Medical Student Research Fellowship for Summer 2007

Mentor: Roger H. Unger, M.D.
Department: Internal Medicine/Touchstone Diabetes Center
Room number: L5.202
Mail Code: 8854
Phone number: 86742
E-mail: roger.unger@utsouthwestern.edu
Project title: Leptin action on adipogenesis in Pref-1 nul mice

Human subjects IRB approved project number (where applicable):

Animal subjects IRB approved project number (where applicable): 0162-06-13-1

Project Type (patient-based research, animal-based research, or basic research; this characterization is only to permit a general classification for grouping similar types of projects) animal-based research

Brief Description of Project:

The summer student will be in our lab for an estimated 9 weeks. Accordingly, we have tried to identify a research project that might possibly be completed within that time frame. The project identified will involve the injection of normal rodents with adenovirus containing the leptin cDNA. This induces intense hyperleptinemia and within 7 days all body fat disappears. In the fat-free adipose tissue we have noted a 20-fold increase in preadipocyte factor 1 (Pref-1) mRNA. Pref-1 is a marker of preadipocytes. Dr. Hei Sook Sul at Berkeley has demonstrated that cleavage of its extracellular domain releases a peptide that inhibits adipogenesis. The phenotype of the hyperleptinemic rodent is a conversion of white adipocytes into fat-free, mitochondrion-rich cells that we call "post adipocytes". The question to be addressed by the student is whether or not Pref-1 upregulation is required for white adipose tissue phenotype of hyperleptinemia, i.e. will the fat disappear and the mitochondria fill the cytoplasm in Pref-1 nul mice?

If the answer is yes, this information would be a prelude to more ambitious studies in rodents and humans designed to elucidate the relationship between Pref-1 expression and adipogenesis.