KMUP-1抑制低氧誘導TRPC1通道表現於肺動脈平滑肌細胞

KMUP-1 Inhibits Hypoxia-Induced TRPC1 Expression in Pulmonary Arterial Smooth Muscle Cells

陳逸真(Yi-Chen Chen)

指導教授 ： 吳炳男

高雄醫學大學/醫學院/藥理學科研究所/碩士(2009年)

摘要

暴露在低氧的情況之下會引起所謂的肺高壓。除此之外，肺動脈平滑肌細胞內鈣離子濃度的增加是引起肺血管的收縮及細胞增生的一個重要因子。
本實驗的研究目的是探討 KMUP-1 能否抑制低氧所導致的 TRPC 陽離子通道的過度表現，其中所參與的機轉，以及 KMUP-1 能否調節藉由鈣池調控鈣離子通道進入的鈣離子濃度。犧牲Spraque-Dawley 大鼠取出肺動脈初代培養肺動脈平滑肌細胞，將細胞置入含氧量為 1% O2/ 5% CO2 的可調節式細胞培養箱中 24 小時來誘導鈣池調控鈣離子通道的過度表現。
KMUP-1 (1 μM) 可以抑制低氧導致 TRPC 陽離子通道家族之蛋白質轉碼成鈣池調控鈣離子通道的過度表現，特別是 TRPC1 陽離子通道。而 KMUP-1 的抑制作用可以被 PKG 及 PKA 的抑制劑 KT5823 (1 μM)、KT5720 (1 μM) 減弱，另外 KMUP-1 會抑制 PKC 的活化劑 PMA (1 μM) 調控的 TRPC1 表現。所以 KMUP-1 的作用由實驗中可發現可能參與了活化 cGMP/PKG 和 cAMP/PKA 並且抑制 PKC 的路徑。除此之外，我們還利用 Fura-2/AM 測量低氧誘導的肺動脈平滑肌細胞其儲存鈣離子的釋放以及經由鈣池調控鈣離子通道進入細胞的鈣離子。發現低氧可以增加經由鈣池調控鈣離子通道之鈣離子。KMUP-1 可以減弱低氧誘導肺動脈平滑肌細胞的鈣離子進入。
因此由實驗當中可以得知，KMUP-1 可以抑制低氧誘導的肺動脈平滑肌細胞 TRPC1 蛋白質的表現並且可以減少經由鈣池調控鈣離子通道進入的鈣離子。

關鍵字

低氧 ； TRPC1 ； 肺動脈平滑肌細胞

並列摘要

Exposure to hypoxia results in the development of pulmonary hypertension An increase in the intracellular Ca2+ concentration ([Ca2+]i) in pulmonary artery smooth muscle cells (PASMCs) is a major trigger for pulmonary vasoconstriction and proliferation.
The aim of this study was to examine the mechanism by which KMUP-1 inhibited the hypoxia-induced canonical transient receptor potential (TRPC) protein overexpression and regulated the [Ca2+]i through store-operated calcium channels (SOCC). Primary PASMCs were cultured from Spraque-Dawley rats and placed in a modular incubator chamber under 1% O2/5% CO2 for 24 hours to induce SOCC overexpression.
KMUP-1 (1 μM) inhibited hypoxia-induced TRPC family encoded for SOCC overexpression, particularly TRPC1. KMUP-1-inhibited TRPC1 attenuated by the PKG inhibitor KT5823 (1 μM) and the PKA inhibitor KT5720 (1 μM). A PKC activator PMA (1 μM)-mediated TRPC1 was attenuated by KMUP-1. Taken together, we suggest that the effects of KMUP-1 on TRPC1 might involve the activation of cGMP/PKG and cAMP/PKA pathways, and inhibition of PKC pathway. Moreover, we use Fura-2/AM to measure the store calcium release from sarcoplasmic reticulum (SR) and calcium entry through SOCC in hypoxic PASMCs. Under hypoxic conditions, the activity of store-operated calcium entry (SOCE) was enhanced. KMUP-1 could refill the stores and attenuate SOCE through SOCC in hypoxic PASMCs.
In conclusion, KMUP-1 inhibited TRPC1 protein expression and reduced CCE could be through the SOCC in hypoxic PASMCs.

並列關鍵字

KMUP-1 ； TRPC1 ； pulmonary arterial smooth muscle cell

參考文獻

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