Knockdown of interleukin-1 receptor 1 is not neuroprotective in the 6-hydroxydopamine striatal lesion rat model of Parkinson's disease

It is well established that neuroinflammation is associated with the progression of many neurodegenerative diseases, including Parkinson's disease (PD). Activated microglia and elevated levels of pro-inflammatory cytokines such as interleukin-1β (IL-1β) have been found in the brain and cerebrospinal fluid of PD patients, suggesting that IL-1β may be involved in the pathogenesis of this disease. This study aimed to knock down the expression of the interleukin-1 type 1 receptor (IL-1R1) to evaluate any potential therapeutic effect of limiting the action of IL-1β in the substantia nigra following a unilateral intrastriatal 6-hydroxydopamine (6-OHDA) lesion in rats. Adult Sprague-Dawley rats received intranigral injections of shRNA specific for IL-1R1, followed 2 weeks later by intrastriatal 6-OHDA. Injection of IL-1R1 shRNA did not prevent 6-OHDA-induced loss of motor function or loss of nigral dopamine neurons. IL-1R1 expression was increased in the midbrain following 6-OHDA injection; this effect was attenuated in 6-OHDA-treated animals that had received IL-1R1 shRNA. These data suggest that while IL-1R1 was increased in 6-OHDA-treated animals and reduced following shRNA injection, the neurodegeneration induced by 6-OHDA was not mediated through IL-1R1

NADPH oxidases in Parkinson’s disease: a systematic review

Abstract Parkinson’s disease (PD) is a progressive movement neurodegenerative disease associated with a loss of dopaminergic neurons in the substantia nigra of the brain. Oxidative stress, a condition that occurs due to imbalance in oxidant and antioxidant status, is thought to play an important role in dopaminergic neurotoxicity. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases are multi-subunit enzymatic complexes that generate reactive oxygen species as their primary function. Increased immunoreactivities for the NADPH oxidases catalytic subunits Nox1, Nox2 and Nox4 have been reported in the brain of PD patients. Furthermore, knockout or genetic inactivation of NADPH oxidases exert a neuroprotective effect and reduce detrimental aspects of pathology in experimental models of the disease. However, the connections between NADPH oxidases and the biological processes believed to contribute to neuronal death are not well known. This review provides a comprehensive summary of our current understanding about expression and physiological function of NADPH oxidases in neurons, microglia and astrocytes and their pathophysiological roles in PD. It summarizes the findings supporting the role of both microglial and neuronal NADPH oxidases in cellular disturbances associated with PD such as neuroinflammation, alpha-synuclein accumulation, mitochondrial and synaptic dysfunction or disruption of the autophagy-lysosome system. Furthermore, this review highlights different steps that are essential for NADPH oxidases enzymatic activity and pinpoints major obstacles to overcome for the development of effective NADPH oxidases inhibitors for PD