A novel compound 4010B-30 upregulates apolipoprotein A-I gene expression through activation of PPARγ in HepG2 cells.
OBJECTIVE
Apolipoprotein (Apo) A-I is the major lipoprotein content of HDL and upregulating endogenous ApoA-I expression has been proposed as a desirable approach to raise the functional HDL. In this study we investigated the effect of a novel small molecule 4010B-30 on transcriptional regulation of ApoA-I gene in HepG2 cells, and the influence on the level of ApoA-I expression and function. Then the mechanisms by which 4010B-30 regulated ApoA-I expression was further explored.


RESULTS
In human hepatic HepG2 cells, 4010B-30 increased the mRNA level and the protein production of ApoA-I both in cell lysates and media. The 4010B-30-induced ApoA-I containing particles increased cholesterol efflux from RAW264.7 macrophages. 4010B-30 also upregulated ABCA1 expression confirmed by transcriptional activity assay and Western blot analysis in both HepG2 and RAW264.7 cells. Promoter luciferase assay was used to identify the 4010B-30-responsive region which is mapped to the proximal -277bp region of the ApoA-I promoter. Further study indicated that the regulation of 4010B-30 on ApoA-I transcription or protein expression in HepG2 cells was abrogated with the suppression of PPARγ by its small interfering RNA or a specific inhibitor, GW9662.


CONCLUSIONS
These findings suggest that the novel small molecular upregulator 4010B-30 increases ApoA-I gene expression, thereby enhances its function of promoting cholesterol efflux, as well as ABCA1 expression in vitro, and activation of PPARγ is required for 4010B-30 to induce hepatic ApoA-I production.
The Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Yu
Y
Du
The Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Li
L
Wang
The Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Shuyi
S
Si
The Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China. Electronic address: yangyuan78@hotmail.com.
Yuan
Y
Yang
The Key Laboratory of Biotechnology of Antibiotics of Ministry of Health, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China. Electronic address: binhong69@hotmail.com.
Bin
B
Hong
D064286:ATP Binding Cassette Transporter 1 / Q000378:metabolism; D000813:Anilides / Q000494:pharmacology; D000818:Animals; D016632:Apolipoprotein A-I / Q000235:genetics / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D047495:PPAR gamma / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D000067996:RAW 264.7 Cells; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects; D013141:Spiro Compounds / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D015854:Up-Regulation
D064286:ATP Binding Cassette Transporter 1; D000813:Anilides; D016632:Apolipoprotein A-I; D002784:Cholesterol; D000960:Hypolipidemic Agents; D047495:PPAR gamma; D010880:Piperidines; D013141:Spiro Compounds; C000603334:(4-fluoro-3-trifluoromethylphenyl)-(8-methyl-3,8-diazaspiro(4,5)decan-3-yl)methanone; C457499:2-chloro-5-nitrobenzanilide; C577836:ABCA1 protein, human; C577833:Abca1 protein, mouse; C505693:APOA1 protein, human
Apolipoprotein (Apo) A-I; Atherosclerosis; Cholesterol efflux; PPARγ; Reverse cholesterol transport (RCT)