Assessment of causal relationships between omega-3 and omega-6 polyunsaturated fatty acids in autoimmune rheumatic diseases: a brief research report from a Mendelian randomization study.

Background: Currently, the association between the consumption of polyunsaturated fatty acids (PUFAs) and the susceptibility to autoimmune rheumatic diseases (ARDs) remains conflict and lacks substantial evidence in various clinical studies. To address this issue, we employed Mendelian randomization (MR) to establish causal links between six types of PUFAs and their connection to the risk of ARDs. Methods: We retrieved summary-level data on six types of PUFAs, and five different types of ARDs from publicly accessible GWAS statistics. Causal relationships were determined using a two-sample MR analysis, with the IVW approach serving as the primary analysis method. To ensure the reliability of our research findings, we used four complementary approaches and conducted multivariable MR analysis (MVMR). Additionally, we investigated reverse causality through a reverse MR analysis. Results: Our results indicate that a heightened genetic predisposition for elevated levels of EPA (ORIVW: 0.924, 95% CI: 0.666-1.283, P IVW = 0.025) was linked to a decreased susceptibility to psoriatic arthritis (PsA). Importantly, the genetically predicted higher levels of EPA remain significantly associated with an reduced risk of PsA, even after adjusting for multiple testing using the FDR method (P IVW-FDR-corrected = 0.033) and multivariable MR analysis (P MV-IVW < 0.05), indicating that EPA may be considered as the risk-protecting PUFAs for PsA. Additionally, high levels of LA showed a positive causal relationship with a higher risk of PsA (ORIVW: 1.248, 95% CI: 1.013-1.538, P IVW = 0.037). It is interesting to note, however, that the effects of these associations were weakened in our MVMR analyses, which incorporated adjustment for lipid profiles (P MV-IVW > 0.05) and multiple testing using the FDR method (P IVW-FDR-corrected = 0.062). Moreover, effects of total omega-3 PUFAs, DHA, EPA, and LA on PsA, were massively driven by SNP effects in the FADS gene region. Furthermore, no causal association was identified between the concentrations of other circulating PUFAs and the risk of other ARDs. Further analysis revealed no significant horizontal pleiotropy and heterogeneity or reverse causality. Conclusion: Our comprehensive MR analysis indicated that EPA is a key omega-3 PUFA that may protect against PsA but not other ARDs. The FADS2 gene appears to play a central role in mediating the effects of omega-3 PUFAs on PsA risk. These findings suggest that EPA supplementation may be a promising strategy for preventing PsA onset. Further well-powered epidemiological studies and clinical trials are warranted to explore the potential mechanisms underlying the protective effects of EPA in PsA.

Investigating causal associations among gut microbiota, metabolites, and psoriatic arthritis: a Mendelian randomization study.

Background: Currently, there has been observed a significant alteration in the composition of the gut microbiome (GM) and serum metabolites in patients with psoriatic arthritis (PsA) compared to healthy individuals. However, previous observational studies have shown inconsistent results regarding the alteration of gut microbiota/metabolites. In order to shed light on this matter, we utilized Mendelian randomization to determine the causal effect of GM/metabolites on PsA. Methods: We retrieved summary-level data of GM taxa/metabolites and PsA from publicly available GWAS statistics. Causal relationships between GM/metabolites and PsA were determined using a two-sample MR analysis, with the IVW approach serving as the primary analysis method. To ensure the robustness of our findings, we conducted sensitivity analyses, multivariable MR analysis (MVMR), and additional analysis including replication verification analysis, LDSC regression, and Steiger test analysis. Furthermore, we investigated reverse causality through a reverse MR analysis. Finally, we conducted an analysis of expression quantitative trait loci (eQTLs) involved in the metabolic pathway to explore potential molecular mechanisms of metabolism. Results: Our findings reveal that eight GM taxa and twenty-three serum metabolites are causally related to PsA (P < 0.05). Notably, a higher relative abundance of Family Rikenellaceae (ORIVW: 0.622, 95% CI: 0.438-0.883, FDR = 0.045) and elevated serum levels of X-11538 (ORIVW: 0.442, 95% CI: 0.250-0.781, FDR = 0.046) maintain significant causal associations with a reduced risk of PsA, even after adjusting for multiple testing correction and conducting MVMR analysis. These findings suggest that Family Rikenellaceae and X-11538 may have protective effects against PsA. Our sensitivity analysis and additional analysis revealed no significant horizontal pleiotropy, reverse causality, or heterogeneity. The functional enrichment analysis revealed that the eQTLs examined were primarily associated with glycerolipid metabolism and the expression of key metabolic factors influenced by bacterial infections (Vibrio cholerae and Helicobacter pylori) as well as the mTOR signaling pathway. Conclusion: In conclusion, our study demonstrates that Family Rikenellaceae and X-11538 exhibit a strong and negative causal relationship with PsA. These particular GM taxa and metabolites have the potential to serve as innovative biomarkers, offering valuable insights into the treatment and prevention of PsA. Moreover, bacterial infections and mTOR-mediated activation of metabolic factors may play an important role in this process.

LILRB2/PirB mediates macrophage recruitment in fibrogenesis of nonalcoholic steatohepatitis.

Inhibition of immunocyte infiltration and activation has been suggested to effectively ameliorate nonalcoholic steatohepatitis (NASH). Paired immunoglobulin-like receptor B (PirB) and its human ortholog receptor, leukocyte immunoglobulin-like receptor B (LILRB2), are immune-inhibitory receptors. However, their role in NASH pathogenesis is still unclear. Here, we demonstrate that PirB/LILRB2 regulates the migration of macrophages during NASH by binding with its ligand angiopoietin-like protein 8 (ANGPTL8). Hepatocyte-specific ANGPTL8 knockout reduces MDM infiltration and resolves lipid accumulation and fibrosis progression in the livers of NASH mice. In addition, PirB-/- bone marrow (BM) chimeras abrogate ANGPTL8-induced MDM migration to the liver. And yet, PirB ectodomain protein could ameliorate NASH by sequestering ANGPTL8. Furthermore, LILRB2-ANGPTL8 binding-promoted MDM migration and inflammatory activation are also observed in human peripheral blood monocytes. Taken together, our findings reveal the role of PirB/LILRB2 in NASH pathogenesis and identify PirB/LILRB2-ANGPTL8 signaling as a potential target for the management or treatment of NASH.

External validation and comparison of two versions of simplified sequential organ failure assessment scores to predict prognosis of septic patients.

BACKGROUND: Evidence shows that simplified SOFA scoring system has better clinical practice. OBJECTIVE: This study aimed to validate and compare the scores acquired with simplified organ dysfunction criteria optimized for electronic health records (eSOFA), and simplified and accurate sequential organ failure assessment (sa-SOFA) for their accuracies in predicting the prognosis of septic patients. METHODS: This retrospective observational study was conducted at three major academic hospitals. Clinical data from 574 patients diagnosed with sepsis following the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)were retrospectively retrieved and analysed. Scores from the quick sequential organ failure assessment (qSOFA) and sequential organ failure assessment (SOFA) were used as reference scores. The area under the receiver operating characteristic curve (AUROC) was used to assess the performance of eSOFA and sa-SOFA scores in predicting in-hospital mortality. RESULTS: AUROC analysis demonstrated the predictability of the four scoring systems for sepsis surveillance, listed in descending order as: sa-SOFA, 0.790 (95% confidence interval [CI]: 0.754-0.822); SOFA, 0.774 (95% CI: 0.738-0.808); eSOFA, 0.729 (95% CI: 0.691-0.765); and qSOFA, 0.618 (95% CI: 0.577-0.658). Moreover, sa-SOFA and SOFA scores (Z = 1.950, P = .051) did not significantly differ from each other in discriminatory power, but the sa-SOFA score had a higher power than eSOFA score (P values < .001). CONCLUSION: sa-SOFA appeared to have performed better than eSOFA score for predicting in-hospital mortality in patients' sepsis. Further large prospective studies are needed to externally validate.

The v-DECAF score can predict 90-day all-cause mortality in patients with COPD exacerbation requiring invasive mechanical ventilation.

INTRODUCTION: The DECAF score is a simple and effective tool for predicting mortality in patients hospitalized with acute exacerbations of chronic obstructive pulmonary disease (AECOPD); however, the DECAF score has not been validated in AECOPD patients requiring invasive mechanical ventilation (IMV). We devised the ventilator (v)-DECAF score, in which "anemia" replaces "acidaemia," for use in AECOPD patients requiring IMV. The objective of this study was to compare the predictive efficacy of the v-DECAF score and the DECAF score. METHODS: This study prospectively recruited 112 consecutive AECOPD patients requiring IMV from a single center. The clinical endpoint was 90-day all-cause mortality. Demographic and clinical data were recorded, as well as APACHE II, GCS, CURB-65, BAP-65 and DECAF scores, and the newly devised v-DECAF score. The discriminatory value of the scoring systems in predicting 90-day all-cause mortality was determined using the area under the receiver operating characteristic (AUROC) curve. RESULTS: In multivariate logistic regression analysis, the v-DECAF score was an independent predictor of 90-day all-cause mortality (odds ratio 3.004, 95% CI 1.658-5.445, P < 0.001). The AUROC of the v-DECAF and DECAF scores were 0.852 (95% CI 0.766-0.938) and 0.777 (95%CI: 0.676-0.878), respectively. The v-DECAF score had a better predictive value for 90-day all-cause mortality compared to the DECAF score (Z = 2.338, P = 0.019). CONCLUSION: The v-DECAF score had good discriminatory power in predicting 90-day all-cause mortality in AECOPD patients requiring IMV.

New ingol-type diterpenes from the latex of Euphorbia resinifera.

Two new ingol-type diterpenes, euphoresins A-B (1-2), have been isolated from the methanol extract of Euphorbium, the latex of Euphorbia resinifera Berg. Their structures were established on the basis of extensive analyses of their HR-ESI-MS, IR, UV, 1D, and 2D NMR spectra. The absolute configurations were confirmed by Mosher's method and circular dichroism (CD) analyses. The two compounds were tested for their cytotoxic activities against MCF-7, U937, and C6 cancer cell lines, but they both exhibited little cytotoxic effect.

[Triterpenoids from Uygur medicine latex of Euphorbia resinifera].

Ten triterpenes compounds were isolated from the methanol extraction of the latex of Euphorbia resinifera by means of various chromatographic methods such as silica gel, ODS and semi-preparative HPLC, Their structures were identified by spectroscopic methods and physicochemical properties. These isolated compounds were identified as 3ß-hydroxy-25,26,27-trinor eupha-8-ene-24-oate (1), iso-maticadienediol (2), 25,26,27-trinorTirucall-8-ene-3ß-ol-4-acid (3), dammarendiol Ⅱ (4), eupha-8,24-diene-3-ol-26-al (5), lnonotusane C (6), eupha-8,24-diene-3ß-ol-7,11-dione (7), inoterpene A (8), inoterpene B (9), and eupha-24-methylene-8-ene-3ß-ol-7,11-dione (10). Among them, compound 1 was a new natural product, compounds 2-4 were firstly isolated from the Euphorbiaceae and compounds 5 and 6 were isolated from the genus Euphorbia for the first time. The cytotoxicity of the compounds 1-10 against MCF-7, U937 and C6 cancer cell lines was evaluated, but none of the compounds was active.

The Relationship Between Serum Interleukin-6 and the Recurrence of Hepatitis B Virus Related Hepatocellular Carcinoma after Curative Resection.

The aim of this study is to assess whether preoperative serum interleukin-6 (IL-6) can predict recurrence of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). The association between preoperative IL-6 levels and HCC recurrence following curative hepatectomy in 146 patients with chronic HBV infection was determined. Patients were divided into groups based on the presence or absence of HCC recurrence. Serum IL-6 levels were compared between groups, and the association between serum IL-6 level and greatest tumor dimension was also analyzed. Receiver operating characteristics (ROC) curve was used to define the optimal cutoff value for predicting recurrence-free survival (RFS) and overall survival (OS) rates. The OS and RFS rates were calculated using the Kaplan-Meier method. Out of 146 patients, 80 (54.8%) patients were documented as having HCC recurrence during the follow-up period. After adjusting for potential confounders, serum IL-6 levels were significantly associated with HCC recurrence, and a saturation effect existed with serum IL-6 levels up to 3.7 pg/mL. In addition, patients with preoperative serum IL-6 levels over 3.1 pg/mL had lower RFS and OS rates (P < 0.01). There was no significant correlation between preoperative serum IL-6 levels and maximal tumor dimension (r = 0.0003, P = 0.84). Elevated serum levels of IL-6 were significantly associated with an increased risk of HBV-associated HCC recurrence suggesting that preoperative IL-6 serum level is potential biomarker for early prediction of HBV-associated HCC recurrence.

Coadministration of hydroxysafflor yellow A with levodopa attenuates the dyskinesia.

Levodopa (L-DOPA) is used as the most effective drug available for the symptomatic treatment of Parkinson's disease (PD). However, long-term treatment of L-DOPA frequently causes complications, including abnormal involuntary movements such as dyskinesia and response fluctuations in PD patients. In the present work, we investigated whether hydroxysafflor yellow A (HSYA) ameliorates L-DOPA-induced dyskinesia and motor fluctuations in the 6-hydroxydopamine-lesioned rat model of PD. Valid PD rats were treated daily with vehicle, HSYA alone, L-DOPA, or a combination of HSYA plus L-DOPA for 21days, respectively. L-DOPA (8mg/kg) and benserazide (15mg/kg) were treated intraperitoneally. HSYA was administrated intraperitoneally at a dose of 10mg/kg. The abnormal involuntary movements and rotational behavior were evaluated. The expression of the dopamine D3 receptor in the striatum was also assayed. The results demonstrated that daily administration of L-DOPA to PD rats for 21days induced a steady expression of dyskinesia. Coadministration of HSYA with L-DOPA significantly ameliorated L-DOPA-induced dyskinesia. The combination treatment also prevented the shortening of the motor response duration that defines wearing off motor fluctuations. HSYA also inhibited the increase of expression of the dopamine D3 receptor in the striatum. These findings demonstrated that HSYA provided anti-dyskinetic relief against L-DOPA in a preclinical model of PD via regulating the expression of the dopamine D3 receptor. The combination of L-DOPA and HSYA also reduced the likelihood of wearing off development, and may thus support the utility of such compounds for the improved treatment of PD.

Effect of ursodeoxycholic acid administration after liver transplantation on serum liver tests and biliary complications: a randomized clinical trial.

BACKGROUND/AIMS: Endogenous hydrophobic bile acids are suspected to be one of the pathogenetic factors of biliary complications after orthotopic liver transplantation (OLT). This study was designed to investigate the effects of hydrophilic ursodeoxycholic acid (UDCA) administration early after OLT on serum liver tests and the incidence of biliary complications. METHODS: 112 adult patients undergoing OLT from donation after cardiac death (DCD) were randomized to UDCA (13-15 mg/kg/day for 4 weeks; 56 patients) or placebo (56 patients). Serum liver tests and serum bile acids of all patients and biliary bile acids in patients with T-tube drainage were determined during the 4 weeks after OLT. Biliary complications as well as patient and graft survival were analyzed during a mean follow-up of 41.6 months. RESULTS: UDCA treatment decreased ALT, AST and GGT (p < 0.05) during the 4 weeks after OLT and the incidence of biliary sludge and casts within the 1st year (p < 0.05). However, no differences in the incidence of other biliary complications as well as 1-, 3- and 5-year graft and patient survival were observed. CONCLUSIONS: UDCA administration early after DCD-OLT improves serum liver tests and decreases the incidence of biliary sludge and casts within the 1st postoperative year but does not affect overall outcome up to 5 years after OLT.

A novel cold-active xylanase from the cellulolytic myxobacterium Sorangium cellulosum So9733-1: gene cloning, expression, and enzymatic characterization.

The cellulolytic myxobacterium Sorangium cellulosum is able to efficiently degrade many kinds of polysaccharides, but none of the enzymes involved have been characterized. In this paper, a xylanase gene (xynA) was cloned from S. cellulosum So9733-1 using thermal asymmetric interlaced PCR. The gene is composed of 1,209 bp and has only 52.27% G + C content, which is much lower than that of most myxobacterial DNA reported (67-72%). Gene xynA encodes a 402 amino acid protein that contains a single catalytic domain belonging to the glycoside hydrolase family 10. The novel xylanase gene, xynA, was expressed in Escherichia coli BL21 (DE3) and the recombinant protein (r-XynA) was purified by Ni-affinity chromatography. The r-XynA had the optimum temperature of 30-35°C and exhibited 33.3% activity at 5°C and 13.7% activity at 0°C. Approximately 80% activity was lost after 20-min pre-incubation at 50°C. These results indicate that r-XynA is a cold-active xylanase with low thermostability. At 30°C, the K (m) values of r-XynA on beechwood xylan, birchwood xylan, and oat spelt xylan were 25.77 ± 4.16, 26.52 ± 4.78, and 38.13 ± 5.35 mg/mL, respectively. The purified r-XynA displayed optimum activity at pH 7.0. The activity of r-XynA was enhanced by the presence of Ca(2+). The r-XynA hydrolyzed beechwood xylan, birchwood xylan, and xylooligosaccharides (xylotriose, xylotetraose, and xylopentose) to produce primarily xylose and xylobiose. To our knowledge, this is the first report on the characterization of a xylanase from S. cellulosum.

Polymorphisms of some cytokines and chronic hepatitis B and C virus infection.

AIM: To study the relationship between the polymorphisms in some cytokines and the outcome of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. METHODS: Samples were obtained from 203 patients infected with HBV and/or HCV while donating plasma in 1987, and 74 controls were obtained from a rural area of North China. Antibodies to HBV or HCV antigens were detected by enzyme-linked immunoassay. The presence of viral particles in the serum was determined by nested reverse-transcriptase polymerase chain reaction (PCR). Hepatocellular injury, as revealed by alanine aminotransferase (ALT) and aspartate aminotransferase level, was detected by a Beckman LX-20 analyzer. DNA was extracted from blood cells. Then, the single nucleotide polymorphisms of IL-2-330, IFN-gamma+874, IL-10-1082/-592 and IL-4-589 were investigated by restriction fragment length polymorphism-PCR or sequence specific primer-PCR. RESULTS: Persistent infection with HBV, HCV, and HBV/HCV coinfection was associated with IL-2-330 TT genotype and T allele, IFN-gamma+874 AA genotype, and IL-10-1082 AA genotype. The clinical outcome of HBV and/or HCV infection was associated with IL-2-330 TT genotype and T allele, IFN-gamma+874 AA genotype, and IL-10-1082 AA genotype. IL-2-330 GG genotype frequency showed a negative correlation with clinical progression, IL-10-1082 AA genotype frequency showed a positive correlation and IL-10-1082 AG genotype frequency showed a negative correlation with clinical progression. HCV RNA positive expression was associated with IL-10-1082 AA genotype and the A allele frequency. Abnormal serum ALT level was associated with IL-10-592 AC genotype frequency and IL-4-589 CC genotype, CT genotype, and the C allele. CONCLUSION: These results suggest that polymorphisms in some cytokine genes influence persistent HBV and HCV infection, clinical outcome, HCV replication, and liver damage.

[Pathogenesis of liver fibrosis in patients with chronic hepatitis B].

OBJECTIVE: To explore the role of sinusoidal endothelial cell in the development of liver fibrosis, and to dissect the relationship among hepatic microcirculation disorders, hepatic sinusoidal capilarization and liver fibrosis. METHODS: Liver biopsy was performed in fifty-six patients with chronic hepatitis B. The liver tissues were observed under light microscope and transmitted electronic microscope. RESULTS: Of 56 cases, 39 cases were mild hepatitis, 10 were moderate hepatitis, and 7 were severe hepatitis. The morphology of hepatic stellate cells (HSCs) was similar to that of fibroblasts in the tissues of the patients with chronic hepatitis B. Collagenous fibers were deposited around the hepatic stellate cells. Electron-dense materials were deposited between sinusoidal endothelial cell and hepatic stellate cell. The size and amount of fenestraes of sinusoidal endothelial cells were reduced in 53 of 56 cases. The consecutive or inconsecutive membrane-like materials were observed along sinusoidal endothelial cells in 20 cases. Collagen fibers were observed in the space of Disse in 15 cases. Even in the patients with normal hepatic functions, red blood cells aggregation and microthrombi could be observed in the liver tissues. CONCLUSION: Sinusoidal endothelial cells are involved in development of liver fibrosis by interacting with hepatic stellate cells. Hepatic microcirculation disorders and sinusoidal capillarization are important changes in the early stage of liver fibrosis.

[Therapeutic effect of liver transplantation on acute liver failure].

OBJECTIVE: To evaluate the short-term and long-term outcomes of emergent liver transplantation recipients with acute liver failure and to identify factors that influenced these outcomes. METHODS: 318 consecutive patients who underwent liver transplantations between January 2001 and December 2004 were analyzed retrospectively (all the cases were followed up to December 2005). According to UNOS grading scale, all recipients preoperative status were evaluated. 54 patients were acute liver failure (Group I, UNOS 1 and 2A), and the other 264 cases were chronic liver diseases (Group II, UNOS 2B and 3). The postoperative effects in different groups were compared, including the survival rates, incidences of complications, rates and causes of retransplantation, rates and causes of death. RESULTS: Comparing UNOS2B/3 to UNOS1/2A, the perioperative mortality were 3.7%; 22.6%, the rate of complications 16.7%; 55.6%, 1 year survival rate 91.3%; 74.1%, 3 year survival rate 86.4%; 68.5%, the retransplantation rate 1.1%; 18.5% respectively. CONCLUSION: Since the technique of liver transplant is very advanced, the effect of surgery is mainly depended on the function of liver and other organs in patients. The recipients with UNOS2B/3 have better short-term and long-term outcomes as comparing to UNOS1/2A. In addition, the recipients with UNOS1/2A are burdened with much higher mortality.

[The investigation of STK15 gene amplification and overexpression in laryngeal squamous cell carcinoma].

OBJECTIVE: To investigate the role of STK15 gene amplification and overexpression to genesis and development of laryngeal squamous cell carcinoma (LSCC). METHODS: STK15 gene amplification in 40 cases carcinoma tissues and normal tissues as control was detected by differential PCR approach. STK15 mRNA and protein levels were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry method. RESULTS: In 40 LSCC cases, STK15 gene amplification was found in 14 tumor tissues(35%), mRNA overexpression in 27 tumor tissues(67.5%), and protein upregulated in 29 tumor tissues(72.5%). Statistics analysis showed that STK15 gene amplification and mRNA overexpression were obviously associated to differentiation degree of LSCC, and protein overexpression was closely associated with both differentiation degree and pathological grades of LSCC. CONCLUSION: This research results suggest that STK15 gene amplification contributes to its mRNA and protein overexpression through affecting the exact replication of centrosome and separation of chromosomes. STK15 gene thus plays a role in LSCC oncogenesis and malignant progression.

Oxidative metabolism of the alkaloid rutaecarpine by human cytochrome P450.

Rutaecarpine is the main active alkaloid of the herbal medicine, Evodia rutaecarpa. To identify the major human cytochrome P450 (P450) participating in rutaecarpine oxidative metabolism, human liver microsomes and bacteria-expressed recombinant human P450 were studied. In liver microsomes, rutaecarpine was oxidized to 10-, 11-, 12-, and 3-hydroxyrutaecarpine. Microsomal 10- and 3-hydroxylation activities were strongly inhibited by ketoconazole. The 11- and 12-hydroxylation activities were inhibited by alpha-naphthoflavone, quinidine, and ketoconazole. These results indicated that multiple hepatic P450s including CYP1A2, CYP2D6, and CYP3A4 participate in rutaecarpine hydroxylations. Among recombinant P450s, CYP1A1 had the highest rutaecarpine hydroxylation activity. Decreased metabolite formation at high substrate concentration indicated that there was substrate inhibition of CYP1A1- and CYP1A2-catalyzed hydroxylations. CYP1A1-catalyzed rutaecarpine hydroxylations had V(max) values of 1,388 to approximately 1,893 pmol/min/nmol P450, K(m) values of 4.1 to approximately 9.5 microM, and K(i) values of 45 to approximately 103 microM. These results indicated that more than one molecule of rutaecarpine is accessible to the CYP1A active site. The major metabolite 10-hydroxyrutaecarpine decreased CYP1A1, CYP1A2, and CYP1B1 activities with respective IC(50) values of 2.56 +/- 0.04, 2.57 +/- 0.11, and 0.09 +/- 0.01 microM, suggesting that product inhibition might occur during rutaecarpine hydroxylation. The metabolite profile and kinetic properties of rutaecarpine hydroxylation by human P450s provide important information relevant to the clinical application of rutaecarpine and E. rutaecarpa.

Advanced glycation end products induce actin rearrangement and subsequent hyperpermeability of endothelial cells.

This study aimed to determine the effects of advanced glycation end products (AGEs) on endothelial cytoskeleton morphology and permeability, and to detect the underlying signaling mechanisms involved in these responses. Cultured endothelial cells (ECs) were exposed to AGE-modified human serum albumin (AGE-HSA), and EC cytoskeletal changes were evaluated by observing fluorescence of F-actin following ligation with labeled antibodies. Endothelial permeability was detected by measuring the flux of TRITC-albumin across the EC monolayers. To explore the signaling pathways behind AGE-induced EC alteration, ECs were treated with either soluble anti-AGE receptor (RAGE) IgG, or the MAPK inhibitors PD98059 and SB203580 before AGE-HSA administration. To further elucidate possible involvement of the ERK and p38 pathways in AGE-induced EC changes, adenovirus-carried recombinant constitutive dominant-negative forms of upstream ERK and p38 kinases, namely MEK1(A) and MKK6b(A), were pre-infected into ECs 24 h prior to AGE-HSA exposure. AGE-HSA induced actin cytoskeleton rearrangement, as well as EC hyperpermeability, in a dose and time-dependent manner. The effects were attenuated in cells pretreated with anti-RAGE IgG, PD98059 or SB203580, respectively. EC pre-infection with MEK1(A) and MKK6b(A) also alleviated the effect of AGEs. Furthermore, adenovirus-mediated administration of activated forms of either MEK1 or MKK6b alone induced rearrangement of F-actin and hyperpermeability. The results indicate that ERK and p38 MAPK play important roles in the mediation of AGE-induced EC barrier dysfunction associated with morphological changes of the F-actin.

[Mechanism of advanced glycation end products-induced hyperpermeability in endothelial cells].

The purpose of the present study was to investigate the effects of advanced glycation end products (AGEs) modified protein on the permeability of endothelium monolayers and morphological changes of actin cytoskeleton. The roles of receptor for AGEs (RAGE), oxidant stress and the activation of p38 MAPK pathway in this pathological procedure were elucidated. Human umbilical vein endothelial cells (HUVECs)-derived cell line (ECV304) were incubated with AGEs modified human serum albumin (AGE-HSA) in concentrations of 12.5, 25, 50, and 100 microg/ml respectively, for 2, 4, 8, 12 and 24 h. As control, HSA of the same concentration was administered to cells. Then TRITC-albumin was added to evaluate Pa value that reflects the permeability of endothelial monolayer. Furthermore, to visualize the morphological changes of actin cytoskeleton, the treated cells were incubated with rhodamine-phalloidin to stain F-actin. The results showed that the trans-endothelial membrane flux of albumin was significantly increased in a concentration- and time-dependent manner upon the stimulation of AGE-HSA, accompanying with actin reorganization. The blockage of AGE and RAGE binding with anti-RAGE IgG and the pharmacological inhibition of NADPH oxidase or p38 MAP kinase greatly attenuated the AGE-induced hyperpermeability response, respectively. These results indicate that RAGE, NADPH oxidase and p38 MAPK are possibly involved in the mediation of AGEs-induced barrier dysfunction and actin cytoskeleton reorganization in endothelial cells.

Myosin light-chain kinase contributes to short-term endothelial cell cytoskeletal alteration induced by serum from burned rats.

OBJECTIVES: To investigate the time-dependent effects of serum from burned rats on cytoskeletal filamentous actin (F-actin) reorganization by visualizing their distribution in human umbilical vein endothelial cell line ECV-304 and evaluate the role of myosin light-chain kinase (MLCK) in this process. METHODS: The serum-starved ECV-304 cells were incubated with the serum from burned rats for 30 min, 1, 2, 4, and 6 h, respectively, and 30 min before or after the incubation, the cells were treated with 5 micromol/L ML-7 for 30 min. F-actin was stained with rhodamine-phalloidin and observed under fluorescence microscope. RESULTS: Under normal condition, F-actin was distributed mainly in the cortical area of the endothelial cells. After stimulation with the burn serum, stress fiber formation could be clearly seen in the endothelial cells, exhibiting a time-dependent enhancement in a time course ranging from 30 min to 6 h. Such an effect could be significantly inhibited by a 30-min pretreatment of the cells with MLCK-specific inhibitor ML-7. Inhibition of MLCK also reversed actin reorganization in the endothelial cells pretreated with the burn serum. CONCLUSION: Serum from burned rats induces characteristic morphological changes in the endothelial cell actin cytoskeleton mainly due to the MLCK activation, an effect that can be reversed by the inhibition of MLCK.