Growth factors expression and ultrastructural morphology after application of low-level laser and natural latex protein on a sciatic nerve crush-type injury

Author(s)

Jose Dias, Fernando ^[1] ; Sassoli Fazan, Valeria Paula ^[2] ; Cury, Diego Pulzatto ^[3] ; Yokomizo de Almeida, Sonia Regina ^[3] ; Borie, Eduardo ^[1] ; Fuentes, Ramon ^[1] ; Coutinho-Netto, Joaquim ^[4] ; Watanabe, Ii-sei ^[3]

Affiliation

^[1] Univ La Frontera, Dent Sch, CICO Res Ctr Dent Sci, Dept Integral Dent, Temuco - Chile

^[2] Univ Sao Paulo, Dept Surg & Anat, Sch Med Ribeirao Preto, Ribeirao Preto - Brazil

^[3] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, Sao Paulo - Brazil

^[4] Univ Sao Paulo, Dept Pharmacol, Sch Med Ribeirao Preto, Ribeirao Preto - Brazil

• Document type: Journal article
• Source: PLoS One; v. 14, n. 1 JAN 9 2019.
• Web of Science Citations: 1

Abstract

The effects of low-level laser therapy (LLLT) and natural latex protein (F1, Hevea brasiliensis) were evaluated on crush-type injuries (15kg) to the sciatic nerve in the expressions of nerve growth factor (NGF) and vascular endothelium growth factor (VEGF) and ultrastructural morphology to associate with previous morphometric data using the same protocol of injury and treatment. Thirty-six male rats were allocated into six experimental groups (n = 6): 1-Control; 2-Exposed nerve; 3-Injured nerve; 4-LLLT (15J/cm(2), 780nm, 30mW, Continuous Wave) treated injured nerve; 5-F1 (0,1mg) treated injured nerve; and 6-LLLT\&F1 treated injured nerve. Four or eight weeks after, sciatic nerve samples were processed for analysis. NGF expression were higher (p<0.05) four weeks after in all injured groups in comparison to Control (Med: 0.8; Q1:0; Q3:55.5% area). Among them, the Injured (Med:70.7; Q1:64.4; Q3:77.5% area) showed the highest expression, and F1 (Med: 17.3; Q1:14.1; Q3:21.7% area) had the lowest. At week 8, NGF expressions decreased in the injured groups. VEGF was expressed in all groups; its higher expression was observed in the injured groups 4 weeks after (Injured. Med: 29.5; F1. Med:17.7 and LLLT\&F1. Med:19.4% area). At week 8, a general reduction of VEGF expression was noted, remaining higher in F1 (Med:35.1; Q1.30.6; Q3.39.6% area) and LLLT\&F1 (Med:18.5; Q1:16; Q3:25% area). Ultrastructural morphology revealed improvements in the treated groups; 4 weeks after, the F1 group presented greater quantity and diameter of the nerve fibers uniformly distributed. Eight weeks after, the F1 and LLLT\&F1 showed similar characteristics to the non-injured groups. In summary, these results and our previous studies indicated that F1 and LLLT may favorably influence the healing of nerve crush injury. Four weeks after nerve injury F1 group showed the best results suggesting recovery acceleration; at 8th week F1 and LLLT\& F1 groups presented better features and higher vascularization that could be associated with VEGF maintenance. (AU)

• FAPESP's process: 14/07253-4 - Effect of the association between the low-level laser and the purified protein from natural latex (Hevea brasiliensis) on the crush injured sciatic nerve in wistar rats: functional, sensorial, morphometric and ultrastructural study
• Grantee: Fernando José Dias
• Support type: Scholarships in Brazil - Post-Doctorate