Conjugation with Methylsulfonylmethane Improves Hyaluronic Acid Anti-Inflammatory Activity in a Hydrogen Peroxide-Exposed Tenocyte Culture In Vitro Model

Abstract

Rotator cuff tears (RCTs) and rotator cuff disease (RCD) are important causes of disability in middle-aged individuals affected by nontraumatic shoulder dysfunctions. Our previous studies have demonstrated that four different hyaluronic acid preparations (HAPs), including Artrosulfur® hyaluronic acid (HA) (Alfakjn S.r.l., Garlasco, Italy), may exert a protective effect in human RCT-derived tendon cells undergoing oxidative stress damage. Recently, methylsulfonylmethane (MSM) (Barentz, Paderno Dugnano, Italy) has proven to have anti-inflammatory properties and to cause pain relief in patients affected by tendinopathies. This study aims at evaluating three preparations (Artrosulfur® HA, MSM, and Artrosulfur® MSM + HA) in the recovery from hydrogen peroxide-induced oxidative stress damage in human tenocyte. Cell proliferation, Lactate Dehydrogenase (LDH) release, and inducible nitric oxide synthases (iNOS) and prostaglandin E2 (PGE2) modulation were investigated. In parallel, expression of metalloproteinases 2 (MMP2) and 14 (MMP14) and collagen types I and III were also examined. Results demonstrate that Artrosulfur® MSM + HA improves cell escape from oxidative stress by decreasing cytotoxicity and by reducing iNOS and PGE2 secretion. Furthermore, it differentially modulates MMP2 and MMP14 levels and enhances collagen III expression after 24 h, proteins globally related to rapid acceleration of the extracellular matrix (ECM) remodelling and thus tendon healing. By improving the anti-cytotoxic effect of HA, the supplementation of MSM may represent a feasible strategy to ameliorate cuff tendinopathies.

Dual Acting Carbon Monoxide Releasing Molecules and Carbonic Anhydrase Inhibitors Differentially Modulate Inflammation in Human Tenocytes

“…Western blot analysis reveals a robust iNOS expression in the DMSO control, accordingly to our previous results [ 4 ]. Intriguingly, the presence of Cmp 2 dramatically raises iNOS expression whereas it is only weakly expressed in the presence of Cmp 7 .…”

“…The analyses of molecules related to the redox equilibrium and to senescence have partly clarified the molecular mechanisms underlying the biological observations obtained with compounds 2 and 7 . It is broadly known that nitric oxide (NO) plays a relevant role in repairing an injured tendon [ 33 ] and our previous work reported a role of inducible nitric oxide synthase (iNOS) in tenocytes under oxidative stress conditions [ 4 ]. Thus, expression levels of iNOS were quantified in the presence of compounds 2 and 7 ( Figure 8 ).…”

“…Human tenocytes isolated from rotator cuff tendons, obtained from the same 10 donors after their informed consent, described in our previous work [ 3 , 4 , 5 , 21 , 22 ], and cryopreserved in vials in liquid nitrogen, were used. Biopsies were harvested from the healthy tissue close to the surgical site.…”

“…The CytoTox 96 ® non-radioactive kit measures the amount of LDH released upon cell lysis using a 30-min coupled enzymatic assay. The assay was carried out as previously reported [ 4 ].…”

“…Intrinsic factors (age or gender), extrinsic factors (sports activity or occupational exposure), and biological factors were identified in the onset and progression of RCTs and RCD [ 2 ]. Our group has reported evidence of a significant change in the modulation of pro-inflammatory cytokine secretion and related molecular cell signaling during rotator cuff tendinopathies [ 3 , 4 ]. In these investigations, it has been highlighted that tendon-derived cells escape from oxidative stress and consequently from apoptosis by reducing prostaglandin (PGE2) secretion [ 4 ] and by activating the nuclear factor erythroid 2-related factor (Nrf2)-related pathways [ 5 ].…”