搜索结果: 'methocult media formulations for human hematopoietic cells serum containing'

Alpha-synuclein (aSyn) post-translational modifications (PTM),especially phosphorylation at serine 129 and C-terminal truncations,are highly enriched in Lewy bodies (LB),Lewy neurites,and other pathological aggregates in Parkinson’s disease and synucleinopathies. However,the precise role of these PTM in pathology formation,neurodegeneration,and pathology spreading remains unclear. Here,we systematically investigated the role of post-fibrillization C-terminal aSyn truncations in regulating uptake,processing,seeding,and LB-like inclusion formation using a neuronal seeding model that recapitulates LB formation and neurodegeneration. We show that C-terminal cleavage of aSyn fibrils occurs rapidly post exogenous fibril internalization and during intracellular LB-like inclusion formation. Blocking cleavage of internalized fibrils does not affect seeding,but inhibiting enzymes such as calpains 1 and 2 alters LB-like inclusion formation. We show that C-terminal truncations,along with other PTMs,regulate fibril interactome remodeling,shortening,lateral association,and packing. These findings reveal distinct roles of C-terminal truncations at different aggregation stages on the pathway to LB formation,highlighting the need for consideration of stage‑specific strategies to target aSyn proteolytic cleavages. View Publication

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract with a complex and multifactorial etiology,making it challenging to treat. While recent advances in immunomodulatory biologics,such as antitumor necrosis factor-α (TNF-α) antibodies,have shown moderate success,systemic administration of antibody therapeutics may lead to several adverse effects,including the risk of autoimmune disorders due to systemic cytokine depletion. Transient RNA interference using exogenous short interfering RNA (siRNA) to regulate target gene expression at the transcript level offers an alternative to systemic immunomodulation. However,siRNAs are susceptible to premature degradation and have poor cellular uptake. Graphene oxide (GO) nanoparticles have been shown to be effective nanocarriers for biologics due to their reduced cytotoxicity and enhanced bioavailability. In this study,we evaluate the therapeutic efficacy of GO mediated TNF-α_siRNA using in vitro models of chronic inflammation generated by treating murine small intestines (enteroids) and large intestines (colonoids) with inflammatory agents IL-1β,TNF-α,and LPS. The organotypic mouse enteroids and colonoids developed an inflammatory phenotype similar to that of IBD,characterized by impaired epithelial homeostasis and an increased production of inflammatory cytokines such as TNF-α,IL-1β,and IL-6. We assessed siRNA delivery to these inflamed organoids using three different GO formulations. Out of the three,small-sized GO with polymer and dendrimer modifications (smGO) demonstrated the highest transfection efficiency,which led to the downregulation of inflammatory cytokines,indicating an attenuation of the inflammatory phenotype. Moreover,the transfection efficiency and inflammation-ameliorating effects could be further enhanced by increasing the TNF-α_siRNA/smGO ratio from 1:1 to 3:1. Overall,the results of this study demonstrate that ex vivo organoids with disease-specific phenotypes are invaluable models for assessing the therapeutic potential of nanocarrier-mediated drug and biologic delivery systems. View Publication

The delicate “Excitatory/Inhibitory balance” between neurons holds significance in neurodegenerative and neurodevelopmental diseases. With the ultimate goal of creating a faithful in vitro model of the human brain,in this study,we investigated the critical factor of heterogeneity,focusing on the interplay between excitatory glutamatergic (E) and inhibitory GABAergic (I) neurons in neural networks. We used high-density Micro-Electrode Arrays (MEA) with 2304 recording electrodes to investigate two neuronal culture configurations: 100% glutamatergic (100E) and 75% glutamatergic / 25% GABAergic (75E25I) neurons. This allowed us to comprehensively characterize the spontaneous electrophysiological activity exhibited by mature cultures at 56 Days in vitro,a time point in which the GABA shift has already occurred. We explored the impact of heterogeneity also through electrical stimulation,revealing that the 100E configuration responded reliably,while the 75E25I required more parameter tuning for improved responses. Chemical stimulation with BIC showed an increase in terms of firing and bursting activity only in the 75E25I condition,while APV and CNQX induced significant alterations on both dynamics and functional connectivity. Our findings advance understanding of diverse neuron interactions and their role in network activity,offering insights for potential therapeutic interventions in neurological conditions. Overall,this work contributes to the development of a valuable human-based in vitro system for studying physiological and pathological conditions,emphasizing the pivotal role of neuron diversity in neural network dynamics. View Publication

Dimethylsulfoxide (DMSO) has conventionally been used for cell cryopreservation both in research and in clinical applications,but has long-term cytotoxic effects. Trehalose,a natural disaccharide,has been proposed as a non-toxic cryoprotectant. However,the lack of specific cell membrane transporter receptors inhibits transmembrane transport and severely limits its cryoprotective capability. This research presents a method to successfully deliver trehalose into mesenchymal stem cells (MSCs) using ultrasound in the presence of microbubbles. The optimised trehalose concentration was shown to be able to not only preserve membrane integrity and cell viability but also the multipotency of MSCs,which are essential for stem cell therapy. Confocal imaging revealed that rhodamine-labelled trehalose was transported into cells rather than simply attached to the membrane. Additionally,the membranes were successfully preserved in lyophilised cells. This study demonstrates that ultrasonication with microbubbles facilitated trehalose delivery,offering promising cryoprotective capability without the cytotoxicity associated with DMSO-based methods. Subject terms: Membrane biophysics,Biomedical engineering View Publication

Acute myeloid leukemia (AML) is a deadly hematopoietic malignancy. Although many patients achieve complete remission with standard induction therapy,a combination of cytarabine and anthracycline,~40% of patients have induction failure. These refractory patients pose a treatment challenge,as they do not respond to salvage therapy or allogeneic stem cell transplant. Herein,we show that AML patients who experience induction failure have elevated expression of the NF-κB target gene tumor necrosis factor alpha-induced protein-3 (TNFAIP3/A20) and impaired necroptotic cell death. A20 High AML are resistant to anthracyclines,while A20 Low AML are sensitive. Loss of A20 in AML restores sensitivity to anthracycline treatment by inducing necroptosis. Moreover,A20 prevents necroptosis in AML by targeting the necroptosis effector RIPK1,and anthracycline-induced necroptosis is abrogated in A20 High AML. These findings suggest that NF-κB-driven A20 overexpression plays a role in failed chemotherapy induction and highlights the potential of targeting an alternative cell death pathway in AML. Subject terms: Acute myeloid leukaemia,Cancer therapeutic resistance View Publication

Mild therapeutic hypothermia showed potential neuroprotective properties during and after cerebral hypoxia or ischemia in experimental animal studies. However,in clinical trials,where hypothermia is mainly applied after reperfusion,results were divergent and neurophysiological effects unclear. In our current study,we employed human-derived neuronal networks to investigate how treatment with hypothermia during hypoxia influences neuronal functionality and whether it improves post-hypoxic recovery. We differentiated neuronal networks from human induced pluripotent stem cells on micro-electrode arrays (MEAs). We studied the effect of hypothermia (34°C)–as well hyperthermia (39°C) ‐ on neuronal functionality during and after hypoxia using MEAs. We also studied the effects on the number of synaptic puncta and cell viability by immunocytochemistry. In comparison to neuronal networks under normothermia,we found that hypothermia during hypoxia improved functional neuronal network recovery,expressed as enhanced neuronal network activity. This was associated with prevention of synaptic loss during and after the hypoxic phase. Furthermore,hypothermia improved cell viability after the hypoxic phase. Instead,hyperthermia during hypoxia had detrimental effects,with an irreversible loss of neuronal network function,loss of synaptic puncta and decreased cell viability. Our results show potential neuroprotective properties of hypothermia occurring during hypoxia,indicating that administering hypothermia to bridge the time to reperfusion may be beneficial in clinical settings. View Publication

Cytolysin A (ClyA) is a pore‐forming protein from a strongly silenced gene in non‐pathogenic Escherichia coli,including typical commensal isolates in the intestinal microbiome of healthy mammalian hosts. Upon overproduction,ClyA‐expressing bacteria display a cytolytic phenotype. However,it remains unclear whether sublytic amounts of native ClyA play a role in commensal E. coli ‐host interactions in vivo. Here,we show that sublytic amounts of ClyA are released via outer membrane vesicles (OMVs) and affect host cells in a remarkable manner. OMVs isolated from ClyA + E. coli were internalised into cultured colon cancer cells. The OMV‐associated ClyA caused reduced levels of cancer‐activating proteins such as H3K27me3,CXCR4,STAT3 and MDM2 via the EZH2/H3K27me3/microRNA 622/CXCR4 signalling axis. Our results demonstrate that sublytic amounts of ClyA in OMVs from non‐pathogenic E. coli can influence the stability of the EZH2 protein,reducing its activity in epigenetic regulation,causing elevated level of the tumour suppressor protein p53. View Publication

Monoclonal antibody-based immune checkpoint inhibitors,which have brought breakthrough effects in cancer treatments,are expected to assist in the treatment of viral diseases. However,antibody therapies may cause immune-related side effects,such as inflammation and pneumonia,due to cytokine storms. Small-molecule PD-1/PD-L1 inhibitors are an alternative to monoclonal antibody-based therapeutics. We have identified a novel small-molecule PD-1/PD-L1 inhibitor having a functional group (disulfide group),namely compound 2 (molecular weight: 456.6),from our library of sulfur-containing protein–protein interaction inhibitor compounds. Compound 2 selectively bound to PD-L1 over PD-1,with the dissociation rate constant (K D ) of 77.60 ± 4.44 nM (obtained by affinity analysis) and showed promising T cell activation recovery. A molecular docking simulation study between 2 and PD-L1 suggested that 2 binds to PD-L1 in a binding mode different from those of other small-molecule PD-L1/PD-1 inhibitors. Notably,oral administration of 2 to mice pre-infected with influenza A virus (A/NWS/33,H1N1 subtype) caused a significant increase in the neutralizing antibody titers,as well as recovery from influenza-induced pneumonia. Overall,2 provides insight for the development of therapeutic drugs against early viral infections,with both virus titer-reducing and antibody titer-boosting effects. Moreover,2 is widely used as a rubber peptizing agent in the production process of tires and other rubber products. Our findings may provide useful information for investigating its influence on living organisms. The online version contains supplementary material available at 10.1038/s41598-025-17982-3. Subject terms: Drug discovery and development,Pharmacology,Screening,Structure-based drug design View Publication

Cell-to-cell communication by exosomes controls normal and pathogenic processes1,2. Viruses can spread in exosomes and thereby avoid immune recognition3. While biogenesis,binding and uptake of exosomes are well characterized4,5,delivery of exosome cargo into the cytoplasm is poorly understood3. We report that the phosphatidylserine receptor HAVCR1 (refs. 6,7) and the cholesterol transporter NPC1 (ref. 8) participate in cargo delivery from exosomes of hepatitis A virus (HAV)-infected cells (exo-HAV) by clathrin-mediated endocytosis. Using CRISPR-Cas9 knockout technology,we show that these two lipid receptors,which interact in the late endosome9,are necessary for the membrane fusion and delivery of RNA from exo-HAV into the cytoplasm. The HAVCR1-NPC1 pathway,which Ebola virus exploits to infect cells9,mediates HAV infection by exo-HAV,which indicates that viral infection via this exosome mimicry mechanism does not require an envelope glycoprotein. The capsid-free viral RNA in the exosome lumen,but not the endosomal uncoating of HAV particles contained in the exosomes,is mainly responsible for exo-HAV infectivity as assessed by methylene blue inactivation of non-encapsidated RNA. In contrast to exo-HAV,infectivity of HAV particles is pH-independent and requires HAVCR1 or another as yet unidentified receptor(s) but not NPC1. Our findings show that envelope-glycoprotein-independent fusion mechanisms are shared by exosomes and viruses,and call for a reassessment of the role of envelope glycoproteins in infection. View Publication

Developmental and/or epileptic encephalopathies (DEEs) are a group of devastating genetic disorders,resulting in early-onset,therapy-resistant seizures and developmental delay. Here we report on 22 individuals from 15 families presenting with a severe form of intractable epilepsy,severe developmental delay,progressive microcephaly,visual disturbance and similar minor dysmorphisms. Whole exome sequencing identified a recurrent,homozygous variant (chr2:64083454A {\textgreater} G) in the essential UDP-glucose pyrophosphorylase (UGP2) gene in all probands. This rare variant results in a tolerable Met12Val missense change of the longer UGP2 protein isoform but causes a disruption of the start codon of the shorter isoform,which is predominant in brain. We show that the absence of the shorter isoform leads to a reduction of functional UGP2 enzyme in neural stem cells,leading to altered glycogen metabolism,upregulated unfolded protein response and premature neuronal differentiation,as modeled during pluripotent stem cell differentiation in vitro. In contrast,the complete lack of all UGP2 isoforms leads to differentiation defects in multiple lineages in human cells. Reduced expression of Ugp2a/Ugp2b in vivo in zebrafish mimics visual disturbance and mutant animals show a behavioral phenotype. Our study identifies a recurrent start codon mutation in UGP2 as a cause of a novel autosomal recessive DEE syndrome. Importantly,it also shows that isoform-specific start-loss mutations causing expression loss of a tissue-relevant isoform of an essential protein can cause a genetic disease,even when an organism-wide protein absence is incompatible with life. We provide additional examples where a similar disease mechanism applies. View Publication

The stimulator of interferon genes (STING) pathway has been proposed as a key regulator of gastrointestinal homeostasis and inflammatory responses. Although STING reportedly protects against gut barrier damage and graft-versus-host disease (GVHD) after major histocompatibility complex (MHC)-mismatched allogeneic hematopoietic stem cell transplantation (aHSCT),its effect in clinically relevant MHC-matched aHSCT is unknown. Studies here demonstrate that STING signaling in nonhematopoietic cells promoted MHC-matched aHSCT-induced GVHD and that STING agonists increased type I interferon and MHC I expression in nonhematopoietic mouse intestinal organoid cultures. Moreover,mice expressing a human STING allele containing three single-nucleotide polymorphisms associated with decreased STING activity also developed reduced MHC-matched GVHD,demonstrating STING's potential clinical importance. STING-/- recipients experienced reduced GVHD with transplant of purified donor CD8+ T cells in both MHC-matched and MHC-mismatched models,reconciling the seemingly disparate results. Further examination revealed that STING deficiency reduced the activation of donor CD8+ T cells early after transplant and promoted recipient MHC class II+ antigen-presenting cell (APC) survival. Therefore,APC persistence in STING pathway absence may account for the increased GVHD mediated by CD4+ T cells in completely mismatched recipients. In total,our findings have important implications for regulating clinical GVHD by targeting STING early after aHSCT and demonstrate that an innate immune pathway has opposing effects on the outcome of aHSCT,depending on the donor/recipient MHC disparity. View Publication