Exosomes rich in Wnt5 improved circadian rhythm dysfunction via enhanced PPARγ activity in the 6-hydroxydopamine model of Parkinson's disease.

Sleep disorder is one of the most common non-motor symptoms in Parkinson's disease (PD) and even appear as early symptoms. Here we investigated the therapeutic potential of mesenchymal stem cell-derived exosomes (MSC-EXOs) on sleep disorder in PD rats. 6-hydroxydopa (6-OHDA) was used to establish the PD rat model. BMSCquiescent-EXO and BMSCinduced-EXO groups were given intravenous injection 100 µg/g per day for 4 weeks, while control groups were given intravenous injection of the same volume of normal saline. The total sleep time, slow-wave sleep time and fast-wave sleep time in the BMSCquiescent-EXO and BMSCinduced-EXO groups were significantly prolonged (P < 0.05) compared with PD group, while the awakening time was significantly shortened (P < 0.05). In addition, increased levels of dopamine (P < 0.05) and 5-hydroxytryptamine (P < 0.05) levels were observed in the striatum of BMSCquiescent-EXO and BMSCinduced-EXO groups. Further, qPCR and western blot revealed that the mRNA levels of CLOCK, BMAL1 and PER2 in suprachiasmatic nucleus (SCN) were notably increased in BMSCquiescent-EXO and BMSCinduced-EXO groups compared to those from PD rats. More importantly, peroxisome proliferation-activated receptor γ (PPARγ) activities were significantly enhanced after treatment with BMSCquiescent-EXO and BMSCinduced-EXO. JC-1 fluorescence staining showed that mitochondrial membrane potential imbalance was repaired after inoculation of BMSCinduced-EXO. In summary, MSC-EXOs showed the improvement of sleep disorder in PD rats through recovering circadian rhythm associated gene expression. The potential mechanisms may be related with increased PPARγ activities and rescued mitochondrial membrane potential imbalance in Parkinson striatum.

Exosomes isolated during dopaminergic neuron differentiation suppressed neuronal inflammation in a rodent model of Parkinson's disease.

Our previous investigation showed Wnt signal pathway was significantly activated during DA neuron differentiation of epiblast-derived stem cells. In this study, we next attempt to examine the therapeutic potential of the purified exosomes derived bone marrow mesenchymal stem cells (BMSCs) by administrating exosomes into the rat striatum of parkinson's disease (PD) animal model. Results revealed that the protein levels of interleukin (IL)-6, IL-1ß, tumor necrosis factor-alpha (TNF-α), and reactive oxygen species (ROS) in the substantia nigra of PD rats were down regulated after injection of BMSC induced-Exosomes into the striatum of PD model compared to BMSC quiescent-Exosomes. In addition, the expression of ionized calcium binding adaptor molecule 1 (Iba1) mRNA was significantly decreased, while the expression of tyrosine hydroxylase (TH) mRNA was increased after injection of BMSC induced-Exosomes. Injection of BMSC induced-Exosomes into the striatum rescued the rotation behavior and climbing speed in the PD rats. More importantly, Wnt5a was found to be enriched in BMSC induced Exosomes, which could be effectively transferred to the substantia nigra of PD rats. In conclusion, these findings demonstrated that exosomes isolated during dopaminergic neuron differentiation could rescue the pathogenic features of Parkinson's disease by reshaping the inflammatory microenvironment in the substantia nigra and repairing the injury to DA nerves.

Cerebrospinal Fluid Extracellular Vesicles with Distinct Properties in Autoimmune Encephalitis and Herpes Simplex Encephalitis.

Encephalitis mediated by autoantibodies against neuronal antigens and herpes simplex encephalitis (HSE) are seemingly separate causes of encephalopathy in adults. Autoimmune encephalitis (AE) is autoimmune in origin, and herpes simplex encephalitis is infectious. The purpose of this study was to examine the role of cerebrospinal fluid (CSF) exosomes from patients with antibody-positive AE and HSE. Towards this, exosomes were isolated from CSF from 13 patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, 11 patients with anti-gamma-aminobutyric acid-B (GABAB) receptor encephalitis, 9 patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis, and 8 patients with anti-contactin-associated protein-like 2 (CASPR2) encephalitis, and 12 control individuals negative of antibodies against neuronal autoantigens. There were ten miRNAs highly expressed in patients with anti-NMDAR encephalitis compared to those in control subjects. Eight miRNAs were found to be lower expressed in anti-NMDAR encephalitis CSF-derived exosomes. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched by AE differential expressed exosomic miRNAs demonstrated that AE-related exosomic miRNAs may participate as a feedback regulation in cancer development. In addition, the exosome concentration in CSF of 9 HSE patients was significantly higher compared to those from 9 HSV( -) patients. This observation was consistent with the results that exosome concentration was found to be higher in the animal model which was inoculated intranasally with HSV-1 compared to controls. Furthermore, western blot demonstrated that the subunits of NMDAR, GABABR, and AMPAR were detected highly expressed in exosomes derived from sera of HSV-1-treated animal model compared to controls. More importantly, exosomes isolated from CSF of HSE patients contained higher expression levels of two miRNAs encoded by HSV, miR-H2-3p, and miR-H4-3p compared to those from HSV( -) patients. In summary, HSV may trigger brain autoimmunity in HSE by presentation of surface autoantigens via exosomes.

Recent Advances on Extracellular Vesicles in Central Nervous System Diseases.

Extracellular vesicles (EVs) are particles released by multiple cells, encapsulated by lipid bilayers and containing a variety of biological materials, including proteins, nucleic acids, lipids and metabolites. With the advancement of separation and characterization methods, EV subtypes and their complex and diverse functions have been recognized. In the central nervous system (CNS), EVs are involved in various physiological and pathological processes, such as regulation of neuronal firing, synaptic plasticity, formation and maintenance of myelin sheath, propagation of neuroinflammation, neuroprotection, and spread and removal of toxic protein aggregates. Activity-dependent alteration of constituents enables EVs to reflect the change of cell and tissue states, and the wide distribution of EVs in biological fluids endows them with potential as diagnostic and prognostic biomarkers for CNS diseases, including neurodegenerative disease, cerebrovascular disease, traumatic brain disease, and brain tumor. Favorable biocompatibility, ability of crossing the blood-brain barrier and protecting contents from degradation, give promising therapeutic effects of EVs, either collected from mesenchymal stem cells culture conditioned media, or designed as drug delivery vehicles loaded with specific agents. In this review, we summarized EVs' basic biological properties, and mainly focused on their applications in CNS diseases.

Exosomes expressing neuronal autoantigens induced immune response in antibody-positive autoimmune encephalitis.

The immunological role of exosomes in autoimmune encephalitis (AE) remains uncharacterized and not examined. In this study we ought to determine whether exosomes are generated in AE and to define the presence of cell surface neuronal autoantigens (autoAgs) in the cargo. Exosomes were isolated from cerebrospinal fluid (CSF) from 12 patients with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis, 8 patients with anti-gamma-aminobutyric acid-B (GABAB) receptor encephalitis, 8 patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis, 8 patients with anti-contactin-associated protein-like 2 (CASPR2) encephalitis, 10 patients with anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid 1,2 (AMPA) receptor encephalitis and 30 control individuals negative of antibodies against neuronal autoAgs. Western blot demonstrated that CSF or sera derived exosomes from AE contained specific neuronal autoAgs in protein aggregates, however, control subjects had no detectable levels of these neuronal autoAgs. In addition, development of antibodies against NMDAR, GABABR, LGI1, CASPR2, and AMPAR were detected in the sera after 30 days immunization of C57BL/6 J mice with exosomes isolated from antibody positive AE patients; Enzyme-linked immunospot (ELISpot) assay demonstrated increased frequency of neuronal autoAgs-specific IL-17 and IFN-γ in splenocytes from AE derived exosomes immunized mice. We concluded that exosomes expressing neuronal autoAgs were present in CSF from antibody positive AE patients, and we propose these exosomes carrying neuronal autoAgs would play an important role in the immune pathogenesis of autoimmune encephalitis.

Neuroprotective Effect of Trans-Resveratrol in Mild to Moderate Alzheimer Disease: A Randomized, Double-Blind Trial.

INTRODUCTION: Amyloid-beta (Aß) protein is a major component of the extracellular plaque found in the brains of individuals with Alzheimer's disease (AD). In this study, we investigated the effect of trans-resveratrol as an antagonist treatment for moderate to mild AD, as well as its safety and tolerability. METHODS: This was a case-control study that enrolled 30 selected patients who had been clinically diagnosed with moderate to mild AD. These patients were randomly divided into two groups, namely, a placebo group (n = 15) and a trans-resveratrol group (n = 15) who received 500 mg trans-resveratrol orally once daily for 52 weeks. Brain magnetic resonance imaging (MRI) examinations were performed on and cerebrospinal fluid (CSF) samples were obtained from all participants before (baseline) and after the study (52 weeks). Enzyme-linked immunosorbent assays were used to determine the levels of plasma Aß40 and Aß42 and CSF Aß40 and Aß42. RESULTS: The results showed that the changes over the study period in the levels of Aß40 in the blood and CSF of the patients treated with trans-resveratrol were not statistically significant (P > 0.05). In contrast, patients who received placebo showed a significant decrease in Aß40 levels compared with that at the beginning of the study (CSF Aß40: P = 0.024, plasma Aß40: P = 0.036). Analysis of the images on the brain MRI scans revealed that the brain volume of the patients treated with trans-resveratrol was significantly reduced at 52 weeks (P = 0.011) compared with that of patients in the placebo treatment group, Further analysis indicated that the level of matrix metallopeptidase 9 in the CSF of the patients treated with trans-resveratrol at 52 weeks decreased by 46% compared with that of patients in the placebo group (P = 0.033). CONCLUSION: These results indicate that trans-resveratrol has potential neuroprotective roles in the treatment of moderate to mild AD and that its mechanism may involve a reduction in the accumulation and toxicity of Aß in the brain of patients, thereby reducing neuroinflammation. TRIAL REGISTRATION: Chinese clinical trial registry: CTR20151780X.

Altered microRNAs in cerebrospinal fluid exosomes in paraneoplastic and autoimmune encephalitis: A possible feedback in cancer development.

AIMS: The purpose of this study was to examine the role of cerebrospinal fluid (CSF) exosomes from patients with paraneoplastic and autoimmune encephalitis (AE). MAIN METHODS: Towards this, microRNA profiling in the exosomes which were isolated from cerebrospinal fluid of 12 patients with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis, 12 patients with anti-gamma-aminobutyric acid-B (GABAB) receptor encephalitis, 12 patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis, and 12 patients with anti-contactin-associated protein-like 2 (CASPR2) encephalitis, and 12 control individuals negative of antibodies against neuronal auto-antigens. Selected findings were validated with quantitative RT-PCR. DIANA-mirPath was chosen for bioinformatic analysis. KEY FINDINGS: There were ten miRNAs higher expressed in AE patients with anti-NMDAR encephalitis compared to those in healthy controls. Further, eight miRNAs were found to be lower expressed in anti-NMDAR encephalitis CSF derived exosomes. In addition, Endometrial cancer, p53 signaling pathway, Non-small cell lung cancer, Small cell lung cancer, Transcriptional misregulation in cancer, Basal cell carcinoma, Acute myeloid leukemia, Renal cell carcinoma, Colorectal cancer, Choline metabolism in cancer, Melanoma, Pancreatic cancer, Prostate cancer, Ras signaling pathway, Glioma, Pathways in cancer, and Proteoglycans in cancer (all p < 0.01) were significantly enriched in differentially expressed miRNAs. SIGNIFICANCES: Exosomes expressing specific miRNAs in antibody positive AE may participate as a feedback regulation in cancer development.

Differential Expression of microRNA Profiles and Wnt Signals in Stem Cell-Derived Exosomes During Dopaminergic Neuron Differentiation.

The role of secreted exosomes during dopaminergic (DA) neuron differentiation is still unknown. To investigate the roles of exosomes in DA neuron fate specification, we profiled exosomal microRNAs (miRNAs) during DA neuron differentiation of epiblast-derived stem cells (EpiSCs). There were 26 miRNAs differentially expressed (relative fold >2, p < 0.05) in EpiSC-derived exosomes at 0, 2, 4, 6, 8, 10, 12, and 14 days of DA epiblast differentiation. Among them, 23 exosomic miRNAs were significantly increased, including miR-124, miR-132, miR-133b, miR-218, miR-9, miR-34b, miR-34c, and miR-135a2, while three exosomic miRNAs (miR-214, miR-7a, and miR-302b) were decreased, when compared with control samples. Bioinformatics analysis by DIANA-mirPath demonstrated that extracellular matrix-receptor interaction, signaling pathways regulating pluripotency of stem cells, FoxO signaling pathway, DA synapse, Wnt signaling pathway, GABAergic synapse, and neurotrophin signaling pathway were significantly enriched in DA differentiation-related miRNA signature (all p-values <0.012). Furthermore, messenger RNAs for nine DA neuronal markers tyrosine hydroxylase (TH), Nr4a2, Pitx3, Drd1a, Lmx1a, Lmx1b, Foxa1, Dmrt5, and Slc18a2 were significantly increased expressed over time in exosomes derived from differentiated EpiSCs. Interestingly, adding with exosomes derived from EpiSC induction experiment resulted in a twofold increase of TH-positive neurons production (35% vs. 17%, p < 0.01) during DA neuronal differentiation from mouse embryonic stem cells (ESCs). In summary, our results suggested exosomal miRNAs are potential regulators of DA neuron differentiation. More importantly, EpiSC-derived exosomes could promote the generation of DA neuron differentiation from ESCs.