Interspecies regulatory landscapes and elements revealed by novel joint systematic integration of human and mouse blood cell epigenomes.

Knowledge of locations and activities of cis-regulatory elements (CREs) is needed to decipher basic mechanisms of gene regulation and to understand the impact of genetic variants on complex traits. Previous studies identified candidate CREs (cCREs) using epigenetic features in one species, making comparisons difficult between species. In contrast, we conducted an interspecies study defining epigenetic states and identifying cCREs in blood cell types to generate regulatory maps that are comparable between species, using integrative modeling of eight epigenetic features jointly in human and mouse in our Validated Systematic Integration (VISION) Project. The resulting catalogs of cCREs are useful resources for further studies of gene regulation in blood cells, indicated by high overlap with known functional elements and strong enrichment for human genetic variants associated with blood cell phenotypes. The contribution of each epigenetic state in cCREs to gene regulation, inferred from a multivariate regression, was used to estimate epigenetic state Regulatory Potential (esRP) scores for each cCRE in each cell type, which were used to categorize dynamic changes in cCREs. Groups of cCREs displaying similar patterns of regulatory activity in human and mouse cell types, obtained by joint clustering on esRP scores, harbored distinctive transcription factor binding motifs that were similar between species. An interspecies comparison of cCREs revealed both conserved and species-specific patterns of epigenetic evolution. Finally, we showed that comparisons of the epigenetic landscape between species can reveal elements with similar roles in regulation, even in the absence of genomic sequence alignment.

Roles of the ABCG2 transporter in protoporphyrin IX distribution and toxicity.

ATP-binding cassette transporter subfamily G member 2 (ABCG2) is a membrane-bound transporter responsible for the efflux of various xenobiotics and endobiotics, including protoporphyrin IX (PPIX), an intermediate in the heme biosynthesis pathway. Certain genetic mutations and chemicals impair the conversion of PPIX to heme and/or increase PPIX production, leading to PPIX accumulation and toxicity. In mice, deficiency of ABCG2 protects against PPIX-mediated phototoxicity and hepatotoxicity by modulating PPIX distribution. In addition, in vitro studies revealed that ABCG2 inhibition increases the efficacy of PPIX-based photodynamic therapy by retaining PPIX inside target cells. In this review, we discuss the roles of ABCG2 in modulating the tissue distribution of PPIX, PPIX-mediated toxicity, and PPIX-based photodynamic therapy. Significance Statement This review summarized the roles of ABCG2 in modulating PPIX distribution and highlighted the therapeutic potential of ABCG2 inhibitors for the management of PPIX-mediated toxicity.

Targeting lysyl oxidase like 2 attenuates OVA-induced airway remodeling partly via the AKT signaling pathway.

BACKGROUND: Airway epithelium is an important component of airway structure and the initiator of airway remodeling in asthma. The changes of extracellular matrix (ECM), such as collagen deposition and structural disturbance, are typical pathological features of airway remodeling. Thus, identifying key mediators that derived from airway epithelium and capable of modulating ECM may provide valuable insights for targeted therapy of asthma. METHODS: The datasets from Gene Expression Omnibus database were analyzed to screen differentially expressed genes in airway epithelium of asthma. We collected bronchoscopic biopsies and serum samples from asthmatic and healthy subjects to assess lysyl oxidase like 2 (LOXL2) expression. RNA sequencing and various experiments were performed to determine the influences of LOXL2 knockdown in ovalbumin (OVA)-induced mouse models. The roles and mechanisms of LOXL2 in bronchial epithelial cells were explored using LOXL2 small interfering RNA, overexpression plasmid and AKT inhibitor. RESULTS: Both bioinformatics analysis and further experiments revealed that LOXL2 is highly expressed in airway epithelium of asthmatics. In vivo, LOXL2 knockdown significantly inhibited OVA-induced ECM deposition and epithelial-mesenchymal transition (EMT) in mice. In vitro, the transfection experiments on 16HBE cells demonstrated that LOXL2 overexpression increases the expression of N-cadherin and fibronectin and reduces the expression of E-cadherin. Conversely, after silencing LOXL2, the expression of E-cadherin is up-regulated. In addition, the remodeling and EMT process that induced by transforming growth factor-ß1 could be enhanced and weakened after LOXL2 overexpression and silencing in 16HBE cells. Combining the RNA sequencing of mouse lung tissues and experiments in vitro, LOXL2 was involved in the regulation of AKT signaling pathway. Moreover, the treatment with AKT inhibitor in vitro partially alleviated the consequences associated with LOXL2 overexpression. CONCLUSIONS: Taken together, the results demonstrated that epithelial LOXL2 plays a role in asthmatic airway remodeling partly via the AKT signaling pathway and highlighted the potential of LOXL2 as a therapeutic target for airway remodeling in asthma.

Necroptosis plays a role in TL1A-induced airway inflammation and barrier damage in asthma.

BACKGROUND: Airway epithelial cell (AEC) necroptosis contributes to airway allergic inflammation and asthma exacerbation. Targeting the tumor necrosis factor-like ligand 1 A (TL1A)/death receptor 3 (DR3) axis has a therapeutic effect on asthmatic airway inflammation. The role of TL1A in mediating necroptosis of AECs challenged with ovalbumin (OVA) and its contribution to airway inflammation remains unclear. METHODS: We evaluated the expression of the receptor-interacting serine/threonine-protein kinase 3(RIPK3) and the mixed lineage kinase domain-like protein (MLKL) in human serum and lung, and histologically verified the level of MLKL phosphorylation in lung tissue from asthmatics and OVA-induced mice. Next, using MLKL knockout mice and the RIPK3 inhibitor GSK872, we investigated the effects of TL1A on airway inflammation and airway barrier function through the activation of necroptosis in experimental asthma. RESULTS: High expression of necroptosis marker proteins was observed in the serum of asthmatics, and necroptosis was activated in the airway epithelium of both asthmatics and OVA-induced mice. Blocking necroptosis through MLKL knockout or RIPK3 inhibition effectively attenuated parabronchial inflammation, mucus hypersecretion, and airway collagen fiber accumulation, while also suppressing type 2 inflammatory factors secretion. In addition, TL1A/ DR3 was shown to act as a death trigger for necroptosis in the absence of caspases by silencing or overexpressing TL1A in HBE cells. Furthermore, the recombinant TL1A protein was found to induce necroptosis in vivo, and knockout of MLKL partially reversed the pathological changes induced by TL1A. The necroptosis induced by TL1A disrupted the airway barrier function by decreasing the expression of tight junction proteins zonula occludens-1 (ZO-1) and occludin, possibly through the activation of the NF-κB signaling pathway. CONCLUSIONS: TL1A-induced airway epithelial necroptosis plays a significant role in promoting airway inflammation and barrier dysfunction in asthma. Inhibition of the TL1A-induced necroptosis pathway could be a promising therapeutic strategy.

Phosphorylated CPI-17 and MLC2 as Biomarkers of Coronary Artery Spasm-Induced Sudden Cardiac Death.

Coronary artery spasm (CAS) plays an important role in the pathogeneses of various ischemic heart diseases and has gradually become a common cause of life-threatening arrhythmia. The specific molecular mechanism of CAS has not been fully elucidated, nor are there any specific diagnostic markers for the condition. Therefore, this study aimed to examine the specific molecular mechanism underlying CAS, and screen for potential diagnostic markers. To this end, we successfully constructed a rat CAS model and achieved in vitro culture of a human coronary-artery smooth-muscle cell (hCASMC) contraction model. Possible molecular mechanisms by which protein kinase C (PKC) regulated CAS through the C kinase-potentiated protein phosphatase 1 inhibitor of 17 kDa (CPI-17)/myosin II regulatory light chain (MLC2) pathway were studied in vivo and in vitro to screen for potential molecular markers of CAS. We performed hematoxylin and eosin staining, myocardial zymogram, and transmission electron microscopy to determine myocardial and coronary artery injury in CAS rats. Then, using immunohistochemical staining, immunofluorescence staining, and Western blotting, we further demonstrated a potential molecular mechanism by which PKC regulated CAS via the CPI-17/MLC2 pathway. The results showed that membrane translocation of PKCα occurred in the coronary arteries of CAS rats. CPI-17/MLC2 signaling was observably activated in coronary arteries undergoing CAS. In addition, in vitro treatment of hCASMCs with angiotensin II (Ang II) increased PKCα membrane translocation while consistently activating CPI-17/MLC2 signaling. Conversely, GF-109203X and calphostin C, specific inhibitors of PKC, inactivated CPI-17/MLC2 signaling. We also collected the coronary artery tissues from deceased subjects suspected to have died of CAS and measured their levels of phosphorylated CPI-17 (p-CPI-17) and MLC2 (p-MLC2). Immunohistochemical staining was positive for p-CPI-17 and p-MLC2 in the tissues of these subjects. These findings suggest that PKCα induced CAS through the CPI-17/MLC2 pathway; therefore, p-CPI-17 and p-MLC2 could be used as potential markers for CAS. Our data provide novel evidence that therapeutic strategies against PKC or CPI-17/MLC2 signaling might be promising in the treatment of CAS.

Plasma TNFRSF11B as a New Predictive Inflammatory Marker of Sepsis-ARDS with Endothelial Dysfunction.

Inflammation plays an important role in the development of sepsis-acute respiratory distress syndrome (ARDS). Olink inflammation-related biomarker panels were used to analyze the levels of 92 inflammation-related proteins in plasma with sepsis-ARDS (n = 25) and healthy subjects (n = 25). There were significant differences in 64 inflammatory factors, including TNFRSF11B in sepsis-ARDS, which was significantly higher than that in controls. Functional analysis showed that TNFRSF11B was closely focused on signal transduction, immune response, and inflammatory response. The TNFRSF11B level in sepsis-ARDS plasma, LPS-induced mice, and LPS-stimulated HUVECs significantly increased. The highest plasma concentration of TNFRSF11B in patients with sepsis-ARDS was 10-20 ng/mL, and 10 ng/mL was selected to stimulate HUVECs. Western blot results demonstrated that the levels of syndecan-1, claudin-5, VE-cadherin, occludin, aquaporin-1, and caveolin-1 in TNFRSF11B-stimulated HUVECs decreased, whereas that of connexin-43 increased in TNFRSF11B-stimulated HUVECs. To the best of the authors' knowledge, this study was the first to reveal elevated TNFRSF11B in sepsis-ARDS associated with vascular endothelial dysfunction. In summary, TNFRSF11B may be a new potential predictive and diagnostic biomarker for vascular endothelium damage in sepsis-ARDS.

Dynamic CTCF binding directly mediates interactions among cis-regulatory elements essential for hematopoiesis.

While constitutive CCCTC-binding factor (CTCF)-binding sites are needed to maintain relatively invariant chromatin structures, such as topologically associating domains, the precise roles of CTCF to control cell-type-specific transcriptional regulation remain poorly explored. We examined CTCF occupancy in different types of primary blood cells derived from the same donor to elucidate a new role for CTCF in gene regulation during blood cell development. We identified dynamic, cell-type-specific binding sites for CTCF that colocalize with lineage-specific transcription factors. These dynamic sites are enriched for single-nucleotide polymorphisms that are associated with blood cell traits in different linages, and they coincide with the key regulatory elements governing hematopoiesis. CRISPR-Cas9-based perturbation experiments demonstrated that these dynamic CTCF-binding sites play a critical role in red blood cell development. Furthermore, precise deletion of CTCF-binding motifs in dynamic sites abolished interactions of erythroid genes, such as RBM38, with their associated enhancers and led to abnormal erythropoiesis. These results suggest a novel, cell-type-specific function for CTCF in which it may serve to facilitate interaction of distal regulatory emblements with target promoters. Our study of the dynamic, cell-type-specific binding and function of CTCF provides new insights into transcriptional regulation during hematopoiesis.

Impairment of human terminal erythroid differentiation by histone deacetylase 5 deficiency.

Histone deacetylases (HDACs) are a group of enzymes that catalyze the removal of acetyl groups from histone and nonhistone proteins. HDACs have been shown to have diverse functions in a wide range of biological processes. However, their roles in mammalian erythropoiesis remain to be fully defined. This study showed that, of the 11 classic HDAC family members, 6 (HDAC1, -2, -3, and HDAC5, -6, -7) are expressed in human erythroid cells, with HDAC5 most significantly upregulated during terminal erythroid differentiation. Knockdown of HDAC5 by either short hairpin RNA or small interfering RNA in human CD34+ cells followed by erythroid cell culture led to increased apoptosis, decreased chromatin condensation, and impaired enucleation of erythroblasts. Biochemical analyses revealed that HDAC5 deficiency resulted in activation of p53 in association with increased acetylation of p53. Furthermore, although acetylation of histone 4 (H4) is decreased during normal terminal erythroid differentiation, HDAC5 deficiency led to increased acetylation of H4 (K12) in late-stage erythroblasts. This increased acetylation was accompanied by decreased chromatin condensation, implying a role for H4 (K12) deacetylation in chromatin condensation. ATAC-seq and RNA sequencing analyses revealed that HDAC5 knockdown leads to increased chromatin accessibility genome-wide and global changes in gene expression. Moreover, pharmacological inhibition of HDAC5 by the inhibitor LMK235 also led to increased H4 acetylation, impaired chromatin condensation, and enucleation. Taken together, our findings have uncovered previously unrecognized roles and molecular mechanisms of action for HDAC5 in human erythropoiesis. These results may provide insights into understanding the anemia associated with HDAC inhibitor treatment.

Identification of a novel role for TL1A/DR3 deficiency in acute respiratory distress syndrome that exacerbates alveolar epithelial disruption.

Alveolar epithelial barrier is a potential therapeutic target for acute respiratory distress syndrome (ARDS). However, an effective intervention against alveolar epithelial barrier has not been developed. Here, based on single-cell RNA and mRNA sequencing results, death receptor 3 (DR3) and its only known ligand tumor necrosis factor ligand-associated molecule 1A (TL1A) were significantly reduced in epithelium from an ARDS mice and cell models. The apparent reduction in the TL1A/DR3 axis in lungs from septic-ARDS patients was correlated with the severity of the disease. The examination of knockout (KO) and alveolar epithelium conditional KO (CKO) mice showed that TL1A deficiency exacerbated alveolar inflammation and permeability in lipopolysaccharide (LPS)-induced ARDS. Mechanistically, TL1A deficiency decreased glycocalyx syndecan-1 and tight junction-associated zonula occludens 3 by increasing cathepsin E level for strengthening cell-to-cell permeability. Additionally, DR3 deletion aggravated barrier dysfunction and pulmonary edema in LPS-induced ARDS through the above mechanisms based on the analyses of DR3 CKO mice and DR3 overexpression cells. Therefore, the TL1A/DR3 axis has a potential value as a key therapeutic signaling for the protection of alveolar epithelial barrier.

Protective effects of sulforaphane on inflammation, oxidative stress and intestinal dysbacteriosis induced by triphenyltin in Cyprinus carpio haematopterus.

The purpose of this experiment was to study the mitigation effect of sulforaphane (SFN) on fish toxicological damage caused by triphenyltin (TPT) pollution. A total of 320 healthy fish (56.9 ± 0.4g) were randomly placed into four groups, each with four duplicates. The control group was fed the basal diet, the TPT group was exposed to 10 ng/L TPT on the basis of the control group, the SFN group was fed a diet supplemented with 10 mg/kg SFN, the SFN + TPT group was exposed to 10 ng/L TPT on the basis of the SFN group. Each tank had 20 fish and the breeding lasted for 8 weeks. The present study found that the antioxidant enzyme activity in the TPT group was significantly lower than that of the control group (P < 0.05). In addition, compared with the control group, the mRNA expression of pro-inflammatory factors (IL-6, TNF-α) were significantly induced, and the anti-inflammatory factor genes (IL-10, TGF) were significantly inhibited (P < 0.05) in TPT group. SFN relieved the changes of inflammatory factors caused by TPT, ameliorated oxidative stress, improved antioxidant enzyme (include SOD, CAT, GSH, GPx) activities (P < 0.05). 16s RNA analysis indicated that exposure to TPT caused changes in intestinal microflora. The results of the study showed that after exposure to TPT, some beneficial genera of bacteria in the gut of Rhizobiaceae, Bdellovibrio and Candidatus Alysiosphaera were decreased. The bacteria associated with intestinal inflammation including Propionibacterium, Rubrobacter, Anaerorhabdus_furcosa_group, Rikenellaceae and Eubacterium_brachy were upregulated. However, the SFN treatment group significantly down-regulated the above five inflammation-related bacteria. The above results indicated that TPT caused oxidative stress and inflammation in fish intestines, changed the intestinal microflora, and dietary SFN could improve antioxidant status, regulate inflammation and intestinal health. Therefore, SFN is a promising diet additive for improving fish damage caused by TPT contamination.

Effects of salinity stress on anxiety behavior and antioxidant capability of guppy (Poecilia reticulata).

The objective of this study was to determine the effect of salinity on anxiety behavior and liver antioxidant capacity in the guppy (Poecilia reticulata). Guppies were exposed to salinities of 0‰, 5‰, 10‰, 15‰ and 20‰ for acute stress tests, and then we analyzed the activity of antioxidant enzymes at 3, 6, 12, 24, 48, 72 and 96 h. During the experiment, the anxiety behavior of guppy was enhanced at salinities of 10‰, 15‰, and 20‰, as evidenced by a significantly higher latency time for the first passage through the upper part than that of the control group (P < 0.05). CAT activity was highest at 24 h in the treatment with the salinity of 10‰, and SOD and GPX activities were highest at 12 h into the treatment with the salinity of 10‰. The SOD and CAT activities were significantly higher than the control group after 96 h of treatment at different salinities (P < 0.05). The MDA contents of the experimental groups at salinities of 5‰ and 10‰ were not significantly different from the control group after 96 h of treatment (P > 0.05). While the MDA contents of the experimental groups at salinities of 15‰ and 20‰ were still significantly higher than the control group after 96 h of treatment (P < 0.05). The experimental results indicated that elevated salinity could lead to oxidative stress in the guppy, altering their anxiety behavior as well as the activity of antioxidant enzymes. In conclusion, drastic changes in salinity during culture should be avoided.

Infrared and Visible Image Fusion via Attention-Based Adaptive Feature Fusion.

Infrared and visible image fusion methods based on feature decomposition are able to generate good fused images. However, most of them employ manually designed simple feature fusion strategies in the reconstruction stage, such as addition or concatenation fusion strategies. These strategies do not pay attention to the relative importance between different features and thus may suffer from issues such as low-contrast, blurring results or information loss. To address this problem, we designed an adaptive fusion network to synthesize decoupled common structural features and distinct modal features under an attention-based adaptive fusion (AAF) strategy. The AAF module adaptively computes different weights assigned to different features according to their relative importance. Moreover, the structural features from different sources are also synthesized under the AAF strategy before reconstruction, to provide a more entire structure information. More important features are thus paid more attention to automatically and advantageous information contained in these features manifests itself more reasonably in the final fused images. Experiments on several datasets demonstrated an obvious improvement of image fusion quality using our method.

N-Methyl Protoporphyrin IX: An Understudied Porphyrin.

N-Methyl protoporphyrin IX (NmePPIX) is a derivative of protoporphyrin IX (PPIX) and the lattice of heme. Certain xenobiotics strongly induce NmePPIX production in the liver. The existence of endogenous NmePPIX in untreated animal liver has also been reported. The detailed mechanisms of NmePPIX biosynthesis remain unclear, but cytochrome P450 enzymes are thought to be critical in xenobiotic-induced NmePPIX production. High levels of NmePPIX cause PPIX accumulation because NmePPIX is a potent inhibitor (Ki = 7 nM) of ferrochelatase, the last enzyme in the heme biosynthesis pathway that converts PPIX to heme. NmePPIX is also involved in several other physiological processes, including inhibition of nitric oxide production and promotion of lamin aggregation. Compared to the two well-characterized porphyrins, PPIX and heme, NmePPIX is understudied regarding the mechanism of formation, fate, and physiological functions. This Review summarizes the current understanding of NmePPIX and provides perspectives on areas of future research on NmePPIX.

The intestinal histopathology, innate immune response and antioxidant capacity of blunt snout bream (Megalobrama amblycephala) in response to Aeromonas hydrophila.

The present study was performed to determine the effects of Aeromonas hydrophila infection on intestinal -histopathology, innate immune response and changes in antioxidant capacity of blunt snout bream (Megalobrama amblycephala). A series of histopathological changes, innate immune enzyme activities, antioxidant enzyme activities, and the corresponding mRNA relative genes expressions in intestines were measured at 0, 1, 2, and 3 weeks post-treatment of Aeromonas hydrophila (1✕107 CFU mL-1) infection. The results showed that Aeromonas hydrophila induced changes in intestinal morphology, including the decreased muscularis thickness, the proliferated goblet cells, and the atrophied intestine villi height. Moreover, the innate immune enzymes activities in serum such as acid phosphatase, alkaline phosphatase, lysozyme activities and immunoglobulin M were significantly reduced after infection at 1week, 2week and 3week. The contents of complement 3 and complement 4 were significantly decreased after infection as well. In addition, the antioxidant enzymes activities, including superoxide dismutase, catalase and glutathione peroxidase in the experimental groups were significantly decreased compared with the control group, whereas the content of malondialdehyde was significantly increased after infection at 1week, 2week and 3week. Furthermore, the mRNA relative expressions of the inflammatory cytokines such as tumor necrosis factor-α, interleukins-1ß, interferon-γ, and interleukins-6 were significantly increased after infection with Aeromonas hydrophila. The TJ-related gene expressions in the intestine of zonula occluden-1, occludin, occludin-1, occludin-2 were significantly reduced throughout the infection period. The mRNA relative expressions of signal transducers and activators of transcription 4 and janus kinase-3 in the intestine were significantly ascended compared with the non-infected group. Overall, the results elucidated that the intestine tissue injury and innate immune response reduction, as well as antioxidant capacity attenuation were occurred against Aeromonas hydrophila infection of the blunt snout bream.

Systematic Analysis of BELL Family Genes in Zizania latifolia and Functional Identification of ZlqSH1a/b in Rice Seed Shattering.

The loss of seed shattering is an important event in crop domestication, and elucidating the genetic mechanisms underlying seed shattering can help reduce yield loss during crop production. This study is the first to systematically identify and analyse the BELL family of transcription factor-encoding genes in Chinese wild rice (Zizania latifolia). ZlqSH1a (Zla04G033720) and ZlqSH1b (Zla02G027130) were identified as key candidate genes involved in seed shattering in Z. latifolia. These genes were involved in regulating the development of the abscission layer (AL) and were located in the nucleus of the cell. Over-expression of ZlqSH1a and ZlqSH1b resulted in a complete AL between the grain and pedicel and significantly enhanced seed shattering after grain maturation in rice. Transcriptome sequencing revealed that 172 genes were differentially expressed between the wild type (WT) and the two transgenic (ZlqSH1a and ZlqSH1b over-expressing) plants. Three of the differentially expressed genes related to seed shattering were validated using qRT-PCR analysis. These results indicate that ZlqSH1a and ZlqSH1b are involved in AL development in rice grains, thereby regulating seed shattering. Our results could facilitate the genetic improvement of seed-shattering behaviour in Z. latifolia and other cereal crops.

Silencing of AHNAK2 restricts thyroid carcinoma progression by inhibiting the Wnt/ß-catenin pathway.

AHNAK nucleoprotein 2 (AHNAK2) has been proposed to have an oncogenic role in various human cancers. However, the functional role of AHNAK2 in thyroid carcinoma (TC) progression has never been explored. In this study, quantitative real-time polymerase chain reaction and western blot were conducted to evaluate the expression of genes. The functional role of AHNAK2 was elucidated by cell count kit-8, colony-forming assay, wound-healing assay, and Transwell invasion assay. We found that AHNAK2 was highly expressed in thyroid carcinoma, and it was tightly correlated with the pathological stage in TC. The mRNA and protein levels of AHNAK2 were increased in TC cells. Silencing of AHNAK2 restricted the proliferation, metastasis, and epithelial-mesenchymal transition (EMT) of TC cells. AHNAK2 silencing inhibited the protein expression of ß-catenin and cyclin D1, and AHNAK2 overexpression had the opposite effects. Moreover, LiCl or ICG-001 exposure counteracted the effects of AHNAK2 silencing or upregulation on malignant phenotypes of TC cells. In conclusion, the knockdown of AHNAK2 restrained the proliferation, metastasis, and EMT of TC cells by inhibiting the Wnt/ß-catenin pathway, providing a new potential mechanism of AHNAK2 in understanding the oncogenesis and progression of TC.

The effects of TPT and dietary quercetin on growth, hepatic oxidative damage and apoptosis in zebrafish.

The objective of this study was to determine the effects of triphenyltin (TPT) and dietary quercetin on the growth, oxidative stress and apoptosis in zebrafish. A total of 240 fish were divided into 4 groups with three replicates as follows: fish were fed with the basal diet as the control group (D1), only 10 ng/L TPT (D2), 10 ng/L TPT + 100 mg/kg quercetin (D3), and only 100 mg/Kg quercetin as the D4 group. At the end of the study period (56 d), the results showed that the growth performance of the fish that were fed 100 mg/kg quercetin was significantly higher than that of fish that were exposed to 10 ng/L TPT. Quercetin ameliorated oxidative stress, which decreased malondialdehyde (MDA) and nitric oxide (NO) levels and improved antioxidant enzyme activities. The mRNA expressions of the key apoptotic gene and pro-inflammatory cytokines were significantly induced by TPT exposure. However, dietary quercetin prevented a marked increase in the Bax, caspase3 and caspase9 transcript abundances that were induced by TPT. In addition, the quercetin treatments decreased inflammation by regulating the NF-kB signalling pathway. In conclusion, our findings suggested that TPT induced oxidative stress and apoptosis in zebrafish and that the pretreatment with quercetin showed an ameliorative role. Dietary 100 mg/ kg quercetin helps to prevent oxidative damage, apoptosis and inflammation in TPT treated zebrafish.

Modulatory effect of fructooligosaccharide against triphenyltin-induced oxidative stress and immune suppression in goldfish (Carassius auratus).

Triphenyltin (TPT) is a widely used pesticide that is highly toxic to a variety of organisms, including humans, and is a potential contributor to environmental pollution. The present study was conducted to evaluate the oxidative stress and immunotoxicity induced by TPT in goldfish (Carassius auratus) and the protective effects of fructooligosaccharide (FOS). Goldfish (mean weight of 13.3 ± 0.2 g) were randomly divided into six groups with three replicates: (G1) the control group, (G2) the 10 ng/L TPT group, (G3) the 0.4% FOS group, (G4) the 10 ng/L TPT + 0.4% FOS group, (G5) the 0.8% FOS group, and (G6) the 10 ng/L TPT + 0.8% FOS group. The results showed that 10 ng/L TPT induced oxidative stress and significantly decreased the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in the liver and the gene expression of SOD, GPx, metallothionein (MT), and peroxiredoxin-4 (Prdx-4). The concentration of malondialdehyde (MDA) and the gene expression of cytochrome P450 (CYP) and glutathione S-transferase (GST) in the liver were significantly increased in the TPT-treated group. Exposure to 10 ng/L TPT in water induced immune suppression and significantly decreased the activities of immune enzymes, such as lysozyme, myeloperoxidase (MPO), alternative complement (ACH50), acid phosphatase (ACP) and alkaline phosphatase (AKP), in the serum. TPT could stimulate the fish to generate large amounts of proinflammatory cytokines, including increased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), and nitric oxide (NO) levels and TNF-α, IL-6, IL-1ß, and NF-κB mRNA expression. However, TPT-induced toxicity was significantly ameliorated in the groups treated with FOS, and FOS partly prevented alterations in the activities of antioxidant enzymes and the expression of antioxidant- and ROS scavenger-related genes. In addition, TPT-induced immune toxicity was significantly ameliorated in the groups treated with FOS. FOS markedly suppressed TNF-α, IL-6, IL-1ß, and NO production and TNF-α, IL-6, and IL-1ß mRNA expression in the TPT-treated groups. The study indicated that TPT-induced oxidative stress may play a critical role in inhibiting immunity. However, FOS administration attenuates TPT-induced oxidative stress and immune suppression in goldfish.

Contrasting effects of carbon source recalcitrance on soil phosphorus availability and communities of phosphorus solubilizing microorganisms.

Carbon (C) additions to soil interact through chemical and microbiological processes to cause changes in soil phosphorus (P) availability. However, the response of soil P transformations and relevant microbial communities to C additions having different degrees of recalcitrance remains uncertain. We studied the effects of glucose, hemicellulose and lignin addition on soil P availability, P transformation processes and relevant microbial activity and communities in a P-deficient flooded soil. Lignin significantly increased soil available P concentrations, which was attributed to chemical release of inorganic P and increased alkaline phosphatase activity. Glucose and hemicellulose additions stimulated microbial metabolism of C thereby enhancing microbial demand for P, with increased soil P availability especially in the early incubation period. Glucose or hemicellulose addition changed soil microbial diversity and community composition, leading to enhanced growth and interactions of P solubilizing microorganisms such as Desulfitobacterium, Bacillus and Desulfosporosinus. Our results infer the importance of pH alteration and competitive sorption between PO4 and functional groups of recalcitrant C (e.g., lignin) with Fe/Al (hydr) oxides in regulating soil P availability. Further, the microbial response to labile C additions led to increased P availability in the P-deficient soil. This study provides important mechanistic information to guide microbially-regulated soil P management in agricultural ecosystems.

[Impact of overexpressed FOXJ2 on mouse spermatogenesis and its action mechanism].

OBJECTIVE: To analyze the phenotype of the male reproductive system in the germline-specific conditional Foxj2 knock-in mouse model (Stra8-cre; Foxj2tg/+), identify a target gene of the transcription factor FOXJ2, and investigate the effect of the overexpression of Foxj2 on mouse spermatogenesis and its action mechanism. METHODS: Based on the Cre-loxP recombination system, we generated a germline-specific conditional Foxj2 knock-in mouse model (Stra8-cre; Foxj2tg/+). We determined male fertility by counting the number of pups per litter and the fertilization rate after intracytoplasmic sperm injection (ICSI), observed the morphology of the testes and epididymides by HE staining, examined the sperm quality by computer assisted sperm analysis (CASA), detected the expression and localization of Cx43 in the testis by RT-qPCR, Western blot and immunohistochemistry, and verified the binding site of FOXJ2 to the Cx43 promoter using ChIP-PCR and dual luciferase reporter assay. RESULTS: The number of pups per litter and fertilization rate after ICSI were lower in the Stra8-cre; Foxj2tg/+ male mice than in the controls, and so were the size and weight of the testis. HE staining exhibited obvious exfoliation of germ cells and dramatically decreased spermatocytes and spermatids in the seminiferous tubules of the Stra8-cre; Foxj2tg/+ mice. Moreover, sperm concentration in the cauda epididymides was reduced, and the transcription and expression levels of Cx43 in the testis were increased. ChIP-PCR and dual luciferase reporter assay showed direct binding of FOXJ2 to the Cx43 promoter in the testis. CONCLUSIONS: Overexpressed FOXJ2 may lead to spermatogenic failure and subfertility in Stra8-cre; Foxj2tg/+ male mice by upregulating the expression of Cx43.