Ustekinumab (UST) is an effective biologic for treatment of inflammatory bowel disease (IBD). However, some patients treated with UST have suboptimal clinical response with standard dosing. The aims ...of this study were to determine the effectiveness of UST dose intensification (DI), identify factors associated with DI, cumulative incidence of DI and persistence of UST among treated patients.
Clinical data of patients with Crohn's disease (CD) and ulcerative colitis (UC) who received UST from September 2017 to October 2022 in Singapore General Hospital were collected. Primary outcome was defined as achieving corticosteroid-free clinical remission, biochemical remission, endoscopic healing and/or transmural healing (CD). Statistical analysis was performed to identify factors, which are predictive of UST DI and effectiveness of UST DI.
Forty-two patients (34 CD and 8 UC) underwent UST DI to either 6-weekly (n = 19, 45.2%) or 4-weekly (n = 23, 35.9%) and the median time to intensification was 31.1 weeks (17.8-65.7). Presence of perianal disease in CD (HR 4.9; 1.47-16.4) was associated with DI. After DI, 16 (38%) patients achieved primary outcome by week 52. The overall drug persistence rates at 1 year and 2 years were 75.7% (95% CI 62.9-84.6) and 63.5% (95% CI 49.9-74.3), respectively.
Two third of IBD patients underwent DI while on UST treatment and the median time to DI was about 6 months after induction. CD patients with perianal disease is more likely to undergo DI. More than one third of dose-intensified patients achieved remission by week 52.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Nrf2 signaling is vital for protecting cells against oxidative stress. However, its hyperactivation is frequently found in liver cancer through excessive build‐up of p62/SQSTM1 bodies that sequester ...Keap1, an adaptor of the E3‐ubiquitin ligase complex for Nrf2. Here, we report that the Bax‐binding protein MOAP‐1 regulates p62‐Keap1‐Nrf2 signaling through disruption of p62 bodies. Upon induction of cellular stresses that stimulate formation of p62 bodies, MOAP‐1 is recruited to p62 bodies and reduces their levels independent of the autophagy pathway. MOAP‐1 interacts with the PB1‐ZZ domains of p62 and interferes with its self‐oligomerization and liquid–liquid phase separation, thereby disassembling the p62 bodies. Loss of MOAP‐1 can lead to marked upregulation of p62 bodies, enhanced sequestration of Keap1 by p62 and hyperactivation of Nrf2 antioxidant target genes. MOAP‐1‐deficient mice exhibit an elevated tumor burden with excessive levels of p62 bodies and Nrf2 signaling in a diethylnitrosamine (DEN)‐induced hepatocarcinogenesis model. Together, our data define MOAP‐1 as a negative regulator of Nrf2 signaling via dissociation of p62 bodies.
Synopsis
Stress‐induced p62/SQSTM1 bodies sequester the E3 ubiquitin ligase Keap1 from Nrf2, which is free to mediate transactivation of its target genes. MOAP‐1 recruitment to p62 bodies promotes their disassembly and reduces Nrf2 activation.
MOAP‐1 interferes with liquid‐liquid phase separation of p62 bodies.
MOAP‐1 disrupts p62 bodies by interfering with self‐oligomerization of p62 through binding to its PB1‐ZZ domains.
Absence of MOAP‐1 leads to hyperactivation of Nrf2 signaling and increased tumorigenesis in a diethylnitrosamine (DEN)‐induced liver cancer mouse model.
Stress‐induced p62/SQSTM1 bodies sequester the E3 ubiquitin ligase Keap1 from Nrf2, which is free to mediate transactivation of its target genes. MOAP‐1 recruitment to p62 bodies promotes their disassembly and reduces Nrf2 activation.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Emerging evidence suggests that hepatocytes are primarily maintained by self-renewal during normal liver homeostasis, as well as in response to a wide variety of hepatic injuries. However, how ...hepatocytes in distinct anatomic locations within the liver lobule are replenished under homeostasis and injury-induced regeneration remains elusive. Using a newly developed bacterial artificial chromosome (BAC)-transgenic mouse model, we demonstrate that Lgr5 expression in the liver is restricted to a unique subset of hepatocytes most adjacent to the central veins. Genetic lineage tracing revealed that pericentral Lgr5⁺ hepatocytes have a long lifespan and mainly contribute to their own lineage maintenance during postnatal liver development and homeostasis. Remarkably, these hepatocytes also fuel the regeneration of their own lineage during the massive and rapid regeneration process following two-thirds partial hepatectomy. Moreover, Lgr5⁺ hepatocytes are found to be the main cellular origin of diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC) and are highly susceptible to neoplastic transformation triggered by activation of Erbb pathway. Our findings establish an unexpected self-maintaining mode for a defined subset of hepatocytes during liver homeostasis and regeneration, and identify Lgr5⁺ pericentral hepatocytes as major cells of origin in HCC development.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
N-acylhomoserine lactone (AHL)-based quorum sensing (QS) is important for the regulation of proteobacterial virulence determinants. Thus, the inhibition of AHL synthases offers non-antibiotics-based ...therapeutic potentials against QS-mediated bacterial infections. In this work, functional AHL synthases of Pseudomonas aeruginosa LasI and RhlI were heterologously expressed in an AHL-negative Escherichia coli followed by assessments on their AHLs production using AHL biosensors and high resolution liquid chromatography-mass spectrometry (LCMS). These AHL-producing E. coli served as tools for screening AHL synthase inhibitors. Based on a campaign of screening synthetic molecules and natural products using our approach, three strongest inhibitors namely are salicylic acid, tannic acid and trans-cinnamaldehyde have been identified. LCMS analysis further confirmed tannic acid and trans-cinnemaldehyde efficiently inhibited AHL production by RhlI. We further demonstrated the application of trans-cinnemaldehyde inhibiting Rhl QS system regulated pyocyanin production in P. aeruginosa up to 42.06%. Molecular docking analysis suggested that trans-cinnemaldehyde binds to the LasI and EsaI with known structures mainly interacting with their substrate binding sites. Our data suggested a new class of QS-inhibiting agents from natural products targeting AHL synthase and provided a potential approach for facilitating the discovery of anti-QS signal synthesis as basis of novel anti-infective approach.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Fas apoptotic signaling regulates diverse physiological processes. Acute activation of Fas signaling triggers massive apoptosis in liver. Upon Fas receptor stimulation, the BH3-only protein Bid is ...cleaved into the active form, tBid. Subsequent tBid recruitment to mitochondria, which is facilitated by its receptor MTCH2 at the outer mitochondrial membrane (OMM), is a critical step for commitment to apoptosis via the effector proteins Bax or Bak. MOAP-1 is a Bax-binding protein enriched at the OMM. Here, we show that MOAP-1-deficient mice are resistant to Fas-induced hepatocellular apoptosis and lethality. In the absence of MOAP-1, mitochondrial accumulation of tBid is markedly impaired. MOAP-1 binds to MTCH2, and this interaction appears necessary for MTCH2 to engage tBid. These findings reveal a role for MOAP-1 in Fas signaling in the liver by promoting MTCH2-mediated tBid recruitment to mitochondria.
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•MOAP-1 is required to mediate Fas apoptotic signaling in liver•Loss of MOAP-1 protects mice from Fas-induced liver injury and lethality•MOAP-1 is required for efficient tBid recruitment to mitochondria•Binding of MOAP-1 to MTCH2 engages the receptor function of MTCH2 for tBid
Activation of Fas apoptotic signaling triggers acute liver injury. Tan et al. show that deletion of the MOAP-1 gene protects mice from this injury. MOAP-1 binds to MTCH2, and the interaction appears necessary for MTCH2 recruitment of tBid to mitochondria, an essential step for executing Fas-induced apoptosis in the liver.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The thioredoxin (Trx) system is one major redox system in mammalian cells. One of its component, Trx, is involved in redox homeostasis and many cellular biological processes through participating in ...disulfide reduction, S-nitrosylation/S-denitrosylation reactions and protein-protein interactions. In this study, we report the identification of a novel interaction between cytosolic/nuclear Trx1 and apoptosis inducing factor (AIF), and the redox sensitivity and biological significance of the Trx-AIF interaction was characterized. Cytosolic Trx1 but not mitochondrial Trx2 was observed to interact with AIF under physiological conditions and Trx1's active site cysteines were crucial for the interaction. Under oxidative stress conditions, Trx-AIF interaction was disrupted. When the treated cells were allowed to recover from oxidative stress by means of removal of the oxidants, interaction between Trx1 and AIF was re-established time-dependently, which underpins the biological relevance of a Trx-dependent redox regulation of AIF-mediated cell death. Indeed, in times of oxidative stress, nuclear translocation of AIF was found to occur concurrently with perturbations to the Trx-AIF interaction. Once localized in the nucleus, reduced Trx1 hindered the interaction between AIF and DNA, thereby bringing about an attenuation of AIF-mediated DNA damage. In conclusion, characterization of the Trx-AIF interaction has led to an understanding of the effect of reduced Trx1 on possibly regulating AIF-dependent cell death through impeding AIF-mediated DNA damage. Importantly, identification of the novel interaction between Trx1 and AIF has provided opportunities to design and develop therapeutically relevant strategies that either promote or prevent this protein-protein interaction for the treatment of different disease states.
•Cytosolic thioredoxin-1 (Trx1) interacted with apoptosis inducing factor (AIF).•Trx-AIF interaction was disrputed under pro-apoptotic oxidative stress conditions.•AIF-mediated DNA damage was attenuated by reduced Trx1.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The E3 ubiquitin ligase HUWE1, deregulated in carcinoma, has been implicated in tumor formation. Here, we uncover a role for HUWE1 in cell migration and invasion through degrading the RAC activator ...TIAM1, implying an additional function in malignant progression. In MDCKII cells in response to HGF, HUWE1 catalyzes TIAM1 ubiquitylation and degradation predominantly at cell-cell adhesions, facilitating junction disassembly, migration, and invasion. Depleting HUWE1 or mutating the TIAM1 ubiquitylation site prevents TIAM1 degradation, antagonizing scattering, and invasion. Moreover, simultaneous depletion of TIAM1 restores migration and invasion in HUWE1-depleted cells. Significantly, we show that HUWE1 stimulates human lung cancer cell invasion through regulating TIAM1 stability. Finally, we demonstrate that HUWE1 and TIAM1 protein levels are inversely correlated in human lung carcinomas. Thus, we elucidate a critical role for HUWE1 in regulating epithelial cell-cell adhesion and provide additional evidence that ubiquitylation contributes to spatiotemporal control of RAC.
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•HGF-induced cell-cell adhesion disassembly, migration, and invasion require HUWE1•HUWE1 ubiquitylates and degrades TIAM1 at cell-cell adhesions in response to HGF•TIAM1 is the key HUWE1 target regulating cell-cell adhesion, motility, and invasion•HUWE1 and TIAM1 expression levels are inversely correlated in lung cancer
Malignant conversion of epithelial tumor cells is incompletely understood. Here, Vaughan et al. demonstrate that the E3 ligase HUWE1 degrades the RAC activator TIAM1 following HGF stimulation, promoting cell junction disassembly, motility, and invasion in epithelial cells including lung cancer cells. This indicates a critical role for HUWE1 in lung cancer dissemination.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Modulator of apoptosis 1 (MOAP-1) is a Bcl-2-associated X Protein (BAX)-associating protein that plays an important role in regulating apoptosis. It is highly enriched in the brain but its function ...in this organ remains unknown. Studies on BAX
−/−
mice suggested that disruption of programmed cell death may lead to abnormal emotional states. We thus hypothesize that MOAP-1
−/−
mice may also display stress-related behavioral differences and perhaps involved in stress responses in the brain and investigated if a depression-like trait exists in MOAP-1
−/−
mice, and if so, whether it is age related, and how it relates to central serotonergic stress response in the dorsal raphe nucleus. Young MOAP-1
−/−
mice exhibit depression-like behavior, in the form of increased immobility time when compared to age-matched wild-type mice in the forced swimming test, which is abolished by acute treatment of fluoxetine. This is supported by data from the tail suspension and sucrose preference tests. Repeated forced swimming stress causes an up-regulation of tryptophan hydroxylase 2 (TPH2) and a down-regulation of brain-derived neurotrophic factor (BDNF) in the dorsal raphe nucleus (DRN) in young wild-type (WT) control mice. In contrast, TPH2 up-regulation was not observed in aged WT mice. Interestingly, such a stress response appears absent in both young and aged MOAP-1
−/−
mice. Aged MOAP-1
−/−
and WT mice also have similar immobility times on the forced swimming test. These data suggest that MOAP-1 is required in the regulation of stress response in the DRN. Crosstalk between BDNF and 5-HT appears to play an important role in this stress response.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Schistosomiasis is a neglected tropical disease that affects more than 200 million people worldwide. The main disease-causing agents, Schistosoma japonicum, S. mansoni and S. haematobium, are blood ...flukes that have complex life cycles involving a snail intermediate host. In Asia, S. japonicum causes hepatointestinal disease (schistosomiasis japonica) and is challenging to control due to a broad distribution of its snail hosts and range of animal reservoir hosts. In China, extensive efforts have been underway to control this parasite, but genetic variability in S. japonicum populations could represent an obstacle to eliminating schistosomiasis japonica. Although a draft genome sequence is available for S. japonicum, there has been no previous study of molecular variation in this parasite on a genome-wide scale. In this study, we conducted the first deep genomic exploration of seven S. japonicum populations from mainland China, constructed phylogenies using mitochondrial and nuclear genomic data sets, and established considerable variation between some of the populations in genes inferred to be linked to key cellular processes and/or pathogen-host interactions. Based on the findings from this study, we propose that verifying intraspecific conservation in vaccine or drug target candidates is an important first step toward developing effective vaccines and chemotherapies against schistosomiasis.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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