title: Protein tyrosine phosphatase 1B regulates migration of ARPE-19 cells through EGFR/ERK signaling pathway.
abstract: OBJECTIVE
  To evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.
  
  
  METHODS
  ARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for α-smooth muscle actin (α-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.
  
  
  RESULTS
  The mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. α-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, α-SMA expression and cell migration.
  
  
  CONCLUSIONS
  PTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.
authors.affiliation: Department of Ophthalmology, Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Zhao-Dong
authors.initials: ZD
authors.lastname: Du
authors.affiliation: Department of Ophthalmology, Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Li-Ting
authors.initials: LT
authors.lastname: Hu
authors.affiliation: Department of Ophthalmology, Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Gui-Qiu
authors.initials: GQ
authors.lastname: Zhao
authors.affiliation: Department of Ophthalmology, Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Ophthalmology, Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Department of Ophthalmology, Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
keywords: cell migration; epidermal growth factor receptor; extracellular signal-regulated kinase; protein tyrosine phosphatase 1B; retinal pigment epithelium