ABSTRACT
Parkinson's disease (PD), the second most common neurodegenerative disease, is clinically characterized by both motor and non-motor symptoms. Although overall great achievements have been made in elucidating the etiology and pathogenesis of PD, the exact mechanisms of this complicated systemic disease are still far from being clearly understood. Consequently, most of the currently-used diagnostic tools and therapeutic options for PD are symptomatic. In this perspective review, we highlight the hot topics in recent PD research for both clinicians and researchers. Some of these hot topics, such as sleep disorders and gut symptoms, have been neglected but are currently emphasized due to their close association with PD. Following these research directions in future PD research may help understand the nature of the disease and facilitate the discovery of new strategies for the diagnosis and therapy of PD.
Subject(s)
Humans , Neurodegenerative Diseases , Parkinson Disease/therapy , Sleep Wake Disorders/therapyABSTRACT
Parkinson’s disease (PD), the second most common neurodegenerative disease, is clinically characterized by both motor and non-motor symptoms. Although overall great achievements have been made in elucidating the etiology and pathogenesis of PD, the exact mechanisms of this complicated systemic disease are still far from being clearly understood. Consequently, most of the currently-used diagnostic tools and therapeutic options for PD are symptomatic. In this perspective review, we highlight the hot topics in recent PD research for both clinicians and researchers. Some of these hot topics, such as sleep disorders and gut symptoms, have been neglected but are currently emphasized due to their close association with PD. Following these research directions in future PD research may help understand the nature of the disease and facilitate the discovery of new strategies for the diagnosis and therapy of PD.
ABSTRACT
OBJECTIVE@#To investigate the regulatory effect of metformin on regulatory T cells (Treg) in acidic environment.@*METHODS@#CD4 CD25 Treg cells were obtained by magnetic bead sorting. Treg and conventional T cells (Tcon) cells were cultured for 24-72 h in pH 7.4 or pH 6.7 medium, and the cell proliferation, apoptosis and Foxp3 expression were detected by flow cytometry. Real-time PCR was used to detect the expression levels of the genes related with glucose metabolism. Thirty-two C57BL/6 male mouse models bearing subcutaneous prostate cancer xenograft derived from RM-1 cells were randomized into 4 equal groups for treatment with PBS, metformin, tumor vaccine, or both metformin and the vaccine. The treatment started on the 4th day following tumor cell injection, and metformin (100 mg/kg) or PBS was administered by intraperitoneal injection on a daily basis; the vaccine was intramuscularly injected every 4 days. The tumor size was continuously monitored, and the mice were euthanized on day 25 after tumor implantation to obtain tumor and blood samples. Flow cytometry was used to detect the changes in CD4, CD8, CD4Foxp3 cell subsets in the tumor tissue and peripheral blood.@*RESULTS@#Treg cells showed significantly enhanced proliferation ( < 0.05) while the proliferation of Tcon cells was suppressed in acidic medium ( < 0.001). Treg cells cultured in acidic medium showed significantly increased expressions of OXPHOS-related genes pgc1a ( < 0.001) and cox5b ( < 0.01), which did not vary significantly in Tcon cells in acidic medium. Treg cells exhibited significantly decreased apoptosis in acidic medium ( < 0.01) with increased Foxp3 cells ( < 0.001) and intracellular alkaline levels ( < 0.01). Metformin obviously reversed the acid tolerance of Treg cells without producing significant effect on Tcon cells. In the animal experiment, both metformin ( < 0.05) and vaccine ( < 0.01) alone reduced the tumor volume, but their combined treatment more potently reduced the tumor volume ( < 0.001). Metformin alone did not obviously affect CD4 cells or CD8 cells but significantly decreased the percentage of CD4Foxp3 ( < 0.05); the vaccine alone significantly increased CD4 cells and CD8 cells ( < 0.001) and also the percentage of CD4Foxp3 cells ( < 0.05). The combined treatment, while reducing the percentage of CD4Foxp3cells to a level lower than that in the vaccine group ( < 0.01), produced the strongest effect to increase CD4 cells and CD8 cells ( < 0.01).@*CONCLUSIONS@#Metformin can inhibit the proliferation and function of regulatory T cells in an acidic environment and enhance the effect of tumor vaccine by reducing the proportion of Treg cells to achieve the anti-tumor effect.
Subject(s)
Animals , Male , Mice , Cell Proliferation , Forkhead Transcription Factors , Metformin , Mice, Inbred C57BL , T-Lymphocytes, RegulatoryABSTRACT
Objective To investigate the roles of neuroinflammation and pathology of peripheral nervous system in the pathogenesis of Parkinson's disease (PD).Methods Immunohistochemical staining was performed to examine the nodose ganglia (containing vagus nerve) and intestine of an autopsy case of PD.The neuroinflammation and morphological changes of vagus nerve and enteric nervous system were observed.Results The expressions and distributions of glial fibrillary acidic protein and ionized calcium binding adapter molecule 1,two typical glia cell biomarkers,were different in vagus nerve and intestinal mucosa.Tumor necrosis factor α and inducible nitric oxide synthase were expressed in intestinal mucosa and myenteric plexus of the PD patient.There was a strong inflammatory reaction in the myenteric plexus,which distributed diffusely.Conclusion Satellite glial cells and intestinal inflammatory response may play a role in the pathogenesis of PD.