PARP-1 inhibition attenuates neuronal loss, microglia activation and neurological deficits after traumatic brain injury
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Updated: May 3, 2026
Controlled Cortical Impact Model for Traumatic Brain Injury
Published on: August 5, 2014
Bogdan A Stoica1, David J Loane, Zaorui Zhao
11 Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research (STAR), National Study Center for Trauma and EMS, University of Maryland , School of Medicine, Baltimore, Maryland.
Abstract:
Traumatic brain injury (TBI) causes neuronal cell death as well as microglial activation and related neurotoxicity that contribute to subsequent neurological dysfunction. Poly (ADP-ribose) polymerase (PARP-1) induces neuronal cell death through activation of caspase-independent mechanisms, including release of apoptosis inducing factor (AIF), and microglial activation. Administration of PJ34, a selective PARP-1 inhibitor, reduced cell death of primary cortical neurons exposed to N-Methyl-N'-Nitro-N-Nitrosoguanidine (MNNG), a potent inducer of AIF-dependent cell death. PJ34 also attenuated lipopolysaccharide and interferon-γ-induced activation of BV2 or primary microglia, limiting NF-κB activity and iNOS expression as well as decreasing generation of reactive oxygen species and TNFα. Systemic administration of PJ34 starting as late as 24 h after controlled cortical impact resulted in improved motor function recovery in mice with TBI. Stereological analysis demonstrated that PJ34 treatment reduced the lesion volume, attenuated neuronal cell loss in the cortex and thalamus, and reduced microglial activation in the TBI cortex. PJ34 treatment did not improve cognitive performance in a Morris water maze test or reduce neuronal cell loss in the hippocampus. Overall, our data indicate that PJ34 has a significant, albeit selective, neuroprotective effect after experimental TBI, and its therapeutic effect may be from multipotential actions on neuronal cell death and neuroinflammatory pathways.
Insights
The PARP-1 inhibitor PJ34 demonstrated neuroprotective effects in experimental traumatic brain injury (TBI). PJ34 reduced neuronal death and neuroinflammation, improving motor function recovery in TBI mice.
Area of Science:
- Neuroscience
- Pharmacology
- Cell Biology
Background:
- Traumatic brain injury (TBI) leads to neuronal death and neuroinflammation via microglial activation.
- Poly (ADP-ribose) polymerase-1 (PARP-1) plays a role in TBI-induced neuronal cell death and microglial activation.
Purpose of the Study:
- To investigate the neuroprotective effects of the PARP-1 inhibitor PJ34 in experimental TBI.
- To evaluate PJ34's impact on neuronal cell death, microglial activation, and functional recovery after TBI.
Main Methods:
- Primary cortical neurons and microglia (BV2) were treated with PJ34 and exposed to neurotoxic agents (MNNG, LPS/IFN-γ).
- Controlled cortical impact (CCI) model of TBI was used in mice, with PJ34 administered systemically post-injury.
- Neuroprotection was assessed by measuring cell death, inflammatory markers (NF-κB, iNOS, TNFα), lesion volume, neuronal loss, microglial activation, and motor/cognitive function.
Main Results:
- PJ34 reduced MNNG-induced neuronal cell death and attenuated microglial activation, NF-κB activity, iNOS, reactive oxygen species, and TNFα production.
- Systemic PJ34 administration post-CCI improved motor function recovery, reduced lesion volume, and decreased neuronal loss in the cortex and thalamus.
- PJ34 did not improve cognitive function in the Morris water maze or reduce hippocampal neuronal loss.
Conclusions:
- PJ34 exhibits significant, selective neuroprotective effects in experimental TBI.
- The therapeutic benefits of PJ34 stem from its actions on both neuronal cell death pathways and neuroinflammatory processes.
- PJ34 represents a potential therapeutic agent for TBI, targeting key pathological mechanisms.
