No abstract

BackgroundEmerging evidence indicates that nod-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome-induced inflammation plays a crucial role in the pathogenesis of Parkinson’s disease (PD). Thus, inhibition of NLRP3 inflammasome activation may offer a therapeutic benefit in the treatment of PD. Tenuigenin, a major active component of Polygala tenuifolia, has been shown to have potential anti-inflammatory activity, but the underlying mechanisms remain obscure.MethodsIn the present study, the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD was established to explore the effect of tenuigenin on dopaminergic neurons in substantia nigra. We next activated NLRP3 inflammasome in both BV2 microglia cells and adult mice to investigate the mechanisms for the neuroprotective effect of tenuigenin.ResultsWe demonstrated that treatment with tenuigenin increased striatal dopaminergic levels and improved motor impairment induced by MPTP. Also, tenuigenin significantly ameliorated the degeneration of dopaminergic neurons and inhibited NLRP3 inflammasome activation in substantia nigra of MPTP mouse model. We further found that tenuigenin reduced intracellular reactive oxygen species (ROS) production and suppressed NLRP3 inflammasome activation, subsequent caspase-1 cleavage, and interleukin-1β secretion in BV2 microglia cells. These data indicate that tenuigenin inhibits the activation of NLRP3 inflammasome via downregulating ROS. Correspondingly, in vivo data showed that tenuigenin attenuates microglia activation induced by lipopolysaccharide (LPS) in substantia nigra via suppressing NLRP3 inflammasome.ConclusionsOur findings reveal that tenuigenin protects dopaminergic neurons from inflammation partly through inhibition of NLRP3 inflammasome activation in microglia, and suggest the promising clinical use of tenuigenin for PD therapy.

BackgroundTenecteplase (TNK) possesses several pharmacological characteristics superior to conventional alteplase (rt-PA), with well-established safety and efficacy profile in Caucasians. There exists controversy over the optimal dose of intravenous rt-PA for East Asians with acute ischaemic stroke (AIS). Current study aimed to determine the safety dose range of recombinant human TNK tissue-type plasminogen activator (rhTNK-tPA) for patients with AIS in China.MethodsThis multicentre, prospective, randomised, open-label, blinded end-point, phase II study compared three tiers of 0.1, 0.25, 0.32 mg/kg rhTNK-tPA (to a maximum of 40 mg) with standard 0.9 mg/kg rt-PA (to a maximum of 90 mg) in patients who were eligible for intravenous thrombolysis. The safety outcome were symptomatic intracranial haemorrhage (sICH) within 36 hours.ResultsBetween May 2018 and February 2020, 240 patients were randomly assigned to four group, 4 of whom did not receive study treatment. The intention-to-treat analysis included 236 patients. There was no difference in the improvement on National Institutes of Health Stroke Scale at day 14 in the 3 tiers and control group (63.3%, 77.2%, 66.7% vs 62.7%). The number of sICH was 3 of 60 (5.0%) in the 0.1 mg/kg group, none in the 0.25 mg/kg group, 2 of 60 (3.3%) in the 0.32 mg/kg group and 1 (1.7%) of 59 in the rt-PA group. There were no significant between-group differences in severe adverse events.ConclusionsSimilar to the Caucasians, rhTNK-tPA was well tolerated in Chinese patients with AIS at all doses administered within 3 hours of symptom onset. The dose-efficacy profile of rhTNK-tPA needs to be established with future investigations.Trial registration numberNCT04676659.