Yan Tang

Publications (2)6.29 Total impact

• Article: Reduction of phosphodiesterase 3B gene expression in peroxisome proliferator-activated receptor gamma (+/-) mice independent of adipocyte size.

  Takahiro Ogura, Haruhiko Osawa, Yan Tang, Hiroshi Onuma, Masaaki Ochi, Tatsuya Nishimiya, Naoto Kubota, Yasuo Terauchi, Takashi Kadowaki, Hideichi Makino
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  ABSTRACT: Phosphodiesterase 3B (PDE3B) gene expression is generally reduced in large adipocytes of obese, insulin-resistant mice. This reduced gene expression is restored by peroxisome proliferator-activated receptor (PPAR) gamma ligands accompanied by a reduced fat cell size. To determine whether PDE3B gene expression is regulated by PPAR gamma itself, we analyzed lean PPAR gamma (+/-) mice with adipocyte size comparable to control PPAR gamma (+/+) mice. In adipocytes of PPAR gamma (+/-) mice, PDE3B mRNA and protein were both reduced to 63% of wild-type levels. Basal PDE activity tended to be decreased to 70% of wild-type levels, and, similarly, insulin-induced PDE activity was significantly decreased to 70%. Thus, PPAR gamma is required for PDE3B gene expression independent of adipocyte size.
  FEBS Letters 06/2003; 542(1-3):65-8. · 3.54 Impact Factor
• Article: Differential regulation of gene expression and insulin-induced activation of phosphodiesterase 3B in adipocytes of lean insulin-resistant IRS-1 (-/-) mice.

  Masaaki Hasegawa, Yan Tang, Haruhiko Osawa, Hiroshi Onuma, Tatsuya Nishimiya, Masaaki Ochi, Yasuo Terauchi, Takashi Kadowaki, Hideichi Makino
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  ABSTRACT: Phosphodiesterase (PDE) 3B, a major isoform of PDE in adipocytes, mediates the antilipolytic action of insulin. PDE3B gene expression is generally reduced in adipocytes of either monogenic or polygenic rodent models of obese, insulin-resistance. An increased fat cell size, a common feature of obesity, could account for this reduction. Insulin receptor substrate-1 (IRS-1) (-/-) mice are lean with a reduced fat cell size and have insulin resistance due to a primary defect of insulin signaling. To determine whether the regulation of PDE3B gene expression is correlated with fat cell size, we examined this gene expression in adipose tissues of IRS-1 (-/-) mice. In IRS-1 (-/-) mice, PDE3B mRNA and protein levels were increased 1.24- and 1.35-fold those in C57BL/6J control mice, respectively. Independently, the fold induction of PDE activity by insulin (insulin-induced/basal) was 1.7-fold in control mice, but was reduced to 1.35-fold in IRS-1 (-/-) mice. Thus, PDE3B gene expression may be inversely correlated with a fat cell size, whereas insulin-induced PDE3B activation is mediated through IRS-1.
  Diabetes Research and Clinical Practice 12/2002; 58(2):79-85. · 2.75 Impact Factor