Differential gene expression in adipose tissue from obese human subjects during weight loss and weight maintenance.
BACKGROUND
Differential gene expression in adipose tissue during diet-induced weight loss followed by a weight stability period is poorly characterized. Markers of these processes may provide a deeper understanding of underlying mechanisms.


OBJECTIVE
We aimed to identify differentially expressed genes in human adipose tissue during weight loss and weight maintenance after weight loss.


METHODS
RNA from subcutaneous abdominal adipose tissue from 9 obese subjects was analyzed by using a complementary DNA microarray at baseline after weight loss on a low-calorie diet and after weight maintenance.


RESULTS
Subjects lost 18.8 ± 1.8% of weight and maintained this loss during weight maintenance (1.1 ± 2.1%; range: -9.3 to 10.6%). Most differentially expressed genes exhibited a reciprocal regulation and returned to baseline after weight loss (2163 genes) and weight maintenance (3175 genes). CETP and ABCG1, both of which participate in the HDL-mediated reverse cholesterol transport (RCT), were among the most upregulated of the 750 genes that were differentially expressed after both processes. Several genes involved in inflammation were downregulated. The use of real-time polymerase chain reaction confirmed or partially confirmed the previously implicated genes TNMD and MMP9 (both downregulated), PNPLA3 (upregulated), and CIDEA and SCD (both reciprocally regulated).


CONCLUSIONS
The beneficial effects of weight loss should be investigated after long-term weight maintenance. The processes of weight loss and weight maintenance should be viewed as biologically distinct. CETP and ABCG1 may be important mediators of these effects through HDL-mediated RCT.
Department of Clinical Sciences Malmö, Clinical Obesity, Lund University Diabetes Centre, Lund University, Malmö, Sweden.
Lovisa E
LE
Johansson
Anders P H
AP
Danielsson
Hemang
H
Parikh
Maria
M
Klintenberg
Fredrik
F
Norström
Leif
L
Groop
Martin
M
Ridderstråle
D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D015992:Body Mass Index; D053480:Cholesterol Ester Transfer Proteins / Q000235:genetics / Q000378:metabolism; D004038:Diet, Reducing; D005260:Female; D005500:Follow-Up Studies; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D009765:Obesity / Q000178:diet therapy / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000378:metabolism; D055502:Secondary Prevention; D050507:Subcutaneous Fat, Abdominal / Q000378:metabolism* / Q000473:pathology; D015431:Weight Loss
C419353:ABCG1 protein, human; D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D018528:ATP-Binding Cassette Transporters; D015415:Biomarkers; C506642:CETP protein, human; D053480:Cholesterol Ester Transfer Proteins; D012333:RNA, Messenger