Basson M D, Modlin I M, Flynn S D, Jena B P, Madri J A
Department of Surgery, Yale University School of Medicine, New Haven, CT 06510.
Surgery. 1992 Aug;112(2):299-307; discussion 307-8.
Gastrointestinal mucosa heals by restitution and proliferation. These are difficult to distinguish in vivo.
Human Caco-2 enterocytes were cultured on matrix proteins (collagen I, laminin, fibronectin) with growth factors (epidermal growth factor [EGF] and transforming growth factor-beta 1 [TGF-beta 1]) and the tyrosine kinase and prostaglandin inhibitors genistein and indomethacin. Healing was modeled by means of monolayer expansion, proliferation by means of 3H-thymidine uptake, and restitution by means of mitomycin-blocked migration.
Changing matrix composition failed to alter proliferation, but collagen I stimulated migration more than laminin or fibronectin (laminin/collagen, 68% +/- 2%; p less than 0.05). EGF (30 ng/ml) increased proliferation on both collagen (225% +/- 11% of basal) and laminin (206% +/- 26%) but increased migration only over laminin (210% +/- 17%) (all, p less than 0.05). TGF-beta 1 (200 pg/ml) stimulated migration over laminin (187% +/- 18%, p less than 0.005) but inhibited migration over collagen (89% +/- 3%, p less than 0.01) and did not affect 3H-thymidine uptake. When cultured on laminin, EGF but not TGF-beta 1 altered organization of the alpha 2 integrin subunit. Genistein (100 mumol/L) inhibited basal and EGF-stimulated 3H-thymidine uptake. In addition, it prevented EGF stimulation of replication-blocked migration (81% +/- 10% vs 190% +/- 20% of basal, p less than 0.0001) without altering basal replication-blocked migration. Indomethacin (10(-5) mol/L) did not alter migration but inhibited basal and EGF-stimulated proliferation by 7% +/- 1% (each, p less than 0.005).
Restitution and proliferation appear independently regulated by matrix and growth factors. It may be possible to individually target specific phases of mucosal healing by means of pharmacologic agents.
胃肠道黏膜通过修复和增殖实现愈合。在体内很难区分这两种过程。
将人Caco-2肠上皮细胞接种于含有生长因子（表皮生长因子[EGF]和转化生长因子-β1[TGF-β1]）以及酪氨酸激酶和前列腺素抑制剂染料木黄酮和吲哚美辛的基质蛋白（I型胶原、层粘连蛋白、纤连蛋白）上进行培养。通过单层扩展模拟愈合过程，通过³H-胸腺嘧啶核苷摄取模拟增殖过程，通过丝裂霉素阻断迁移模拟修复过程。
改变基质组成未能改变增殖，但I型胶原比层粘连蛋白或纤连蛋白更能刺激迁移（层粘连蛋白/胶原，68%±2%；p<0.05）。EGF（30 ng/ml）可增加I型胶原（基础水平的225%±11%）和层粘连蛋白（基础水平的206%±26%）上的增殖，但仅增加层粘连蛋白上的迁移（基础水平的210%±17%）（所有p值均<0.05）。TGF-β1（200 pg/ml）刺激层粘连蛋白上的迁移（基础水平的187%±18%，p<0.005），但抑制I型胶原上的迁移（基础水平的89%±3%，p<0.01），且不影响³H-胸腺嘧啶核苷摄取。当接种于层粘连蛋白上时，EGF而非TGF-β1改变了α2整合素亚基的组织。染料木黄酮（100 μmol/L）抑制基础水平及EGF刺激的³H-胸腺嘧啶核苷摄取。此外，它可阻止EGF刺激的复制阻断迁移（基础水平的81%±10%对基础水平的190%±20%，p<0.0001），而不改变基础水平的复制阻断迁移。吲哚美辛（10⁻⁵ mol/L）不改变迁移，但抑制基础水平及EGF刺激的增殖7%±1%（均p<0.005）。
修复和增殖似乎由基质和生长因子独立调节。通过药物有可能分别针对黏膜愈合的特定阶段。
