INK4a knockout mice exhibit increased fibrosis under normal conditions and in response to unilateral ureteral obstruction.
INK4a knockout mice exhibit increased fibrosis under normal conditions and in response to unilateral ureteral obstruction.
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DOI：
10.1152/ajprenal.00378.2010
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发表时间：
2010-12
期刊：
影响因子：
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通讯作者：
Jesse M Wolstein;David H. Lee;Jennine M Michaud;Venessa Buot;Beth Stefanchik;M. Plotkin
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文献类型：
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作者：
Jesse M Wolstein;David H. Lee;Jennine M Michaud;Venessa Buot;Beth Stefanchik;M. Plotkin
INK 4a蛋白p16（INK 4a）和p19（ARF）调节细胞周期停滞和衰老。然而，这些蛋白质在正常肾脏和损伤后控制这些过程中的作用尚不清楚。我们在2至3个月大的野生型（WT）C57/B6和INK 4a基因敲除小鼠中进行单侧输尿管梗阻（UUO）诱导纤维化。通过定量RT-PCR，在UUO后7天，WT小鼠的p16（INK 4a）水平增加了6倍，而p19（ARF）仍然检测不到。检查肾切片以确定p16（INK 4a）、凋亡、纤维化和衰老细胞的水平和定位。在正常条件下，INK 4a基因敲除小鼠显示肾小球系膜细胞增殖、基质沉积增加和肌成纤维细胞分化。在UUO后，与WT小鼠相比，INK 4a敲除小鼠显示肾小管和间质细胞增殖增加10倍，集合管凋亡减少75%，胶原和纤连蛋白沉积增加2倍，并且通过衰老相关β-半乳糖苷酶染色没有细胞衰老。与WT样品相比，通过ELISA，INK 4a敲除的系膜细胞和来自损伤后敲除小鼠的肾裂解物均显示升高的IL-6水平。当暴露于转化生长因子-β时，INK 4a敲除上皮细胞培养物显示间充质细胞标志物增加。这些结果证实了p16（INK 4a）控制细胞增殖和基质产生并减轻损伤后的纤维化，并表明该机制涉及限制炎症和细胞增殖的作用。
The INK4a proteins p16(INK4a) and p19(ARF) regulate cell cycle arrest and senescence. However, the role of these proteins in controlling these processes in the normal kidney and following injury is unknown. We performed unilateral ureteral obstruction (UUO) to induce fibrosis in 2- to 3-mo-old wild-type (WT) C57/B6 and INK4a knockout mice. By quantitative RT-PCR, p16(INK4a) levels were increased sixfold in WT mice 7 days after UUO and p19(ARF) remained undetectable. Kidney sections were examined to determine levels and localization of p16(INK4a), apoptosis, fibrosis, and senescent cells. INK4a knockout mice displayed mesangial cell proliferation, increased matrix deposition, and myofibroblast differentiation under normal conditions. Following UUO, INK4a knockout mice displayed 10-fold increased tubular and interstitial cell proliferation, 75% decreased collecting duct apoptosis, 2-fold greater collagen and fibronectin deposition, and no cell senescence by senescence-associated β-galactosidase staining compared with WT mice. Both INK4a knockout mesangial cells and kidney lysates from knockout mice following injury showed elevated levels of IL-6 by ELISA compared with WT samples. INK4a knockout epithelial cell cultures displayed increased mesenchymal cell markers when exposed to transforming growth factor-β. These results confirm that p16(INK4a) controls cell proliferation and matrix production and mitigates fibrosis following injury and suggest that the mechanism involves a role in limiting inflammation and cell proliferation.