Loss of Function Mutation in ELF4 Causes Autoinflammatory and Immunodeficiency Disease in Human.

Monogenic autoinflammatory diseases (mAIDs) are a heterogeneous group of diseases affecting primarily innate immunity, with various genetic causes. Genetic diagnosis of mAIDs can assist in the patient's management and therapy. However, a large number of sporadic and familial cases remain genetically uncharacterized. Deficiency in ELF4, X-linked (DEX) is recently identified as a novel mAID. Here, we described a pediatric patient suffering from recurrent viral and bacterial respiratory infection, refractory oral ulcer, constipation, and arthritis. Whole-exome sequencing found a hemizygous variant in ELF4 (chrX:129205133 A > G, c.691 T > C, p.W231R). Using cells from patient and point mutation mice, we showed mutant cells failed to restrict viral replication effectively and produced more pro-inflammatory cytokines. RNA-seq identified several potential critical antiviral and anti-inflammation genes with decreased expression, and ChIP-qPCR assay suggested mutant ELF4 failed to bind to the promoters of these genes. Thus, we presented the second report of DEX.

Epigenetic regulation in antiviral innate immunity.

Emerging life-threatening viruses have posed great challenges to public health. It is now increasingly clear that epigenetics plays a role in shaping host-virus interactions and there is a great need for a more thorough understanding of these intricate interactions through the epigenetic lens, which may represent potential therapeutic opportunities in the clinic. In this review, we highlight the current understanding of the roles of key epigenetic regulators - chromatin remodeling and histone modification - in modulating chromatin openness during host defense against virus. We also discuss how the RNA modification m6A (N6-methyladenosine) affects fundamental aspects of host-virus interactions. We conclude with future directions for uncovering more detailed functions that epigenetic regulation exerts on both host cells and viruses during infection.

Hepatic epithelioid angiomyolipoma mimicking hepatocellular carcinoma on MR and 18F-FDG PET/CT imaging: A case report and literature review.

Hepatic epithelioid angiomyolipoma (HEAML) is a rare hepatic mesenchymal tumor with malignant potential. Unlike hepatic angiomyolipoma, HEAML is devoid of adipocytes. Thus, it is easy to be misdiagnosed as other tumors of liver, especially hepatocellular carcinoma (HCC) on preoperative imaging examinations. Herein, we present a case of HEAML mimicking HCC on magnetic resonance (MR) and fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in a 50-year-old female. After the primary diagnosis of HCC, the patient underwent a laparoscopic resection. The histopathology and immunohistochemical staining helped to reach the final diagnosis of HEAML. The important sign of central vessel can be seen on MRI in this case. The average apparent diffusion coefficient (ADC) value of the HEAML is 0.86±0.13x10-3mm2/s, which is lower than that of 0.97±0.02?10-3mm2/s of the normal liver. Previous literature on 18F-FDG PET/CT imaging of HEAML is limited to only 2 cases. The 18F-FDG PET/CT images of HEAML with high 18F-FDG accumulation with a maximum standardized uptake value (SUVmax) of 8.88 and extensive necrosis are presented, indicating its malignant potential. This case aims to improve the ability of differential diagnosis from HCC on multimodal imaging, and provides values for further 18F-FDG PET/CT related studies.

Furin Enzyme and pH Synergistically Triggered Aggregation of Gold Nanoparticles for Activated Photoacoustic Imaging and Photothermal Therapy of Tumors.

Specific and effective accumulation of nanoparticles within tumors is highly crucial for precise cancer diagnosis and treatment. Therefore, spatiotemporally manipulating the aggregation of small gold nanoparticles (AuNPs) in a tumor microenvironment is of great significance for enhancing the diagnostic and therapeutic efficacy of tumors. Herein, we reported a novel furin enzyme/acidic pH synergistically triggered small AuNP aggregation strategy for activating the photoacoustic (PA) imaging and photothermal (PTT) functions of AuNPs in vivo. Smart gold nanoparticles decorated with furin-cleavable RVRR (Arg-Val-Arg-Arg) peptides (Au-RRVR) were rationally designed and fabricated. Both in vitro and in vivo experiments demonstrated that such Au-RRVR nanoparticles could be simultaneously induced by furin and acidic pH to form large aggregates within tumorous tissue resulting in improved tumor accumulation and retention, which can further activate the PA and PTT effect of AuNPs for sensitive imaging and efficient therapy of tumors. Thus, we believe that this dual-stimuli-responsive aggregation system may offer a universal platform for effective cancer diagnosis and treatment.

Quantitatively Visualizing Tumor-Related Protease Activity in Vivo Using a Ratiometric Photoacoustic Probe.

The abnormal expression of tumor-related proteases plays a critical role in cancer invasion, progression, and metastasis. Therefore, it is considerably meaningful to non-invasively assess the proteases' activity in vivo for both tumor diagnosis and therapeutic evaluation. Herein, we report an activatable probe constructed with a near-infrared dye (Cy5.5) and a quencher (QSY21) covalently linked through a peptide substrate of matrix metalloproteinases-2 (MMP-2) that was chosen as a model for tumor-associated proteases. Upon cleavage with activated MMP-2, this probe emitted an MMP-2-concentration-dependent fluorescence. Quite unexpectedly, owing to the variation in the aggregation state of both the dye and its quencher as a consequence of the cleavage, the responsive probe presented a dramatic MMP-2-concentration-dependent absorption at around 680 nm, while that at around 730 nm was MMP-2 concentration independent. These features allowed detection of MMP-2 activity via both fluorescence and photoacoustic (PA) imaging in vitro, respectively. Moreover, taking the PA signal at 730 nm as an internal reference, the PA signal at 680 nm allowed quantitative detection of MMP-2 expression in breast cancer in vivo. We thus envision that our current approach would offer a useful tool for studying the malignant impacts of versatile tumor-associated proteases in vivo.

Light-Triggered Covalent Coupling of Gold Nanoparticles for Photothermal Cancer Therapy.

Manipulating the cross-coupling of gold nanoparticles (AuNPs) to maximize the photothermal effect is a promising strategy for cancer therapy. Here, by taking advantage of the well-known tetrazole/alkene photoclick chemistry, we have demonstrated for the first time that small AuNPs (23 nm) decorated with both 2,5-diphenyltetrazole and methacrylic acid on their surfaces can form covalently crosslinked aggregates upon laser irradiation (λ=405 nm). In vitro studies indicated that the light-triggered assembling shifted the surface plasmon resonance of AuNPs significantly to near-infrared (NIR) regions, which as a consequence effectively enhanced the efficacy of photothermal therapy for 4T1 breast cancer cells. We thus believe that this new light-triggered cross-coupling approach might offer a valuable tool for cancer treatment.

Simple Light-Triggered Fluorescent Labeling of Silica Nanoparticles for Cellular Imaging Applications.

A simple and mild light-triggered fluorescent labeling approach, based on the photolysis and reactive carbene insertion of diazirine, to rapidly generate fluorescent nanoparticles is reported. Proof of concept studies demonstrated that the non-fluorescent SiNPs could be covalently labeled by diazirine-conjugated fluorescein (dFITC) upon photo irradiation (λ=365 nm) to afford fluorescent SiNPs with good fluorescent stability and low cytotoxicity. In vitro cellular imaging results indicated that the internalization of SiNPs into living cells could be readily visualized based on fluorescein-labeled SiNPs (F-SiNPs) in real time. We believe that the light-triggered labeling approach may offer a valuable method for surface modification of nanomaterials to achieve new functions.

Light-initiated aggregation of gold nanoparticles for synergistic chemo-photothermal tumor therapy.

The combination of chemotherapy with photothermal therapy (PTT) has attracted extensive attention due to its excellent synergetic effect attributing to the fact that hyperthermia can effectively promote the tumor uptake of chemotherapeutic drugs. Herein, we propose a light-initiated gold nanoparticle (AuNP) aggregation boosting the uptake of chemotherapeutic drugs for enhanced chemo-photothermal tumor therapy. Novel light-responsive AuNPs (tm-AuNPs) were rationally designed and fabricated by conjugating both 2,5-diphenyltetrazole (Tz) and methacrylic acid (Ma) onto the surface of AuNPs with small size (∼20 nm). Upon the irradiation of 405 nm laser, AuNPs could be initiated to form aggregates specifically within tumors through the covalent cycloaddition reaction between Tz and Ma. Taking advantage of the controllable photothermal effect of Au aggregates under NIR excitation, improved enrichment of doxorubicin (DOX) in tumor tissues was realized, combined with PTT, resulting in outstanding synergetic anti-tumor efficacy in living mice. We thus believe that this light-initiated AuNP aggregation approach would offer a valuable and powerful tool for precisely synergistic chemo-photothermal tumor therapy.

The collateral activity of RfxCas13d can induce lethality in a RfxCas13d knock-in mouse model.

BACKGROUND: The CRISPR-Cas13 system is an RNA-guided RNA-targeting system and has been widely used in transcriptome engineering with potentially important clinical applications. However, it is still controversial whether Cas13 exhibits collateral activity in mammalian cells. RESULTS: Here, we find that knocking down gene expression using RfxCas13d in the adult brain neurons caused death of mice, which may result from the collateral activity of RfxCas13d rather than the loss of target gene function or off-target effects. Mechanistically, we show that RfxCas13d exhibits collateral activity in mammalian cells, which is positively correlated with the abundance of target RNA. The collateral activity of RfxCas13d could cleave 28s rRNA into two fragments, leading to translation attenuation and activation of the ZAKα-JNK/p38-immediate early gene pathway. CONCLUSIONS: These findings provide new mechanistic insights into the collateral activity of RfxCas13d in mammalian cells and warn that the biosafety of the CRISPR-Cas13 system needs further evaluation before application to clinical treatments.

Inhibiting ACSL1-Related Ferroptosis Restrains Murine Coronavirus Infection.

Murine hepatitis virus strain A59 (MHV-A59) was shown to induce pyroptosis, apoptosis, and necroptosis of infected cells, especially in the murine macrophages. However, whether ferroptosis, a recently identified form of lytic cell death, was involved in the pathogenicity of MHV-A59 is unknown. We utilized murine macrophages and a C57BL/6 mice intranasal infection model to address this. In primary macrophages, the ferroptosis inhibitor inhibited viral propagation, inflammatory cytokines released, and cell syncytia formed after MHV-A59 infection. In the mouse model, we found that in vivo administration of liproxstatin-1 ameliorated lung inflammation and tissue injuries caused by MHV-A59 infection. To find how MHV-A59 infection influenced the expression of ferroptosis-related genes, we performed RNA-seq in primary macrophages and found that MHV-A59 infection upregulates the expression of the acyl-CoA synthetase long-chain family member 1 (ACSL1), a novel ferroptosis inducer. Using ferroptosis inhibitors and a TLR4 inhibitor, we showed that MHV-A59 resulted in the NF-kB-dependent, TLR4-independent ACSL1 upregulation. Accordingly, ACSL1 inhibitor Triacsin C suppressed MHV-A59-infection-induced syncytia formation and viral propagation in primary macrophages. Collectively, our study indicates that ferroptosis inhibition protects hosts from MHV-A59 infection. Targeting ferroptosis may serve as a potential treatment approach for dealing with hyper-inflammation induced by coronavirus infection.

Combined clinical and imaging features better predict the critical outcomes of patients with SARS-COV-2.

ABSTRACT: The purpose of this study was to investigate the predictive value of combined clinical and imaging features, compared with the clinical or radiological risk factors only. Moreover, the expected results aimed to improve the identification of severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) patients who may have critical outcomes.This retrospective study included laboratory-confirmed SARS-COV-2 cases between January 18, 2020, and February 16, 2020. The patients were divided into 2 groups with noncritical illness and critical illness regarding severity status within the hospitalization. Univariable and multivariable logistic regression models were used to explore the risk factors associated with clinical and radiological outcomes in patients with SARS-COV-2. The ROC curves were performed to compare the prediction performance of different factors.A total of 180 adult patients in this study included 20 critical patients and 160 noncritical patients. In univariate logistic regression analysis, 15 risk factors were significantly associated with critical outcomes. Of importance, C-reactive protein (1.051, 95% confidence interval 1.024-1.078), D-dimer (1.911, 95% CI, 1.050-3.478), and CT score (1.29, 95% CI, 1.053-1.529) on admission were independent risk factors in multivariate analysis. The combined model achieved a better performance in disease severity prediction (P = .05).CRP, D-dimer, and CT score on admission were independent risk factors for critical illness in adults with SARS-COV-2. The combined clinical and radiological model achieved better predictive performance than clinical or radiological factors alone.

Suppression of ELF4 in ulcerative colitis predisposes host to colorectal cancer.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease, characterized by relapsing and remitting colon mucosal inflammation. For patients suffering from UC, a higher risk of colon cancer has been widely recognized. Here, we found that Elf4 -/- mice developed colon tumors with 3 cycles of dextran sulfate sodium salt (DSS) treatment alone. We further showed that ELF4 suppression was prevalent in both patients with UC and DSS-induced mice models, and this suppression was caused by promoter region methylation. ELF4, upon PARylation by PARP1, transcriptionally regulated multiple DNA damage repair machinery components. Consistently, ELF4 deficiency leads to more severe DNA damage both in vitro and in vivo. Oral administration of montmorillonite powder can prevent the reduction of ELF4 in DSS-induced colitis models and lower the risk of colon tumor development during azoxymethane (AOM) and DSS induced colitis-associated cancer (CAC). These data provided additional mechanism of CAC initiation and supported the "epigenetic priming model of tumor initiation".

Induction of alarmin S100A8/A9 mediates activation of aberrant neutrophils in the pathogenesis of COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic poses an unprecedented public health crisis. Evidence suggests that SARS-CoV-2 infection causes dysregulation of the immune system. However, the unique signature of early immune responses remains elusive. We characterized the transcriptome of rhesus macaques and mice infected with SARS-CoV-2. Alarmin S100A8 was robustly induced in SARS-CoV-2-infected animal models as well as in COVID-19 patients. Paquinimod, a specific inhibitor of S100A8/A9, could rescue the pneumonia with substantial reduction of viral loads in SARS-CoV-2-infected mice. Remarkably, Paquinimod treatment resulted in almost 100% survival in a lethal model of mouse coronavirus infection using the mouse hepatitis virus (MHV). A group of neutrophils that contributes to the uncontrolled pathological damage and onset of COVID-19 was dramatically induced by coronavirus infection. Paquinimod treatment could reduce these neutrophils and regain anti-viral responses, unveiling key roles of S100A8/A9 and aberrant neutrophils in the pathogenesis of COVID-19, highlighting new opportunities for therapeutic intervention.

Light-triggered crosslinking of gold nanoparticles for remarkably improved radiation therapy and computed tomography imaging of tumors.

Aim: We aimed to characterize the tumor-targeting and radiosensitization properties of the photo-responsive gold nanoparticles (AuNPs) decorated photolabile diazirine group and folic acid for improved radiotherapy and computed tomography imaging of tumors. Methods: Folic acid and photolabile diazirine group were covalently conjugated on the surface of AuNPs to afford the desired photo-responsive dAuNP-FA (AuNPs capped with poly(ethylene) glycol ligands bearing photolabile diazirine group and folic acid). The probes were intravenously injected into tumor-bearing mice followed by photocrosslinking upon 405 nm laser irradiation for radiotherapy and computed tomography imaging of tumors in vivo. Results: Light-triggered crosslinking of AuNPs in vivo remarkably enhanced the accumulation and retention of AuNPs within tumors. Conclusion: We have successfully developed a novel photo-responsive Au particle-based tumor theranostic probe showing remarkably improved tumor targeting ability and radiosensitization effect.

An acidic pH/reduction dual-stimuli responsive nanoprobe for enhanced CT imaging of tumours in vivo.

Computed tomography (CT) is one of the most frequently used diagnostic imaging modalities in clinics. However, the fast clearance of CT contrast agents through the kidney and short circulation time severely restrict their in vivo applications. Herein, taking advantage of the biocompatible CBT condensation reaction, we rationally designed and synthesized a new smart acidic pH/glutathione (GSH) dual-stimuli responsive nanoprobe (1) which can intermolecularly undergo condensation and form a nanoparticle assembly (I-NPs) in the tumour microenvironment. In vivo CT imaging results indicated that probe 1 could be successfully applied for enhanced CT imaging of tumours in nude mice with a low dose of 21.79 mg I per kg body weight, which may offer a promising tool for precise tumor diagnosis.