Comparing two methods for assessment of perfusion-diffusion mismatch in a rodent model of ischaemic stroke: a pilot study

This stroke experiment was designed to define the mismatch between perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) in MRI by applying early or instantly acquired PWI. Eight rats were induced with stroke through photothrombotic occlusion of the middle cerebral artery and scanned serially between 1 h and day 3 after induction using DWI and PWI with a 1.5 T MR scanner. The relative lesion volumes (rLV) on MRI and triphenyl tetrazolium chloride-stained specimens were defined as the proportion of lesion volume over brain volume. Discrepancies in the rLV between PWI- and DWI-derived apparent diffusion coefficient (ADC) maps were expressed by subtraction of the ADC from PWI, resulting in three possible patterns: (i) (PWI-ADC > 10% of PWI) denoting a mismatch; (ii) (-(10% of PWI) <or= PWI-ADC <or= 10% of PWI) denoting a match; and (iii) (PWI-ADC < -(10% of PWI)) denoting a reverse mismatch. The differences were compared with the minuend being either early PWI (ePWI) or instant PWI (iPWI) and the subtrahend being instant ADC (iADC). The occurrence and evolution of PWI-ADC patterns were analysed. Over time, PWI-ADC discrepancies evolved from mismatch, through to match, to reversed mismatch. The PWI-ADC mismatch still existed 3 days after MCA occlusion in one to three of the eight cases. The rLVs and mismatch incidences between the ePWI-iADC and iPWI-iADC models were linear correlated. A higher mismatch rate occurred in iPWI-iADC within day 1 and in ePWI-iADC at day 3. Both ePWI and iPWI proved useful to define PWI-ADC patterns within day 1. At day 3, iPWI appeared more adequate.

Lack of B-RAF mutations in head and neck squamous cell carcinoma

B-RAF is one of the most commonly mutated oncogenes in human cancer. However, the mutation status of B-RAF has not been established completely in HNSCC. We have analysed the mutation status of the kinase domain of the B-RAF gene (exons 11 and 15) in 91 Japanese HNSCC patients as well as 12 HNSCC cell lines. DNA was extracted and amplified by PCR. Mutations were then analysed by SSCP mutation detection method. Since V600EB-RAF constitutes 90 % of the mutations identified in B-RAF in human cancers, we also used MASA analysis to specifically detect this mutation in exon 15 of B-RAF. Using both methods, no mutation was found in both exon 11 and 15 in all patients and cell lines. Mu tations are absent or rare in the kinase domain of B-RAF in Japanese HNSCC. However, more studies are still needed to determine its usefulness as a target for molecular therapy in these patients.

Deletion mapping of chromosome 4q22-35 and identification of four frequently deleted regions in head and neck cancers

Head and neck squamous cell carcinoma (HNSCC) is a diverse group of cancers that are frequently aggressive in their biologic behavior. Inactivation of tumor suppressor gene (TSG) is one of the most critical steps leading to HNSCC. Loss of heterozygosity analysis is very sensitive method for the detection of frequent allelic loss in a chromosomal locus. This method has been considered as an important evidence for the localization of TSGs. We analyzed loss of heterozygosity (LOH) at chromosome 4q22-35 region by using 14 polymorphic microsatellite markers in 83 matched normal and HNSCC tissues. LOH was detected at least in one location in 71 of 83 (86%) tumor tissues. Frequent deletions were detected at the location of microsatellite markers, D4S2909 (46%), D4S2623 (51%), D4S406 (48%), D4S1644 (45%) and D4S2979 (40%). Four different frequently deleted regions at 4q22, 4q25, 4q31 and 4q34-35 were observed. These regions include several putative TSGs such as Caspase-6, SMARCAD1, SMARCA5, SAP30 and ING2. Further molecular analysis of each gene should be performed to clarify their roles in head and neck squamous cell carcinogenesis.

Macular Pigment Lutein Is Antiinflammatory in Preventing Choroidal Neovascularization

Background— Choroidal neovascularization (CNV) is a critical pathogenesis in age-related macular degeneration, the most common cause of blindness in the developed countries. The aim of the current study was to investigate the effect of lutein supplementation on the development of the murine model of laser-induced CNV together with underlying molecular mechanisms.

Methods and Results— Mice were orally pretreated with lutein daily from 3 days before laser photocoagulation untill the end of the study. The index of CNV volume was significantly suppressed by the treatment with lutein, compared with vehicle-treated animals. Lutein treatment led to significant inhibition of macrophage infiltration into CNV and of the in vivo and in vitro expression of inflammation-related molecules including vascular endothelial growth factor, monocyte chemotactic protein −1, and intercellular adhesion molecule-1. Importantly, lutein suppressed IκB-α degradation and nuclear translocation of nuclear factor (NF)-κB p65 both in vivo and in vitro. Additionally, the development of CNV was significantly suppressed by inhibiting NF-κB p65 nuclear translocation, to the levels seen in the lutein treatment.

Conclusions— Lutein treatment led to significant suppression of CNV development together with inflammatory processes including NF-κB activation and subsequent upregulation of inflammatory molecules, providing molecular evidence of potential validity of lutein supplementation as a therapeutic strategy to suppress CNV.

Suppression of choroidal neovascularization by dendritic cell vaccination targeting VEGFR2

PURPOSE

To investigate whether the induction of cellular immunity against vascular endothelial growth factor receptor (VEGFR) 2 inhibits the development of choroidal neovascularization (CNV).

METHODS

H-2Db-restricted peptide corresponding to amino acids 400 to 408 of VEGFR2 was used as an epitope peptide. Dendritic cells (DCs) were harvested from bone marrow progenitors of C57BL/6 mice. Six-week-old C57BL/6 mice received subcutaneous injections of the epitope peptide-pulsed mature DCs three times at 6-day intervals. After the third immunization, laser photocoagulation was performed to induce CNV. One week after photocoagulation, mice were killed to harvest the choroid and splenocytes. CNV volume was evaluated by volumetric measurements. To confirm the specific immunogenicity of the epitope peptides in C57BL/6 mice, CD8 T cells isolated from harvested splenocytes were restimulated to measure interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha production through enzyme-linked immunospot assay and ELISA. To determine the T-cell subset responsible for the immunotherapy, mice were intraperitoneally injected with an anti-CD4 or anti-CD8 depletion antibody.

RESULTS

CNV volume was significantly lower in mice immunized with the VEGFR2 epitope peptide than in those not immunized or immunized with a control peptide gp70. Cytokine assays showed the peptide-specific production of IFN-gamma and TNF-alpha from the CD8 T cells in a dose-dependent manner. In vivo depletion of CD8, but not CD4, T cells significantly reversed the suppressive effect of the VEGFR2 peptide-pulsed DC vaccination on CNV to the level observed in nonimmunized or gp70-immunized animals.

CONCLUSIONS

These results indicate that the VEGFR2 peptide-specific induction of cellular immunity inhibits CNV through the cytotoxicity of CD8 T cells. Results of the present study suggested the possibility of DC vaccination targeting VEGFR2 as a novel therapeutic strategy for CNV.

Notch signaling in mandibular condylar cartilage development

OBJECTIVE

The purpose of this study was to investigate the expression pattern of Notch signaling in mandibular condylar cartilage, as a type of secondary cartilage.

METHODS

Mandibular condyle of ddY mice were fixed from embryonic day 14 (E14) through just after birth (equivalent to E19). Samples were cut into 4 mum serial sections through the central area of the mandibular condyle at the sagittal plane. Serial sections were examined using histological, immunohistochemical (IHC) and in situ hybridization (ISH) techniques.

RESULTS

At E14, there were no developmental features of mandibular condyle. At the distal upper portion of developmental mandibular bone, mesenchymal cell proliferation and condensation without metacholomatic reaction to toluidine blue (TB) were seen. At E15, mandibular condylar cartilage was clearly evident, as TB metacholomasia. In IHC specimens at E14, expression of Notch1 intracellular domain (NICD) was observed in the nuclei of coagulating mesenchymal cells. After E15, NICD appeared in the nuclei and the cytoplasms of cells. In ISH examination at E14, expressions of Notch1 mRNA appeared in cytoplasm of proliferating chondrocytes. From E15 to E19, Notch1 mRNA was detected throughout almost all cytoplasm in all layers.

CONCLUSION

These IHC and ISH results suggest that Notch signaling plays an essential role for mandibular condylar cartilage morphogenesis and development.

Eicosapentaenoic acid is anti-inflammatory in preventing choroidal neovascularization in mice

PURPOSE

To investigate the role of eicosapentaenoic acid (EPA), the major omega-3 polyunsaturated fatty acid (PUFA), in the development of choroidal neovascularization (CNV), together with underlying molecular mechanisms.

METHODS

Six-week-old C57BL/6 mice were fed with laboratory chow with 5% EPA or the omega-6 PUFA linoleic acid (LA) for 4 weeks. Laser photocoagulation was performed to induce CNV, and the volume of CNV tissue was evaluated by volumetric measurements. The expression and production of intercellular adhesion molecule (ICAM)-1, monocyte chemotactic protein (MCP)-1, vascular endothelial growth factor (VEGF) and interleukin (IL)-6 in the retinal pigment epithelium (RPE)-choroid in vivo, and stimulated b-End3 endothelial cells and RAW264.7 macrophages in vitro were evaluated by RT-PCR and ELISA. Fatty acid composition in the serum and the RPE-choroid was analyzed by gas chromatography and high-performance liquid chromatography, respectively. Serum levels of C-reactive protein (CRP), IL-6, VEGF, MCP-1, and soluble ICAM-1 were examined by ELISA.

RESULTS

The CNV volume in EPA-fed animals was significantly suppressed compared with that in control mice, whereas the LA-rich diet did not affect CNV. The mRNA expression and protein levels of ICAM-1, MCP-1, VEGF, and IL-6 after CNV induction were significantly reduced in EPA-supplemented mice. In vitro, EPA application led to significant inhibition of mRNA and protein levels of ICAM-1 and MCP-1 in endothelial cells and VEGF and IL-6 in macrophages. EPA-fed mice exhibited significantly higher levels of EPA and lower levels of the omega-6 PUFA arachidonic acid in the serum and the RPE-choroid than control animals. EPA supplementation also led to significant reduction of serum levels of IL-6 and CRP after CNV induction.

CONCLUSIONS

The present study demonstrates for the first time that an EPA-rich diet results in significant suppression of CNV and CNV-related inflammatory molecules in vivo and in vitro. These results suggest that frequent consumption of omega-3 PUFAs may prevent CNV and lower the risk of blindness due to age-related macular degeneration.

Suppression of diabetes-induced retinal inflammation by blocking the angiotensin II type 1 receptor or its downstream nuclear factor-kappaB pathway

PURPOSE

To investigate the involvement of the renin-angiotensin system (RAS) and the nuclear factor (NF)-kappaB pathway with diabetes-induced retinal inflammation.

METHODS

Six weeks after induction of diabetes, C57BL/6 mice were treated with the angiotensin II type 1 receptor (AT1-R) blocker (ARB) telmisartan or valsartan, the AT2-R blocker PD123319, or the NF-kappaB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) daily for 1 week. Retinal mRNA and protein levels of the RAS components were examined by RT-PCR and Western blot, respectively. Leukocyte adhesion to the retinal vasculature was evaluated with a concanavalin A lectin perfusion-labeling technique. Retinal expression levels of intercellular adhesion molecule (ICAM)-1 and vascular endothelial growth factor (VEGF) were examined by RT-PCR and ELISA. ARB or DHMEQ was applied to murine capillary endothelial (b-End3) cells stimulated with a high concentration of glucose to analyze nuclear translocation of NF-kappaB via immunohistochemistry for p65 and mRNA and protein levels of ICAM-1 and monocyte chemotactic protein (MCP)-1.

RESULTS

Induction of diabetes led to a significant increase in retinal expression and production of the RAS components including angiotensin II, AT1-R, and AT2-R. Retinal adherent leukocytes were significantly suppressed by AT1-R, but not by AT2-R, blockade. Administration of the ARB, but not of PD123319, inhibited diabetes-induced retinal expression of ICAM-1 and VEGF. DHMEQ also suppressed these cellular and molecular inflammatory parameters in the diabetic retina to the levels obtained with ARB treatment. In vitro, glucose-induced nuclear translocation of NF-kappaB p65 and upregulation of ICAM-1 and MCP-1 were significantly suppressed by application of the ARB. The in vivo treatment with the ARB, as well as DHMEQ, attenuated the diabetes-induced retinal expression of angiotensin II and AT1-R, per se.

CONCLUSIONS

The present data revealed significant a contribution of the AT1-R/NF-kappaB pathway to diabetes-induced retinal inflammation, providing a mechanistic reason for targeting AT1-R or NF-kappaB in the treatment of diabetic retinopathy.

In vitro cell culture model for anti-cataract drug penetration studies

Immortalized human corneal epithelial cells (HCECs) and human lens epithelial cells (HLECs) were cultured in vitro. Cells were observed under a phase-contrast microscope and the integrity of cell monolayers was assayed by transepithelial electrical resistance (TEER) determination. The permeability of disulfiram (DSF) through a HCECs monolayer was compared with that of DSF through an excised rabbit cornea. The permeability coefficients of DSF through a HCECs monolayer and excised rabbit cornea were 29.5 +/- 4.8 x 10(-6) cm/s and 34.7 +/- 5.2 x 10(-6) cm/s, respectively. Diethyldithiocarbamate (DDC) had high permeability through HLECs monolayer with a permeability coefficient of 44.6 +/- 7.1 x 10(-6) cm/s. The cytotoxicity of DDC against HLECs was investigated using the trypan blue exclusion test. For a DDC concentration of 5 mmol/l, more than 85% cells were viable. DH3a1 mRNA was expressed in cultured HLECs. The expression of aldehyde dehydrogenase 3a1 (ALDH3a1), which may be be responsible for DSF-DDC conversion, was detected using RT-PCR and agarose gels electrophoresis. These results demonstrate that the permeability of DSF can be detected and intra-ocular drug action may be predicted using the cultured HCEC and HLEC monolayers as model.

Stromelysin-1 (MMP-3) is critical for intracranial bleeding after t-PA treatment of stroke in mice

BACKGROUND

Tissue-type plasminogen activator (t-PA) is approved for treatment of ischemic stroke patients, but it may increase the risk of intracranial bleeding (ICB). Matrix metalloproteinases (MMPs), which can be activated through the plasminogen/plasmin system, may contribute to ICB after ischemic stroke.

OBJECTIVES

To explore the contribution of plasminogen, MMP-3 and MMP-9 to ICB associated with t-PA treatment after ischemic stroke.

METHODS

Using a thrombotic middle cerebral artery occlusion (MCA-O) model, ICB was studied in mice with genetic deficiencies of plasminogen (Plg(-/-)), stromelysin-1 (MMP-3(-/-)), or gelatinase B (MMP-9(-/-)) and their corresponding wild-type (WT) littermates. The induction of MMP-3 and MMP-9 was also studied in C57BL/6 WT mice.

RESULTS

ICB induced by t-PA (10 mg kg(-1)) was significantly less than WT in Plg(-/-) (P < 0.05) and MMP-3(-/-) (P < 0.05) but not in MMP-9(-/-) mice. Furthermore, administration of the broad-spectrum MMP inhibitor GM6001 after t-PA treatment reduced ICB significantly (P < 0.05) in MMP-3(+/+) mice, but had no effect on MMP-3(-/-) mice. MMP-3 expression was significantly enhanced at the ischemic hemisphere; with placebo treatment, it was expressed only in neurons, whereas it was up-regulated in endothelial cells with t-PA treatment. Although MMP-9 expression was also significantly enhanced at the ischemic brain, the amount and the distribution were comparable in mice with and without t-PA treatment.

CONCLUSIONS

Our data with gene-deficient mice thus suggest that plasminogen and MMP-3 are relatively more important than MMP-9 for the increased ICB induced by t-PA treatment of ischemic stroke.

Plasminogen activator inhibitor-1 contributes to the deleterious effect of obesity on the outcome of thrombotic ischemic stroke in mice

BACKGROUND

It is widely accepted that obesity is a risk factor for ischemic heart disease, but the association with stroke is less clear. Adipose tissue is an important source of plasminogen activator inhibitor-1 (PAI-1), the main inhibitor of plasminogen activation.

OBJECTIVE

To test the hypothesis that elevated PAI-1 levels associated with obesity negatively affect the outcome of thrombotic ischemic stroke.

METHODS

Middle cerebral artery (MCA) occlusion was induced photochemically in mice with nutritionally induced or genetically determined obesity and their lean counterparts.

RESULTS

The MCA occlusion time (to obtain complete occlusion) was significantly shorter in obese (nutritionally induced) than in lean wild-type (WT) C57Bl/6 mice, whereas the infarct size was significantly larger and intracranial hemorrhage (ICH) was enhanced (all P < 0.05). Similar observations were made in genetically obese ob/ob mice, as compared to lean WT littermates. In both strains, obesity was associated with markedly elevated circulating PAI-1 levels, probably originating from the fat tissue. In contrast, PAI-1-deficient lean and obese mice did not display significant differences in MCA occlusion time, infarct volume or ICH.

CONCLUSIONS

Plasminogen activator inhibitor-1 may play a functional role in the deleterious effect of obesity on the outcome of thrombotic ischemic stroke in mice.

Surgical effects and complications of indocyanine green-assisted internal limiting membrane peeling for idiopathic macular hole

PURPOSE

To compare the surgical outcomes and complications of vitrectomy with internal limiting membrane (ILM) peeling with or without indocyanine green (ICG) staining in eyes with an idiopathic macular hole.

METHODS

This study involved a non-randomized, single-centre, retrospective, interventional case series. Rates of anatomical closure, visual acuities (VAs) and postoperative complications in 35 eyes of 31 patients who underwent ICG-assisted ILM peeling during macular hole surgery (stained group) were compared with those in 18 eyes of 16 patients who underwent the same procedure without ICG staining (non-stained group).

RESULTS

Macular holes were closed following the initial surgery in 97% of the stained group and 94% of the non-stained group (p > 0.999). There was no significant difference in mean final VA between the stained and non-stained groups, but there was a lower percentage of eyes with postoperative vision > 20/25 in the stained group (15%) than in the non-stained group (44%) after 2 years (p = 0.036). Posterior retinal pigment epithelium atrophy, retinoschisis and visual field defects were observed only in the stained group.

CONCLUSIONS

The difference in mean final VA between the two groups was not significant. However, a lower percentage of eyes obtained VA > or = 20/25 and a higher incidence of postoperative complications occurred in the stained group. These results indicate that some consideration should be made before ICG is used in macular hole surgery.

Interleukin-6 receptor-mediated activation of signal transducer and activator of transcription-3 (STAT3) promotes choroidal neovascularization

Interleukin (IL)-6, a potent proinflammatory cytokine, is suggested to be a risk factor for choroidal neovascularization (CNV) because of its increased levels in the serum of patients with age-related macular degeneration; however, the role of IL-6 in CNV has not been defined. The present study reveals the critical contribution of IL-6 signaling and its downstream STAT3 pathway to the murine model of laser-induced CNV. CNV induction by laser treatment stimulated IL-6 expression in the retinal pigment epithelium-choroid complex, and antibody-based blockade of IL-6 receptor or genetic ablation of IL-6 led to significant suppression of CNV. CNV generation was accompanied by STAT3 activation in choroidal endothelial cells and macrophages, and IL-6 receptor blockade resulted in selectively inhibited phosphorylation of STAT3 but not extracellular signal-regulated kinase 1/2. Consistently, pharmacological blockade of STAT3 pathway also suppressed CNV. In addition, IL-6 receptor neutralization led to significant inhibition of the in vivo and in vitro expression of inflammation-related molecules including monocyte chemotactic protein, intercellular adhesion molecule-1, and vascular endothelial growth factor, and of macrophage infiltration into CNV. These results indicate the significant involvement of IL-6 receptor-mediated activation of STAT3 inflammatory pathway in CNV generation, suggesting the possibility of IL-6 receptor blockade as a therapeutic strategy to suppress CNV associated with age-related macular degeneration.

Binding of ADAM28 to P-selectin glycoprotein ligand-1 enhances P-selectin-mediated leukocyte adhesion to endothelial cells

ADAMs (a disintegrin and metalloproteinases) are a recently discovered gene family of multifunctional proteins with the disintegrin-like and metalloproteinase domains. To analyze the biological functions of ADAM28, we screened binding molecules to secreted-type ADAM28 (ADAM28s) by the yeast two-hybrid system and identified P-selectin glycoprotein ligand-1 (PSGL-1). Binding between the disintegrin-like domain of ADAM28s and the extracellular portion of PSGL-1 was determined by yeast two-hybrid assays, binding assays of the domain-specific recombinant ADAM28s species using PSGL-1 stable transfectants and leukocyte cell lines expressing native PSGL-1 (HL-60 cells and Jurkat cells), and co-immunolocalization and co-immunoprecipitation of the molecules in these cells. Incubation of HL-60 cells with recombinant ADAM28s enhanced the binding to P-selectin-coated wells and P-selectin-expressing endothelial cells. In addition, intravenous injection of ADAM28s-treated HL-60 cells increased their accumulation in the pulmonary microcirculation and alveolar spaces in a mouse model of endotoxin-induced inflammation. These data suggest a novel function that ADAM28s promotes PSGL-1/P-selectin-mediated leukocyte rolling adhesion to endothelial cells and subsequent infiltration into tissue spaces through interaction with PSGL-1 on leukocytes under inflammatory conditions.

Suppression of Choroidal Neovascularization by Inhibiting Angiotensin-Converting Enzyme: Minimal Role of Bradykinin

PURPOSE

Angiotensin-converting enzyme (ACE), also known as kininase II, functions not only to convert angiotensin I to angiotensin II, but also to cleave bradykinin into inactive fragments. Thus, ACE inhibition causes the tissue accumulation of bradykinin, exerting either of two opposite effects: anti- or proangiogenic. The purpose of the present study was to investigate the role of bradykinin in the development of choroidal neovascularization (CNV), with or without ACE inhibition.

METHODS

Laser photocoagulation was used to induce CNV in wild-type C57BL/6J mice and angiotensin II type 1 receptor (AT1-R)-deficient mice. Wild-type mice were pretreated with the ACE inhibitor imidapril, with or without the bradykinin B2 receptor (B2-R) antagonist icatibant daily for 6 days before photocoagulation, and the treatment was continued daily until the end of the study. CNV response was analyzed by volumetric measurements using confocal microscopy 1 week after laser injury. The mRNA and protein levels of vascular endothelial growth factor (VEGF), intercellular adhesion molecule (ICAM)-1, and monocyte chemotactic protein (MCP)-1 in the retinal pigment epithelium-choroid complex were examined by RT-PCR and ELISA, respectively.

RESULTS

ACE inhibition led to significant suppression of CNV development to the level seen in AT1-R-deficient mice. B2-R blockade together with high-dose but not low-dose ACE inhibition resulted in more potent suppression of CNV than did ACE inhibition alone. B2-R blockade alone exhibited little or no effect on CNV. VEGF, ICAM-1, and MCP-1 levels, elevated by CNV induction, were significantly suppressed by ACE inhibition. VEGF but not ICAM-1 or MCP-1 levels were further attenuated by B2-R blockade with ACE inhibition.

CONCLUSIONS

These results suggest a limited contribution of the kallikrein-kinin system to the pathogenesis of CNV, in which the renin-angiotensin system plays more essential roles for facilitating angiogenesis. The present study indicates the possibility of ACE inhibition as a novel therapeutic strategy to inhibit CNV.

Role of nonproteolytically activated prorenin in pathologic, but not physiologic, retinal neovascularization

PURPOSE

Recently, it was revealed that the inhibition of nonproteolytic activation of prorenin led to significant suppression of ocular inflammation in endotoxin-induced uveitis. The purpose of the present study was to investigate whether nonproteolytically activated prorenin plays a role in ischemia-induced retinal neovascularization.

METHODS

C57BL/6 neonatal mice were reared in an 80% concentration of oxygen from postnatal (P) day 7 to P12, followed by room-air breathing to P17 to induce ischemia-initiated retinal neovascularization. Tissue localization of activated prorenin and prorenin receptor was examined by immunohistochemistry. Animals received intraperitoneal injections of handle-region peptide (HRP), a decoy peptide corresponding to the handle region of prorenin, which inhibits prorenin receptor-mediated upregulation of the renin-angiotensin system (RAS). A concanavalin A lectin perfusion-labeling technique was used to evaluate the areas of physiologic and pathologic retinal new vessels and the number of leukocytes adhering to the vasculature. Retinal mRNA expression and protein levels of intercellular adhesion molecule (ICAM)-1, vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)-1, and VEGFR-2 were examined by RT-PCR and ELISA.

RESULTS

Retinal vessels in ischemic retinopathy eyes were positive for activated prorenin and prorenin receptor. Pathologic, but not physiologic, retinal neovascularization was significantly attenuated in HRP-treated mice compared with vehicle- or control peptide-treated animals. The number of adherent leukocytes was also significantly reduced. Retinal mRNA expression and protein levels of ICAM-1, VEGF, VEGFR-1, and VEGFR-2 in ischemic retinopathy were also significantly suppressed by the application of HRP.

CONCLUSIONS

The present findings suggest that nonproteolytic activation of prorenin selectively promotes pathologic, but not physiologic, retinal neovascularization through the inflammatory processes related to pathologic neovascularization.

Neuroprotective Effects of Angiotensin II Type 1 Receptor (AT1R) Blocker, Telmisartan, via Modulating AT1R and AT2R Signaling in Retinal Inflammation

PURPOSE

To investigate the retinal neural damage that occurs during inflammation and the therapeutic effects of the angiotensin II type 1 receptor (AT1R) blocker, telmisartan, using a model of endotoxin-induced uveitis (EIU).

METHODS

The localization of AT1R and AT2R was shown by immunohistochemistry. EIU was induced by intraperitoneal injection of lipopolysaccharide (LPS). Animals were treated with telmisartan for 2 days and were evaluated 24 hours later. Expression levels of angiotensin II, STAT3 activation induced by inflammatory cytokines, and retinal proteins essential for neural activities (e.g., synaptophysin, rhodopsin) were analyzed by immunoblot. An AT2R antagonist was administered to evaluate the contribution of AT2R signaling in this therapy. Dark-adapted full-field electroretinography (ERG) was also performed.

RESULTS

AT1R and AT2R were expressed in presynaptic terminals in most of the retinal neurons. AT1R was also expressed in Müller glial cells. During inflammation, angiotensin II expression was elevated, STAT3 was activated, and synaptophysin and rhodopsin expression were reduced. The expression of glial fibrillary acidic protein (GFAP), downstream of STAT3 activation, was induced in Müller glial cells. However, treatment with telmisartan successfully avoided all these changes. An AT2R antagonist lowered synaptophysin expression despite the treatment. STAT3 activity was negatively correlated with rhodopsin expression. Furthermore, ERG responses, which were mostly prevented by telmisartan, were disturbed during inflammation.

CONCLUSIONS

Retinal protein expression and visual function are both disturbed by inflammation. Treatment with the AT1R blocker telmisartan efficiently prevented these signs of retinal neural damage through the reduction of local angiotensin II expression, the blockade of AT1R, and the relative upregulation of AT2R function.

Angiotensin II type 1 receptor-mediated inflammation is required for choroidal neovascularization

BACKGROUND

Choroidal neovascularization (CNV) is a critical pathogenesis in age-related macular degeneration, the most common cause of blindness in the developed countries. The aim of the current study was to determine the involvement of the renin-angiotensin system (RAS) with the development of CNV, using human surgical samples and the murine model of laser-induced CNV.

METHODS AND RESULTS

In the human and murine CNV tissues, the vascular endothelium expressed angiotensin II type 1 receptor (AT1-R), AT2-R, and angiotensin II. The CNV volume was significantly suppressed by treatment with an AT1-R blocker telmisartan, but not with an AT2-R blocker. AT1-R signaling blockade with telmisartan inhibited various inflammatory mechanisms including macrophage infiltration and upregulation of VEGF, intercellular adhesion molecule-1 (ICAM-1), MCP-1, and IL-6 in the retinal pigment epithelium-choroid complex. A PPAR-gamma antagonist partially but significantly reversed the suppressive effect of telmisartan on in vivo induction of CNV and in vitro upregulation of ICAM-1 and MCP-1 in endothelial cells and IL-6 in macrophages, showing the dual contribution of PPAR-gamma-agonistic and AT1-R-antagonistic actions in the telmisartan treatment.

CONCLUSIONS

AT1-R-mediated inflammation plays a pivotal role in the development of CNV, indicating the possibility of AT1-R blockade as a novel therapeutic strategy to inhibit CNV.

Suppression of ocular inflammation in endotoxin-induced uveitis by inhibiting nonproteolytic activation of prorenin

PURPOSE

A recent study revealed that angiotensin receptor signaling mediates ocular inflammation and neovascularization. It was also found that prorenin undergoes nonproteolytic activation leading to upregulation of the renin-angiotensin system (RAS) when prorenin receptor interacts specifically with the handle region of prorenin. The purpose of the present study was to elucidate the role of the receptor-dependent nonproteolytic activation of prorenin in ocular inflammation in endotoxin-induced uveitis (EIU).

METHODS

EIU was induced in Long-Evans rats by a single intraperitoneal injection of 100 microg lipopolysaccharide (LPS). Tissue localization of total prorenin, prorenin receptor, and activated prorenin in the EIU retina was examined by immunohistochemistry. To inhibit the prorenin receptor-mediated upregulation of the RAS, a decoy handle-region peptide (HRP) was intraperitoneally administered 24 hours before and immediately after the injection of LPS. Twenty-four hours after LPS injection, leukocyte adhesion to the retinal vasculature was evaluated with a concanavalin A lectin perfusion-labeling technique. In addition, leukocyte infiltration into the vitreous cavity and protein concentration in the anterior chamber were also measured. Retinal mRNA and protein levels of intercellular adhesion molecule (ICAM)-1, interleukin (IL)-6, and C-C chemokine ligand (CCL) 2/monocyte chemotactic protein (MCP)-1 were examined by RT-PCR and ELISA.

RESULTS

Retinal vessels in rats with EIU were strongly positive for total prorenin, prorenin receptor, and activated prorenin. Systemic treatment with HRP resulted in dose- and time-dependent inhibition of the leukocyte adhesion and infiltration and the protein leakage, all of which were increased by the induction of EIU. Retinal mRNA expression and protein levels of ICAM-1, CCL2/MCP-1 and IL-6, induced in rats with EIU, were also significantly suppressed with application of HRP.

CONCLUSIONS

These findings demonstrate for the first time that nonproteolytically activated prorenin plays a significant role in the development of ocular inflammation in the EIU model. The present study suggests the potential use of HRP, a decoy peptide binding to the prorenin receptor, as a therapeutic agent to reduce ocular inflammation.

Villoglandular papillary adenocarcinoma of the uterine cervix responding to neoadjuvant chemotherapy with docetaxel and cisplatin: a case report

Villoglandular papillary adenocarcinoma (VGPA) of the uterine cervix is a rare neoplasm, and its treatment has rarely been reported. We report a patient with VGPA stage IIA responding to neoadjuvant chemotherapy with docetaxel (60 mg/m2 as an intravenous infusion) and cisplatin (70 mg/m2 as an intra-arterial infusion). At 3 weeks after completing one course of this regimen, the tumor size was reduced from 5.3 x 4.0 cm to 2.0 x 2.0 cm (81.1% reduction), revealed by computed tomography. Accordingly, the patient underwent radical hysterectomy, and there have been no signs of recurrence. Thus, the combination of docetaxel and cisplatin is suggested to be useful for neoadjuvant chemotherapy of cervical adenocarcinoma.

Immunohistochemical examination of cytological differentiation in osteosarcomas

In this immunohistochemical examination, the expression of Runx2, Notch1, Delta and Osteopontin peptides were detected in neoplastic cells in 10 Japanese cases of osteosarcoma. Immunohistochemically, Runx2 peptide expression appeared in the cytoplasm of almost all neoplastic cells of the 10 cases examined. However, Notch1 peptide expression appeared in the cytoplasm of neoplastic cells in the localized and comparatively well-differentiated area of osteosarcoma, which osteoblastic and chondroblastic containing osteoid and/or chondroid tissues. No expression of Notch1 peptide was detected in the fibroblastic and poorly differentiated areas. Delta peptide appearance was nearly the same pattern of Notch1 peptide. Expression of Osteopontin peptide appeared in almost all cells and the strength expression was shown in the area of comparatively well-differentiated tissues. Therefore, these results suggest that Runx2, Notch1, and Delta peptides are closely related to cytological differentiation or acquisition of tissue specific characteristics in neoplastic cells in osteosarcomas.

Cooperative interaction of Angiopoietin-like proteins 1 and 2 in zebrafish vascular development

Angiopoietin-like protein (Angptl) 1 and Angptl2, which are considered orphan ligands, are highly homologous, particularly in the fibrinogen-like domain containing the putative receptor binding site. This similarity suggests potentially cooperative functions between the two proteins. In this report, the function of Angptl1 and Angptl2 is analyzed by using morpholino antisense technology in zebrafish. Knockdown of both Angptl1 and Angptl2 produced severe vascular defects due to increased apoptosis of endothelial cells at the sprouting stage. In vitro studies showed that Angptl1 and Angptl2 have antiapoptotic activities through the phosphatidylinositol 3-kinase/Akt pathway, and coinjection of constitutively active Akt/protein kinase B mRNA rescued impaired vascular development seen in double knockdown embryos. These results provide a physiological demonstration of the cooperative interaction of Angptl1 and Angptl2 in endothelial cells through phosphatidylinositol 3-kinase/Akt mediated antiapoptotic activities.

Suppression of Ocular Inflammation in Endotoxin-Induced Uveitis by Blocking the Angiotensin II Type 1 Receptor

PURPOSE

To examine whether the angiotensin II type 1 receptor (AT1-R) signaling plays a role in ocular inflammation in endotoxin-induced uveitis (EIU).

METHODS

EIU was induced in C57BL/6 mice by a single intraperitoneal injection of 150 mug lipopolysaccharide (LPS). Tissue localization, mRNA expression, and protein levels of AT1-R in murine retinas were examined by immunohistochemistry, RT-PCR, and Western blot analyses, respectively. Telmisartan, an AT1-R antagonist widely used as an antihypertensive agent, was administered intraperitoneally at a dose of 10 mg/kg daily for 5 days until the injection of LPS. Twenty-four hours after administration, leukocyte adhesion to the retinal vasculature was evaluated with a concanavalin A lectin perfusion-labeling technique. Retinal mRNA and protein levels of intercellular adhesion molecule (ICAM)-1 were examined by RT-PCR and ELISA, respectively. Protein concentration and inflammatory cells in the aqueous humor were also measured.

RESULTS

Retinal vessels were positive for AT1-R. In mice with EIU, retinal AT1-R mRNA and protein levels were significantly increased when compared to the normal control. EIU animals also showed significant increases in the number of inflammatory cells infiltrating the anterior chamber and adhering to the retinal vessels and in retinal ICAM-1 levels. Administration of telmisartan to EIU mice resulted in significant suppression of retinal ICAM-1 expression and leukocyte adhesion and infiltration compared with vehicle treatment. Protein concentration in the aqueous humor of telmisartan-treated EIU mice tended to be lower than that of vehicle-treated EIU mice, but the difference was not statistically significant.

CONCLUSIONS

AT1-R signaling blockade inhibited retinal ICAM-1 upregulation and leukocyte adhesion and infiltration in the EIU model. These results suggest the potential use of an AT1-R antagonist as a therapeutic agent to reduce ocular inflammation.

Effects of plasminogen activator inhibitor-1 on ischemic brain injury in permanent and thrombotic middle cerebral artery occlusion models in mice

BACKGROUND AND OBJECTIVES

Tissue plasminogen activator (t-PA) improves the outcome of ischemic stroke by recanalization of occluded vessels, but has neurotoxic side effects in experimental stroke models. Here, the effect of plasminogen activator inhibitor-1 (PAI-1), an endogenous inhibitor of t-PA, on ischemic infarct volume was studied.

METHODS

After either permanent ligation or thrombotic occlusion of the middle cerebral artery (MCA), infarct volume, spontaneous reperfusion of thrombosed MCA, t-PA/PAI-1 complex level, and blood-brain barrier (BBB) permeability in the ischemic region was studied in transgenic mice with overexpression of PAI-1 and wild-type littermate controls and in mice with intracerebroventricular injection of human PAI-1.

RESULTS

Infarct volume was smaller in PAI-1 transgenic mice (2.9 +/- 3.7 mm3, mean +/- SD) than in controls (8.9 +/- 5.0 mm3, P < 0.05) after permanent MCA ligation (plasma PAI-1 level 39 +/- 23 ng mL(-1) in transgenic mice vs. 1.5 +/- 0.6 ng mL(-1) in controls), whereas after MCA thrombosis it was larger in transgenics (13.1 +/- 3.1 mm3) than in controls (8.0 +/- 3.2 mm3, P < 0.05). Spontaneous reperfusion of the thrombosed MCA was significantly delayed in transgenic vs. control mice. In the ligation model, t-PA/PAI-1 complex levels were higher and BBB disruption was more pronounced in the ischemic region. Human PAI-1 injection reduced infarct volume by about 50% in wild-type mice but not in t-PA gene deficient mice.

CONCLUSIONS

High PAI-1 levels reduced infarct volume in the permanent MCA ligation model, but enhanced it in the MCA thrombosis model.