| Objective: To study the effects of central nesfatin-1 and obese SD rats on feeding behavior and its corresponding signaling pathways after bariatric surgery.Therefore,first of all,the changes of nesfatin-1 level in hypothalamus of obese SD rats after significant weight loss surgery should be observed.In order to further study the mechanism of nesfatin-1 in hypothalamus and detect its related signaling pathways.Methods: SD rats were fed on a uniform 45% high-fat diet of 180-200 g in the laboratory without specific pathogens.After 5 weeks feeding,SD rats weighing more than 10% of the normal diet were regarded as obese rats.After successful construction of obese rats,they were divided into five groups: group 1,non-surgical high-fat diet(HFD)group;group 2,sham-HFD group;group 3,sham-operated restricted diet(HFRD)group;group4,gastric sleeve resection(SG)group;group 5,gastric bypass(RYGB)group.After operation,the animals were fed for 4 weeks,and their weight and food intake were recorded.Blood,cerebrospinal fluid,hypothalamus and other specimens were collected.After centrifugation,blood and cerebrospinal fluid were frozen in the refrigerator at-80 C for reserve.The content of nesfatin-1 in blood and cerebrospinal fluid was measured by elisa,and the expression of nesfatin-1 in hypothalamus was measured by RT-PCR and Western blot.Nesfatin-1-related signaling pathway,melanocortin 3/4 receptor(MC3/4R),and extracellular regulated protein kinase(ERK)protein expression were further measured.The obese rats were fed for 5 weeks.After the third ventricle intubation,the obese rats underwent gastric sleeve resection(SG)and gastric bypass(RYGB),respectively.Ventricular catheterization + gastric sleeve resection(SG)rats and ventricular catheterization + gastric bypass(RYGB)rats were divided into three groups:saline(NS)group,morpholine antisense oligonucleotide(MON)group and receptor inhibitor(SHU9119)group.One week after modeling,NS was added to the preset catheter at a fixed time every day as control,MON inhibited the expression of nesfatin-1in hypothalamus,SHU9119 blocked the melanocortin 3/4 receptor(MC3/4R).The changes of food intake and body weight in rats were observed.After 10 days of administration,the hypothalamus was taken and the changes of nesfatin-1,MC3/4R andERK protein in hypothalamus were measured by Western blot.Result: 1.After 5 weeks of high-fat diet feeding,the body weight of obese rats was 510 g.The rats were divided into 5 groups and fed for 4 weeks(non-operative high-fat diet group,sham-operated high-fat diet group,sham-operated limited diet group,gastric sleeve resection group and gastric bypass group).We found that the weight of SD rats in sham-operated limited diet group,gastric sleeve resection group,gastric bypass group decreased significantly compared with those in non-operative high-fat diet group and sham-operated high-fat diet group(p < 0.05).There was no significant difference between the two groups.The weight loss rate of SD rats in sleeve gastrectomy group and by-pass gastrectomy group was significantly faster than that in 3-4 weeks in the first two weeks.The weight loss rate in sham-operated high-fat diet group was relatively stable.The weight of sham-operated high-fat diet group rose after a slight drop in the first week,and the weight of non-operated high-fat diet group did not decrease.The intake of SD rats in sleeve gastrectomy group and by-pass gastrectomy group decreased significantly in the first week and then increased slowly,but it was always lower than that in non-operative high-fat diet group and sham-operated high-fat diet group(p < 0.05),and higher than that in sham-operated restricted diet group(p < 0.05).There was no significant change in the intake of rats in non-operative and sham-operated high-fat diet groups.2.The levels of nesfatin-1 in serum of SD rats in non-operative high-fat diet group,sham-operated high-fat diet group,sham-operated restricted diet group,gastric sleeve resection group and gastric bypass group were 15121±1172,15446±2248,18267±1742,19323±1354,and18191±1790(pg/ml),respectively.The levels of nesfatin-1in CSF of the five groups were267.4±39.7,267.5±40.4,403.6±29.1,389.9±50.3,and341.7±54.1(pg/ml),respectively.Nesfatin-1 levels in serum and cerebrospinal fluid in sham-operated restricted diet group,gastric sleeve resection group and gastric bypass group were higher than those in non-operated high-fat diet group and sham-operated high-fat diet group(p < 0.05).There was no significant difference between sham-operated restricted diet group,gastric sleeve resection group and gastric bypass group,while those in non-operated high-fat diet group and sham-operated high-fat diet group were higher.There was no statistical difference between the fat diet groups.Regression analysis of nesfatin-1 values in serum and cerebrospinal fluid(p g/ml)andbody weight(g)showed that nesfatin-1 levels in serum were negatively correlated with body weight(r = 0.7911,P < 0.0001)and nesfatin-1 levels in cerebrospinal fluid were negatively correlated with body weight(r = 0.7757,P < 0.0001).3.The expression of nesfatin-1,MC3 R,MC4R,ERK and p-ERK in hypothalamus of SD rats in non-operative high-fat diet group,sham-operated high-fat diet group,sham-operated restricted diet group,gastric sleeve resection group and gastric bypass group were detected by Western blot.The expression of nesfatin-1,MC3 R,MC4R and p-ERK in hypothalamus of SD rats in sham-operated high-fat diet group,sham-operated high-fat diet group,sham-operated high-fat diet group,sham There was a significant difference in the expression in hypothalamus between the high-fat diet group and the sham-operated high-fat diet group(p < 0.05).There was no significant difference in the corresponding proteins in hypothalamus between sham-operated restricted diet group,sleeve gastrectomy group and gastric bypass group.There was no significant difference in the corresponding proteins in hypothalamus between non-operative high-fat diet group and sham-operated high-fat diet group.There was no significant difference in the expression of ERK between groups.4.The expression levels of nesfatin-1,MC3 R,MC4R,ERK 1 and ERK2 in hypothalamus of SD rats in sham-operated restricted diet group,sleeve gastrectomy group and gastric bypass group were measured by RT-PCR.The expression levels of nesfatin-1,MC3 R and MC4 R in hypothalamus of SD rats in sham-operated restricted diet group,gastric sleeve resection group and gastric bypass group were higher than those in non-operated high-fat diet group and sham-operated high-fat diet group.Academic significance(p < 0.05).There was no significant difference in the corresponding genes in hypothalamus of SD rats between sham-operated restricted diet group,sleeve gastrectomy group and gastric bypass group.There was no significant difference in the corresponding mRNA in hypothalamus between non-operative high-fat diet group and sham-operated high-fat diet group.There was no significant difference in the expression of ERK1 and ERK2 between groups.5.In the model of gastric sleeve resection-ventricular catheterization,SD rats in NS group,MON group and SHU9119 group were given orally for 10 days(once a day)one week after the establishment of the model.The food intake of rats in MON group was significantly higher than that of rats in NS group.The food intake of rats in SHU9119 group was higher than that of rats in NSgroup(p < 0.05).The food intake of rats in SHU9119 group was higher than that of rats in MON group(p < 0.05).The food intake of rats in SHU9119 group was higher than that of rats in NS group(p < 0.05).The body weight of rats in morpholine antisense oligonucleotide(MON)group was significantly higher than that in NS group(p < 0.05);the weight of rats in SHU9119 group was significantly higher than that in NS group(p <0.05);the weight of rats in SHU9119 group was significantly higher than that in NS group(p < 0.05);the weight of rats in SHU9119 group was significantly higher than that in morpholine antisense oligonucleotide group(p < 0.05);and the weight of rats in SHU9119 group was significantly higher than that in morph After administration of morpholine antisense oligonucleotide(MON)and receptor inhibitor(SHU9119),the food intake and body weight of rats after operation were still lower than those before operation.Western blot measurements of the expression of nesfatin-1,MC3 R,MC4R,ERK and p-ERK in hypothalamus of rats showed that after administration of MON,the expression of nesfatin-1 in brain decreased,the expression of p-ERK decreased,and the other indicators did not change significantly;after administration of SHU9119,the expression of p-ERK decreased,and the degree of p-ERK decreased was more obvious than that after Administration of MON,while the other indicators did not change significantly.6.In the model of gastric bypass-ventricular catheterization,the changes of each index in NS group,MON group and SHU9119 group were similar to those in the model of gastric sleeve resection-ventricular catheterization.After a week of administration,rats were fed with morpholine antisense oligonucleotide(MON)for 10 days(once a day).The results showed that the rats fed more morpholine antisense oligonucleotide(MON)group than the rats fed normal saline(NS)group(p < 0.05).The rats fed more morpholine antisense oligonucleotide(MON)group than the rats fed normal saline(NS)group(p < 0.05).The rats fed more morpholine antisense oligonucleotide(MON)group than the rats(p < 0.05);the intake of rats in SHU9119 group was higher than that of rats in MON group(p <0.05).The body weight of rats in morpholine antisense oligonucleotide(MON)group was significantly higher than that in NS group(p < 0.05);the weight of rats in SHU9119 group was significantly higher than that in NS group(p < 0.05);the weight of rats in SHU9119 group was significantly higher than that in NS group(p < 0.05);the weight of rats in SHU9119 group was significantly higher than that in morpholine antisenseoligonucleotide group(p < 0.05);and the weight of rats in SHU9119 group was significantly higher than that in morph After administration of morpholine antisense oligonucleotide(MON)and receptor inhibitor(SHU9119),the food intake and body weight of rats after operation were still lower than those before operation.Western blot measurements of the expression of nesfatin-1,MC3 R,MC4R,ERK and p-ERK in hypothalamus of rats showed that after administration of MON,the expression of nesfatin-1 in brain decreased,the expression of p-ERK decreased,and the other indicators did not change significantly;after administration of SHU9119,the expression of p-ERK decreased,and the degree of p-ERK decreased was more obvious than that after Administration of MON,while the other indicators did not change significantly.Conclusion: The increase of nesfatin-1 in hypothalamus after gastric sleeve resection and gastric bypass surgery in obese SD rats is one of the reasons for the decrease of food intake and body weight.The mechanism is that the expression of p-ERK protein increases after the increase of nesfatin-1 in the hypothalamus after operation,and the activation of ERK1/2 phosphorylation signal leads to anorexia in the central system,thereby controlling body weight.Therefore,the hypothalamic nesfatin-1-MC3/4R-pERK1/2 signaling pathway is involved in feeding and weight regulation after gastric bypass and sleeve gastrectomy. |
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