The IL-13/periostin/IL-24 pathway causes epidermal barrier dysfunction in allergic skin inflammation.

BACKGROUND: Barrier dysfunction is an important feature of atopic dermatitis (AD) in which IL-4 and IL-13, signature type 2 cytokines, are involved. Periostin, a matricellular protein induced by IL-4 or IL-13, plays a crucial role in the onset of allergic skin inflammation, including barrier dysfunction. However, it remains elusive how periostin causes barrier dysfunction downstream of the IL-13 signal. METHODS: We systematically identified periostin-dependent expression profile using DNA microarrays. We then investigated whether IL-24 downregulates filaggrin expression downstream of the IL-13 signals and whether IL-13-induced IL-24 expression and IL-24-induced downregulation of filaggrin expression are dependent on the JAK/STAT pathway. To build on the significance of in vitro findings, we investigated expression of IL-24 and activation of STAT3 in mite-treated mice and in AD patients. RESULTS: We identified IL-24 as an IL-13-induced molecule in a periostin-dependent manner. Keratinocytes are the main IL-24-producing tissue-resident cells stimulated by IL-13 in a periostin-dependent manner via STAT6. IL-24 significantly downregulated filaggrin expression via STAT3, contributing to barrier dysfunction downstream of the IL-13/periostin pathway. Wild-type mite-treated mice showed significantly enhanced expression of IL-24 and activation of STAT3 in the epidermis, which disappeared in both STAT6-deficient and periostin-deficient mice, suggesting that these events are downstream of both STAT6 and periostin. Moreover, IL-24 expression was enhanced in the epidermis of skin tissues taken from AD patients. CONCLUSIONS: The IL-13/periostin pathway induces IL-24 production in keratinocytes, playing an important role in barrier dysfunction in AD.

Renin-angiotensin system regulates neurodegeneration in a mouse model of normal tension glaucoma.

Glaucoma, one of the leading causes of irreversible blindness, is characterized by progressive degeneration of optic nerves and retinal ganglion cells (RGCs). In the mammalian retina, excitatory amino acid carrier 1 (EAAC1) is expressed in neural cells, including RGCs, and the loss of EAAC1 leads to RGC degeneration without elevated intraocular pressure (IOP). In the present study, we found that expressions of angiotensin II type 1 receptor (AT1-R) and Toll-like receptor 4 (TLR4) are increased in RGCs and retinal Müller glia in EAAC1-deficient (KO) mice. The orally active AT1-R antagonist candesartan suppressed TLR4 and lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) expressions in the EAAC1 KO mouse retina. Sequential in vivo retinal imaging and electrophysiological analysis revealed that treatment with candesartan was effective for RGC protection in EAAC1 KO mice without affecting IOP. In cultured Müller glia, candesartan suppressed LPS-induced iNOS production by inhibiting the TLR4-apoptosis signal-regulating kinase 1 pathway. These results suggest that the renin-angiotensin system is involved in the innate immune responses in both neural and glial cells, which accelerate neural cell death. Our findings raise intriguing possibilities for the management of glaucoma by utilizing widely prescribed drugs for the treatment of high blood pressure, in combination with conventional treatments to lower IOP.

Brimonidine prevents neurodegeneration in a mouse model of normal tension glaucoma.

Glaucoma is one of the leading causes of irreversible blindness that is characterized by progressive degeneration of optic nerves and retinal ganglion cells (RGCs). In the mammalian retina, excitatory amino-acid carrier 1 (EAAC1) is expressed in neural cells, including RGCs, and the loss of EAAC1 leads to RGC degeneration without elevated intraocular pressure (IOP). Brimonidine (BMD) is an α2-adrenergic receptor agonist and it is commonly used in a form of eye drops to lower IOP in glaucoma patients. Recent studies have suggested that BMD has direct protective effects on RGCs involving IOP-independent mechanisms, but it is still controversial. In the present study, we examined the effects of BMD in EAAC1-deficient (KO) mice, an animal model of normal tension glaucoma. BMD caused a small decrease in IOP, but sequential in vivo retinal imaging and electrophysiological analysis revealed that treatment with BMD was highly effective for RGC protection in EAAC1 KO mice. BMD suppressed the phosphorylation of the N-methyl-D-aspartate receptor 2B (NR2B) subunit in RGCs in EAAC1 KO mice. Furthermore, in cultured Müller glia, BMD stimulated the production of several neurotrophic factors that enhance RGC survival. These results suggest that, in addition to lowering IOP, BMD prevents glaucomatous retinal degeneration by stimulating multiple pathways including glia-neuron interactions.

Inhibition of ASK1-p38 pathway prevents neural cell death following optic nerve injury.

Optic nerve injury (ONI) induces retinal ganglion cell (RGC) death and optic nerve atrophy that lead to visual loss. Apoptosis signal-regulating kinase 1 (ASK1) is an evolutionarily conserved mitogen-activated protein kinase (MAPK) kinase kinase and has an important role in stress-induced RGC apoptosis. In this study, we found that ONI-induced p38 activation and RGC loss were suppressed in ASK1-deficient mice. Sequential in vivo retinal imaging revealed that post-ONI treatment with a p38 inhibitor into the eyeball was effective for RGC protection. ONI-induced monocyte chemotactic protein-1 production in RGCs and microglial accumulation around RGCs were suppressed in ASK1-deficient mice. In addition, the productions of tumor necrosis factor and inducible nitric oxide synthase in microglia were decreased when the ASK1-p38 pathway was blocked. These results suggest that ASK1 activation in both neural and glial cells is involved in neural cell death, and that pharmacological interruption of ASK1-p38 pathways could be beneficial in the treatment of ONI.

Mutations of the epigenetics-modifying gene (DNMT3a, TET2, IDH1/2) at diagnosis may induce FLT3-ITD at relapse in de novo acute myeloid leukemia.

Gene mutations were found in acute myeloid leukemia (AML) and their importance has been noted. To clarify the importance and stability of mutations, we examined gene mutations in paired samples at diagnosis and relapse of 34 adult AML patients. Five acquired gene mutations were detected at relapse. Of the 45 gene mutations at diagnosis, 11 of them were lost at relapse. The acquired mutations at relapse were all class I mutations as Fms-like tyrosine kinase 3 (FLT3) and rat sarcoma viral oncogene homolog (RAS) mutations. The disappeared mutations at relapse were 3 of 11 internal tandem duplications of FLT3 (FLT3-ITD) (27.3%), 3 of 3 FLT3 tyrosine kinase domain (FLT3-TKD) (100%), 3 of 13 Nucleophosmin 1 (23.1%) and 2 of 5 CCAAT/enhancer-binding protein-α (40%) mutations. However, epigenetics-modifying gene (DNMT3a, TET2 and IDH1/2) mutations had no change between diagnosis and relapse samples, and may become minimal residual disease marker. The frequency of FLT3-ITD at relapse in patients with DNMT3a mutation at diagnosis is significantly higher than those in patients without them (P=0.001). Moreover, the high frequency of FLT3-ITD at relapse is also seen in AML cases that initially present with any epigenetics-modifying gene mutations (P<0.001). Our results indicate that epigenetics-modifying gene mutations may cause genetic instability and induce FLT3-ITD, leading to resistance to therapy and relapse.

Energy filtering transmission electron microscopy immunocytochemistry and antigen retrieval of surface layer proteins from Tannerella forsythensis using microwave or autoclave heating with citraconic anhydride.

Tannerella forsythensis (Bacteroides forsythus), an anaerobic Gram-negative species of bacteria that plays a role in the progression of periodontal disease, has a unique bacterial protein profile. It is characterized by two unique protein bands with molecular weights of more than 200 kDa. It also is known to have a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane. We examined the relationship between high molecular weight proteins and the S-layer using electron microscopic immunolabeling with chemical fixation and an antigen retrieval procedure consisting of heating in a microwave oven or autoclave with citraconic anhydride. Immunogold particles were localized clearly at the outermost cell surface. We also used energy-filtering transmission electron microscopy (EFTEM) to visualize 3, 3'-diaminobenzidine tetrahydrochloride (DAB) reaction products after microwave antigen retrieval with 1% citraconic anhydride. The three-window method for electron spectroscopic images (ESI) of nitrogen by the EFTEM reflected the presence of moieties demonstrated by the DAB reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies instead of immunogold particles. The mapping patterns of net nitrogen were restricted to the outermost cell surface.

Importance of c-kit mutation detection method sensitivity in prognostic analyses of t(8;21)(q22;q22) acute myeloid leukemia.

Recently, c-kit mutations have been reported as a novel adverse prognostic factor of acute myeloid leukemia with t(8;21)(q22;q22) translocation (t(8;21) AML). However, much remains unclear about its clinical significance. In this study, we developed a highly sensitive mutation detection method known as mutation-biased PCR (MB-PCR) and investigated the relationship between c-kit mutations and prognosis. When c-kit mutations were analyzed for 26 cases of t(8;21) AML using the direct sequence (DS) and MB-PCR, the latter had a much higher detection rate of c-kit mutations at initial presentation (DS 5/26(19.2%) vs MB-PCR 12/26(46.2%)). Interestingly for the three cases, in which c-kit mutations were observed only at relapse with the DS, c-kit mutations were detected at initial presentation using the MB-PCR. This result suggests that a minor leukemia clone with c-kit mutations have resistance to treatment and are involved in relapse. In univariate analyses, the presence of a c-kit mutation using DS was not an adverse prognostic factor (P = 0.355), but was a factor when using MB-PCR (P = 0.014). The presence of c-kit mutations with MB-PCR was also an independent adverse prognostic factor by multivariate analyses (P = 0.006). We conclude that sensitivity of c-kit mutation detection method is important to predict prognosis for t(8;21) AML.

ASK1 deficiency attenuates neural cell death in GLAST-deficient mice, a model of normal tension glaucoma.

Apoptosis signal-regulating kinase 1 (ASK1) is an evolutionarily conserved mitogen-activated protein kinase (MAPK) kinase kinase and has an important role in stress-induced retinal ganglion cell (RGC) apoptosis. In the mammalian retina, glutamate/aspartate transporter (GLAST) is a major glutamate transporter, and the loss of GLAST leads to optic nerve degeneration similar to normal tension glaucoma (NTG). In GLAST⁻(/)⁻ mice, the glutathione level in the retina is decreased, suggesting the involvement of oxidative stress in NTG pathogenesis. To test this hypothesis, we examined the histology and visual function of GLAST(+/)⁻:ASK1⁻(/)⁻ and GLAST⁻(/)⁻:ASK1⁻(/)⁻ mice by multifocal electroretinograms. ASK1 deficiency protected RGCs and decreased the number of degenerating axons in the optic nerve. Consistent with this finding, visual function was significantly improved in GLAST(+/)⁻:ASK1⁻(/)⁻ and GLAST⁻(/)⁻:ASK1⁻(/)⁻ mice compared with GLAST(+/)⁻ and GLAST⁻(/)⁻ mice, respectively. The loss of ASK1 had no effects on the production of glutathione or malondialdehyde in the retina or on the intraocular pressure. Tumor necrosis factor (TNF)-induced activation of p38 MAPK and the production of inducible nitric oxide synthase were suppressed in ASK1-deficient Müller glial cells. In addition, TNF-induced cell death was suppressed in ASK1-deficient RGCs. These results suggest that ASK1 activation is involved in NTG-like pathology in both neural and glial cells and that interrupting ASK1-dependent pathways could be beneficial in the treatment of glaucoma, including NTG.

Relationship between peripheral visual field loss and vision-related quality of life in patients with retinitis pigmentosa.

PURPOSE: To determine the vision-related quality of life (VRQOL) with the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) in patients with retinitis pigmentosa (RP), and to examine the relationship between VRQOL and peripheral visual field defects. DESIGN: Prospective study. METHODS: The Japanese version of the NEI VFQ-25 was used to study 40 patients with typical RP whose visual acuity was >/=0.7 (better than 0.15 in log MAR). For control, 40 volunteers with normal vision were studied in the same way. The peripheral visual field was evaluated by Goldmann's perimetry, and the degree of field loss was classified into seven grades. The correlation between the mean of the total composite score of the NEI VFQ-25 and the degree of the visual field loss was determined. RESULTS: The mean NEI VFQ-25 score was 68.4 in RP patients and 90.1 in normal controls. This difference was highly significant (P=0.00004). Among RP patients, there was a significant negative correlation between the mean NEI VFQ-25 score and the degree of visual field loss (r=-0.519, P=0.0006). CONCLUSION: The significant correlation between the peripheral visual field loss and VRQOL score obtained with the NEI VFQ-25, indicates that a good estimate of the QOL can be determined by the degree of visual field loss in RP patients.

Functional and morphological changes of macula after subthreshold micropulse diode laser photocoagulation for diabetic macular oedema.

PURPOSE: To examine the early changes of retinal sensitivity by fundus-related microperimetry after subthreshold micropulse diode laser photocoagulation (SMDLP) for diabetic macular oedema (DMO). METHODS: Twenty-eight eyes of 28 patients with diffuse DMO were treated with SMDLP. The mean retinal sensitivity within the central 10 degrees measured with a fundus-related microperimeter, MP1, best corrected visual acuity (BCVA) in logarithm of minimum angle of resolution units, and optical coherence tomography-determined foveal thickness (FT) were examined before and 3 months after SMDLP. The pretreatment values of the retinal sensitivity, FT, BCVA, and funduscopic findings were compared with the corresponding values at 3 months after SMDLP. RESULTS: At 3 months, the BCVA was significantly improved (P=0.03), and the FT was significantly reduced (P=0.0043). The mean retinal sensitivity within the central 10 degree, however, did not change significantly (P=0.70). The correlation between the changes in the retinal sensitivities and the decrease in the FT was not significant. The correlation between the changes in the retinal sensitivities and the BCVA was also not significant. CONCLUSIONS: Significant improvements in retinal sensitivities within the central 10 degrees were not observed even though the decrease in FT and the improvement of BCVA were significant. On account of this difference of changes in retinal sensitivity and BCVA, the combination of retinal sensitivity by MP1 and BCVA may be beneficial in assessing the visual function from various angles after SMDLP for eyes with DMO.

Correlation between visual function and photoreceptor inner/outer segment junction in patients with retinitis pigmentosa.

PURPOSE: To determine whether a significant correlation exists between the visual acuity or foveal thickness and the status of the inner and outer segment junction (IS/OS) of the photoreceptor in patients with retinitis pigmentosa (RP). METHODS: Three hundred eyes of 163 patients with RP were examined with the optical coherence tomography (OCT). The IS/OS appeared as a distinct, highly reflective line just vitread of the retinal pigment epithelium in the OCT3 images. The IS/OS line was graded into three groups. The correlations between the grade of the IS/OS and age, best-corrected visual acuity (BCVA), and central foveal thickness (CFT) were determined. RESULTS: Grade 1 included 93 eyes (31.0%) in which an IS/OS line was not seen, Grade 2 included 67 eyes (22.3%) with an abnormal IS/OS, and Grade 3 included 140 eyes (46.7%) with a normal IS/OS. The correlation between the IS/OS grade and age was not significant (P=0.5536). The IS/OS grade was significantly correlated with BCVA and CFT (both P<0.0001). The BCVA was significantly better in Grade 3 eyes than Grades 1 and 2 (both P<0.0001). The CFT was significantly thinner in Grade 1 eyes than in Grades 2 and 3 (both P<0.0001). In Grade 3, the mean length of the IS/OS was 2.51+/-1.42 mm (+/-SD). The length of the IS/OS was significantly correlated with the BCVA (P<0.0001, r=-0.375). CONCLUSIONS: The presence of the IS/OS was associated with better visual acuity and thicker fovea in RP patients. The absence of an IS/OS may reflect a foveal dysfunction in RP patients.

Comparison of photodynamic therapy to transpupillary thermotherapy for polypoidal choroidal vasculopathy.

PURPOSE: To compare the therapeutic efficacy of photodynamic therapy (PDT) to that of transpupillary thermotherapy (TTT) for polypoidal choroidal vasculopathy (PCV). METHODS: PDT or TTT was performed on 46 eyes of 46 patients with PCV; 19 eyes were treated with TTT (TTT group) and 27 eyes with PDT (PDT group). PCV was diagnosed by fundus examination, fluorescein angiography (FA) , and indocyanine green angiography (ICGA) . The best-corrected visual acuity (BCVA) in logarithm of the minimum angle of resolution (logMAR) units and OCT-determined foveal thickness were evaluated before and after treatment. For statistical analyses, the Student's t-test and chi(2) test were used. RESULTS: The number of treatments during the 12-month follow-up period was significantly higher in the TTT group (1.7 times) than in the PDT group (1.3 times; P=0.0134). The difference in the BCVA between the TTT and PDT groups at the baseline was not significant (P=0.3150), but the BCVA in the PDT group was significantly better than that in the TTT group at 3, 6, and 12 months after treatment (P=0.0093, P=0.0074, P=0.0006, respectively). The foveal thickness decreased markedly at 6 months after treatment in the PDT group (P<0.0001) but not significantly in the TTT group (P=0.8982). A vitreous haemorrhage was observed after treatment in two eyes in the TTT group. CONCLUSIONS: BCVA was significantly better and the fovea was significantly thinner in the PDT group than in the TTT group after treatment. Thus, PDT may be more effective than TTT for the treatment of eyes with PCV.

Correlation of visual recovery with presence of photoreceptor inner/outer segment junction in optical coherence images after epiretinal membrane surgery.

AIMS: To investigate the relationship between the presence of the photoreceptor inner and outer segment (IS/OS) junction and visual acuity after epiretinal membrane (ERM) surgery. METHODS: Seventy eyes of 70 consecutive patients who had undergone vitrectomy for idiopathic ERM were examined by optical coherence tomography before and 3 and 6 months after surgery. The IS/OS junction was graded into three grades. The time course of recovery of the IS/OS junction, central foveal thickness (CFT) and best corrected visual acuity (BCVA) during the postoperative period was studied. RESULTS: A normal IS/OS junction was detected in 47.1% of the eyes before surgery and in 65.7% at 3 months and 75.7% at 6 months after. There was a significant correlation between the IS/OS grade and BCVA before and at 3 and 6 months after the operation (p = 0.0001, p<0.0001, p<0.0001, respectively). The preoperative IS/OS junction grade correlated significantly with BCVA at 6 months (p = 0.0239). CFT did not correlate significantly with BCVA at 3 and 6 months. CONCLUSIONS: The presence of a normal IS/OS junction was associated with good visual acuity after ERM surgery. A normal IS/OS junction probably indicates morphological and functional recovery of the photoreceptors.

Application of a magnetic fluid seal to rotary blood pumps.

A magnetic fluid seal enables mechanical contact-free rotation of a shaft without frictional heat and material wear and hence has excellent durability. However, the durability of a magnetic fluid seal decreases in liquid. The life of a seal applied to a rotary blood pump is not known. We have developed a magnetic fluid seal that has a shield mechanism minimizing the influence of the rotary pump on the magnetic fluid. The developed magnetic fluid seal worked for over 286 days in a continuous flow condition, for 24 days (on-going) in a pulsatile flow condition and for 24 h (electively terminated) in blood flow. The magnetic fluid seal is promising as a shaft seal for rotary blood pumps.

Three-dimensional computer-aided design based design sensitivity analysis and shape optimization of the stem using adaptive p-method.

The number of stem designs for total hip arthroplasty is increasing, and occasionally design changes have yielded unexpected clinical results. At present, we are not able to clearly identify which parameter of the stem is most important, and the optimum value of many parameters. The goals of this study were to identify which parameter is most important, to understand the effect of design change, and to find the optimum stem shape. For this purpose, we used adaptive p-method together with three-dimensional computer-aided design software program for the design sensitivity analysis (DSA) and shape optimization of the stem. The results suggested that increasing the lateral and medial width of the distal cross-section together with decreasing the medial-lateral width and the medial radius of the distal cross-section from the default value would lead to a decrease in the largest maximum principal stress of the distal cement. The medial width of middle cross-section, however, was not so simple. The result of DSA suggested that decreasing this parameter from the default value decreased the stress in the distal cement, but the optimum shape was obtained by increasing this parameter. The method used in this study will assist our engineers and surgeons in the process of modifying and optimizing the stem design.