Suppression of lipin-1 expression increases monocyte chemoattractant protein-1 expression in 3T3-L1 adipocytes.
Lipin-1 plays a crucial role in the regulation of lipid metabolism and cell differentiation in adipocytes. Expression of adipose lipin-1 is reduced in obesity, and metabolic syndrome. However, the significance of this reduction remains unclear. This study investigated if and how reduced lipin-1 expression affected metabolism. We assessed mRNA expression levels of various genes related to adipocyte metabolism in lipin-1-depleted 3T3-L1 adipocytes by introducing its specific small interfering RNA. In lipin-1-depleted adipocytes, mRNA and protein expression levels of monocyte chemoattractant protein-1 (MCP-1) were significantly increased, although the other genes tested were not altered. The conditioned media from the cells promoted monocyte chemotaxis. The increase in MCP-1 expression was prevented by treatment with quinazoline or salicylate, inhibitors of nuclear factor-κB activation. Because MCP-1 is related to adipose inflammation and systemic insulin resistance, these results suggest that a reduction in adipose lipin-1 in obesity may exacerbate adipose inflammation and metabolism.
Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023, Japan. ntkhs@hoku-iryo-u.ac.jp
Nobuhiko
N
Takahashi
Takayuki
T
Yoshizaki
Natsumi
N
Hiranaka
Takeshi
T
Suzuki
Tomoo
T
Yui
Masayasu
M
Akanuma
Kazuya
K
Oka
Kaoru
K
Kanazawa
Mika
M
Yoshida
Sumiyoshi
S
Naito
Mikihiro
M
Fujiya
Yutaka
Y
Kohgo
Masahiro
M
Ieko
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000378:metabolism*; D000818:Animals; D018932:Chemokine CCL2 / Q000096:biosynthesis*; D002633:Chemotaxis; D015870:Gene Expression; D007333:Insulin Resistance; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D010711:Phosphatidate Phosphatase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis; D011799:Quinazolines / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering / Q000235:genetics; D012459:Salicylates / Q000494:pharmacology
C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; D016328:NF-kappa B; D009687:Nuclear Proteins; D011799:Quinazolines; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012459:Salicylates; C418978:Lpin1 protein, mouse; D010711:Phosphatidate Phosphatase