10779/rcsi.10793960.v1
C Greene
C
Greene
J Kealy
J
Kealy
M M. Humphries
M M.
Humphries
Y Gong
Y
Gong
J Hou
J
Hou
N Hudson
N
Hudson
L M. Cassidy
L M.
Cassidy
R Martiniano
R
Martiniano
V Shashi
V
Shashi
S R. Hooper
S R.
Hooper
G A. Grant
G A.
Grant
P F. Kenna
P F.
Kenna
K Norris
K
Norris
C K. Callaghan
C K.
Callaghan
M D. Islam
M D.
Islam
S M. O'Mara
S M.
O'Mara
Z Najda
Z
Najda
S G. Campbell
S G.
Campbell
J S. Pachter
J S.
Pachter
J Thomas
J
Thomas
N M. Williams
N M.
Williams
P Humphries
P
Humphries
Kieran C. Murphy
Kieran C.
Murphy
M Campbell
M
Campbell
Dose-dependent expression of claudin-5 is a modifying factor in schizophrenia.
Royal College of Surgeons in Ireland
2019
IR content
Psychiatry (incl. Psychotherapy)
2019-11-22 17:07:33
Journal contribution
https://repository.rcsi.com/articles/journal_contribution/Dose-dependent_expression_of_claudin-5_is_a_modifying_factor_in_schizophrenia_/10793960
<p>Schizophrenia is a neurodevelopmental disorder that affects up to 1% of the general population. Various genes show associations with schizophrenia and a very weak nominal association with the tight junction protein, claudin-5, has previously been identified. Claudin-5 is expressed in endothelial cells forming part of the blood-brain barrier (BBB). Furthermore, schizophrenia occurs in 30% of individuals with 22q11 deletion syndrome (22q11DS), a population who are haploinsufficient for the claudin-5 gene. Here, we show that a variant in the claudin-5 gene is weakly associated with schizophrenia in 22q11DS, leading to 75% less claudin-5 being expressed in endothelial cells. We also show that targeted adeno-associated virus-mediated suppression of claudin-5 in the mouse brain results in localized BBB disruption and behavioural changes. Using an inducible 'knockdown' mouse model, we further link claudin-5 suppression with psychosis through a distinct behavioural phenotype showing impairments in learning and memory, anxiety-like behaviour and sensorimotor gating. In addition, these animals develop seizures and die after 3-4 weeks of claudin-5 suppression, reinforcing the crucial role of claudin-5 in normal neurological function. Finally, we show that anti-psychotic medications dose-dependently increase claudin-5 expression in vitro and in vivo while aberrant, discontinuous expression of claudin-5 in the brains of schizophrenic patients post mortem was observed compared to age-matched controls. Together, these data suggest that BBB disruption may be a modifying factor in the development of schizophrenia and that drugs directly targeting the BBB may offer new therapeutic opportunities for treating this disorder.Molecular Psychiatry advance online publication, 10 October 2017; doi:10.1038/mp.2017.156.</p>