Development of spontaneous neuropathy in NF-κBp50-deficient mice by calcineurin-signal involving impaired NF-κB activation

信州大学博士（医学）・学位論文・平成24年3月28日授与（乙第21144号）・中村朋子Purpose: The transcriptional regulator, nuclear factor-kappa B (NF-kappa B)/Rel family are involved in neuronal cell death and survival. Previously, we reported that NF-kappa Bp50-deficient (p50-deficient) mice exhibit many features resembling human normal tension glaucoma (NTG). The developmental mechanism of human NTG is not clearly understood, and a radical curative treatment has yet to be established. Our aim is to elucidate the signal cascade which mediates the spontaneous optic neuropathy in p50-deficient mice as a model of NTG. Methods: To demonstrate the expression and activation of pro-apoptotic factors, which mediate the death of retinal ganglion cells (RGCs) in p50-deficient mice, western blot (WB) and luciferase reporter assays with retinas from p50-deficient and wild type mice, and cultured RGC-5 cells were performed. Furthermore, we tested the neuroprotective effects of chemical reagents (memantine, lomerizine, and tacrolimus) against N-methyl-D-aspartate (NMDA)-susceptible RGC damage according to in vitro experiments with RGC-5 cells. To elucidate the NF-kappa B-mediated death signaling, the effects of chemical reagents on spontaneous optic neuropathy were examined by histopathological studies. Results: WB experiments and luciferase reporter assays showed that NF-kappa B-inducible BCL2-associated X protein (Bax) and a pro-apoptotic factor, activated caspase 3 were expressed in the retina of p50-deficient mice as well as NMDA-treated RGC-5 cells. Further, the constitutively active cleaved forms of calcineurin (CaN), which have been reported to lead to apoptosis, were detected in the retina of p50-deficient mice as well as NMDA-treated RGC-5 cells. Pre-treatment with tacrolimus markedly protected RGC-5 cells from NMDA-induced neurotoxicity, and then both spontaneous RGC death and degenerative changes to the optic nerve in p50-deficient mice were significantly reduced by the chronic administration of tacrolimus. The experiments with cultured RGC-5 cells supported the results of histological examinations with p50-deficient mice, suggesting that CaN activation leads to NF-kappa B-induced Bax activation and caspase 3 activation, and mediates spontaneous optic neuropathy in p50-deficient mice. Conclusions: Research findings show that the chronic administration of tacrolimus significantly reduces spontaneous optic neuropathy in p50-deficient mice. We demonstrated a potential CaN signal cascade, which spontaneously induces age-dependent RGC death and degenerative optic nerve changes in p50-deficient mice.ArticleMOLECULAR VISION. 17:2157-2170 (2011)journal articl

Development of spontaneous neuropathy in NF-kappa Bp50-deficient mice by calcineurin-signal involving impaired NF-kappa B activation

信州大学博士（医学）・学位論文・平成24年3月28日授与（乙第21144号）・中村朋子Purpose: The transcriptional regulator, nuclear factor-kappa B (NF-kappa B)/Rel family are involved in neuronal cell death and survival. Previously, we reported that NF-kappa Bp50-deficient (p50-deficient) mice exhibit many features resembling human normal tension glaucoma (NTG). The developmental mechanism of human NTG is not clearly understood, and a radical curative treatment has yet to be established. Our aim is to elucidate the signal cascade which mediates the spontaneous optic neuropathy in p50-deficient mice as a model of NTG. Methods: To demonstrate the expression and activation of pro-apoptotic factors, which mediate the death of retinal ganglion cells (RGCs) in p50-deficient mice, western blot (WB) and luciferase reporter assays with retinas from p50-deficient and wild type mice, and cultured RGC-5 cells were performed. Furthermore, we tested the neuroprotective effects of chemical reagents (memantine, lomerizine, and tacrolimus) against N-methyl-D-aspartate (NMDA)-susceptible RGC damage according to in vitro experiments with RGC-5 cells. To elucidate the NF-kappa B-mediated death signaling, the effects of chemical reagents on spontaneous optic neuropathy were examined by histopathological studies. Results: WB experiments and luciferase reporter assays showed that NF-kappa B-inducible BCL2-associated X protein (Bax) and a pro-apoptotic factor, activated caspase 3 were expressed in the retina of p50-deficient mice as well as NMDA-treated RGC-5 cells. Further, the constitutively active cleaved forms of calcineurin (CaN), which have been reported to lead to apoptosis, were detected in the retina of p50-deficient mice as well as NMDA-treated RGC-5 cells. Pre-treatment with tacrolimus markedly protected RGC-5 cells from NMDA-induced neurotoxicity, and then both spontaneous RGC death and degenerative changes to the optic nerve in p50-deficient mice were significantly reduced by the chronic administration of tacrolimus. The experiments with cultured RGC-5 cells supported the results of histological examinations with p50-deficient mice, suggesting that CaN activation leads to NF-kappa B-induced Bax activation and caspase 3 activation, and mediates spontaneous optic neuropathy in p50-deficient mice. Conclusions: Research findings show that the chronic administration of tacrolimus significantly reduces spontaneous optic neuropathy in p50-deficient mice. We demonstrated a potential CaN signal cascade, which spontaneously induces age-dependent RGC death and degenerative optic nerve changes in p50-deficient mice.ArticleMOLECULAR VISION. 17:2157-2170 (2011)journal articl

Evaluation of Asthenopia Caused by Game Consoles

A visual function test and a questionnaire survey on asthenopia were performed before and after the use of a game console and compared to clarify the influence of the use of a game console on the visual function and asthenopia of healthy young people. The subjects were 20 healthy young persons aged 20.0 ± 0.5 years (17 females and 3 males). The near point, the rate of high frequency component (HFC) of accommodative microfluctuation, and lacrimal secretion were measured and an original questionnaire survey on asthenopia was performed before and after carrying out a task using a game console. The task was continuous playing of an action race game,‘MARIOKART 8’ (Nintendo) using Wii U (Nintendo), for 2 hours at a visual distance of 170 cm. The near point was 11.86D before the task and it significantly extended to 10.98D after the task (p < 0.05). The rates of HFC of the dominant eye before and after the task were 13.3 and 8.6%, respectively. Those of the non-dominant eye were 8.4 and 8.2%, respectively. And the lacrimal secretions were 21.2 and 21.0 mm, respectively. All the tasks showed no significant changes after each task in any parameter. The score of the subjective questionnaire survey was 14.6 before the task and it significantly increased to 34.8 after the task (p < 0.05). The task of continuous 2-hour operation of the game console significantly extended the near point and caused subjective fatigue

Characterization of the human herpesvirus 6A U23 gene

AbstractHuman herpesvirus 6 (HHV-6), which replicates abundantly in T cells, belongs to the Roseolovirus genus within the betaherpesvirus subfamily. Members of the Roseolovirus genus encode seven unique genes, U20, U21, U23, U24, U24A, U26, and U100. The present study focused on one of these, U23, by analyzing the characteristics of its gene product in HHV-6A-infected cells. The results indicated that the U23 protein was expressed at the late phase of infection as a glycoprotein, but was not incorporated into virions, and mostly stayed within the trans Golgi network (TGN) in HHV-6A-infected cells. Furthermore, analysis using a U23-defective mutant virus showed that the gene is nonessential for viral replication in vitro

Arginine enriched EN after total gastrectomy

The effects of early enteral arginine-rich nutrition (EAN) were analyzed among patients undergoing curative-intent total gastrectomy for gastric cancer. There were 19 patients in this prospective study, all randomly assigned to either a parenteral nutrition (PN) group or an EAN group for the first seven days after surgery. The EAN group received 1.8-fold greater arginine (10.1 g / day) compared with the PN group, which was administered through an enteral tube inserted into the jejunal loop. Both groups were provided almost identical amounts of total amino acids (54 g / day), and the total energy was set at 65% of the total requirement (25 kcal / kg / day). No significant differences were observed between the two groups in postoperative complications, length of hospital stay, oral intake, nutritional status, or body weight. The serum arginine profile was similar in the two groups, as it decreased significantly on postoperative day (POD) 1, and gradually returned to preoperative levels by POD 7. The nitrogen balance remained negative until POD 7 in the PN group, but turned neutral at POD 7 in the EAN group. While we could not confirm body weight loss improvement, these results suggested that early arginine-rich enteral nutrition could improve the nitrogen balance after total gastrectomy