Induction of epithelial-to-mesenchymal transition in proximal tubular epithelial cells on microfluidic devices.
In proteinuric nephropathy, epithelial-to-mesenchymal transition (EMT) is an important mechanism that causes renal interstitial fibrosis. The precise role of EMT in the pathogenesis of fibrosis remains controversial, partly due to the absence of suitable in vitro or in vivo models. We developed two microfluidic and compartmental chips that reproduced the fluidic and three-dimensional microenvironment of proximal tubular epithelial cells in vivo. Using one microfluidic device, we stimulated epithelial cells with a flow of healthy human serum, heat-inactivated serum and complement C3a, which mimicked the flow of urine within the proximal tubule. We observed that epithelial cells exposed to serum proteins became apoptotic or developed a mesenchymal phenotype. Incubating cells with C3a induced similar features. However, cells exposed to heat-inactivated serum did not adopt the mesenchymal phenotype. Furthermore, we successfully recorded the cellular morphological changes and the process of transmigration into basement membrane extract during EMT in real-time using another three-dimensional microdevice. In conclusion, we have established a cell-culture system that mimics the native microenvironment of the proximal tubule to a certain extent. Our data indicates that EMT did occur in epithelial cells that were exposed to serum proteins, and C3a plays an essential role in this pathological process.
Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, No. 222 Zhongshan Rd, Dalian 116011, China.
Mengying
M
Zhou
Department of Biotechnology, Dalian Institute of Chemical Physics, CAS, No. 457 Zhongshan Rd, Dalian 116023, China; College of Medical Laboratory, Dalian Medical University, 9 Western Section, Lvshun South Street, Lvshunkou District, Dalian 116044, China.
Huipeng
H
Ma
Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, No. 222 Zhongshan Rd, Dalian 116011, China. Electronic address: linhongli@vip.163.com.
Hongli
H
Lin
Department of Biotechnology, Dalian Institute of Chemical Physics, CAS, No. 457 Zhongshan Rd, Dalian 116023, China. Electronic address: jhqin@dicp.ac.cn.
Jianhua
J
Qin
D017209:Apoptosis; D002461:Cell Line, Transformed; D002465:Cell Movement; D004847:Epithelial Cells / Q000166:cytology; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000187:drug effects*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008954:Models, Biological; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
D053773:Transforming Growth Factor beta1
Biomimetic of proximal tubule; C3a; Epithelial-to-mesenchymal transition; Microfluidic; Migration