Université de Fribourg

Arginase-ii deficiency extends lifespan in mice

Xiong, Yuyan ; Yepuri, Gautham ; Montani, Jean-Pierre ; Ming, Xiu-Fen ; Yang, Zhihong

In: Frontiers in Physiology, 2017, vol. 8, p. -

The mitochondrial arginase type II (Arg-II) has been shown to interact with ribosomal protein S6 kinase 1 (S6K1) and mitochondrial p66Shc and to promote cell senescence, apoptosis and inflammation under pathological conditions. However, the impact of Arg-II on organismal lifespan is not known. In this study, we demonstrate a significant lifespan extension in mice with Arg-II gene deficiency...

Université de Fribourg

Arginase-II promotes tumor necrosis Factor-α release from pancreatic acinar cells causing β-cell apoptosis in aging

Xiong, Yuyan ; Yepuri, Gautham ; Necetin, Sevil ; Montani, Jean-Pierre ; Ming, Xiu-Fen ; Yang, Zhihong

In: Diabetes, 2017, vol. 66, no. 6, p. 1636–1649

Aging is associated with glucose intolerance. Arginase-II (Arg-II), the type-II L-arginine- ureahydrolase, is highly expressed in pancreas. However, its role in regulation of pancreatic β-cell function is not known. Here we show that female (not male) mice deficient in Arg-II (Arg-II−/−) are protected from age-associated glucose intolerance and reveal greater glucose induced-insulin...

Université de Fribourg

Positive crosstalk between arginase-II and S6K1 in vascular endothelial inflammation and aging

Yepuri, Gautham ; Velagapudi, Srividya ; Xiong, Yuyan ; Rajapakse, Angana G. ; Montani, Jean-Pierre ; Ming, Xiu-Fen ; Yang, Zhihong

In: Aging Cell, 2012, p. -

Augmented activities of both arginase and S6K1 are involved in endothelial dysfunction in aging. This study was to investigate whether or not there is a crosstalk between arginase and S6K1 in endothelial inflammation and aging in senescent human umbilical vein endothelial cells and in aging mouse models. We show increased arginase-II (Arg-II) expression/activity in senescent endothelial cells....

Université de Fribourg

Arginase iI promotes macrophage inflammatory responses through mitochondrial reactive oxygen species, contributing to insulin resistance and atherogenesis

Ming, Xiu‐Fen ; Rajapakse, Angana G. ; Yepuri, Gautham ; Xiong, Yuyan ; Carvas, João M. ; Ruffieux, Jean ; Scerri, Isabelle ; Wu, Zongsong ; Popp, Katja ; Li, Jianhui ; Sartori, Claudio ; Scherrer, Urs ; Kwak, Brenda R. ; Montani, Jean‐Pierre ; Yang, Zhihong

In: Journal of the American Heart Association, 2012, p. -

Background Macrophage‐mediated chronic inflammation is mechanistically linked to insulin resistance and atherosclerosis. Although arginase I is considered antiinflammatory, the role of arginase II (Arg‐II) in macrophage function remains elusive. This study characterizes the role of Arg‐II in macrophage inflammatory responses and its impact on obesity‐linked type II...

Université de Fribourg

Hyperactive S6K1 mediates oxidative stress and endothelial dysfunction in aging: inhibition by resveratrol

Rajapakse, Angana Gupta ; Yepuri, Gautham ; Carvas, João M. ; Stein, Sokrates ; Matter, Christian M. ; Scerri, Isabelle ; Ruffieux, Jean ; Montani, Jean-Pierre ; Ming, Xiu-Fen ; Yang, Zhihong

In: PLoS ONE, 2011, vol. 6, no. 4, p. e19237

Mammalian target of rapamycin (mTOR)/S6K1 signalling emerges as a critical regulator of aging. Yet, a role of mTOR/S6K1 in aging-associated vascular endothelial dysfunction remains unknown. In this study, we investigated the role of S6K1 in aging-associated endothelial dysfunction and effects of the polyphenol resveratrol on S6K1 in aging endothelial cells. We show here that senescent endothelial...