Glycine improves the remodeling process of tenocytes in vitro

Abstract

Tendinitis changes the biochemical and morphological properties of the tendon, promoting an increase of activity of metalloproteinases and disorganization of collagen bundles. Tenocytes, the primary cells in tendon, are scattered throughout the collagenic fibers, and are responsible of tendon remodeling and tissue repair in pathological condition. In vivo, glycine, component of the typical Gly-X-Y collagen tripeptide, showed beneficial effects in biochemical and biomechanical properties of Achilles tendon with tendinitis. In this study, we analyzed the effect of glycine in tenocytes subjected to inflammation. Tenocytes from Achilles tendon of rats were treated with TNF-α (10 ng/mL) with and without previous treatment with glycine (20 mM). Cell proliferation and migration were evaluated, as well as the expression of matrix molecules such as glycosaminoglycans, metalloproteinases (MMPs), TIMPs, and collagen I. Glycine can revert the inflammation due to the action of TNF-α by controlling the MMPs quantity and activity. These data indicated that the molecules involved to remodeling process of extracellular matrix are modulated both by TNF-α and the availability of collagen precursors; in fact, this study indicates the glycine can be useful for treatment of inflammation and for modulating tenocytes metabolism in tendons.

The effects of collagen peptide supplementation on body composition, collagen synthesis, and recovery from joint injury and exercise: a systematic review

“…The participants were able to return to running after the treatment but did not reach preinjury levels within the duration of the study. The COL used contained 22% glycine, which is known to enhance collagen matrix organisation strength, reduce inflammation and influence tenocyte metabolism in tendons (Vieira et al 2018). The eccentric training protocol used may have also improved the tendon structure and reduced neovascularization (associated with tendinosis; Ohberg and Alfredson 2004).…”

Oral Supplementation of Specific Collagen Peptides Combined with Calf-Strengthening Exercises Enhances Function and Reduces Pain in Achilles Tendinopathy Patients

“…These clinical findings extend on two earlier studies [32,33], that reported respectively a pain modulating and in vitro anti-inflammatory effect of a nutraceutical containing collagen, mucopolysaccharides and vitamin C. Furthermore, in a rodent model of collagenase-induced Achilles tendinopathy, a 5% glycine-rich diet for 3 weeks improved hydroxyproline, glyosaminoglycans and non-collagenous protein content of the Achilles tendon [12]. Glycine has also been shown to improve collagen matrix organisation strength and tenocyte remodelling, most likely by modulating both TNF-alpha, matrix metalloproteases and the availability of collagen precursors [14]. As the sCP supplement in the present study contains 22% of glycine [11], it could be postulated that the increased intake of 1.1 g of glycine per day may have contributed to observed clinical improvements in VISA-A scores during sCP supplementation.…”

“…Although clinical studies are still scarce, a recent International Olympic Committee (IOC) consensus statement on dietary supplements in high-performance athletes [6] proposes that dietary supplementation containing gelatin or hydrolysed collagen could potentially be useful for athletic populations as increased intake of collagen-derived peptides has been shown to modulate collagen synthesis [7] and reduce tendon- [8] and joint-related pain [9,10]. Others have shown that glycine, as the most abundant component of collagen hydrolysates [11], has disease-modifying properties in both animal [12,13] and in vitro [14] models of tendinopathy. There is also first evidence, that collagen peptides might improve functional ankle properties in chronic ankle instability [15].…”

From the perspective of embryonic tendon development: various cells applied to tendon tissue engineering

“…Tenocytes are highly specialized mesenchyme-derived cells with important roles in synthesizing ECM and maintaining tendon structures in vivo (23). Cao et al constructed tissueengineered artificial tendons for the first time (24), but they also indicated that tenocytes are relatively difficult to grow and expand in vitro.…”

“…Thus, many researchers have explored the strategies to promote proliferation and at the same time, support a stable phenotype of tenocytes. At present, it has been reported that thyroid hormone T3, transforming growth factor (TGF)-b1, glycine, platelet-rich plasma, and insulinlike growth factor 1 could enhance the proliferation and differentiation capacity of tenocytes, as well as stimulate the secretion of ECM (23,(26)(27)(28)(29). Mechanical force can also regulate tenocyte differentiation (30).…”