Nuclear Receptor PPARα as a Therapeutic Target in Diseases Associated with Lipid Metabolism Disorders

Lipid metabolic diseases have substantial morbidity and mortality rates, posing a significant threat to human health. PPARα, a member of the peroxisome proliferator-activated receptors (PPARs), plays a crucial role in lipid metabolism and immune regulation. Recent studies have increasingly recognized the pivotal involvement of PPARα in diverse pathological conditions. This comprehensive review aims to elucidate the multifaceted role of PPARα in metabolic diseases including liver diseases, diabetes-related diseases, age-related diseases, and cancers, shedding light on the underlying molecular mechanisms and some regulatory effects of natural/synthetic ligands of PPARα. By summarizing the latest research findings on PPARα, we aim to provide a foundation for the possible therapeutic exploitation of PPARα in lipid metabolic diseases.

Curcumin derived from medicinal homologous foods: its main signals in immunoregulation of oxidative stress, inflammation, and apoptosis

It has been for thousands of years in China known medicinal homologous foods that can be employed both as foods and medicines to benefit human and animal health. These edible herbal materials perform divert roles in the regulation of metabolic disorders, cancers, and immune-related diseases. Curcumin, the primary component derived from medicinal homologous foods like curcuma longa rhizome, is reported to play vital actions in organic activities, such as the numerous pharmacological functions including anti-oxidative stress, anti-inflammation and anti/pro-apoptosis in treating various diseases. However, the potential mechanisms of curcumin-derived modulation still need to be developed and attract more attention worldwide. Given that these signal pathways are enrolled in important bioactive reactions, we collected curcumin's last achievements predominantly on the immune-regulation signals with the underlying targetable strategies in the last 10 years. This mini-review will be helpful to accelerate curcumin and other extracts from medicinal homologous foods use in future human clinical applications.

iTRAQ-based quantitative proteomic analysis of the therapeutic effects of 2% hydrogen gas inhalation on brain injury in septic mice

Sepsis encephalopathy (SAE) has a high incidence and mortality rate in patients with sepsis; however, there is currently no effective treatment. Our previous studies have reported that 2% hydrogen (H₂) gas inhalation had a protective effect on sepsis and SAE; however, the specific mechanism have not been fully elucidated. In the current study, male Institute of Cancer Research mice were either used to create the cecal ligation and puncture (CLP) model or for sham surgery, followed by 2% H₂ gas inhalation for 60 min beginning at 1 and 6 h following sham or CLP surgeries. The isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, hematoxylin and eosin (H&E) staining, Nissl staining, and western blot analysis were used to investigate the effects of H₂ on brain injury in mice with sepsis. The results of the H&E, and Nissl staining indicated that the CLP mice had a significant brain injury, which was characterized by aggravated pathological damage and was alleviated by 2% H₂ inhalation. Quantitative proteomics based on iTRAQ combined with LC-MS/MS analysis quantified a total of 5317 proteins, of which 39 were connected with the protective mechanism of H₂. In addition, H₂ could regulate the immune and the coagulation systems. Furthermore, western blot analysis revealed that H₂ decreased SAE in septic mice by downregulating the protein expression levels of SMAD4, DPYS, PTGDS and upregulating the expression level of CUL4A. These results provide insights into the mechanism of the positive effect of H₂ on SAE and contribute to the clinical application of H₂ in patients with sepsis.

The Perceived Stress Scale-10 (PSS-10) is reliable and has construct validity in Chinese patients with systemic lupus erythematosus

Systemic lupus erythematosus is a chronic, progressive, autoimmune disease that causes significant stress on patients. There is no specific instrument for assessing stress in Chinese systemic lupus erythematosus patients. The objective of this study was to test the reliability and validity of the 10-item Perceived Stress Scale in Chinese systemic lupus erythematosus patients. Validity evaluation included structural and construct validity (convergent and discriminant validity). Structural validity was assessed by exploratory factor analysis. Convergent validity was assessed by correlating the total score of the 10-item Perceived Stress Scale with the Patient Health Questionnaire-9, Self-Efficacy for Managing Chronic Disease 6-Item Scale, the Simplified Coping Style Questionnaire, and the Systemic Lupus Erythematosus Disease Activity Index. Discriminant validity was determined by the statistically significant differences in perceived stress scores among patients with different education levels and disease activity. Reliability was assessed by internal consistency and test-retest reliability. The test-retest reliability was measured at 1-week intervals. Exploratory factor analysis extracted two dimensions that explained 66.45% of the variation. Moderate-to-strong correlations were also found between the 10-item Perceived Stress Scale and the Patient Health Questionnaire-9, Self-Efficacy for Managing Chronic Disease 6-Item Scale, the Simplified Coping Style Questionnaire, and Systemic Lupus Erythematosus Disease Activity Index. Excellent test-retest reliability (intraclass correlation coefficient = 0.954) and internal consistency (Cronbach's alpha = 0.810) were demonstrated. In conclusion, the 10-item Perceived Stress Scale can be used to measure stress among Chinese systemic lupus erythematosus patients and serve as a basis for further research.

The Effect of Thermo-Chemical Treatment on the Water Resistance of Defatted Soybean Flour-Based Wood Adhesive

The aim of this study was to effectively improve the water resistance of a defatted soybean flour (DSF)-based adhesive by subjecting DSF to thermo-chemical treatment in the presence of sodium dodecyl sulfate (SDS), and then the crosslinking with epichlorohydrin-modified polyamide (EMPA). The effect of thermo-chemical treatment on the structures and properties of the DSF and DSF-based adhesive were investigated by plywood evaluation, boiling-water-insoluble content, and acetaldehyde value measurements, as well as FTIR, X-ray photoelectron spectroscopic (XPS), X-ray diffraction spectroscopy (XRD), thermogravimetric analysis (TGA), and rheology analyses. The test results revealed that the water resistance of the DSF-based adhesive was significantly improved, attributed to the formation of a solid three-dimensional crosslinked network structure resulted from the repolymerization of DSF, the Maillard reaction between the protein and carbohydrate, and chemical crosslinking between the crosslinker and DSF. Moreover, SDS destroyed the hydrophobic interactions within protein and inhibited macromolecular aggregations during the thermal treatment. Therefore, more reactive groups buried within the globular structure of the soybean protein component of DSF could be released, which supported the repolymerization, Maillard reaction, and chemical crosslinking of DSF, thereby leading to an improved crosslinking density of the cured DSF-based adhesive. In addition, the adhesive composed of thermo-chemically treated DSF and EMPA exhibited preferable viscosity and viscosity stability suitable for the production of wood composites.

Identification of Natural Infections in Sheep/Goats with HoBi-like Pestiviruses in China

The natural infections of HoBi-like pestiviruses in cattle have been reported in South America, Europe and Asia. In China, although the detections of HoBi-like pestivirus have been reported, the epidemiological investigation was limited. From January 2014 to October 2015, several flocks of sheep/goats in Henan province in central China suffered respiratory diseases which were recovered slowly after antibiotics treatment. To test whether it is the HoBi-like pestivirus caused this symptom, 49 serum samples and 22 nasal swabs were then collected for analysis by serology and RT-PCR. Serological result revealed that prevalence of pestivirus in small ruminants was 12.2% (6/49) in central China. Sequence analysis of partial 5'-UTR nucleotides of pestivirus-positive samples suggested that HoBi-like pestivirus might have circulated in sheep/goats of China for a period and have evolved into new genotype clusters. It is apparent that the study provides the molecular evidence of natural infections in goat/sheep species with HoBi-like pestiviruses in China.

Combined application of ultrasound and SPECT/CT has incremental value in detecting parathyroid tissue in SHPT patients

PURPOSE

The goal of this study is to investigate whether combined application of ultrasound and 99mTc-sestamibi SPECT/CT had the incremental value in accurately detecting parathyroid tissue in patients with SHPT over either method alone.

PATIENTS AND METHODS

Sixty patients with SHPT on hemodialysis were evaluated preoperatively with parathyroid 99mTc-sestamibi SPECT/CT scintigraphy and ultrasound prior to parathyroidectomy. The sensitivity, specificity and accuracy of 99mTc-sestamibi SPECT/CT scintigraphy, ultrasound and combined application were determined respectively.

RESULTS

The sensitivity, specificity and accuracy of ultrasound were 81% (155/192), 47% (17/36) and 82% (172/228), respectively. The sensitivity, specificity and accuracy of 99mTc-sestamibi SPECT/CT were 85% (163/192), 58% (21/36) and 89% (184/228) respectively. The accuracy of 99mTc-sestamibi SPECT/CT in the diagnosis of parathyroid tissue in patients with SHPT is significantly higher than that of ultrasound. The sensitivity, specificity and accuracy of combined application of ultrasound and 99mTc-sestamibi SPECT/CT were 93% (178/192), 61% (22/36) and 97% (200/228). The sensitivity, specificity and accuracy of combined application of ultrasound and 99mTc-sestamibi SPECT/CT were higher than those of either ultrasound or 99mTc-sestamibi SPECT/CT.

CONCLUSIONS

The combined application of ultrasound and 99mTc-sestamibi SPECT/CT had incremental value in accurately detecting parathyroid tissue in patients with SHPT over either method alone.

Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis

AIM

The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty.

METHODS

A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection.

RESULTS

Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis.

CONCLUSION

In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

Effects of Echinacea extract on the performance, antibody titres, and intestinal histology of layer chicks

1. This research was conducted to determine the effect of diet supplementation with Echinacea extract (cichoric acid) on the growth performance, antibody titres and intestinal tissue histology of layer chicks. 2. White, 1-d-old, Hy-Line hybrid chicks (n = 540) were divided into three treatments, each consisting of 6 groups of 30 chicks (n = 180): (1) control; (2) 2·5 mg/kg cichoric-acid-fed; and (3) 5 mg/kg cichoric-acid-fed. The trial lasted 60 d. 3. While the growth performance of the chicks was depressed between d 1 and 45, it was found to improve between d 45 and 60. 4. Feed consumption was lower in both of the cichoric-acid-fed groups than in the control group between d 1-15 and 15-30, but was higher between d 30 and 45. Overall, mean feed consumption did not differ between the control and cichoric-acid-fed groups during the 60 d study period. 5. During the 60 d evaluation period, live weight gain, feed utilisation rate and final live weight were higher in the control group than in both of the cichoric-acid-fed groups. 6. Antibody titres against infectious bronchitis and infectious bursal disease did not differ between the three groups, but those for Newcastle disease were higher in the 2·5 mg/kg cichoric-acid-fed group than in the control group after 45 d. 7. Height and width of the jejunal villus and the thickness of the muscle layer were lower in the 5 mg/kg cichoric-acid-fed group than in both the control and the 2·5 mg/kg cichoric-acid-fed groups. The height of the ileal villus was also lower in the 5 mg/kg cichoric-acid-fed group than in the other two groups. 8. Echinacea extract supplementation for layer chicks appears not to benefit growth performance and intestinal histology during the growing period.

The diagnostic value of neutrophil: lymphocyte ratio in adults with suspected acute appendicitis

AIM

To validate the use of neutrophil : lymphocyte ratio (NLR) in diagnosing appendicitis.

MATERIALS AND METHODS

Patients who had had an appendicectomy but where no post-operative histology was available and those under the age of 16, or those who had undergone an interval appendicectomy in a non-emergency setting were excluded from this study. The NLR, WCC, CRP and NLR x CRP were recorded for all patients and these were then compared to their postoperative histology. To determine whether NLR on admission to hospital was an independent predictor of positive appendicitis histology, a multiple logistic regression model was constructed, using factors with a p-value of 0.1 or less in univariate analysis.

RESULTS

One thousand one hundred and seventeen (1117) patients who underwent an appendicectomy between January 2005 and January 2009 were included in this study. The median age was 34 years, with a range of 16-94 years. The area under the ROC curve for NLR was 0.836, compared to 0.779 for WCC, 0.732 for CRP and 0.815 for NLR x CRP.

CONCLUSION

The results of this study suggest that as an adjunct to clinical examination, NLR appears to be of greater diagnostic accuracy than either WCC or CRP alone.

Expression of steroidogenic factor 1 (SF-1) and steroidogenic acute regulatory protein (StAR) in endometriosis is associated with endometriosis severity

This study was designed to investigate the levels of expression of steroidogenic factor 1 (SF-1) and steroidogenic acute regulatory protein (StAR) in endometriosis, and to explore the association between these two factors and the menstrual cycle and the severity of endometriosis. Levels of SF-1 and StAR protein were evaluated using immunohistochemistry in 38 cases of endometriosis with ectopic endometria and in 25 normal endometria (controls). The SF-1 and StAR protein levels were significantly higher in ectopic endometria than in normal endometria. There was a significant correlation between the level of SF-1 and StAR in ectopic endometriotic tissues. It is concluded that protein levels of SF-1 and StAR are upregulated in ectopic endometria and are significantly correlated with the severity of endometriosis.

Acetylcholinesterase inhibitory and antioxidant properties of Cyclotrichium niveum, Thymus praecox subsp. caucasicus var. caucasicus, Echinacea purpurea and E. pallida

The dichloromethane, ethyl acetate, ethanol, and aqueous extracts of Cyclotrichium niveum (CN) and Thymus praecox subsp. caucasicus var. caucasicus (TP), Echinacea purpurea (EPU), and E. pallida (EPA) along with the essential oils of CN and TP were assessed for their anti-acetylcholinesterase (AChE) and antioxidant activities. AChE inhibition was estimated using spectrophotometric method of Ellman. Antioxidant activity was evaluated by 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and ferrous ion-chelating power tests. Ferric-reducing antioxidant power (FRAP) of CN and TP were also tested. CN essential oil was found to contain isomenthone (56.21%) and pulegone (19.76%). The ethyl acetate (83.11-87.98%) and dichloromethane (73.45-84.02%) extracts of CN showed the highest AChE inhibition. The ethyl acetate and ethanol extracts of TP exerted significant DPPH scavenger effect. The water extracts of CN and TP and the chloroform extract of the aerial parts of EPU displayed the highest ferrous ion-chelating effect. The leaf and flower essential oils of TP had the best FRAP.

Effects of Celecoxib and Nimesulide on the Proliferation of Ectopic Endometrial Stromal Cells in vitro

The effects of cyclooxygenase 2 (COX-2) selective inhibitors on the proliferation of ectopic endometrial stromal cells in vitro were investigated. Ectopic endometrial stromal cells were treated with either celecoxib or nimesulide for 24 and 48 h. The results showed that (i) both celecoxib and nimesulide inhibited the proliferation of ectopic endometrial stromal cells in vitro in a time- and dose-dependent manner; (ii) the expression of prostaglandin E2 was significantly inhibited by both celecoxib and nimesulide in a dose-dependent manner; (iii) the percentage of apoptotic cells was significantly higher for cells treated with celecoxib or nimesulide than for untreated cells; and (iv) the percentage of the cells in the G0/G1 phase increased after the cells were treated with either agent in a dose-dependent manner. These data suggest that celecoxib and nimesulide inhibited proliferation of ectopic endometrial stromal cells by inducing apoptosis and blocking the cell cycle at the G0/G1 phase.

Recognition of emotion from moving facial and prosodic stimuli in depressed patients

BACKGROUND

It has been suggested that depressed patients have a "negative bias" in recognising other people's emotions; however, the detailed structure of this negative bias is not fully understood.

OBJECTIVES

To examine the ability of depressed patients to recognise emotion, using moving facial and prosodic expressions of emotion.

METHODS

16 depressed patients and 20 matched (non-depressed) controls selected one basic emotion (happiness, sadness, anger, fear, surprise, or disgust) that best described the emotional state represented by moving face and prosody.

RESULTS

There was no significant difference between depressed patients and controls in their recognition of facial expressions of emotion. However, the depressed patients were impaired relative to controls in their recognition of surprise from prosodic emotions, judging it to be more negative.

CONCLUSIONS

We suggest that depressed patients tend to interpret neutral emotions, such as surprise, as negative. Considering that the deficit was seen only for prosodic emotive stimuli, it would appear that stimulus clarity influences the recognition of emotion. These findings provide valuable information on how depressed patients behave in complicated emotional and social situations.

11-year experience with anatomical and extra-anatomical repair of mycotic aortic aneurysms

BACKGROUND

We have reviewed our management, of both ruptured and non-ruptured, abdominal and thoraco-abdominal mycotic aneurysms in order to determine the safety and efficacy of in situ and extra-anatomical prosthetic repairs.

METHODS

Data regarding presenting symptoms, investigations, operative techniques and outcome, were collected on patients treated at a singe centre over 11 years.

RESULTS

There were 11 men and four women, with a median age of 70 years (range, 24-79). All but one patient were symptomatic and six had a contained leak on admission. In six patients no organisms were identified in either blood or tissue cultures. Pre-operative CT identified; four infra-renal, four juxta-renal, three (Crawford thoraco-abdominal) type IV, three type III and one type II, aortic aneurysms. Thirteen were repaired with in situ prostheses and two required axillo-femoral prosthetic grafts. There were four early deaths. All surviving patients have been followed-up for a median duration of 38 months (range 1/2-112 months). There were two late deaths at 3 months (juxta-renal) and at 2 years (type III), the latter relating to graft infection.

CONCLUSIONS

In the absence of uncontrolled sepsis, repair of mycotic aortic aneurysms using prosthetic grafts can achieve durable results.

Goadsporin, a chemical substance which promotes secondary metabolism and Morphogenesis in streptomycetes. II. Structure determination

The structure of goadsporin was determined by using spectroscopic techniques. NMR analysis revealed that goadsporin consists of 19 amino acids, two of which are dehydroalanines (Deala), and six of which are cyclized to oxazoles (Oxz) and thiazoles (Thz) by dehydrative cyclization and dehydrogenation from serine, threonine and cysteine. NMR analysis established seven partial structures, and their sequence was determined by CID-MS/MS. Negative mode FAB-MS/MS gave product ions arising from charge-remote fragmentation that allowed determination of the sequence of the amino acid components as AcNH-Ala-MeOxz-Val-Deala-MeOxz-Ile-Leu-Thz-Ser-Gly-Gly-MeOxz-Leu-Deala-Oxz-Ala-Gly-Thz-Val-OH. The chiral amino acids were determined by the advanced Marfey's method to have L-configurations.

Structure elucidation of ostreocin D, a palytoxin analog isolated from the dinoflagellate Ostreopsis siamensis

The structure of ostreocin D, a palytoxin analog isolated from the marine dinoflagellate Ostreopsis siamensis, was found to be 42-hydroxy-3,26-didemethyl-19,44-dideoxypalytoxin by detailed 2D NMR analyses of intact ostreocin D and its ozonolysis products. Partial stereochemical assignments were done. This result indicates that the dinoflagellate O. siamensis is one of the biogenetic origins of palytoxin.

Supraclinoid carotid dissection in a pediatric patient

The authors present the case of a 13-year-old boy with a left temporal lobe infarction that developed during a 400-m run. Magnetic resonance (MR) angiography showed segmental narrowing of the left supraclinoid internal carotid artery (ICA) and a duplicated left middle cerebral artery (MCA). MR angiographic source images revealed a crescent-shaped left carotid lumen, indicative of a supraclinoid carotid dissection.

Conformational study of a highly specific CXCR4 inhibitor, T140, disclosing the close proximity of its intrinsic pharmacophores associated with strong anti-HIV activity

We report the solution structure of T140, a truncated polyphemusin peptide analogue that efficiently inhibits infection of target cells by T-cell line-tropic strains of HIV-1 through its specific binding to a chemokine receptor, CXCR4. Nuclear magnetic resonance analysis and molecular dynamic calculations revealed that T140 has a rigidly structured conformation constituted by an antiparallel beta-sheet and a type II' beta-turn. A protuberance is formed on one side of the beta-sheet by the side-chain functional groups of the three amino acid residues (L-3-(2-naphthyl)alanine, Tyr5 and Arg14), each of which is indispensable for strong anti-HIV activity. These findings provide a rationale to dissect the structural basis for the ability of this compound to block the interaction between CXCR4 and envelope glycoproteins from T-tropic strains of HIV-1.

Cyclic malyl anthocyanins in Dianthus caryophyllus

3,5-Di-O-(beta-glucopyranosyl) pelargonidin 6''-O-4,6'''-O-1-cyclic malate and a previously reported cyanidin equivalent, 3,5-di-O-(beta-glucopyranosyl) cyanidin 6''-O-4,6'''-O-1-cyclic malate were identified from petals of deep pink and red-purple flower cultivars of Dianthus caryophyllus, respectively.

New malyngamides from the Hawaiian cyanobacterium Lyngbya majuscula

Isomalyngamides A and B (1, 2) were isolated and characterized from a collection of the cyanobacterium Lyngbya majuscula from Hawaiian waters. These compounds represent a new type of malyngamide, similar to malyngamides Q and R, in which the conformation of the chloromethylene group is opposite from the majority of previously reported malyngamides. The geometry of the chloromethylene moiety was elucidated from the long-range coupling constants ((3)J(C)(-)(H)) obtained from editing-HETLOC and phase-sensitive HMBC experiments. Isomalyngamides A and B (1, 2) showed lethal toxicity to crayfish.

Synthesis, biological evaluation, and conformational analysis of A-ring diastereomers of 2-methyl-1,25-dihydroxyvitamin D(3) and their 20-epimers: unique activity profiles depending on the stereochemistry of the A-ring and at C-20

All eight possible A-ring diastereomers of 2-methyl-1, 25-dihydroxyvitamin D(3) (2) and 2-methyl-20-epi-1, 25-dihydroxyvitamin D(3) (3) were convergently synthesized. The A-ring enyne synthons 19 were synthesized starting with methyl (S)-(+)- or (R)-(-)-3-hydroxy-2-methylpropionate (8). This was converted to the alcohol 14 as a 1:1 epimeric mixture in several steps. After having been separated by column chromatography, each isomer led to the requisite A-ring enyne synthons 19 again as 1:1 mixtures at C-1. Coupling of the resulting A-ring enynes 20a-h with the CD-ring portions 5a,b in the presence of a Pd catalyst afforded the 2-methyl analogues 2a-h and 3a-h in good yield. In this way, all possible A-ring diastereomers were synthesized. The synthesized analogues were biologically evaluated both in vitro and in vivo. The potency was highly dependent on the stereochemistry of each isomer. In particular, the alpha alpha beta-isomer 2g exhibited 4-fold higher potency than 1 alpha,25-dihydroxyvitamin D(3) (1) both in bovine thymus VDR binding and in elevation of rat serum calcium concentration and was twice as potent as the parent compound in HL-60 cell differentiation. Furthermore, its 20-epimer, that is, 20-epi-alpha alpha beta 3g, exhibited exceptionally high activities: 12-fold higher in VDR binding affinity, 7-fold higher in calcium mobilization, and 590-fold higher in HL-60 cell differentiation, as compared to 1 alpha,25-dihydroxyvitamin D(3) (1). Accordingly, the double modification of 2-methyl substitution and 20-epimerization resulted in unique activity profiles. Conformational analysis of the A-ring by (1)H NMR and an X-ray crystallographic analysis of the alpha alpha beta-isomer 2g are also described.

Vasoactive intestinal peptide and pituitary adenylyl cyclase-activating polypeptide inhibit tumor necrosis factor-alpha production in injured spinal cord and in activated microglia via a cAMP-dependent pathway

Tumor necrosis factor-alpha (TNF-alpha) production accompanies CNS insults of all kinds. Because the neuropeptide vasoactive intestinal peptide (VIP) and the structurally related peptide pituitary adenylyl cyclase-activating polypeptide (PACAP) have potent anti-inflammatory effects in the periphery, we investigated whether these effects extend to the CNS. TNF-alpha mRNA was induced within 2 hr after rat spinal cord transection, and its upregulation was suppressed by a synthetic VIP receptor agonist. Cultured rat microglia were used to examine the mechanisms underlying this inhibition because microglia are the likely source of TNF-alpha in injured CNS. In culture, increases in TNF-alpha mRNA resulting from lipopolysaccharide (LPS) stimulation were reduced significantly by 10(-7) m VIP and completely eliminated by PACAP at the same concentration. TNF-alpha protein levels were reduced 90% by VIP or PACAP at 10(-7) m. An antagonist of VPAC(1) receptors blocked the action of VIP and PACAP, and a PAC(1) antagonist blocked the action of PACAP. A direct demonstration of VIP binding on microglia and the existence of mRNAs for VPAC(1) and PAC(1) (but not VPAC(2)) receptors argue for a receptor-mediated effect. The action of VIP is cAMP-mediated because (1) activation of cAMP by forskolin mimics the action; (2) PKA inhibition by H89 reverses the neuropeptide-induced inhibition; and (3) the lipophilic neuropeptide mimic, stearyl-norleucine(17) VIP (SNV), which does not use a cAMP-mediated pathway, fails to duplicate the inhibition. We conclude that VIP and PACAP inhibit the production of TNF-alpha from activated microglia by a cAMP-dependent pathway.

Arisostatins A and B, new members of tetrocarcin class of antibiotics from Micromonospora sp. TP-A0316. II. Structure determination

Structures of arisostatins A and B were determined by spectroscopic analyses. Arisostatins were found to be new analogs of tetrocarcin A and possess an iso-butanoyldigitoxose unit instead of the acetyldigitoxose one. NMR analyses of arisostatins and tetrocarcin A led to the revision of the anomeric configurations in the tetrasaccharide moiety of tetrocarcin A.

An active-site mutation causes enhanced reactivity and altered regiospecificity of transglucosylation catalyzed by the Bacillus sp. SAM1606 α-glucosidase

Bacillus sp. SAM1606 alpha-glucosidase catalyzes the transglucosylation of sucrose to produce three regioisomers of the glucosylsucroses, with theanderose (6-O(G)-glucosylsucrose) as the most abundant transfer product. To find the active-site amino acid residues which can affect the reactivity and regiospecificity of the glucosyl transfer, 16 mutants with amino acid substitutions near the active site were allowed to react with 1.75 M sucrose at 60 degrees C, pH 6.0, and the course of transglucosylation as well as the product specificity were analyzed. The sites of the amino acid substitutions were selected by comparing the conserved amino acid sequences located near the active site of the SAM1606 enzyme with those of the Bacillus oligo-1,6-glucosidases (O16G), which have very high amino acid sequence similarities near the active site but have a distinct substrate specificity. The results showed that, among the mutated SAM1606 enzymes examined, only the mutants with substitution of Gly273 with Pro showed an altered reactivity and specificity of transglucosylation; these mutants exhibited a significantly enhanced initial velocity of glucosyl transfer, yielding isomelezitose (6-O(F)-glucosylsucrose) instead of theanderose as the major transfer product. These results indicate that the substitution of Gly273 with Pro critically governs the enhanced reactivity and altered specificity of the transglucosylation. The notion that the amino acid residue at this position is the determinant of the glucosyl-transfer specificity was further confirmed by observation that the Bacillus cereus O16G, which has a proline at the corresponding position, produced isomelezitose as the major transfer product during transglucosylation with sucrose.

A new depsipeptide from the sacoglossan mollusk Elysia ornata and the green alga Bryopsis species

A new cyclic depsipeptide, kahalalide O (1), was isolated from the sacoglossan Elysia ornata and its algal diet Bryopsis sp. The structure was elucidated primarily by NMR and MS spectral methods, and the stereochemistry of the amino acid residues was determined by chiral HPLC and Marfey analyses. Unlike the related metabolite kahalalide F, which is in development as a potential anticancer agent, kahalalide O (1) was inactive in arresting the growth of P-388, A549, HT29, and MEL28 cancer cell lines in vitro.

Kahalalide K: A new cyclic depsipeptide from the hawaiian green alga bryopsis species

Kahalalide K (1), a new cyclic depsipeptide, was isolated from the Hawaiian green alga Bryopsis sp. Kahalalide K was determined to possess a new array of three L- and three D-amino acids, including a 3-hydroxy-9-methyldecanoic acid that had been previously reported in kahalalides E, H, and J.

Long-distance charge transport in duplex DNA: the phonon-assisted polaron-like hopping mechanism

An anthraquinone-linked duplex DNA oligomer containing 60 base pairs was synthesized by PCR. The strand complementary to the quinone-containing strand has four isolated GG steps, which serve as traps for a migrating radical cation. Irradiation of the quinone leads to electron transfer from the DNA to the quinone forming the anthraquinone radical anion and a base radical cation. The radical cation migrates through the DNA, causing reaction at GG steps revealed as strand breaks. The efficiency of strand cleavage falls off exponentially with distance from the quinone (slope = -0.02 A(-1)). This finding necessitates reinterpretation of mechanisms proposed for radical cation migration in DNA. We propose that radical cations form self-trapped polarons that migrate by thermally activated hopping.

Identification of the major antioxidative metabolites in biological fluids of the rat with ingested (+)-catechin and (-)-epicatechin

(+)-Catechin and (-)-epicatechin are known to be biologically effective antioxidants present in the human diet, particularly in wine and tea. We studied the metabolism of these compounds to elucidate the truly active structures in biological fluids by their oral administration to rats. Without any treatment with beta-glucuronidase and sulfatase, a pair of metabolites were detected at much higher concentrations in the plasma, bile, and urine than the originally ingested compounds. Each major metabolite found in the plasma at the highest concentration was excreted in both the bile and urine, and was purified from urine. Their chemical structures were established to be (+)-catechin 5-O-beta-glucuronide and (-)-epicatechin 5-O-beta-glucuronide by MS and NMR analyses. These glucuronide conjugates exhibited high antioxidative activities as superoxide anion radical scavengers like their parent compounds. It is concluded that (+)-catechin 5-O-beta-glucuronide and (-)-epicatechin 5-O-beta-glucuronide are the biologically active in vivo structures of the ingested polyphenolic antioxidants.

Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide inhibit tumor necrosis factor alpha transcriptional activation by regulating nuclear factor-kB and cAMP response element-binding protein/c-Jun

Tumor necrosis factor alpha (TNFalpha), an early cytokine produced by activated macrophages, plays an essential role in normal and pathological inflammatory reactions. The excessive production of TNFalpha is prevented by the so-called "macrophage-deactivating factors." This study examines the role of two structurally related neuropeptides, the vasoactive intestinal peptide (VIP) and the pituitary adenylate cyclase-activating peptide (PACAP), as inhibitors of TNFalpha. Both VIP and PACAP inhibit TNFalpha production from lipopolysaccharide-stimulated RAW 246.7 cells in a dose- and time-dependent manner. Although the activated cells express mRNA for all three VIP/PACAP receptors, agonist and antagonist studies indicate that the major receptor involved is VIP1R. VIP/PACAP inhibit TNFalpha gene expression by affecting both NF-kB binding and the composition of the cAMP responsive element binding complex (CREB/c-Jun). Two transduction pathways, a cAMP-dependent and a cAMP-independent pathway, are involved in the inhibition of TNFalpha gene expression and appear to differentially regulate the transcriptional factors involved. Because TNFalpha plays a central role in various inflammatory diseases such as endotoxic shock, multiple sclerosis, cerebral malaria, and various autoimmune conditions, the down-regulatory effect of VIP/PACAP may have a significant therapeutic potential.

Enzymatic reaction with unnatural substrates: DNA photolyase (Escherichia coli) recognizes and reverses thymine [2+2] dimers in the DNA strand of a DNA/PNA hybrid duplex

Peptide nucleic acids (PNA) are mimics with normal bases connected to a pseudopeptide chain that obey Watson-Crick rules to form stable duplexes with itself and natural nucleic acids. This has focused attention on PNA as therapeutic or diagnostic reagents. Duplexes formed with PNA mirror some but not all properties of DNA. One fascinating aspect of PNA biochemistry is their reaction with enzymes. Here we show an enzyme reaction that operates effectively on a PNA/DNA hybrid duplex. A DNA oligonucleotide containing a cis, syn-thymine [2+2] dimer forms a stable duplex with PNA. The hybrid duplex is recognized by photolyase, and irradiation of the complex leads to the repair of the thymine dimer. This finding provides insight into the enzyme mechanism and provides a means for the selective repair of thymine photodimers.

Malyngamides M and N from the Hawaiian Red Alga Gracilaria coronopifolia

Two new malyngamides, M and N (1, 2), were isolated along with malyngamide I acetate (3) from the Hawaiian red alga Gracilaria coronopifolia. Our results suggest that malyngamide N (2) is a revised structure of deacetoxystylocheilamide (5). The absolute configuration of malyngamide I acetate was deduced to be 3 using the reversed octant rule.

Selective stabilization of triplex DNA by anthraquinone sulfonamide derivatives

A series of cationic anthraquinone derivatives was investigated for their ability to stabilize duplex and triplex DNA. Thermal denaturation experiments demonstrate that each of these compounds stabilizes the [poly(dT) x poly(dA) x poly(dT)] triplex without significantly affecting the [poly(dT) x poly(dA)] duplex. The amount of stabilization is determined by the number and placement of the cationic substituents on the anthraquinone skeleton. The stabilization arises primarily from higher affinity binding of the quinones to the triplex relative to the duplex structures. Phosphorescence quenching and viscometric titrations indicate that the quinones bind to the triplex by intercalation.

Antisweet natural products. XII. Structures of sitakisosides XI-XX from Stephanotis lutchuensis Koidz. var. japonica

From the fresh stem of Stephanotis lutchuensis var. japonica, ten new oleanane-type triterpenoid glycosides, named sitakisosides XI-XX (1-10), were isolated. Their structures were determined on the basis of spectroscopic data and chemical evidence. The results show that all have a 3-O-beta-D-xylopyranosyl(1 --> 6)-beta-D-glucopyranosyl(1 --> 6)- beta-D-glucopyranosyl moiety and the aglycones of sitakisosides XI-XV, XVI and XVII, XVIII and XIX, and XX are sitakisogenin, chichipegenin, marsglobiferin and longispinogenin, respectively. Sitakisosides XI-XIII, XVI and XVIII, having an acyl group, showed antisweet activity.

Steroidal glycosides from the fresh stem of Stephanotis lutchuensis var. japonica (Asclepiadaceae). Chemical structures of stephanosides K-Q

The structural elucidation of seven related oxypregnane-oligoglycosides stephanosides K (1), L (2), M (3), N (4), O (5), P (6), and Q (7) from the fresh stem of Stephanotis lutchuensis var. japonica (Asclepiadaceae) was achieved through on a detailed study of their high-field 1H- and 13C-NMR spectra. The results show that all the sugars are beta (1-->4)-linked. The aglycones of stephanosides K, M, and O, and stephanosides L, N, and P were identified as 12-O-cinnamoyl-20-O-(E)-2-methyl-2-butenoyl, and 12-O-cinnamoyl-20-O-nicotinoyl derivatives of (20S)-pregn-6-ene-3 beta,5 alpha,8 beta,12 beta,14 beta,17 beta,20-heptaol, respectively. The aglycone of stephanoside Q was 12-O-cinnamoyldeacetylmetaplexigenin (kidjoranin).