Response of macrophages in rat skeletal muscle after eccentric exercise

Purpose： Macrophages are known to be important for healing numerous injured tissues depending on their functional phenotypes in response to different stimuli. The objective of this study was to reveal macrophage phenotypic changes involved in exercise-induced skeletal muscle injury and regeneration. Methods： Adult male Sprague-Dawley rats experienced one session of downhill running （16~ decline, 16 m/min） for 90 min. After exercise the blood and soleus muscles were collected at 0 h, 6 h, 12 h, 1 d, 2 d, 3 d, 1 w and 2 w after exercise, separately. Results： It was showed that CD6B＋ M1 macrophages mainly infiltrated into musc｜e necrotic sites at 1-3 d, while CD163＋ M2 macrophages were present in muscles from 0 h to 2 weeks after exercise. Using transmission electron microscopy, we observed activated satellite cells 1 d after exercise. Thl-associated transcripts of iNOS and Cc12 were inhibited post exercise, while COX-2 mRNA was dramatically increased 12 h after running （p 〈 0.01 ）. M2 phenotype marker Arg-1 increased 12 h and 3 d （p 〈 0.05, p 〈 0.01 ） after exercise, and Clecl0a and Mrc2 were up-regulated in muscles 12 h following exercise （p 〈 0.05, p 〈 0.05）. Conclusion： The data demonstrate the dynamic patterns of macrophage phenotype in skeletal muscle upon eccentric exercise stimuli, and M1 and M2 phenotypes perform different functions during exercise- induced skeletal muscle injury and recovery.

Differentially expressed proteins on postoperative 3 days healing in rabbit Achilles tendon rupture model after early kinesitherapy

Objectives： Surgical repair of Achilles tendon （AT） rupture should immediately be followed by active tendon mobilization. The optimal time as to when the mobilization should begin is important yet controversial. Early kinesitherapy leads to reduced rehabilitation period. However, an insight into the detailed mechanism of this process has not been gained. Proteomic technique can be used to separate and purify the proteins by differential expression profile which is related to the function of different proteins, but research in the area of proteomic analysis of AT 3 days after repair has not been studied so far. Methods： Forty-seven New Zealand white rabbits were randomized into 3 groups. Group A （immobilization group, n=l 6） received postoperative cast immobilization; Group B （early motion group, n= 16） received early active motion treatments immediately following the repair of AT rupture from tenotomy. Another 15 rabbits served as control group （Group C）. The AT samples were prepared 3 days following the microsurgery. The proteins were separated employing two- dimensional polyacrylamide gel electrophoresis （2D-PAGE）. PDQuest software version 8.0 was used to identify differentially expressed proteins, followed by peptide mass fingerprint （PMF） and tandem mass spectrum analysis, using the National Center for Biotechnology Information （NCBI） protein database retrieval and then for bioinformatics analysis. Results： Amean of 446.33,436.33 and 462.67 protein spots on Achilles tendon samples of 13 rabbits in Group A, 14 rabbits in Group B and 13 rabbits in Group C were suc- cessfully detected in the 2D-PAGE. There were 40, 36 and 79 unique proteins in Groups A, B and C respectively. Some differentially expressed proteins were enzyme with the gel, matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS）. We successfully identified 9 and 11 different proteins in Groups A and B, such as GAPDH, phosphoglycerate kinase 1, pro-alpha-1 type 1 collagen, peroxiredoxin 1, alpha-l-antiproteinase E a-1 and MAD2L1 binding protein, etc. And some with the molecular chaperone, oxidative stress, energy metabolism, signal transduetion, coupled with the tendon cell expression and protein synthesis, proliferate, differentiate and are closely related to the AT healing. The GAPDH protein was further validated through Western blotting. It was indicated that some differentially expressed proteins were involved in various metabolism pathways and may play an important role in initial healing of AT rupture. Conclusion： Differentially expressed proteins in rabbit healing AT model may contribute to 3 days healing of AT rupture through a new mechanobiological mechanism due to the application of postoperative early kinesitherapy.

Combined extracorporeal shockwave therapy and exercise for the treatment of tendinopathy:A narrative review

Tendinopathy is a chronic degenerative musculoskeletal disorder that is common in both athletes and the general population.Exercise and extracorporeal shockwave therapy(ESWT)is among the most common treatments used to mediate tendon healing and regeneration.The review presents the current understanding of mechanisms of action of ESWT and exercise in isolation and briefly synthesises evidence of their effectiveness for various tendinopathies.The central purpose of the review is to synthesize research findings investigating the combination of ESWT and exercise for five common tendinopathies(plantar heel pain,rotator cuff,lateral elbow,Achilles,and patellar tendinopathy)and provide recommendations on clinical applicability.Collectively,the available evidence indicates that ESWT combined with exercise in the form of eccentric training,tissue-specific stretching,or heavy slow resistance training are effective for specific tendinopathies and can therefore be recommended in treatment.Whilst there are at present a limited number of studies investigating combined EWST and exercise approaches,there is evidence to suggest that the combination improves outcomes in the treatment of plantar heel pain,Achilles,lateral elbow,and rotator cuff tendinopathy.However,despite overall positive outcomes in patellar tendinopathy,the combined treatment has not been shown at present to offer additional benefit over eccentric exercise alone.