Comparative effects of diet on inflammatory responses of subcutaneous and visceral adipose tissue and liver in ponies and horses

• Applicant: Privatdozentin Dr. Ingrid Vervuert
• Subject Area: Animal Breeding, Animal Nutrition, Animal Husbandry
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 267411511

Obesity is a common problem in horses and ponies, especially in the so-called easy keepers. In that context, pony breeds seemed to be more predisposed to become insulin resistant and to develop laminitis than horse breeds. The difference in susceptibility to become insulin resistant is still unclear between ponies and horses; therefore the project proposal is focused on supposed underlying mechanisms. In humans, different mechanisms have been proposed by which obesity may contribute to insulin resistance. For example, recent data suggest that white adipocytes and infiltrated macrophages in the visceral adipose tissue are a source of inflammatory cytokines such as TNF-alpha, interleukin-6 (IL-6), or interleukin-1beta (IL-1beta) which may directly or indirectly interfere with insulin signaling. However in ponies and horses, it is hypothesized that the visceral fat and the subcutaneous fat depots may contribute to inflammatory state. However, the role of the liver as a source of inflammatory cytokines has not been investigated in ponies and horses. Therefore, the project proposal is focused on different adipose tissues and for the first time, the role of liver will be included in an obesity model in ponies and horses. The main objective of this study is to compare the consequences of a two-years lasting excessive energy intake on insulin sensitivity as well as on macrophage invasion and on adipose and liver tissue cytokine expression between ponies and horses. In the present study we will use the lipopolysaccharide stimulus to investigate the inflammatory responses in adipose tissues and liver in the different metabolic states - non-obese or obese - in ponies and horses.

• DFG Programme: Research Grants