Effects of low-dose T-2 toxin on cultured cartilage cells and molecular mechanism / 中华地方病学杂志

ABSTRACT

Objective Through observing the effect of low-dose T-2 toxin on chondrocyte,to study the molecular mechanism of cartilage damage.Methods The primary chondrocytes were isolated from articular cartilage of d 1-2 Wistar neonate rats through enzymatic digestion.Different doses (0.005,0.010,0.100 μg/L) of T-2 toxin were added after 24 h in vitro culture.The survival rate of chondrocytes was detected with Trypan blue staining.Echylosis (matrix metalloproteinase,MMP1) was analyzed by immunohistochemistry.The damage of articular chondrocyte was observed by transmission electron microscope.Results ①Cell morphology of in vitro cultured chondrocyte:the newly isolated chondrocytes were spherical.After 24 hours,the adherent cells gradually began to stretch the triangle or polygon;the nucleus was large and round;the cell was clear and transparent,containing secretory granules.②Cell proliferation:T-2 toxin had a significant inhibitory effect on chondrocyte proliferation,the higher the concentration of T-2 toxin,the significant the inhibitory effects [0.000 μg/L (control) group:3.45 × 108/L,0.005 μg/L T-2 toxin group:3.45 × 108/L,0.010 μg/L T-2 toxin group:2.06 × 108/L,x2 =9.554,P ＜ 0.05].③Immunohistochemical observation:dysplasia,nucleus condensation and membrane rupture were observed in T-2 toxin treated group,brown staining was observed in all groups at varying degrees.The deepest staining was in 0.005 μg/L T-2 toxin group,with the strongest secretion of MMP1;with increasing doses of the toxin,the damage to cartilage cells was severe,MMP1 secretion was less,staining was weak,and the weakest staining was in the 0.100 μg/L T-toxin group.④Under transmission electron microscopy:in control group,cytoplasm was rich in rough endoplasmic reticulum,nuclear membrane and cell membrane were clear;in 0.005 μg/L T-2 toxin group,the cell nucleus showed pyknosis,organelles were decreased in cytoplasm;in 0.100 μg/L T-2 toxin group,the microvilli was dropped out of cartilage surface,nuclear changes were obvious,and mitochondria was myeloid degeneration;rough endoplasmic reticulum was degranulation and expansion into cystiform,chondrocytes were apoptosis occasionally,the cell nucleus showed pyknosis,and the formation of high-density plaque.Conclusion Low dose of T-2 toxin could damage the primary cultured articular chondrocyte in vitro.The results have showed that there are damaged cytostasis,chondrocyte degeneration,necrosis and apoptosis.