MedicalResearch.com Interview with:
Harold P. Erickson Ph.D.
James B. Duke Professor, Department of Cell Biology
Duke Univ. Med. Center Durham, NC 27710
MedicalResearch: What is the background for this study?
Dr. Erickson: In Jan 2012 a paper reported the discovery of irisin, a hormone reportedly lopped off a precursor in muscle and sent through the bloodstream to fat tissue, where it turned white fat into brown fat. Brown fat burns calories, and is what hibernating animals – and even human babies -- use to keep warm. Turning on brown fat had exciting promise for obesity, diabetes, etc. Dozens of labs around the world jumped on the discovery and started trials in animals and humans of how irisin levels in blood were altered by exercise and a variety of metabolic challenges.
MedicalResearch: What are the main findings? Early reports.
Dr. Erickson: The follow-up studies from different labs reported a huge range of values for the level of irisin in blood, so they could not all be right. And most of them failed to find any significant effect of exercise. In 2013 two papers criticized the irisin study. A commentary article by Harold Erickson (Adipocyte 2:289-93) reported two substantial flaws in the original study. A research paper by S. Raschke, J. Eckel and colleagues (PloS one 8:e73680) concluded that humans did not make significant amount of irisin. The human gene for irisin has a deleterious mutation in the start codon, and Raschke et al showed that this reduced irisin expression to only 1% the level with the normal start. These two reports may have slowed new labs entering the field, but many groups already invested continued to publish. (more…)MedicalResearch.com Interview with:
Harold P. Erickson Ph.D.
James B. Duke Professor, Department of Cell Biology
Duke Univ. Med. Center Durham, NC 27710
MedicalResearch: What is the background for this study?
Dr. Erickson: In Jan 2012 a paper reported the discovery of irisin, a hormone reportedly lopped off a precursor in muscle and sent through the bloodstream to fat tissue, where it turned white fat into brown fat. Brown fat burns calories, and is what hibernating animals – and even human babies -- use to keep warm. Turning on brown fat had exciting promise for obesity, diabetes, etc. Dozens of labs around the world jumped on the discovery and started trials in animals and humans of how irisin levels in blood were altered by exercise and a variety of metabolic challenges.
MedicalResearch: What are the main findings? Early reports.
Dr. Erickson: The follow-up studies from different labs reported a huge range of values for the level of irisin in blood, so they could not all be right. And most of them failed to find any significant effect of exercise. In 2013 two papers criticized the irisin study. A commentary article by Harold Erickson (Adipocyte 2:289-93) reported two substantial flaws in the original study. A research paper by S. Raschke, J. Eckel and colleagues (PloS one 8:e73680) concluded that humans did not make significant amount of irisin. The human gene for irisin has a deleterious mutation in the start codon, and Raschke et al showed that this reduced irisin expression to only 1% the level with the normal start. These two reports may have slowed new labs entering the field, but many groups already invested continued to publish. (more…)