CAJ | 학술논문

目的探讨近曲小管肝型脂肪酸结合蛋白(L-FABP)对骨髓移植诱导的小鼠IgAN的肾脏保护作用.方法通过骨髓移植在肾小管高表达人类L-FABP(hL-FABP)基因的转基因鼠(Tg)和相同背景的野生鼠(WT)上重建IgAN.受体鼠分别在骨髓移植后第6和12周处死,留取肾脏标本.用实时荧光定量PCR方法检测肾脏hL-FABP、纤连蛋白(FN)和单核细胞趋化蛋白1(MCP-1)的mRNA表达;免疫组化法检测hL-FABP和FN的蛋白表达分布;Western印迹法检测hL-FABP、4-羟壬烯醛(4-HNE)、血红素加氧酶1(HO-1)、FN、Ⅳ型胶原的蛋白表达水平;ELISA法检测血清IgA、尿白蛋白和尿hL-FABP水平.结果骨髓移植在受体转基因鼠(Tg-ddY)和野生鼠(WT-ddY)上均重建了IgAN,血清IgA水平升高伴有系膜区IgA沉积,组间差异无统计学意义.正常Tg鼠的肾小管表达hL-FABP.与正常Tg鼠相比,骨髓移植后第6周,Tg-ddY鼠肾脏hL-FABP的mRNA(1.62±0.32比0.46±0.09,P＜0.01)和蛋白(1.74±0.76比1.14±0.31,P＜0.01)表达水平显著上调,伴有尿hL-FABP水平(μg/g肌酐)显著升高(59.87±26.75比31.01±14.86,P＜0.05).与Tg-ddY鼠相比,WT-ddY鼠在第12周出现明显的白蛋白尿(mg/L)(828±656比82±22,P＜0.01)、明显的系膜基质扩张(P＜0.01),并在肾小球出现更多的FN及Ⅳ型胶原沉积.Tg-ddY鼠的肾脏HO-1和4-HNE修饰蛋白(均P＜0.05)以及MCP-1 mRNA的表达(P＜0.01)被显著抑制.结论肾小管L-FABP可能通过抑制氧化应激和炎性介质的产生减轻肾小球损伤,在IgAN早期发挥了肾脏保护作用.
목적 탐토근곡소관간형지방산결합단백(L-FABP)대골수이식유도적소서IgAN적신장보호작용.방법 통과골수이식재신소관고표체인류L-FABP(hL-FABP)기인적전기인서(Tg)화상동배경적야생서(WT)상중건IgAN.수체서분별재골수이식후제6화12주처사,류취신장표본.용실시형광정량PCR방법검측신장hL-FABP、섬련단백(FN)화단핵세포추화단백1(MCP-1)적mRNA표체;면역조화법검측hL-FABP화FN적단백표체분포;Western인적법검측hL-FABP、4-간임희철(4-HNE)、혈홍소가양매1(HO-1)、FN、Ⅳ형효원적단백표체수평;ELISA법검측혈청IgA、뇨백단백화뇨hL-FABP수평.결과 골수이식재수체전기인서(Tg-ddY)화야생서(WT-ddY)상균중건료IgAN,혈청IgA수평승고반유계막구IgA침적,조간차이무통계학의의.정상Tg서적신소관표체hL-FABP.여정상Tg서상비,골수이식후제6주,Tg-ddY서신장hL-FABP적mRNA(1.62±0.32비0.46±0.09,P＜0.01)화단백(1.74±0.76비1.14±0.31,P＜0.01)표체수평현저상조,반유뇨hL-FABP수평(μg/g기항)현저승고(59.87±26.75비31.01±14.86,P＜0.05).여Tg-ddY서상비,WT-ddY서재제12주출현명현적백단백뇨(mg/L)(828±656비82±22,P＜0.01)、명현적계막기질확장(P＜0.01),병재신소구출현경다적FN급Ⅳ형효원침적.Tg-ddY서적신장HO-1화4-HNE수식단백(균P＜0.05)이급MCP-1 mRNA적표체(P＜0.01)피현저억제.결론 신소관L-FABP가능통과억제양화응격화염성개질적산생감경신소구손상,재IgAN조기발휘료신장보호작용.
Objective To investigate the renoprotection of tubular L-FABP in murine IgA nephropathy (IgAN) induced by bone marrow transplantation(BMT). Methods IgAN models were reconstituted by BMT from IgAN-prone mice into mice (Tg) transgenically tubular overexpressing human L-FABP (hL-FABP) and wild type (WT) mice. These recipients were sacrificed at 6 and 12 weeks after BMT and their kidneys were collected. The expressions of hL-FABP, fibronectin (FN)and monocyte chemoattractant protein-1 (MCP-1) mRNA were detected by real-time PCR. hL-FABP,FN, type Ⅳ collagen (Col Ⅳ ), hemeoxygenase-1 (HO-1) and 4-hydroxy-2-nonenal (4-HNE)modified proteins were detected by Western blotting. The distribution of hL-FABP and FN protein in kidney was detected by immunohistochemistry. The level of serum IgA, urinary albumin and urinary hL-FABP was detected by ELISA. Results (1) IgAN was reconstituted in both Tg and WT mice by BMT: mesangial IgA deposition and up-regulation of serum IgA. The levels were not significantly different between two groups (Tg-ddY and WT-ddY). (2) hL-FABP was expressed in proximal tubular cells of normal Tg mice. The mRNA (1.62±0.32 vs 0.46±0.09, P＜0.01) and protein expression (1.74±0.76 vs 1.14±0.31, P＜0.01) of hL-FABP was up-regulated in Tg-ddY kidney and urinary hL-FABP level (μg/g creatinine) was significantly increased (59.87±26.75 vs 31.01±14.86, P＜0.05) at the 6th week after BMT. (3) WT-ddY mice showed a significantly higher urinary albumin level (mg/L) (828±656 vs 82±22, P＜0.01), severer mesangial matrix expansion (P＜0.01),more glomerular FN and Col Ⅳ deposition at the 12th week. (4) Up-regulation of renal hL-FABP was associated with significant suppression of renal HO-1 expression (P ＜0.05),accumulation of 4-HNE modified proteins (P＜0.05) and MCP-1 mRNA expression (P＜0.01) in Tg-ddY mice. Conclusion Tubular L-FABP may lessen the progression of glomerular damage at early stages of IgAN by reducing oxidative stress and inflammatory mediators.