技术资料

Protein disulfide isomerase (PDI,PDIA1) is an emerging therapeutic target in oncology. PDI inhibitors have demonstrated a unique propensity to selectively induce apoptosis in cancer cells and overcome resistance to existing therapies,although drug candidates have not yet progressed to the stage of clinical development. We recently reported the discovery of lead indene compound E64FC26 as a potent pan-PDI inhibitor that enhances the cytotoxic effects of proteasome inhibitors in panels of Multiple Myeloma (MM) cells and MM mouse models. An extensive medicinal chemistry program has led to the generation of a diverse library of indene-containing molecules with varying degrees of proteasome inhibitor potentiating activity. These compounds were generated by a novel nucleophilic aromatic ring cyclization and dehydration reaction from the precursor ketones. The results provide detailed structure activity relationships (SAR) around this indene pharmacophore and show a high degree of correlation between potency of PDI inhibition and bortezomib (Btz) potentiation in MM cells. Inhibition of PDI leads to ER and oxidative stress characterized by the accumulation of misfolded poly-ubiquitinated proteins and the induction of UPR biomarkers ATF4,CHOP,and Nrf2. This work characterizes the synthesis and SAR of a new chemical class and further validates PDI as a therapeutic target in MM as a single agent and in combination with proteasome inhibitors. View Publication

Lambda interferons (IFN-$\lambda$s) are a major component of the innate immune defense to viruses,bacteria,and fungi. In human liver,IFN-$\lambda$ not only drives antiviral responses,but also promotes inflammation and fibrosis in viral and non-viral diseases. Here we demonstrate that macrophages are primary responders to IFN-$\lambda$,uniquely positioned to bridge the gap between IFN-$\lambda$ producing cells and lymphocyte populations that are not intrinsically responsive to IFN-$\lambda$. While CD14+ monocytes do not express the IFN-$\lambda$ receptor,IFNLR1,sensitivity is quickly gained upon differentiation to macrophages in vitro. IFN-$\lambda$ stimulates macrophage cytotoxicity and phagocytosis as well as the secretion of pro-inflammatory cytokines and interferon stimulated genes that mediate immune cell chemotaxis and effector functions. In particular,IFN-$\lambda$ induced CCR5 and CXCR3 chemokines,stimulating T and NK cell migration,as well as subsequent NK cell cytotoxicity. Using immunofluorescence and cell sorting techniques,we confirmed that human liver macrophages expressing CD14 and CD68 are highly responsive to IFN-$\lambda$ ex vivo. Together,these data highlight a novel role for macrophages in shaping IFN-$\lambda$ dependent immune responses both directly through pro-inflammatory activity and indirectly by recruiting and activating IFN-$\lambda$ unresponsive lymphocytes. View Publication

Hodgkin Lymphoma (HL) is a malignancy that frequently affects young adults. Although,there are effective treatments not every patient responds,necessitating the development of novel therapeutic approaches,especially for relapsed and refractory cases. The two TNF receptor family members CD30 and CD137 are expressed on Hodgkin and Reed Sternberg (HRS) cells,the malignant cells in HL. We found that this co-expression is specific for HRS cells. Based on this discovery we developed a bispecific antibody that binds preferentially to the CD30,CD137-double positive HRS cells. The CD30,CD137 bispecific antibody gets internalized into HRS cells opening up the possibility to use it as a carrier for a toxin. This antibody also induces antibody-dependent,cell-mediated cytotoxicity in CD30,CD137-double positive HRS cells. The enhances specificity of the CD30,CD137 bispecific antibody to HRS cells makes it a promising candidate for development as a novel HL treatment. View Publication

(1) Background: The cannabinoid 2 receptor (CB2R) is a promising anti-inflammatory drug target and development of selective CB2R ligands may be useful for treating sight-threatening ocular inflammation. (2) Methods: This study examined the pharmacology of three novel chemically-diverse selective CB2R ligands: CB2R agonists,RO6871304,and RO6871085,as well as a CB2R inverse agonist,RO6851228. In silico molecular modelling and in vitro cell-based receptor assays were used to verify CB2R interactions,binding,cell signaling ({\ss}-arrestin and cAMP) and early absorption,distribution,metabolism,excretion,and toxicology (ADMET) profiling of these receptor ligands. All ligands were evaluated for their efficacy to modulate leukocyte-neutrophil activity,in comparison to the reported CB2R ligand,HU910,using an in vivo mouse model of endotoxin-induced uveitis (EIU) in wild-type (WT) and CB2R-/- mice. The actions of RO6871304 on neutrophil migration and adhesion were examined in vitro using isolated neutrophils from WT and CB2R-/- mice,and in vivo in WT mice with EIU using adoptive transfer of WT and CB2R-/- neutrophils,respectively. (3) Results: Molecular docking studies indicated that RO6871304 and RO6871085 bind to the orthosteric site of CB2R. Binding studies and cell signaling assays for RO6871304 and RO6871085 confirmed high-affinity binding to CB2R and selectivity for CB2R {\textgreater} CB1R,with both ligands acting as full agonists in cAMP and {\ss}-arrestin assays (EC50s in low nM range). When tested in EIU,topical application of RO6871304 and RO6871085 decreased leukocyte-endothelial adhesion and this effect was antagonized by the inverse agonist,RO6851228. The CB2R agonist,RO6871304,decreased in vitro neutrophil migration of WT neutrophils but not neutrophils from CB2R-/-,and attenuated adhesion of adoptively-transferred leukocytes in EIU. (4) Conclusions: These unique ligands are potent and selective for CB2R and have good immunomodulating actions in the eye. RO6871304 and RO6871085,as well as HU910,decreased leukocyte adhesion in EIU through inhibition of resident ocular immune cells. The data generated with these three structurally-diverse and highly-selective CB2R agonists support selective targeting of CB2R for treating ocular inflammatory diseases. View Publication

The aim of this study was to vascularize brain organoids with a patient's own endothelial cells (ECs). Induced pluripotent stem cells (iPSCs) of one UC Davis patient were grown into whole-brain organoids. Simultaneously,iPSCs from the same patient were differentiated into ECs. On day 34,the organoid was re-embedded in Matrigel with 250 000 ECs. Vascularized organoids were grown in vitro for 3-5 weeks or transplanted into immunodeficient mice on day 54,and animals were perfused on day 68. Coating of brain organoids on day 34 with ECs led to robust vascularization of the organoid after 3-5 weeks in vitro and 2 weeks in vivo. Human CD31-positive blood vessels were found inside and in-between rosettes within the center of the organoid after transplantation. Vascularization of brain organoids with a patient's own iPSC-derived ECs is technically feasible. View Publication

AIMS Current treatment for congenital long QT syndrome Type 2 (cLQTS2),an electrical disorder that increases the risk of life-threatening cardiac arrhythmias,is aimed at reducing the incidence of arrhythmia triggers (beta-blockers) or terminating the arrhythmia after onset (implantable cardioverter-defibrillator). An alternative strategy is to target the underlying disease mechanism,which is reduced rapid delayed rectifier current (IKr) passed by Kv11.1 channels. Small molecule activators of Kv11.1 have been identified but the extent to which these can restore normal cardiac signalling in cLQTS2 backgrounds remains unclear. Here,we examined the ability of ICA-105574,an activator of Kv11.1 that impairs transition to the inactivated state,to restore function to heterozygous Kv11.1 channels containing either inactivation enhanced (T618S,N633S) or expression deficient (A422T) mutations. METHODS AND RESULTS ICA-105574 effectively restored Kv11.1 current from heterozygous inactivation enhanced or expression defective mutant channels in heterologous expression systems. In a human-induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) model of cLQTS2 containing the expression defective Kv11.1 mutant A422T,cardiac repolarization,estimated from the duration of calcium transients in isolated cells and the rate corrected field potential duration (FPDc) in culture monolayers of cells,was significantly prolonged. The Kv11.1 activator ICA-105574 was able to reverse the prolonged repolarization in a concentration-dependent manner. However,at higher doses,ICA-105574 produced a shortening of the FPDc compared to controls. In vitro and in silico analysis suggests that this overcorrection occurs as a result of a temporal redistribution of the peak IKr to much earlier in the plateau phase of the action potential,which results in early repolarization. CONCLUSION Kv11.1 activators,which target the primary disease mechanism,provide a possible treatment option for cLQTS2,with the caveat that there may be a risk of overcorrection that could itself be pro-arrhythmic. View Publication

Environmental factors contribute to Type 1 diabetes (T1D) susceptibility. The gut microbiome,which includes bacteria,viruses,and fungi,contributes to this environmental influence,and can induce immunological changes. The gut viral component of the microbiome,related to T1D has mostly focused on coxsackieviruses and rotavirus. The role of norovirus,another common enteric virus,in susceptibility to T1D was hitherto unknown. Norovirus is highly infectious and encountered by many children. We studied the mouse norovirus 4 (MNV4),related to human noroviruses,in the Non-obese diabetic (NOD) mouse model,to determine its role in influencing susceptibility to T1D. We infected MNV-free NOD mice with MNV4 by exposing the mice to MNV4-positive bedding from an endemically-infected mouse colony to mimic a natural infection. Control MNV-free NOD mice were exposed to MNV-free bedding from the same colony. Interestingly,MNV4 infection protected NOD mice from the development of T1D and was associated with an expansion of Tregs and reduced proinflammatory T cells. We also found MNV4 significantly modified the gut commensal bacteria composition,promoting increased $\alpha$-diversity and Firmicutes/Bacteroidetes ratio. To elucidate whether T1D protection was directly related to MNV4,or indirectly through modulating gut microbiota,we colonized germ-free (GF) NOD mice with the MNV4-containing or non-MNV4-containing viral filtrate,isolated from filtered fecal material. We found that MNV4 induced significant changes in mucosal immunity,including altered Tuft cell markers,cytokine secretion,antiviral immune signaling markers,and the concentration of mucosal antibodies. Systemically,MNV4-infection altered the immune cells including B cell subsets,macrophages and T cells,and especially induced an increase in Treg number and function. Furthermore,in vitro primary exposure of the norovirus filtrate to na{\{i}}ve splenocytes identified significant increases in the proportion of activated and CTLA4-expressing Tregs. Our data provide novel knowledge that norovirus can protect NOD mice from T1D development by inducing the expansion of Tregs and reducing inflammatory T cells. Our study also highlights the importance of distinguishing the mucosal immunity mediated by bacteria from that by enteric viruses." View Publication

Latent proviruses persist in central (TCM),transitional (TTM),and effector (TEM) memory cells. We measured the levels of cellular factors involved in HIV gene expression in these subsets. The highest levels of acetylated H4,active nuclear factor $\kappa$B (NF-$\kappa$B),and active positive transcription elongation factor b (P-TEFb) were measured in TEM,TCM,and TTM cells,respectively. Vorinostat and romidepsin display opposite abilities to induce H4 acetylation across subsets. Protein kinase C (PKC) agonists are more efficient at inducing NF-$\kappa$B phosphorylation in TCM cells but more potent at activating PTEF-b in the TEM subset. We selected the most efficient latency-reversing agents (LRAs) and measured their ability to reverse latency in each subset. While ingenol alone has modest activities in the three subsets,its combination with a histone deacetylase inhibitor (HDACi) dramatically increases latency reversal in TCM cells. Altogether,these results indicate that cellular HIV reservoirs are differentially responsive to common LRAs and suggest that combination of compounds will be required to achieve latency reversal in all subsets. View Publication

Microenvironmental factors such as oxygen concentration mediate key effects on the biology of mesenchymal stromal cells (MSCs). Herein,we performed an in-depth characterization of the metabolic behavior of MSCs derived from the placenta,umbilical cord,and adipose tissue (termed hPMSCs,UC-MSCs,and AD-MSCs,respectively) at physiological (hypoxic; 5{\%} oxygen [O2]) and standardized (normoxic; 21{\%} O2) O2 concentrations using chemical isotope labeling liquid chromatography-mass spectrometry. 12C- and 13C-isotope dansylation (Dns) labeling was used to analyze the amine/phenol submetabolome,and 2574 peak pairs or metabolites were detected and quantified,from which 52 metabolites were positively identified using a library of 275 Dns-metabolite standards; 2189 metabolites were putatively identified. Next,we identified six metabolites using the Dns library,as well as 14 hypoxic biomarkers from the human metabolome database out of 96 altered metabolites. Ultimately,metabolic pathway analyses were performed to evaluate the associated pathways. Based on pathways identified using the Kyoto Encyclopedia of Genes and Genomes,we identified significant changes in the metabolic profiles of MSCs in response to different O2 concentrations. These results collectively suggest that O2 concentration has the strongest influence on hPMSCs metabolic characteristics,and that 5{\%} O2 promotes arginine and proline metabolism in hPMSCs and UC-MSCs but decreases gluconeogenesis (alanine-glucose) rates in hPMSCs and AD-MSCs. These changes indicate that MSCs derived from different sources exhibit distinct metabolic profiles. View Publication

Cyclic dinucleotides are second messengers in the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway,which plays an important role in recognizing tumor cells and viral or bacterial infections. They bind to the STING adaptor protein and trigger expression of cytokines via TANK binding kinase 1 (TBK1)/interferon regulatory factor 3 (IRF3) and inhibitor of nuclear factor-$\kappa$B (I$\kappa$B) kinase (IKK)/nuclear factor-$\kappa$B (NF$\kappa$B) signaling cascades. In this work,we describe an enzymatic preparation of 2'-5',3'-5'-cyclic dinucleotides (2'3'CDNs) with use of cyclic GMP-AMP synthases (cGAS) from human,mouse,and chicken. We profile substrate specificity of these enzymes by employing a small library of nucleotide-5'-triphosphate (NTP) analogues and use them to prepare 33 2'3'CDNs. We also determine affinity of these CDNs to five different STING haplotypes in cell-based and biochemical assays and describe properties needed for their optimal activity toward all STING haplotypes. Next,we study their effect on cytokine and chemokine induction by human peripheral blood mononuclear cells (PBMCs) and evaluate their cytotoxic effect on monocytes. Additionally,we report X-ray crystal structures of two new CDNs bound to STING protein and discuss structure-activity relationship by using quantum and molecular mechanical (QM/MM) computational modeling. View Publication

In a screen for human kinases that regulate Xenopus laevis embryogenesis,we identified Nagk and other components of the UDP-GlcNAc glycosylation salvage pathway as regulators of anteroposterior patterning and Wnt signaling. We find that the salvage pathway does not affect other major embryonic signaling pathways (Fgf,TGF$\beta$,Notch,or Shh),thereby demonstrating specificity for Wnt signaling. We show that the role of the salvage pathway in Wnt signaling is evolutionarily conserved in zebrafish and Drosophila. Finally,we show that GlcNAc is essential for the growth of intestinal enteroids,which are highly dependent on Wnt signaling for growth and maintenance. We propose that the Wnt pathway is sensitive to alterations in the glycosylation state of a cell and acts as a nutritional sensor in order to couple growth/proliferation with its metabolic status. We also propose that the clinical manifestations observed in congenital disorders of glycosylation (CDG) in humans may be due,in part,to their effects on Wnt signaling during development. View Publication

Products derived from bacterial members of the gut microbiota evoke immune signalling pathways of the host that promote immunity and barrier function in the intestine. How immune reactions to enteric viruses support intestinal homeostasis is unknown. We recently demonstrated that infection by murine norovirus (MNV) reverses intestinal abnormalities following depletion of bacteria,indicating that an intestinal animal virus can provide cues to the host that are typically attributed to the microbiota. Here,we elucidate mechanisms by which MNV evokes protective responses from the host. We identify an important role for the viral protein NS1/2 in establishing local replication and a type I interferon (IFN-I) response in the colon. We further show that IFN-I acts on intestinal epithelial cells to increase the proportion of CCR2-dependent macrophages and interleukin (IL)-22-producing innate lymphoid cells,which in turn promote pSTAT3 signalling in intestinal epithelial cells and protection from intestinal injury. In addition,we demonstrate that MNV provides a striking IL-22-dependent protection against early-life lethal infection by Citrobacter rodentium. These findings demonstrate novel ways in which a viral member of the microbiota fortifies the intestinal barrier during chemical injury and infectious challenges. View Publication