Inhibition of poly(ADP-ribose) polymerase-1 attenuates the toxicity of carbon tetrachloride

Oxidative DNA Damage-induced PARP-1-mediated Autophagic Flux Disruption Contributes to Bupivacaine-induced Neurotoxicity During Pregnancy

OBJECTIVE

Severe neurologic complications after spinal anesthesia are rare but highly distressing, especially in pregnant women. Bupivacaine is widely used in spinal anesthesia, but its neurotoxic effects have gained attention.

METHODS

Furthermore, the etiology of bupivacaine-mediated neurotoxicity in obstetric patients remains unclear. Female C57BL/6 mice were intrathecally injected with 0.75% bupivacaine on the 18th day of pregnancy. We used immunohistochemistry to examine DNA damage after bupivacaine treatment in pregnant mice and measured γ-H2AX (Ser139) and 8-OHdG in the spinal cord. A PARP-1 inhibitor (PJ34) and autophagy inhibitor (3-MA) were administered with bupivacaine in pregnant mice. Parp-1flox/flox mice were crossed with Nes-Cre transgenic mice to obtain neuronal conditional knockdown mice. Then, LC3B and P62 staining were performed to evaluate autophagic flux in the spinal cords of pregnant wild-type (WT) and Parp-1-/- mice. We performed transmission electron microscopy (TEM) to evaluate autophagosomes.

RESULTS

The present study showed that oxidative stress-mediated DNA damage and neuronal injury were increased after bupivacaine treatment in the spinal cords of pregnant mice. Moreover, PARP-1 was significantly activated, and autophagic flux was disrupted. Further studies revealed that PARP-1 knockdown and autophagy inhibitors could alleviate bupivacaine-mediated neurotoxicity in pregnant mice.

CONCLUSION

Bupivacaine may cause neuronal DNA damage and PARP-1 activation in pregnant mice. PARP-1 further obstructed autophagic flux and ultimately led to neurotoxicity.

Discovery of 7-aminophenanthridin-6-one as a new scaffold for matrix metalloproteinase inhibitors with multitarget neuroprotective activity

Matrix metalloproteinases (MMPs) are zinc-dependent hydrolytic enzymes of great biological relevance, and some of them are key to the neuroinflammatory events and the brain damage associated to stroke. Non-zinc binding ligands are an emerging trend in drug discovery programs in this area due to their lower tendency to show off-target effects. 7-Amino-phenanthridin-6-one is disclosed as a new framework able to inhibit matrix metalloproteinases by binding to the distal part of the enzyme S1' site, as shown by computational studies. A kinetic study revealed inhibition to be noncompetitive. Some of the compounds showed some degree of selectivity for the MMP-2 and MMP-9 enzymes, which are crucial for brain damage associated to ischemic stroke. Furthermore, some compounds also had a high neuroprotective activity against oxidative stress, which is also very relevant aspect of ischaemic stroke pathogenesis, both decreasing lipid peroxidation and protecting against the oxidative stress-induced reduction in cell viability. One of the compounds, bearing a 2-thienyl substituent at C-9 and a 4-methoxyphenylamino at C-7, had the best-balanced multitarget profile and was selected as a lead on which to base future structural manipulation.