Microglia-derived exosomes modulate myelin regeneration via miR-615-5p/MYRF axis.

Demyelination and failure of remyelination in the central nervous system (CNS) characterize a number of neurological disorders. Spontaneous remyelination in demyelinating diseases is limited, as oligodendrocyte precursor cells (OPCs), which are often present in demyelinated lesions in abundance, mostly fail to differentiate into oligodendrocytes, the myelinating cells in the CNS. In addition to OPCs, the lesions are assembled numbers of activated resident microglia/infiltrated macrophages; however, the mechanisms and potential role of interactions between the microglia/macrophages and OPCs are poorly understood. Here, we generated a transcriptional profile of exosomes from activated microglia, and found that miR-615-5p was elevated. miR-615-5p bound to 3'UTR of myelin regulator factor (MYRF), a crucial myelination transcription factor expressed in oligodendrocyte lineage cells. Mechanistically, exosomes from activated microglia transferred miR-615-5p to OPCs, which directly bound to MYRF and inhibited OPC maturation. Furthermore, an effect of AAV expressing miR-615-5p sponge in microglia was tested in experimental autoimmune encephalomyelitis (EAE) and cuprizone (CPZ)-induced demyelination model, the classical mouse models of multiple sclerosis. miR-615-5p sponge effectively alleviated disease progression and promoted remyelination. This study identifies miR-615-5p/MYRF as a new target for the therapy of demyelinating diseases.

Quercetin regulates dendritic cell activation by targeting STAT4 in the treatment of experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is a class of autoimmune diseases mainly caused by the immune system attacking the myelin sheath of the axons in the nervous system. Although the pathogenesis of MS is complex, studies have shown that dendritic cells (DCs) play a vital role in the pathogenesis of MS. Quercetin (QU) has a unique advantage in clinical application, especially for treating autoimmune diseases. However, the mechanism of QU in the treatment of experimental autoimmune encephalomyelitis (EAE) remains unclear. In this study, we explore the potential role of QU in EAE. Finally, we find that QU has anti-inflammatory activities and neural protective effects in EAE. The experimental results suggest that the cellular basis for QU's function is to inhibit the activation of DCs while modulating the Th17 cell differentiation in the co-culture system. Further, QU may target STAT4 to inhibit its activation in DCs. This work will be of great significance for the future development and utilization of QU.

[Randomized,double-blind,parallel controlled,multicenter clinical trial of effectiveness and safety of Shexiang Zhuifeng Zhitong Ointment in alleviating pain in knee osteoarthritis(syndrome of cold-dampness obstruction)].

The Shexiang Zhuifeng Zhitong Ointment with the effects of dispelling wind, removing dampness, dissipating cold, and relieving pain is used for treating arthralgia, muscular pain, and sprain pain caused by cold-dampness obstruction. To evaluate the efficacy and safety of Shexiang Zhuifeng Zhitong Ointment in relieving the pain due to knee osteoarthritis(syndrome of cold-dampness obstruction), a randomized, double-blind, parallel controlled, multicenter clinical trial was conducted. The stratified randomization method was used to randomize the 240 subjects into a treatment group and a control group in a ratio of 1∶1. In each group, 60 patients received external application for 12 h and the other 60 patients received external application for 6 h. The treatment group received external application of Shexiang Zhuifeng Zhitong Ointment, while the control group received external application of Shexiang Zhuifeng Ointment. The treatment lasted for 21 days in both groups. Follow-up was conducted on days 7, 14, and 21 of treatment. The results based on the full analysis set were as follows.(1)In visual analog scale(VAS) score, the mean difference in the VAS score between baseline and 12 h post-treatment was 3.02 in the treatment group and 2.31 in the control group, with a significant difference(P<0.05). The mean difference in the VAS score between baseline and 6 h post-treatment was 3.19 in the treatment group and 2.48 in the control group, with a significant difference(P<0.05).(2)Response rate in terms of VAS score, after treatment for 12 h, the response rate was 93.22% in the treatment group and 73.33% in the control group, with a significant difference(P<0.05). After treatment for 6 h, theresponse rate in the treatment group was 88.33%, which was higher than that(63.33%) in the control group(P<0.05).The results showed that Shexiang Zhuifeng Zhitong Ointment applied for 12 and 6 h effectively relieved the knee joint pain of patients with knee osteoarthritis due to cold-dampness obstruction, as demonstrated by the reduced VAS score, Western Ontario and McMaster Universities Arthritis Index(WOMAC), stiffness, and joint function score. Moreover, Shexiang Zhuifeng Zhitong Ointment outperformed the positive control Shexiang Zhuifeng Ointment in terms of reducing the VAS score, demonstrating a definitetherapeutic effect on the pain due to knee osteoarthritis(syndrome of cold-dampness obstruction).In addition, Shexiang Zhuifeng Zhitong Ointment did not cause other adverse reactions except for mild allergic reactions, which were common in the external application of traditional Chinese medicine plasters on the skin, inseveral patients.Neither other adverse reactions nor abnormalities of liver and kidney functions and electrocardiogram were observed. This ointment had high safety and could be popularized in clinical application.

A targeted extracellular vesicles loaded with montelukast in the treatment of demyelinating diseases.

The main pathological characteristics of demyelinating diseases are central nervous system (CNS) myelin damage, and the differentiation of oligodendrocyte precursor cells is the therapeutic target of myelin repair. Previous studies have found that a large number of platelet-derived growth factor receptor α(PDGFRα) positive oligodendrocyte progenitor cells (OPCs) accumulate in the lesion area of myelin injury, and differentiation is blocked. However, the therapeutic effects of drugs currently used clinically on OPCs differentiation and myelin repair are limited. The main reason is that it is difficult to reach the effective concentration of the drug in the lesion area. Therefore, efficiently delivering into the CNS lesion area is of great significance for the treatment of MS. Natural exosomes have good biocompatibility and are ideal drug carriers. The delivery of drugs to lesion areas can be achieved by giving the exosomes armed targeting ligand. Therefore, in this study, combining exosomes with PDGFA helps them accumulate in OPCs in vitro and in vivo. Further, load montelukast into exosomes to achieve targeted therapy for cuprizone-induced demyelination animal model. The implementation of this research will help provide effective treatments for demyelinating diseases and lay a theoretical foundation for its application in the clinical treatment of different demyelinating diseases.

Treatment with anacardic acid modulates dendritic cell activation and alleviates the disease development of autoimmune neuroinflammation in mice.

Anacardic acid (AA) is a phenolic acid extract found in a number of plants, crops, and fruits. It exhibits a wide range of biological activities. This study displayed that AA effectively alleviated EAE, a classical mouse model of multiple sclerosis. AA administered to the EAE greatly decreased inflammatory cell infiltration to the CNS and protected the myelin integrity in the white matter of the spinal cord. AA could block lipopolysaccharide-induced DC activation. inhibited the polarization of 2D2 mice-derived T cells by inhibiting the DCs activity. Immunoblot results indicated that the phosphorylation of NF-κB is significantly suppressed in AA-treated DCs. This work displayed that AA possessed a potential anti-inflammatory therapeutic effect for the treatment of autoimmune disease.

Integrative analysis of differentially expressed mRNAs and proteins induced by PGC-1ß in breast cancer cells.

Breast cancer is one of the most frequent malignancies in females. The molecular mechanism of how breast cancer development and recurrence still need to be explored. Peroxisome gamma coactivator-1ß (PGC-1ß) was engaged in cancer energy metabolism and tumor genesis. However, the mechanisms of PGC-1ß in breast cancer have not been fully understood. In this study, PCG-1ß overexpressed and knockdown vectors were transferred into MCF-7 cells. With the association-quantitative connection analysis, the different expressions of mRNAs and proteins were examined. Additionally, the terms on differentially expressed mRNAs and proteins were enriched by GO and KEGG. Based on the results, 1872 differentially expressed genes were identified in the up-regulated of PGC-1ß group, and 1318 genes were found in the down-regulated of PGC-1ß cells. With the label-free technique, 221 differentially expressed proteins were screened in PGC-1ß up-regulated group, and 459 proteins were identified in PGC-1ß down-regulated group. Correlation analysis showed that 49 significantly expressed mRNA-protein pairs in OV vs CT groups and 25 paired in SI vs CT groups. Combined analysis of transcriptome and proteome demonstrated that PGC-1ß plays a important role in cancer energy metabolism and boosting the pace of chemical processes in the proliferation of breast cancer cells. Additional investigation about PGC-1ß and energy metabolism in cancer cells may shed fresh light on the growth and treatment of breast cancer cells.

Methamphetamine induces intestinal injury by altering gut microbiota and promoting inflammation in mice.

Methamphetamine (METH) is a psychostimulant abused worldwide. Its abuse induces intestinal toxicity. Moreover, the gut microbiota is altered by drugs, which induces intestinal injury. Whether gut microbiota mediates METH-induced intestinal toxicity remains to be validated. In the present study, wild-type and TLR4-/- mice were treated with METH. Gut microbiota was determined using 16S rRNA gene sequencing. Transcriptomics of the intestinal mucosa was performed by RNA-Sequencing. Blood levels of pro-inflammatory cytokines and lipopolysaccharide (LPS), the intestinal barrier, and inflammation were also assessed. METH treatment weakened the intestinal barrier and increased pro-inflammatory cytokines and LPS levels in the blood. Moreover, METH treatment significantly decreased the diversity of probiotics but increased the abundance of pathogenic gut microbiota, contributing to the over-production of LPS and disruption of intestinal barrier. Inflammatory pathways were enriched in the intestinal mucosa of METH-treated mice by KEGG analysis. Consistently, activation of the TLR4 pathway was determined in METH-treated mice, which confirmed intestinal inflammation. However, pretreatment with antibiotics or Tlr4 silencing significantly alleviated METH-induced gut microbiota dysbiosis, LPS over-production, intestinal inflammation, and disruption of the intestinal barrier. These findings suggested that the gut microbiota and LPS-mediated inflammation took an important role in METH-induced intestinal injury. Taken together, these findings suggest that METH-induced intestinal injury is mediated by gut microbiota dysbiosis and LPS-associated inflammation.

Silencing the Tlr4 Gene Alleviates Methamphetamine-Induced Hepatotoxicity by Inhibiting Lipopolysaccharide-Mediated Inflammation in Mice.

Methamphetamine (METH) is a stimulant drug. METH abuse induces hepatotoxicity, although the mechanisms are not well understood. METH-induced hepatotoxicity was regulated by TLR4-mediated inflammation in BALB/c mice in our previous study. To further investigate the underlying mechanisms, the wild-type (C57BL/6) and Tlr4-/- mice were treated with METH. Transcriptomics of the mouse liver was performed via RNA-sequencing. Histopathological changes, serum levels of metabolic enzymes and lipopolysaccharide (LPS), and expression of TLR4-mediated proinflammatory cytokines were assessed. Compared to the control, METH treatment induced obvious histopathological changes and significantly increased the levels of metabolic enzymes in wild-type mice. Furthermore, inflammatory pathways were enriched in the liver of METH-treated mice, as demonstrated by expression analysis of RNA-sequencing data. Consistently, the expression of TLR4 pathway members was significantly increased by METH treatment. In addition, increased serum LPS levels in METH-treated mice indicated overproduction of LPS and gut microbiota dysbiosis. However, antibiotic pretreatment or silencing Tlr4 significantly decreased METH-induced hepatic injury, serum LPS levels, and inflammation. In addition, the dampening effects of silencing Tlr4 on inflammatory pathways were verified by the enrichment analysis of RNA-sequencing data in METH-treated Tlr4-/- mice compared to METH-treated wild-type mice. Taken together, these findings implied that Tlr4 silencing, comparable to antibiotic pretreatment, effectively alleviated METH-induced hepatotoxicity by inhibiting LPS-TLR4-mediated inflammation in the liver.

Montelukast alleviates inflammation in experimental autoimmune encephalomyelitis by altering Th17 differentiation in a mouse model.

Montelukast is a leukotriene receptor antagonist that is known to prevent allergic rhinitis and asthma. Blocking the Cysteinyl leukotriene receptor (CysLTR1), one of the primary receptors of leukotrienes, has been demonstrated to be efficacious in ameliorating experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), through disrupting chemotaxis of infiltrating T cells. However, the role of CysLTR1 in the pathogenesis of MS is not well understood. Here, we show that MS patients had higher expression of CysLTR1 in the circulation and central nervous system (CNS). The majority of CD4+ T cells expressed CysLTR1 in MS lesions. Among T-cell subsets, Th17 cells had the highest expression of CysLTR1, and blocking CysLTR1 signalling abrogated their development in vitro. Inhibition of CysLTR1 by montelukast suppressed EAE development in both a prophylactic and therapeutic manner and inhibited myelin loss in EAE mice. Similarly, the in vivo results showed that montelukast inhibited Th17 response in EAE mice and that Th17 cells treated with montelukast had reduced encephalitogenic in adoptive EAE. Our findings strongly suggest that targeting Th17 response by inhibiting CysLTR1 signalling could be a promising therapeutic strategy for the treatment of MS and CNS inflammatory diseases.

Thyroid surgery without antibiotic prophylaxis: experiences with 1,030 patients from a teaching hospital in China.

OBJECTIVE: Our objective was to evaluate the outcome of thyroidectomy without the use of prophylactic antibiotics. This study was held from January 2005 to May 2012 in a teaching hospital in Dongguan, China. METHODS: A total of 1,030 thyroidectomy patients were retrospectively reviewed and basic data were recorded, including age, sex, peri-operative antibiotic use, type of thyroid surgery done, and post-operative complications. Either an open approach or an endoscopic approach was performed according to the doctor's or patient's preference following a strict aseptic technique. The drain was routinely placed. Any complications were analyzed. RESULTS: A total of 834 (81 %) females and 196 (19 %) males were included, giving a ratio of 4.2:1. The average age was 38.3 years. The mean operation time was 85.3 min. Pathological type included 818 (79.4 %) nodular goiter, 34 (3.3 %) Graves' disease, 102 (9.9 %) nodular papillary hyperplasia, 12 (1.2 %) Hashimoto's disease, 62 (6 %) papillary carcinoma, and 2 (0.2 %) medullary carcinoma. Four patients had postoperative bleeding, four had temporally recurrent nerve paralysis. Only one had wound infection (0.09 %). CONCLUSION: Antibiotic prophylaxis in elective thyroidectomy is not an essential pre-operation preparation for all patients, if guidelines for antibiotic prophylaxis in clean surgery are adhered to and surgeons have sophisticated skills in the procedure.

Clinical Diagnostic Value of circ-ARHGER28 for Breast Cancer and its Effect on MCF 7 Cell Proliferation and Apoptosis.

BACKGROUND/AIM: Clinical diagnostic value of circ-ARHGER28 in breast cancer (BC), and the biological functions of circ-ARHGER28 on the proliferation and apoptosis of MCF-7 cells were investigated. MATERIALS AND METHODS: Human circRNA microarray was performed to analyze the expression of circRNAs in BC patients. RT-qPCR combined with bioinformatics analysis was applied to verify the candidate circRNAs in BC tissues and peripheral blood samples. Circ-ARHGER28 was chosen as the candidate gene for further research. The clinical diagnostic value and biological functions of circ-ARHGER28 were analyzed. The overexpression and negative control vector of circ-ARHGER28 were constructed and transfected to MCF-7 cells. The CCK 8 assay and clone formation experiments were applied to detect the cell proliferative and migratory abilities. Flow cytometry was used to analyze cell apoptosis and cell cycle distribution. RT-qPCR and Western blot were performed to detect apoptosis and expression of PI3K/AKT/mTOR-associated genes and proteins. RESULTS: Overexpression of circ-ARHGER28 inhibited the proliferation, colony formation and migration of MCF-7 cells, while increasing the population of the cells in the G2/M phase and the apoptotic rate. Apoptosis associated genes and proteins were significantly increased, whereas gene and protein expression of PI3K, AKT and mTOR were decreased in the cells. CONCLUSION: Circular RNA ARHGER28 exhibits promising diagnostic value for BC. Circ-ARHGER28 inhibited MCF-7 cell proliferation and increased the apoptotic rate. The function of circ-ARHGER28 was associated with the PI3K/AKT/mTOR signaling pathway. Circ-ARHGER28 could be an ideal biomarker for BC diagnosis and a novel target for BC therapy.

Exosome-specific loading Sox10 for the treatment of Cuprizone-induced demyelinating model.

Demyelination is a pathological feature commonly observed in various central nervous system diseases. It is characterized by the aggregation of oligodendrocyte progenitor cells (OPCs) in the lesion area, which face difficulties in differentiating into mature oligodendrocytes (OLGs). The differentiation of OPCs requires the presence of Sox10, but its expression decreases under pathological conditions. Therefore, we propose a therapeutic strategy to regulate OPCs differentiation and achieve myelin repair by endogenously loading Sox10 into exosomes. To accomplish this, we generated a lentivirus-armed Sox10 that could anchor to the inner surface of the exosome membrane. We then infected HEK293 cells to obtain exosomes with high expression of Sox10 (exosomes-Sox10, ExoSs). In vitro, experiments confirmed that both Exos and ExoSs can be uptaken by OPCs, but only ExoSs exhibit a pro-differentiation effect on OPCs. In vivo, we administered PBS, Exos, and ExoSs to cuprizone-induced demyelinating mice. The results demonstrated that ExoSs can regulate the differentiation of PDGFRα+ OPCs into APC+ OLGs and reduce myelin damage in the corpus callosum region of the mouse brain compared to other groups. Further testing suggests that Sox10 may have a reparative effect on the myelin sheath by enhancing the expression of MBP, possibly facilitated by the exosome delivery of the protein into the lesion. This endogenously loaded technology holds promise as a strategy for protein-based drugs in the treatment of demyelinating diseases.

Autophagy in Multiple Sclerosis: Phagocytosis and Autophagy of Oligodendrocyte Precursor Cells.

Multiple sclerosis (MS) is a leading cause of chronic neurological dysfunction in young to middle-aged adults, affecting approximately 2.5 million people worldwide. It is characterized by inflammation, multifocal demyelination, axonal loss, and white and gray matter gliosis. Autophagy is a highly conserved protein degradation pathway. Polymorphisms in autophagy-related genes have been implicated in a variety of autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, psoriasis and MS. However, the significance of autophagy in MS remains to be elucidated. This paper aims to explore the potential role of autophagy-related genes in MS diseases by using bioinformatics combined with machine learning methods. Finally, we obtained 9 autophagy genes with the highest correlation with MS, and further changes in these autophagy genes were verified in the experimental autoimmune encephalomyelitis (EAE) model and oligodendrocyte precursor cells (OPCs) engulfed myelin debris (MD). Combined with bioinformatic analysis and experimental data, Becn1 showed obvious expression abnormalities suggesting that this gene has vital functions in autophagy and MD engulfed by OPCs. This work will be of great significance for the further exploration of autophagy-related genes in demyelinating diseases.

Engineered PDGFA-ligand-modified exosomes delivery T3 for demyelinating disease targeted therapy.

Demyelination is a proper syndrome in plenty of central nervous system (CNS) diseases, which is the main obstacle to recovery and still lacks an effective treatment. To overcome the limitations of the brain-blood barrier on drug permeability, we modified an exosome secreted by neural stem cells (NSCs), which had transfected with lentivirus armed with platelet-derived growth factors A (PDGFA)-ligand. Through the in vivo and in vitro exosomes targeting test, the migration ability to the lesion areas and OPCs significantly improved after ligand modification. Furthermore, the targeted exosomes loaded with 3,5, 30-L-triiodothyronine (T3) have a critical myelination ability in CNS development, administrated to the cuprizone animal model treatment. The data shows that the novel drug vector loaded with T3 significantly promotes remyelination compared with T3 alone. At the same time, it improved the CNS microenvironment by reducing astrogliosis, inhibiting pro-inflammatory microglia, and alleviating axon damage. This investigation provides a straightforward strategy to produce a targeting exosome and indicates a possible therapeutic manner for demyelinating disease.

A comprehensive analysis of listeriosis in 13 pregnant women and 27 newborns in Xi'an from 2011 to 2020.

Background: Listeriosis is a severe foodborne infection associated with high mortality. Pregnant women and newborns are at a particularly high risk of infection. However, the data on epidemiology of maternal-neonatal listeriosis in Xi'an are little known. The aim of this study was to investigate the epidemiological and clinical features of maternal-neonatal listeriosis in Xi'an. Methods: A total of 40 cases of listeriosis confirmed by positive cultures [blood or cerebrospinal fluid (CSF)] and admitted to the Northwest Women's and Children's Hospital (NWCH) from 2011 to 2020 were enrolled. Data from all patients were collected from the hospital's electronic medical records. Data analysis and epidemiological investigation were carried out by demographic information, time of onset, clinical and laboratory characteristics. Descriptive statistical indicators were obtained using SPSS21.0 and were expressed as median, mean, standard deviation and interquartile range. Results: The incidence of maternal and neonatal listeriosis in NWCH over the last decade was 5/100,000 and 10.4/100,000 respectively and Listeriosis was more likely to occur in spring and summer. The most common symptom was as follows: (I) maternal: fever (85%), abdominal pain (77%), vaginal fluid or colporrhagia (46%); (II) neonatal: respiratory distress (52%), fever (33%). Laboratary results were as follows: (I) maternal: elevated C-reactive protein (CRP) (100%), white blood cells (WBC) or neutrophil (NEUT#) (85%), and monocyte counts (MONO#) (77%); (II) neonatal: increased WBC (81%), MONO# (81%), CRP (78%), NEUT# and lymphocytes (73%); and elevated protein (PRO) (95%) and WBC count (86%) in CSF while decreased in glucose (GLU) (73%). Compared to neonatal group, the ratio of neutrophils to lymphocytes in maternal group raise to a higher level (92% to 42%). The outcomes of maternal were favorable and 54% of them suffered acute chorioamnionitism. Yet neonatal deaths account for up to 33%. Conclusions: Listeriosis is a rare disease with extremely variable clinical characteristics in Xi'an. Our data indicated that unexplained fever, abdominal pain, signs of premature and respiratory symptoms accompanied by a progressive increase in WBC, CRP, NEUT#, MONO# even include WBC and PRO in CSF while GLU decreased, the possibility of an LM infection should be considered.

An entropy-driven three-dimensional multipedal-DNA walker for ultrasensitive detection of cancer cells.

Sensitive and accurate detection of cancer cells is of great significance for the early diagnosis and treatment of cancer. In this work, we developed a simple fluorescent signal amplification biosensor based on an entropy-driven three-dimensional (3D) multipedal-DNA walker for highly sensitive detection of cancer cells. Firstly, DNA tetrahedron nanostructures (DTNs) combined with AS1411 aptamer were used as the capture probe to achieve efficient capture of cancer cells. Then, the bipedal hairpin fuel chain hybridized with DTNs and exposed two catalytic "legs" to form a walker probe. Finally, the walker probe autonomously walked on polystyrene microspheres (PS) via entropy-driven catalytic reaction. DTNs rolled on the PS to achieve multipedal walking, realizing fluorescence signal amplification due to fluorescence recovery of DNA-CdTe quantum dots on the PS surface. This fluorescence signal amplification strategy showed excellent selectivity and sensitivity toward cancer cells with the detection limit of 7 cell mL-1. This entropy-driven 3D multipedal DNA walker fluorescence exhibited great potential in detecting circulating tumor cells and tumor markers used for early diagnosis and clinical treatment of cancer.

Gene and protein expression profiles of olfactory ensheathing cells from olfactory bulb versus olfactory mucosa.

Olfactory ensheathing cells (OECs) from the olfactory bulb (OB) and the olfactory mucosa (OM) have the capacity to repair nerve injury. However, the difference in the therapeutic effect between OB-derived OECs and OM-derived OECs remains unclear. In this study, we extracted OECs from OB and OM and compared the gene and protein expression profiles of the cells using transcriptomics and non-quantitative proteomics techniques. The results revealed that both OB-derived OECs and OM-derived OECs highly expressed genes and proteins that regulate cell growth, proliferation, apoptosis and vascular endothelial cell regeneration. The differentially expressed genes and proteins of OB-derived OECs play a key role in regulation of nerve regeneration and axon regeneration and extension, transmission of nerve impulses and response to axon injury. The differentially expressed genes and proteins of OM-derived OECs mainly participate in the positive regulation of inflammatory response, defense response, cytokine binding, cell migration and wound healing. These findings suggest that differentially expressed genes and proteins may explain why OB-derived OECs and OM-derived OECs exhibit different therapeutic roles. This study was approved by the Animal Ethics Committee of the General Hospital of Ningxia Medical University (approval No. 2017-073) on February 13, 2017.

Methamphetamine Disturbs Gut Homeostasis and Reshapes Serum Metabolome, Inducing Neurotoxicity and Abnormal Behaviors in Mice.

As an illicit psychostimulant, repeated methamphetamine (MA) exposure results in addiction and causes severe neurotoxicity. Studies have revealed complex interactions among gut homeostasis, metabolism, and the central nervous system (CNS). To investigate the disturbance of gut homeostasis and metabolism in MA-induced neurotoxicity, 2 mg/kg MA or equal volume saline was intraperitoneally (i.p.) injected into C57BL/6 mice. Behavioral tests and western blotting were used to evaluate neurotoxicity. To determine alterations of colonic dysbiosis, 16s rRNA gene sequencing was performed to analyze the status of gut microbiota, while RNA-sequencing (RNA-seq) and Western Blot analysis were performed to detect colonic damage. Serum metabolome was profiled by LC-MS analysis. We found that MA induced locomotor sensitization, depression-, and anxiety-like behaviors in mice, along with dysfunction of the dopaminergic system and stimulation of autophagy as well as apoptosis in the striatum. Notably, MA significantly decreased microbial diversity and altered the component of microbiota. Moreover, findings from RNA-seq implied stimulation of the inflammation-related pathway after MA treatment. Western blotting confirmed that MA mediated colonic inflammation by activating the TLR4-MyD88-NF-κB pathway and impaired colonic barrier. In addition, serum metabolome was reshaped after MA treatment. Specifically, bacteroides-derived sphingolipids and serotonin were obviously altered, which were closely correlated with locomotor sensitization, depression-, and anxiety-like behaviors. These findings suggest that MA disrupts gut homeostasis by altering its microbiome and arousing inflammation, and reshapes serum metabolome, which provide new insights into understanding the interactions between gut homeostasis and MA-induced neurotoxicity.

Engineered extracellular vesicles encapsulated Bryostatin-1 as therapy for neuroinflammation.

Targeted and effective drug delivery to central nervous system (CNS) lesions is a major challenge in the treatment of multiple sclerosis (MS). Extracellular vesicles (EVs) have great promise as a drug delivery nanosystem given their unique characteristics, including a strong cargo-loading capacity, low immunogenicity, high biocompatibility, inherent stability, high delivery efficiency, ease of manipulation, and blood-brain barrier (BBB) penetration. Clinical applications are, however, limited by their insufficient targeting capability and "dilution effects" upon systemic administration. Neural stem cells (NSCs) provide an abundant source of EVs because of their remarkable capacity for self-renewal. Here, we developed a novel therapeutic strategy for local delivery and treatment using EVPs, which are derived from NSCs with the expression of the CNS lesion targeting ligand-PDGFRα. Furthermore, we used EVPs as a targeting carrier for encapsulating Bryostatin-1 (Bryo-1), a natural compound with remarkable anti-inflammation ability. Our data showed that Bryo-1 delivered by EVPs was more stable and concentrated in the CNS than native Bryo-1. Systemic injection of a low dosage (1 × 108 particles) of EVPs + Bryo-1, versus only EVPs or Bryo-1 administration, significantly ameliorated clinical disease development, decreased the infiltration of pro-inflammatory cells, blocked myelin loss and astrogliosis, protected BBB integrity, and altered microglia pro-inflammatory phenotype in the CNS of EAE mice. Taken as a whole, our study showed that engineered EVs have a CNS targeting capacity, and it provides potentially powerful therapeutic effects for the treatment of various neuroinflammatory diseases.

Targeting central nervous system extracellular vesicles enhanced triiodothyronine remyelination effect on experimental autoimmune encephalomyelitis.

The lack of targeted and high-efficiency drug delivery to the central nervous system (CNS) nidus is the main problem in the treatment of demyelinating disease. Extracellular vesicles (EVs) possess great promise as a drug delivery vector given their advanced features. However, clinical applications are limited because of their inadequate targeting ability and the "dilution effects" after systemic administration. Neural stem cells (NSCs) supply a plentiful source of EVs on account of their extraordinary capacity for self-renewal. Here, we have developed a novel therapeutic system using EVs from modified NSCs with high expressed ligand PDGF-A (EVPs) and achieve local delivery. It has been demonstrated that EVPs greatly enhance the target capability on oligodendrocyte lineage. Moreover, EVPs are used for embedding triiodothyronine (T3), a thyroid hormone that is critical for oligodendrocyte development but has serious side effects when systemically administered. Our results demonstrated that systemic injection of EVPs + T3, versus EVPs or T3 administration individually, markedly alleviated disease development, enhanced oligodendrocyte survival, inhibited myelin damage, and promoted myelin regeneration in the lesions of experimental autoimmune encephalomyelitis mice. Taken together, our findings showed that engineered EVPs possess a remarkable CNS lesion targeting potential that offers a potent therapeutic strategy for CNS demyelinating diseases as well as neuroinflammation.