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Biology subjects

Ogura, M.

Publications and source records attributed to Ogura, M..

2 recordsLinked to original sources

Nobiletin, a Polymethoxyflavonoid, Activates the Desuccinylase Activity of SIRT5 and Prevents the Development of Heart Failure

Nobiletin is a natural compound useful for the prevention and treatment of several diseases. However, the precise role of nobiletin in heart failure is unclear. Nobiletin treatment prevents pressure overload- and myocardial infarction-induced heart failure. Using affinity purification of biotinylated nobiletin from rat heart cell lysates, we identified sirtuin 5 (SIRT5) as a novel nobiletin-binding protein. Nobiletin enhanced the desuccinylase activity of SIRT5 in vitro. Compared to wild-type mice, SIRT5-overexpressing transgenic mice resisted pressure overload-induced systolic dysfunction. Conversely, SIRT5 knockout disrupted the nobiletin-mediated therapeutic effects on heart failure in mice. SIRT5 desuccinylated p300 at lysine 1568 and reduced the histone acetyltransferase (HAT) activity of p300. The desuccinylated p300 mutant suppressed the phenylephrine-induced cardiomyocyte hypertrophic responses. These findings suggest that nobiletin prevents heart failure development through SIRT5-dependent inhibition of p300-HAT activity. Nobiletin, a nontoxic dietary compound, is a potential therapeutic agent for heart failure in humans.

molecular biology↗

Three-dimensional analysis of β-cell proliferation by a novel mouse model

Inducing {beta}-cell proliferation could inhibit diabetes progression. Many factors have been suggested as potential {beta}-cell mitogens, but their impact on {beta}-cell replication has not been confirmed due to the lack of a standardized {beta}-cell proliferation assay. In this study, we developed a novel method that specifically labels replicating {beta} cells and yields more reproducible results than current immunohistochemical assays. We established a mouse line expressing the fluorescent ubiquitination-based cell cycle indicator (Fucci2a) reporter only in {beta} cells through Cre-mediated recombination under the control of the rat insulin promoter (RIP-Cre;Fucci2aR). Three-dimensional imaging of optically cleared pancreas tissue from these mice enabled the quantification of replicating {beta} cells in islets and morphometric analysis of islets following mitogen treatment. Intravital imaging of RIP-Cre;Fucci2aR mice revealed cell cycle progression of {beta} cells. Thus, this novel mouse line is a powerful tool for spatiotemporal analysis of {beta}-cell proliferation in response to mitogen stimulation.

cell biology↗