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THE MISSION
The mission of the Division of Experimental Obesity is to enhance understanding of the causes and consequences of obesity; and to use this understanding to promote new approaches to the treatment and prevention of obesity.
Obesity is most simply defined as accumulation of excess adipose tissue and the condition develops when energy intake chronically exceeds energy expenditure. A highly integrated set of regulatory systems function to maintain energy balance by continuously modifying energy intake and expenditure. Dysregulation of this homeostatic network compromises its ability to match energy intake and expenditure, setting up conditions which over time lead to excess accumulation of adipose tissue. The faculty of the Experimental Obesity Division are devoted to understanding the regulatory systems and communication networks which control energy balance. |
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A second unifying theme within our division is the extensive use of genetically modified animal models as in vivo approachs to explore how specific genes affect energy balance. These models include targeted gene disruption, transgenic overexpression, and naturally occurring mutations of specific genes. The common goal of these studies is to expand our understanding of how specific genes function to modify energy intake and/or expenditure. The reverse approach is also used in genetic mapping studies, where strain variation in specific components of energy balance are used to identify the genetic basis for phenotypic differences. A common feature of these studies is the extensive use of metabolic phenotyping to obtain longitudinal, noninvasive measures of energy expenditure, respiratory quotient, locomotor activity, and body composition. The Pennington Center has created and maintains state of the art metabolic phenotyping facilities within the Department of Comparative Biology. Expertise in applying this technology to gain fundamental insights into the role of specific genes in energy balance represents a collective strength of the Experimental Obesity Division. During the last year, the Division committed additional resources to improve our systems used to monitor food intake and expand our ability to use miniaturized implantable telemetry probes to measure heat production from specific organs. These investments have enhanced the ability of faculty within the Experimental Obesity Division to better understand how specific components of energy balance are being affected in the animal models that are central to the work in which we are engaged.
FACULTY
The creation of the Nutrition and the Brain division in 2005 at the Pennington Center involved redistribution of several faculty from Experimental Obesity into this new division. Given the multidisciplinary nature of work on obesity and energy balance, this redistribution has been beneficial in the sense that it has increased collaborative studies using complementary expertise found within each division. This has led to significant cross fertilization between the divisions with respect to ideas, experimental approaches, and technology. An important example is the expansion of imaging based approaches to study signaling events in cultured cells in real time. The value of these approaches has been embraced more broadly with the commitment of institutional resources, and coupled with support from our Center Grants (COBRE & CNRU), led to establishment of the Cell Biology & Bioimaging Core Facility. Key to establishment of this new Core was the recruitment of Dr. David Burk, an expert in confocal microscopy, to become the first Director of this facility. This valuable new facility is the product of collaborative thinking and a nimble institutional response to the powerful experimental approaches provided through application of this emerging technology. With the recruitment of Drs. Tom Burris and Vishwa Dixit to the Pennington Center this year, we have also expanded the Division’s perspective and technical repertoire to include studies of nuclear receptor signaling and the links between energy balance and immunology. Dr. Burris is a recognized leader in nuclear receptor signaling, and given the key role of nuclear receptors in adipocyte differentiation and development, his addition will provide important new expertise in this area. And Dr. Dixit’s important observations concerning the role of ectopic fat deposition to function of the thymus provide a novel perspective on the implications of adipogenesis to thymic involution. A significant shared need for several Pennington Divisions is the recruitment of additional expertise in the area of mitochondrial biology. This need was also identified as a priority in our recent center-wide strategic planning process. Recruitment of a cell biologist specializing in mitochondrial function is a priority for our Division in the coming year.
RESOURCES AND SUPPORT
The 16 faculty within the Experimental Obesity Division are supported by 34 extramural grants from NIH, USDA, and ADA, one training grant and three center grants from NIH. Junior faculty who obtained their initial independent funding in recent years will soon need to submit applications for continuation of funding. Our more senior faculty face similar challenges and are also working to develop new funding. An important divisional goal in the next 2 years is to maintain and expand extramural support for our work. To meet this goal in the present funding climate, we have contracted with Dr. Israel Goldberg of Health Research Associates to provide intensive one on one grantsmanship support to divisional faculty. In the last NIH review cycle, 3 division faculty received high priority scores that should translate into 3 new grants within the division. During the last year, the Pennington Center was also awarded a NIH Center of Biomedical Research Excellence (COBRE) grant entitled, “Mentoring Obesity & Diabetes Research in Louisiana”. This new funding provides support to enhance research infrastructure at the Pennington Center and support 4 junior investigators making the transition to independent funding. The COBRE award complements the contributions of the CNRU and Botanicals Center to Pennington’s core facilities by providing support to establish the Cell Biology and Bioimaging Core and expand the capabilities of the Genomics Core Facility. The additional resources from the CNRU to support the Transgenic Core will improve the ability of Divisional faculty to develop new genetically modified animal models and test hypotheses concerning the in vivo function of their genes of interest.
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