CN violet-band emission as a time-resolved optical probe of transient temperature induced by laser ablation of type I collagen from bovine Achilles tendon

Human connective tissue, e.g., tendon, responds dynamically to physical activity, with collagen synthesis being increased after both acute and prolonged exercise or training. Markers of collagen synthesis and degradation as well as concentration of several potential growth factors have been shown to increase markedly in the peritendinous tissue around the human Achilles tendon following exercise. Of these potential growth factors interleukin-6 (IL-6) showed the largest fold increase, suggesting that IL-6 may be involved in transforming mechanical loading into collagen synthesis in human tendon tissue. In the present study the tissue levels of type I collagen turnover markers [procollagen type I NH2-terminal propeptide (PINP) and C-OOH terminal telopeptide of type I collagen (ICTP)] were measured by the use of microdialysis in peritendinous tissue of the Achilles tendon in 14 male volunteers, who had recombinant human IL-6 (rhIL-6) infused into the peritendinous tissue of the Achilles' tendon in one leg, with the other leg serving as control. Subjects were randomly assigned to either a resting group or an exercise group performing a 1-h treadmill run (12 km/h, 2% uphill) before infusion. In addition to IL-6, serum concentrations of collagen turnover markers PINP, ICTP, and COOH-terminal telopeptide of type I collagen (ICTX) were measured. The peritendinous concentration of PINP rose markedly in response to rhIL-6 infusion in both the exercise and the rest group, demonstrating that infusion of IL-6 significantly stimulates collagen synthesis in the peritendinous tissue in humans. Exercise alone did not result in an increased collagen synthesis. This indicates that IL-6 is involved in the collagen synthesis and supports the hypothesis that IL-6 is an important growth factor of the connective tissue in healthy human tendons.

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Low-level laser irradiation promotes cell proliferation and mRNA expression of type I collagen and decorin in porcine achilles tendon fibroblastsIn Vitro

Journal of Orthopaedic Research® ◽

10.1002/jor.20800 ◽

2009 ◽

Vol 27 (5) ◽

pp. 646-650 ◽

Cited By ~ 38

Author(s):

Chia-Hsin Chen ◽

Jin-Lian Tsai ◽

Yan-Hsiung Wang ◽

Chia-Ling Lee ◽

June-Kai Chen ◽

...

Keyword(s):

Cell Proliferation ◽

Achilles Tendon ◽

Mrna Expression ◽

Laser Irradiation ◽

Type I Collagen ◽

Type I ◽

Low Level ◽

Low Level Laser ◽

Level Laser ◽

Low Level Laser Irradiation

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Effects of long-term immobilization and recovery on human triceps surae and collagen turnover in the Achilles tendon in patients with healing ankle fracture

Journal of Applied Physiology ◽

10.1152/japplphysiol.00201.2008 ◽

2008 ◽

Vol 105 (2) ◽

pp. 420-426 ◽

Cited By ~ 24

Author(s):

Britt Christensen ◽

Eva Dyrberg ◽

Per Aagaard ◽

Susanne Enehjelm ◽

Michael Krogsgaard ◽

...

Keyword(s):

Connective Tissue ◽

Achilles Tendon ◽

Ankle Fracture ◽

Collagen Synthesis ◽

Type I Collagen ◽

Calf Muscle ◽

Triceps Surae ◽

Type I ◽

Collagen Turnover ◽

Synthesis And Degradation

The aim of the present study was to analyze how human tendon connective tissue responds to an ∼7-wk period of immobilization and a remobilization period of a similar length, in patients with unilateral ankle fracture, which is currently unknown. Calf muscle cross-sectional area (CSA) decreased by 15% (5,316 to 4,517 mm2) and strength by 54% (239 to 110 N·m) in the immobilized leg after 7 wk. During the 7-wk remobilization, the CSA increased by 9% (to 4,943 mm2) and strength by 37% (to 176 Nm). Achilles tendon CSA did not change significantly during either immobilization or remobilization. Local collagen turnover was measured as the peritendinous concentrations of NH2-terminal propeptide of type I collagen (PINP) and COOH-terminal telopeptide region of type I collagen (ICTP), markers thought to be indexes of type I collagen synthesis and degradation, respectively. Both markers were increased (PINP: 257 vs. 56 ng/ml; ICTP: 9.8 vs. 2.1 μg/l) in the immobilized leg compared with the control leg after the 7 wk of immobilization, and levels decreased again in the immobilized leg during the recovery period (PINP: 103 vs. 44 ng/ml; ICTP: 4.2 vs. 1.9 μg/l). A significant reduction in calf muscle CSA and strength was found in relation to 7 wk of immobilization. Immobilization increased both collagen synthesis and degradation in tendon near tissue. However, it cannot be excluded that the facture of the ankle in close proximity could have affected these data. Remobilization increased muscle size and strength and tendon synthesis and degradation decreased to baseline levels. These dynamic changes in tendon connective tissue turnover were not associated with macroscopic changes in tendon size.

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The effects of high glucose condition on rat tenocytesin vitroand rat Achilles tendonin vivo

Bone and Joint Research ◽

10.1302/2046-3758.75.bjr-2017-0126.r2 ◽

2018 ◽

Vol 7 (5) ◽

pp. 362-372 ◽

Cited By ~ 8

Author(s):

Y. Ueda ◽

A. Inui ◽

Y. Mifune ◽

R. Sakata ◽

T. Muto ◽

...

Keyword(s):

Cell Proliferation ◽

Achilles Tendon ◽

High Glucose ◽

Type I Collagen ◽

Diabetic Rats ◽

Type I ◽

High Glucose Condition ◽

Glucose Condition

ObjectivesThe aim of this study was to investigate the effect of hyperglycaemia on oxidative stress markers and inflammatory and matrix gene expression within tendons of normal and diabetic rats and to give insights into the processes involved in tendinopathy.MethodsUsing tenocytes from normal Sprague-Dawley rats, cultured both in control and high glucose conditions, reactive oxygen species (ROS) production, cell proliferation, messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4, interleukin-6 (IL-6), matrix metalloproteinase (MMP)-2, tissue inhibitors of matrix metalloproteinase (TIMP)-1 and -2 and type I and III collagens were determined after 48 and 72 hours in vitro. In an in vivo study, using diabetic rats and controls, NOX1 and 4 expressions in Achilles tendon were also determined.ResultsIn tenocyte cultures grown under high glucose conditions, gene expressions of NOX1, MMP-2, TIMP-1 and -2 after 48 and 72 hours, NOX4 after 48 hours and IL-6, type III collagen and TIMP-2 after 72 hours were significantly higher than those in control cultures grown under control glucose conditions. Type I collagen expression was significantly lower after 72 hours. ROS accumulation was significantly higher after 48 hours, and cell proliferation after 48 and 72 hours was significantly lower in high glucose than in control glucose conditions. In the diabetic rat model, NOX1 expression within the Achilles tendon was also significantly increased.ConclusionThis study suggests that high glucose conditions upregulate the expression of mRNA for NOX1 and IL-6 and the production of ROS. Moreover, high glucose conditions induce an abnormal tendon matrix expression pattern of type I collagen and a decrease in the proliferation of rat tenocytes. Cite this article: Y. Ueda, A. Inui, Y. Mifune, R. Sakata, T. Muto, Y. Harada, F. Takase, T. Kataoka, T. Kokubu, R. Kuroda. The effects of high glucose condition on rat tenocytes in vitro and rat Achilles tendon in vivo. Bone Joint Res 2018;7:362–372. DOI: 10.1302/2046-3758.75.BJR-2017-0126.R2

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Pefloxacin-Induced Achilles Tendon Toxicity in Rodents: Biochemical Changes in Proteoglycan Synthesis and Oxidative Damage to Collagen

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.4.867-872.2000 ◽

2000 ◽

Vol 44 (4) ◽

pp. 867-872 ◽

Cited By ~ 64

Author(s):

Marie-Agnes Simonin ◽

Pascale Gegout-Pottie ◽

Alain Minn ◽

Pierre Gillet ◽

Patrick Netter ◽

...

Keyword(s):

Oxidative Damage ◽

Achilles Tendon ◽

Type I Collagen ◽

Ex Vivo ◽

Proteoglycan Synthesis ◽

Type I ◽

Carbonyl Derivative ◽

Low Incidence ◽

Serum Sulfate

ABSTRACT Despite a relatively low incidence of serious side effects, fluoroquinolones and the fluoroquinolone pefloxacin have been reported to occasionally promote tendinopathy that might result in the complication of spontaneous rupture of tendons. In the present study, we investigated in rodents the intrinsic deleterious effect of pefloxacin (400 mg/kg of body weight) on Achilles tendon proteoglycans and collagen. Proteoglycan synthesis was determined by measurement of in vivo and ex vivo radiosulfate incorporation in mice. Collagen oxidative modifications were measured by carbonyl derivative detection by Western blotting. An experimental model of tendinous ischemia (2 h) and reperfusion (3 days) was achieved in rats. Biphasic changes in proteoglycan synthesis were observed after a single administration of pefloxacin, consisting of an early inhibition followed by a repair-like phase. The depletion phase was accompanied by a marked decrease in the endogenous serum sulfate level and a concomitant increase in the level of sulfate excretion in urine. Studies of ex vivo proteoglycan synthesis confirmed the in vivo results that were obtained. The decrease in proteoglycan anabolism seemed to be a direct effect of pefloxacin on tissue metabolism rather than a consequence of the low concentration of sulfate. Pefloxacin treatment for several days induced oxidative damage of type I collagen, with the alterations being identical to those observed in the experimental tendinous ischemia and reperfusion model. Oxidative damage was prevented by coadministration of N-acetylcysteine (150 mg/kg) to the mice. These results provide the first experimental evidence of a pefloxacin-induced oxidative stress in the Achilles tendon that altered proteoglycan anabolism and oxidized collagen.

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Collagen fibrillogenesis in vitro: interaction of types I and V collagen

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100142670 ◽

1986 ◽

Vol 44 ◽

pp. 210-211

Author(s):

Arthur J. Wasserman ◽

Kathy C. Kloos ◽

David E. Birk

Keyword(s):

Type I Collagen ◽

Corneal Stroma ◽

Minor Component ◽

Homogeneous Distribution ◽

Type I ◽

Type V Collagen ◽

Fibril Morphology ◽

Type V ◽

In Vitro Interaction

Type I collagen is the predominant collagen in the cornea with type V collagen being a quantitatively minor component. However, the content of type V collagen (10-20%) in the cornea is high when compared to other tissues containing predominantly type I collagen. The corneal stroma has a homogeneous distribution of these two collagens, however, immunochemical localization of type V collagen requires the disruption of type I collagen structure. This indicates that these collagens may be arranged as heterpolymeric fibrils. This arrangement may be responsible for the control of fibril diameter necessary for corneal transparency. The purpose of this work is to study the in vitro assembly of collagen type V and to determine whether the interactions of these collagens influence fibril morphology.

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