Dunsmore S E, Rannels S R, Grove R N, Rannels D E
Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey 17033, USA.
Am J Physiol. 1995 Jun;268(6 Pt 1):L885-93. doi: 10.1152/ajplung.1995.268.6.L885.
Previous studies suggested an association between changes in extracellular matrix (ECM) and pulmonary epithelial cell growth and differentiation in lungs of adrenalectomized rats. The role of adrenal hormones to modulate synthesis of cell and ECM proteins by type II epithelial cells was thus investigated. In cells isolated from lungs of adrenalectomized animals, synthesis of ECM proteins was stimulated to a greater extent than was synthesis of cell proteins. This resulted in increased relative synthesis of matrix components. Conversely, dexamethasone (200 nM) treatment in vitro reduced the effects of adrenalectomy and, in control cells, decreased relative ECM synthesis. The magnitude of these effects depended on time in culture and serum conditions. For example, culture of normal cells in serum-free medium mimicked the effects of adrenalectomy, whereas there were no effects of dexamethasone in the presence of serum. These results indicate a role for adrenal steroid hormones to modulate ECM metabolism by type II pulmonary epithelial cells and suggest that consequent effects on ECM biological activity may modify epithelial cell differentiation or growth.
先前的研究表明，细胞外基质（ECM）的变化与肾上腺切除大鼠肺组织中肺上皮细胞的生长和分化之间存在关联。因此，研究了肾上腺激素对II型上皮细胞合成细胞和ECM蛋白的调节作用。在从肾上腺切除动物的肺中分离出的细胞中，ECM蛋白的合成比细胞蛋白的合成受到更大程度的刺激。这导致基质成分的相对合成增加。相反，体外给予地塞米松（200 nM）可减轻肾上腺切除的影响，而在对照细胞中，则会降低ECM的相对合成。这些作用的程度取决于培养时间和血清条件。例如，在无血清培养基中培养正常细胞可模拟肾上腺切除的作用，而在有血清存在的情况下，地塞米松则无作用。这些结果表明，肾上腺类固醇激素在调节II型肺上皮细胞的ECM代谢中起作用，并提示对ECM生物活性的后续影响可能会改变上皮细胞的分化或生长。
