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Zhang Z, Li B, Jiang Q, Li Q, Pierro A, Li L. Hirschsprung-Associated Enterocolitis: Transformative Research from Bench to Bedside. Eur J Pediatr Surg 2022; 32:383-390. [PMID: 35649434 DOI: 10.1055/s-0042-1745780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Hirschsprung disease (HSCR) is a congenital disease that is characterized by the absence of intrinsic ganglion cells in the submucosal and myenteric plexuses of the distal colon and is the most common cause of congenital intestinal obstruction. Hirschsprung-associated enterocolitis (HAEC) is a life-threatening complication of HSCR, which can occur either before or after surgical resection of the aganglionic bowel. Even though HAEC is a leading cause of death in HSCR patients, its etiology and pathophysiology remain poorly understood. Various factors have been associated with HAEC, including the mucus barrier, microbiota, immune function, obstruction of the colon, and genetic variations. In this review, we examine our current mouse model of HAEC and how it informs our understanding of the disease. We also describe current emerging research that highlights the potential future of HAEC treatment.
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Affiliation(s)
- Zhen Zhang
- Department of General Surgery, Capital Institute of Pediatrics, Beijing, Beijing, China
| | - Bo Li
- Translational Medicine Program, Division of General and Thoracic Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Qian Jiang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Qi Li
- Department of General Surgery, Capital Institute of Pediatrics, Beijing, Beijing, China
| | - Agostino Pierro
- Department of Paediatric Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Long Li
- Department of General Surgery, Capital Institute of Pediatrics, Beijing, Beijing, China
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Chen KC, Chen KC, Song ZM, Croaker GD. Structural heart defects associated with ET B mutation, a cause of Hirschsprung disease. BMC Cardiovasc Disord 2021; 21:475. [PMID: 34600481 PMCID: PMC8487587 DOI: 10.1186/s12872-021-02281-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HSCR, a colonic neurocristopathy affecting 1/5000 births, is suggested to associate with cardiac septal defects and conotruncal malformations. However, we question subtle cardiac changes maybe more commonly present due to multi-regulations by HSCR candidate genes, in this instance, ETB. To investigate, we compared the cardiac morphology and quantitative measurements of sl/sl rat to those of the control group. METHODS Eleven neonatal rats were generated from heterozygote (ETB+/-) crossbreeding. Age and bodyweight were recorded at time of sacrifice. Diffusion-staining protocols with 1.5% iodine solution was completed prior to micro-CT scanning. All rats were scanned using an in vivo micro-CT scanner, Caliper Quantum FX, followed by two quality-control scans using a custom-built ex vivo micro-CT system. All scans were reviewed for gross cardiac dysmorphology. Micro-CT data were segmented semi-automatically post-NLM filtering for: whole-heart, LV, RV, LA, RA, and aortic arch. Measurements were taken with Drishti. Following image analysis, PCR genotyping of rats was performed: five sl/sl rats, three wildtype, and three heterozygotes. Statistical comparisons on organ volume, growth rate, and organ volume/bodyweight ratios were made between sl/sl and the control group. RESULTS Cardiac morphology and constituents were preserved. However, significant volumetric reductions were recorded in sl/sl rats with respect to the control: whole heart (38.70%, p value = 0.02); LV (41.22%, p value = 0.01), RV (46.15%, p value = 0.02), LA (44.93%, p value = 0.06), and RA (39.49%, p value = 0.02). Consistent trend was observed in growth rate (~ 20%) and organ-volume/bodyweight ratios (~ 25%). On the contrary, measurements on aortic arch demonstrated no significant difference among the two groups. CONCLUSION Despite the presence of normal morphology, significant cardiac growth retardation was detected in sl/sl rat, supporting the likely association of cardiac anomalies with HSCR, at least in ETB-/- subtype. Structural reduction was likely due to a combination of failure to thrive from enteric dysfunction, alterations to CaNCC colonization, and importantly coronary hypoperfusion from elevated ET-1/ETA-mediated hypervasoconstriction. Little correlation was detected between aortic arch development and sl/sl rat, supporting minor ETB role in large vessels. Although further clinical study is warranted, HSCR patients may likely require cardiac assessment in view of potential congenital cardiac defects.
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Affiliation(s)
- Ko-Chin Chen
- Australian National University Medical School, Florey Building 54 Mills Road, Acton, ACT 2601 Australia
| | - Ko-Chien Chen
- MD Anderson Cancer Centre, University of Texas, Houston, TX 77030 USA
| | - Zan-Min Song
- The John Curtin School of Medical Research, Australian National University Medical School, Acton, ACT 2601 Australia
| | - Geoffrey D. Croaker
- Australian National University Medical School, Florey Building 54 Mills Road, Acton, ACT 2601 Australia
- Paediatric Surgery, The Canberra Hospital, Garran, ACT Australia
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Gulati A, Agrawal N, Vibha D, Misra UK, Paul B, Jain D, Pandian J, Borgohain R. Safety and Efficacy of Sovateltide (IRL-1620) in a Multicenter Randomized Controlled Clinical Trial in Patients with Acute Cerebral Ischemic Stroke. CNS Drugs 2021; 35:85-104. [PMID: 33428177 PMCID: PMC7872992 DOI: 10.1007/s40263-020-00783-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/05/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND Sovateltide (IRL-1620, PMZ-1620), an endothelin-B receptor agonist, has been previously shown to increase cerebral blood flow, have anti-apoptotic activity and produce neurovascular remodeling when administered intravenously following acute cerebral ischemic stroke in rats. Its safety and tolerability were confirmed in healthy human volunteers (CTRI/2016/11/007509). OBJECTIVE Our objective was to determine the safety, tolerability and efficacy of sovateltide as an addition to standard of care (SOC) in patients with acute cerebral ischemic stroke. METHODS A prospective, multicentric, randomized, double-blind, placebo-controlled study was conducted to compare the safety (primary objective) and efficacy (secondary objective) of sovateltide in patients with acute cerebral ischemic stroke. Adult males or females aged 18-70 years who had experienced a radiologically confirmed ischemic stroke within the last 24 h were included in the study. Patients with intracranial hemorrhage and those receiving endovascular therapy were excluded. Patients randomized to the sovateltide group received three doses of sovateltide (each dose 0.3 µg/kg) administered as an intravenous bolus over 1 min at an interval of 3 ± 1 h on day 1, day 3 and day 6 (total dose of 0.9 µg/kg/day). Patients randomized to the placebo group received an equal volume of saline. Every patient in both groups received SOC for stroke. Efficacy was evaluated using neurological outcomes based on National Institute of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS) and Barthel Index (BI) scores from day 1 through day 90. Quality of life was measured using the EuroQoL-5 Dimensions (EQ-5D) and Stroke-Specific Quality of Life (SSQoL) at 60 and 90 days of follow-up. RESULTS A total of 40 patients with acute cerebral ischemic stroke were enrolled in this study, of whom 36 completed the 90-day follow-up. Patients received saline (n = 18; 11 male and 7 female) or sovateltide (n = 18; 15 male and 3 female) within 24 h of onset of stroke. The number of patients receiving investigational drug within 20 h of onset of stroke was 14/18 in the saline group and 10/18 in the sovateltide group. The baseline characteristics and SOC in both cohorts was similar. Sovateltide was well-tolerated, and all patients received complete treatment with no incidence of drug-related adverse events. Hemodynamic, biochemical or hematological parameters were not affected by sovateltide. Sovateltide treatment resulted in improved mRS and BI scores on day 6 compared with day 1 (p < 0.0001), an effect not seen in the saline group. Sovateltide increased the frequency of favorable outcomes at 3 months. An improvement of ≥ 2 points on the mRS was observed in 60 and 40% of patients in the sovateltide and saline groups, respectively (p = 0.0519; odds ratio [OR] 5.25). An improvement on the BI of ≥ 40 points was seen in 64 and 36% of the sovateltide and saline groups, respectively (p = 0.0112; OR 12.44). An improvement of ≥6 points on the NIHSS was seen in 56% of patients in the sovateltide group versus 43% in the saline group (p = 0.2714; OR 2.275). The number of patients with complete recovery (defined as an NIHSS score of 0 and a BI of 100) was significantly greater (p < 0.05) in the sovateltide group than in the saline group. An assessment of complete recovery using an mRS score of 0 did not show a statistically significant difference between the treatment groups. Sovateltide treatment resulted in improved quality of life as measured by the EQ-5D and SSQoL on day 90. CONCLUSION Sovateltide was safe and well-tolerated and resulted in improved neurological outcomes in patients with acute cerebral ischemic stroke 90 days post-treatment. TRIAL REGISTRATION The study is registered at CTRI/2017/11/010654 and NCT04046484.
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Affiliation(s)
- Anil Gulati
- Pharmazz, Inc., 50 West 75th Street, Suite 105, Willowbrook, IL, 60527, USA.
- Midwestern University, Downers Grove, IL, USA.
| | | | - Deepti Vibha
- All India Inst of Medical Sciences, New Delhi, India
| | - U K Misra
- Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Yulianda D, Sati AI, Makhmudi A, Gunadi. Risk factors of preoperative Hirschsprung-associated enterocolitis. BMC Proc 2019; 13:18. [PMID: 31890011 PMCID: PMC6912936 DOI: 10.1186/s12919-019-0172-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Hirschsprung-associated enterocolitis (HAEC) is a life-threatening complication of Hirschsprung disease (HSCR), that might occur preoperatively. We investigated the risk factors of preoperative HAEC. Method We retrospectively reviewed all medical records of HSCR patients admitted at Dr. Sardjito Hospital, Indonesia from March 2012 until March 2015. Diagnosis of HAEC was determined using the Delphi scoring system. Results Sixty-one HSCR patients were involved in this study, of whom 48 were males and 13 females. Eighteen percent (11/61) patients had a preoperative HAEC. The most common findings of the HAEC score found in our patients were distended abdomen (100%) and dilated loops of bowel (100%), followed by lethargy (72.7%), cut-off sign in rectosigmoid with absence of distal air (72.7%), leukocytosis (72.7%), and shift to left (63.6%). There was no association between gender, age of HSCR diagnosis, early/late diagnosis during neonatal period, aganglionosis type, albumin level nor body mass index with preoperative HAEC (p = 0.69, 0.76, 0.33, 1.0, 0.86, and 0.50, respectively). In addition, the maternal age, gestational age, and maternal education level also did not correlate with the development of preoperative HAEC (p = 0.71, 0.59, and 0.32, respectively). Conclusion The incidence of preoperative HAEC in our hospital is considered relatively moderate, with the most common findings of distended abdomen and dilated loops of bowel. None of the identified risk factors have an association with the development of HAEC in our patients.
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Affiliation(s)
- Dicky Yulianda
- Pediatric Surgery Division, Department of Surgery, Faculty of Medicine, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, 55281 Indonesia
| | - Andy Indra Sati
- Pediatric Surgery Division, Department of Surgery, Faculty of Medicine, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, 55281 Indonesia
| | - Akhmad Makhmudi
- Pediatric Surgery Division, Department of Surgery, Faculty of Medicine, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, 55281 Indonesia
| | - Gunadi
- Pediatric Surgery Division, Department of Surgery, Faculty of Medicine, Universitas Gadjah Mada/Dr. Sardjito Hospital, Yogyakarta, 55281 Indonesia
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Briyal S, Ranjan AK, Hornick MG, Puppala AK, Luu T, Gulati A. Anti-apoptotic activity of ET B receptor agonist, IRL-1620, protects neural cells in rats with cerebral ischemia. Sci Rep 2019; 9:10439. [PMID: 31320660 PMCID: PMC6639304 DOI: 10.1038/s41598-019-46203-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/04/2019] [Indexed: 02/08/2023] Open
Abstract
Endothelin-B receptor agonist, IRL-1620, provides significant neuroprotection following cerebral ischemia in rats. Whether this neuroprotection is due to inhibition of apoptosis is unknown. IRL-1620-treated rats following permanent middle cerebral artery occlusion (MCAO) showed significant improvement in neurological and motor functions along with a decrease in infarct volume at 24 h (-81.3%) and day 7 (-73.0%) compared to vehicle group. Cerebral blood flow (CBF) significantly improved in IRL-1620-treated animals compared to vehicle by day 7 post MCAO. IRL-1620-treated rats showed an increase in phospho-Akt and decrease in Bad level 7 h post-occlusion compared to vehicle, while Akt and Bad expression was similar in cerebral hemispheres at 24 h post-MCAO. The phospho-Bad level was lower in vehicle- but not in IRL-1620-treated rats at 24 h. Anti-apoptotic Bcl-2 expression decreased, while pro-apoptotic Bax expression increased in vehicle-treated MCAO rats, these changes were attenuated (P < 0.01) by IRL-1620. Mitochondrial membrane-bound Bax intensity significantly decreased in IRL-1620 compared to vehicle-treated MCAO rats. IRL-1620 treatment reduced (P < 0.001) the number of TUNEL-positive cells compared to vehicle at 24 h and day 7 post MCAO. The results demonstrate that IRL-1620 is neuroprotective and attenuates neural damage following cerebral ischemia in rats by increasing CBF and reducing apoptosis.
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Affiliation(s)
- Seema Briyal
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, 60515, USA
| | - Amaresh K Ranjan
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, 60515, USA
| | - Mary G Hornick
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, 60515, USA
| | - Anupama K Puppala
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, 60515, USA
| | - Thanh Luu
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL, 60515, USA
| | - Anil Gulati
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, 60515, USA. .,Pharmazz, Inc., Research and Development, Willowbrook, IL, USA.
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Gulati A, Hornick MG, Briyal S, Lavhale MS. A novel neuroregenerative approach using ET(B) receptor agonist, IRL-1620, to treat CNS disorders. Physiol Res 2018; 67:S95-S113. [PMID: 29947531 DOI: 10.33549/physiolres.933859] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Endothelin B (ET(B)) receptors present in abundance the central nervous system (CNS) have been shown to have significant implications in its development and neurogenesis. We have targeted ET(B) receptors stimulation using a highly specific agonist, IRL-1620, to treat CNS disorders. In a rat model of cerebral ischemia intravenous administration IRL-1620 significantly reduced infarct volume and improved neurological and motor functions compared to control. This improvement, in part, is due to an increase in neuroregeneration. We also investigated the role of IRL-1620 in animal models of Alzheimer's disease (AD). IRL-1620 improved learning and memory, reduced oxidative stress and increased VEGF and NGF in Abeta treated rats. IRL-1620 also improved learning and memory in an aged APP/PS1 transgenic mouse model of AD. These promising findings prompted us to initiate human studies. Successful chemistry, manufacturing and control along with mice, rat and dog toxicological studies led to completion of a human Phase I study in healthy volunteers. We found that a dose of 0.6 microg/kg of IRL-1620 can be safely administered, three times every four hours, without any adverse effect. A Phase II clinical study with IRL-1620 has been initiated in patients with cerebral ischemia and mild to moderate AD.
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Affiliation(s)
- A Gulati
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, USA.
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Jiao CL, Chen XY, Feng JX. Novel Insights into the Pathogenesis of Hirschsprung's-associated Enterocolitis. Chin Med J (Engl) 2017; 129:1491-7. [PMID: 27270548 PMCID: PMC4910376 DOI: 10.4103/0366-6999.183433] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Objective: To systematically summary the updated results about the pathogenesis of Hirschsprung's-associated enterocolitis (HAEC). Besides, we discussed the research key and direction based on these results. Data Sources: Our data cited in this review were obtained mainly from PubMed from 1975 to 2015, with keywords “Hirschsprung enterocolitis”, “Hirschsprung's enterocolitis”, “Hirschsprung's-associated enterocolitis”, “Hirschsprung-associated enterocolitis”, “HAEC”, and “EC”. Study Selection: Articles regarding the pathogenesis of HAEC were selected, and the articles mainly regarding the diagnosis, surgical approach, treatment, and follow-up were excluded. Results: Several factors, mainly including mucus barrier, intestinal microbiota, and immune function, as well as some other factors such as genetic variations and surgical reasons, have been found to be related to the pathogenesis of HAEC. Changed quantity and barrier property of mucus, different composition of microbiota, and an abnormal immune state work together or separately trigger HAEC. Conclusions: The maintenance of intestinal homeostasis is due to a well cooperation of microbiota, mucus barrier, and immune system. If any part presents abnormal, intestinal homeostasis will be broken. Meanwhile, for patients with Hirschsprung's disease or HAEC, dysfunction of these parts has been found. Thus, the happening of HAEC may be mainly attributed to the disorders of intestinal microbiota, mucus barrier, and immune system.
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Affiliation(s)
- Chun-Lei Jiao
- Department of Pediatric Surgery, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430000, China
| | - Xu-Yong Chen
- Department of Pediatric Surgery, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430000, China
| | - Jie-Xiong Feng
- Department of Pediatric Surgery, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430000, China
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Ayala-Valdovinos MA, Galindo-García J, Sánchez-Chiprés D, Duifhuis-Rivera T. New test for endothelin receptor type B (EDNRB) mutation genotyping in horses. Mol Cell Probes 2016; 30:182-4. [DOI: 10.1016/j.mcp.2016.03.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 03/18/2016] [Accepted: 03/24/2016] [Indexed: 10/22/2022]
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Puppala B, Awan I, Briyal S, Mbachu O, Leonard M, Gulati A. Ontogeny of endothelin receptors in the brain, heart, and kidneys of neonatal rats. Brain Dev 2015; 37:206-15. [PMID: 24815227 DOI: 10.1016/j.braindev.2014.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 04/16/2014] [Accepted: 04/17/2014] [Indexed: 01/15/2023]
Abstract
BACKGROUND Endothelin (ET) plays an important role in many physiological functions. It has been demonstrated that endogenous ET-1 concentration in the central nervous system (CNS) changes with age; however the ontogeny of ETA and ETB receptors in the brain, heart, and kidneys during postnatal development has not been studied. METHODS Brains, hearts and kidneys of rats at postnatal days 1, 7, 14 and 28 were evaluated for the expression of ETA and ETB receptors via Western blot. ETB receptors within the developing brain were further accessed via immunofluorescence. RESULTS The mean organ and body weights increased proportionally with advancing age demonstrating normal growth. The expression of ETA receptors in the brain, heart, and kidneys and ETB receptor expression in the heart and kidneys was similar in these rats at postnatal ages 1, 7, 14 and 28days. However, brain ETB receptor expression significantly (P<0.001) decreased by 72% on day 28 compared to the levels on postnatal day 1. Upon immunofluorescent analysis, the intensity of ETB staining in the cerebral cortex and subventricular zones of the developing rat brain decreased significantly from day 1 to day 7 (P<0.001) and from day 7 to day 14 (P<0.0001). There was no further decrease in ETB intensity noted in the cerebral cortex and subventricular zones between day 14 and day 28 of postnatal age. The intensity of ETB receptor staining within the cerebrovasculature, on the other hand, increased significantly (P<0.05) from days 1 and 7 to day 14. CONCLUSIONS These results demonstrate that expression of ETA receptors does not change with postnatal development. On the other hand ETB receptors in the cerebral cortex and subventricular zones of the brain decrease with age, while ETB receptors in the cerebrovasculature increase with age, implicating ETB receptor involvement in the structural maturity and development of the CNS.
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Affiliation(s)
- Bhagya Puppala
- Department of Pediatrics, Division of Neonatology, Advocate Lutheran General Children's Hospital, Park Ridge, IL, USA; Advocate Medical Group, Park Ridge, IL, USA.
| | - Imran Awan
- Department of Pediatrics, Division of Neonatology, Advocate Lutheran General Children's Hospital, Park Ridge, IL, USA.
| | - Seema Briyal
- Department of Pharmaceutical Sciences, Midwestern University Chicago College of Pharmacy, Downers Grove, IL, USA.
| | - Obinna Mbachu
- Department of Pharmaceutical Sciences, Midwestern University Chicago College of Pharmacy, Downers Grove, IL, USA.
| | - Mary Leonard
- Department of Pharmaceutical Sciences, Midwestern University Chicago College of Pharmacy, Downers Grove, IL, USA.
| | - Anil Gulati
- Department of Pharmaceutical Sciences, Midwestern University Chicago College of Pharmacy, Downers Grove, IL, USA.
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Frykman PK, Cheng Z, Wang X, Dhall D. Enterocolitis causes profound lymphoid depletion in endothelin receptor B- and endothelin 3-null mouse models of Hirschsprung-associated enterocolitis. Eur J Immunol 2015; 45:807-17. [PMID: 25487064 DOI: 10.1002/eji.201444737] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 11/17/2014] [Accepted: 12/02/2014] [Indexed: 02/02/2023]
Abstract
Potentially life-threatening enterocolitis is the most frequent complication in children with colonic aganglionosis (Hirschsprung disease, HSCR), and little is known about the mechanisms leading to enterocolitis. Splenic lymphopenia has been reported in the Endothelin Receptor B (Ednrb)-null mouse model of HSCR that develops enterocolitis. In this study, we sought to identify molecular mechanisms underlying this immune phenotype. We employed the Ednrb(-/-) mouse, and the knockout of its ligand, Edn3 (Edn3(-/-)). The major finding is that enterocolitis in the Ednrb(-/-) and Edn3(-/-) mice lead to thymic involution, splenic lymphopenia, and suppression of B lymphopoiesis as a consequence of colonic aganglionosis, not an intrinsic Edn3-Ednrb signaling defect directly affecting the lymphoid organs. We showed that adoptive transfer of Ednrb(-/-) marrow repopulated the RAG2-null mice marrow, thymus and spleen without development of enterocolitis. We identified the glucocorticoid corticosterone, as a potential mediator of the immune phenotype. This previously unrecognized pattern of immune abnormalities in mouse is nearly identical to lymphoid depletion in neonatal sepsis during severe physiological stress, suggesting that the mouse model used here could be also used for sepsis studies.
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Affiliation(s)
- Philip K Frykman
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Young HM, Cane KN, Anderson CR. Development of the autonomic nervous system: a comparative view. Auton Neurosci 2010; 165:10-27. [PMID: 20346736 DOI: 10.1016/j.autneu.2010.03.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2009] [Revised: 02/27/2010] [Accepted: 03/01/2010] [Indexed: 12/15/2022]
Abstract
In this review we summarize current understanding of the development of autonomic neurons in vertebrates. The mechanisms controlling the development of sympathetic and enteric neurons have been studied in considerable detail in laboratory mammals, chick and zebrafish, and there are also limited data about the development of sympathetic and enteric neurons in amphibians. Little is known about the development of parasympathetic neurons apart from the ciliary ganglion in chicks. Although there are considerable gaps in our knowledge, some of the mechanisms controlling sympathetic and enteric neuron development appear to be conserved between mammals, avians and zebrafish. For example, some of the transcriptional regulators involved in the development of sympathetic neurons are conserved between mammals, avians and zebrafish, and the requirement for Ret signalling in the development of enteric neurons is conserved between mammals (including humans), avians and zebrafish. However, there are also differences between species in the migratory pathways followed by sympathetic and enteric neuron precursors and in the requirements for some signalling pathways.
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Affiliation(s)
- Heather M Young
- Department of Anatomy & Cell Biology, University of Melbourne, VIC Australia.
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12
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Cheng Z, Dhall D, Zhao L, Wang HL, Doherty TM, Bresee C, Frykman PK. Murine model of Hirschsprung-associated enterocolitis. I: phenotypic characterization with development of a histopathologic grading system. J Pediatr Surg 2010; 45:475-82. [PMID: 20223308 PMCID: PMC4370315 DOI: 10.1016/j.jpedsurg.2009.06.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 06/06/2009] [Accepted: 06/08/2009] [Indexed: 12/25/2022]
Abstract
PURPOSE The aim of the study was to characterize enterocolitis in the Ednrb-null (Ednrb-/-) mouse with aganglionosis of the colon and to develop and validate a semiquantitative histopathologic grading system to assess enterocolitis. METHODS We isolated colon and ileal specimens of Ednrb-/- and control mice (Ednrb+/+) and performed histochemical staining (H&E) on tissue sections. After establishing inflammation grading criteria, 2 blinded pathologists independently assessed the severity and depth of inflammation of proximal colon segments on 2 separate occasions. Interclass correlations (ICCs) and coefficient of variation (CV) were calculated to determine interrater and intrarater agreement. We then prospectively applied the enterocolitis grading system to Ednrb-/- mice that became clinically ill. A cohort of Ednrb-/- mice were observed until they developed clinical illness, at which time they were euthanized and had multiple organ homogenates cultured for bacteria, and colon and small bowel were histopathologically graded for enterocolitis. Spearman's rank correlations comparing enterocolitis scores with level of bacteremia were performed. RESULTS Intra- and interrater ICCs of the histologic scoring system were satisfactory (0.61 and 0.94, respectively), as were intra- and interrater CVs (18% and 9%, respectively). Of the Ednrb-/- mice, 65% developed bacteremia. Those with bacteremia had significantly higher enterocolitis scores than those without bacteremia (P < .01). Ednrb-/- mice that developed bacteremia showed a strong positive correlation between total enterocolitis scores and number of bacterial colony forming units in peritoneal lavage, liver, kidney, and aerobic spleen. CONCLUSIONS The Ednrb-/- mouse with aganglionosis develops enterocolitis and has features similar to Hirschsprung-associated enterocolitis in humans. Our grading system is a reliable way to assess enterocolitis. By performing microsurgical pull-through, we can now perform controlled, hypothesis-driven, mechanistic studies to evaluate etiologic factors affecting enterocolitis in the Ednrb-/- mouse.
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Affiliation(s)
- Zhi Cheng
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Deepti Dhall
- Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Lifu Zhao
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Hanlin L. Wang
- Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Terence M. Doherty
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Catherine Bresee
- The Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Philip K. Frykman
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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Zhao L, Dhall D, Cheng Z, Wang HL, Doherty TM, Bresee C, Frykman PK. Murine model of Hirschsprung-associated enterocolitis II: Surgical correction of aganglionosis does not eliminate enterocolitis. J Pediatr Surg 2010; 45:206-11; discussion 211-2. [PMID: 20105605 PMCID: PMC4375950 DOI: 10.1016/j.jpedsurg.2009.10.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Accepted: 10/06/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Hirschsprung disease (HD) results from aganglionosis of the colon, is linked to acute and chronic enterocolitis (known as Hirschsprung-associated enterocolitis) despite successful corrective surgery, and can lead to bacteremia and even death. The genetic and molecular mechanisms underlying these disorders are largely unknown. METHODS We developed a microsurgical corrective pull-through procedure in mice, and applied that to Ednrb(-/-) mice, which manifest aganglionic megacolon that is very similar to HD. Wild-type littermates (Ednrb(+/+)) also underwent identical surgery. At prespecified time points postoperatively, mice were sacrificed, and histopathologic analyses of intestinal inflammation were performed. Mice of both genotypes were sacrificed after the postoperative recovery period to determine if corrective surgery itself caused inflammation. Stooling patterns were assessed as well to determine if intestinal function normalized after surgery. RESULTS There was no difference in histopathological enterocolitis scores after recovery from surgery. Stooling patterns in Ednrb(-/-) and Ednrb(+/+) mice were similar postoperatively, suggesting normalization of intestinal function. However, with time, approximately 40% of Ednrb(-/-) mice developed clinical illness consistent with enterocolitis. No control (Ednrb(+/+)) mice developed clinical enterocolitis. Histopathological enterocolitis scores in the 40% of Ednrb(-/-) mice that developed clinical enterocolitis postoperatively were significantly worse than those of healthy postoperative Ednrb(-/-) mice. In contrast, none of the Ednrb(+/+) control mice exhibited postoperative long-term inflammation. CONCLUSIONS Microsurgical pull-through operation in Ednrb(-/-) mice produces a mouse model that closely resembles key features of Hirschsprung-associated enterocolitis, enabling controlled study of genetic and molecular mechanisms in Ednrb(-/-) mice and other genotypes that produce similar phenotypes.
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Affiliation(s)
- Lifu Zhao
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Deepti Dhall
- Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Zhi Cheng
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Hanlin L. Wang
- Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Terence M. Doherty
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Catherine Bresee
- The Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Philip K. Frykman
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA, Corresponding author. Tel.: +1 310 423 2331; fax: +1 310 423 4850., (P.K. Frykman)
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Binder C, Hagemann T, Sperling S, Schulz M, Pukrop T, Grimshaw MJ, Ehrenreich H. Stromal endothelin B receptor-deficiency inhibits breast cancer growth and metastasis. Mol Cancer Ther 2009; 8:2452-60. [PMID: 19671740 DOI: 10.1158/1535-7163.mct-09-0032] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The endothelin (ET) axis, often deregulated in cancers, is a promising target for anticancer strategies. Whereas previous investigations have focused mostly on ET action in malignant cells, we chose a model allowing separate assessment of the effects of ETs and their receptors ET(A)R and ET(B)R in the tumor cells and the stromal compartment, which is increasingly recognized as a key player in cancer progression. In homozygous spotting lethal rats (sl/sl), a model of constitutive ET(B)R deficiency, we showed significant reduction of growth and metastasis of MAT B III rat mammary adenocarcinoma cells overexpressing ET(A)R and ET-1 but negative for ET(B)R. Lack of stromal ET(B)R expression did not influence angiogenesis. However, it was correlated with diminished infiltration by tumor-associated macrophages and with reduced production of tumor necrosis factor-alpha, both known as powerful promoters of tumor progression. These effects were almost completely abolished in transgenic sl/sl rats, wherein ET(B)R function is restored by expression of an intact ET(B)R transgene. This shows that tumor growth and metastasis are critically dependent on ET(B)R function in cells of the microenvironment and suggests that successful ETR antagonist therapy should also target the stromal component of ET signaling
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Affiliation(s)
- Claudia Binder
- Department of Hematology/Oncology, Georg-August-University, D-37099 Goettingen, Germany.
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Zhao L, Cheng Z, Dhall D, Doherty TM, Frykman PK. A novel corrective pullthrough surgery in a mouse model of Hirschsprung's disease. J Pediatr Surg 2009; 44:759-66. [PMID: 19361637 PMCID: PMC4372194 DOI: 10.1016/j.jpedsurg.2008.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 06/10/2008] [Accepted: 06/11/2008] [Indexed: 01/21/2023]
Abstract
BACKGROUND/PURPOSE The study aimed to develop a mouse model of post-pullthrough Hirschsprung's disease that will allow investigation of mechanisms that cause postoperative complications. METHODS We developed a novel microsurgical pullthrough operation on Balb/C mice and evaluated its effect on growth rate and stooling pattern. Histologic assessment of the pullthrough colon was performed. The pullthrough operation was then performed on Ednrb-/- mice that have aganglionic megacolon and Ednrb+/+ littermate controls, and the outcomes compared. RESULTS The Balb/C pullthrough group had 97% survival at 1 week and 70% survival at 2 weeks. Body weight of the pullthrough animals declined 15% in the first week after surgery and subsequently normalized. The stooling pattern showed consistently softer stools in the pullthrough group, but no difference in frequency compared to controls. Histopathologic analyses 4 weeks postoperatively showed well-healed coloanal anastomoses. Two-week survival after pullthrough surgery in Ednrb-/- and Ednrb+/+ mice was 50.0%, and 69.2%, respectively (P = NS). Increased mortality in the Ednrb-/- mice was related to the technical challenge of performing microsurgery on smaller-sized mice with poor baseline health status. CONCLUSIONS Our microsurgical pullthrough operation in mice is feasible and allows systematic investigations into potential mechanisms mediating post-pullthrough complications and poor long-term results in mouse models of Hirschsprung's disease.
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Affiliation(s)
- Lifu Zhao
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Zhi Cheng
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Deepti Dhall
- Section of Gastrointestinal Pathology, Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Terence M. Doherty
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Philip K. Frykman
- Division of Pediatric Surgery and The Pediatric Surgery Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA,Corresponding author. Tel.: +1 310 423 2331; fax: +1 310 423 4850. (P.K. Frykman)
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Vidovic M, Chen MM, Lu QY, Kalloniatis KF, Martin BM, Tan AHY, Lynch C, Croaker GDH, Cass DT, Song ZM. Deficiency in endothelin receptor B reduces proliferation of neuronal progenitors and increases apoptosis in postnatal rat cerebellum. Cell Mol Neurobiol 2008; 28:1129-38. [PMID: 18683040 DOI: 10.1007/s10571-008-9292-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 06/17/2008] [Indexed: 12/19/2022]
Abstract
Endothelins regulate cellular functions in the mammalian brain through the endothelin receptors A and B (EDNRA and EDNRB). In this study, we investigated the role of EDNRB on cell proliferation in the cerebellum by using the spotting lethal (sl) rat, which carries a naturally occurring deletion in the EDNRB gene. Proliferating cells in the three genotypes, wild-type (+/+), heterozygous (+/sl) and homozygous mutant (sl/sl) rats were labelled by intraperitoneal injection of 5-bromo-2'-deoxyuridine (BrdU) at postnatal day 2. The density of BrdU-positive cells (per mm(2)) in the external germinal layer of sl/sl rats (Mean +/- SEM, 977 +/- 388) was significantly reduced compared to +/+ (4915 +/- 631) and +/sl (2304 +/- 557) rats. Subsequently, we examined the effects of EDNRB mutation on neural apoptosis by terminal deoxynucleotidyltransferase-mediated dUTP nick end-labelling assay. This showed that the density of apoptotic cells in the cerebella of sl/sl rats (9.3 +/- 0.5/mm(2)) was significantly more increased than +/+ rats (4 +/- 0.7). The expression of brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) were measured with standard ELISA, but were unchanged in all genotypes. These results suggest that ENDRB mediates neural proliferation and have anti-apoptotic effects in the cerebellum of the postnatal rat, and that these effects are independent of changes in the expression of BDNF and GDNF. Our findings will lead to better understanding of the morphological changes in the cerebellum of Hirschsprung's disease patients with congenital EDNRB mutation.
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Affiliation(s)
- Maria Vidovic
- Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, ACT 0200, Australia
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Mochizuki K, Ohno Y, Kanematsu T, Sakurai-Yamashita Y, Niwa M, Hishikawa Y, Koji T. Possible protection of sinusoidal endothelial cells by endothelin B receptor during hepatic warm ischemia-reperfusion. Surg Today 2007; 37:460-7. [PMID: 17522762 DOI: 10.1007/s00595-006-3411-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2006] [Accepted: 11/13/2006] [Indexed: 12/31/2022]
Abstract
PURPOSE Endothelins (ETs) are important regulators of the hepatic microcirculation. We investigated the pure biological roles of endothelin B receptors (ETB-Rs) on hepatic warm ischemia-reperfusion (I/R) injury using ETB-R deficient spotting lethal (sl) rats. METHODS Homozygous (sl/sl) and wild-type (+/+) rats were exposed to 60 min of 92% partial hepatic ischemia and then were killed at 2, 6, and 24 h, and 3 and 7 days after reperfusion. We measured the serum alanine aminotransferase (ALT) levels to assess hepatocyte injury, and the serum hyaluronic acid (HA) levels and factor VIII-related antigen (FVIIIRAg) staining to assess sinusoidal endothelial cell (SEC) injury. We also measured the concentrations of ET-1 and nitrite (NO2-) and nitrate (NO3-) of liver tissue samples. RESULTS Although no significant difference was observed in the ALT levels, the HA levels were significantly elevated at an early stage after reperfusion in the sl/sl rats. Regarding FVIIIRAg staining, positive SECs were enhanced in the sl/sl rats. The ET-1 levels were also significantly elevated at an early stage after reperfusion in the sl/sl rats. Regarding the NO2- and NO3- levels, no significant difference was observed. CONCLUSION Endothelin B receptor was shown to have a protective effect on SECs through the inhibition of ET-1 during hepatic warm I/R injury.
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Affiliation(s)
- Kyoko Mochizuki
- Department of Transplantation and Digestive Surgery, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, Nagasaki, 852-8501, Japan
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Kinoshita K, Horiguchi K, Fujisawa M, Kobirumaki F, Yamato S, Hori M, Ozaki H. Possible involvement of muscularis resident macrophages in impairment of interstitial cells of Cajal and myenteric nerve systems in rat models of TNBS-induced colitis. Histochem Cell Biol 2006; 127:41-53. [PMID: 16871386 DOI: 10.1007/s00418-006-0223-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2006] [Indexed: 12/19/2022]
Abstract
Resident macrophages are distributed in the network of interstitial cells of Cajal (ICC) and the myenteric nerve within the myenteric plexus. We evaluated changes in chemoattractant protein mRNA expression in macrophages and neutrophils, the ICC, nerve and macrophages in the myenteric plexus of model rats with TNBS-induced colitis. Chemoattractant proteins, MCP-1, GRO, MIP-2 and CINC-2alpha were upregulated in the colonic muscle layer after inflammation. Leukocyte infiltration and MPO activity were increased in the muscle layer. Electron microscopy indicated an irregular contour of the myenteric ganglia into which numerous macrophages had penetrated. Macrophages were also distributed near the ICC in the inflamed myenteric plexus. Immunohistochemistry showed that the ICC network and myenteric nerve system had disappeared from the inflamed region, whereas the number of resident macrophages was increased. TTX-insensitive, possibly ICC-mediated, rhythmic contractions of circular smooth muscle strips and enteric neuron-mediated TTX-sensitive peristalsis in the whole proximal colon tissue were significantly inhibited in the inflamed colon, indicating that the ICC-myenteric nerve system was dysfunctional in the inflamed muscle layer. Their accumulation around the myenteric nerve plexus and the ICC network suggests that macrophages play an important role in inducing intestinal dysmotility in gut inflammation.
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Affiliation(s)
- Kazuya Kinoshita
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Tokyo 113-8657, Japan
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Elsinghorst TAM. First cases of animal diseases published in 2005. Vet Q 2005; 27:127-37. [PMID: 16238112 DOI: 10.1080/01652176.2005.9695193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022] Open
Abstract
In 2003, Veterinary Quarterly started with the publication of a series of articles reviewing reports on "first cases" of animal diseases. Till now six articles have been published. They were arranged in order of animal species. Each article concerned only one species. Starting at this seventh publication, each article discusses "first cases" on more than one animal species. In this article 15 cases published in 2005 are discussed: one in birds, two in cats, three in cattle, four in dogs, two in goats, one in hares, and two in horses. Of each case a short introduction, the bibliographical data of the publication, the abstract of the author(s) (except one case) and some additional information (mainly) derived from the article are given.
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Riechers CC, Knabe W, Sirén AL, Gariepy CE, Yanagisawa M, Ehrenreich H. Endothelin B receptor deficient transgenic rescue rats: a rescue phenomenon in the brain. Neuroscience 2004; 124:719-23. [PMID: 15026112 DOI: 10.1016/j.neuroscience.2003.10.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2003] [Indexed: 11/26/2022]
Abstract
Homozygous endothelin B receptor deficiency leads to congenital aganglionosis of the gut in rats and mice, equivalent to human Hirschsprung disease. Homozygous endothelin B receptor deficient rats (spotting lethal rats, sl/sl) are characterized not only by this developmental disorder of the enteric nervous system, which limits their life span to 3-4 weeks, but exhibit an increased rate of apoptosis in the dentate gyrus compared to wildtype (+/+) rats. Recently, endothelin B receptor deficient transgenic rescue rats (sl/sl, tg/tg) were created to further investigate the role of the endothelin B receptor in mature animals. Linkage of the human dopamine-beta-hydroxylase promoter to the rat endothelin B receptor gene and expression of this transgenic construct results in normal development of the enteric nervous system. We investigated the expression pattern of this transgenic construct in the brain by using reverse transcriptase polymerase chain reaction. Unexpectedly, transgene mRNA expression was not restricted to the brain stem where adrenergic and noradrenergic nuclei are known to be present but, in addition, was also detectable in hippocampus and cortex. Using in situ tailing technique, cleaved caspase-3 immunohistochemistry and analysis of hematoxylin-eosin-stained serial sections, we found that all studied transgenic animals were rescued from the increased rate of apoptosis in the dentate gyrus characteristic for non-transgenic sl/sl rats. This finding supports our previous observation that the endothelin B receptor might be an important regulatory element supporting cellular survival in the hippocampus during postnatal development. The endothelin B receptor deficient transgenic rescue rats used here are rescued from developmental disorders both in the gut and in the brain.
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Affiliation(s)
- C-C Riechers
- Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Strasse 3, D-37075 Göttingen, Germany
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21
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Tanoue A, Koshimizu TA, Tsuchiya M, Ishii K, Osawa M, Saeki M, Tsujimoto G. Two novel transcripts for human endothelin B receptor produced by RNA editing/alternative splicing from a single gene. J Biol Chem 2002; 277:33205-12. [PMID: 12080062 DOI: 10.1074/jbc.m203972200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hirschsprung disease is a heterogeneous genetic disorder, causative genes of which include the endothelin B receptor (ETB). To investigate the mutations of ETB in Hirschsprung disease, expression of the ETB gene in lymphoblastoid cells from patients and normal healthy adults was examined, and novel mutant transcripts were found. The mutant ETB gene transcripts lacked a 134-bp nucleotide sequence corresponding to exon 5, and some also contained a substitution from A to G at position 950 in exon 4, resulting in an amino acid substitution from glutamine (Q) to arginine (R). This substitution was suspected to be the result of RNA editing because it was not present in the genomic sequence. Transfection experiments using ETB minigenes containing the editing site with or without the gene for double-strand RNA deaminases (ADAR1 and ADAR2) revealed that the deaminases were involved in RNA editing. Furthermore, a c-Myc-tagged mutant ETB protein was not detected by Western blot analysis. The present results show that the mutant ETB transcripts were novel splice variants, which might not be translated, or that the products translated from splice variants might be quickly degraded, presumably because of their instability. The preferential production of this null function ETB by RNA editing/splicing could be involved in the etiology of some cases of Hirschsprung disease.
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Affiliation(s)
- Akito Tanoue
- Department of Molecular, Cell Pharmacology, National Center for Child Health and Development Research Institute 3-35-31, Taishi-do, Setagaya-Ku, Tokyo 154-8567, Japan
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Sirén AL, Lewczuk P, Hasselblatt M, Dembowski C, Schilling L, Ehrenreich H. Endothelin B receptor deficiency augments neuronal damage upon exposure to hypoxia-ischemia in vivo. Brain Res 2002; 945:144-9. [PMID: 12113963 DOI: 10.1016/s0006-8993(02)02911-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The role of functional endothelin-B (ETB)-receptors on neuronal survival upon hypoxia-ischemia (HI) has been investigated in 14-day-old ETB-receptor-deficient spotting lethal (sl/sl) and wildtype (+/+) rats. Carotid ligation followed by exposure to 8% oxygen for 2 h produced distinct cortical and hippocampal neuronal damage. Damage severity 24 h after HI was mild to intermediate in +/+ rats whereas large cortical infarcts and profound apoptosis of the hippocampus evolved in sl/sl rats. The number of apoptotic cells in the dentate 24 h after HI amounted to 30 +/- 7 cells/0.1 mm(2) in sl/sl compared to 9 +/- 3 cells/0.1 mm(2) in wildtype rats (mean +/- S.E.M., n=10-11, P=0.0093). In-vitro hypoxia (15 h) resulted in a comparable increase in cell death in primary pure neuronal hippocampal cultures from both groups (49.8 +/- 1.6% in sl/sl, 51.4 +/- 0.9% in +/+, mean +/- S.E.M., n=5, P=0.0560). To conclude, absence of functional ETB receptors is associated with an increased susceptibility to HI in-vivo, which is not intrinsic to neurons. Antagonism of ETB receptors seems not to be desirable in ischemic stroke.
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Affiliation(s)
- Anna-Leena Sirén
- Department of Neurology, Georg-August-University, and Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Strasse 3, D-37075 Göttingen, Germany.
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Abstract
This review, which is presented in two parts, summarizes and synthesizes current views on the genetic, molecular, and cell biological underpinnings of the early embryonic phases of enteric nervous system (ENS) formation and its defects. In the first part, we describe the critical features of two principal abnormalities of ENS development: Hirschsprung's disease (HSCR) and intestinal neuronal dysplasia type B (INDB) in humans, and the similar abnormalities in animals. These represent the extremes of the diagnostic spectrum: HSCR has agreed and unequivocal diagnostic criteria, whereas the diagnosis and even existence of INDB as a clinical entity is highly controversial. The difficulties in diagnosis and treatment of both these conditions are discussed. We then review the genes now known which, when mutated or deleted, may cause defects of ENS development. Many of these genetic abnormalities in animal models give a phenotype similar or identical to HSCR, and were discovered by studies of humans and of mouse mutants with similar defects. The most important of these genes are those coding for molecules in the GDNF intercellular signaling system, and those coding for molecules in the ET-3 signaling system. However, a range of other genes for different signaling systems and for transcription factors also disturb ENS formation when they are deleted or mutated. In addition, a large proportion of HSCR cases have not been ascribed to the currently known genes, suggesting that additional genes for ENS development await discovery.
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Affiliation(s)
- Donald Newgreen
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, 3052, Victoria, Australia
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Ehrenreich H, Nau TR, Dembowski C, Hasselblatt M, Barth M, Hahn A, Schilling L, Brück W. Endothelin b receptor deficiency is associated with an increased rate of neuronal apoptosis in the dentate gyrus. Neuroscience 2000; 95:993-1001. [PMID: 10682706 DOI: 10.1016/s0306-4522(99)00507-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The dentate gyrus retains neuronal proliferative potential throughout life. Using immature endothelin B receptor-deficient (sl/sl) rats, a rabbit model of pneumococcal meningitis and autopsy brains from humans who died from pneumococcal meningitis, we explored the role of endothelin B receptors in physiological and pathological neuronal apoptosis in the dentate gyrus. At postnatal days 3-4, the rate of apoptosis in the dentate gyrus was high in all rats, declining to low levels in wild-type rats (+/+) on days 14 and 22, but remaining high in both homozygous (sl/sl) and heterozygous (sl/+) endothelin B receptor-deficient rats. Increased apoptosis was not significantly compensated for by neuronal proliferation. Hippocampal neuronal cultures also exhibited genotype-dependent apoptosis with the highest rate in neurons from homozygous endothelin B receptor-deficient (sl/sl) rats. In rabbit and human pneumococcal meningitis, increased apoptosis in the dentate gyrus was associated with loss of neuronal endothelin B receptor immunoreactivity. In conclusion, endothelin B receptors appear to act as neuronal survival factors in the dentate gyrus in rodents and man, both during postnatal development and under pathological conditions.
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Affiliation(s)
- H Ehrenreich
- Max-Planck-Institute for Experimental Medicine and Department of Neurology, Göttingen, Germany.
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