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1.
JCI Insight ; 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38954467

ABSTRACT

Pulmonary disorders impact 40% to 80% of individuals with obesity. Respiratory muscle dysfunction is linked to these conditions; however, its pathophysiology remains largely undefined. Mice subjected to diet-induced obesity (DIO) develop diaphragmatic weakness. Increased intra-diaphragmatic adiposity and extracellular matrix (ECM) content correlate with reductions in contractile force. Thrombospondin-1 (THBS1) is an obesity-associated matricellular protein linked with muscular damage in genetic myopathies. THBS1 induces proliferation of fibro-adipogenic progenitors (FAPs) - mesenchymal cells that differentiate into adipocytes and fibroblasts. We hypothesized that THBS1 drives FAP-mediated diaphragm remodeling and contractile dysfunction in DIO. We tested this by comparing the effects of dietary challenge on diaphragms of wild-type (WT) and Thbs1 knockout (Thbs1-/-) mice. Bulk and single-cell transcriptomics demonstrated DIO-induced stromal expansion in WT diaphragms. Diaphragm FAPs displayed upregulation of ECM and TGF ß-related expression signatures and augmentation of a Thy1-expressing sub-population previously linked to type 2 diabetes. Despite similar weight gain, Thbs1-/- mice were protected from these transcriptomic changes and from obesity-induced increases in diaphragm adiposity and ECM deposition. Unlike WT controls, Thbs1-/- diaphragms maintained normal contractile force and motion after DIO challenge. These findings establish THBS1 as a necessary mediator of diaphragm stromal remodeling and contractile dysfunction in overnutrition and a potential therapeutic target in obesity-associated respiratory dysfunction.

2.
Elife ; 122023 Dec 22.
Article in English | MEDLINE | ID: mdl-38131691

ABSTRACT

The acute traumatic or surgical loss of skeletal muscle, known as volumetric muscle loss (VML), is a devastating type of injury that results in exacerbated and persistent inflammation followed by fibrosis. The mechanisms that mediate the magnitude and duration of the inflammatory response and ensuing fibrosis after VML remain understudied, and as such, the development of regenerative therapies has been limited. To address this need, we profiled how lipid mediators, which are potent regulators of the immune response after injury, varied with VML injuries that heal or result in fibrosis. We observed that non-healing VML injuries displayed increased pro-inflammatory eicosanoids and a lack of pro-resolving lipid mediators. Treatment of VML with a pro-resolving lipid mediator synthesized from docosahexaenoic acid, called Maresin 1, ameliorated fibrosis through reduction of neutrophils and macrophages and enhanced recovery of muscle strength. These results expand our knowledge of the dysregulated immune response that develops after VML and identify a novel immuno-regenerative therapeutic modality in Maresin 1.


Subject(s)
Docosahexaenoic Acids , Muscular Diseases , Humans , Muscle, Skeletal/physiology , Muscular Diseases/pathology , Fibrosis
3.
Phys Ther ; 103(12)2023 Dec 06.
Article in English | MEDLINE | ID: mdl-37815938

ABSTRACT

Integrative health is an emerging specialty inside multiple disciplines within the medical community, yet the practice of integrative physical therapy remains undefined. This perspective paper suggests a set of guiding principles to support the role of physical therapy in integrative health. These guiding principles, including therapeutic partnership, whole person health, living systems, movement as an integrative experience, and salutogenesis, are described and explored in-depth as they relate to all aspects of patient care and clinician experience. These guiding principles are articulated within the context of social determinants of health and the interrelated roles that environment, trauma, stress, and lifestyle all play within an integrative physical therapy plan of care. Examples of current integrative physical therapy practices that embody these principles are described. The 5 guiding principles are designed to elicit interprofessional inquiry into how integrative health models can be applied to the art and science of physical therapy practice. The expansion of integrative health into the field of physical therapy has the potential to improve individual and population health, as integrative physical therapy can be used to address prevention, health promotion, primary care, and wellness while acknowledging the complex, dynamic, and interconnected nature of the human condition. IMPACT: This perspective article presents 5 guiding principles to establish a framework to define and shape the growing application of an integrative health model to physical therapy practice. These integrative physical therapy guiding principles aim to improve the quality of whole-person, patient-centered care.


Subject(s)
Complementary Therapies , Humans , Health Promotion , Patient-Centered Care , Physical Therapy Modalities
4.
bioRxiv ; 2023 Aug 19.
Article in English | MEDLINE | ID: mdl-37645822

ABSTRACT

Pulmonary disorders impact 40-80% of individuals with obesity. Respiratory muscle dysfunction is linked to these conditions; however, its pathophysiology remains largely undefined. Mice subjected to diet-induced obesity (DIO) develop diaphragmatic weakness. Increased intra-diaphragmatic adiposity and extracellular matrix (ECM) content correlate with reductions in contractile force. Thrombospondin-1 (THBS1) is an obesity-associated matricellular protein linked with muscular damage in genetic myopathies. THBS1 induces proliferation of fibro-adipogenic progenitors (FAPs)-mesenchymal cells that differentiate into adipocytes and fibroblasts. We hypothesized that THBS1 drives FAP-mediated diaphragm remodeling and contractile dysfunction in DIO. We tested this by comparing effects of dietary challenge on diaphragms of wild-type (WT) and Thbs1 knockout ( Thbs1 -/- ) mice. Bulk and single-cell transcriptomics demonstrated DIO-induced stromal expansion in WT diaphragms. Diaphragm FAPs displayed upregulation of ECM and TGFß-related expression signatures, and augmentation of a Thy1 -expressing sub-population previously linked to type 2 diabetes. Despite similar weight gain, Thbs1 -/- mice were protected from these transcriptomic changes, and from obesity-induced increases in diaphragm adiposity and ECM deposition. Unlike WT controls, Thbs1 -/- diaphragms maintained normal contractile force and motion after DIO challenge. These findings establish THBS1 as a necessary mediator of diaphragm stromal remodeling and contractile dysfunction in overnutrition, and potential therapeutic target in obesity-associated respiratory dysfunction.

5.
Geroscience ; 45(3): 1899-1912, 2023 06.
Article in English | MEDLINE | ID: mdl-36952126

ABSTRACT

Progressive muscle atrophy and loss of muscle strength associated with old age have been well documented. Although age-associated impairments in skeletal muscle regeneration following injury have been demonstrated, less is known about whether aging impacts the regenerative response of neuromuscular junctions (NMJ) following contraction-induced injury. Reduced ability of NMJs to regenerate could lead to increased numbers of denervated muscle fibers and therefore play a contributing role to age-related sarcopenia. To investigate the relationship between age and NMJ regeneration following injury, extensor digitorum longus (EDL) muscles of middle-aged (18-19 months) and old mice (27-28 months) were subjected to a protocol of lengthening contractions (LC) that resulted in an acute force deficit of ~55% as well as functional and histological evidence of a similar magnitude of injury 3 days post LCs that was not different between age groups. After 28 days, the architecture and innervation of the NMJs were evaluated. The numbers of fragmented endplates increased and of fully innervated NMJs decreased post-injury for the muscle of both middle-aged and old mice and for contralateral uninjured muscles of old compared with uninjured muscles of middle-aged controls. Thus, the diminished ability of the skeletal muscle of old mice to recover following injury may be due in part to an age-related decrease in the ability to regenerate NMJs in injured muscles. The impaired ability to regenerate NMJs may be a triggering factor for degenerative changes at the NMJ contributing to muscle fiber weakness and loss in old age.


Subject(s)
Muscle Contraction , Neuromuscular Junction , Mice , Animals , Muscle Fibers, Skeletal , Muscle, Skeletal/pathology , Regeneration
7.
bioRxiv ; 2023 Oct 07.
Article in English | MEDLINE | ID: mdl-38370853

ABSTRACT

Understanding neuromuscular junction (NMJ) repair mechanisms is essential for addressing degenerative neuromuscular conditions. Here, we focus on the role of muscle-resident Schwann cells in NMJ reinnervation. In young Sod1-/- mice, a model of progressive NMJ degeneration, we identified a clear NMJ 'regenerative window' that allowed us to define regulators of reinnervation and crossing Sod1-/- mice with S100GFP-tg mice permitted visualization and analysis of Schwann cells. High-resolution imaging and single-cell RNA sequencing provide a detailed analysis of Schwann cell number, morphology, and transcriptome revealing multiple subtypes, including a previously unrecognized terminal Schwann cell (tSC) population expressing a synapse promoting signature. We also discovered a novel SPP1-driven cellular interaction between myelin Schwann cells and tSCs and show that it promotes tSC proliferation and reinnervation following nerve injury in wild type mice. Our findings offer important insights into molecular regulators critical in NMJ reinnervation that are mediated through tSCs to maintain NMJ function.

8.
Curr Oncol ; 29(5): 3698-3707, 2022 05 19.
Article in English | MEDLINE | ID: mdl-35621686

ABSTRACT

Despite the known importance and necessity of the standardized collection and use of patient-reported outcomes (PROs), there remain challenges to successful clinical implementation. Facilitated through a quality improvement initiative spearheaded by the Canadian Partnership for Quality Radiotherapy (CPQR), and now guided by the Canadian Association of Radiation Oncology (CARO)'s Quality and Standards Committee, patient representatives and early-adopter radiation treatment programs continue to champion the expansion of PROs initiatives across the country. The current review discusses the evolution of a pan-Canadian approach to PROs use, striving to fill in gaps between clinical practice and guideline recommendations through multi-centre and multidisciplinary collaboration.


Subject(s)
Patient Reported Outcome Measures , Radiation Oncology , Canada , Humans
10.
Proc Natl Acad Sci U S A ; 119(15): e2111445119, 2022 04 12.
Article in English | MEDLINE | ID: mdl-35377804

ABSTRACT

Volumetric muscle loss (VML) overwhelms the innate regenerative capacity of mammalian skeletal muscle (SkM), leading to numerous disabilities and reduced quality of life. Immune cells are critical responders to muscle injury and guide tissue resident stem cell­ and progenitor-mediated myogenic repair. However, how immune cell infiltration and intercellular communication networks with muscle stem cells are altered following VML and drive pathological outcomes remains underexplored. Herein, we contrast the cellular and molecular mechanisms of VML injuries that result in the fibrotic degeneration or regeneration of SkM. Following degenerative VML injuries, we observed the heightened infiltration of natural killer (NK) cells as well as the persistence of neutrophils beyond 2 wk postinjury. Functional validation of NK cells revealed an antagonistic role in neutrophil accumulation in part via inducing apoptosis and CCR1-mediated chemotaxis. The persistent infiltration of neutrophils in degenerative VML injuries was found to contribute to impairments in muscle stem cell regenerative function, which was also attenuated by transforming growth factor beta 1 (TGFß1). Blocking TGFß signaling reduced neutrophil accumulation and fibrosis and improved muscle-specific force. Collectively, these results enhance our understanding of immune cell­stem cell cross talk that drives regenerative dysfunction and provide further insight into possible avenues for fibrotic therapy exploration.


Subject(s)
Killer Cells, Natural , Muscle, Skeletal , Muscular Diseases , Neutrophils , Regeneration , Satellite Cells, Skeletal Muscle , Animals , Fibrosis , Killer Cells, Natural/immunology , Mice , Muscle, Skeletal/immunology , Muscle, Skeletal/pathology , Muscular Diseases/immunology , Muscular Diseases/pathology , Neutrophil Infiltration , Neutrophils/immunology , Regeneration/immunology , Satellite Cells, Skeletal Muscle/immunology , Transforming Growth Factor beta/metabolism
11.
Autophagy ; 18(10): 2303-2322, 2022 Oct.
Article in English | MEDLINE | ID: mdl-34964695

ABSTRACT

By promoting anabolism, MTORC1 is critical for muscle growth and maintenance. However, genetic MTORC1 upregulation promotes muscle aging and produces age-associated myopathy. Whether MTORC1 activation is sufficient to produce myopathy or indirectly promotes it by accelerating tissue aging is elusive. Here we examined the effects of muscular MTORC1 hyperactivation, produced by simultaneous depletion of TSC1 and DEPDC5 (CKM-TD). CKM-TD mice produced myopathy, associated with loss of skeletal muscle mass and force, as well as cardiac failure and bradypnea. These pathologies were manifested at eight weeks of age, leading to a highly penetrant fatality at around twelve weeks of age. Transcriptome analysis indicated that genes mediating proteasomal and macroautophagic/autophagic pathways were highly upregulated in CKM-TD skeletal muscle, in addition to inflammation, oxidative stress, and DNA damage signaling pathways. In CKM-TD muscle, autophagosome levels were increased, and the AMPK and ULK1 pathways were activated; in addition, autophagy induction was not completely blocked in CKM-TD myotubes. Despite the upregulation of autolysosomal markers, CKM-TD myofibers exhibited accumulation of autophagy substrates, such as SQSTM1/p62 and ubiquitinated proteins, suggesting that the autophagic activities were insufficient. Administration of a superoxide scavenger, tempol, normalized most of these molecular pathologies and subsequently restored muscle histology and force generation. However, CKM-TD autophagy alterations were not normalized by rapamycin or tempol, suggesting that they may involve non-canonical targets other than MTORC1. These results collectively indicate that the concomitant muscle deficiency of TSC1 and DEPDC5 can produce early-onset myopathy through accumulation of oxidative stress, which dysregulates myocellular homeostasis.Abbreviations: AMPK: AMP-activated protein kinase; CKM: creatine kinase, M-type; COX: cytochrome oxidase; DEPDC5: DEP domain containing 5, GATOR1 subcomplex subunit; DHE: dihydroethidium; EDL: extensor digitorum longus; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; GAP: GTPase-activating protein; GTN: gastrocnemius; MTORC1: mechanistic target of rapamycin kinase complex 1; PLA: plantaris; QUAD: quadriceps; RPS6KB/S6K: ribosomal protein S6 kinase beta; SDH: succinate dehydrogenase; SOL: soleus; SQSTM1: sequestosome 1; TA: tibialis anterior; TSC1: TSC complex subunit 1; ULK1: unc-51 like autophagy activating kinase 1.


Subject(s)
Heart Diseases , Muscular Diseases , AMP-Activated Protein Kinases/metabolism , Animals , Autophagy , Autophagy-Related Protein-1 Homolog/metabolism , Creatine Kinase, MM Form/metabolism , Cyclic N-Oxides , Electron Transport Complex IV/metabolism , Electron Transport Complex IV/pharmacology , GTPase-Activating Proteins/metabolism , Heart Diseases/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Mice , Muscular Diseases/metabolism , Myocardium/metabolism , Oxidative Stress , Peptide Initiation Factors/metabolism , Polyesters/metabolism , Polyesters/pharmacology , Ribosomal Protein S6 Kinases/metabolism , Ribosomal Protein S6 Kinases/pharmacology , Sequestosome-1 Protein/metabolism , Sirolimus/pharmacology , Spin Labels , Succinate Dehydrogenase/metabolism , Succinate Dehydrogenase/pharmacology , Superoxides/metabolism , Tuberous Sclerosis Complex 1 Protein , Ubiquitinated Proteins/metabolism
12.
J Cancer Educ ; 37(6): 1834-1841, 2022 12.
Article in English | MEDLINE | ID: mdl-34518991

ABSTRACT

Patient engagement and education have been mandated across Canadian radiation oncology programs (ROP). Guidance documents include the 2014 Canadian Association of Radiation Oncology (CARO) Radiation Therapy Patient Charter, the 2016 Canadian Partnership for Quality Radiotherapy (CPQR) Patient Engagement Guidelines (PEG) for Canadian Radiation Treatment Programs, and Accreditation Canada's 2017 refresh of Cancer Care Standards. Since little is known regarding uptake of these guidance statements, Canadian ROP were surveyed to assess current patient engagement and education practices. An e-survey was sent to Canadian ROP (n = 44). The survey focused on awareness and uptake of the CARO Patient Charter, CPQR PEG, and patient education practices. Survey development was guided by these documents and expert consensus, including CARO's Quality and Standards Patient Education/Engagement working group. Many (71%) responding ROP were familiar with the CARO Patient Charter, while 24% reported use. More than half (53%) of ROP were aware of the CPQR PEG, but approximately third (37%) had previously completed a self-audit. Most (88%) ROP view a pan-Canadian, evidence-based approach to educational materials beneficial and feasible (80%), with the majority (89%) willing to share their best practices across the radiotherapy community. Patient engagement and education are nationally mandated and supported by guidance documents. However, gaps have been identified across ROP for awareness and use of available tools, as well as uptake of their processes critical to quality of care. Understanding current practices will inform CPQR/CARO-supported pan-Canadian initiatives to optimize uptake, including development of CPQR Patient Education Guidance for Canadian Radiation Treatment Programs.


Subject(s)
Radiation Oncology , Humans , Patient Participation , Canada , Surveys and Questionnaires
13.
Animals (Basel) ; 11(11)2021 Nov 12.
Article in English | MEDLINE | ID: mdl-34827974

ABSTRACT

The slow adoption of innovations is a key challenge that the European sheep sector faces for its sustainability. The future of the sector lies on the adoption of best practices, modern technologies and innovations that can improve its resilience and mitigate its dependence on public support. In this study, the concept of technical efficiency was used to reveal the most efficient sheep meat farms and to identify the best practices and farm innovations that could potentially be adopted by other farms of similar production systems. Data Envelopment Analysis was applied to farm accounting data from 458 sheep meat farms of intensive, semi-intensive and extensive systems from France, Spain and the UK, and the structural and economic characteristics of the most efficient farms were analyzed. These best farmers were indicated through a survey, which was conducted within the Innovation for Sustainable Sheep and Goat Production in the Europe (iSAGE) Horizon 2020 project, the management and production practices and innovations that improve their economic performance and make them better than their peers.

14.
Int J Mol Sci ; 22(19)2021 Oct 04.
Article in English | MEDLINE | ID: mdl-34639076

ABSTRACT

Skeletal muscle suffers atrophy and weakness with aging. Denervation, oxidative stress, and mitochondrial dysfunction are all proposed as contributors to age-associated muscle loss, but connections between these factors have not been established. We examined contractility, mitochondrial function, and intracellular calcium transients (ICTs) in muscles of mice throughout the life span to define their sequential relationships. We performed these same measures and analyzed neuromuscular junction (NMJ) morphology in mice with postnatal deletion of neuronal Sod1 (i-mn-Sod1-/- mice), previously shown to display accelerated age-associated muscle loss and exacerbation of denervation in old age, to test relationships between neuronal redox homeostasis, NMJ degeneration and mitochondrial function. In control mice, the amount and rate of the decrease in mitochondrial NADH during contraction was greater in middle than young age although force was not reduced, suggesting decreased efficiency of NADH utilization prior to the onset of weakness. Declines in both the peak of the ICT and force were observed in old age. Muscles of i-mn-Sod1-/- mice showed degeneration of mitochondrial and calcium handling functions in middle-age and a decline in force generation to a level not different from the old control mice, with maintenance of NMJ morphology. Together, the findings support the conclusion that muscle mitochondrial function decreases during aging and in response to altered neuronal redox status prior to NMJ deterioration or loss of mass and force suggesting mitochondrial defects contribute to sarcopenia independent of denervation.


Subject(s)
Aging , Calcium/metabolism , Mitochondria, Muscle/pathology , Neurons/pathology , Oxidative Stress , Sarcopenia/pathology , Superoxide Dismutase-1/physiology , Animals , Denervation , Female , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitochondria, Muscle/metabolism , Muscle Contraction , Neurons/metabolism , Oxidation-Reduction , Sarcopenia/etiology
16.
Anaerobe ; 72: 102447, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34560274

ABSTRACT

OBJECTIVES: To assess the differences in antimicrobial susceptibility of UK Bacteroides species across two distinct cohorts from 2000 to 2016. METHODS: Strain identification was performed using matrix-assisted laser-desorption ionisation time of flight mass spectrometry (MALDI-TOF MS) or by partial 16S rRNA sequencing. Minimum inhibitory concentrations (MICs) were determined using agar dilution, following CLSI guidelines (CLSI, 2012; 2017). RESULTS: 224 isolates were included from 2000 to 168 from 2016. Bacteroides fragilis was the most common species, comprising 68% of the 2000 cohort, and 77% in 2016. For all antimicrobials tested, there was an overall increase in the rates of non-susceptible isolates between the cohorts. CONCLUSIONS: The antibiogram of Bacteroides species in the UK is no longer predictable. Multi-drug resistant isolates although rare, are on the rise, and require testing to guide therapy. The monitoring and surveillance of resistance trends is imperative, as is the development of standardised, robust and accessible antimicrobial susceptibility testing methodology for clinical laboratories.


Subject(s)
Bacteroides Infections/epidemiology , Bacteroides Infections/microbiology , Bacteroides/classification , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Typing Techniques , Bacteroides/drug effects , Bacteroides/isolation & purification , Bacteroides Infections/drug therapy , Bacteroides Infections/history , Drug Resistance, Bacterial/drug effects , History, 21st Century , Humans , Longitudinal Studies , Microbial Sensitivity Tests , Public Health Surveillance , RNA, Ribosomal, 16S/genetics , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , United Kingdom/epidemiology
17.
Aging Cell ; 20(6): e13393, 2021 06.
Article in English | MEDLINE | ID: mdl-34075679

ABSTRACT

Specialized pro-resolving mediators actively limit inflammation and support tissue regeneration, but their role in age-related muscle dysfunction has not been explored. We profiled the mediator lipidome of aging muscle via liquid chromatography-tandem mass spectrometry and tested whether treatment with the pro-resolving mediator resolvin D1 (RvD1) could rejuvenate the regenerative ability of aged muscle. Aged mice displayed chronic muscle inflammation and this was associated with a basal deficiency of pro-resolving mediators 8-oxo-RvD1, resolvin E3, and maresin 1, as well as many anti-inflammatory cytochrome P450-derived lipid epoxides. Following muscle injury, young and aged mice produced similar amounts of most pro-inflammatory eicosanoid metabolites of cyclooxygenase (e.g., prostaglandin E2 ) and 12-lipoxygenase (e.g., 12-hydroxy-eicosatetraenoic acid), but aged mice produced fewer markers of pro-resolving mediators including the lipoxins (15-hydroxy-eicosatetraenoic acid), D-resolvins/protectins (17-hydroxy-docosahexaenoic acid), E-resolvins (18-hydroxy-eicosapentaenoic acid), and maresins (14-hydroxy-docosahexaenoic acid). Similar absences of downstream pro-resolving mediators including lipoxin A4 , resolvin D6, protectin D1/DX, and maresin 1 in aged muscle were associated with greater inflammation, impaired myofiber regeneration, and delayed recovery of strength. Daily intraperitoneal injection of RvD1 had minimal impact on intramuscular leukocyte infiltration and myofiber regeneration but suppressed inflammatory cytokine expression, limited fibrosis, and improved recovery of muscle function. We conclude that aging results in deficient local biosynthesis of specialized pro-resolving mediators in muscle and that immunoresolvents may be attractive novel therapeutics for the treatment of muscular injuries and associated pain in the elderly, due to positive effects on recovery of muscle function without the negative side effects on tissue regeneration of non-steroidal anti-inflammatory drugs.


Subject(s)
Aging/physiology , Inflammation/metabolism , Mass Spectrometry/methods , Metabolism/physiology , Muscle, Skeletal/metabolism , Tissue Engineering/methods , Animals , Humans , Mice
18.
Front Aging ; 2: 821904, 2021.
Article in English | MEDLINE | ID: mdl-35821997

ABSTRACT

Aging results in the progressive accumulation of senescent cells in tissues that display loss of proliferative capacity and acquire a senescence-associated secretory phenotype (SASP). The tumor suppressor, p16 INK4A , which slows the progression of the cell cycle, is highly expressed in most senescent cells and the removal of p16-expressing cells has been shown to be beneficial to tissue health. Although much work has been done to assess the effects of cellular senescence on a variety of different organs, little is known about the effects on skeletal muscle and whether reducing cellular senescent load would provide a therapeutic benefit against age-related muscle functional decline. We hypothesized that whole-body ablation of p16-expressing cells in the advanced stages of life in mice would provide a therapeutic benefit to skeletal muscle structure and function. Treatment of transgenic p16-3MR mice with ganciclovir (GCV) from 20 to 26 months of age resulted in reduced p16 mRNA levels in muscle. At 26 months of age, the masses of tibialis anterior, extensor digitorum longus, gastrocnemius and quadriceps muscles were significantly larger in GCV-treated compared with vehicle-treated mice, but this effect was limited to male mice. Maximum isometric force for gastrocnemius muscles was also greater in GCV-treated male mice compared to controls. Further examination of muscles of GCV- and vehicle-treated mice showed fewer CD68-positive macrophages present in the tissue following GCV treatment. Plasma cytokine levels were also measured with only one, granulocyte colony stimulating factor (G-CSF), out of 22 chemokines analyzed was reduced in GCV-treated mice. These findings show that genetic ablation of p16+ senescent cells provides moderate and sex specific therapeutic benefits to muscle mass and function.

19.
Animals (Basel) ; 10(12)2020 Dec 17.
Article in English | MEDLINE | ID: mdl-33348834

ABSTRACT

The European sheep and goat sector is characterized by low professionalization and management training. Moreover, it is fragmented in terms of production aims and farming systems. Here, iSAGEDSS, a web-based application allowing dairy and meat small ruminant farmers in different countries to make annual management plans by testing future scenarios, is presented. Data were obtained for the meat sheep (United Kingdom and Spain), dairy sheep (France and Greece) and dairy goat production systems (Greece) from partners of the Innovation for Sustainable Sheep and Goat Production in Europe (iSAGE) project. These were used to set default values and ranges for all important farm parameters in each system and country. An algorithm was developed assessing nutritional management and its impact on production and financial performance. Reports focus on profitability, productivity and environmental sustainability. A case study in three dairy sheep farms in Greece was performed. In each case, an evaluation scenario was created using actual farm data that were compared with the estimated ones. Two scenarios testing management decisions for gross margin maximization and milk pricing fluctuations were created. Application results showed high prediction accuracy for gross margin and production estimation (error of circa 9% and 4%, respectively). Moreover, the ability to promote financial, production and grazing management efficiency was demonstrated.

20.
Am J Sports Med ; 48(13): 3245-3254, 2020 11.
Article in English | MEDLINE | ID: mdl-33136456

ABSTRACT

BACKGROUND: Blood flow restriction therapy (BFRT) has been increasingly applied to improve athletic performance and injury recovery. Validation of BFRT has lagged behind commercialization, and currently the mechanism by which this therapy acts is unknown. BFRT is one type of ischemic therapy, which involves exercising with blood flow restriction. Repetitive restriction of muscle blood flow (RRMBF) is another ischemic therapy type, which does not include exercise. HYPOTHESIS/PURPOSE: The purpose was to develop a rat model of ischemic therapy, characterize changes to muscle contractility, and evaluate local and systemic biochemical and histologic responses of 2 ischemic therapy types. We hypothesized that ischemic therapy would improve muscle mass and strength as compared with the control group. STUDY DESIGN: Controlled laboratory study. METHODS: Four groups of 10 Sprague-Dawley rats were established: control, stimulation, RRMBF, and BFRT. One hindlimb of each subject underwent 8 treatment sessions over 4 weeks. To simulate exercise, the stimulation group underwent peroneal nerve stimulation for 2 minutes. The RRMBF group used a pneumatic cuff inflated to 100 mm Hg with a 48-minute protocol. The BFRT group involved 100-mm Hg pneumatic cuff inflation and peroneal nerve stimulation for a 5-minute protocol. Four methods of evaluation were performed: in vivo contractility testing, histology, immunohistochemistry, and ELISA. Analysis of variance with post hoc Tukey test and linear mixed effects modeling were used to compare the treatment groups. RESULTS: There was no difference in muscle mass among groups (P = .40) or between hindlimbs (P = .73). In vivo contractility testing showed no difference in maximum contractile force among groups (P = .64) or between hindlimbs (P = .30). On histology, myocyte cross-sectional area was not different among groups (P = .55) or between hindlimbs (P = .44). Pax7 immunohistochemistry demonstrated no difference in muscle satellite cell density among groups (P = .06) or between hindlimbs (P = .046). ELISA demonstrated the RRMBF group as eliciting elevated GH levels as compared with the other groups (P < .001). CONCLUSION: Ischemic therapy did not induce gains in muscle mass, contractility strength, fiber cross-sectional area, or satellite cell density locally or systemically in this model, although the RRMBF group did have elevated GH levels on ELISA. CLINICAL RELEVANCE: This animal model does not support ischemic therapy as a method to improve muscle mass, function, or satellite cell density.


Subject(s)
Lower Extremity , Muscle Contraction , Muscle, Skeletal/blood supply , Regional Blood Flow , Animals , Hindlimb , Models, Animal , Rats , Rats, Sprague-Dawley
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