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Briefly (10 min) exposing C2C12 myotubes to low amplitude (1.5 mT) pulsed electromagnetic fields (PEMFs) generated a conditioned media (pCM) that was capable of mitigating breast cancer cell growth, migration, and invasiveness in vitro, whereas the conditioned media harvested from unexposed myotubes, representing constitutively released secretome (cCM), was less effective. Administering pCM to breast cancer microtumors engrafted onto the chorioallantoic membrane of chicken eggs reduced tumor volume and vascularity. Blood serum collected from PEMF-exposed or exercised mice allayed breast cancer cell growth, migration, and invasiveness. A secretome preconditioning methodology is presented that accentuates the graded anticancer potencies of both the cCM and pCM harvested from myotubes, demonstrating an adaptive response to pCM administered during early myogenesis that emulated secretome-based exercise adaptations observed in vivo. HTRA1 was shown to be upregulated in pCM and was demonstrated to be necessary and sufficient for the anticancer potency of the pCM; recombinant HTRA1 added to basal media recapitulated the anticancer effects of pCM and antibody-based absorption of HTRA1 from pCM precluded its anticancer effects. Brief and non-invasive PEMF stimulation may represent a method to commandeer the secretome response of muscle, both in vitro and in vivo, for clinical exploitation in breast and other cancers.
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Neoplasias da Mama , Campos Eletromagnéticos , Serina Peptidase 1 de Requerimento de Alta Temperatura A , Secretoma , Animais , Camundongos , Meios de Cultivo Condicionados , Fibras Musculares Esqueléticas , Secretoma/metabolismo , Serina Peptidase 1 de Requerimento de Alta Temperatura A/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/terapiaRESUMO
Background: Metabolic disruption commonly follows Anterior Cruciate Ligament Reconstruction (ACLR) surgery. Brief exposure to low amplitude and frequency pulsed electromagnetic fields (PEMFs) has been shown to promote in vitro and in vivo murine myogeneses via the activation of a calcium-mitochondrial axis conferring systemic metabolic adaptations. This randomized-controlled pilot trial sought to detect local changes in muscle structure and function using MRI, and systemic changes in metabolism using plasma biomarker analyses resulting from ACLR, with or without accompanying PEMF therapy. Methods: 20 patients requiring ACLR were randomized into two groups either undergoing PEMF or sham exposure for 16 weeks following surgery. The operated thighs of 10 patients were exposed weekly to PEMFs (1 âmT for 10 âmin) for 4 months following surgery. Another 10 patients were subjected to sham exposure and served as controls to allow assessment of the metabolic repercussions of ACLR and PEMF therapy. Blood samples were collected prior to surgery and at 16 weeks for plasma analyses. Magnetic resonance data were acquired at 1 and 16 weeks post-surgery using a Siemens 3T Tim Trio system. Phosphorus (31P) Magnetic Resonance Spectroscopy (MRS) was utilized to monitor changes in high-energy phosphate metabolism (inorganic phosphate (Pi), adenosine triphosphate (ATP) and phosphocreatine (PCr)) as well as markers of membrane synthesis and breakdown (phosphomonoesters (PME) and phosphodiester (PDE)). Quantitative Magnetization Transfer (qMT) imaging was used to elucidate changes in the underlying tissue structure, with T1-weighted and 2-point Dixon imaging used to calculate muscle volumes and muscle fat content. Results: Improvements in markers of high-energy phosphate metabolism including reductions in ΔPi/ATP, Pi/PCr and (Pi â+ âPCr)/ATP, and membrane kinetics, including reductions in PDE/ATP were detected in the PEMF-treated cohort relative to the control cohort at study termination. These were associated with reductions in the plasma levels of certain ceramides and lysophosphatidylcholine species. The plasma levels of biomarkers predictive of muscle regeneration and degeneration, including osteopontin and TNNT1, respectively, were improved, whilst changes in follistatin failed to achieve statistical significance. Liquid chromatography with tandem mass spectrometry revealed reductions in small molecule biomarkers of metabolic disruption, including cysteine, homocysteine, and methionine in the PEMF-treated cohort relative to the control cohort at study termination. Differences in measurements of force, muscle and fat volumes did not achieve statistical significance between the cohorts after 16 weeks post-ACLR. Conclusion: The detected changes suggest improvements in systemic metabolism in the post-surgical PEMF-treated cohort that accords with previous preclinical murine studies. PEMF-based therapies may potentially serve as a manner to ameliorate post-surgery metabolic disruptions and warrant future examination in more adequately powered clinical trials. The Translational Potential of this Article: Some degree of physical immobilisation must inevitably follow orthopaedic surgical intervention. The clinical paradox of such a scenario is that the regenerative potential of the muscle mitochondrial pool is silenced. The unmet need was hence a manner to maintain mitochondrial activation when movement is restricted and without producing potentially damaging mechanical stress. PEMF-based therapies may satisfy the requirement of non-invasively activating the requisite mitochondrial respiration when mobility is restricted for improved metabolic and regenerative recovery.
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We conducted an epidemiological study to identify the demographics and pre-operative characteristics of patients undergoing primary anterior cruciate ligament (ACL) reconstruction in a multi-ethnic Asian population. A retrospective study was performed on 696 patients who registered in our ACL reconstruction registry from January 2013 to August 2016. Important inter-ethnic differences were found. Indian patients were significantly older compared to Malay and Chinese patients. Malay and Indian patients were more likely to be male, overweight, and obese compared to Chinese patients. Soccer was the predominant sport involved, although ethnic predominance in specific sports exists. Novel findings from this study include increased prevalence of concomitant chondral injuries in the Chinese population compared to Malays and Indians, and significantly higher rates of concomitant intra-articular injuries in soccer and basketball compared to netball. Identification of these high-risk subgroups would serve useful in guiding the formulation of prevention strategies within our multi-ethnic community.
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Lesões do Ligamento Cruzado Anterior/epidemiologia , Reconstrução do Ligamento Cruzado Anterior/estatística & dados numéricos , Povo Asiático/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Lesões do Ligamento Cruzado Anterior/etnologia , Artroscopia , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/etnologia , Índice de Massa Corporal , Distribuição de Qui-Quadrado , China/etnologia , Feminino , Humanos , Índia/etnologia , Indonésia/etnologia , Masculino , Pessoa de Meia-Idade , Sistema de Registros/estatística & dados numéricos , Estudos Retrospectivos , Estatísticas não Paramétricas , Adulto JovemRESUMO
Pulsed electromagnetic fields (PEMFs) are capable of specifically activating a TRPC1-mitochondrial axis underlying cell expansion and mitohormetic survival adaptations. This study characterizes cell-derived vesicles (CDVs) generated from C2C12 murine myoblasts and shows that they are equipped with the sufficient molecular machinery to confer mitochondrial respiratory capacity and associated proliferative responses upon their fusion with recipient cells. CDVs derived from wild type C2C12 myoblasts include the cation-permeable transient receptor potential (TRP) channels, TRPC1 and TRPA1, and directly respond to PEMF exposure with TRPC1-mediated calcium entry. By contrast, CDVs derived from C2C12 muscle cells in which TRPC1 has been genetically knocked-down using CRISPR/Cas9 genome editing, do not. Wild type C2C12-derived CDVs are also capable of restoring PEMF-induced proliferative and mitochondrial activation in two C2C12-derived TRPC1 knockdown clonal cell lines in accordance to their endogenous degree of TRPC1 suppression. C2C12 wild type CDVs respond to menthol with calcium entry and accumulation, likewise verifying TRPA1 functional gating and further corroborating compartmental integrity. Proteomic and lipidomic analyses confirm the surface membrane origin of the CDVs providing an initial indication of the minimal cellular machinery required to recover mitochondrial function. CDVs hence possess the potential of restoring respiratory and proliferative capacities to senescent cells and tissues.
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Proliferação de Células/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Mitocôndrias/efeitos dos fármacos , Canais de Cátion TRPC , Animais , Sistemas CRISPR-Cas , Linhagem Celular , Micropartículas Derivadas de Células/metabolismo , Edição de Genes , Camundongos , Canais de Cátion TRPC/genética , Canais de Cátion TRPC/metabolismo , Canais de Cátion TRPC/farmacocinética , Canais de Cátion TRPC/farmacologiaRESUMO
Exercise modulates metabolism and the gut microbiome. Brief exposure to low mT-range pulsing electromagnetic fields (PEMFs) was previously shown to accentuate in vitro myogenesis and mitochondriogenesis by activating a calcium-mitochondrial axis upstream of PGC-1α transcriptional upregulation, recapitulating a genetic response implicated in exercise-induced metabolic adaptations. We compared the effects of analogous PEMF exposure (1.5 mT, 10 min/week), with and without exercise, on systemic metabolism and gut microbiome in four groups of mice: (a) no intervention; (b) PEMF treatment; (c) exercise; (d) exercise and PEMF treatment. The combination of PEMFs and exercise for 6 weeks enhanced running performance and upregulated muscular and adipose Pgc-1α transcript levels, whereas exercise alone was incapable of elevating Pgc-1α levels. The gut microbiome Firmicutes/Bacteroidetes ratio decreased with exercise and PEMF exposure, alone or in combination, which has been associated in published studies with an increase in lean body mass. After 2 months, brief PEMF treatment alone increased Pgc-1α and mitohormetic gene expression and after >4 months PEMF treatment alone enhanced oxidative muscle expression, fatty acid oxidation, and reduced insulin levels. Hence, short-term PEMF treatment was sufficient to instigate PGC-1α-associated transcriptional cascades governing systemic mitohormetic adaptations, whereas longer-term PEMF treatment was capable of inducing related metabolic adaptations independently of exercise.
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Microbioma Gastrointestinal/fisiologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Adaptação Fisiológica/fisiologia , Animais , Bacteroidetes/crescimento & desenvolvimento , Composição Corporal/fisiologia , Ácidos Graxos/metabolismo , Feminino , Firmicutes/crescimento & desenvolvimento , Seguimentos , Expressão Gênica/fisiologia , Insulina/metabolismo , Campos Magnéticos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Desenvolvimento Muscular/fisiologia , Músculo Esquelético/metabolismo , Condicionamento Físico Animal/fisiologia , Transcrição Gênica/fisiologia , Ativação Transcricional/fisiologiaRESUMO
We show that both supplemental and ambient magnetic fields modulate myogenesis. A lone 10 min exposure of myoblasts to 1.5 mT amplitude supplemental pulsed magnetic fields (PEMFs) accentuated in vitro myogenesis by stimulating transient receptor potential (TRP)-C1-mediated calcium entry and downstream nuclear factor of activated T cells (NFAT)-transcriptional and P300/CBP-associated factor (PCAF)-epigenetic cascades, whereas depriving myoblasts of ambient magnetic fields slowed myogenesis, reduced TRPC1 expression, and silenced NFAT-transcriptional and PCAF-epigenetic cascades. The expression levels of peroxisome proliferator-activated receptor γ coactivator 1α, the master regulator of mitochondriogenesis, was also enhanced by brief PEMF exposure. Accordingly, mitochondriogenesis and respiratory capacity were both enhanced with PEMF exposure, paralleling TRPC1 expression and pharmacological sensitivity. Clustered regularly interspaced short palindromic repeats-Cas9 knockdown of TRPC1 precluded proliferative and mitochondrial responses to supplemental PEMFs, whereas small interfering RNA gene silencing of TRPM7 did not, coinciding with data that magnetoreception did not coincide with the expression or function of other TRP channels. The aminoglycoside antibiotics antagonized and down-regulated TRPC1 expression and, when applied concomitantly with PEMF exposure, attenuated PEMF-stimulated calcium entry, mitochondrial respiration, proliferation, differentiation, and epigenetic directive in myoblasts, elucidating why the developmental potential of magnetic fields may have previously escaped detection. Mitochondrial-based survival adaptations were also activated upon PEMF stimulation. Magnetism thus deploys an authentic myogenic directive that relies on an interplay between mitochondria and TRPC1 to reach fruition.-Yap, J. L. Y., Tai, Y. K., Fröhlich, J., Fong, C. H. H., Yin, J. N., Foo, Z. L., Ramanan, S., Beyer, C., Toh, S. J., Casarosa, M., Bharathy, N., Kala, M. P., Egli, M., Taneja, R., Lee, C. N., Franco-Obregón, A. Ambient and supplemental magnetic fields promote myogenesis via a TRPC1-mitochondrial axis: evidence of a magnetic mitohormetic mechanism.
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Campos Magnéticos , Mitocôndrias Musculares/metabolismo , Desenvolvimento Muscular , Mioblastos Esqueléticos/metabolismo , Transdução de Sinais , Canais de Cátion TRPC/metabolismo , Animais , Linhagem Celular , Camundongos , Mitocôndrias Musculares/genética , Mioblastos Esqueléticos/citologia , Canais de Cátion TRPC/genéticaRESUMO
PURPOSE: To verify the correlation of time to surgery with the prevalence of concomitant intra-articular injuries detected on arthroscopy during anterior cruciate ligament (ACL) reconstruction. METHODS: The medical records of 653 patients who underwent ACL reconstruction surgery were retrospectively analyzed. Univariate and multivariate logistic regression analysis was performed to identify factors that were associated with the presence of at least one intra-articular injury, medial meniscus tears, lateral meniscus tears and chondral injuries at the time of surgery. Further univariate analysis was conducted to determine the earliest time-point for surgery, after which the rate of concomitant injuries was significantly higher. RESULTS: Longer time to surgery (OR 1.019 95% CI 1.010, 1.028, p = 0.000), male sex (OR 1.695 95% CI 1.074, 2.675 p = 0.023), and higher BMI (OR 1.050 95% CI 1.006, 1.097 p = 0.025) were correlated with a higher prevalence of medial meniscus tears. There was an increased prevalence of medial meniscus tears when surgery was carried out more than 12 months after the index injury (OR 2.274 95% CI 1.469, 3.522, p = 0.000). The correlation between longer time to surgery and chondral injuries approached statistical significance (OR 1.006 95% CI 0.999, 1.012, p = 0.073). However, a longer time to surgery was not associated with an increased prevalence of lateral meniscus tears (OR 1.003 95% CI 0.998, 1.009, p = n.s.). CONCLUSIONS: Longer time to surgery is associated with an increased prevalence of medial meniscus tears in ACL reconstruction. Surgery performed within 12 months of the index injury reduces the prevalence of medial meniscus tears. Prioritizing males and overweight patients for counselling and early intervention can be considered. LEVEL OF EVIDENCE: Therapeutic level III retrospective cohort study.
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Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Complicações Pós-Operatórias/prevenção & controle , Lesões do Menisco Tibial/prevenção & controle , Adolescente , Adulto , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Prevalência , Estudos Retrospectivos , Fatores de Risco , Lesões do Menisco Tibial/epidemiologia , Lesões do Menisco Tibial/etiologia , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE: Increased knee pain at the time of anterior cruciate ligament (ACL) reconstruction may predict increased pain post-operatively, a prolonged recovery and a more difficult rehabilitation. The main objective of our study was to identify preoperative factors, such as concomitant intra-articular injuries and bone bruises, that may be associated with increased knee pain and symptoms in patients undergoing ACL reconstruction. METHODS: Patient data was queried from our institution's prospectively maintained ACL reconstruction registry. Two-hundred and seventy patients who underwent primary ACL reconstruction within 3 months of injury were included in the study. Predictors such as demographic characteristics (age, body mass index and gender) and injury characteristics (mechanism of injury, meniscal injury, chondral injury and bone bruise) were recorded. The association between the pre-operative knee injury and Osteoarthritis Outcome Score (KOOS) pain and symptom subscales and the Short Form-36 (SF-36) bodily pain subscale, and the predictors were assessed using logistic regression for categorical variables and linear regression for continuous variables. RESULTS: The mean age of our patient group was 25.4 years with 211 out of 270 (78%) being males. Bone bruise was present in 243 patients (90%), meniscal injury in 165 (61%) patients and chondral injury in 40 (15%) patients. The presence of bone bruise, meniscal injury or chondral injury was not significantly associated with worse preoperative KOOS pain and symptom and SF-36 bodily pain scores. Other factors that were not associated were demographic characteristics (age, BMI and gender) and mechanism of injury. CONCLUSION: The presence of bone bruise and concomitant intra-articular injuries does not affect pre-operative knee pain and symptoms in patients undergoing ACL reconstruction within 3 months of injury. This knowledge would aid the surgeon in pre-operative counselling, and prognostication of post-operative pain and rehabilitation after ACL reconstruction.
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Reconstrução do Ligamento Cruzado Anterior , Artralgia/etiologia , Cartilagem Articular/lesões , Contusões/complicações , Medidas de Resultados Relatados pelo Paciente , Lesões do Menisco Tibial/complicações , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Adulto JovemRESUMO
BACKGROUND: To determine the extent to which a strategy of routinely preparing a 5-strand hamstring autograft would increase graft size in anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 64 patients were enrolled in a prospective randomized controlled study comparing 5-strand and quadrupled semitendinosus-gracilis autografts in single-bundle ACL reconstruction (5-strand group, n = 32; 4-strand group, n = 32). In the 5-strand group, the diameter of the 4-strand construct and the subsequent 5-strand graft used were measured, whereas in the 4-strand group, the diameter of the quadrupled graft used was measured. Quadrupled graft diameter and hamstring tendon lengths were correlated with patient gender, height, weight, and body mass index (BMI). RESULTS: The mean diameter of the final graft used in the 5-strand group was 8.8 ± 0.8 mm, whereas that in the 4-strand group was 7.8 ± 0.7 mm (P < .001). The mean increase in graft size achieved with the use of the 5-strand technique was 1.4 ± 0.3 mm. In the 5-strand group, 24 of 32 (75%) patients had graft diameters exceeding 8 mm compared with 9 of 32 (28%) patients in the 4-strand group (P < .001). Quadrupled graft diameter was significantly correlated with patient height and BMI, whereas the gracilis and semitendinosus lengths were significantly correlated with patient height. CONCLUSIONS: The 5-strand hamstring autograft provides a significantly larger diameter graft compared with the quadrupled hamstring autograft in ACL reconstruction. Graft sizes exceeding 8 mm are achievable in 75% of patients with the routine application of this technique. This is significantly more than that obtained with the standard quadrupled hamstring graft. Hamstring tendon length and quadrupled hamstring graft diameter are also significantly correlated with patient height. LEVEL OF EVIDENCE: Level 1, prospective randomized controlled trial.
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Reconstrução do Ligamento Cruzado Anterior/métodos , Autoenxertos/anatomia & histologia , Tendões dos Músculos Isquiotibiais/transplante , Adulto , Feminino , Humanos , Masculino , Estudos ProspectivosRESUMO
BACKGROUND: Quadrupled (4-strand) hamstring tendon autografts are commonly used in anterior cruciate ligament (ACL) reconstruction, but there is significant variability in their diameter. The 5-strand hamstring autograft has been used as a means of increasing the graft diameter in patients with undersized hamstring grafts. PURPOSE: To report the outcomes of primary ACL reconstruction using 5-strand hamstring autografts in patients in whom the 4-strand configuration produced a graft diameter of <8 mm and to compare these outcomes with those of ACL reconstruction using 4-strand semitendinosus-gracilis autografts with a graft diameter of ≥8 mm. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The primary study group comprised 25 patients who underwent ACL reconstruction using a 5-strand hamstring autograft. The comparison group comprised 20 patients who underwent ACL reconstruction using a 4-strand hamstring autograft with a graft diameter of ≥8 mm. Interference screw fixation was used at the tibial and femoral ends for both groups of patients. Subjective questionnaires, including the Knee injury and Osteoarthritis Outcome Score (KOOS), the Lysholm score, and the Physical Component Summary and Mental Component Summary of the Short Form-36 (SF-36), were administered preoperatively as well as at 1- and 2-year follow-up visits. RESULTS: There were no significant differences in the patient demographics and preoperative scores between the 2 groups. The mean graft diameter was 9.06 ± 0.60 mm in the 5-strand group and 8.13 ± 0.32 mm in the 4-strand group (P < .05). There was no statistically significant difference between groups on postoperative Lysholm, KOOS Pain, KOOS Symptoms, KOOS Activities of Daily Living, KOOS Sports, KOOS Quality of Life, and SF-36 Physical Component Summary scores. CONCLUSION: In primary ACL reconstruction, the 5-strand hamstring autograft achieves clinical outcomes that are comparable to those of the 4-strand hamstring autograft with a graft diameter of ≥8 mm. The 5-strand graft technique is therefore a useful means of increasing the graft diameter when faced with an undersized hamstring graft.
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BACKGROUND: Chinese ethnicity is associated with the presence of knee osteoarthritis. This raises the possibility that it may similarly be associated with concomitant meniscus and cartilage injuries in patients with anterior cruciate ligament (ACL) tears. There are currently no published data on the effect of Chinese ethnicity in this regard. PURPOSE: The primary aim was to determine whether Chinese ethnicity is associated with concomitant intra-articular injuries in patients with ACL tears and to verify the correlation of age, sex, body mass index, mechanism of injury, cause of injury, and presence of bone contusions on magnetic resonance imaging with such injuries. A secondary purpose was to determine the optimal time frame for surgical reconstruction in patients with identified risk factors for concomitant injuries. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The medical records of 696 patients from a multiethnic population who underwent ACL reconstruction from January 2013 to August 2016 were retrospectively analyzed. Univariate and multivariate logistic regression analyses were performed to identify patient factors that were associated with medial meniscus tears, lateral meniscus tears, and cartilage injuries. Further univariate analysis was conducted to determine the earliest time point for surgery, after which the rate of concomitant injuries was significantly higher. RESULTS: Over half (69.1%, n = 481) of our study population sustained at least 1 other concomitant knee injury. Meniscus tears were most frequently associated with ACL tears (24.1% medial, 25.6% lateral, and 15.5% medial and lateral meniscus tears). Cartilage injuries were present in 18.4% of our cohort. Chinese ethnicity was associated with concomitant cartilage injuries. Increased age (≥30 years) was significantly associated with cartilage injuries and male sex with medial and lateral meniscus tears. Among patients with these factors, significantly fewer medial meniscus tears and cartilage injuries were noted when surgery was carried out within 12 months of the index trauma. CONCLUSION: This is one of the first studies to have identified an association between Chinese ethnicity and concomitant cartilage injuries in ACL tears. This study also found an association between increased age and an increased prevalence of cartilage injuries. Male sex was associated with both medial and lateral meniscus tears. Definitive surgery should be performed within 12 months of the index injury to minimize further intra-articular injuries.