Obesity is one of the most common metabolic diseases around the world, which is distinguished by the abnormal buildup of triglycerides within adipose cells. Recent research has revealed that autophagy regulates lipid mobilization to maintain energy balance. TIGAR (Trp53 induced glycolysis regulatory phosphatase) has been identified as a glycolysis inhibitor, whether it plays a role in the metabolism of lipids is unknown. Here, we found that TIGAR transgenic (TIGAR+/+) mice exhibited increased fat mass and trended to obesity phenotype. Non-target metabolomics showed that TIGAR caused the dysregulation of the metabolism profile. The quantitative transcriptome sequencing identified an increased levels of LRRK2 and RAB7B in the adipose tissue of TIGAR+/+ mice. It was confirmed in vitro that TIGAR overexpression increased the levels of LRRK2 by inhibiting polyubiquitination degradation, thereby suppressing macroautophagy and chaperone-mediated autophagy (CMA) while increasing lipid accumulation which were reversed by the LRRK2 inhibitor DNL201. Furthermore, TIGAR drove LRRK2 to interact with RAB7B for suppressing lysosomal degradation of lipid droplets, while the increased lipid droplets in adipocytes were blocked by the RAB7B inhibitor ML282. Additionally, fat-specific TIGAR knockdown of TIGAR+/+ mice alleviated the symptoms of obesity, and adipose tissues-targeting superiority DNL201 nano-emulsion counteracted the obesity phenotype in TIGAR+/+ mice. In summary, the current results indicated that TIGAR performed a vital function in the lipid metabolism through LRRK2-mediated negative regulation of macroautophagy and CMA in adipocyte. The findings suggest that TIGAR has the potential to serve as a viable therapeutic target for treating obesity and its associated metabolic dysfunction.
Pan Liuliu,Zhang Xiaodan,Wang Danhan,Huang Min,Huang Qiusui,Duan Ping,Mei Jie
Discovering compounds with anti-cervical cancer effect and clarifying their targets will help promoting the precise treatment of cervical cancer. The present study intended to clarify the effect of osthole on cervical cancer cells, and to explore the possibility of DCLK1 as its target.
Annexin V-PE staining and flow cytometry methods were used to determine cell apoptosis. Meanwhile, apoptosis related biomarkers were probed by immunoblotting. The MTT assay was employed to study the effect of osthole in combined with or without LRRK2-IN-1 (a DCLK1 inhibitor) on cell proliferation.
Then, combination index was determined. To examine the interaction of osthole with DCLK1, molecular docking was carried out. Based on the biological database from cBioPortal, the association between DCLK1 and clinical manifestations of cervical cancer were evaluated. The results showed that
osthole can significantly induce apoptosis of HeLa and Me-180. When combined with LRRK2-IN-1, the effect of osthole on cell proliferation was antagonized, suggesting that it might competitive binding to DCLK1. Furthermore, molecular docking showed that osthole interacts with Val468 residues
of DCLK1 to form hydrogen bonds. The analysis of database showed that DCLK1 frequently mutant and deleted in cervical cancer, and is related to cell survival, tumor progression and recurrence. However, no obvious correlations were found between DCLK1 and lymphatic metastasis/differentiation.
In conclusion, osthole significantly inhibits the survival of cervical cancer cells. It's probably target DCLK1 mechanistically via interacting with Val468. DCLK1 could be a potential therapeutic target for cervical cancer.