Glaesserella parasuis serotype 4 exploits fibronectin via RlpA for tracheal colonization following porcine circovirus type 2 infection.

Porcine circovirus type 2 (PCV2) often causes disease through coinfection with other bacterial pathogens, including Glaesserella parasuis (G. parasuis), which causes high morbidity and mortality, but the role played by PCV2 and bacterial and host factors contributing to this process have not been defined. Bacterial attachment is assumed to occur via specific receptor-ligand interactions between adhesins on the bacterial cell and host proteins adsorbed to the implant surface. Mass spectrometry (MS) analysis of PCV2-infected swine tracheal epithelial cells (STEC) revealed that the expression of Extracellular matrix protein (ECM) Fibronectin (Fn) increased significantly on the infected cells surface. Importantly, efficient G. parasuis serotype 4 (GPS4) adherence to STECs was imparted by interactions with Fn. Furthermore, abrogation of adherence was gained by genetic knockout of Fn, Fn and Integrin ß1 antibody blocking. Fn is frequently exploited as a receptor for bacterial pathogens. To explore the GPS4 adhesin that interacts with Fn, recombinant Fn N-terminal type I and type II domains were incubated with GPS4, and the interacting proteins were pulled down for MS analysis. Here, we show that rare lipoprotein A (RlpA) directly interacts with host Fibronectin mediating GPS4 adhesion. Finally, we found that PCV2-induced Fibronectin expression and adherence of GPS4 were prevented significantly by TGF-ß signaling pathway inhibitor SB431542. Our data suggest the RlpA-Fn interaction to be a potentially promising novel therapeutic target to combat PCV2 and GPS4 coinfection.

Glaesserella parasuis serotype 5 breaches the porcine respiratory epithelial barrier by inducing autophagy and blocking the cell membrane Claudin-1 replenishment.

Glaesserella parasuis (G. parasuis), the primary pathogen of Glässer's disease, colonizes the upper respiratory tract and can break through the epithelial barrier of the respiratory tract, leading to lung infection. However, the underlying mechanisms for this adverse effect remain unclear. The G. parasuis serotype 5 SQ strain (HPS5-SQ) infection decreased the integrity of piglets' lung Occludin and Claudin-1. Autophagy regulates the function of the epithelial barrier and tight junction proteins (TJs) expression. We tested the hypothesis that HPS5-SQ breaking through the porcine respiratory epithelial barrier was linked to autophagy and Claudin-1 degradation. When HPS5-SQ infected swine tracheal epithelial cells (STEC), autophagosomes encapsulated, and autolysosomes degraded oxidatively stressed mitochondria covered with Claudin-1. Furthermore, we found that autophagosomes encapsulating mitochondria resulted in cell membrane Claudin-1 being unable to be replenished after degradation and damaged the respiratory tract epithelial barrier. In conclusion, G. parasuis serotype 5 breaks through the porcine respiratory epithelial barrier by inducing autophagy and interrupting cell membrane Claudin-1 replenishment, clarifying the mechanism of the G. parasuis infection and providing a new potential target for drug design and vaccine development.

α-Glucosidase inhibitory effect of an anthraquinonoid produced by Fusarium incarnatum GDZZ-G2.

α-Glucosidase is the key enzyme on carbohydrate metabolism, and its bioactive inhibitors are supposed to be an effective therapeutic for type 2 diabetes mellitus. During our continuing study for discovering α-glucosidase inhibitors, a fungus GDZZ-G2 which is derived from a medicinal plant Callicarpa kwangtungensis Chun, exhibited significant inhibition on α-glucosidase. The strain was identified as Fusarium incarnatum by morphological and molecular methods. Further bioassay-guided fractionation result in six known secondary metabolites (1-6). All the compounds except 4 were isolated from F. incarnatum for the first time. Among them, an anthraquinonoid (S)-1,3,6-trihydroxy-7-(1-hydroxyethyl)anthracene-9,10-dione (compound 1) exhibited strong inhibitory effect against α-glucosidase (IC50 = 77.67 ± 0.67 µΜ), compared with acarbose (IC50 = 711.8 ± 5 µΜ). An enzyme kinetics analysis revealed that compound 1 was an uncompetitive inhibitor. Besides, docking simulations predicted that compound 1 inhibited α-glucosidase substrate complex by binding Gln322, Gly306, Thr307, and Ser329 through hydrogen-bond interactions. Our findings suggested that compound 1 can be considered a lead compound for further modifications and the development of a new effective drug candidate in the treatment of type 2 diabetes mellitus.

α-Glucosidase inhibitory triterpenoids from Euonymus fortunei.

α-Glucosidase plays an important role in catalyzing the hydrolytic cleavage of disaccharides into monosaccharides. In this study, a phytochemical investigation of the potential α-glucosidase inhibitory fraction from the aerial parts of Euonymus fortunei led to the isolation and identification of two new tetracyclic triterpenoids, fortunenones A and B (1-2), together with 11 known triterpenoids (3-13). Fortunenones A and B are rare C32 triterpenoids possessing a 24,24-dimethyl group. The partial isolated compounds were evaluated their effects on α-glucosidase, of which echinochlorin D (5), lupenone (7), wilforlide B (12), and wilforlide A (13) exhibited remarkable inhibitory effects with the half inhibitory concentration ranged from 207.2 × 10-6 M to 388.3 × 10-6 M compared with the positive control, acarbose. An enzyme kinetics analysis by Lineweaver-Burk plots revealed that the inhibition types of the four active compounds were all mixed inhibition. Molecular docking further revealed that hydrophobic interactions and hydrogen bonds play an important role in the inhibition of α-glucosidase activity. Our results demonstrate the potential of E. fortunei extract and its constituents to inhibit α-glucosidase.

Comparison of Hospital Anxiety and Depression Scale (HADS) and Zung Self-Rating Anxiety/Depression Scale (SAS/SDS) in Evaluating Anxiety and Depression in Patients with Psoriatic Arthritis.

BACKGROUND: This study aimed to compare the Hospital Anxiety and Depression Scale (HADS) and the Zung Self-Rating Anxiety/Depression Scale (SAS/SDS) in evaluating anxiety and depression in psoriatic arthritis (PsA) patients. METHODS: A total of 70 PsA patients were enrolled. Demographic and clinical characteristics were collected after enrollment. HADS-A and SAS were used to evaluate the anxiety of PsA patients, while HADS-D and SDS were used to evaluate the depression of PsA patients. RESULTS: Similar results were observed in detecting the rate of anxiety by HADS-A and SAS (27.1 vs. 21.4%, p = 0.424), and there was no difference in classifying the severity of anxiety by HADS-A and SAS (p = 0.347). The Spearman test also disclosed that HADS-A score was positively associated with SAS score (p <0.001). The rates of depression were similar by HADS-D and SDS (27.1 vs. 40.0%; p = 0.108). However, different results were observed in grading the severity of anxiety by HADS-D and SDS (p = 0.009), and no correlation was observed between HADS-D and SDS scores (p = 0.138). The consumption of time for HADS assessment was shorter than that for SAS/SDS assessment (p < 0.001). In addition, a positive correlation of HADS-A score with patients' global assessment (PGA) (p = 0.022) and fatigue scores (p = 0.028) was discovered, and HADS-D score was positively associated with PGA score (p = 0.019). SAS or SDS score presented less correlation with clinical features of PsA patients, which illuminated that only SAS score was positively associated with duration of psoriasis (p = 0.030). CONCLUSION: HADS seems to be a better option for anxiety and depression assessment than SAS/SDS in PsA patients.

Comprehensive analyses of long non-coding RNA expression profiles by RNA sequencing and exploration of their potency as biomarkers in psoriatic arthritis patients.

BACKGROUND: The aim of the current study was to investigate the long non-coding RNA (lncRNA) expression profiles in psoriatic arthritis (PSA) patients by RNA sequencing, and to further explore potential biomarkers that were able to predict PSA risk and activity. METHODS: LncRNA and mRNA expression profiles in peripheral blood mononuclear cells (PBMC) of 4 PSA patients and 4 normal controls (NCs) were detected by RNA sequencing, followed by comprehensive bioinformatic analyses. Subsequently, 3 top upregulated and 2 top downregulated lncRNAs were chosen for further validation in 93 PSA patients and 93 NCs by quantitative polymerase chain reaction (qPCR) assay. RESULTS: Totally 76 upregulated and 54 downregulated lncRNAs, as well as 231 upregulated and 102 downregulated mRNAs were discovered in PSA patients compared with NCs. Enrichment analyses revealed that they were mostly associated with nucleosome, extracellular exosome and extracellular matrix, and the top enriched pathways were systemic lupus erythematosus (SLE), alcoholism and viral carcinogenesis. qPCR assay showed that lnc-RP11-701H24.7 and lnc-RNU12 were upregulated in PSA patients compared with NCs, and they could predict PSA risk with high area under curves. Besides, lnc-RP11-701H24.7 was positively associated with ESR, SJC, TJC and pain VAS score while lnc-RNU12 was positively correlated with PASI score, CRP and PGA score, implying that both of them were positively correlated with disease activity. CONCLUSION: Our study facilitates comprehensive understanding of lncRNA expression profiles in PSA pathogenesis, and discovers that lnc-RP11-701H24.7 and lnc-RNU12 might be served as novel biomarkers for PSA risk and activity.

Bacterial ß-glucuronidase alleviates dextran sulfate sodium-induced colitis in mice: A possible crucial new diagnostic and therapeutic target for inflammatory bowel disease.

OBJECTIVE: Inflammatory bowel diseases (IBD) including ulcerative colitis and Crohn's disease are devastating diseases of the gut. At present, all the treatments are mainly targeting symptoms like inflammation. The disease remains regarded as incurable, largely due to lacking of knowledge on its etiology. Our previous studies suggested that impaired inactivation of digestive proteases by deconjugated bilirubin in experimental colitis, thus bacterial ß-glucuronidase for catalyzing the reaction, may have played critical role in the pathogenesis of IBD. METHODS: We first analyzed ß-glucuronidase activity in gut tissue and feces of mice by a colitis model. Then the effect of ß-glucuronidase on experimental colitis was investigated in detail by administration of ß-glucuronidase (from E. coli) and fecal material transplantation to mice with 3% DSS in drinking water for 7 days. RESULTS: Mice with colitis showed unchanged activity of ß-glucuronidase in colon tissue but decreased activity in feces. Treatment with bacterial ß-glucuronidase at 100 U or above alleviated DSS-induced colitis as demonstrated by the less body weight loss, less disease activity score, increased expression of tight junction proteins and decreased gut permeability, decreases in MPO, TNF-α, IL-1ß, TLR-4 and MyD88, and increase in IL-10 and IκBα in gut, restored fecal ß-glucuronidase and gut microbiota along with decreases in fecal digestive proteases. Transplantation of fecal material from control to colitis mice showed similar effects as treatment with ß-glucuronidase. CONCLUSIONS: Bacterial ß-glucuronidase showed strong inhibition on colitis along with the reduction in fecal digestive proteases, which may be a crucial diagnostic and therapeutic target for IBD.

(5R)-5-Hydroxytriptolide (LLDT-8) inhibits osteoclastogenesis via RANKL/RANK/OPG signaling pathway.

BACKGROUND: The aim of this study was to investigate the regulative activity of (5R)-5-hydroxytriptolide (LLDT-8) on receptor activator of nuclear factor κ-B ligand (RANKL)/receptor activator of nuclear factor κ-B (RANK)/Osteoprotegerin (OPG) system in rheumatoid arthritis (RA) and its anti-osteoclastogenesis mechanism. METHODS: The expression of OPG, RANK and RANKL in CD3(+) T leukomonocytes in both peripheral blood and synovial fluid of RA patients was evaluated by flow cytometry. The levels of interleukin (IL) 1ß, IL-6, IL-10, IL-21 and IL-23 in the supernatants of peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) were assayed by ELISA. Tartaric acid phosphatase (TRAP) staining was used to identify the osteoclast-like cells derived from RAW264.7. Western blotting analysis was used to check the downstream molecules of RANKL. RESULTS: LLDT-8 increased the rate of OPG expression in CD3(+) T leukomonocytes in peripheral blood as well as the ratio of OPG/RANKL in both peripheral blood and synovial fluid. LLDT-8 inhibited IL-1ß, IL-6, IL-21 and IL-23 secretion, but promoted the secretion of IL-10 in the supernatants of PBMCs and SFMCs. In addition, LLDT-8 decreased the number of TRAP-positive cells derived from RAW264.7 in the presence of RANKL and M-CSF. Furthermore, LLDT-8 also inhibited the expression of p-IκB, a key regulator of RANKL signaling pathway. CONCLUSIONS: LLDT-8 exerts its anti-osteoclastogenesis effect in RA probably through regulating RANKL/RANK/OPG system and its downstream signaling pathway as well as cytokine productions.

Identification of disulfidptosis- and ferroptosis-related transcripts in periodontitis by bioinformatics analysis and experimental validation.

Background: Disulfidptosis and ferroptosis are forms of programmed cell death that may be associated with the pathogenesis of periodontitis. Our study developed periodontitis-associated biomarkers combining disulfidptosis and ferroptosis, which provides a new perspective on the pathogenesis of periodontitis. Methods: Firstly, we obtained the periodontitis dataset from public databases and found disulfidptosis- and ferroptosis-related differentially expressed transcripts based on the disulfidptosis and ferroptosis transcript sets. After that, transcripts that are tissue biomarkers for periodontitis were found using three machine learning methods. We also generated transcript subclusters from two periodontitis microarray datasets: GSE16134 and GSE23586. Furthermore, three transcripts with the best classification efficiency were further screened. Their expression and classification efficacy were validated using qRT-PCR. Finally, periodontal clinical indicators of 32 clinical patients were collected, and the correlation between three transcripts above and periodontal clinical indicators was analyzed. Results: We identified six transcripts that are tissue biomarkers for periodontitis, the top three transcripts with the best classification, and delineated two expression patterns in periodontitis. Conclusions: Our study found that disulfidptosis and ferroptosis were associated with immune responses and may involve periodontitis genesis.

Glaesserella parasuis serotype 5 induces pyroptosis via the RIG-I/MAVS/NLRP3 pathway in swine tracheal epithelial cells.

Glaesserella parasuis (G. parasuis) is a common Gram-negative commensal bacterium in the upper respiratory tract of swine that can cause Glässer's disease under stress conditions. Pyroptosis is an important immune defence mechanism of the body that plays a crucial role in clearing pathogen infections and endogenous danger signals. This study aimed to investigate the mechanism of G. parasuis serotype 5 SQ (GPS5-SQ)-induced pyroptosis in swine tracheal epithelial cells (STECs). The results of the present study demonstrated that GPS5-SQ infection induces pyroptosis in STECs by enhancing the protein level of the N-terminal domain of gasdermin D (GSDMD-N) and activating the NOD-like receptor protein 3 (NLRP3) inflammasome. Furthermore, the levels of pyroptosis-related proteins, including GSDMD-N and cleaved caspase-1 were considerably decreased in STECs after the knockdown of retinoic acid inducible gene-I (RIG-I) and mitochondrial antiviral signaling protein (MAVS). These results indicated that GPS5-SQ might trigger pyroptosis through the activation of the RIG-I/MAVS/NLRP3 signaling pathway. More importantly, the reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) repressed the activation of the RIG-I/MAVS/NLRP3 signaling and rescued the decrease in Occludin and zonula occludens-1 (ZO-1) after GPS5-SQ infection. Overall, our findings show that GPS5-SQ can activate RIG-I/MAVS/NLRP3 signaling and destroy the integrity of the epithelial barrier by inducing ROS generation in STECs, shedding new light on G. parasuis pathogenesis.

Network pharmacology analysis of the regulatory effects and mechanisms of ALAE on sow reproduction in vivo and in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Reproductive ability of sows is a primary element influencing the development of pig farming. Herbal extracts of Angelica sinensis (Oliv.) Diels, Astragalus mongholicus Bunge, Eucommia ulmoides Oliv., and Polypodium glycyrrhiza D.C.Eaton showed effects on improvement of reproduction in sows. AIMS OF THE STUDY: To investigate the mechanism of the treatment effects by a compound of these four Chinese herbs in a 1:1:1:1 ratio (ALAE) on endometriosis, endometritis, uterine adhesion, intrauterine growth retardation, pre-eclampsia, and its enhancement of reproductive efficiency in sows. MATERIALS AND METHODS: Active components of ALAE were identified by using ultra-performance liquid chromatography-mass spectrometry analysis and network pharmacology. Then we used the results to construct a visualization network. Key targets and pathways of ALAE involved in sow reproduction improvement were validated in sow animals and porcine endometrial epithelial cells (PEECs). RESULTS: A total of 62 active compounds were found in ALAE (41 in Polypodium glycyrrhiza D.C.Eaton, 5 in Astragalus mongholicus Bunge, 11 in Eucommia ulmoides Oliv., 5 in Angelica sinensis (Oliv.) Diels) with 563 disease-related targets (e.g. caspase-3, EGFR, IL-6) involved in EGFR tyrosine kinase inhibitor resistance, PI3K-AKT, and other signaling pathways. Molecular docking results indicated GC41 (glabridin), GC18 (medicarpin), EGFR and CCND1 are possible key components and target proteins related to reproductive improvement in sows. In PEECs, EGFR expression decreased at the mRNA and protein levels by three doses (160, 320, and 640 µg/mL) of ALAE. The phosphorylation of downstream pathway PI3K-AKT1 was enhanced. The expression of inflammatory factors (IL-6, IL-1ß), ESR1 and caspase-3 decreased through multiple pathways. Additionally, the expression levels of an anti-inflammatory factor (IL-10), angiogenesis-related factors (MMP9, PIGF, PPARγ, IgG), and placental junction-related factors (CTNNB1, occludin, and claudin1) increased. Furthermore, the total born number of piglets, the number of live and healthy litters were significantly increased. The number of stillbirths decreased by ALAE treatment in sow animals. CONCLUSIONS: Dministration of ALAE significantly increased the total number of piglets born, the numbers of live and healthy litters and decreased the number of stillbirths through improving placental structure, attenuating inflammatory response, modulating placental angiogenesis and growth factor receptors in sows. The improvement of reproductive ability may be related to activation of the EGFR-PI3K-AKT1 pathway in PEECs. Moreover, ALAE maybe involved in modulation of estrogen receptors, apoptotic factors, and cell cycle proteins.

Siraitia grosvenorii Extract Protects Lipopolysaccharide-Induced Intestinal Inflammation in Mice via Promoting M2 Macrophage Polarization.

Siraitia grosvenorii has anti-inflammatory, antioxidant, and immune-regulating effects, while macrophages play an important role in reducing inflammation. However, it is still unclear whether Siraitia grosvenorii extract (SGE) is effective in reducing inflammation by regulating macrophages. This study investigated the regulatory effect of SGE on macrophage polarization in a lipopolysaccharide (LPS)-induced intestinal inflammation model after establishing the model in vitro and in vivo. The results from the in vivo model showed that, compared with the LPS group, SGE significantly improved ileal morphology, restored the ileal mucosal barrier, and reduced intestinal and systemic inflammation by increasing CD206 and reducing iNOS proteins. In the in vitro model, compared with the LPS group, SGE significantly reduced the expression of iNOS protein and cytokines (TNF-α, IL-1ß, and IFN-γ) while significantly increasing the protein expression of CD206 in RAW264.7 cells. In conclusion, SGE can alleviate intestinal inflammation, protect the mucus barrier, and block the systemic immunosuppressive response by increasing M2 macrophages.

Porcine circovirus type 2 and Glaesserella parasuis serotype 4 co-infection activates Snail1 to disrupt the intercellular junctions and facilitate bacteria translocation across the tracheal epithelium.

Clinically, Porcine circovirus type 2 (PCV2) often causes disease through coinfection with other bacterial pathogens, including Glaesserella parasuis (G. parasuis), which causes high morbidity and mortality. However, the mechanism of PCV2 and G. parasuis serotype 4 (GPS4) co-infection is still not fully understood. In this study, swine tracheal epithelial cells (STEC) were used as a barrier model, and our results showed that PCV2 infection increased the adhesion of GPS4 to STEC, while decreasing the levels of ZO-1, Occludin and increasing tracheal epithelial permeability, and ultimately facilitated GPS4 translocation. Snail1 is a transcriptional repressor, and has been known to induce epithelial-to-mesenchymal transition (EMT) during development or in cancer metastasis. Importantly, we found that Snail1, as a transcriptional repressor, was crucial in destroying the tracheal epithelial barrier induced by PCV2, GPS4, PCV2 and GPS4 coinfection. For the first time, we found that PCV2, GPS4, PCV2 and GPS4 coinfection cross-activates TGF-ß and p38/MAPK signaling pathways to upregulate the expression of Snail1, down-regulate the levels of ZO-1 and Occludin, and thus disrupt the integrity of tracheal epithelial barrier then promoting GPS4 translocation. Finally, PCV2 and GPS4 co-infection also can activate TGF-ß and p38/MAPK signaling pathways in vivo and upregulate Snail1, ultimately down-regulating the expression of ZO-1 and Occludin. Our study elucidates how PCV2 infection promotes GPS4 to breach the tracheal epithelial barrier and aggravate clinical manifestations.

Baicalin methyl ester prevents the LPS - induced mice intestinal barrier damage in vivo and in vitro via P65/TNF-α/MLCK/ZO-1 signal pathway.

The effect of baicalin methyl ester (BME) on the regulation of mice intestinal barrier in the inflammatory response was studied in vivo and in vitro. Thirty six C57/BL mice were randomly divided into six groups (n = 6): control group; LPS group (LPS 3.5 mg/kg given intraperitoneal [ip] on day 7 of the study only), PBS group, and three BME groups (low: 50 mg/kg; medium: 100 mg/kg; high: 200 mg/kg) orally dosed with BME for 7d and LPS ip on day 7. All mice were sacrificed on day 8, and jejunum tissue collected for histopathology (H&E and PAS staining), protein expression of pro-inflammatory factors (TNF-α, IL-6, IL-8, IFN-γ) by ELISA, and intestinal tight junction proteins (ZO-1, occludin, claudin-1 and claudin-4) by Western Blot. Compared with the control group, LPS significantly increased the serum cytokines DAO (p < 0.01) and DLA (p < 0.01), upregulated the expression of pro-inflammatory factors, MLCK proteins (p <0.05) and increased the MLCK/ZO-1ratio (p <0.001). LPS also decreased the expression of claudin-4 (p < 0.01) in the jejunum and induced an inflammatory response damaging the jejunal mucosal barrier. Pretreatment with BME (100-200 mg/kg) significantly decreased the cytokines DAO (p < 0.05) and DLA (p < 0.01) in the serum, pro-inflammatory factors in the jejunum, significantly down-regulated the expression of MLCK (p <0.05) and the ratio of MLCK/ZO-1(p <0.001) but upregulated the expressions of ZO-1(p < 0.01), occludin (p < 0.05), claudin-1(p < 0.05) and claudin-4 (p < 0.05), and thereby restored the intestinal tissue structure, suggestive of alleviation of LPS-induced intestinal inflammation by BME. In vitro, MODE-K cells (derived from mice intestinal epithelium) were exposed to BME at 0 (control group-No LPS), 10, 20 and 40 µM BME for 24 h prior to LPS addition at 50 µg/mL for 2 h. LPS significantly increased the expression of pro-inflammatory factors, MLCK (p < 0.01) and the ratio of MLCK/ZO-1(p <0.001), decreased the expressions of ZO-1 (p < 0.05), occludin (p < 0.01), claudin-1 (p < 0.01) and claudin-4 (p < 0.01) in MODE-K cells compared with the control group. Compared with the LPS group, BME (10 - 40 µM) significantly decreased the expression of pro-inflammatory factors, MLCK (p < 0.05) and the ratio of MLCK/ZO-1(p <0.01) but increased the expressions of ZO-1(p < 0.01), occludin (p < 0.05) and claudin-4(p < 0.01) indicating an up-regulation of the expression of tight junction proteins by BME. On addition of extrinsic TNF-α plus LPS, the TNF- α level increased (p < 0.001) in MODE-K cells and the protein expression of MLCK (p < 0.01) was markedly up-regulated. Molecular docking predicted BME interacted with P65 by forming hydrogen bonds. IP-WB further confirmed that BME was directly bound to P65 protein in MODE-K cells. In conclusion, BME was able to restore the intestinal barrier through the P65 / TNF-α / MLCK / ZO-1 signaling pathway.

Coinfection with porcine circovirus type 2 and Glaesserella parasuis serotype 4 enhances pathogenicity in piglets.

Coinfection of Porcine circovirus type 2 (PCV2) and Glaesserella parasuis type 4 (GPS4) is widespread clinically, resulting in high morbidity and mortality, however, interactions between the two pathogens during coinfection and the coinfection pathogenesis are poorly understood. In this study, a piglet model coinfected with PCV2 and GPS4 was established; coinfection of the piglets' group showed more obvious symptoms, such as high fever and emaciation, and more severe histological lesions appeared in various organs. Importantly, piglets in the coinfection group produced lower levels of PCV2 and GPS4 antibodies, and showed high levels of inflammatory cytokines, TLR2, and TLR4, while the levels of CD4, CD8, MHC II, costimulatory molecules, and IL-12p40 were decreased. In addition, a model of macrophage 3D4/21 cells coinfection with PCV2 and GPS4 was established, coinfected cells exhibited increased expression of the cytokines IL-6, IL-8, TNF-α, IL-1ß, and the receptors TLR2, TLR4, while decreased MHC II. We further demonstrate that cytokine production is associated with the activation of NF-κB and NLRP3 inflammasome signaling pathways, and TLR4 is also involved. Altogether, our findings suggest that coinfection with PCV2 and GPS4 exacerbates the inflammatory response, resulting in severe tissue damage, and probably impaired macrophage antigen presentation and T cell activation, resulting in immune dysregulation, aggravating host infection.

Fluorescent double network ionogels with fast self-healability and high resilience for reliable human motion detection.

Fascinating properties are displayed by high-performance ionogel-based flexible strain sensors, thereby gaining increasing attention in various applications ranging from human motion monitoring to soft robotics. However, the integration of excellent properties such as optical and mechanical properties and satisfactory sensing performance for one ionogel sensor is still a challenge. In particular, fatigue-resistant and self-healing properties are essential to continuous sensing. Herein, we design a flexible ion-conductive sensor based on a multifunctional ionogel with a double network using polyacrylamide, amino-modified agarose, 1,3,5-benzenetricarboxaldehyde and 1-ethyl-3-methylimidazolium chloride. The ionogel exhibits comprehensive properties including high transparency (>95%), nonflammability, strong adhesion and good temperature tolerance (about -96 to 260 °C), especially adaptive for extreme conditions. The dynamic imine bonds and abundant hydrogen bonds endow the ionogel with excellent self-healing capability, to realize rapid self-repair within minutes, as well as good mechanical properties and ductility to dissipate input energy and realize high resilience. Notably, unexpected fluorescence has been observed for the ionogel because of the gelation-induced emission phenomenon. Flexible strain sensors prepared directly from ionogels can sensitively monitor and differentiate various human motions, exhibiting a fast response time (38 ms), high sensitivity (gauge factor = 3.13 at 800% strain), good durability (>1000 cycles) and excellent stability over a wide temperature range (-30 to 80 °C). Therefore, the prepared ionogel as a high-performance flexible strain sensor in this study shows tremendous potential in wearable devices and soft ionotronics.

A link between STK signalling and capsular polysaccharide synthesis in Streptococcus suis.

Synthesis of capsular polysaccharide (CPS), an important virulence factor of pathogenic bacteria, is modulated by the CpsBCD phosphoregulatory system in Streptococcus. Serine/threonine kinases (STKs, e.g. Stk1) can also regulate CPS synthesis, but the underlying mechanisms are unclear. Here, we identify a protein (CcpS) that is phosphorylated by Stk1 and modulates the activity of phosphatase CpsB in Streptococcus suis, thus linking Stk1 to CPS synthesis. The crystal structure of CcpS shows an intrinsically disordered region at its N-terminus, including two threonine residues that are phosphorylated by Stk1. The activity of phosphatase CpsB is inhibited when bound to non-phosphorylated CcpS. Thus, CcpS modulates the activity of phosphatase CpsB thereby altering CpsD phosphorylation, which in turn modulates the expression of the Wzx-Wzy pathway and thus CPS production.

Discovery of mycotoxin alternariol as a potential lead compound targeting xanthine oxidase.

Xanthine oxidase (XO) catalyzes the oxidation of hypoxanthine to xanthine, which is further converted to uric acid. The excessive production or reduced excretion of the purine terminal metabolite may lead to hyperuricemia. In our ongoing search for new xanthine oxidase inhibitors, 14 endophytic fungi were isolated for the first time from a medicinal plant Callicarpa kwangtungensis Chun, and the ethyl acetate extracts of their culture filtrates were screened for XO inhibitory activity. The extract from an endophytic fungus, characterized as Alternaria alternata GDZZ-J6, exhibited the most potent inhibition of XO. Further fractionation of its secondary metabolites led to the isolation of six compounds. Among them, mycotoxin alternariol (AOH), a dibenzo-α-pyrone derivative, had strong inhibitory activity on XO, and the IC50 value was 0.23 ± 0.01 µM. The potency of XO inhibition by AOH was >12-fold higher as compared to allopurinol (2.98 ± 0.07 µM), a XO inhibitor that has been used clinically. The IC50 values of three dibenzo-α-pyrones from gut microbial metabolites of ellagic acid, urolithins A, B, and C, against XO were further compared, and their structure-activity relationships were discussed. Inhibition kinetic analysis by double-reciprocal Lineweaver-Burk plots demonstrated that AOH was an uncompetitive inhibitor. Follow-up docking studies showed that Gln957, Lys1257, and Phe1153 played an important role by forming hydrogen bonds with AOH. Our findings suggest that AOH may be used as a lead compound for further modification to develop future drug for treating hyperuricemia.

Sucralose enhances the susceptibility to dextran sulfate sodium (DSS) induced colitis in mice with changes in gut microbiota.

Sucralose is one of the most widely used artificial sweeteners, free of nutrients and calories. Its approval and uses correlate with many of the worldwide epidemiological changes in inflammatory bowel disease (IBD). Multiple animal studies by us and others showed that sucralose exacerbated ileitis in SAMP1/YitFc mice and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. In this study, we further investigated the effect of sucralose on dextran sulfate sodium (DSS)-induced colitis in mice and the associated mechanisms. Male C57BL/6 mice received 1.5 mg ml-1 sucralose in drinking water for 6 weeks. Then, 2.5% DSS was added to drinking water for 7 days to induce ulcerative colitis (UC). The results showed that, compared with the DSS group, administration of sucralose exacerbated the severity of colitis as indicated by the further decrease in body weight, increase in disease activity index (DAI) and the expression of pro-inflammatory cytokines, as well as the activation of the TLR5-MyD88-NF-κB signaling pathway, and the disturbances of intestinal barrier function, along with changes in the intestinal microbiota. Our findings indicate that sucralose may increase the susceptibility to DSS-induced colitis through causing dysbiosis of intestinal microbiota and damage to the intestinal barrier.

MicroRNA Variants and HLA-miRNA Interactions are Novel Rheumatoid Arthritis Susceptibility Factors.

Genome-wide association studies have identified >100 genetic risk factors for rheumatoid arthritis. However, the reported genetic variants could only explain less than 40% heritability of rheumatoid arthritis. The majority of the heritability is still missing and needs to be identified with more studies with different approaches and populations. In order to identify novel function SNPs to explain missing heritability and reveal novel mechanism pathogenesis of rheumatoid arthritis, 4 HLA SNPs (HLA-DRB1, HLA-DRB9, HLA-DQB1, and TNFAIP3) and 225 common SNPs located in miRNA, which might influence the miRNA target binding or pre-miRNA stability, were genotyped in 1,607 rheumatoid arthritis and 1,580 matched normal individuals. We identified 2 novel SNPs as significantly associated with rheumatoid arthritis including rs1414273 (miR-548ac, OR = 0.84, p = 8.26 × 10-4) and rs2620381 (miR-627, OR = 0.77, p = 2.55 × 10-3). We also identified that rs5997893 (miR-3928) showed significant epistasis effect with rs4947332 (HLA-DRB1, OR = 4.23, p = 0.04) and rs2967897 (miR-5695) with rs7752903 (TNFAIP3, OR = 4.43, p = 0.03). In addition, we found that individuals who carried 8 risk alleles showed 15.38 (95%CI: 4.69-50.49, p < 1.0 × 10-6) times more risk of being affected by RA. Finally, we demonstrated that the targets of the significant miRNAs showed enrichment in immune related genes (p = 2.0 × 10-5) and FDA approved drug target genes (p = 0.014). Overall, 6 novel miRNA SNPs including rs1414273 (miR-548ac, p = 8.26 × 10-4), rs2620381 (miR-627, p = 2.55 × 10-3), rs4285314 (miR-3135b, p = 1.10 × 10-13), rs28477407 (miR-4308, p = 3.44 × 10-5), rs5997893 (miR-3928, p = 5.9 × 10-3) and rs45596840 (miR-4482, p = 6.6 × 10-3) were confirmed to be significantly associated with RA in a Chinese population. Our study suggests that miRNAs might be interesting targets to accelerate understanding of the pathogenesis and drug development for rheumatoid arthritis.