Cathepsin D in intestinal ganglion cells. A potential aid to diagnosis in suspected Hirschsprung's disease

Intrauterine exposure to oxidative stress induces caspase-1-dependent enteric nerve cell pyroptosis

PURPOSE

This study determined whether oxidative stress causes the developmental abnormalities of the enteric nervous system during the embryonic period.

METHODS

Using the test results of tissue specimens of children with Hirschsprung disease (HSCR), we established a pregnant rat model of oxidative stress and a cellular oxidative stress model to conduct related molecular, cellular, and histopathological experiments for exploration and validation.

RESULTS

The results of the quantitative real-time polymerase chain reaction assay indicated overexpression of pyroptosis markers (NLRP3, ASC, and caspase-1) in HSCR lesions and newborn pups in the oxidative stress group (treated with D-galactose). The expression of cathepsin D was significantly decreased in intestinal tissues of newborn pups in the oxidative stress group compared to the control group. Reactive oxygen species scavengers (N-acetyl-cysteine, NAC), the caspase-1 inhibitor (VX-765), and the NLRP3 siRNA could reverse the release of LDH, decrease the number of propidium iodide stained cells, and reduce the percentage of TUNEL/caspase-3 double-positive cells in the H₂O₂-treated group.

CONCLUSION

Oxidative stress can induce the death of enteric nerve cells by activating caspase-1-dependent pyroptosis through NLRP3 inflammasomes, which may contribute to abnormal enteric nervous system development.

Multiple 'omics'-analysis reveals the role of prostaglandin E2 in Hirschsprung's disease

The etiology and pathogenesis of Hirschsprung's disease (HSCR) remain largely unknown. We examined colon tissues from three independent populations with a combined analysis of metabolomics, transcriptomics and proteomics to understand HSCR pathogenesis, according to which mouse model was used to examine prostaglandin E2 (PGE2) induced clinical presentation of HSCR. SH-SY5Y and SK-N-BE(2) cell lines were studied for PGE2 inhibited cell migration through EP2. Our integrated multiple 'omics'-analysis suggests that the levels of PGE2, the expression of the gene encoding PGE2 receptor (EP2), and PGE2 synthesis enzyme genes (PTGS1 and PTGES) increased in HSCR colon tissues, together with a decreased synthesis of PGE2-related byproducts. In vivo, the pregnant mice treated with PGE2 gave birth to offspring with the decrease of ganglion cells in their colon and gut function. In in vitro study, when EP2 was blocked, the PGE2-inhibited cell migration was recovered. Our study identified a novel pathway highlighting the link between expression of PTGS1 and PTGES, levels of PGE2, expression of PTGER2, and neural crest cell migration in HSCR, providing a novel strategy for future diagnosis and prevention of HSCR.

Colonic electrical stimulation promotes colonic motility through regeneration of myenteric plexus neurons in slow transit constipation beagles

Slow transit constipation (STC) is a common disease characterized by markedly delayed colonic transit time as a result of colonic motility dysfunction. It is well established that STC is mostly caused by disorders of relevant nerves, especially the enteric nervous system (ENS). Colonic electrical stimulation (CES) has been regarded as a valuable alternative for the treatment of STC. However, little report focuses on the underlying nervous mechanism to normalize the delayed colonic emptying and relieve symptoms. In the present study, the therapeutic effect and the influence on ENS triggered by CES were investigated in STC beagles. The STC beagle model was established by oral administration of diphenoxylate/atropine and alosetron. Histopathology, electron microscopy, immunohistochemistry, Western blot analysis and immunofluorescence were used to evaluate the influence of pulse train CES on myenteric plexus neurons. After 5 weeks of treatment, CES could enhance the colonic electromyogram (EMG) signal to promote colonic motility, thereby improving the colonic content emptying of STC beagles. HE staining and transmission electron microscopy confirmed that CES could regenerate ganglia and synaptic vesicles in the myenteric plexus. Immunohistochemical staining showed that synaptophysin (SYP), protein gene product 9.5 (PGP9.5), cathepsin D (CAD) and S-100B in the colonic intramuscular layer were up-regulated by CES. Western blot analysis and immunofluorescence further proved that CES induced the protein expression of SYP and PGP9.5. Taken together, pulse train CES could induce the regeneration of myenteric plexus neurons, thereby promoting the colonic motility in STC beagles.

Modified Rapid AChE Method (MRAM) for Hirschsprung Disease Diagnosis: A Journey from Meier-Ruge Until Now

Hirschsprung disease (HSCR) can be diagnosed using a variety of histological and immunohistochemical methods and stains. Because of the nature of the condition and the need for a rapid diagnostic confirmation, those methods with high accuracy and fast turnaround times are preferred. The authors of this paper have used rapid acetylcholinesterase (AChE) immunohistochemistry in conjunction with standard H&E in order to optimize diagnostic accuracy, and present a modified rapid AChE method (MRAM) that has been successfully utilized for over 20 years. The authors also present a list of over 30 different methods and stains that have been proposed for Hirschsprung disease diagnosis.

Neonatal functional intestinal obstruction and the presence of severely immature ganglion cells on rectal biopsy: 6 year experience

PURPOSE

We report our experience of managing eight babies who presented with neonatal intestinal obstruction and whose rectal biopsies showed severely immature ganglion cells.

METHODS

Neonatal unit records were reviewed to detect patients with suspected Hirschsprung's disease or functional intestinal obstruction. Those with intestinal atresia, anorectal malformation, malrotation, cystic fibrosis and prematurity were excluded.

RESULTS

We identified 73 patients born at term. Twenty-seven did not need a rectal biopsy. Twenty-one had biopsy proven Hirschsprung's disease, while 17 had a normal rectal biopsy. Eight patients, all of whom presented with severe abdominal distension, showed immature ganglion cells. Seven had failed to pass meconium after birth. X-rays in all patients showed distended loops of bowel. Two neonates underwent an emergency laparotomy and a stoma. A repeat biopsy at 3 months showed maturation of ganglion cells and the stoma was reversed. Rectal biopsy was repeated in two other patients 2-9 months after the first biopsy and showed mature ganglion cells. At follow-up, one patient still suffers from severe constipation. Seven are asymptomatic now, including the two patients who needed a stoma.

CONCLUSION

Immature ganglion cells on rectal biopsy may be an indicator of transient functional immaturity of the intestine.

Utilization of peripherin and S-100 immunohistochemistry in the diagnosis of Hirschsprung disease

Evaluation of rectal biopsies for ganglion cells is performed for patients suspected of having Hirschsprung disease. At times, identification of ganglion cells can be difficult, especially in newborns. To assist in diagnosis, frozen tissue can be collected for acetylcholinesterase histochemical staining. At our institution, we developed a protocol using peripherin and S-100 immunostaining as an adjunct to hematoxylin and eosin (H&E) for the identification of ganglion cells. Further, at the time of frozen section, we performed Diff Quik staining to highlight ganglion cells. One hundred and thirty eight rectal biopsies submitted for evaluation of Hirschsprung disease were compiled from the archives of the Medical College of Georgia from 2002 to 2009. Initial evaluation consisted of eight levels of H&E-stained slides and two unstained slides each for immunostaining with peripherin and S-100. If on initial evaluation, ganglion cells were not identified, additional H&E and peripherin immunostains were performed. Peripherin immunostaining was unequivocally identified in the cytoplasm of ganglion cells of patients at all ages. Of the 136 patients with diagnostic biopsies, 80% had ganglion cells. Of these, 93% of cases were diagnosed on the original eight levels. Twenty-seven cases were devoid of ganglion cells, and of these, 81% showed submucosal neural hypertrophy on S-100 staining. Twenty-six patients had confirmed aganglionic segments at the time of colonic resection. One patient had colostomy only. A total of 54 frozen sections were performed on 25 patients over this same period of time. Diff Quick staining was found to be very useful. In this study, our protocol proved to be very sensitive, specific, and efficient for the diagnosis of Hirschsprung disease.

[Conventional histological diagnostics in coloproctology]

With the introduction of immunohistochemical methods, histopathological diagnosis based on formalin fixed, paraffin embedded tissue in coloproctology has substantially improved. In recent years, the routine use of immunohistochemistry for S100, cathepsin D and a picrosirius red staining has proven to be sufficient for the diagnosis of hypoganglionosis of the myenteric plexus and desmosis of the muscularis propria. In some cases, an immunohistochemical reaction for CD 117 is also necessary for the evaluation of Cajal cells. In contrast, in ultrashort Hirschsprung's disease, aganglionosis of the anal ring, aganglionosis of the musculus corrugator cutis ani, and internal sphincter, the histochemical acetylcholinesterase reaction is essential and not replaceable by any immunohistochemical method.Immunohistochemistry, classical histological stains and enzyme histochemistry are complementary histopathological techniques. In contrast to immunohistochemistry, enzyme histochemistry requires native cryostat sections for the assessment of enzyme activity. As a consequence, biopsy performance and transport to pathology departments should be particularly well organized.

Diagnostic scoring system of Hirschsprung's disease in the neonatal period

OBJECTIVE

Eighty to ninety percent of Hirschsprung's disease (HD) patients present in newborns. However, the diagnosis of HD in the neonatal period remains difficult. Our present study aims to propose a diagnostic scoring system and hope this will increase early diagnosis of HD and avoid unnecessary rectal biopsy.

METHODS

In the first study period, 57 suspected HD patients (0-3 months) completed our predetermined study protocol in which barium enema (BE), rectal manometry (RM) and full-thickness rectal biopsy were performed. Symptoms, signs and investigations were analysed for their correlation with HD diagnosis. A HD diagnostic scoring system was developed according to the statistical results and was assessed in 74 patients in the second study period.

RESULTS

Forty-five patients were diagnosed with HD in the first study period. A HD scoring system was developed in which delayed meconium, tight anus, BE and RM were diagnostic factors. A cut-off point of 3 provided 84% of HD patients score >3, whereas 75% non-HD patients score <or=3 (p < 0.05). In the second study group, patients with score <or=3 were selected for rectal biopsy.

CONCLUSION

In the neonatal period, using a HD scoring system may help to select patients for further invasive investigation so that unnecessary biopsy can be avoided.

Intestinal neuronal dysplasia type B: one giant ganglion is not good enough

In this "Current Practice in Pediatric Pathology" article, 2 experts in the field and an associate editor of Pediatric and Developmental Pathology discuss the definition, diagnosis, clinical significance, and management of intestinal neuronal dysplasia type B. Intestinal neuronal dysplasia type B has constituted a diagnostic challenge ever since its first description more than 30 years ago. Intestinal neuronal dysplasia type B is regarded by many as a subtle malformation of the enteric nervous system that is limited to the submucosal plexus of the colon. The precise etiology remains unknown, and, to date, no specific diagnostic test exists other than morphology. Over time, with increasing experience, obligate pathological features have been adapted and refined, leading to contemporary diagnostic criteria that are enunciated in this review and placed into context with prior published data. Rigorous application of these criteria, under standardized laboratory conditions, is crucial for accurate diagnosis and future advances in this field.

[Congenital disorders of the colonic innervation. A diagnostic guide]

Hirschsprung's disease (HD, aganglionosis) is the most important form of congenital disturbance of intestinal innervation, requiring surgical intervention. Furthermore, hypoganglionosis of the transitional zone forms the most significant factor in morbidity. Pre-operative definition of the length of neuronally disturbed segment is still a diagnostic challenge for both clinical physician and pathologist. Enzyme histochemical studies form the method of choice, but certain limitations in their use must be observed. Other dysganglionoses, particularly the so-called "Intestinal Neuronal Dysplasia" (IND) cannot-because of an excessive overlapping with age-correlated normal values-unequivocally be defined as an entity on its own. The only exception to this, is the ganglionic neuromatosis, which arises as part of a genetic illness.

Detection of ganglion cells in the colonic plexuses by immunostaining for neuron-specific marker NeuN: an aid for the diagnosis of Hirschsprung disease

The majority of ganglion cells in the colonic plexuses can be easily and specifically identified by immunostaining for neuronal marker NeuN. The distance between the neighboring solitary ganglion cells or groups of ganglion cells varied from 0.18 to 4.0 mm, average 1.0 mm, in ganglionic segments of colons of patients with Hirschsprung disease, and from 0.3 to 6.3 mm, average 1.43 mm, in colons of pediatric patients with chronic constipation of various etiologies. No ganglion cells were detected in aganglionic colonic segments of patients with Hirschsprung disease by this method.

Diagnosis of hirschsprung disease using the rectal biopsy: multi-institutional survey

Diagnostic pathologists remain uncomfortable with the diagnosis of Hirschsprung disease (HD) via rectal (mucosal/submucosal) biopsy and with performance and interpretation of the associated acetylcholinesterase (AChE) assay. This report details the different diagnostic approaches taken by four major pediatric institutions-Children's Hospital, Columbus, OH; Children's Hospital Medical Center, Cincinnati, OH; Children's Hospital, Pittsburgh, PA; Children's Hospital, Los Angeles, CA-in confirming or excluding the presence of HD. The Columbus approach emphasizes serial morphologic examination of rectal biopsies, while Cincinnati emphasizes the primary diagnostic utility of the AChE stain. Pittsburgh and Los Angeles emphasize a detailed gross and microscopic analysis of rectal biopsies to detect both conventional HD and its more rare subtypes. The diagnostic approaches of these four institutions can be used on a complementary basis to the advantage of the general diagnostic pathologist, especially in HD cases with subtle clinical presentations. The need for careful and continual communication between the clinician and pathologist in diagnosing or excluding the presence of HD is imperative.