Examining the Potential of Vitamin C Supplementation in Tissue-Engineered Equine Superficial Digital Flexor Tendon Constructs.

Because equine tendinopathies are slow to heal and often recur, therapeutic strategies are being considered that aid tendon repair. Given the success of utilizing vitamin C to promote tenogenesis in other species, we hypothesized that vitamin C supplementation would produce dose-dependent improvements in the tenogenic properties of tendon proper (TP) and peritenon (PERI) cells of the equine superficial digital flexor tendon (SDFT). Equine TP- and PERI-progenitor-cell-seeded fibrin three-dimensional constructs were supplemented with four concentrations of vitamin C. The gene expression profiles of the constructs were assessed with 3'-Tag-Seq and real-time quantitative polymerase chain reaction (RT-qPCR); collagen content and fibril ultrastructure were also analyzed. Moreover, cells were challenged with dexamethasone to determine the levels of cytoprotection afforded by vitamin C. Expression profiling demonstrated that vitamin C had an anti-inflammatory effect on TP and PERI cell constructs. Moreover, vitamin C supplementation mitigated the degenerative pathways seen in tendinopathy and increased collagen content in tendon constructs. When challenged with dexamethasone in two-dimensional culture, vitamin C had a cytoprotective effect for TP cells but not necessarily for PERI cells. Future studies will explore the effects of vitamin C on these cells during inflammation and within the tendon niche in vivo.

A combination of omega-3 and exercise reduces experimental Achilles tendinopathy induced with a type-1 collagenase in rats.

This study aimed to evaluate the effectiveness of omega-3 supplementation with exercise in a collagenase-induced Achilles tendinopathy (AT) rat model. Experimental groups (healthy control (HC), AT, exercise (Ex), omega-3 (W), and Ex+W) were randomly allocated. After a week of adaptation, oral omega-3 was initiated for 8 weeks (5 days/week). The exercise groups performed treadmill running for 30 min/day (5 days/week, 20 m/min, 8 weeks) following one week of adaptation (10 m/min, 15 min/day). Matrix metalloproteinase-13 (MMP-13), interleukin-1 beta (IL-1ß), tumor necrosis factor-alpha (TNF-α), and total antioxidant-oxidant status (TAS) levels were determined in serum samples. Tendon samples were obtained for biomechanical, histopathological, and immunohistochemical assessments. Ultimate tensile force, yield force, stiffness values, collagen type-I alpha 1 expression, and serum TAS significantly decreased (P < 0.05) in AT vs. HC. These values and expression significantly increased in the Ex+W group vs. AT. Serum MMP-13, IL-1ß, and TNF-α levels decreased in all treatment groups vs. AT. The most significant decrease was found in the Ex+W group (P < 0.01). Histopathologically, the improvement in degeneration was statistically significant in the Ex+W group (P < 0.05). Immunohistochemically, MMP-13, IL-1ß, TNF-α, and nitric oxide synthase-2 expression was decreased in all treatment groups vs. AT. In conclusion, omega-3 and exercise might be recommended in AT patients.

Photobiomodulation therapy on expression of HSP70 protein and tissue repair in experimental acute Achilles tendinitis.

The aim of the present study was to investigate the effects of photobiomodulation (PBM) therapy on the expression of heat shock protein 70 (HSP70) and tissue repair in an experimental model of collagenase-induced Achilles tendinitis. Thirty Wistar rats (aged 12 weeks) were randomly distributed among control group (n = 8), tendinitis group (n = 11), and LED group (n = 11). Tendinitis was induced in the tendinitis and LED groups through a peritendinous injection of collagenase (100 µl). The LED group animals received the first irradiation 1 h after injury. A 630 ± 20 nm, 300-mW continuous wave light-emitting diode (LED), spot size 1 cm2, was placed in contact with the skin. One point over the tendon was irradiated for 30 s, delivering 9 J (9 J/cm2). LED irradiation was performed once daily for 7 days, with the total energy delivered being 63 J. The tendons were surgically removed and expression of the HSP70 protein was calculated using semi-quantitative analyses of immunohistochemistry (HSCORE). Number of fibroblasts and amount of collagen were measured using histological and histochemical analyses. An increase in the mean HSCORE for HSP70, in the number of fibroblasts, and in the amount of collagen were found in the LED group compared with those in the tendinitis and control group (P ≤ 0.05). PBM therapy increased the expression of the HSP70, number of fibroblasts, and amount of collagen in the acute Achilles tendinitis in rats.

Molecular and Structural Effects of Percutaneous Interventions in Chronic Achilles Tendinopathy.

Achilles tendinopathy (AT) is a common problem, especially in people of working age, as well as in the elderly. Although the pathogenesis of tendinopathy is better known, therapeutic management of AT remains challenging. Various percutaneous treatments have been applied to tendon lesions: e.g., injectable treatments, platelet-rich plasma (PRP), corticosteroids, stem cells, MMP inhibitors, and anti-angiogenic agents), as well as percutaneous procedures without any injection (percutaneous soft tissue release and dry needling). In this review, we will describe and comment on data about the molecular and structural effects of these treatments obtained in vitro and in vivo and report their efficacy in clinical trials. Local treatments have some impact on neovascularization, inflammation or tissue remodeling in animal models, but evidence from clinical trials remains too weak to establish an accurate management plan, and further studies will be necessary to evaluate their value.

Photobiomodulation of Matrix Metalloproteinases in Rat Calcaneal Tendons.

Objective: The main objective was to verify the modulatory effects of MMP-1, MMP-3, and MMP-13 levels on the partially injured calcaneal tendons of rat exposure to photobiomodulation. Background: Photobiomodulation has been shown to have anti-inflammatory and regenerative effects on tendon injuries. However, there is still uncertainty regarding the beneficial effects in matrix metalloproteinase (MMP) levels, especially MMP-1, -3, and -13. Materials and methods: Sixty-five male Wistar rats were used. Sixty were submitted to a direct trauma on the calcaneal tendons and were randomly distributed into the following six groups: LASER 1, 3, and 7 (10 partially injured calcaneal tendons in each group treated with photobiomodulation for 1, 3, and 7 days, respectively) and Sham 1, 3, and 7 (same injury, with simulated photobiomodulation). The remaining five animals were allocated to the normal group (no injury or treatment procedure). The 780 nm low-level laser was applied with 70 mW of mean power and 17.5 J/cm2 of fluency for 10 sec, once a day. The tendons were surgically removed and analyzed for MMP-1, MMP-3, and MMP-13 through immunohistochemistry. Results: MMP-3 levels remained close to normal in all experimental groups (p > 0.05); however, reductions (p < 0.05) in MMP-1 and MMP-13 levels were detected in the groups submitted to one, three, and seven low level laser therapy applications. Conclusions: The photobiomodulation protocol was able to reduce MMP-1 and MMP-13 levels in injured calcaneal tendons.

Low level laser therapy accelerates the extracellular matrix reorganization of inflamed tendon.

In tendon lesions, inflammation indicates the beginning of tissue repair and influences cell proliferation and the remodeling of the extracellular matrix (ECM). Low level laser (LLL) therapy has been an important method to induce tissue repair, and several studies have sought to better understand the therapeutic possibilities of this modality. This study analyzed the effect of LLL on the ECM of rat tendons during the early phase of the inflammatory process. Wistar rats received an intratendinous application of carrageenan adjacent to the osteotendinous region in the right paw. The animals were divided into the following groups: G1-intact, G2-animals with no treatment after the inflammation induction, G3-animals treated with LLL 1 and 3h after induction of inflammation (4J/cm2 continuous). After 4h of application, the animals of the two groups were euthanized with isoflurane overdose. Our results demonstrate that LLL therapy can promote decrease in non-collagenous protein and glycosaminoglycans content, as well as an increase in metalloproteinases -9, which proved, for the first time, that LLL therapy promotes alterations in the inflamed tendons even when analyzed only four hours after this process occur and could be a useful tool to improve the balance in inflamed tissues.

MicroRNAs Associated with Shoulder Tendon Matrisome Disorganization in Glenohumeral Arthritis.

The extracellular matrix (ECM) provides core support which is essential for the cell and tissue architectural development. The role of ECM in many pathological conditions has been well established and ECM-related abnormalities leading to serious consequences have been identified. Though much has been explored in regards to the role of ECM in soft tissue associated pathologies, very little is known about its role in inflammatory disorders in tendon. In this study, we performed microRNA (miRNA) expression analysis in the long head of the human shoulder biceps tendon to identify key genes whose expression was altered during inflammation in patients with glenohumeral arthritis. We identified differential regulation of matrix metalloproteinases (MMPs) that could be critical in collagen type replacement during tendinopathy. The miRNA profiling showed consistent results between the groups and revealed significant changes in the expression of seven different miRNAs in the inflamed tendons. Interestingly, all of these seven miRNAs were previously reported to have either a direct or indirect role in regulating the ECM organization in other pathological disorders. In addition, these miRNAs were also found to alter the expression levels of MMPs, which are the key matrix degrading enzymes associated with ECM-related abnormalities and pathologies. To our knowledge, this is the first report which identifies specific miRNAs associated with inflammation and the matrix reorganization in the tendons. Furthermore, the findings also support the potential role of these miRNAs in altering the collagen type ratio in the tendons during inflammation which is accompanied with differential expression of MMPs.

Do Dietary Factors Influence Tendon Metabolism?

There is very little direct research to conclusively prove the relevance of diet in primary tendinopathies, however it seems prudent to ask whether our current knowledge about the impact of nutrition on collagen metabolism could be useful in assessing, preventing, or treating tendinopathy. The objective of this chapter is to discuss the potential impact (negative or positive) that nutrition may have on the metabolism of tendons by summarizing the related research. The chapter briefly discusses the roles that specific vitamins, amino acids, lipids, and antioxidants have in various processes of the body that may be directly or indirectly related to tenocyte metabolism.

Green Tea and Glycine Modulate the Activity of Metalloproteinases and Collagen in the Tendinitis of the Myotendinous Junction of the Achilles Tendon.

The myotendinous junction (MTJ) is the weakest element in the muscle-tendon unit of the heel, and thus the most susceptible to injuries. The scarcity of adequate treatments means that tendinitis is a major concern to athletes and other groups who depend on their physical fitness, although green tea and glycine have both been shown to have beneficial effects on the inflammation. The present study investigated the remodeling effects of green tea and glycine in the MTJ of rats with tendinitis. For this, male Wistar rats were divided into five groups: animals without tendinitis and animals with tendinitis; animals with tendinitis supplied with green tea; animals with tendinitis supplied with a glycine diet; animals with tendinitis supplied with a green tea and glycine diet. Tendinitis was induced and the treatment with green tea (700 mg/kg/day) and a 5% glycine diet lasted 7 days. The treatments regulated the activity of metalloproteinases (MMP)-2, -8, and -9, and induced the synthesis of type I collagen, glycosaminoglycans, and non-collagenous proteins. Changes were also noted in the compaction of the collagen molecules and the amount of tenocytes. When combined, green tea and glycine modulated the inflammatory process and induced the synthesis of the elements involved in the post-lesion recovery of the tissue. The data from the MTJ were different when compared with results already published using the whole Achilles tendon. These data indicate that each region of the inflamed tendon can exhibit different responses during the treatment and therefore, modify its extracellular matrix components to facilitate recovery and repair. Anat Rec, 299:918-928, 2016. © 2016 Wiley Periodicals, Inc.

The low level laser therapy (LLLT) operating in 660 nm reduce gene expression of inflammatory mediators in the experimental model of collagenase-induced rat tendinitis.

Tendinopathy is a common disease with a variety of treatments and therapies. Laser therapy appears as an alternative treatment. Here, we investigate the effects of laser irradiation in an experimental model of tendinitis induced by collagenase injection on rats' Achilles tendon, verifying its action in important inflammatory markers. Male Wistar rats were used and divided into five groups: control saline (C), non-treated tendinitis (NT) and tendinitis treated with sodium diclofenac (D) or laser (1 J) and (3 J). The tendinitis was induced by collagenase (100 µg/tendon) on the Achilles tendon, which was removed for further analyses. The gene expression for COX-2; TNF-α; IL-6; and IL-10 (RT-PCR) was measured. The laser irradiation (660 nm, 100 mW, 3 J) used in the treatment of the tendinitis induced by collagenase in Achilles tendon in rats was effective in the reduction of important pro-inflammatory markers such as IL-6 and TNF-α, becoming a promising tool for the treatment of tendon diseases.

Low-level laser therapy in IL-1ß, COX-2, and PGE2 modulation in partially injured Achilles tendon.

This study evaluated IL-1ß, COX-2, and PGE2 modulation in partially injured Achilles tendons treated with low-level laser therapy (LLLT). Sixty-five male Wistar rats were used. Sixty were submitted to a direct injury on Achilles tendon and then distributed into six groups: LASER 1 (a single LLLT application), LASER 3 (three LLLT applications), and LASER 7 (seven LLLT applications) and Sham 1, 3, and 7 (the same injury but LLLT applications were simulated). The five remaining animals were allocated at control group (no procedure performed). LLLT (780 nm) was applied with 70 mW of mean power and 17.5 J/cm(2) of fluency for 10 s, once a day. The tendons were surgically removed and assessed immunohistochemically for IL-1ß, COX-2, and PGE2. In comparisons with control (IL-1ß: 100.5 ± 92.5 / COX-2: 180.1 ± 97.1 / PGE2: 187.8 ± 128.8) IL-1ß exhibited (mean ± SD) near-normal level (p > 0.05) at LASER 3 (142.0 ± 162.4). COX-2 and PGE2 exhibited near-normal levels (p > 0.05) at LASER 3 (COX-2: 176.9 ± 75.4 / PGE2: 297.2 ± 259.6) and LASER 7 (COX-2: 259.2 ± 190.4 / PGE2: 587.1 ± 409.7). LLLT decreased Achilles tendon's inflammatory process.

Identification of differentially expressed genes and small molecule drugs for the treatment of tendinopathy using microarray analysis.

Tendinopathy is a critical clinical problem as it is often asymptomatic at onset and during development, and is only recognized upon rupture of the tendon. It is common among recreational and competitive athletes. The present study sought to examine the molecular mechanism of the progression of tendinopathy by screening out differentially expressed genes (DEGs) and investigating their functions. In addition, the present study aimed to identify the small molecules, which exhibit potential effects, which could be utilized for the treatment of tendinopathy. The gene expression profile of tendinopathy, GSE26051 was downloaded from the Gene Expression Omnibus database, which included 23 control samples and 18 samples of tendinopathy. The DEGs were identified using the Limma package in the R programming language, and gene ontology and pathway enrichment analysis were performed. In addition, the potential regulatory microRNAs and the target sites of the transcription factors were screened out based on the molecular signature database. In addition, the DEGs were mapped to the connectivity map database to identify the potential small molecule drugs. A total of 318 genes were filtered as DEGs between diseased samples and normal control tendons. Additionally, genes, including laminin, α4, platelet­derived growth factor α, laminin γ1 and Src homology 2 transforming protein 1 may induce tendinopathy through the focal adhesion pathway. Furthermore, the transcription factor, lymphoid enhancer­binding factor 1 and its target genes, pantothenate kinase 2 and G protein­coupled receptor kinase 5 were identified. The most significant microRNA, miR­499, was screened and was found to regulate specific genes, including CUGBP2 and MYB. Additionally, the small molecules, Prestwick­1082 and viomycin were identified to have the potential to repair disordered metabolic pathways and furthermore to remedy tendinopathy. The results of the present study assessed the mechanism of tendinopathy and screened small molecule drugs as potential treatments for this condition. In addition, the present findings have the potential for use in a clinical setting for the treatment of tendinopathy in the future.

Effects of low-power LED and therapeutic ultrasound in the tissue healing and inflammation in a tendinitis experimental model in rats.

This work evaluated the anti-inflammatory response of low-power light-emitting diode (LED) and ultrasound (US) therapies and the quality and rapidness of tendon repair in an experimental model of tendinitis, employing histomorphometry and Raman spectroscopy. Tendinitis was induced by collagenase into the right tendon of 35 male Wistar rats with an average weight of 230 g. The animals were randomly separated into seven groups of five animals each: tendinitis without treatment-control (TD7 and TD14, where 1 and 2 indicated sacrifice on the 7th and 14th day, respectively), tendinitis submitted to US therapy (US7 and US14) and tendinitis submitted to LED therapy (LED7 and LED14). Contralateral tendons of the TD group at the 14th day were used as the healthy group (H). US treatment was applied in pulsed mode at 10 %, 1 MHz frequency, 0.5 W/cm(2), 120 s. LED therapy parameters were 4 J/cm(2), 120 s, daily dose at the same time and same point. Sacrifice was performed on the 7th or 14th day. Histomorphometric analysis showed lower number of fibroblasts on the 14th day of therapy for the US-treated group, compared to the TD and LED, indicating lower tissue inflammation. Raman showed that the LED group had an increase in the amount of collagen I and III from the 7th to the 14th day, which would indicate more organized fibers and a better quality of the healing, and US showed lower collagen I synthesis in the 14th day compared to H, indicating a lower tissue reorganization.

Low-level laser therapy (LLLT; 780 nm) acts differently on mRNA expression of anti- and pro-inflammatory mediators in an experimental model of collagenase-induced tendinitis in rat.

Low-level laser therapy (LLLT) has been found to produce anti-inflammatory effects in a variety of disorders. Tendinopathies are directly related to unbalance in expression of pro- and anti-inflammatory cytokines which are responsible by degeneration process of tendinocytes. In the current study, we decided to investigate if LLLT could reduce mRNA expression for TNF-α, IL-1ß, IL-6, TGF-ß cytokines, and COX-2 enzyme. Forty-two male Wistar rats were divided randomly in seven groups, and tendinitis was induced with a collagenase intratendinea injection. The mRNA expression was evaluated by real-time PCR in 7th and 14th days after tendinitis. LLLT irradiation with wavelength of 780 nm required for 75 s with a dose of 7.7 J/cm(2) was administered in distinct moments: 12 h and 7 days post tendinitis. At the 12 h after tendinitis, the animals were irradiated once in intercalate days until the 7th or 14th day in and them the animals were killed, respectively. In other series, 7 days after tendinitis, the animals were irradiated once in intercalated days until the 14th day and then the animals were killed. LLLT in both acute and chronic phases decreased IL-6, COX-2, and TGF-ß expression after tendinitis, respectively, when compared to tendinitis groups: IL-6, COX-2, and TGF-ß. The LLLT not altered IL-1ß expression in any time, but reduced the TNF-α expression; however, only at chronic phase. We conclude that LLLT administered with this protocol reduces one of features of tendinopathies that is mRNA expression for pro-inflammatory mediators.

Diabetes and rheumatic diseases.

PURPOSE OF REVIEW: This review summarizes recent advances in the field of diabetes and rheumatic disease. These conditions exert a significant healthcare burden on our society and much remains to be learned regarding their pathophysiology and treatment. RECENT FINDINGS: We summarize new insights into diabetes and its association with osteoarthritis, rheumatoid arthritis, carpal tunnel syndrome, osteoporosis, diffuse idiopathic skeletal hyperostosis, crystalline arthropathy, neuropathic arthropathy, and tendinopathy. Diabetes has major effects on connective tissues, which have significant impact on both the development and outcome of these diseases of cartilage, bone, ligament, and tendon. An improved understanding of the mechanisms through which diabetes alters connective tissue metabolism should lead to better preventive and therapeutic interventions. SUMMARY: Incremental progress has been made in understanding the interactions between diabetes and common musculoskeletal syndromes. Although this review highlights exciting areas of future interest, more work in this field is certainly warranted.

[Hydroxyapatite rheumatism (multiple tendon calcification disease). II. - Microscopic study - HL-A antigen - Experimental arthritis - Pathogeny]. / Le rhumatisme à hydroxyapatite (la maladie des calcifications tendineuses multiples). II - Etude microscopique - Antigène HLA - Arthrite expérimentale - Pathogénie.

Optical and electron microscopic studies of the articular fluid in multiple calcification disease reveals the existence of rounded intra- and extracellular crystalline formations. These crystalline formations of calcium and phosphorus are made up of accumulations of tiny crystals shaped like fine needles 200 nm X 15-20 nm and are highly suggestive of hydroxyapatite. Crystals injected into the plantar pads of rats or the knees of rabbits induce an acute inflammatory reaction maximal at 5 hours and recovering in 24 72 hours. Hydroxyapatite crystals are swiftly dissolved in serum and more rapidly still when cells are present. Their dissolution releases calcium into the surrounding area. HLA typing of patients with multiple tendinous calcification (28 cases) or single tendinous calcification (10 cases) shows an increased frequency of HLA A2 and BW 35 in comparison with controls.