| Objective: To investigate the protective effect of dimethyl fumarate on skeletal muscle and kidney injury in rats.Methods: Twenty-four rats were randomly divided into 4 groups,including Control group,Model group,DMF group and pretreated Nrf2 blocker group(DMF+ML385group),with 6 rats in each group.The model of rat lower extremity crush injury was designed by using the upper wooden groove.The single hind limb femoral end has a weight of 3 kg and the limbs have a total weight of 6 kg.In the model group,the lower limbs of rats were placed in a crush injury mold,and the 6 kg weight squeezed the lower extremity femoral muscles for 6 h.The reperfusion time after decompression is 12 h;In the control group,the lower limbs of rats were placed only on the test bench,and the extrusion was not used,and the rest of the operation was the same as the model group;In the DMF group,the lower limbs of rats were placed in a crush injury mold,and the 6 kg weight squeezed the lower extremity femoral muscles for 6 h.Immediately after decompression,DMF 20 mg/kg was injected intraperitoneally,and the reperfusion time was 12 h;In the DMF+ML385 group(blocker pretreatment group),ML385 20 mg/kg was intraperitoneally injected 6 h before extrusion,and the remaining operation was the same as the DMF group.At the end of the experiment,the general condition of rats was observed,and the abdominal aorta was sacrificed after anesthesia.Detecting the skeletal muscle wet/dry ratio;Serum Mb levels were measured by ELISA;Automatic blood biochemical analyzer to detect serum CK,BUN,Cr levels;The kit method was used to detect serum T-SOD and MDA content;Hematoxylin-eosin staining was used to observe the injury of the skeletal muscle and renal tubular cells;Immunohistochemical staining of Nrf2 and HO-1 proteins was performed in skeletal muscle and kidney sections.Results: There were no death or femoral fracture of rats in each group during the experiment.The skeletal muscle wet/dry ratio showed a significant increase in the model group compared with the control group(P<0.05).The degree of edema in the DMF group was reduced compared with the model group(P<0.05).The wet/dry ratio of DMF+ML385 group was higher than the DMF group(P<0.05).The ELISA results showed that the serum myoglobin level in the model group was higher than the control group(P<0.05),The DMF group was lower than the model group(P<0.05),The DMF+ML385 group was higher than the DMF group(P<0.05).The results of blood biochemical examination showed that the serum creatine kinase level of the model group was higher than the control group(P<0.05).The DMF group was lower than the model group(P<0.05).Compared with DMF group,serum creatine kinase level was increased in the DMF+ML385 group(P<0.05).BUN level was increased in the model group compared with the control group(P<0.05).BUN level was decreased in the DMF group compared with the model group(P<0.05),BUN levels were higher in the DMF+ML385 group than the DMF group(P<0.05).In addition,the Cr level was increased in the model group compared with the control group,and the Cr level was decreased in the DMF group compared with the model group(P<0.05).Compared with the DMF group,the Cr level in the DMF+ML385 group was increased(P<0.05).Serum T-SOD and MDA results were shown the T-SOD levels were reduced in the model group compared with the control group(P<0.05).The T-SOD level was increased in the DMF group compared with the model group(P<0.05).Compared with the DMF group,the DMF+ML385 group was decreased(P<0.05).At the same time,the MDA level was increased in the model group compared with the control group(P<0.05).Compared with the model group,the DMF group decreased MDA levels(P<0.05).Compared with the DMF group,the DMF+ML385 group had improved MDA levels(P<0.05).The results of skeletal muscle HE staining showed the control group had intact muscle cells,normal intercellular spaces,no destruction,lysis,and inflammatory cell infiltration.Compared with the control group,the model group had skeletal muscle cell lysis,a large amount of inflammatory cell infiltration,incomplete muscle cell contour,unclear muscle texture,and severe injury to the contour of the tissue.The skeletal muscle cells were less injuryd in the DMF group than the model group.Compared with the DMF group,the DMF+ML385 group had a more severe injury to the muscle cells.Skeletal muscle cell injury score results show.Compared with the control group,the model group had a large degree of skeletal muscle injury(P<0.05).Compared with the model group,the injury of skeletal muscle cells was lighter in the DMF group(P<0.05).Compared with the DMF group,the DMF+ML385 group had a more severe injury in the muscle cells(P<0.05).Renal HE staining results showed the control group,the renal tubular cells were intact,the wall of the tube was smooth,no injury,and there was no content obstruction in the lumen of the renal tubule.Compared with the control group,the model group was injuryd,the tube wall was rough,the renal tubular epithelial cells were degenerated and necrotic,and a large amount of homogeneous substances were seen in the lumen.Compared with the model group,the DMF group had less degeneration and necrosis of renal tubular epithelial cells and less homogenized material in the lumen of the renal tubules.Compared with DMF group,the DMF+ML385 group had obvious degeneration and necrosis of renal tubular epithelial cells,and more homogeneous substances in the lumen.The results of renal tubular injury scores showed that the renal tubules were severe injuryd in the model group compared with the control group(P<0.05).Compared with the model group,the tubular cells in the DMF group were less injuryd(P<0.05).Compared with the DMF group,the DMF+ML385 group had more severe tubular injury(P<0.05).The results of immunohistochemistry showed the positions of Nrf2 and HO-1 in skeletal muscle and kidney tissues are in the cytoplasm.The expression of Nrf2 and HO-1 protein in the cytoplasm of skeletal muscle and renal tubular cells in the control group was weakened.The intensity of Nrf2 protein expression in skeletal muscle cells was increased in the model group compared with the control group.The intensity of Nrf2 protein expression was increased in the DMF group compared to the model group.The intensity of Nrf2 protein expression in skeletal muscle cells was weakened in the DMF+ML385 group compared with the DMF group.The semi-quantitative results of immunohistochemistry showed that the Nrf2 protein density value in the skeletal muscle cells was higher than that in the control group(P<0.05).The optical density of Nrf2 protein was increased in the DMF group compared with the model group(P<0.05).The optical density of Nrf2 protein was decreased in the DMF+ML385 group compared with the DMF group(P<0.05).The average optical density of Nrf2 in renal tubular cells,the optical density of Nrf2 protein was increased in the model group compared with the control group(P<0.05).Conclusion: DMF can reduce the degree of skeletal muscle and kidney injury in rats after CI,and its protective effect may be related to inhibition of oxidative stress and activation of Nrf2-ARE pathway. |
PDF Full Text Request