The
pathogenesis of neurosyphilis remains unclear. A previous study
found a noteworthy up-regulation of a disintegrin and metalloproteinase
with thrombospondin type 1 motif 5 (ADAMTS5) gene in human brain
microvascular endothelial cells cocultured with Treponema
pallidum subspecies pallidum (Tp).
To investigate the ADAMTS5 role in Tp invading the central nervous
system (CNS), we conducted relevant experiments. Our study revealed
that Tp caused an increase in human cortical microvascular endothelial
cell/D3 (hCMEC/D3) barrier permeability and significantly enhanced
ADAMTS5 expression. The heightened permeability of the hCMEC/D3 barrier
was effectively mitigated by inhibiting ADAMTS5. During this process,
Tp promoted interleukin-1β production, which, in turn, facilitated
ADAMTS5 expression. Furthermore, Tp significantly reduced the glycocalyx
on the surface of hCMEC/D3 cells, which was also ameliorated by inhibiting
ADAMTS5. Additionally, ADAMTS5 and endothelial glycocalyx components
notably increased in the cerebrospinal fluid of HIV-negative neurosyphilis
patients. This research provided the first demonstration of the ADAMTS5
role in Tp invading the CNS and offered new insight into neurosyphilis
pathogenesis.