Tubastatin A (TBA), a selective HDAC6 inhibitor, has been reported to suppress neuroinflammation through epigenetic modulation. Vagus nerve stimulation (VNS) is also known to regulate immune responses via the activation of the cholinergic anti-inflamm...
Tubastatin A (TBA), a selective HDAC6 inhibitor, has been reported to suppress neuroinflammation through epigenetic modulation. Vagus nerve stimulation (VNS) is also known to regulate immune responses via the activation of the cholinergic anti-inflammatory pathway. However, the combined effects of TBA and VNS on the vagus nerve–spleen axis remain to be explored. This study aimed to investigate whether local HDAC6 inhibition by TBA modulates vagal signaling and whether subsequent VNS further enhances anti-inflammatory responses.
TBA (1 μL) was locally applied to the vagus nerve, and systemic inflammation was induced 24 h later by intraperitoneal injection of lipopolysaccharide (LPS). In the VNS group, identical TBA pretreatment was followed by 5 min of VNS during LPS administration. Two hours after treatment, TBA alone significantly increased GAP-43 mRNA and acetylated histone H3 (Ac-H3) expression in the vagus nerve, indicating local epigenetic modulation. In the brainstem, c-Fos expression, ERK1/2 phosphorylation, and choline acetyltransferase (ChAT) levels were elevated. In the spleen, α7 nicotinic acetylcholine receptor (α7 nAChR) mRNA expression was increased, and accompanied by reduced levels of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6.
VNS along with TBA treatment significantly enhanced Akt phosphorylation, further amplifying the anti-inflammatory response. These findings suggest that local HDAC6 inhibition by TBA modulates vagal epigenetic signaling, while VNS primarily augments both central and peripheral anti-inflammatory pathways, providing a additive effect in modulating the vagus nerve–spleen axis.
These findings suggest that local HDAC6 inhibition by TBA modulates vagal epigenetic signaling, while VNS primarily augments central and peripheral anti-inflammatory pathways along the vagus nerve–spleen axis. The combined application of TBA and VNS provides mechanistic insight into neuroimmune modulation targeting the vagus nerve.