發(fā)布時間：2018-05-25 22:24

  本文選題：IGF-1 + TGF-β1　； 參考：《天津醫(yī)科大學》2008年碩士論文

【摘要】： 本實驗在成功建立碘缺乏和碘過量Wistar大鼠、Balb/c小鼠動物模型的基礎上,觀察不同碘攝入水平下大、小鼠的甲狀腺形態(tài)及功能的變化,同時檢測甲狀腺組織的胰島素樣生長因子-1(IGF-1)、轉化生長因子-β1(TGF-β1)的mRNA和蛋白質表達水平,進而探討IGF-1、TGF-β1在碘缺乏和碘過量所致甲狀腺生長及功能變化中的可能作用。 本實驗選用Wistar大鼠和Balb/c小鼠,分別隨機分為3組:低碘組(LI)、正常碘組(NI)、50倍高碘組(50HI)。LI組動物飼料的平均碘含量為50μg/kg,NI組和50HI組動物飼料的平均碘含量為300μg/kg;LI組和NI組動物飲用去離子水,50HI組動物飲用加碘化鉀的去離子水。根據(jù)大、小鼠每日進食量和飲水量估算各組動物每日總碘攝入量,大鼠各組分別為:1μg/d(LI組)、6μg/d(NI組)、300μg/d(50HI組),小鼠各組分別為:0.25μg/d(LI組)、1.5μg/d(NI組)、75μg/d(50HI組)。分別在飼養(yǎng)3、6個月后處死動物,測定尿碘、甲狀腺組織碘、甲狀腺組織激素、甲狀腺形態(tài)學觀察、形態(tài)計量學測量甲狀腺球蛋白的儲存及含量;同時采用實時熒光定量PCR、半定量PCR、免疫組織化學等實驗技術,檢測甲狀腺組織IGF-1和TGF-β1的mRNA、蛋白質表達水平的變化。 實驗結果顯示: 1尿碘和甲狀腺組織碘水平:LI組大、小鼠的尿碘水平都很低,幾乎測不出,NI組和50HI組的尿碘水平與其碘攝入水平基本一致;各組甲狀腺組織碘含量隨著碘攝入量的增加而增加,但增加的幅度遠不及尿碘,與其碘攝入水平不一致。 2甲狀腺組織激素水平:各時段LI組大、小鼠甲狀腺組織T_3和T_4水平均明顯低于同期NI組,T_3/T_4明顯高于NI組;而50HI組大、小鼠之間不完全相同,表現(xiàn)為各時段50HI組大鼠甲狀腺組織T_3含量低于同期NI組,T_4含量與NI組相比無明顯差別,T_3/T_4顯著降低;50HI組小鼠于3個月時,甲狀腺組織T_3和T_4含量均較NI組明顯增高,6個月時,T_3水平接近正常,T_4仍有所升高,但不如3個月時明顯;3、6個月時T_3/T_4均較NI組有所降低,但無統(tǒng)計學差異。 3甲狀腺形態(tài)學變化:大、小鼠NI組甲狀腺濾泡均多為中等大小,上皮細胞為單層立方或扁平狀,濾泡腔內膠質豐富;LI組甲狀腺均呈現(xiàn)小濾泡增生性甲狀腺腫改變;而50HI組大、小鼠則表現(xiàn)不同,50HI組大鼠甲狀腺與NI組比較,甲狀腺出現(xiàn)多型性變化,表現(xiàn)為既有部分濾泡明顯增大,濾泡腔內充滿濃染膠質,上皮細胞扁平,又有部分濾泡接近正常,同時增生現(xiàn)象明顯,表現(xiàn)為濾泡變小,上皮細胞變?yōu)橹鶢?濾泡腔變小,膠質減少,提示TSH刺激征象;50HI組小鼠甲狀腺與NI組比較,濾泡腔內膠質蓄積、豐滿,濾泡腔增大,上皮細胞變扁平,呈現(xiàn)膠質蓄積性甲狀腺腫,此改變與高碘大鼠不同之處在于,高碘小鼠發(fā)生了膠質蓄積性甲狀腺腫,未發(fā)現(xiàn)甲狀腺增生表現(xiàn),即無明顯TSH刺激征象。 4甲狀腺膠質蓄積水平的形態(tài)計量學測量結果:各時段50HI組大鼠的濾泡腔截面積、大中小濾泡腔所占比率變化不明顯,不提示大鼠發(fā)生大濾泡性膠質蓄積;3個月時50HI組大鼠膠質面積與視場面積比值較NI組升高,而6個月時卻低于NI組,3個月時50HI組膠質平均灰度低于NI組,6個月時與NI組相比無差別,表明大鼠在高碘攝入情況下,其甲狀腺球蛋白總含量變化不明顯。與大鼠不同,50HI組小鼠的甲狀腺濾泡腔截面積明顯增大,小、中等濾泡腔明顯減少,大濾泡腔明顯增多,提示小鼠發(fā)生了大濾泡性膠質蓄積;50HI組小鼠的甲狀腺膠質面積與視場面積比值以及膠質的平均灰度均明顯高于NI組,表明小鼠在高碘攝入下甲狀腺球蛋白總含量明顯增加。 5大、小鼠甲狀腺IGF-1和TGF-β1mRNA及其蛋白表達水平:3個月時大鼠,與NI組相比,LI組和50HI組甲狀腺IGF-1mRNA表達水平均升高,其中50HI組升高更為顯著(P＜0.01);6個月時大鼠,與NI組相比,LI組甲狀腺IGF-1mRNA表達水平較NI組明顯下降,50HI組與NI組比較無統(tǒng)計學差異。3個月時大鼠,與NI組相比,LI組和50HI組IGF-1蛋白表達顯著增加,在甲狀腺上皮細胞胞漿內可見明顯的陽性顆粒;6個月時大鼠,LI組IGF-1蛋白表達顯著弱于NI組,50HI組與NI相比無明顯差別。各時段小鼠甲狀腺IGF-1mRNA表達水平,LI組顯著高于NI組,50HI組與NI組比較無統(tǒng)計學差異。3、6個月時小鼠,與NI組相比,LI組IGF-1蛋白表達顯著增加,50HI組IGF-1蛋白表達無明顯變化。結果表明,各組大、小鼠甲狀腺IGF-1mRNA和蛋白表達水平基本一致。 3、6個月時大鼠,LI組和50HI組甲狀腺TGF-β1mRNA表達水平均較NI組明顯升高,其中LI組升高更為顯著。3個月時大鼠,LI組甲狀腺TGF-β1蛋白表達顯著弱于NI組,50HI組與NI相比無明顯差別;6個月時大鼠,與NI組相比,LI組TGF-β1蛋白表達顯著增高,50HI組顯著降低。3、6個月時小鼠甲狀腺TGF-β1mRNA水平,LI組和50HI組均顯著高于NI組。3個月時小鼠,LI組TGF-β1蛋白表達與NI相比無明顯差別,50HI組顯著弱于NI組;6個月時小鼠,與NI組相比,LI組TGF-β1蛋白表達顯著增高,50HI組無明顯差別。結果表明,只有6個月時LI組大、小鼠的甲狀腺TGF-β1mRNA和蛋白質表達水平一致,3個月時LI組和各時段50HI組大、小鼠甲狀腺TGF-β1mRNA和蛋白質表達水平不一致。 從上述實驗結果可以得出如下結論: 1碘缺乏時大、小鼠均表現(xiàn)為明顯甲狀腺功能減退,代償性出現(xiàn)小濾泡增生性甲狀腺腫。碘過量時,大鼠甲狀腺僅發(fā)生了多型性改變,未形成甲狀腺腫;而小鼠發(fā)生了典型膠質蓄積性甲狀腺腫。大鼠和小鼠對碘過量均具有較強的適應能力,但它們之間在穩(wěn)定甲狀腺內碘含量、穩(wěn)定激素水平(激素合成、轉化、釋放)、以及甲狀腺隨之發(fā)生的結構改變存在較大差異;從總體看來,大鼠比小鼠對高碘攝入具有更強的適應能力。 2本研究觀察到碘缺乏時大鼠甲狀腺IGF-1表達呈一過性升高,小鼠甲狀腺IGF-1表達始終維持在較高水平;提示IGF-1參與了碘缺乏誘發(fā)甲狀腺增生性腫大的發(fā)病過程;碘過量時大、小鼠甲狀腺IGF-1表達水平變化不完全相同,但與各自發(fā)生的甲狀腺形態(tài)學改變相一致。對于甲狀腺自分泌的IGF-1與碘缺乏和碘過量所致甲狀腺功能改變的關系尚需進一步研究和深入探討。 3碘缺乏時,大鼠和小鼠甲狀腺自分泌TGF-β1升高,抑制甲狀腺濾泡細胞的增生(此時甲狀腺呈增生狀態(tài)),體現(xiàn)甲狀腺器官的自穩(wěn)調控機制;碘過量時,大鼠和小鼠甲狀腺自分泌TGF-β1mRNA表達也升高,可能分別參與了高碘所致大鼠甲狀腺呈多型性變化但無腫大形成、小鼠甲狀腺膠質蓄積性甲狀腺腫形成的調控過程。
[Abstract]:In this experiment, on the basis of the successful establishment of iodine deficiency and iodine excess Wistar rats and Balb/c mice model, the changes in the thyroid morphology and function of mice under different iodine intake levels were observed, and the mRNA and protein expression levels of IGF - beta 1 (TGF- beta 1) in the thyroid tissue were detected. The possible role of IGF-1 and TGF- beta 1 in the growth and function of thyroid gland induced by iodine deficiency and iodine excess was further explored.
Wistar rats and Balb/c mice were randomly divided into 3 groups: low iodine group (LI), normal iodine group (NI), 50 times high iodine group (50HI) group.LI animal feed average iodine content was 50 mu g/kg, NI and 50HI group animal feed average iodine content was 300 mu g/kg; LI group and NI group animals drinking deionized water. Ion water. According to the daily intake and drinking amount of the mice, the daily total iodine intake was estimated in each group: 1 mu g/d (group LI), 6 mu g/d (group NI), 300 mu g/d (group 50HI), respectively: 0.25 mu g/d (LI group), 1.5 micron g/d (NI group), 75 mu g/d (50HI group). Iodine, thyroid hormone, thyroid morphologic observation, morphometry were used to measure the storage and content of thyroid globulin; meanwhile, real-time fluorescence quantitative PCR, semi quantitative PCR, immunohistochemistry and other experimental techniques were used to detect the mRNA of IGF-1 and TGF- beta 1 in thyroid tissue and the changes of protein expression level.
The experimental results show that:
1 urinary iodine and iodine level of thyroid tissue: group LI was large and the level of urine iodine was very low in mice. The iodine levels in group NI and 50HI were almost the same as those of iodine intake. Iodine content in thyroid tissue in each group increased with the increase of iodine intake, but the increase was far less than that of urine iodine, which was not consistent with the iodine intake level.
2 the level of thyroid hormone: the level of LI in each time period was large and the level of T_3 and T_4 in the thyroid tissue of mice was significantly lower than that in the same period NI group. T_3/T_4 was significantly higher than that of the NI group, while the 50HI group was large and the mice were not exactly the same. The thyroid T_3 content of 50HI group was lower than that of the same stage NI group, and the T_4 content was not significantly different from that of the NI group. The levels of T_3 and T_4 in the thyroid tissue in the 50HI group were significantly higher than those in the NI group at 3 months. At 6 months, the level of T_3 was close to normal, and the T_4 was still higher, but it was not as obvious as that at 3 months. T_3/T_4 was lower in 3,6 months than in the NI group, but there was no statistical difference.
3 the morphological changes of thyroid were large, the thyroid follicles of the NI group were all medium size, the epithelial cells were single or flat, and the colloid in the follicular cavity was rich. In group LI, the thyroid gland showed small follicular hyperplastic goiter, while the group 50HI was large and the mice were different. The thyroid gland of the group 50HI rats was compared with the NI group, and the thyroid gland appeared multiple types. Sex changes, manifested as a significant increase in the follicular follicles, the follicle filled with dense staining gelatin, epithelial cells flat, and some follicles close to normal, at the same time, the proliferation phenomenon is obvious, showing that follicles become smaller, epithelial cells become columnar, follicular cavity becomes smaller, glial decrease, and TSH stimulation signs; 50HI group thyroid gland is compared with group NI, follicular The accumulation of colloid in the cavity, the enlargement of the follicle cavity, the flattening of the epithelial cells and the appearance of the glial accumulative goiter were different from those of the high iodine rats. The high iodine mice had a glial accumulative goiter, and no thyroid hyperplasia was found, that is, there was no obvious sign of TSH stimulation.
4 the results of morphometric measurement of the level of thyroid gland accumulation: the intercepting area of follicular cavity in group 50HI rats at each time period, the ratio of large and medium follicle cavity is not obvious, and the large follicular glial accumulation is not suggested in rats, and the ratio of the area to the field area of the rats in group 50HI is higher than that of the NI group at the time of 3 months, but it is lower than that of the NI group at 6 months. The average gray level of the glia in 50HI group was lower than that of the NI group at the time of 6 months, and there was no difference compared with the NI group. It showed that the total content of thyroid globulin in the rats was not significantly changed under the high iodine intake. Different from the rats, the section area of the thyroid follicle in the 50HI group was obviously increased, small, the medium follicle cavity decreased obviously, and the large follicle cavity increased obviously, suggesting that small follicle cavity increased significantly. The rats had large follicle accumulation, and the ratio of thyroid area to the field area and the average gray level of the glia were significantly higher in the 50HI group than that in the NI group, indicating that the total content of thyroid globulin in the mice was significantly increased under the high iodine intake.
5, the expression level of IGF-1 and TGF- beta 1mRNA and protein in the thyroid gland of mice: at 3 months, the expression level of IGF-1mRNA in the thyroid gland of the LI group and the 50HI group increased significantly in the LI group and the 50HI group, and the increase in the 50HI group was more significant (P < 0.01). At the time of 6 months, the expression level of the thyroid gland IGF-1mRNA in the LI group was significantly lower than that in the NI group. Compared with group NI, the expression of IGF-1 protein in LI group and 50HI group was significantly increased in group LI and 50HI, and obvious positive particles were found in the cytoplasm of thyroid epithelial cells. At 6 months, the expression of IGF-1 protein in group LI was significantly weaker than that in NI group, and there was no obvious difference between 50HI group and NI. The IGF-1mRNA expression level of thyroid gland in mice at various periods, LI The group of group 50HI was significantly higher than group NI, and there was no statistical difference between group 50HI and NI group at.3,6 months. Compared with group NI, the expression of IGF-1 protein in group LI increased significantly, and the expression of IGF-1 protein in 50HI group had no obvious change. The results showed that the thyroid IGF-1mRNA and protein expression levels were the same in each group.
In 3,6 months, the expression level of TGF- beta 1mRNA in the thyroid gland in the LI group and the 50HI group was significantly higher than that in the NI group, and the increase of the LI group was more significant at.3 months. The expression of TGF- beta 1 protein in the LI group was significantly weaker than that in the NI group, and there was no significant difference between the 50HI group and the 50HI group. At 6 months, the expression of the beta 1 protein in the group was significantly higher than that in the group. The level of TGF- beta 1mRNA in the thyroid gland of mice was significantly reduced at.3,6 months. The LI and 50HI groups were significantly higher than those in the NI group at.3 months. The TGF- beta 1 protein expression in LI group was not significantly different from NI, and the 50HI group was significantly weaker than the NI group. At 6 months, the expression of beta 1 protein in the mice was significantly higher than that in the group. The results showed that there was no significant difference between the group and the group. The results showed that only 6 In group LI, the expression level of TGF- beta 1mRNA and protein in mice was the same at the same month. At 3 months, the LI group and 50HI group were large, and the level of TGF- beta 1mRNA and protein expression in the thyroid gland of mice was not consistent.
From the above experimental results, we can draw the following conclusions:
At the time of 1 iodine deficiency, all mice showed obvious hypothyroidism and compensatory form of small follicular hyperplastic goiter. When iodine excess, the thyroid gland had only a variety of changes and did not form goiter, and the mice had a typical glial goiter. Both rats and mice had strong adaptability to iodine excess. However, there are significant differences in the iodine content in the thyroid gland, the level of stable hormone (hormone synthesis, transformation, release), and the structural changes of the thyroid gland. In general, the rats have a stronger adaptability than the mice.
2 this study observed that the thyroid IGF-1 expression in the rat thyroid gland was elevated in a hyperactivity, and the expression of IGF-1 in the thyroid gland was maintained at a high level in mice. It suggested that IGF-1 was involved in the pathogenesis of hyperthyroid enlargement induced by iodine deficiency. When iodine excess was excessive, the expression of IGF-1 in the thyroid gland of mice was not exactly the same, but it was the same as that of the thyroid gland. The morphological changes in the glands of the thyroid gland are consistent. The relationship between thyroid autocrine IGF-1 and thyroid function changes caused by iodine deficiency and iodine excess need further study and in-depth study.
In 3 iodine deficiency, the thyroid autocrine TGF- beta 1 increased in rats and mice, inhibited the proliferation of thyroid follicle cells (at this time the thyroid hyperplasia state), and reflected the autocrat regulation mechanism of thyroid organs. When iodine excess, the expression of the thyroid autocrine TGF- beta 1mRNA in rats and mice increased, which may be involved in the thyroid gland of rats induced by high iodine, respectively. The regulation process of mouse thyroid goiter accumulating goiter was caused by polymorphic change but no enlargement.
【學位授予單位】：天津醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2008
【分類號】：R363

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相關期刊論文 前10條

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本文編號：1934866