Maternal obesity accelerates fetal pancreatic beta-cell but not alpha-cell development in sheep: prenatal consequences. Stephen P Ford, Liren Zhang, Meijun Zhu, Myrna M Miller, Derek T Smith, Bret W Hess, Gary E Moss, Peter W Nathanielsz, Mark J Nijland, Stephen P Ford, Liren Zhang, Meijun Zhu, Myrna M Miller, Derek T Smith, Bret W Hess, Gary E Moss, Peter W Nathanielsz, Mark J Nijland, Stephen P Ford, Liren Zhang, Meijun Zhu, Myrna M Miller, Derek T Smith, Bret W Hess, Gary E Moss, Peter W Nathanielsz, Mark J Nijland American journal of physiology. Regulatory, integrative and comparative physiology
297
R835-43
2009
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Maternal obesity affects offspring weight, body composition, and organ function, increasing diabetes and metabolic syndrome risk. We determined effects of maternal obesity and a high-energy diet on fetal pancreatic development. Sixty days prior to breeding, ewes were assigned to control [100% of National Research Council (NRC) recommendations] or obesogenic (OB; 150% NRC) diets. At 75 days gestation, OB ewes exhibited elevated insulin-to-glucose ratios at rest and during a glucose tolerance test, demonstrating insulin resistance compared with control ewes. In fetal studies, ewes ate their respective diets from 60 days before to 75 days after conception when animals were euthanized under general anesthesia. OB and control ewes increased in body weight by approximately 43% and approximately 6%, respectively, from diet initiation until necropsy. Although all organs were heavier in fetuses from OB ewes, only pancreatic weight increased as a percentage of fetal weight. Blood glucose, insulin, and cortisol were elevated in OB ewes and fetuses on day 75. Insulin-positive cells per unit pancreatic area were 50% greater in fetuses from OB ewes as a result of increased beta-cell mitoses rather than decreased programmed cell death. Lambs of OB ewes were born earlier but weighed the same as control lambs; however, their crown-to-rump length was reduced, and their fat mass was increased. We conclude that increased systemic insulin in fetuses from OB ewes results from increased glucose exposure and/or cortisol-induced accelerated fetal beta-cell maturation and may contribute to premature beta-cell function loss and predisposition to obesity and metabolic disease in offspring. Article en texte intégral | 19605766
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Biochemical and morphological detection of inclusion bodies in autophagy-deficient mice. Satoshi Waguri,Masaaki Komatsu Methods in enzymology
453
2009
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Autophagy-deficient mice exhibit the formation of ubiquitin-inclusions in the liver and brain, which is not attributed to the dysfunction of the ubiquitin-proteasome system. Moreover, it is also clear that a multifunctional protein p62/A170/SQSTM1 (hereafter referred to as p62) links autophagy and inclusion formation, being one of the key components of the ubiquitin inclusions. The ubiquitin/p62 inclusions can be detected in the detergent-insoluble fraction by western blot analysis, while morphological information can be obtained by immunohistochemistry at both the light and electron microscopy levels. Importantly, p62 has become a reliable marker, with which we can identify inclusions and estimate autophagic activity in diseased tissues or cells. In this chapter, we describe the methods used for biochemical and morphological detection of ubiquitin/p62-inclusions in autophagy-suppressed Atg7-deficient mice. These methods are suitable for examination of cells and tissues with conditions associated with reduced autophagy (e.g., aging and mice models of intractable diseases such as Alzheimer's disease), and their applications should enhance our understanding of the pathophysiological mechanisms involved in the formation of intracellular inclusions. | 19216907
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