Quantifying cell behaviors in negative-pressure induced monolayer cell movement.
BACKGROUND
Negative-pressure of 125 mmHg (NP) has been shown to accelerate wound healing. Effects of NP on human keratinocyte behaviors during wound healing process were highlighted in this study.


METHODS
An NP incubator incorporating the electric cell-substrate impedance sensing (ECIS) technique has been built to quantify monolayer keratinocytes movement in serum-free media at the ambient pressure (AP) and NP for 12 h. Monolayer cell motions were continuously recorded by ECIS in the frequency range of 22.5-64 kHz. Membrane capacitance (Cm), cell-substratum resistance (α), and cell-cell junction resistance (Rb) were evaluated in cells at the different pressures.


RESULTS
A greater monolayer cell migration distance was found in cells at NP. Decreased cell-substratum adhesion reflected in the significantly low α (AP:NP = ∼5 Ω(0.5):∼3 Ω(0.5)⋅cm), decreased integrin expression, and increased cell-substratum distance were seen in cells at NP. A significantly increased Cm (AP:NP = ∼4:∼8 μF/cm(2)) in association with increased membrane ruffling and microtubule filaments were observed early in the monolayer cell movement at NP. A progressive drop in the Rb from 1.2 Ω·cm(2) to 0.8 Ω·cm(2) corresponding to the gradually decreased E-cadherin expressions were observed 6 h after wound closure after NP treatment.


CONCLUSIONS
A quick membrane ruffling formation, an early cell-substratum separation, and an ensuing decrease in the cellular interaction occur in cells at NP. These specific monolayer cell behaviors at NP have been quantified and possibly accelerate wound healing.
Department of Nature Science, Center for General Studies, Chang Gung University, Taoyuan, Taiwan.
Shu-Er
SE
Chow
Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital at Taipei, Taipei, Taiwan.
Carl Pai-Chu
CP
Chen
Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan; School of Traditional Chinese Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan. Electronic address: steele0618@gmail.com.
Chih-Chin
CC
Hsu
Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
Wen-Chung
WC
Tsai
Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Jong-Shyan
JS
Wang
Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan.
Ning-Chun
NC
Hsu
D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D006801:Humans; D007365:Intercellular Junctions / Q000502:physiology*; D015603:Keratinocytes / Q000378:metabolism*; D014945:Wound Healing
Cell movement; Cytoskeleton; Intercellular junctions; Negative-pressure wound therapy; Wound healing