Paenibacillus polygoni sp. nov., an endophytic bacterium isolated from Polygonum lapathifolium L. in wetland.

A Gram-stain-positive, aerobic, rod-shaped, non-motile, yellowish and glossy strain, C31T, was isolated from a wetland plant Polygonum lapathifolium L. located south of Poyang Lake, Jiangxi Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain C31T showed similarity values of lower than 97.0 % to other type species belonging to the genus Paenibacillus. The genomic average nucleotide identity values between strain C31T and its reference type species ranged from 68.9-70.9 % and the digital DNA-DNA hybridization values were lower than 27.8 %. The genomic DNA G+C content of strain C31T was 41.9 mol%. The optimal growth temperature, pH and NaCl concentration were 37 °C, pH 7 and 0.5 %, respectively. The major cellular fatty acids (>5.0 %) of strain C31T were anteiso-C15 : 0 (73.7 %), anteiso-C17 : 0 (8.4 %) and iso-C15 : 0 (5.2 %). The polar lipids of strain C31T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unidentified phospholipids. The respiratory quinone was MK-7. Based on these phylogenetic and phenotypic characterizations, strain C31T represents a novel species within the genus Paenibacillus. Therefore, the proposed name for this newly identified species is Paenibacillus polygoni sp. nov. and the type strain is C31T (=CCTCC AB 2022349T=KCTC 43565T).

Metabolomic and transcriptomice analyses of flavonoid biosynthesis in apricot fruits.

Introduction: Flavonoids, as secondary metabolites in plants, play important roles in many biological processes and responses to environmental factors. Methods: Apricot fruits are rich in flavonoid compounds, and in this study, we performed a combined metabolomic and transcriptomic analysis of orange flesh (JN) and white flesh (ZS) apricot fruits. Results and discussion: A total of 222 differentially accumulated flavonoids (DAFs) and 15855 differentially expressed genes (DEGs) involved in flavonoid biosynthesis were identified. The biosynthesis of flavonoids in apricot fruit may be regulated by 17 enzyme-encoding genes, namely PAL (2), 4CL (9), C4H (1), HCT (15), C3'H (4), CHS (2), CHI (3), F3H (1), F3'H (CYP75B1) (2), F3'5'H (4), DFR (4), LAR (1), FLS (3), ANS (9), ANR (2), UGT79B1 (6) and CYP81E (2). A structural gene-transcription factor (TF) correlation analysis yielded 3 TFs (2 bHLH, 1 MYB) highly correlated with 2 structural genes. In addition, we obtained 26 candidate genes involved in the biosynthesis of 8 differentially accumulated flavonoids metabolites in ZS by weighted gene coexpression network analysis. The candidate genes and transcription factors identified in this study will provide a highly valuable molecular basis for the in-depth study of flavonoid biosynthesis in apricot fruits.

Polymorphisms of adiponectin gene and gene-lipid interaction with hypertension risk in Chinese coal miners: A matched case-control study.

OBJECTIVE: Low serum adiponectin level can predict hypertension development, and adiponectin gene (ADIPOQ) polymorphisms have been reported to be linked with hypertension risk. Whereas, the interaction between ADIPOQ polymorphisms and environmental factors on the susceptibility of hypertension remained unclear. The purpose of this study was to explore the relationship of ADIPOQ polymorphisms with hypertension risk and their interaction with lipid levels in coal miners. METHODS: A matched case-control study with 296 case-control pairs was performed in a large coal mining group located in North China. The participants were questioned by trained interviewers, and their ADIPOQ genotype and lipid levels were determined. Logistic regression, stratified analysis, and crossover analysis were applied to evaluate the effects of rs2241766, rs1501299, and rs266729 genotypes and gene-lipid interaction on hypertension risk. RESULTS: In this matched case-control study, the genotypes of rs2241766 TG+GG, rs1501299 GT+TT, and rs266729 CG+GG were marginally related to hypertension risk. Individuals with high total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) level were susceptible to hypertension (TC: odds ratio [OR] = 1.807, 95% confidence intervals [95%CI] = 1.266-2.581; LDL-C: OR = 1.981, 95%CI = 1.400-2.803; HDL-C: OR = 1.559, 95%CI = 1.093-2.223). Antagonistic interactions were detected between rs2241766 and TC, rs1501299 and TC, rs2241766 and LDL-C, and rs1501299 and HDL-C (rs2241766 and TC: OR = 0.393, 95%CI = 0.191-0.806; rs1501299 and TC: OR = 0.445, 95%CI = 0.216-0.918; rs2241766 and LDL-C: OR = 0.440, 95%CI = 0.221-0.877; rs1501299 and HDL-C: OR = 0.479, 95%CI = 0.237-0.967). Stratified analysis showed that hypertension risk was high for the subjects with rs2241766 TG+GG or rs1501299 GG under the low lipid level but low for those under the high lipid level. In the case group, the TC and LDL-C levels for rs2241766 TG+GG were lower than those for rs2241766 GG, and the TC and HDL-C levels for rs1501299 GT+TT were higher than those for rs1501299 GG. CONCLUSIONS: Although the effects of ADIPOQ polymorphisms alone were not remarkable, an antagonistic interaction was observed between ADIPOQ polymorphisms and lipid levels.

Roles of E3 Ubiquitin Ligases in Plant Responses to Abiotic Stresses.

Plants are frequently exposed to a variety of abiotic stresses, such as those caused by salt, drought, cold, and heat. All of these stressors can induce changes in the proteoforms, which make up the proteome of an organism. Of the many different proteoforms, protein ubiquitination has attracted a lot of attention because it is widely involved in the process of protein degradation; thus regulates many plants molecular processes, such as hormone signal transduction, to resist external stresses. Ubiquitin ligases are crucial in substrate recognition during this ubiquitin modification process. In this review, the molecular mechanisms of plant responses to abiotic stresses from the perspective of ubiquitin ligases have been described. This information is critical for a better understanding of plant molecular responses to abiotic stresses.

Evolutionary history and global spatiotemporal pattern of alfalfa mosaic virus.

Alfalfa mosaic virus (AMV) is an important plant virus causing considerable economic loss to alfalfa production. Knowledge of the evolutionary and demographic history of the pathogen is limited but essential to the development of effective and sustainable pathogen management schemes. In this study, we performed worldwide phylodynamic analyses of AMV based on 154 nucleotide sequences of the coat protein gene, sampled from 1985 to 2020, to understand the epidemiology of this pathogen. Bayesian phylogenetic reconstruction estimates that the crown group of AMV dates back to 1840 (95% credibility interval, 1687-1955). We revealed that AMV continuously evolves at a rate of 4.14 × 10-4 substitutions/site/year (95% credibility interval, 1.04 × 10-4 - 6.68 × 10-4). Our phylogeographic analyses identified multiple migration links between Europe and other regions, implying that Europe played a key role in spreading the virus worldwide. Further analyses showed that the clustering pattern of AMV isolates is significantly correlated to geographic regions, indicating that geography-driven adaptation may be a factor that affects the evolution of AMV. Our findings may be potentially used in the development of effective control strategies for AMV.

Identification of Key Genes Controlling Carotenoid Metabolism during Apricot Fruit Development by Integrating Metabolic Phenotypes and Gene Expression Profiles.

To explore the metabolic basis of carotenoid accumulation in different developmental periods of apricot fruits, targeted metabonomic and transcriptomic analyses were conducted in four developmental periods (S1-S4) in two cultivars (Prunus armeniaca cv. "Kuchebaixing" with white flesh and P. armeniaca cv. "Shushangganxing" with orange flesh) with different carotenoid contents. 14 types of carotenes and 27 types of carotene lipids were identified in apricot flesh in different developmental periods. In S3 and S4, the carotenoid contents of the two cultivars were significantly different, and ß-carotene and (E/Z)-phytoene were the key metabolites that caused the difference in the total carotenoid content between the examined cultivars. Twenty-five structural genes (including genes in the methylerythritol 4-phosphate and carotenoid biosynthesis pathways) related to carotenoid biosynthesis were identified among the differentially expressed genes in different developmental periods of the two cultivars, and a carotenoid metabolic pathway map of apricot fruits was drawn according to the KEGG pathway map. The combined analysis of carotenoid metabolism data and transcriptome data showed that PSY, NCED1, and CCD4 were the key genes leading to the great differences in the total carotenoid content. The results provide a new approach to study the synthesis and accumulation of carotenoids in apricot fruits.

Transcriptome analysis insight into ethylene metabolism and pectinase activity of apricot (Prunus armeniaca L.) development and ripening.

Ethylene metabolism is very important for climacteric fruit, and apricots are typical climacteric fruit. The activity of pectinase is closely related to fruit firmness, which further affects fruit quality. To better understand ethylene metabolism, pectinase activity and their molecular regulation mechanisms during the development and ripening of apricot fruit, ethylene metabolism, pectinase activity and the "Luntaibaixing" apricot fruit transcriptome were analyzed at different developmental stages. Ethylene metabolic precursors, enzyme activities and ethylene release increased during fruit development and ripening, with significant differences between the ripening stage and other stages (P < 0.05). Fruit firmness decreased significantly from the S1 to S5 stages, and polygalacturonase, pectin methylesterase, and pectin lyase activities were significantly higher in the S5 stage than in other stages. RNA sequencing (RNA-seq) analysis of fruit resulted in the identification of 22,337 unigenes and 6629 differentially expressed genes (DEGs) during development and ripening, of which 20,989 unigenes are annotated in public protein databases. In functional enrichment analysis, DEGs among the three stages were found to be involved in plant hormone signal transduction. Four key genes affecting ethylene metabolism, six key ethylene signal transduction genes and seven genes related to pectinase in apricot fruit were identified by KEGG pathway analysis. By RNA-sequencing, we not only clarified the molecular mechanism of ethylene metabolism during the ripening of "Luntaibaixing" apricot fruit but also provided a theoretical basis for understanding pectin metabolism in apricot fruit.

Phylogeography of Prunus armeniaca L. revealed by chloroplast DNA and nuclear ribosomal sequences.

To clarify the phytogeography of Prunus armeniaca L., two chloroplast DNA fragments (trnL-trnF and ycf1) and the nuclear ribosomal DNA internal transcribed spacer (ITS) were employed to assess genetic variation across 12 P. armeniaca populations. The results of cpDNA and ITS sequence data analysis showed a high the level of genetic diversity (cpDNA: HT = 0.499; ITS: HT = 0.876) and a low level of genetic differentiation (cpDNA: FST = 0.1628; ITS: FST = 0.0297) in P. armeniaca. Analysis of molecular variance (AMOVA) revealed that most of the genetic variation in P. armeniaca occurred among individuals within populations. The value of interpopulation differentiation (NST) was significantly higher than the number of substitution types (GST), indicating genealogical structure in P. armeniaca. P. armeniaca shared genotypes with related species and may be associated with them through continuous and extensive gene flow. The haplotypes/genotypes of cultivated apricot populations in Xinjiang, North China, and foreign apricot populations were mixed with large numbers of haplotypes/genotypes of wild apricot populations from the Ili River Valley. The wild apricot populations in the Ili River Valley contained the ancestral haplotypes/genotypes with the highest genetic diversity and were located in an area considered a potential glacial refugium for P. armeniaca. Since population expansion occurred 16.53 kyr ago, the area has provided a suitable climate for the population and protected the genetic diversity of P. armeniaca.

Relative Telomere Length in Peripheral Blood Cells and Hypertension Risk among Mine Workers: A Case-Control Study in Chinese Coal Miners.

Hypertension is a common chronic disease in middle-aged and elderly people and is an important risk factor for many cardiovascular diseases. Its pathogenesis remains unclear. Epidemiological studies have found that the loss of telomere length in peripheral blood cells can increase the risk of coronary heart disease, myocardial infarction, and other diseases. However, a correlation between loss of telomere length and hypertension has not been established. In this study, we aimed to explore the association between telomere length and the risk of essential hypertension (EH) in Chinese coal miners. A case-control study was performed with 215 EH patients and 222 healthy controls in a large coal mining group located in North China. Face-to-face interviews were conducted by trained staff with the necessary medical knowledge. Relative telomere length (RTL) was measured by a quantitative real-time PCR assay using DNA extracted from peripheral blood. In the control group, the age-adjusted RTL was statistically significantly lower in miners performing hard physical labour compared with nonphysical labour (P = 0.043). A significantly shorter age-adjusted RTL was found in the control group of participants who consumed alcohol regularly compared with those who do not consume alcohol (P = 0.024). Age-adjusted RTL was negatively correlated with body mass index (BMI) and alcohol consumption. Hypertension was also found to be significantly correlated with factors such as age, BMI, alcohol consumption, smoking, and tea consumption. Our results suggest that RTL is associated with hypertension in coal miners.

Analysis of carotenoid content and diversity in apricots (Prunus armeniaca L.) grown in China.

The carotenoids in the peel and flesh of 41 apricot cultivars were qualitatively and quantitatively analysed by UHPLC-APCI-MS/MS, and the L*, a*, b* and quality indexes of the fruits were determined. The results showed that the L*, a*, b* and quality indexes of the fruits were quite different, and 13 carotenoids were detected in the peel and flesh of apricots, among which ε-carotene, α-cryptoxanthin and apocarotenal were newly detected carotenoids in apricots. The total carotenoid content of the 41 apricot cultivars varied from 20.983 to 320.278 µg/g FW, and the total carotenoid content varied from 17.353 to 222.098 µg/g FW in the peel and from 2.536 to 98.179 µg/g FW in the flesh. The main components of apricot fruits were ß-carotene and (E/Z)-phytoene, followed by ß-cryptoxanthin and lutein. This study shows that carotenoids in apricot fruits have rich metabolic diversity.

Genetic diversity, population structure, and relationships of apricot (Prunus) based on restriction site-associated DNA sequencing.

Single-nucleotide polymorphisms (SNPs) are the most abundant form of genomic polymorphisms and are widely used in population genetics research. Here, high-throughput sequencing was used to examine the genome-level diversity, population structure, and relationships of apricot, which are important for germplasm conservation and molecular breeding. Restriction site-associated DNA sequencing (RAD-seq) was adopted to sequence 168 Prunus spp. accessions distributed in five ecological groups, including 74 accessions of cultivated Prunus armeniaca L. and 94 accessions of wild apricots (P. armeniaca L. and Prunus sibirica L.), which generated 417,961 high-quality SNPs. We used cluster, genetic structure, and principal component analyses to examine the genetic diversities and genetic relationships of the 168 accessions. The Dzhungar-Ili ecological group accessions showed the highest genetic diversity in terms of private allele number, observed heterozygosity, and nucleotide diversity. We speculate that the Central Asian ecological group accessions were domesticated from the Dzhungar-Ili ecological group accessions. The population structure and gene flow of the North China and European ecological group accessions suggested a genetic background of P. sibirica. We argue that the two groups should be considered hybrid swarms connected to P. sibirica by continuous and extensive gene flow. P. armeniaca originated in Northwest China (Ili Valley), subsequently spread throughout Central Asia, and eventually spread to Europe. In addition, selective sweep signatures in P. armeniaca during domestication from wild to cultivated apricots, combined with differentially expressed genes, underlie distinct fruit traits, including sugars, aromas, organic acids, and carotenoids. This study provides substantive and valuable genomic resources that will significantly advance apricot improvement and effective utilization.

Genetic Diversity of Potato virus Y in Potato Production Areas in Northeast China.

In 2011-2014, ELISA or nucleic acid spot hybridization (NASH) testing for common potato viruses or Potato spindle tuber viroid (PSTVd) was performed on 500 leaf samples collected in potato fields in the northeast provinces Heilongjiang and Inner Mongolia, China. The results revealed that 38.4% (Heilongjiang) and 27.7% (Inner Mongolia) were positive for Potato virus Y (PVY). To unveil the strain composition and population structure of PVY in the region, the multiplex RT-PCR described by Chikh-Ali et al. was performed on all of the ELISA-PVY-positive samples. Of the 158 samples whose PVY strain scenarios could be determined, PVYNTN-NW-SYR-II and PVYN-Wi were the most abundant strains, occurring in 58.9 and 47.5% samples, followed by PVYNTN-NW-SYR-I (31.0%), PVYN:O (19.6%), Eu-PVYNTN (7.6%), NA-PVYN (1.3%), and PVYO (0.6%). In the 84 single-strain-infected samples, PVYN-Wi accounted for 41.7%, PVYNTN-NW-SYR-II for 40.5%, PVYNTN-NW-SYR-I for 14.3%, and PVYN:O and Eu-PVYNTN for 3.6% each. Seven isolates representing PVYNTN-NW-SYR-I (HLJ-6-1 and HLJ-9-4), PVYNTN-NW-SYR-II (INM-W-369-12 and SC-1-1-2), PVYN:O (HLJ-30-2), and PVYN-Wi (HLJ-BDH-2 and HLJ-C-429) were sequenced and analyzed molecularly. Whereas the sequence identities for isolates belonging to the same strain group were >98.5%, they fell for isolates belonging to different strain groups to 92.7-98.1% at the genome level and 96.1-98.4% at the polyprotein level. Interestingly, the exact location of the recombination events varied among isolates within a strain group. Phylogenetic analysis of all 42 full length PVY sequences from China indicated that most clustered to various recombinant groups, despite the fact that the PVY isolates were isolated from at least five host species. Pathological analysis of four isolates representing PVYN:O, PVYN-Wi, PVYNTN-NW-SYR-I, and PVYNTN-NW-SYR-II revealed that the PVYNTN-NW-SYR-II isolate incited the most severe symptoms on potato cultivar Kexin 13, followed by PVYNTN-NW-SYR-I, PVYN:O and PVYN-Wi. The PVYNTN-NW-SYR-I and PVYNTN-NW-SYR-II isolates also caused necrotic ringspots on the tubers of Kexin 13, indicating their ability to induce the potato tuber necrotic ringspot disease in potato.

Complete genome sequence of a novel lytic bacteriophage isolated from Ralstonia solanacearum.

A lytic podophage RSPI1 was isolated from tobacco field soil collected in Fujian Province, South China using host bacterium Ralstonia solanacearum Tb15-14. Whole genome sequencing of this phage was performed using the high-throughput Ion Torrent PGM Sequencer. The complete genome of RSPI1 was 43,211 bp in length with a mean DNA G + C content of 61.5%. A total of 48 open reading frames were identified with lengths ranging from 132 bp to 5,061 bp, of which, 11, 12 and 25 were identified as functional, structural and unknown genes, respectively. A BLAST analysis revealed that this phage genome had a query cover of 78-79% and a highest identity of 84% with four podophages that infect Burkholderia pseudomallei. Two neighbor-joining phylogenetic trees were constructed using phage DNA polymerase I and tail fiber protein sequences and showed that this phage is closely related to Burkholderia phage Bp-AMP1, and also related to several phages that infect Ralstonia solanacearum. These findings indicate that RSPI1 is a novel phage that infects the notorious plant pathogen Ralstonia solanacearum.

A Novel Recombined Potato virus Y Isolate in China.

This study reports the findings of a distinct Potato virus Y (PVY) isolate found in Northeast China. One hundred and ten samples (leaves and tubers) were collected from potato plants showing mosaic symptoms around the city of Harbin in Heilongjiang province of China. The collected tubers were planted and let to grow in a greenhouse. New potato plants generated from these tubers showed similar symptoms, except for one plant. Subsequent serological analyses revealed PVY as the causing agent of the disease. A novel PVY isolate (referred to as HLJ-C-44 in this study) was isolated from this sample showing unique mild mosaic and crisped leaf margin symptoms. The complete genome of this isolate was analyzed and determined. The results showed that HLJ-C-44 is a typical PVY isolate. Phylogenetic analysis indicated that this isolate belongs to the N-Wi strain group of PVY recombinants (PVYN-Wi) and also shared the highest overall sequence identity (nucleotide and amino acid) with other members of this strain group. However, recombination analysis of isolate HLJ-C-44 revealed a recombination pattern that differed from that of other PVYN-Wi isolates. Moreover, biological assays in four different potato cultivars and in Nicotiana tabacum also revealed a different phenotypic response than that of a typical PVYN-Wi isolate. This data, combined, suggest that HLJ-C-44 is a novel PVY recombinant with distinct biological properties.

[Isolation and phylogenetic analysis of major capsid gene (g23) of bacteriophages infecting Sinorhizobium meliloti].

Objective: In order to provide scientific data for studying the ecology of phage infecting Sinorhizobium meliloti, we examined morphological characteristics of rhizobiophages and their phylogenetic status of the major captain protein g23. Methods: Rhizobiophages were isolated by the double-layer plate method with host Sinorhizobium meliloti USDA1002T. The morphological characteristic of rhizobiophages were studied by transmission electron microscope. Meanwhile, rhizobiophage DNA was extracted, and the g23 that encodes the major capsid protein of bacteriophages was chosen as objective gene in PCR amplification. Results: Three rhizobiophages were isolated, all had an icosahedral head with approximately 81 to 86 nm in diameter and a long contractile tail with 54 to 70 nm in length. Basic local alignment search tool searches in website of national center for biotechnology information (NCBI) revealed that the g23 amino acid sequences obtained in this study had high identity with each other, but had very lower identity with those from T-evens, PseudoT-evens, SchizoT-evens and ExoT-evens. Phylogenetic analysis showed that the isolated g23 sequences formed a unique clade with those clones obtained from different ecosystem. Conclusion: All results indicated that the isolated rhizobiophages belong to family Myoviridae, a new group of T4 phages, which had lower identity with the g23 clones obtained in different environment.

[Characteristics of P1 gene of potato virus Y in Heilongjiang].

Objective: Based on different potato virus Y isolates gene sequencing, we studied the diversity of potato virus Y strains, to provide information for molecular detection, prevention and control of the virus. Methods: P1 gene of 15 samples of potato virus Y of Heilongjiang Province was cloned and then the sequences of genes were analyzed by using phylogenetic tree. Results: Samples were divided into two groups. According to a comparative analysis, 10 samples have highly conservative and homologous genes. They are the dominant population in the research area and have certain genetic distance to other domestic samples and foreign samples. In another group, 5 samples differ significantly with local dominant population in term of P1 gene. These 5 samples also have some differences and their P1 genes are close to those of other domestic samples and foreign samples. By comparing PVY strain data provided by uploaded sequences in GenBank, it found that P1 gene of test samples is similar with PVYNTN-NW strains. These 15 samples as well as other domestic samples are evolved from PVYN strains. Conclusions: The P1 gene analysis demonstrated that PVY is influenced by environment significantly and PVY of 10 samples in Heilongjiang develops local characteristics in the long-term evolution. The later 5 samples reflect that most PVY in China may be introduced by foreign cultivars. At the same time, PVY spreads through regional resource exchange and tuber transportation in China.

Heme oxygenase-1 attenuates inflammation and oxidative damage in a rat model of smoke-induced emphysema.

Emphysema is a serious disease of the respiratory system and is associated with inflammation and oxidative stress. Heme oxygenase-1 (HO-1), a rate-limiting enzyme involved in heme biosynthesis, exerts potent anti-inflammatory, antioxidant, anti-apoptotic and anti­proliferative effects in various diseases. In the present study, we examined the effects of HO-1 on smoke­induced emphysema, as well as the underlying mechanisms in a rat model of smoke-induced emphysema. Rats were either exposed to cigarette smoke or sham­exposed for 20 weeks to establish the model of smoke-induced emphysema. The rats were subcutaneously injected with protoporphyrin IX [tin-protoporphyrin IX (SnPP) or ferriprotoporphyrin IX chloride (hemin)] during this period to examine the protective effects of HO-1. Subsequently, the development of emphysema, inflammatory cells, the levels of inflammatory mediators, particularly interleukin (IL)-17, tumor necrosis factor (TNF)­α, monocyte chemotactic protein­1 [MCP­1, also known as chemokine (C-C motif) ligand 2 (CCL2)], IL-8 [also known as chemokine (C-X-C motif) ligand 8 (CXCL8)], macrophage inflammatory protein­2α [MIP-2α, also known as chemokine (C-X-C motif) ligand 2 (CXCL2)] and IL-10, as well as the malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) content were determined. Exposure to smoke increased the total cell, neutrophil and macrophage counts in the bronchoalveolar lavage fluid (BALF). It also increased the levels of the inflammatory mediators, IL-17, TNF-α, MCP-1, IL-8 and MIP-2α, as well as the MDA content and induced emphysema. Treatment with hemin upregulated HO-1 expression and attenuated the development of smoke-induced emphysema by reducing inflammatory cell infiltration, decreasing the levels of inflammatory mediators and attenuating oxidative damage, to a certain extent. In conclusion, our findings demonstrate that HO-1 exerts anti-inflammatory and antioxidant effects, thus attenuating the development of smoke-induced emphysema.

Bilirubin treatment suppresses pulmonary inflammation in a rat model of smoke-induced emphysema.

BACKGROUND: Cigarette smoking is a significant risk factor for emphysema, which is characterized by airway inflammation and oxidative damage. OBJECTIVES: To assess the capacity of bilirubin to protect against smoke-induced emphysema. METHODS: Smoking status and bilirubin levels were recorded in 58 patients with chronic obstructive pulmonary diseases (COPD) and 71 non-COPD participants. The impact of smoking on serum bilirubin levels and exogenous bilirubin (20 mg/kg/day) on pulmonary injury was assessed in a rat model of smoking-induced emphysema. At sacrifice lung histology, airway leukocyte accumulation and cytokine and chemokine levels in serum, bronchoalveolar lavage fluid (BALF) and lung were analyzed. Oxidative lipid damage and anti-oxidative components was assessed by measuring malondialdehyde, superoxide dismutase (SOD) activity and glutathione. RESULTS: Total serum bilirubin levels were lower in smokers with or without COPD than non-smoking patients without COPD (P < 0.05). Indirect serum bilirubin levels were lower in COPD patients than patients without COPD (P < 0.05). In rats, cigarette smoke reduced serum total and indirect bilirubin levels. Administration of bilirubin reduced mean linear intercept and mean alveoli area, increased mean alveoli number, reduced macrophage, neutrophil and TNF-α content of BALF, and increased BALF and serum IL-10 level, but lowered local and systemic CCL2, CXCL2, CXCL8 and IL-17 levels. Bilirubin suppressed the smoke-induced systemic and regional oxidative lipid damage associated with increased SOD activity. CONCLUSION: Bilirubin attenuated smoking-induced pulmonary injury by suppressing inflammatory cell recruitment and pro-inflammatory cytokine secretion, increasing anti-inflammatory cytokine levels, and anti-oxidant SOD activity in a rat model of smoke-induced emphysema.

Stimulation of Na+-Ca2+ exchange by purified antibody against alpha-2 repeat of Na+-Ca2+ exchanger in rat cardiomyocytes.

AIM: The aim of the present study was to investigate the effect of the antibody against alpha-2 repeat on Na+-Ca2+ exchanger (NCX) current (I(Na/Ca)). To evaluate the functional specificity of this antibody, its effects on L-type Ca2+ current (I(Ca,L)), voltage-gated Na+ current (I(Na)) and delayed rectifier K+ current (I(K)) were also observed. METHODS: The whole-cell patch-clamp technique was used in this study. RESULTS: The antibody against alpha-2 repeat augmented both the outward and inward Na+-Ca2+ exchanger current concentration-dependently, with EC(50) values of 27.9 nmol/L and 24.7 nmol/L, respectively. Meanwhile, the antibody could also increase I(Ca,L) in a concentration-dependent manner with the EC(50) of 33.6 nmol/L. Effects of the antibody on I(Na) and I(K) were not observed in the present study. CONCLUSION: The present results suggest that antibody against alpha-2 repeat is a stimulating antibody to NCX and could also increase I(Ca,L) in a concentration-dependent manner, but did not have an obvious effect on I(Na) and I(K).