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Chu T, Zhang YP, Tian Z, Ye C, Zhu M, Shields LBE, Kong M, Barnes GN, Shields CB, Cai J. Dynamic response of microglia/macrophage polarization following demyelination in mice. J Neuroinflammation 2019; 16:188. [PMID: 31623610 PMCID: PMC6798513 DOI: 10.1186/s12974-019-1586-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/11/2019] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND The glial response in multiple sclerosis (MS), especially for recruitment and differentiation of oligodendrocyte progenitor cells (OPCs), predicts the success of remyelination of MS plaques and return of function. As a central player in neuroinflammation, activation and polarization of microglia/macrophages (M/M) that modulate the inflammatory niche and cytokine components in demyelination lesions may impact the OPC response and progression of demyelination and remyelination. However, the dynamic behaviors of M/M and OPCs during demyelination and spontaneous remyelination are poorly understood, and the complex role of neuroinflammation in the demyelination-remyelination process is not well known. In this study, we utilized two focal demyelination models with different dynamic patterns of M/M to investigate the correlation between M/M polarization and the demyelination-remyelination process. METHODS The temporal and spatial features of M/M activation/polarization and OPC response in two focal demyelination models induced by lysolecithin (LPC) and lipopolysaccharide (LPS) were examined in mice. Detailed discrimination of morphology, sensorimotor function, diffusion tensor imaging (DTI), inflammation-relevant cytokines, and glial responses between these two models were analyzed at different phases. RESULTS The results show that LPC and LPS induced distinctive temporal and spatial lesion patterns. LPS produced diffuse demyelination lesions, with a delayed peak of demyelination and functional decline compared to LPC. Oligodendrocytes, astrocytes, and M/M were scattered throughout the LPS-induced demyelination lesions but were distributed in a layer-like pattern throughout the LPC-induced lesion. The specific M/M polarization was tightly correlated to the lesion pattern associated with balance beam function. CONCLUSIONS This study elaborated on the spatial and temporal features of neuroinflammation mediators and glial response during the demyelination-remyelination processes in two focal demyelination models. Specific M/M polarization is highly correlated to the demyelination-remyelination process probably via modulations of the inflammatory niche, cytokine components, and OPC response. These findings not only provide a basis for understanding the complex and dynamic glial phenotypes and behaviors but also reveal potential targets to promote/inhibit certain M/M phenotypes at the appropriate time for efficient remyelination.
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Affiliation(s)
- Tianci Chu
- Department of Pediatrics, Pediatric Research Institute, University of Louisville School of Medicine, Donald Baxter Building, Suite 321B, 570 S. Preston Street, Louisville, KY, 40202, USA
| | - Yi Ping Zhang
- Norton Neuroscience Institute, Norton Healthcare, 210 East Gray Street, Suite 1102, Louisville, KY, 40202, USA
| | - Zhisen Tian
- Department of Pediatrics, Pediatric Research Institute, University of Louisville School of Medicine, Donald Baxter Building, Suite 321B, 570 S. Preston Street, Louisville, KY, 40202, USA
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, 130033, People's Republic of China
| | - Chuyuan Ye
- Department of Pediatrics, Pediatric Research Institute, University of Louisville School of Medicine, Donald Baxter Building, Suite 321B, 570 S. Preston Street, Louisville, KY, 40202, USA
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Mingming Zhu
- Department of Radiology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Lisa B E Shields
- Norton Neuroscience Institute, Norton Healthcare, 210 East Gray Street, Suite 1102, Louisville, KY, 40202, USA
| | - Maiying Kong
- Department of Bioinformatics and Biostatistics, University of Louisville School of Public Health and Information Sciences, Louisville, KY, 40202, USA
| | - Gregory N Barnes
- Department of Pediatrics, Pediatric Research Institute, University of Louisville School of Medicine, Donald Baxter Building, Suite 321B, 570 S. Preston Street, Louisville, KY, 40202, USA
- Department of Neurology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA
| | - Christopher B Shields
- Norton Neuroscience Institute, Norton Healthcare, 210 East Gray Street, Suite 1102, Louisville, KY, 40202, USA.
- Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
| | - Jun Cai
- Department of Pediatrics, Pediatric Research Institute, University of Louisville School of Medicine, Donald Baxter Building, Suite 321B, 570 S. Preston Street, Louisville, KY, 40202, USA.
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA.
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Sharma S, Laule C, Moore GRW, Li DKB, Zhang Y. Correlating new directional measures of myelin and axonal integrity in T2-weighted MRI with quantitative histology in multiple sclerosis. J Neurosci Methods 2019; 311:369-376. [PMID: 30240805 DOI: 10.1016/j.jneumeth.2018.09.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/17/2018] [Accepted: 09/17/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Imaging measurement of structure alignment has shown increasing importance in determining tissue properties. It is not known if a similar ability for characterizing neuropathology exists. NEW METHODS This study aimed to validate a new alignment-assessing method for measuring myelin and axonal properties using quantitative histological metrics. The new method involved analysis of the Fourier transform (FT) power spectrum in standard magnetic resonance imaging (MRI). T2-weighted MRI were collected from 10 post-mortem multiple sclerosis (MS) brain samples. Three tissue types were examined: lesions, diffusely abnormal white matter, and normal appearing white matter. MRI analysis included computing the FT power spectrum; extracting alignment histograms; and calculating dominant orientation and alignment complexity (angular entropy). Post MRI, the brain samples were processed for myelin and axonal staining, and the stained images were used to derive quantitative orientation measures using structure tensor analysis for MRI comparison. RESULTS There were significant differences in orientation metrics between tissue types in both MRI and histology, and MRI measurements correlated strongly with histological indices. Moreover, the joint effect of myelin and axonal entropy explained over 95% of the variance of MRI angular entropy. COMPARISON WITH EXISTING METHOD There is no established method for characterizing myelin and axonal pathology using standard MRI. Advanced MRI methods have the potential to do this but are still in research development and are not yet routinely acquired in clinical practice. CONCLUSIONS Alignment measurement using clinical MRI scans may become a valuable new method for characterizing myelin and axonal properties in MS patients.
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Affiliation(s)
- Shrushrita Sharma
- Department of Radiology, University of Calgary, Alberta, Canada; Department of Clinical Neurosciences, University of Calgary, Alberta, Canada; Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
| | - Cornelia Laule
- Department of Radiology, University of British Columbia, British Columbia, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, British Columbia, Canada; International Collaboration on Repair Discoveries (ICORD), University of British Columbia, British Columbia, Canada; Department of Physics & Astronomy, University of British Columbia, British Columbia, Canada
| | - G R Wayne Moore
- Department of Pathology and Laboratory Medicine, University of British Columbia, British Columbia, Canada; International Collaboration on Repair Discoveries (ICORD), University of British Columbia, British Columbia, Canada
| | - David K B Li
- Department of Radiology, University of British Columbia, British Columbia, Canada
| | - Yunyan Zhang
- Department of Radiology, University of Calgary, Alberta, Canada; Department of Clinical Neurosciences, University of Calgary, Alberta, Canada; Hotchkiss Brain Institute, University of Calgary, Alberta, Canada.
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Luo T, Oladosu O, Rawji KS, Zhai P, Pridham G, Hossain S, Zhang Y. Characterizing Structural Changes With Devolving Remyelination Following Experimental Demyelination Using High Angular Resolution Diffusion MRI and Texture Analysis. J Magn Reson Imaging 2018; 49:1750-1759. [PMID: 30230112 DOI: 10.1002/jmri.26328] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 08/19/2018] [Accepted: 08/20/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Changes in myelin integrity are associated with the pathophysiology of many neurological diseases, including multiple sclerosis. However, noninvasive measurement of myelin injury and repair remains challenging. Advanced MRI techniques including diffusion tensor imaging (DTI), neurite orientation dispersion and density index (NODDI), and texture analysis have shown promise in quantifying subtle abnormalities in white matter structure. PURPOSE To determine whether and how these advanced imaging methods help understand remyelination changes after demyelination using a mouse model. STUDY TYPE Prospective, longitudinal. ANIMAL MODEL Demyelination was induced in the thoracic spinal cord of 21 mice using the chemical toxin lysolecithin. FIELD STRENGTH/SEQUENCES 9.4T ASSESSMENT: Imaging was done at day 7 (demyelination) and days 14 to 35 (ongoing remyelination) postsurgery, followed by histology. Image analysis focused on both lesions and peri-lesional areas where remyelination began. In histology, we quantified the complexity of tissue alignment using angular entropy, in addition to staining area. STATISTICAL ANALYSIS Two-way analysis of variance was performed for assessing differences between tissue types and across timepoints, followed by post-hoc analysis to correct for multiple comparisons (P < 0.05). RESULTS All diffusion and texture parameters were worse in lesions than the control tissue (P < 0.05) except orientation dispersion index (ODI) and neurite density index (NDI) over late remyelination. Longitudinally, ODI decreased and NDI increased persistently in both lesions and peri-lesion regions (P < 0.05). Fractional anisotropy showed a mild decrease at day 35 after increase, when lesion texture heterogeneity showed a trend to decrease (P > 0.05). Both lesion size and angular entropy decreased over time, and no change in any measure in the control tissue. DATA CONCLUSION Diffusion and MRI texture metrics may provide compensatory information on myelin repair and ODI and NDI could be sensitive measures of evolving remyelination, deserving further validation. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:1750-1759.
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Affiliation(s)
- Tim Luo
- Bachelor of Health Sciences Program, University of Calgary, AB, Canada
| | | | - Khalil S Rawji
- Department of Neuroscience, University of Calgary, AB, Canada
| | - Peng Zhai
- Department of Radiology, University of Calgary, AB, Canada.,Department of Clinical Neurosciences, University of Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, AB, Canada
| | - Glen Pridham
- Department of Radiology, University of Calgary, AB, Canada.,Department of Clinical Neurosciences, University of Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, AB, Canada
| | | | - Yunyan Zhang
- Department of Radiology, University of Calgary, AB, Canada.,Department of Clinical Neurosciences, University of Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, AB, Canada
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Sharma S, Zhang Y. Fourier transform power spectrum is a potential measure of tissue alignment in standard MRI: A multiple sclerosis study. PLoS One 2017; 12:e0175979. [PMID: 28414816 PMCID: PMC5393867 DOI: 10.1371/journal.pone.0175979] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/03/2017] [Indexed: 12/11/2022] Open
Abstract
Loss of tissue coherency in brain white matter is found in many neurological diseases such as multiple sclerosis (MS). While several approaches have been proposed to evaluate white matter coherency including fractional anisotropy and fiber tracking in diffusion-weighted imaging, few are available for standard magnetic resonance imaging (MRI). Here we present an image post-processing method for this purpose based on Fourier transform (FT) power spectrum. T2-weighted images were collected from 19 patients (10 relapsing-remitting and 9 secondary progressive MS) and 19 age- and gender-matched controls. Image processing steps included: computation, normalization, and thresholding of FT power spectrum; determination of tissue alignment profile and dominant alignment direction; and calculation of alignment complexity using a new measure named angular entropy. To test the validity of this method, we used a highly organized brain white matter structure, corpus callosum. Six regions of interest were examined from the left, central and right aspects of both genu and splenium. We found that the dominant orientation of each ROI derived from our method was significantly correlated with the predicted directions based on anatomy. There was greater angular entropy in patients than controls, and a trend to be greater in secondary progressive MS patients. These findings suggest that it is possible to detect tissue alignment and anisotropy using traditional MRI, which are routinely acquired in clinical practice. Analysis of FT power spectrum may become a new approach for advancing the evaluation and management of patients with MS and similar disorders. Further confirmation is warranted.
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Affiliation(s)
- Shrushrita Sharma
- Biomedical Engineering Program, Faculty of Graduate Studies, University of Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
| | - Yunyan Zhang
- Biomedical Engineering Program, Faculty of Graduate Studies, University of Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
- Department of Clinical Neurosciences, University of Calgary, Alberta, Canada
- Department of Radiology, University of Calgary, Alberta, Canada
- * E-mail:
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