Effects of rosiglitazone on intramyocellular lipid accumulation in Psammomys obesus

Abstract

Since smaller IMCL droplets are associated with improvements in insulin sensitivity, we propose that this may be an important mechanism by which rosiglitazone affects glucose tolerance.

Not only accumulation, but also saturation status of intramuscular lipids is significantly affected by PPARγ activation

“…It is quite well established that the accumulation of intramyocellular lipids is strongly associated with highfat diet intervention, and several studies suggested that the activation of PPARc (rosiglitazone or pioglitazone) reduces this toxic accumulation of lipids in muscles (Hockings et al 2003, Jucker et al 2003, Ye et al 2004, Molero et al 2010. We found that, irrespective of diet, rosiglitazone induces fibrespecific (soleus and red gastrocnemius) accumulation of intramuscular lipids (FFA and TAG).…”

“…It is quite well established that the accumulation of intramyocellular lipids is strongly associated with highfat diet intervention, and several studies suggested that the activation of PPARc (rosiglitazone or pioglitazone) reduces this toxic accumulation of lipids in muscles (Hockings et al 2003, Jucker et al 2003, Ye et al 2004, Molero et al 2010. In the aforementioned studies, the proposed mechanism of PPARc actions appeared to be related to the sequestration of lipids away from skeletal muscle to adipose tissue with secondary decrease in serum FAs and subsequent reduction in an intramuscular lipid content (Kliewer et al 1994, Jucker et al 2003, Ye et al 2004, Molero et al 2010. However, there is an increase body of evidence showing also rosiglitazone-induced enhancement of skeletal muscles' insulin sensitivity, with no evident change in intramuscular lipid pool(s) (Mayerson et al 2002).…”

“…The principle mechanism of its action is thought to involve the activation of peroxisome proliferator-activated receptors gamma (PPARc), abundantly present in adipocytes (Kliewer et al 1994). Others reported a decrease in triacylglycerol (TAG) content after rosiglitazone treatment (Jucker et al 2003, Ye et al 2004, Molero et al 2010. rosiglitazone) on skeletal muscle lipid metabolism are still controversial.…”

“…A number of studies have found either no change (Mayerson et al 2002) or an increase in intramyocellular lipid content following rosiglitazone treatment (Muurling et al 2003, Lessard et al 2004. Others reported a decrease in triacylglycerol (TAG) content after rosiglitazone treatment (Jucker et al 2003, Ye et al 2004, Molero et al 2010. The confusing reports raise the possibility that PPARc activation results in a greater infiltration of skeletal muscles by the adipocytes, which affects total muscular lipid content, especially when assessed with biochemical approaches.…”

LipiD-QuanT: a novel method to quantify lipid accumulation in live cells

“…triggers new LD formation during adipogenesis ( 59 ). However, prolonged treatment is known to be antiobesogenic, to promote lipolysis, and to block LD fusion, resulting adipocytes containing small LDs ( 60,61 ).…”