The Experts below are selected from a list of 705 Experts worldwide ranked by ideXlab platform
Nikhil Thapar - One of the best experts on this subject based on the ideXlab platform.
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Stem cell therapy in severe pediatric motility disorders.
Current opinion in pharmacology, 2018Co-Authors: Conor J. Mccann, Osvaldo Borrelli, Nikhil ThaparAbstract:Pediatric gastrointestinal motility disorders represent a range of severe developmental or acquired conditions that disrupt Enteric neuromuscular function. Current medical and surgical therapeutic options are very limited but recent advances have highlighted the possibility of improved or curative stem cell-based treatments. Not only has the ability to harvest, propagate and transplant human-derived Enteric neural stem cells (ENSCs) been demonstrated but recent in vivo transplantation studies have confirmed that ENSCs are capable of engraftment within recipient intestine of animal models of Enteric Neuropathy and effecting functional rescue. Pluripotent stem cell-derived cells and pharmacological modulation of both endogenous and transplanted neural stem cells have further enhanced the exciting prospect of clinical application of such stem cell-based therapies in the near future.
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Transplantation of Enteric nervous system stem cells rescues nitric oxide synthase deficient mouse colon
Nature Communications, 2017Co-Authors: Conor J. Mccann, Julie E. Cooper, Dipa Natarajan, Benjamin Jevans, Laura E. Burnett, Alan J. Burns, Nikhil ThaparAbstract:Isolated human and mouse Enteric nervous system stem cells (ENSCs) are capable of integrating and promoting innervation of the mouse colon. Here the authors show that transplantation of mouse ENSCs into a mouse model of human Enteric Neuropathy restores colon motility. Enteric nervous system Neuropathy causes a wide range of severe gut motility disorders. Cell replacement of lost neurons using Enteric neural stem cells (ENSC) is a possible therapy for these life-limiting disorders. Here we show rescue of gut motility after ENSC transplantation in a mouse model of human Enteric Neuropathy, the neuronal nitric oxide synthase ( nNOS ^ −/− ) deficient mouse model, which displays slow transit in the colon. We further show that transplantation of ENSC into the colon rescues impaired colonic motility with formation of extensive networks of transplanted cells, including the development of nNOS^+ neurons and subsequent restoration of nitrergic responses. Moreover, post-transplantation non-cell-autonomous mechanisms restore the numbers of interstitial cells of Cajal that are reduced in the nNOS ^ −/− colon. These results provide the first direct evidence that ENSC transplantation can modulate the Enteric neuromuscular syncytium to restore function, at the organ level, in a dysmotile gastrointestinal disease model.
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Transplantation of Enteric nervous system stem cells rescues nitric oxide synthase deficient mouse colon.
Nature communications, 2017Co-Authors: Conor J. Mccann, Julie E. Cooper, Dipa Natarajan, Benjamin Jevans, Laura E. Burnett, Alan J. Burns, Nikhil ThaparAbstract:Enteric nervous system Neuropathy causes a wide range of severe gut motility disorders. Cell replacement of lost neurons using Enteric neural stem cells (ENSC) is a possible therapy for these life-limiting disorders. Here we show rescue of gut motility after ENSC transplantation in a mouse model of human Enteric Neuropathy, the neuronal nitric oxide synthase (nNOS-/-) deficient mouse model, which displays slow transit in the colon. We further show that transplantation of ENSC into the colon rescues impaired colonic motility with formation of extensive networks of transplanted cells, including the development of nNOS+ neurons and subsequent restoration of nitrergic responses. Moreover, post-transplantation non-cell-autonomous mechanisms restore the numbers of interstitial cells of Cajal that are reduced in the nNOS-/- colon. These results provide the first direct evidence that ENSC transplantation can modulate the Enteric neuromuscular syncytium to restore function, at the organ level, in a dysmotile gastrointestinal disease model.
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Update on Foregut Molecular Embryology and Role of Regenerative Medicine Therapies
Frontiers Media S.A., 2017Co-Authors: Conor J. Mccann, Nikhil Thapar, Osvaldo Borrelli, Silvia Perin, Paolo De CoppiAbstract:Esophageal atresia (OA) represents one of the commonest and most severe developmental disorders of the foregut, the most proximal segment of the gastrointestinal (GI) tract (esophagus and stomach) in embryological terms. Of intrigue is the common origin from this foregut of two very diverse functional entities, the digestive and respiratory systems. OA appears to result from incomplete separation of the ventral and dorsal parts of the foregut during development, resulting in disruption of esophageal anatomy and frequent association with tracheo-oesophageal fistula. Not surprisingly, and likely inherent to OA, are associated abnormalities in components of the Enteric neuromusculature and ultimately loss of esophageal functional integrity. An appreciation of such developmental processes and associated defects has not only enhanced our understanding of the etiopathogenesis underlying such devastating defects but also highlighted the potential of novel corrective therapies. There has been considerable progress in the identification and propagation of neural crest stem cells from the GI tract itself or derived from pluripotent cells. Such cells have been successfully transplanted into models of Enteric Neuropathy confirming their ability to functionally integrate and replenish missing or defective Enteric nerves. Combinatorial approaches in tissue engineering hold significant promise for the generation of organ-specific scaffolds such as the esophagus with current initiatives directed toward their cellularization to facilitate optimal function. This chapter outlines the most current understanding of the molecular embryology underlying foregut development and OA, and also explores the promise of regenerative medicine
Kulmira Nurgali - One of the best experts on this subject based on the ideXlab platform.
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Targeting eotaxin-1 and CCR3 receptor alleviates Enteric Neuropathy and colonic dysfunction in TNBS-induced colitis in guinea pigs
Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 2018Co-Authors: Rhiannon Filippone, Rhian Stavely, Ainsley M Robinson, Valentina Jovanovska, Vasso Apostolopoulos, Joel C. Bornstein, Kulmira NurgaliAbstract:Background The accumulation of eosinophils is mediated by the chemokine receptor-3 (CCR3)-eotaxin axis. Increased expression of eotaxin and its receptor is associated with inflammatory bowel disease (IBD). Activation of eosinophils causes the release of cationic proteins that are neurotoxic such as eosinophil-derived neurotoxin (EDN). Damage to Enteric neurons alters neurally controlled functions of the gut correlated with intestinal inflammation. We hypothesized that inhibition of the CCR3-eotaxin axis will prevent inflammation-induced functional changes to the gastrointestinal tract. Methods Hartley guinea pigs were administered with trinitrobenzene sulfonate (TNBS; 30 mg/kg in 30% ethanol) intrarectally to induce colitis. A CCR3 receptor antagonist (SB 328437 [SB3]) was injected intraperitoneally 1 hour postinduction of colitis. Animals were euthanized 7 days post-treatment and colon tissues were collected for ex vivo studies. The EDN-positive eosinophils in the colon, indicating eosinophil activation, were quantified by immunohistochemistry. Effects of SB3 treatment on gross morphological damage, Enteric Neuropathy, and colonic dysmotility were determined by histology, immunohistochemistry, and organ bath experiments. Key results The number of EDN-positive eosinophils was significantly increased in the lamina propria in close proximity to myEnteric ganglia in inflamed colon. The TNBS-induced inflammation caused significant damage to colonic architecture and inhibition of colonic motility. Treatment with SB3 antagonist attenuated inflammation-associated morphological damage in the colon, reduced infiltration of EDN-positive eosinophils and restored colonic motility to levels comparable to control and sham-treated guinea pigs. Conclusion & inferences This is the first study demonstrating that inhibition of CCR3-eotaxin axis alleviates Enteric Neuropathy and restores functional changes in the gut associated with TNBS-induced colitis.
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Irinotecan-Induced Gastrointestinal Dysfunction Is Associated with Enteric Neuropathy, but Increased Numbers of Cholinergic MyEnteric Neurons
Frontiers in physiology, 2017Co-Authors: Rachel M Mcquade, Joel C. Bornstein, Vanesa Stojanovska, Elizabeth L. Donald, Ahmed Ehsanur Rahman, Dean G Campelj, Raquel Abalo, Emma Rybalka, Kulmira NurgaliAbstract:Gastrointestinal dysfunction is a common side-effect of chemotherapy leading to dose reductions and treatment delays. These side-effects may persist up to 10 years post-treatment. A topoisomerase I inhibitor, irinotecan (IRI), commonly used for the treatment of colorectal cancer, is associated with severe acute and delayed-onset diarrhoea. The long-term effects of IRI may be due to damage to Enteric neurons innervating the gastrointestinal tract and controlling its functions. Balb/c mice received intraperitoneal injections of IRI (30 mg/kg-1) 3 times a week for 14 days, sham-treated mice received sterile water (vehicle) injections. In vivo analysis of gastrointestinal transit via serial x-ray imaging, faecal water content, assessment of gross morphological damage and immunohistochemical analysis of myEnteric neurons were performed at 3, 7 and 14 days following the first injection and at 7 days post-treatment. Ex vivo colonic motility was analysed at 14 days following the first injection and 7 days post-treatment. Mucosal damage and inflammation were found following both short and long-term treatment with IRI. IRI-induced neuronal loss and increases in the number and proportion of ChAT-IR neurons and the density of VAChT-IR fibres were associated with changes in colonic motility, gastrointestinal transit and faecal water content. These changes persisted in post-treatment mice. Taken together this work has demonstrated for the first time that IRI-induced inflammation, neuronal loss and altered cholinergic expression is associated with the development of IRI-induced long-term gastrointestinal dysfunction and diarrhoea.
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Role of oxidative stress in oxaliplatin-induced Enteric Neuropathy and colonic dysmotility in mice.
British journal of pharmacology, 2016Co-Authors: Rachel M Mcquade, Ainsley M Robinson, Joel C. Bornstein, Simona E. Carbone, Vanesa Stojanovska, Ahmed A. Rahman, Rachel M Gwynne, Craig A. Goodman, Kulmira NurgaliAbstract:Background and Purpose Oxaliplatin is a platinum-based chemotherapeutic drug used as a first-line therapy for colorectal cancer. However, its use is associated with severe gastrointestinal side-effects resulting in dose limitations and/or cessation of treatment. In this study, we tested whether oxidative stress, caused by chronic oxaliplatin treatment, induces Enteric neuronal damage and colonic dysmotility Experimental Approach Oxaliplatin (3 mg/kg/d) was administered in vivo to Balb/c mice intraperitoneally three times a week. The distal colon was collected at day 14 of treatment. Immunohistochemistry was performed in wholemount preparations of submucosal and myEnteric ganglia. Neuromuscular transmission was studied by intracellular electrophysiology. Circular muscle tone was studied by force transducers. Colon propulsive activity studied in organ bath experiments and faeces were collected to measure water content. Key Results Chronic in vivo oxaliplatin treatment resulted in increased formation of reactive oxygen species (O2ˉ), nitration of proteins, mitochondrial membrane depolarisation resulting in the release of cytochrome c, loss of neurons, increased iNOS expression and apoptosis in both the submucosal and myEnteric plexuses of the colon. Oxaliplatin treatment enhanced nitric oxide (NO)-mediated inhibitory junction potentials and altered the response of circular muscles to the NO donor, sodium nitroprusside. It also reduced the frequency of colonic migrating motor complexes and decreased circular muscle tone, effects reversed by the NO synthase inhibitor, Nω-Nitro-L-arginine. Conclusion and Implications Our study is the first to provide evidence that oxidative stress is a key player in Enteric Neuropathy and colonic dysmotility leading to symptoms of chronic constipation observed in oxaliplatin-treated mice.
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Allogeneic guinea pig mesenchymal stem cells ameliorate neurological changes in experimental colitis
Stem Cell Research & Therapy, 2015Co-Authors: Rhian Stavely, Ainsley M Robinson, Richard L. Boyd, Samy Sakkal, Sarah Miller, Kulmira NurgaliAbstract:The use of mesenchymal stem cells (MSCs) to treat inflammatory bowel disease (IBD) is of great interest because of their immunomodulatory properties. Damage to the Enteric nervous system (ENS) is implicated in IBD pathophysiology and disease progression. The most commonly used model to study inflammation-induced changes to the ENS is 2,4,6-trinitrobenzene-sulfonate acid (TNBS)-induced colitis in guinea pigs; however, no studies using guinea pig MSCs in colitis have been performed. This study aims to isolate and characterise guinea pig MSCs and then test their therapeutic potential for the treatment of Enteric Neuropathy associated with intestinal inflammation. MSCs from guinea pig bone marrow and adipose tissue were isolated and characterised in vitro. In in vivo experiments, guinea pigs received either TNBS for the induction of colitis or sham treatment by enema. MSCs were administered at a dose of 1 × 106 cells via enema 3 h after the induction of colitis. Colon tissues were collected 24 and 72 h after TNBS administration to assess the level of inflammation and damage to the ENS. The secretion of transforming growth factor-β1 (TGF-β1) was analysed in MSC conditioned medium by flow cytometry. Cells isolated from both sources were adherent to plastic, multipotent and expressed some human MSC surface markers. In vitro characterisation revealed distinct differences in growth kinetics, clonogenicity and cell morphology between MSC types. In an in vivo model of TNBS-induced colitis, guinea pig bone marrow MSCs were comparatively more efficacious than adipose tissue MSCs in attenuating weight loss, colonic tissue damage and leukocyte infiltration into the mucosa and myEnteric plexus. MSCs from both sources were equally neuroprotective in the amelioration of Enteric neuronal loss and changes to the neurochemical coding of neuronal subpopulations. MSCs from both sources secreted TGF-β1 which exerted neuroprotective effects in vitro. This study is the first evaluating the functional capacity of guinea pig bone marrow and adipose tissue-derived MSCs and providing evidence of their neuroprotective value in an animal model of colitis. In vitro characteristics of MSCs cannot be extrapolated to their therapeutic efficacy. TGF-β1 released by both types of MSCs might have contributed to the attenuation of Enteric Neuropathy associated with colitis.
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Human adult stem cells derived from adipose tissue and bone marrow attenuate Enteric Neuropathy in the guinea-pig model of acute colitis
Stem cell research & therapy, 2015Co-Authors: Rhian Stavely, Ainsley M Robinson, Richard L. Boyd, Samy Sakkal, Sarah Miller, Kulmira NurgaliAbstract:Introduction Mesenchymal stem cells (MSCs) have been identified as a viable treatment for inflammatory bowel disease (IBD). MSCs derived from bone marrow (BM-MSCs) have predominated in experimental models whereas the majority of clinical trials have used MSCs derived from adipose tissue (AT-MSCs), thus there is little consensus on the optimal tissue source. The therapeutic efficacies of these MSCs are yet to be compared in context of the underlying dysfunction of the Enteric nervous system innervating the gastrointestinal tract concomitant with IBD. This study aims to characterise the in vitro properties of MSCs and compare their in vivo therapeutic potential for the treatment of Enteric Neuropathy associated with intestinal inflammation.
Ainsley M Robinson - One of the best experts on this subject based on the ideXlab platform.
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Stem cell therapies for the treatment of Enteric Neuropathy associated with inflammatory bowel disease
2019Co-Authors: Ainsley M RobinsonAbstract:Although not associated with mortality, symptoms, complications and the relapsing nature of inflammatory bowel disease (IBD) severely impact patient’s quality of life. Current treatments are coupled with side effects and loss of patient response. Damage to the Enteric neurons is consistently associated with intestinal inflammation and considered to underlie the generation of symptoms. Therefore, the Enteric neurons are a potential target for novel IBD therapies. Mesenchymal stem cells (MSCs) exhibit anti-inflammatory, immunomodulating, and neuroprotective effects and are demonstrated to participate in tissue regeneration and repair in many pathological conditions. Hence, they are a viable option for the treatment of Enteric Neuropathy associated with IBD. The studies in this thesis aim to investigate the effects of MSC therapy in averting Enteric Neuropathy in acute and chronic models of IBD. The results of our studies demonstrated that MSC and conditioned medium attenuated inflammation and averted Enteric Neuropathy and colonic dysmotility in an acute model of IBD. The effects of MSC treatment are dose-dependent and occur as early as 24h post treatment. We characterized changes to colonic innervation, motility, transit time, microbiota and metabolome in the Winnie mouse model of spontaneously occurring chronic colitis. Our results demonstrated that the Winnie mouse is highly representative of human IBD. The mechanisms underlying colonic dysmotility in Winnie mice were due to inhibition of neuromuscular transmission and smooth muscle responses. We found that multiple high dose MSC treatments induce anti-inflammatory and neurotrophic effects in mice with chronic colitis. Single dose and multiple low dose MSC administrations were ineffective in this model. Overall, we have established the capacity of MSC treatments to attenuate inflammation and Enteric Neuropathy in acute and chronic models of IBD. These findings are both novel and highly relevant for clinical translation and future investigations of MSC therapy for the treatment of IBD.
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Targeting eotaxin-1 and CCR3 receptor alleviates Enteric Neuropathy and colonic dysfunction in TNBS-induced colitis in guinea pigs
Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 2018Co-Authors: Rhiannon Filippone, Rhian Stavely, Ainsley M Robinson, Valentina Jovanovska, Vasso Apostolopoulos, Joel C. Bornstein, Kulmira NurgaliAbstract:Background The accumulation of eosinophils is mediated by the chemokine receptor-3 (CCR3)-eotaxin axis. Increased expression of eotaxin and its receptor is associated with inflammatory bowel disease (IBD). Activation of eosinophils causes the release of cationic proteins that are neurotoxic such as eosinophil-derived neurotoxin (EDN). Damage to Enteric neurons alters neurally controlled functions of the gut correlated with intestinal inflammation. We hypothesized that inhibition of the CCR3-eotaxin axis will prevent inflammation-induced functional changes to the gastrointestinal tract. Methods Hartley guinea pigs were administered with trinitrobenzene sulfonate (TNBS; 30 mg/kg in 30% ethanol) intrarectally to induce colitis. A CCR3 receptor antagonist (SB 328437 [SB3]) was injected intraperitoneally 1 hour postinduction of colitis. Animals were euthanized 7 days post-treatment and colon tissues were collected for ex vivo studies. The EDN-positive eosinophils in the colon, indicating eosinophil activation, were quantified by immunohistochemistry. Effects of SB3 treatment on gross morphological damage, Enteric Neuropathy, and colonic dysmotility were determined by histology, immunohistochemistry, and organ bath experiments. Key results The number of EDN-positive eosinophils was significantly increased in the lamina propria in close proximity to myEnteric ganglia in inflamed colon. The TNBS-induced inflammation caused significant damage to colonic architecture and inhibition of colonic motility. Treatment with SB3 antagonist attenuated inflammation-associated morphological damage in the colon, reduced infiltration of EDN-positive eosinophils and restored colonic motility to levels comparable to control and sham-treated guinea pigs. Conclusion & inferences This is the first study demonstrating that inhibition of CCR3-eotaxin axis alleviates Enteric Neuropathy and restores functional changes in the gut associated with TNBS-induced colitis.
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Role of oxidative stress in oxaliplatin-induced Enteric Neuropathy and colonic dysmotility in mice.
British journal of pharmacology, 2016Co-Authors: Rachel M Mcquade, Ainsley M Robinson, Joel C. Bornstein, Simona E. Carbone, Vanesa Stojanovska, Ahmed A. Rahman, Rachel M Gwynne, Craig A. Goodman, Kulmira NurgaliAbstract:Background and Purpose Oxaliplatin is a platinum-based chemotherapeutic drug used as a first-line therapy for colorectal cancer. However, its use is associated with severe gastrointestinal side-effects resulting in dose limitations and/or cessation of treatment. In this study, we tested whether oxidative stress, caused by chronic oxaliplatin treatment, induces Enteric neuronal damage and colonic dysmotility Experimental Approach Oxaliplatin (3 mg/kg/d) was administered in vivo to Balb/c mice intraperitoneally three times a week. The distal colon was collected at day 14 of treatment. Immunohistochemistry was performed in wholemount preparations of submucosal and myEnteric ganglia. Neuromuscular transmission was studied by intracellular electrophysiology. Circular muscle tone was studied by force transducers. Colon propulsive activity studied in organ bath experiments and faeces were collected to measure water content. Key Results Chronic in vivo oxaliplatin treatment resulted in increased formation of reactive oxygen species (O2ˉ), nitration of proteins, mitochondrial membrane depolarisation resulting in the release of cytochrome c, loss of neurons, increased iNOS expression and apoptosis in both the submucosal and myEnteric plexuses of the colon. Oxaliplatin treatment enhanced nitric oxide (NO)-mediated inhibitory junction potentials and altered the response of circular muscles to the NO donor, sodium nitroprusside. It also reduced the frequency of colonic migrating motor complexes and decreased circular muscle tone, effects reversed by the NO synthase inhibitor, Nω-Nitro-L-arginine. Conclusion and Implications Our study is the first to provide evidence that oxidative stress is a key player in Enteric Neuropathy and colonic dysmotility leading to symptoms of chronic constipation observed in oxaliplatin-treated mice.
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Allogeneic guinea pig mesenchymal stem cells ameliorate neurological changes in experimental colitis
Stem Cell Research & Therapy, 2015Co-Authors: Rhian Stavely, Ainsley M Robinson, Richard L. Boyd, Samy Sakkal, Sarah Miller, Kulmira NurgaliAbstract:The use of mesenchymal stem cells (MSCs) to treat inflammatory bowel disease (IBD) is of great interest because of their immunomodulatory properties. Damage to the Enteric nervous system (ENS) is implicated in IBD pathophysiology and disease progression. The most commonly used model to study inflammation-induced changes to the ENS is 2,4,6-trinitrobenzene-sulfonate acid (TNBS)-induced colitis in guinea pigs; however, no studies using guinea pig MSCs in colitis have been performed. This study aims to isolate and characterise guinea pig MSCs and then test their therapeutic potential for the treatment of Enteric Neuropathy associated with intestinal inflammation. MSCs from guinea pig bone marrow and adipose tissue were isolated and characterised in vitro. In in vivo experiments, guinea pigs received either TNBS for the induction of colitis or sham treatment by enema. MSCs were administered at a dose of 1 × 106 cells via enema 3 h after the induction of colitis. Colon tissues were collected 24 and 72 h after TNBS administration to assess the level of inflammation and damage to the ENS. The secretion of transforming growth factor-β1 (TGF-β1) was analysed in MSC conditioned medium by flow cytometry. Cells isolated from both sources were adherent to plastic, multipotent and expressed some human MSC surface markers. In vitro characterisation revealed distinct differences in growth kinetics, clonogenicity and cell morphology between MSC types. In an in vivo model of TNBS-induced colitis, guinea pig bone marrow MSCs were comparatively more efficacious than adipose tissue MSCs in attenuating weight loss, colonic tissue damage and leukocyte infiltration into the mucosa and myEnteric plexus. MSCs from both sources were equally neuroprotective in the amelioration of Enteric neuronal loss and changes to the neurochemical coding of neuronal subpopulations. MSCs from both sources secreted TGF-β1 which exerted neuroprotective effects in vitro. This study is the first evaluating the functional capacity of guinea pig bone marrow and adipose tissue-derived MSCs and providing evidence of their neuroprotective value in an animal model of colitis. In vitro characteristics of MSCs cannot be extrapolated to their therapeutic efficacy. TGF-β1 released by both types of MSCs might have contributed to the attenuation of Enteric Neuropathy associated with colitis.
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Human adult stem cells derived from adipose tissue and bone marrow attenuate Enteric Neuropathy in the guinea-pig model of acute colitis
Stem cell research & therapy, 2015Co-Authors: Rhian Stavely, Ainsley M Robinson, Richard L. Boyd, Samy Sakkal, Sarah Miller, Kulmira NurgaliAbstract:Introduction Mesenchymal stem cells (MSCs) have been identified as a viable treatment for inflammatory bowel disease (IBD). MSCs derived from bone marrow (BM-MSCs) have predominated in experimental models whereas the majority of clinical trials have used MSCs derived from adipose tissue (AT-MSCs), thus there is little consensus on the optimal tissue source. The therapeutic efficacies of these MSCs are yet to be compared in context of the underlying dysfunction of the Enteric nervous system innervating the gastrointestinal tract concomitant with IBD. This study aims to characterise the in vitro properties of MSCs and compare their in vivo therapeutic potential for the treatment of Enteric Neuropathy associated with intestinal inflammation.
Conor J. Mccann - One of the best experts on this subject based on the ideXlab platform.
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Stem cell therapy in severe pediatric motility disorders.
Current opinion in pharmacology, 2018Co-Authors: Conor J. Mccann, Osvaldo Borrelli, Nikhil ThaparAbstract:Pediatric gastrointestinal motility disorders represent a range of severe developmental or acquired conditions that disrupt Enteric neuromuscular function. Current medical and surgical therapeutic options are very limited but recent advances have highlighted the possibility of improved or curative stem cell-based treatments. Not only has the ability to harvest, propagate and transplant human-derived Enteric neural stem cells (ENSCs) been demonstrated but recent in vivo transplantation studies have confirmed that ENSCs are capable of engraftment within recipient intestine of animal models of Enteric Neuropathy and effecting functional rescue. Pluripotent stem cell-derived cells and pharmacological modulation of both endogenous and transplanted neural stem cells have further enhanced the exciting prospect of clinical application of such stem cell-based therapies in the near future.
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Transplantation of Enteric nervous system stem cells rescues nitric oxide synthase deficient mouse colon
Nature Communications, 2017Co-Authors: Conor J. Mccann, Julie E. Cooper, Dipa Natarajan, Benjamin Jevans, Laura E. Burnett, Alan J. Burns, Nikhil ThaparAbstract:Isolated human and mouse Enteric nervous system stem cells (ENSCs) are capable of integrating and promoting innervation of the mouse colon. Here the authors show that transplantation of mouse ENSCs into a mouse model of human Enteric Neuropathy restores colon motility. Enteric nervous system Neuropathy causes a wide range of severe gut motility disorders. Cell replacement of lost neurons using Enteric neural stem cells (ENSC) is a possible therapy for these life-limiting disorders. Here we show rescue of gut motility after ENSC transplantation in a mouse model of human Enteric Neuropathy, the neuronal nitric oxide synthase ( nNOS ^ −/− ) deficient mouse model, which displays slow transit in the colon. We further show that transplantation of ENSC into the colon rescues impaired colonic motility with formation of extensive networks of transplanted cells, including the development of nNOS^+ neurons and subsequent restoration of nitrergic responses. Moreover, post-transplantation non-cell-autonomous mechanisms restore the numbers of interstitial cells of Cajal that are reduced in the nNOS ^ −/− colon. These results provide the first direct evidence that ENSC transplantation can modulate the Enteric neuromuscular syncytium to restore function, at the organ level, in a dysmotile gastrointestinal disease model.
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Transplantation of Enteric nervous system stem cells rescues nitric oxide synthase deficient mouse colon.
Nature communications, 2017Co-Authors: Conor J. Mccann, Julie E. Cooper, Dipa Natarajan, Benjamin Jevans, Laura E. Burnett, Alan J. Burns, Nikhil ThaparAbstract:Enteric nervous system Neuropathy causes a wide range of severe gut motility disorders. Cell replacement of lost neurons using Enteric neural stem cells (ENSC) is a possible therapy for these life-limiting disorders. Here we show rescue of gut motility after ENSC transplantation in a mouse model of human Enteric Neuropathy, the neuronal nitric oxide synthase (nNOS-/-) deficient mouse model, which displays slow transit in the colon. We further show that transplantation of ENSC into the colon rescues impaired colonic motility with formation of extensive networks of transplanted cells, including the development of nNOS+ neurons and subsequent restoration of nitrergic responses. Moreover, post-transplantation non-cell-autonomous mechanisms restore the numbers of interstitial cells of Cajal that are reduced in the nNOS-/- colon. These results provide the first direct evidence that ENSC transplantation can modulate the Enteric neuromuscular syncytium to restore function, at the organ level, in a dysmotile gastrointestinal disease model.
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Update on Foregut Molecular Embryology and Role of Regenerative Medicine Therapies
Frontiers Media S.A., 2017Co-Authors: Conor J. Mccann, Nikhil Thapar, Osvaldo Borrelli, Silvia Perin, Paolo De CoppiAbstract:Esophageal atresia (OA) represents one of the commonest and most severe developmental disorders of the foregut, the most proximal segment of the gastrointestinal (GI) tract (esophagus and stomach) in embryological terms. Of intrigue is the common origin from this foregut of two very diverse functional entities, the digestive and respiratory systems. OA appears to result from incomplete separation of the ventral and dorsal parts of the foregut during development, resulting in disruption of esophageal anatomy and frequent association with tracheo-oesophageal fistula. Not surprisingly, and likely inherent to OA, are associated abnormalities in components of the Enteric neuromusculature and ultimately loss of esophageal functional integrity. An appreciation of such developmental processes and associated defects has not only enhanced our understanding of the etiopathogenesis underlying such devastating defects but also highlighted the potential of novel corrective therapies. There has been considerable progress in the identification and propagation of neural crest stem cells from the GI tract itself or derived from pluripotent cells. Such cells have been successfully transplanted into models of Enteric Neuropathy confirming their ability to functionally integrate and replenish missing or defective Enteric nerves. Combinatorial approaches in tissue engineering hold significant promise for the generation of organ-specific scaffolds such as the esophagus with current initiatives directed toward their cellularization to facilitate optimal function. This chapter outlines the most current understanding of the molecular embryology underlying foregut development and OA, and also explores the promise of regenerative medicine
Rhian Stavely - One of the best experts on this subject based on the ideXlab platform.
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Targeting eotaxin-1 and CCR3 receptor alleviates Enteric Neuropathy and colonic dysfunction in TNBS-induced colitis in guinea pigs
Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 2018Co-Authors: Rhiannon Filippone, Rhian Stavely, Ainsley M Robinson, Valentina Jovanovska, Vasso Apostolopoulos, Joel C. Bornstein, Kulmira NurgaliAbstract:Background The accumulation of eosinophils is mediated by the chemokine receptor-3 (CCR3)-eotaxin axis. Increased expression of eotaxin and its receptor is associated with inflammatory bowel disease (IBD). Activation of eosinophils causes the release of cationic proteins that are neurotoxic such as eosinophil-derived neurotoxin (EDN). Damage to Enteric neurons alters neurally controlled functions of the gut correlated with intestinal inflammation. We hypothesized that inhibition of the CCR3-eotaxin axis will prevent inflammation-induced functional changes to the gastrointestinal tract. Methods Hartley guinea pigs were administered with trinitrobenzene sulfonate (TNBS; 30 mg/kg in 30% ethanol) intrarectally to induce colitis. A CCR3 receptor antagonist (SB 328437 [SB3]) was injected intraperitoneally 1 hour postinduction of colitis. Animals were euthanized 7 days post-treatment and colon tissues were collected for ex vivo studies. The EDN-positive eosinophils in the colon, indicating eosinophil activation, were quantified by immunohistochemistry. Effects of SB3 treatment on gross morphological damage, Enteric Neuropathy, and colonic dysmotility were determined by histology, immunohistochemistry, and organ bath experiments. Key results The number of EDN-positive eosinophils was significantly increased in the lamina propria in close proximity to myEnteric ganglia in inflamed colon. The TNBS-induced inflammation caused significant damage to colonic architecture and inhibition of colonic motility. Treatment with SB3 antagonist attenuated inflammation-associated morphological damage in the colon, reduced infiltration of EDN-positive eosinophils and restored colonic motility to levels comparable to control and sham-treated guinea pigs. Conclusion & inferences This is the first study demonstrating that inhibition of CCR3-eotaxin axis alleviates Enteric Neuropathy and restores functional changes in the gut associated with TNBS-induced colitis.
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Mechanisms of Mesenchymal Stem Cell Therapy for Enteric Neuropathy Associated with Colitis
2018Co-Authors: Rhian StavelyAbstract:Due to the limited efficacy and high toxicity of current treatments, the development of novel therapies is crucial for inflammatory bowel disease (IBD). Mesenchymal stem cell (MSC) therapies have demonstrated positive outcomes in IBD patients that are refractory to conventional treatment options and produce fewer side-effects. To develop and optimise MSC therapies, their mechanism of action must be fully elucidated. This thesis aims to explore the mechanisms of MSC treatments in experimental intestinal inflammation with a focus on damage to the Enteric nervous system (ENS). The guinea-pig model of TNBS-induced colitis was utilised in proof of principle experiments to evaluate the neuroprotective potential of MSCs. Treatments with MSCs attenuated acute inflammation as well as neuronal and nerve fibre loss. MSCs suppressed leukocyte infiltration to the myEnteric plexus (plexitis) and the production of superoxide by myEnteric neurons. Furthermore, MSCs derived from the bone-marrow (BM-MSCs) were more efficacious than those isolated from adipose tissue (AT-MSCs) in ameliorating damage to the ENS. For the first time, the effects of MSC treatments were explored in a model of spontaneous chronic colitis (Winnie mice). Using high-throughput RNA sequencing, Winnie mice were determined to closely replicate the transcriptome of human IBD with a high degree of accuracy not observed previously in models of chemically-induced colitis. Treatments with BM-MSCs decreased the disease activity of colitis and reduced leukocyte infiltration to the mucosa in Winnie mice. BM-MSCs were determined to reduce the expression of many proinflammatory factors in Winnie mice that contribute to IBD in human patients. The concordance of inflammatory gene expression in Winnie mice was highly representative of IBD. Thus, this model and in vitro organotypic cultures of longitudinal muscle-myEnteric plexus were used to elucidate mechanisms of inflammation-associated Enteric Neuropathy. The expression of many genes associated with the ENS and neurotransmission pathways were normalised by BM-MSC treatments in Winnie mice. BM-MSCs restored neuronal density and attenuated plexitis in Winnie mice to near control levels. This correlated with a reduction in the disease activity of colitis and may have contributed to their ability to normalise many neuronal and synapse-associated genes. In Winnie mice, myEnteric neurons were sensitive to oxidative stress with a strong accumulation of oxidised DNA/RNA adducts and superoxide generation from the mitochondria. This was attenuated to control levels by BM-MSCs. In in vitro studies, oxidative stimuli caused neuronal loss which was inhibited by BM-MSCs in a paracrine manner and was mediated, at least in part, by superoxide dismutase 1. BM-MSC treatments also upregulated several genes associated with metabolism and antioxidant defences in Winnie mice that may contribute to the resolution of oxidative injury. In vitro experiments provided evidence that cytoplasmic translocation of the damage associated molecular pattern, high-mobility group box 1 (HMGB1) protein, is induced by oxidative stress in myEnteric neurons. HMGB1 was determined to be translocated in myEnteric neurons of Winnie mice which correlated with neuronal loss. Treatment with BM-MSCs inhibited HMGB1 translocation in myEnteric neurons of Winnie mice in vivo and organotypic cultures in vitro. Pharmacological inhibition of HMGB1 attenuated neuronal loss in Winnie mice without reducing plexitis and mitochondrial superoxide production. This suggests that BM-MSC treatments increased neuronal density by attenuating plexitis and oxidative stress which is upstream of HMGB1 translocation and myEnteric neuronal death. In these studies, we have defined potent neuroprotective properties elicited by BM-MSCs which ameliorate damage to the myEnteric ganglia in experimental colitis. The use of high-throughput transcriptome sequencing illustrates the complex alterations to the nervous system in chronic experimental colitis and IBD patients. The results of this thesis may be utilised as a reference to provide future direction in the fields of MSC therapies and ENS pathophysiology in intestinal inflammation.
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Allogeneic guinea pig mesenchymal stem cells ameliorate neurological changes in experimental colitis
Stem Cell Research & Therapy, 2015Co-Authors: Rhian Stavely, Ainsley M Robinson, Richard L. Boyd, Samy Sakkal, Sarah Miller, Kulmira NurgaliAbstract:The use of mesenchymal stem cells (MSCs) to treat inflammatory bowel disease (IBD) is of great interest because of their immunomodulatory properties. Damage to the Enteric nervous system (ENS) is implicated in IBD pathophysiology and disease progression. The most commonly used model to study inflammation-induced changes to the ENS is 2,4,6-trinitrobenzene-sulfonate acid (TNBS)-induced colitis in guinea pigs; however, no studies using guinea pig MSCs in colitis have been performed. This study aims to isolate and characterise guinea pig MSCs and then test their therapeutic potential for the treatment of Enteric Neuropathy associated with intestinal inflammation. MSCs from guinea pig bone marrow and adipose tissue were isolated and characterised in vitro. In in vivo experiments, guinea pigs received either TNBS for the induction of colitis or sham treatment by enema. MSCs were administered at a dose of 1 × 106 cells via enema 3 h after the induction of colitis. Colon tissues were collected 24 and 72 h after TNBS administration to assess the level of inflammation and damage to the ENS. The secretion of transforming growth factor-β1 (TGF-β1) was analysed in MSC conditioned medium by flow cytometry. Cells isolated from both sources were adherent to plastic, multipotent and expressed some human MSC surface markers. In vitro characterisation revealed distinct differences in growth kinetics, clonogenicity and cell morphology between MSC types. In an in vivo model of TNBS-induced colitis, guinea pig bone marrow MSCs were comparatively more efficacious than adipose tissue MSCs in attenuating weight loss, colonic tissue damage and leukocyte infiltration into the mucosa and myEnteric plexus. MSCs from both sources were equally neuroprotective in the amelioration of Enteric neuronal loss and changes to the neurochemical coding of neuronal subpopulations. MSCs from both sources secreted TGF-β1 which exerted neuroprotective effects in vitro. This study is the first evaluating the functional capacity of guinea pig bone marrow and adipose tissue-derived MSCs and providing evidence of their neuroprotective value in an animal model of colitis. In vitro characteristics of MSCs cannot be extrapolated to their therapeutic efficacy. TGF-β1 released by both types of MSCs might have contributed to the attenuation of Enteric Neuropathy associated with colitis.
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Human adult stem cells derived from adipose tissue and bone marrow attenuate Enteric Neuropathy in the guinea-pig model of acute colitis
Stem cell research & therapy, 2015Co-Authors: Rhian Stavely, Ainsley M Robinson, Richard L. Boyd, Samy Sakkal, Sarah Miller, Kulmira NurgaliAbstract:Introduction Mesenchymal stem cells (MSCs) have been identified as a viable treatment for inflammatory bowel disease (IBD). MSCs derived from bone marrow (BM-MSCs) have predominated in experimental models whereas the majority of clinical trials have used MSCs derived from adipose tissue (AT-MSCs), thus there is little consensus on the optimal tissue source. The therapeutic efficacies of these MSCs are yet to be compared in context of the underlying dysfunction of the Enteric nervous system innervating the gastrointestinal tract concomitant with IBD. This study aims to characterise the in vitro properties of MSCs and compare their in vivo therapeutic potential for the treatment of Enteric Neuropathy associated with intestinal inflammation.
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human adult stem cells derived from adipose tissue and bone marrow attenuate Enteric Neuropathy in the guinea pig model of acute colitis
Stem Cell Research & Therapy, 2015Co-Authors: Rhian Stavely, Ainsley M Robinson, Richard L. Boyd, Samy Sakkal, Sarah Miller, Kulmira NurgaliAbstract:Mesenchymal stem cells (MSCs) have been identified as a viable treatment for inflammatory bowel disease (IBD). MSCs derived from bone marrow (BM-MSCs) have predominated in experimental models whereas the majority of clinical trials have used MSCs derived from adipose tissue (AT-MSCs), thus there is little consensus on the optimal tissue source. The therapeutic efficacies of these MSCs are yet to be compared in context of the underlying dysfunction of the Enteric nervous system innervating the gastrointestinal tract concomitant with IBD. This study aims to characterise the in vitro properties of MSCs and compare their in vivo therapeutic potential for the treatment of Enteric Neuropathy associated with intestinal inflammation. BM-MSCs and AT-MSCs were validated and characterised in vitro. In in vivo experiments, guinea-pigs received either 2,4,6-trinitrobenzene-sulfonate acid (TNBS) for the induction of colitis or sham treatment by enema. MSCs were administered at a dose of 1x106 cells via enema 3 hours after the induction of colitis. Colon tissues were collected 24 and 72 hours after TNBS administration to assess the level of inflammation and damage to the ENS. MSC migration to the myEnteric plexus in vivo was elucidated by immunohistochemistry and in vitro using a modified Boyden chamber assay. Cells exhibited multipotency and a typical surface immunophenotype for validation as bona fide MSCs. In vitro characterisation revealed distinct differences in growth kinetics, clonogenicity and cell morphology between MSC types. In vivo, BM-MSCs were comparatively more effective than AT-MSCs in attenuating leukocyte infiltration and neuronal loss in the myEnteric plexus. MSCs from both sources equally ameliorated body weight loss, gross morphological damage to the colon, changes in the neurochemical coding of neuronal subpopulations and the reduction in density of extrinsic and intrinsic nerve fibres innervating the colon. MSCs from both sources migrated to the myEnteric plexus in in vivo colitis and in an in vitro assay. These data from in vitro experiments suggest that AT-MSCs are ideal for cellular expansion. However, BM-MSCs were more therapeutic in the treatment of Enteric Neuropathy and plexitis. These characteristics should be considered when deciding on the MSC tissue source.