Lipid Accumulation in Smooth Muscle Cells Under LDL Loading Is Independent of LDL Receptor Pathway and Enhanced by Hypoxic Conditions
2002; Lippincott Williams & Wilkins; Volume: 22; Issue: 10 Linguagem: Inglês
10.1161/01.atv.0000033834.57737.9b
ISSN1524-4636
AutoresYouichiro Wada, Akira Sugiyama, Takashi Yamamoto, Makoto Naito, Noriko Noguchi, Shinji Yokoyama, Maki Tsujita, Yoshiki Kawabe, Mika Kobayashi, Akashi Izumi, Takahide Kohro, Toshiya Tanaka, Hirokazu Taniguchi, Hidenori Koyama, Ken‐ichi Hirano, Shizuya Yamashita, Yūji Matsuzawa, Etsuo Niki, Takao Hamakubo, Tatsuhiko Kodama,
Tópico(s)Adipokines, Inflammation, and Metabolic Diseases
ResumoThe effect of a variety of hypoxic conditions on lipid accumulation in smooth muscle cells (SMCs) was studied in an arterial wall coculture and monocultivation model.Low density lipoprotein (LDL) was loaded under various levels of oxygen tension. Oil red O staining of rabbit and human SMCs revealed that lipid accumulation was greater under lower oxygen tension. Cholesterol esters were shown to accumulate in an oxygen tension-dependent manner by high-performance liquid chromatographic analysis. Autoradiograms using radiolabeled LDL indicated that LDL uptake was more pronounced under hypoxia. This result holds in the case of LDL receptor-deficient rabbit SMCs. However, cholesterol biosynthesis and cellular cholesterol release were unaffected by oxygen tension.Hypoxia significantly increases LDL uptake and enhances lipid accumulation in arterial SMCs, exclusive of LDL receptor activity. Although the molecular mechanism is not clear, the model is useful for studying lipid accumulation in arterial wall cells and the difficult-to-elucidate events in the initial stage of atherogenesis.
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