Genome-wide expression analysis of cells expressing gain of function mutant D374Y-PCSK9.
Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key regulator of serum cholesterol. The possibility that PCSK9 also functions in other pathways needs to be addressed. We have transfected HepG2 cells with mutant D374Y-PCSK9 or control vector. Gene expression signatures were determined using the Affymetrix GeneChip technology, and the expression pattern of selected genes was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR). Data was normalized and analyzed using a model-based background adjustment for oligonucleotide expression arrays, then filtered based upon expression within treatments group, and subjected to moderated t-statistics. Five hundred twenty transcripts had altered expression levels between D374Y-PCSK9 and control vector. Among the 520 probes on our top list, 312 were found to have an assigned Gene Ontology (GO) term, and 96 were found in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Genome-wide expression profiling revealed that "steroid biosynthesis," "sterol metabolism," and "cholesterol biosynthsis" were affected by D374Y-PCSK9. Also, the GO biological process terms "response to stresss," "response to virus," "response to unfolded protein," and "immune response" were influenced by D374Y-PCSK9. Our results suggest that D374Y-PCSK9 results in up-regulation of genes involved in sterol biosynthesis and down-regulation of stress-response genes and specific inflammation pathways.
Department of Medical Genetics, Rikshospitalet University Hospital, Oslo, Norway. trine.ranheim@rikshospitalet.no
Trine
T
Ranheim
Morten
M
Mattingsdal
Jessica M
JM
Lindvall
Oystein L
OL
Holla
Knut Erik
KE
Berge
Mari Ann
MA
Kulseth
Trond P
TP
Leren
D045744:Cell Line, Tumor; D018946:Chemokine CCL5 / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D006801:Humans; D007249:Inflammation / Q000235:genetics; D016209:Interleukin-8 / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics; D008099:Liver / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D020411:Oligonucleotide Array Sequence Analysis; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics; D014162:Transfection
C483024:CCL5 protein, human; C508606:CXCL8 protein, human; D018946:Chemokine CCL5; D017077:Culture Media, Conditioned; D016209:Interleukin-8; D012333:RNA, Messenger; C472125:PCSK9 protein, human; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases; D012697:Serine Endopeptidases