|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Pediatrics, Columbia University, NY, NY, USA
2 New York Obesity Research Center, St Luke's-Roosevelt Hospital, New York, NY, USA
3 Department of Biomedical Engineering, Columbia University, New York, NY, USA
* To whom correspondence should be addressed. E-mail: sc569{at}columbia.edu.
We have generated mice that are homozygous for a leptin receptor transgene that is expressed exclusively in neurons (NSE-LEPR-B). We had previously shown that this transgene in the hemizygous state is effective in ameliorating almost all aspects of leptin receptor deficiency. Now, in the homozygous state, we show that the transgene almost fully corrects the excess adiposity of LEPR-deficient (db/db) mice. Body composition analyses indicate that the transgene is able to restrain the massive increase in adiposity observed in LEPR-deficient mice. Examination of hypothalamic AGRP and POMC mRNA shows normalization of these leptin-regulated transcripts. Interestingly, despite normalization of circulating leptin concentrations by the transgene in the fed state, transgenic db3J/db mice did not show fasting-induced reductions of circulating leptin. Increased adiposity of the transgenic db/db mice at 4 weeks of age, immediately post-weaning, suggests the transgene is less effective in correcting the preferential fat deposition caused by LEPR deficiency. We noted that the morphology of brown adipose tissue is nearly normal, concordant with the cold tolerance conferred by the transgene. Aspects of the diabetes phenotype are also corrected: glucose and insulin concentrations are nearly normal; and islet hyperplasia is greatly diminished. The transgene also corrects the infertility of db/db females and confers the ability to lactate sufficiently to nurse normal sized litters. Finally, the slightly increased adiposity and mild insulin resistance of transgenic db/db dams was not a contributory factor to the increased fat content of transgenic db/db male progeny.
This article has been cited by other articles:
![]() |
Genetically Modified Animals in Endocrinology Endocr. Rev., June 1, 2004; 25(3): 512 - 519. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |