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Dilley A, Harris M, Barbe MF, Bove GM. Aberrant Neuronal Activity in a Model of Work-Related Upper Limb Pain and Dysfunction. THE JOURNAL OF PAIN 2022; 23:852-863. [PMID: 34958943 PMCID: PMC9086086 DOI: 10.1016/j.jpain.2021.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/26/2021] [Accepted: 12/03/2021] [Indexed: 05/03/2023]
Abstract
Work-related musculoskeletal disorders associated with intense repetitive tasks are highly prevalent. Painful symptoms associated with such disorders can be attributed to neuropathy. In this study, we characterized the neuronal discharge from the median nerve in rats trained to perform an operant repetitive task. After 3-weeks of the task, rats developed pain behaviors and a decline in grip strength. Ongoing activity developed in 17.7% of slowly conducting neurons at 3-weeks, similar to neuritis. At 12-weeks, an irregular high frequency neuronal discharge was prevalent in >88.4% of slow and fast conducting neurons. At this time point, 8.3% of slow and 21.2% of fast conducting neurons developed a bursting discharge, which, combined with a reduction in fast-conducting neurons with receptive fields (38.4%), is consistent with marked neuropathology. Taken together, we have shown that an operant repetitive task leads to an active and progressive neuropathy that is characterized by marked neuropathology following 12-weeks task that mainly affects fast conducting neurons. Such aberrant neuronal activity may underlie painful symptoms in patients with work-related musculoskeletal disorders. PERSPECTIVE: Aberrant neuronal activity, similar to that reported in this study, may contribute to upper limb pain and dysfunction in patients with work-related musculoskeletal disorders. In addition, profiles of instantaneous frequencies may provide an effective way of stratifying patients with painful neuropathies.
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Affiliation(s)
- Andrew Dilley
- Department of Neuroscience, Brighton and Sussex Medical School, University of Sussex, Brighton, England
| | - Michele Harris
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Mary F Barbe
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Geoffrey M Bove
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania; Bove Consulting, Kennebunkport, Maine.
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Barbe MF, Panibatla ST, Harris MY, Amin M, Dorotan JT, Cruz GE, Bove GM. Manual Therapy With Rest as a Treatment for Established Inflammation and Fibrosis in a Rat Model of Repetitive Strain Injury. Front Physiol 2021; 12:755923. [PMID: 34803739 PMCID: PMC8600143 DOI: 10.3389/fphys.2021.755923] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Repetitive strain injuries caused by repetitive occupational work are difficult to prevent for multiple reasons. Therefore, we examined the effectiveness of manual therapy (MT) with rest to treat the inflammation and fibrosis that develops through the performance of a repetitive task. We hypothesized that this treatment would reduce task-induced sensorimotor declines and neuromuscular inflammation. Methods: Twenty-nine female Sprague-Dawley rats performed a reaching and lever-pulling task for 14weeks. All ceased performing the task at 14weeks. Ten were euthanized at this timepoint (TASK). Nine received manual therapy to their upper extremities while resting 7weeks (MTR); 10 were assigned to rest alone (REST). Ten additional food restricted rats were included that neither performed the task nor received manual therapy (FRC). Results: Confirming previous experiments, TASK rats showed behavioral changes (forepaw mechanical hypersensitivity, reduced grip strength, lowered forelimb/forepaw agility, and noxious cold temperature sensitivity), reduced median nerve conduction velocity (NCV), and pathological tissue changes (myelin degradation, increased median nerve and muscle inflammation, and collagen production). Manual therapy with rest (MTR) ameliorated cold sensitivity seen in REST rats, enhanced muscle interleukin 10 (IL-10) more than in REST rats, lead to improvement in most other measures, compared to TASK rats. REST rats showed improved grip strength, lowered nerve inflammation and degraded myelin, and lowered muscle tumor necrosis factor alpha (TNFα) and collagen I levels, compared to TASK rats, yet maintained lowered forelimb/forepaw agility and NCV, and increased neural fibrosis. Conclusion: In our model of repetitive motion disorder, manual therapy during rest had modest effects on behavioral, histological, and physiological measures, compared to rest alone. These findings stand in contrast to the robust preventive effects of manual therapy in this same model.
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Affiliation(s)
- Mary F Barbe
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Siva Tejaa Panibatla
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Michele Y Harris
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Mamta Amin
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Jocelynne T Dorotan
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Geneva E Cruz
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Geoffrey M Bove
- Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States.,Bove Consulting, Kennebunkport, ME, United States
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Quinelato V, Bonato LL, Vieira AR, Granjeiro JM, Menezes K, Borojevic R, Casado PL, Calasans-Maia JA, Tesch R. PAX7 gene polymorphism in muscular temporomandibular disorders as potentially related to muscle stem cells. BMC Musculoskelet Disord 2021; 22:959. [PMID: 34789211 PMCID: PMC8600756 DOI: 10.1186/s12891-021-04846-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 10/07/2021] [Indexed: 11/10/2022] Open
Abstract
Background Temporomandibular disorders (TMD) are a group of painful and debilitating disorders, involving the masticatory muscles and/or the temporomandibular joint (TMJ). Chronic TMD pain can be associated with genetic changes in the key muscle development genes. Objective To evaluate the association between polymorphisms in the PAX7 (paired box 7) gene and masticatory myalgia in patients with temporomandibular disorders (TMD). Materials and methods This is a case-control study. Patients with TMD were divided into two groups: (a) presence of muscular TMD (n = 122) and (b) absence of muscular TMD (n = 49). Genomic DNA was obtained from saliva samples from all participants to allow for genotyping single nucleotide polymorphisms in PAX7 (rs766325 and rs6659735). Over-representation of alleles was tested using chi-square or Fisher’s exact tests. Values of p < 0.05 were considered to be statistically significant. Results Individuals without muscular TMD were less likely to have the PAX7 rs6659735 GG genotype (p = 0.03). No associations were found for PAX7 rs766325. Conclusions Alterations in PAX7 may influence muscular pathophysiology and individuals with TMD and the rs6659735 homozygous genotype (GG) are seemingly associated with muscular involvement of the disorder. No associations were found in the region rs766325.
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Affiliation(s)
- Valquiria Quinelato
- School of Dentistry, Universidade Federal Fluminense, Mario Santos Braga St, 28 - Center, Niterói, RJ, 24020-140, Brazil.
| | - Letícia Ladeira Bonato
- School of Dentistry, Universidade Federal Fluminense, Mario Santos Braga St, 28 - Center, Niterói, RJ, 24020-140, Brazil
| | | | | | - Karla Menezes
- School of Medicine of Petropolis, Petropolis, Brazil
| | | | - Priscila Ladeira Casado
- School of Dentistry, Universidade Federal Fluminense, Mario Santos Braga St, 28 - Center, Niterói, RJ, 24020-140, Brazil
| | - Jose Albuquerque Calasans-Maia
- School of Dentistry, Universidade Federal Fluminense, Mario Santos Braga St, 28 - Center, Niterói, RJ, 24020-140, Brazil
| | - Ricardo Tesch
- School of Medicine of Petropolis, Petropolis, Brazil
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Barbe MF, Hilliard B, Fisher PW, White AR, Delany SP, Iannarone VJ, Harris MY, Amin M, Cruz GE, Popoff SN. Blocking substance P signaling reduces musculotendinous and dermal fibrosis and sensorimotor declines in a rat model of overuse injury. Connect Tissue Res 2020; 61:604-619. [PMID: 31443618 PMCID: PMC7036028 DOI: 10.1080/03008207.2019.1653289] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Purpose/Aim: Substance P-NK-1R signaling has been implicated in fibrotic tendinopathies and myositis. Blocking this signaling with a neurokinin 1 receptor antagonist (NK1RA) has been proposed as a therapeutic target for their treatment.Materials and Methods: Using a rodent model of overuse injury, we pharmacologically blocked Substance P using a specific NK1RA with the hopes of reducing forelimb tendon, muscle and dermal fibrogenic changes and associated pain-related behaviors. Young adult rats learned to pull at high force levels across a 5-week period, before performing a high repetition high force (HRHF) task for 3 weeks (2 h/day, 3 days/week). HRHF rats were untreated or treated in task weeks 2 and 3 with the NK1RA, i.p. Control rats received vehicle or NK1RA treatments.Results: Grip strength declined in untreated HRHF rats, and mechanical sensitivity and temperature aversion increased compared to controls; these changes were improved by NK1RA treatment (L-732,138). NK1RA treatment also reduced HRHF-induced thickening in flexor digitorum epitendons, and HRHF-induced increases of TGFbeta1, CCN2/CTGF, and collagen type 1 in flexor digitorum muscles. In the forepaw upper dermis, task-induced increases in collagen deposition were reduced by NK1RA treatment.Conclusions: Our findings indicate that Substance P plays a role in the development of fibrogenic responses and subsequent discomfort in forelimb tissues involved in performing a high demand repetitive forceful task.
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Affiliation(s)
- MF Barbe
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - B Hilliard
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - PW Fisher
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - AR White
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - SP Delany
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - VJ Iannarone
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - MY Harris
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - M Amin
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - GE Cruz
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
| | - SN Popoff
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, United States
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The Pelvic Girdle Pain deadlock: 2. Topics that, so far, have remained out of focus. Musculoskelet Sci Pract 2020; 48:102166. [PMID: 32560869 DOI: 10.1016/j.msksp.2020.102166] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 03/30/2020] [Accepted: 04/06/2020] [Indexed: 12/19/2022]
Abstract
INTRODUCTION In our preceding paper, we concluded that Pelvic Girdle Pain (PGP) should be taken seriously. Still, we do not know its causes. Literature reviews on treatment fail to reveal a consistent pattern, and there are patients who do not respond well to treatment. We designated the lack of progress in research and in the clinic as 'deadlock', and proposed a 'deconstruction' of PGP, that is to say, taking PGP apart into its relevant dimensions. PURPOSE We examine the proposition that PGP may emerge as local inflammation. Inflammation would be a new dimension to be taken into account, between biomechanics and psychology. To explore the consequences of this idea, we present four different topics that, so far, have remained out of focus. One: The importance of microtrauma. Two: Ways to counteract chronification. Three: The importance of sickness behaviour when systemic inflammation turns into neuroinflammation of the brain. And Four: The mainly emotional and cognitive nature of chronic pain, and how aberrant neuroinflammation may render chronic pain intractable. For intractable pain, sleep and stress management are promising treatment options. IMPLICATIONS The authors hope that the present paper helps to stimulate the flexible creativity that is required to deal with the biological and psychological impact of PGP. Measuring inflammatory mediators in PGP should be a research priority. It should be understood that the boundaries between biology and psychology are becoming blurred. Clinicians must frequently monitor pain, disability, and mood, and be ready to switch treatment whenever the patient does not improve.
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Ijaz M, Ahmad SR, Akram MM, Thygerson SM, Ali Nadeem F, Khan WU. Cross-Sectional Survey of Musculoskeletal Disorders in Workers Practicing Traditional Methods of Underground Coal Mining. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17072566. [PMID: 32283589 PMCID: PMC7177932 DOI: 10.3390/ijerph17072566] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/22/2020] [Accepted: 04/03/2020] [Indexed: 12/23/2022]
Abstract
Background: In subcontinental underground mines, coal mining is carried out manually and requires many laborers to practice traditional means of coal excavation. Each task of this occupation disturbs workers’ musculoskeletal order. In order to propose and practice possible ergonomic interventions, it is necessary to know what tasks (drilling and blasting, coal cutting, dumping, transporting, timbering and supporting, loading and unloading) cause disorder in either upper limbs, lower limbs, or both. Methods: To this end, R-programming, version R 3.1.2 and SPSS, software 20, were used to calculate data obtained by studying 260 workers (working at different tasks of coal mining) from 20 mines of four districts of Punjab, Pakistan. In addition, a Standard Nordic Musculoskeletal Questionnaire (SNMQ) and Rapid Upper Limb Assessment (RULA) sheet were used to collect data and to analyze postures respectively. Results: In multi regression models, significance of the five tasks for upper and lower limb disorder is 0.00, which means that task based prevalence of upper and lower limb disorders are common in underground coal mines. The results of the multiple bar chart showed that 96 coal cutters got upper limb disorders and 82 got lower limb disorders. The task of timbering and supporting was shown to be dangerous for the lower limbs and relatively less dangerous for the upper limbs, with 25 workers reporting pain in their lower limbs, and 19 workers reporting pain in their upper limbs. Documented on the RULA sheet, all tasks got the maximum possible score (7), meaning that each of these tasks pose a threat to the posture of 100% of workers. The majority of participants (182) fell in the age group of 26 to 35 years. Of those workers, 131 reported pain in the lower limbs and slight discomfort (128) in the upper limbs. The significance value of age was 0.00 for upper limb disorder and was 0.012 for lower limb disorder. Frequency graphs show age in direct proportion to severity of pain while in inverse proportion with number of repetitions performed per min. Conclusions: All findings infer that each task of underground coal mining inflicts different levels of disorder in a workers’ musculoskeletal structure of the upper and lower limbs. It highlighted the need for urgent intervention in postural aspects of each task.
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Affiliation(s)
- Madiha Ijaz
- College of Earth and Environmental Sciences, New campus, University of the Punjab, Lahore 54590, Pakistan; (S.R.A.); (M.M.A.); (W.U.K.)
- Correspondence: ; Tel.: +92-423-595-3102
| | - Sajid Rashid Ahmad
- College of Earth and Environmental Sciences, New campus, University of the Punjab, Lahore 54590, Pakistan; (S.R.A.); (M.M.A.); (W.U.K.)
| | - Muhammad M. Akram
- College of Earth and Environmental Sciences, New campus, University of the Punjab, Lahore 54590, Pakistan; (S.R.A.); (M.M.A.); (W.U.K.)
| | - Steven M. Thygerson
- Department of Public Health, College of Life Sciences, Brigham Young University, Provo, UT 84604, USA;
| | - Falaq Ali Nadeem
- College of Statistical and Actuarial Sciences, University of the Punjab, Lahore 54590, Pakistan;
| | - Waheed Ullah Khan
- College of Earth and Environmental Sciences, New campus, University of the Punjab, Lahore 54590, Pakistan; (S.R.A.); (M.M.A.); (W.U.K.)
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Manual therapy prevents onset of nociceptor activity, sensorimotor dysfunction, and neural fibrosis induced by a volitional repetitive task. Pain 2019; 160:632-644. [PMID: 30461558 DOI: 10.1097/j.pain.0000000000001443] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Painful and disabling musculoskeletal disorders remain prevalent. In rats trained to perform repetitive tasks leading to signs and dysfunction similar to those in humans, we tested whether manual therapy would prevent the development of the pathologies and symptoms. We collected behavioral, electrophysiological, and histological data from control rats, rats that trained for 5 weeks before performing a high-repetition high-force (HRHF) task for 3 weeks untreated, and trained rats that performed the task for 3 weeks while being treated 3x/week using modeled manual therapy (MMT) to the forearm (HRHF + MMT). The MMT included bilateral mobilization, skin rolling, and long axis stretching of the entire upper limb. High-repetition high-force rats showed decreased performance of the operant HRHF task and increased discomfort-related behaviors, starting after training. HRHF + MMT rats showed improved task performance and decreased discomfort-related behaviors compared with untreated HRHF rats. Subsets of rats were assayed for presence or absence of ongoing activity in C neurons and slow Aδ neurons in their median nerves. Neurons from HRHF rats had a heightened proportion of ongoing activity and altered conduction velocities compared with control and MMT-treated rats. Median nerve branches in HRHF rats contained increased numbers of CD68 macrophages and degraded myelin basic protein, and showed increased extraneural collagen deposition, compared with the other groups. We conclude that the performance of the task for 3 weeks leads to increased ongoing activity in nociceptors, in parallel with behavioral and histological signs of neuritis and nerve injury, and that these pathophysiologies are largely prevented by MMT.
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Effectiveness of conservative interventions for sickness and pain behaviors induced by a high repetition high force upper extremity task. BMC Neurosci 2017; 18:36. [PMID: 28356066 PMCID: PMC5371184 DOI: 10.1186/s12868-017-0354-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 03/16/2017] [Indexed: 11/29/2022] Open
Abstract
Background Systemic inflammation is known to induce sickness behaviors, including decreased social interaction and pain. We have reported increased serum inflammatory cytokines in a rat model of repetitive strain injury (rats perform an upper extremity reaching task for prolonged periods). Here, we sought to determine if sickness behaviors are induced in this model and the effectiveness of conservative treatments. Methods Experimental rats underwent initial training to learn a high force reaching task (10 min/day, 5 days/week for 6 weeks), with or without ibuprofen treatment (TRHF vs. TRHF + IBU rats). Subsets of trained animals went on to perform a high repetition high force (HRHF) task for 6 or 12 weeks (2 h/day, 3 days/week) without treatment, or received two secondary interventions: ibuprofen (HRHF + IBU) or a move to a lower demand low repetition low force task (HRHF-to-LRLF), beginning in task week 5. Mixed-effects models with repeated measures assays were used to assay duration of social interaction, aggression, forepaw withdrawal thresholds and reach performance abilities. One-way and two-way ANOVAs were used to assay tissue responses. Corrections for multiple comparisons were made. Results TRHF + IBU rats did not develop behavioral declines or systemic increases in IL-1beta and IL-6, observed in untreated TRHF rats. Untreated HRHF rats showed social interaction declines, difficulties performing the operant task and forepaw mechanical allodynia. Untreated HRHF rats also had increased serum levels of several inflammatory cytokines and chemokines, neuroinflammatory responses (e.g., increased TNFalpha) in the brain, median nerve and spinal cord, and Substance P and neurokinin 1 immunoexpression in the spinal cord. HRHF + IBU and HRHF-to-LRLF rats showed improved social interaction and reduced inflammatory serum, nerve and brain changes. However, neither secondary treatment rescued HRHF-task induced forepaw allodynia, or completely attenuated task performance declines or spinal cord responses. Conclusions These results suggest that inflammatory mechanisms induced by prolonged performance of high physical demand tasks mediate the development of social interaction declines and aggression. However, persistent spinal cord sensitization was associated with persistent behavioral indices of discomfort, despite use of conservative secondary interventions indicating the need for prevention or more effective interventions. Electronic supplementary material The online version of this article (doi:10.1186/s12868-017-0354-3) contains supplementary material, which is available to authorized users.
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Tyburski AL, Cheng L, Assari S, Darvish K, Elliott MB. Frequent mild head injury promotes trigeminal sensitivity concomitant with microglial proliferation, astrocytosis, and increased neuropeptide levels in the trigeminal pain system. J Headache Pain 2017; 18:16. [PMID: 28176234 PMCID: PMC5296267 DOI: 10.1186/s10194-017-0726-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/18/2017] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Frequent mild head injuries or concussion along with the presence of headache may contribute to the persistence of concussion symptoms. METHODS In this study, the acute effects of recovery between mild head injuries and the frequency of injuries on a headache behavior, trigeminal allodynia, was assessed using von Frey testing up to one week after injury, while histopathological changes in the trigeminal pain pathway were evaluated using western blot, ELISA and immunohistochemistry. RESULTS: A decreased recovery time combined with an increased mild closed head injury (CHI) frequency results in reduced trigeminal allodynia thresholds compared to controls. The repetitive CHI group with the highest injury frequency showed the greatest reduction in trigeminal thresholds along with greatest increased levels of calcitonin gene-related peptide (CGRP) in the trigeminal nucleus caudalis. Repetitive CHI resulted in astrogliosis in the central trigeminal system, increased GFAP protein levels in the sensory barrel cortex, and an increased number of microglia cells in the trigeminal nucleus caudalis. CONCLUSIONS Headache behavior in rats is dependent on the injury frequency and recovery interval between mild head injuries. A worsening of headache behavior after repetitive mild head injuries was concomitant with increases in CGRP levels, the presence of astrocytosis, and microglia proliferation in the central trigeminal pathway. Signaling between neurons and proliferating microglia in the trigeminal pain system may contribute to the initiation of acute headache after concussion or other traumatic brain injuries.
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Affiliation(s)
- Ashley L Tyburski
- Department of Neurosurgery, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA
| | - Lan Cheng
- Department of Neurosurgery, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA
| | | | | | - Melanie B Elliott
- Department of Neurosurgery, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA.
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Bove GM, Harris MY, Zhao H, Barbe MF. Manual therapy as an effective treatment for fibrosis in a rat model of upper extremity overuse injury. J Neurol Sci 2016; 361:168-80. [PMID: 26810536 PMCID: PMC4729290 DOI: 10.1016/j.jns.2015.12.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Revised: 12/16/2015] [Accepted: 12/17/2015] [Indexed: 01/08/2023]
Abstract
Key clinical features of carpal tunnel syndrome and other types of cumulative trauma disorders of the hand and wrist include pain and functional disabilities. Mechanistic details remain under investigation but may involve tissue inflammation and/or fibrosis. We examined the effectiveness of modeled manual therapy (MMT) as a treatment for sensorimotor behavior declines and increased fibrogenic processes occurring in forearm tissues of rats performing a high repetition high force (HRHF) reaching and grasping task for 12 weeks. Young adult, female rats were examined: food restricted control rats (FRC, n=12); rats that were trained for 6 weeks before performing the HRHF task for 12 weeks with no treatment (HRHF-CON, n=11); and HRHF task rats received modeled manual therapy (HRHF-MMT, n=5) for 5 days/week for the duration of the 12-week of task. Rats receiving the MMT expressed fewer discomfort-related behaviors, and performed progressively better in the HRHF task. Grip strength, while decreased after training, improved following MMT. Fibrotic nerve and connective tissue changes (increased collagen and TGF-β1 deposition) present in 12-week HRHF-CON rats were significantly decreased in 12-week HRHF-MMT rats. These observations support the investigation of manual therapy as a preventative for repetitive motion disorders.
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Affiliation(s)
- Geoffrey M Bove
- Department of Biomedical Sciences, University of New England College of Osteopathic Medicine, 11 Hills Beach Rd, Biddeford, ME 04005, USA
| | - Michele Y Harris
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Huaqing Zhao
- Department of Clinical Sciences and Biostatistical Consulting Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Mary F Barbe
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA, USA.
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Massicotte VS, Frara N, Harris MY, Amin M, Wade CK, Popoff SN, Barbe MF. Prolonged performance of a high repetition low force task induces bone adaptation in young adult rats, but loss in mature rats. Exp Gerontol 2015; 72:204-17. [PMID: 26517953 PMCID: PMC4655973 DOI: 10.1016/j.exger.2015.10.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 10/06/2015] [Accepted: 10/26/2015] [Indexed: 10/22/2022]
Abstract
We have shown that prolonged repetitive reaching and grasping tasks lead to exposure-dependent changes in bone microarchitecture and inflammatory cytokines in young adult rats. Since aging mammals show increased tissue inflammatory cytokines, we sought here to determine if aging, combined with prolonged performance of a repetitive upper extremity task, enhances bone loss. We examined the radius, forearm flexor muscles, and serum from 16 mature (14-18 months of age) and 14 young adult (2.5-6.5 months of age) female rats after performance of a high repetition low force (HRLF) reaching and grasping task for 12 weeks. Young adult HRLF rats showed enhanced radial bone growth (e.g., increased trabecular bone volume, osteoblast numbers, bone formation rate, and mid-diaphyseal periosteal perimeter), compared to age-matched controls. Mature HRLF rats showed several indices of radial bone loss (e.g., decreased trabecular bone volume, and increased cortical bone thinning, porosity, resorptive spaces and woven bone formation), increased osteoclast numbers and inflammatory cytokines, compared to age-matched controls and young adult HRLF rats. Mature rats weighed more yet had lower maximum reflexive grip strength, than young adult rats, although each age group was able to pull at the required reach rate (4 reaches/min) and required submaximal pulling force (30 force-grams) for a food reward. Serum estrogen levels and flexor digitorum muscle size were similar in each age group. Thus, mature rats had increased bone degradative changes than in young adult rats performing the same repetitive task for 12 weeks, with increased inflammatory cytokine responses and osteoclast activity as possible causes.
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Affiliation(s)
- Vicky S Massicotte
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St., Philadelphia, PA 19140, USA
| | - Nagat Frara
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St., Philadelphia, PA 19140, USA
| | - Michele Y Harris
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St., Philadelphia, PA 19140, USA
| | - Mamta Amin
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St., Philadelphia, PA 19140, USA
| | - Christine K Wade
- Department of Physical Therapy, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Steven N Popoff
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St., Philadelphia, PA 19140, USA
| | - Mary F Barbe
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St., Philadelphia, PA 19140, USA; Department of Physical Therapy, Temple University, Philadelphia, PA 19140, USA.
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Increased CCN2, substance P and tissue fibrosis are associated with sensorimotor declines in a rat model of repetitive overuse injury. J Cell Commun Signal 2015; 9:37-54. [PMID: 25617052 DOI: 10.1007/s12079-015-0263-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 01/14/2015] [Indexed: 01/24/2023] Open
Abstract
Key clinical features of cumulative trauma disorders include pain, muscle weakness, and tissue fibrosis, although the etiology is still under investigation. Here, we characterized the temporal pattern of altered sensorimotor behaviors and inflammatory and fibrogenic processes occurring in forearm muscles and serum of young adult, female rats performing an operant, high repetition high force (HRHF) reaching and grasping task for 6, 12, or 18 weeks. Palmar mechanical sensitivity, cold temperature avoidance and spontaneous behavioral changes increased, while grip strength declined, in 18-week HRHF rats, compared to controls. Flexor digitorum muscles had increased MCP-1 levels after training and increased TNFalpha in 6-week HRHF rats. Serum had increased IL-1beta, IL-10 and IP-10 after training. Yet both muscle and serum inflammation resolved by week 18. In contrast, IFNγ increased at week 18 in both muscle and serum. Given the anti-fibrotic role of IFNγ, and to identify a mechanism for the continued grip strength losses and behavioral sensitivities, we evaluated the fibrogenic proteins CCN2, collagen type I and TGFB1, as well as the nociceptive/fibrogenic peptide substance P. Each increased in and around flexor digitorum muscles and extracellular matrix in the mid-forearm, and in nerves of the forepaw at 18 weeks. CCN2 was also increased in serum at week 18. At a time when inflammation had subsided, increases in fibrogenic proteins correlated with sensorimotor declines. Thus, muscle and nerve fibrosis may be critical components of chronic work-related musculoskeletal disorders. CCN2 and substance P may serve as potential targets for therapeutic intervention, and CCN2 as a serum biomarker of fibrosis progression.
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Role of inflammation in the aging bones. Life Sci 2014; 123:25-34. [PMID: 25510309 DOI: 10.1016/j.lfs.2014.11.011] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 11/03/2014] [Accepted: 11/17/2014] [Indexed: 12/15/2022]
Abstract
Chronic inflammation in aging is characterized by increased inflammatory cytokines, bone loss, decreased adaptation, and defective tissue repair in response to injury. Aging leads to inherent changes in mesenchymal stem cell (MSC) differentiation, resulting in impaired osteoblastogenesis. Also, the pro-inflammatory cytokines increase with aging, leading to enhanced myelopoiesis and osteoclastogenesis. Bone marrow macrophages (BMMs) play pivotal roles in osteoblast differentiation, the maintenance of hematopoietic stem cells (HSCs), and subsequent bone repair. However, during aging, little is known about the role of macrophages in the differentiation and function of MSC and HSC. Aged mammals have higher circulating pro-inflammatory cytokines than young adults, supporting the hypothesis of increased inflammation with aging. This review will aid in the understanding of the potential role(s) of pro-inflammatory (M1) and anti-inflammatory (M2) macrophages in differentiation and function of osteoblasts and osteoclasts in relation to aging.
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Macolino CM, Daiutolo BV, Albertson BK, Elliott MB. Mechanical allodynia induced by traumatic brain injury is independent of restraint stress. J Neurosci Methods 2014; 226:139-146. [PMID: 24486873 DOI: 10.1016/j.jneumeth.2014.01.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 12/20/2013] [Accepted: 01/13/2014] [Indexed: 01/28/2023]
Abstract
BACKGROUND This study identifies the relationship between a test for post-traumatic headache and a marker for acute stress in rodent models of traumatic brain injury. NEW METHOD C57BL/6 mice and Sprague Dawley rats were divided into Controlled Cortical Impact (CCI) injury, craniotomy (CR), and incision groups. Periorbital and paw allodynia were evaluated using the von Frey test prior to injury and up to four weeks post-operatively. Serum corticosterone was evaluated in groups with and without mild restraint. RESULTS Periorbital and forepaw thresholds, but not hindpaw thresholds, were reduced in CCI and CR mice compared to incision (p<0.0001 and p<0.01). In contrast to mice, reduced periorbital and forepaw periorbital thresholds were found in CCI rats but not CR rats compared to incision (p<0.0001). Right periorbital thresholds were reduced compared to left thresholds for both rat and mouse at one week (p<0.01), but there were no side differences for forepaw thresholds. Hindpaw thresholds did not change from baseline values for any groups of mice or rats. In mice serum corticosterone levels were increased at one, two and four weeks post-CCI and CR, while the levels for rats were not different from incision (p<0.0001). Corticosterone levels were not different in mice subjected to restraint compared to no restraint. COMPARISON WITH EXISTING METHODS This study presents novel data for allodynia in a rat model of TBI, and differences among mouse and rat species. CONCLUSIONS Mechanical allodynia occurs independent of evoked restraint stress, while hypothalamic pituitary adrenal axis activity is dependent on head trauma and species.
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Affiliation(s)
- Christine M Macolino
- Department of Neurological Surgery, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
| | - Brittany V Daiutolo
- Department of Neurological Surgery, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
| | - Brad K Albertson
- Jefferson Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA.
| | - Melanie B Elliott
- Department of Neuroscience, Jefferson Hospital for Neuroscience Chairs Office 900 Walnut Street, Philadelphia, PA 19107, USA.
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Barbe MF, Gallagher S, Massicotte VS, Tytell M, Popoff SN, Barr-Gillespie AE. The interaction of force and repetition on musculoskeletal and neural tissue responses and sensorimotor behavior in a rat model of work-related musculoskeletal disorders. BMC Musculoskelet Disord 2013; 14:303. [PMID: 24156755 PMCID: PMC3924406 DOI: 10.1186/1471-2474-14-303] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 10/22/2013] [Indexed: 12/01/2022] Open
Abstract
Background We examined the relationship of musculoskeletal risk factors underlying force and repetition on tissue responses in an operant rat model of repetitive reaching and pulling, and if force x repetition interactions were present, indicative of a fatigue failure process. We examined exposure-dependent changes in biochemical, morphological and sensorimotor responses occurring with repeated performance of a handle-pulling task for 12 weeks at one of four repetition and force levels: 1) low repetition with low force, 2) high repetition with low force, 3) low repetition with high force, and 4) high repetition with high force (HRHF). Methods Rats underwent initial training for 4–6 weeks, and then performed one of the tasks for 12 weeks, 2 hours/day, 3 days/week. Reflexive grip strength and sensitivity to touch were assayed as functional outcomes. Flexor digitorum muscles and tendons, forelimb bones, and serum were assayed using ELISA for indicators of inflammation, tissue stress and repair, and bone turnover. Histomorphometry was used to assay macrophage infiltration of tissues, spinal cord substance P changes, and tissue adaptative or degradative changes. MicroCT was used to assay bones for changes in bone quality. Results Several force x repetition interactions were observed for: muscle IL-1alpha and bone IL-1beta; serum TNFalpha, IL-1alpha, and IL-1beta; muscle HSP72, a tissue stress and repair protein; histomorphological evidence of tendon and cartilage degradation; serum biomarkers of bone degradation (CTXI) and bone formation (osteocalcin); and morphological evidence of bone adaptation versus resorption. In most cases, performance of the HRHF task induced the greatest tissue degenerative changes, while performance of moderate level tasks induced bone adaptation and a suggestion of muscle adaptation. Both high force tasks induced median nerve macrophage infiltration, spinal cord sensitization (increased substance P), grip strength declines and forepaw mechanical allodynia by task week 12. Conclusions Although not consistent in all tissues, we found several significant interactions between the critical musculoskeletal risk factors of force and repetition, consistent with a fatigue failure process in musculoskeletal tissues. Prolonged performance of HRHF tasks exhibited significantly increased risk for musculoskeletal disorders, while performance of moderate level tasks exhibited adaptation to task demands.
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Affiliation(s)
- Mary F Barbe
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St, Philadelphia 19140, PA, USA.
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Kietrys DM, Barr-Gillespie AE, Amin M, Wade CK, Popoff SN, Barbe MF. Aging contributes to inflammation in upper extremity tendons and declines in forelimb agility in a rat model of upper extremity overuse. PLoS One 2012; 7:e46954. [PMID: 23056540 PMCID: PMC3463562 DOI: 10.1371/journal.pone.0046954] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 09/10/2012] [Indexed: 01/08/2023] Open
Abstract
We sought to determine if tendon inflammatory and histopathological responses increase in aged rats compared to young rats performing a voluntary upper extremity repetitive task, and if these changes are associated with motor declines. Ninety-six female Sprague-Dawley rats were used in the rat model of upper extremity overuse: 67 aged and 29 young adult rats. After a training period of 4 weeks, task rats performed a voluntary high repetition low force (HRLF) handle-pulling task for 2 hrs/day, 3 days/wk for up to 12 weeks. Upper extremity motor function was assessed, as were inflammatory and histomorphological changes in flexor digitorum and supraspinatus tendons. The percentage of successful reaches improved in young adult HRLF rats, but not in aged HRLF rats. Forelimb agility decreased transiently in young adult HRLF rats, but persistently in aged HRLF rats. HRLF task performance for 12 weeks lead to increased IL-1beta and IL-6 in flexor digitorum tendons of aged HRLF rats, compared to aged normal control (NC) as well as young adult HRLF rats. In contrast, TNF-alpha increased more in flexor digitorum tendons of young adult 12-week HRLF rats than in aged HRLF rats. Vascularity and collagen fibril organization were not affected by task performance in flexor digitorum tendons of either age group, although cellularity increased in both. By week 12 of HRLF task performance, vascularity and cellularity increased in the supraspinatus tendons of only aged rats. The increased cellularity was due to increased macrophages and connective tissue growth factor (CTGF)-immunoreactive fibroblasts in the peritendon. In conclusion, aged rat tendons were overall more affected by the HRLF task than young adult tendons, particularly supraspinatus tendons. Greater inflammatory changes in aged HRLF rat tendons were observed, increases associated temporally with decreased forelimb agility and lack of improvement in task success.
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Affiliation(s)
- David M. Kietrys
- Department of Rehabilitation and Movement Sciences, University of Medicine and Dentistry of New Jersey, School of Health Related Professions, Stratford, New Jersey, United States of America
| | - Ann E. Barr-Gillespie
- College of Health Professions, Pacific University, Hillsboro, Oregon, United States of America
| | - Mamta Amin
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Christine K. Wade
- Department of Physical Therapy, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Steve N. Popoff
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Mary F. Barbe
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
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Abdelmagid SM, Barr AE, Rico M, Amin M, Litvin J, Popoff SN, Safadi FF, Barbe MF. Performance of repetitive tasks induces decreased grip strength and increased fibrogenic proteins in skeletal muscle: role of force and inflammation. PLoS One 2012; 7:e38359. [PMID: 22675458 PMCID: PMC3364991 DOI: 10.1371/journal.pone.0038359] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 05/04/2012] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND This study elucidates exposure-response relationships between performance of repetitive tasks, grip strength declines, and fibrogenic-related protein changes in muscles, and their link to inflammation. Specifically, we examined forearm flexor digitorum muscles for changes in connective tissue growth factor (CTGF; a matrix protein associated with fibrosis), collagen type I (Col1; a matrix component), and transforming growth factor beta 1 (TGFB1; an upstream modulator of CTGF and collagen), in rats performing one of two repetitive tasks, with or without anti-inflammatory drugs. METHODOLOGY/RESULTS To examine the roles of force versus repetition, rats performed either a high repetition negligible force food retrieval task (HRNF), or a high repetition high force handle-pulling task (HRHF), for up to 9 weeks, with results compared to trained only (TR-NF or TR-HF) and normal control rats. Grip strength declined with both tasks, with the greatest declines in 9-week HRHF rats. Quantitative PCR (qPCR) analyses of HRNF muscles showed increased expression of Col1 in weeks 3-9, and CTGF in weeks 6 and 9. Immunohistochemistry confirmed PCR results, and also showed greater increases of CTGF and collagen matrix in 9-week HRHF rats than 9-week HRNF rats. ELISA, and immunohistochemistry revealed greater increases of TGFB1 in TR-HF and 6-week HRHF, compared to 6-week HRNF rats. To examine the role of inflammation, results from 6-week HRHF rats were compared to rats receiving ibuprofen or anti-TNF-α treatment in HRHF weeks 4-6. Both treatments attenuated HRHF-induced increases in CTGF and fibrosis by 6 weeks of task performance. Ibuprofen attenuated TGFB1 increases and grip strength declines, matching our prior results with anti-TNFα. CONCLUSIONS/SIGNIFICANCE Performance of highly repetitive tasks was associated with force-dependent declines in grip strength and increased fibrogenic-related proteins in flexor digitorum muscles. These changes were attenuated, at least short-term, by anti-inflammatory treatments.
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Affiliation(s)
- Samir M. Abdelmagid
- Department of Surgery, Plastic and Reconstructive Division, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Ann E. Barr
- College of Health Professions, Pacific University, Hillsboro, Oregon, United States of America
| | - Mario Rico
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Mamta Amin
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Judith Litvin
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Musculoskeletal Research Group, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Steven N. Popoff
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Musculoskeletal Research Group, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Fayez F. Safadi
- Musculoskeletal Research Group, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University (NEOMED), Rootstown, Ohio, United States of America
| | - Mary F. Barbe
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- Musculoskeletal Research Group, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
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Elliott MB, Oshinsky ML, Amenta PS, Awe OO, Jallo JI. Nociceptive neuropeptide increases and periorbital allodynia in a model of traumatic brain injury. Headache 2012; 52:966-84. [PMID: 22568499 DOI: 10.1111/j.1526-4610.2012.02160.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE This study tests the hypothesis that injury to the somatosensory cortex is associated with periorbital allodynia and increases in nociceptive neuropeptides in the brainstem in a mouse model of controlled cortical impact (CCI) injury. METHODS Male C57BL/6 mice received either CCI or craniotomy-only followed by weekly periorbital von Frey (mechanical) sensory testing for up to 28 days post-injury. Mice receiving an incision only and naïve mice were included as control groups. Changes in calcitonin gene-related peptide (CGRP) and substance P (SP) within the brainstem were determined using enzyme-linked immunosorbent assay and immunohistochemistry, respectively. Activation of ionized calcium-binding adaptor molecule-1-labeled macrophages/microglia and glial fibrillary acidic protein (GFAP)-positive astrocytes were evaluated using immunohistochemistry because of their potential involvement in nociceptor sensitization. RESULTS Incision-only control mice showed no changes from baseline periorbital von Frey mechanical thresholds. CCI significantly reduced mean periorbital von Frey thresholds (periorbital allodynia) compared with baseline and craniotomy-only at each endpoint, analysis of variance P < .0001. Craniotomy significantly reduced periorbital threshold at 14 days but not 7, 21, or 28 days compared with baseline threshold, P < .01. CCI significantly increased SP immunoreactivity in the brainstem at 7 and 14 days but not 28 days compared with craniotomy-only and controls, P < .001. CGRP levels in brainstem tissues were significantly increased in CCI groups compared with controls (incision-only and naïve mice) or craniotomy-only mice at each endpoint examined, P < .0001. There was a significant correlation between CGRP and periorbital allodynia (P < .0001, r = -0.65) but not for SP (r = 0.20). CCI significantly increased the number of macrophage/microglia in the injured cortex at each endpoint up to 28 days, although cell numbers declined over weeks post-injury, P < .001. GFAP(+) immunoreactivity was significantly increased at 7 but not 14 or 28 days after CCI, P < .001. Craniotomy resulted in transient periorbital allodynia accompanied by transient increases in SP, CGRP, and GFAP immunoreactivity compared with control mice. There was no increase in the number of macrophage/microglia cells compared with controls after craniotomy. CONCLUSION Injury to the somatosensory cortex results in persistent periorbital allodynia and increases in brainstem nociceptive neuropeptides. Findings suggest that persistent allodynia and increased neuropeptides are maintained by mechanisms other than activation of macrophage/microglia or astrocyte in the injured somatosensory cortex.
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Affiliation(s)
- Melanie B Elliott
- Department of Neurological Surgery, Thomas Jefferson University, 1025 Walnut Street, Philadelphia, PA 19107, USA.
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Kietrys DM, Barr AE, Barbe MF. Exposure to repetitive tasks induces motor changes related to skill acquisition and inflammation in rats. J Mot Behav 2011; 43:465-76. [PMID: 22087754 DOI: 10.1080/00222895.2011.627897] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The authors elucidate exposure-response relationships between repetitive tasks, inflammation, and motor changes with work-related musculoskeletal disorders. Using a rat model of reaching and handle pulling, they examined effects of performing a high-repetition, low-force (HRLF); low-repetition, high-force (LRHF); or high-repetition, high-force (HRHF) task (2 hr/day, 3 days/week, 12 weeks) on reach rate and force, percentage of successful reaches, duration of participation, and grip strength. Reach rate and reach force improved with HRLF, and percentage success increased in all groups in Week 9, and in HRLF and HRHF in Week 12, indicative of skill acquisition. Duration and grip strength showed force-dependent declines with task performance. A subset of HRHF rats received ibuprofen in Weeks 5-12. Ibuprofen significantly improved reach rate, reach force, and duration in treated rats, indicative of an inflammatory influence on reach performance. Ibuprofen improved percentage of successful reaches in Week 9, although this increase was not sustained. However, declines in grip strength, a nocifensive behavior, were not prevented by ibuprofen. Examination of cervical spinal cords of untreated and ibuprofen treated HRHF rats showed increased IL-1beta, an inflammatory cytokine, in neurons. These findings suggest that only a preventive intervention could have addressed all motor declines.
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Affiliation(s)
- David M Kietrys
- Department of Rehabilitation and Movement Sciences, University of Medicine and Dentistry of New Jersey, School of Health Related Professions, Stratford, New Jersey, USA
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Mackey AL, Andersen LL, Frandsen U, Sjøgaard G. Strength training increases the size of the satellite cell pool in type I and II fibres of chronically painful trapezius muscle in females. J Physiol 2011; 589:5503-15. [PMID: 21946848 DOI: 10.1113/jphysiol.2011.217885] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
While strength training has been shown to be effective in mediating hypertrophy and reducing pain in trapezius myalgia, responses at the cellular level have not previously been studied. This study investigated the potential of strength training targeting the affected muscles (SST, n = 18) and general fitness training (GFT, n = 16) to augment the satellite cell (SC) and macrophage pools in the trapezius muscles of women diagnosed with trapezius myalgia. A group receiving general health information (REF, n = 8) served as a control. Muscle biopsies were collected from the trapezius muscles of the 42 women (age 44 ± 8 years; mean ± SD) before and after the 10 week intervention period and were analysed by immunohistochemistry for SCs, macrophages and myonuclei. The SC content of type I and II fibres was observed to increase significantly from baseline by 65% and 164%, respectively, with SST (P < 0.0001), together with a significant correlation between the baseline number of SCs and the extent of hypertrophy (r = -0.669, P = 0.005). SST also resulted in a 74% enhancement of the trapezius macrophage content (P < 0.01), accompanied by evidence for the presence of an increased number of actively dividing cells (Ki67(+)) post-SST (P < 0.001). GFT resulted in a significant 23% increase in the SC content of type II fibres, when expressed relative to myonuclear number only (P < 0.05). No changes in the number of myonuclei per fibre or myonuclear domain were detected in any group. These findings provide strong support at the cellular level for the potential of SST to induce a strong myogenic response in this population.
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Affiliation(s)
- Abigail L Mackey
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, and Centre for Healthy Ageing, Faculty of Health Sciences,University of Copenhagen, Denmark.
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Elliott MB, Tuma RF, Amenta PS, Barbe MF, Jallo JI. Acute effects of a selective cannabinoid-2 receptor agonist on neuroinflammation in a model of traumatic brain injury. J Neurotrauma 2011; 28:973-81. [PMID: 21332427 DOI: 10.1089/neu.2010.1672] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Proposed therapeutic strategies for attenuating secondary traumatic brain injury (TBI) include modulation of acute neuroimmune responses. The goal of this study was to examine the acute effects of cannabinoid-2 receptor (CB(2)R) modulation on behavioral deficits, cerebral edema, perivascular substance P, and macrophage/microglial activation in a murine model of TBI. Thirty male C57BL/6 mice underwent sham surgery, or cortical contusion impact injury (CCI). CCI mice received vehicle or the CB(2)R agonist 0-1966 at 1 and 24 h after injury. Performance on the rotarod, forelimb cylinder, and open-field tests were evaluated before and at 48 h after sham or CCI surgery. Cerebral edema was evaluated using the wet-dry weight technique. Immunohistochemical analysis was used to examine changes in substance P and macrophage/microglia-specific Iba1 protein immunoreactivity. Locomotor performance and exploratory behavior were significantly improved in mice receiving 0-1966 (CB(2)R agonist) compared to vehicle-treated mice. Significant reductions were found for cerebral edema, number of perivascular areas of substance P immunoreactivity, and number of activated macrophages/microglial cells in the injured brains of 0-1966-treated mice compared to vehicle-treated mice. The findings show that the effects of the CB(2)R agonist 0-1966 on edema, substance P immunoreactivity, and macrophage/microglial activation, were associated with recovery of acute motor and exploratory deficits. This study provides evidence of acute neuroprotective effects derived from selective CB(2)R activation that may represent an avenue for further development of novel therapeutic agents in the treatment of TBI.
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Affiliation(s)
- Melanie B Elliott
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
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Xin DL, Harris MY, Wade CK, Amin M, Barr AE, Barbe MF. Aging enhances serum cytokine response but not task-induced grip strength declines in a rat model of work-related musculoskeletal disorders. BMC Musculoskelet Disord 2011; 12:63. [PMID: 21447183 PMCID: PMC3072947 DOI: 10.1186/1471-2474-12-63] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 03/29/2011] [Indexed: 05/26/2023] Open
Abstract
Background We previously reported early tissue injury, increased serum and tissue inflammatory cytokines and decreased grip in young rats performing a moderate demand repetitive task. The tissue cytokine response was transient, the serum response and decreased grip were still evident by 8 weeks. Thus, here, we examined their levels at 12 weeks in young rats. Since aging is known to enhance serum cytokine levels, we also examined aged rats. Methods Aged and young rats, 14 mo and 2.5 mo of age at onset, respectfully, were trained 15 min/day for 4 weeks, and then performed a high repetition, low force (HRLF) reaching and grasping task for 2 hours/day, for 12 weeks. Serum was assayed for 6 cytokines: IL-1alpha, IL-6, IFN-gamma, TNF-alpha, MIP2, IL-10. Grip strength was assayed, since we have previously shown an inverse correlation between grip strength and serum inflammatory cytokines. Results were compared to naïve (grip), and normal, food-restricted and trained-only controls. Results Serum cytokines were higher overall in aged than young rats, with increases in IL-1alpha, IFN-gamma and IL-6 in aged Trained and 12-week HRLF rats, compared to young Trained and HRLF rats (p < 0.05 and p < 0.001, respectively, each). IL-6 was also increased in aged 12-week HRLF versus aged normal controls (p < 0.05). Serum IFN-gamma and MIP2 levels were also increased in young 6-week HRLF rats, but no cytokines were above baseline levels in young 12-week HRLF rats. Grip strength declined in both young and aged 12-week HRLF rats, compared to naïve and normal controls (p < 0.05 each), but these declines correlated only with IL-6 levels in aged rats (r = -0.39). Conclusion Aging enhanced a serum cytokine response in general, a response that was even greater with repetitive task performance. Grip strength was adversely affected by task performance in both age groups, but was apparently influenced by factors other than serum cytokine levels in young rats.
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Affiliation(s)
- Dong L Xin
- Department of Physical Therapy, Temple University, 3307 North Broad St,, Philadelphia, PA 19140, USA
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Joint inflammation and early degeneration induced by high-force reaching are attenuated by ibuprofen in an animal model of work-related musculoskeletal disorder. J Biomed Biotechnol 2011; 2011:691412. [PMID: 21403884 PMCID: PMC3051200 DOI: 10.1155/2011/691412] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Accepted: 12/11/2010] [Indexed: 11/18/2022] Open
Abstract
We used our voluntary rat model of reaching and grasping to study the effect of performing a high-repetition and high-force (HRHF) task for 12 weeks on wrist joints. We also studied the effectiveness of ibuprofen, administered in the last 8 weeks, in attenuating HRHF-induced changes in these joints. With HRHF task performance, ED1+ and COX2+ cells were present in subchondral radius, carpal bones and synovium; IL-1alpha and TNF-alpha increased in distal radius/ulna/carpal bones; chondrocytes stained with Terminal deoxynucleotidyl Transferase- (TDT-) mediated dUTP-biotin nick end-labeling (TUNEL) increased in wrist articular cartilages; superficial structural changes (e.g., pannus) and reduced proteoglycan staining were observed in wrist articular cartilages. These changes were not present in normal controls or ibuprofen treated rats, although IL-1alpha was increased in reach limbs of trained controls. HRHF-induced increases in serum C1,2C (a biomarker of collagen I and II degradation), and the ratio of collagen degradation to synthesis (C1,2C/CPII; the latter a biomarker of collage type II synthesis) were also attenuated by ibuprofen. Thus, ibuprofen treatment was effective in attenuating HRHF-induced inflammation and early articular cartilage degeneration.
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Mackey AL, Andersen LL, Frandsen U, Suetta C, Sjøgaard G. Distribution of myogenic progenitor cells and myonuclei is altered in women with vs. those without chronically painful trapezius muscle. J Appl Physiol (1985) 2010; 109:1920-9. [DOI: 10.1152/japplphysiol.00789.2010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
It is hypothesized that repeated recruitment of low-threshold motor units is an underlying cause of chronic pain in trapezius myalgia. This study investigated the distribution of satellite cells (SCs), myonuclei, and macrophages in muscle biopsies from the trapezius muscle of 42 women performing repetitive manual work, diagnosed with trapezius myalgia (MYA; 44 ± 8 yr; mean ± SD) and 20 matched healthy controls (CON; 45 ± 9 yr). Our hypothesis was that muscle of MYA, in particular type I fibers, would demonstrate higher numbers of SCs, myonuclei, and macrophages compared with CON. SCs were identified on muscle cross sections by combined immunohistochemical staining for Pax7, type I myosin, and laminin, allowing the number of SCs associated with type I and II fibers to be determined. We observed a pattern of SC distribution in MYA previously only reported for individuals above 70 yr of age. Compared with CON, MYA demonstrated 19% more SCs per fiber associated with type I fibers (MYA 0.098 ± 0.039 vs. CON 0.079 ± 0.031; P < 0.05) and 40% fewer SCs associated with type II fibers (MYA 0.047 ± 0.017 vs. CON 0.066 ± 0.035; P < 0.05). The finding of similar numbers of macrophages between the two groups was not in line with our hypothesis and suggests that the elevated SC content of MYA was not due to heightened inflammatory cell contents, but rather to provide new myonuclei. The findings of greater numbers of SCs in type I fibers of muscle subjected to repeated low-intensity work support our hypothesis and provide new insight into stimuli capable of regulating SC content.
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Affiliation(s)
- Abigail L. Mackey
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, and Centre for Healthy Ageing, Faculty of Health Sciences, University of Copenhagen, and
| | - Lars L. Andersen
- National Research Centre for the Working Environment, Copenhagen; and
| | - Ulrik Frandsen
- Institute of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Charlotte Suetta
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, and Centre for Healthy Ageing, Faculty of Health Sciences, University of Copenhagen, and
| | - Gisela Sjøgaard
- Institute of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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