NF-κB-inducing kinase maintains T cell metabolic fitness in antitumor immunity.

Metabolic reprograming toward aerobic glycolysis is a pivotal mechanism shaping immune responses. Here we show that deficiency in NF-κB-inducing kinase (NIK) impairs glycolysis induction, rendering CD8+ effector T cells hypofunctional in the tumor microenvironment. Conversely, ectopic expression of NIK promotes CD8+ T cell metabolism and effector function, thereby profoundly enhancing antitumor immunity and improving the efficacy of T cell adoptive therapy. NIK regulates T cell metabolism via a NF-κB-independent mechanism that involves stabilization of hexokinase 2 (HK2), a rate-limiting enzyme of the glycolytic pathway. NIK prevents autophagic degradation of HK2 through controlling cellular reactive oxygen species levels, which in turn involves modulation of glucose-6-phosphate dehydrogenase (G6PD), an enzyme that mediates production of the antioxidant NADPH. We show that the G6PD-NADPH redox system is important for HK2 stability and metabolism in activated T cells. These findings establish NIK as a pivotal regulator of T cell metabolism and highlight a post-translational mechanism of metabolic regulation.

The deubiquitinase Otub1 controls the activation of CD8+ T cells and NK cells by regulating IL-15-mediated priming.

CD8+ T cells and natural killer (NK) cells are central cellular components of immune responses against pathogens and cancer, which rely on interleukin (IL)-15 for homeostasis. Here we show that IL-15 also mediates homeostatic priming of CD8+ T cells for antigen-stimulated activation, which is controlled by a deubiquitinase, Otub1. IL-15 mediates membrane recruitment of Otub1, which inhibits ubiquitin-dependent activation of AKT, a kinase that is pivotal for T cell activation and metabolism. Otub1 deficiency in mice causes aberrant responses of CD8+ T cells to IL-15, rendering naive CD8+ T cells hypersensitive to antigen stimulation characterized by enhanced metabolic reprograming and effector functions. Otub1 also controls the maturation and activation of NK cells. Deletion of Otub1 profoundly enhances anticancer immunity by unleashing the activity of CD8+ T cells and NK cells. These findings suggest that Otub1 controls the activation of CD8+ T cells and NK cells by functioning as a checkpoint of IL-15-mediated priming.

NIK signaling axis regulates dendritic cell function in intestinal immunity and homeostasis.

Dendritic cells (DCs) play an integral role in regulating mucosal immunity and homeostasis, but the signaling network mediating this function of DCs is poorly defined. We identified the noncanonical NF-κB-inducing kinase (NIK) as a crucial mediator of mucosal DC function. DC-specific NIK deletion impaired intestinal immunoglobulin A (IgA) secretion and microbiota homeostasis, rendering mice sensitive to an intestinal pathogen, Citrobacter rodentium. DC-specific NIK was required for expression of the IgA transporter polymeric immunoglobulin receptor (pIgR) in intestinal epithelial cells, which in turn relied on the cytokine IL-17 produced by TH17 cells and innate lymphoid cells (ILCs). NIK-activated noncanonical NF-κB induced expression of IL-23 in DCs, contributing to the maintenance of TH17 cells and type 3 ILCs. Consistent with the dual functions of IL-23 and IL-17 in mucosal immunity and inflammation, NIK deficiency also ameliorated colitis induction. Thus, our data suggest a pivotal role for the NIK signaling axis in regulating DC functions in intestinal immunity and homeostasis.

USP15 stabilizes MDM2 to mediate cancer-cell survival and inhibit antitumor T cell responses.

Deubiquitinases (DUBs) are a new class of drug targets, although the physiological function of only few DUBs has been characterized. Here we identified the DUB USP15 as a crucial negative regulator of T cell activation. USP15 stabilized the E3 ubiquitin ligase MDM2, which in turn negatively regulated T cell activation by targeting the degradation of the transcription factor NFATc2. USP15 deficiency promoted T cell activation in vitro and enhanced T cell responses to bacterial infection and tumor challenge in vivo. USP15 also stabilized MDM2 in cancer cells and regulated p53 function and cancer-cell survival. Our results suggest that inhibition of USP15 may both induce tumor cell apoptosis and boost antitumor T cell responses.

The E3 ubiquitin ligase Peli1 regulates the metabolic actions of mTORC1 to suppress antitumor T cell responses.

Metabolic fitness of T cells is crucial for immune responses against infections and tumorigenesis. Both the T cell receptor (TCR) signal and environmental cues contribute to the induction of T cell metabolic reprogramming, but the underlying mechanism is incompletely understood. Here, we identified the E3 ubiquitin ligase Peli1 as an important regulator of T cell metabolism and antitumor immunity. Peli1 ablation profoundly promotes tumor rejection, associated with increased tumor-infiltrating CD4 and CD8 T cells. The Peli1-deficient T cells display markedly stronger metabolic activities, particularly glycolysis, than wild-type T cells. Peli1 controls the activation of a metabolic kinase, mTORC1, stimulated by both the TCR signal and growth factors, and this function of Peli1 is mediated through regulation of the mTORC1-inhibitory proteins, TSC1 and TSC2. Peli1 mediates non-degradative ubiquitination of TSC1, thereby promoting TSC1-TSC2 dimerization and TSC2 stabilization. These results establish Peli1 as a novel regulator of mTORC1 and downstream mTORC1-mediated actions on T cell metabolism and antitumor immunity.

Endothelial FIS1 DeSUMOylation Protects Against Hypoxic Pulmonary Hypertension.

BACKGROUND: Hypoxia is a major cause and promoter of pulmonary hypertension (PH), a representative vascular remodeling disease with poor prognosis and high mortality. However, the mechanism underlying how pulmonary arterial system responds to hypoxic stress during PH remains unclear. Endothelial mitochondria are considered signaling organelles on oxygen tension. Results from previous clinical research and our studies suggested a potential role of posttranslational SUMOylation (small ubiquitin-like modifier modification) in endothelial mitochondria in hypoxia-related vasculopathy. METHODS: Chronic hypoxia mouse model and Sugen/hypoxia rat model were employed as PH animal models. Mitochondrial morphology and subcellular structure were determined by transmission electron and immunofluorescent microscopies. Mitochondrial metabolism was determined by mitochondrial oxygen consumption rate and extracellular acidification rate. SUMOylation and protein interaction were determined by immunoprecipitation. RESULTS: The involvement of SENP1 (sentrin-specific protease 1)-mediated SUMOylation in mitochondrial remodeling in the pulmonary endothelium was identified in clinical specimens of hypoxia-related PH and was verified in human pulmonary artery endothelial cells under hypoxia. Further analyses in clinical specimens, hypoxic rat and mouse PH models, and human pulmonary artery endothelial cells and human embryonic stem cell-derived endothelial cells revealed that short-term hypoxia-induced SENP1 translocation to endothelial mitochondria to regulate deSUMOylation (the reversible process of SUMOylation) of mitochondrial fission protein FIS1 (mitochondrial fission 1), which facilitated FIS1 assembling with fusion protein MFN2 (mitofusin 2) and mitochondrial gatekeeper VDAC1 (voltage-dependent anion channel 1), and the membrane tethering activity of MFN2 by enhancing its oligomerization. Consequently, FIS1 deSUMOylation maintained the mitochondrial integrity and endoplasmic reticulum-mitochondria calcium communication across mitochondrial-associated membranes, subsequently preserving pulmonary endothelial function and vascular homeostasis. In contrast, prolonged hypoxia disabled the FIS1 deSUMOylation by diminishing the availability of SENP1 in mitochondria via inducing miR (micro RNA)-138 and consequently resulted in mitochondrial dysfunction and metabolic reprogramming in pulmonary endothelium. Functionally, introduction of viral-packaged deSUMOylated FIS1 within pulmonary endothelium in mice improved pulmonary endothelial dysfunction and hypoxic PH development, while knock-in of SUMO (small ubiquitin-like modifier)-conjugated FIS1 in mice exaggerated the diseased cellular and tissue phenotypes. CONCLUSIONS: By maintaining endothelial mitochondrial homeostasis, deSUMOylation of FIS1 adaptively preserves pulmonary endothelial function against hypoxic stress and consequently protects against PH. The FIS1 deSUMOylation-SUMOylation transition in pulmonary endothelium is an intrinsic pathogenesis of hypoxic PH.

FGFR1 SUMOylation coordinates endothelial angiogenic signaling in angiogenesis.

Angiogenesis contributes fundamentally to embryonic development, tissue homeostasis, and wound healing. Basic fibroblast growth factor (FGF2) is recognized as the first proangiogenic molecule discovered, and it facilitates angiogenesis by activating FGF receptor 1 (FGFR1) signaling in endothelial cells. However, the precise roles of FGFR and the FGF/FGFR signaling axis in angiogenesis remain unclear, especially because of the contradictory phenotypes of in vivo FGF and FGFR gene deficiency models. Our previous study results suggested a potential role of posttranslational small ubiquitin-like modifier modification (SUMOylation), with highly dynamic regulatory features, in vascular development and disorder. Here, we identified SENP1-regulated endothelial FGFR1 SUMOylation at conserved lysines responding to proangiogenic stimuli, while SENP1 functioned as the deSUMOylase. Hypoxia-enhanced FGFR1 SUMOylation restricted the tyrosine kinase activation of FGFR1 by modulating the dimerization of FGFR1 and FGFR1 binding with its phosphatase PTPRG. Consequently, it facilitated the recruitment of FRS2α to VEGFR2 but limited additional recruitment of FRS2α to FGFR1, supporting the activation of VEGFA/VEGFR2 signaling in endothelial cells. Furthermore, SUMOylation-defective mutation of FGFR1 resulted in exaggerated FGF2/FGFR1 signaling but suppressed VEGFA/VEGFR2 signaling and the angiogenic capabilities of endothelial cells, which were rescued by FRS2α overexpression. Reduced angiogenesis and endothelial sprouting in mice bearing an endothelial-specific, FGFR1 SUMOylation-defective mutant confirmed the functional significance of endothelial FGFR1 SUMOylation in vivo. Our findings identify the reversible SUMOylation of FGFR1 as an intrinsic fine-tuned mechanism in coordinating endothelial angiogenic signaling during neovascularization; SENP1-regulated FGFR1 SUMOylation and deSUMOylation controls the competitive recruitment of FRS2α by FGFR1 and VEGFR2 to switch receptor-complex formation responding to hypoxia and normoxia angiogenic environments.

All Roads Lead to Rome: Comparing Nanoparticle- and Small Molecule-Driven Cell Autophagy.

Autophagy, vital for removing cellular waste, is triggered differently by small molecules and nanoparticles. Small molecules, like rapamycin, non-selectively activate autophagy by inhibiting the mTOR pathway, which is essential for cell regulation. This can clear damaged components but may cause cytotoxicity with prolonged use. Nanoparticles, however, induce autophagy, often causing oxidative stress, through broader cellular interactions and can lead to a targeted form known as "xenophagy." Their impact varies with their properties but can be harnessed therapeutically. In this review, the autophagy induced by nanoparticles is explored and small molecules across four dimensions: the mechanisms behind autophagy induction, the outcomes of such induction, the toxicological effects on cellular autophagy, and the therapeutic potential of employing autophagy triggered by nanoparticles or small molecules. Although small molecules and nanoparticles each induce autophagy through different pathways and lead to diverse effects, both represent invaluable tools in cell biology, nanomedicine, and drug discovery, offering unique insights and therapeutic opportunities.

Ubc13 maintains the suppressive function of regulatory T cells and prevents their conversion into effector-like T cells.

The maintenance of immune homeostasis requires regulatory T cells (Treg cells). Here we found that Treg cell­specific ablation of Ubc13, a Lys63 (K63)-specific ubiquitin-conjugating enzyme, caused aberrant T cell activation and autoimmunity. Although Ubc13 deficiency did not affect the survival of Treg cells or expression of the transcription factor Foxp3, it impaired the in vivo suppressive function of Treg cells and rendered them sensitive to the acquisition of T helper type 1 (TH1) cell­ and interleukin 17 (IL-17)-producing helper T (TH17) cell­like effector phenotypes. This function of Ubc13 involved its downstream target, the kinase IKK. The Ubc13-IKK signaling axis controlled the expression of specific Treg cell effector molecules, including IL-10 and SOCS1. Collectively, our findings suggest that the Ubc13-IKK signaling axis regulates the molecular program that maintains Treg cell function and prevents Treg cells from acquiring inflammatory phenotypes.

Enhanced Sensitivity of A549 Cells to Doxorubicin with WS2 and WSe2 Nanosheets via the Induction of Autophagy.

The excellent physicochemical properties of two-dimensional transition-metal dichalcogenides (2D TMDCs) such as WS2 and WSe2 provide potential benefits for biomedical applications, such as drug delivery, photothermal therapy, and bioimaging. WS2 and WSe2 have recently been used as chemosensitizers; however, the detailed molecular basis underlying WS2- and WSe2-induced sensitization remains elusive. Our recent findings showed that 2D TMDCs with different thicknesses and different element compositions induced autophagy in normal human bronchial epithelial cells and mouse alveolar macrophages at sublethal concentrations. Here, we explored the mechanism by which WS2 and WSe2 act as sensitizers to increase lung cancer cell susceptibility to chemotherapeutic agents. The results showed that WS2 and WSe2 enhanced autophagy flux in A549 lung cancer cells at sublethal concentrations without causing significant cell death. Through the autophagy-specific RT2 Profiler PCR Array, we identified the genes significantly affected by WS2 and WSe2 treatment. Furthermore, the key genes that play central roles in regulating autophagy were identified by constructing a molecular interaction network. A mechanism investigation uncovered that WS2 and WSe2 activated autophagy-related signaling pathways by interacting with different cell surface proteins or cytoplasmic proteins. By utilizing this mechanism, the efficacy of the chemotherapeutic agent doxorubicin was enhanced by WS2 and WSe2 pre-treatment in A549 lung cancer cells. This study revealed a feature of WS2 and WSe2 in cancer therapy, in which they eliminate the resistance of A549 lung cancer cells against doxorubicin, at least partially, by inducing autophagy.

Lightweight Cross-Modal Information Mutual Reinforcement Network for RGB-T Salient Object Detection.

RGB-T salient object detection (SOD) has made significant progress in recent years. However, most existing works are based on heavy models, which are not applicable to mobile devices. Additionally, there is still room for improvement in the design of cross-modal feature fusion and cross-level feature fusion. To address these issues, we propose a lightweight cross-modal information mutual reinforcement network for RGB-T SOD. Our network consists of a lightweight encoder, the cross-modal information mutual reinforcement (CMIMR) module, and the semantic-information-guided fusion (SIGF) module. To reduce the computational cost and the number of parameters, we employ the lightweight module in both the encoder and decoder. Furthermore, to fuse the complementary information between two-modal features, we design the CMIMR module to enhance the two-modal features. This module effectively refines the two-modal features by absorbing previous-level semantic information and inter-modal complementary information. In addition, to fuse the cross-level feature and detect multiscale salient objects, we design the SIGF module, which effectively suppresses the background noisy information in low-level features and extracts multiscale information. We conduct extensive experiments on three RGB-T datasets, and our method achieves competitive performance compared to the other 15 state-of-the-art methods.

Development of an LFD-RPA Assay for Rapid Detection of Pentatrichomonas hominis Infection in Dogs.

Pentatrichomonas hominis is a trichomonad protozoan that infects the cecum and colon of humans and other mammals. It is a zoonotic pathogen that causes diarrhea in both animals and humans. As companion animals, dogs infected with P. hominis pose a risk of transmitting it to humans. Current methods, such as direct smears and polymerase chain reaction (PCR), used for P. hominis detection have limitations, including low detection rates and the need for specialized equipment. Therefore, there is an urgent need to develop rapid, sensitive, and simple detection methods for clinical application. Recombinase polymerase amplification (RPA) has emerged as a technology for rapid pathogen detection. In this study, we developed a lateral flow dipstick (LFD)-RPA method based on the highly conserved SPO11-1 gene for detecting P. hominis infection by optimizing the primers, probes, and reaction conditions, and evaluating cross-reactivity with genomes of Giardia duodenalis and other parasites. The LFD-RPA method was then used to test 128 dog fecal samples collected from Changchun. The results confirmed the high specificity of the method with no cross-reactivity with the five other parasites. The lowest detection limit of the method was 102 copies/µL, and its sensitivity was 100 times higher than that of the conventional PCR method. Consistent with the positivity rate observed using nested PCR, 12 samples (out of 128) tested positive using this method (positivity rate, 9.38%). In conclusion, the LFD-RPA method developed in this study represents a simple and sensitive assay that allows for the rapid detection of P. hominis infection in dogs, especially in this field.

The ubiquitin ligase Peli1 negatively regulates T cell activation and prevents autoimmunity.

T cell activation is subject to tight regulation to avoid inappropriate responses to self antigens. Here we show that genetic deficiency in the ubiquitin ligase Peli1 caused hyperactivation of T cells and rendered T cells refractory to suppression by regulatory T cells and transforming growth factor-ß (TGF-ß). As a result, Peli1-deficient mice spontaneously developed autoimmunity characterized by multiorgan inflammation and autoantibody production. Peli1 deficiency resulted in the nuclear accumulation of c-Rel, a member of the NF-κB family of transcription factors with pivotal roles in T cell activation. Peli1 negatively regulated c-Rel by mediating its Lys48 (K48) ubiquitination. Our results identify Peli1 as a critical factor in the maintenance of peripheral T cell tolerance and demonstrate a previously unknown mechanism of c-Rel regulation.

A phase 1 open-label study to assess the relative bioavailability of TAK-931 tablets in reference to powder-in-capsule in patients with advanced solid tumors.

In this phase 1 open-label study, we assessed the relative bioavailability of a prototype tablet formulation of TAK-931, a cell division cycle 7 kinase inhibitor, in reference to the current powder-in-capsule (PIC) formulation in patients with advanced solid tumors for whom no effective standard treatment was available. Adult patients were randomized 1:1 in a crossover fashion to receive one dose of TAK-931 80 mg PIC on Day 1 and one dose of TAK-931 80 mg tablet on Day 3 (or the reverse sequence), followed by TAK-931 50 mg PIC once daily (QD) for 12 days starting from Day 5, before a 7-day rest period (Cycle 0). From Cycle 1, all patients received 50 mg PIC QD on Days 1-14 followed by a 7-day rest period. Twenty patients were enrolled. Median Tmax was achieved approximately 2 h post-dose of TAK-931 80 mg for both tablet and PIC. Geometric mean Cmax, AUC exposures, and T1/2z of TAK-931 were similar for both formulations. Geometric mean Cmax, AUClast, and AUCinf ratios were 0.936 (90% confidence interval [CI]: 0.808-1.084), 1.004 (90% CI: 0.899-1.120), and 1.007 (90% CI: 0.903-1.123), respectively, for TAK-931 tablet in reference to PIC. Discontinuation of TAK-931 due to treatment-emergent adverse events (TEAEs) occurred in 1 patient. Four (20%) patients experienced a serious TEAE; none were considered related to TAK-931. Pharmacokinetics and systemic exposure profiles were similar following administration of both formulations, supporting the transition from PIC to tablet in the clinical development of TAK-931. (Trial registration number ClinicalTrials.gov NCT03708211. Registration date October 12, 2018).

Inflammatory T cell responses rely on amino acid transporter ASCT2 facilitation of glutamine uptake and mTORC1 kinase activation.

Glutamine has been implicated as an immunomodulatory nutrient, but how glutamine uptake is mediated during T cell activation is poorly understood. We have shown that naive T cell activation is coupled with rapid glutamine uptake, which depended on the amino acid transporter ASCT2. ASCT2 deficiency impaired the induction of T helper 1 (Th1) and Th17 cells and attenuated inflammatory T cell responses in mouse models of immunity and autoimmunity. Mechanistically, ASCT2 was required for T cell receptor (TCR)-stimulated activation of the metabolic kinase mTORC1. We have further shown that TCR-stimulated glutamine uptake and mTORC1 activation also required a TCR signaling complex composed of the scaffold protein CARMA1, the adaptor molecule BCL10, and the paracaspase MALT1. This function was independent of IKK kinase, a major downstream target of the CARMA1 complex. These findings highlight a mechanism of T cell activation involving ASCT2-dependent integration of the TCR signal and a metabolic signaling pathway.

Predictors of In-Hospital Mortality and Home Discharge in Patients with Aneurysmal Subarachnoid Hemorrhage: A 4-Year Retrospective Analysis.

BACKGROUND: Factors associated with discharge disposition and mortality following aneurysmal subarachnoid hemorrhage (aSAH) are not well-characterized. We used a national all-payer database to identify factors associated with home discharge and in-hospital mortality. METHODS: The National Inpatient Sample was queried for patients with aSAH within a 4-year range. Weighted multivariable logistic regression models were constructed and adjusted for age, sex, race, household income, insurance status, comorbidity burden, National Inpatient Sample SAH Severity Score, disease severity, treatment modality, in-hospital complications, and hospital characteristics (size, teaching status, and region). RESULTS: Our sample included 37,965 patients: 33,605 were discharged alive and 14,350 were discharged home. Black patients had lower odds of in-hospital mortality compared with White patients (adjusted odds ratio [aOR] = 0.67, 95% confidence interval [CI] 0.52-0.86, p = 0.002). Compared with patients with private insurance, those with Medicare were less likely to have a home discharge (aOR = 0.58, 95% CI 0.46-0.74, p < 0.001), whereas those with self-pay (aOR = 2.97, 95% CI 2.29-3.86, p < 0.001) and no charge (aOR = 3.21, 95% CI 1.57-6.55, p = 0.001) were more likely to have a home discharge. Household income percentile was not associated with discharge disposition or in-hospital mortality. Paradoxically, increased number of Elixhauser comorbidities was associated with significantly lower odds of in-hospital mortality. CONCLUSIONS: We demonstrate independent associations with hospital characteristics, patient characteristics, and treatment characteristics as related to discharge disposition and in-hospital mortality following aSAH, adjusted for disease severity.

Mental Health of Primary and Secondary School Teachers in the Remote Mountain Areas.

Background and objective: Teaching is widely recognized as a highly stressful profession. Job stress leads to emotional exhaustion, which in turn triggers teacher attrition. The cost is estimated as USD 2.2 billion annually for teacher dropouts. It is therefore important to understand the mental state of teachers and the factors that may influence it in order to provide the appropriate early intervention. In the past, more attention has been paid to the mental status of teachers in economically developed cities, but less research has been conducted in remote cities. In this study, we selected primary and secondary school teachers in a typical area to assess their mental health, thereby contributing to the development of effective mental health education programs for teachers in primary and secondary schools. Materials and methods: In this study, 1102 teachers from a typical city in Ningxia Province, characterized by remote mountain areas, minority communities, and a low economic level, participated. The mental status of the teachers was assessed by a Symptom Checklist-90 (SCL-90). The effects of gender, age, level of education, place of work, and marital status on the total SCL-90 score were recorded and compared. The subscale scores of the SCL-90 and the differences among the respondents with various characteristics were analyzed. Results: In total, 1025 data were valid and used for statistical analysis. The effective rate of this study was 93.01%. The analysis showed that 25.17% of the subjects had possible mental problems. There were significant differences in age and marital status (p < 0.001). The score of teachers less than 30 years old was lower than that of other teachers (p = 0.001 vs. 30-39; p < 0.001 vs. 40-49; p < 0.001 vs. ≥50). The no-marriage teachers had the lowest score than the married group or others (p < 0.001 vs. married; p < 0.05 vs. others). Compared to the norm, teachers' mental status was poor, especially in somatization (p < 0.001), obsessive-compulsive symptoms (p < 0.001), depression (p < 0.001), anxiety (p < 0.001), hostility (p < 0.001), phobic anxiety (p < 0.001), and psychosis (p < 0.001). There were gender differences in obsessive-compulsive symptoms (p < 0.05) and depression (p < 0.05). Conclusions: These data indicate that the mental status of these teachers is not optimistic, and married female teachers aged 40-55 years need to be given more attention. Mental health examinations can be incorporated into daily physical examination items to facilitate the timely detection and early intervention of negative emotions.

Peli1 signaling blockade attenuates congenital zika syndrome.

Zika virus (ZIKV) infects pregnant women and causes devastating congenital zika syndrome (CZS). How the virus is vertically transmitted to the fetus and induces neuronal loss remains unclear. We previously reported that Pellino (Peli)1, an E3 ubiquitin ligase, promotes p38MAPK activation in microglia and induction of lethal encephalitis by facilitating the replication of West Nile virus (WNV), a closely related flavivirus. Here, we found that Peli1 expression was induced on ZIKV-infected human monocytic cells, peripheral blood mononuclear cells, human first-trimester placental trophoblasts, and neural stem cell (hNSC)s. Peli1 mediates ZIKV cell attachment, entry and viral translation and its expression is confined to the endoplasmic reticulum. Moreover, Peli1 mediated inflammatory cytokine and chemokine responses and induced cell death in placental trophoblasts and hNSCs. ZIKV-infected pregnant mice lacking Peli1 signaling had reduced placental inflammation and tissue damage, which resulted in attenuated congenital abnormalities. Smaducin-6, a membrane-tethered Smad6-derived peptide, blocked Peli1-mediated NF-κB activation but did not have direct effects on ZIKV infection. Smaducin-6 reduced inflammatory responses and cell death in placental trophoblasts and hNSCs, and diminished placental inflammation and damage, leading to attenuated congenital malformations in mice. Collectively, our results reveal a novel role of Peli1 in flavivirus pathogenesis and suggest that Peli1 promotes ZIKV vertical transmission and neuronal loss by mediating inflammatory cytokine responses and induction of cell death. Our results also identify Smaducin-6 as a potential therapeutic candidate for treatment of CZS.

Metabolism and Disposition of [14C]Pevonedistat, a First-in-Class NEDD8-Activating Enzyme Inhibitor, after Intravenous Infusion to Patients with Advanced Solid Tumors.

Metabolism and disposition of pevonedistat, an investigational, first-in-class inhibitor of the NEDD8-activating enzyme (NAE), were characterized in patients with advanced solid tumors after intravenous infusion of [14C]pevonedistat at 25 mg/m2 (∼60-85 µCi radioactive dose). More than 94% of the administered dose was recovered, with ∼41% and ∼53% of drug-related material eliminated in urine and feces, respectively. The metabolite profiles of [14C]pevonedistat were established in plasma using an accelerator mass spectrometer and excreta with traditional radiometric analysis. In plasma, unchanged parent drug accounted for approximately 49% of the total drug-related material. Metabolites M1 and M2 were major (>10% of the total drug-related material) circulating metabolites and accounted for approximately 15% and 22% of the drug-related material, respectively. Unchanged [14C]pevonedistat accounted for approximately 4% and 17% of the dose in urine and feces, respectively. Oxidative metabolites M1, M2, and M3 appeared as the most abundant drug-related components in the excreta and represented approximately 27%, 26%, and 15% of the administered dose, respectively. Based on the unbound plasma exposure in cancer patients and in vitro NAE inhibition, the contribution of metabolites M1 and M2 to overall in vivo pharmacological activity is anticipated to be minimal. The exposure to these metabolites was higher at safe and well tolerated doses in rat and dog (the two preclinical species used in toxicology evaluation) plasma than that observed in human plasma. Reaction phenotyping studies revealed that CYP3A4/5 are primary enzymes responsible for the metabolic clearance of pevonedistat. SIGNIFICANCE STATEMENT: This study details the metabolism and clearance mechanisms of pevonedistat, a first-in-class NEDD8-activating enzyme inhibitor, after intravenous administration to patients with cancer. Pevonedistat is biotransformed to two major circulating metabolites with higher exposure in nonclinical toxicological species than in humans. The pharmacological activity contribution of these metabolites is minimal compared to the overall target pharmacological effect of pevonedistat. Renal clearance was not an important route of excretion of unchanged pevonedistat (∼4% of the dose).