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Liu Z, Wang Y, Ma X, Zhang L, Wang C. Role of epidural fat in the local milieu: what we know and what we don't. Connect Tissue Res 2024; 65:102-116. [PMID: 38493368 DOI: 10.1080/03008207.2024.2329871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/08/2024] [Indexed: 03/18/2024]
Abstract
PURPOSE Traditionally, the epidural fat (EF) is known as a physical buffer for the dural sac against the force and a lubricant facilitating the relative motion of the latter on the osseous spine. Along with the development of the studies on EF, controversies still exist on vital questions, such as the underlying mechanism of the spinal epidural lipomatosis. Meanwhile, the scattered and fragmented researches hinder the global insight into the seemingly dispensable tissue. METHODS Herein, we reviewed literature on the EF and its derivatives to elucidate the dynamic change and complex function of EF in the local milieu, especially at the pathophysiological conditions. We start with an introduction to EF and the current pathogenic landscape, emphasizing the interlink between the EF and adjacent structures. We generally categorize the major pathological changes of the EF into hypertrophy, atrophy, and inflammation. RESULTS AND CONCLUSIONS It is acknowledged that not only the EF (or its cellular components) may be influenced by various endogenic/exogenic and focal/systematic stimuli, but the adjacent structures can also in turn be affected by the EF, which may be a hidden pathogenic clue for specific spinal disease. Meanwhile, the unrevealed sections, which are also the directions the future research, are proposed according to the objective result and rational inference. Further effort should be taken to reveal the underlying mechanism and develop novel therapeutic pathways for the relevant diseases.
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Affiliation(s)
- Zhiming Liu
- Department of Spine Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yida Wang
- Department of Spine Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xuexiao Ma
- Department of Spine Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Lu Zhang
- Department of Medical Research Center, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Chao Wang
- Department of Spine Surgery, the Affiliated Hospital of Qingdao University, Qingdao, China
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2
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Atterholt J, Wedel MJ. A computed tomography-based survey of paramedullary diverticula in extant Aves. Anat Rec (Hoboken) 2023; 306:29-50. [PMID: 35338748 PMCID: PMC10084189 DOI: 10.1002/ar.24923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 01/29/2023]
Abstract
Avian respiratory systems are comprised of rigid lungs connected to a hierarchically organized network of large, regional air sacs, and small diverticula that branch from them. Paramedullary diverticula are those that rest in contact with the spinal cord, and frequently invade the vertebral canal. Here, we review the historical study of these structures and provide the most diverse survey to date of paramedullary diverticula in Aves, consisting of observations from 29 taxa and 17 major clades. These extensions of the respiratory system are present in nearly all birds included in the study, with the exception of falconiforms, gaviiforms, podicipediforms, and piciforms. When present, they share connections most commonly with the intertransverse and supravertebral diverticula, but also sometimes with diverticula arising directly from the lungs and other small, more posterior diverticula. Additionally, we observed much greater morphological diversity of paramedullary airways than previously known. These diverticula may be present as one to four separate tubes (dorsal, lateral, or ventral to the spinal cord), or as a single large structure that partially or wholly encircles the spinal cord. Across taxa, paramedullary diverticula are largest and most frequently present in the cervical region, becoming smaller and increasingly absent moving posteriorly. Finally, we observe two osteological correlates of paramedullary diverticula (pneumatic foramina and pocked texturing inside the vertebral canal) that can be used to infer the presence of these structures in extinct taxa with similar respiratory systems.
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Affiliation(s)
- Jessie Atterholt
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California, USA
| | - Mathew J Wedel
- College of Osteopathic Medicine of the Pacific & College of Podiatric Medicine, Western University of Health Sciences, Pomona, California, USA
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3
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Mudigonda S, Shah S, Das N, Corpuz JM, Ninkovic N, Al-Jezani N, Underhill TM, Salo PT, Mitha AP, Lyons FG, Cho R, Schmidt TA, Dufour A, Krawetz RJ. Proteoglycan 4 is present within the dura mater and produced by mesenchymal progenitor cells. Cell Tissue Res 2022; 389:483-499. [PMID: 35704103 DOI: 10.1007/s00441-022-03647-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/02/2022] [Indexed: 11/25/2022]
Abstract
Mesenchymal progenitor cells (MPCs) have been recently identified in human and murine epidural fat and have been hypothesized to contribute to the maintenance/repair/regeneration of the dura mater. MPCs can secrete proteoglycan 4 (PRG4/lubricin), and this protein can regulate tissue homeostasis through bio-lubrication and immunomodulatory functions. MPC lineage tracing reporter mice (Hic1) and human epidural fat MPCs were used to determine if PRG4 is expressed by these cells in vivo. PRG4 expression co-localized with Hic1+ MPCs in the dura throughout skeletal maturity and was localized adjacent to sites of dural injury. When Hic1+ MPCs were ablated, PRG4 expression was retained in the dura, yet when Prx1+ MPCs were ablated, PRG4 expression was completely lost. A number of cellular processes were impacted in human epidural fat MPCs treated with rhPRG4, and human MPCs contributed to the formation of epidural fat, and dura tissues were xenotransplanted into mouse dural injuries. We have shown that human and mouse MPCs in the epidural/dura microenvironment produce PRG4 and can contribute to dura homeostasis/repair/regeneration. Overall, these results suggest that these MPCs have biological significance within the dural microenvironment and that the role of PRG4 needs to be further elucidated.
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Affiliation(s)
- Sathvika Mudigonda
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada
| | - Sophia Shah
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada.,Biomedical Engineering Graduate Program, University of Calgary, Calgary, AB, Canada
| | - Nabangshu Das
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada
| | - Jessica May Corpuz
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada.,Biomedical Engineering Graduate Program, University of Calgary, Calgary, AB, Canada
| | - Nicoletta Ninkovic
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada
| | - Nedaa Al-Jezani
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada
| | - T Michael Underhill
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Paul T Salo
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada.,Department of Surgery, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Alim P Mitha
- Biomedical Engineering Graduate Program, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Frank G Lyons
- Department of Surgery, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Roger Cho
- Department of Surgery, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Tannin A Schmidt
- Biomedical Engineering Department, University of Connecticut Health Center, Farmington, CT, USA
| | - Antoine Dufour
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada.,Biomedical Engineering Graduate Program, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Roman J Krawetz
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada. .,Biomedical Engineering Graduate Program, University of Calgary, Calgary, AB, Canada. .,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. .,Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
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Epidural Fat Tissue Is More Effective for Scar Prevention Than Conventional Subcutaneous Fat Grafting After Laminectomy in a Mouse Model. Spine (Phila Pa 1976) 2022; 47:E485-E493. [PMID: 34802027 DOI: 10.1097/brs.0000000000004281] [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: 02/01/2023]
Abstract
STUDY DESIGN Basic science study. OBJECTIVE The aim of this study was to examine whether epidural fat tissue (EFT) transplantation can prevent epidural adhesion after laminectomy more efficiently than subcutaneous fat tissue (SFT) transplantation. SUMMARY OF BACKGROUND DATA Epidural adhesion is almost inevitable after laminectomy. Although many materials have been used to prevent adhesion, none has been widely accepted. As EFT is an ectopic fat tissue located on the dura mater and there is no adhesion between EFT and the dura mater, we focused on the efficacy of EFT for adhesion prevention. METHODS We examined the differences in histology and gene expression between EFT and SFT of mice. We performed laminectomy at the 10th thoracic level and immediately transplanted EFT or SFT to the dura mater in mice. At 6 weeks after transplantation, we performed histological and gene expression analyses and evaluated the adhesion tenacity. In addition, we examined the characteristic differences between human EFT and SFT. RESULTS The adipocytes of EFT were significantly smaller than those of SFT in mice and humans. The gene expression of inflammatory cytokine and fibrosis-related factors was significantly higher in SFT than in EFT. At 6 weeks after transplantation, the percentage of the remaining fat area over the dura mater was significantly greater in the EFT group than in SFT group, and the adhesion tenacity score was significantly lower in the EFT group than that in the SFT group. An RNA sequencing analysis revealed 1921 differentially expressed genes (DEGs) between human EFT and SFT, and a Gene Ontology term associated with the inflammatory response was most highly enriched in SFT. CONCLUSION EFT has different molecular and histological profiles from SFT and EFT grafting is more effective for epidural adhesion prevention than conventional SFT transplantation after laminectomy in a mouse model.Level of Evidence: N/A.
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Cui H, Du X, Liu C, Chen S, Cui H, Liu H, Wang J, Zheng Z. Visfatin promotes intervertebral disc degeneration by inducing IL-6 expression through the ERK/JNK/p38 signalling pathways. Adipocyte 2021; 10:201-215. [PMID: 33853482 PMCID: PMC8057091 DOI: 10.1080/21623945.2021.1910155] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Visfatin reportedly induces the expression of proinflammatory cytokines. Severe grades of intervertebral disc disease (IVDD) exhibit higher expression of visfatin than mild ones. However, the direct relationship between visfatin and IVDD remains to be elucidated. This study aimed to clarify whether stimulation of visfatin in IVDD is mediated by IL-6. To investigate the role of visfatin in IVDD, a rat model of anterior disc puncture was established by injecting visfatin or PBS using a 27-gauge needle. Results revealed an obvious aggravation of the histological morphology of IVDD in the visfatin group. On treating human NP cellswith visfatin, the levels of collagenII and aggrecan decreased and those of matrix metallopeptidase 3 and IL-6 gradually increased. A rapid increase in ERK, JNK, and p38 phosphorylation was also noted after visfatin treatment. Compared to those treated with visfatin alone, NP cells pretreated with ERK1/2, JNK, and p38 inhibitors or siRNA targeting p38, ERK, and JNK exhibited a significant suppression of IL-6. Our data represent the first evidence that visfatin promotes IL-6 expression in NP cells via the JNK/ERK/p38-MAPK signalling pathways. Further, our findings suggest epidural fat and visfatin as potential therapeutic targets for controlling IVDD-associated inflammation.
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Affiliation(s)
- Haitao Cui
- Department of Spine Surgery, The 1st Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, PR China
| | - Xianfa Du
- Department of Spine Surgery, The 1st Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, PR China
| | - Caijun Liu
- The Third Affiliated Hospital of Guangzhou, University of Traditional Chinese Medicine, Guangzhou, Guangdong, PR China
| | - Shunlun Chen
- Department of Spine Surgery, The 1st Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, PR China
| | - Haowen Cui
- Department of Spine Surgery, The 1st Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, PR China
| | - Hui Liu
- Department of Spine Surgery, The 1st Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, PR China
| | - Jianru Wang
- Department of Spine Surgery, The 1st Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, PR China
| | - Zhaomin Zheng
- Department of Spine Surgery, The 1st Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, PR China
- Pain Research Center, Sun Yat-sen University, Guangzhou, PR China
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ÇANKAL F, PATAT D, ŞİRİNOĞLU T. Radiological evaluation of spinal canal, dural sac, epidural fat and superior articular process in diagnosis of lumbar spinal stenosis. JOURNAL OF HEALTH SCIENCES AND MEDICINE 2021. [DOI: 10.32322/jhsm.973905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Sung SE, Seo MS, Kang KK, Choi JH, Lee SJ, Lim JH, Yang SY, Kim SK, Lee GW. Isolation and Characterization of Extracellular Vesicle from Mesenchymal Stem Cells of the Epidural Fat of the Spine. Asian Spine J 2021; 16:153-161. [PMID: 34461688 PMCID: PMC9066249 DOI: 10.31616/asj.2021.0129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/11/2021] [Indexed: 01/18/2023] Open
Abstract
Study Design An experimental study with extracellular vesicles (EVs) from mesenchymal stem cell (MSC) of the epidural fat (EF) of the spine. Purpose This study aims to isolate the exosomes from epidural fat-derived mesenchymal stem cells (EF-MSCs) and fully characterize the EF-MSC-EVs. Overview of Literature EF-MSCs were reported in 2019, and a few studies have shown the positive outcomes of using EF-MSCs to treat specific spine pathologies. However, MSCs have significant limitations for conducting basic studies or developing therapeutic agents. Although EVs are an emerging research topic, no studies have focused on EVs, especially exosomes, from EF and EF-MSCs. Methods In this study, we isolated the exosomes using the tangential flow filtration (TFF) system with exosome-depleted fetal bovine serum and performed the characterization tests via western blotting, reverse transcription–polymerase chain reaction, nanoparticle tracking analysis (NTA), and transmission electron microscopy. Results In transmission electron microscopy, the exosome had a diameter of approximately 100–200 nm and had a spherical shape, whereas in the NTA, the exosome had an average diameter of 142.8 nm with a concentration of 1.27×1010 particles/mL. The flow cytometry analysis showed the expression of CD63 and CD81. The western blotting analysis showed the positive markers. Conclusions These findings showed that isolating the exosomes via TFF resulted in high-quality EF-MSC exosome yield. Further studies with exosomes from EF-MSC are needed to evaluate the function and role of the EF tissue.
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Affiliation(s)
- Soo-Eun Sung
- Department of Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Min-Soo Seo
- Department of Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Kyung-Ku Kang
- Department of Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Joo-Hee Choi
- Department of Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Si-Joon Lee
- Department of Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Ju-Hyeon Lim
- New Drug Development Center, Osong Medical Innovation Foundation, Cheonju, Korea.,Department of Orthopedic Surgery, Yeungnam University Medical Center, Yeungnam University College of Medicine, Daegu, Korea
| | - Seung Yun Yang
- Department of Biomaterials Science (BK21 Four Program), Pusan National University, Pusan, Korea
| | - Seul-Ki Kim
- Efficacy Evaluation Team, Food Science R&D Center, KolmarBNH Co. Ltd., Seoul, Korea
| | - Gun Woo Lee
- Department of Orthopedic Surgery, Yeungnam University Medical Center, Yeungnam University College of Medicine, Daegu, Korea
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Shah S, Mudigonda S, Mitha AP, Salo P, Krawetz RJ. Epidural fat mesenchymal stem cells: Important microenvironmental regulators in health, disease, and regeneration: Do EF-MSCs play a role in dural homeostasis/maintenance? Bioessays 2020; 43:e2000215. [PMID: 33191529 DOI: 10.1002/bies.202000215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/01/2020] [Accepted: 10/06/2020] [Indexed: 12/26/2022]
Abstract
Mesenchymal stem cells (MSCs) are present in fat tissues throughout the body, yet little is known regarding their biological role within epidural fat. We hypothesize that debridement of epidural fat and/or subsequent loss of MSCs within this tissue, disrupts homeostasis in the vertebral environment resulting in increased inflammation, fibrosis, and decreased neovascularization leading to poorer functional outcomes post-injury/operatively. Clinically, epidural fat is commonly considered a space-filling tissue with limited functionality and therefore typically discarded during surgery. However, the presence of MSCs within epidural fat suggests that itis more biologically active than historically believed and may contribute to the regulation of homeostasis and regeneration in the dural environment. While the current literature supports our hypothesis, it will require additional experimentation to determine if epidural fat is an endogenous driver of repair and regeneration and if so, this tissue should be minimally perturbed from its original location in the spinal canal. Also see the video abstract here https://youtu.be/MIol_IWK1os.
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Affiliation(s)
- Sophia Shah
- McCaig institute for Bone and Joint Health, University of Calgary, Calgary, Alberta, Canada.,Biomedical Engineering Graduate Program, University of Calgary, Calgary, Alberta, Canada
| | - Sathvika Mudigonda
- McCaig institute for Bone and Joint Health, University of Calgary, Calgary, Alberta, Canada
| | - Alim P Mitha
- Biomedical Engineering Graduate Program, University of Calgary, Calgary, Alberta, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Paul Salo
- McCaig institute for Bone and Joint Health, University of Calgary, Calgary, Alberta, Canada.,Department of Surgery, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Roman J Krawetz
- McCaig institute for Bone and Joint Health, University of Calgary, Calgary, Alberta, Canada.,Biomedical Engineering Graduate Program, University of Calgary, Calgary, Alberta, Canada.,Department of Surgery, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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