京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22327号 / 医博第4568号 / 新制||医||1041(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 竹内 理, 教授 江藤 浩之, 教授 生田 宏一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Yes / Recent clinical trials of the hypoglycaemic sodium-glucose co-transporter-2 (SGLT2) inhibitors, which inhibit renal glucose reabsorption, have reported beneficial cardiovascular outcomes. Whether SGLT2 inhibitors directly affect cardiovascular tissues, however, remains unclear. We have previously reported that the SGLT2 inhibitor canagliflozin activates AMP-activated protein kinase (AMPK) in immortalised cell lines and murine hepatocytes. As AMPK has anti-inflammatory actions in vascular cells, we examined whether SGLT2 inhibitors attenuated inflammatory signalling in cultured human endothelial cells. Incubation with clinically-relevant concentrations of canagliflozin, but not empagliflozin or dapagliflozin activated AMPK and inhibited IL-1β-stimulated adhesion of pro-monocytic U937 cells and secretion of IL-6 and monocyte chemoattractant protein-1 (MCP-1). Inhibition of MCP-1 secretion was attenuated by expression of dominant-negative AMPK and was mimicked by the direct AMPK activator, A769662. Stimulation of cells with either canagliflozin or A769662 had no effect on IL-1β-stimulated cell surface levels of adhesion molecules or nuclear factor-κB signalling. Despite these identical effects of canagliflozin and A769662, IL-1β-stimulated IL-6/MCP-1 mRNA was inhibited by canagliflozin, but not A769662, whereas IL-1β-stimulated c-jun N-terminal kinase phosphorylation was inhibited by A769662, but not canagliflozin. These data indicate that clinically-relevant canagliflozin concentrations directly inhibit endothelial pro-inflammatory chemokine/cytokine secretion by AMPK-dependent and -independent mechanisms without affecting early IL-1β signalling. / Project Grant (PG/13/82/30483 to IPS and TMP) and PhD studentships (FS/16/55/32731 and FS/14/61/31284 to DB and AS) from the British Heart Foundation and an equipment grant (BDA11/0004309 to IPS and TMP) from Diabetes UK. OJK was supported by a Scholarship from the Iraqi Ministry of Higher Education and Scientific Research. TAA was supported by a Libyan Ministry of Education PhD Studentship.

Glukokortikoide (GK) zählen zu den effizientesten Medikamenten bei der Behandlung akuter und chronischer Entzündungskrankheiten. Ihr Einsatz ist häufig durch das Auftreten zahlreicher und teilweise irreversibler Nebenwirkungen beeinträchtigt. Aus diesem Grund wurden neue Glukokortikoid-Rezeptor-Liganden, wie die nicht-steroidalen selektiven Glukokortikoid-Rezeptor-Agonisten (SEGRAs), die eine potente anti-entzündliche Wirkung bei gleichzeitig vermindertem Nebenwirkungspotential aufweisen sollen, entwickelt. Im Rahmen der vorliegenden Arbeit wurde die SEGRA-Substanz BAY1155975 hinsichtlich ihrer hemmenden Wirkung auf die CD28-kostimulierte Aktivierung primärer humaner T-Zellpopulationen mit der von klassischen GK, wie z.B. Prednisolon, verglichen. In humanen Gedächtnis/Effektor- CD4+ T-Zellen wies die höchste Konzentration von BAY1155975 im Vergleich zu Prednisolon eine statistisch signifikant größere Hemmung der CD28-kostimulierten Sekretion von Effektorzytokinen (IFN-gamma, TNF-alpha, IL17 und IL22) auf. Proliferation, Apoptose und die Expression verschiedener Aktivierungsmarker wurden dagegen durch BAY1155975 und Prednisolon gleichermaßen reguliert. Es wird eine stärkere Hemmung des Kalzium-Kalzineurin-NFAT Signalweges durch BAY1155975 in diesen Zellen vermutet. In vivo zeigten BAY1155975 und Prednisolon eine ähnlich starke Hemmung der T-Zell-vermittelten Hautentzündung im DNFB-induzierten Kontaktallergiemodell in Mäusen, wenn die Behandlung der Mäuse mit den Substanzen vor dem Challenge erfolgte. Bei einer Substanzbehandlung der Mäuse während der Sensibilisierung wurde die Hautentzündung dagegen deutlich stärker durch BAY1155975 als durch Prednisolon gehemmt. Zusammenfassend geben die Ergebnisse dieser Arbeit einen Hinweis auf eine stärkere Hemmung der T-Zellsensibilisierung und der Effektorzytokinsekretion durch die SEGRA Substanz BAY1155975 im Vergleich zum klassischen GK Prednisolon. / Glucocorticoids (GCs) are the most effective therapeutic agents for the treatment of acute and chronic inflammatory diseases. Their use is often accompanied with numerous and sometimes irreversible side-effects. Therefore, new glucocorticoid receptor (GR) ligands with should have potent anti inflammatory efficacy but a reduced side-effect profile have been developed. Non steroidal selective glucocorticoid receptor agonists (SEGRAs) represent a new class of GR ligands with an improved therapeutic index. In this study, we compared the SEGRA, BAY1155975, and the classical GC, prednisolone, regarding their suppressive effect on CD28-costimulated activation of human primary T cell subpopulations. In human memory/effector CD4+ T cells, BAY1155975 at the highest concentration exhibited a significantly stronger inhibition of CD28-costimulated effector cytokine secretion (IFN-gamma, TNF-alpha, IL17 and IL22) in comparison to prednisolone. Interestingly, proliferation, apoptosis and expression of activation markers were similarly regulated by BAY1155975 and prednisolone. Further studies on different signal transduction pathways suggested that BAY1155975 stronger inhibited the calcium-calcineurin-NFAT pathway than prednisolone in these cells. In vivo BAY1155975 and prednisolone showed comparable efficacy in inhibition of T cell dependent skin inflammation in DNFB-induced contact hypersensitivity models in mice, when mice were treated before hapten challenge. In contrast, when mice were treated around hapten sensitization markedly stronger inhibition of skin inflammation was observed for BAY1155975 than prednisolone. In summary, the data of this study give evidence for a stronger inhibition of T cell sensitization and effector cytokine secretion by the SEGRA, BAY1155975, in comparison to the classical GC, prednisolone.