Tetradecylthioacetic acid attenuates dyslipidaemia in male patients with type 2 diabetes mellitus, possibly by dual PPAR-alpha/delta activation and increased mitochondrial fatty acid oxidation.
OBJECTIVE
We previously demonstrated that a modified fatty acid, tetradecylthioacetic acid (TTA), improves transport and utilization of lipids and increases mitochondrial fatty acid oxidation in animal and cell studies. We conducted an exploratory study of safety and effects of this novel drug in patients with type 2 diabetes mellitus and investigated the mechanism of action in human cell lines.


METHODS
Sixteen male patients with type 2 diabetes mellitus received 1 g TTA daily for 28 days in an open-labelled study, with measurement of parameters of lipid metabolism, glucose metabolism and safety (ClinicalTrials.gov NCT00605787). The mechanism of action was further investigated in a human liver cell line (HepG2) and in cultured human skeletal muscle cells (myotubes).


RESULTS
Mean LDL cholesterol level declined from 4.2 to 3.7 mmol/l (p < 0.001), accompanied by increased levels of the HDL apolipoproteins A1 and A2, and a decline in LDL/HDL ratio from 4.00 to 3.66 (p = 0.008). Total fatty acid levels declined, especially the fraction of the polyunsaturated n-3 fatty acids docosahexaenoic acid (-13%, p = 0.002) and eicosapentaenoic acid (-10%, p = 0.07). Glucose metabolism was not altered and the drug was well tolerated. In cultured liver cells, TTA acted as a pan-PPAR agonist with predominant PPAR-alpha and PPAR-delta activation at low TTA concentrations. In myotubes, TTA and a PPAR-delta agonist, but not the PPAR-alpha or PPAR-gamma agonists, increased the fatty acid oxidation.


CONCLUSIONS
We demonstrate for the first time that TTA attenuates dyslipidaemia in patients with type 2 diabetes mellitus. These effects may occur through mechanisms involving PPAR-alpha and PPAR-delta activation, resulting in increased mitochondrial fatty acid oxidation.
Løvås
K
K
Institute of Medicine, University of Bergen, Bergen, Norway. kristian.lovas@helse-bergen.no
Røst
T H
TH
Skorve
J
J
Ulvik
R J
RJ
Gudbrandsen
O A
OA
Bohov
P
P
Wensaas
A J
AJ
Rustan
A C
AC
Berge
R K
RK
Husebye
E S
ES
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002478:Cells, Cultured; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D050171:Dyslipidemias / Q000097:blood / Q000188:drug therapy*; D005227:Fatty Acids / Q000097:blood; D006801:Humans; D000960:Hypolipidemic Agents / Q000627:therapeutic use*; D050356:Lipid Metabolism / Q000187:drug effects; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism; D047493:PPAR alpha / Q000819:agonists / Q000378:metabolism; D047494:PPAR delta / Q000819:agonists / Q000378:metabolism; D013440:Sulfides / Q000627:therapeutic use*; D014407:Tumor Cells, Cultured
D001786:Blood Glucose; D005227:Fatty Acids; D000960:Hypolipidemic Agents; D008055:Lipids; D008074:Lipoproteins; D047493:PPAR alpha; D047494:PPAR delta; D013440:Sulfides; C062078:1-(carboxymethylthio)tetradecane