TY - JOUR
T1 - Lipopolysaccharide from Escherichia coli induces the expression of vascular endothelial growth factor via toll-like receptor 4 in human limbal fibroblasts
AU - Rodríguez-Martínez, Sandra
AU - Cancino-Diaz, Mario E.
AU - Miguel, Pedroza Seres
AU - Cancino-Diaz, Juan C.
N1 - Funding Information:
This work was supported by CONACYT (grant 47424) and by the Instituto Politécnico Nacional (20060748). Sandra Rodríguez-Martínez received scholarships from CONACYT and PIFI-IPN for her graduate studies in CQB. Mario E Cancino-Diaz and Juan C Cancino-Diaz are fellows of COFAA-IPN, EDI-IPN and SNI-CONACYT.
PY - 2006/12
Y1 - 2006/12
N2 - Corneal neovascularization can be induced by a severe ocular infection, injury or immunological diseases. The vascular endothelial growth factor (VEGF) is the main cytokine involved in this phenomenon, inducing angiogenesis from the vascularized ocular tissues. As the limbal tissue is located between conjunctival and corneal tissues, we suggest that the limbal cells are participating in the production of VEGF induced by bacterial components as LPS. In this work, RT-PCRs and immunoblots were used to investigate the expression of VEGF and other pro-angiogenic genes in primary cultures of human limbal fibroblasts (PCHLF) treated with lipopolysaccharide (LPS) from Escherichia coli. We found that the expression of VEGF was initiated at 6 h and reaches its highest expression at 72 h after stimulation with LPS. Up-regulation of toll-like receptor 4 (TLR4) after 3 h of treatment was also observed. LPS-induced the expression of VEGF in a dose-dependent manner, and the blocking of TLR4 with an anti-TLR4 antibody prevented VEGF expression. We also analyzed the molecules that modulate VEGF expression. LPS did not induce the up-regulation of LL-37 nor the hypoxia induced factor 1 alpha (HIF-1α) mRNA expression, however, an up-regulation of interleukin 13 receptor alpha 1 (IL-13Rα1) and interleukin 4 receptor alpha (IL-4Rα) were observed after 3 and 12 h of stimulation, respectively. The expression of interleukin 13 did not change throughout the treatment. These results suggest that TLR4, IL-13Rα1 and IL-4Rα induced by LPS in PCHLF could be playing an important role in the corneal neovascularization.
AB - Corneal neovascularization can be induced by a severe ocular infection, injury or immunological diseases. The vascular endothelial growth factor (VEGF) is the main cytokine involved in this phenomenon, inducing angiogenesis from the vascularized ocular tissues. As the limbal tissue is located between conjunctival and corneal tissues, we suggest that the limbal cells are participating in the production of VEGF induced by bacterial components as LPS. In this work, RT-PCRs and immunoblots were used to investigate the expression of VEGF and other pro-angiogenic genes in primary cultures of human limbal fibroblasts (PCHLF) treated with lipopolysaccharide (LPS) from Escherichia coli. We found that the expression of VEGF was initiated at 6 h and reaches its highest expression at 72 h after stimulation with LPS. Up-regulation of toll-like receptor 4 (TLR4) after 3 h of treatment was also observed. LPS-induced the expression of VEGF in a dose-dependent manner, and the blocking of TLR4 with an anti-TLR4 antibody prevented VEGF expression. We also analyzed the molecules that modulate VEGF expression. LPS did not induce the up-regulation of LL-37 nor the hypoxia induced factor 1 alpha (HIF-1α) mRNA expression, however, an up-regulation of interleukin 13 receptor alpha 1 (IL-13Rα1) and interleukin 4 receptor alpha (IL-4Rα) were observed after 3 and 12 h of stimulation, respectively. The expression of interleukin 13 did not change throughout the treatment. These results suggest that TLR4, IL-13Rα1 and IL-4Rα induced by LPS in PCHLF could be playing an important role in the corneal neovascularization.
KW - IL-13Rα1
KW - IL-4Rα
KW - LPS
KW - TLR4
KW - VEGF
KW - angiogenesis
KW - cornea
KW - neovascularization
UR - http://www.scopus.com/inward/record.url?scp=33750467668&partnerID=8YFLogxK
U2 - 10.1016/j.exer.2006.07.015
DO - 10.1016/j.exer.2006.07.015
M3 - Artículo
C2 - 16997297
SN - 0014-4835
VL - 83
SP - 1373
EP - 1377
JO - Experimental Eye Research
JF - Experimental Eye Research
IS - 6
ER -