contractile activity of reduced amplitude. A small-cell carcinoma of the lung was found at autopsy. Pathologic study of the gut showed widespread degeneration of the myenteric plexus, which was infiltrated by plasma cells and lymphocytes and contained significantly reduced numbers of neurons. The extra-intestinal nervous system had neuronal loss and lymphocytic infiltrates in dorsal root ganglia. Thus, a gastrointestinal neuropathy causing intestinal pseudo-obstruction may be the presenting manifestation of a paraneoplastic syndrome associated with small-cell carcinoma.     

Key elements determining the intestinal region-specific environment of enteric neurons in type 1 diabetes

Diabetes,as a metabolic disorder,is accompanied with several gastrointestinal(GI) symptoms,like abdominal pain,gastroparesis,diarrhoea or constipation.Serious and complex enteric nervous system damage is confirmed in the background of these diabetic motility complaints.The anatomical length of the GI tract,as well as genetic,developmental,structural and functional differences between its segments contribute to the distinct,intestinal region-specific effects of hyperglycemia.These observations su...     

沉香化气胶囊对糖尿病大鼠小肠ICC和肌间神经丛的影响

目的:探讨沉香化气胶囊对糖尿病(diabetes mellitus,DM)大鼠小肠Cajal间质细胞(interstitial cells of Cajal,ICC)、肌间神经丛的影响.方法:将健康♂SD大鼠分为正常对照组、DM模型组、DM模型+中药组.大鼠一次性腹腔注射(ip)链脲佐菌素(STZ,60mg/kg)造模,选取成功模型,DM模型+中药组每天给予中药灌胃,模型组和正常对照组每天给予同等容量的蒸馏水,持续灌胃4wk.所有大鼠干预4wk结束后,给予印度墨汁灌胃测定小肠传输速率,利用免疫组织化学和图像分析观察十二指肠c-Kit、突触素(synaptophysin,Syn)、蛋白基因产物9.5(protein gene product 9.5,PGP9.5)的表达.结果:灌胃4wk后,DM模型+中药组小肠传输速率均比DM模型组明显增加(71.26±5.22 vs 45.52±6.42,P<0.01),仍低于对照组(71.26±5.22 vs 80.40±7.33,P<0.05);DM模型+中药组c-Kit、突触素、PGP9.5的阳性产物面积和吸光度值均比DM模型组明显增加(443.28±24.40 vs 358.83±35.03,832.33±58.78 vs 488.83±58.56,889.17±82.75 vs 445.17±64.06,0.16±0.02 vs 0.13±0.02,0.25±0.02 vs 0.16±0.01,0.24±0.02 vs 0.15±0.01,均P<0.01),仍低于正常对照组(443.28±24.40 vs 557.28±42.35,P<0.01;832.33±58.78 vs 937.67±101.23,P<0.05;889.17±82.75 vs 1050.50±90.22,P<0.01;0.16±0.02 vs 0.18±0.02,P<0.05;0.25±0.02 vs 0.29±0.03,P<0.01;0.24±0.02 vs 0.27±0.02,P<0.01).结论:沉香化气胶囊可以促进糖尿病大鼠小肠肌间神经丛c-Kit、突触素和PGP9.5的表达,提示对受损的DM大鼠小肠ICC、肌间神经丛有部分恢复作用,从而对糖尿病大鼠的胃肠动力障碍有一定的改善效应.     

Enteric neuropathology of congenital intestinal obstruction： A case report

Experimental evidence indicates that chronic mechanical sub-occlusion of the intestine may damage the enteric nervous system (ENS),although data in humans are lacking. We here describe the first case of enteric degenerative neuropathy related to a congenital obstruction of the gut. A 3-year and 9-mo old girl began to complain of vomiting, abdominal distension, constipation with air-fluid levels at plane abdominal radiology. Her subsequent medical history was characterized by 3 operations: the first showed dilated duodeno-jejunal loops in the absence of occlusive lesions; the second (2 years later) was performed to obtain full-thickness biopsies of the dilated intestinal loops and revealed hyperganglionosis at histopathology; the third (9 years after the hyperganglionosis was identified) disclosed a Ladd's band which was removed and the associated gut malrotation was corrected. Repeated intraoperative full-thickness biopsies showed enteric degenerative neuropathy along with reduced interstitial cells of Cajal network in dilated loops above the obstruction and a normal neuromuscular layer below the Ladd's band. One year after the latest surgery the patient tolerated oral feeding and did well, suggesting that congenital (partial) mechanical obstruction of the small bowel in humans can evoke progressive adaptive changes of the ENS which are similar to those found in animal models of intestinal mechanical occlusion. Such ENS changes mimic neuronal abnormalities observed in intestinal pseudoobstruction.     

Idiopathic megacolon

This leading article refers to the paper by Meier-Ruge WA, Muller-Lobeck H, Stoss F, Bruder E. The pathogenesis of idiopathic megacolon. Eur J Gastroenterol Hepatol 2006; 18:1209-1215. We apologise to all concerned for the dissociation between the two papers, which was due to an administrative error. The pathogenesis of idiopathic megacolon is still unclear. Besides abnormalities of the enteric nervous system, alterations in the function of intestinal smooth muscle cells and connective tissue elements might play an important role. A permanent extension of the bowel diameter without concrete hints to its aetiology is termed idiopathic megacolon. Evidence exists that idiopathic megacolon comprises a heterogeneous group of conditions characterized by alterations of the enteric nervous system, smooth muscle cells and/or connective tissue. Innovative molecular techniques are needed to get further insights into the pathogenesis of these intestinal motility disorders.     

Autonome Neuropathie und mehr

In patients with diabetes almost all relevant regulatory systems and effector organs which are of importance for physiological functioning of gastrointestinal motility, secretion and sensitivity may be altered. Possible disturbances with negative effects on the gastrointestinal tract include autonomic neuropathy, enteric neuropathy with alterations of the myenteric and submucosal plexus, loss of interstitial cells of Cajal (ICC), altered secretion of insulin and other regulatory peptide hormones and diabetic myopathy of smooth muscles of the gastrointestinal canal. Moreover, almost all gastrointestinal functions are also impaired by hyperglycemia. In individual patients with gastrointestinal functional disturbances and corresponding complaints it is usually impossible to clarify the exact role of these mechanisms for the pathogenesis of symptoms; however, there is preliminary evidence that improved understanding may lead to new therapeutic options.