摘要：
The outbreak of mass mortality occurred in Tachysurus fulvidraco farm in Hubei province of China. The pathogenic strain of Streptococcus iniae (termed 2022SI08) was isolated and identified from diseased T. fulvidraco, based on morphological, physiological, and biochemical characteristics, as well as 16S rRNA gene sequence and phylogenetic analysis. Further, the whole genome of isolate S. iniae was sequenced and predicted to contain one single circular chromosome of 1,776,777 bp with a GC content of 37.14%. The genomic sequence analysis showed that 2022SI08 was positive for 204 virulent and 127 antibiotic resistant genes. The experimental challenge demonstrated the high pathogenicity of the retrieved isolate of S. iniae, with a median lethal dosage (LD(50)) 9.53 × 10(5) CFU/g. Histopathological examination indicated that the 2022SI08 strain could induce extensive tissue cell degeneration, necrosis, hemorrhage, and inflammation in the skin, gill, fin, spleen, liver, kidney, intestine, eye, and brain. Moreover, the innate immune enzyme activities in serum such as acid phosphatase and alkaline phosphatase were increased significantly at 24 and 48 h post infection (hpi) and then decreased at 168 hpi. The transcriptional profile of immune associated gene in T. fulvidraco following bacterial infection was detected at each point of time, and the results revealed clear transcriptional activation of those genes, which proving their reacting and regulatory role during the response of the host against S. iniae infection. The results revealed that S. iniae was an etiological agent in the mass mortalities of T. fulvidraco and this research will be conducive for increasing our understanding on pathogenesis and host defensive system in S. iniae invasion.
摘要：
Cyanobacteria are the oldest prokaryotic photoautotrophic microorganisms and have evolved complicated post-translational modification (PTM) machinery to respond to environmental stress. Lysine 2-hydroxyisobutyrylation (Khib) is a newly identified PTM that is reported to play important roles in diverse biological processes, however, its distribution and function in cyanobacteria have not been reported. Here, we performed the first systematic studies of Khib in a model cyanobacterium Synechococcus sp. strain PCC 7002 (Syn7002) using peptide prefractionation, pan-Khib antibody enrichment, and high-accuracy mass spectrometry (MS) analysis. A total of 1875 high-confidence Khib sites on 618 proteins were identified, and a large proportion of Khib sites are present on proteins in the cellular metabolism, protein synthesis, and photosynthesis pathways. Using site-directed mutagenesis and functional studies, we showed that Khib of glutaredoxin (Grx) affects the efficiency of the PS II reaction center and H(2)O(2) resistance in Syn7002. Together, this study provides novel insights into the functions of Khib in cyanobacteria and suggests that reversible Khib may influence the stress response and photosynthesis in both cyanobacteria and plants.
摘要：
Oxidative stress occurs in the process of egg storage. Antioxidants as feed additives can enhance egg quality and extend the shelf life of eggs. Selenium-enriched Cardamine violifolia (SEC) has strongly antioxidant properties. The objective of this study was to assess the effects of dietary supplementation with SEC on egg quality and the yolk antioxidant capacity of eggs stored at 4 degrees C and 25 degrees C. Four hundred fifty 65-week-old, Roman hens that were similar in laying rate (90.79 +/- 1.69%) and body weight (2.19 +/- 0.23 kg) were divided into 5 groups. The birds were fed diets supplemented with 0 mg/kg selenium (Se) (CON), 0.3 mg/kg Se from sodium selenite (SS), 0.3 mg/kg Se from Se-enriched yeast (SEY), 0.3 mg/kg Se for selenium-enriched Cardamine violifolia (SEC) or 0.3 mg/kg Se from Se-enriched Cardamine violifolia and 0.3 mg/kg Se from Se-enriched yeast (SEC + SEY) for 8 weeks. The eggs were collected on the 8th week and were analyzed for egg quality and oxidative stability of yolk during storage at 4 degrees C or 25 degrees C for 0, 2, 4, or 6 weeks. Dietary SEC and SEC + SEY supplementation increased the Haugh unit (HU) and albumen foam stability in eggs stored at 4 degrees C and 25 degrees C (p < 0.05). SS and SEC supplementation increased the yolk index in eggs stored at 25 degrees C (p < 0.05). SEC or SEC + SEY slowed down an increase in albumen pH and gel firmness in eggs stored at 4 degrees C and 25 degrees C (p < 0.05). Moreover, SEC or SEC + SEY alleviated the increase in malonaldehyde (MDA), and the decrease in total antioxidant capacity (T-AOC) level and total superoxide dismutase (T-SOD) activity in yolks stored at 4 degrees C and 25 degrees C (p < 0.05). These results indicate that SEC mitigated egg quality loss and improved the antioxidant capacity of yolks during storage. SEC supplementation would be advantageous to extend the shelf life of eggs.
关键词：
Gansulinema gen. nov.;Komarkovaeasiopsis gen. nov.;cyanobacteria;polyphasic methods;taxonomy
摘要：
To increase the understanding of simple thin filamentous cyanobacteria in harsh environmental areas, we previously isolated and identified four strains (XN101, XN102, GS121, NX122) from desert soils and hot spring in China. As a result, two new Oculatellacean genera of these four strains, Gansulinema gen. nov. and Komarkovaeasiopsis gen. nov., are described based on a polyphasic approach. The ultrastructure of these strains showed a similar arrangement of peripheral thylakoids with three to four parallel layers, indicating that they belonged to the orders Nodosilineales, Oculatellales, or Leptolyngbyales. In the 16S rRNA gene phylogeny, two sequences of the Gansulinema strains and the two sequences of the Komarkovaeasiopsis strains formed two independent and robust clusters, within the order Oculatellales. The 16S rRNA gene sequences of strains of Komarkovaeasiopsis and Gansulinema showed low identity to each other (≤93.2%) and to other sequences of the Oculatellacean genera (≤94.5% and ≤93.3%, respectively). Furthermore, the 16S-23S internal transcribed spacer rRNA region secondary structures of strains of Komarkovaeasiopsis and Gansulinema were not consistent with all existing descriptions of Oculatellacean taxa. These data suggest that cyanobacterial communities are rich sources of new taxa in under-exploited areas, such as desert soils and hot spring in China.
关键词：
ferroptosis;natural active compounds;liver disease;therapeutic implications
摘要：
Ferroptosis is an emerging type of regulated cell death usually accompanied by the accumulation of ferrous ions (Fe2+) and lipid peroxides. As the metabolic hub of the body, the liver is crucial for iron storage and lipid metabolism. The liver seems to be closely related to ferroptosis through iron and lipid metabolism. Liver disease greatly threatens host health, and exploring effective interventions is essential. Mounting studies have demonstrated that ferroptosis is one of the possible pathogenic mechanisms involved in liver disease. Targeting ferroptosis may provide a promising opportunity for treating liver disease. However, drugs targeting ferroptosis are extremely limited. Therefore, it is an urgent need to develop new and safe ferroptosis regulators. Natural active compounds (NAC), especially those derived from traditional Chinese medicine, have recently shown great therapeutic potential in liver disease via modulating ferroptosis-related genes or pathways. Here, we outline the molecular mechanism of ferroptosis and systematically summarize the regulatory function of NAC on ferroptosis in liver disease. Finally, we discuss the application prospects and potential problems concerning NAC as ferroptosis regulators for managing liver disease.
摘要：
Porcine epidemic diarrhea virus (PEDV) has caused severe damage to the global pig industry in the past 20 years, creating an urgent demand for the development of associated medications. Flavonoids have emerged as promising candidates for combating coronaviruses. It is believed that certain flavonoids can directly inhibit the 3C-like protease (3CL(pro)), thus displaying antiviral activity against coronaviruses. In this investigation, we applied a flavonoid library to screen for natural compounds against PEDV 3CL(pro). Baicalein and baicalin were found to efficiently inhibit PEDV 3CL(pro)in vitro, with the IC(50) value of 9.50 ± 1.02 μM and 65.80 ± 6.57 μM, respectively. A docking analysis supported that baicalein and baicalin might bind to the active site and binding pocket of PEDV 3CL(pro). Moreover, both baicalein and baicalin successfully suppressed PEDV replication in Vero and LLC-PK1 cells, as indicated by reductions in viral RNA, protein, and titer. Further investigation revealed that baicalein and baicalin mainly inhibited the early viral replication of the post-entry stage. Furthermore, baicalein showed potential effects on the attachment or invasion step of PEDV. Collectively, our findings provide experimental proof for the inhibitory effects of baicalein and baicalin on PEDV 3CL(pro) activity and PEDV infection. These discoveries may introduce novel therapeutic strategies for controlling porcine epidemic diarrhea (PED).
摘要：
The present study was conducted to decipher the protection effects of ellagic acid (EA) on piglets infected with porcine epidemic diarrhea virus (PEDV). Thirty 7-day-old piglets were randomly assigned to three treatment groups: control, PEDV, and EA + PEDV groups. After a 3-day period of adaption, piglets in the EA + PEDV group were orally administered with 20 mg/kg·BW EA during days 4-11 of the trial. On day 8, piglets were orally administered with PEDV at a dose of 10(6) TCID(50) (50% tissue culture infectious dose) per pig. Additionally, intestinal porcine epithelial (IPEC-1) cells infected with PEDV were used to investigate the anti-PEDV effect of EA in vitro. The results showed that EA at a dose of 10-40 μmol/L increased the viability of PEDV-infected IPEC-1 cells, and EA administration mitigated intestinal edema in piglets challenged with PEDV. Further studies indicated that EA treatment significantly increased the proportion of white blood cells in blood and concentrations of IL-6, IL-1β, and IL-10 in the serum, but decreased the TNF-α content and gene expression of IL-6, IL-1β, TNF-α, and CXCL2 in the jejunum. Moreover, EA intervention considerably elevated the activity of total superoxide dismutase (T-SOD), but decreased the H(2)O(2) concentration in the ileum of piglets. Importantly, EA suppressed the increased expression of antiviral-related genes and proteins (including MXI, ISG15, HSP70, and p-IRF7) induced by PEDV challenge in the jejunum. Furthermore, PEDV infection increased the protein abundance of p-JAK2 and p-STAT3, which were further enhanced by EA supplementation. In conclusion, our results revealed that EA could promote the restoration of intestinal homeostasis by regulating the interferon pathway that was interrelated with the activation of JAK2/STAT3 signaling. These findings provide theoretical basis for the use of EA as a therapy targeting PEDV infection in piglets.
作者机构：
[Liu, Mingkang; Xu, Xiao; Ma, Deying; Zhao, Ziyun; Xu, X; Wei, Yu; Li, Luyang; Dai, Ziyi] Wuhan Polytech Univ, Hubei Key Lab Anim Nutr & Feed Sci, Wuhan 430023, Peoples R China.;[Xue, Lingfeng] China Anim Husb Ind Co Ltd, Beijing 100071, Peoples R China.;[Weng, Yuxiao; Wang, Haifeng] P&O Biotechnol Hubei Co Ltd, Wuhan 436043, Peoples R China.
通讯机构：
[Xu, X ] W;Wuhan Polytech Univ, Hubei Key Lab Anim Nutr & Feed Sci, Wuhan 430023, Peoples R China.
关键词：
protein hydrolysate;black soldier fly larvae;schizochytrium;palatability;antioxidant;diarrhea;dogs
摘要：
Protein hydrolysate from black soldier fly larvae (BSFP) has garnered great attention with its lower allergenicity, high amount of essential amino acids, and small bioactive peptides. Schizochytrium is a promising alternative source of n-3 FUFA because it has enriched docosahexaenoic acid (DHA, C22: 6). The aim of this study was to assess palatability, the presence of diarrhea, plasma biochemistry panels, anti-oxidative and anti-inflammatory effects, and immune function in beagle dogs when supplementing a mixture of protein hydrolysate from black soldier fly larvae and schizochytrium (BSFPs) into their diets. Experiment I: 24 young beagle dogs (16 males and 8 females; 4-5 months; BW: 6.40 ± 0.15 kg) were randomly divided into four groups: (1) control (CON), (2) 5% BSFPs, (3) 10% BSFPs, (4) 15% BSFPs. Their body weights and fecal scores were recorded, and blood samples were collected for analysis. Experiment II: three diets containing 5%, 10%, and 15% BSFPs were evaluated by comparing them with a basal diet (CON) to evaluate palatability. These results suggested that a lower presence of diarrhea existed in the BSFP diet than the CON diet (p < 0.05). Three treatment groups remarkably increased their total protein (TP) and albumin (ALB) contents and decreased their concentrations of triglyceride (TG) and total cholesterol (TC) in plasma (p < 0.05). Moreover, the 5% and 15% BSFPs groups had a higher calcium (CA) content in plasma, and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and contents of creatinine (CREA) and urea nitrogen (BUN) were significantly reduced by supplementing BSFP in their diets (p < 0.05). Their anti-oxidative enzyme activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) were dramatically enhanced, and their malondialdehyde (MDA) concentrations were remarkably reduced (p < 0.05). Immunoglobulin A and G (IgA and IgG) concentrations in the plasma in the 10% and 15% BSFPs groups were significantly increased (p < 0.05). Furthermore, lower interleukin-8 (IL-8) contents were shown in the BSFP diets than the CON diet (p < 0.05). Similarly, the diets supplemented with BSFPs exhibited a positive effect on palatability (p < 0.05). To sum up, the diets supplemented with BSFPs significantly enhanced palatability, immune function, and anti-oxidative and anti-inflammatory capacity to alleviate diarrhea and improve the general health of the beagle dogs.
通讯机构：
[Xu, X ] W;Wuhan Polytech Univ, Hubei Key Lab Anim Nutr & Feed Sci, Wuhan 430023, Peoples R China.
关键词：
protein hydrolysate;black soldier fly larvae;schizochytrium;palatability;anti-inflammation;cats
摘要：
Protein hydrolysate has been a premium protein source in animal feed and is more easily absorbed in animal intestines compared with crude protein, which has a higher rate of pure protein and free amino acids with a high protein efficiency ratio. Previous studies have shown that black soldier fly larvae have been considered one of the most promising proteins for replacing fish meal, especially in the pet market. Recently, the synthesis and functional identification of protein hydrolysate from black soldier fly larvae (BSFP) have received a great deal of attention. In addition, schizochytrium is a marine microalga which has a high content of lipids and polyunsaturated fatty acids (PUFAs), especially an abundant docosahexaenoic (DHA) concentration. Previous research has demonstrated that schizochytrium is promisingly able to substitute for soybean and fish oil in feed and possesses some physiological functions. The objective of this research was to evaluate palatability, plasma biochemistry, antioxidative and anti-inflammatory capacity, and immune levels in cats by feeding supplementing inclusion of different levels of a mixture of protein hydrolysate from black soldier fly larvae and schizochytrium (BSFPs) in diets. In the feed experiment, a total of 24 adult cats (12 females and 12 males; BW: 3.02 +/- 0.06 kg) were randomly divided into four groups: (1) diet with chicken and fish meal as primary protein resource (CON); (2) diet with 5% BSFPs replacing chicken meal, fish meal, chicken oil, and fish oil (5% BSFPs); (3) 10% BSFPs; and (4) 15% BSFPs. The body weight and feed intake were recorded, and a blood sample was collected for analysis. In the palatability experiment, three diets containing 5%, 10%, and 15% BSFPs were evaluated by comparing with CON. These results suggested that different levels of BSFPs could improve palatability in cat diets by enhancing the first sniff, the first bite, and feed intake (p < 0.05). However, no significant influence existed in body weight and average daily feed intake (p > 0.05). In comparison to the CON group, 5% and 15% BSFPs significantly increased the total protein content, and all treatment groups decreased the triglyceride content and enhanced the calcium concentration in plasma; in addition, the activity of aspartate aminotransferase and alanine aminotransferase and the content of creatinine and urea nitrogen were significantly reduced by the supplementation inclusion of BSFPs in the diets (p < 0.05). The enzyme activity of glutathione peroxidase was dramatically enhanced by the supplementation of 10% and 15% BSFPs in diets compared with the CON diet, and the activity of superoxide dismutase was increased and the malondialdehyde concentration was remarkably reduced in all three treatments (p < 0.05). Compared with the CON group, different levels of BSFPs in the diets significantly increased the immunoglobulin A content in plasma; similarly, the immunoglobulin G concentration was significantly enhanced by the supplementation of 10% and 15% BSFPs in the diets (p < 0.05). Furthermore, the interleukin-1 beta content was significantly reduced in the inclusion of 10% and 15% BSFPs in the diets, and 15% BSFPs remarkably decreased the content of interleukin-8 in plasma compared with the CON diet (p < 0.05). To sum up, the supplementation of different levels of BSFPs exhibited a positive effect on palatability and enhanced the antioxidant, anti-inflammatory, and immune capacity. Particularly, the addition levels of 10% and 15% BSFPs were more effective in antioxidation, anti-inflammation, and immunity.
摘要：
Glaesserella parasuis, an important respiratory bacterial pathogen, causes Glässer’s disease in piglets, with potential immunosuppression. We established a piglet infection model and explored the immunosuppression mechanism to improve our understanding of the host immune response to G. parasuis. Twenty piglets were randomly divided into two groups (n = 10). The infection group was intraperitoneally challenged with 2 × 108 CFU of G. parasuis in 2 mL TSB. The control group was intraperitoneally injected with equivalent TSB. After 72 h, the piglets were sacrificed, and spleen tissue was collected. PD-1/PD-L1 expression was determined. The splenocytes were isolated to detect CD3+ T, CD3+CD4+ T, CD3+CD8+ T and CD3−CD21+cell differentiation. Via data-independent acquisition (DIA), we compared the proteomics of healthy and infected spleen tissues. Glaesserella parasuis modified CD3+ T, CD3+CD4+ T, CD3+CD8+ T and CD3−CD21+ cell differentiation and PD-1/PD-L1 expression in the spleen. The infection group had 596 proteins with significant differences in expression, of which 301 were significantly upregulated and 295 downregulated. Differentially expressed proteins (DEPs) were mainly related to immune responses. This is the first study on PD-1/PD-L1 expression in the spleen associated with immunosuppression in a piglet model to explore the protein changes related to immune responses via DIA.
摘要：
The aim of this study was to investigate the effects of dietary l-glutamine (Gln) supplementation on the morphology and function of the intestine and the growth of muscle in piglets. In this study, sixteen 21-day-old piglets were randomly divided into two groups: the Control group (fed a basal diet) and the Gln group (fed a basal diet supplemented with 0.81% Gln). Blood, gut, and muscle samples were collected from all piglets on Day 20 of the trial. Compared with the Control group, the supplementation of Gln increased (p < 0.05) the villus height, villus width, villus surface area, and villus height/crypt depth ratio of the small intestine. Furthermore, the supplementation of Gln increased (p < 0.05) total protein, total protein/DNA, and RNA/DNA in both the jejunum and ileum. It also increased (p < 0.05) the concentrations of carnosine and citrulline in the jejunal mucosa, as well as citrulline and cysteine concentrations in the ileum. Conversely, Gln supplementation decreased (p < 0.05) Gln concentrations in both the jejunum and ileum, along with β-aminoisobutyric acid and 1-Methylhistidine concentrations, specifically in the ileum. Subsequent research revealed that Gln supplementation increased (p < 0.05) the mRNA levels for glutathione-S-transferase omega 2 and interferon-β in the duodenum. In addition, Gln supplementation led to an increase (p < 0.05) in the number of Lactobacillus genus in the colon, but a decrease (p < 0.05) in the level of HSP70 in the jejunum and the activity of diamine oxidase in plasma. Also, Gln supplementation reduced (p < 0.05) the mRNA levels of glutathione-S-transferase omega 2 and interferon stimulated genes, such as MX1, OAS1, IFIT1, IFIT2, IFIT3, and IFIT5 in both the jejunum and ileum, and the numbers of Clostridium coccoides, Enterococcus genus, and Enterobacterium family in the colon. Moreover, Gln supplementation enhanced (p < 0.05) the concentrations of total protein, RNA/DNA, and total protein/DNA ratio in the longissimus dorsi muscle, the concentrations of citrulline, ornithine, arginine, and hydroxyproline, and the mRNA level of peptide transporter 1, while reducing the contents of hydrogen peroxide and malondialdehyde and the mRNA level of glutathione-S-transferase omega 2 in the longissimus dorsi muscle. In conclusion, dietary Gln supplementation can improve the intestinal function of piglets and promote the growth of the longissimus dorsi muscle.
摘要：
Selenium-enriched Cardamine violifolia (SEC), a cruciferous plant, exerts excellent antioxidant and anti-inflammatory capacity, but its effect on hepatic function is unclear. This study investigated the effect and potential mechanism of SEC on hepatic injury induced by lipopolysaccharide (LPS). Twenty-four weaned piglets were randomly allotted to treatment with SEC (0.3 mg/kgSe) and/or LPS (100 μg/kg). After 28 days of the trial, pigs were injected with LPS to induce hepatic injury. These results indicated that SEC supplementation attenuated LPS-induced hepatic morphological injury and reduced aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities in plasma. SEC also inhibited the expression of pro-inflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) after the LPS challenge. In addition, SEC improved hepatic antioxidant capacity via enhancing glutathione peroxidase (GSH-Px) activity and decreasing malondialdehyde (MDA) concentration. Moreover, SEC downregulated the mRNA expression of hepatic myeloid differentiation factor 88 (MyD88) and nucleotide-binding oligomerization domain proteins 1 (NOD1) and its adaptor molecule receptor interacting protein kinase 2 (RIPK2). SEC also alleviated LPS-induced hepatic necroptosis by inhibiting RIPK1, RIPK3, and mixed-lineage kinase domain-like (MLKL) expression. These data suggest that SEC potentially mitigates LPS-induced hepatic injury via inhibiting Toll-like receptor 4 (TLR4)/NOD2 and necroptosis signaling pathways in weaned piglets.
摘要：
Molecular docking, molecular dynamics, and in vitro experiments were used in this study to verify that baicalin inhibits monosodium urate crystal‐induced renal tubular epithelial cell pyroptosis through the NLRP3/GSDMD and Panx‐1/P2X7 pathways. Abstract Pyroptosis is a programmed cell death process that frequently occurs in many diseases, including hyperuricemic nephropathy (HN). In HN, a range of stimuli mediates inflammation, leading to the activation of inflammasomes and the production of gasdermin D (GSDMD). Baicalin (BA), a natural flavonoid renowned for its antioxidant and anti‐inflammatory properties, was investigated for its role in HN in this study. Initially, HN‐like inflammation and pyroptosis were induced in HK‐2 cells with treatment of monosodium urate (MSU), followed by the BA treatment. The expression of pyroptosis‐associated genes, Panx‐1 and P2X7, at both mRNA and protein levels was assessed through real‐time polymerase chain reaction (RT‐qPCR) and Western blotting (WB) without or with BA treatment. The results showed that expression of Panx‐1 and P2X7 at mRNA and protein levels was increased in MSU‐treated HK‐2 cells, which subsequently decreased upon the BA treatment. Further experiments showed that BA could combine NLRP3 inflammasome and GSDMD, destabilizing GSDMD protein. Moreover, BA protected the cell membrane from MSU‐induced damage, as evidenced by Hoechst 33342 and PI double staining, lactate dehydrogenase (LDH) assays, and electron microscopy observations. These results suggest that BA is involved in the regulating Panx‐1/P2X7 pathways and thus inhibits pyroptosis, highlighting its potential therapeutic effect for HN.
作者机构：
[Zhang, Qi; Ge, Feng; Yang, Mingkun; Zhao, Jindong; Jia, Kun; Liu, Xin; Cao, Gaoxiang] Chinese Acad Sci, State Key Lab Freshwater Ecol & Biotechnol, Inst Hydrobiol, Wuhan 430072, Peoples R China.;[Zhang, Qi; Ge, Feng; Yang, Mingkun; Jia, Kun; Cao, Gaoxiang] Univ Chinese Acad Sci, Coll Adv Agr Sci, Beijing 100049, Peoples R China.;[Liu, Xin] Wuhan Polytech Univ, Sch Anim Sci & Nutr Engn, Wuhan 430070, Peoples R China.;[Zhao, Jindong] Peking Univ, Coll Life Sci, State Key Lab Prot & Plant Genet Engn, Beijing 100871, Peoples R China.
通讯机构：
[Ge, F; Zhao, JD ] C;[Ge, F ] U;Chinese Acad Sci, State Key Lab Freshwater Ecol & Biotechnol, Inst Hydrobiol, Wuhan 430072, Peoples R China.;Univ Chinese Acad Sci, Coll Adv Agr Sci, Beijing 100049, Peoples R China.;Peking Univ, Coll Life Sci, State Key Lab Prot & Plant Genet Engn, Beijing 100871, Peoples R China.
摘要：
Lysine acetylation is a conserved regulatory posttranslational protein modification that is performed by lysine acetyltransferases (KATs). By catalyzing the transfer of acetyl groups to substrate proteins, KATs play critical regulatory roles in all domains of life; however, no KATs have yet been identified in cyanobacteria. Here, we tested all predicted KATs in the cyanobacterium Synechococcus sp. PCC 7002 (Syn7002) and demonstrated that A1596, which we named cyanobacterial Gcn5-related N-acetyltransferase (cGNAT2), can catalyze lysine acetylation in vivo and in vitro. Eight amino acid residues were identified as the key residues in the putative active site of cGNAT2, as indicated by structural simulation and site-directed mutagenesis. The loss of cGNAT2 altered both growth and photosynthetic electron transport in Syn7002. In addition, quantitative analysis of the lysine acetylome identified 548 endogenous substrates of cGNAT2 in Syn7002. We further demonstrated that cGNAT2 can acetylate NAD(P)H dehydrogenase J (NdhJ) in vivo and in vitro, with the inability to acetylate K89 residues, thus decreasing NdhJ activity and affecting both growth and electron transport in Syn7002. In summary, this study identified a KAT in cyanobacteria and revealed that cGNAT2 regulates growth and photosynthesis in Syn7002 through an acetylation-mediated mechanism. The cyanobacterial Gcn5-related N-acetyltransferase regulates the growth and photosynthesis of Synechococcus PCC 7002 through an acetylation-mediated mechanism.
摘要：
Glaesserella parasuis (G. parasuis) causes systemic infection in pigs, but its effects on skeletal muscle and underlying mechanisms are poorly understood. We investigated G. parasuis infection in colostrum-deprived piglets, observing decreased daily weight gain and upregulation of inflammatory factors in skeletal muscle. Muscle fiber area and diameter were significantly reduced in the treated group (n = 3) compared to the control group (n = 3), accompanied by increased expression of FOXO1, FBXO32, TRIM63, CTSL, and BNIP3. Based on mRNA and microRNA (miRNA) sequencing, we identified 1642 differentially expressed (DE) mRNAs and 19 known DE miRNAs in skeletal muscle tissues between the two groups. We predicted target genes with opposite expression patterns to the 19 miRNAs and found significant enrichment and activation of the FoxO signaling pathway. We found that the upregulated core effectors FOXO1 and FOXO4 were targeted by downregulated ssc-miR-486, ssc-miR-370, ssc-miR-615, and ssc-miR-224. Further investigation showed that their downstream upregulated genes involved in protein degradation were also targeted by the downregulated ssc-miR-370, ssc-miR-615, ssc-miR-194a-5p, and ssc-miR-194b-5p. These findings suggest that G. parasuis infection causes skeletal muscle atrophy in piglets through accelerated protein degradation mediated by the "miRNAs-FOXO1/4" axis, while further research is necessary to validate the regulatory relationships. Our results provide new insights into the understanding of systemic inflammation growth mechanisms caused by G. parasuis and the role of miRNAs in bacterial infection pathogenesis.
摘要：
Solid‐state fermentation of faba bean (Vicia faba L.) meal. Summary Solid‐state fermentation (SSF) is widely used to improve the utility value in the food and feed industries. In the present research, Lactobacillus plantarum and Saccharomycopsis fibuligera were used for SSF, and then, the nutritional values, anti‐nutritional factors (ANFs) and antioxidant activities of faba bean meal (FBM) were comparatively analysed. The results revealed that SSF with S. fibuligera and L. plantarum effectively reduce the tannin and phytic acid contents and improve the nutritional quality and antioxidant capacity in FBM. Meanwhile, the effects of SSF with L. plantarum on degrading tannin and increasing titratable acidity, trichloroacetic acid‐soluble protein and in vitro protein digestibility were better treated with S. fibuligera. However, antioxidant activities and the amount of phenol and flavonoid were improved more in FBM treated with S. fibuligera than those fermented with L. plantarum. Taken together, the results indicated that both L. plantarum and S. fibuligera could be used for SSF of FBM, and SSF with those two microorganisms has great potential in improving the nutritional values, antioxidant capacities and decreasing ANFs contents of FBM.
摘要：
The purpose of this study was to determine the efficacy of tannic acid on the antioxidative function, immunity, and intestinal barrier of broilers co-infected with coccidia and Clostridium perfringens (CCP). A total of 294 1-day-old arbor acres(AA) broilers were divided into three groups: control group (CON), CCP co-infected group (CCP), and 1000 mg/kg TA + CCP co-infected group (CTA). This trial lasted for 28 days. The results showed that the CCP group decreased the activity of glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), catalase (CAT), and total antioxidant capacity (T-AOC) levels and increased the contents of hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) in the jejunum (p < 0.05). The mRNA levels of GSH-Px3 and CAT in the liver and jejunum, and the mRNA levels of GSH-Px3, SOD, HO-1, and NAD(P)H quinone oxidoreductase I (NQO1) in the liver were down-regulated by CCP challenge (p < 0.05). In addition, the Keap1 and Nrf2 mRNA levels in the liver and jejunum, jejunal glutathione S-transferase (GST), and heme-oxygenase-1 (HO-1) were upregulated in the CCP group compared with CON (p < 0.05). The mRNA levels of interleukin 8 (IL-8), IL-1β, inducible nitric oxide synthase (iNOS), and interferon γ (IFN-γ) in the jejunum were elevated, and jejunal mRNA levels of IL-10, zonula occludens protein1 (ZO-1), claudin-1, claudin-2, and occludin were decreased in the CCP treatment (p < 0.05). Dietary supplementation with 1000 mg/kg TA increased the activity of GSH-Px, T-SOD, CAT, and T-AOC and decreased the contents of H(2)O(2) and MDA in the jejunum (p < 0.05). Compared with the CCP group, TA decreased the mRNA level of Keap1 and Nrf2 in the liver and jejunum, increased the GSH-Px3, SOD, and CAT mRNA in the liver, and alleviated the rise of IL-8, IL-1β, iNOS, and IFN-γ and decrease in IL-10, occludin gene expression in the jejunum (p < 0.05). In conclusion, the addition of 1000 mg/kg TA to the diet improved the jejunal barrier, mitigated the jejunal inflammation, and increased the antioxidant capacity of the liver and jejunum through the activation of the transcription factor Nrf2 downstream of the Nrf2-Keap1 pathway in broilers with NE condition.
摘要：
Protein homeostasis is essential for cyanobacteria to maintain proper cellular function under adverse and fluctuating conditions. The AAA+ superfamily of proteolytic complexes in cyanobacteria plays a critical role in this process, including ClpXP, which comprises a hexameric ATPase ClpX and a tetradecameric peptidase ClpP. Despite the physiological effects of ClpX on growth and photosynthesis, its potential substrates and underlying mechanisms in cyanobacteria remain unknown. In this study, we employed a streptavidin-biotin affinity pull-down assay coupled with label-free proteome quantitation to analyze the interactome of ClpX in the model cyanobacterium Synechocystis sp. PCC 6803 (hereafter Synechocystis). We identified 503 proteins as potential ClpX-binding targets, many of which had novel interactions. These ClpX-binding targets were found to be involved in various biological processes, with particular enrichment in metabolic processes and photosynthesis. Using protein-protein docking, GST pull-down, and biolayer interferometry assays, we confirmed the direct association of ClpX with the photosynthetic proteins, ferredoxin-NADP(+) oxidoreductase (FNR) and phycocyanin subunit (CpcA). Subsequent functional investigations revealed that ClpX participates in the maintenance of FNR homeostasis and functionality in Synechocystis grown under different light conditions. Overall, our study provides a comprehensive understanding of the extensive functions regulated by ClpX in cyanobacteria to maintain protein homeostasis and adapt to environmental challenges.
摘要：
Contamination with fumonisin B1 (FB1) represents a global health problem. FB1 exposure may also trigger intestinal injury by activating inflammatory responses, leading to a reduction in production performance and economic benefits. However, the mechanism of FB1-induced intestinal inflammatory injury is still unclear. At the same time, it is urgent to develop antibiotic alternatives and therapeutic targets to alleviate antibiotic resistance and to ensure effective treatment of intestinal inflammatory injury. We combined network pharmacology and in vitro experiments to explore the core therapeutic targets and potential mechanism of luteolin in FB1-induced intestinal inflammatory injury. Network pharmacology and molecular docking revealed that nuclear factor kappa B (NF-kappa B) p65, extracellular signal-regulated kinase (ERK), interleukin 6 (IL-6) and IL-1 beta are the important targets, and the NF-kappa B and ERK signalling pathways are critical in FB1-induced intestinal inflammatory injury. Besides, in vitro experiments further demonstrated that luteolin can inhibit FB1-induced intestinal inflammatory injury by inhibiting activation of the NF-kappa B and ERK signalling pathways and reducing the expression of IL-6 and IL-1 beta in IPEC-J2 cells. We have comprehensively illustrated the potential targets and molecular mechanism by which luteolin can alleviate FB1-induced intestinal inflammatory injury. Luteolin may be an effective antibiotic alternative to prevent intestinal inflammatory injury.
