Low-level laser and adipose-derived stem cells altered remodelling genes expression and improved collagen reorganization during tendon repair.

Letícia D Lucke,André L Bombeiro,Viviane Theodoro,Edson R Pimentel,Luciana P Cartarozzi,Marcelo A M Esquisatto,Maíra Felonato,Fernanda A S Mendonça,Lucas Fujii,Alexandre L R Oliveira,Giane D Carneiro,Cristina Pontes Vicente,Andrea A De Aro,Rodrigo A Dalia,Fernanda O Bortolazzo

doi:10.1111/cpr.12580

Abstract

ObjectivesThe cellular therapy using adipose‐derived mesenchymal stem cells (ASCs) aims to improve tendon healing, considering that repaired tendons often result in a less resistant tissue. Our objective was to evaluate the effects of the ASCs combination with a low‐level laser (LLL), an effective photobiostimulation for the healing processes.Materials and methodsRats calcaneal tendons were divided into five groups: normal (NT), transected (T), transected and ASCs (SC) or LLL (L), or with ASCs and LLL (SCL).ResultsAll treated groups presented higher expression of Dcn and greater organization of collagen fibres. In comparison with T, LLL also up‐regulated Gdf5 gene expression, ASCs up‐regulated the expression of Tnmd, and the association of LLL and ASCs down‐regulated the expression of Scx. No differences were observed for the expression of Il1b, Timp2, Tgfb1, Lox, Mmp2, Mmp8 and Mmp9, neither in the quantification of hydroxyproline, TNF‐α, PCNA and in the protein level of Tnmd. A higher amount of IL‐10 was detected in SC, L and SCL compared to T, and higher amount of collagen I and III was observed in SC compared to SCL.ConclusionsTransplanted ASCs migrated to the transected region, and all treatments altered the remodelling genes expression. The LLL was the most effective in the collagen reorganization, followed by its combination with ASCs. Further investigations are needed to elucidate the molecular mechanisms involved in the LLL and ASCs combination during initial phases of tendon repair.

Highlights

The calcaneus tendon is one of the most affected tendons by rup‐ tures, and its recovery after an injury turns to be a challenge in the current clinical practice.[1]
A previous study of our group has shown the presence of transplanted adipose‐derived mesenchymal stem cells (ASCs) on 3rd and 14th days after tendon transection, probably in response to the intense initial inflammatory process.[19]
No differ‐ ences were observed in the expression of Tgfb[1] among groups, but the higher concentration of IL‐10 in the suture; ASC (SC) group corroborates the During the calcaneus tendon repair using level laser (LLL), a study of Abid and Abid[31] demonstrated a higher collagen deposition and signifi‐ cant number of tenocytes

Summary

| INTRODUCTION

The calcaneus tendon is one of the most affected tendons by rup‐ tures, and its recovery after an injury turns to be a challenge in the current clinical practice.[1]. In certain regions of the tendons, especially where there is ac‐ cumulation of specific growth factors, there are mesenchymal stem cells (MSCs) native to the tissue. These cells decrease with age,[4] and factors such as obesity, diabetes and hormonal changes influence their proliferative and differentiation capacity.[5]. The objective of the present study was to analyse the effects of the as‐ sociation of LLL (808 nm) to cell therapy with ASCs, especially on remodelling genes and on the recovery of the collagen fibres, at the 14th day of the calcaneus tendon repair

| MATERIALS AND METHODS

Findings

| DISCUSSION