技术资料

Although regenerative medicine products are at the forefront of scientific research,technological innovation,and clinical translation,their reproducibility and large-scale production are compromised by automation,monitoring,and standardization issues. To overcome these limitations,new technologies at software (e.g.,algorithms and artificial intelligence models,combined with imaging software and machine learning techniques) and hardware (e.g.,automated liquid handling,automated cell expansion bioreactor systems,automated colony-forming unit counting and characterization units,and scalable cell culture plates) level are under intense investigation. Automation,monitoring and standardization should be considered at the early stages of the developmental cycle of cell products to deliver more robust and effective therapies and treatment plans to the bedside,reducing healthcare expenditure and improving services and patient care. View Publication

Autophagy is a cellular catabolic process responsible for the degradation of cytoplasmic constituents,including organelles and long-lived proteins,that helps maintain cellular homeostasis and protect against various cellular stresses. Verteporfin is a benzoporphyrin derivative used clinically in photodynamic therapy to treat macular degeneration. Verteporfin was recently found to inhibit autophagosome formation by an unknown mechanism that does not require exposure to light. We report that verteporfin directly targets and modifies p62,a scaffold and adaptor protein that binds both polyubiquitinated proteins destined for degradation and LC3 on autophagosomal membranes. Western blotting experiments revealed that exposure of cells or purified p62 to verteporfin causes the formation of covalently crosslinked p62 oligomers by a mechanism involving low-level singlet oxygen production. Rose bengal,a singlet oxygen producer structurally unrelated to verteporfin,also produced crosslinked p62 oligomers and inhibited autophagosome formation. Co-immunoprecipitation experiments demonstrated that crosslinked p62 oligomers retain their ability to bind to LC3 but show defective binding to polyubiquitinated proteins. Mutations in the p62 PB1 domain that abolish self-oligomerization also abolished crosslinked oligomer formation. Interestingly,small amounts of crosslinked p62 oligomers were detected in untreated cells,and other groups noted the accumulation of p62 forms with reduced SDS-PAGE mobility in cellular and animal models of oxidative stress and aging. These data indicate that p62 is particularly susceptible to oxidative crosslinking and lead us to propose a model whereby oxidized crosslinked p62 oligomers generated rapidly by drugs like verteporfin or over time during the aging process interfere with autophagy. View Publication

We used synthetic lethal high-throughput screening to interrogate 23,550 compounds for their ability to kill engineered tumorigenic cells but not their isogenic normal cell counterparts. We identified known and novel compounds with genotype-selective activity,including doxorubicin,daunorubicin,mitoxantrone,camptothecin,sangivamycin,echinomycin,bouvardin,NSC146109,and a novel compound that we named erastin. These compounds have increased activity in the presence of hTERT,the SV40 large and small T oncoproteins,the human papillomavirus type 16 (HPV) E6 and E7 oncoproteins,and oncogenic HRAS. We found that overexpressing hTERT and either E7 or LT increased expression of topoisomerase 2alpha and that overexpressing RAS(V12) and ST both increased expression of topoisomerase 1 and sensitized cells to a nonapoptotic cell death process initiated by erastin. View Publication

BACKGROUND While essential to the normal differentiation of ciliated airway epithelial cells,upregulated Wnt signaling in chronic rhinosinusitis with nasal polyps (CRSwNP) has been proposed to result in abnormal epithelial morphology and dysfunctional mucociliary clearance. The mechanism of epithelial Wnt signaling dysregulation in CRSwNP is unknown,and importantly cellular sources of Wnt ligands in CRSwNP have not yet been investigated. METHODS Human sinonasal epithelial cells (hSNECs) and human sinonasal fibroblasts (hSNFs) were collected from 34 human subjects (25 control and 9 CRSwNP) and differentiated as primary air-liquid interface (ALI) and organoid co-cultures. hSNECs were isolated to the apical compartment of the transwell and hSNFs were isolated to the basolateral compartment. After 21 days of ALI culture,ciliary expression and sinonasal epithelial morphology were examined by immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qRT-PCR). An organoid model was used to evaluate proliferation of basal cells in presence of hSNFs. RESULTS Epithelial cells co-cultured with CRSwNP-hSNFs revealed significantly decreased ciliated cells,altered epithelial cell morphology,and increased colony forming efficiency compared to epithelial cells co-cultured with control-hSNFs. CRSwNP-hSNFs showed significantly higher messenger RNA (mRNA) expression of canonical WNT3A. A Wnt agonist,CHIR99021,replicated CRSwNP-hSNF co-cultures,and treatment with the Wnt inhibitor IWP2 prevented abnormal morphologies. CONCLUSION These results suggest that abnormal interactions between epithelial cells and fibroblasts may contribute to CRSwNP pathogenesis and supports the concept that dysregulated Wnt signaling contributes impairment to epithelial function in CRSwNP. View Publication

Although arsenic trioxide (As(2)O(3)) is an effective therapy in acute promyelocytic leukemia (APL),its use in other malignancies is limited by the toxicity of concentrations required to induce apoptosis in non-APL tumor cells. We looked for agents that would synergize with As(2)O(3) to induce apoptosis in malignant cells,but not in normal cells. We found that trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid),a widely known antioxidant,enhances As(2)O(3)-mediated apoptosis in APL,myeloma,and breast cancer cells. Treatment with As(2)O(3) and trolox increased intracellular oxidative stress,as evidenced by heme oxygenase-1 (HO-1) protein levels,c-Jun terminal kinase (JNK) activation,and protein and lipid oxidation. The synergistic effects of trolox may be specific to As(2)O(3),as trolox does not add to toxicity induced by other chemotherapeutic drugs. We explored the mechanism of this synergy using electron paramagnetic resonance and observed the formation of trolox radicals when trolox was combined with As(2)O(3),but not with doxorubicin. Importantly,trolox protected nonmalignant cells from As(2)O(3)-mediated cytotoxicity. Our data provide the first evidence that trolox may extend the therapeutic spectrum of As(2)O(3). Furthermore,the combination of As(2)O(3) and trolox shows potential specificity for tumor cells,suggesting it may not increase the toxicity associated with As(2)O(3) monotherapy in vivo. View Publication

Skeletal aging is a complex process,characterized by a decrease in bone formation,an increase in marrow fat,and stem cell exhaustion. Loss of H3K9me3,a heterochromatin mark,has been proposed to be associated with aging. Here,we report that loss of KDM4B in mesenchymal stromal cells (MSCs) exacerbated skeletal aging and osteoporosis by reducing bone formation and increasing marrow adiposity via increasing H3K9me3. KDM4B epigenetically coordinated $\beta$-catenin/Smad1-mediated transcription by removing repressive H3K9me3. Importantly,KDM4B ablation impaired MSC self-renewal and promoted MSC exhaustion by inducing senescence-associated heterochromatin foci formation,providing a mechanistic explanation for stem cell exhaustion with aging. Moreover,while KDM4B was required for parathyroid hormone-mediated bone anabolism,KDM4B depletion accelerated bone loss and marrow adiposity induced by a high-fat diet. Our results suggest that the epigenetic rejuvenation and reversing bone-fat imbalance might be new strategies for preventing and treating skeletal aging and osteoporosis by activating KDM4B in MSCs. View Publication

Cystic fibrosis (CF),a disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene,is characterized by chronic bacterial infections and inflammation in the lung. Having previously shown that deletion of CFTR is associated with lower expression of the endogenous anti-inflammatory protein Annexin A1 (AnxA1),we investigated further this possible functional connection using a validated CFTR inhibitor. Treatment of mice with the CFTR inhibitor-172 (CFTR(172)) augmented the acute peritonitis promoted by zymosan,an effect associated with lower AnxA1 levels in peritoneal cells. Similar results were obtained with another,chemically distinct,CFTR inhibitor. The pro-inflammatory effect of CFTR(172) was lost in AnxA1(-/-),as well as CFTR(-/-) mice. Importantly,administration of hrAnxA1 and its peptido-mimetic to CFTR(-/-) animals or to animals treated with CFTR(172) corrected the exaggerated leukocyte migration seen in these animals. In vitro assays with human Polymorphonuclear leukocyte (PMN) demonstrated that CFTR(172) reduced cell-associated AnxA1 by promoting release of the protein in microparticles. We propose that the reduced impact of the counterregulatory properties of AnxA1 in CF cells contributes to the inflammatory phenotype characteristic of this disease. Thus,these findings provide an important insight into the mechanism underlying the inflammatory disease associated with CFTR inhibition while,at the same time,providing a novel pharmacological target for controlling the inflammatory phenotype of CF. View Publication

Latrunculin A,a toxin purified from the red sea sponge Latrunculia magnifica,was found previously to induce striking reversible changes in the morphology of mammalian cells in culture and to disrupt the organization of their microfilaments. We now provide evidence that latrunculin A affects the polymerization of pure actin in vitro in a manner consistent with the formation of a 1:1 molar complex between latrunculin A and G-actin. The equilibrium dissociation constant (Kd) for the reaction in vitro is about 0.2 microM whereas the effects of the drug on cultured cells are detectable at concentrations in the medium of 0.1-1 microM. View Publication

Receptor tyrosine kinases (RTK) are therapeutic targets for the treatment of malignancy. However,tumor cells develop resistance to targeted therapies through the activation of parallel signaling cascades. Recent evidence has shown that redundant or compensatory survival signals responsible for resistance are initiated by nontargeted glycoprotein RTKs coexpressed by the cell. We hypothesized that disrupting specific functions of the posttranslational machinery of the secretory pathway would be an effective strategy to target both primary and redundant RTK signaling. Using the N-linked glycosylation inhibitor,tunicamycin,we show that expression levels of several RTKS (EGFR,ErbB2,ErbB3,and IGF-IR) are exquisitely sensitive to inhibition of N-linked glycosylation. Disrupting this synthetic process reduces both cellular protein levels and receptor activity in tumor cells through retention of the receptors in the endoplasmic reticulum/Golgi compartments. Using U251 glioma and BXPC3 pancreatic adenocarcinoma cell lines,two cell lines resistant to epidermal growth factor receptor-targeted therapies,we show that inhibiting N-linked glycosylation markedly reduces RTK signaling through Akt and radiosensitizes tumor cells. In comparison,experiments in nontransformed cells showed neither a reduction in RTK-dependent signaling nor an enhancement in radiosensitivity,suggesting the potential for a therapeutic ratio between tumors and normal tissues. This study provides evidence that enzymatic steps regulating N-linked glycosylation are novel targets for developing approaches to sensitize tumor cells to cytotoxic therapies. View Publication

Air-liquid interface (ALI) culture of nasal epithelial cells is a valuable tool in the diagnosis and research of primary ciliary dyskinesia (PCD). Ex vivo samples often display secondary dyskinesia from cell damage during sampling,infection or inflammation confounding PCD diagnostic results. ALI culture enables regeneration of healthy cilia facilitating differentiation of primary from secondary ciliary dyskinesia. We describe a revised ALI culture method adopted from April 2018 across three collaborating PCD diagnostic sites,including current University Hospital Southampton COVID-19 risk mitigation measures,and present results. Two hundred and forty nasal epithelial cell samples were seeded for ALI culture and 199 (82.9{\%}) were ciliated. Fifty-four of 83 (63.9{\%}) ex vivo samples which were originally equivocal or insufficient provided diagnostic information following in vitro culture. Surplus basal epithelial cells from 181 nasal brushing samples were frozen in liquid nitrogen; 39 samples were ALI-cultured after cryostorage and all ciliated. The ciliary beat patterns of ex vivo samples (by high-speed video microscopy) were recapitulated,scanning electron microscopy demonstrated excellent ciliation,and cilia could be immuno-fluorescently labelled (anti-alpha-tubulin and anti-RSPH4a) in representative cases that were ALI-cultured after cryostorage. In summary,our ALI culture protocol provides high ciliation rates across three centres,minimising patient recall for repeat brushing biopsies and improving diagnostic certainty. Cryostorage of surplus diagnostic samples was successful,facilitating PCD research. View Publication