Abstract
Pannexin 1 (Panx1) forms ATP-permeable membrane channels that play
essential roles in purinergic signaling in the nervous system. Several
studies suggest a link between Panx1-based channels activity and
neurodegenerative disorders including Parkinson’s disease (PD), but
experimental evidence is limited. Here, we applied behavioral and
molecular screening of zebrafish larvae to examine the role of Panx1 in
both pathological and normal conditions, using electrical stimulation in
a microfluidic chip and RT-qPCR. A zebrafish model of PD was produced by
exposing wildtype (panx1a+/+ ) and Panx1a knock
out (panx1a-/- ) zebrafish larvae to 250µM
6-hydroxydopamine (6-OHDA). After 72hrs treatment with 6-OHDA a reduced
electric-induced locomotor activity was observed in 5 days post
fertilization (dpf) panx1a+/+ larvae. The 5dpfpanx1a-/- larvae were not different from
affected. The RT-qPCR data showed a reduction in tyrosine hydroxylase
(TH) expression level in both panx1a+/+ andpanx1a-/- groups. However, TH expression of
6-OHDA exposed panx1a-/- larvae was not
decreased when compared to untreated mutants. Extending 6-OHDA treatment
duration to 120hrs caused a significant reduction in the locomotor
response of 7dpf panx1a-/- larvae when compared
to the untreated panx1a-/- group. The RT-qPCR
data also confirmed a significant decrease in TH expression levels after
120hrs treatments with 6-OHDA for both genotypes. Our results suggest
that the absence of Panx1a channels compromised dopaminergic signaling
in 6-OHDA-treated zebrafish larvae. We here propose that zebrafish
Panx1a models offer great opportunities to shed light on the
physiological and molecular basis of PD. Panx1a might play a preventive
role on the progression of PD, and therefore deserves further
investigation.
Keywords: Microfluidics; Zebrafish; Panx1a knockout;
Parkinson’s disease model; Electric-induced response; RT-qPCR