(A high-quality digital representation of this figure is available in the online issue.) For further confirmation of the phenotype of Tg mice, the standard gene-targeting method was used to produce vaspin knockout mice (Supplementary Fig. cells. The addition of recombinant human vaspin in the cultured H-4-II-E-C3 cells also increased the phosphorylation of Akt and AMP-activated protein kinase (AMPK) in a dose-dependent manner, and anti-GRP78 antibodies completely abrogated the vaspin-induced upregulation of pAkt and pAMPK. Vaspin is usually a novel ligand for cell-surface GRP78/MTJ-1 complex, and its subsequent signals exert beneficial effects on ER stressCinduced metabolic dysfunctions. Obesity is usually associated with low-grade and chronic inflammation, which is a crucial link between obesity and related metabolic dysfunction, such as insulin resistance and type 2 diabetes. Upstream of the obesity-induced inflammatory responses, endoplasmic reticulum (ER) stress and related signaling networks are emerging as a potential site for the conversation of inflammation and metabolic diseases (1). ER stress is induced by the accumulation of de novo synthesized unfolded proteins, and the unfolded protein response (UPR) is usually activated. The canonical UPR is usually linked to inflammatory and stress signal systems such as nuclear factor-B (NF-B)CIB kinase, Jun NH2-terminal kinaseCactivator protein 1 (AP1) pathways, and oxidative stress responses. Three major pathways of UPR, dsRNA-dependent Zibotentan (ZD4054) protein kinaseClike eukaryotic initiation factor 2 Tmprss11d kinase (PERK)Cmediated attenuation of translation, the activation of inositol requiring enzyme 1 (IRE1) after splicing of mRNA of X-box binding protein 1 (XBP1), and activating transcription factor 6 (ATF6) pathway, have all been shown to be linked to inflammatory signaling (1). Causality between susceptibility to ER stress and insulin resistance Zibotentan (ZD4054) has been shown to be supported by genetic manipulation of XBP1 (2) and ER chaperone proteins such as oxygen-regulated protein 150 (3,4) and 78-kDa glucoseCregulated protein (GRP78) (5,6). In previous studies, XBP1 haploinsufficiency in mice resulted in insulin resistance (2) and oxygen-related protein 150 deficiency resulted in impaired glucose tolerance (3,4). Similarly, overexpression of GRP78 in the liver has been shown to result in beneficial metabolic effects in mice (6), and intriguingly, GRP78 heterozygosity has been shown to result in a compensatory increase in other ER chaperones, which enhanced overall ER capacity and consequently metabolic benefits (5). We previously reported the cloning of Zibotentan (ZD4054) visceral adipose tissueCderived serine proteinase inhibitor (vaspin), belonging to serpin clade A (test in the comparison of two groups and two-way ANOVA in the comparison of more than three groups. Oxygen consumption was compared by ANCOVA with body weight as a covariant. 0.05 was regarded as statistically significant. The data were analyzed with PASW Statistics 18 (SPSS, Chicago, IL). RESULTS Vaspin improves insulin sensitivity in vivo. Vaspin Tg C57BL/6JJcl mice under the control of aP2 promoter were produced (Supplementary Fig. 1and and and and lipogenesis genes (Supplementary Fig. 4and = 20). = 5C9). B.W., body weight. = 5C9). = 5C9). = 4C10). All values are presented as means SEM. * 0.05, ** 0.01 vs. WT HFHS mice; # 0.05, ## 0.01 vs. WT HFHS mice. (A Zibotentan (ZD4054) high-quality digital representation of this figure is available in the online issue.) For further confirmation of the phenotype of Tg mice, the standard gene-targeting method was used to produce vaspin knockout mice (Supplementary Fig. 7and and Supplementary Fig. 6and and Supplementary Fig. 3and and and = 20). = 8C12). B.W., body weight. = 5). = 5C7). Values are presented as means SEM in 0.05, ** 0.01 vs. vaspin+/+ HFHS mice; # 0.05, ## 0.01 vs. vaspin+/+ HFHS mice. (A high-quality digital representation of this figure is available in the online issue.) Vaspin interacts with GRP78. Serpin clade A members consist of classical serine proteases inhibitors, such as antitrypsin (and and and = 3). With the treatment of siRNA-GRP78, beneficial effects in.