TY - JOUR
T1 - Vectorial release of matrix metalloproteinases (MMPs) from porcine RPE-choroid explants following selective retina therapy (SRT): Towards slowing the macular ageing process
AU - Treumer, F.
AU - Klettner, A.
AU - Baltz, J.
AU - Hussain, A. A.
AU - Miura, Y.
AU - Brinkmann, R.
AU - Roider, J.
AU - Hillenkamp, J.
PY - 2012/4/1
Y1 - 2012/4/1
N2 - The purpose of this study was to investigate release of matrix metalloproteinases (MMP) 2 and 9 during retinal pigment epithelium (RPE) wound healing after Selective Retina Therapy (SRT) with laser energy levels below and above the threshold of RPE cell death. Following exposure to SRT using a prototype pulsed Nd:YLF laser with energies of 80-180 mJ/cm 2 fresh porcine RPE-monolayers with Bruch's membrane and choroid were cultured in modified Ussing chambers which separate the apical (RPE-facing) and basal (choroid facing) sides of the RPE monolayer. Threshold energy for RPE cell death and wound healing were determined with calcein-AM viability test. Inactive and active forms of MMP 2 and 9 were quantified within tissue samples and in the culture medium of the apical and basal compartments of the Ussing chamber using gelatine zymography. Laser energies of 160-180 mJ/cm 2 resulted in cell death within 1 h while 120-140 mJ/cm 2 resulted in delayed death of exposed RPE cells. All cells survived 80 and 100 mJ/cm 2. Laser spots healed within 6 days after SRT accompanied by a transient vectorial increase of MMPs. SRT with 180 mJ/cm 2 increased active MMP 2 by 1.9 (p < 0.05) and 1.6 (p < 0.05) fold in tissue and basal compartments, respectively, without alterations in the apical compartment. Pro-MMP 2 levels were also significantly increased in all compartments (p < 0.05). Release of MMP 9 was not altered. Laser energy below the threshold of RPE cell death did not alter the release of MMP 2 or 9. The findings suggest that the release of active MMP 2 on the basal side of the RPE during wound healing following SRT may address age-related pathological changes of Bruch's membrane with a potential to slow degenerative macular ageing processes before irreversible functional loss has occurred.
AB - The purpose of this study was to investigate release of matrix metalloproteinases (MMP) 2 and 9 during retinal pigment epithelium (RPE) wound healing after Selective Retina Therapy (SRT) with laser energy levels below and above the threshold of RPE cell death. Following exposure to SRT using a prototype pulsed Nd:YLF laser with energies of 80-180 mJ/cm 2 fresh porcine RPE-monolayers with Bruch's membrane and choroid were cultured in modified Ussing chambers which separate the apical (RPE-facing) and basal (choroid facing) sides of the RPE monolayer. Threshold energy for RPE cell death and wound healing were determined with calcein-AM viability test. Inactive and active forms of MMP 2 and 9 were quantified within tissue samples and in the culture medium of the apical and basal compartments of the Ussing chamber using gelatine zymography. Laser energies of 160-180 mJ/cm 2 resulted in cell death within 1 h while 120-140 mJ/cm 2 resulted in delayed death of exposed RPE cells. All cells survived 80 and 100 mJ/cm 2. Laser spots healed within 6 days after SRT accompanied by a transient vectorial increase of MMPs. SRT with 180 mJ/cm 2 increased active MMP 2 by 1.9 (p < 0.05) and 1.6 (p < 0.05) fold in tissue and basal compartments, respectively, without alterations in the apical compartment. Pro-MMP 2 levels were also significantly increased in all compartments (p < 0.05). Release of MMP 9 was not altered. Laser energy below the threshold of RPE cell death did not alter the release of MMP 2 or 9. The findings suggest that the release of active MMP 2 on the basal side of the RPE during wound healing following SRT may address age-related pathological changes of Bruch's membrane with a potential to slow degenerative macular ageing processes before irreversible functional loss has occurred.
UR - http://www.scopus.com/inward/record.url?scp=84859508530&partnerID=8YFLogxK
U2 - 10.1016/j.exer.2012.02.011
DO - 10.1016/j.exer.2012.02.011
M3 - Journal articles
C2 - 22387137
AN - SCOPUS:84859508530
SN - 0014-4835
VL - 97
SP - 63
EP - 72
JO - Experimental Eye Research
JF - Experimental Eye Research
IS - 1
ER -
