Enhancing Neuroprotection in Mouse Model of Parkinson's Disease through Protein Nanosystem Conjugation with ApoE Peptide for miR-124 Delivery.

Parkinson's disease (PD) affects millions of people's lives worldwide. The main pathogenesis of PD is dopaminergic neuron necrosis and neuroinflammation mediated by activated microglia cells. In recent years, the anti-inflammatory ability and neuroprotective effects of miR-124 in PD models were well proved, but the in vivo delivery of miR-124 remains challenging. Herein, we report a protein nanosystem modified with a brain-targeting peptide ApoE that could efficiently deliver miR-124 across the blood-brain barrier (BBB). This nanosystem showed good cell viability on brain endothelial cells and microglia cells, and administration of this nanosystem significantly decreased the neuroinflammation and dopaminergic neuron loss, as well as recovered parts of neurobehavioral deficits. This ApoE peptide-based protein nanosystem holds great promise for the delivery of RNA therapeutics to the brain and for realizing neuron protection in PD treatment.

Maintaining Drosha expression with Cdk5 inhibitors as a potential therapeutic strategy for early intervention after TBI.

Traumatic brain injury (TBI) is a major cause of death and disability in adults. The pathological process of TBI involves a multifactorial cascade in which kinases have been proven contribute to interactions between relevant factors and amplification of signaling cascades. Cyclin-dependent kinase 5 (Cdk5) is a promising kinase that has been implicated in various brain disorders, including TBI. However, the mechanism by which Cdk5 induces neuronal damage remains unclear. Here, we show for the first time that Drosha, a key enzyme in microRNA biogenesis, is a pivotal substrate of abnormally activated Cdk5. Cdk5-mediated phosphorylation decreases Drosha expression and exacerbates nerve injury in TBI. We proved that maintaining Drosha expression via the administration of repurposed Cdk5 inhibitors that were previously studied in clinical trials is a promising approach for the early treatment of TBI. Together, our work identifies Drosha as a novel target for neuroprotective strategies after TBI and suggests Cdk5-mediated regulation of Drosha expression as a potential therapeutic strategy for early TBI intervention.

Factors associated with the disease family burden of caregivers of myasthenia gravis patients in northwestern China: A cross-sectional study.

BACKGROUND: Patients with myasthenia gravis (MG) lose part of their working or living ability due to illness, and bring burden to caregivers. The purpose of this study was to explore the factors related to caregivers' disease family burden for MG patients in Northwest China. METHODS: The study utilized our Myasthenia Gravis database and distributed online questionnaires to both MG patients and their caregivers. The questionnaires included a general data collection form, the Patient Health Questionnaire-9 (PHQ-9) scale, and the Caregivers' Family Burden Scale of Disease (FBSD). Univariate analysis and multivariate linear regression analysis were run, with FBSD as the outcome variable for separate analyses. RESULTS: 178 MG patients were eligible for inclusion in the analysis, of whom 80 patients' caregivers had a positive family burden of MG. The daily activity burden of the family and the economic burden of the family were the heaviest among the six dimensions of the caregivers' family disease burdens. The factors independently associated with FBSD were depression symptom level, MG severity classification and family's monthly per capita income (p < 0.05). CONCLUSIONS: Depression symptom level, MG severity classification and family's monthly per capita income are independent factors related to the caregivers' disease family burden for MG patients.

Direct regulation of FNIP1 and FNIP2 by MEF2 sustains MTORC1 activation and tumor progression in pancreatic cancer.

MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1) orchestrates diverse environmental signals to facilitate cell growth and is frequently activated in cancer. Translocation of MTORC1 from the cytosol to the lysosomal surface by the RRAG GTPases is the key step in MTORC1 activation. Here, we demonstrated that transcription factors MEF2A and MEF2D synergistically regulated MTORC1 activation via modulating its cyto-lysosome shutting. Mechanically, MEF2A and MEF2D controlled the transcription of FNIP1 and FNIP2, the components of the FLCN-FNIP1 or FNIP2 complex that acts as a RRAGC-RRAGD GTPase-activating element to promote the recruitment of MTORC1 to lysosome and its activation. Furthermore, we determined that the pro-oncogenic protein kinase SRC/c-Src directly phosphorylated MEF2D at three conserved tyrosine residues. The tyrosine phosphorylation enhanced MEF2D transcriptional activity and was indispensable for MTORC1 activation. Finally, both the protein and tyrosine phosphorylation levels of MEF2D are elevated in human pancreatic cancers, positively correlating with MTORC1 activity. Depletion of both MEF2A and MEF2D or expressing the unphosphorylatable MEF2D mutant suppressed tumor cell growth. Thus, our study revealed a transcriptional regulatory mechanism of MTORC1 that promoted cell anabolism and proliferation and uncovered its critical role in pancreatic cancer progression.Abbreviation: ACTB: actin beta; ChIP: chromatin immunoprecipitation; EGF: epidermal growth factor; EIF4EBP1: eukaryotic translation initiation factor 4E binding protein 1; FLCN: folliculin; FNIP1: folliculin interacting protein 1; FNIP2: folliculin interacting protein 2; GAP: GTPase activator protein; GEF: guanine nucleotide exchange factors; GTPase: guanosine triphosphatase; LAMP2: lysosomal associated membrane protein 2; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MEF2: myocyte enhancer factor 2; MEF2A: myocyte enhancer factor 2A; MEF2D: myocyte enhancer factor 2D; MEF2D-3YF: Y131F, Y333F, Y337F mutant; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; NR4A1: nuclear receptor subfamily 4 group A member 1; RPTOR: regulatory associated protein of MTOR complex 1; RHEB: Ras homolog, mTORC1 binding; RPS6KB1: ribosomal protein S6 kinase B1; RRAG: Ras related GTP binding; RT-qPCR: real time-quantitative PCR; SRC: SRC proto-oncogene, non-receptor tyrosine kinase; TMEM192: transmembrane protein 192; WT: wild-type.

Several miRNAs derived from serum extracellular vesicles are potential biomarkers for early diagnosis and progression of Parkinson's disease.

BACKGROUND: Blood-based test for predicting disease progression and early diagnosis of Parkinson's disease (PD) is an unmet need in the clinic. The profiles of microRNAs (miRNAs) are regarded as potential diagnostic biomarkers for human diseases, whereas miRNAs in the periphery are susceptible to the influence of various components. MiRNAs enriched in serum extracellular vesicles (EVs) have demonstrated disease-specific advantages in diagnosis due to their high abundance, stability and resistance to degradation. This study was aimed to screen differentially expressed EV-derived miRNAs between healthy controls and PD patients to aid in diagnosis of PD. METHODS: A total of 31 healthy controls and 72 patients with a diagnosis of PD at different Hoehn and Yahr stages in Tangdu Hospital were included. In total, 185 differentially expressed miRNAs were obtained through RNA sequencing of serum EVs as well as edgeR and t-test analyses. Subsequently, the weighted gene co-expression network analysis (WGCNA) was utilized to identify the commonly expressed miRNAs in all stages of PD by constructing connections between modules, and specifically expressed miRNAs in each stage of PD by functional enrichment analysis. After aligning these miRNAs with PD-related miRNAs in Human miRNA Disease Database, the screened miRNAs were further validated by receiver operating characteristic (ROC) curves and quantitative real-time polymerase chain reaction (qRT-PCR) using peripheral blood EVs from 40 more participants. RESULTS: WGCNA showed that 4 miRNAs were commonly associated with all stages of PD and 13 miRNAs were specifically associated with different stages of PD. Of the 17 obtained miRNAs, 7 were validated by ROC curve analysis and 7 were verified in 40 more participants by qRT-PCR. Six miRNAs were verified by both methods, which included 2 miRNAs that were commonly expressed in all stages of PD and 4 miRNAs that were specifically expressed in different stages of PD. CONCLUSIONS: The 6 serum EV-derived miRNAs, hsa-miR-374a-5p, hsa-miR-374b-5p, hsa-miR-199a-3p, hsa-miR-28-5p, hsa-miR-22-5p and hsa-miR-151a-5p, may potentially be used as biomarkers for PD progression and for early diagnosis of PD in populations.