Frontiers in Pharmacology
·
2024
·
IF 4.4
Li Lin,Jingchuan Yan,Jin Sun,Jianfeng Zhang,Bo Liao
Objective: The PRAS40 is an essential inhibitory subunit of the mTORC1 complex, which regulates autophagy. It has been suggested that Erxian Decoction (EXD) could treat spinal cord injury (SCI) via the autophagy pathway. However, the mechanism of whether EXD acts through PRAS40 remains unclear. Methods: With the help of immobilized PRAS40, isothermal titration calorimetry (ITC) and molecular docking, the bioactive metabolites in the EXD were screened. To establish in vitro SCI models, PC12 cells were exposed to hydrogen peroxide (H2O2) and then treated with the identified EXD substances. Furthermore, Western blot assay was carried out to identify potential molecular mechanisms involved. For assessing the effect of metabolites in vivo , the SCI model rats were first pretreated with or without the metabolite and then subjected to the immunohistochemistry (IHC) staining, Basso, Beattie & Bresnahan (BBB) locomotor rating scale, and H&E staining. Results: The immobilized PRAS40 isolated indole, 4-nitrophenol, terephthalic acid, palmatine, sinapinaldehyde, and 3-chloroaniline as the potential ligands binding to PRAS40. Furthermore, the association constants of palmatine and indole as 2.84 × 106 M-1 and 3.82 × 105 M-1 were elucidated via ITC due to the drug-like properties of these two metabolites. Molecular docking results also further demonstrated the mechanism of palmatine binding to PRAS40. Western blot analysis of PC12 cells demonstrated that palmatine inhibited the expression of p-mTOR by binding to PRAS40, activating the autophagic flux by markedly increasing LC3. The injection of palmatine (10μM and 20 μM) indicated notably increased BBB scores in the SCI rat model. Additionally, a dose-dependent increase in LC3 was observed by IHC staining. Conclusion: This research proved that EXD comprises PRAS40 antagonists, and the identified metabolite, palmatine, could potentially treat SCI by activating the autophagic flux.
研究领域:
药理学
·
神经科学
·
中医
·
生物化学
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产品关联
DOI
PubMed
高影响因子
NEOPLASIA
·
2026
·
IF 4.8
Hongming Teng,Yuxin Guo,Xinran Chen,Anlian Fan,Chengfei Zhang,Ting Zhang,Yuanyuan Luo,Lin Huang
Colorectal cancer (CRC) progression could be fueled by the activation of the unfolded protein response (UPR) triggered by endoplasmic reticulum (ER) stress. The proline-rich Akt1 substrate of 40 kDa (PRAS40) is implicated in cancer progression, but its role in the UPR remains unclear. Herein, we demonstrate that PRAS40 promotes the inositol-requiring enzyme 1α (IRE1α)-X-box binding protein 1 (XBP1) axis-dependent UPR in driving CRC progression. Mechanistically, PRAS40 interacts with ER chaperone glucose-regulated protein 78 (GRP78) and enhances its N-glycosylation. Moreover, PRAS40 improves the interaction between GRP78 and ST6 β-galactoside α-2, 6-sialyltransferase 1 (ST6Gal1), leading to increased α-2, 6-sialylation of GRP78 and the UPR triggered by ER stress. Furthermore, we identified the natural compound β-sitosterol as a novel ST6Gal1 inhibitor, which attenuated PRAS40-triggered tumor growth. Collectively, these findings unveil a PRAS40-ST6Gal1-GRP78 axis that drives CRC progression through activating the IRE1α-XBP-1-mediated UPR and nominate ST6Gal1 as a promising therapeutic target.
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DOI
高影响因子
Regenerative Biomaterials
·
2019
·Vol. 6
·期 4
·221-229
·
IF 3.382
Duan Jimei,Du Jiuju,Jin Rongrong,Zhu Wencheng,Liu Li,Yang Li,Li Mengye,Gong Qiyong,Song Bin,Anderson James M,Ai Hua
Dextran-coated superparamagnetic iron oxide nanoparticles (Dex-SPIONs) are excellent magnetic resonance imaging contrast agents for disease diagnosis and therapy. They can be delivered to target tissues mainly though vascular endothelium cells, which are major targets of oxidative stress. In cardiovascular cells, autophagy serves primarily on a pro-survival approach that protects the cells from oxidative stress even some autophagy inducers have been developed for adjuvant therapy of cardiovascular disorders. Our study demonstrated that the nanoparticles could be taken up by human umbilical vein endothelial cells (HUVECs) without causing obvious cytotoxicity but triggering autophagy. Furthermore, our results revealed that Dex-SPIONs could enhance HUVECs survival and reverse the reduction of nitric oxide secretion under the condition of H2O2 damage. However, these effects could be diminished by the autophagy inhibitor. In particular, we discovered that Dex-SPIONs evoked autophagy in HUVECs by reducing the phosphorylation of PRAS40, an upstream regulator of autophagy initiation. These results suggested that Dex-SPIONs functions as an autophagic-related antioxidant in HUVECs which may be utilized as an adjuvant therapy to cardiovascular disease associated with oxidative stress.
研究领域:
纳米技术
·
生物医学工程
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心血管科学
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细胞生物学
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产品关联
DOI
PubMed
高影响因子
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