Influence of Hyaluronidase-1 deficiency in a diet-induced insulin resistance model

: assessment of HA accumulation in muscle and adipose tissue by gender

Abstract

Obesity and metabolic syndrome are both worldwide diseases. Individuals suffering from metabolic syndrome present a high risk to develop either type 2 diabetes or cardiovascular disease. The insulin resistance and a pro-inflammatory state characterize this syndrome. In this master thesis, the influence of the Hyaluronidase-1 (HYAL1) deficiency on glucose tolerance after induction of metabolic syndrome in both male and female mice was assessed. In this condition, male obese KO mice present an exacerbated insulin resistance, an increased HA accumulation in muscle and in white adipose tissue as well as an increased adipocyte size compared to obese WT mice. This suggest HYAl1 play a role in insulin resistance and the development of metabolic syndrome, via HA metabolism. Then, the evalutation of the inflammation in the adipose tissue show an increased expression of IL-6 in male KO mice. Those results confirm the link with the development of the insulin resistance in KO HFD mice. In the female mice, the development of insulin resistance cannot be observed during the tolerance test. This can be explained by similar results obtained in the quantification of HA in muscle and serum, quantification of CD44 in both muscle and adipose tissue and finally, by no changes in the expression of pro- and anti-inflammatory cytokines (IL-6; TNF-α and adiponectin). However, differences were observed in the quantity of HA present in the adipose tissue, as well as, in the size of the adipocyte. Indeed, the size of the adipocyte increase during the development of the MetS as observed in the male mice. Finally, the comparison between the male and the female highlight: more HA accumulation in muscle, bigger adipocytes and higher expression of IL-6 in male mice compared to female mice.

Date of Award	16 Jan 2020
Original language	English
Awarding Institution	University of Namur
Supervisor	Nathalie Caron (Supervisor) & Sophie Dogne (Co-Supervisor)