Expression Of PLA Research Articles

Integrated metabolomics and lipidomics investigation of the mechanism of Danggui Sini Decoction on improving lipid homeostasis in primary dysmenorrhea

BackgroundDanggui Sini Decoction (DGSND) is a classic prescription for treating primary dysmenorrhea (PD), while, the ameliorating effects of DGSND on PD and its mechanisms are not yet fully understood. PurposeThe present study is devoted to investigate the protective effect of DGSND against PD and the possible mechanism from the perspective of metabolomics as well as lipidomics. MethodsDGSND was characterized by UPLC-Q-TOF/MS. The PD rat model was induced by estradiol benzoate and oxytocin, and traditional pharmacology, including writhing times, latency time, biochemical index, organ index, and histopathology were performed to evaluated the efficacy of DGSND on PD. Urine metabolomics strategy combined with functional analysis was adopted to delineate the therapeutic effect of DGSND on PD rats and anchor the crucial pathway, and lipidomics analysis was further performed with the uterine tissue as the research object to elucidate the protective mechanism of DGSND from the perspective of lipid homeostasis. Finally, western blot analysis was used to validate the expression of key metabolic enzymes in lipid metabolism. ResultsDGSND was effective in ameliorating writhing times, latency time, the value of prostaglandin F2α (PGF2α)/PGE2, uterus index, and morphological changes of PD rats. Metabolic signature of PD rats was primarily characterized by the disturbance of steroid hormone metabolism, amino acid metabolism, and lipid metabolism. Functional analysis revealed the urine biomarkers of PD were most related with lipid abnormality. Further lipidomics analysis indicated DGSND exerted anti-PD effects by remodeling lipid homeostasis, which might be due to the significant correlations between different kinds of lipids, especially the extremely high correlation of phosphatidylethanolamine, phosphatidylcholine, and fatty acids. Moreover, the key metabolic enzymes expression of CK, PLA2, LPCAT3, COX-2, and 5-LOX can be greatly downregulated by DGSND. ConclusionOur findings demonstrated a novel protective mechanism of DGSND against PD by regulating lipid homeostasis.

Quercetin alleviates inflammation induced by porcine reproductive and respiratory syndrome virus in MARC-145 cells through the regulation of arachidonic acid and glutamine metabolism.

Porcine reproductive and respiratory syndrome virus (PRRSV) infection causes severe inflammatory response, respiratory disease and sow reproductive failure. Quercetin is among the widely occurring polypheno found abundantly in nature. Quercetin has anti-inflammatory, anti-oxidative and anti-viral properties. This study aimed to explore the effect and mechanism of quercetin on PRRSV-induced inflammation in MARC-145 cells. Observing the cytopathic effect and measurements of inflammatory markers in MARC-145 cells collectively demonstrate that quercetin elicits a curative effect on PRRSV-induced inflammation. Liquid chromatography-mass spectrometry was further used for a non-targeted metabolic analysis of the role of quercetin in the metabolic regulation of PRRSV inflammation in MARC-145 cells. It was shown that quercetin attenuated PRRSV-induced cytopathy in MARC-145 cells. Quercetin treatment inhibited PRRSV replication in MARC-145 cells in a dose-dependent manner. We also found that quercetin inhibited PRRSV-induced mRNA expression and secretion levels of tumour necrosis factor-α, interleukin 1β and interleukin 6. Metabolomics analysis revealed that quercetin ameliorated PRRSV-induced inflammation. Pathway analysis results revealed that PRRSV-induced pathways including arachidonic acid metabolism, linoleic acid, glycerophospholipid and alanine, aspartate and glutamate metabolism were suppressed by quercetin. Moreover, we confirmed that quercetin inhibited the activation of NF-κB/p65 pathway, probably by attenuating PLA2, ALOX and COX mRNA expression. These results provide a crucial insight into the molecular mechanism of quercetin in alleviating PRRSV-induced inflammation.

Identification and Validation of Reliable Reference Genes for Gene Expression Studies in Koelreuteria paniculata.

RT-qPCR is considered a rapid and reliable technique for analyzing gene expression. This technique is commonly used to analyze the expression of various genes at diverse transcriptional levels in different samples. However, few studies have characterized ornamental Koelreuteria species for reliable reference genes. In this study, eight reference genes were evaluated as controls in RT-qPCR with SYBR green to quantify gene expression in different Koelreuteria paniculata samples. All selected reference genes showed a broad range of Ct values in all samples, which was supportive of their variable expression. Our results showed significant variation in the stable expression of K. paniculata genes. Sample data, analyzed using geNorm, NormFinder, and BestKeeper, showed that phospholipase (PLA2) and β-actin (ACT) were the most suitable and statistically reliable reference genes, whereas ribosomal protein L13 (RPL13) and elongation factor 1-α (EF1α) were less stable and unsuitable for use as internal controls. To compare gene expression levels, two or more reference genes should be used for data normalization. Thus, the stability and expression of both PLA2 and ACT were believed to provide better normalization and quantification of the transcript levels for gene expression studies in K. paniculata.

Dietary DHA and ARA level and ratio affect the occurrence of skeletal anomalies in pikeperch larvae (Sander lucioperca) through a regulation of immunity and stress related gene expression

Several causative factors have been proposed for the occurrence of skeletal anomalies in fish larvae, among which we quote nutritional factors, such as LC-PUFAs. This study aimed to investigate the effect of different dietary DHA and ARA level and ratio on pikeperch (Sander lucioperca) larval development and performance, digestive capacity, fatty acids composition, skeleton anomalies and molecular markers of oxidative stress status (sod, gpx, and cat), stress response (StAR, gr, pparα, hsl and pepck), fatty acid synthesis (fadsd6, elovl5), eicosanoids synthesis (pla2, cox2, lox5, pge2, and lta4h), and bone development (twist, mef2c, sox9, and alp). Pikeperch larvae were fed six microdiets containing two different dietary levels of DHA (0.5% and 3.5%) combined with three levels of ARA (1.2%, 0.6%, and 0.3%). Dietary fatty acid changes did not affect growth performance but significantly influenced enzymatic activities. A significant increase in skeletal anomalies with DHA intake increment was recorded. StAR, cox2, pla2 and hsl expression were significantly depressed in 2.5% DHA larvae. An opposite effect of dietary DHA elevation was recorded in gpx expression. Both DHA and ARA had a significant effect on pparα, gr, and pge2 expressions. Although no significant interactions were found, pge2, gr, and pparα displayed a differential pattern of expression between the different treatments. A strong association was found for the larval tissue amount of ARA and DHA with eicosanoid metabolism, stress response and skeleton anomaly related genes. These results denoted the effects of dietary LC-PUFAs on immune/stress gene regulation and their potential implication in skeleton development.

Establishment of a New Model of Lumbar Intervertebral Disc Degeneration With Pathological Characteristics.

A prospective study. Intervertebral disc degenerative disease is a common and frequently-occurring disease in adults and is the main cause of lower back pain. However, there is a lack of universal animal models to study disc degeneration. Forty-two male New Zealand white rabbits aged 12 months were used in this study. We established an endplate ischemic disc degeneration model though surgical ligation of rabbit lumbar vertebral body segment arteries. Two weeks after surgery, 6 experimental animals were randomly selected for follow-up tests. First, ischemia and lumbar disc degeneration were confirmed using imaging techniques. Then, immunohistochemical staining was performed to observe the growth of the annulus fibrosus. Finally, quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting were used to detect mRNA expression and protein content of IL-1α, TNFα, collagen II, MMP-3, aggrecan, and PLA2 in the nucleus pulposus of the disc. Imaging examination confirmed the successful construction of a lumbar disc degeneration model. Histological analysis and biochemical analysis showed a damaged intervertebral disc structure, and collagen II and aggrecan, the key extracellular matrix components of intervertebral discs, were reduced in synthesis and content. The synthesis and expression of IL-1α, TNFα, PLA2, and MMP-3 related to disc catabolism and inflammatory response were enhanced. We successfully constructed a lumbar disc degeneration ischemia model, which provides a novel approach to study the pathological mechanisms involved in discogenic low back pain and to prevent and treat discogenic low back pain.

The Genome of Shaw's Sea Snake (Hydrophis curtus) Reveals Secondary Adaptation to Its Marine Environment.

The transition of terrestrial snakes to marine life ∼10Ma is ideal for exploring adaptive evolution. Sea snakes possess phenotype specializations including laterally compressed bodies, paddle-shaped tails, valvular nostrils, cutaneous respiration, elongated lungs, and salt glands, yet, knowledge on the genetic underpinnings of the transition remains limited. Herein, we report the first genome of Shaw's sea snake (Hydrophis curtus) and use it to investigate sea snake secondary marine adaptation. A hybrid assembly strategy obtains a high-quality genome. Gene family analyses date a pulsed coding-gene expansion to ∼20Ma, and these genes associate strongly with adaptations to marine environments. Analyses of selection pressure and convergent evolution discover the rapid evolution of protein-coding genes, and some convergent features. Additionally, 108 conserved noncoding elements appear to have evolved quickly, and these may underpin the phenotypic changes. Transposon elements may contribute to adaptive specializations by inserting into genomic regions around functionally related coding genes. The integration of genomic and transcriptomic analyses indicates independent origins and different components in sea snake and terrestrial snake venom; the venom gland of the sea snake harbors the highest PLA2 (17.23%) expression in selected elapids and these genes may organize tandemly in the genome. These analyses provide insights into the genetic mechanisms that underlay the secondary adaptation to marine and venom production of this sea snake.

9t18:1 and 11t18:1 activate the MAPK pathway to regulate the expression of PLA2 and cause inflammation in HUVECs.

trans fatty acids (TFAs) have been reported to promote vascular diseases mainly by promoting apoptosis and inflammation of vascular endothelial cells. However, it has been reported in recent years that elaidic acid (9t18:1) and vaccenic acid (11t18:1) may have different effects on vascular health. This study investigated the effects of 9t18:1 and 11t18:1 on human umbilical vein endothelial cell (HUVEC) function and the possible mechanism of inflammation by analyzing the changes in the phospholipid composition and the relationship between phospholipase A2 (PLA2) and MAPK pathway. Here we found that the effect of 11t18:1 on cell viability, membrane damage and cellular inflammation was significantly lower than that of 9t18:1 (p < 0.05). And 9t18:1 and 11t18:1 had different effects on phospholipid composition. Both 9t18:1 and 11t18:1 significantly increased the protein expression of PLA2. Moreover, the MAPK pathway regulated the expression of PLA2, inflammatory cytokines and cyclooxygenase-2 (COX-2) and the secretion of prostaglandin E2 (PGE2) in HUVECs induced by 9t18:1 and 11t18:1. In conclusion, 9t18:1 and 11t18:1 activated the MAPK pathway which regulated the expression of PLA2 to cause inflammation in HUVECs.

Metabolomic and lipidomic analysis of the effect of pioglitazone on hepatic steatosis in a rat model of obese Type 2 diabetes.

Background and PurposeThiazolidinediones, acting as PPAR‐γ ligands, reduce hepatic steatosis in humans and animals. However, the underlying mechanism of this action remains unclear. The purpose of this study was to investigate changes in hepatic metabolites and lipids in response to treatment with the thiazolidinedione pioglitazone in an animal model of obese Type 2 diabetes.Experimental ApproachMale Otsuka Long‐Evans Tokushima Fatty (OLETF) rats were orally administered either vehicle (control) or pioglitazone (30 mg·kg−1) and fed a high‐fat diet (60% kcal fat) for 12 weeks. Hepatic metabolites were analysed via metabolomic and lipidomic analyses. Gene expression and PLA2 activity were analysed in livers from pioglitazone‐treated and control rats.Key ResultsOLETF rats that received pioglitazone showed decreased fat accumulation and improvement of lipid profiles in the liver compared to control rats. Pioglitazone treatment significantly altered levels of hepatic metabolites, including free fatty acids, lysophosphatidylcholines and phosphatidylcholines, in the liver. In addition, pioglitazone significantly reduced the expression of genes involved in hepatic de novo lipogenesis and fatty acid uptake and transport, whereas genes related to fatty acid oxidation were up‐regulated. Gene expression and enzyme activity of PLA2, which hydrolyzes phosphatidylcholines to release lysophosphatidylcholines and free fatty acids, were significantly decreased in the livers of pioglitazone‐treated rats compared to control rats.Conclusions and ImplicationsOur results present evidence for the ameliorative effect of pioglitazone on hepatic steatosis, largely due to the regulation of lipid metabolism, including fatty acids, lysophosphatidylcholines, phosphatidylcholines and related gene‐expression patterns.

Role of the placenta in serum autotaxin elevation during maternal cholestasis.

Intrahepatic cholestasis of pregnancy (ICP) is frequently accompanied by pruritus, whose etiology has been associated with an enhanced production of lysophosphatidic acid (LPA) by the combined action of phospholipase A1/A2 (PLA1/PLA2) and autotaxin (ATX). Here, we have investigated whether the placenta is involved in LPA release to maternal circulation during ICP. Serum levels of ATX and LPA (determined by ELISA) were elevated in women with ICP, and a correlation between both parameters was found. No relationship between serum levels of ATX or LPA and bile acids was found. Expression levels of ATX and PLA2 were determined by RT-qPCR and Western blot. Placenta ATX but not PLA2 was significantly upregulated in ICP, and a tendency to increase was found at the protein level. A correlation between serum ATX and placental ATX mRNA levels was found. In human placenta at term, ATX was clearly detected (by immunofluorescence) in Hofbauer cells, but only faintly in trophoblast cells. In pregnant rats, the expression of Atx and Pla2 in placenta was lower than in liver. When obstructive cholestasis was imposed by bile duct ligation from day 14 of gestation until term, placenta Atx and Pla2 expression was markedly enhanced, and overexpression was confirmed at the protein level for Pla2, whereas Atx protein was not detected. In conclusion, the placenta substantially participates in LPA production during gestation. This contribution is markedly higher during maternal cholestasis and hence, may be involved in ICP-associated pruritus. NEW & NOTEWORTHY Fetal placental macrophages and, to a lesser extent, trophoblast cells express high levels of autotaxin at term. An increased expression of mRNA and protein autotaxin, the key secretory enzyme responsible for the production of lysophosphatidic acid in serum, has been observed in placentas of women with cholestasis of pregnancy, which supports that the placenta can contribute to an increased production of this pruritogenic compound in women suffering from this liver disease.

Toll immune signal activates cellular immune response via eicosanoids

Upon immune challenge, insects recognize nonself. The recognition signal will propagate to nearby immune effectors. It is well-known that Toll signal pathway induces antimicrobial peptide (AMP) gene expression. Eicosanoids play crucial roles in mediating the recognition signal to immune effectors by enhancing humoral immune response through activation of AMP synthesis as well as cellular immune responses, suggesting a functional cross-talk between Toll and eicosanoid signals. This study tested a cross-talk between these two signals. Two signal transducing factors (MyD88 and Pelle) of Toll immune pathway were identified in Spodoptera exigua. RNA interference (RNAi) of either SeMyD88 or SePelle expression interfered with the expression of AMP genes under Toll signal pathway. Bacterial challenge induced PLA2 enzyme activity. However, RNAi of these two immune factors significantly suppressed the induction of PLA2 enzyme activity. Furthermore, RNAi treatment prevented gene expression of cellular PLA2. Inhibition of PLA2 activity reduced phenoloxidase activity and subsequent suppression in cellular immune response measured by hemocyte nodule formation. However, immunosuppression induced by RNAi of Toll signal molecules was significantly reversed by addition of arachidonic acid (AA), a catalytic product of PLA2. The addition also significantly reduced the enhanced fungal susceptibility of S. exigua treated by RNAi against two Toll signal molecules. These results indicate that there is a cross-talk between Toll and eicosanoid signals in insect immunity.

Differential expression of Lp-PLA2 in obesity and type 2 diabetes and the influence of lipids

Aims/hypothesisLipoprotein-associated phospholipase A2 (Lp-PLA2) is a circulatory macrophage-derived factor that increases with obesity and leads to a higher risk of cardiovascular disease (CVD). Despite this, its role in adipose tissue and the adipocyte is unknown. Therefore, the aims of this study were to clarify the expression of Lp-PLA2 in relation to different adipose tissue depots and type 2 diabetes, and ascertain whether markers of obesity and type 2 diabetes correlate with circulating Lp-PLA2. A final aim was to evaluate the effect of cholesterol on cellular Lp-PLA2 in an in vitro adipocyte model.MethodsAnalysis of anthropometric and biochemical variables from a cohort of lean (age 44.4 ± 6.2 years; BMI 22.15 ± 1.8 kg/m2, n = 23), overweight (age 45.4 ± 12.3 years; BMI 26.99 ± 1.5 kg/m2, n = 24), obese (age 49.0 ± 9.1 years; BMI 33.74 ± 3.3 kg/m2, n = 32) and type 2 diabetic women (age 53.0 ± 6.13 years; BMI 35.08 ± 8.6 kg/m2, n = 35), as part of an ethically approved study. Gene and protein expression of PLA2 and its isoforms were assessed in adipose tissue samples, with serum analysis undertaken to assess circulating Lp-PLA2 and its association with cardiometabolic risk markers. A human adipocyte cell model, Chub-S7, was used to address the intracellular change in Lp-PLA2 in adipocytes.ResultsLp-PLA2 and calcium-independent PLA2 (iPLA2) isoforms were altered by adiposity, as shown by microarray analysis (p < 0.05). Type 2 diabetes status was also observed to significantly alter gene and protein levels of Lp-PLA2 in abdominal subcutaneous (AbdSc) (p < 0.01), but not omental, adipose tissue. Furthermore, multivariate stepwise regression analysis of circulating Lp-PLA2 and metabolic markers revealed that the greatest predictor of Lp-PLA2 in non-diabetic individuals was LDL-cholesterol (p = 0.004). Additionally, in people with type 2 diabetes, oxidised LDL (oxLDL), triacylglycerols and HDL-cholesterol appeared important predictors, accounting for 59.7% of the variance (p < 0.001). Subsequent in vitro studies determined human adipocytes to be a source of Lp-PLA2, as confirmed by mRNA expression, protein levels and immunochemistry. Further in vitro experiments revealed that treatment with LDL-cholesterol or oxLDL resulted in significant upregulation of Lp-PLA2, while inhibition of Lp-PLA2 reduced oxLDL production by 19.8% (p < 0.05).Conclusions/interpretationOur study suggests adipose tissue and adipocytes are active sources of Lp-PLA2, with differential regulation by fat depot and metabolic state. Moreover, levels of circulating Lp-PLA2 appear to be influenced by unfavourable lipid profiles in type 2 diabetes, which may occur in part through regulation of LDL-cholesterol and oxLDL metabolism in adipocytes.

Inhibition of 5-lipoxygenase inhibitor zileuton in high-fat diet-induced nonalcoholic fatty liver disease progression model.

Objective(s):Arachidonic Acid/5-lipoxygenase (AA/5-LOX) pathway connects lipid metabolism and proinflammatory cytokine, which are both related to the development and progression of nonalcoholic fatty liver disease (NAFLD). Therefore, the present study was designed to investigate the role of AA/5-LOX pathway in progression of NAFLD, and the effect of zileuton, an inhibitor of 5-LOX, in this model.Materials and Methods:Animal model for progression of NAFLD was established via feeding high saturated fat diet (HFD). Liver function, HE staining, NAFLD activity score (NAS) were used to evaluate NAFLD progression. We detected the lipid metabolism substrates: free fatty acids (FFA) and AA, products: cysteinyl-leukotrienes (CysLTs), and changes in gene and protein level of key enzyme in AA/5-LOX pathway including PLA2 and 5-LOX. Furthermore, we determined whether NAFLD progression pathway was delayed or reversed when zileuton (1-[1-(1-benzothiophen-2-yl)ethyl]-1-hydroxyurea) was administrated.Results:Rat model for progression of NAFLD was well established as analyzed by liver transaminase activities, hematoxylin-eosin (HE) staining and NAS. The concentrations of substrates and products in AA/5-LOX pathway were increased with the progression of NAFLD. mRNA and protein expression of PLA2 and 5-LOX were all enhanced. Moreover, administration of zileuton inhibited AA/5-LOX pathway and reversed the increased transamine activities and NAS.Conclusion:AA/5-LOX pathway promotes the progression of NAFLD, which can be reversed by zileuton.

The flavonoid rutin improves kidney and heart structure and function in an adenine-induced rat model of chronic kidney disease

Many foods contain rutin, a flavonoid with many health benefits. Here we tested rutin to reverse chronic kidney disease (CKD) and associated cardiovascular disease, using an established rodent model with adenine diet (0.25%) over 16weeks. Rutin was added to the diet for the final 8weeks. We measured kidney function (blood urea nitrogen/BUN, plasma creatinine/PCr, plasma uric acid, proteinuria); kidney structure (tubular damage, fibrosis, inflammation); cardiovascular function and structure (blood pressure, left ventricular stiffness, vascular responses, echocardiography, histology); and biomarkers for oxidative stress (HO-1), inflammation (PLA-2, TNF-α) and fibrosis (TGF-β). Adenine diet increased CKD characteristics (tubulointerstitial atrophy and fibrosis, inflammation, proteinuria, BUN, PCr, uric acid) and CKD-associated cardiovascular disease. Rutin improved kidney and heart structure and function, decreased HO-1 and PLA-2 expression, but did not reduce TGF-β or TNF-α. Decreased expression of HO-1 and PLA-2 appears to be a mechanistic pathway for reno- and cardioprotection.

Lysophosphatidic acid expression in theca cells depends on the type of bovine ovarian follicle.

Lysophosphatidic acid (LPA) exerts various actions on the mammalian reproductive system. In cows, LPA stimulates the synthesis and secretion of luteotropic factors in the ovary, which affects the growth and development of ovarian follicles. The role of LPA in granulosa cells, oocyte and oocyte-cumulus complex (COC) has previously been investigated; but its role in the theca layer, which is an important structural and functional component of the ovarian follicle, is still unclear. The goal of this study was to investigate the expression of LPA in theca cells originating from different bovine ovarian follicle types. Theca cells were separated from healthy, transitional and atretic ovarian follicles, based on intrafollicular estradiol: progesterone ratios. LPA concentration in the follicular fluid (FF) in different follicle types was measured, and expression of the enzymes responsible for LPA synthesis (autotaxin [AX], phospholipase A2 [PLA2]) and receptors for LPA (LPAR1-4) were determined. The obtained results confirmed the follicle-type dependent presence of LPA in the FF of the bovine ovarian follicles. The highest concentration of LPA was detected in follicles classified as healthy and dominant. LPAR1-4, PLA2 and AX expression in theca cells in all of the types of follicles examined were detected at mRNA and protein level. These results suggest that theca cells can be a source of LPA synthesis other than granulosa cells and COCs, as well as the target for its action in the bovine ovarian follicle, with PLA2 and LPAR4 playing major roles in LPA synthesis and action.

Expression and DNA methylation of phospholipase A2 in Thai native honeybees (Hymenoptera: Apidae)

Phospholipase A2 (PLA2; EC 3.1.1.4) is a lipolytic enzyme and is one of the important components of the honeybee venom. Total RNA was extracted from four native honeybees in Thailand: Apis andreniformis, A. florea, A. cerana indica and A. dorsata. In each species, pupae’s whole body, house bees’ and foragers’ abdomen were used for RNA source. Reverse transcriptase polymerase chain reaction (RT-PCR) revealed PLA2 transcript expression levels were highest in house bees in all four tested species and were also highly expressed in foragers of A. florea and A. dorsata. However, there was no detectable PLA2 transcript expression in pupae. Furthermore, the crude protein extracts were isolated from the whole bodies of black-eyed pupae and abdomen of house bees. The PLA2 activity and specific activity levels in crude protein extracts mirrored the transcript pattern, being very low in the black-eyed pupae (0.01 to 0.05 μmol min–1 mL–1 and 0 Units (U)/mg) and higher in the house bees (1.46 to 5.64 μmol min–1 mL–1 and 1.78 to 2.26 U/mg in A. andreniformis, A. cerana indica and A. dorsata but only 0.29 μmol min–1 mL–1 and 0.72 U/mg in A. florea). DNA methylation in PLA2, investigated by bisulfite treatment and pyrosequencing, revealed a higher percentage of DNA methylation in A. florea and A. dorsata pupae (27.5 and 12%) than in house bees (9.4 and 7.0%). On the contrary, this was not the case in A. andreniformis or A. cerana indica, where no marked differences in the net DNA methylation level were found between developmental stadia. However, the percentage of DNA methylation was studied in about 120-bp fragment corresponding to the gene body. Thus, if DNA methylation is involved in the control of PLA2 expression in all four honeybee species, it may involve methylation of other sites outside of the investigated fragment and/or more specific localized CG islands.

Non-steroidal anti-inflammatory drugs attenuate the vascular responses in aging metabolic syndrome rats.

Metabolic syndrome (MS) and aging are low-grade systemic inflammatory conditions, and inflammation is a key component of endothelial dysfunction. The aim of this study was to investigate the effects of non-steroidal anti-inflammatory drugs (NSAIDs) upon the vascular reactivity in aging MS rats. MS was induced in young male rats by adding 30% sucrose in drinking water over 6, 12, and 18 months. When the treatment was finished, the blood samples were collected, and aortas were dissected out. The expression of COX isoenzymes and PLA2 in the aortas was analyzed using Western blot analysis. The contractile responses of aortic rings to norepinephrine (1 μmol/L) were measured in the presence or absence of different NSAIDs (10 μmol/L for each). Serum levels of pro-inflammatory cytokines (IL-6, TNF-α, and IL-1β) in control rats were remained stable during the aging process, whereas serum IL-6 in MS rats were significantly increased at 12 and 18 months. The levels of COX isoenzyme and PLA2 in aortas from control rats increased with the aging, whereas those in aortas from MS rats were irregularly increased with the highest levels at 6 months. Pretreatment with acetylsalicylic acid (a COX-1 preferential inhibitor), indomethacin (a non-selective COX inhibitor) or meloxicam (a COX-2 preferential inhibitor) decreased NE-induced contractions of aortic rings from MS rats at all the ages, with meloxicam being the most potent. Acetylsalicylic acid also significantly reduced the maximum responses of ACh-induced vasorelaxation of aortic rings from MS rats, but indomethacin and meloxicam had no effect. NSAIDs can directly affect vascular responses in aging MS rats. Understanding the effects of NSAIDs on blood vessels may improve the treatment of cardiovascular diseases and MS in the elders.

Posttranscriptional Regulation of the Yersinia pestis Cyclic AMP Receptor Protein Crp and Impact on Virulence

ABSTRACTThe cyclic AMP receptor protein (Crp) is a transcriptional regulator that controls the expression of numerous bacterial genes, usually in response to environmental conditions and particularly by sensing the availability of carbon. In the plague pathogen Yersinia pestis, Crp regulates the expression of multiple virulence factors, including components of the type III secretion system and the plasminogen activator protease Pla. The regulation of Crp itself, however, is distinctly different from that found in the well-studied Escherichia coli system. Here, we show that at physiological temperatures, the synthesis of Crp in Y. pestis is positively regulated at the posttranscriptional level. The loss of the small RNA chaperone Hfq results in decreased Crp protein levels but not in steady-state Crp transcript levels, and this regulatory effect occurs within the 5′ untranslated region (UTR) of the Crp mRNA. The posttranscriptional activation of Crp synthesis is required for the expression of pla, and decoupling crp from Hfq through the use of an exogenously controlled promoter and 5′ UTR increases Pla protein levels as well as partially rescues the growth defect associated with the loss of Hfq. Finally, we show that both Hfq and the posttranscriptional regulation of Crp contribute to the virulence of Y. pestis during pneumonic plague. The Hfq-dependent, posttranscriptional regulation of Crp may be specific to Yersinia species, and thus our data help explain the dramatic growth and virulence defects associated with the loss of Hfq in Y. pestis.

Anti-inflammatory Effect of Acetylpuerarin on Eicosanoid Signaling Pathway in Primary Rat Astrocytes

Astrocytes activation has been implicated in the inflammatory responses underlying brain injury and neurodegenerative diseases including bacterial infections, cerebral ischemia, and Parkinson's diseases. Acetylpuerarin is a newly modified isoflavone based on puerarin that has neuroprotective and antioxidant effects. In this study, we investigated the anti-inflammatory action of acetylpuerarin in regulating the eicosanoids generation and its underlying molecular mechanisms in lipopolysaccharide (LPS)-induced production of arachidonic acid (AA) metabolites in primary rat astrocytes. The results showed that acetylpuerarin concentration dependently inhibited the LPS-induced production of AA metabolites such as prostaglandin E2 (PGE2) and leukotriene C4 (LTC4), and acetylpuerarin significantly attenuated the expression and immunoreactivity of group V secretory phospholipase A2 (sPLA2) protein induced by LPS in astrocytes. Furthermore, in astrocytes pretreated with acetylpuerarin, the time course of phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and of cytosolic PLA2 alpha (cPLA2α) and expression of transcription factors, nuclear factor kappa B (NF-κB), was markedly truncated. Acetylpuerarin concentration dependently abolished the LPS-induced expressions of AA-metabolizing enzymes including cyclooxygenase-2 (COX-2) and lipooxygenase-5 (LOX-5). This study indicates that acetylpuerarin inhibited LPS-induced AA-metabolizing enzymes and AA metabolites in astrocytes via downregulation expression of group V sPLA2 and phosphorylation of ERK1/2, cPLA2α, and NF-κB. These findings reveal, in part, the molecular basis underlying the anti-inflammatory properties of acetylpuerarin.

Effects of oxytocin, lipopolysaccharide (LPS), and polyunsaturated fatty acids on prostaglandin secretion and gene expression in equine endometrial explant cultures

Increased secretion of prostaglandin F2α (PGF2α) within the uterus because of uterine inflammation can cause luteolysis and result in early embryonic loss. Supplementation with polyunsaturated fatty acids (PUFAs) has been shown to influence PG production in many species, although the effects on the mare remain unknown. The present study aimed to determine fatty acid uptake in equine endometrial explants and evaluate their influence on PG secretion and expression of enzymes involved in PG synthesis in vitro. Equine endometrial explants were treated with 100 μM arachidonic acid, eicosapentaenoic acid, or docosahexaenoic acid and then challenged with oxytocin (250 nM) or lipopolysaccharide (LPS; 1 μg/mL). Production of PGF2α and PG E2 (PGE2) was measured, and mRNA expression of enzymes involved in PG synthesis was determined with quantitative real-time PCR. Media concentrations of PGF2α and PGE2 were higher (P < 0.0001) from endometrial explants challenged with oxytocin or LPS compared with controls despite which fatty acid was added. Only DHA lowered (P < 0.0001) media concentrations of PGF2α and PGE2 from explants. Endometrial explants stimulated with oxytocin had increased expression of PG-endoperoxide synthase 1 (PTGS1; P < 0.02), PG-endoperoxide synthase 2 (PTGS2; P < 0.001), PG F2α synthase (PGFS; P < 0.01), PG E2 synthase (PGES; P < 0.01), and phospholipase A2 (PLA2; P < 0.005) compared with controls and regardless of fatty acid treatment; whereas stimulation with LPS increased expression of PTGS2 (P < 0.004), PGFS (P < 0.03), PGES (P < 0.01), and PLA2 (P < 0.01) compared with controls and regardless of fatty acid treatment. Treatment with PUFAs, specifically DHA, can influence PG secretion in vitro through mechanisms other than enzyme expression.

Rice PLASTOCHRON genes regulate leaf maturation downstream of the gibberellin signal transduction pathway

Rice PLASTOCHRON 1 (PLA1) and PLA2 genes regulate leaf maturation and plastochron, and their loss-of-function mutants exhibit small organs and rapid leaf emergence. They encode a cytochrome P450 protein CYP78A11 and an RNA-binding protein, respectively. Their homologs in Arabidopsis and maize are also associated with plant development/organ size. Despite the importance of PLA genes in plant development, their molecular functions remain unknown. Here, we investigated how PLA1 and PLA2 genes are related to phytohormones. We found that gibberellin (GA) is the major phytohormone that promotes PLA1 and PLA2 expression. GA induced PLA1 and PLA2 expression, and conversely the GA-inhibitor uniconazole suppressed PLA1 and PLA2 expression. In pla1-4 and pla2-1 seedlings, expression levels of GA biosynthesis genes and the signal transduction gene were similar to those in wild-type seedlings. GA treatment slightly down-regulated the GA biosynthesis gene GA20ox2 and up-regulated the GA-catabolizing gene GA2ox4, whereas the GA biosynthesis inhibitor uniconazole up-regulated GA20ox2 and down-regulated GA2ox4 both in wild-type and pla mutants, suggesting that the GA feedback mechanism is not impaired in pla1 and pla2. To reveal how GA signal transduction affects the expression of PLA1 and PLA2, PLA expression in GA-signaling mutants was examined. In GA-insensitive mutant, gid1 and less-sensitive mutant, Slr1-d1, PLA1 and PLA2 expression was down-regulated. On the other hand, the expression levels of PLA1 and PLA2 were highly enhanced in a GA-constitutive-active mutant, slr1-1, causing ectopic overexpression. These results indicate that both PLA1 and PLA2 act downstream of the GA signal transduction pathway to regulate leaf development.