Black Phosphorus Nanosheets Protect Neurons by Degrading Aggregative α-syn and Clearing ROS in Parkinson's Disease.

Although evidence indicates that the abnormal accumulation of α-synuclein (α-syn) in dopamine neurons of the substantia nigra is the main pathological feature of Parkinson's disease (PD), no compounds that have both α-syn antiaggregation and α-syn degradation functions have been successful in treating the disease in the clinic. Here, it is shown that black phosphorus nanosheets (BPNSs) interact directly with α-syn fibrils to trigger their disaggregation for PD treatment. Moreover, BPNSs have a specific affinity for α-syn through van der Waals forces. And BPNSs are found to activate autophagy to maintain α-syn homeostasis, improve mitochondrial dysfunction, reduce reactive oxygen species levels, and rescue neuronal death and synaptic loss in PC12 cells. It is also observed that BPNSs penetrate the blood-brain barrier and protect against dopamine neuron loss, alleviating behavioral disorders in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced mouse model and hA53T α-syn transgenic mice. Together, the study reveals that BPNSs have the potential as a novel integrated nanomedicine for clinical diagnosis and treatment of neurological diseases.

Wild Rosa roxburghii Tratt Juices Grown at Different Altitudes Regulate Blood Glucose in Type 1 Diabetic Mice via the PI3K/Akt Pathway.

To explore hypoglycemic effect of wild Rosa roxburghii tratt (RRT) juice at different altitudes on type 1 diabetes mellitus (T1DM). The T1DM mouse model was induced by streptozotocin (STZ), and the experiment included a normal group (NC), model group (MC), wild RRT juice groups high (HF), medium (MF), low altitude (DF) and cultivated control group (PC). During experiment, food intake, water intake, body weight, and fasting blood glucose were measured. After 28 days of administration, glucose tolerance, glycogen level, lipid profiles, and antioxidation levels in serum and liver were measured, and histomorphological changes of liver and kidney were observed by hematoxylin and eosin staining. The results showed that wild RRT juice reduced blood glucose level, alleviated liver and kidney tissue damage, improved glucose and lipid metabolism disorders and attenuated oxidative damage in T1DM mice. Western blot showed that wild RRT juice at grown at different altitudes significantly increased protein abundance of PI3K, Akt, and GLUT2 in liver of T1DM mice. In conclusion, wild RRT juice from different altitudes improved glucose and lipid metabolism disorders and oxidative damage in T1DM mice, which may be attributed to activation of PI3K/Akt pathway. Overall effect: MF > PC > HF > DF.

Alpha lipoic acid ameliorates motor deficits by inhibiting ferroptosis in Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disease. Ferroptosis shares several features with PD pathophysiology, and anti-ferroptosis molecules are neuroprotective in PD animal models. As an antioxidant and iron chelating agent, alpha lipoic acid (ALA) has a neuroprotective effect on PD; however, the influence of ALA on ferroptosis in PD remains unclear. This study aimed to determine the mechanism of ALA in regulating ferroptosis in PD models. Results showed that ALA could ameliorate motor deficits in PD models and regulate iron metabolism by upregulating ferroportin (FPN) and ferritin heavy chain 1 (FTH1) and downregulating iron importer divalent metal transporter 1 (DMT1). Moreover, ALA decreased the accumulation of reactive oxygen species (ROS) and lipid peroxidation, rescued mitochondrial damage, and prevented ferroptosis effectively by inhibiting the downregulation of glutathione peroxidase 4 (GPX4) and cysteine/glutamate transporter (xCT) in PD. Mechanistic study indicated that the activation of SIRT1/NRF2 pathway was involved in the upregulation effect of GPX4 and FTH1. Thus, ALA ameliorates motor deficits in PD models by regulating iron metabolism and mitigating ferroptosis through the SIRT1/NRF2 signaling pathway.

Alpha-Lipoic Acid Mediates Clearance of Iron Accumulation by Regulating Iron Metabolism in a Parkinson's Disease Model Induced by 6-OHDA.

The disruption of neuronal iron homeostasis and oxidative stress are related to the pathogenesis of Parkinson's disease (PD). Alpha-lipoic acid (ALA) is a naturally occurring enzyme cofactor with antioxidant and iron chelator properties and has many known effects. ALA has neuroprotective effects on PD. However, its underlying mechanism remains unclear. In the present study, we established PD models induced by 6-hydroxydopamine (6-OHDA) to explore the neuroprotective ability of ALA and its underlying mechanism in vivo and in vitro. Our results showed that ALA could provide significant protection from 6-OHDA-induced cell damage in vitro by decreasing the levels of intracellular reactive oxygen species and iron. ALA significantly promoted the survival of the dopaminergic neuron in the 6-OHDA-induced PD rat model and remarkably ameliorated motor deficits by dramatically inhibiting the decrease in tyrosine hydroxylase expression and superoxide dismutase activity in the substantia nigra. Interestingly, ALA attenuated 6-OHDA-induced iron accumulation both in vivo and in vitro by antagonizing the 6-OHDA-induced upregulation of iron regulatory protein 2 and divalent metal transporter 1. These results indicated that the neuroprotective mechanism of ALA against neurological injury induced by 6-OHDA may be related to the regulation of iron homeostasis and reduced oxidative stress levels. Therefore, ALA may provide neuroprotective therapy for PD and other diseases related to iron metabolism disorder.

[Alpha-lipoic acid inhibits the expression of α-synuclein in PC12 cells induced by 6-hydroxydopamine and its mechanism].

Objective To investigate the effects of α-lipoic acid (α-LA) on the expression of α-synuclein(α-syn)in cellular models of Parkinson's disease (PD) induced by 6-hydroxydopamine (6-OHDA) and its mechanism. Methods PC12 cells were induced by 6-OHDA to establish the cellular models of PD, which was treated with α-LA. Cell viability was detected using MTT assay. The contents of intracellular iron and malondialdehyde (MDA) were detected by colorimetry.The level of intracellular reactive oxygen species (ROS) was detected by 2, 7-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. Western blot analysis was performed to detect the level of α-syn protein. Results Compared with the normal control group, the cell viability of the model group was significantly decreased, the contents of intracellular iron and MDA and the level of ROS were significantly increased, and the expression level of α-syn was significantly increased; compared with the model group, the cell viability of the α-LA treat group was significantly increased, the contents of intracellular iron and MDA and the level of ROS were significantly decreased, and the expression level of α-syn was significantly decreased. Conclusion α-LA can inhibit the overexpression of α-syn and attenuate the damage of PC12 cells induced by 6-OHDA, which may be related to the decrease of contents of intracellular iron and oxidative stress level by α-LA.

[Mechanism of α-lipoic acid promoting iron efflux in substantia nigra cells of Parkinson's disease rats].

Objective To observe the effect of α-lipoic acid (α-LA) on the expressions of iron regulatory protein 2 (IRP2) and ferroportin1 (FP1) in substantia nigra of rats with Parkinson's disease (PD) and explore the mechanism by which α-LA regulates iron efflux in substantia nigra cells of PD rat models. Methods Sixty healthy male SD rats were randomly divided into a sham group (n=15) and a model group (n=45). To establish the PD model, the rats of the model group were injected with 6-hydroxydopamine (6-OHDA) into their right striatum by the stereotactic technique, and the sham operation group was injected with the same dose of normal saline. Four weeks later, 30 model rats were randomly picked and divided into a PD model group (n=15) and a PD treatment group (n=15). The PD treatment group was intraperitoneally injected with α-LA (50 mg/kg) daily for 2 weeks, and the PD model group was given the same dose of saline. After 14 days of treatment, the left forelimb use rate was tested by cylinder test. The right middle cerebral substantia nigra was taken from each group, and the expression and distribution of tyrosine hydroxylase (TH) was detected by immunohistochemical staining; the number of iron positive cells was determined by Prussian blue staining; and the levels of IRP2 and FP1 were examined by Western blotting. Results Compared with the sham operation group, the left forelimb use rate of the PD model group was significantly reduced. The number of TH positive cells significantly decreased, and the number of iron positive cells in the substantia nigra significantly increased. The level of IRP2 significantly increased, and the level of FP1 decreased remarkably. Compared with PD model group, the left forelimb use rate of the PD treatment group was significantly raised. The number of TH positive cells was significantly elevated, and the number of iron positive cells in the substantia nigra was significantly reduced. The IRP2 level decreased and the FP1 level increased. Conclusion By decreasing the IRP2 level and via the IRP2/IRE pathway, α-LA can increase FP1 level, promote the outflow of iron ions from cells, and reduce iron deposition in the substantia nigra of PD model rats, thereby alleviating brain injury in PD rats induced by 6-OHDA.

CRISPR/Cas9-mediated efficient genome editing via blastospore-based transformation in entomopathogenic fungus Beauveria bassiana.

Beauveria bassiana is an environmentally friendly alternative to chemical insecticides against various agricultural insect pests and vectors of human diseases. However, its application has been limited due to slow kill and sensitivity to abiotic stresses. Understanding of the molecular pathogenesis and physiological characteristics would facilitate improvement of the fungal performance. Loss-of-function mutagenesis is the most powerful tool to characterize gene functions, but it is hampered by the low rate of homologous recombination and the limited availability of selectable markers. Here, by combining the use of uridine auxotrophy as recipient and donor DNAs harboring auxotrophic complementation gene ura5 as a selectable marker with the blastospore-based transformation system, we established a highly efficient, low false-positive background and cost-effective CRISPR/Cas9-mediated gene editing system in B. bassiana. This system has been demonstrated as a simple and powerful tool for targeted gene knock-out and/or knock-in in B. bassiana in a single gene disruption. We further demonstrated that our system allows simultaneous disruption of multiple genes via homology-directed repair in a single transformation. This technology will allow us to study functionally redundant genes and holds significant potential to greatly accelerate functional genomics studies of B. bassiana.