Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
Articles by K Miyata
Total Records ( 2 ) for K Miyata
  N Honda , T Miyai , R Nejima , K Miyata , T Mimura , T Usui , M Aihara , M Araie and S. Amano

Objective  To investigate the effect of topical latanoprost on the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase 1 (TIMP-1) on the ocular surface.

Methods  Tears were collected from 39 patients with glaucoma who used latanoprost, 0.005%, eyedrops (Xalatan) and 28 healthy volunteers. The MMP-9 concentration was measured. Conjunctival epithelial cells were collected from 10 eyes of 10 patients before and 1 to 3 months after starting to take topical latanoprost, 0.005%, and MMP-1, MMP-9, and TIMP-1 messenger RNA (mRNA) expression was analyzed. Both eyes of 48 mice were treated once a day with latanoprost, 0.005%, timolol gel, 0.5%, eyedrops, vehicle of Xalatan, or phosphate-buffered saline, and MMP-9 and TIMP-1 mRNA expression was analyzed.

Results  The median MMP-9 concentration in latanoprost-treated cases was 91.2 ng/mL (in controls, 19.7 ng/mL; P < .001). In latanoprost-treated cases, the relative ratio of MMP-9 to glyceraldehyde 3-phosphate dehydrogenase mRNA was significantly increased from 6.42 to 21.3 (P = .04, paired t test) and the relative amount of TIMP-1 was significantly decreased from 154 to 105 (P = .009). The relative amount of MMP-1 to GAPDH mRNA before and after latanoprost use was not significantly different (P = .16). In mice, MMP-9 expression was increased and TIMP-1 expression was decreased on the ocular surface at 8 weeks after latanoprost use.

Conclusion  The topical use of latanoprost increases MMP-1 and MMP-9 and decreases TIMP-1 on the ocular surface.

Clinical Relevance  The use of topical latanoprost might not be recommended in patients with keratoconus or after laser-assisted in situ keratomileusis.

  R Satou , K Miyata , A Katsurada , L. G Navar and H. Kobori

Angiotensinogen (AGT) expression in renal proximal tubular cells (RPTCs) and intrarenal tumor necrosis factor- (TNF-) levels are increased in hypertension and renal diseases However, the contribution of TNF- to AGT expression in RPTCs has not been established. Therefore, the objective of the present study was to determine influence of TNF- on AGT expression in RPTCs. Human kidney-2 (HK-2) cells, immortalized human RPTCs, were treated with several concentrations of TNF- up to 24 h. AGT mRNA and protein expression were evaluated by RT-PCR and ELISA, respectively. Activation of nuclear factor-B (NF-B) by TNF- was evaluated by Western blot analysis, immunocytochemistry, and electrophoretic mobility shift assay (EMSA). TNF- suppressed AGT mRNA expression in a dose- and time-dependent manner. Maximum AGT mRNA reduction was caused by 40 ng/ml of TNF- (0.52 ± 0.09, ratio to control, at 24 h) and at 24 h (0.66 ± 0.05, ratio to control, by 10 ng/ml TNF-). TNF- reduced AGT protein accumulation in the medium between 8 and 24 h (0.62 ± 0.13 by 40 ng/ml TNF-, ratio to control). TNF- activated and induced translocalization of p50 and p65, which are NF-B subunits. Elevated formation of p50/p65 and p50/p50 dimers by TNF- were observed by EMSA and supershift assay. Gene silencing of p50, but not p65, attenuated the effect of TNF- on reduction of AGT expression in RPTCs. These results indicate that TNF- suppresses AGT expression through p50/p50 homodimer formation in human RPTCs, suggesting a possible counteracting mechanism that limits excessive intrarenal AGT production.

Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility