Colston J T, de la Rosa S D, Koehler M, Gonzales K, Mestril R, Freeman G L, Bailey S R, Chandrasekar B
Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
Am J Physiol Heart Circ Physiol. 2007 Sep;293(3):H1839-46. doi: 10.1152/ajpheart.00428.2007. Epub 2007 Jul 6.
Wnt1-induced secreted protein-1 (WISP-1) is a member of the cysteine-rich 61, connective tissue growth factor, and nephroblastoma overexpressed (CCN) family of growth factors and is expressed in the heart at low basal levels. The purpose of this study was to investigate whether WISP-1 is upregulated in postinfarct myocardium and whether WISP-1 exerts prohypertrophic and mitogenic effects stimulating myocyte hypertrophy, cardiac fibroblast (CF) proliferation, and collagen expression. Male C57Bl/6 (25 g) mice underwent permanent occlusion of the left anterior descending coronary artery. mRNA and protein levels were analyzed by Northern and Western blot analyses. Cardiomyocyte hypertrophy was quantified by protein and DNA synthesis. CF proliferation was quantified by CyQuant assay, and soluble collagen release by Sircol assay. A time-dependent increase in WISP-1 expression was detected in vivo in the noninfarct zone of the left ventricle, which peaked at 24 h (3.1-fold, P < 0.01). Similarly, biglycan expression was increased by 3.71-fold (P < 0.01). IL-1beta and TNF-alpha expression preceded WISP-1 expression in vivo and stimulated WISP-1 expression in neonatal rat ventricular myocytes in vitro. WISP-1-induced cardiomyocyte hypertrophy was evidenced by increased protein (2.78-fold), but not DNA synthesis, and enhanced Akt phosphorylation and activity. Treatment of primary CF with WISP-1 significantly stimulated proliferation at 48 h (6,966 +/- 264 vs. 5,476 +/- 307 cells/well, P < 0.01) and enhanced collagen release by 72 h (18.4 +/- 3.1 vs. 8.4 +/- 1.0 ng/cell, P < 0.01). Our results demonstrate for the first time that WISP-1 and biglycan are upregulated in the noninfarcted myocardium in vivo, suggesting a positive amplification of WISP-1 signaling. WISP-1 stimulates cardiomyocyte hypertrophy, fibroblast proliferation, and ECM expression in vitro. These results suggest that WISP-1 may play a critical role in post-myocardial infarction remodeling.
Wnt1诱导分泌蛋白-1（WISP-1）是富含半胱氨酸61、结缔组织生长因子和过表达的肾母细胞瘤（CCN）生长因子家族的成员，在心脏中以低基础水平表达。本研究的目的是调查WISP-1在心肌梗死后心肌中是否上调，以及WISP-1是否发挥促肥大和有丝分裂作用，刺激心肌细胞肥大、心脏成纤维细胞（CF）增殖和胶原蛋白表达。雄性C57Bl/6（25克）小鼠接受左冠状动脉前降支永久性闭塞。通过Northern和Western印迹分析来分析mRNA和蛋白质水平。通过蛋白质和DNA合成来定量心肌细胞肥大。通过CyQuant测定法对CF增殖进行定量，通过Sircol测定法对可溶性胶原蛋白释放进行定量。在体内左心室非梗死区检测到WISP-1表达呈时间依赖性增加，在24小时达到峰值（3.1倍，P<0.01）。同样，双糖链蛋白聚糖表达增加了3.71倍（P<0.01）。体内IL-1β和TNF-α表达先于WISP-1表达，并在体外刺激新生大鼠心室肌细胞中的WISP-1表达。WISP-1诱导的心肌细胞肥大表现为蛋白质增加（2.78倍），但DNA合成未增加，同时Akt磷酸化和活性增强。用WISP-1处理原代CF在48小时时显著刺激增殖（6,966±264对5,476±307个细胞/孔，P<0.01），并在72小时时增强胶原蛋白释放（18.4±3.1对8.4±1.0纳克/细胞，P<0.01）。我们的结果首次证明，体内非梗死心肌中WISP-1和双糖链蛋白聚糖上调，提示WISP-1信号的正性放大。WISP-1在体外刺激心肌细胞肥大、成纤维细胞增殖和细胞外基质表达。这些结果表明，WISP-1可能在心肌梗死后重塑中起关键作用。
