Adiponectin and Skeletal Muscle

Abstract

Upregulation of muscular adiponectin could act as a local protective mechanism to counteract cellular damage in obesity by weakening inflammation, oxidative stress, and apoptosis. To test this hypothesis, adiponectin-knockout (KO) and wild-type (WT) mice were fed a Western diet (WD). WT mice under WD conditions displayed 63% higher adiponectin expression in myocytes than those under standard laboratory diet (SLD) conditions (P = 0.011). WD-fed KO mice exhibited approximately threefold larger myocyte degeneration than WT mice (P = 0.003). Even under SLD conditions, myotubes of KO mice displayed already moderate immunolabeling for markers of oxidative stress (peroxiredoxin-3/5) and for a lipid peroxidation product (hydroxynonenal). Expression of tumor necrosis factor-α (TNF-α) and caspase-6, a marker of apoptosis, was also present. After WD challenge, immunoreactivity for these markers was strong in muscle of KO mice, although it was detected to a lesser extent in WT mice. Activation of NF-κB and caspase-6 doubled in myocytes of WD-fed KO mice when compared to WT mice (P < 0.001). Furthermore, muscle electrotransfer of the adiponectin gene prevented these abnormalities in WD-fed KO mice. Finally, gene abrogation of the adiponectin receptor 1 (AdipoR1) by siRNA recapitulated a pro-inflammatory state in C2C12 myotubes. Thus, upregulation of muscular adiponectin may be triggered by obesity and be crucial locally to counteract oxidative stress, inflammation, and apoptosis. These effects operate in an autocrine/paracrine manner via AdipoR1 and down-regulation of NF-κB signaling.

Estradiol stimulates mitochondrial biogenesis and adiponectin expression in skeletal muscle

“…As AdipoR1 has been reported to mediate the autocrine effects of adiponectin (Jortay et al 2012, Patel et al 2012, our results indicate a role of E 2 in the enhancement of not only skeletal muscle adiponectin production but also of its local action. Moreover, the E 2 -mediated increase in Sirt1 expression at the mRNA level further supports the idea that this hormone could play a role in the stimulation of adiponectin signaling in skeletal muscle, given that Sirt1 is a downstream effector of the adiponectin signaling pathway that promotes PGC1a activation (Iwabu et al 2010), which induces an improvement in mitochondrial function and biogenesis.…”

Skeletal muscle secretome in Duchenne muscular dystrophy: a pivotal anti-inflammatory role of adiponectin

“…We have previously shown that in an environment of acute or chronic inflammation, ApN was overproduced in vivo by the “normal” mouse skeletal muscle to locally counteract excessive and deleterious inflammatory reactions [29, 30]. By contrast, the skeletal muscle of mdx mice was unable to overproduce local ApN {[18], data not shown}.…”

Adipose tissue lipolysis and remodeling during the transition period of dairy cows

“…Adiponectin, also known as ACRP30, is secreted primarily by adipocytes, but is also expressed by cardiomyocytes and skeletal muscle [50]. Adiponectin improves insulin sensitivity and lipogenesis in adipocytes, and FA β-oxidation in myocytes and hepatocytes [9].…”