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Kulkarni S, Micci MA, Leser J, Shin C, Tang SC, Fu YY, Liu L, Li Q, Saha M, Li C, Enikolopov G, Becker L, Rakhilin N, Anderson M, Shen X, Dong X, Butte MJ, Song H, Southard-Smith EM, Kapur RP, Bogunovic M, Pasricha PJ. Adult enteric nervous system in health is maintained by a dynamic balance between neuronal apoptosis and neurogenesis. Proc Natl Acad Sci U S A 2017; 114:E3709-E3718. [PMID: 28420791 PMCID: PMC5422809 DOI: 10.1073/pnas.1619406114] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
According to current dogma, there is little or no ongoing neurogenesis in the fully developed adult enteric nervous system. This lack of neurogenesis leaves unanswered the question of how enteric neuronal populations are maintained in adult guts, given previous reports of ongoing neuronal death. Here, we confirm that despite ongoing neuronal cell loss because of apoptosis in the myenteric ganglia of the adult small intestine, total myenteric neuronal numbers remain constant. This observed neuronal homeostasis is maintained by new neurons formed in vivo from dividing precursor cells that are located within myenteric ganglia and express both Nestin and p75NTR, but not the pan-glial marker Sox10. Mutation of the phosphatase and tensin homolog gene in this pool of adult precursors leads to an increase in enteric neuronal number, resulting in ganglioneuromatosis, modeling the corresponding disorder in humans. Taken together, our results show significant turnover and neurogenesis of adult enteric neurons and provide a paradigm for understanding the enteric nervous system in health and disease.
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Affiliation(s)
- Subhash Kulkarni
- Center for Neurogastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Maria-Adelaide Micci
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555
| | - Jenna Leser
- Center for Neurogastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Changsik Shin
- Department of Microbiology and Immunology, College of Medicine, Pennsylvania State University, Hershey, PA 17033
| | | | - Ya-Yuan Fu
- Center for Neurogastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Liansheng Liu
- Center for Neurogastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Qian Li
- Center for Neurogastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Monalee Saha
- Center for Neurogastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Cuiping Li
- Center for Neurogastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Grigori Enikolopov
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
- Center for Developmental Genetics, Department of Anesthesiology, Stony Brook University, Stony Brook, NY 11794
| | - Laren Becker
- Division of Gastroenterology, Stanford University School of Medicine, Stanford, CA 94305
| | - Nikolai Rakhilin
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
- School of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853
| | - Michael Anderson
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
- Department of Dermatology, Center for Sensory Biology, The Johns Hopkins University, School of Medicine, Baltimore, MD 21205
- Howard Hughes Medical Institute, The Johns Hopkins University, School of Medicine, Baltimore, MD 21205
| | - Xiling Shen
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
- School of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853
| | - Xinzhong Dong
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
- Department of Dermatology, Center for Sensory Biology, The Johns Hopkins University, School of Medicine, Baltimore, MD 21205
- Howard Hughes Medical Institute, The Johns Hopkins University, School of Medicine, Baltimore, MD 21205
| | - Manish J Butte
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Hongjun Song
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
- Institute for Cellular Engineering, Department of Neurology, The Johns Hopkins University, School of Medicine, Baltimore, MD 21205
| | | | - Raj P Kapur
- Department of Laboratories, Seattle Children's Hospital, Seattle, WA 98105
| | - Milena Bogunovic
- Department of Microbiology and Immunology, College of Medicine, Pennsylvania State University, Hershey, PA 17033
| | - Pankaj J Pasricha
- Center for Neurogastroenterology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205;
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Fumagalli S, Perego C, Ortolano F, De Simoni MG. CX3CR1 deficiency induces an early protective inflammatory environment in ischemic mice. Glia 2013; 61:827-42. [PMID: 23440897 DOI: 10.1002/glia.22474] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 01/07/2013] [Indexed: 12/15/2022]
Abstract
The studies on fractalkine and its unique receptor CX3CR1 in neurological disorders yielded contrasting results. We have explored the consequences of CX3CR1 deletion in ischemic (30' MCAo) mice on: (1) brain infarct size; (2) microglia dynamism and morphology; (3) expression of markers of microglia/macrophages (M/M) activation and polarization. We observed smaller infarcts in cx3cr1(-/-) (26.42 ± 7.41 mm(3) , mean ± sd) compared to wild type (36.29 ± 11.57) and cx3cr1(-/+) (34.49 ± 8.91) mice. We longitudinally analyzed microglia by in vivo two-photon microscopy before, 1 and 24 h after transient ischemia. Microglia were stationary in both cx3cr1(-/-) and cx3cr1(-/+) mice throughout the study. In cx3cr1(-/-) mice, they displayed a significantly higher number of ramifications >10 μm at baseline and at 24 h after ischemia compared to cx3cr1(-/+) mice, indicating that CX3CR1 deficiency impaired the development of microglia hypertrophic/amoeboid morphology. At 24 h after ischemia, we performed post mortem quantitative immunohistochemistry for different M/M markers. In cx3cr1(-/-) immunoreactivity for CD11b (M/M activation) and for CD68 (associated with phagocytosis) were decreased, while that for CD45(high) (macrophage and leukocyte recruitment) was increased. In addition, immunoreactivity for Ym1 (M2 polarization) was enhanced, while that for iNOS (M1) was decreased. Our data show that in cx3cr1(-/-) mice protection from ischemia at early time points after injury is associated with a protective inflammatory milieu, characterized by the promotion of M2 polarization markers.
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Affiliation(s)
- Stefano Fumagalli
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milan, Italy
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Fumagalli S, Coles JA, Ejlerskov P, Ortolano F, Bushell TJ, Brewer JM, De Simoni MG, Dever G, Garside P, Maffia P, Carswell HV. In vivo real-time multiphoton imaging of T lymphocytes in the mouse brain after experimental stroke. Stroke 2011; 42:1429-36. [PMID: 21441145 DOI: 10.1161/strokeaha.110.603704] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND PURPOSE To gain a better understanding of T cell behavior after stroke, we have developed real-time in vivo brain imaging of T cells by multiphoton microscopy after middle cerebral artery occlusion. METHODS Adult male hCD2-GFP transgenic mice that exhibit green fluorescent protein-labeled T cells underwent permanent left distal middle cerebral artery occlusion by electrocoagulation (n=6) or sham surgery (n=6) and then multiphoton laser imaging 72 hours later. RESULTS Extravasated T cell number significantly increased after middle cerebral artery occlusion versus sham. Two T cell populations existed after middle cerebral artery occlusion, possibly driven by 2 T cell subpopulations; 1 had significantly lower and the other significantly higher track velocity and displacement rate than sham. CONCLUSIONS The different motilities and behaviors of T cells observed using our imaging approach after stroke could reveal important mechanisms of immune surveillance for future therapeutic exploitations.
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Affiliation(s)
- Stefano Fumagalli
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
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Kelly KJ, Sandoval RM, Dunn KW, Molitoris BA, Dagher PC. A novel method to determine specificity and sensitivity of the TUNEL reaction in the quantitation of apoptosis. Am J Physiol Cell Physiol 2003; 284:C1309-18. [PMID: 12676658 DOI: 10.1152/ajpcell.00353.2002] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Apoptosis is an important mode of cell death under both physiological and pathophysiological conditions. Numerous techniques are available for the study and quantitation of apoptosis in cell culture, but only few are useful when applied to complex tissues. Among these, the terminal transferase-mediated dUTP nick end-labeling (TUNEL) assay remains the most widely used technique. However, its specificity and sensitivity for the detection of apoptosis remain controversial. We developed a technique consisting of staining live cells and tissues with Hoechst 33342 and the vital dye propidium iodide (PI), followed by fixation and the TUNEL reaction. We demonstrate excellent retention of PI in necrotic cells after fixation. We also examined the distribution of TUNEL staining among necrotic and apoptotic cells in various models of cell injury in vitro and in vivo. We show that the sensitivity of the TUNEL varied between 61 and 90% in the models examined. The specificity exceeded 87% in all models but fell to 70% when a predominantly necrotic injury was induced. This novel and simple method will permit the determination of indices of sensitivity and specificity for the TUNEL assay in other tissues and experimental conditions.
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Affiliation(s)
- K J Kelly
- Department of Medicine, Division of Nephrology, Indiana Center for Biological Microscopy, Indiana University, Indianapolis, Indiana 46202, USA
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