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OBJECTIVE The etiology of Parkinson disease(PD)is still unknown.Until now,oxidative stress and neuroinflammation play a crucial role in the patho-genesis of PD.However,the specific synergistic role of oxidative stress and neuroinflammation in the occurrence and development of PD remains unclear.METHODS The changes in motor behavior,dopamine(DA)neurons quantification and their mitochondrial respiratory chain,glial cells activation and secreted cytokines,Nrf2 signal-ing pathway,and redox balance in the brain of rats were evaluated.RESULTS Lipopolysaccharide(LPS)-induced neuroinflammation and rotenone(ROT)-induced oxidative stress synergistically aggravated motor dysfunc-tion,DA neuron damage,activation of glial cells,and release of related mediators,activation of Nrf2 signaling and destruction of oxidative balance.In addition,further studies indicated that after ROT-induced oxidative stress caused direct damage to DA neurons,LPS-induced inflammatory effects had stronger promoting neurotoxic effects on the above aspects.CONCLUSION Neuroinflammation and oxidative stress synergistically aggravated DA neuronal loss.Furtherly,oxidative stress followed by neuroinflammation caused more DA neuro-nal loss than neuroinflammation followed by oxidative stress.
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Parkinson's disease(PD)is a degenera-tive disease of the central nervous system characterized by the loss of dopamine(DA)neurons in the dense sub-stantia nigra and the depletion of DA neurons.Clinically,the treatment of PD is mainly supplementing dopamine deficiency or using DA receptor agonists,but these drugs can only alleviate the symptoms of PD patients,but cannot prevent neuronal loss and delay disease progres-sion.Natural bioactive polysaccharides have the advan-tages of multi-target,low toxicity and synergistic effect,and have great potential in the prevention and treatment of PD.Numerous studies have shown that polysaccha-rides can be involved in neuronal protection and preven-tion of neurodegenerative diseases through mechanisms such as oxidative stress,reducing neuroinflammation,and inhibiting anti-apoptosis.①Anti-oxidative stress.Oxi-dative stress is caused by increased reactive oxygen spe-cies(ROS)products and weakened antioxidant capacity,resulting in destruction of lipids,proteins,and DNA.Oxi-dative stress-induced mitochondrial dysfunction is thought to be an important cause of DA neuronal loss in PD mice.Polysaccharides reduce the damage of DA neurons in the substantia nigra by increasing the activity of antioxidant enzymes and inhibiting the formation of reactive oxygen species.② Reduce neuroinflammation.Neuroinflamma-tory response is the main causative factor of neurodegener-ation,microglia are innate immune cells present in the central nervous system,and their continuous activation is a key link in central nervous system neuroinflammation.Polysaccharides can regulate the expression of inflamma-somes,reduce the levels of pro-inflammatory cytokines and cytotoxic factors,inhibit the excessive activation of microglia,reduce PD neuroinflammatory damage,and then exert neuroprotective effects.③ Inhibiting apopto-sis.Apoptosis(APO)is the process of cell death caused by the activation of cell death procedures by various fac-tors.During the pathogenesis of PD,due to changes in the internal and external environment of DA neurons,some apoptosis-related genes cause DA neuronal death by regulating cell death signaling pathways.Polysaccha-rides can reduce the Bax/Bcl2 ratio,weaken the activa-tion of caspase-related proteins,improve the viability of PC12 cells,reduce apoptosis,and protect the activity of dopamine neurons.In summary,traditional Chinese med-icine polysaccharides can effectively treat and improve PD,and its mechanism of action involves anti-oxidative stress,reducing neuroinflammation and apoptosis.There-fore,traditional Chinese medicine polysaccharides have great development potential in the field of medicine and health.
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Objective To investigate the effects of human adult T lymphoblastic leukemia virus typeⅠ (HTLV-1) infection on the production of reactive oxygen species (ROS) and mitochondrial damage in host cells. Methods A cell model of HTLV-1 infection was established by co-culturing HTLV-1-positive cell line MT2 with HeLa cells. ROS, mitochondrial membrane potential ( MMP) and total mitochondria were detected using specific fluorescence probe labeling method. Cell apoptosis was detected by Annexin V-FITC/PI method. Western blot was performed to detect viral proteins Tax and p19, as well as mitochondrial pro-teins TIM23 and TOM20. After the treatment of MT2 cells with different concentrations of reverse transcrip-tion inhibitors ( ZDV) , relative viral loads were detected by quantitative real-time PCR and Western blot, and the mass of mitochondria was analyzed by flow cytometry. Results After co-culturing HeLa cells with MT2 cells for 24 h, the ROS level in host cells increased without obvious cell apoptosis, while the mitochon-drial membrane potential, mitochondrial protein expression and total mitochondria decreased significantly. When the replication of HTLV-1 in MT2 cells was inhibited by ZDV, the ROS level and total mitochondria increased. Conclusions HTLV-1 infection can cause oxidative stress in host cells, resulting in mitochon-drial damage. Autophagy might be activated to degrade mitochondrial damage and maintain cell homeostasis during the infection.
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Aim To research dynamically the changes of endogenous cystathionine- β-synthase/hydrogen sul-fide system in PC12 cells injury induced by rotenone. Methods Rotenone-induced injury in PC12 cells ( characteristic of dopaminergic neurons) was used as a PD cell model. The expression of CBS was evaluated by Western blot. Intracellular CBS activity and H2 S production were detected by Methylene blue spectro-phot-ometric method. The viability of PC12 cells was measured by CCK-8 assay. GSH detection kit was used to detect the intracellular GSH content. Results In the groups of 6 and 12 hours, the expression and activ-ity of CBS were elevated, and the production of H2 S was increased. In the groups of 24 and 48 hours, CBS expression and activity were significantly decreased, and the amount of H2 S was significantly reduced. Ap-plication of 1. 5 μmol·L-1 rotenone for different time (6-48h) could decrease the cell viability and intra-cellular GSH contents in a time-dependent manner. Conclusions The expression and activity of endoge-nous CBS, stimulated by rotenone, are elevated firstly and then decreased. The generation of H2 S, stimulated by rotenone, is increased and then reduced significant-ly, which may be related to PC12 cells against oxida-tive stress damage induced by rotenone.