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Tatsuro Ishibashi

Publications and source records attributed to Tatsuro Ishibashi.

At least 19 recordsLinked to original sources
PubMed2007

Transforming growth factor-beta2 and connective tissue growth factor in proliferative vitreoretinal diseases: possible involvement of hyalocytes and therapeutic potential of Rho kinase inhibitor.

The critical association of connective tissue growth factor (CTGF), which is thought to be one of the downstream mediators of transforming growth factor-beta (TGF-beta), with vitreoretinal diseases remains to be clarified. In the current study, we first demonstrated the correlation between the concentrations of TGF-beta2 as well as CTGF in the vitreous and CTGF gene regulation in cultured hyalocytes. Concentrations of TGF-beta2 and CTGF in the vitreous from patients with proliferative vitreoretinal diseases were significantly higher than in those with nonproliferative diseases, and there was a positive correlation between their concentrations (r = 0.320, P < 0.01). Cultured hyalocytes expressed CTGF mRNA, which was enhanced in the presence of TGF-beta2, associated with nuclear accumulation of Smad4. TGF-beta2-dependent Smad4 translocation and CTGF gene expression were mediated through Rho kinase and at least partially via p38 mitogen-activated protein kinase. Finally, fasudil, a Rho kinase inhibitor already in clinical use, inhibited both Smad4 translocation and CTGF gene expression. In conclusion, combined effects of TGF-beta2 and CTGF appear to be involved in the pathogenesis of proliferative vitreoretinal diseases. Hyalocytes may be a possible source of CTGF and thus might play a role in vitreoretinal interface diseases. Furthermore, Rho kinase inhibitors might have therapeutic potential to control fibrotic disorders in the eye.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2006

Preclinical investigation of fluorometholone acetate as a potential new adjuvant during vitreous surgery.

OBJECTIVE: To examine the effects of intravitreal fluorometholone acetate (FMT) on the morphology and function of the retina and to investigate its possible use for vitreous surgery. METHODS: Brown Norway rat eyes (n = 6, 12 groups) were injected with 0.05 ml of SF6 gas for vitrectomization. Four weeks later, FMT solution was injected into the vitreous cavity/subretinal space of the vitrectomized eyes at doses of 10, 20, and 40 mg/ml (0.05 ml/eye, n = 12 for each group). The retinal function was evaluated by electroretinography (ERG) at 4 and 8 weeks after FMT injection. Retinal toxicity was also assessed histologically by a light microscopy. Sham-operated eyes (0.05 ml of irrigating solution, n = 12) were used as control animals. FMT-assisted pars plana vitrectomy with internal limiting membrane (ILM) peeling was performed in primate eyes (n = 2). Retinal toxicity was assessed by ophthalmoscope, fluorescein angiography and electron microscopy three months after the vitreous surgery. RESULTS: There was no remarkable reduction in any ERG waves at either time interval at 4 and 8 weeks after the intravitreal/subretinal injection of FMT. No obvious histological change was observed in any of the rat eyes either. Using ophthalmoscope, fluorescein angiography and electron microscopy, the appearance of the primate retinas remained to be in a non-pathological condition. CONCLUSION: FMT appears to be a potentially useful tool in assisting vitreous surgery including safe ILM peeling.

Animals↗
PubMed2006

Rapid detection of SAG 926delA mutation using real-time polymerase chain reaction.

PURPOSE: Mutation 926delA of the arrestin/S-antigen SAG gene is the main cause of Oguchi disease in the Japanese. The purpose of this study was to develop a rapid diagnostic assay to detect mutations in the SAG gene. METHODS: Two sequence-specific primers and fluorophore-labeled probes for exon 11 of the SAG gene were designed, and the region spanning the mutations was amplified by polymerase chain reaction (PCR) using the LightCycler detection system (Roche Diagnostics, Mannheim, Germany). The mutations were then identified by melting curve analyses of the hybrid formed between the PCR product and a specific fluorescent probe. RESULTS: We clearly distinguished each SAG genotype (homozygous and heterozygous 926delA and wild type) by the distinct melting peaks at different temperatures. One thermal cycling required approximately 54 min to process, and the results were 100% in concordance with the genotypes determined by DNA sequencing. CONCLUSIONS: We have succeeded in developing a rapid method to detect the most frequent mutation in the SAG gene. This method will help in identifying gene mutations associated with Oguchi disease with a rapid and reliable identification or the exclusion of the frequent mutations in the SAG gene.

Adolescent↗
PubMed2006

Novel triple missense mutations of GUCY2D gene in Japanese family with cone-rod dystrophy: possible use of genotyping microarray.

PURPOSE: To report a novel mutation in the GUCY2D gene in a Japanese family with autosomal dominant cone-rod dystrophy (adCORD), and to examine the possible use of arrayed primer extension (APEX)-based genotyping chip in detecting mutations. METHODS: Genomic DNA was extracted from the peripheral blood of family members with adCORD. It was PCR-amplified, fragmented, and hybridized to APEX-based genotyping microarrays on which known disease-associated sequence variations were arrayed for patients with early-onset retinal dystrophy. All coding exons of the GUCY2D gene were directly sequenced. The PCR amplicon carrying a novel mutation was subcloned, and each clone was sequenced. RESULTS: Five single nucleotide polymorphisms in AIPL1, RPGRIP1, and GUCY2D were detected in the proband by microarray screening, and all were validated by direct sequencing. A novel heterozygous triple missense mutation of c.2540_2542delinsTCC (p.Gln847_Lys848delinsLeuGln amino acid substitutions) was found in both the proband and his father, and the three nucleotide changes were located on the same chromosome. Electroretinography (ERGs) demonstrated a significant reduction in rod function and a complete absence of cone function in both affected individuals. CONCLUSIONS: A novel heterozygous triple consecutive missense mutation in the GUCY2D gene has been linked to adCORD. Our study demonstrates that the APEX-based gene screening can be used to identify simultaneously disease-modifying sequence changes as well as disease-causing mutations, once proper and comprehensive sites of sequence variations of the disease are arrayed.

Aged↗
PubMed2006

WSX-1 plays a significant role for the initiation of experimental autoimmune uveitis.

WSX-1 is a subunit of the IL-27R, which plays a critical role in the initiation of T(h)1 responses. Murine experimental autoimmune uveitis (EAU) is a model of human autoimmune uveitis, in which a T(h)1 response predominates in the pathogenetic process. To explore the role of WSX-1 in this model, WSX-1(-/-) mice were immunized with interphotoreceptor retinoid-binding protein peptide 1-20 to induce EAU. We found that the EAU clinical and histological scores were lower in the WSX-1(-/-) mice up to day 21, whereas after day 21, the EAU scores were the same between the wild-type (WT) and WSX-1(-/-) mice with both declining at the same rate. In contrast to T lymphocytes from WT mice, WSX-1(-/-) T lymphocytes on day 9 after immunization failed to produce IFN-gamma. Similarly, expression of T(h)1-related chemokines, such as regulated on activation, normal T cell expressed and secreted and IP-10, in the eye was reduced in WSX-1(-/-) mice compared with WT mice on day 13 after immunization. In addition, sub-retinal transfer of lymphocytes from WSX-1(-/-) mice on day 9 after immunization did not induce EAU in the recipient mice. Importantly, IFN-gamma production, chemokine expression and the transferability of disease by lymphocytes became comparable for WSX-1(-/-) and WT mice at later stages. Thus, IL-27/WSX-1 affects the early development of EAU, and might be a target for therapy during the onset of autoimmune uveitis in humans.

Animals↗
PubMed2006

Two-sided roles of IL-27: induction of Th1 differentiation on naive CD4+ T cells versus suppression of proinflammatory cytokine production including IL-23-induced IL-17 on activated CD4+ T cells partially through STAT3-dependent mechanism.

Recent lines of evidence have demonstrated that IL-27, a newly identified IL-12-related cytokine, has two apparently conflicting roles in immune responses: one as an initiator of Th1 responses and the other as an attenuator of inflammatory cytokine production. Although the IL-27-mediated Th1 initiation mechanism has been elucidated, little is known about the molecular basis for the suppression of cytokine production. In the present study, we demonstrated that IL-27 suppressed the production of various proinflammatory cytokines by fully activated CD4+ T cells while it had no effect on the cytokine production by CD4+ T cells at early phases of activation. IL-27 also suppressed IL-17 production by activated CD4+ T cells, thereby counteracting IL-23, another IL-12-related cytokine with proinflammatory effects. In fully activated CD4+ T cells, STAT3 was preferentially activated by IL-27 stimulation, whereas both STAT1 and 3 were activated by IL-27 in early activated CD4+ T cells. Lack of STAT3 in fully activated cells impaired the suppressive effects of IL-27. These data indicated that the preferential activation of STAT3 in fully activated CD4+ T cells plays an important role in the cytokine suppression by IL-27/WSX-1.

Animals↗
PubMed2006

Identification of resident and inflammatory bone marrow derived cells in the sclera by bone marrow and haematopoietic stem cell transplantation.

AIMS: To characterise bone marrow derived cells in the sclera under normal and inflammatory conditions, we examined their differentiation after transplantation from two different sources, bone marrow and haematopoietic stem cells (HSC). METHODS: Bone marrow and HSC from green fluorescent protein (GFP) transgenic mice were transplanted into irradiated wild-type mice. At 1 month after transplantation, mice were sacrificed and their sclera examined by histology, immunohistochemistry (CD11b, CD11c, CD45), and transmission and scanning electron microscopy. To investigate bone marrow derived cell recruitment under inflammatory conditions, experimental autoimmune uveitis (EAU) was induced in transplanted mice. RESULTS: GFP positive cells were distributed in the entire sclera and comprised 22.4 (2.8)% (bone marrow) and 28.4 (10.9)% (HSC) of the total cells in the limbal zone and 18.1 (6.7)% (bone marrow) and 26.3 (3.4)% (HSC) in the peripapillary zone. Immunohistochemistry showed that GFP (+) CD11c (+), GFP (+) CD11b (+) cells migrated in the sclera after bone marrow and HSC transplantation. Transmission and scanning electron microscopy revealed antigen presenting cells among the scleral fibroblasts. In EAU mice, vast infiltration of GFP (+) cells developed into the sclera. CONCLUSION: We have provided direct and novel evidence for the migration of bone marrow and HSC cells into the sclera differentiating into macrophages and dendritic cells. Vast infiltration of bone marrow and HSC cells was found to be part of the inflammatory process in EAU.

Animals↗
PubMed2006

The regulation of vascular endothelial growth factors (VEGF-A, -C, and -D) expression in the retinal pigment epithelium.

The vascular endothelial growth factor (VEGF) family plays an essential role in vascular development, angiogenesis and lymphangiogenesis. VEGF-A is a key regulator of endothelial cell functions and VEGF-C and VEGF-D are known to stimulate both angiogenesis and lymphangiogenesis. In a surgically removed subretinal vascular membrane of an age-related macular degeneration (AMD) patient, both VEGF-C and VEGF-D were confirmed, in addition to VEGF-A, to be markedly positive in the retinal pigment epithelium (RPE). There is no lymph vessel in ocular tissue, so it is possible that VEGF-C and VEGF-D expression in the RPE play some role in ocular angiogenesis, as well as VEGF-A. Next, we assessed the transition of VEGF-A, -C, and -D expression on several conditions, in human RPE. Hypoxia proverbially induced VEGF-A mRNA expression, meanwhile VEGF-C and VEGF-D mRNA expression was down-regulated. The Ca(2+) deprivation from culture medium strongly up-regulated VEGF-A and VEGF-D mRNA expression. Culture on plastic flasks precoated with poly-2-hydroxyethyl methacrylate up-regulated VEGF-D expression. Meanwhile, no significant change of VEGF-C mRNA expression was found in the blockade of cell-cell and/or cell-matrix adhesion. These findings suggest the possibility that VEGF-C and VEGF-D expression in RPE modify the ocular angiogenesis as angiogenic stimulators.

Aged↗
PubMed2006

Sphere formation of ocular epithelial cells in the ciliary body is a reprogramming system for neural differentiation.

It is well known that neural stem/progenitor cells of the central nervous system (CNS) can proliferate to form neurospheres (CNS-neurospheres) that are positive for nestin, an intermediate filament for neural progenitors. Retinal stem/progenitor properties were also isolated from the ciliary body (CB) of the eye where, as in the CNS, such stem/progenitors also form spheres and have been considered to expand only via expansion by their proliferation even from the single-cell level (called spheres of pigment cells from the ciliary margin: PCM-spheres). We here found a new and distinct process underlying the growth of CB cell-derived spheres (CB-spheres) that is unlike the mechanism of CNS- and PCM-sphere expansion; this new process is a cell proliferation-independent incorporation of neighbor spheres and cells cultured at high density (200 cells/mul). The majority of cells in CB-spheres consisted of nestin-negative epithelia-like cells and started to express nestin during the course of their expansion by high-density cultivation. The growth of CNS-neurospheres was sensitive to a cell-cycle inhibitor, whereas the growth of CB-spheres was not seriously affected by cell proliferation; rather, the spheres grew by incorporating other CB-spheres and nestin-negative adherent cells, the latter of which started to express nestin and lost the expression of epithelial markers after being incorporated. These results indicate that CB-spheres do not form by the accumulation of neural progenitors but rather by a reprogramming system from epithelia-like cells for neural differentiation, a clearly distinct mechanism from sphere formation by single-cell expansion of retinal stem/progenitor populations.

Animals↗
PubMed2006

Staining ability and biocompatibility of brilliant blue G: preclinical study of brilliant blue G as an adjunct for capsular staining.

OBJECTIVE: To evaluate the effectiveness and biocompatibility of brilliant blue G (BBG) for capsular visualization for continuous curvilinear capsulorrhexis. METHODS: The capsular staining ability of BBG was evaluated at graded concentrations of 10.0, 1.0, 0.5, 0.25, 0.1, and 0.01 mg/mL in enucleated pig's eyes. The biocompatibility of BBG was assessed in rat's eyes for 2 months. The eyes were analyzed using light, fluorescence, transmission electron, and scanning electron microscopy. TUNEL (terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling) was used to detect apoptotic cells, and endothelial cell counts were analyzed using scanning electron microscopy. The results were compared using indocyanine green and trypan blue. RESULTS: The BBG improved capsular visualization, and a complete capsulorrhexis could be performed. In the rat model, no apparent toxic effect was observed using biomicroscopy during 2 months. Histologically, BBG showed satisfactory biocompatibility. Apoptotic cell death of the endothelial cells was detected in only the trypan blue group. In contrast to BBG, indocyanine green and trypan blue showed degeneration of corneal endothelial cells using transmission and scanning electron microscopy. CONCLUSION: The BBG contributed to better capsular visualization and caused no apparent complications to the corneal endothelium.Clinical Relevance The BBG is effective and safe capsular staining for continuous curvilinear capsulorrhexis.

Animals↗
PubMed2006

Cellular migration associated with macular hole: a new method for comprehensive bird's-eye analysis of the internal limiting membrane.

OBJECTIVE: To elucidate the pathogenesis of macular hole formation, focusing in particular on the possible role of cellular migration on the cortical vitreous and internal limiting membrane (ILM) around the macular hole. METHODS: To gain a comprehensive overview of the ILM excised in macular hole surgery (n = 36), the ILMs were carefully unfolded and spread out onto glass slides as continuous flat sheets that each contained a macular hole. The specimens were observed by light microscopy and transmission electron microscopy (n = 9), and the cellular distribution was analyzed by scanning electron microscopy in a quantitative manner (n = 27). Immunohistochemistry for glial fibrillary acidic protein and cytokeratin 18 was carried out for cellular characterization. Cellular proliferation was assessed by immunohistochemistry for proliferating cell nuclear antigen and Ki-67. RESULTS: Cellular migration was not apparent around the macular hole in the early stage of development of the macular hole (stage 2, 0 microm). As the macular hole passed through the later stages of development, cellular migration developed around the macular hole (stage 3, 84 microm) and the area of cellular migration gradually enlarged (stage 4, 420 microm). The immunophenotypic analysis showed that these cells were mainly glial fibrillary acidic protein-positive glial cells and cytokeratin 18-positive retinal pigment epithelial cells. The proliferating cell nuclear antigen and Ki-67 immunohistochemistry showed that some of these cells were proliferating on the ILM. CONCLUSIONS: Cellular migration on the ILM is not necessary for the initial formation of a macular break. Cellular migration developed after the macular break occurred, and the migration and proliferation increased gradually from the macular hole. CLINICAL RELEVANCE: This study provides a new method for understanding the ultrastructural analysis of the pathogenesis of the macular hole.

Basement Membrane↗
PubMed2006

Granulocytapheresis in patients with refractory ocular Behcet's disease.

Intraocular inflammation (uveoretinitis) is one major complication of Behcet's disease (BD) and responds poorly to drug therapy. This open prospective study was to assess the efficacy of selective granulocytapheresis in patients with refractory uveoretinitis of BD. Fourteen patients aged 20-56 years were treated. Granulocytapheresis was done with an Adacolumn filled with cellulose acetate leucocyte carries or beads that adsorb granulocytes and monocytes from the blood in the column. Each patient received 5 Adacolumn sessions at one session/week over 5 consecutive weeks. The study was designed to allow each patient to serve as his or her own control. The total numbers of ocular attacks (OA) were monitored for 6 months before and after 5 Adacolumn sessions. The number of OA (mean +/- SD) per patient for the 6 months before Adacolumn was 4.21 +/- 1.6 and for the 6 months post Adacolumn was 2.93 +/- 1.39 ( P = 0.0275). Nine patients (64%) improved and 5 did not change or worsened. Further, for a sub-group (n = 7) with duration of BD > or =5 years, the number of OA were 4.71 +/- 1.89 for the first 6 months and 2.29 +/- 1.38 for the second 6 months ( P = 0.0054). The corresponding values for a sub-group (n = 7) with duration of BD<5 years were 3.71 +/- 1.25 and 3.57 +/- 1.13, indicating that patients with long duration of BD are better responders. We conclude that granulocytapheresis might be effective and safe for patients with refractory ocular BD. Further studies are necessary to fully evaluate the clinical efficacy of granulocytapheresis for BD.

Adult↗
PubMed2006

Apoptosis in perforated cornea of a patient with graft-versus-host disease.

CASE REPORT: Although ocular complications associated with graft-versus-host disease (GVHD) can include corneal dysfunction, corneal perforation is not common. We report the presence of apoptotic cells in a perforated cornea of a patient with GVHD. A 72-year-old man with the angioimmunoblastic type of malignant lymphoma developed chronic GVHD after allogeneic peripheral blood stem cell transplantation. Despite systemic and topical treatment, both corneas perforated, and penetrating keratoplasty with cataract extraction and intraocular lens implantation was performed on both eyes. COMMENTS: The corneal button excised from the right eye was examined histologically and stained for apoptotic cells by TdT-mediated dUTP nick end labeling (TUNEL). This revealed thinning of the epithelial cell layer and stroma, with cells, including lymphocytes, infiltrating to the site of the perforation. Some of the epithelial cells and keratocytes were TUNEL positive. The presence of apoptotic cells in our case suggests that apoptosis may be involved in the perforation of the cornea in patients with GVHD.

Aged↗
PubMed2006

Prognostic DNA testing and counselling for dominant optic atrophy due to a novel OPA1 mutation.

CASE REPORT: To report the case of a 26-year-old woman with a family history of dominant optic atrophy who requested DNA testing and counselling. Ophthalmologic examination showed her affected father had bilateral temporal papillary pallor. Direct genomic sequencing of the OPA1 gene revealed a novel heterozygous nonsense mutation (Arg879stop). Because no mutation in OPA1 was detected in the daughter, we could counsel her that the possibility was very low that she was a carrier or would pass the disease-causing gene to her children. COMMENTS: Our study provides evidence of the apparent value of molecular genetic analysis of OPA1 gene as predictive DNA testing, although the exact risk and benefit of this type of analysis awaits further study.

Adult↗
PubMed2006

Evaluating adjunctive surgical procedures during vitrectomy for diabetic macular edema.

PURPOSE: To evaluate the long-term outcomes of adjunctive surgical procedures during pars plana vitrectomy (PPV) for the treatment of diabetic macular edema (DME). METHODS: In this nonrandomized study, we retrospectively analyzed 57 eyes of 54 patients who had DME and had undergone PPV. We performed PPV using three different surgical procedures: conventional PPV (group PVD; 13 eyes), triamcinolone acetonide (TA)-assisted PPV (group TA; 22 eyes), and TA-assisted PPV combined with internal limiting membrane (ILM) peeling (group ILM; 22 eyes). We also evaluated the preoperative and postoperative best-corrected visual acuity (BCVA) results. RESULTS: The overall mean preoperative BCVA was 0.86 logarithm of the minimal angle of resolution unit. In groups PVD, TA, and ILM, BCVAs were 0.99, 0.90, and 0.74 (P = 0.310), respectively. The mean postoperative BCVA for all patients improved to 0.68 (P = 0.005). The postoperative BCVA improved in 47% of the treated eyes, it remained unchanged in 37% of the treated eyes, and it deteriorated in 16% of the treated eyes. However, we observed no significant difference in the mean postoperative BCVAs between the three groups. Furthermore, we found that there was no significant difference in postoperative BCVA improvements between any of the groups (P = 0.450). CONCLUSION: The present study suggests that these 3 PPV approaches do not significantly affect postoperative BCVAs after 18 months of DME treatment.

Adult↗
PubMed2006

Prostaglandin F2alpha, but not latanoprost, increases the Ca2+ sensitivity of the pig iris sphincter muscle.

PURPOSE: To determine the mechanisms underlying prostaglandin (PG) F(2)alpha-(,) carbachol (CCh)-, or latanoprost (a PGF(2)alpha analogue)-induced contraction of the pig iris sphincter muscle. METHODS: Effects of these agents on myofilament Ca(2+) sensitivity were evaluated and compared with the use of receptor-coupled permeabilized preparations by alpha-toxin. The effects of PGF(2)alpha and CCh on the phosphorylation of myosin light chain (MLC) were also analyzed. RESULTS: In the intact strips, all three of these agents induced contractions. In permeabilized strips, PGF(2)alpha and CCh, but not latanoprost, caused an additional tension development at a fixed intracellular Ca(2+) concentration ([Ca(2+)](i)) and also shifted the [Ca(2+)](i)-tension curve to the left, thus indicating that PGF(2)alpha and CCh, but not latanoprost, induced increases in Ca(2+) sensitivity (Ca(2+) sensitization). This Ca(2+) sensitization could have been inhibited by Y27632, a rho kinase inhibitor, but not by GF109203X, a protein kinase C (PKC) inhibitor or by PD98059, a mitogen-activated protein (MAP) kinase inhibitor. PGF(2)alpha increased the level of MLC phosphorylation at a constant [Ca(2+)](i). CONCLUSIONS: PGF(2)alpha, but not latanoprost, induced Ca(2+) sensitization of the pig iris sphincter muscle in an MLC phosphorylation-dependent manner through the rho-rho kinase pathway. The effect of latanoprost on the Ca(2+) sensitization mechanism was different from that of PGF(2)alpha and was thought to play a beneficial role in glaucoma treatment.

Animals↗
PubMed2005

Critical role of the Rho-kinase pathway in TGF-beta2-dependent collagen gel contraction by retinal pigment epithelial cells.

Retinal pigment epithelial cells (RPEs) are thought to be one of the main components of fibrous membrane observed in eyes with proliferative vitreo-retinopathy. We investigated the signalling mechanisms of TGF-beta2-dependent collagen gel contraction by RPEs. An in vitro type I collagen gel contraction assay was performed to evaluate the effect of TGF-beta2 on gel contraction. The expression of alpha-smooth muscle actin (alpha-SMA) and the phosphorylation state of myosin light chain (MLC) were analyzed by Western blotting. The involvement of protein kinases such as p44/42 mitogen-activated protein kinase (MAPK), protein kinase C (PKC), p38 MAPK and phosphatidylinositol-3 kinase was investigated. The contribution of Rho-kinase and/or MLC-kinase was also evaluated using respective kinase inhibitors (Y27632, hydroxyfasudil and ML7). Additionally, RPEs were immunostained to examine whether the expression of alpha-SMA detected in our western blotting correlated to the stress fiber formation within the cells. TGF-beta2 caused time (0-5 days)-and dose (0 10 ng ml(-1))-dependent gel contraction associated with overexpression of alpha-SMA and phosphorylation of MLC (p < 0.01, respectively). PKC inhibitor (GF109203X, 5 microM) and p38 MAPK inhibitor (SB203580, 10 microM) significantly attenuated TGF-beta2-elicited gel contraction via partial downregulation of both alpha-SMA expression and MLC phosphorylation (p < 0.01, respectively). The gel contraction was prominently inhibited in the presence of Y27632 (10 microM) or hydroxyfasudil (10 microM) with strong suppression of MLC phosphorylation but had no significant effect on alpha-SMA expression. Treatment with ML7, in contrast, resulted in a marginal inhibition of MLC phosphorylation and gel contraction. Finally, pretreatment of the cells with Y27632 or hydroxyfasudil prevented the formation of stress fiber within the cells. These results indicate that TGF-beta2-dependent myofibroblastic transdifferentiation and MLC phosphorylation by RPEs involve both PKC and p38 MAPK pathways at least in part. Myofibroblastic transdifferentiation of RPEs appears to be independent of the Rho-kinase pathway, and the presence of alpha-SMA does not necessarily reflect the contractile potential of a cell. While Rho-kinase inhibitors are incapable of preventing myofibroblastic transdifferentiation itself, this pathway could be one of the critical targets of cell-mediated contraction of the tissue containing fibrillar collagens by transdifferentiated RPEs.

Actins↗
PubMed2005

Infiltration of COX-2-expressing macrophages is a prerequisite for IL-1 beta-induced neovascularization and tumor growth.

Inflammatory angiogenesis is a critical process in tumor progression and other diseases. The inflammatory cytokine IL-1beta promotes angiogenesis, tumor growth, and metastasis, but its mechanisms remain unclear. We examined the association between IL-1beta-induced angiogenesis and cell inflammation. IL-1beta induced neovascularization in the mouse cornea at rates comparable to those of VEGF. Neutrophil infiltration occurred on day 2. Macrophage infiltration occurred on days 4 and 6. The anti-Gr-1 Ab-induced depletion of infiltrating neutrophils did not affect IL-1beta- or VEGF-induced angiogenesis. The former was reduced in monocyte chemoattractant protein-1-deficient (MCP-1(-/-)) mice compared with wild-type mice. After day 4, clodronate liposomes, which kill macrophages, reduced IL-1beta-induced angiogenesis and partially inhibited VEGF-induced angiogenesis. Infiltrating macrophages near the IL-1beta-induced neovasculature were COX-2 positive. Lewis lung carcinoma cells expressing IL-1beta (LLC/IL-1beta) developed neovasculature with macrophage infiltration and enhanced tumor growth in wild-type but not MCP-1(-/-) mice. A COX-2 inhibitor reduced tumor growth, angiogenesis, and macrophage infiltration in LLC/IL-1beta. Thus, macrophage involvement might be a prerequisite for IL-1beta-induced neovascularization and tumor progression.

Animals↗