Human Schwann Cell-Derived Extracellular Vesicle Isolation, Bioactivity Assessment, and Omics Characterization

Aisha Khan,1,2 Julia Oliveira,2 Yee-Shuan Lee,1 James D Guest,2,3 Risset Silvera,2 Yelena Pressman,2 Damien D Pearse,2,3 Adriana E Nettina,1,2 Pascal J Goldschmidt-Clermont,4 Hassan Al-Ali,2 Indigo Williams,2 Allan D Levi,2,3 W Dalton Dietrich2,3 1Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, FL, USA; 2The Miami Project to Cure Paralysis, Miller School of Medicine, University of Miami, Miami, FL, USA; 3Neurological Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA; 4Miller School of Medicine, University of Miami, Miami, FL, USACorrespondence: Aisha Khan, Email [email protected]: Schwann cell-derived extracellular vesicles (SCEVs) have demonstrated favorable effects in spinal cord, peripheral nerve, and brain injuries. Herein, a scalable, standardized, and efficient isolation methodology of SCEVs obtaining a high yield with a consistent composition as measured by proteomic, lipidomic, and miRNA analysis of their content is described for future clinical use.Methods: Human Schwann cells were obtained ethically from nine donors and cultured in a defined growth medium optimized for proliferation. At confluency, the culture was replenished with an isolation medium for 48 hours, then collected and centrifuged sequentially at low and ultra-high speeds to collect purified EVs. The EVs were characterized with mass spectrometry to identify and quantify proteins, lipidomic analysis to assess lipid composition, and next-generation sequencing to confirm miRNA profiles. Each batch of EVs was assessed to ensure their therapeutic potential in promoting neurite outgrowth and cell survival.Results: High yields of SCEVs were consistently obtained with similar comprehensive molecular profiles across samples, indicating the reproducibility and reliability of the isolation method. Bioactivity to increase neurite process growth was confirmed in vitro. The predominance of triacylglycerol and phosphatidylcholine suggested its role in cellular membrane dynamics essential for axon regeneration and inflammation mitigation. Of the 2517 identified proteins, 136 were closely related to nervous system repair and regeneration. A total of 732 miRNAs were cataloged, with the top 30 miRNAs potentially contributing to axon growth, neuroprotection, myelination, angiogenesis, the attenuation of neuroinflammation, and key signaling pathways such as VEGFA-VEGFR2 and PI3K-Akt signaling, which are crucial for nervous system repair.Conclusion: The study establishes a robust framework for SCEV isolation and their comprehensive characterization, which is consistent with their therapeutic potential in neurological applications. This work provides a valuable proteomic, lipidomic, and miRNA dataset to inform future advancements in applying SCEV to the experimental treatment of neurological injuries and diseases.Keywords: myelination, axon growth, neuroprotection, regeneration, lipidomi

Controlling Population Evolution in the Laboratory to Evaluate Methods of Historical Inference

Natural populations of known detailed past demographic history are extremely valuable to evaluate methods of historical inference, yet are extremely rare. As an alternative approach, we have generated multiple replicate microsatellite data sets from laboratory-cultured populations of a gonochoric free-living nematode, Caenorhabditis remanei, that were constrained to pre-defined demographic histories featuring different levels of migration among populations or bottleneck events of different magnitudes. These data sets were then used to evaluate the performances of two recently developed population genetics methods, BayesAss+, that estimates recent migration rates among populations, and Bottleneck, that detects the occurrence of recent bottlenecks. Migration rates inferred by BayesAss+ were generally over-estimates, although these were often included within the confidence interval. Analyses of data sets simulated in-silico, using a model mimicking the laboratory experiments, produced less biased estimates of the migration rates, and showed increased efficiency of the program when the number of loci and sampled genotypes per population was higher. In the replicates for which the pre-bottleneck laboratory-cultured populations did not significantly depart from a mutation/drift equilibrium, an important assumption of the program Bottleneck, only a portion of the bottleneck events were detected. This result was confirmed by in-silico simulations mirroring the laboratory bottleneck experiments. More generally, our study demonstrates the feasibility, and highlights some of the limits, of the approach that consists in generating molecular genetic data sets by controlling the evolution of laboratory-reared nematode populations, for the purpose of validating methods inferring population history

The Mitotic Arrest Deficient Protein MAD2B Interacts with the Clathrin Light Chain A during Mitosis

Contains fulltext : 87811.pdf (publisher's version ) (Open Access)BACKGROUND: Although the mitotic arrest deficient protein MAD2B (MAD2L2) is thought to inhibit the anaphase promoting complex (APC) by binding to CDC20 and/or CDH1 (FZR1), its exact role in cell cycle control still remains to be established. METHODOLOGY/PRINCIPAL FINDINGS: Using a yeast two-hybrid interaction trap we identified the human clathrin light chain A (CLTA) as a novel MAD2B binding protein. A direct interaction was established in mammalian cells via GST pull-down and endogenous co-immunoprecipitation during the G2/M phase of the cell cycle. Through subsequent confocal laser scanning microscopy we found that MAD2B and CLTA co-localize at the mitotic spindle. Clathrin forms a trimeric structure, i.e., the clathrin triskelion, consisting of three heavy chains (CLTC), each with an associated light chain. This clathrin structure has previously been shown to be required for the function of the mitotic spindle through stabilization of kinetochore fibers. Upon siRNA-mediated MAD2B depletion, we found that CLTA was no longer concentrated at the mitotic spindle but, instead, diffusely distributed throughout the cell. In addition, we found a marked increase in the percentage of misaligned chromosomes. CONCLUSIONS/SIGNIFICANCE: Previously, we identified MAD2B as an interactor of the renal cell carcinoma (RCC)-associated protein PRCC. In addition, we found that fusion of PRCC with the transcription factor TFE3 in t(X;1)(p11;q21)-positive RCCs results in an impairment of this interaction and a concomitant failure to shuttle MAD2B to the nucleus. Our current data show that MAD2B interacts with CLTA during the G2/M phase of the cell cycle and that depletion of MAD2B leads to a marked increase in the percentage of misaligned chromosomes and a redistribution of CLTA during mitosis

Tracking human multiple myeloma xenografts in NOD-Rag-1/IL-2 receptor gamma chain-null mice with the novel biomarker AKAP-4

<p>Abstract</p> <p>Background</p> <p>Multiple myeloma (MM) is a fatal malignancy ranking second in prevalence among hematological tumors. Continuous efforts are being made to develop innovative and more effective treatments. The preclinical evaluation of new therapies relies on the use of murine models of the disease.</p> <p>Methods</p> <p>Here we describe a new MM animal model in NOD-Rag1null IL2rgnull (NRG) mice that supports the engraftment of cell lines and primary MM cells that can be tracked with the tumor antigen, AKAP-4.</p> <p>Results</p> <p>Human MM cell lines, U266 and H929, and primary MM cells were successfully engrafted in NRG mice after intravenous administration, and were found in the bone marrow, blood and spleen of tumor-challenged animals. The AKAP-4 expression pattern was similar to that of known MM markers, such as paraproteins, CD38 and CD45.</p> <p>Conclusions</p> <p>We developed for the first time a murine model allowing for the growth of both MM cell lines and primary cells in multifocal sites, thus mimicking the disease seen in patients. Additionally, we validated the use of AKAP-4 antigen to track tumor growth <it>in vivo </it>and to specifically identify MM cells in mouse tissues. We expect that our model will significantly improve the pre-clinical evaluation of new anti-myeloma therapies.</p

Postoperative acute kidney injury in adult non-cardiac surgery:joint consensus report of the Acute Disease Quality Initiative and PeriOperative Quality Initiative

Postoperative acute kidney injury (PO-AKI) is a common complication of major surgery that is strongly associated with short-term surgical complications and long-term adverse outcomes, including increased risk of chronic kidney disease, cardiovascular events and death. Risk factors for PO-AKI include older age and comorbid diseases such as chronic kidney disease and diabetes mellitus. PO-AKI is best defined as AKI occurring within 7 days of an operative intervention using the Kidney Disease Improving Global Outcomes (KDIGO) definition of AKI; however, additional prognostic information may be gained from detailed clinical assessment and other diagnostic investigations in the form of a focused kidney health assessment (KHA). Prevention of PO-AKI is largely based on identification of high baseline risk, monitoring and reduction of nephrotoxic insults, whereas treatment involves the application of a bundle of interventions to avoid secondary kidney injury and mitigate the severity of AKI. As PO-AKI is strongly associated with long-term adverse outcomes, some form of follow-up KHA is essential; however, the form and location of this will be dictated by the nature and severity of the AKI. In this Consensus Statement, we provide graded recommendations for AKI after non-cardiac surgery and highlight priorities for future research

World Society of Emergency Surgery (WSES) guidelines for management of skin and soft tissue infections

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