Circular RNA COL1A1 promotes Warburg effect and tumor growth in nasopharyngeal carcinoma.

OBJECTIVE: Circular RNAs (circRNAs), pivotal in the pathogenesis and progression of nasopharyngeal carcinoma (NPC), remain a significant point of investigation for potential therapeutic interventions. Our research was driven by the objective to decipher the roles and underlying mechanisms of hsa_circ_0044569 (circCOL1A1) in governing the malignant phenotypes and the Warburg effect in NPC. METHODS: We systematically collected samples from NPC tissues and normal nasopharyngeal epithelial counterparts. The expression levels of circCOL1A1, microRNA-370-5p (miR-370-5p), and prothymosin alpha (PTMA) were quantitatively determined using quantitative polymerase chain reaction (qPCR) and Western blotting. Transfections in NPC cell lines were conducted using small interfering RNAs (siRNAs) or vectors carrying the pcDNA 3.1 construct for overexpression studies. We interrogated the circCOL1A1/miR-370-5p/PTMA axis's role in cellular functions through a series of assays: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide for cell viability, colony formation for growth, Transwell assays for migration and invasion, and Western blotting for protein expression profiling. To elucidate the molecular interactions, we employed luciferase reporter assays and RNA immunoprecipitation techniques. RESULTS: Our investigations revealed that circCOL1A1 was a stable circRNA, highly expressed in both NPC tissues and derived cell lines. A correlation analysis with clinical pathological features demonstrated a significant association between circCOL1A1 expression, lymph node metastasis, and the tumor node metastasis staging system of NPC. Functionally, silencing circCOL1A1 led to substantial suppression of cell proliferation, migration, invasion, and metabolic alterations characteristic of the Warburg effect in NPC cells. At the molecular level, circCOL1A1 appeared to modulate PTMA expression by acting as a competitive endogenous RNA or 'sponge' for miR-370-5p, which in turn promoted the malignant characteristics of NPC cells. CONCLUSION: To conclude, our findings delineate that circCOL1A1 exerts its oncogenic influence in NPC through the modulation of the miR-370-5p/PTMA signaling axis.

Evolutionarily conserved IL-22 participates in gut mucosal barrier through its receptors IL-22BP, IL-10R2 and IL-22RA1 during bacterial infection in teleost.

IL-22 is a critical cytokine of epithelial mucosal barrier. In humans, IL-22 signals through a heteroduplex receptor consisting of IL-22R and IL-10Rß. In fish, IL-22 and its receptors homologues have been cloned in a number of species, however, no studies have been reported how the receptors are involved in IL-22 transduction. For this purpose, in this study we identified IL-22 and its soluble receptor IL-22BP and transmembrane receptors IL-22RA1 and IL-10R2 in Carassius cuvieri × Carassius auratus red var. (named WR-IL-22, WR-IL-22BP, WR-IL10R2 and WR-IL22RA1, respectively). WR-IL-22, WR-IL-22BP, WR-IL10R2 and WR-IL22RA1 were relatively conserved in the evolutionary process, sharing the same conserved domains as their higher vertebrate homologues. When the fish were infected with the Aeromonas hydrophila, the expression of WR-IL-22, WR-IL-22BP, WR-IL10R2 and WR-IL22RA1 were significantly induced in the gut. The co-IP assay showed that WR-IL-22 not only interacted with WR-IL-22BP, but also with WR-IL10R2 and WR-IL22RA1. When introduced in vivo, WR-IL-22 activated the JAK1-STAT3 axis and protected the gut mucosa from A. hydrophila infection. However, overexpression of WR-IL-22BP or knockdown of transmembrane receptors WR-IL10R2 and WR-IL22RA1 significantly inhibited the activation of WR-IL-22-mediated JAK1-STAT3 axis and promoted bacterial colonization in the gut. These results provided new insights into the role of IL-22 and its receptors in the gut mucosa barrier and immune response in teleost.

WR-PTXF, a novel short pentraxin, protects gut mucosal barrier and enhances the antibacterial activity in Carassius cuvieri × Carassius auratus red var.

The pentraxin family is an evolutionarily conserved group that plays an important role in innate immunity. C-reactive protein (CRP) and serum amyloid P component (SAP) are classical members of the short pentraxins and are known to be the major acute phase proteins. In this work, we have cloned a novel pentraxin fusion protein, WR-PTXF, from Carassius cuvieri × Carassius auratus red var. In fish, the biological function of PTXF is essentially unknown. For this purpose, we report the identification and analysis of WR-PTXF and elucidate its role in the antibacterial innate immunity. WR-PTXF contains 224 amino acids and shares 79.8% and 23.0% sequence identities with crucian carp CRP and SAP, respectively. Blast analysis shows that WR-PTXF and goldfish PTXF had the highest similarity (97.3%). WR-PTXF is expressed in multiple tissues and is upregulated by Aeromonas hydrophila infection. WR-PTXF contains a short pentraxin domain and recombinant WR-PTXF protein (rWR-PTXF) can bind the A. hydrophila in a concentration-dependent manner. Further, rWR-PTXF displays apparent bacteriostatic activity against A. hydrophila in vitro by enhancing the uptake of the bound bacteria by host phagocytes. When introduced in vivo, rWR-PTXF not only protects the gut mucosa but also limits the colonization of A. hydrophila in systemic immune organs. Consistently, knockdown of WR-PTXF significantly promotes bacterial dissemination in the tissues of host. These results indicate that WR-PTXF is a classic pattern recognition molecule that exerts a protective effect against bacterial infection.

Aeromonas hydrophila Ssp1: A secretory serine protease that disrupts tight junction integrity and is essential for host infection.

Aeromonas hydrophila is a Gram-negative bacterial pathogen with a broad host range, including fish and humans. In this study, we examined the function of a secretory serine protease (named Ssp1) identified in pathogenic A. hydrophila CCL1. Ssp1 possesses a trypsin-like serine protease domain and contains two conserved PDZ domains. Recombinant Ssp1 protein (rSsp1) treatment increased intestinal permeability by downregulating and redistributing tight junction protein Occludin in intestinal Caco-2 cells in vitro. Western blot demonstrated that rSsp1 treatment in Caco-2 cells resulted in marked increases in the expressions of myosin light chain kinase (MLCK) and phosphorylated myosin light chain (p-MLC). For virulence analysis, an isogenic CCL1 mutant ΔSsp1 was created. ΔSsp1 bears an in-frame deletion of the Ssp1 gene. A live infection study in crucian carps showed that, compared to CCL1, ΔSsp1 infection exhibited increased Occludin expression, reduced intestinal permeability and tissue dissemination capacity, and attenuated overall virulence in vivo. However, ΔSsp1 showed no differences in the biofilm formation, swimming motility, and resistance to environmental stress. These lost virulence capacities of ΔSsp1 were restored by complementation with the Ssp1 gene. Global transcriptome analysis and quantitative real-time RT-PCR showed that compared to CCL1 infection, ΔSsp1 promoted the expressions of antimicrobial molecules (MUC2, LEAP-2, Hepcidin-1, and IL-22). Finally, CCL1 infection caused significant dysbiosis of the gut microbiota, including increased Vibrio and Deefgea compared to ΔSsp1 infected fish. Taken together, these results indicate that Ssp1 is essential for the virulence of A. hydrophila and is required for the perturbation of intestinal tight junction barrier.

A novel ladderlectin from hybrid crucian carp possesses antimicrobial activity and protects intestinal mucosal barrier against Aeromonas hydrophila infection.

Ladderlectin is a pattern recognition receptor (PRR) in fish that is critical for rapid detection of bacteria in vitro, but the immunological function of ladderlectin in vivo is essentially unknown. In this study, we examined the expression and function of a ladderlectin homologue (WR-ladderlectin) from hybrid crucian carp. WR-ladderlectin contains 157 amino acids and possesses the conserved C-type lectin domain. WR-ladderlectin is mainly expressed in the intestine and is upregulated by bacterial infection. Recombinant WR-ladderlectin (rWR-ladderlectin) agglutinated Aeromonas hydrophila and Escherichia coli. rWR-ladderlectin also bound the A. hydrophila and E. coli in a protein dose-dependent manner. As well as its ability to bind bacterial cells, rWR-ladderlectin displayed apparent bactericidal activity against A. hydrophila and E. coli in vitro. When introduced in vivo, rWR-ladderlectin induced significant expression of the antimicrobial molecules and tight junctions in the intestine. In addition, rWR-ladderlectin prevented significant decrease in the length of intestine villus and enhanced the host's resistance to bacterial infection. These results indicate that WR-ladderlectin is a classic pattern recognition molecule that protects intestinal mucosal barrier against bacterial infection.

Differential Circulating Fungal Microbiome in Prostate Cancer Patients Compared to Healthy Control Individuals.

BACKGROUNDS: Infection and inflammation play an important role in prostate cancer (PCa) etiology and pathogenesis. However, the environmental drivers for PCa are not fully understood. METHODS: In a cross-sectional study, we analyzed circulating fungal microbiome in plasma samples from age and race-matched healthy control men (n = 34) and preoperative PCa patients (n = 31). RESULTS: The fungal community in the plasma exhibited differences between individuals with PCa and healthy controls according to the beta diversity; there was no difference in the alpha diversity. Moreover, the relative abundance of several fungi differed between the two study groups from the class to species levels. The most significant differences were Filobasidiales family, Pyronemataceae family, and Cryptococcus ater species, which were enriched in PCa patients compared to controls. The increased Bipolaris genus was associated with low prostate-specific antigen (PSA) levels, increased Sordariomycetes class was associated with severe pathological stage, and decreased Phoma herbarum species was associated with disease relapse, compared to corresponding controls. Several fungi from class to species levels were increased in the controls compared to patients. CONCLUSION: This is the first study to show plasma distinct fungal microbiome and its associations with PSA levels, relapse, and pathology stages in PCa patients.

WR-GLP2, a glucagon-like peptide 2 from hybrid crucian carp that protects intestinal mucosal barrier and inhibits bacterial infection.

Glucagon-like peptide 2 (GLP2) is a proglucagon-derived peptide produced by intestinal enteroendocrine L-cells. The main biological actions of GLP2 in mammals are related to regulating energy absorption and maintaining the morphology, integrity of intestinal mucosa. However, the in vivo function of fish GLP2 in intestinal barrier and immune defense is essentially unknown. With an aim to elucidate the antimicrobial mechanism of GLP2 in fish, we in this study examined the function of GLP2 from hybrid crucian carp. Hybrid crucian carp GLP2 (WR-GLP2) possesses the conserved glucagon like hormones 2 domain. WR-GLP2 is mainly expressed in the intestine and is significantly upregulated after Aeromonas hydrophila infection. AB-PAS staining analysis showed WR-GLP2 significantly increased the number of goblet cells in intestine. WR-GLP2 induced significant inductions in the expression of the antimicrobial molecules (MUC2, Lyzl-1, Hepcidin-1 and LEAP-2) and tight junctions (ZO-1, Occludin and Claudin-4). In addition, WR-GLP2 significantly alleviated the intestinal apoptosis, thereby enhancing host's resistance against Aeromonas hydrophila infection. Together these results indicate that WR-GLP2 is involved in intestinal mucosal barrier and immune defense against pathogen infection.

Oral Enrichment of Streptococcus and its Role in Systemic Inflammation Related to Monocyte Activation in Humans with Cocaine Use Disorder.

Cocaine use is commonly associated with increased chronic systemic inflammation. However, the drivers for cocaine use-mediated systemic inflammation are not fully understood. In the current study, we recruited individuals with cocaine use disorder and healthy individuals who did not use cocaine and collected paired saliva and blood samples. The saliva samples were used to assess the oral microbiome, and the plasma samples were evaluated for 33 cytokines and chemokines. Cocaine users exhibited decreased saliva microbial diversities compared to non-users. Streptococcus was the only increased genus in the saliva from cocaine users, whereas several genera were decreased in cocaine users compared to non-users. Notably, cocaine users exhibited increased plasma levels of several monocyte activation markers, including monocyte chemoattractant protein (MCP)-4, macrophage inflammatory protein (MIP)-3α, macrophage-derived chemokine (MDC), and thymus and activation-regulated chemokine (TARC), all of which were correlated with increased saliva levels of three Streptococcus species. Furthermore, treatment with Streptococcus or its lipoteichoic acid preferentially activated primary human monocytes to produce proinflammatory cytokines and chemokines, such as MIP-3α and TARC, in vitro compared to controls. However, monocytes failed to produce these chemokines after exposure to cocaine or cocaine plus bacteria compared to medium or bacteria alone. This study revealed that chronic cocaine use-associated inflammation in the blood may result from increased oral Streptococcus and its effects on myeloid cell activation, but does not result from cocaine directly.

Nicotinamide phosphoribosyltransferase (Nampt) of hybrid crucian carp protects intestinal barrier and enhances host immune defense against bacterial infection.

Nicotinamide phosphoribosyltransferase (Nampt) can act extracellularly as a mediator of inflammation or intracellularly as a rate-limiting enzyme, regulating nicotinamide adenine dinucleotide (NAD) biosynthesis in the NAD salvage pathway. Nampt exerts important immunological functions during infection in mammals. However, the in vivo function of fish Nampt in immune regulation and inflammation is essentially unknown. With an aim to elucidate the antimicrobial mechanism of Nampt in fish, we in this study examined the function of Nampt from hybrid crucian carp. Hybrid crucian carp Nampt (WR-Nampt) possesses the conserved nicotinamide phosphoribosyltransferase domain and shows high similarity to that of mammalian Nampt. WR-Nampt is expressed in multiple tissues and is upregulated by bacterial infection. Overexpression of WR-Nampt significantly increased the number of goblet cells of distal intestine. In addition, WR-Nampt induced significant inductions in the expression of the antimicrobial molecules (IL-22, Hepcidin-1, LEAP-2 and MUC2) and tight junctions (ZO-1 and Occludin). Consistent with this, fish administered with WR-Nampt significantly alleviated the intestinal permeability and apoptosis, thereby enhancing host's resistance against bacterial infection. Together these results revealed the potential effect of WR-Nampt in intestinal barrier and immune defense against bacterial infection.

Cocaine administration protects gut mucosa barrier and reduces plasma level of TNF-α.

Background: Cocaine affects not only the central nervous system, but also systemic immunity. The role of cocaine in gut mucosal integrity is not fully understood. Methods: Here we evaluated the effect of cocaine use on gut endothelial permeability and system inflammation in rats that self-administered cocaine or saline and in humans using immunohistochemistry, qPCR, ELISA, and Transepithelial/transendothelial electrical resistance (TEER). Results: Cocaine administration maintained intact and undisturbed intestinal mucosal structures, increased tight junction claudin 1 and 2 mRNA expression, and decreased plasma TNF-α levels, compared to the control group, at the end of study in rats. Further, cocaine treatment decreased gut endothelial permeability in a dose-dependent manner in human epithelial Caco-2 cells in vitro. Consistently, chronic cocaine users exhibited decreased plasma levels of TNF-α compared with non-drug users in vivo. However, plasma IL-6 levels were similar between cocaine use and control groups both in humans and rats in vivo. Conclusions: Our results from both human and rat studies in vivo and in vitro suggest that cocaine use may exert a protective effect on the integrity of gut mucosa and suppresses plasma TNF-α levels. This study may provide information on some beneficial effects of cocaine use on gut endothelial cells integrity and systemic inflammation.

Chronic cannabis smoking-enriched oral pathobiont drives behavioral changes, macrophage infiltration, and increases ß-amyloid protein production in the brain.

BACKGROUND: Little is known about chronic cannabis smoking-associated oral microbiome and its effects on central nervous system (CNS) functions. METHODS: In the current study, we have analyzed the saliva microbiome in individuals who chronically smoked cannabis with cannabis use disorder (n = 16) and in non-smoking controls (n = 27). The saliva microbiome was analyzed using microbial 16S rRNA sequencing. To investigate the function of cannabis use-associated oral microbiome, mice were orally inoculated with live Actinomyces meyeri, Actinomyces odontolyticus, or Neisseria elongata twice per week for six months, which mimicked human conditions. FINDINGS: We found that cannabis smoking in humans was associated with oral microbial dysbiosis. The most increased oral bacteria were Streptococcus and Actinomyces genus and the most decreased bacteria were Neisseria genus in chronic cannabis smokers compared to those in non-smokers. Among the distinct species bacteria in cannabis smokers, the enrichment of Actinomyces meyeri was inversely associated with the age of first cannabis smoking. Strikingly, oral exposure of Actinomyces meyeri, an oral pathobiont, but not the other two control bacteria, decreased global activity, increased macrophage infiltration, and increased ß-amyloid 42 protein production in the mouse brains. INTERPRETATION: This is the first study to reveal that long-term oral cannabis exposure is associated oral enrichment of Actinomyces meyeri and its contributions to CNS abnormalities.

Treatment of oil-based drilling cuttings using the demulsification separation-Fenton oxidation method.

In this study, demulsification separation-Fenton oxidation technology was employed as a combined technology to treat total petroleum hydrocarbons (TPH) in oil-based drill cuttings (OBDC). Batch experiments were carried out to optimize the technology parameter. Under the optimal condition, 70% and 51% TPH removal rate was obtained for demulsification technology and Fenton oxidation technology, respectively. Eighty-five percent of TPH removal rate was obtained using combination technology of demulsification separation and Fenton oxidation. Multiple characterizations were used to analyze the physical and chemical properties of treated OBDC. The result of XRD pattern indicated the combination technology had no obvious effect for structure phase of OBDC. The results of FTIR, GC-MS, TG-DTG and SEM were used to characterize the treated OBDC. This paper provides an efficient and feasible combined technology for OBDC treatment, which expands a new strategy for the removal of TPH from solid waste.

Molecular-level variation of dissolved organic matter and microbial structure of produced water during its early storage in Fuling shale gas field, China.

Shale gas-produced water (PW), the waste fluid generated during gas production, contains a large number of organic contaminants and high salinity matrix. Previous studies generally focused on the end-of-pipe treatment of the PW and ignored the early collection process. In this study, the transformation of the molecular composition and microbial community structure of the PW in the transportation and storage process (i.e., from the gas-liquid separator to the storage tank) were investigated. As the PW was transported from the gas-liquid separator to the portable storage tank, the dissolved organic matter (DOM) showed greater saturation, less oxidation, and lower polarity. DOMs with high O/C and low H/C ratios (numbers of oxygen and hydrogen divided by numbers of carbon) were eliminated, which may be due to precipitation or adsorption by the solids suspended in the PW. The values of double-bond equivalent (DBE), DBE/C (DBE divided by the number of carbon), and aromatic index (AI) decreased, likely because of the microbial degradation of aromatic compounds. The PW in the gas-liquid separator presented a lower biodiversity than that in the storage tank. The microbial community in the storage tank showed the coexistence of anaerobes and aerobes. Genera related to biocorrosion and souring were detected in the two facilities, thus indicating the necessity of more efficient anticorrosion strategies. This study helps to enhance the understanding of the environmental behavior of PW during shale gas collection and provides a scientific reference for the design and formulation of efficient transportation and storage strategies to prevent and control the environmental risk of shale gas-derived PW.

CMPK2 of triploid crucian carp is involved in immune defense against bacterial infection.

Cytidine/uridine monophosphate kinase 2 (CMPK2) is a thymidylate kinase and in mammals is known to be involved in mitochondrial DNA (mtDNA) synthesis and antiviral immunity. However, very little is known about the function of CMPK2 in fish. With an aim to elucidate the antimicrobial mechanism of CMPK2 in fish, we in this study examined the function of CMPK2 from triploid crucian carp (3nCmpk2). 3nCmpk2 is 426 residues in length and possesses the conserved thymidylate kinase domain. The deduced amino acid sequence of 3nCmpk2 shares 53.2%-99.1% overall identities with the CMPK2 of several fish species. Quantitative real time RT-PCR (qRT-PCR) analysis showed that 3nCmpk2 expression occurred in multiple tissues and was upregulated by bacterial infection in a time-dependent manner. Recombinant 3nCmpk2 (r3nCmpk2) induced mtDNA synthesis and NLRP3 activation. Overexpression of 3nCmpk2 protects the intestinal barrier and hampers the bacterial colonization in fish tissues. These results provide the first evidence that 3nCmpk2 is involved in host innate immunity and plays a protective role in antimicrobial responses during bacterial infection.

3nLcn2, a teleost lipocalin 2 that possesses antimicrobial activity and inhibits bacterial infection in triploid crucian carp.

Lipocalin 2 (Lcn2) has been identified in mammals, however, the in vivo function of fish Lcn2 is essentially unknown. Triploid crucian carp (3n = 150) of red crucian carp (female, 2n = 100) and allotetraploid (male, 4n = 200) shows better resistance to pathogenic infections. To elucidate the antimicrobial mechanism of triploid crucian carp, we examined the function of a novel Lcn2 from triploid crucian carp (3nLcn2). 3nLcn2 is 183 residues in length and contains a conserved lipocalin domain. Quantitative real time reverse transcription PCR (qRT-PCR) analysis showed that 3nLcn2 expression occurred in multiple tissues and was upregulated by bacterial infection in a time-dependent manner. We found that purified recombinant 3nLcn2 (r3nLcn2) exerted bactericidal activity to Aeromonas hydrophila and Escherichia coli. qRT-PCR detected increased expression of pro-inflammatory cytokines and tight junctions in fish with 3nLcn2 overexpression. Fish administered with 3nLcn2 exhibited enhanced intestinal barrier and resistance against bacterial infection. These results provide the first evidence that 3nLcn2 is a functional lipocalin with antimicrobial activity and plays a positive role in the immune defense during bacterial infection.

Progesterone decreases gut permeability through upregulating occludin expression in primary human gut tissues and Caco-2 cells.

Progesterone plays a protective role in preventing inflammation and preterm delivery during pregnancy. However, the mechanism involved is unknown. Microbial product translocation from a permeable mucosa is demonstrated as a driver of inflammation. To study the mechanism of the protective role of progesterone during pregnancy, we investigated the effect of physiologic concentrations of progesterone on tight junction protein occludin expression and human gut permeability in vitro and systemic microbial translocation in pregnant women in vivo. Plasma bacterial lipopolysaccharide (LPS), a representative marker of in vivo systemic microbial translocation was measured. We found that plasma LPS levels were significantly decreased during 24 to 28 weeks of gestation compared to 8 to 12 weeks of gestation. Moreover, plasma LPS levels were negatively correlated with plasma progesterone levels but positively correlated with plasma tumor necrosis factor-alpha (TNF-α) levels at 8 to 12 weeks of gestation but not at 24 to 28 weeks of gestation. Progesterone treatment increased intestinal trans-epithelial electrical resistance (TEER) in primary human colon tissues and Caco-2 cells in vitro through upregulating tight junction protein occludin expression. Furthermore, progesterone exhibited an inhibitory effect on nuclear factor kappa B (NF-κB) activation following LPS stimulation in Caco-2 cells. These results reveal a novel mechanism that progesterone may play an important role in decreasing mucosal permeability, systemic microbial translocation, and inflammation during pregnancy.

A Link Between Plasma Microbial Translocation, Microbiome, and Autoantibody Development in First-Degree Relatives of Systemic Lupus Erythematosus Patients.

OBJECTIVE: Systemic lupus erythematosus (SLE) is characterized by the production of antibodies against self antigens. However, the events underlying autoantibody formation in SLE remain unclear. This study was undertaken to investigate the role of plasma autoantibody levels, microbial translocation, and the microbiome in SLE. METHODS: Plasma samples from 2 cohorts, one with 18 unrelated healthy controls and 18 first-degree relatives and the other with 19 healthy controls and 21 SLE patients, were assessed for autoantibody levels by autoantigen microarray analysis, measurement of lipopolysaccharide (LPS) levels by Limulus amebocyte assay, and determination of microbiome composition by microbial 16S ribosomal DNA sequencing. RESULTS: First-degree relatives and SLE patients exhibited increased plasma autoantibody levels compared to their control groups. Parents and children of lupus patients exhibited elevated plasma LPS levels compared to controls (P = 0.02). Plasma LPS levels positively correlated with plasma anti-double-stranded DNA IgG levels in first-degree relatives (r = 0.51, P = 0.03), but not in SLE patients. Circulating microbiome analysis revealed that first-degree relatives had significantly reduced microbiome diversity compared to their controls (observed species, P = 0.004; Chao1 index, P = 0.005), but this reduction was not observed in SLE patients. The majority of bacteria that were differentially abundant between unrelated healthy controls and first-degree relatives were in the Firmicutes phylum, while differences in bacteria from several phyla were identified between healthy controls and SLE patients. Bacteria in the Paenibacillus genus were the only overlapping differentially abundant bacteria in both cohorts, and were reduced in first-degree relatives (adjusted P [Padj ] = 2.13 × 10-12 ) and SLE patients (Padj = 0.008) but elevated in controls. CONCLUSIONS: These results indicate a possible role of plasma microbial translocation and microbiome composition in influencing autoantibody development in SLE.

Systemic translocation of Staphylococcus drives autoantibody production in HIV disease.

BACKGROUND: Increased autoreactive antibodies have been reported in HIV disease; however, the mechanism accounting for autoantibody induction in HIV remains unknown. RESULTS: Herein, we show that seasonal influenza vaccination induces autoantibody production (e.g., IgG anti-nuclear antibody (ANA) and anti-double-stranded DNA antibody (anti-dsDNA)) in some viral-suppressed antiretroviral therapy (ART)-treated HIV+ subjects, but not in healthy controls. These autoantibodies were not derived from antigen-specific B cells but from activated "bystander" B cells analyzed by single-cell assay and by study of purified polyclonal ANAs from plasma. To explore the mechanism of autoantibody generation in HIV+ subjects, plasma level of microbial products, gene expression profile of B cells, and B cell receptor (BCR) repertoires were analyzed. We found that autoantibody production was associated with increased plasma level of microbial translocation; the patients with high autoantibodies had skewed B cell repertoires and upregulation of genes related to innate immune activation in response to microbial translocation. By analyzing circulating microbial 16S rDNA in plasma, the relative abundance of Staphylococcus was found to be associated with autoantibody production in HIV+ subjects. Finally, we found that injection of heat-killed Staphylococcus aureus promoted germinal center B cell responses and autoantibody production in mice, consistent with the notion that autoantibody production in HIV+ patients is triggered by microbial products. CONCLUSIONS: Our results showed that translocation of Staphylococcus can promote B cell activation through enhancing germinal center response and induces autoantibody production. It uncovers a potential mechanism linking microbial translocation and autoimmunity in HIV+ disease and provides a strong rationale for targeting Staphylococcus to prevent autoantibody production.

Topotecan Alleviates Lipopolysaccharide-Mediated Acute Lung Injury Via the NF-κB Signaling Pathway.

BACKGROUND: The topoisomerase 1 (Top1) inhibitor has been reported to inhibit inflammatory genes induced by virus and protect mice from sepsis. Its role in acute lung injury (ALI) remains unknown. This study aimed to explore the effects of topotecan (TPT), a Top 1 inhibitor, in lipopolysaccharide (LPS)-ALI. MATERIALS AND METHODS: THP-1 cells were stimulated with LPS and then treated with or without TPT. Inflammatory cytokines expression was measured by ELISA. In vivo, we also detected the effect of TPT in LPS-induced ALI mouse model through hematoxylin-eosin staining of lung tissue and the quantification of total protein, total cell count, and cytokines in bronchoalveolar lavage fluid. To investigate the effect of TPT on transcriptome levels, microarray analyses were performed. KEGG analysis was applied to determine potential pathways modified by TPT. Microarray results were confirmed by real-time PCR and Western blot. RESULTS: TPT significantly decreased the expression of TNF-α and IL-1ß induced by LPS in THP-1 cells. In an LPS-induced ALI mouse model, TPT significantly attenuated lung injury and decreased the levels of total protein, total cell count, and inflammatory cytokine expression in bronchoalveolar lavage fluid. Microarray results showed that TPT significantly increased expression of 958 genes and decreased expression of 1400 genes in THP-1 cells upon LPS stimulation. KEGG analysis demonstrated that differentially expressed genes function in multiple signaling pathways, including the nuclear factor (NF)-κB signaling pathway. The downstream gene of NF-κB, including c-IAP1/2, c-FLIP, Bcl-2, IL-8, and VCAM-1, and the phosphorylation of NF-κB p105, p65, and IκB-α were significantly decreased after TPT administration in THP-1 cells. CONCLUSIONS: In conclusion, TPT attenuates LPS-induced ALI through inhibiting the NF-κB signaling pathway, suggesting that TPT might serve as a useful therapeutic for ALI. Thus, our study has provided new insight for current ALI treatment.