Ameliorated Effects of Fucoidan on Dextran Sulfate Sodium-Induced Ulcerative Colitis and Accompanying Anxiety and Depressive Behaviors in Aged C57BL/6 Mice.

Fucoidan has shown better effects on the improvement of acute ulcerative colitis (UC). However, the specific mechanisms by which fucoidan improves UC-related behavioral disorders in aged mice, especially its effect on the gut-brain axis, remain to be further explored. C57BL/6 male mice aged 8 months were gavaged with 400 or 100 mg/kg bw day fucoidan for five consecutive weeks, with UC being induced by ad libitum to dextran sulfate sodium (DSS) solution in the fifth week. The results showed that fucoidan ameliorated UC and accompanying anxiety- and depressive-like behaviors with downregulated expressions of (NOD)-like receptor family and pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein (ASC), cysteine aspartate-specific protease-1 (Caspase-1) and interlekin-1ß (IL-1ß), and elevated mRNA levels of brain-derived neurotrophic factor (Bdnf) and postsynaptic-density protein 95 (Psd-95) in cortex and hippocampus. Furthermore, fucoidan improved the permeability of intestinal barrier and blood-brain barrier and restored the abnormal structure of the gut microbiota with a significantly decreased ratio of Firmicutes to Bacteroidota (F/B) and obviously increased abundance of Akkermansia. As a diet-derived bioactive ingredient, fucoidan might be a better alternative for the prevention of UC and accompanying anxiety- and depressive-like behaviors.

Comparative transcriptome reveals importance of export apparatus subunit (ascR) in type III secretion system and its roles on biological properties, gene expression profiles, virulence and colonization of Aeromonas veronii.

Aeromonas veronii, an opportunistic pathogen, is known to cause serious infections across various species. In our previous study, we discovered that A. veronii GL2 exhibited a virulence up to ten times greater than that of FO1. To ascertain the factors contributing to the disparity in virulence between the two strains, we conducted a comparative transcriptome analysis. This analysis reveals a significant upregulation (P < 0.05) of the ascR gene in GL2 compared with FO1. Additionally, six differentially expressed genes (DEGs) were identified within the "Bacterial secretion system" pathway (map03070), with ascR being an essential component of type III secretion system (T3SS). AscR, considered as SctR family export apparatus subunit within the T3SS, has ambiguous roles in the biological properties, gene expression profiles, virulence and colonization of A. veronii. Therefore, we constructed a mutant strain (ΔascR) by homologous recombination. Comparative analysis with the wide-type GL2 reveals no significant differences in terms of colony morphology, growth curve, hemolytic activity and protease activity. However, significant reductions (P < 0.01) were observed in the abilities of biofilm formation and swimming mobility. No remarkable difference was noted in the lengths of flagella. The LD50 value of ΔascR was to be 5.15 times higher than that of GL2. Interestingly, the mRNA expression of ascC, ascD, ascJ and ascI genes in the T3SS, and mshB, mshE, mshK and mshP genes in the MSHA type pili were significantly upregulated (P < 0.05) in ΔascR, potentially due to transcriptional compensation. Further analysis of enzymatic biomarkers revealed that ΔascR might not destruct the recognition of innate immune response in host remarkably, but the colonization levels of A.veronii were significantly suppressed (P < 0.01) in ΔascR group. In conclusion, the ascR gene may be a key determinant in regulating the virulence of A. veronii, and the destruction of the T3SS caused by ascR deficiency results in these notable changes.

Immune protection of grass carp by oral vaccination with recombinant Bacillus methylotrophicus expressing the heterologous tolC gene.

In the field of aquaculture, the enhancement of animal health and disease prevention is progressively being tackled using alternatives to antibiotics, including vaccines and probiotics. This study was designed to evaluate the potential of a recombinant Bacillus methylotrophicus, engineered to express the outer membrane channel protein TolC of Aeromonas hydrophila AH3 and the green fluorescent protein GFP, as an oral vaccine. Initially, the genes encoding tolC and GFP were cloned into a prokaryotic expression system, and anti-TolC mouse antiserum was generated. Subsequently, the tolC gene was subcloned into a modified pMDGFP plasmid, which was transformed into B. methylotrophicus WM-1 for protein expression. The recombinant B. methylotrophicus BmT was then administered to grass carp via co-feeding, and its efficacy as an oral vaccine was assessed. Our findings demonstrated successful expression of the 55 kDa TolC and 28 kDa GFP proteins, and the preparation of polyclonal antibodies with high specificity. The BmT exhibited stable expression of the GFP-TolC fusion protein and excellent genetic stability. Following oral immunization, significant elevations were observed in serum-specific IgM levels and the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), and lysozyme (LZM) in grass carp. Concurrently, significant upregulation of immune-related genes, including IFN-I, IL-10, IL-1ß, TNF-α, and IgT, was noted in the intestines, head kidney, and spleen of the grass carp. Colonization tests further revealed that the BmT persisted in the gut of immunized fish even after a fasting period of 7 days. Notably, oral administration of BmT enhanced the survival rate of grass carp following A. hydrophila infection. These results suggest that the oral BmT vaccine developed in this study holds promise for future applications in aquaculture.

Apple polyphenol extract ameliorates sugary-diet-induced depression-like behaviors in male C57BL/6 mice by inhibiting the inflammation of the gut-brain axis.

To explore whether apple polyphenol extract (APE) ameliorates sugary-diet-induced depression-like behaviors, thirty male C57BL/6 mice (3-4 weeks old) were assigned to three groups randomly to receive different treatments for 8 consecutive weeks: (1) control group (CON), (2) S-HSD group (60% high sucrose diet feeding with 0.1 mg mL-1 sucralose solution as drinking water), and (3) S-APE group (S-HSD feeding with 500 mg per (kg bw day) APE solution gavage). The S-HSD group showed significant depression-like behaviors compared with the CON group, which was manifested by an increased number of buried marbles in the marble burying test, prolonged immobility time in both the tail suspension test and forced swimming test, and cognitive impairment based on the Morris water maze test. However, APE intervention significantly improved the depression-like behaviors by reducing serum levels of corticosterone and adrenocorticotropic hormone, and increasing the serum level of IL-10. Moreover, APE intervention inhibited the activation of the NF-κB inflammatory pathway, elevated colonic MUC-2 protein expression, and elevated the colonic and hippocampal tight junction proteins of occludin and ZO-1. Furthermore, APE intervention increased the richness and diversity of gut microbiota by regulating the composition of microbiota, with increased relative abundance of Firmicutes and Bacteroidota, decreased relative abundance of Verrucomicrobiota at the phylum level, significantly lowered relative abundance of Akkermansia at the genus level, and rebalanced abnormal relative abundance of Muribaculaceae_unclassified, Coriobacteriaceae_UCG-002, and Lachnoclostridium induced by S-HSD feeding. Thus, our study supports the potential application of APE as a dietary intervention for ameliorating depression-like behavioral disorders.

Aeromonas veronii tolC modulates its virulence and the immune response of freshwater pearl mussels, Hyriopsis cumingii.

Aeromonas veronii is an opportunistic pathogen that causes diseases in aquatic animals, but its key virulence factors remain unclear. We screened the gene tolC with significantly different expression levels in the two isolates, A. veronii GL2 (higher virulence) and A. veronii FO1 (lower virulence). Therefore, we constructed mutant strain ΔtolC and analyzed its immunological properties. ΔtolC exhibited the reduced ability of biofilms formation, inhibited envelope stress response mediated by several antibiotics except cefuroxime, implying the ability to evade host immunity might be restrained. Challenge tests showed that the LD50 of ΔtolC was 10.89-fold than that of GL2. Enzymatic activities of ΔtolC group were significantly lower and peak time was delayed to 12 h, as demonstrated by qRT-PCR results. Histopathological examination displayed that the degree of tissue damage in ΔtolC group was alleviated. The results show that tolC is an important virulence factor of A. veronii, which provides references for live-attenuated vaccine.

Fucoidan alleviated dextran sulfate sodium-induced ulcerative colitis with improved intestinal barrier, reshaped gut microbiota composition, and promoted autophagy in male C57BL/6 mice.

Although previous research has unveiled the remedial effects of fucoidan, an extract from marine algae, on ulcerative colitis (UC), the precise mechanisms remain elusive. Animal studies have suggested a connection between autophagy and the beneficial influences of fucoidan intervention. We hypothesized that fucoidan's alleviative effects on dextran sulfate sodium (DSS)-induced UC could be ascribed to autophagy. For our study, we chose 36 male C57BL/6 mice and administered 100 or 400 mg/(kg/body weight/day) of fucoidan via gavage for 5 consecutive weeks. During the last week, the mice were given 3% DSS in drinking water to induce UC. In contrast to the DSS-induced UC model, fucoidan intervention prevented DSS-induced body weight loss, mitigated colon shortening, improved colon mucosa damage, enhanced the intestinal barrier, and reduced serum inflammatory factor concentrations. Furthermore, fucoidan intervention reshaped the gut microbiota compositions, increased the relative abundance of Bacteroidota, Muribaculaceae_unclassified, Clostridiales_unclassified, and Lachnospiraceae_NK4A136_group, and decreased the relative abundance of Firmicutes, Proteobacteria, and Escherichia-Shigella, which led to a lower Firmicutes/Bacteroidota ratio. Additionally, fucoidan treatment enhanced autophagy, as evidenced by upregulated protein expressions of BECLIN1, ATG5, ATG7, and an increased microtubule-associated-proteinlight-chain-3-II/microtubule-associated-proteinlight-chain-3-I ratio. Our findings corroborated the ameliorating effects of fucoidan intervention on DSS-induced UC through autophagy activation, reorganization of gut microbiota, and fortification of the intestinal barrier. This lends support to the therapeutic potential of fucoidan as a natural bioactive ingredient for future UC treatments in humans.

Preventive Effects of Apple Polyphenol Extract on High-Fat-Diet-Induced Hepatic Steatosis Are Related to the Regulation of Hepatic Lipid Metabolism, Autophagy, and Gut Microbiota in Aged Mice.

Our previous study confirmed that the ameliorated effects of an intervention with an apple polyphenol extract (APE) on hepatic steatosis induced by a high-fat diet (HFD) are dependent on SIRT1. Since SIRT1 expression decreases with age, it remains unclear whether APE intervention is effective against hepatic steatosis in aged mice. Thus, 12-month-old C57BL/6 male mice were fed with an HFD to establish an aging model of hepatic steatosis and treated with 500 mg/(kg·bw·d) APE for 12 weeks. Young mice (two months old) and baseline mice were used as controls to examine the effects of natural aging on hepatic steatosis. Compared with baseline mice, no obvious difference in hepatic histopathological assessment was observed for both young and aged mice on normal diets. Meanwhile, HFD induced much higher nonalcoholic fatty liver disease (NAFLD) activity scores in aged mice than in young mice. APE intervention ameliorated lipid and glucose metabolic disorders and liver injury in HFD-fed aged mice, improved hepatic steatosis, and reduced NAFLD activity scores. The upregulated expressions of SIRT1, HSL, ATG5, Ulk1, and Becn1 and downregulated expressions of HMGCR and FOXO1 suggested improved lipid metabolism and activated autophagy. APE intervention decreased the ratio of Firmicutes/Bacteroidetes and elevated the Akkermansia probiotics abundance. In summary, HFD showed a more significant effect on hepatic steatosis compared to the natural aging process in aged mice, and APE might be a promising dietary ingredient for alleviating hepatic steatosis.

Apple Polyphenol Extract Ameliorates Atherosclerosis and Associated Cognitive Impairment through Alleviating Neuroinflammation by Weakening TLR4 Signaling and NLRP3 Inflammasome in High-Fat/Cholesterol Diet-Fed LDLR-/- Male Mice.

Although studies have supported the beneficial effects of the ingredients of apple polyphenol extract (APE), a polyphenol mixture being extracted from whole fresh apples, on neurodegenerative diseases, the role of APE in atherosclerosis-related cognitive impairment remains unclear. To clarify the role of APE in regulating cognitive dysfunction in mice with atherosclerosis and the underlying mechanisms, high-fat/cholesterol diet-fed male LDLR-/- mice were gavaged with 125 or 500 mg/(kg·bw·d) APE solution or sterile double-distilled water for consecutive 8 weeks, and age-matched C57BL/6 male mice were employed as normal control. APE intervention increased the serum concentration of high-density apolipoprotein cholesterol, improved atherosclerosis, and ameliorated cognitive function of mice by inhibiting the phosphorylation of tau protein, supporting with significantly reduced platform latency and obviously increased swimming distance in the target quadrant according to the Morris water maze test. APE intervention alleviated neuroinflammation by attenuating the activation of microglia and astrocytes and inhibiting TLR4 signaling with reduced protein expression of NF-κB, MyD88, TRIF, and IKKß. Meanwhile, APE intervention inactivated NLRP3 inflammasome with downregulated protein expression of caspase-1, IL-18, and IL-1ß. Additionally, APE intervention improved the damaged brain barrier structure by upregulating the protein expression of ZO-1 and occludin. Therefore, our research supplemented new data, supporting the potential of APE as an effective dietary bioactive ingredient to improve atherosclerosis and associated cognitive impairment.

Pathogenicity and inactivated vaccine treatment of Aeromonas veronii JW-4 on crucian carp.

Aeromonas veronii is a common bacterium found in a variety of aquatic environments, capable of causing a diverse array of diseases in both aquatic animals and humans. Therefore, evaluating the pathogenicity of A. veronii and implementing measures to control its spread are essential. In this study, a strain JW-4, identified as A. veronii, was isolated from diseased Scaphesthes macrolepis, a grade Ⅱ protected animal in China. To investigate the pathogenicity of the strain, fish were fed with serial levels JW-4 supplemented diet or basal diet (control group 1, CG1) for 28 days (d). Results showed that JW-4 stimulated an immune response, evidenced by an increase in immune-related enzyme activities (GOT and GPT) of serum and liver and an upregulation of genes expression levels (TNF-α and IFN-γ) of liver and spleen, and these effects gradually decreased over time. Histopathological examination revealed that JW-4 could alter the tissue structure of immune organs, such as liver and kidney. These changes were accompanied by vacuolar degeneration, nuclear dissolution, and an increased lymphocyte count. To assess protective effects of a vaccine against this strain, fish were injected with an inactivated vaccine (immunization group, IG) or 0.85% sterile saline (control group 2, CG2) for 28-day observation period, then challenged with JW-4 on the 28th day. The inactivated vaccine enhanced total and specific IgM to A. veronii levels of the fish, resulting in a relative percentage survival of 75% in IG. These findings provide a foundation for identifying pathogenic bacteria and developing more effective prophylactic strategies in aquaculture.

Manufacture and evaluation of a HER2-positive breast cancer immunotoxin 4D5Fv-PE25.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) positive breast cancer is an aggressive subtype, accounting for around 20% of all breast cancers. The development of HER2-targeted therapy has substantially improved patient outcomes. Nevertheless, the increasing rate of side effects and resistance to targeted drugs limit their efficacy in clinical practice. In this study, we designed and synthesized a new immunotoxin, 4D5Fv-PE25, which targets HER2-positive breast cancer, and evaluated its effectiveness in vitro and in vivo. RESULTS: The 4D5Fv-PE25 was expressed in high-density Escherichia coli (E. coli.) using the fermentor method and refined via hydrophobicity, ion exchange, and filtration chromatography, achieving a 56.06% recovery rate. Additionally, the semi-manufactured product with 96% purity was prepared into freeze-dried powder by the lyophilized process. Flow cytometry was used to detect the expression of HER2 in SK-BR-3, BT-474, MDA-MB-231, and MDA-MB-468 breast cancer cell lines. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method was used for cytotoxicity assay, and the half-maximal inhibitory concentration (IC50) of 4D5Fv-PE25 lyophilized products to HER2-positive cell line SK-BR-3 was 12.53 ng/mL. The 4D5Fv-PE25 was injected into xenograft tumor mice via the tail vein on the 1st, 4th, and 8th day, it indicated that the growth of tumor volume was effectively inhibited for 24 days, although the 4D5Fv-PE25 was metabolized within 60 min by measuring the release of 3 H-Thymidine radiation. CONCLUSION: we succeeded in producing the 4D5Fv-PE25 freeze-dried powder using the prokaryotic expression method, and it could be employed as a potential drug for treating HER2-positive breast cancer.

Dysfunction of Prkcaa Links Social Behavior Defects with Disturbed Circadian Rhythm in Zebrafish.

Protein kinase Cα (PKCα/PRKCA) is a crucial regulator of circadian rhythm and is associated with human mental illnesses such as autism spectrum disorders and schizophrenia. However, the roles of PRKCA in modulating animal social behavior and the underlying mechanisms remain to be explored. Here we report the generation and characterization of prkcaa-deficient zebrafish (Danio rerio). The results of behavioral tests indicate that a deficiency in Prkcaa led to anxiety-like behavior and impaired social preference in zebrafish. RNA-sequencing analyses revealed the significant effects of the prkcaa mutation on the expression of the morning-preferring circadian genes. The representatives are the immediate early genes, including egr2a, egr4, fosaa, fosab and npas4a. The downregulation of these genes at night was attenuated by Prkcaa dysfunction. Consistently, the mutants demonstrated reversed day-night locomotor rhythm, which are more active at night than in the morning. Our data show the roles of PRKCA in regulating animal social interactions and link the social behavior defects with a disturbed circadian rhythm.

Molecular Cloning and Expression Analysis of Thyrotropin-Releasing Hormone, and Its Possible Role in Gonadal Differentiation in Rice Field eel Monopterus albus.

Rice field eel (Monopterus albus), a protogynous hermaphrodite fish, is a good model for the research of sex determination and gonadal differentiation in teleosts. In this study, we cloned the full-length cDNA sequence of trh, which encoded a predicted protein with 270 amino acids. Trh mainly expressed in the brain, followed by the ovary, testis, muscle and pituitary, and had low levels in other peripheral tissues. During natural sex reversal, trh mRNA expression levels exhibited a significant increase at the late intersexual stage in the hypothalamus. In the gonad, trh mRNA expression levels showed a trend of increase followed by decrease, and only increased significantly at the middle intersexual stage. No matter static incubation or intraperitoneal (IP) injection, TRH had no significant effect on trh and thyroid-stimulating hormone ßsubunit (tshß) mRNA expression levels, and serum T3, T4 and TRH release. After static incubation of ovarian fragments by TRH, the expression of gonadal soma derived factor (gsdf) was up-regulated significantly at both the doses of 10 and 100 nM. IP injection of TRH stimulated the expression of gsdf, and inhibited the expression of ovarian aromatase gene (cyp19a1a), accompanied by the increase of serum 11-KT levels. The results indicated that TRH may play a novel role in gonadal differentiation by the regulation of gonadal differentiation-related gene expression and sex steroid hormone secretion in rice field eel.

Research progress in relationships between freshwater bivalves and algae.

Eutrophication in freshwater has become increasingly severe around the world, resulting in phytoplankton overgrowth and benthic algae reduction. Bivalves can change the density, dominant species and community structure of phytoplankton, increase available light levels, and provide physical habitats and growth conditions for benthic algae. The nutritional composition, density, community structure, and toxin of algae affect the growth, feeding, digestion, metabolism, immunity of bivalves in return. Interactions of bivalves and algae and effects of environmental factors on these interactions need a synthesis of studies, when using bivalves as a biomanipulation tool to control eutrophication. Whether bivalves can effectively suppress phytoplankton and promote benthic algae is related to the collective filtration and excretion capacity determined by size, species, population densities of bivalves, the quantity and quality of algae, and environmental factors such as temperature, dissolved oxygen, pH, and hydrodynamic. Small scale bivalve biomanipulation experiments are mostly conducted in lakes, urban ponds, and reservoirs with some success, applying in the whole ecosystem should consider more questions such as natural conditions, selection and death or reproduction of bivalves, and ecological disturbances. This review provides new considerations for technical issues such as the sustainable cultivation of bivalves and the implementation of biomanipulation in eutrophic waters.

Differentiated Functions of Potassium Interface Passivation and Doping on Charge-Carrier Dynamics in Perovskite Solar Cells.

The inclusion of potassium in perovskite solar cells (PSCs) has been widely demonstrated to enhance the power conversion efficiency and eliminate the hysteresis effect. However, the effects of the locations K+ cations on the charge-carrier dynamics remain unknown with respect to achieving a more delicate passivation design for perovskite interfaces and bulk films. Herein, we employ the combined electrical and ultrafast dynamics analysis for the perovskite film to distinguish the effects of bulk doping and interfacial passivation of the potassium cation. Transient absorption spectroscopy indicates an enhancement of charge-carrier diffusion for K+-doped PSCs (from 808 to 605 ps), and charge-carrier transfer is significantly promoted by K+ interface passivation (from 12.34 to 1.23 ps) compared with that of the pristine sample. Importantly, K+ doping can suppress the formation of wide bandgap perovskite phases (e.g., FAPbI0.6Br2.4 and FAPbI1.05Br1.95) that generate an energy barrier on the charge-carrier transport channel.

Apple polyphenol extract modulates bile acid metabolism and gut microbiota by regulating the circadian rhythms in daytime-restricted high fat diet feeding C57BL/6 male mice.

The homeostasis of circadian clock linked to bile acid (BA) metabolism and gut microbiota has profound benefits in maintaining the health status of the host. The aim of this study was to investigate the prevention and regulation of apple polyphenol extract (APE) on BA metabolism and gut microbiota by means of modulation of circadian rhythms in mice. Eighty male C57BL/6 mice were randomized into four groups: 24-hour ad libitum standard chow group (AC), ad libitum HFD group (AF), restricted 12 h daytime HFD feeding group (DF), and daytime HFD feeding with APE treatment group (DP). Five weeks later, the mice were sacrificed at 6 h intervals over a 24 h period. The results showed that APE decreased body weight and induced daily rhythms of Cry1 and Rorα in the suprachiasmatic nucleus (SCN) and Clock, Cry1 and Cry2 in the ileum in daytime HFD mice. APE significantly increased the expression of hepatic FXR at ZT0 and BSEP at ZT12 and inhibited the expression of ileac FXR at ZT12, reduced levels of fecal TBAs, secondary BAs, and unconjugated BAs at ZT0. Meanwhile, APE regulated the diversity and composition of the gut microbiota, and increased the abundance of probiotics. Therefore, our work revealed that APE as a clock-regulating natural compound could modulate BA metabolism and gut microbiota and protect against circadian disruption in a clock-dependent manner.

Identification and expression analysis of thyroid-stimulating hormone ß subunit, and effects of T3 on gonadal differentiation-related gene expression in rice field eel, Monopterus albus.

Thyroid-stimulating hormone (TSH) is an important glycoprotein in hypothalamic-pituitary-thyroid axis, which plays a crucial role in the synthesis and release of thyroid hormones in vertebrates. Rice field eel, Monopterus albus, a protogynous hermaphroditic fish, which undergoes sex reversal from a functional female to a male, is an ideal model to investigate the regulation of sex differentiation. In this study, we obtained the cDNA sequence of thyroid-stimulating hormone ß subunit (tshß) from rice field eel, which contained a complete open reading frame and encoded a putative protein of 151 amino acids. Multiple alignment of protein sequences showed that tshß was highly conserved in teleost. The tissue distribution indicated that tshß showed high expression in the pituitary, moderate expression in the brain region, gonad, intestine and liver, and low expression in other peripheral tissues. During natural sex reversal, the expression of tshß had no significant difference in the pituitary. Compared to that in the ovary, the expression of tshß increased significantly in the gonad at late intersexual and male stages. After treatment by different doses of triiodothyronine (T3) (1 µg/g, 10 µg/g and 100 µg/g body weight), serum T3 and free triiodothyronine (FT3) increased sharply, while the expression of tshß were inhibited significantly in the pituitary. Although T3 had no significant effect on the levels of serum E2, it stimulated the release of serum 11-KT at high-dose group. We also detected the effects of T3 on the expression of gonadal differentiation-related genes in rice field eel. T3 treatment inhibited the expression of foxl2, cyp19a1a and dax1, while stimulated the expression of sox9a1. These results indicate that TSH may be involved in sex differentiation, and THs may play roles in the regulation of male development and sex reversal in rice field eel.

Histopathology, antioxidant responses, transcriptome and gene expression analysis in triangle sail mussel Hyriopsis cumingii after bacterial infection.

Bacterial disease outbreaks in filter feeder bivalve Hyriopsis cumingii as water contamination become more frequent in the water ecosystem, especially in intensive aquaculture habitats. To characterize host-pathogen interactions between H. cumingii and bacterial infection, we investigated the effects of Stenotrophomonas maltophilia HOP3 and Aeromonas veronii GL1 on the antioxidant response, tissue invasion and transcriptome expression of H. cumingii by infectivity trials. We showed that bacterial infections resulted in tubular necrosis of the hepatopancreas and induced the acute immune response in H. cumingii. The transcriptomic study identified a total of 5957 differentially expressed genes (DEGs) after A. veronii challenge. These DEGs were implicated in 302 KEGG pathways, notably in Apoptosis, Phagosome and Lysosome. The results showed that the relative expressions of all six immune-related DEGs were effectively stimulated with A. veronii, accompanied by tissue differences. Overall, these findings will contribute to an analysis of the immune response of H. cumingii to bacterial infection at the transcriptomic level and its genomic resource for research.

Characterization of microRNA profile in IgE-mediated mouse BMMCs degranulation.

BACKGROUND: Mast cells play a central role in innate and adaptive immunity by releasing pre-formed and de novo synthesized mediators, which include microRNAs. Although miRNAs have been confirmed to function in cell proliferation, differentiation, apoptosis, and the immune response, their functions are still limited in mast cells degranulation. METHODS: Here, we survey miRNA expression profiles in activated mouse bone marrow-derived mast cells (BMMCs) with a miRNA microarray and compare the profiles to those from resting BMMCs. Partial miRNAs were selected for confirmation by qPCR, and let-7i was selected for function discover in mast cell degranulation process. TargetScan Mouse database were used for target genes prediction, gene ontology (GO) were used for gene molecular function classifications, and Cytoscape software were used to construct gene network of degranulation. RESULTS: We found 13 up-regulated miRNAs and 7 down-regulated miRNAs in DNP activated BMMCs by miRNA microarray; and let-7b, let-7c, let-7d, let-7f, let-7i, and miR-652 were up-regulated, and miR-296-3p was down-regulated in DNP-stimulated BMMCs by qPCR. In the function research, let-7i can inhibit mast cell degranulation by suppress Exco8 expression. Overall, the data indicate that miRNAs participate in mast cell activation, especial for mast cell degranulation process.

A monoclonal antibody that tracks endospore formation in the microsporidium Nosema bombycis.

Nosema bombycis, the first identified microsporidium, is a destructive pathogen of the silkworm Bombyx mori and causes severe worldwide economic losses in sericulture. Major microsporidian structural proteins, such as the spore wall protein (SWP), are known to be involved in host invasion. In this study, the reactivity of the monoclonal antibody 2B10 was tested against an endospore protein of N. bombycis with a molecular weight size at 50-kDa, using Western blotting. The antigen was purified after immunoprecipitation and was further identified as EOB13320 according to MALDI-TOF MS assay. We found that EOB13320 locates to the surface of the different developmental stages of the parasite, mostly the sporoblast stage and the mature spore after immunoelectron microscopy examination. EOB13320 was also widely distributed in the developing endospore, especially at the sporoblast stage. This endospore protein also accumulated in the cytoplasm of both the merogony and sporoblast stages. These results imply that EOB13320 detected by monoclonal antibody 2B10 is expressed throughout the life cycle of the parasite, notably during the stage when the endospore is formed, and that this protein is important for spore-coat formation and parasite maintenance. Our study could be instrumental in the understanding of spore wall formation and will help to gain greater insight into the biology of this parasite.

Mast cells protect against Pseudomonas aeruginosa-induced lung injury.

Pseudomonas aeruginosa, an opportunistic pathogen, is the leading cause of morbidity and mortality in immune-compromised individuals. Maintaining the integrity of the respiratory epithelium is critical for an effective host response to P. aeruginosa. Given the close spatial relationship between mast cells and the respiratory epithelium, and the importance of tightly regulated epithelial permeability during lung infections, we examined whether mast cells influence airway epithelial integrity during P. aeruginosa lung infection in a mouse model. We found that mast cell-deficient Kit(W-sh)/Kit(W-sh) mice displayed greatly increased epithelial permeability, bacterial dissemination, and neutrophil accumulation compared with wild-type animals after P. aeruginosa infection; these defects were corrected on reconstitution with mast cells. An in vitro Transwell co-culture model further demonstrated that a secreted mast cell factor decreased epithelial cell apoptosis and tumor necrosis factor production after P. aeruginosa infection. Together, our data demonstrate a previously unrecognized role for mast cells in the maintenance of epithelial integrity during P. aeruginosa infection, through a mechanism that likely involves prevention of epithelial apoptosis and tumor necrosis factor production. Our understanding of mechanisms of the host response to P. aeruginosa will open new avenues for the development of successful preventative and treatment strategies.