Extracellular vesicles from alveolar macrophages harboring phagocytosed methicillin-resistant Staphylococcus aureus induce necroptosis.

Methicillin-resistant Staphylococcus aureus (MRSA) infection, a major cause of hospital- and community-acquired pneumonia, still has a high mortality rate. Extracellular vesicles (EVs), as crucial mediators of intercellular communication, have a significant impact on infectious diseases. However, the role of EVs from alveolar macrophages (AMs) in MRSA pneumonia remains unclear. We report that AMs phagocytose MRSA and release more EVs in mice with MRSA pneumonia. EVs from AMs harboring phagocytosed MRSA exhibit significant proinflammatory effects and induce necroptosis by delivering tumor necrosis factor α (TNF-α) and miR-146a-5p. Mechanically, the upregulated miR-146a-5p in these EVs enhances the phosphorylation of RIPK1, RIPK3, and MLKL by targeting TNF receptor-associated factor 6 (TRAF6), thereby promoting TNF-α-induced necroptosis. The combination of a TNF-α antagonist and an miR-146a-5p antagomir effectively improves the outcomes of mice with MRSA pneumonia. Overall, we reveal the pronecrotic effect of EVs from MRSA-infected AMs and provide a promising target for the prevention and treatment of MRSA pneumonia.

Blockade of CD93 in pleural mesothelial cells fuels anti-lung tumor immune responses.

Background: CD93 reportedly facilitates tumor angiogenesis. However, whether CD93 regulates antitumor immunity remains undeciphered. Methods: Lung tumor tissues, malignant pleural effusions (MPEs) were obtained from lung cancer patients. Blood was obtained from healthy volunteers and lung cancer patients with anti-PD-1 therapy. Furthermore, p53fl/flLSL-KrasG12D, Ccr7-/-, Cd93-/- mice and CD11c-DTR mice were generated. Specifically, EM, NTA and western blotting were utilized to identify Tumor extracellular vesicles (TEVs). EV labeling, detection of EV uptake in vitro and in vivo, degradation of EV proteins and RNAs were performed to detect the role of TEVs in tumor progression. Pleural mesothelial cells (pMCs) were isolated to investigate related signaling pathways. Recombinant proteins and antibodies were generated to test which antibody was the most effective one to increase CCL21a in p-pMCs. RNA-Seq, MiRNA array, luciferase reporter assay, endothelial tube formation assay, protein labeling and detection, transfection of siRNAs and the miRNA mimic and inhibitor, chemotaxis assay, immunohistochemical staining, flow cytometry, Real-time PCR, and ELISA experiments were performed. Results: We show that CD93 of pMCs reduced lung tumor migration of dendritic cells by preventing pMCs from secreting CCL21, thereby suppressing systemic anti-lung tumor T-cell responses. TEV-derived miR-5110 promotes CCL21 secretion by downregulating pMC CD93, whereas C1q, increasing in tumor individuals, suppresses CD93-mediated CCL21 secretion. CD93-blocking antibodies (anti-CD93) inhibit lung tumor growth better than VEGF receptor-blocking antibodies because anti-CD93 inhibit tumor angiogenesis and promote CCL21 secretion from pMCs. Anti-CD93 also overcome lung tumor resistance to anti-PD-1 therapy. Furthermore, lung cancer patients with higher serum EV-derived miR-5193 (human miR-5110 homolog) are more sensitive to anti-PD-1 therapy, while patients with higher serum C1q are less sensitive, consistent with their regulatory functions on CD93. Conclusions: Our study identifies a crucial role of CD93 in controlling anti-lung tumor immunity and suggests a promising approach for lung tumor therapy.

UBE2M-mediated neddylation of TRIM21 regulates obesity-induced inflammation and metabolic disorders.

Inflammation is closely associated with obesity and related metabolic disorders. However, its origin during obesity is largely unknown. Here, we report that ubiquitin-conjugating enzyme E2M (UBE2M) is critical to obesity-related inflammation induced by macrophages. In mice with UBE2M-deficient macrophages, obesity, insulin resistance, and hepatic steatosis induced by a high-fat diet are greatly alleviated, an effect related to the decreased proinflammatory activity of macrophages due to reduced IL-1ß production. Mechanistically, UBE2M deficiency inhibits the neddylation of E3 ubiquitin ligase TRIM21 on K129/134, leading to reduced recruitment and ubiquitination-mediated degradation of E3 ubiquitin ligase VHL. Subsequently, VHL reduces HIF-1α-induced IL-1ß production by degrading HIF-1α. Targeting macrophage TRIM21 with Trim21 antisense oligonucleotide-loaded red blood cell extracellular vesicles effectively inhibits obesity-induced inflammation and related metabolic disorders. Thus, our results demonstrate that macrophage UBE2M is essential for obesity-induced inflammation and that TRIM21 is a proof-of-concept target for treating obesity and associated metabolic diseases.

Comprehensive analysis to identify the influences of SARS-CoV-2 infections to inflammatory bowel disease.

Background: Coronavirus disease 2019 (COVID-19) and inflammatory bowel disease (IBD) are both caused by a disordered immune response and have direct and profound impacts on health care services. In this study, we implemented transcriptomic and single-cell analysis to detect common molecular and cellular intersections between COVID-19 and IBD that help understand the linkage of COVID-19 to the IBD patients. Methods: Four RNA-sequencing datasets (GSE147507, GSE126124, GSE9686 and GSE36807) from Gene Expression Omnibus (GEO) database are extracted to detect mutual differentially expressed genes (DEGs) for IBD patients with the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to find shared pathways, candidate drugs, hub genes and regulatory networks. Two single-cell RNA sequencing (scRNA-eq) datasets (GSE150728, PRJCA003980) are used to analyze the immune characteristics of hub genes and the proportion of immune cell types, so as to find common immune responses between COVID-19 and IBD. Results: A total of 121 common DEGs were identified among four RNA-seq datasets, and were all involved in the functional enrichment analysis related to inflammation and immune response. Transcription factors-DEGs interactions, miRNAs-DEGs coregulatory networks, and protein-drug interactions were identified based on these datasets. Protein-protein interactions (PPIs) was built and 59 hub genes were identified. Moreover, scRNA-seq of peripheral blood monocyte cells (PBMCs) from COVID-19 patients revealed a significant increase in the proportion of CD14+ monocytes, in which 38 of 59 hub genes were highly enriched. These genes, encoding inflammatory cytokines, were also highly expressed in inflammatory macrophages (IMacrophage) of intestinal tissues of IBD patients. Conclusions: We conclude that COVID-19 may promote the progression of IBD through cytokine storms. The candidate drugs and DEGs-regulated networks may suggest effective therapeutic methods for both COVID-19 and IBD.

Ferroptosis-related gene signature predicts prognosis in kidney renal papillary cell carcinoma.

Ferroptosis, an iron-dependent form of selective cell death, is involved in the development of many cancers. However, the role of ferroptosis-related genes (FRGs) in kidney renal papillary cell carcinoma (KIRP) is unclear. In this study, we examined the mRNA expression profiles and clinical data of patients with KIRP from the TCGA cohort. Consequently, 41 differentially-expressed FRGs were screened using the limma package, and 17 prognostic-related FRGs were identified by survival analysis and univariate Cox regression analyses. Thereafter, a ferroptosis-related gene prognostic index (FRGPI) was constructed based on five FRGs (AKR1C3, SAT1, FANCD2, HSBP1 and SQLE), using lasso Cox and multivariate Cox regression analyses. KIRP patients with high FRGPI scores displayed worse outcomes. Furthermore, the FRGPI was shown to be a reliable independent prognostic factor in both the training and testing cohorts. Comprehensive analysis also showed that the FRGPI can distinguish gene mutation, functional enrichment of immune cells and molecular function-related pathways. Interestingly, low FRGPI score could be more benefit from immune checkpoint inhibitors (ICIs) therapy. Then, the two hub prognostic genes (AKR1C3 and FANCD2) as a risk gene for KIRP were identified based on the FRGPI module, and the expression profiles of these two genes were validated using human KIRP cells, besides, we furthermore discovered that Fancd2 is significantly up-regulated in most cancers and is associated with prognosis. In conclusion, these findings showed that FRGPI can accurately predict the prognosis of patients with KIRP, suggesting that this risk model is a promising prognostic biomarker for these patients. Moreover, targeting ferroptosis (FANCD2) could be a potential therapeutic alternative for various cancers.

Ursodeoxycholic acid reduces antitumor immunosuppression by inducing CHIP-mediated TGF-ß degradation.

TGF-ß is essential for inducing systemic tumor immunosuppression; thus, blocking TGF-ß can greatly enhance antitumor immunity. However, there are still no effective TGF-ß inhibitors in clinical use. Here, we show that the clinically approved compound ursodeoxycholic acid (UDCA), by degrading TGF-ß, enhances antitumor immunity through restraining Treg cell differentiation and activation in tumor-bearing mice. Furthermore, UDCA synergizes with anti-PD-1 to enhance antitumor immunity and tumor-specific immune memory in tumor-bearing mice. UDCA phosphorylates TGF-ß at T282 site via TGR5-cAMP-PKA axis, causing increased binding of TGF-ß to carboxyl terminus of Hsc70-interacting protein (CHIP). Then, CHIP ubiquitinates TGF-ß at the K315 site, initiating p62-dependent autophagic sorting and subsequent degradation of TGF-ß. Notably, results of retrospective analysis shows that combination therapy with anti-PD-1 or anti-PD-L1 and UDCA has better efficacy in tumor patients than anti-PD-1 or anti-PD-L1 alone. Thus, our results show a mechanism for TGF-ß regulation and implicate UDCA as a potential TGF-ß inhibitor to enhance antitumor immunity.

Screening and Identification of Potential Biomarkers in Hepatitis B Virus-Related Hepatocellular Carcinoma by Bioinformatics Analysis.

Hepatocellular carcinoma (HCC) is one of the most lethal cancers globally. Hepatitis B virus (HBV) infection might cause chronic hepatitis and cirrhosis, leading to HCC. To screen prognostic genes and therapeutic targets for HCC by bioinformatics analysis and determine the mechanisms underlying HBV-related HCC, three high-throughput RNA-seq based raw datasets, namely GSE25599, GSE77509, and GSE94660, were obtained from the Gene Expression Omnibus database, and one RNA-seq raw dataset was acquired from The Cancer Genome Atlas (TCGA). Overall, 103 genes were up-regulated and 127 were down-regulated. A protein-protein interaction (PPI) network was established using Cytoscape software, and 12 pivotal genes were selected as hub genes. The 230 differentially expressed genes and 12 hub genes were subjected to functional and pathway enrichment analyses, and the results suggested that cell cycle, nuclear division, mitotic nuclear division, oocyte meiosis, retinol metabolism, and p53 signaling-related pathways play important roles in HBV-related HCC progression. Further, among the 12 hub genes, kinesin family member 11 (KIF11), TPX2 microtubule nucleation factor (TPX2), kinesin family member 20A (KIF20A), and cyclin B2 (CCNB2) were identified as independent prognostic genes by survival analysis and univariate and multivariate Cox regression analysis. These four genes showed higher expression levels in HCC than in normal tissue samples, as identified upon analyses with Oncomine. In addition, in comparison with normal tissues, the expression levels of KIF11, TPX2, KIF20A, and CCNB2 were higher in HBV-related HCC than in HCV-related HCC tissues. In conclusion, our results suggest that KIF11, TPX2, KIF20A, and CCNB2 might be involved in the carcinogenesis and development of HBV-related HCC. They can thus be used as independent prognostic genes and novel biomarkers for the diagnosis of HBV-related HCC and development of pertinent therapeutic strategies.

CircRNA CircRIMS Acts as a MicroRNA Sponge to Promote Gastric Cancer Metastasis.

Circular RNAs (circRNAs), a new category of noncoding RNA, have emerged in recent years as novel biomolecules with important biological functions. Increasing evidence and reports have revealed that circRNAs play an important role in human carcinogenesis and tumor progression. Gastric cancer (GC) is one of the most prevalent life-threatening malignancies worldwide, and in the present study, a novel circRNA molecule (circRIMS) was shown to be associated GC metastasis using next-generation sequencing. CircRIMS remarkably promoted GC cell metastasis in vitro, functioning as a sponge for hsa-miR-148a-5p and hsa-miR-218-5p. In addition, the results of rescue experiments showed that hsa-miR-148a-5p and hsa-miR-218-5p mimics could reverse the tumor-promoting roles of circRIMS in GC. Thus, circRIMS has potential as an early biomarker for use in predicting invasive metastasis in GC and to guide clinical diagnosis and treatment for precision medicine.

[Construction of FANCA mutant protein from Fanconi anemia patient and analysis of its function].

OBJECTIVE: To study FANCA protein expression in Fanconi anemia patient's (FA) cells and explore its function. METHODS: FANCA protein expression was analyzed in 3 lymphoblast cell lines derived from 3 cases of type A FA (FA-A) patients using Western blot. Nucleus and cytoplasm localization of FANCA protein was analyzed in one case of FA-A which contained a truncated FANCA (exon 5 deletion). The FANCA mutant was constructed from the same patient and its interaction with FANCG was evaluated by mammalian two-hybrid (M2H) assay. RESULTS: FANCA protein was not detected in the 3 FA-A patients by rabbit anti-human MoAb, but a truncated FANCA protein was detected in 1 of them by mouse anti-human MoAb. The truncated FANCA could not transport from cytoplasm into nucleus. The disease-associated FANCA mutant was defective in binding to FANCG in M2H system. CONCLUSIONS: FANCA proteins are defective in the 3 FA-A patients. Disfunction of disease-associated FANCA mutant proved to be the pathogenic mutations in FANCA gene. Exon 5 of FANCA gene was involved in the interaction between FANCA and FANCG.

Effects of low molecular weight heparin on platelet surface P-selectin expression and serum interleukin-8 production in rats with trinitrobenzene sulphonic acid-induced colitis.

AIM: To observe the effects of low molecular weight heparin (LMWH) on platelet surface P-selectin expression and serum interleukin-8 production in rats with trinitrobenzene sulphonic acid (TNBS) induced colitis. METHODS: Colitis was induced in female Sprague-Dawley rats by colonic administration of 2, 4, 6-TNBS. LMWH, a dalteparin (150 U/kg, 300 U/kg), was subcutaneously administrated one hour before induction of colitis and went on once a day for 6 days. Then a half dose was given for the next 7 days. Control animals received the same volume of normal saline once a day for 14 days after treated by TNBS. Animals were sacrificed at 24 h, days 7 and 14 after induction of colitis. The colon was excised for the evaluation of macroscopic and histological findings and TNF-alpha immunohistochemical assay. Platelet surface P-selectin expression was determined by radioimmunoassay and serum IL-8 production was assayed by ELISA method. RESULTS: LMWH treatment in a dose of 300 U/kg for 14 days significantly improved colonic inflammation by histological examination. Serum IL-8 production in the 300 U/kg treatment group was more significantly decreased at day 14 than that at 24 h (P<0.05). However, platelet surface P-selectin expression and TNF-alpha staining in colonic tissue were not significantly different among the three groups. CONCLUSION: LMWH has an anti-inflammatory effect on TNBS induced colitis in rats. The effect is possibly related to inhibition of proinflammatory cytokine IL-8, but not involved platelet surface P-selectin expression.

[A primary investigation on disseminated histoplasmosis in Hubei].

OBJECTIVE: To investigate the epidemiologic features of disseminated histoplasmosis (PDH) in Hubei province. METHODS: Bone marrow smears of 12 patients diagnosed as Kala-azer in Hubei province including 4 patients in Jingsan, 2 patients in Shashi and each 1 in Yichang, Jinmen, Zhongxiang, Luotian, Xianning and Guanghua respectively were re-examed under microscope. Peripheral blood and bone marrow smears of several patients were detected. After inoculated the bone marrow, peripheral blood, liver and spleen tissue of patients in MLI, the single colony was trans-inoculated in BHIB, SDA and CMA and incubated at 25 degrees C and 35 degrees C. Bone marrow, peripheral blood and bacterial fluid of yeast-phase Histoplasma capsulatum (H.cap) were injected into the abdominal cavity of Kunming mice and nude mice. When symptoms and signs developed, the spleen tissue was separated, then observed under microscope and cultured. Mycelium-phase and Yeast-phase H.cap were inoculated in urase and gelatin medium, then incubated at 25 degrees C and 35 degrees C. Histoplasmin was injected subcutaneously into patients, and then followed for 48 - 72 hours. Amphotericin B was selected to treat the PDH patients. RESULTS: Moriform cell cluster and sausage-shaped cell were not observed in mononuclear-macrophages in the bone marrow smears from 12 patients. Leishman-Donovan body was found only in one patient. There wasn't kinetoplast in the cellular plasm of spores in 11 patients and no transeptae was found. The reaction of H.cap to urease was positive and H.cap did not liquefy the gelatin. It appeared to be mycelium-phase at 25 degrees C but no penicillus and catenulate conidia was found. The characteristic denticle macroconidia was observed but produced red coloring matter. It also appeared to be yeast-phase at 35 degrees C. Yeast-phase spores were observed under microscope. No sausage-shaped spore and transeptae were identified. H.cap could be acquired in the spleen tissue in Kunming mice and nude mice. Bacterium forms, characteristics under microscope and biochemical reaction of mycelium-phase and yeast-phase H.cap were different from some other kinds of dimorphic fungi such as Penicillium marneffei and Histoplasm duboisii etc. CONCLUSION: There were scattered epidemics of PDH in Hubei province. The detection rate of PDH was higher in the southeast area then in the northwest area. The golden standards of clinic diagnosis were mycological culture and inoculation to animals. Amphotericin B was necommended as the first choice for treatment.