High carbohydrate ingestion induces lipid accumulation through enhancing SCAP O-GlcNAcylation to activate SREBP1 in fish
Yuan Luo , Chen-Chen Wu , Mai Wang , Yu-Cheng Qian , Jun-Xian Wang , Yan-Yu Zhang , Fang Qiao , Mei-Ling Zhang , Samwel Mchele Limbu , Zhen-Yu Du
Marine Life Science & Technology ›› : 1 -12.
Fish are prone to lipid deposition when fed a high carbohydrate diet (HCD), making them suitable models for investigating the potential mechanisms of HCD-induced fat accumulation. In the present study, Nile tilapia and zebrafish liver cell lines (ZFL) were used to investigate the potential mechanisms of high carbohydrate-induced fat deposition. Our results found that HCD induces hepatic lipid accumulation and insulin resistance in fish. HCD activates the hexosamine biosynthetic pathway (HBP), increasing UDP-GlcNAc levels and upregulating hepatic OGT expression and O-GlcNAcylation. Interestingly, supplementing with the O-GlcNAcylation substrate glucosamine and inhibiting O-GlcNAcase (OGA) both promote triglyceride accumulation in ZFL. In contrast, inhibiting O-GlcNAc transferase (OGT) can block the triglyceride accumulation induced by glucose. Our further study results indicate that high carbohydrate enhances the protein stability of sterol regulatory element-binding protein cleavage-activating protein (SCAP) by increasing its O-GlcNAcylation level. This, in turn, promotes the formation of the SCAP-sterol regulatory element-binding protein 1 (SREBP1) complex, as well as the cleavage and nuclear translocation of SREBP1. Consequently, these processes regulate lipid anabolism and induce hepatic lipid accumulation. This finding provides a plausible explanation for the sustained activation of SREBP1 in the context of insulin resistance induced by HCD.
High carbohydrate / O-GlcNAcylation / SCAP / SREBP1 / Lipid accumulation
| [1] |
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| [2] |
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| [3] |
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| [4] |
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| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
|
| [36] |
|
| [37] |
|
| [38] |
|
| [39] |
|
| [40] |
|
| [41] |
|
| [42] |
|
| [43] |
|
| [44] |
|
| [45] |
|
| [46] |
|
| [47] |
|
| [48] |
|
| [49] |
|
| [50] |
|
The Author(s), under exclusive licence to Ocean University of China
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