角膜血管・リンパ管新生に関与する新規調節因子の探索

学位の種別:課程博士University of Tokyo(東京大学

On the Emerging Role of the Taste Receptor Type 1 (T1R) Family of Nutrient-Sensors in the Musculoskeletal System.

The special sense of taste guides and guards food intake and is essential for body maintenance. Salty and sour tastes are sensed via ion channels or gated ion channels while G protein-coupled receptors (GPCRs) of the taste receptor type 1 (T1R) family sense sweet and umami tastes and GPCRs of the taste receptor type 2 (T2R) family sense bitter tastes. T1R and T2R receptors share similar downstream signaling pathways that result in the stimulation of phospholipase-C-β2. The T1R family includes three members that form heterodimeric complexes to recognize either amino acids or sweet molecules such as glucose. Although these functions were originally described in gustatory tissue, T1R family members are expressed in numerous non-gustatory tissues and are now viewed as nutrient sensors that play important roles in monitoring global glucose and amino acid status. Here, we highlight emerging evidence detailing the function of T1R family members in the musculoskeletal system and review these findings in the context of the musculoskeletal diseases sarcopenia and osteoporosis, which are major public health problems among the elderly that affect locomotion, activities of daily living, and quality of life. These studies raise the possibility that T1R family member function may be modulated for therapeutic benefit

Use of human serum for human corneal endothelial cell culture

Background/aims To study human corneal endothelial cells (HCECs) cultured in vitro with human serum (HS) supplemented media (HS-SM) compared with HCEC cultured in fetal bovine serum (FBS) supplemented media (FBS-SM).Methods One cornea from a donor aged 21 years and a pair of corneas from a 16 year-old donor were obtained from the eye bank and used to create two different cell populations. At the first passage, the cell populations were equally divided and seeded in two different wells containing FBS-SM or HS-SM. in subsequent passages, HS-SM was compared with FBS-SM by morphology, growth curves, immunohistochemistry and real-time reverse-transcriptase PCR for endothelial cell markers.Results No difference in morphology could be seen in P2, P5 or in any other passages for cells grown in the two media. By growth curves, cell counts were similar in FBS-SM and HS-SM from days 1 to 5, with a trend towards higher cell counts in HS-SM at day 7. Cells grown in FBS-SM and HS-SM media showed similar expression of endothelial cell markers when assessed by immunohistochemistry and real-time reverse-transcriptase PCR.Conclusions HS-SM was similar to FBS-SM for HCEC culture when assessed by cell morphology, proliferation and protein/gene expression.J Willard and Alice S Marriott FoundationNational Eye InstituteCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)State University of Rio de JaneiroJohns Hopkins Sch Med, Dept Ophthalmol, Cornea & Anterior Segment Serv, Wilmer Eye Inst, Baltimore, MD 21231 USAUniversidade Federal de São Paulo, Paulista Sch Med, Dept Ophthalmol, São Paulo, BrazilUniv Estado Rio de Janeiro, Rio de Janeiro, BrazilLions VisionGift, Portland, OR USAUniversidade Federal de São Paulo, Paulista Sch Med, Dept Ophthalmol, São Paulo, BrazilNational Eye Institute: EY001765Web of Scienc

Activation of the Sphingosine 1 Phosphate–Rho Pathway in Pterygium and in Ultraviolet-Irradiated Normal Conjunctiva

Sphingosine 1 phosphate (S1P) is a bioactive lipid that regulates cellular activity, including proliferation, cytoskeletal organization, migration, and fibrosis. In this study, the potential relevance of S1P–Rho signaling in pterygium formation and the effects of ultraviolet (UV) irradiation on activation of the S1P/S1P receptor axis and fibrotic responses were investigated in vitro. Expressions of the S1P2, S1P4, and S1P5 receptors were significantly higher in pterygium tissue than in normal conjunctiva, and the concentration of S1P was significantly elevated in the lysate of normal conjunctival fibroblast cell (NCFC) irradiated with UV (UV-NCFCs). RhoA activity was significantly upregulated in pterygium fibroblast cells (PFCs) and UV-NCFCs, and myosin phosphatase–Rho interacting protein (MRIP) was upregulated, and myosin phosphatase target subunit 1 (MYPT1) was downregulated in PFCs. Fibrogenic changes were significantly upregulated in both PFCs and UV-NCFCs compared to NCFCs. We found that the activation of the S1P receptor–Rho cascade was observed in pterygium tissue. Additionally, in vitro examination showed S1P–rho activation and fibrogenic changes in PFCs and UV-NCFCs. S1P elevation and the resulting upregulation of the downstream Rho signaling pathway may be important in pterygium formation; this pathway offers a potential therapeutic target for suppressing pterygium generation

Impact of rigid gas-permeable contact lens on keratometric indices and corneal thickness of keratoconus eyes examined with anterior segment optical coherence tomography.

Purpose/aimDetecting keratoconus (KC) progression helps determine the surgical indication for corneal cross-linking (CXL). This retrospective observational study aimed to examine changes in keratometric indices and corneal thickness in patients with KC who used rigid gas-permeable (RGP) contact lenses.Materials and methodsThis study involved 31 eyes (31 patients) diagnosed with KC. No patient had used RGP or any other type of contact lenses for at least 1 month. Corneal topographic data were obtained using three-dimensional anterior segment optical coherence tomography before and after >1 month of RGP lens use.ResultsThe average and maximum keratometry values changed after using an RGP lens (-1.05 ± 1.92 D, p ConclusionsKeratometry and spherical components of the anterior corneal surface values decreased after RGP lens use; keratometric changes were greater in eyes with severe KC than in those with moderate KC. Corneal progression indices, including corneal thickness, posterior keratometry, and irregular astigmatism values, mostly remained unchanged. It is important to consider these findings when evaluating corneal topography of KC and preparing CXL

Screening and Characterization of Drugs That Protect Corneal Endothelial Cells Against Unfolded Protein Response and Oxidative Stress

Purpose To screen for and characterize compounds that protect corneal endothelial cells against unfolded protein response (UPR) and oxidative stress. Methods: Bovine corneal endothelial cells (BCECs) were treated for 48 hours with 640 compounds from a Food and Drug Administration (FDA)-approved drug library and then challenged with thapsigargin or H2O2 to induce UPR or oxidative stress, respectively. Cell viability was measured using the CellTiter-Glo survival assay. Selected “hits” were subjected to further dose-response testing, and their ability to modulate expression of UPR and oxidative stress markers was assessed by RT-PCR, Western blot, and measurement of protein carbonyl and 8-hydroxydeoxyguanosine (8-OHdG) adducts in immortalized human corneal endothelial cells (iHCECs). Results: Forty-one drugs at 20 μM and 55 drugs at 100 μM increased survival of H2O2-challenged cells, and 8 drugs at 20 μM and 2 drugs at 100 μM increased survival of thapsigargin-challenged cells, compared with untreated control cells. Nicergoline, ergothioneine, nimesulide, oxotremorine, and mefenamic acid increased survival of both H2O2- and thapsigargin-challenged cells. Oxotremorine altered DNA damage inducible 3 (CHOP) gene expression, glucose-regulated protein 78 kDa (GRP78) and activating transcription factor 4 (ATF4) protein expression, and protein carbonyl and 8-OHdG levels. Mefenamic acid altered GRP78 protein expression and protein carbonyl and 8-OHdG levels. Conclusions: Oxotremorine and mefenamic acid are potential survival factors for corneal endothelial cells under UPR and oxidative stress. The described assay can be further expanded to screen additional drugs for potential therapeutic effect in corneal endothelial diseases such as Fuchs' endothelial corneal dystrophy