McConnell Beth B, Ghaleb Amr M, Nandan Mandayam O, Yang Vincent W
Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA.
Bioessays. 2007 Jun;29(6):549-57. doi: 10.1002/bies.20581.
The Krüppel-like factors (KLFs) comprise a family of evolutionarily conserved zinc finger transcription factors that regulate numerous biological processes including proliferation, differentiation, development and apoptosis. KLF4 and KLF5 are two closely related members of this family and are both highly expressed in epithelial tissues. In the intestinal epithelium, KLF4 is expressed in terminally differentiated epithelial cells at the villus borders of the mucosa and inhibits cell growth, while KLF5 is expressed in proliferating epithelial cells at the base of the intestinal crypts and promotes cell growth. KLF4 and KLF5 respond to a myriad of external stress stimuli and are likely involved in restoring cellular homeostasis following exposure to stressors. Confirming their importance in maintaining tissue integrity, KLF4 and KLF5 are both dysregulated in various types of cancer. Here we review the recent advances in defining the physiological and pathobiological roles of KLF4 and KLF5, focusing on their functions in the intestinal epithelium.
Krüppel样因子（KLFs）是一类进化上保守的锌指转录因子家族，可调节包括增殖、分化、发育和凋亡在内的众多生物学过程。KLF4和KLF5是该家族两个密切相关的成员，在上皮组织中均高表达。在肠道上皮中，KLF4在黏膜绒毛边缘的终末分化上皮细胞中表达，并抑制细胞生长，而KLF5在肠隐窝底部的增殖上皮细胞中表达，并促进细胞生长。KLF4和KLF5对多种外部应激刺激作出反应，可能参与应激源暴露后恢复细胞内稳态。KLF4和KLF5在各种类型的癌症中均表达失调，这证实了它们在维持组织完整性方面的重要性。在此，我们综述了在确定KLF4和KLF5的生理和病理生物学作用方面的最新进展，重点关注它们在肠道上皮中的功能。
