Metagenomics Reveals That Proper Placement After Long-Distance Transportation Significantly Affects Calf Nasopharyngeal Microbiota and Is Critical for the Prevention of Respiratory Diseases

Transportation is an inevitable phase for the cattle industry, and its effect on the respiratory system of transported cattle remains controversial. To reveal cattle’s nasopharyngeal microbiota dynamics, we tracked a batch of beef calves purchased from an auction market, transported to a farm by vehicle within 3 days, and adaptively fed for 7 days. Before and after the transport and after the placement, a total of 18 nasopharyngeal mucosal samples were collected, and microbial profiles were obtained using a metagenomic shotgun sequencing approach. The diversity, composition, structure, and function of the microbiota were collected at each time point, and their difference was analyzed. The results showed that, before the transportation, there were a great abundance of potential bovine respiratory disease (BRD)-related pathogens, and the transportation did not significantly change their abundance. After the transportation, 7 days of placement significantly decreased the risk of BRD by decreasing the abundance of potential BRD-related pathogens even if the diversity was decreased. We also discussed the controversial results of transportation’s effect in previous works and the decrease in diversity induced by placement. Our work provided more accurate information about the effect of transportation and the followed placement on the calf nasopharyngeal microbial community, indicated the importance of adaptive placement after long-distance transport, and is helpful to prevent BRD induced by transportation stress.

Copper exposure induces hepatic G0/G1 cell-cycle arrest through suppressing the Ras/PI3K/Akt signaling pathway in mice

Copper (Cu), as a common chemical contaminant in environment, is known to be toxic at high concentrations. The current research demonstrates the effects of copper upon hepatocyte cell-cycle progression (CCP) in mice. Institute of cancer research (ICR) mice (n = 240) at an age of four weeks were divided randomly into groups treated with different doses of Cu (0, 4, 8, and 16 mg/kg) for 21 and 42 days. Results showed that high Cu exposure caused hepatocellular G0/G1 cell-cycle arrest (CCA) and reduced cell proportion in the G2/M phase. G0/G1 CCA occurred with down-regulation (p < 0.05) of Ras, p-PI3K (Tyr458), p-Akt (Thr308), p-forkhead box O3 (FOXO3A) (Ser253), p-glycogen synthase kinase 3-β (GSK3-β) (Ser9), murine double minute 2 (MDM2) protein, and mRNA expression levels, and up-regulation (p < 0.05) of PTEN, p-p53 (Ser15), p27, p21 protein, and mRNA expression levels, which subsequently suppressed (p < 0.05) the protein and mRNA expression levels of CDK2/4 and cyclin E/D. These results indicate that Cu exposure suppresses the Ras/PI3K/Akt signaling pathway to reduce the level of CDK2/4 and cyclin E/D, which are essential for the G1-S transition, and finally causes hepatocytes G0/G1 CCA.

Quinolone Resistance of Actinobacillus pleuropneumoniae Revealed through Genome and Transcriptome Analyses

Actinobacillus pleuropneumoniae is a pathogen that infects pigs and poses a serious threat to the pig industry. The emergence of quinolone-resistant strains of A.pleuropneumoniae further limits the choice of treatment. However, the mechanisms behind quinolone resistance in A.pleuropneumoniae remain unclear. The genomes of a ciprofloxacin-resistant strain, A. pleuropneumoniae SC1810 and its isogenic drug-sensitive counterpart were sequenced and analyzed using various bioinformatics tools, revealing 559 differentially expressed genes. The biological membrane, plasmid-mediated quinolone resistance genes and quinolone resistance-determining region were detected. Upregulated expression of efflux pump genes led to ciprofloxacin resistance. The expression of two porins, OmpP2B and LamB, was significantly downregulated in the mutant. Three nonsynonymous mutations in the mutant strain disrupted the water–metal ion bridge, subsequently reducing the affinity of the quinolone–enzyme complex for metal ions and leading to cross-resistance to multiple quinolones. The mechanism of quinolone resistance in A. pleuropneumoniae may involve inhibition of expression of the outer membrane protein genes ompP2B and lamB to decrease drug influx, overexpression of AcrB in the efflux pump to enhance its drug-pumping ability, and mutation in the quinolone resistance-determining region to weaken the binding of the remaining drugs. These findings will provide new potential targets for treatment.

Protective effect of MitoQ on oxidative stress-mediated senescence of canine bone marrow mesenchymal stem cells via activation of the Nrf2/ARE pathway

The destruction of biological activity such as senescence and apoptosis caused by oxidative stress could play a pivotal role in the poor therapeutic efficiency of bone marrow mesenchymal stem cells (BMSCs) transplantation. Mitoquinone (MitoQ) has a highly effective mitochondrial antioxidant effect, and has been widely used in many oxidative damage models. This study aimed to investigate the protective effect of MitoQ on the oxidative stress-mediated senescence of canine BMSCs and the underlying mechanism. The senescence of BMSCs was determined by senescence-associated β-galactosidase staining and quantitative real-time PCR. The expression of p-Nrf2 protein was detected by Western blotting. The results demonstrated that, as BMSCs were expanded in vitro, the senescent phenotype appeared. And the senescence of BMSCs may be caused by oxidative stress, manifested by increasing the level of ROS and decreasing the activity of antioxidant enzymes. Treatment of MitoQ down-regulated the mRNA levels of senescence-related and apoptosis-related genes, but up-regulated the mRNA levels of proliferation-related genes. Meanwhile, ROS generation and senescent activity were reduced in MitoQ-treated BMSCs. Further mechanism studies showed that MitoQ obviously promoted Nrf2 phosphorylation, and also facilitated the translocation of Nrf2 into the nucleus. Moreover, treatment of MitoQ increased the mRNA levels of downstream antioxidant genes and enhanced the activities of superoxide dismutase, catalase, and glutathione peroxidase. Thus, our study revealed that MitoQ, via the Nrf2/ARE signaling pathway, exerts an antioxidant effect as well as potentially delays OS-mediated senescence during BMSCs that were expanded in vitro, which may serve as a novel strategy to optimize the clinical application of BMSCs.

Cu-induced spermatogenesis disease is related to oxidative stress-mediated germ cell apoptosis and DNA damage

Copper is considered as an indispensable trace element for living organisms. However, over-exposure to Cu can lead to adverse health effects on human. In this study, CuSO₄ decreased sperm concentration and motility, increased sperm malformation rate. Concurrently, testicular damage including testicular histopathological aberrations and reduction of testis relative weight were observed. Then, the mechanism underlying Cu-induced testicular toxicity was explored. According to the results, CuSO₄ elevated ROS production while reducing antioxidant function. Additionally, CuSO₄ induced apoptosis which was featured by MMP depolarization and up-regulated levels of cleaved-caspase-3, cleaved-caspase-8, cleaved-caspase-9, caspase-12, cleaved-PARP and Bax, whereas down-regulated Bcl-2 expression. Meanwhile, CuSO₄ caused testis DNA damage (up-regulation of γ-H2AX protein expression) and suppressed DNA repair pathways including BER, NER, HR, MMR, together with the NHEJ repair pathways, yet did not affect MGMT. To investigate the role of oxidative stress in CuSO₄-induced apoptosis and DNA damage, the antioxidant NAC was co-treated with CuSO₄. NAC attenuated CuSO₄-induced ROS production, inhibited apoptosis and DNA damage. Furthermore, the spermatogenesis disorder was also abolished in the co-treatment with CuSO₄ and NAC group. Altogether, abovementioned results indicated that CuSO₄-induced spermatogenesis disorder is related to oxidative stress-mediated DNA damage and germ cell apoptosis, impairing male reproductive function.

Characterization of serum adiponectin and leptin in healthy perinatal dairy cows or cows with ketosis, and their effectson ketosis involved indices

We investigated changes in concentrations of ADP (adiponectin), LEP (leptin), BHBA (beta-hydroxybutyric acid), NEFA (non-esterified fatty acid), Glucose (Glu) and INS (insulin) in serum of healthy perinatal dairy cows and cows with ketosis. Twenty-one healthy cows and seventeen cows with ketosis from a herd of a total 60 Holstein cows (near dry period i.e. 56 days antepartum) were selected. Blood was collected through the tail vein every 7 days, from 56 day antepartum to 56 day postpartum. Serum ADP, LEP, BHBA, NEFA, Glu, and INS concentrations were determined, and ketosis was diagnosed through serum BHBA (≥1.2 mmol/L). We showed the concentration of serum adipokines and energy balancing indices were stable during antepar- tum period. However, ADP concentration increased while LEP decreased, and there were a significant increase in cows with ketosis compared to that of in healthy cows. Serum BHBA and NEFA concentrations increased significantly at first, and then gradually decreased in both healthy cows and cows with ketosis. However, cows with ketosis showed higher concentrations of BHBA and NEFA which restored later. The serum concentration of Glu in both healthy dairy cows and cows with ketosis showed a decreasing trend. INS concentration in healthy cows was decreased while it was increased in cows with ketosis. The results reflect the extent of hypo- glycemia and lipid mobilization postpartum, suggest IR exists in cows with ketosis while serum ADP and LEP might play roles in the development of ketosis.

Skin Microbiota of the Captive Giant Panda (Ailuropoda Melanoleuca) and the Distribution of Opportunistic Skin Disease-Associated Bacteria in Different Seasons

The giant panda is one of the rarest animals in the world. Skin diseases seriously endanger the health of giant panda and are considered the second major cause of its morbidity. Skin microbiota is a complex ecosystem, and the community structure and the pathogenic potential of bacteria on giant panda skin remain largely unclear. In order to understand the skin bacterial flora of captive giant pandas, the microbiota in giant panda skin samples collected during different seasons was profiled via 16S rRNA gene sequencing. In total, 522 genera from 53 bacterial phyla were detected, with Proteobacteria (40.5%), Actinobacteria (23.1%), Firmicutes (21.1%), Bacteroidetes (9.5%), Cyanobacteria (2.1%), and Thermi (1.2%) as the predominant phyla and Streptococcus (13.9%), Acinetobacter (9.2%), Staphylococcus (2.9%), Pseudomonas (5.9%), Dermacoccus (4.8%), Brachybacterium (2.9%), Escherichia (2.7%), Chryseobacterium (2.1%), Arthrobacter (1.6%), Kocuria (1.5%), Psychrobacter (1.2%), Deinococcus (1.1%), and Flavobacterium (1.1%) as the predominant genera. The results indicated that the diversity was lower in winter than in other seasons and higher in autumn than in other seasons, and the abundance in spring was significantly higher than that in other seasons. Several skin disease-associated bacteria were detected as opportunists in the skin microbiota of healthy giant pandas. In this study, the results indicated that the high diversity and abundance of the skin bacteria may have enhanced the occurrence of skin disease in autumn and spring and that skin disease-associated bacteria are the normal components of the skin microbiota.

Resistin, a Novel Host Defense Peptide of Innate Immunity

Resistin, a cysteine-rich protein, expressed in adipocytes, was initially proposed as a link between obesity and diabetes in mice. In humans, resistin is considered to be a pro-inflammatory molecule expressed in immune cells, which plays a regulatory role in many chronic inflammatory diseases, metabolic diseases, infectious diseases, and cancers. However, increasing evidence shows that resistin functions as a host defense peptide of innate immunity, in terms of its wide-spectrum anti-microbial activity, modulation of immunity, and limitation of microbial product-induced inflammation. To date, the understanding of resistin participating in host defense mechanism is still limited. The review aims to summarize current knowledge about the biological properties, functions, and related mechanisms of resistin in host defense, which provides new insights into the pleiotropic biological function of resistin and yields promising strategies for developing new antimicrobial therapeutic agents.

TGF-β1-induced EMT activation via both Smad-dependent and MAPK signaling pathways in Cu-induced pulmonary fibrosis

Copper (Cu) is considered as an essential trace element for living organisms. However, over-exposure to Cu can lead to adverse health effects on human and animals. There are limited researches on pulmonary toxicity induced by Cu. Here, we found that copper sulfate (CuSO4)-treatment could induce pulmonary fibrosis with Masson staining and up-regulated protein and mRNA expression of Collagen I and α-Smooth Muscle Actin (α-SMA) in mice. Next, the mechanism underlying Cu-induced pulmonary fibrosis was explored, including transforming growth factor-β1 (TGF-β1)-mediated Smad pathway, mitogen-activated protein kinases (MAPKs) pathway and epithelial-mesenchymal transition (EMT). CuSO4 triggered pulmonary fibrosis by activation of the TGF-β1/Smad pathway, which was accomplished by increasing TGF-β1, p-Smad2 and p-Smad3 protein and mRNA expression levels. Also, up-regulated protein and mRNA expression of p-JNK, p-ERK, and p-p38 demonstrated that CuSO4 activated MAPKs pathways. Concurrently, EMT was activated by increasing vimentin and N-cadherin while decreasing E-cadherin protein and mRNA expression levels. Altogether, the abovementioned findings indicate that CuSO4 treatment may induce pulmonary fibrosis through the activation of EMT induced by TGF-β1/Smad pathway and MAPKs pathways, revealing the mechanism Cu-caused pulmonary toxicity.

Effects of Selenium on Arsenic-Induced Liver Lesions in Broilers

The aim of the present study was to investigate the abilities of selenium to counteract the toxic damage of arsenic (As). Two hundred 1-day-old healthy male broilers were randomly divided into five groups and fed the following diets: control group (0.1 mg/kg As + 0.2 mg/kg Se), As group (3 mg/kg As + 0.2 mg/kg Se), As + Se group I (3 mg/kg As + 5 mg/kg Se), As + Se group II (3 mg/kg As + 10 mg/kg Se), and As + Se group III (3 mg/kg As + 15 mg/kg Se), respectively. The relative weight of the liver, hepatic protein content, GSH-Px levels, SOD activities, NO contents, iNOS and tNOS activities, and increased malondialdehyde contents, ALT and AST activities, and the apoptotic hepatocytes were analyzed. Adding 3 mg/kg arsenic to the diet caused the growth and development of chicken liver to be blocked, resulting in decrease of protein contents in liver tissue, decrease of SOD and GSH-Px activities, increase of MDA contents, decrease of NO contents, decrease of iNOS and TNOs activities, increase of ALT and AST activities, increase of apoptosis rates of liver cells. Compared to the 3-mg/kg arsenic group, adding 5 mg/kg and 10 mg/kg selenium, respectively, could repair the liver growth retardation and steatosis caused by arsenic, increase the protein contents in liver tissue, increase the activities of SOD and GSH-Px, reduce the contents of MDA, increase the contents of NO, enhance the activities of iNOS and TNOs, reduce the activities of ALT and AST, and reduce the rates of apoptosis of liver cells, in which the best effects are to add 10 mg/kg selenium. While 15 mg/kg of sodium selenite may induce progression of As-induced hepatic lesions, the results indicated that 5 and 10 mg/kg of sodium selenite supplied in the diet, through mechanisms of oxidative stress and apoptosis regulation, may ameliorate As-induced hepatic lesions in a dose-dependent manner.

The complete mitochondrial genome of the beef cattle hookworm Bunostomum phlebotomum (Nematoda: Bunostominae)

The bovine hookworm Bunostomum phlebotomum (Nematoda: Bunostominae) is a blood-feeding nematode with important socioeconomic impact in the cattle breeding industry. In the present study, the complete mitochondrial genome sequence of a representative individual of B. phlebotomum from beef cattle in Southwest China was determined using the next generation sequencing technology. The genome was 13,799 bp in size and encoded 12 protein-coding genes, 22 tRNA genes and two rRNA genes. The phylogeny revealed that although B. phlebotomum from Chinese beef cattle and yaks were more closely related to each other than to that from Australian cows, these three bovine-originated B. phlebotomum grouped together and formed paraphyletic relationships with Bunostomum trigonocephalum (goat/sheep hookworm) and Necator americanus (human hookworm), supporting their sister-species relationships within Bunostominae. The cumulative mitochondrial DNA data provides a better understanding of phylogenetic relationships of this species in cattle.

Metagenomics Reveals That Intravenous Injection of Beta-Hydroxybutyric Acid (BHBA) Disturbs the Nasopharynx Microflora and Increases the Risk of Respiratory Diseases

It is widely accepted that maintenance of microbial diversity is essential for the health of the respiratory tract; however, there are limited reports on the correlation between starvation and respiratory tract microbial diversity. In the present study, saline/β-hydroxybutyric acid (BHBA) intravenous injection after dietary restriction was used to imitate different degrees of starvation. A total of 13 healthy male yaks were imposed to different dietary restrictions and intravenous injections, and their nasopharyngeal microbiota profiles were obtained by metagenomic shotgun sequencing. In healthy yaks, the main dominant phyla were Proteobacteria (33.0%), Firmicutes (22.6%), Bacteroidetes (17.2%), and Actinobacteria (13.2%); the most dominated species was Clostridium botulinum (10.8%). It was found that 9 days of dietary restriction and 2 days of BHBA injection (imitating severe starvation) significantly decreased the microbial diversity and disturbed its structure and functional composition, which increased the risk of respiratory diseases. This study also implied that oral bacteria played an important role in maintaining nasopharynx microbial homeostasis. In this study, the correlation between starvation and nasopharynx microbial diversity and its potential mechanism was investigated for the first time, providing new ideas for the prevention of respiratory diseases.

Nickel carcinogenesis mechanism: cell cycle dysregulation

Nickel (Ni) is a widely distributed metal in the environment and an important pollutant due to its widespread industrial applications. Ni has various toxicity in humans and experimental animals, including carcinogenicity. However, the carcinogenic effects of Ni remain troublesome. Cell cycle dysregulation may be an important carcinogenic mechanism and is also a potential molecular mechanism for Ni complexes anti-cancerous effects. Therefore, we conducted a literature review to summarize the effects of Ni on cell cycle. Up to now, there were three different reports on Ni-induced cell cycle arrest: (i) Ni can induce cell cycle arrest in G0/G1 phase, phosphorylation and degradation of IkappaB kinase-alpha (IKKα)-dependent cyclin D1 and phosphoinositide-3-kinase (PI3K)/serine-threonine kinase (Akt) pathway-mediated down-regulation of expressions of cyclin-dependent kinases 4 (CDK4) play important role in it; (ii) Ni can induce cell cycle arrest in S phase, but the molecular mechanism is not known; (iii) G2/M phase is the target of Ni toxicity, and Ni compounds cause G2/M cell cycle phase arrest by reducing cyclinB1/Cdc2 interaction through the activation of the ataxia telangiectasia mutated (ATM)-p53-p21 and ATM-checkpoint kinase inhibitor 1 (Chk1)/Chk2-cell division cycle 25 (Cdc25) pathways. Revealing the mechanisms of cell cycle dysregulation associated with Ni exposure may help in the prevention and treatment of Ni-related carcinogenicity and toxicology.

Vitamin E protects against cadmium-induced sub-chronic liver injury associated with the inhibition of oxidative stress and activation of Nrf2 pathway

Hepatic oxidative stress, as one important mechanism of cadmium (Cd)-induced hepatic toxicity, could, as known, be ameliorated by vitamin E (VE). However, the underlying mechanism remains to be elucidated. To investigate whether the antioxidant vitamin E can protect against Cd-induced sub-chronic liver injury associated with oxidative stress and nuclear factor erythrocyte 2-related factor 2 (Nrf2) pathway, male Sprague-Dawley rats (nine-week-old) were randomly divided into four groups (eight rats/group), namely, control, VE (100 mg/kg VE), Cd (5 mg/kg CdCl₂) and VE+Cd (100 mg/kg VE+5 mg/kg CdCl₂), and received intragastric administration of Cd and/or VE for four weeks. Cd-exposure alone resulted in reduced liver weight, liver histological alteration and oxidative stress, accumulation of Cd in the liver, elevated ALT and AST concentrations in serum together with decreased mRNA and protein expressions of Nrf2 pathway related molecules (Nrf2, HO-1, NQO-1, GCLC, GCLM and GST). However, the co-treatment of Cd and VE significantly ameliorated the changes mentioned above, and promoted the expression of genes and proteins of Nrf2 pathway related molecules in comparison to the Cd-exposure alone. Our results indicate that the protective effect of VE against Cd-induced sub-chronic hepatic damage in rats is associated with the inhibition of oxidative stress and activation of Nrf2 pathway.

Copper induces hepatocyte autophagy via the mammalian targets of the rapamycin signaling pathway in mice

Although copper is among the indispensable trace elements in animal physiological processes, it exerts toxicity upon over-exposure. The present study aimed to investigate hepatocyte autophagy induced by CuSO₄ and its potential mechanism. A total of 240 ICR mice (four-week-old, 120 males and 120 females) were randomly divided into four groups, in which mice separately received 0, 4, 8, and 16 mg/kg of Cu (Cu²⁺-CuSO₄) for 42 d. The results of increased autophagosomes and autophagy marker LC3B brown cell staining showed that excessive intake of Cu enhanced hepatocyte autophagy. Simultaneously, Cu inhibited the activity of mTOR through suppressing mRNA and protein expressions in mTOR, which in turn up-regulated expression levels of ULK1 and initiated autophagy. Also, over-exposure to Cu increased mRNA and protein expressions of Beclin1, Atg12, Atg5, Atg16L1, Atg7, Atg3, and LC3 and decreased mRNA and protein expressions of p62. These results indicate that excess Cu can enhance hepatocyte autophagy via inhibiting the mTOR signaling pathway and regulating mRNA and protein expressions of factors implicated to autophagy in mice.

Relationships between placental adiponectin, leptin, visfatin and resistin and birthweight in cattle

Adipokines can affect intrauterine development while calf birthweight (CBW) is a breeding standard of calves, which reflects the status of fetal intrauterine development. To explore the correlation between placental adipokines and CBW, 54 healthy Chinese Holstein cows were used in the present study. The cows were grouped according to the CBW of their calves. Placentas were collected immediately after delivery and enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction were used to detect the placental expression levels of adiponectin, leptin, visfatin and resistin. Our results show that the mRNA transcription and blood placental content of adiponectin, leptin, visfatin and resistin increased with increasing CBW. The analysis showed that the mRNA transcription levels of placental adiponectin, leptin and resistin were positively correlated with CBW. The mRNA and protein expression levels of adiponectin, leptin and visfatin between the three groups were significantly correlated. Placental resistin mRNA levels correlated positively with adiponectin mRNA, but not leptin or visfatin. The protein expression levels of resistin were significantly positively correlated with those of adiponectin, leptin and visfatin. These results suggest that placental adipokines play important roles in regulating calf intrauterine growth.

Complete genome analysis of Vibrio mimicus strain SCCF01, a highly virulent isolate from the freshwater catfish

Vibrio mimicus is a foodborne pathogen, which is widely distributed in the aquatic environment. Moreover, it is often involved in aquatic animal diseases. In recent years, V. mimicus is an emerging pathogen in some species of Siluriformes. The strain SCCF01 was isolated from yellow catfish (Pelteobagrus fulvidraco). In this study, we aimed to perform genomic analysis of V. mimicus strain SCCF01 to identify genetic features and evolutionary relationships. Information on gene function and classification was obtained by functional annotation, and circular graph of strain SCCF01 genome, which was created by Circos v0.64. Information on virulence genes (adhesion, flagellum system, exotoxin, and secretory system, etc.) was obtained by virulence genes annotation. Genome element prediction showed that most of the mobile elements were distributed in chromosome I. Therefore, chromosome I of SCCF01 genome has more plasticity than chromosome II and might be larger in size. Genomic linear relationship between the strain of V. mimicus and strain SCCF01 was analyzed by linear pairwise comparison but was unable to determine the relationship. Gene family analysis predicted that the evolutionary direction of strain SCCF01 was: clinical strain → environmental strain → SCCF01 strain. Phylogenetic analysis showed that the strain SCCF01 was more closely related to environmental strains. According to gene family analysis and phylogenetic analysis, we speculated that strain SCCF01 has probably diverged from environmental strains.

Autophagy: a promising therapeutic target for improving mesenchymal stem cell biological functions

Mesenchymal stem cells (MSCs) are considered to be a promising therapeutic material due to their capacities for self-renewal, multilineage differentiation, and immunomodulation and have attracted great attention in regenerative medicine. However, MSCs may lose their biological functions because of donor age or disease and environmental pressure before and after transplantation, which hinders the application of MSC-based therapy. As a major intracellular lysosome-dependent degradative process, autophagy plays a pivotal role in maintaining cellular homeostasis and withstanding environmental pressure and may become a potential therapeutic target for improving MSC functions. Recent studies have demonstrated that the regulation of autophagy is a promising approach for improving the biological properties of MSCs. More in-depth investigations about the role of autophagy in MSC biology are required to contribute to the clinical application of MSCs. In this review, we focus on the role of autophagy regulation by various physical and chemical factors on the biological functions of MSCs in vitro and in vivo, and provide some strategies for enhancing the therapeutic efficacy of MSCs.

Nocardia seriolae: a serious threat to the largemouth bass Micropterus salmoides industry in Southwest China

Nocardia seriolae is the causative agent of nocardiosis in both marine and freshwater fish. Here, we report on multiple outbreaks of nocardiosis associated with elevated mortality (23-35%) in farmed largemouth bass in Sichuan, China, from 2017 to 2018. A total of 9 strains isolated from diseased largemouth bass were identified as N. seriolae by phenotypic characterization, 16S rRNA and hsp65 gene sequence analysis. The clinical signs of infected largemouth bass included hemorrhage, skin ulcers and prominent tubercles varying in size in the gill, liver, spleen and kidney. Experimental infection indicated that these isolates were the pathogens responsible for the mortalities. In vitro antibacterial activities of 12 antibiotics against N. seriolae isolates were determined as minimum inhibitory concentrations. Histopathological observation of diseased fish infected with N. seriolae showed necrotizing granulomatous hepatitis, nephritis, splenitis, epithelial hypertrophy and hyperplasia with degenerative changes of the epithelium in the gill. Large quantities of bacterial aggregates were found in the necrotic area of the granuloma by Lillie-Twort Gram stain and immunocytochemistry. Our findings indicated that N. seriolae is a serious threat to the largemouth bass Micropterus salmoides industry in Southwest China.

Extensible artificial intelligence model predicts post-ablation AF recurrence using coronary sinus electrogram

Background

Atrial fibrillation (AF) is a major public health problem with significant adverse outcomes and catheter ablation is a widely adopted treatment. The CABANA trial showed that catheter ablation reduced AF recurrence to a greater extent than medications. However, some of patients who underwent this procedure still experience relapse. Here, we present an innovative way to identify this subgroup using an artificial intelligence (AI) -assisted coronary sinus electrogram.

Hypothesis

Our hypothesis is that credible features in the electrogram can be extracted by AI for prediction, therefore rigorous drug administration, close follow-up or potential second procedure can be applied to these patients.

Methods

67 patients from two independent hospitals (SPH & ZSH) with non-valvular persistent AF undergoing circumferential pulmonary vein isolation were enrolled in this study, 23 of which experienced recurrence 6 months after the procedure. We collected standard 2.5-second fragments of coronary sinus electrogram from ENSITE NAVX (SPH) and Carto (ZSH)system before the ablation started. A total of 1429 fragments were obtained and a transfer learning-based ResNet model was employed in our study. Fragments from ZSH were used for training and SPH for validation of deep convolutional neural networks (DCNN). The AI model performance was evaluated by accuracy, recall, precision, F-Measure and AUC.

Results

The prediction accuracy of the DCNN in single center reached 96%, while that in different ablation systems reached 74.3%. Also, the algorithm yielded values for the AUC, recall, precision and F-Measure of 0.76, 86.1%, 95.9% and 0.78, respectively, which shows satisfactory classification results and extensibility in different cardiology centers and brands of electroanatomic mapping instruments.

Conclusions

Our work has revealed the potential intrinsic correlation between coronary sinus electrical activity and AF recurrence using DCNN-based model. Moreover, the DCNN model we developed shows great prospects in the relapse prediction for personalized post-procedural management.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The National Natural Science Foundation of China

Immunotoxicity of nickel: Pathological and toxicological effects

Nickel (Ni) is a widely distributed metal in the environment and an important pollutant because of its many industrial applications. With increasing incidences of Ni contamination, Ni toxicity has become a global public health concern and recent evidence suggests that Ni adversely affects the immune system. Hence, this paper reviews the literature on immune-related effects of Ni exposure, the immunotoxicological effects of Ni, and the underlying mechanism of Ni immunotoxicity. The main focus was on the effect of Ni on the development of organs of immune system, lymphocyte subpopulations, cytokines, immunoglobulins, natural killer (NK) cells, and macrophages. Moreover, Ni toxicity also induces inflammation and several studies demonstrated that Ni could induce immunotoxicity. Excessive Ni exposure can inhibit the development of immune organs by excessively inducing apoptosis and inhibiting proliferation. Furthermore, Ni can decrease T and B lymphocytes, the specific mechanism of which requires further research. The effects of Ni on immunoglobulin A (IgA), IgG, and IgM remain unknown and while Ni inhibited IgA, IgG, and IgM levels in an animal experiment, the opposite result was found in research on humans. Ni inhibits the production of cytokines in non-inflammatory responses. Cytokine levels increased in Ni-induced inflammation responses, and Ni activates inflammation through toll like (TL)4-mediated nuclear factor-κB (NF-κB) and signal transduction cascades mitogen-activated protein kinase (MAPK) pathways. Ni has been indicated to inactivate NK cells and macrophages both in vitro and in vivo. Identifying the mechanisms underlying the Ni-induced immunotoxicity may help to explain the growing risk of infections and cancers in human populations that have been exposed to Ni for a long time. Such knowledge may also help to prevent and treat Ni-related carcinogenicity and toxicology.

Copper induces hepatic inflammatory responses by activation of MAPKs and NF-κB signalling pathways in the mouse

The present study investigated the expressions of signalling molecules and inflammatory cytokines involved in copper-induced inflammatory responses of the mouse liver. A total of 240 institute of cancer research (ICR) mice (half male and half female) aged four weeks were randomly allocated to four groups treated with 0, 4, 8, and 16 mg/kg of [Cu] (Cu²⁺-CuSO₄) for 42 days, respectively. [Cu] exceeding 4 mg/kg was found to induce inflammatory responses of the liver. Results showed significant up-regulation of mRNA and protein levels of apoptosis signal-regulating kinase 1 (ASK1), mitogen-activated protein kinase kinases 3/6 (MEK3/6), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (p38 MAPK), mitogen-activated protein kinase kinases 4/7 (MEK4/7), mitogen-activated protein kinase kinases 1/2 (MEK1/2), and extracellular signal-regulated protein kinases 1/2 (Erk1/2) due to Cu. By doing so, copper could activate the mitogen-activated protein kinases (MAPKs) signalling pathway. Concurrently, the nuclear factor-kappa B (NF-κB) signalling pathway was also activated in the Cu-treatment, as demonstrated by higher expressions of NF-κB and cyclooxygenase-2 (COX-2), activities of inducible nitric oxide synthase (iNOS), contents of nitric oxide (NO) and prostaglandin E2 (PGE2), and reducing levels of expression of inhibitory kappa B (IκB). High Cu intake also up-regulated expression levels of some pro-inflammatory mediators such as interleukin-2 (IL-2), interleukin-1β (IL-1β), and interleukin-8 (IL-8), and down-regulated the levels of expression of transforming growth factor beta (TGF-β), an anti-inflammatory mediator. Additionally, our results indicated that Cu caused hepatic dysfunction, with evidence of occurrence of histopathological lesions and higher serum activities of alkaline phosphatase (AKP), aspartic acid transferase (AST), alanine amino transferase (ALT), and gamma-glutamyl transpeptidase (GGT), contents of albumin (ALB) and total bilirubin (TBIL). Altogether, the aforementioned results indicate that [Cu], at more than 4 mg/kg, induces the inflammatory responses in the liver via NF-κB and MAPKs signalling pathways, subsequently inducing hepatic dysfunction.

Characterization and genomic analysis of a ranavirus associated with cultured black-spotted pond frogs (Rana nigromaculata) tadpoles mortalities in China

Ranaviruses are globally emerging pathogens causing mass mortality in both farmed and wild populations. In this study, we confirmed that a novel ranavirus was related to mass die-offs of black-spotted pond frogs (Rana nigromaculata) in Sichuan Province, China. Histological examination revealed marked degeneration or necrosis in parenchymatous organs, and intracytoplasmic inclusions can be observed in the liver and intestine cells. The virus was isolated from diseased tadpoles (tentatively named the virus as RNRV), and the ranavirus-like particles could be observed in infected EPC cells by the electron microscope. The tadpoles challenged with the isolated virus displayed similar clinical symptoms and pathogenicity as those naturally infected. Physicochemical characteristics showed that it was sensitive to chloroform treatment, trypsin treatment, heating treatment, acidity and alkalinity. Biological characteristics showed that RNRV can induce cytopathic effect (CPE) in various fish cell lines and the optimum growth temperature is 25~28°C. In addition, the complete genome sequence of RNRV was determined (GenBank accession number MG791866) and analysed. The results showed that the genome of RNRV consists of 104,286 bp containing 55.2% GC content and 104 predicted ORFs were identified in the genome. Phylogenetic analysis of the complete genome revealed that RNRV should belong to the FV3-like group in genus Ranavirus, and is more closely related to RGV and STIV. These studies confirmed that the RNRV was the causative agent of this natural epizootic event and genome analysis indicated that it belongs to the FV3-like group. In addition, viral physicochemical and biological characteristics will provide a scientific basis for prevention and control.

Oxidative stress, apoptosis and inflammatory responses involved in copper-induced pulmonary toxicity in mice

At present, there are few studies focused on the relationship between copper (Cu) and oxidative stress, apoptosis, or inflammatory responses in animal and human lungs. This study was conducted to explore the effects of Cu on pulmonary oxidative stress, apoptosis and inflammatory responses in mice orally administered with 0 mg/kg (control), 10 mg/kg, 20 mg/kg, and 40 mg/kg of CuSO₄ for 42 days. The results showed that CuSO₄ increased ROS production, and MDA, 8-OHdG and NO contents as well as iNOS activities and mRNA expression levels. Meanwhile, CuSO₄ reduced the activities and mRNA expression levels of antioxidant enzymes (GSH-Px, CAT, and SOD) and GSH contents, and ASA and AHR abilities. Also, CuSO₄ induced apoptosis, which was accompanied by decreasing Bcl-2, Bcl-xL mRNA expression levels and protein expression levels, and increasing Bax, Bak, cleaved-caspase-3, cleaved-caspase-9 mRNA, and protein expression levels, and Bax/Bcl-2 ratio. Concurrently, CuSO₄ caused inflammation by increasing MPO activities and activating the NF-κB signalling pathway, and down-regulating the mRNA and protein expression levels of anti-inflammatory cytokines (IL-2, IL-4, IL-10). In conclusion, the abovementioned findings demonstrated that over 10 mg/kg CuSO₄ can cause oxidative stress, apoptosis, and inflammatory responses, which contribute to pulmonary lesions and dysfunction in mice.

A positive, growth-based PAM screen identifies noncanonical motifs recognized by the S. pyogenes Cas9

CRISPR technologies have overwhelmingly relied on the Streptococcus pyogenes Cas9 (SpyCas9), with its consensus NGG and less preferred NAG and NGA protospacer-adjacent motifs (PAMs). Here, we report that SpyCas9 also recognizes sequences within an N(A/C/T)GG motif. These sequences were identified on the basis of preferential enrichment in a growth-based screen in Escherichia coli. DNA binding, cleavage, and editing assays in bacteria and human cells validated recognition, with activities paralleling those for NAG(A/C/T) PAMs and dependent on the first two PAM positions. Molecular-dynamics simulations and plasmid-clearance assays with mismatch-intolerant variants supported induced-fit recognition of an extended PAM by SpyCas9 rather than recognition of NGG with a bulged R-loop. Last, the editing location for SpyCas9-derived base editors could be shifted by one nucleotide by selecting between (C/T)GG and adjacent N(C/T)GG PAMs. SpyCas9 and its enhanced variants thus recognize a larger repertoire of PAMs, with implications for precise editing, off-target predictions, and CRISPR-based immunity.

Hepatic histopathology and apoptosis in diet-induced-obese mice under Escherichia coli pneumonia

This research was to investigate the difference of hepatic histopathology and apoptosis between the diet-induced obesity (DIO) and normal (lean) mice after Escherichia coli (E. coli) pneumonia. A total of 128 ICR mice were selected to be challenged intranasally with phosphate-buffered saline (PBS) or 4×10⁹CFUs/mL of E. coli, and the liver histopathology and apoptosis were examined pre- and post-infection. Results showed that the liver index, levels of lipid droplets, cytokines, adipocytokines, oxidative stress, apoptotic percentage, and apoptotic related factors in the E. coli-infected mice were generally higher than those in the uninfected mice, whereas the hepatic glycogen and Bcl-2 were the opposite. Interestingly, after E. coli infection, the DIO-E. coli mice exhibited decreased liver index and apoptotic percentages, and reduced levels of TNF-α, IL-6, resistin, MDA, GSH, CAT, Caspase-3, Caspase-9, Bax as well as Bax/Bcl-2 ratio in comparison to the lean-E. coli mice. Our results indicated that E. coli-induced pneumonia caused hepatic histopathological damage, increased hepatic apoptosis, oxidative damages, and higher levels of cytokines and adipocytokines. However, such changes showed less severely in the DIO mice than in the lean mice following E. coli pneumonia.

Regulation of MAVS Expression and Signaling Function in the Antiviral Innate Immune Response

Viral infection is controlled by host innate immune cells that express specialized receptors for viral components. Engagement of these pattern recognition receptors triggers a series of signaling pathways that culminate in the production of antiviral mediators such as type I interferons. Mitochondrial antiviral-signaling protein (MAVS) acts as a central hub for signal transduction initiated by RIG-I-like receptors, which predominantly recognize viral RNA. MAVS expression and function are regulated by both post-transcriptional and post-translational mechanisms, of which ubiquitination and phosphorylation play the most important roles in modulating MAVS function. Increasing evidence indicates that viruses can escape the host antiviral response by interfering at multiple points in the MAVS signaling pathways, thereby maintaining viral survival and replication. This review summarizes recent studies on the mechanisms by which MAVS expression and signaling are normally regulated and on the various strategies employed by viruses to antagonize MAVS activity, which may provide new insights into the design of novel antiviral agents.

Effect of intranasal instillation of Escherichia coli on apoptosis of spleen cells in diet-induced-obese mice

Splenic immune function was enhanced in diet-induced-obese (DIO) mice caused by Escherichia coli. The changes in spleen function on apoptosis were still unknown. Two hundred mice in groups Lean-E. coli and DIO-E. coli were intranasal instillation of E. coli. And another two hundred mice in groups Lean-PBS and DIO-PBS were given phosphate-buffered saline (PBS). Subsequently, spleen histology was analyzed. Then the rates of spleen cell (SC) apoptosis, and expression of the genes and proteins of Bcl-2, Bax, caspase-3 and caspase-9 were quantified in each group at 0 h (uninfected), 12 h, 24 h, and 72 h postinfection. The SC apoptosis rates of the DIO-E. coli groups were lower than those of the DIO-PBS groups at 12, 24 and 72 h (p < 0.05). Anti-apoptotic Bcl-2 expression gene and protein of the DIO-E. coli groups were higher than those of the DIO-PBS groups (p < 0.05). Gene expressions of pro-apoptotic Bax, caspase-3 and caspase-9 of the DIO-E. coli groups were lower than those of DIO-PBS groups at 12, 24 and 72 h (p < 0.05). The SC apoptosis rates of the Lean-E. coli groups were higher than those of the Lean- PBS groups at 12 h and 24 h (p < 0.05). Interestingly, the SC apoptosis rates in the DIO-E. coli groups were lower than those of the Lean-E. coli groups at 12 h (p < 0.05). In conclusion, our results suggested that the DIO mice presented stronger anti-apoptotic abilities than Lean mice in non-fatal acute pneumonia induced by E. coli infection, which is more conducive to protecting the spleen and improving the immune defense ability of the body.

Copper sulfate-induced endoplasmic reticulum stress promotes hepatic apoptosis by activating CHOP, JNK and caspase-12 signaling pathways

Copper (Cu), a transition metal, is an essential trace element in human and animal nutrition at low concentration, but Cu has toxic effects on tissues and organs at high concentration. Endoplasmic reticulum (ER) is a toxicological target in Cu poison. Thus far, no studies have focused on the relationship among copper, endoplasmic reticulum (ER) stress and apoptosis in animal and human livers. In the present study, mice treated with copper sulfate (CuSO₄) were used to assess the impacts of copper on ER stress and hepatic apoptosis. A total of 240 mice were orally administered with 0 (control), 10, 20 and 40 mg/kg of CuSO₄ for 42 days. The results indicated that CuSO₄ at 10 mg/kg markedly induced hepatocyte apoptosis and ER stress. In addition, ER stress was characterized by the increased mRNA and protein levels of glucose-regulated protein 78 (GRP78) and 94 (GRP94). Furthermore, ER stress-triggered 3 apoptotic pathways were also activated by the increased intracellular calcium and up-regulated expression levels of genes involved in growth arrest- and DNA damage-inducible gene 153 (Gadd153/CHOP), c-Jun N-terminal kinase (JNK) and cysteine aspartate-specific protease 12 (caspase-12) signaling pathways in CuSO₄-treated mice. In conclusion, CuSO₄-induced ER stress can promote hepatic apoptosis in mice by activating CHOP, JNK and caspase-12 signaling pathways.

Relationship of adiponectin, leptin, visfatin and IGF-1 in cow's venous blood and venous cord blood with calf birth weight

The Intrauterine fetal development process is complicated and affected by many regulating factors such as maternal nutritional status, transcription factors and adipokines. Adipokines are kinds of active substances secreted by adipose tissue, including more than 50 kinds of molecules. To explore the correlation between calf birth weights and adipokines including adiponectin, leptin, visfatin, and IGF-1 in cows venous and venous cord blood. Fifty-four healthy multiparous Chinese Holstein cows were used; in which, cows with a calf weight less than 40 kg were included in group A (n=9); those with a calf weight between 40 kg~45 kg were included in group B (n=25) and ≥45 kg were included in group C (n=20), venous blood and cord venous blood was collected. An ELISA kit was used to evaluate the concentration of adiponectin, leptin, visfatin, and IGF-1, correlations between index-index and index-calf birth weight were analysed. In both cows venous and cord venous blood, adiponectin, leptin, visfatin, and IGF-1 levels were significantly correlated with each other (p⟨0.01), and levels of these adipokines in venous blood were significantly higher than cord venous blood (p⟨0.01). Adiponectin, leptin, visfatin, and IGF-1 in venous cord blood were positively correlated with calf birth weights, and significantly correlated with calf birth weights respectively (p⟨0.01). Our study showed that adiponectin, leptin, and IGF-1 were found in venous blood and cord venous blood, and adiponectin, leptin, and IGF-1 in venous and cord venous blood potentially inter-regulated each other; adiponectin, leptin, and IGF-1 in venous blood were not significantly correlated with calf birth weights, while adiponectin, leptin, visfatin, and IGF-1 in venous cord blood were significantly correlated with calf birth weights, respectively.

First report on aberrant Ascaris suum infection in a dog, China

An aberrant Ascaris suum infection in a domestic dog in China in 2019 is described for the first time. This pathogen is a common roundworm of pigs with few reported cases in domestic animals. Our findings suggest a wider infection range with a possible transmission of A. suum to domestic animals that interact with humans.

Occurrence and multilocus genotyping of Giardia duodenalis in captive non-human primates from 12 zoos in China

Giardia duodenalis is a common enteric protozoan that infects a range of hosts including humans and other mammals. Multilocus genotyping of G. duodenalis in captive non-human primates (NHPs) from zoos in China is limited. In this study, we evaluated 302 NHP fecal samples collected from 32 different NHP species. The primates were from 12 zoos distributed across eight provinces and two municipalities (Chongqing and Beijing) of China. The overall infection rate was 8.3% (25/302). The six G. duodenalis-positive zoos and their infection rates were: Suzhou Zoo (40.0%, 4/10), Yangzhou Zoo (22.2%, 2/9), Dalian Zoo (16.7%, 4/24), Chengdu Zoo (12.8%, 6/47), Guiyang Forest Wildlife Zoo (12.1%, 7/58), and Changsha Zoo (4.7%, 2/43). Molecular analysis of three loci, beta-giardin (bg), triose phosphate isomerase (tpi), and glutamate dehydrogenase (gdh), showed high genetic heterogeneity, and seven novel subtypes (BIII-1, MB10-1, WB8-1, B14-1, MB9-1, DN7-1, and BIV-1) were detected within assemblage B. Additional analysis revealed 12 different assemblage B multilocus genotypes (MLGs), one known MLG and 11 novel MLGs. Based on phylogenetic analysis, 12 assemblage B MLGs formed two main clades, MLG-SW (10-12, 18) and MLG-SW (13, 14, 16, 17), the other four MLG-SW (15, 19, 20, 21) were scattered throughout the phylogenetic tree in this study. Using multilocus genotyping, this study expands our understanding of the occurrence of Giardia infection and genetic variation in Giardia in captive non-human primates from zoos in China.

Ethnic Groups Differences in the Prevalence of Sarcopenia Using the AWGS Criteria

OBJECTIVES

To estimate the prevalence of sarcopenia in different ethnic groups and the association with cultural life styles in west China.

DESIGN

A cross-sectional study.

SETTINGS

The communities in Yunnan, Guizhou, Sichuan, and Xinjiang provinces.

PARTICIPANTS

4500 participants aged 50 years or older in west China were enrolled in this study. Sarcopenia was defined according to the diagnostic algorithm of the Asia Working Group for Sarcopenia (AWGS).

MEASUREMENTS

We measured gait speed, handgrip strength and muscle mass by using bioelectrical impedance analysis (BIA) for all eligible participants. Life-style information were collected by reviewers. Relationships between sarcopenia and ethnic groups were analyzed using univariate and multivariate analyses.

RESULTS

We found 869 (19.31%) adults aged 50 years old or older were sarcopenia. The mean age is 62.4±8.3 years. The main ethnic groups enrolled in this study is Han, Tibetan, Qiang, Yi and Hui. The crude prevalence of sarcopenia is 22.3% in Han, 18.2% in Tibetan, 11.8% in Qiang, 34.7% in Yi and 26.7% in Hui. Compared to Han, after adjusting sex and age, Qiang has a lower prevalence of sarcopenia (odds ratio [OR]: 0.44, 95% CI 0.35-0.55), Yi has a higher prevalence of sarcopenia (OR: 1.78, 95% CI 1.29-2.43). While adding adjusting other potential cofounders, sarcopenia is still less prevalent in Qiang (OR: 0.44, 95% CI 0.34-0.57).

CONCLUSIONS

The crude prevalence of sarcopenia is 22.3% in Han, 18.2% in Tibetan, 11.8% in Qiang, 34.7% in Yi and 26.7% in Hui. Sarcopenia was less prevalent in Qiang compared with Han. Further studies to determine related factors of sarcopenia among different ethnic groups are recommended.

Association Between Number of Teeth, Denture Use and Frailty: Findings from the West China Health and Aging Trend Study

OBJECTIVE

Frailty and poor oral health are both common age-related conditions. However, the association between oral health and frailty has not been explored thoroughly among older Chinese adults. We aimed to investigate the associations between number of teeth, denture use, and frailty among older adults in western China.

DESIGN

Cross-sectional study.

SETTING

Community-based.

PARTICIPANTS

Participants were 4037 community-dwelling individuals aged 60 and older from the West China Health and Aging Trend (WCHAT) study.

MEASUREMENTS

Frailty was assessed using the physical frailty phenotype (PFP) and categorized as non-frail, prefrail and frail. In addition, number of teeth and denture use were examined by calibrated dentists. Multinomial logistic regression models were performed to examine the association between number of teeth, denture use, and frailty.

RESULTS

The overall prevalence of frailty was 6.7% among 4037 participants aged 60 and older in western China. Participants with no more than 20 teeth were associated with higher odds of being prefrail or frail whether wearing dentures or not. Denture using could not help lower the odds of being prefrail or frail for older adults with fewer teeth.

CONCLUSIONS

This study suggested that frailty was associated with having fewer teeth (≤20 teeth) among older Chinese adults. Future research involving targeted interventions addressing number of teeth may help provide information to establish effective strategies for frailty prevention in older adults.

AMPKα pathway involved in hepatic triglyceride metabolism disorder in diet-induced obesity mice following Escherichia coli Infection

To investigate the different effects of acute pulmonary infection induced by Escherichia coli (E. coli) on lipid metabolism between diet-induced obesity (DIO, fed with high-fat diet) mice and lean mice. A total of 180 ICR mice were selected to be challenged intranasally with phosphate-buffered saline or 10⁹ CFUs/mL of E. coli, and the body character indexes, biochemical indexes and expressions of genes and proteins involved in lipid metabolism were examined pre- and post-infection. Results revealed that, before infection, DIO mice had significantly higher body weight, adipose and liver indexes, free fatty acid and triglyceride contents than lean mice. After infection, increased free fatty acid and triglyceride contents, increased expressions of resistin, SREBP-1c, ACC1, FAS and SCD-1, and declined PPARα, CPT-1α expressions and AMPKα phosphorylation were detected in the infected group, while the change rates were more serious in the lean mice than the DIO mice. The above-mentioned findings verified that, after being infected with E. coli, hepatic lipid metabolism disorder was aggravated by activating SREBP-1c related lipid synthesis pathway and inhibiting PPARα related fatty acid oxidation pathway. However, infection-induced lipid metabolic disorders was slighter in the DIO mice than the lean mice through AMPKα pathway.

Sodium fluoride impairs splenic innate immunity via inactivation of TLR2/MyD88 signaling pathway in mice

Fluoride is known to affect the inflammatory process and autoregulation of immune responses, but the molecular mechanism by which fluoride causes innate immune injury remain largely unknown. Also, studies on sodium fluoride (NaF)-caused alteration of TLR signaling are still lacking. In the present study, we examined the effects of NaF on the mRNA and protein expression levels of TLR2/MyD88 signaling pathway molecules in the mouse spleen by using the methods of qRT-PCR and Western blotting. Consequently, we elucidated the mechanism underlying the effects of NaF on innate immunity. Two hundred and forty ICR mice were randomly divided into 4 groups with intragastric administration of distilled water in the control group and 12, 24, 48 mg/kg of NaF treatment in the experiment groups for 42 days. The findings revealed that NaF impaired splenic innate immunity in mice via inactivation of TLR2/MyD88 signaling pathway. NaF-inactivated TLR2/MyD88 signaling pathway was identified by prominently downregulated mRNA and protein expression levels of TLR2/MyD88, IRAK4, IRAK1, TRAF6, TAK1, MKK4/MKK7 and c-Jun, which ultimately altered the expression levels of IL-1β, IL-4, IL-6 and IL-8 to attenuate innate immunity.

Two metabolites isolated from endophytic fungus Coniochaeta sp. F-8 in Ageratina adenophora exhibit antioxidative activity and cytotoxicity

Ageratina adenophora is an invasive plant of global importance and has a broad distribution in the Western Himalayas. Endophtytic fungus Coniochaeta sp.F-8 was found in Ageratina adenophora. In this paper, we aim to investigate the antioxidative activity and cytotoxicity of the metabolites from Coniochaeta sp.F-8. Consequently, two compounds Phomoxanthone A and Penialidin A were isolated from the endophytic fungus of Ageratina adenophora for the first time. The structures of compounds were identified by IR, NMR and ESI-MS methods. Moreover, both of those compounds showed considerable antioxidative activity in vitro and resulted cytotoxicity in mouse embryo fibroblasts cell line Balb/c3T3. The present study provides a theoretical foundation for the development and utilization of endophytic fungi in Ageratina adenophora as a medicinal substance.

Delayed Pulmonary Apoptosis of Diet-Induced Obesity Mice following Escherichia coli Infection through the Mitochondrial Apoptotic Pathway

Escherichia coli (E. coli) is one of pathogens causing nosocomial pneumonia and could induce pulmonary excessive apoptosis. Although much has been learned about metabolic diseases induced by obesity, the information linking bacterial pneumonia to obesity is limited. Accordingly, we investigated the apoptosis of normal (lean) and diet-induced obesity (DIO, fed a high-fat diet) mice after nasal instillation with E. coli. Lung tissues were obtained at 0 (preinfection), 12, 24, and 72 h after infection, and acute pulmonary inflammation was observed at 12 h. Elevated cell apoptosis and percentage of pulmonary cells depolarized with collapse of the mitochondrial transmembrane potential (Δψm) occurred in response to bacterial infection. The relative mRNA and protein expressions of Bax, caspase-3, and caspase-9 increased, but Bcl-2 decreased in the lung. Interestingly, the apoptotic percentage and most of apoptosis-associated factors mentioned above peaked at 12 or 24 h in the lean-E. coli group, while at 24 or 72 h in the DIO-E. coli group. Taken together, these findings indicated that the E. coli pneumonia caused excessive pulmonary apoptosis through the mitochondria-mediated pathway, and the apoptosis was delayed in the DIO mice with E. coli pneumonia.

Characterization of the complete mitochondrial genome sequence of the dog roundworm Toxascaris leonina (Nematoda, Ascarididae) from China

Toxascaris leonina (Nematoda, Ascarididae) is a cosmopolitan nematode of canids and felids and poses potential threats to public health due to aberrant larva migrans. Herein, the complete mitochondrial genome sequence of a representative of this nematode from the dog in China was determined using next-generation sequencing technology. The assembled genome was 14,357 bp in length and encoded 36 genes, including 12 protein-coding genes, 22 transfer RNAs and 2 ribosomal RNAs. The phylogeny revealed that the canid-originated T. leonina were phylogenetic distinctiveness from the felid-originated T. leonina within the genus Toxascaris of Ascarididae, supporting that T. leonina may represent a species complex.

Sodium fluoride induces splenocyte autophagy via the mammalian targets of rapamycin (mTOR) signaling pathway in growing mice

Fluoride is known to impair organism’s development and function via adverse effects, and autophagy plays a regulation role in human or animal health and disease. At present, there are no reports focused on fluoride-induced autophagy in the animal and human spleen. The objective of this study was to investigate sodium fluoride (NaF)-induced splenocyte autophagy and the potential mechanism via regulation of p-mTOR in growing mice by using the methods of transmission electron microscopy (TEM), immunohistochemistry (IHC), quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. A total of 240 ICR mice were equally allocated into four groups with intragastric administration of distilled water in the control group and 12, 24, 48 mg/kg NaF solution in the experimental groups for 42 days. Results revealed that NaF increased autophagosomes or autolysosomes in spleen. Simultaneously, the autophagy marker LC3 brown punctate staining was increased with NaF dosage increase. On the other hand, NaF caused inhibition of mTOR activity, which was characterized by down-regulation of PI3K, Akt and mTOR mRNA and protein expression levels. And the suppression of mTOR activity in turn resulted in the significantly increased of ULK1 and Atg13 expression levels. Concurrently, NaF increased the levels of mRNA and protein expression of autophagy markers LC3, Beclin1, Atg16L1, Atg12, Atg5 and decreased the mRNA and protein expression levels of p62. The above-mentioned findings verify that NaF induces autophagy via mTOR signaling pathway. The inhibition of mTOR activity and alteration of autophagy-related genes and proteins are the potential molecular mechanism of NaF-induced splenocyte autophagy.

The mitochondrial genome of the dog hookworm Ancylostoma caninum (Nematoda, Ancylostomatidae) from Southwest China

The dog hookworm Ancylostoma caninum (Nematoda, Ancylostomatidae) is a blood-feeding intestinal parasitic nematode and can cause ancylostomiasis in humans. In this study, the complete mitochondrial genome of this anthropozoonotic hookworm was sequenced through Illumina deep sequencing technology. The whole genome was 13,721 bp in length and encoded 36 genes including 12 protein-coding genes, 22 transfer RNAs, and 2 ribosomal RNAs. Phylogeny revealed that A. caninum grouped with species from Ancylostomatinae and separated from species of Bunostominae in the family Ancylostomatidae. Amongst the subfamily Ancylostomatinae, three dog-originated A. caninum, regardless of isolate origins, clustered together and were more closely related to the cat hookworm A. tubaeforme and the human hookworm A. duodenale than to the dog/cat hookworm A. ceylanicum and the sea lion hookworm Uncinaria sanguinis. Taken together, the cumulative mitochondrial DNA data provides insights into phylogenetic studies among Ancylostomatidae nematodes.

Sequencing and analysis of the complete mitochondrial genome of dog roundworm Toxocara canis (Nematoda: Toxocaridae) from USA

The dog roundworm Toxocara canis (Nematoda: Toxocaridae) is an important zoonotic parasitic nematode and cause toxocariasis in human with a worldwide distribution. Herein, the complete mitochondrial genome of a representative of this nematode from USA was determined through next generation sequencing platform. The whole genome was 14,309 bp in size and encoded 12 protein-coding genes, 22 transfer RNAs, and 2 ribosomal RNAs. Phylogeny showed that although T. canis from USA and Australia were more closely related to each other than to that from Chinese, three T. canis isolates clustered together and formed paraphyletic relationships with T. cati and T. malayensis, supporting them as sister species among the family Toxocaridae. These cumulative mitochondrial DNA data should contribute to a better understanding of the phylogenetic relationship of this species.

Characterization of the complete mitochondrial genome of Spirometra decipiens (Cestoda: Diphyllobothriidae) from China

The plerocercoid larvae (spargana) of Spirometra decipiens (Cestoda: Diphyllobothriidae) can parasitize humans, causing the zoonotic sparganosis. In this study, the complete mitochondrial genome of this tapeworm was determined using an Illumina sequencing platform. The entire genome was 13,642 bp in length and contained 12 protein-coding genes, 22 transfer RNAs, two ribosomal RNAs, and two non-coding regions. The phylogeny indicated that S. decipiens was closely related to Spirometra erinaceieuropaei and supported the monophyletic relationships between Spirometra, Diphyllobothrium, and Diplogonoporus within the Dipyllobothriidae. These results should contribute to a better understanding of the phylogenetic position of this species.

Multiplex genome editing by natural transformation in Vibrio mimicus with potential application in attenuated vaccine development

Vibrio mimicus (V. mimicus) is a significant pathogen in freshwater catfish, though knowledge of virulence determinants and effective vaccine is lacking. Multiplex genome editing by natural transformation (MuGENT) is an easy knockout method, which has successfully used in various bacteria except for V. mimicus. Here, we found V. mimicus strain SCCF01 can uptake exogenous DNA and insert it into genome by natural transformation assay. Subsequently, we exploited this property to make five mutants (△Hem, △TS1, △TS2, △TS1△TS2, and △II), and removed the antibiotic resistance marker by Flp-recombination. Finally, all of the mutants were identified by PCR and RT-PCR. The results showed that combination of natural transformation and FLP-recombination can be applied successfully to generate targeted gene disruptions without the antibiotic resistance marker in V. mimicus. In addition, the five mutants showed mutant could be inherited after several subcultures and a 668-fold decrease in the virulence to yellow catfish (Pelteobagrus fulvidraco). This study provides a convenient method for the genetic manipulation of V. mimicus. It will facilitate the identification and characterization of V. mimicus virulence factors and eventually contribute to a better understanding of V. mimicus pathogenicity and development of attenuated vaccine.

Effects of antibacterial peptides on rumen fermentation function and rumen microorganisms in goats

Although many studies have confirmed that antimicrobial peptides (AMPs: PBD-mI and LUC-n) can be used as feed additives, there are few reports of their use in ruminants. The present study aimed to investigate the impact of AMPs on ameliorating rumen fermentation function and rumen microorganisms in goats. Eighteen 4-month-old Chuanzhong black goats were used in a 60-day experiment (6 goats per group). Group I was used as the control and was fed a basal diet, the group II were fed the basal diet supplemented with 2 g of AMPs [per goat/day] and group III were fed the basal diet supplemented 3 g of AMPs [per goat/day], respectively. Rumen fluid samples were collected at 0, 20 and 60 days. Bacterial 16S rRNA genes and ciliate protozoal 18S rRNA genes were amplified by PCR from DNA extracted from rumen samples. The amplicons were sequenced by Illumina MiSeq. Rumen fermentation parameters and digestive enzyme activities were also examined. Our results showed that dietary supplementation with AMPs increased the levels of the bacterial genera Fibrobacter, Anaerovibrio and Succiniclasticum and also increased the ciliates genus Ophryoscolex, but reduced the levels of the bacterial genera Selenomonas, Succinivibrio and Treponema, and the ciliate genera Polyplastron, Entodinium, Enoploplastron and Isotricha. Supplementation with AMPs increased the activities of xylanase, pectinase and lipase in the rumen, and also increased the concentrations of acetic acid, propionic acid and total volatile fatty acids. These changes were associated with improved growth performance in the goats. The results revealed that the goats fed AMPs showed improved rumen microbiota structures, altered ruminal fermentation, and improved efficiency regarding the utilization of feed; thereby indicating that AMPs can improve growth performance. AMPs are therefore suitable as feed additives in juvenile goats.

Complete mitogenome of the dog cucumber tapeworm Dipylidium caninum (Cestoda, Dilepididae) from Southwest China

The cucumber tapeworm Dipylidium caninum (Cestoda, Dilepididae) is a common intestinal parasite of dogs and cats and can cause dipylidiasis in humans, especially in infants and children. In this study, the complete mitogenome of this tapeworm was sequenced using next-generation sequencing technology. The entire genome was 14,226 bp in size and encoded 36 genes, including 12 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. The phylogeny revealed that D. caninum grouped with other species from the order Cyclophyllidea and separated from species of Pseudophyllidea. Within the Dipylidiidae, both dog-originated D. caninum were phylogenetic distinctiveness from cat-originated D. caninum, suggesting that D. caninum may represent a species complex. Altogether, the complete mitogenome of D. caninum sequenced here should contribute to a better understanding of the phylogenetic and taxonomic placement of this species.