TRIM21 promotes ubiquitination of SARS-CoV-2 nucleocapsid protein to regulate innate immunity.

The innate immune response is the first line of host defense against viral infections, but its role in immunity against SARS-CoV-2 remains unclear. By using immunoprecipitation coupled with mass spectroscopy, we observed that the E3 ubiquitin ligase TRIM21 interacted with the SARS-CoV-2 nucleocapsid (N) protein and ubiquitinated it at Lys375 . Upon determining the topology of the TRIM21-mediated polyubiquitination chain on N protein, we then found that polyubiquitination led to tagging of the N protein for degradation by the host cell proteasome. Furthermore, TRIM21 also ubiquitinated the N proteins of SARS-CoV-2 variants of concern, including Alpha, Beta, Gamma, Delta, and Omicron together with SARS-CoV and MERS-CoV variants. Herein, we propose that ubiquitylation and degradation of the SARS-CoV-2 N protein inhibited SARS-CoV-2 viral particle assembly, by which it probably involved in preventing cytokine storm. Eventually, our study has fully revealed the association between the host innate immune system and SARS-CoV-2 N protein, which may aid in developing novel SARS-CoV-2 treatment strategies.

Computed tomography imaging features of malignant 'triton' tumor to facilitate its clinical diagnosis: report of two cases.

BACKGROUND: Malignant 'triton' tumor is an extremely rare subtype of malignant periphery nerve sheath tumors. Clinical diagnosis of malignant triton tumor is difficult before surgery due to its low incidence and the lack of knowledge. Therefore, to describe and summarize the CT imaging characteristics of malignant triton tumor is of great assistance for early and preoperative diagnosis. CASE PRESENTATION: Two cases suspected of MTT by CT scan before operation were closely observed. The diagnosis of malignant triton tumor was eventually confirmed by immunochemical assay, which verified speculation of CT scans. Huge, irregular, well-circumscribed lobulated mass-like shadows can be observed from these patients by CT scans. Besides, heterogeneity of density within the body of tumor was well-established by CT scans, together with linear septum. Meanwhile, CT scans demonstrated that calcifications were remarkable at the margin of tumor body. CONCLUSIONS: Some CT image features from two cases were presented as a reference for the preoperative consideration of MTT: (i) enormity of mass-like shadow; (ii) presence of well-circumscribed lobulated shape; (iii) septum within the well-defined mass accompanied with hemorrhage, necrosis and cystic changes as well as calcification, especially within neurofibromatosis type 1 patients.

E3 Ubiquitin Ligase FBXO3 Drives Neuroinflammation to Aggravate Cerebral Ischemia/Reperfusion Injury.

Ischemic stroke, one of the most universal causes of human mortality and morbidity, is pathologically characterized by inflammatory cascade, especially during the progression of ischemia/reperfusion (I/R) injury. F-Box Protein 3 (FBXO3), a substrate-recognition subunit of SKP1-cullin 1-F-box protein (SCF) E3 ligase complexes, has recently been proven to be severed as an underlying pro-inflammatory factor in pathological processes of diverse diseases. Given these considerations, the current study aims at investigating whether FBXO3 exerts impacts on inflammation in cerebral I/R injury. In this study, first, it was verified that FBXO3 protein expression increased after a middle cerebral artery occlusion/reperfusion (MCAO/R) model in Sprague-Dawley (SD) rats and was specifically expressed in neurons other than microglia or astrocytes. Meanwhile, in mouse hippocampal neuronal cell line HT22 cells, the elevation of FBXO3 protein was observed after oxygen and glucose deprivation/reoxygenation (OGD/R) treatment. It was also found that interference of FBXO3 with siRNA significantly alleviated neuronal damage via inhibiting the inflammatory response in I/R injury both in vivo and in vitro. The FBXO3 inhibitor BC-1215 was used to confirm the pro-inflammatory effect of FBXO3 in the OGD/R model as well. Furthermore, by administration of FBXO3 siRNA and BC-1215, FBXO3 was verified to reduce the protein level of Homeodomain-Interacting Protein Kinase 2 (HIPK2), likely through the ubiquitin-proteasome system (UPS), to aggravate cerebral I/R injury. Collectively, our results underline the detrimental effect FBXO3 has on cerebral I/R injury by accelerating inflammatory response, possibly through ubiquitylating and degrading HIPK2. Despite the specific interaction between FBXO3 and HIPK2 requiring further study, we believe that our data suggest the therapeutic relevance of FBXO3 to ischemic stroke and provide a new perspective on the mechanism of I/R injury.

Origin of the Overpotential for the Oxygen Evolution Reaction on a Well-Defined Graphene Electrode Probed by in Situ Sum Frequency Generation Vibrational Spectroscopy.

To develop an efficient material for the cathode of the lithium-oxygen (Li-O2) secondary battery, the oxygen reduction and evolution reactions (ORR and OER) on a well-defined graphene electrode have been investigated in a typical organic solvent, dimethyl sulfoxide (DMSO). The adsorption and desorption behaviors of the solvents on the graphene electrode surface were evaluated by an intrinsically surface-selective vibrational spectroscopy of sum frequency generation (SFG) during the ORR and OER. After the initial ORR depositing lithium peroxide (Li2O2) on the graphene electrode surface in a LiClO4/DMSO solution, the SFG spectroscopy revealed that the subsequent OER oxidizing the Li2O2 preferentially proceeds at the interface between the Li2O2 and graphene rather than that between the Li2O2 and bulk solution. Therefore, the OER tends to reduce the electric conductivity between the Li2O2 and graphene by decreasing their contact area before a large part of the deposited Li2O2 was oxidized, which elucidates the origin of the high overpotential for the OER.

Theoretical and experimental examination of SFG polarization analysis at acetonitrile-water solution surfaces.

Sum frequency generation (SFG) spectroscopy is widely used to observe molecular orientation at interfaces through a combination of various types of polarization. The present work thoroughly examines the relation between the polarization dependence of SFG signals and the molecular orientation, by comparing SFG measurements and molecular dynamics (MD) simulations of acetonitrile/water solutions. The present SFG experiment and MD simulations yield quite consistent results on the ratios of χ(2) elements, supporting the reliability of both means. However, the subsequent polarization analysis tends to derive more upright tilt angles of acetonitrile than the direct MD calculations. The reasons for discrepancy are examined in terms of three issues; (i) anisotropy of the Raman tensor, (ii) cross-correlation, and (iii) orientational distribution. The analysis revealed that the issues (i) and (iii) are the main causes of errors in the conventional polarization analysis of SFG spectra. In methyl CH stretching, the anisotropy of Raman tensor cannot be estimated from the simple bond polarizability model. The neglect of the orientational distribution is shown to systematically underestimate the tilt angle of acetonitrile. Further refined use of polarization analysis in collaboration with MD simulations should be proposed.

Phase transition behaviors of the supported DPPC bilayer investigated by sum frequency generation (SFG) vibrational spectroscopy and atomic force microscopy (AFM).

The phase transition behaviors of a supported bilayer of dipalmitoylphosphatidyl-choline (DPPC) have been systematically evaluated by in situ sum frequency generation (SFG) vibrational spectroscopy and atomic force microscopy (AFM). By using an asymmetric bilayer composed of per-deuterated and per-protonated monolayers, i.e., DPPC-d75/DPPC and a symmetric bilayer of DPPC/DPPC, we were able to probe the molecular structural changes during the phase transition process of the lipid bilayer by SFG spectroscopy. It was found that the DPPC bilayer is sequentially melted from the top (adjacent to the solution) to bottom leaflet (adjacent to the substrate) over a wide temperature range. The conformational ordering of the supported bilayer does not decrease (even slightly increases) during the phase transition process. The conformational defects in the bilayer can be removed after the complete melting process. The phase transition enthalpy for the bottom leaflet was found to be approximately three times greater than that for the top leaflet, indicating a strong interaction of the lipids with the substrate. The present SFG and AFM observations revealed similar temperature dependent profiles. Based on these results, the temperature-induced structural changes in the supported lipid bilayer during its phase transition process are discussed in comparison with previous studies.

Molecular orientation of organic thin films on dielectric solid substrates: a phase-sensitive vibrational SFG study.

Broadband phase-sensitive vibrational sum frequency generation (SFG) spectroscopy was utilized to study the molecular orientation of molecules adsorbed on dielectric solid substrates. A gold thin film was employed to generate a SFG signal as a local oscillator (LO). To simplify the phase measurement, a self-assembled monolayer (SAM) of octadecyltrichlorosilane (OTS) was used as a standard sample for phase correction of the phase-sensitive SFG measurements on the solid/air interface. It was demonstrated that the absolute orientation of molecules in the LB films on a fused quartz surface can be clearly distinguished by phase-sensitive SFG measurement. In addition, the observation on the SAM of d35-OTS reveals that the two C-H stretching modes for α-CH2 group are in opposite phase. Furthermore, by using the present phase-sensitive SFG setup, the orientation flipping of water molecules on positively and negatively charged solid/liquid interface can be distinguished.

Reprogramming exosomes for immunity-remodeled photodynamic therapy against non-small cell lung cancer.

Traditional treatments against advanced non-small cell lung cancer (NSCLC) with high morbidity and mortality continue to be dissatisfactory. Given this situation, there is an urgent requirement for alternative modalities that provide lower invasiveness, superior clinical effectiveness, and minimal adverse effects. The combination of photodynamic therapy (PDT) and immunotherapy gradually become a promising approach for high-grade malignant NSCLC. Nevertheless, owing to the absence of precise drug delivery techniques as well as the hypoxic and immunosuppressive characteristics of the tumor microenvironment (TME), the efficacy of this combination therapy approach is less than ideal. In this study, we construct a novel nanoplatform that indocyanine green (ICG), a photosensitizer, loads into hollow manganese dioxide (MnO2) nanospheres (NPs) (ICG@MnO2), and then encapsulated in PD-L1 monoclonal antibodies (anti-PD-L1) reprogrammed exosomes (named ICG@MnO2@Exo-anti-PD-L1), to effectively modulate the TME to oppose NSCLC by the synergy of PDT and immunotherapy modalities. The ICG@MnO2@Exo-anti-PD-L1 NPs are precisely delivered to the tumor sites by targeting specially PD-L1 highly expressed cancer cells to controllably release anti-PD-L1 in the acidic TME, thereby activating T cell response. Subsequently, upon endocytic uptake by cancer cells, MnO2 catalyzes the conversion of H2O2 to O2, thereby alleviating tumor hypoxia. Meanwhile, ICG further utilizes O2 to produce singlet oxygen (1O2) to kill tumor cells under 808 nm near-infrared (NIR) irradiation. Furthermore, a high level of intratumoral H2O2 reduces MnO2 to Mn2+, which remodels the immune microenvironment by polarizing macrophages from M2 to M1, further driving T cells. Taken together, the current study suggests that the ICG@MnO2@Exo-anti-PD-L1 NPs could act as a novel drug delivery platform for achieving multimodal therapy in treating NSCLC.

Reprogramming Exosomes to Escape from Immune Surveillance for Mitochondrial Protection in Hepatic Ischemia-Reperfusion Injury.

Background: Therapeutic interventions such as synthetic drugs and microRNA (miR) modulators have created opportunities for mitigating hepatic ischemia/reperfusion injury (HIRI) by alleviating mitochondrial dysfunction. However, delivering multi-therapeutic ingredients with low toxicity to hepatocytes still lags behind its development. Methods: In this study, we endowed exosomes with delivery function to concentrate on hepatocytes for multidimensionally halting mitochondria dysfunction during HIRI. Concretely, exosomes were reprogrammed with a transmembrane protein CD47, which acted as a "camouflage cloak" to mimic the "don't eat me" mechanism to escape from immune surveillance. Besides, HuR was engineered bridging to the membrane by fusing with CD47 and located in the cytoplasm for miR loading. Results: This strategy successfully delivered dual payloads to hepatocytes and efficiently protected mitochondria by inhibiting the opening of mitochondrial permeability transition pore (mPTP) and upregulating mitochondrial transcription factor A (TFAM), respectively. Conclusions: The reprogramming of exosomes with CD47 and HuR for targeted delivery of CsA and miR inhibitors represents a promising therapeutic strategy for addressing HIRI. This approach shows potential for safe and effective clinical applications in the treatment of HIRI.

Effect of functional group on the monolayer structures of biodegradable quaternary ammonium surfactants.

The monolayer structures and conformational ordering of cationic surfactants including the biodegradable quaternary ammonium molecules have been systematically characterized by π-A isotherm, surface potential, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and sum frequency generation (SFG) vibrational spectroscopy. It was found that the monolayer of the typical dialkyl dimethylammonium on the water surface was less densely packed along with many conformational gauche defects. The packing density and ordering of these monolayers were improved as halide ions were added to the subphase. A similar condensation effect was also observed when amide or ester groups are present in the alkyl tails of the surfactant. These results are discussed on the basis of the repulsive electrostatic interactions between the terminal ammonium moieties, the hydrogen bonding between the functional groups in the alkyl chains, as well as the flexibility of the alkyl chains in these surfactants. The present study is crucial to understanding the relationship between the interfacial structures and the functionalities of the biodegradable quaternary ammonium surfactants.

Emerging chemical engineering of exosomes as "bioscaffolds" in diagnostics and therapeutics.

All cells release extracellular vesicles (EVs) as part of their normal physiology. As one of the subtypes, exosomes (EXOs) have an average size range of approximately 40 nm-160 nm in diameter. Benefiting from their inherent immunogenicity and biocompatibility, the utility of autologous EXOs has the potential for both disease diagnosis/treatment. EXOs are generally employed as "bioscaffolds" and the whole diagnostic and therapeutic effects are mainly ascribed to exogenous cargos on the EXOs, such as proteins, nucleic acids, and chemotherapeutic agents and fluorophores delivered into specific cells or tissues. Surface engineering of EXOs for cargo loadings is one of the prerequisites for EXO-mediated diagnosis/treatment. After revisiting EXO-mediated diagnosis/treatment, the most popular strategies to directly undertake loadings of exogenous cargos on EXOs include genetic and chemical engineering. Generally, genetically-engineered EXOs can be merely produced by living organisms and intrinsically face some drawbacks. However, chemical methodologies for engineered EXOs diversify cargos and extend the functions of EXOs in the diagnosis/treatment. In this review, we would like to elucidate different chemical advances on the molecular level of EXOs along with the critical design required for diagnosis/treatment. Besides, the prospects of chemical engineering on the EXOs were critically addressed. Nevertheless, the superiority of EXO-mediated diagnosis/treatment via chemical engineering remains a challenge in clinical translation and trials. Furthermore, more chemical crosslinking on the EXOs is expected to be explored. Despite substantial claims in the literature, there is currently no review to exclusively summarize the chemical engineering to EXOs for diagnosis/treatment. We envision chemical engineering of EXOs will encourage more scientists to explore more novel technologies for a wider range of biomedical applications and accelerate the successful translation of EXO-based drug "bioscaffolds" from bench to bedside.

Aptamer and Peptide-Engineered Polydopamine Nanospheres for Target Delivery and Tumor Perfusion in Synergistic Chemo-Phototherapy of Pancreatic Cancer.

Pancreatic cancer (PC) is the fourth leading cause of cancer death, and the 5 year survival rate is only 4%. Chemotherapy is the treatment option for the majority of PC patients diagnosed at an advanced stage, whereas the desmoplastic stroma of PC could block the perfusion of chemotherapeutic agents to tumor tissues and contribute generally to chemoresistance. Therefore, the clinical status of PC calls for an urgent exploration in the effective treatment strategy. Chemo-phototherapy is an emerging modality against malignant tumors, but owing to the low targeting ability of theranostic agents or unspecific accumulation in the tumor region, majority of chemo-phototherapy techniques have disappointing therapeutic efficiencies. Herein, we have explored CD71-specific targeting aptamers and paclitaxel (PTX)-modified polydopamine (PDA) nanospheres with the conjugation of peptidomimetic AV3 (termed Apt-PDA@PTX/AV3 bioconjugates) to specifically target and combat PC in vivo by synergistic chemo-phototherapy. After the delivery of nanotheranostic agents to the tumor microenvironment (TME) or subsequent endocytic uptake by PC cells, a simultaneous release of AV3 and PTX from Apt-PDA@PTX/AV3 bioconjugates via near-infrared (NIR) irradiation can decrease desmoplastic stroma to enhance tumor perfusion and tumor-killing effects. Meanwhile, PDA cores utilize NIR laser to create unendurable hyperthermia within TME to "cook" tumors. Taken together, the current study finally suggests that our Apt-PDA@PTX/AV3 bioconjugates could act as a novel therapeutic approach by synergistic chemo-phototherapy for the programmable inhibition of PC.

Necroptosis-Related Prognostic Model for Pancreatic Carcinoma Reveals Its Invasion and Metastasis Potential through Hybrid EMT and Immune Escape.

Necroptosis, pro-inflammatory programmed necrosis, has been reported to exert momentous roles in pancreatic cancer (PC). Herein, the objective of this study is to construct a necroptosis-related prognostic model for detecting pancreatic cancer. In this study, the intersection between necroptosis-related genes and differentially expressed genes (DEGs) of pancreatic ductal adenocarcinoma (PDAC) was obtained based on GeneCards database, GEO database (GSE28735 and GSE15471), and verified using The Cancer Genome Atlas (TCGA). Next, a prognostic model with Cox and LASSO regression analysis, and divided the patients into high-risk and low-risk groups. Subsequently, the Kaplan-Meier (KM) survival curve and the receiver operating characteristic (ROC) curves were generated to assess the predictive ability of overall survival (OS) of PC patients. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to predict the potential biofunction and possible mechanical pathways. The EMTome database and an immune analysis were applied to further explore underlying mechanism. Finally, clinical samples of PDAC patients were utilized to verify the expression of model genes via immunohistochemistry (IHC), and the normal human pancreatic ductal cell line, hTERT-HPNE as well as human pancreatic ductal carcinoma cell lines, PANC-1 and PL45, were used to identify the levels of model genes by Western blot (WB) and immunofluorescence (IF) in vitro. The results showed that 13 necroptosis-related DEGs (NRDEGs) were screened based on GEO database, and finally four of five prognostic genes, including KRT7, KRT19, IGF2BP3, CXCL5, were further identified by TCGA to successfully construct a prognostic model. Univariate and multivariate Cox analysis ultimately confirmed that this prognostic model has independent prognostic significance, KM curve suggested that the OS of low-risk group was longer than high-risk group, and the area under receiver (AUC) of ROC for 1, 3, 5 years was 0.733, 0.749 and 0.667, respectively. A GO analysis illustrated that model genes may participate in cell-cell junction, cadherin binding, cell adhesion molecule binding, and neutrophil migration and chemotaxis, while KEGG showed involvement in PI3K-Akt signaling pathway, ECMreceptor interaction, IL-17 signaling pathway, TNF signaling pathway, etc. Moreover, our results showed KRT7 and KRT19 were closely related to EMT markers, and EMTome database manifested that KRT7 and KRT19 are highly expressed in both primary and metastatic pancreatic cancer, declaring that model genes promoted invasion and metastasis potential through EMT. In addition, four model genes were positively correlated with Th2, which has been reported to take part in promoting immune escape, while model genes except CXCL5 were negatively correlated with TFH cells, indicating that model genes may participate in immunity. Additionally, IHC results showed that model genes were higher expressed in PC tissues than that in adjacent tumor tissues, and WB and IF also suggested that model genes were more highly expressed in PANC-1 and PL45 than in hTERT-HPNE. Tracing of a necroptosis-related prognostic model for pancreatic carcinoma reveals its invasion and metastasis potential through EMT and immunity. The construction of this model and the possible mechanism of necroptosis in PDAC was preliminarily explored to provide reliable new biomarkers for the early diagnosis, treatment, and prognosis for pancreatic cancer patients.

Intelligent recognition of CTCs from gallbladder cancer by ultrasensitive electrochemical cytosensor and diagnosis of chemotherapeutic resistance.

Gallbladder carcinoma (GBC) is one of most aggressive and lethal malignancies. Early diagnosis of GBC is crucial for determining appropriate treatment and improving chances of cure. Chemotherapy represents the main therapeutic regimen for unresectable GBC patients to inhibit tumor growth & metastasis. But, chemoresistance is the major cause of GBC recurrence. Thus, there is an urgent need to explore potentially non-invasive and point-of-care approaches to screen GBC and monitor their chemoresistance. Herein, we established an electrochemical cytosensor to specifically detect circulating tumor cells (CTCs) and their chemoresistance. Trilayer of CdSe/ZnS quantum dots (QDs) were cladded upon SiO2 nanoparticles (NPs), forming Tri-QDs/PEI@SiO2 electrochemical probes. Upon conjugation of anti-ENPP1, the electrochemical probes were able to specifically label captured CTCs from GBC. The detection of CTCs and chemoresistance were realized by square wave anodic stripping voltammetric (SWASV) responses to anodic stripping current of Cd 2+ ion when cadmium in electrochemical probes was dissolved and eventually electrodeposited on bismuth film-modified glassy carbon electrode (BFE). Taking use of this cytosensor, one ensured the screening of GBC and limit of detection for CTCs approaches to ～10 cells/mL. Furthermore, by monitoring phenotypic changes of CTCs after drug treatment, the diagnosis of chemoresistance was achieved by our cytosensor.

Integrated proteogenomic characterization reveals an imbalanced hepatocellular carcinoma microenvironment after incomplete radiofrequency ablation.

BACKGROUND: Efforts to precisely assess tumor-specific T-cell immune responses still face major challenges, and the potential molecular mechanisms mediating hepatocellular carcinoma (HCC) microenvironment imbalance after incomplete radiofrequency ablation (iRFA) are unclear. This study aimed to provide further insight into the integrated transcriptomic and proteogenomic landscape and identify a new target involved in HCC progression following iRFA. METHODS: Peripheral blood and matched tissue samples were collected from 10 RFA-treated HCC patients. Multiplex immunostaining and flow cytometry were used to assess local and systemic immune responses. Differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) were explored via transcriptomic and proteogenomic analyses. Proteinase-3 (PRTN3) was identified in these analyses. And then, the ability of PRTN3 to predict overall survival (OS) was assessed in 70 HCC patients with early recurrence after RFA. In vitro CCK-8, wound healing and transwell assays were conducted to observe interactions between Kupffer cells (KCs) and HCC cells induced by PRTN3. The protein levels of multiple oncogenic factors and signaling pathway components were detected by western blotting. A xenograft mouse model was built to observe the tumorigenic effect of PRTN3 overexpression on HCC. RESULTS: Multiplex immunostaining revealed no immediate significant change in local immune cell counts in periablational tumor tissues after 30 min of iRFA. Flow cytometry showed significantly increased levels of CD4+ T cells, CD4+CD8+ T cells, and CD4+CD25+CD127- Tregs and significantly decreased the levels of CD16+CD56+ natural killer cells on day 5 after cRFA (p < 0.05). Transcriptomics and proteomics revealed 389 DEGs and 20 DEPs. Pathway analysis showed that the DEP-DEGs were mainly enriched in the immunoinflammatory response, cancer progression and metabolic processes. Among the DEP-DEGs, PRTN3 was persistently upregulated and closely associated with the OS of patients with early recurrent HCC following RFA. PRTN3 expressed in KCs may affect the migration and invasion of heat stress-treated HCC cells. PRTN3 promotes tumor growth via multiple oncogenic factors and the PI3K/AKT and P38/ERK signaling pathways. CONCLUSIONS: This study provides a comprehensive overview of the immune response and transcriptomic and proteogenomic landscapes of the HCC milieu induced by iRFA, revealing that PRTN3 promotes HCC progression after iRFA. TRIAL REGISTRATION: ChiCTR2200055606, http://www.chictr.org.cn/showproj.aspx?proj=32588 .

Characterizing the photoinduced switching process of a nitrospiropyran self-assembled monolayer using in situ sum frequency generation spectroscopy.

Sum frequency generation (SFG) vibrational spectroscopy is employed to investigate the reversible, photoinduced spiro→merocyanine isomerization of a self-assembled monolayer, the result of attachment of nitrospiropyran to a gold surface using a dithiolane anchoring group. The attachment of these molecular "alligator clips" to spiropyran molecules provide an easily accessible method to self-assemble a robust monolayer of spiropyran on a gold surface, which allows photoswitching of the spiropyran units. Probing the symmetric and antisymmetric stretching modes of the nitro group allows the determination of the structural orientation of the charged moiety with respect to the surface normal as well as the isomerization rates under photoinduced switching conditions. The photoisomerization of the spiropyran SAM on the gold surface is much faster than the rates of switching spiropyrans in a solid crystalline form, and the rate of thermal relaxation of the opened to closed form in this study is found to be on the same time scale as the relaxation of spiropyran when present in solutions with polar solvents.

NLRP6-Dependent Pyroptosis-Related lncRNAs Predict the Prognosis of Hepatocellular Carcinoma.

Pyroptosis, a novel pro-inflammatory type of programmed cell death, is involved in the tumorigenesis of various cancers. Recent findings have implicated long non-coding RNAs (lncRNAs) in the serial steps of cancer development. However, the expression and prognostic signatures of pyroptosis-related lncRNAs in hepatocellular carcinoma (HCC) remain largely unknown. Therefore, a pyroptosis-related lncRNA prognostic model was constructed for HCC. Thirty-four pyroptosis-related genes were obtained from previous reviews, and gene expression data were collected from The Cancer Genome Atlas (TCGA) database. Spearman's correlation test was used to identify potential pyroptosis-related lncRNAs. Cox and LASSO regression analyses were used to construct a prognostic model. Subsequently, receiver operating characteristic (ROC) curves were constructed to assess the model's predictive ability for the overall survival (OS) of HCC patients. CytoHubba was used to screen out the potential hub gene, whose expression was verified using clinical samples from HCC patients. Finally, nine pyroptosis-related differentially expressed lncRNAs in HCC were identified, and a prognostic model with four pyroptosis-related lncRNAs was constructed with an area under the ROC curve (AUC) of approximately 0.734. Single-sample gene set enrichment analysis and TCGA revealed different immune infiltration and immune checkpoints between the two risk groups. Moreover, these lncRNAs are closely related to the pyroptosis-related gene, NLRP6, which may be considered a hub gene. NLRP6 was lower-expressed in HCC samples, and patients with lower expression of NLRP6 had the longer OS. In conclusion, NLRP6-dependent pyroptosis-related lncRNAs play important roles in tumor immunity and may be potential predictors and therapeutic targets for HCC.

ACE2 Affects the Expression and Function of IFITM3 During SARS-CoV-2 Pseudovirus Infection in Vero E6 Cells.

COVID-19 is a globally infectious viral epidemic of great public health concern caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Angiotensin-converting enzyme 2 (ACE2) plays its role as the receptor for SARS-CoV-2 through binding with S protein and the binding results in ACE2 expression decrease. The change of ACE2 is supposed to elicit a series of cellular and molecular events. Other than as the receptor, ACE2's roles on infection by regulating other molecules need to be further studied during SARS-CoV-2 infection. In the present study, we established the ACE2 knockdown model using Vero E6 cells to study how ACE2 influenced the downstream signaling molecules. Analysis of transcriptome sequencing discovered that ACE2 alteration per se caused the alteration of immune factors, including some related to the viral infection-related signaling pathways. We found that ACE2 silencing induced the reduced interferon-induced transmembrane protein 3 (IFITM3) expression. Overexpression of IFITM3 promoted the SARS-CoV-2 pseudovirus infection of Vero E6 cells lacking the ACE2. It indicates that ACE2 can affect IFITM3 expression and function to affect the SARS-CoV-2 infection. Our results reveal possible mechanisms influencing SARS-CoV-2 infectivity and contribute to explaining the rapid spread and pathogenesis especially in the case of ACE2 low expression.

Enhanced electrocatalytic performance of TiO2 nanoparticles by Pd doping toward ammonia synthesis under ambient conditions.

The traditional Haber-Bosch process in industry to produce NH3 leads to excessive CO2 emissions and a large amount of energy consumption. Ambient electrochemical N2 reduction is emerging as a green and sustainable alternative method to convert N2 to NH3, but is in sore need of efficient and stable electrocatalysts. Herein, we propose using Pd-doped TiO2 nanoparticles as a high-efficiency electrocatalyst to synthesize NH3 under ambient conditions. The Pd-TiO2 catalyst delivers a large NH3 yield (17.4 µg h-1 mgcat.-1) and a high faradaic efficiency (12.7%) at -0.50 V versus reversible hydrogen electrode in a neutral electrolyte, outperforming most Pd- and Ti-based electrocatalysts recently reported for N2 reduction. Most importantly, it also demonstrates extraordinary long-term electrochemical stability.

The PNA mouse may be the best animal model of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) exerts negative effects on females of childbearing age. It is important to identify more suitable models for fundamental research on PCOS. We evaluated animal models from a novel perspective with the aim of helping researchers select the best model for PCOS. RNA sequencing was performed to investigate the mRNA expression profiles in the ovarian tissues of mice with dehydroepiandrosterone (DHEA) plus high-fat diet (HFD)-induced PCOS. Meanwhile, 14 datasets were obtained from the Gene Expression Omnibus (GEO), including eight studies on humans, three on rats and three on mice, and genes associated with PCOS were obtained from the PCOSKB website. We compared the consistency of each animal model and human PCOS in terms of DEGs and pathway enrichment analysis results. There were 239 DEGs shared between prenatally androgenized (PNA) mice and PCOS patients. Moreover, 1113 genes associated with PCOS from the PCOSKB website were identified among the DEGs of PNA mice. A total of 134 GO and KEGG pathways were shared between PNA mice and PCOS patients. These findings suggest that the PNA mouse model is the best animal model to simulate PCOS.