Expression Ym-1Protein In Adipose Tissue In High-fat Diet C57BL/6J Mice

Objective Todynamically observe the mice liver and adipose tissue pathologicalstructure, biochemical marker, and the changes in the macrophage M2marker,specifically in Ym-1, and to discuss the relationship between the expression ofalternativemacrophages,specificallymarker Ym-1, and insulin resisitance in high-fatdietC57BL/6J mice．Methods28male C57BL/6J mice were randomly and respectively assigned into2groups:the standard chow group (group A n=14) that was fed with basic dietandhigh-fat diet group (group B n=14) that was fed with high-fat diet.After6and12weeks of post-high-fat diet,the levels of fasting peripheral blood glucose (FBG),fasting plasma insulin (FINS) andinsulin resistance index(HOMA-IR) in serum weredetectedand the contents of liver homogenate triglyceride (TG),cholesterol (TC) andglutamic pyruvic transaminase (ALT) were measured. The liver andpathologicalchanges in adipose tissue were observed by H-E staining.The expression ofYm1proteinin liver and adipose tissue was detectedby DAB staining andImmunofluorescent Staining respectively.Results1. After having been fed for6and12weeks respectively,the body mass in group Bwas higherthan the group A, the difference was statistically significant（P<0.05，P<0.01）. 2. After having been fed for6weeks,the level of FBG in group A andgroup B werebothwithin the normal range and had nosignificant difference (P>0.05);the levelsofFINS and HOMA-IR in group B were higher than the group A（P<0.01）. The levelof FBG, FINS and HOMA-IR in group B were Significantly higher compared withthe group Aafter12weeks（P<0.01）.3. After having been fed for6weeks,the level of TC in liver homogenate in group Bincreased significantly compared with group A (P<0.01). the level of TG in liverhomogenate had no significant difference between the group A and group B（P>0.05).The level ofALT in group B was slightly higher than groupA;however,the result had no statistically significant (P>0.05). After12weeks, thelevels of TC and TG in group B were significantly higher compared with the groupA（P<0.01）; the level of ALT in group B was higher than the group A, the differencewas statistically significant（P<0.01）.4. After having been fed for6weeks, the liver in group A was presentedin bright redcoloring and smooth surface;Liver volume in group B didn’t show obvious increase;and the liverwas presentedinslightly yellow, on which yellow fat spotswere visibled.after12weeks, the liver in group A had no obvious abnormity and was presentedinbright red coloring and smooth surface; The liver in group B showed in yellow, edgeblunting, greasy feeling, on which yellow fat spots were visible and the liver volumein group B showed great increase.5. After having been fed for6weeks,the H-E staining results showed that there was nopathological lesion of liver in group A; diffuse distribution of micro lipid droplet ofliver were visibled in group B. After12weeks, distribution of micro lipid droplet ofliver were much more obvious in group B,the liver cells had ballooningdegeneration.6. After having been fed for12weeks,the H-E staining results showed that the size and shape of abdominal adipocytes were within normal limits in group A. In abdominaladipocytes of group A, there was a small amount of inflammatory cellsinfiltration.In group B, the size of abdominal adipocyteswasobvious augmentation,abdominal adipose tissue cells wall were not completed and more inflammatorycells infiltration were observed.7. After having been fed for6and12weeks respectively, there was no Ym-1proteinexpression in liver of group A andgroup B through detection of DAB stainingand Immunofluorescent Stainingrespectively.8. After having been fed12weeks,there was a small amount of M2macrophagesexpression of adipose tissue in group A, detected by DAB staining andImmunofluorescent Staining. M2macrophages/adipocytes of group B were morecompared with group A（P<0.05）; the expression ofYm-1protein in adiposetissueshowed significant increase in group B at the12th week（P<0.01）.In addition,the expression ofYm-1proteinin adipose tissuedetected by DAB staining showedpositive correlations with FBG,FINS,and HOMA-IR.The expression ofYm-1proteinin adipose tissuedetected by Immunofluorescent Staining showed positivecorrelations with FINS and HOMA-IR, except for FBG.Conclusion1. The body weight, FBG, FINS, HOMA-IR, TC, TG, ALT of C57BL/6J mice wereincreased by high-fat diet.2. The expression ofYm-1proteinin liver was not obvious. Further research is neededto clarify whether short feeding period is the reason.3. Over expression of Ym-1proteininadipose tissue in high-fat diet C57BL/6J mice,macrophages polarization may plays an important role in the development ofobesity-related insulin resistance.4. The expression of Ym-1protein of adipose tissuewas positively correlated withFBG, FINS and HOMA-IR.Further research will prove whether the proinflammatoryeffects of M1macrophages are greater than the anti-inflammatory effects of M2macrophages.