August Krogh Seminar

White, Brown and Pink adipocytes: the extraordinary plasticity of The Adipose Organ

v/ Professor Saverio Cinti, Department of Experimental and Clinical Medicine, University of Ancona, Italy

Abstract

Most of white and brown adipocytes, in spite of their well known different functions: i.e. storing energy (white) and thermogenesis (brown), are contained together in visceral and subcutaneous depots (adipose organ) in all mammals including humans (S Cinti The Adipose Organ, Kurtis Milan 1999, A Frontini et al Cell Metab 2010).

A growing body of evidence suggests that the reason for this anatomical mixture could reside in the fact that adipocytes have peculiar plastic properties allowing them to convert directly each other under appropriate stimuli (S Cinti Am J Physiol EM 2009).

Under chronic cold exposure white convert into brown to support the need for thermogenesis and under obesogenic diet brown convert into white to satisfy the need of energy storing. Adipocyte population in the mammary gland offers another striking example of adipocyte plasticity: during pregnancy and lactation adipocytes transdifferentiate into milk-producing epithelial cells (we propose to call them: pink adipocytes) and vice versa in the post-lactation period (Morroni M et al PNAS 2004, DeMatteis R et al Stem Cells 2009).

The white into brown transdifferentiation is of great medical interest because the brown phenotype of the adipose organ is associated with obesity resistance and drugs inducing the brown phenotype curb obesity and related disorders. 

Type 2 diabetes is the most common disorder associated to visceral obesity. Macrophages infiltrating the adipose organ are thought to be responsible for the low-grade chronic inflammation dealing to insulin resistance and T2 diabetes. Macrophages form characteristic histopathologic figures we called: crown like structures (CLS) due to the need of removal debris deriving from the death of adipocytes . Death of adipocytes is tightly related to their hypertrophy up to the critical death size (Cinti S et J Lip Res 2005).

We recently showed that most hypertrophic adipocytes of genetically obese mice have ultrastructural features consistent with a stressed state. Some hypertrophic adipocytes show also degenerative signs before CLS formation. Visceral adipocytes are more stressed than subcutaneous adipocytes and have a critical death size smaller than subcutaneous adipocytes, thus offering an explaination for the higher inflammation and morbidity of visceral fat (Murano et al J Lip Res 2008).

Time

28 June 2013 13:00-14:30

Venue

Auditorium 1, August Krogh Building, Universitetsparken 13, DK-2100 Copenhagen

Registration

Participation is free, but please register here.

For PhD students

PhD students participating in August Krogh seminars receive 0,2 ECTS per seminar

Contact

Christian Frøsig, CFrosig@ifi.ku.dk, mobile +45 2875 1617 

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