Genetic redundancy of 4-hydroxybenzoate 3-hydroxylase genes ensures the catabolic safety of Pigmentiphaga sp. H8 in 3-bromo-4-hydroxybenzoate-contaminated habitats.

Genetic redundancy is prevalent in organisms and plays important roles in the evolution of biodiversity and adaptation to environmental perturbation. However, selective advantages of genetic redundancy in overcoming metabolic disturbance due to structural analogues have received little attention. Here, functional divergence of the three 4-hydroxybenzoate 3-hydroxylase (PHBH) genes (phbh1~3) was found in Pigmentiphaga sp. strain H8. The genes phbh1/phbh2 were responsible for 3-bromo-4-hydroxybenzoate (3-Br-4-HB, an anthropogenic pollutant) catabolism, whereas phbh3 was primarily responsible for 4-hydroxybenzoate (4-HB, a natural intermediate of lignin) catabolism. 3-Br-4-HB inhibited 4-HB catabolism by competitively binding PHBH3 and was toxic to strain H8 cells especially at high concentrations. The existence of phbh1/phbh2 not only enabled strain H8 to utilize 3-Br-4-HB but also ensured the catabolic safety of 4-HB. Molecular docking and site-directed mutagenesis analyses revealed that Val199 and Phe384 of PHBH1/PHBH2 were required for the hydroxylation activity towards 3-Br-4-HB. Phylogenetic analysis indicated that phbh1 and phbh2 originated from a common ancestor and evolved specifically in strain H8 to adapt to 3-Br-4-HB-contaminated habitats, whereas phbh3 evolved independently. This study deepens our understanding of selective advantages of genetic redundancy in prokaryote's metabolic robustness and reveals the factors driving the divergent evolution of redundant genes in adaptation to environmental perturbation.

Comparative Genomic Analysis of Pseudoxanthomonas sp. X-1, a Bromoxynil Octanoate-Degrading Bacterium, and Its Related Type Strains.

Most Pseudoxanthomonas species described have been derived from water, plants, or contaminated soils. Here, a strain Pseudoxanthomonas sp. X-1 isolated from bromoxynil octanoate (BO)-contaminated soil is presented. Strain X-1 could degrade BO and produce bromoxynil. The optimal conditions for degradation of BO by strain X-1 were an initial BO concentration of 0.1 mM, 30 °C, pH 7, and Mn2+ concentration of 1.0 mM. The bacterial morphological, physiological, and biochemical characteristics of strain X-1 were described, which showed differences comparing with other related type strains. The genome of strain X-1 was sequenced, and a comparative genomic analysis of X-1 and other Pseudoxanthomonas species was conducted to explore the mechanisms underlying the differences among these strains. The genome of strain X-1 encodes 4160 genes, 4078 of which are protein-coding genes and 68 are RNA coding genes. Specifically, strain X-1 encodes enzymes belonging to 778 Enzyme Commission (EC) numbers, much more than those of other related strains, and 62 of them are unique. Eight genes coding esterase are detected in strain X-1 which leads to the ability of BO degradation. This study provides strain, enzyme, and genome resources for the microbial remediation of environments polluted by herbicide BO.

Effects of Cigarette Smoke Exposure on the Gut Microbiota and Liver Transcriptome in Mice Reveal Gut-Liver Interactions.

Cigarette smoke exposure has a harmful impact on health and increases the risk of disease. However, studies on cigarette-smoke-induced adverse effects from the perspective of the gut-liver axis are lacking. In this study, we evaluated the adverse effects of cigarette smoke exposure on mice through physiological, biochemical, and histopathological analyses and explored cigarette-smoke-induced gut microbiota imbalance and changes in liver gene expression through a multiomics analysis. We demonstrated that cigarette smoke exposure caused abnormal physiological indices (including reduced body weight, blood lipids, and food intake) in mice, which also triggered liver injury and induced disorders of the gut microbiota and liver transcriptome (especially lipid metabolism). A significant correlation between intestinal bacterial abundance and the expression of lipid-metabolism-related genes was detected, suggesting the coordinated regulation of lipid metabolism by gut microbiota and liver metabolism. Specifically, Salmonella (harmful bacterium) was negatively and positively correlated with up- (such as Acsl3 and Me1) and downregulated genes (such as Angptl4, Cyp4a12a, and Plin5) involved in lipid metabolism, while Ligilactobacillus (beneficial bacterium) showed opposite trends with these genes. Our results clarified the key role of gut microbiota in liver damage and metabolism and improved the understanding of gut-liver interactions caused by cigarette smoke exposure.

Bioaugmentation of acetamiprid-contaminated soil with Pigmentiphaga sp. strain D-2 and its effect on the soil microbial community.

Bioaugmentation, a strategy based on microbiome engineering, has been proposed for bioremediation of pollutant-contaminated environments. However, the complex microbiome engineering processes for soil bioaugmentation, involving interactions among the exogenous inoculum, soil environment, and indigenous microbial microbiome, remain largely unknown. Acetamiprid is a widely used neonicotinoid insecticide which has caused environmental contaminations. Here, we used an acetamiprid-degrading strain, Pigmentiphaga sp. D-2, as inoculum to investigate the effects of bioaugmentation on the soil microbial community and the process of microbiome reassembly. The bioaugmentation treatment removed 94.8 and 92.5% of acetamiprid within 40 days from soils contaminated with 50 and 200 mg/kg acetamiprid, respectively. A decrease in bacterial richness and diversity was detected in bioaugmentation treatments, which later recovered with the removal of acetamiprid from soil. Moreover, the bioaugmentation treatment significantly influenced the bacterial community structure, whereas application of acetamiprid alone had little influence on the soil microbial community. Furthermore, the bioaugmentation treatment improved the growth of bacteria associated with acetamiprid degradation, and the inoculated and recruited taxa significantly influenced the keystone taxa of the indigenous microbiome, resulting in reassembly of the bacterial community yielding higher acetamiprid-degrading efficiency than that of the indigenous and acetamiprid-treated communities. Our results provide valuable insights into the mechanisms of microbiome engineering for bioaugmentation of acetamiprid-contaminated soils.

Beclin1 Haploinsufficiency accentuates second-hand smoke exposure -induced myocardial Remodeling and contractile dysfunction through a STING-mediated mechanism.

Second-hand smoking evokes inflammation and cardiovascular diseases. Recent evidence has revealed a pivotal role for deranged autophagy in smoke exposure-induced cardiac anomalies. This study evaluated the impact of haploinsufficiency of the mTOR-independent autophagy protein Beclin1 on side-stream smoke exposure-induced cardiac anomalies and mechanism(s) involved. Adult WT and Beclin1 haploinsufficiency (Becn+/-) mice were exposed to cigarette smoke for 1 h daily for 90 days. Echocardiographic, cardiomyocyte function, intracellular Ca2+, autophagy, mitophagy, apoptosis and inflammation were examined. DHE staining was employed to evaluate O2- level. Our data revealed that Beclin1 deficiency exacerbated smoke exposure-induced myocardial anomalies in geometry, fractional shortening, cardiomyocyte function, intracellular Ca2+ handling, TEM ultrastructure, and inflammation along with pronounced apoptosis and O2- production. Side-stream smoke provoked excessive autophagy/mitophagy, mtDNA release, and activation of innate immune response signals cyclic GMP-AMP synthase (cGAS) and its effector - stimulator of interferon genes (STING), the effect was abolished or unaffected by Becn haploinsufficiency. STING phosphorylation was overtly promoted by smoke exposure in Becn+/- mice. Smoke exposure also suppressed phosphorylation of mTOR although it facilitated that of ULK1 in both groups. In vitro data revealed that inhibition of cGAS or STING failed to affect smoke extract-induced mitophagy although they abrogated smoke extract-induced cardiomyocyte dysfunction except cGAS inhibition in Becn+/- mice. These data suggest that Beclin1 is integral in the maintenance of cardiac homeostasis under side-stream smoke exposure via a STING-mediated mechanism.

Knockout of macrophage migration inhibitory factor accentuates side-stream smoke exposure-induced myocardial contractile dysfunction through dysregulated mitophagy.

Second hand smoke exposure increases the prevalence of chronic diseases partly attributed to inflammatory responses. Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, is involved in the pathogenesis of multiple diseases although its role in second hand smoke exposure-induced cardiac anomalies remains elusive. This study evaluated the impact of MIF knockout on side-stream smoke exposure-induced cardiac pathology and underlying mechanisms. Adult WT and MIF knockout (MIFKO) mice were placed in a chamber exposed to cigarette smoke for 1 h daily for 60 consecutive days. Echocardiographic, cardiomyocyte function and intracellular Ca2+ handling were evaluated. Autophagy, mitophagy and apoptosis were examined using western blot. DHE staining was used to evaluate superoxide anion (O2-) generation. Masson trichrome staining was employed to assess interstitial fibrosis. Our data revealed that MIF knockout accentuated side-stream smoke-induced cardiac anomalies in fractional shortening, cardiomyocyte function, intracellular Ca2+ homeostasis, myocardial ultrastructure and mitochondrial content along with overt apoptosis and O2- generation. In addition, unfavorable effects of side-stream smoke were accompanied by excessive formation of autophagolysosome and elevated TFEB, the effect of which was exacerbated by MIF knockout. Recombinant MIF rescued smoke extract-induced myopathic anomalies through promoting AMPK activation, mitophagy and lysosomal function. Taken together, our data suggest that MIF serves as a protective factor against side-stream smoke exposure-induced myopathic changes through facilitating mitophagy and autophagolysosome formation.

Enhanced and Complete Removal of Phenylurea Herbicides by Combinational Transgenic Plant-Microbe Remediation.

The synergistic relationships between plants and their rhizospheric microbes can be used to develop a combinational bioremediation method, overcoming the constraints of individual phytoremediation or a bioaugmentation method. Here, we provide a combinational transgenic plant-microbe remediation system for a more efficient removal of phenylurea herbicides (PHs) from contaminated sites. The transgenic Arabidopsis thaliana plant synthesizing the bacterial N-demethylase PdmAB in the chloroplast was developed. The constructed transgenic Arabidopsis plant exhibited significant tolerance to isoproturon (IPU), a typical PH, and it took up the IPU through the roots and transported it to leaves, where the majority of the IPU was demethylated to 3-(4-isopropylphenyl)-1-methylurea (MDIPU). The produced intermediate was released outside the roots and further metabolized by the combinationally inoculated MDIPU-mineralizing bacterium Sphingobium sp. strain 1017-1 in the rhizosphere, resulting in an enhanced and complete removal of IPU from soil. Mutual benefits were built for both the transgenic Arabidopsis plant and strain 1017-1. The transgenic Arabidopsis plant offered strain 1017-1 a suitable accommodation, and in return, strain 1017-1 protected the plant from the phytotoxicity of MDIPU. The biomass of the transgenic Arabidopsis plant and the residence of the inoculated degrading microbes in the combinational treatment increased significantly compared to those in their respective individual transgenic plant treatment or bioaugmentation treatment. The influence of the structure of bacterial community by combinational treatment was between that of the two individual treatments. Overall, the combination of two approaches, phytoremediation by transgenic plants and bioaugmentation with intermediate-mineralizing microbes in the rhizosphere, represents an innovative strategy for the enhanced and complete remediation of pollutant-contaminated sites.IMPORTANCE Phytoremediation of organic pollutant-contaminated sites using transgenic plants expressing bacterial enzyme has been well described. The major constraint of transgenic plants transferred with a single catabolic gene is that they can also accumulate/release intermediates, still causing phytotoxicity or additional environmental problems. On the other hand, bioaugmentation with degrading strains also has its drawbacks, including the instability of the inoculated strains and low bioavailability of pollutants. In this study, the synergistic relationship between a transgenic Arabidopsis plant expressing the bacterial N-demethylase PdmAB in the chloroplast and the inoculated intermediate-mineralizing bacterium Sphingobium sp. strain 1017-1 in the rhizosphere is used to develop an intriguing bioremediation method. The combinational transgenic plant-microbe remediation system shows a more efficient and complete removal of phenylurea herbicides from contaminated sites and can overcome the constraints of individual phytoremediation or bioaugmentation methods.

Complete Genome Sequence of Cd(II)-Resistant Arthrobacter sp. PGP41, a Plant Growth-Promoting Bacterium with Potential in Microbe-Assisted Phytoremediation.

Microbe-assisted phytoremediation has great potential for practical applications. Plant growth-promoting bacteria (PGPB) with heavy metal (HM) resistance are important for the implementation of PGPB-assisted phytoremediation of HM-contaminated environments. Arthrobacter sp. PGP41 is a Cd(II)-resistant bacterium isolated from the rhizosphere soils of a Cd(II) hyperaccumulator plant, Solanum nigrum. Strain PGP41 can significantly improve plant seedling and root growth under Cd(II) stress conditions. This bacterium exhibited the ability to produce high levels of indole-3-acetic acid (IAA), as well as the ability to fix nitrogen and solubilize phosphate, and it possessed 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. Here, we present the complete genome sequence of strain PGP41. The genome consists of a single chromosome with a G+C content of 65.38% and no plasmids. The genome encodes 3898 genes and contains 49 tRNA and 12 rRNA genes. Multiple genes associated with plant growth promotion were identified in the genome. The whole genome sequence of PGP41 provides information useful for further clarifying the molecular mechanisms behind plant growth promotion by PGPB and facilitates its potential use as an inoculum in the bioremediation of HM-contaminated environments.

Epstein-Barr Virus-associated Hemophagocytic Lymphohistiocytosis in Adults: A Retrospective Analysis of 23 Patients in China.

BACKGROUND: Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disease with poor prognosis despite intensive therapy. OBJECTIVES: To discuss the ideal therapy of EBV-associated HLH for adults. METHODS: We retrospectively studied 23 adult patients with EBV-associated HLH at our institution between January 2000 and June 2015. The clinical characteristics, treatment, and prognosis of adult EBV-associated HLH were analyzed. The median age was 38 years (range 18-72). RESULTS: All patients were found to have high fever, thrombocytopenia, abnormal liver function, elevated ferritin, and lactate dehydrogenase. Leukopenia, anemia, coagulopathy, hypofibrinogenemia, and splenomegaly were found in more than 80% of patients. Ten patients were treated with HLH-2004 protocol. Eventually, 95.7% of patients died of EBV-associated HLH. Non-HLH-2004 treatment and bone marrow suppression may predict early relapse independently, and the poor performance status and high lactate dehydrogenase level can be poor prognostic factors. It was also validated in comprehensive analysis of published articles. CONCLUSIONS: Adult EBV-associated HLH occurs most often in people of Asian descent who are older than 35 years. These patients had a disappointing outcome despite intensive treatment, especially with high lactate dehydrogenase levels, poor performance status, and bone marrow suppression. HLH-2004 protocol has shown a glimmer of hope in the adult populations.

Genome-wide comparative analysis of putative Pth11-related G protein-coupled receptors in fungi belonging to Pezizomycotina.

BACKGROUND: G-protein coupled receptors (GPCRs) are the largest family of transmembrane receptors in fungi, where they play important roles in signal transduction. Among them, the Pth11-related GPCRs form a large and divergent protein family, and are only found in fungi in Pezizomycotina. However, the evolutionary process and potential functions of Pth11-related GPCRs remain largely unknown. RESULTS: Twenty genomes of fungi in Pezizomycotina covering different nutritional strategies were mined for putative Pth11-related GPCRs. Phytopathogens encode much more putative Pth11-related GPCRs than symbionts, saprophytes, or entomopathogens. Based on the phylogenetic tree, these GPCRs can be divided into nine clades, with each clade containing fungi in different taxonomic orders. Instead of fungi from the same order, those fungi with similar nutritional strategies were inclined to share orthologs of putative Pth11-related GPCRs. Most of the CFEM domain-containing Pth11-related GPCRs, which were only included in two clades, were detected in phytopathogens. Furthermore, many putative Pth11-related GPCR genes of phytopathogens were upregulated during invasive plant infection, but downregulated under biotic stress. The expressions of putative Pth11-related GPCR genes of saprophytes and entomopathogens could be affected by nutrient conditions, especially the carbon source. The gene expressions revealed that Pth11-related GPCRs could respond to biotic/abiotic stress and invasive plant infection with different expression patterns. CONCLUSION: Our results indicated that the Pth11-related GPCRs existed before the diversification of Pezizomycotina and have been gained and/or lost several times during the evolutionary process. Tandem duplications and trophic variations have been important factors in this evolution.

Production of chlorothalonil hydrolytic dehalogenase from agro-industrial wastewater and its application in raw food cleaning.

BACKGROUND: To reduce the fermentation cost for industrialization of chlorothalonil hydrolytic dehalogenase (Chd), agro-industrial wastewaters including molasses, corn steep liquor (CSL) and fermentation wastewater were used to substitute for expensive carbon and nitrogen sources and fresh water for lab preparation. RESULTS: The results showed that molasses and CSL could replace 5% carbon source and 100% organic nitrogen source respectively to maintain the same fermentation level. Re-fermentation from raffinate of ultra-filtered fermentation wastewater could achieve 61.03% of initial Chd activity and reach 96.39% activity when cultured in a mixture of raffinate and 50% of original medium constituent. Typical raw foods were chosen to evaluate the chlorothalonil removal ability of Chd. After Chd treatment for 2 h at room temperature, 97.40 and 75.55% of 30 mg kg-1 chlorothalonil on cherry tomato and strawberry respectively and 60.29% of 50 mg kg-1 chlorothalonil on Chinese cabbage were removed. Furthermore, the residual activity of the enzyme remained at 78-82% after treatment, suggesting its potential for reuse. CONCLUSION: This study proved the cost-feasibility of large-scale production of Chd from agro-industrial wastewater and demonstrated the potential of Chd in raw food cleaning. © 2016 Society of Chemical Industry.

Permissive role of AMPK and autophagy in adiponectin deficiency-accentuated myocardial injury and inflammation in endotoxemia.

BACKGROUND: Adiponectin (APN), an adipose-derived adipokine, alleviates lipopolysaccharide (LPS)-induced injury in multiple organs including hearts although the underlying mechanism in endotoxemia remains elusive. This study was designed to examine the role of adiponectin in LPS-induced cardiac anomalies and inflammation as well as the underlying mechanism with a focus on autophagy - a conserved machinery for bulk degradation of intracellular components. METHODS AND RESULTS: Wild-type (WT) and APN(-/-) mice were challenged with LPS (4mg/kg) or saline for 6h. Echocardiography, cardiomyocyte contractile and intracellular Ca(2+) properties were evaluated. Markers of autophagy, apoptosis and inflammation including LC3B, p62, Beclin1, AMPK, mTOR, ULK, Caspase 3, Bcl-2, Bax, TLR4, TRAF6, MyD88, IL-1B, TNFα, HMGB1, JNK and IκB were examined using Western blot or RT-PCR. Our results showed that LPS challenge reduced fractional shortening, compromised cardiomyocyte contractile capacity, intracellular Ca(2+) handling properties, apoptosis and inflammation, which were accentuated by adiponectin ablation. Adiponectin ablation unmasked the LPS-induced cardiac remodeling (left ventricular end systolic diameter) and prolongation of cell shortening. The detrimental effects of adiponectin ablation were associated with dampened autophagy in response to LPS through an AMPK-mTOR-ULK1-dependent mechanism. In vivo administration of AMPK activator AICAR or the autophagy inducer rapamycin effectively attenuated or obliterated LPS-induced and adiponectin deficiency-accentuated responses without affecting TLR4, TRAF6 and MyD88. CONCLUSIONS: The findings suggest that AMPK and autophagy may play a permissive role in the adiponectin deficiency-exacerbated cardiac dysfunction, apoptosis and inflammation under LPS challenge possibly at the post-TLR4 receptor level.

Role of autophagy in metabolic syndrome-associated heart disease.

Metabolic syndrome is a constellation of multiple metabolic risk factors including abdominal obesity, glucose intolerance, insulin resistance, dyslipidemia and hypertension. Over the past decades, the prevalence of metabolic syndrome has increased dramatically, imposing a devastating, pandemic health threat. More importantly, individuals with metabolic syndrome are at an increased risk of diabetes mellitus and overall cardiovascular diseases. One of the common comorbidities of metabolic syndrome is heart anomalies leading to the loss of cardiomyocytes, cardiac dysfunction and ultimately heart failure. Up-to-date, a plethora of cell signaling pathways have been postulated for the pathogenesis of cardiac complications in obesity including lipotoxicity, inflammation, oxidative stress, apoptosis and sympathetic overactivation although the precise mechanism of action underscoring obesity-associated heart dysfunction remains elusive. Recent evidence has indicated a potential role of protein quality control in components of metabolic syndrome. Within the protein quality control system, the autophagy-lysosome pathway is an evolutionarily conserved pathway responsible for bulk degradation of large intracellular organelles and protein aggregates. Autophagy has been demonstrated to play an indispensible role in the maintenance of cardiac geometry and function under both physiological and pathological conditions. Accumulating studies have demonstrated that autophagy plays a pivotal role in the etiology of cardiac anomalies under obesity and metabolic syndrome. In this minireview, we will discuss on how autophagy is involved in the regulation of cardiac function in obesity and metabolic syndrome. This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases.

Targeted deletion of PTEN in cardiomyocytes renders cardiac contractile dysfunction through interruption of Pink1-AMPK signaling and autophagy.

Phosphatase and tensin homolog (PTEN) deleted from chromosome 10 has been implicated in the maintenance of cardiac homeostasis although the underlying mechanism(s) remains elusive. We generated a murine model of cardiomyocyte-specific knockout of PTEN to evaluate cardiac geometry and contractile function, as well as the effect of metformin on PTEN deficiency-induced cardiac anomalies, if any. Cardiac histology, autophagy and related signaling molecules were evaluated. Cardiomyocyte-specific PTEN deletion elicited cardiac hypertrophy and contractile anomalies (echocardiographic and cardiomyocyte contractile dysfunction) associated with compromised intracellular Ca(2+) handling. PTEN deletion-induced cardiac hypertrophy and contractile anomalies were associated with dampened phosphorylation of PTEN-inducible kinase 1 (Pink1) and AMPK. Interestingly, administration of AMPK activator metformin (200mg/kg/d, in drinking H2O for 4weeks) rescued against PTEN deletion-induced geometric and functional defects as well as interrupted autophagy and autophagic flux in the heart. Moreover, metformin administration partially although significantly attenuated PTEN deletion-induced accumulation of superoxide. RNA interference against Pink1 in H9C2 myoblasts overtly increased intracellular ATP levels and suppressed AMPK phosphorylation, confirming the role of AMPK as a downstream target for PTEN-Pink1. Further scrutiny revealed that activation of AMPK and autophagy using metformin and rapamycin, respectively, rescued against PTEN deletion-induced mechanical anomalies with little additive effect. These data demonstrated that cardiomyocyte-specific deletion of PTEN leads to the loss of Pink1-AMPK signaling, development of cardiac hypertrophy and contractile defect. Activation of AMPK rescued against PTEN deletion-induced cardiac anomalies associated with restoration of autophagy and autophagic flux. This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases.

Comparative genomic analysis of isoproturon-mineralizing sphingomonads reveals the isoproturon catabolic mechanism.

The worldwide use of the phenylurea herbicide, isoproturon (IPU), has resulted in considerable concern about its environmental fate. Although many microbial metabolites of IPU are known and IPU-mineralizing bacteria have been isolated, the molecular mechanism of IPU catabolism has not been elucidated yet. In this study, complete genes that encode the conserved IPU catabolic pathway were revealed, based on comparative analysis of the genomes of three IPU-mineralizing sphingomonads and subsequent experimental validation. The complete genes included a novel hydrolase gene ddhA, which is responsible for the cleavage of the urea side chain of the IPU demethylated products; a distinct aniline dioxygenase gene cluster adoQTA1A2BR, which has a broad substrate range; and an inducible catechol meta-cleavage pathway gene cluster adoXEGKLIJC. Furthermore, the initial mono-N-demethylation genes pdmAB were further confirmed to be involved in the successive N-demethylation of the IPU mono-N-demethylated product. These IPU-catabolic genes were organized into four transcription units and distributed on three plasmids. They were flanked by multiple mobile genetic elements and highly conserved among IPU-mineralizing sphingomonads. The elucidation of the molecular mechanism of IPU catabolism will enhance our understanding of the microbial mineralization of IPU and provide insights into the evolutionary scenario of the conserved IPU-catabolic pathway.

Genome-Wide Characterization and Expression Analysis of the Germin-Like Protein Family in Rice and Arabidopsis.

Previous studies have shown that germin-like proteins (GLPs) are present ubiquitously in rice and Arabidopsis. However, the understanding regarding their role in development and abiotic/biotic stress resistance remains limited. In the present study, we report genome-wide identification, characterisation, subcellular localization, enzyme activity, and expression analysis of the GLP gene family in rice and Arabidopsis to study their functions. In total, 43 and 32 GLPs in the rice and Arabidopsis genome were identified based on a systematic analysis, respectively. The GLP genes were clustered into six clades based on phylogenetic analysis, and many stress and developmental-related cis-elements were detected in promoters of GLP genes. In addition, subcellular location and superoxide dismutase (SOD) analysis demonstrated that the random selected OsGLP genes on chromosomes 8 and 4 of rice were expressed in the cell wall with SOD activity. Overall, our results showed that tandem duplication events, especially the clusters of tandem duplication genes on chromosome 8 in rice, play a major role in expansion of the GLP family and thus increase our understanding of the role of the GLP family in abiotic/biotic stress and development.

Aldehyde dedydrogenase-2 plays a beneficial role in ameliorating chronic alcohol-induced hepatic steatosis and inflammation through regulation of autophagy.

BACKGROUND & AIMS: Mitochondrial aldehyde dehydrogenase (ALDH2) plays a critical role in the detoxification of the ethanol metabolite acetaldehyde. This study was designed to examine the impact of global ALDH2 overexpression on alcohol-induced hepatic steatosis. METHODS: Wild type Friend virus B (FVB) and ALDH2 transgenic mice were placed on a 4% alcohol or control diet for 12 weeks. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin and cholesterol, hepatic triglyceride, steatosis, fat metabolism-related proteins, pro-inflammatory cytokines, glutathione (GSH), oxidized glutathione (GSSG), autophagy and autophagy signalling were examined. The role of autophagy was evaluated in alcohol dehydrogenase 1 (ADH1)-transfected human hepatocellular liver carcinoma cells (VA-13) treated with or without the autophagy inducer rapamycin and lysosomal inhibitors. RESULTS: Chronic alcohol intake led to elevated AST-, ALT-levels, bilirubin, AST/ALT ratio, cholesterol, hepatic triglycerides and hepatic fat deposition as evidenced by H&E and Oil Red O staining. Hepatic fat deposition was associated with disturbed levels of fat metabolism-related proteins (fatty acid synthase, SCD1), upregulated interleukin-6, TNF-α, cyclooxygenase, oxidative stress, and loss of autophagy, effects which were attenuated or ablated by the ALDH2 transgene. Moreover, ethanol (100 mM) and acetaldehyde (100 and 500 µM) increased levels of IL-6 and IFN-γ, and suppressed autophagy in VA-13 cells, effects which were markedly alleviated by rapamycin. In addition, lysosomal inhibitors mimicked ethanol-induced p62 accumulation with little additive effect with ethanol. Ethanol significantly suppressed LC3 conversion in the presence of lysosomal inhibitors. CONCLUSIONS: In summary, our results revealed that ALDH2 plays a beneficial role in ameliorating chronic alcohol intake-induced hepatic steatosis and inflammation through regulation of autophagy.

DIDS reduces ischemia/reperfusion-induced myocardial injury in rats.

BACKGROUND/AIMS: Anion channels such as chloride channel are known to participate in the regulation of a wide variety of cellular processes including development, differentiation, proliferation, apoptosis and regeneration. This study was designed to examine the effect of the non-selective anion channel blocker 4,4'-Diisothiocyanostilbene-2, 2'-disulfonic acid (DIDS) on cardiac function and apoptosis using a rat model of ischemia/reperfusion (I/R). METHODS: Fifty male SD rats were randomly divided into the following groups including sham, I/R and I/R+DIDS (7, 14 or 28 mg/kg). In DIDS group, rats received DIDS treatment (4 ml/kg/hr) at the beginning of reperfusion for 2 hrs using a programmed micro-pump. Cardiac function was evaluated including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP) as well as positive and negative maximal derivatives of left ventricular pressure (± dP/dt(max)). Myocardial infarct size was detected using the double staining with 2, 3, 5-triphenyl-2H-tetra-zolium chloride (TTC) and Evan's blue dye. DNA ladder, TUNEL assay, Bax and Bcl-2 protein levels were evaluated. Levels of ROS and Akt phosphorylation were detected. RESULTS: I/R injury compromised cardiac function as manifested by reduced LVSP and ± dP/dt(max) as well as pronounced apoptosis. I/R-induced cardiac anomalies were markedly ameliorated by DIDS. DIDS retarded I/R-induced myocardial infarct and apoptosis. In addition, DIDS ameliorated I/R-induced ROS production and Akt dephosphorylation in the heart. CONCLUSION: Taken together, our data revealed that DIDS may protect cardiomyocytes against I/R injury as evidenced by improved cardiac function, Bcl-2, Akt phosphorylation, and reduced myocardial apoptosis, Bax expression, ROS production and myocardial infarct size.

Comparison of Four Comamonas Catabolic Plasmids Reveals the Evolution of pBHB To Catabolize Haloaromatics.

Comamonas plasmids play important roles in shaping the phenotypes of their hosts and the adaptation of these hosts to changing environments, and understanding the evolutionary strategy of these plasmids is thus of great concern. In this study, the sequence of the 119-kb 3,5-dibromo-4-hydroxybenzonitrile-catabolizing plasmid pBHB from Comamonas sp. strain 7D-2 was studied and compared with those of three other Comamonas haloaromatic catabolic plasmids. Incompatibility group determination based on a phylogenetic analysis of 24 backbone gene proteins, as well as TrfA, revealed that these four plasmids all belong to the IncP-1ß subgroup. Comparison of the four plasmids revealed a conserved backbone region and diverse genetic-load regions. The four plasmids share a core genome consisting of 40 genes (>50% similarities) and contain 12 to 50 unique genes each, most of which are xenobiotic-catabolic genes. Two functional reductive dehalogenase gene clusters are specifically located on pBHB, showing distinctive evolution of pBHB for haloaromatics. The higher catabolic ability of the bhbA2B2 cluster than the bhbAB cluster may be due to the transcription levels and the character of the dehalogenase gene itself rather than that of its extracytoplasmic binding receptor gene. The plasmid pBHB is riddled with transposons and insertion sequence (IS) elements, and ISs play important roles in the evolution of pBHB. The analysis of the origin of the bhb genes on pBHB suggested that these accessory genes evolved independently. Our work provides insights into the evolutionary strategies of Comamonas plasmids, especially into the adaptation mechanism employed by pBHB for haloaromatics.