The effect of oxidised low density lipoprotein in the regulation of inflammation

Abstract

Chronic inflammation is a process associated with the cause of many chronic human diseases. The accumulation of immune cells in the visceral compartment has been linked with systemic inflammation, in particular the development of insulin resistance and atherosclerosis.

The oxidation of low density lipoproteins is thought to play an important role in the development of foam cells linked to atherosclerosis and plays a significant immunological role in the control of many inflammatory cells.

Previous studies in animals have shown that immunisation with oxidised low density lipoproteins can reduce atherosclerosis based on protective immunological effects.

In this thesis we were able to show that oxidised low density lipoprotein isolated from both human and mice serum has anti-inflammatory effects when incubated with either TLR3 or TLR4 ligands in-vitro studies.

We also designed an in-vivo experiment where dietary-induced obese C57BL/6J mice where immunised with oxidised low density lipoprotein and were found to have reduced insulin resistance parameters based on reduced fasting glucose, fasting insulin and reduced area under the curve following insulin tolerance and intraperitoneal glucose tolerance test.

Further in-vivo studies also showed that injection with oxidised low density lipoprotein is able to reduce systemic TNF-alpha secretion when mice were stimulated by a potent TLR4 ligand like lipopolysaccharide.

The results indicate a protective effect of oxidised low density lipoproteins against inflammation and based on the in-vivo study further research is warranted on whether the use of oxidised lipoproteins could be used in the future in the protection against development of insulin resistance and atherosclerosis.