Animal Models as Tools for Translational Research: Focus on Atherosclerosis, Metabolic Syndrome and Type-II Diabetes Mellitus

Animal models in burn research

“…Small animals like the mouse and rat are generally not ideal models of metabolism research in burns since their metabolic profile is significantly different from that of humans. For instance, rodents typically have low levels of total cholesterol (TC) and density lipoprotein-cholesterol (LDL-C) but high levels of high density lipoprotein-cholesterol HDL-C, whereas the reverse is true for humans [53],[54]. Rodents lack the plasma cholesteryl ester transfer protein (CETP) which causes the contrasting cholesterol profile and, therefore, about 70% of the plasma TC is found in HDL particles [53].…”

“…For instance, rodents typically have low levels of total cholesterol (TC) and density lipoprotein-cholesterol (LDL-C) but high levels of high density lipoprotein-cholesterol HDL-C, whereas the reverse is true for humans [53],[54]. Rodents lack the plasma cholesteryl ester transfer protein (CETP) which causes the contrasting cholesterol profile and, therefore, about 70% of the plasma TC is found in HDL particles [53]. The ability of rodents to maintain their cholesterol profile when challenged with high fat diet presents major problems in conducting research to uncover the mechanisms behind impaired insulin secretion and impaired insulin action, which is a phenotype of the hypermetabolic response post-burn.…”

“…The ability of rodents to maintain their cholesterol profile when challenged with high fat diet presents major problems in conducting research to uncover the mechanisms behind impaired insulin secretion and impaired insulin action, which is a phenotype of the hypermetabolic response post-burn. In fact, when these small animal models are artificially pushed to develop a diabetic phenotype with its associated hyperlipidemia, they still fail to display the same islet pathology as humans with type 2 diabetes (T2D) [53]. In this context, researchers working with mice have turned to populating human hepatocytes in mice to study human liver mediated metabolism [55].…”

“…In fact, studies have shown that larger animals inflicted with a 25% TBSA burn generates a hypermetabolic response greater than smaller animals and closer to that seen in human patients [57],[58]. These larger animals also serve as attractive biomedical models for studying energy metabolism because they are devoid of brown fat like humans [53],[58]. This is an important consideration because brown fat has the ability to regulate energy balance and other aspects of energy homeostasis.…”

“…Porcine models have been useful in this regard, as it has been shown that they also present with similar phenotypic alterations such as hypertrophic adipocytes and fat deposit in the liver post burns [60]. Moreover, researchers have turned to larger animals because proportionally these larger animals have similar organ sizes to humans [53]. This is critical as the larger size can allow multiple assays to be carried out in adipose and muscle tissue without pooling multiple animal samples together [53],[57].…”