摘要
目的:观察不同碘营养水平哺乳期大鼠乳腺组织促甲状腺激素受体(TSHR)、蛋白激酶A(PKA)、钠碘转运体(NIS)mRNA和蛋白的表达,探讨促甲状腺激素(TSH)-THSR-环磷酸腺苷(cAMP)-PKA信号通路在哺乳期乳腺摄碘过程中的作用。方法:采用成组设计,按体质量(80~100 g)采用随机数字表法将110只雌性Wistar大鼠分为适碘(NI)组、重度低碘(SID)组、中度低碘(MID)组、中度高碘(MIE)组、重度高碘(SIE)组,每组22只。另选取22只雄性Wistar大鼠,喂养情况与NI组一致。饲养3个月时,收集雌鼠24 h尿样,并将雌鼠与雄鼠合笼(5∶1),交配后,每只雌鼠单独喂养,在生育10 d时,处死哺乳期大鼠取甲状腺、乳腺组织。采用砷铈催化分光光度法测定尿碘;HE染色观察甲状腺和乳腺组织形态学改变;实时荧光定量PCR(real-time PCR)法检测甲状腺和乳腺组织TSHR、PKA及NIS mRNA表达水平;蛋白免疫印迹法(Western blot)检测乳腺组织TSHR、PKA、磷酸化PKA(p-PKA)及NIS蛋白表达水平。结果:与NI组比较(162.59μg/L),SID、MID组雌鼠尿碘中位数(3.16、6.36μg/L)均较低,MIE、SIE组雌鼠尿碘中位数(2356.27、11507.29μg/L)均较高(P均<0.01)。HE染色可见,不同摄碘水平对甲状腺滤泡产生不同的影响:NI组多为均匀的圆形或椭圆形滤泡;MID组小滤泡增多,上皮细胞呈单层柱状或立方,滤泡腔变小,胶质减少;SID组滤泡变小,上皮细胞呈柱状或高柱状,滤泡腔内胶质减少或缺如;SIE、MIE组甲状腺滤泡出现多形性变化,既有部分滤泡明显增大,又有部分小滤泡增生。不同摄碘水平对乳腺大导管也产生不同的影响:与NI组相比,SID、MID组乳腺大导管周围的结缔组织呈明显的纤维化,而MIE、SIE组纤维化明显减轻。real-time PCR结果显示,不同碘营养水平哺乳期大鼠甲状腺组织TSHR、PKA、NIS mRNA表达水平比较,差异均有统计学意义(F=10.73、92.37、115.75,P均<0.01);乳腺组织TSHR、PKA、NIS mRNA表达水平比较,差异均有统计学意义(F=40.25、39.63、14.92,P均<0.05)。Western blot结果显示,不同碘营养水平哺乳期大鼠乳腺组织TSHR、PKA、p-PKA、NIS蛋白表达水平比较,差异均有统计学意义(F=4.14、6.73、8.48、4.51,P均<0.05),其中MIE、SIE组TSHR蛋白表达水平均低于NI组(P均<0.05);SID、MID组PKA蛋白表达水平均高于NI组(P均<0.05);SID组p-PKA蛋白表达水平高于NI组,但SIE组低于NI组(P均<0.05);SID组NIS蛋白表达水平高于NI组(P<0.05)。结论:哺乳期大鼠高碘摄入时乳腺组织TSHR mRNA、蛋白表达水平均降低,低碘摄入时PKA、NIS mRNA和蛋白表达水平均升高。哺乳期大鼠乳腺组织可能通过TSH-TSHR-cAMP-PKA信号通路参与调控碘的摄入,从而对自身及子代产生保护作用。
Objective To observe the mRNA and protein expression levels of thyroid stimulating hormone receptor(TSHR),protein kinase A(PKA)and sodium iodine transporter(NIS)in mammary gland tissue of lactating rats with different iodine nutrition levels,and to explore the role of thyroid stimulating hormone(TSH)-THSR-cyclic adenosine monophosphate(cAMP)-PKA signal pathway in the process of mammary iodine uptake during lactation.Methods Using a group design,according to body weight(80-100 g),110 Wistar female rats were randomly divided into normal iodine(NI)group,severe iodine deficiency(SID)group,moderately iodine deficiency(MID)group,moderately iodine excess(MIE)group and severe iodine excess(SIE)group,with 22 rats in each group.Another 22 Wistar male rats were selected,and the feeding situation was consistent with that of NI group.After 3 months of feeding,24-hour urine samples of female rats were collected,and the female rats were caged with the male rats(5∶1).After mating,each female rat was fed separately.At 10 days of childbirth,the lactating rats were sacrificed and thyroid and mammary gland tissues were taken.The urinary iodine was determined by arsenic cerium catalytic spectrophotometry.The morphological changes of thyroid and mammary gland tissues were observed by HE staining.The mRNA expression levels of TSHR,PKA and NIS in thyroid and mammary gland tissues were measured by real-time PCR;the protein expression levels of TSHR,PKA,phosphorylated PKA(p-PKA),and NIS in mammary gland tissue were measured by Western blotting.Results Compared with NI group(162.59μg/L),the median urinary iodine of female rats in SID and MID groups(3.16,6.36μg/L)was lower,and the median urinary iodine of female rats in MIE and SIE groups(2356.27,11507.29μg/L)was higher(P<0.01).HE staining showed that different levels of iodine uptake had different effects on thyroid follicles:most of the follicles in NI group were uniform round or oval;in MID group,the number of small follicles increased,the epithelial cells were monolayer columnar or cubic,the follicular cavity became smaller,and the glia decreased;the follicles in SID group became smaller,and the epithelial cells were columnar or high columnar,with reduced or absent glia in the follicular cavity;pleomorphic changes were found in thyroid follicles in SIE and MIE groups,with some follicles significantly enlarged and some small follicles hyperplasia.Different levels of iodine intake had different effects on mammary duct:compared with NI group,the connective tissue around the mammary duct in SID and MID groups showed obvious fibrosis,while the fibrosis in MIE and SIE groups was significantly reduced.The results of real-time PCR showed that there were significant differences in the mRNA expression levels of TSHR,PKA and NIS in thyroid tissues of lactating rats with different levels of iodine nutrition(F=10.73,92.37,115.75,P<0.01).There were statistically differences in the mRNA expression levels of TSHR,PKA and NIS in mammary gland tissues of lactating rats with different levels of iodine nutrition(F=40.25,39.63,14.92,P<0.05).Western blotting results showed that there were significant differences in the protein expression levels of TSHR,PKA,p-PKA and NIS in mammary gland tissues of lactating rats with different levels of iodine nutrition(F=4.14,6.73,8.48,4.51,P<0.05).Among them,the protein expression level of TSHR in MIE and SIE groups was lower than that in NI group(P<0.05);the protein expression level of PKA in SID and MID groups was higher than that in NI group(P<0.05);the protein expression level of p-PKA in SID group was higher than that in NI group,but that in SIE group was lower than that in NI group(P<0.05),the protein expression level of NIS in SID group was higher than that in NI group(P<0.05).Conclusions The mRNA and protein expression levels of TSHR are decreased in mammary gland tissues of lactating rats with high iodine intake,while the mRNA and protein expression levels of PKA and NIS are increased in low iodine intake.TSH-TSHR-cAMP-PKA signal pathway may be involved in the regulation of iodine intake in mammary gland tissue of lactating rats,which may protect itself and its offspring.
作者
薛靓
文达
史新竹
金星
王丹丹
刘丽香
申红梅
Xue Liang;Wen Da;Shi Xinzhu;Jin Xing;Wang Dandan;Liu Lixiang;Shen Hongmei(Institute for Iodine Deficiency Disorders Control,Center for Endemic Disease Control,Chinese Center for Disease Control and Prevention,Key Laboratory of Etiology and Epidemiology,National Health Commission&Education Bureau of Heilongjiang Province,Harbin Medical University,Harbin 150081,China)
出处
《中华地方病学杂志》
CAS
北大核心
2022年第7期532-539,共8页
Chinese Journal of Endemiology
基金
国家自然科学基金(81273012)。
关键词
碘
促甲状腺激素受体
蛋白激酶A
钠碘转运体
大鼠
哺乳期
乳腺
信号通路
Iodine
Thyroid stimulating hormone receptor
Protein kinase A
Sodium iodide symporter
Rats
Lactation
Mammary gland
Signaling pathway
