Toll-like 4 and protease-activated receptor 2 in physiology and pathophysiology of the nervous system: more than just receptor cooperation?

Widera, D. ORCID: https://orcid.org/0000-0003-1686-130X, Martinez-Aguilar, R. and Cottrell, G. ORCID: https://orcid.org/0000-0001-9098-7627 (2019) Toll-like 4 and protease-activated receptor 2 in physiology and pathophysiology of the nervous system: more than just receptor cooperation? Neural Regeneration Research, 14 (7). pp. 1196-1201. ISSN 1673-5374 doi: 10.4103/1673-5374.251290

Abstract/Summary

Toll-like receptor 4 (TLR4) and protease-activated receptor 2 (PAR2) play pivotal roles in the mammalian innate immune response. Notably, in addition to their involvement in detection of invading pathogens, PAR2 and TLR4 modulate the levels of cell death-induced sterile inflammation by activating pro- or anti-inflammatory downstream signalling cascades. Within the central nervous system, there is emerging evidence that both receptors are involved in synaptic transmission and brain plasticity. Furthermore, due to their prominent role in mediating neuroinflammation, PAR2 and TLR4 are associated with development and progression of neurodegenerative disorders including but not limited to Alzheimer`s disease (AD), Parkinson`s disease (PD) and Multiple Sclerosis. In this article, we summarise the current knowledge on the cooperation between PAR2 and TLR4, discuss the potential cross-talk levels and highlight the impact of the cross-coupling on neuroinflammation.