本文選題：UVB照射 + 黑素小體轉(zhuǎn)運(yùn)�。� 參考：《第四軍醫(yī)大學(xué)》2012年碩士論文

【摘要】：人體皮膚顏色多樣，主要是由表皮細(xì)胞中的色素沉著決定的。色素沉著是一個(gè)復(fù)雜而精密的多步驟過程，目前研究認(rèn)為主要可以分為四步，首先是黑素在黑素細(xì)胞中的黑素小體內(nèi)合成，，接著是由核周沿著樹突延伸的方向向遠(yuǎn)端運(yùn)輸，然后是向周圍的角質(zhì)形成細(xì)胞轉(zhuǎn)運(yùn)，最后在角質(zhì)形成細(xì)胞中再分布、降解[1]。黑素小體由核周向樹突遠(yuǎn)端轉(zhuǎn)移轉(zhuǎn)移至周圍的角質(zhì)形成細(xì)胞的過程被人們稱為黑素小體的轉(zhuǎn)運(yùn)[2]。 在色素沉著的過程中，黑素合成固然重要，但黑素小體轉(zhuǎn)運(yùn)也必不少的。樹突不僅是黑素細(xì)胞的形態(tài)學(xué)標(biāo)志，更重要是黑素小體轉(zhuǎn)運(yùn)的中介點(diǎn)，其數(shù)量及形態(tài)的變化在黑素轉(zhuǎn)運(yùn)中起著極為重要的作用，調(diào)控樹突的形成可以對(duì)色素沉著產(chǎn)生明顯的影響[3]。研究發(fā)現(xiàn)，很多因素能夠影響樹突的形成。Scott等研究發(fā)現(xiàn)，Rho家族小GTP酶，尤其是Rac1和RhoA在黑素細(xì)胞樹突形成方面起重要作用[4]，其中Rac1起著促進(jìn)樹突形成與延伸的作用，而RhoA則具有相反的作用。我們前期研究發(fā)現(xiàn)，UVB照射可以通過調(diào)控樹突形成相關(guān)因子Rac1和RhoA的表達(dá)明顯促進(jìn)黑素細(xì)胞樹突的形成和延長(zhǎng)，但是，UVB照射調(diào)控Rac1和RhoA表達(dá)的機(jī)制尚不清楚。 近年來(lái)，環(huán)氧合酶(cyclooxygenase，COX)在腫瘤的形成和發(fā)展中的作用成為人們關(guān)注的熱點(diǎn)。有研究顯示，COX-2抑制劑能抑制αvβ3調(diào)節(jié)的Cdc42/Rac1依賴的內(nèi)皮細(xì)胞的遷移[5]，并且，COX-2特異性抑制劑NS-398能夠使腫瘤細(xì)胞絲狀偽足消失及細(xì)胞侵襲能力下降，表明COX-2和Cdc42/Rac1都是NSAIDs引起細(xì)胞絲狀偽足消失和體外侵襲能力下降的重要分子[6]。這些研究提示環(huán)氧合酶與樹突的形成可能具有一定的關(guān)系。 因此，我們通過檢測(cè)UVB照射后黑素細(xì)胞COX水平的變化及觀察抑制COX活性對(duì)黑素細(xì)胞樹突形態(tài)及Rac1、RhoA的影響，深入探討環(huán)氧合酶在UVB照射誘導(dǎo)黑素細(xì)胞樹突形成中的作用及機(jī)制，為闡明UVB照射后色素沉著的發(fā)生機(jī)制以及防止提供新思路和新策略。 實(shí)驗(yàn)方法： 本研究采用永生化的人表皮黑素細(xì)胞系PIG1，常規(guī)培養(yǎng)后分為5組，分別為：①對(duì)照組；②100mJ/3潂2UVB照射組；③100mJ/3潂2UVB照射+ASA；④100mJ/3潂2UVB照射+NS-398；⑤100mJ/3潂2UVB照射+SC-560。首先，應(yīng)用Western blot和RT-PCR檢測(cè)UVB照射對(duì)黑素細(xì)胞中COX-1、COX-2表達(dá)的影響；然后，顯微鏡下觀察不同處理對(duì)黑素細(xì)胞樹突形態(tài)的影響；最后，提取蛋白和RNA應(yīng)用Western blot和PT-PCR方法檢測(cè)不同處理對(duì)黑素細(xì)胞Rac1和RhoA表達(dá)的影響。 實(shí)驗(yàn)結(jié)果： 1．100mJ/3潂2UVB照射后COX-1和COX-2mRNA及蛋白的表達(dá)均明顯增高； 2．100μmol/L ASA及30μmol/L NS-398均可以抑制UVB照射誘導(dǎo)的人黑素細(xì)胞系PIG1樹突的形成和延長(zhǎng)，而10μmol/L SC-560對(duì)UVB照射誘導(dǎo)的人黑素細(xì)胞系PIG1樹突的形成和延長(zhǎng)沒有明顯的抑制作用； 3．ASA濃度在50~150μmol/L內(nèi)時(shí)，可翻轉(zhuǎn)UVB照射引起的人黑素細(xì)胞系PIG1中Rac1的高表達(dá)以及RhoA的低表達(dá)，并呈劑量依賴關(guān)系；100μmol/L ASA和30μmol/L NS-398均可以抑制UVB照射誘導(dǎo)的人黑素細(xì)胞系PIG1樹突形態(tài)相關(guān)分子Rac-1的高表達(dá)及RhoA的低表達(dá),但SC-560并沒有類似效果。 結(jié)論： 1．一定劑量UVB照射可促進(jìn)黑素細(xì)胞表達(dá)COX-1和COX-2； 2．環(huán)氧合酶在樹突的形成及延長(zhǎng)中起一定作用，其中，COX-2起著主導(dǎo)作用。
[Abstract]:The color of human skin is varied, mainly determined by the pigmentation in the epidermal cells. Pigmentation is a complex and precise multistep process. It is considered to be mainly divided into four steps. First, melanin is synthesized in melanin corpuscle in melanocytes, then it is transported to the distal end from the direction of the dendrite along the dendrite. Later, the keratinocytes are transported to the surrounding keratinocytes, and then redistributed in the keratinocytes, and the process of degrading the [1]. melanosomes from the perinuclear to the distal dendrites to the surrounding keratinocytes is called the transport of the melanosomes of the [2]..
In the process of pigmentation, melanin synthesis is important, but the transport of melanosomes must be quite a few. Dendrites are not only the morphological markers of melanocytes, but also the mediating point of melanosomes transport. The changes in quantity and morphology play an important role in melanin transport, and the regulation of dendrites can produce pigmentation. [3]. studies have found that many factors can affect the formation of dendrites, such as.Scott, and other studies have found that small GTP enzymes in the Rho family, especially Rac1 and RhoA, play an important role in the formation of dendrites of melanocytes, in which Rac1 plays the role of promoting the formation and extension of dendrites, while RhoA has the opposite effect. Our previous study found UV, UV. B irradiation can promote the formation and prolongation of the dendrites of melanocytes by regulating the expression of Rac1 and RhoA by regulating the dendrites. However, the mechanism of UVB irradiation to regulate the expression of Rac1 and RhoA is still unclear.
In recent years, the role of cyclooxygenase (COX) in the formation and development of tumors has become a focus of attention. Some studies have shown that COX-2 inhibitors can inhibit the migration of [5] in the Cdc42/Rac1 dependent endothelial cells of the Cdc42/Rac1 dependent V beta 3, and the COX-2 specific inhibitor NS-398 can cause the disappearance of filamentous pseudo foot and cell invasion in tumor cells. The decrease in capacity indicates that both COX-2 and Cdc42/Rac1 are important molecules that cause the disappearance of cell filamentous pseudo foot and the decrease of invasion ability in vitro. These studies suggest that the cyclooxygenase may have a certain relationship with the formation of dendrites.
Therefore, by detecting the changes in the COX level of melanocytes after UVB irradiation and observing the effect of inhibition of COX activity on the dendritic morphology of melanocytes and the effect of Rac1 and RhoA, we explored the role and mechanism of cyclooxygenase in the formation of melanocyte dendritic cells induced by UVB irradiation, in order to clarify the mechanism of pigmentation after UVB irradiation and to provide a new way to prevent it. Ideas and new strategies.
Experimental methods:
The immortalized human epidermal melanocyte line PIG1 was used in this study and was divided into 5 groups after routine culture: (1) the control group, (2) 100mJ/3 2UVB irradiation group; (3) 100mJ/3 2UVB irradiation +ASA; (4) 100mJ/3 2UVB irradiation +NS-398; (5) 100mJ/3 2UVB 2UVB irradiation +SC-560. first. The effects of COX-1 and COX-2 expression were observed. Then, the effects of different treatments on the dendritic morphology of melanocytes were observed under the microscope. Finally, the effects of different treatments on the expression of Rac1 and RhoA in melanocytes were detected by extracting protein and RNA using Western blot and PT-PCR methods.
Experimental results:
The expression of COX-1 and COX-2mRNA and protein increased significantly after irradiation with 1.100mJ/3 2UVB.
2.100 mol/L ASA and 30 mol/L NS-398 inhibited the formation and extension of PIG1 dendritic in human melanocyte line induced by UVB irradiation, while 10 mu mol/L SC-560 had no obvious inhibitory effect on the formation and extension of PIG1 dendrites in the human melanocyte line induced by UVB irradiation.
When the concentration of 3.ASA is within 50~150 mol/L, the high expression of Rac1 and the low expression of RhoA in human melanocyte line PIG1 caused by flipping UVB irradiation are in a dose-dependent manner, and 100 u mol/L ASA and 30 micron mol/L NS-398 can inhibit the high expression of the dendritic form related molecules of the human melanocyte line induced by UVB irradiation and the low table Yes, but SC-560 does not have a similar effect.
Conclusion:
1. certain doses of UVB irradiation can promote the expression of COX-1 and COX-2 in melanocytes.
2. cyclooxygenase plays a role in the formation and extension of dendrites, and COX-2 plays a leading role.

【學(xué)位授予單位】：第四軍醫(yī)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類號(hào)】：R751

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