血清學活動臨床穩定全身性紅斑性狼瘡探討影響吞噬作用及清除凋亡細胞之因素

The study of pathogenesis of Serology Active Clinically Quiescent Patients with Systemic Lupus Erythematosus in affecting phagocytosis and clearance of apoptotic cells

黃文男(Wen-Nan Huang)

指導教授 ： 蔡嘉哲

中山醫學大學/醫學院/醫學研究所/博士(2012年)

https://doi.org/10.6834/CSMU.2012.00024

摘要

血清學活動臨床穩定的全身性紅斑性狼瘡患者是一個特別的族群，約占所有患者的8-12%，此類的病患是否真為臨床穩定則有所爭議。疾病活動度高的全身性紅斑性狼瘡巨噬細胞吞噬能力下降。但是，血清學活動臨床穩定患者的情況則有待釐清。
18位符合血清學活動臨床穩定診斷定義的紅斑性狼瘡病患，另有18位健康對照組。實驗方法是用經修改後的無血清吞噬檢測。本研究使用從單核球自然分化的巨噬細胞，去吞噬由多核型嗜中性球變成的凋亡細胞。吞噬試驗結果顯示，血清學活動臨床穩定的患者低於健康對照組。
血清學活動臨床穩定的全身性紅斑性狼瘡患者仍有顯著的巨噬細胞吞噬能力低下，這樣的現象至少部分強調此類病患仍有復發機會，而由於研究方法中排除血清因子，更證實紅斑性狼瘡患者巨噬細胞功能低下有內在因子(intrinsic factor)的存在。
另一個研究是要檢驗全身性紅斑性狼瘡患者第二型轉麩胺酶表現量。先前的研究也證實第二型轉麩胺酶是參與細胞凋亡及凋亡小體形成的潛在因子。
這個研究的目的是要檢驗全身性紅斑性狼瘡患者，周邊血液單核球第二型轉麩胺酶表現量及與臨床表現關聯性。
38位全身性紅斑性狼瘡患者及33位健康對照組參與此研究。取得受試者的血液樣本並分離出周邊血液單核球後，利用Trizol試劑來抽取細胞RNA，之後藉由反轉錄聚合酶反應將RNA轉錄為cDNA，將cDNA編碼至第二型轉麩胺酶和GAPDH特異性引子，再反轉錄聚合酶反應後用洋菜膠電泳呈現。
研究結果顯示全身性紅斑性狼瘡患者周邊血液單核球第二型轉麩胺酶表現量有顯著高於健康對照組。但是，其他的臨床因子，包括年紀、疾病活動度、病期、藥物及血清數據皆無統計學顯著相關。
先前的研究顯示，凋亡細胞會促使巨噬細胞表現第二型轉麩胺酶表現及增加吞噬凋亡細胞的能力。但是，全身性紅斑性狼瘡患具有高凋亡細胞及低的吞噬能力，推論周邊血液單核球第二型轉麩胺酶表現增加可能是代償性增加。目前的研究結果尚且無法證實巨噬細胞吞噬能力低落的關連性，更強化先前研究推論intrinsic factor影響的可能性，未來可能需要更多的研究分析證實其相關性。

關鍵字

血清學活動臨床穩定全身性紅斑性狼瘡 ； 凋亡細胞 ； 巨噬細胞 ； 第二型轉麩胺酶

並列摘要

Serologically active clinically quiescent (SACQ) patients was 8-12% of the total SLE population. SACQ is controversial in true inactive lupus or not. Impaired phagocytosis and clearance of apoptotic cells have been found in active lupus patients. However, this phenomenon is still controversial in SACQ lupus patients.
Eighteen SACQ lupus patients were enrolled in this study. Eighteen age-matched healthy females served as controls. Macrophage phagocytosis of apoptotic cells was assessed in vitro using the serum-free phagocytosis assay with minor modifications. Adherent human monocyte-derived macrophages were used in this study. Compared to healthy controls, clinically inactive patients with SLE had significantly decreased phagocytosis ratio.
SACQ SLE patients significantly impaired phagocytosis and clearance of apoptotic cells were still observed. Such phenomena might at least in part amplify further disease progression, also more enhanced the importance of intrinsic factor.
The mechanism of autoimmune disease remains unclear. It has been thought that balance of cell survival and death is the main reason of autoimmune disease. Several studies indicated that transglutaminase 2 plays a potential role in cell apoptosis.
The aim of this study was to investigate the mRNA expression of TG2 on peripheral blood mononuclear cells (PBMCs) in lupus patients and further to determine its association with clinical features.
Thirty-eight female lupus patients were enrolled in this study. Thirty three age-matched healthy subjects served as controls. Total RNA was isolated from PBMCs of patients with SLE and healthy subjects. The first-strand cDNA for RT-PCR was synthesized from total RNA using the RT-PCR system. The cDNAs encoding human TG2 and GAPDH were amplified by RT-PCR using the appropriate primer pairs, respectively.
The mRNA expression of TG2 in SLE patients was significantly higher than healthy controls. However, there was no significant difference for mRNA expression of TG2 between different age, disease activity, disease duration or serology data.
In previous study, apopotic cell induced TG2 expression and enhanced phagocytosis. SLE patient impaired phagocysosis and increased apopotosis, such phenomenon may postulate apoptotic cell compensatively increased TG2 overexpression on PMBC in SLE. It can’t conclude the mechanism of impaired phagocytosis in SLE patients, which emphasized macrophage defect itself and needs further investigation.

並列關鍵字

Systemic lupus erythematousus ； serologically active clinically quiescent ； phagocytosis ； apoptosis ； Transglutaminase2

參考文獻

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