Inhibition of autophagy-dependent pyroptosis attenuates cerebral ischaemia/reperfusion injury.

Autophagy is closely associated with cerebral ischaemia/reperfusion injury, but the underlying mechanisms are unknown. We investigated whether Spautin-1 ameliorates cerebral ischaemia/reperfusion injury by inhibiting autophagy and whether its derived pyroptosis is involved in this process. We explored the mechanism of Spautin-1 in cerebral ischaemia/reperfusion. To answer these questions, healthy male Sprague-Dawley rats were exposed to middle cerebral artery occlusion for 60 minutes followed by reperfusion for 24 hours. We found that cerebral ischaemia/reperfusion increased the expression levels of autophagy and pyroptosis-related proteins. Treatment with Spautin-1 reduced the infarct size and water content and restored some neurological functions. In vitro experiments were performed using oxygen-glucose deprivation/reoxygenation to model PC12 cells. The results showed that PC12 cells showed a significant decrease in cell viability and a significant increase in ROS and autophagy levels. Spautin-1 treatment reduced autophagy and ROS accumulation and attenuated NLRP3 inflammasome-dependent pyroptosis. However, these beneficial effects were greatly blocked by USP13 overexpression, which significantly counteracted the inhibition of autophagy and NLRP3 inflammasome-dependent ferroptosis by Spautin-1. Together, these results suggest that Spautin-1 may ameliorate cerebral ischaemia-reperfusion injury via the autophagy/pyroptosis pathway. Thus, inhibition of autophagy may be considered as a promising therapeutic approach for cerebral ischaemia-reperfusion injury.

Diversity in clinical manifestations and imaging features of neurosyphilis: obstacles to the diagnosis and treatment (report of three cases).

OBJECTIVE: To explore the clinical manifestations and imaging features of neurosyphilis and to discuss the obstacles in the diagnosis and treatment of neurosyphilis. METHODS: We present this case study involving three cases of definite neurosyphilis, focusing on their clinical data. RESULTS: Case 1 is a patient with numb and weak left lower limb. Case 2 showed slow reaction and dementia behaviors including worse memory and the decrease of calculation and orientation ability in this patient. Case 3 is a peripheral incomplete left oculomotor nerve palsy patient. Magnetic resonance imaging findings of three patients are different. And single photon emission computed tomography showed the regional cerebral blood flow was all hypoperfused. There were some difficulties in diagnosing and treating the patients in these three cases. CONCLUSION: The clinical manifestations and imaging findings of neurosyphilis are diverse. Clinicians should pay attention to neurosyphilis. After clear diagnosis, patients would receive norm treatment in time.

Neuroprotective effects of salidroside through PI3K/Akt pathway activation in Alzheimer's disease models.

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by deposits of aggregated amyloid-ß (Aß) peptide and neurofibrillary tangles in the brain parenchyma. Despite considerable research to elucidate the pathological mechanisms and identify therapeutic strategies for AD, effective treatments are still lacking. In the present study, we found that salidroside (Sal), a phenylpropanoid glycoside isolated from Rhodiola rosea L., can protect against Aß-induced neurotoxicity in four transgenic Drosophila AD models. Both longevity and locomotor activity were improved in Sal-fed Drosophila. Sal also decreased Aß levels and Aß deposition in brain and ameliorated toxicity in Aß-treated primary neuronal culture. The neuroprotective effect of Sal was associated with upregulated phosphatidylinositide 3-kinase (PI3K)/Akt signaling. Our findings identify a compound that may possess potential therapeutic benefits for AD and other forms of neurodegeneration.

Small peptide inhibitor of JNK3 protects dopaminergic neurons from MPTP induced injury via inhibiting the ASK1-JNK3 signaling pathway.

INTRODUCTION AND AIMS: The ASK1-JNK3 signaling pathway plays a pivotal role in the pathogenesis of Parkinson's disease (PD). The specific binding of ß-arrestin2 to JNK3 is essential for activation of the ASK1-JNK3 cascade, representing a potential therapeutic target for preventing dopaminergic neuronal death in PD. The aim of this study was to identify a novel strategy for the prevention of dopaminergic neuronal death in PD. METHODS: Based on the specific binding of ß-arrestin2 to JNK3, a 21-amino-acid fusion peptide, termed JNK3-N-Tat, was synthesized. We evaluated the ability of this peptide to inhibit the binding of ß-arrestin2 to its target domain in JNK3 in vitro and in vivo. RESULTS: The JNK3-N-Tat peptide inhibited activation of the ASK1-JNK3 cascade by disrupting the interaction between ß-arrestin2 and JNK3. JNK3-N-Tat exerted beneficial effects through pathways downstream of JNK3 and improved mitochondrial function, resulting in attenuated MPP+/MPTP-induced damage. JNK3-N-Tat protected mesencephalic dopaminergic neurons against MPTP-induced toxicity. CONCLUSIONS: JNK3-N-Tat, a JNK3-inhibitory peptide, protects dopaminergic neurons against MPP+/MPTP-induced injury by inhibiting the ASK1-JNK3 signaling pathway.

Curcumin could reduce the monomer of TTR with Tyr114Cys mutation via autophagy in cell model of familial amyloid polyneuropathy.

Transthyretin (TTR) familial amyloid polyneuropathy (FAP) is an autosomal dominant inherited neurodegenerative disorder caused by various mutations in the transthyretin gene. We aimed to identify the mechanisms underlying TTR FAP with Tyr114Cys (Y114C) mutation. Our study showed that TTR Y114C mutation led to an increase in monomeric TTR and impaired autophagy. Treatment with curcumin resulted in a significant decrease of monomeric TTR by recovering autophagy. Our research suggests that impairment of autophagy might be involved in the pathogenesis of TTR FAP with Y114C mutation, and curcumin might be a potential therapeutic approach for TTR FAP.

MicroRNA-494 reduces DJ-1 expression and exacerbates neurodegeneration.

Oxidative stress is believed to be a significant cause of Parkinson's disease (PD). DJ-1 is thought to be an oxidative sensor that protects cells from oxidative insult. It was reported that the level of total DJ-1 protein was significantly reduced in the substantia nigra of sporadic PD patients, suggesting that abnormal DJ-1 expression might contribute to PD pathogenesis. However, the molecular mechanisms underlying the regulation of DJ-1 expression are still not fully explored. As a post-transcriptional regulation of target gene expression, the roles of microRNAs in development and disease progression have received widespread concerns. Therefore, we hypothesized that microRNAs might participate in the regulation of the DJ-1 expression. In the present study, we found that miR-494 could bind to the 3'UTR of DJ-1. Overexpression of miR-494 significantly decreased the level of DJ-1 in vitro and rendered cells more susceptible to oxidative stress. In a MPTP mouse model, overexpression of miR-494 negatively regulated DJ-1 levels and exacerbated MPTP-induced neurodegeneration, as illustrated by the loss of dopaminergic neurons. In conclusion, upregulation of miR-494 contributed to oxidative stress induced neuronal death by inhibiting expression of DJ-1.