Omentin protects against LPS-induced ARDS through suppressing pulmonary inflammation and promoting endothelial barrier via an Akt/eNOS-dependent mechanism

Acute respiratory distress syndrome (ARDS) is characterized by increased pulmonary inflammation and endothelial barrier permeability. Omentin has been shown to benefit obesity-related systemic vascular diseases; however, its effects on ARDS are unknown. In the present study, the level of circulating omentin in patients with ARDS was assessed to appraise its clinical significance in ARDS. Mice were subjected to systemic administration of adenoviral vector expressing omentin (Ad-omentin) and one-shot treatment of recombinant human omentin (rh-omentin) to examine omentin''s effects on lipopolysaccharide (LPS)-induced ARDS. Pulmonary endothelial cells (ECs) were treated with rh-omentin to further investigate its underlying mechanism. We found that a decreased level of circulating omentin negatively correlated with white blood cells and procalcitonin in patients with ARDS. Ad-omentin protected against LPS-induced ARDS by alleviating the pulmonary inflammatory response and endothelial barrier injury in mice, accompanied by Akt/eNOS pathway activation. Treatment of pulmonary ECs with rh-omentin attenuated inflammatory response and restored adherens junctions (AJs), and cytoskeleton organization promoted endothelial barrier after LPS insult. Moreover, the omentin-mediated enhancement of EC survival and differentiation was blocked by the Akt/eNOS pathway inactivation. Therapeutic rh-omentin treatment also effectively protected against LPS-induced ARDS via the Akt/eNOS pathway. Collectively, these data indicated that omentin protects against LPS-induced ARDS by suppressing inflammation and promoting the pulmonary endothelial barrier, at least partially, through an Akt/eNOS-dependent mechanism. Therapeutic strategies aiming to restore omentin levels may be valuable for the prevention or treatment of ARDS.Acute respiratory distress syndrome (ARDS) is a devastating condition with a 30–60% mortality rate.^{1, 2} Although the pathogenesis of ARDS is complex, the inflammatory response and endothelial barrier disruption play important roles in the development of ARDS.^{3, 4, 5} Therefore, in addition to conventional anti-inflammatory treatments, therapeutic strategies aim to restore pulmonary endothelial barrier integrity and function through regulating inter-endothelial AJs and the endothelial cytoskeleton to minimize protein leakage and leukocyte infiltration under ARDS conditions.^{6, 7}Obesity, especially visceral obesity, has clearly been shown to impair systemic vasculature and to lead to the initiation and progression of vascular disorders.^{8, 9, 10} Although different from the well-documented impacts of obesity on cardiovascular disease, the relationships between obesity and ARDS have not been well elucidated. Clinical and experimental data focused on pertinent physiological changes in obesity indicate that the obesity may alter ARDS pathogenesis by ‘priming'' the pulmonary endothelial barrier for insult and amplifying the early inflammatory response, thus lowering the threshold to initiate ARDS.^{11, 12} Contrary to conventional dogma, adipose tissue is now appreciated as an important endocrine tissue that secretes various bioactive molecules called adipokines, which contribute to the progression of diverse vascular diseases, including hypertension, cardiovascular disease and atherosclerosis.^{13, 14, 15, 16} Although ARDS is not a classified pulmonary vascular disease, it is a severe inflammatory lung condition with widespread pulmonary endothelial breakdown. Clinical evidence has indicated that the obesity might be an emerging risk factor for ARDS and that circulating adipokines levels are associated with the initiation and progression of ARDS.^{11, 12, 17, 18} Moreover, experimental studies have suggested that some anti-inflammatory adipokines, such as adiponectin and apelin, exert beneficial actions on ARDS.^{19, 20, 21}Omentin is an anti-inflammatory adipokine that is abundant in human visceral fat tissue.^{22, 23} Paradoxically, higher circulating omentin-1 levels are present in lean and healthy individuals compared with the obese and diabetic patients. Moreover, as a novel biomarker of endothelial dysfunction, reduced circulating omentin levels are related to the pathological mechanism of obesity-linked vascular disorders, including type 2 diabetes, atherosclerosis, hypertension and cardiovascular disease.^{24, 25, 26, 27, 28} Furthermore, experimental studies have found that omentin stimulates vasodilation in isolated blood vessels and suppresses cytokine-stimulated inflammation in endothelial cells (ECs).^{29, 30, 31} Thus, these data suggest that omentin may protect against obesity-related vascular complications through its anti-inflammatory and vascular-protective properties; however, little is known regarding its role in lung tissue. It was reported that decreased circulating omentin-1 levels could be regarded as an independent predictive marker for the obstructive sleep apnea syndrome and that omentin protects against pulmonary arterial hypertension through inhibiting vascular structure remodeling and abnormal contractile reactivity.^{32, 33, 34} However, to our knowledge, no study has assessed the impact of omentin on ARDS.Akt-related signaling pathways function as an endogenous negative feedback mechanism in response to the injurious stimulus. Our prior studies have demonstrated that Akt-related signaling contributes to protection against ARDS.^{35, 36} Moreover, omentin has been reported to exert anti-inflammatory, pro-survival and pro-angiogenic functions in various cells via an Akt-dependent mechanism.^{30, 31, 37, 38, 39, 40, 41, 42}Collectively, given that ARDS is ultimately an obesity-related disorder of vascular function and that omentin is a favorable pleiotropic adipokine capable of anti-inflammatory, pro-angiogenic and anti-apoptotic abilities; omentin may exert beneficial effects on ARDS. In the present study, we first aimed to appraise the clinical significance of omentin in ARDS and then specifically evaluated its impact on inflammation and the endothelial barrier. Furthermore, we mechanistically investigated the role of Akt-related signaling pathways in these effects induced by omentin in vivo and in vitro.     

Comparison of Risk Factor between Lacunar Stroke and Large Artery Atherosclerosis Stroke: A Cross-Sectional Study in China

Background

Stroke is the second most common cause of mortality in China. Although most subtypes of ischemic stroke share similar risk factors, they have different etiologies. Our study aimed to evaluate the different risk factor profiles between the stroke subtypes, lacunar infarcts (LI) and large-artery atherosclerosis (LAA), and clarify the characteristics of current acute ischemic stroke in China.

Methods

In this cross-sectional study, we analyzed the clinical characteristics of 1982 patients with acute ischemic stroke who were admitted to the neurology department at the Peking University First Hospital between 2007 and 2014. Ischemic stroke was further classified into LAA, LI, cardioembolism (CE) and undetermined causes of infarction (UDI) according to TOAST classification. Demographic characteristics, risk factors, as well as the findings of laboratory and imaging tests of 1773 patients with LAA and LI, were analyzed by univariate and multivariate logistic analysis.

Results

Of the 1982 ischemic stroke patients included in this study, 1207 were diagnosed with LAA, 566 with LI, 173 with cardioembolism (CE) and 36 with undetermined causes of infarction (UDI). By comparing the risk factors in multivariate logistic regression analysis, hypertension [odds ratio (OR) = 1.832] and white matter leukoaraiosis (WML) (OR = 1.865) were found to be more strongly correlated with LI than LAA. Low density lipoprotein- cholesterol (LDL-c) (OR = 0.774) were more strongly related to LAA than LI.

Conclusions

This study found that hypertension and WML were more strongly correlated with LI than LAA. LDL-c was more strongly related to LAA than LI.     

Role of Gemcitabine and Pemetrexed as Maintenance Therapy in Advanced NSCLC: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Gemcitabine and pemetrexed have been used as maintenance therapy. However, few systematic reviews and meta-analyses have assessed their effects in the newest studies. This systematic review and meta-analysis were conducted to assess the role of gemcitabine and pemetrexed in the maintenance treatment of non-small-cell lung carcinoma (NSCLC).

Methods

We performed a literature search using PubMed, EMBASE and Cochrane library databases from their inceptions to September 16, 2015. We also searched the American Society of Clinical Oncology (ASCO), European Society for Medical Oncology (ESMO), and National Comprehensive Cancer Network (NCCN) databases from 2008 to 2015. Two authors independently extracted the data. The Cochrane Collaboration’s risk of bias graph was used to assess the risk of bias. The GRADE system was used to assess the grading of evidence, and a meta-analysis was conducted using Stata 11.0 software.

Results

Eleven randomized controlled trial (RCT) studies were collected. Ten studies were included in the meta-analysis and divided into the following 4 groups: gemcitabine vs. best supportive care (BSC)/observation, pemetrexed vs. BSC/placebo, pemetrexed + bevacizumab vs. bevacizumab and pemetrexed vs. bevacizumab. Gemcitabine exhibited significantly improved progression-free survival (PFS) compared with BSC (hazard ratio (HR) = 0.62, p = 0.000). Pemetrexed exhibited significantly improved PFS (HR = 0.54, p = 0.000) and OS (HR = 0.75, p = 0.000) compared with BSC. Pemetrexed + bevacizumab almost exhibited significantly improved PFS (HR = 0.71, p = 0.051) compared with bevacizumab. Pemetrexed exhibited no improvement in PFS or overall survival (OS) compared with bevacizumab. Regarding the grade, the GRADE system indicated that the gemcitabine group was "MODERATE", the pemetrexed group was "HIGH", and both the pemetrexed + bevacizumab vs. bevacizumab groups and pemetrexed vs. B groups were "LOW".

Conclusions

Gemcitabine or pemetrexed compared with BSC/observation/placebo significantly improved PFS or OS. Whether pemetrexed + bevacizumab compared with bevacizumab alone significantly improves PFS requires further investigation.     

The Sublethal Effects of β-Ecdysterone,a Highly Active Compound from Achyranthes bidentata Blume,on Grape Phylloxera,Daktulosphaira vitifoliae Fitch

Grape phylloxera, Daktulosphaira vitifoliae (Fitch) (Hemiptera, Phylloxeridae), is a very destructive insect pest of grapevines. Intercropping of Achyranthes bidentata Blume (f. Amaranthaceae) and Vitis spp. grapevines can be useful to control this pest. In the present study, the toxicity of 22 compounds, known to be present in A. bidentata, to grape phylloxera was evaluated. All treatments were toxic towards grape phylloxera but the degree of toxicity differed between treatments. Among the 22 tested compounds, several of which proved toxic towards grape phylloxera. However β-ecdysterone had higher toxic effects against grape phylloxera, with LC₅₀ values of 175.73 mg a.i. liter^-1. In addition, we assessed the sublethal effects of LC₁₀, LC₂₀ and LC₄₀ of β-ecdysterone on grape phylloxera. The fourth instar and adult developmental periods and total life span were significantly prolonged by LC₄₀ of β-ecdysterone. Fecundity decreased when grape phylloxera were exposed to LC₂₀ and LC₄₀ of β-ecdysterone. In addition, LC₄₀ of β-ecdysterone decreased the intrinsic rate of increase (r_m) and the finite rate of increase (λ) and prolonged the population doubling time (DT). The net reproductive rate (R₀) was significantly reduced by both the LC₂₀ and LC₄₀ β-ecdysterone treatments. Our results demonstrated that β-ecdysterone had higher toxic effects and significant sublethal effects on grape phylloxera, and showed potential control of grape phylloxera.     

Yersinia spp. Identification Using Copy Diversity in the Chromosomal 16S rRNA Gene Sequence

API 20E strip test, the standard for Enterobacteriaceae identification, is not sufficient to discriminate some Yersinia species for some unstable biochemical reactions and the same biochemical profile presented in some species, e.g. Yersinia ferderiksenii and Yersinia intermedia, which need a variety of molecular biology methods as auxiliaries for identification. The 16S rRNA gene is considered a valuable tool for assigning bacterial strains to species. However, the resolution of the 16S rRNA gene may be insufficient for discrimination because of the high similarity of sequences between some species and heterogeneity within copies at the intra-genomic level. In this study, for each strain we randomly selected five 16S rRNA gene clones from 768 Yersinia strains, and collected 3,840 sequences of the 16S rRNA gene from 10 species, which were divided into 439 patterns. The similarity among the five clones of 16S rRNA gene is over 99% for most strains. Identical sequences were found in strains of different species. A phylogenetic tree was constructed using the five 16S rRNA gene sequences for each strain where the phylogenetic classifications are consistent with biochemical tests; and species that are difficult to identify by biochemical phenotype can be differentiated. Most Yersinia strains form distinct groups within each species. However Yersinia kristensenii, a heterogeneous species, clusters with some Yersinia enterocolitica and Yersinia ferderiksenii/intermedia strains, while not affecting the overall efficiency of this species classification. In conclusion, through analysis derived from integrated information from multiple 16S rRNA gene sequences, the discrimination ability of Yersinia species is improved using our method.     

Genomic location and expression analysis of expansin gene family reveals the evolutionary and functional significance in <Emphasis Type="Italic">Triticum aestivum</Emphasis>

The plant-specific expansin proteins constitute an ancient and major gene family known to have roles in regulating diverse biological processes in plants. Although the functions of many expansin genes have been identified in wheat and other species, little is known about the evolution and genomic locations of the expansin genes in wheat (Triticum aestivum). In this study, a total of 87 expansin genes were identified in the wheat genome, including 52 EXPAs, 42 EXPBs and 4 EXLAs. The EXLB gene was not found in the wheat genome. Phylogenetic tree and comparative analysis revealed amplification of the EXPBs in rice, maize and wheat. The predicted wheat expansins were distributed across 14 of 21 chromosomes with different densities, 3 tightly co-located clusters and 15 paralogous pairs, indicating that tandem duplication and segmental duplication events also played roles in the evolution of expansins in wheat. In addition, the gene structures and conserved protein domains of wheat expansins suggest high levels of conservation within the phylogenetic subgroups. Analysis of a published microarray database showed that most wheat expansin genes exhibit different expression levels in different tissues and developmental stages. To our knowledge, this is the first report of a genome-wide analysis of the wheat expansin gene family, which should provide valuable information for further elucidating the classification and putative functions of the entire gene family.     

Anti-Inflammatory and Antinociceptive Properties of Flavonoids from the Fruits of Black Mulberry (Morus nigra L.)

We analyzed the anti-inflammatory and antinociceptive activities of total flavonoids (TF) found in black mulberry fruits. The TF content was 20.9 mg/g (dry weight). Two anthocyanins, cyanidin-3-O-glucoside (8.3 mg/g) and cyanidin-3-O-rutinoside (2.9 mg/g), were identified in the fruits by UPLC. The TF of black mulberry fruits had significant reducing power and radical (OH^-,O2.−, DPPH and ABTS) scavenging activities that was demonstrated in a dose-response curve. The TF had inhibitory activities on xylene-induced ear edema and carrageenan-induced paw edema in mice. In addition, TF had antinociceptive activities in the two nociceptive phases of formalin test. We used ELISA to detect the pro-inflammatory cytokines IL-1β, TNF-α, IFN-γ, and NO in the serum of mice. These cytokines were significantly inhibited or scavenged by TF (50 and 100 mg/kg). The results demonstrated that TF of black mulberry possess anti-inflammatory and analgesic effects that might correlate to its antioxidant activities and inhibition of pro-inflammatory cytokines.     

High-level expression and biochemical characterization of a novel cold-active lipase from <Emphasis Type="Italic">Rhizomucor endophyticus</Emphasis>

Objectives

To identify novel cold-active lipases from fungal sources and improve their production by heterologous expression in Pichia pastoris.

Results

A novel cold-active lipase gene (ReLipB) from Rhizomucor endophyticus was cloned. ReLipB was expressed at a high level in Pichia pastoris using high cell-density fermentation in a 5-l fermentor with the highest lipase activity of 1395 U/ml. The recombinant lipase (RelipB) was purified and biochemically characterized. ReLipB was most active at pH 7.5 and 25 °C. It was stable from pH 4.5–9.0. It exhibited broad substrate specificity towards p-nitrophenyl (pNP) esters (C₂–C₁₆) and triacylglycerols (C₂–C₁₂), showing the highest specific activities towards pNP laurate (231 U/mg) and tricaprylin (1840 U/mg), respectively. In addition, the enzyme displayed excellent stability with high concentrations of organic solvents including cyclohexane, n-hexane, n-heptane, isooctane and petroleum ester and surfactants.

Conclusions

A novel cold-active lipase from Rhizomucor endophyticus was identified, expressed at a high level and biochemically characterized. The high yield and unique enzymatic properties make this lipase of some potential for industrial applications.

     

Chinese Cretaceous larva exposes a southern Californian living fossil (Insecta,Coleoptera, Eucnemidae)

Palaeoxenus sinensis Chang, Muona & Teräväinen sp. nov. (Coleoptera, Eucnemidae) is described on the basis of a Cretaceous larva found from the Yixian Formation in Huangbanjigou, Liaoning Province, China. The only previously known member of this clade is a southern Californian endemic, Dohrn's elegant eucnemid beetle (Palaeoxenus dohrni), a species that develops in conifers, especially the incense cedar (Calocedrus decurrens). The new find proves that the highly specialized main eucnemid lineages had evolved 123 Mya, before the main radiation of the angiosperms and probably as an adaptation to development in gymnosperms.