LIVER INTERNATIONAL
·
2025
·Vol. 45
·期 4
·e70053
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IF 5.2
Peng Ma,Hao Ou,Junze Cai,Yuanli Zhang,Yu Ou
Background & Aims G protein-coupled receptors (GPCRs) are important potential drug targets for the treatment of metabolic disorders. The D2 dopamine receptor (DRD2), a GPCR receptor, is a member of the dopamine receptor family. However, the role of DRD2 in regulating lipid metabolism, especially in hepatic steatosis, is unclear. Methods Eight-week male mice were fed HFHC/MCD to induce the MASH model. AAV2/8 containing the TBG promoter was used to knock down and overexpress DRD2 in mouse liver. Co-immunoprecipitation, Western lotting, immunofluorescence, and immunohistochemistry were used to investigate the mechanisms and screen DRD2 antagonists. Results The study found that activation of PKC leads to the elevation and internalisation of DRD2 in a high-fat environment. Knockdown of DRD2 in mouse liver can effectively interfere with the progression of MASH, while overexpression of DRD2 significantly aggravates the process of MASH. The study on the mechanism of DRD2 regulating lipid metabolism found that the internalisation of DRD2 could lead to dephosphorylation of pAKT (T308) by binding to β-arrestin2 and pAKT, thereby inducing ubiquitin-dependent degradation of AMPK and exacerbating steatosis. L-741626, a DRD2 antagonist, was found to interfere with the internalisation of DRD2 in a high-fat environment. It has been shown that L-741626 can treat MASH by regulating the AKT-AMPK signalling axis in vitro and in vivo. Conclusions In conclusion, this study demonstrated that internalisation of DRD2 in a high-fat environment aggravated MASH progression through the AKT-AMPK signalling axis. Furthermore, L-741626, as a DRD2 antagonist, has the potential to treat MASH.
研究领域:
代谢性疾病
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肝病学
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药理学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Cancer Genetics
·
2023
·
IF 1.9
Shuoyi Zhang,Ming Zhong,Hongbo Zhu,Qinghua You,Hao Yuan,Yongping Li
ABSTRACT We investigated the effect of stem cell marker dopamine receptor D2 (DRD2) on the proliferation of hormone-receptor-negative breast cancer cells. High-throughput DNA methylation sequencing on an 850K chip was used to pre-screen breast cancer tissues with significant methylation differences. The expression of DRD2 in breast cancer and normal breast tissues, and clinical risk factors, were detected by pyrophosphoric acid validation and immunohistochemistry. In vitro and in vivo experiments verified the possible molecular signaling pathways. DRD2 promoter region was hypomethylated in hormone-receptor-negative breast cancer or with high-risk factors compared to the normal tissues. The proliferation of breast cancer cells was enhanced after DRD2 was upregulated and decreased after DRD2 was downregulated. In vivo experiments found that tumor growth and the expression of antigen KI-67 (Ki67) and the cluster of differentiation 31 (CD31) were improved by the overexpression of DRD2 and inhibited by the down expression of DRD2. In vivo and in vitro experiments demonstrated the phosphorylation of filamin A and extracellular signal-regulated kinase (FLNA-ERK) was influenced by the expression of DRD2, suggesting DRD2 plays a role in the FLNA-ERK signaling pathway. Methylation inhibitors (5-aza-2-deoxycytidine, 5-azadc) partially reversed the inhibitory effect of DRD2 down expression on cell proliferation, migration, and tumor growth in animal models, indicating that inhibition of DRD2 methylation promotes cancer development. This study demonstrated the DRD2 promoter region is hypomethylated in hormone-receptor-negative breast cancer or with high-risk factors. The methylation status of the DRD2 promoter and FLNA-ERK signaling pathway and the DRD2 expression in breast cancer treatment need to be considered.
研究领域:
肿瘤学
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分子生物学
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癌症遗传学
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产品关联
DOI
PubMed
高影响因子
OPHTHALMIC RESEARCH
·
2022
·Vol. 65
·期 6
·678-684
·
IF 3.031
Fan Yuzhuo,Li Jiarui,Huang Lvzhen,Wang Kai,Zhao Mingwei
Introduction: The goal of this study was to investigate the presence of ADORA2A-DRD2 heterodimers in human retinal pigment epithelial (RPE) cells; determine if 7-methylxanthine (7-MX), a nonselective adenosine receptor antagonist which was used to control myopia progression, can influence the behavior of RPE cells through the ADORA2A-DRD2 receptor pathway; and assess the changes in the expression of signaling molecules during cellular signal transduction. Methods: Human RPE cells were cultured in vitro in the presence or absence of 7-MX. Cell proliferation was evaluated with the CCK-8 assay. Apoptosis and necrosis rates were determined by annexin V–FITC/propidium iodide staining and flow cytometry. Immunofluorescence and coimmunoprecipitation were used to examine the protein expression and colocalization of ADORA2A and DRD2 in RPE cells. ADORA2A and DRD2 were knocked down with small interfering RNAs (siRNAs). Changes in the protein expression of ERK1/2 and phospho-ERK1/2 (pERK 1/2), which are signaling molecules downstream of dopamine receptors, were evaluated by Western blot analysis. Results: Immunofluorescence and coimmunoprecipitation showed that ADORA2A and DRD2 were colocalized in RPE cells. The expression of ADORA2A in RPE cells was inhibited by treatment with 50 µmol/L 7-MX for 48 h, and the expression of DRD2, ERK1/2, and pERK1/2 was increased after treatment with 50 µmol/L 7-MX for 48 h. After siRNA-mediated knockdown of DRD2 in RPE cells and further treatment with 50 µmol/L 7-MX for 48 h, the expression of DRD2 was nearly restored to the level observed in the native control. At the experimental concentrations, 7-MX and siRNAs did not affect the proliferation or apoptosis of human RPE cells. Conclusions: ADORA2A and DRD2 heterodimers were present in RPE cells. 7-MX may affect the behaviors of RPE cells through the ADORA2A-DRD2 receptor pathway. 7-MX is an inhibitor of ADORA2A receptors that can prevent inhibition of the DRD2 receptor pathway and increase DRD2 receptor pathway activity. This phenomenon may explain the mechanism of action through which 7-MX can control myopia progression
研究领域:
眼科学
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细胞生物学
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药理学
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产品关联
DOI
PubMed
高影响因子
PHARMACOLOGICAL RESEARCH
·
2021
·
IF 7.658
Yujiao Yang,Junke Song,NanNan Liu,Guangyi Wei,Shan Liu,Sen Zhang,Nan Jiang,Haiguang Yang,Guanhua Du
Chronic cerebral ischemia (CCI) refers to long-term hypoperfusion of cerebral blood flow with the main clinical manifestations of progressive cognitive impairment . The pathological mechanism of CCI is complex, and there is a lack of effective treatments. Salvianolic acid A (SalA) is a neuroprotective extract of Salvia miltiorrhiza with the effects of anti-inflammation and anti-apoptosis. In this study, the effect of SalA on cognitive function and Drd2/Cryab/NF-κB signaling pathway in rats with CCI was investigated. Morris water maze and open field test were used to observe the effects of SalA on the cognitive function of CCI rats. The pathological changes in the brain were observed by HE, Nissl, and LFB staining. TUNEL staining, enzyme-linked immunosorbent assay, and western blot analysis were used to detect the inflammatory and apoptosis in the cortex and hippocampus. The expression of Drd2/Cryab/NF-κB pathway-related molecules and Drd2 localization were detected by western blotting and dual immunofluorescence, respectively. SH-SY5Y cells were exposed to chronic hypoglycemic and hypoxic injury in vitro, and Drd2 inhibitor haloperidol was used to verify the involved pathway. The results showed that SalA could improve the cognitive function of CCI rats, reduce pathological damage of cortex and hippocampus, inhibit neuroinflammation and apoptosis, and suppress the activation of NF-κB by regulating Drd2/Cryab pathway. And SalA inhibited NF-κB activation and nuclear translocation in SH-SY5Y cells by upregulating Drd2/Cryab pathway, which was reversed by haloperidol interference. In conclusion, SalA could relieve CCI-induced cognitive impairment in rats, at least partly through the Drd2/Cryab/NF-κB pathway.
研究领域:
神经科学
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药理学
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分子生物学
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病理学
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产品关联
DOI
PubMed
高影响因子
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