1
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Dar A, Li A, Petrigliano FA. Lineage tracing reveals a novel PDGFRβ + satellite cell subset that contributes to myo-regeneration of chronically injured rotator cuff muscle. Sci Rep 2024; 14:9668. [PMID: 38671006 PMCID: PMC11053018 DOI: 10.1038/s41598-024-58926-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
Massive rotator cuff (RC) tendon tears are associated with progressive fibro-adipogenesis and muscle atrophy that altogether cause shoulder muscle wasting. Platelet derived growth factor β (PDGFRβ) lineage cells, that co-express PDGFRα have previously been shown to directly contribute to scar formation and fat accumulation in a mouse model of irreversible tendon and nerve transection (TTDN). Conversely, PDGFRβ+ lineage cells have also been shown to be myogenic in cultures and in other models of skeletal muscle injury. We therefore hypothesized that PDGFRβ demarcates two distinct RC residing subpopulations, fibro-adipogenic and myogenic, and aimed to elucidate the identity of the PDGFRβ myogenic precursors and evaluate their contribution, if any, to RC myo-regeneration. Lineage tracing revealed increasing contribution of PDGFRβ+ myo-progenitors to the formation of GFP+ myofibers, which were the most abundant myofiber type in regenerated muscle at 2 weeks post-TTDN. Muscle regeneration preceded muscle atrophy and both advanced from the lateral site of tendon transection to the farthest medial region. GFP+/PDGFRβ+Sca-1-lin-CXCR4+Integrin-β1+ marked a novel subset of satellite cells with confirmed myogenic properties. Further studies are warranted to identify the existence of PDGFRβ+ satellite cells in human and other mouse muscles and to define their myo-regenerative potential following acute and chronic muscle injury.
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Affiliation(s)
- Ayelet Dar
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
| | - Angela Li
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Frank A Petrigliano
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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2
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Bedi A, Bishop J, Keener J, Lansdown DA, Levy O, MacDonald P, Maffulli N, Oh JH, Sabesan VJ, Sanchez-Sotelo J, Williams RJ, Feeley BT. Rotator cuff tears. Nat Rev Dis Primers 2024; 10:8. [PMID: 38332156 DOI: 10.1038/s41572-024-00492-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/08/2024] [Indexed: 02/10/2024]
Abstract
Rotator cuff tears are the most common upper extremity condition seen by primary care and orthopaedic surgeons, with a spectrum ranging from tendinopathy to full-thickness tears with arthritic change. Some tears are traumatic, but most rotator cuff problems are degenerative. Not all tears are symptomatic and not all progress, and many patients in whom tears become more extensive do not experience symptom worsening. Hence, a standard algorithm for managing patients is challenging. The pathophysiology of rotator cuff tears is complex and encompasses an interplay between the tendon, bone and muscle. Rotator cuff tears begin as degenerative changes within the tendon, with matrix disorganization and inflammatory changes. Subsequently, tears progress to partial-thickness and then full-thickness tears. Muscle quality, as evidenced by the overall size of the muscle and intramuscular fatty infiltration, also influences symptoms, tear progression and the outcomes of surgery. Treatment depends primarily on symptoms, with non-operative management sufficient for most patients with rotator cuff problems. Modern arthroscopic repair techniques have improved recovery, but outcomes are still limited by a lack of understanding of how to improve tendon to bone healing in many patients.
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Affiliation(s)
- Asheesh Bedi
- Department of Orthopedic Surgery, University of Chicago, Chicago, IL, USA
- NorthShore Health System, Chicago, IL, USA
| | - Julie Bishop
- Department of Orthopedic Surgery, The Ohio State Wexner Medical Center, Columbus, OH, USA
| | - Jay Keener
- Department of Orthopedic Surgery, Washington University, St. Louis, MO, USA
| | - Drew A Lansdown
- Department of Orthopedic Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Ofer Levy
- Reading Shoulder Unit, Berkshire Independent Hospital, Reading, UK
| | - Peter MacDonald
- Department of Surgery, Max Rady College of Medicine, Winnipeg, Manitoba, Canada
| | - Nicola Maffulli
- Department of Trauma and Orthopaedic Surgery, Faculty of Medicine and Psychology, University of Rome Sapienza, Rome, Italy
| | - Joo Han Oh
- Department of Orthopedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, Korea
| | - Vani J Sabesan
- HCA Florida JFK Orthopaedic Surgery Residency Program, Atlantis Orthopedics, Atlantis, FL, USA
| | | | - Riley J Williams
- Department of Orthopedic Surgery, Hospital for Special Surgery, New York, NY, USA
| | - Brian T Feeley
- Department of Orthopedic Surgery, University of California San Francisco, San Francisco, CA, USA.
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3
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Ye J, Wang Y, Zeng W, Li Y, Yao B, Wang S, Wu J, Hou J. Local Injection of Rapamycin-Loaded Pcl-Peg Nanoparticles for Enhanced Tendon Healing in Rotator Cuff Tears via Simultaneously Reducing Fatty Infiltration and Drug Toxicity. Adv Healthc Mater 2024; 13:e2300612. [PMID: 37931903 DOI: 10.1002/adhm.202300612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 10/20/2023] [Indexed: 11/08/2023]
Abstract
As a common cause of shoulder pain, rotator cuff tears (RCTs) are difficult to treat clinically because of their unsatisfactory prognosis due to the fatty infiltration caused by muscle-derived stem cells (MDSCs). Previous studies have found that rapamycin (RAPA) can inhibit fatty infiltration. However, systemic administration of RAPA may cause complications such as infection and nausea, while local administration of RAPA may lead to the cytotoxicity of tendon cells, affecting the healing of rotator cuffs. In this study, biocompatible and clinically approved polycaprolactone-polyethylene glycol (PCL-PEG) is formulated into an injectable nanoparticle for the sustained release of RAPA. The results indicate that the RAPA/PCL-PEG nanoparticles (NPs) can efficiently prolong the release of RAPA and significantly reduce the cytotoxicity of tendon cells caused by RAPA. The study of the fatty infiltration model in rats with delayed rotator cuff repair shows that weekly intraarticular injection of RAPA/PCL-PEG NPs can more effectively reduce the fatty infiltration and muscle atrophy of rat rotator cuffs and leads to better mechanical properties and gait improvements than a daily intraarticular injection of RAPA. These findings imply that local injection of RAPA/PCL-PEG NPs in the shoulder joints can be a potential clinical option for RCTs patients with fatty infiltration.
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Affiliation(s)
- Jichao Ye
- Department of Orthopedics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, P. R. China
| | - Yongbo Wang
- Department of Orthopedics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, P. R. China
- Bioscience and Biomedical Engineering Thrust, The Hong Kong University of Science and Technology (Guangzhou), Nansha, Guangzhou, 511458, China
| | - Weike Zeng
- School of Biomedical Engineering, Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, China
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, P. R. China
| | - Yuxiang Li
- Department of Orthopedics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, P. R. China
| | - Bin Yao
- Department of Orthopedics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, P. R. China
| | - Siheng Wang
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, P. R. China
| | - Jun Wu
- Bioscience and Biomedical Engineering Thrust, The Hong Kong University of Science and Technology (Guangzhou), Nansha, Guangzhou, 511458, China
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, SAR, 999077, P. R. China
| | - Jingyi Hou
- Department of Orthopedics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, P. R. China
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4
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Lin X, Wang P, Wang W, Zhou H, Zhu S, Feng S, Chen Y, Zhou H, Wang Q, Xin H, Shao X, Wang J. Suppressed Akt/GSK-3β/β-catenin signaling contributes to excessive adipogenesis of fibro-adipogenic progenitors after rotator cuff tears. Cell Death Discov 2023; 9:312. [PMID: 37626040 PMCID: PMC10457376 DOI: 10.1038/s41420-023-01618-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/08/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
Muscular fatty infiltration is a common and troublesome pathology after rotator cuff tears (RCT), which mainly derives from fibro-adipogenic progenitors (FAPs). Compared to the RCT, fatty infiltration is not so severe in Achilles tendon tears (ATT). The knowledge of why fatty infiltration is more likely to occur after RCT is limited. In this study, more severe fatty infiltration was verified in supraspinatus than gastrocnemius muscles after tendon injury. Additionally, we revealed higher adipogenic differentiation ability of RCT-FAPs in vitro. Activation of Akt significantly stimulated GSK-3β/β-catenin signaling and thus decreased PPARγ expression and adipogenesis of RCT-FAPs, while the inhibition effect was attenuated by β-catenin inhibitor. Furthermore, Wnt signaling activator BML-284 limited adipogenesis of RCT-FAPs, alleviated muscular fatty infiltration, and improved parameters in gait analysis and treadmill test for RCT model. In conclusion, our study demonstrated that suppressed Akt/GSK-3β/β-catenin signaling increased PPARγ expression and thus contributed to excessive adipogenesis in RCT-FAPs. Modulation of Akt/GSK-3β/β-catenin signaling ameliorated excessive fatty infiltration of rotator cuff muscles and improved shoulder function after RCT.
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Affiliation(s)
- Xingzuan Lin
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peng Wang
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Wang
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
| | - Hao Zhou
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Siyuan Zhu
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | | | - Yuzhou Chen
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Han Zhou
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qichao Wang
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hanlong Xin
- Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Taizhou, China.
| | - Xiexiang Shao
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Jianhua Wang
- Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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5
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Li A, Anbuchelvan M, Fathi A, Abu-Zahra M, Evseenko D, Petrigliano FA, Dar A. Distinct human skeletal muscle-derived CD90 progenitor subsets for myo-fibro-adipogenic disease modeling and treatment in multiplexed conditions. Front Cell Dev Biol 2023; 11:1173794. [PMID: 37143896 PMCID: PMC10151706 DOI: 10.3389/fcell.2023.1173794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 04/03/2023] [Indexed: 05/06/2023] Open
Abstract
Chronic muscle injuries, such as massive rotator cuff tears, are associated with progressive muscle wasting, fibrotic scarring, and intramuscular fat accumulation. While progenitor cell subsets are usually studied in culture conditions that drive either myogenic, fibrogenic, or adipogenic differentiation, it is still unknown how combined myo-fibro-adipogenic signals, which are expected to occur in vivo, modulate progenitor differentiation. We therefore evaluated the differentiation potential of retrospectively generated subsets of primary human muscle mesenchymal progenitors in multiplexed conditions in the presence or absence of 423F drug, a modulator of gp130 signaling. We identified a novel CD90+CD56- non-adipogenic progenitor subset that maintained a lack of adipogenic potential in single and multiplexed myo-fibro-adipogenic culture conditions. CD90-CD56- demarcated fibro-adipogenic progenitors (FAP) and CD56+CD90+ progenitors were typified as myogenic. These human muscle subsets exhibited varying degrees of intrinsically regulated differentiation in single and mixed induction cultures. Modulation of gp130 signaling via 423F drug mediated muscle progenitor differentiation in a dose-, induction-, and cell subset-dependent manner and markedly decreased fibro-adipogenesis of CD90-CD56- FAP. Conversely, 423F promoted myogenesis of CD56+CD90+ myogenic subset, indicated by increased myotube diameter and number of nuclei per myotube. 423F treatment eliminated FAP-derived mature adipocytes from mixed adipocytes-FAP cultures but did not modify the growth of non-differentiated FAP in these cultures. Collectively, these data demonstrate that capability of myogenic, fibrogenic, or adipogenic differentiation is largely dependent on the intrinsic features of cultured subsets, and that the degree of lineage differentiation varies when signals are multiplexed. Moreover, our tests performed in primary human muscle cultures reveal and confirm the potential triple-therapeutic effects of 423F drug which simultaneously attenuates degenerative fibrosis, fat accumulation and promotes myo-regeneration.
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Affiliation(s)
- Angela Li
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Madhavan Anbuchelvan
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Amir Fathi
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Maya Abu-Zahra
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Denis Evseenko
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Department of Stem Cell Research and Regenerative Medicine, University of Southern California, Los Angeles, CA, United States
| | - Frank A. Petrigliano
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Ayelet Dar
- Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- *Correspondence: Ayelet Dar,
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6
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Meyer GA, Shen KC. A unique sarcopenic progression in the mouse rotator cuff. J Cachexia Sarcopenia Muscle 2022; 13:561-573. [PMID: 34708577 PMCID: PMC8818692 DOI: 10.1002/jcsm.12808] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/04/2021] [Accepted: 08/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In response to chronic injury, the muscles of the rotator cuff (RC) experience a unique degeneration characterized by extensive fatty infiltration and loss of contractile function. Human studies suggest this degeneration is also a feature of RC sarcopenia and may precede RC injury. In this study, we investigated whether RC muscles exhibit a similar unique sarcopenia in the mouse. METHODS Male and female mice were subdivided into four age groups: 3, 9, 18, and 24 months. The supraspinatus (SS) and infraspinatus muscles of the RC and the tibialis anterior (TA) muscle of the hindlimb were assessed. Muscle mass, contractile function, fibre cross-sectional areas and numbers, fatty infiltration, and fibrosis were assessed at each time point. Targeted transcriptional analyses were performed to assess the role of metabolic and inflammatory derangement in the pathology. RESULTS The 24-month-aged female mice exhibited decreased mass (25% lower than at 9 and 18 months, P < 0.01) in all muscles tested. However, only RC muscles also exhibited decreased contractile tension at this time point (20% lower than at 18 months, P < 0.005). Similarly, only female RC muscles exhibited increased fatty infiltration at 24 months (20% higher than 9 months, P < 0.05) and had elevated transcriptional markers of adipogenesis (2.4-fold higher Pparg and 3.8-fold higher Adipoq expression compared with 9 months, P < 0.001). Unbiased metabolic transcriptional profiling identified up-regulation of the antigen presentation (Z scores of 2.3 and 1.9 for SS and TA, respectively) and cytokine and chemokine signalling (Z scores of 3.1 and 2.4 for SS and TA, respectively) pathways in 24 month female muscle compared with 9. Further transcriptional analysis supported increased expression of pro-adipogenic inflammatory signals (6.3-fold increase in Il6 and 5.0-fold increase in Anxa2, P < 0.01) and increased presence of fibro-adipogenic progenitors (2.5-fold) in the 24-month-aged female RC compared with 9 months that together exacerbate fatty infiltration. CONCLUSIONS These data indicate that female mice replicate the unique sarcopenic pathology in the ageing human RC. Furthermore, they suggest that the exacerbated fatty infiltration is due to an interaction between higher resident fibro-adipogenic progenitor numbers and an elevated systemic inflammation in aged female mice. We conclude that female mouse RC muscle is a novel system to study both human RC degeneration and the signals that regulate sarcopenic fatty infiltration in general, which is prevalent in humans but largely absent from the rodent hindlimb.
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Affiliation(s)
- Gretchen A Meyer
- Program in Physical Therapy, Washington University, St. Louis, MO, USA.,Departments of Orthopaedic Surgery, Neurology and Biomedical Engineering, Washington University, St. Louis, MO, USA
| | - Karen C Shen
- Program in Physical Therapy, Washington University, St. Louis, MO, USA
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7
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Wu G, Hu VJ, McClintick DJ, Gatto JD, Aderibigbe T, Lu L, Jensen AR, Dar A, Petrigliano FA. Lateral to medial fibro-adipogenic degeneration are greater in infraspinatus than supraspinatus following nerve and tendon injury of murine rotator cuff. J Orthop Res 2021; 39:184-195. [PMID: 32886404 DOI: 10.1002/jor.24847] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 08/19/2020] [Accepted: 08/24/2020] [Indexed: 02/04/2023]
Abstract
Small animal models of massive tears of the rotator cuff (RC) were introduced a decade ago and have been extensively used to study the pathophysiology of chronically injured RC. Transection of rodent suprascapular nerve and RC tendon results in progressive muscle atrophy, fibrosis and fat accumulation and affect the infraspinatus and supraspinatus muscles similarly to that seen in the setting of massive RC tears in humans. The purpose of this study was to perform a comprehensive and detailed analysis of the kinetics of fibrotic scar and adipose tissue development comparing phenotypic differences between chronically injured infraspinatus and supraspinatus. Automatic mosaic imaging was used to create large image of whole infraspinatus or supraspinatus sectioned area for quantification of spatial heterogeneity of muscle damage. Pathologic changes advanced from the lateral site of transection to the medial region far from the transection site. A prominent, accelerated muscle fibrosis and fat accumulation was measured in injured infraspinatus compared to supraspinatus. Furthermore, adipose tissue occupied significantly larger area than that of fibrotic tissue in both muscles but was greater in infraspinatus within 6 weeks post induction of injury. Our findings confirm that infraspinatus is more susceptible to accelerated chronic degeneration and can be used to identify the physiological functions that distinguish between the response of infraspinatus and supraspinatus in the setting of massive tears. Whether these pathologic differences observed in mice are reflected in humans is one key aspect that awaits clarification.
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Affiliation(s)
- Genbin Wu
- Department of Joint Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, China.,Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Vivian J Hu
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Daniel J McClintick
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Jonathan D Gatto
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Temidayo Aderibigbe
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Liangyu Lu
- Department of Joint Surgery, Shanghai East Hospital, Tongji University, School of Medicine, Shanghai, China
| | - Andrew R Jensen
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Ayelet Dar
- Epstein Family Center for Sports Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Frank A Petrigliano
- Epstein Family Center for Sports Medicine, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
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8
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Agha O, Mueller‐Immergluck A, Liu M, Zhang H, Theologis AA, Clark A, Kim HT, Liu X, Feeley BT, Bailey JF. Intervertebral disc herniation effects on multifidus muscle composition and resident stem cell populations. JOR Spine 2020; 3:e1091. [PMID: 32613166 PMCID: PMC7323461 DOI: 10.1002/jsp2.1091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 04/14/2020] [Accepted: 04/19/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Paraspinal muscles are crucial for vertebral stabilization and movement. These muscles are prone to develop fatty infiltration (FI), fibrosis, and atrophy in many spine conditions. Fibro-adipogenic progenitors (FAPs), a resident muscle stem cell population, are the main contributors of muscle fibrosis and FI. FAPs are involved in a complex interplay with satellite cells (SCs), the primary myogenic progenitor cells within muscle. Little is known about the stem cell composition of the multifidus. The aim of this study is to examine FAPs and SCs in the multifidus in disc herniation patients. Multifidus muscle samples were collected from 10 patients undergoing decompressive spine surgery for lumbar disc herniation. Hamstring muscle was collected from four patients undergoing hamstring autograft ACL reconstruction as an appendicular control. Multifidus tissue was analyzed for FI and fibrosis using Oil-Red-O and Masson's trichrome staining. FAPs and SCs were visualized using immunostaining and quantified with fluorescence-activated cell sorting (FACS) sorting. Gene expression of these cells from the multifidus were analyzed with reverse transcription-polymerase chain reaction and compared to those from hamstring muscle. FI and fibrosis accounted for 14.2%± 7.4% and 14.8%±4.2% of multifidus muscle, respectively. The multifidus contained more FAPs (11.7%±1.9% vs 1.4%±0.2%; P<.001) and more SCs (3.4%±1.6% vs 0.08%±0.02%; P=.002) than the hamstring. FAPs had greater α Smooth Muscle Actin (αSMA) and adipogenic gene expression than FAPs from the hamstring. SCs from the multifidus displayed upregulated expression of stem, proliferation, and differentiation genes. CONCLUSION The multifidus in patients with disc herniation contains large percentages of FAPs and SCs with different gene expression profiles compared to those in the hamstring. These results may help explain the tendency for the multifidus to atrophy and form FI and fibrosis as well as elucidate potential approaches for mitigating these degenerative changes by leveraging these muscle stem cell populations.
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Affiliation(s)
- Obiajulu Agha
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Department of Orthopaedic SurgerySan Francisco Veterans Affair Health Care SystemSan FranciscoCaliforniaUSA
| | - Andreas Mueller‐Immergluck
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Department of Orthopaedic SurgerySan Francisco Veterans Affair Health Care SystemSan FranciscoCaliforniaUSA
| | - Mengyao Liu
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Department of Orthopaedic SurgerySan Francisco Veterans Affair Health Care SystemSan FranciscoCaliforniaUSA
| | - He Zhang
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Department of Orthopaedic SurgerySan Francisco Veterans Affair Health Care SystemSan FranciscoCaliforniaUSA
- Department of Exercise PhysiologyBeijing Sport UniversityBeijingChina
| | - Alekos A. Theologis
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Department of Orthopaedic SurgerySan Francisco Veterans Affair Health Care SystemSan FranciscoCaliforniaUSA
| | - Aaron Clark
- Department of NeurosurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Hubert T. Kim
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Department of Orthopaedic SurgerySan Francisco Veterans Affair Health Care SystemSan FranciscoCaliforniaUSA
| | - Xuhui Liu
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Department of Orthopaedic SurgerySan Francisco Veterans Affair Health Care SystemSan FranciscoCaliforniaUSA
| | - Brian T. Feeley
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
- Department of Orthopaedic SurgerySan Francisco Veterans Affair Health Care SystemSan FranciscoCaliforniaUSA
| | - Jeannie F. Bailey
- Department of Orthopaedic SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
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9
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Lee C, Agha O, Liu M, Davies M, Bertoy L, Kim HT, Liu X, Feeley BT. Rotator Cuff Fibro-Adipogenic Progenitors Demonstrate Highest Concentration, Proliferative Capacity, and Adipogenic Potential Across Muscle Groups. J Orthop Res 2020; 38:1113-1121. [PMID: 31799698 PMCID: PMC9262119 DOI: 10.1002/jor.24550] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/30/2019] [Indexed: 02/04/2023]
Abstract
Fatty infiltration (FI) of rotator cuff (RC) muscles is common in patients with RC tears. Studies have demonstrated that fibro-adipogenic progenitors (FAPs), a population of resident muscle stem cells, are the main contributors of FI, which adversely affects muscle quality and RC repair success. Although FI is common in RC injuries, it is not frequently reported after other musculotendinous injuries. Additionally, studies have shown the development of different pathology patterns across muscle groups suggestive of intrinsic differences in cellular composition and behavior. This study evaluates FAP distribution and differentiation properties across anatomic locations in mice. Muscles from seven different anatomic locations were harvested from PDGFRα-eGFP FAP reporter mice. FAPs were quantified using histology and FACS sorting with BD Aria II with CD31- /CD45- /Integrinα7- /Sca-1+ and PDGFRα reporter signal (n = 3 per muscle). The cells were analyzed for adipogenesis using immunocytochemistry and for proliferation properties with Brdu-Ki67 staining. In a separate group of mice, RC and tibialis anterior muscles received glycerol injection and were harvested after 2 weeks for FI quantification (n = 4). One-way analysis of variance was used for statistical comparisons among groups, with significance at p < 0.05. FAPs from the RC, masseter, and paraspinal muscles were more numerous and demonstrated greater proliferative capacity and adipogenic potency than those from the tibialis anterior and gastrocnemius. The RC demonstrated significantly greater levels of FI than the tibialis anterior after glycerol-injection injury. Clinical Significance: This study suggests differences in FAP distribution and differentiation characteristics may account for the propensity to develop FI in RC tears as compared with other musculotendinous injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1113-1121, 2020.
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Affiliation(s)
- Carlin Lee
- San Francisco Veteran Affairs Health Care System, San Francisco, California, 94158,Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California, 94158
| | - Obiajulu Agha
- San Francisco Veteran Affairs Health Care System, San Francisco, California, 94158,Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California, 94158
| | - Mengyao Liu
- San Francisco Veteran Affairs Health Care System, San Francisco, California, 94158,Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California, 94158
| | - Michael Davies
- San Francisco Veteran Affairs Health Care System, San Francisco, California, 94158,Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California, 94158
| | - Lauren Bertoy
- San Francisco Veteran Affairs Health Care System, San Francisco, California, 94158,Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California, 94158
| | - Hubert T. Kim
- San Francisco Veteran Affairs Health Care System, San Francisco, California, 94158,Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California, 94158
| | - Xuhui Liu
- San Francisco Veteran Affairs Health Care System, San Francisco, California, 94158,Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California, 94158
| | - Brian T. Feeley
- San Francisco Veteran Affairs Health Care System, San Francisco, California, 94158,Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, California, 94158
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10
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Talarek JR, Piacentini AN, Konja AC, Wada S, Swanson JB, Nussenzweig SC, Dines JS, Rodeo SA, Mendias CL. The MRL/MpJ Mouse Strain Is Not Protected From Muscle Atrophy and Weakness After Rotator Cuff Tear. J Orthop Res 2020; 38:811-822. [PMID: 31696955 PMCID: PMC7071998 DOI: 10.1002/jor.24516] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 11/04/2019] [Indexed: 02/04/2023]
Abstract
Chronic rotator cuff tears are a common source of shoulder pain and disability. Patients with rotator cuff tears often have substantial weakness, fibrosis, and fat accumulation, which limit successful surgical repair and postoperative rehabilitation. The Murphy Roths Large (MRL) strain of mice have demonstrated superior healing and protection against pathological changes in several disease and injury conditions. We tested the hypothesis that, compared with the commonly used C57Bl/6 (B6) strain, MRL mice would have less muscle fiber atrophy and fat accumulation, and be protected against the loss in force production that occurs after cuff tear. Adult male B6 and MRL mice were subjected to a rotator cuff tear, and changes in muscle fiber contractility and histology were measured. RNA sequencing and shotgun metabolomics and lipidomics were also performed. The muscles were harvested one month after tear. B6 and MRL mice had a 40% reduction in relative muscle force production after rotator cuff tear. RNA sequencing identified an increase in fibrosis-associated genes and a reduction in mitochondrial metabolism genes. The markers of glycolytic metabolism increased in B6 mice, while MRL mice appeared to increase amino acid metabolism after tear. There was an accumulation of lipid after injury, although there was a divergent response between B6 and MRL mice in the types of lipid species that accrued. There were strain-specific differences between the transcriptome, metabolome, and lipidome of B6 and MRL mice, but these differences did not protect MRL mice from weakness and pathological changes after rotator cuff tear. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:811-822, 2020.
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Affiliation(s)
| | | | | | | | | | | | - Joshua S Dines
- Hospital for Special Surgery, New York, NY
- Department of Orthopaedic Surgery, Weill Cornell Medical College, New York, NY
| | - Scott A Rodeo
- Hospital for Special Surgery, New York, NY
- Department of Orthopaedic Surgery, Weill Cornell Medical College, New York, NY
| | - Christopher L Mendias
- Hospital for Special Surgery, New York, NY
- Department of Orthopaedic Surgery, Weill Cornell Medical College, New York, NY
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY
- Corresponding Author: Christopher Mendias, PhD, Hospital for Special Surgery, 535 E 70th St, New York, NY 10021, USA, +1 212-606-1785 office, +1 212-249-2373 fax,
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Sarver DC, Sugg KB, Talarek JR, Swanson JB, Oliver DJ, Hinken AC, Kramer HF, Mendias CL. Prostaglandin D 2 signaling is not involved in the recovery of rat hind limb tendons from injury. Physiol Rep 2019; 7:e14289. [PMID: 31782241 PMCID: PMC6882956 DOI: 10.14814/phy2.14289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 12/19/2022] Open
Abstract
Injured tendons heal through the formation of a fibrovascular scar that has inferior mechanical properties compared to native tendon tissue. Reducing inflammation that occurs as a result of the injury could limit scar formation and improve functional recovery of tendons. Prostaglandin D2 (PGD2 ) plays an important role in promoting inflammation in some injury responses and chronic disease processes, and the inhibition of PGD2 has improved healing and reduced disease burden in animal models and early clinical trials. Based on these findings, we sought to determine the role of PGD2 signaling in the healing of injured tendon tissue. We tested the hypothesis that a potent and specific inhibitor of hematopoietic PGD synthase (HPGDS), GSK2894631A, would improve the recovery of tendons of adult male rats following an acute tenotomy and repair. To test this hypothesis, we performed a full-thickness plantaris tendon tenotomy followed by immediate repair and treated rats twice daily with either 0, 2, or 6 mg/kg of GSK2894631A. Tendons were collected either 7 or 21 days after surgical repair, and mechanical properties of tendons were assessed along with RNA sequencing and histology. While there were some differences in gene expression across groups, the targeted inhibition of HPGDS did not impact the functional repair of tendons after injury, as HPGDS expression was surprisingly low in injured tendons. These results indicate that PGD2 signaling does not appear to be important in modulating the repair of injured tendon tissue.
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Affiliation(s)
- Dylan C. Sarver
- Department of Orthopaedic SurgerySection of Plastic & Reconstructive SurgeryUniversity of Michigan Medical SchoolAnn ArborMIUSA
- Present address:
Department of PhysiologyJohns Hopkins University School of MedicineBaltimoreMDUSA
| | - Kristoffer B. Sugg
- Department of Orthopaedic SurgerySection of Plastic & Reconstructive SurgeryUniversity of Michigan Medical SchoolAnn ArborMIUSA
- Department of Molecular & Integrative PhysiologySection of Plastic & Reconstructive SurgeryUniversity of Michigan Medical SchoolAnn ArborMIUSA
- Department of SurgerySection of Plastic & Reconstructive SurgeryUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Jeffrey R. Talarek
- Department of Orthopaedic SurgerySection of Plastic & Reconstructive SurgeryUniversity of Michigan Medical SchoolAnn ArborMIUSA
- Department of Molecular & Integrative PhysiologySection of Plastic & Reconstructive SurgeryUniversity of Michigan Medical SchoolAnn ArborMIUSA
- Hospital for Special SurgeryNew YorkNYUSA
| | | | | | - Aaron C. Hinken
- Muscle Metabolism DPUGlaxoSmithKline PharmaceuticalsKing of PrussiaPAUSA
| | - Henning F. Kramer
- Muscle Metabolism DPUGlaxoSmithKline PharmaceuticalsKing of PrussiaPAUSA
| | - Christopher L. Mendias
- Department of Orthopaedic SurgerySection of Plastic & Reconstructive SurgeryUniversity of Michigan Medical SchoolAnn ArborMIUSA
- Department of Molecular & Integrative PhysiologySection of Plastic & Reconstructive SurgeryUniversity of Michigan Medical SchoolAnn ArborMIUSA
- Hospital for Special SurgeryNew YorkNYUSA
- Department of Physiology & BiophysicsWeill Cornell Medical CollegeNew YorkNYUSA
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Schubert MF, Noah AC, Bedi A, Gumucio JP, Mendias CL. Reduced Myogenic and Increased Adipogenic Differentiation Capacity of Rotator Cuff Muscle Stem Cells. J Bone Joint Surg Am 2019; 101:228-238. [PMID: 30730482 PMCID: PMC6791507 DOI: 10.2106/jbjs.18.00509] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Fat accumulation commonly occurs in chronically torn rotator cuff muscles, and increased fat within the rotator cuff is correlated with poor clinical outcomes. The extent of lipid deposition is particularly pronounced in injured rotator cuff muscles compared with other commonly injured muscles such as the gastrocnemius. Satellite cells, which are a tissue-resident muscle stem-cell population, can differentiate into fat cells. We hypothesized that satellite cells from the rotator cuff have greater intrinsic adipogenic differentiation potential than do gastrocnemius satellite cells, and this difference is due to variations in epigenetic imprinting between the cells. METHODS Satellite cells from gastrocnemius and rotator cuff muscles of mice were cultured in adipogenic media, and the capacity to differentiate into mature muscle cells and adipogenic cells was assessed (n ≥ 9 plates per muscle group). We also performed DNA methylation analysis of gastrocnemius and rotator cuff satellite cells to determine whether epigenetic differences were present between the 2 groups (n = 5 mice per group). RESULTS Compared with the gastrocnemius, satellite cells from the rotator cuff had a 23% reduction in myogenic differentiation and an 87% decrease in the expression of the differentiated muscle cell marker MRF4 (myogenic regulatory factor 4). With respect to adipogenesis, rotator cuff satellite cells had a 4.3-fold increase in adipogenesis, a 12-fold increase in the adipogenic transcription factor PPARγ (peroxisome proliferator-activated receptor gamma), and a 65-fold increase in the adipogenic marker FABP4 (fatty-acid binding protein 4). Epigenetic analysis identified 355 differentially methylated regions of DNA between rotator cuff and gastrocnemius satellite cells, and pathway enrichment analysis suggested that these regions were involved with lipid metabolism and adipogenesis. CONCLUSIONS Satellite cells from rotator cuff muscles have reduced myogenic and increased adipogenic differentiation potential compared with gastrocnemius muscles. There appears to be a cellular and genetic basis behind the generally poor rates of rotator cuff muscle healing. CLINICAL RELEVANCE The reduced myogenic and increased adipogenic capacity of rotator cuff satellite cells is consistent with the increased fat content and poor muscle healing rates often observed for chronically torn rotator cuff muscles. For patients undergoing rotator cuff repair, transplantation of autologous satellite cells from other muscles less prone to fatty infiltration may improve clinical outcomes.
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Affiliation(s)
- Manuel F. Schubert
- Departments of Orthopaedic Surgery (M.F.S., A.C.N., A.B, J.P.G, and C.L.M.) and Molecular and Integrative Physiology (A.C.N, J.P.G., and C.L.M.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Andrew C. Noah
- Departments of Orthopaedic Surgery (M.F.S., A.C.N., A.B, J.P.G, and C.L.M.) and Molecular and Integrative Physiology (A.C.N, J.P.G., and C.L.M.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Asheesh Bedi
- Departments of Orthopaedic Surgery (M.F.S., A.C.N., A.B, J.P.G, and C.L.M.) and Molecular and Integrative Physiology (A.C.N, J.P.G., and C.L.M.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Jonathan P. Gumucio
- Departments of Orthopaedic Surgery (M.F.S., A.C.N., A.B, J.P.G, and C.L.M.) and Molecular and Integrative Physiology (A.C.N, J.P.G., and C.L.M.), University of Michigan Medical School, Ann Arbor, Michigan
| | - Christopher L. Mendias
- Departments of Orthopaedic Surgery (M.F.S., A.C.N., A.B, J.P.G, and C.L.M.) and Molecular and Integrative Physiology (A.C.N, J.P.G., and C.L.M.), University of Michigan Medical School, Ann Arbor, Michigan,Hospital for Special Surgery, New York, NY,Departments of Physiology and Biophysics and Orthopaedic Surgery, Weill Cornell Medical College, New York, NY
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Reversal of Fatty Infiltration After Suprascapular Nerve Compression Release Is Dependent on UCP1 Expression in Mice. Clin Orthop Relat Res 2018; 476:1665-1679. [PMID: 30020151 PMCID: PMC6259770 DOI: 10.1097/corr.0000000000000335] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND In large rotator cuff tears, retraction of the supraspinatus muscle creates suprascapular nerve traction and compression. However, suprascapular nerve transection, when used in previous models, is different from chronic compression of the suprascapular nerve in patients. To define the role of suprascapular nerve chronic injury in rotator cuff muscle atrophy and fatty infiltration, we developed a novel reversible suprascapular nerve compression mouse model. QUESTIONS/PURPOSES We asked: (1) Can suprascapular nerve injury be induced by compression but reversed after compression release? (2) Can muscle fatty infiltration be induced by suprascapular nerve compression and reversed after compression release? (3) Is white fat browning involved in fatty infiltration resorption? METHODS Mice in a common strain of C57BL/6J were randomly assigned to suprascapular nerve transection (n = 10), nerve compression (n = 10), nerve compression and release (n = 10), or sham control (n = 10) groups. To study the role or white fat browning on muscle fatty infiltration, additional UCP1 reporter mice (n = 4 for nerve compression and n = 4 for nerve compression release) and knockout mice (n = 4 for nerve compression and n = 4 for nerve compression release) were used. Nerve injury was testified using osmium tetroxide staining and neural muscular junction staining and then semiquantified by counting the degenerating axons and disrupted junctions. Muscle fatty infiltration was evaluated using Oil Red O staining and then semiquantified by measuring the area fraction of fat. Immunofluorescent and Oil Red O staining on UCP1 transgenic mice was conducted to testify whether white fat browning was involved in fatty infiltration resorption. Ratios of UCP1 positively stained area and fat area to muscle cross-section area were measured to semiquantify UCP1 expression and fatty infiltration in muscle by blinded reviewers. Analysis of variance with Tukey post hoc comparisons was used for statistical analysis between groups. RESULTS Suprascapular nerve injury was induced by compression but reversed after release. The ratios of degenerating axons were: sham control: 6% ± 3% (95% confidence interval [CI], 3%-10%); nerve compression: 58% ± 10% (95% CI, 45%-70% versus sham, p < 0.001); and nerve compression and release: 15% ± 9% (95% CI, 5%-26% versus sham, p = 0.050). The supraspinatus muscle percentage area of fatty infiltration increased after 6 weeks of nerve compression (19% ± 1%; 95% CI, 18%-20%; p < 0.001) but showed no difference after compression release for 6 weeks (5% ± 3%; 95% CI, 1%-10%; p = 0.054) compared with sham (2% ± 1%; 95% CI, 1%-3%). However, the fat area fraction in UCP1 knockout mice did not change after nerve compression release (6% ± 1%; 95% CI, 4%-8% at 2 weeks after compression and 5% ± 0.32%; 95% CI, 4%-6% after 2 weeks of release; p = 0.1095). CONCLUSIONS We developed a clinically relevant, reversible suprascapular nerve compression mouse model. Fatty infiltration resorption after compression release was mediated through white fat browning. CLINICAL RELEVANCE If the mechanism of browning of white fat in rotator cuff muscle fatty infiltration can be confirmed in humans, a UCP1 agonist may be an effective treatment for patients with suprascapular nerve injury.
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14
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Lim J, Munivez E, Jiang MM, Song IW, Gannon F, Keene DR, Schweitzer R, Lee BH, Joeng KS. mTORC1 Signaling is a Critical Regulator of Postnatal Tendon Development. Sci Rep 2017; 7:17175. [PMID: 29215029 PMCID: PMC5719403 DOI: 10.1038/s41598-017-17384-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/24/2017] [Indexed: 12/11/2022] Open
Abstract
Tendons transmit contractile forces between musculoskeletal tissues. Whereas the biomechanical properties of tendons have been studied extensively, the molecular mechanisms regulating postnatal tendon development are not well understood. Here we examine the role of mTORC1 signaling in postnatal tendon development using mouse genetic approaches. Loss of mTORC1 signaling by removal of Raptor in tendons caused severe tendon defects postnatally, including decreased tendon thickness, indicating that mTORC1 is necessary for postnatal tendon development. By contrast, activation of mTORC1 signaling in tendons increased tendon cell numbers and proliferation. In addition, Tsc1 conditional knockout mice presented severely disorganized collagen fibers and neovascularization in the tendon midsubstance. Interestingly, collagen fibril diameter was significantly reduced in both Raptor and Tsc1 conditional knockout mice, albeit with variations in severity. We performed RNA-seq analysis using Achilles tendons to investigate the molecular changes underlying these tendon phenotypes. Raptor conditional knockout mice showed decreased extracellular matrix (ECM) structure-related gene expression, whereas Tsc1 conditional knockout mice exhibited changes in genes regulating TGF-β/BMP/FGF signaling, as well as in genes controlling ECM structure and disassembly. Collectively, our studies suggest that maintaining physiological levels of mTORC1 signaling is essential for postnatal tendon development and maturation.
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Affiliation(s)
- Joohyun Lim
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Elda Munivez
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Ming-Ming Jiang
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - I-Wen Song
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Francis Gannon
- Department of Pathology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Douglas R Keene
- Research Center, Shriners Hospital for Children, Portland, OR, 97239, USA
| | - Ronen Schweitzer
- Research Center, Shriners Hospital for Children, Portland, OR, 97239, USA
| | - Brendan H Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
| | - Kyu Sang Joeng
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
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Morita W, Dakin SG, Snelling SJB, Carr AJ. Cytokines in tendon disease: A Systematic Review. Bone Joint Res 2017; 6:656-664. [PMID: 29203638 PMCID: PMC5935810 DOI: 10.1302/2046-3758.612.bjr-2017-0112.r1] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 08/21/2017] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVES Emerging evidence indicates that tendon disease is an active process with inflammation that is critical to disease onset and progression. However, the key cytokines responsible for driving and sustaining inflammation have not been identified. METHODS We performed a systematic review of the literature using MEDLINE (U.S. National Library of Medicine, Bethesda, Maryland) in March 2017. Studies reporting the expression of interleukins (ILs), tumour necrosis factor alpha (TNF-α) and interferon gamma in diseased human tendon tissues, and animal models of tendon injury or exercise in comparison with healthy control tissues were included. RESULTS IL-1β, IL-6, IL-10, and TNF-α are the cytokines that have been most frequently investigated. In clinical samples of tendinopathy and tendon tears, the expression of TNF-α tended not to change but IL-6 increased in tears. Healthy human tendons showed increased IL-6 expression after exercise; however, IL-10 remained unchanged. Animal tendon injury models showed that IL-1β, IL-6, and TNF-α tend to increase from the early phase of tendon healing. In animal exercise studies, IL-1β expression showed a tendency to increase at the early stage after exercise, but IL-10 expression remained unchanged with exercise. CONCLUSIONS This review highlights the roles of IL-1β, IL-6, IL-10, and TNF-α in the development of tendon disease, during tendon healing, and in response to exercise. However, there is evidence accumulating that suggests that other cytokines are also contributing to tendon inflammatory processes. Further work with hypothesis-free methods is warranted in order to identify the key cytokines, with subsequent mechanistic and interaction studies to elucidate their roles in tendon disease development.Cite this article: W. Morita, S. G. Dakin, S. J. B. Snelling, A. J. Carr. Cytokines in tendon disease: A Systematic Review. Bone Joint Res 2017;6:656-664. DOI: 10.1302/2046-3758.612.BJR-2017-0112.R1.
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Affiliation(s)
- W Morita
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington OX3 7LD, UK and NIHR Oxford Biomedical Research Centre, Botnar Research Centre, University of Oxford, Windmill Road, Headington OX3 7LD, UK
| | - S G Dakin
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington OX3 7LD, UK and NIHR Oxford Biomedical Research Centre, Botnar Research Centre, University of Oxford, Windmill Road, Headington OX3 7LD, UK
| | - S J B Snelling
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington OX3 7LD, UK and NIHR Oxford Biomedical Research Centre, Botnar Research Centre, University of Oxford, Windmill Road, Headington OX3 7LD, UK
| | - A J Carr
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Headington OX3 7LD, UK and NIHR Oxford Biomedical Research Centre, Botnar Research Centre, University of Oxford, Windmill Road, Headington OX3 7LD, UK
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16
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Valencia AP, Iyer SR, Spangenburg EE, Gilotra MN, Lovering RM. Impaired contractile function of the supraspinatus in the acute period following a rotator cuff tear. BMC Musculoskelet Disord 2017; 18:436. [PMID: 29121906 PMCID: PMC5679320 DOI: 10.1186/s12891-017-1789-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 10/26/2017] [Indexed: 01/16/2023] Open
Abstract
Background Rotator cuff (RTC) tears are a common clinical problem resulting in adverse changes to the muscle, but there is limited information comparing histopathology to contractile function. This study assessed supraspinatus force and susceptibility to injury in the rat model of RTC tear, and compared these functional changes to histopathology of the muscle. Methods Unilateral RTC tears were induced in male rats via tenotomy of the supraspinatus and infraspinatus. Maximal tetanic force and susceptibility to injury of the supraspinatus muscle were measured in vivo at day 2 and day 15 after tenotomy. Supraspinatus muscles were weighed and harvested for histologic analysis of the neuromuscular junction (NMJ), intramuscular lipid, and collagen. Results Tenotomy resulted in eventual atrophy and weakness. Despite no loss in muscle mass at day 2 there was a 30% reduction in contractile force, and a decrease in NMJ continuity and size. Reduced force persisted at day 15, a time point when muscle atrophy was evident but NMJ morphology was restored. At day 15, torn muscles had decreased collagen-packing density and were also more susceptible to contraction-induced injury. Conclusion Muscle size and histopathology are not direct indicators of overall RTC contractile health. Changes in NMJ morphology and collagen organization were associated with changes in contractile function and thus may play a role in response to injury. Although our findings are limited to the acute phase after a RTC tear, the most salient finding is that RTC tenotomy results in increased susceptibility to injury of the supraspinatus.
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Affiliation(s)
- Ana P Valencia
- Department of Orthopaedics, University of Maryland School of Medicine, AHB, Rm 540, 100 Penn St., Baltimore, MD, 21201, USA.,Department of Kinesiology, University of Maryland School of Public Health, College Park, USA
| | - Shama R Iyer
- Department of Orthopaedics, University of Maryland School of Medicine, AHB, Rm 540, 100 Penn St., Baltimore, MD, 21201, USA
| | - Espen E Spangenburg
- Department of Physiology, East Carolina Diabetes and Obesity Institute, Brody School of Medicine, East Carolina University, Greenville, USA
| | - Mohit N Gilotra
- Department of Orthopaedics, University of Maryland School of Medicine, AHB, Rm 540, 100 Penn St., Baltimore, MD, 21201, USA
| | - Richard M Lovering
- Department of Orthopaedics, University of Maryland School of Medicine, AHB, Rm 540, 100 Penn St., Baltimore, MD, 21201, USA.
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Reloading Promotes Recovery of Disuse Muscle Loss by Inhibiting TGFβ Pathway Activation in Rats After Hind Limb Suspension. Am J Phys Med Rehabil 2017; 96:430-437. [PMID: 27610551 DOI: 10.1097/phm.0000000000000617] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The purpose of this paper was to study the effect of transforming growth factor beta (TGFβ) signaling pathway on reloading-mediated restoration of disuse muscle loss induced by hind limb suspension in rats. DESIGN Rats were divided into 4 groups: control group (CON), HLS group (hind limb suspension for 2 weeks), HLS + R group (hind limb suspension for 2 weeks followed by 2 weeks of natural reloading), and HRS + E group (hind limb suspension for 2 weeks followed by 2 weeks of treadmill exercise). Body weight, and weight and protein concentration of gastrocnemius were determined. The expression of members of canonical and noncanonical TGFβ signaling pathways, including TGFβ1, myostatin (MSTN), phospho-smad2/3, phospho-mitogen-activated protein kinases (p38, JNK1/2, and extracellular signal-regulated kinase 1 [ERK1]/ERK2), as well as the corresponding downstream effectors of muscle mass-p21, Pax7, MyoD, and MyoG-was determined at protein or messenger RNA (mRNA) levels. RESULTS Reloading increased MyoD mRNA and restored the decreased gastrocnemius weight/body weight ratio, protein concentration of gastrocnemius, phospho-ERK2, Pax7 and the increased TGFβ1, MSTN, phospho-smad2/3, phospho-p38, phospho-JNK1/2, and p21 induced by hind limb suspension. Moreover, the effects of exercise reloading on the restoration of gastrocnemius weight/body weight ratio, TGFβ1, MSTN, phospho-smad2, phospho-p38, phospho-JNK2, Pax7, as well as the induction of MyoD mRNA were stronger than those of natural reloading. CONCLUSIONS Disuse muscle loss can be recovered by reloading in an intensity-dependent manner through canonical and noncanonical TGFβ signaling pathways. Pax7 and MyoD might be the effectors of TGFβ pathway in mediating the recovery effect of reloading.
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18
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Davies MR, Lee L, Feeley BT, Kim HT, Liu X. Lysophosphatidic acid-induced RhoA signaling and prolonged macrophage infiltration worsens fibrosis and fatty infiltration following rotator cuff tears. J Orthop Res 2017; 35:1539-1547. [PMID: 27505847 PMCID: PMC5502767 DOI: 10.1002/jor.23384] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/05/2016] [Indexed: 02/04/2023]
Abstract
Previous studies have suggested that macrophage-mediated chronic inflammation is involved in the development of rotator cuff muscle atrophy and degeneration following massive tendon tears. Increased RhoA signaling has been reported in chronic muscle degeneration, such as muscular dystrophy. However, the role of RhoA signaling in macrophage infiltration and rotator muscle degeneration remains unknown. Using a previously established rat model of massive rotator cuff tears, we found RhoA signaling is upregulated in rotator cuff muscle following a massive tendon-nerve injury. This increase in RhoA expression is greatly potentiated by the administration of a potent RhoA activator, lysophosphatidic acid (LPA), and is accompanied by increased TNFα and TGF-β1 expression in rotator cuff muscle. Boosting RhoA signaling with LPA significantly worsened rotator cuff muscle atrophy, fibrosis, and fatty infiltration, accompanied with massive monocytic infiltration of rotator cuff muscles. Co-staining of RhoA and the tissue macrophage marker CD68 showed that CD68+ tissue macrophages are the dominant cell source of increased RhoA signaling in rotator cuff muscles after tendon tears. Taken together, our findings suggest that LPA-mediated RhoA signaling in injured muscle worsens the outcomes of atrophy, fibrosis, and fatty infiltration by increasing macrophage infiltraion in rotator cuff muscle. Clinically, inhibiting RhoA signaling may represent a future direction for developing new treatments to improve muscle quality following massive rotator cuff tears. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1539-1547, 2017.
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Affiliation(s)
- Michael R. Davies
- San Francisco Veterans Affairs Health Care System, Department of Veterans Affairs, 1700 Owens Street, Room 364 San Francisco, California 94153
- Department of Orthopaedic Surgery, University of California, San Francisco, California
| | - Lawrence Lee
- San Francisco Veterans Affairs Health Care System, Department of Veterans Affairs, 1700 Owens Street, Room 364 San Francisco, California 94153
| | - Brian T. Feeley
- San Francisco Veterans Affairs Health Care System, Department of Veterans Affairs, 1700 Owens Street, Room 364 San Francisco, California 94153
- Department of Orthopaedic Surgery, University of California, San Francisco, California
| | - Hubert T. Kim
- San Francisco Veterans Affairs Health Care System, Department of Veterans Affairs, 1700 Owens Street, Room 364 San Francisco, California 94153
- Department of Orthopaedic Surgery, University of California, San Francisco, California
| | - Xuhui Liu
- San Francisco Veterans Affairs Health Care System, Department of Veterans Affairs, 1700 Owens Street, Room 364 San Francisco, California 94153
- Department of Orthopaedic Surgery, University of California, San Francisco, California
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19
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Naimark M, Berliner J, Zhang AL, Davies M, Ma CB, Feeley BT. Prevalence of Rotator Cuff Atrophy and Fatty Infiltration in Patients Undergoing Total Shoulder Arthroplasty. J Shoulder Elb Arthroplast 2017. [DOI: 10.1177/2471549217708323] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Micah Naimark
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, California
| | - Jonathan Berliner
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, California
| | - Alan L Zhang
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, California
| | - Michael Davies
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, California
| | - C Benjamin Ma
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, California
| | - Brian T Feeley
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, California
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Zingman A, Li H, Sundem L, DeHority B, Geary M, Fussel T, Mooney R, Zuscik M, Elfar J. Shoulder arthritis secondary to rotator cuff tear: A reproducible murine model and histopathologic scoring system. J Orthop Res 2017; 35:506-514. [PMID: 27500994 PMCID: PMC5837043 DOI: 10.1002/jor.23383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 07/26/2016] [Indexed: 02/04/2023]
Abstract
Untreated rotator cuff tears can progress to a distinct form of shoulder arthritis, and the mechanism of this progression is poorly understood. Biomechanical, molecular and genetic factors may be at play, and a reliable animal model is needed to enable further research. The purpose of this study was to create a reproducible model of posttraumatic shoulder arthritis in the mouse, and to develop a scoring system for this model to enable future research on interventions, the role of various gene products, and the development of therapies to alter the natural course of the disease. Forty-five mice underwent operative ligation of the rotator cuff tendons and were followed for 45 weeks following surgery, with free cage activity post-operatively. Mice were sacrificed at various intervals from 2 to 45 weeks post-injury and histopathologic scoring was developed and tested by blinded reviewers using both quantitative computational analysis of coronal sections of the shoulder joint and semi-quantitative grading. The scoring system revealed a progressive, time-dependent set of tissue changes in the shoulder joint with features similar to human cuff tear arthropathy including acetabularization of the acromion and femoralization of the humeral head. This model establishes that osteoarthritis of the shoulder is distinct from osteoarthritis of the knee or hip, with different stages of degeneration and unique histopathologic features. Using the novel grading procedure and quantitative assessments presented here, future research using this model will enable investigators to test established and novel therapies and evaluate the role of inflammatory factors and gene products in shoulder arthritis. This study provides a reproducible mouse model of shoulder arthritis following isolated injury to the rotator cuff which elucidates characteristics of cuff tear arthropathy and provides a scoring system and venue for future research. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:506-514, 2017.
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Affiliation(s)
- Alissa Zingman
- Johns Hopkins Hospital, Bloomberg School of Public Health, Baltimore, Maryland
| | - Hiayan Li
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY
| | - Leigh Sundem
- University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Becca DeHority
- University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Michael Geary
- University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Theron Fussel
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY
| | - Robert Mooney
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY
| | - Michael Zuscik
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY
| | - John Elfar
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY,Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY
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21
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Rothrauff BB, Pauyo T, Debski RE, Rodosky MW, Tuan RS, Musahl V. The Rotator Cuff Organ: Integrating Developmental Biology, Tissue Engineering, and Surgical Considerations to Treat Chronic Massive Rotator Cuff Tears. TISSUE ENGINEERING PART B-REVIEWS 2017; 23:318-335. [PMID: 28084902 DOI: 10.1089/ten.teb.2016.0446] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The torn rotator cuff remains a persistent orthopedic challenge, with poor outcomes disproportionately associated with chronic, massive tears. Degenerative changes in the tissues that comprise the rotator cuff organ, including muscle, tendon, and bone, contribute to the poor healing capacity of chronic tears, resulting in poor function and an increased risk for repair failure. Tissue engineering strategies to augment rotator cuff repair have been developed in an effort to improve rotator cuff healing and have focused on three principal aims: (1) immediate mechanical augmentation of the surgical repair, (2) restoration of muscle quality and contractility, and (3) regeneration of native enthesis structure. Work in these areas will be reviewed in sequence, highlighting the relevant pathophysiology, developmental biology, and biomechanics, which must be considered when designing therapeutic applications. While the independent use of these strategies has shown promise, synergistic benefits may emerge from their combined application given the interdependence of the tissues that constitute the rotator cuff organ. Furthermore, controlled mobilization of augmented rotator cuff repairs during postoperative rehabilitation may provide mechanotransductive cues capable of guiding tissue regeneration and restoration of rotator cuff function. Present challenges and future possibilities will be identified, which if realized, may provide solutions to the vexing condition of chronic massive rotator cuff tears.
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Affiliation(s)
- Benjamin B Rothrauff
- 1 Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania.,2 McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Thierry Pauyo
- 3 Division of Sports Medicine, Department of Orthopaedic Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Richard E Debski
- 2 McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Mark W Rodosky
- 3 Division of Sports Medicine, Department of Orthopaedic Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Rocky S Tuan
- 1 Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania.,2 McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Volker Musahl
- 2 McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania.,3 Division of Sports Medicine, Department of Orthopaedic Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania.,4 Orthopaedic Robotics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
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22
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TGF-β Small Molecule Inhibitor SB431542 Reduces Rotator Cuff Muscle Fibrosis and Fatty Infiltration By Promoting Fibro/Adipogenic Progenitor Apoptosis. PLoS One 2016; 11:e0155486. [PMID: 27186977 PMCID: PMC4871364 DOI: 10.1371/journal.pone.0155486] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Accepted: 04/29/2016] [Indexed: 12/21/2022] Open
Abstract
Rotator cuff tears represent a large burden of muscle-tendon injuries in our aging population. While small tears can be repaired surgically with good outcomes, critical size tears are marked by muscle atrophy, fibrosis, and fatty infiltration, which can lead to failed repair, frequent re-injury, and chronic disability. Previous animal studies have indicated that Transforming Growth Factor-β (TGF-β) signaling may play an important role in the development of these muscle pathologies after injury. Here, we demonstrated that inhibition of TGF-β1 signaling with the small molecule inhibitor SB431542 in a mouse model of massive rotator cuff tear results in decreased fibrosis, fatty infiltration, and muscle weight loss. These observed phenotypic changes were accompanied by decreased fibrotic, adipogenic, and atrophy-related gene expression in the injured muscle of mice treated with SB431542. We further demonstrated that treatment with SB431542 reduces the number of fibro/adipogenic progenitor (FAP) cells-an important cellular origin of rotator cuff muscle fibrosis and fatty infiltration, in injured muscle by promoting apoptosis of FAPs. Together, these data indicate that the TGF-β pathway is a critical regulator of the degenerative muscle changes seen after massive rotator cuff tears. TGF-β promotes rotator cuff muscle fibrosis and fatty infiltration by preventing FAP apoptosis. TGF-β regulated FAP apoptosis may serve as an important target pathway in the future development of novel therapeutics to improve muscle outcomes following rotator cuff tear.
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23
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Developmental Biology and Regenerative Medicine: Addressing the Vexing Problem of Persistent Muscle Atrophy in the Chronically Torn Human Rotator Cuff. Phys Ther 2016; 96:722-33. [PMID: 26847008 PMCID: PMC4858662 DOI: 10.2522/ptj.20150029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 01/24/2016] [Indexed: 12/18/2022]
Abstract
Persistent muscle atrophy in the chronically torn rotator cuff is a significant obstacle for treatment and recovery. Large atrophic changes are predictive of poor surgical and nonsurgical outcomes and frequently fail to resolve even following functional restoration of loading and rehabilitation. New insights into the processes of muscle atrophy and recovery gained through studies in developmental biology combined with the novel tools and strategies emerging in regenerative medicine provide new avenues to combat the vexing problem of muscle atrophy in the rotator cuff. Moving these treatment strategies forward likely will involve the combination of surgery, biologic/cellular agents, and physical interventions, as increasing experimental evidence points to the beneficial interaction between biologic therapies and physiologic stresses. Thus, the physical therapy profession is poised to play a significant role in defining the success of these combinatorial therapies. This perspective article will provide an overview of the developmental biology and regenerative medicine strategies currently under investigation to combat muscle atrophy and how they may integrate into the current and future practice of physical therapy.
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24
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Valencia AP, Iyer SR, Pratt SJP, Gilotra MN, Lovering RM. A method to test contractility of the supraspinatus muscle in mouse, rat, and rabbit. J Appl Physiol (1985) 2015; 120:310-7. [PMID: 26586911 DOI: 10.1152/japplphysiol.00788.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/17/2015] [Indexed: 01/06/2023] Open
Abstract
The rotator cuff (RTC) muscles not only generate movement but also provide important shoulder joint stability. RTC tears, particularly in the supraspinatus muscle, are a common clinical problem. Despite some biological healing after RTC repair, persistent problems include poor functional outcomes with high retear rates after surgical repair. Animal models allow further exploration of the sequela of RTC injury such as fibrosis, inflammation, and fatty infiltration, but there are few options regarding contractility for mouse, rat, and rabbit. Histological findings can provide a "direct measure" of damage, but the most comprehensive measure of the overall health of the muscle is contractile force. However, information regarding normal supraspinatus size and contractile function is scarce. Animal models provide the means to compare muscle histology, imaging, and contractility within individual muscles in various models of injury and disease, but to date, most testing of animal contractile force has been limited primarily to hindlimb muscles. Here, we describe an in vivo method to assess contractility of the supraspinatus muscle and describe differences in methods and representative outcomes for mouse, rat, and rabbit.
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Affiliation(s)
- Ana P Valencia
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland; and Department of Kinesiology, University of Maryland School of Public Health, College Park, Maryland
| | - Shama R Iyer
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland; and
| | - Stephen J P Pratt
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland; and
| | - Mohit N Gilotra
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland; and
| | - Richard M Lovering
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland; and
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