Growth factor dependence of the proliferation and survival of cultured lacrimal gland epithelial cells isolated from late-embryonic mice.

Epidermal growth factor (EGF) and hepatocyte growth factor (HGF) regulate the growth and morphogenesis of various exocrine glands with branched morphologies. Their roles in lacrimal gland (LG) development remain unknown, but fibroblast growth factor (FGF) 10 is crucial for early LG organogenesis. To clarify the roles of EGF, HGF, and FGF10 in LG development, LG epithelial cells were isolated from late-embryonic and neonatal mice; cultured; and treated with EGF, HGF, or FGF10 and their respective receptor tyrosine kinase (RTK) inhibitors AG1478, PHA665752, or SU5402. EGF and HGF increased the number of viable cells by enhancing DNA synthesis, FGF10 and SU5402 showed no such effect, and RTK inhibitors exhibited the opposite effect. EGF and HGF receptors were immunostained in cultured late-embryonic LG epithelial cells and terminal LG acini from late embryos and adult mice. HGF was detected in neonatal LG epithelial cell culture supernatants by western blotting. In the absence of EGF and HGF RTK inhibitors, growth factor addition increased the number of viable cells and suppressed cell death. However, when one RTK was inhibited and a growth factor targeting an intact RTK was added, the number of dead cells increased as the number of viable cells increased. No cells survived when both RTKs were inhibited. In explant cultures of LGs from embryos, AG1478 or PHA665752 decreased the number of Ki67-positive proliferating epithelial cells in terminal acini. Thus, EGF and HGF may function in a cooperative autocrine manner, supporting cell proliferation and survival during LG development in late-embryonic and neonatal mice.

Inflammatory Factors of Macular Atrophy in Eyes With Neovascular Age-Related Macular Degeneration Treated With Aflibercept.

Background: Neovascular age-related macular degeneration (nAMD) is a leading cause of blindness in older people. Low-grade inflammation is well-known as one of the pathogenic mechanisms in nAMD. Anti-vascular endothelial growth factor (VEGF) therapy is the first-line treatment for nAMD, although macula atrophy (MA) developed under anti-VEGF therapy causes irreversible visual function impairment and is recognized as a serious disorder. Here, we show specific expression patterns of aqueous humor (AH) cytokines in nAMD eyes developing MA under intravitreal injection of aflibercept (IVA) as an anti-VEGF antibody and present predictive cytokines as biomarkers for the incidence of MA in nAMD eyes under IVA treatment. Methods: Twenty-eight nAMD patients received three consecutive monthly IVA, followed by a pro re nata regimen for 2 years. AH specimens were collected before first IVA (pre-IVA) and before third IVA (post-IVA). AH cytokine levels, visual acuity (VA), and central retinal thickness (CRT) were measured. Results: Two-year incidence of MA was 21.4%. In nAMD eyes developing MA [MA (+) group], pre-IVA levels of monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein (MIP)-1ß, VEGF and post-IVA level of MCP-1 were higher than those in nAMD eyes without MA [MA (-) group]. In hierarchical cluster analysis, pre-IVA MCP-1 and VEGF were grouped into the same subcluster, as were post-IVA MCP-1 and CRT. In principal component analysis, principal component loading (PCL) of pre-IVA interferon-γ-inducible protein 10 (IP-10) was 0.61, but PCL of post-IVA IP-10 decreased to -0.09. In receiver operating characteristic analysis and Kaplan-Meier curves, pre-IVA MCP-1, MIP-1ß, and VEGF and post-IVA interleukin-6, MCP-1, and MIP-1ß were detected as predictive factors for MA incidence. In 2-year clinical course, changes of VA in groups with high levels of pre-IVA MIP-1ß (over 39.9 pg/ml) and VEGF (over 150.4 pg/ml) were comparable to those in MA (+) group. Conclusion: Substantial loss of IP-10 effects and persistent inflammation contribute to incidence of MA, and screening of AH cytokine levels could be a useful method to predict MA incidence in nAMD eyes under anti-VEGF therapy.

Profiles of Cytokines Secreted by ARPE-19 Cells Exposed to Light and Incubated with Anti-VEGF Antibody.

The retinal pigment epithelium (RPE) is the major source of cytokines in the retina regulating the intraocular immune environment, and a primary target of photodamage. Here, we examined 27 types of cytokines secreted by ARPE-19 cells exposed to visible light and incubated with aflibercept or ranibizumab, which are two anti-vascular endothelial growth factor (VEGF) antibodies. The cells were cultured for 24 h in the dark or under 2000 lux irradiation from a daylight-colored fluorescent lamp, and cytokine levels in the culture supernatant were measured. In the light-irradiated culture, the levels of IL-9, IL-17A and bFGF were higher, and the levels of IL-6, IL-7, IL-8 and MCP-1 were lower than those in the dark culture, while there was no significant difference with the VEGF-A level. In subgroup analyses of the light-irradiated culture, the bFGF level under 250 to 2000 lux irradiation was elevated in a light intensity-dependent manner. In culture exposed to blue, green or red light, the bFGF level was elevated by blue light and was high compared to that by green or red light. In culture with aflibercept or ranibizumab in the dark, the levels of IL-6, IL-8, bFGF and MCP-1 were increased, and the IL-12 level decreased synchronously with a reduction in the VEGF-A level. Our findings indicate that continuous irradiation of visible light and VEGF suppression may be an influential factor in expression patterns of inflammatory cytokines secreted by human RPE cells.

Programmed Cell Death-1 Pathway Deficiency Enhances Autoimmunity Leading to Dacryoadenitis of Mice.

Programmed cell death protein (PD)-1 is a coinhibitory molecule that suppresses immune response and maintains immune homeostasis. Moreover, the PD-1 pathway blocks cancers from being attacked by immune cells. Anti-PD-1 antibody therapy such as nivolumab improves survival in cancer patients. However, the occurrence of autoimmune inflammatory disorders in various organs has been increasingly reported as an adverse effect of nivolumab. Of the disorders associated with nivolumab, Sicca syndrome occurs in 3% to 11% of cases and has unknown pathologic mechanisms. Whether the absence of the PD-1 pathway causes functional and morphologic disorders in lacrimal glands was determined by analyzing PD-1 gene-knockout (Pdcd1-/-) mice. Histopathologic analysis showed that Pdcd1-/- mice developed dacryoadenitis beginning at 3 to 4 months of age, and deteriorated with age. Flow-cytometric analysis confirmed that cells infiltrating the affected lacrimal glands consisted mainly of CD3+ T cells and only a small proportion of CD19+ B cells. Among infiltrating T cells, the CD4+ Th-cell subset consisted of Th1 cells producing interferon-γ in an early stage of dacryoadenitis in Pdcd1-/- mice. Experiments of lymphocyte transfer from Pdcd1-/- into irradiated wild-type mice confirmed that CD4+ T cells from Pdcd1-/- mice induced dacryoadenitis. These results indicate that PD-1 plays an important role in the prevention of autoimmune inflammatory disorders in lacrimal glands caused by activated CD4+ Th1 cells.

Retinal changes in mice spontaneously developing diabetes by Th17-cell deviation.

Elevated level of interleukin (IL)-17, predominantly produced by T helper (Th) 17 cells, has been implicated in diabetic retinopathy (DR), but it remains unclear whether IL-17 is involved in the pathogenesis of DR. Ins2Akita (Akita) mice spontaneously develop diabetes, and show early pathophysiological changes in diabetic complications. On the other hand, interferon-γ knock out (GKO) mice exhibit high differentiation and activation of Th2 and Th17 cells as a result of Th1 cell inhibition. In this study, Ins2Akita IFN-γ-deficient (Akita-GKO) mice were established by crossbreeding Akita mice with GKO mice, and Th17-mediated immune responses on DR were investigated. Blood glucose levels (BGL) of Akita mice and Akita-GKO mice were significantly higher than those of age-matched wild type (WT) or GKO mice, and there was no significant difference in BGL between Akita and Akita-GKO mice. Relative mRNA expression of ROR-γt that is a transcriptional factor of Th17 cells but not GATA-3 that is for Th2 cells was significantly upregulated only in Akita-GKO mice compared with WT mice, and the proportions of IL-17 and IL-22-producing splenic CD4+ cells were significantly higher in Akita-GKO mice than in wild type (WT), Akita, or GKO mice. In the retina, mRNA expression of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1) were increased in Akita-GKO mice more than in Akita or GKO mice, and statistically significant differences were observed between Akita-GKO mice and WT mice. Leukostasis in retinal vessels and ocular level of VEGF protein increased significantly in Akita-GKO mice compared with the other groups. Edematous change in the retinal surface layer, retinal exudative lesions depicted as areas of hyperfluorescence in fluorescein angiography (FA), and vascular basement membrane thickening in all layers of the retina were also observed in Akita-GKO mice at 9-week-old but not in age-matched Akita or GKO mice. These results suggested that Th17 cell-mediated immune responses might be involved in promotion of functional and morphological changes in the retina of mice spontaneously developing diabetes.

Comprehensive expression patterns of inflammatory cytokines in aqueous humor of patients with neovascular age-related macular degeneration.

Neovascular age-related macular degeneration (nAMD) is a complex and multi-factorial disease, and low-grade inflammation is associated with pathogenesis of nAMD. Aqueous humor could reflect intraocular immune environments in various eye diseases. The research so far used aqueous humor samples and revealed that inflammation is involved in pathophysiology of nAMD, although immunological roles of cytokines were evaluated inadequately with aspect to individual effects. Here we used 27 kinds of cytokines covering general immunologic reactions, examined specific expression patterns of cytokines, and assessed relationships between inflammation and pathophysiology of nAMD by multivariate analyses. In nAMD eyes, principal component analysis showed that IL-7, MCP-1, MIP-1ß and VEGF had high principal component loadings of over 0.6 in the first principal component constituting 32.6% of all variability of the data. In exploratory factor analysis, IL-6, MCP-1 and MIP-1ß had high factor loadings (FL) of over 0.5 in Factor 1 constituting 32.6% of all variability, while VEGF had FL of over 1.0 in Factor 3 constituting 10.7% of all variability. In hierarchical cluster analysis, MCP-1 and VEGF were located in the cluster of first proximate mutual distance to central retinal thickness. These data could suggest that low-grade inflammation is a principal contributor in nAMD.

Protective effects of dexamethasone on hypoxia-induced retinal edema in a mouse model.

Hypoxia-induced retinal edema primarily induced by vascular lesion is seen in various conditions such as diabetic retinopathy (DR) and retinal vein occlusion (RVO). The edematous changes in these conditions occur mainly in intermediate and deep layers of retina as a result of disruption of the inner blood-retinal barrier (iBRB). However, the effect of direct and acute hypoxia on iBRB remains to be elucidated. To investigate direct and acute hypoxia-induced changes in retina, especially in astrocytes/Müller cells that are involved in the maintenance of retinal structure and function, we developed an adult mouse model of hypoxia-induced retinal edema by 24-h exposure in a 6% oxygen environment. Immunohistochemical staining of glial fibrillary acidic protein (GFAP) was enhanced mainly in the superficial layer of the hypoxic retina, corresponding to edematous change. Electron microscopic observation of the hypoxic retina showed vacuole formation in astrocyte/Müller cell foot processes around capillaries in the superficial layer, while no abnormal findings in the perivascular areas were found in intermediate and deep layers. Increase in vascular leakage quantified by Evans blue dye and tight junction breakdown detected by electron-dense tracer were observed in the hypoxia group. In the hypoxic retina, microglia was activated and relative gene expressions of pro-inflammatory cytokines were significantly upregulated. Dexamethasone suppressed these hypoxia-induced pathological reactions. Thus, unlike DR and RVO that induce iBRB breakdown in deeper retinal layers, atmospheric hypoxia induced iBRB disruption with subsequent edematous change mainly in the superficial layer of the retina, and that dexamethasone prevented these pathological changes. In this mouse model, direct and acute hypoxia induces retinal edema in the superficial layer of the retina with morphological changes of astrocytes/Müller cells, and is potentially useful for ophthalmic research in the field related to retinal hypoxia and its treatment.

Potential Phototoxicity of Indocyanine Green in Retinal Pigment Epithelial Cells after Angiography under Ambient Illumination.

Indocyanine green (ICG) angiography is an indispensable inspection to diagnose and treat for chorioretinal diseases. In this study, we investigated the phototoxicity of ICG on RPE cells at the levels of residual ICG after angiography under ambient light. After incubation of ARPE-19 cells in a colorless medium containing 0 to 10 µg/mL ICG for 24 hours in the dark or under 2000 lx illumination from a fluorescent lamp, cell viability decreased and cell death rate increased in cultures with more than 5.0 µg/mL ICG under illumination. In culture with 10 µg/mL ICG under illumination, morphology of cells changed to be oval and TUNEL- and malondialdehyde-positive cells increased compared to other cultures with ICG in the dark or without ICG under illumination. Furthermore, the level of intracellular reactive oxygen species was also elevated. On the other hand, toxicity of ICG denatured by illumination was not observed. Blocking green to red light overlapping wavelengths of ICG absorbance exhibited decreased cell death rate. The present study indicated that ICG at the estimated intravenous concentrations after ICG angiography induces potential phototoxicity on human RPE cells via oxidative damage under continuous ambient illumination and that the cytotoxicity is reduced by blocking green to red light wavelengths.

Intraocular inflammatory cytokines in patients with neovascular age-related macular degeneration before and after initiation of intravitreal injection of anti-VEGF inhibitor.

Age-related macular degeneration (AMD) is a cause of blindness in people older than 50 years. Accumulating evidence indicates the involvement of systemic and local inflammation in the pathogenesis and progression of AMD. Aflibercept is an anti-vascular endothelial growth factor (VEGF) inhibitor, and intravitreal injection of aflibercept (IVA) is the approved treatments of neovascular AMD (nAMD), but the effect on inflammatory response remains unclear. The aim of our study was to investigate the profiles of inflammatory cytokines in the aqueous humor of nAMD patients before and after initiation of IVA. In nAMD patients, IP-10 level was significantly higher and IL-6 level was significantly lower compared with those of cataract patients as controls. Logistic regression analysis identified IP-10 as a positive factor and IL-6 a negative factor associated with the pathogenesis of nAMD. In addition, IP-10 level correlated positively with the mean thickness of macula in the central 1-mm diameter circle. After initiation of IVA, IP-10 level was further elevated, and correlated negatively with VEGF level. These data suggest that IP-10 plays a critical role as an antiangiogenic factor and at the same time an inflammatory factor in the pathogenesis and pathophysiology of nAMD eyes at onset and after IVA initiation.

Association between aqueous humor and vitreous fluid levels of Th17 cell-related cytokines in patients with proliferative diabetic retinopathy.

Inflammation is known to be involved in the progression of diabetic retinopathy. We have recently reported that vitreous levels of IL-4, IL-17A, IL-22, IL-31, and TNFα are higher than the respective serum levels in proliferative diabetic retinopathy (PDR) patients, and that vitreous levels of these cytokines are higher in PDR than in other non-inflammatory vitreoretinal diseases or uveitis associated with sarcoidosis. In the present study, we investigated inflammatory cytokines including Th17 cell-related cytokines in aqueous humor samples obtained from eyes with PDR, and analyzed the association between the aqueous humor and vitreous fluid levels of individual cytokines. The study group consisted of 31 consecutive type 2 diabetic patients with PDR who underwent cataract surgery and vitrectomy for vitreous hemorrhage and/or tractional retinal detachment. Undiluted aqueous humor was collected during cataract surgery, and then vitreous fluid was obtained using a 25G vitreous cutter inserted into the mid-vitreous cavity at the beginning of vitrectomy. IL-1ß, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, soluble CD40 ligand (sCD40L), and TNFα levels in the aqueous humor and vitreous fluid were measured using a beads-array system. Although IL-17A was detected in the aqueous humor of eyes with PDR and the level correlated with IL-17A level in the vitreous fluid, both percent detectable and level of IL-17A in the aqueous humor were significantly lower than those in the vitreous fluid. Vitreous IL-17A level was related significantly to IL-10, IL-22, and TNFα levels in aqueous humor as well as in vitreous fluid, On the other hand, aqueous IL-17A level was not related significantly to aqueous or vitreous levels of IL-10, IL-22 or TNFα level. The present study demonstrated that IL-17A level and detectable rate in the aqueous humor of patients with PDR are markedly lower than those in the vitreous fluid and aqueous IL-17A does not correlate with vitreous levels of other cytokines, and hence should not be used as a surrogate for IL-17A in the vitreous fluid.

Analysis of Th Cell-related Cytokine Production in Behçet Disease Patients with Uveitis Before and After Infliximab Treatment.

PURPOSE: To examine antigen-stimulated cytokine production by Behçet disease patients (BD) before and after infliximab infusion. METHODS: PBMCs were obtained before and after infliximab infusion in BD patients with or without recurrent uveitis during at least 1 year of infliximab therapy, and from healthy subjects. PBMCs were cultured with IRBP, and Th-related cytokines in cultures were measured. RESULTS: Levels of IL-4, IL-6, IL-10 IL-17A, IL-17F, IL-31, IFN-γ, and TNFα were higher in BD before infliximab infusion than in healthy subjects, and these levels were the highest in BD with recurrent uveitis. After infliximab infusion, these cytokine levels were reduced to a greater extent in BD without recurrent uveitis than in BD with recurrence. CONCLUSIONS: Th-related cytokines produced by IRBP-stimulated PBMCs were elevated in BD, and infliximab infusion suppressed these cytokines to a greater extent in BD without recurrent uveitis than in those with recurrence.

Tension Force Downregulates Matrix Metalloproteinase Expression and Upregulates the Expression of Their Inhibitors through MAPK Signaling Pathways in MC3T3-E1 cells.

OBJECTIVE: Matrix metalloproteinases (MMPs), produced by osteoblasts, catalyze the turnover of extracellular matrix (ECM) molecules in osteoid, and the regulation of MMP activity depends on interactions between MMPs and tissue inhibitors of metalloproteinases (TIMPs). We focused on the degradation process of ECM in osteoid that was exposed to mechanical strain, and conducted an in vitro study using MC3T3-E1 osteoblastic cells to examine the effects of tension force (TF) on the expression of MMPs and TIMPs, and activation of mitogen-activated protein kinase (MAPK) pathways. DESIGN: Cells were incubated on flexible-bottomed culture plates and stimulated with or without cyclic TF for 24 hours. The expression of MMPs and TIMPs was examined at mRNA and protein levels by real-time RT-PCR and Western blotting, respectively. The phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38 MAPK, and stress-activated protein kinases/c-jun N-terminal kinases (SAPK/JNK) were examined by Western blotting. RESULTS: TF decreased the expression of MMP-1, -3, -13 and phosphorylated ERK1/2. In contrast, TF increased the expression of TIMP-2, -3 and phosphorylated SAPK/JNK. The expression of MMP-2, -14, TIMP-1, -4 and phosphorylated p38 MAPK was unaffected by TF. MMP-1, -3 and -13 expression decreased in cells treated with the ERK inhibitor PD98059 compared with untreated control cells. The JNK inhibitor SP600125 inhibited the TF-induced upregulation of TIMP-2 and -3. CONCLUSIONS: The results suggest that TF suppresses the degradation process that occurs during ECM turnover in osteoid via decreased production of MMP-1, -3 and -13, and increased production of TIMP-2 and -3 through the MAPK signaling pathways in osteoblasts.

Elevated Levels of Cytokines Associated with Th2 and Th17 Cells in Vitreous Fluid of Proliferative Diabetic Retinopathy Patients.

Macrophages are involved in low-grade inflammation in diabetes, and play pathogenic roles in proliferative diabetic retinopathy (PDR) by producing proinflammatory cytokines. T cells as well as other cells are also activated by proinflammatory cytokines, and infiltration into the vitreous of patients with PDR has been shown. In this study, we measured helper T (Th) cell-related cytokines in the vitreous of PDR patients to define the characteristics of Th-mediated immune responses associated with PDR. The study group consisted of 25 type 2 diabetic patients (25 eyes) with PDR. The control group consisted of 27 patients with epiretinal membrane (ERM), 26 patients with idiopathic macular hole (MH), and 26 patients with uveitis associated with sarcoidosis. Vitreous fluid was obtained at the beginning of vitrectomy, and centrifuging for cellular removals was not performed. Serum was also collected from PDR patients. IL-1ß, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, soluble sCD40L, and TNFα in the vitreous and serum samples were measured. Both percent detectable and levels of IL-4, IL-6, IL-17A, IL-21, IL-22, and TNFα in the vitreous were significantly higher than those in the serum in PDR patients. Vitreous levels of these cytokines and IL-31 were significantly higher in PDR than in ERM or MH patients. Vitreous levels of IL-4, IL-17A, IL-22, IL-31, and TNFα in PDR patients were also significantly higher than those of sarcoidosis patients. In PDR patients, vitreous IL-17A level correlated significantly with vitreous levels of IL-22 and IL-31, and especially with IL-4 and TNFα. Although it is unclear whether these cytokines play facilitative roles or inhibitory roles for the progression of PDR, the present study indicated that Th2- and Th17-related immune responses are involved in the pathogenesis of PDR.

High-magnitude mechanical strain inhibits the differentiation of bone-forming rat calvarial progenitor cells.

PURPOSE: Orthodontic tooth movement occurs during the bone remodeling induced by therapeutic mechanical strain. It is important to investigate the relation between the strength of mechanical stress and bone formation activity. The aim of this study was to determine the effect of high-magnitude mechanical strain on bone formation in detail. MATERIALS AND METHODS: Osteoblast-like cells isolated from fetal rat calvariae were loaded with 18% cyclic tension force (TF) for 48 h. To phenotypically investigate the effect of TF, we measured the number and the size of bone nodules stained by von Kossa technique on day 21 after cell seeding and determined the calcium content of bone nodules on day 14. Furthermore, we examined the gene expression of BMP-2, Runx2 and Msx2, which are important factors for bone nodule formation, on days 1, 4 and 7 after TF loading. RESULTS: The maximum bone nodule size in the control group was 1620 and 719 µm in the TF group. Furthermore, the mean number of bone nodules sized over 360 µm in the TF group was significantly decreased compared to the control group. The calcium content was also significantly decreased to 42% by TF loading. The mRNA expression of BMP-2, Runx2 and Msx2 was decreased 1 and 4 days after TF loading. CONCLUSION: The differentiation of bone forming progenitor cells into bone nodule forming cells was inhibited by TF due to the decreased expression of bone formation related factors such as BMP-2, Runx2 and Msx2.

Functional role of TGF-ß receptors during palatal fusion in vitro.

OBJECTIVE: Reported expression patterns for TGF-ß receptors (TßR-I, -II, and -III) during palatogenesis suggest that they play essential roles in the mechanisms leading to palatal fusion. The purpose of this study was to compare the functions of the three TßRs during palatal fusion. METHODS: Using organ culture of mouse palatal shelves, expression levels of TßR-I, -II, and -III were suppressed by transfecting the siRNAs siTßR-I, -II, and -III, respectively. Phosphorylation of SMAD2 was examined as an indicator of downstream signalling via each TßR. Linkage between TGF-ß signalling and critical events in palatal fusion led to the use of, MMP-13 expression as an outcome measure for the function of the TGF-ß receptors. RESULTS: The siRNA treatment decreased the expression level of each receptor by more than 85%. When treated with either siTßR-I or -II, palatal shelves at E13+72 h were not fused, with complete clefting in the anterior and posterior regions. The middle palatal region following treatment with either siTßR-I or -II had fusion from one-half or one-third of the palatal region. Treatment with siTßR-III resulted in a persistent midline seam of medial edge epithelium (MEE) in the anterior region with islands of persistent MEE in the middle and posterior regions of the midline. Treatment with all three siTßRs altered the pattern of SMAD2 phosphorylation. Palatal shelf cultures treated with siTßR-I or -II, but not -III, showed altered MMP-13 expression levels. CONCLUSION: The ability to identify and recover MEE and palatal mesenchymal cells during palatal fusion will aid in the evaluation of the different mechanistic events regulated by each TßR during palatogenesis.

Longitudinal quantitative evaluation of the mid-palatal suture after rapid expansion using in vivo micro-CT.

New bone formation is known to occur between the opened palatal bones after rapid mid-palatal expansion (RME), although the time-dependent changes in the mid-palatal suture after RME have not been fully examined. Thus, we investigated time-dependent morphological changes in the mid-palatal suture using in vivo micro-computed tomography (mCT) and the expression of bone morphogenetic factors. RME was performed by inserting a 1.5-mm-thick circular metal ring between the maxillary incisors of rats, and morphological changes in the mid-palatal suture were investigated using in vivo mCT imaging after RME. Bone morphogenetic protein 2 (BMP-2) and insulin-like growth factor-I (IGF-I) expression in the suture were also examined using reverse-transcription polymerase chain reaction and immunohistochemistry. The bone volume of the mid-palatal suture decreased after RME to a minimum of -0.34mm(3) on day 12, then increased with bone formation over time and reached -0.13mm(3) on day 24. Significant increases in BMP-2 and IGF-I mRNA expression after RME were found on day 3 compared with day 0. By immunohistochemistry, BMP-2 and IGF-I were detected in osteoblasts on days 5 and 7, in endothelial cells of blood vessels, and fibroblasts on day 7. Expansion of the mid-palatal suture continues for 12 days after a single RME, and restoration requires more than 30 days. Additionally, BMP-2 and IGF-I may play important roles in the restoration process.

Evaluation of mouse experimental autoimmune uveoretinitis by spectral domain optical coherence tomography.

AIMS: To evaluate the efficacy of spectral domain optical coherence tomography (SD-OCT) in monitoring the development of mouse experimental autoimmune uveoretinitis (EAU) as an animal model of endogenous uveitis, and to develop an OCT-based grading system for EAU severity. METHODS: C57BL/6 mice were immunised with human interphotoreceptor retinoid-binding protein (amino acid sequence 1-20) peptide and complete Freund's adjuvant to induce EAU. The development of EAU was monitored by SD-OCT serially throughout the disease course, and the images were graded from 1 to 4 and compared with the clinical and histopathological grades. RESULTS: SD-OCT images depicted retinal lamella structures including the inner segment/outer segment (IS/OS) line in normal mice. Retinal structural changes were observed on SD-OCT images in mice that developed EAU clinically scored as grade 1 or higher, which precisely corresponded to the pathological findings. The SD-OCT images of EAU were graded as follows: grade 1, a few infiltrating cells in the vitreous and retina; grade 2, increased vitreous cells, retinal vasculitis, and granulomatous lesion; grade 3, cell infiltration into the whole retina, disappearance of IS/OS line, and destruction of the retinal layer structure; and grade 4, disappearance of the outer retina. The SD-OCT grade of EAU based on these criteria correlated significantly with both the clinical grade (R(2)=0.282, p<0.005) and histopathological grade (R(2)=0.846, p<0.0001). CONCLUSIONS: SD-OCT is useful for evaluating the development and severity of mouse EAU. The SD-OCT scoring system we developed accurately reflects clinical and histopathological changes.

Assessment of damping capacity as an index of root proximity in self-drilling orthodontic mini-implants.

OBJECTIVES: This study aims to investigate orthodontic mini-implant root proximity, placement torque, and damping capacity and to determine whether placement torque and damping capacity (Periotest value (PTV)) are useful indices for the estimation of mini-implant root proximity. MATERIALS AND METHODS: The root proximity of 143 orthodontic mini-implants (1.6 mm diameter, 8 mm screw thread length) was evaluated in 79 patients (24 males, 55 females; mean age, 22.5 ± 8 years) using cone-beam computed tomography. The placement torque and PTV of each implant were determined using a torque tester and the Periotest, respectively. Variability in these values according to root proximity was evaluated. RESULTS: PTVs of mini-implants with multiple (two or more) points of contact between the root and implant were significantly larger than those of mini-implants with no root contact in the self-drilling group. Placement torque did not differ significantly according to root proximity. In the self-drilling group, the odds ratio for root contact was 20.82 (P = 0.000) for a PTV >6. CONCLUSIONS: Placement torque could not be used to estimate root proximity. The PTV was significantly affected by root proximity in the self-drilling group. CLINICAL RELEVANCE: A threshold of PTV >6 could be applied clinically for the estimation of self-drilling mini-implant root proximity.

A preliminary study of the effects of low-intensity pulsed ultrasound exposure on the stability of orthodontic miniscrews in growing rats.

BACKGROUND: Orthodontic miniscrews placed in growing subjects often loosen during orthodontic treatment. The ability to place miniscrews, regardless of age, would be clinically beneficial. OBJECTIVES: To assess the effects of low-intensity pulsed ultrasound (LIPUS) on the stability of orthodontic miniscrews in growing rats. MATERIALS/METHODS: The mobility of miniscrews after placement was recorded and the miniscrew-bone interface was examined histomorphometrically using tibiae of seven male Sprague-Dawley rats (aged 6 weeks). Field-emission scanning electron microscopic images were used to evaluate the bone-miniscrew interface, and a mobility test device was used to assess the stiffness of miniscrew placement. Fourteen custom-made miniscrews with 1.4mm diameters and 4.0mm lengths were placed in the right and left tibiae. LIPUS was used to stimulate right tibiae at the sites of miniscrew placement, and left tibiae were left untreated as controls. RESULTS: Significantly lower mobility was observed in the LIPUS-treated group compared with the control group (P < 0.05). Histomorphometric evaluation indicated that bone-miniscrew adhesion was significantly better in the LIPUS-treated group than in the control group (P < 0.05). LIMITATIONS: This in vivo study used tibiae rather than jaw bones because the jaw bones of 6-week-old rats were too small to allow miniscrew placement. CONCLUSIONS: LIPUS was able to increase the bone-miniscrew contact and reduce the mobility of miniscrews in growing subjects. IMPLICATIONS: LIPUS may accelerate the bone healing process after miniscrew placement in growing subjects and can reduce the latent period.

Phototoxicity of indocyanine green and Brilliant Blue G under continuous fluorescent illumination on cultured human retinal pigment epithelial cells.

PURPOSE: We compared the phototoxicity of indocyanine green (ICG) and Brilliant Blue G (BBG) in cultured RPE cells under fluorescent lamp illumination imitating ambient light. METHODS: Cultured human RPE line cells were stained with ICG or BBG solution at concentrations of clinical use, and cultured in a colorless medium for 24 hours in the dark or under illumination from a fluorescent lamp. After culture, cell morphology and TUNEL-positive apoptotic cells were observed. Cell viability and cell death rate were evaluated. Absorption spectral changes of BBG before and after incubation were measured. RESULTS: ICG-stained cells cultured under illumination changed to an oval morphology with increased number of apoptotic cells, whereas ICG-stained cells cultured in the dark, and BBG-stained cells cultured under illumination and dark conditions maintained a flat morphology without increase in apoptotic cells. Cell viability decreased and cell death rate increased only in cells stained by ICG followed by culture under illumination. Staining cells with ICG at one-tenth concentration of clinical usage induced no cytotoxicity after culture under illumination. Approximately 30% of total BBG retained in the stained cells was released into the culture supernatant after incubation for 24 hours. The absorption spectrum of BBG did not change after fluorescent light irradiation. CONCLUSIONS: Illumination with a fluorescent lamp caused cell death via apoptosis in ICG-exposed, but not in BBG-exposed cultured RPE cells. BBG may be a safer dye than ICG because of low light-induced cytotoxicity and rapid elution from stained cells.