title: Regulation of proximal tubular cell differentiation and proliferation in primary culture by matrix stiffness and ECM components.
abstract: To explore whether matrix stiffness affects cell differentiation, proliferation, and transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) in primary cultures of mouse proximal tubular epithelial cells (mPTECs), we used a soft matrix made from monomeric collagen type I-coated polyacrylamide gel or matrigel (MG). Both kinds of soft matrix benefited primary mPTECs to retain tubular-like morphology with differentiation and growth arrest and to evade TGF-β1-induced EMT. However, the potent effect of MG on mPTEC differentiation was suppressed by glutaraldehyde-induced cross-linking and subsequently stiffening MG or by an increasing ratio of collagen in the soft mixed gel. Culture media supplemented with MG also helped mPTECs to retain tubular-like morphology and a differentiated phenotype on stiff culture dishes as soft MG did. We further found that the protein level and activity of ERK were scaled with the matrix stiffness. U-0126, a MEK inhibitor, abolished the stiff matrix-induced dedifferentiation and proliferation. These data suggest that the ERK signaling pathway plays a vital role in matrix stiffness-regulated cell growth and differentiation. Taken together, both compliant property and specific MG signals from the matrix are required for the regulation of epithelial differentiation and proliferation. This study provides a basic understanding of how physical and chemical cues derived from the extracellular matrix regulate the physiological function of proximal tubules and the pathological development of renal fibrosis.
authors: Institute of Basic Medical Sciences, National Cheng-Kung University Medical College, Tainan, Taiwan; and.
authors: Wan-Chun
authors: WC
authors: Chen
authors: Department of Physiology, National Cheng-Kung University Medical College, Tainan, Taiwan.
authors: Hsi-Hui
authors: HH
authors: Lin
authors: Institute of Basic Medical Sciences, National Cheng-Kung University Medical College, Tainan, Taiwan; and Department of Physiology, National Cheng-Kung University Medical College, Tainan, Taiwan mjtang1@mail.ncku.edu.tw.
authors: Ming-Jer
authors: MJ
authors: Tang
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D058750:Epithelial-Mesenchymal Transition; D005109:Extracellular Matrix / Q000502:physiology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000166:cytology*; D008297:Male; D008810:Mice, Inbred C57BL; D013552:Swine; D053773:Transforming Growth Factor beta1
chemical_list: C508961:Tgfb1 protein, mouse; D053773:Transforming Growth Factor beta1; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: differentiation; extracellular matrix; matrix stiffness; proliferation; renal proximal tubule cell; transforming growth factor-β1-induced epithelial-mesenchymal transition