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

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

Brain organoids have been proposed as suitable human brain model candidates for a variety of applications. However,the lack of appropriate maturation limits the transferability of such functional tools. Here,we present a method to facilitate neuronal maturation by integrating astrocyte-secreted factors into hPSC-derived 2D and 3D neural culture systems. We demonstrate that protein- and nutrient-enriched astrocyte-conditioned medium (ACM) accelerates neuronal differentiation with enlarged neuronal layer and the overproduction of deep-layer cortical neurons. We captured the elevated changes in the functional activity of neuronal networks within ACM-treated organoids using comprehensive electrophysiological recordings. Furthermore,astrocyte-secreted cues can induce lipid droplet accumulation in neural cultures,offering protective effects in neural differentiation to withstand cellular stress. Together,these data indicate the potential of astrocyte secretions to promote neural maturation. Subject terms: Neurological models,Neuronal development View Publication

Cerebral cavernous malformations (CCMs) are clusters of thin-walled enlarged blood vessels in the central nervous system that are prone to recurrent hemorrhage and can occur in both sporadic and familial forms. The familial form results from loss-of-function variants in the CCM1,CCM2,or CCM3 gene. Despite a better understanding of CCM pathogenesis in recent years,it is still unclear why CCM3 mutations often lead to a more aggressive phenotype than CCM1 or CCM2 variants. By combining high-throughput differentiation of blood vessel organoids from human induced pluripotent stem cells (hiPSCs) with a CCM1,CCM2,or CCM3 knockout,single-cell RNA sequencing,and high-content imaging,we uncovered both shared and distinct functions of the CCM proteins. While there was a significant overlap of differentially expressed genes in fibroblasts across all three knockout conditions,inactivation of CCM1,CCM2,or CCM3 also led to specific gene expression patterns in neuronal,mesenchymal,and endothelial cell populations,respectively. Taking advantage of the different fluorescent labels of the hiPSCs,we could also visualize the abnormal expansion of CCM1 and CCM3 knockout cells when differentiated together with wild-type cells into mosaic blood vessel organoids. In contrast,CCM2 knockout cells showed even reduced proliferation. These observations may help to explain the less severe clinical course in individuals with a pathogenic variant in CCM2 and to decode the molecular and cellular heterogeneity in CCM disease. Finally,the excellent scalability of blood vessel organoid differentiation in a 96-well format further supports their use in high-throughput drug discovery and other biomedical research studies. The online version contains supplementary material available at 10.1007/s10456-025-09985-5. 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

A mysterious feature of Crohn's disease (CD) is the extra-intestinal manifestation of creeping fat" (CrF) defined as expansion of mesenteric adipose tissue around the inflamed and fibrotic intestine. In the current study we explore whether microbial translocation in CD serves as a central cue for CrF development. We discovered a subset of mucosal-associated gut bacteria that consistently translocated and remained viable in CrF in CD ileal surgical resections and identified Clostridium innocuum as a signature of this consortium with strain variation between mucosal and adipose isolates suggesting preference for lipid-rich environments. Single-cell RNA sequencing characterized CrF as both pro-fibrotic and pro-adipogenic with a rich milieu of activated immune cells responding to microbial stimuli which we confirm in gnotobiotic mice colonized with C. innocuum. Ex vivo validation of expression patterns suggests C. innocuum stimulates tissue remodeling via M2 macrophages leading to an adipose tissue barrier that serves to prevent systemic dissemination of bacteria." View Publication

BACKGROUND The nonsense mutation,c.3846G{\textgreater}A (aka: W1282X-CFTR) leads to a truncated transcript that is susceptible to nonsense-mediated decay (NMD) and produces a shorter protein that is unstable and lacks normal channel activity in patient-derived tissues. However,if overexpressed in a heterologous expression system,the truncated mutant protein has been shown to mediate CFTR channel function following the addition of potentiators. In this study,we asked if a quadruple combination of small molecules that together inhibit nonsense mediated decay,stabilize both halves of the mutant protein and potentiate CFTR channel activity could rescue the functional expression of W1282X-CFTR in patient derived nasal cultures. METHODS We identified the CFTR domains stabilized by corrector compounds supplied from AbbVie using a fragment based,biochemical approach. Rescue of the channel function of W1282X.-CFTR protein by NMD inhibition and small molecule protein modulators was studied using a bronchial cell line engineered to express W1282X and in primary nasal epithelial cultures derived from four patients homozygous for this mutation. RESULTS We confirmed previous studies showing that inhibition of NMD using the inhibitor: SMG1i,led to an increased abundance of the shorter transcript in a bronchial cell line. Interestingly,on top of SMG1i,treatment with a combination of two new correctors developed by Galapagos/AbbVie (AC1 and AC2-2,separately targeting either the first or second half of CFTR and promoting assembly,significantly increased the potentiated channel activity by the mutant in the bronchial epithelial cell line and in patient-derived nasal epithelial cultures. The average rescue effect in primary cultures was approximately 50{\%} of the regulated chloride conductance measured in non-CF cultures. CONCLUSIONS These studies provide the first in-vitro evidence in patient derived airway cultures that the functional defects incurred by W1282X,has the potential to be effectively repaired pharmacologically. View Publication

Antiviral strategies to inhibit Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) and the pathogenic consequences of COVID-19 are urgently required. Here,we demonstrate that the NRF2 antioxidant gene expression pathway is suppressed in biopsies obtained from COVID-19 patients. Further,we uncover that NRF2 agonists 4-octyl-itaconate (4-OI) and the clinically approved dimethyl fumarate (DMF) induce a cellular antiviral program that potently inhibits replication of SARS-CoV2 across cell lines. The inhibitory effect of 4-OI and DMF extends to the replication of several other pathogenic viruses including Herpes Simplex Virus-1 and-2,Vaccinia virus,and Zika virus through a type I interferon (IFN)-independent mechanism. In addition,4-OI and DMF limit host inflammatory responses to SARS-CoV2 infection associated with airway COVID-19 pathology. In conclusion,NRF2 agonists 4-OI and DMF induce a distinct IFN-independent antiviral program that is broadly effective in limiting virus replication and in suppressing the pro-inflammatory responses of human pathogenic viruses,including SARS-CoV2. View Publication