Diversity, Complexity, and Specificity of Bacterial Lipopolysaccharide (LPS) Structures Impacting Their Detection and Quantification

Endotoxins are toxic lipopolysaccharides (LPSs), extending from the outer membrane of Gram-negative bacteria and notorious for their toxicity and deleterious effects. The comparison of different LPSs, isolated from various Gram-negative bacteria, shows a global similar architecture corresponding to a glycolipid lipid A moiety, a core oligosaccharide, and outermost long O-chain polysaccharides with molecular weights from 2 to 20 kDa. LPSs display high diversity and specificity among genera and species, and each bacterium contains a unique set of LPS structures, constituting its protective external barrier. Some LPSs are not toxic due to their particular structures. Different, well-characterized, and highly purified LPSs were used in this work to determine endotoxin detection rules and identify their impact on the host. Endotoxin detection is a major task to ensure the safety of human health, especially in the pharma and food sectors. Here, we describe the impact of different LPS structures obtained under different bacterial growth conditions on selective LPS detection methods such as LAL, HEK-blue TLR-4, LC-MS2, and MALDI-MS. In these various assays, LPSs were shown to respond differently, mainly attributable to their lipid A structures, their fatty acid numbers and chain lengths, the presence of phosphate groups, and their possible substitutions.

Early detection of oral bacteria causing gum infections and dental caries in children

Background and Objectives

Periodontal diseases are resulted from gum infections and dental plaques, which are mainly caused by the bacterial agents. Since dental monitoring includes important prognostic roles, the aim of this study was to detect the most common periodontal pathogenic bacteria in children.

Materials and Methods

A total of 200 clinical samples were collected from dental plaques and gingival grooves. Target-specific primers were designed for hbpA in Aggregatibacter actinomycetemcomitans, fimA in Porphyromonas gingivalis and 16S rRNA in Prevotella intermedia, Tannerella forsythia and Treponema denticola. Then, a multiplex polymerase chain reaction method was optimized for the highlighted bacterial agents.

Results

In general, the highest and the lowest bacterial prevalence rates belonged to Tannerella forsythia (88%) and Porphyromonas gingivalis (13%), respectively. Furthermore, prevalence rates of Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Treponema denticola were 25, 21 and 45% in samples, respectively.

Conclusion

There were significant associations between dental/oral health and microbial community. Metabolism of the oral bacteria, including biofilm formation, can affect gums and develop dental plaques and hence dental caries, especially in children. Early diagnosis of dental caries in children via rapid, accurate molecular methods can increase the diagnostic capacity in clinical cases and therefore prevent periodontal infections in adulthood.

Integrated omics approach for the identification of HDL structure-function relationships in PCSK9-related familial hypercholesterolemia

BACKGROUND

The role of proprotein convertase subtilisin/kexin type 9 (PCSK9) in dyslipidemia may go beyond its immediate effects on low-density lipoprotein receptor (LDL-R) activity.

OBJECTIVE

This study aimed to assess PCSK9-derived alterations of high-density lipoprotein (HDL) physiology, which bear a potential to contribute to cardiovascular risk profile.

METHODS

HDL was isolated from 33 patients with familial autosomal dominant hypercholesterolemia (FH), including those carrying PCSK9 gain-of-function (GOF) genetic variants (FH-PCSK9, n = 11), together with two groups of dyslipidemic patients employed as controls and carrying genetic variants in the LDL-R not treated (ntFH-LDLR, n = 11) and treated (tFH-LDLR, n = 11) with statins, and 11 normolipidemic controls. Biological evaluations paralleled by proteomic, lipidomic and glycomic analyses were applied to characterize functional and compositional properties of HDL.

RESULTS

Multiple deficiencies in the HDL function were identified in the FH-PCSK9 group relative to dyslipidemic FH-LDLR patients and normolipidemic controls, which involved reduced antioxidative, antiapoptotic, anti-thrombotic and anti-inflammatory activities. By contrast, cellular cholesterol efflux capacity of HDL was unchanged. In addition, multiple alterations of the proteomic, lipidomic and glycomic composition of HDL were found in the FH-PCSK9 group. Remarkably, HDLs from FH-PCSK9 patients were systematically enriched in several lysophospholipids as well as in A2G2S2 (GP13) glycan and apolipoprotein A-IV. Based on network analysis of functional and compositional data, a novel mosaic structure-function model of HDL biology involving FH was developed.

CONCLUSION

Several metrics of anti-atherogenic HDL functionality are altered in FH-PCSK9 patients paralleled by distinct compositional alterations. These data provide a first-ever overview of the impact of GOF PCSK9 genetic variants on structure-function relationships in HDL.

Identification of the specific molecular and functional signatures of pre-beta-HDL: relevance to cardiovascular disease

While low concentrations of high-density lipoprotein-cholesterol (HDL-C) are widely accepted as an independent cardiovascular risk factor, HDL-C-rising therapies largely failed, suggesting the importance of both HDL functions and individual subspecies. Indeed HDL particles are highly heterogeneous, with small, dense pre-beta-HDLs being considered highly biologically active but remaining poorly studied, largely reflecting difficulties for their purification. We developed an original experimental approach allowing the isolation of sufficient amounts of human pre-beta-HDLs and revealing the specificity of their proteomic and lipidomic profiles and biological activities. Pre-beta-HDLs were enriched in highly poly-unsaturated species of phosphatidic acid and phosphatidylserine, and in an unexpectedly high number of proteins implicated in the inflammatory response, including serum paraoxonase/arylesterase-1, vitronectin and clusterin, as well as in complement regulation and immunity, including haptoglobin-related protein, complement proteins and those of the immunoglobulin class. Interestingly, amongst proteins associated with lipid metabolism, phospholipid transfer protein, cholesteryl ester transfer protein and lecithin:cholesterol acyltransferase were strongly enriched in, or restricted to, pre-beta-HDL. Furthermore, pre-beta-HDL potently mediated cellular cholesterol efflux and displayed strong anti-inflammatory activities. A correlational network analysis between lipidome, proteome and biological activities highlighted 15 individual lipid and protein components of pre-beta-HDL relevant to cardiovascular disease, which may constitute novel diagnostic targets in a pathological context of altered lipoprotein metabolism.

Phosphatidylserine enhances anti-inflammatory effects of reconstituted HDL in macrophages via distinct intracellular pathways

Phosphatidylserine (PS) is a minor phospholipid constituent of high-density lipoprotein (HDL) that exhibits potent anti-inflammatory activity. It remains indeterminate whether PS incorporation can enhance anti-inflammatory effects of reconstituted HDL (rHDL). Human macrophages were treated with rHDL containing phosphatidylcholine alone (PC-rHDL) or PC and PS (PC/PS-rHDL). Interleukin (IL)-6 secretion and expression was more strongly inhibited by PC/PS-rHDL than PC-rHDL in both tumor necrosis factor (TNF)-α- and lipopolysaccharide (LPS)-stimulated macrophages. siRNA experiments revealed that the enhanced anti-inflammatory effects of PC/PS-rHDL required scavenger receptor class B type I (SR-BI). Furthermore, PC/PS-rHDL induced a greater increase in Akt1/2/3 phosphorylation than PC-rHDL. In addition, PC/PS but not PC-rHDL decreased the abundance of plasma membrane lipid rafts and p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation. Finally, when these rHDL formulations were administered to dyslipidemic low-density lipoprotein (LDL)-receptor knockout mice fed a high-cholesterol diet, circulating IL-6 levels were significantly reduced only in PC/PS-rHDL-treated mice. In parallel, enhanced Akt1/2/3 phosphorylation by PC/PS-rHDL was observed in the mouse aortic tissue using immunohistochemistry. We concluded that the incorporation of PS into rHDLs enhanced their anti-inflammatory activity by modulating Akt1/2/3- and p38 MAPK-mediated signaling through SR-BI in stimulated macrophages. These data identify PS as a potent anti-inflammatory component capable of enhancing therapeutic potential of rHDL-based therapy.

High-density lipoproteins (HDL): Novel function and therapeutic applications

The failure of high-density lipoprotein (HDL)-raising agents to reduce cardiovascular disease (CVD) together with recent findings of increased cardiovascular mortality in subjects with extremely high HDL-cholesterol levels provide new opportunities to revisit our view of HDL. The concept of HDL function developed to explain these contradictory findings has recently been expanded by a role played by HDL in the lipolysis of triglyceride-rich lipoproteins (TGRLs) by lipoprotein lipase. According to the reverse remnant-cholesterol transport (RRT) hypothesis, HDL critically contributes to TGRL lipolysis via acquirement of surface lipids, including free cholesterol, released from TGRL. Ensuing cholesterol transport to the liver with excretion into the bile may reduce cholesterol influx in the arterial wall by accelerating removal from circulation of atherogenic, cholesterol-rich TGRL remnants. Such novel function of HDL opens wide therapeutic applications to reduce CVD in statin-treated patients, which primarily involve activation of cholesterol flux upon lipolysis.

An efficient method to solve fuzzy Volterra integral equations using Fibonacci polynomials

According to a huge interest in implementation of the fuzzy Volterra integral equations, especially the second kind, researchers have been investigating to solve such equations using numerical methods since analytical ones might not be accessible usually. In this research paper, we introduce a new approach based on Fibonacci polynomials collocation method to numerically solve them. Several properties of such polynomials were considered to implement in the collocation method due to approximate the solution of the second kind of fuzzy Volterra integral equations. We approved the existence, uniqueness of the solution, convergence and the error analysis of the proposed method in detail. In order to show the authenticity and applicability of the proposed method, we employed several illustrative examples. The numerical results show that the convergence and precision of the recent method were in a good settlement with the exact solution. Also, the calculations of the suggested method are simple and low computational complexity in respect to other methods as an advantage feature of the presented approach.

Phospholipid transfer to high-density lipoprotein (HDL) upon triglyceride lipolysis is directly correlated with HDL-cholesterol levels and is not associated with cardiovascular risk

BACKGROUND AND AIMS

While low concentrations of high-density lipoprotein-cholesterol (HDL-C) represent a well-established cardiovascular risk factor, extremely high HDL-C is paradoxically associated with elevated cardiovascular risk, resulting in the U-shape relationship with cardiovascular disease. Free cholesterol transfer to HDL upon lipolysis of triglyceride-rich lipoproteins (TGRL) was recently reported to underlie this relationship, linking HDL-C to triglyceride metabolism and atherosclerosis. In addition to free cholesterol, other surface components of TGRL, primarily phospholipids, are transferred to HDL during lipolysis. It remains indeterminate as to whether such transfer is linked to HDL-C and cardiovascular disease.

METHODS AND RESULTS

When TGRL was labelled with fluorescent phospholipid 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI), time- and dose-dependent transfer of DiI to HDL was observed upon incubations with lipoprotein lipase (LPL). The capacity of HDL to acquire DiI was decreased by -36% (p<0.001) in low HDL-C patients with acute myocardial infarction (n = 22) and by -95% (p<0.001) in low HDL-C subjects with Tangier disease (n = 7), unchanged in low HDL-C patients with Type 2 diabetes (n = 17) and in subjects with high HDL-C (n = 20), and elevated in subjects with extremely high HDL-C (+11%, p<0.05) relative to healthy normolipidemic controls. Across all the populations combined, HDL capacity to acquire DiI was directly correlated with HDL-C (r = 0.58, p<0.001). No relationship of HDL capacity to acquire DiI with both overall and cardiovascular mortality obtained from epidemiological studies for the mean HDL-C levels observed in the studied populations was obtained.

CONCLUSIONS

These data indicate that the capacity of HDL to acquire phospholipid from TGRL upon LPL-mediated lipolysis is proportional to HDL-C and does not reflect cardiovascular risk in subjects widely differing in HDL-C levels.

Free cholesterol transfer to high-density lipoprotein (HDL) upon triglyceride lipolysis underlies the U-shape relationship between HDL-cholesterol and cardiovascular disease

BACKGROUND

Low concentrations of high-density lipoprotein cholesterol (HDL-C) represent a well-established cardiovascular risk factor. Paradoxically, extremely high HDL-C levels are equally associated with elevated cardiovascular risk, resulting in the U-shape relationship of HDL-C with cardiovascular disease. Mechanisms underlying this association are presently unknown. We hypothesised that the capacity of high-density lipoprotein (HDL) to acquire free cholesterol upon triglyceride-rich lipoprotein (TGRL) lipolysis by lipoprotein lipase underlies the non-linear relationship between HDL-C and cardiovascular risk.

METHODS

To assess our hypothesis, we developed a novel assay to evaluate the capacity of HDL to acquire free cholesterol (as fluorescent TopFluor® cholesterol) from TGRL upon in vitro lipolysis by lipoprotein lipase.

RESULTS

When the assay was applied to several populations markedly differing in plasma HDL-C levels, transfer of free cholesterol was significantly decreased in low HDL-C patients with acute myocardial infarction (-45%) and type 2 diabetes (-25%), and in subjects with extremely high HDL-C of >2.59 mmol/L (>100 mg/dL) (-20%) versus healthy normolipidaemic controls. When these data were combined and plotted against HDL-C concentrations, an inverse U-shape relationship was observed. Consistent with these findings, animal studies revealed that the capacity of HDL to acquire cholesterol upon lipolysis was reduced in low HDL-C apolipoprotein A-I knock-out mice and was negatively correlated with aortic accumulation of [³H]-cholesterol after oral gavage, attesting this functional characteristic as a negative metric of postprandial atherosclerosis.

CONCLUSIONS

Free cholesterol transfer to HDL upon TGRL lipolysis may underlie the U-shape relationship between HDL-C and cardiovascular disease, linking HDL-C to triglyceride metabolism and atherosclerosis.

Small dense HDLs display potent vasorelaxing activity, reflecting their elevated content of sphingosine-1-phosphate

The functional heterogeneity of HDL is attributed to its diverse bioactive components. We evaluated whether the vasodilatory effects of HDL differed across HDL subpopulations, reflecting their distinct molecular composition. The capacity of five major HDL subfractions to counteract the inhibitory effects of oxidized LDL on acetylcholine-induced vasodilation was tested in a rabbit aortic rings model. NO production, an essential pathway in endothelium-dependent vasorelaxation, was studied in simian vacuolating virus 40-transformed murine endothelial cells (SVECs). Small dense HDL3 subfractions displayed potent vasorelaxing activity (up to +31% vs. baseline, P < 0.05); in contrast, large light HDL2 did not induce aortic-ring relaxation when compared on a total protein basis. HDL3 particles were enriched with sphingosine-1-phosphate (S1P) (up to 3-fold vs. HDL2), with the highest content in HDL3b and -3c that concomitantly revealed the strongest vasorelaxing properties. NO generation was enhanced by HDL3c in SVECs (1.5-fold, P < 0.01), a phenomenon that was blocked by the S1P receptor antagonist, VPC 23019. S1P-enriched reconstituted HDL (rHDL) was a 1.8-fold (P < 0.01) more potent vasorelaxant than control rHDL in aortic rings. Small dense HDL3 particles displayed potent protective effects against oxidative stress-associated endothelium dysfunction, potentially reflecting their elevated content of S1P that might facilitate interaction with S1P receptors and ensuing NO generation.

Primary Culture of Human Cumulus Cells Requires Stearoyl-Coenzyme A Desaturase 1 Activity for Steroidogenesis and Enhancing Oocyte In Vitro Maturation

Stearoyl-coenzyme A desaturase 1 (SCD1) is a key enzyme in lipid metabolism and is expressed in cumulus cells. The objective of the present study was to evaluate the effect of SCD1 inhibition in human cumulus cells on triglyceride content, steroidogenesis, and oocyte in vitro maturation. Human cumulus cells were exposed to SCD1 inhibitor CAY10566 (SCDinhib) alone or in combination with oleic acid in primary culture. The SCDinhib markedly suppressed triglyceride accumulation (-47%, P = .01), aromatase gene expression (-36%, P = .02), and estradiol production (-49%, P = .01) even at a dose not affecting cell viability and apoptosis. Human immature oocytes at the germinal vesicle (GV) stage were cocultured with pretreated cumulus cells. The rate of oocytes reaching the metaphase II stage was significantly lower in coculture with SCDinhib-treated cumulus cells than with control cumulus cells (-18%, P < .01), which recovered by oleic acid supplementation. This finding on in vitro maturation rate was also reproducible with mouse GV oocytes. The results suggest that SCD1 activity is required for cumulus cell lipid storage and steroidogenesis. In addition, oocyte maturation is negatively affected by SCD1 inhibition in cumulus cells, possibly due to a deficient lipid-mediated paracrine support.

Phosphatidylserine in atherosclerosis

PURPOSE OF REVIEW

It is now widely acknowledged that phosphatidylserine is a multifunctional bioactive lipid. In this review, we focus on the function of phosphatidylserine in modulating cholesterol metabolism, influencing inflammatory response and regulating coagulation system, and discuss promising phosphatidylserine-based therapeutic approaches and detection techniques in atherosclerosis.

RECENT FINDINGS

Phosphatidylserine has been suggested to play important roles in physiological processes, such as apoptosis, inflammation, and coagulation. Recent data demonstrate atheroprotective potential of phosphatidylserine, reflecting its capacity to inhibit inflammation, modulate coagulation, and enhance HDL functionality. Furthermore, modern lipidomic approaches have enabled the investigation of phosphatidylserine properties relevant to the lipid-based drug delivery and development of reconstituted HDL.

SUMMARY

Studies of phosphatidylserine in relation to atherosclerosis represent an area of opportunity. Additional research elucidating mechanisms underlying experimentally observed atheroprotective effects of phosphatidylserine is required to fully explore therapeutic potential of this naturally occurring phospholipid in cardiovascular disease.

Therapeutic applications of reconstituted HDL: When structure meets function

Reconstituted forms of HDL (rHDL) are under development for infusion as a therapeutic approach to attenuate atherosclerotic vascular disease and to reduce cardiovascular risk following acute coronary syndrome and ischemic stroke. Currently available rHDL formulations developed for clinical use contain apolipoprotein A-I (apoA-I) and one of the major lipid components of HDL, either phosphatidylcholine or sphingomyelin. Recent data have established that quantitatively minor molecular constituents of HDL particles can strongly influence their anti-atherogenic functionality. Novel rHDL formulations displaying enhanced biological activities, including cellular cholesterol efflux, may therefore offer promising prospects for the development of HDL-based, anti-atherosclerotic therapies. Indeed, recent structural and functional data identify phosphatidylserine as a bioactive component of HDL; the content of phosphatidylserine in HDL particles displays positive correlations with all metrics of their functionality. This review summarizes current knowledge of structure-function relationships in rHDL formulations, with a focus on phosphatidylserine and other negatively-charged phospholipids. Mechanisms potentially underlying the atheroprotective role of these lipids are discussed and their potential for the development of HDL-based therapies highlighted.

Expression Levels of PPARγ and CYP-19 in Polycystic Ovarian Syndrome Primary Granulosa Cells: Influence of ω-3 Fatty Acid

BACKGROUND

The omega-3 fatty acid (ω-3 fatty acid) such as eicosapentaenoic acid (EPA) is currently used in the clinic as a nutritional supplement in the treatment of poly- cystic ovarian syndrome (PCOS). The present study was designed to investigate the ef- fect of EPA on the expression levels of peroxisome proliferator-activated receptor gamma (PPARγ) and cytochrome P450 aromatase (encoded by the CYP-19) in primary cultured granulosa cells (GC) from patients undergoing in vitro fertilization (IVF), and also to compare these effects with those in GC of PCOS patients.

MATERIALS AND METHODS

In this experimental study, human GC were isolated, pri- mary cultured in vitro, exposed to a range of concentrations of the EPA and in- vestigated with respect to gene expression levels of PPARγ and CYP-19 using real time-polymerase chain reaction (PCR). The participants (n=30) were the patients admitted to the IVF Center in February-March 2013 at Alzahra Hospital, Tabriz, Iran, who were divided into two groups as PCOS (n=15) and non-PCOS (n=15) women (controls).

RESULTS

All doses of the EPA significantly induced PPARγ mRNA gene expression level as compared to the control recombinant follicle stimulating hormone (rFSH) alone condi- tion. High doses of EPA in the presence of rFSH produced a stimulatory effect on expres- sion level of PPARγ (2.15-fold, P=0.001) and a suppressive effect (0.56-fold, P=0.01) on the expression level of CYP-19, only in the PCOS GC.

CONCLUSION

EPA and FSH signaling pathway affect differentially on the gene ex- pression levels of PPARγ and CYP-19 in PCOS GC. Altered FSH-induced PPARγ activity in PCOS GC may modulate the CYP-19 gene expression in response to EPA, and possibly modulates the subsequent steroidogenesis of these cells.

Immunohistochemichal Assessment of the CrkII Proto-oncogene Expression in Common Malignant Salivary Gland Tumors and Pleomorphic Adenoma

Background and aims. Various morphologies are seen in different salivary gland tumorsor within an individual tumor, and the lesions show divers biological behaviors. Experimental results support the hypothesis that increased CrkII proto-oncogene is associated with cytokine-induced tumor initiation and progression by altering cell motility signaling pathway. The aim of this study was to assess the CrkII expression in common malignant salivary gland tumors and pleomorphic ade-noma.

Materials and methods. Immunohistochemical analysis of CrkII expression was performed on paraffin blocks of 64 car-cinomas of salivary glands, 10 pleomorphic adenomas, and 10 normal salivary glands. Biopsies were subjected to immu-nostaining with EnVision detection system using monoclonal anti-CrkII. Evaluation of immunoreactivity of CrkII was based on the immunoreaction intensity and percentage of stained tumor cells which were scored semi-quantitatively on a scale with four grades 0 to 3. Kruskal-wallis test and additional Mann-Whitney statistical test were used for analysis of CrkII expression levels.

Results. Increased expression of CrkII was seen (P=0.005) in malignant tumors including: mucoepidermoid carcinoma, adenoid cystic carcinoma, and carcinoma ex pleomorphic adenoma, but CrkII expression in acinic cell carcinoma was weak. CrkII expression in pleomorphic adenoma was weak or negative. A weak staining was sparsely seen in normal acinar serous cell.

Conclusion. Increased expression of CrkII and its higher intensity of staining in tumors with more aggressive biologic behavior in carcinomas of salivary gland is consistent with a role for this proto-oncogene in salivary gland tumorigenesis and cancer progression.

The 763C>G Polymorphism of The Secretory PLA2IIa Gene Is Associated with Endometriosis in Iranian Women

Background

Endometriosis is a chronic gynecological disease resulting from complex interactions between genetic, hormonal, environmental and oxidative stress and intrinsic inflammatory components. The aim of this study was to investigate the potential association of the 763C>G polymorphism in the secretory phospholipase A2 group IIa gene (PLA2G2A) with the risk of endometriosis in Iranian women.

Materials and Methods

Ninety seven patients with endometriosis along with 107 women who were negative for endometriosis after laparoscopy and laparatomy, and served as the control group, were enrolled for this cross-sectional study. Samples were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method.

Results

Multivariate analysis was used to examine the association between the risk of endometriosis and the 763C>G polymorphism of PLA2G2A. Genotype distributions of PLA2G2A were significantly different between patients and the controls (p<0.001, OR=0.22, 95% CI=0.21-0.39). Correlation analysis showed that there was a significant association between the normal homozygous genotype and susceptibility to endometriosis (p<0.001).

Conclusion

The present study suggests that the 763C>G polymorphism of PLA2G2A plays an important role as an independent factor in the risk of endometriosis in Iranian women.

Effect of PPARδ agonist on stearoyl-CoA desaturase 1 in human pancreatic cancer cells: role of MEK/ERK1/2 pathway

OBJECTIVE

The stearoyl-CoA desaturase 1 (SCD1), also known as Δ9-desaturase, is a regulatory enzyme in the cellular lipid modification process that has been linked to pancreatic cancer and diabetes. The aim of the present study was to investigate the effect of peroxisome proliferative-activated receptor δ (PPARδ) agonist and ERK1/2- and EGF receptor (EGFR)-dependent pathways on the expression of SCD1 in human pancreatic carcinoma cell line PANC-1.

METHODS

PANC-1 cells cultured in RPMI-1640 were exposed to the commonly used MEK inhibitor PD98059, EGFR-selective inhibitor AG1478, and PPARδ agonist GW0742. Changes in mRNA, protein expression and activity index of SCD1 were then determined using real-time reverse transcription polymerase chain reaction, Western blot and gas liquid chromatography, respectively.

RESULTS

The activity index and expression of SCD1 (p<0.01) decreased following treatment with PPARδ agonist at both mRNA and protein levels, whereas significant increases were observed after treatment with MEK or EGFR inhibitor. It was also found that the activity index of SCD1 were lower (p<0.01) in the combined treatment compared to the incubation with either inhibitor alone.

CONCLUSIONS

PPARδ and MEK/ERK1/2- and EGFR-dependent pathways affect the expression and activity of SCD1 in pancreatic cancer cells. Furthermore, the aforementioned kinase signalling pathways were involved in an inhibitory effect on the expression and activity of SCD1 in these cells, possibly via PPARδ activation.

Tissue fatty acid composition and secretory phospholipase-A2 activity in oral squamous cell carcinoma

PURPOSE

Oral squamous cell carcinoma (OSCC) is a remarkable health problem worldwide, but its pathogenesis remains unknown. The aim of this study was to compare fat composition and secretory phospholipase-A2 (sPLA2) activity between the malignant and adjacent normal squamous tissues in patients with OSCC.

METHODS

Paired samples of malignant squamous and adjacent normal-appearing tissues were collected from 27 patients with OSCC. The fatty acid composition in the obtained tissues was determined by gas liquid chromatography. Tissue enzyme activities of sPLA2 were measured using the standard assay with Diheptanoyl Thio-Phosphatidylcholine as substrate.

RESULTS

In the OSCC tissue, the level of stearic acid (18:0) and activity of sPLA2 were higher (P < 0.001), and the levels of oleic acid (18:1n-9) and linoleic acid (18:2n-6) were lower than that in the adjacent normal-appearing squamous tissue (P < 0.001). The activity of sPLA2 in OSCC was strongly negatively correlated with the amount of 18:2n-6 (r = -0.41, P < 0.001). Negative significant associations were observed between the OSCC invasion and tissue levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHE).

CONCLUSION

The changes in the fatty acid composition and sPLA2 activity may be regarded as indicators of altered lipid metabolism occurring in vivo during squamous cell carcinogenesis.

Fatty Acid Composition of Tissue Cultured Breast Carcinoma and the Effect of Stearoyl-CoA Desaturase 1 Inhibition

Purpose

Stearoyl-CoA desaturase 1 (SCD1) is a novel therapeutic target in various malignancies, including breast cancer. The present study was designed to investigate the effect of the pharmacologic inhibition of SCD1 on fatty acid composition in tissue explant cultures of human breast cancer and to compare these effects with those in adjacent nonneoplastic breast tissue.

Methods

Paired samples of tumor and adjacent noncancerous tissue were isolated from 12 patients with infiltrating ductal breast cancer. Samples were explant cultured in vitro, exposed to the highly selective SCD1 inhibitor CAY10566, and examined for fatty acid composition by gas liquid chromatography. The cytotoxic and antigrowth effects were evaluated by quantification of lactate dehydrogenase release and by sulforhodamine B (SRB) measurement, respectively.

Results

Breast cancer tissue samples were found to have higher levels of monounsaturated fatty acids (MUFA) (p<0.001) and arachidonic acid (20:4n-6, p<0.001) and a lower level of linoleic acid (18:2n-6, p=0.02) than the normal-appearing breast tissues. While exhibiting no evident cytotoxicity, treatment with the SCD1 inhibitor, CAY10566 (0.1-1 µM), for 48 hours significantly increased 18:2n-6 levels in both the tumor and adjacent normal-appearing tissue (approximately 1.2 fold, p<0.05). However, the breast cancer tissue samples showed significant increases in the levels of MUFA and 20:4n-6 compared to the normal-appearing breast tissues (p<0.05). The SRB growth assay revealed a higher rate of inhibition with the SCD1 inhibitor in breast cancer tissues than in normal-appearing tissues (p<0.01, 41% vs. 29%). The SCD1 inhibitor also elevated saturated fatty acid (1.46-fold, p=0.001) levels only in the tumor tissue explant.

Conclusion

The fatty acid composition and response to SCD1 inhibition differed between the explant cultures from breast cancer and the adjacent normal-appearing tissue. Altered fatty acid composition induced by SCD1 inhibition may also, in addition to Δ9 desaturation, modulate other reactions in de novo fatty acid synthesis and lipogenesis, and subsequently affect the overall survival and progression of breast cancer.

Epidemiological situation of toxocariasis in Iran: meta-analysis and systematic review

Toxocariasis is the clinical terms applied to infection of human with ascarid nematodes in the order Ascaridida, named toxocara canis and toxocara cati. It is transmitted from dog and cat to humans. Accidental ingestion of parasite eggs causes ocular and visceral larva migrans in human. The aim of this study is to study epidemiology of toxocariasis in Iran using meta-analysis and systematic review. Using main key words of toxocariasis including epidemiology, Toxocara spp. Iran, dog and cat in databases such as SID, Google scholar, Pubmed, Magiran and Iranmedex, a number of 50 articles was extracted. A number of 27 articles of them were eligible for meta-analysis. Data extracted from articles and archived in excel software for analysis. Variance of each study obtained using binomial distribution. Heterogeny of studies surveyed using Cochrans Q test. Data analyzed using Random Effect Model test. Overall prevalence of toxocariasis obtained 21.6% in Iran. In total of 27 articles, 6911 samples including 1543 carnivores, (13 articles), 4569 human sera (10 articles) and 799 soil samples (4 articles) has been investigated. Seropositivity for human toxocariasis 15.8% (95%CI, 9.2-22.5), soil contamination for Txocara spp. eggs 21.6% (95%CI,-1.6-44.8) and dogs and cats infections with adult worm 26.8% (95%CI, 18.7-36.8) was obtained. Results of this study show that prevalence of toxocariasis has a growing trend in Iran. It could be decreased using education, culture making and giving information to people.

I405V polymorphism of CETP gene and lipid profile in women with endometriosis

Genetic factors have an important role in the pathophysiology of endometriosis. In addition, abnormalities in lipid profile and intrinsic inflammatory status are associated with disease progression. The purpose of this study was to evaluate the effect of the I405V polymorphism of cholesteryl ester transfer protein (CETP) gene and lipid profile with the risk of endometriosis in women. Ninety-seven women with laparoscopy-diagnosed endometriosis were recruited for this study, and 107 patients with no evidence of endometriosis confirmed by laparoscopy served as controls. Samples were analyzed for polymorphism of the CETP gene using polymerase chain reaction-restriction fragment length polymorphism-based methods. After adjustment for body mass index, high-density lipoprotein-C and low-density lipoprotein-C, the risk of endometriosis in patients with normal genotype homozygous was more of the rare allele (p < 0.001, odds ratio = 0.21, 95% confidence interval = 0.09-0.45). Our results suggest that I405V polymorphism of CETP gene plays an important role as independent factor in the risk of endometriosis in women.

Tissue fatty acid composition in human urothelial carcinoma

Bladder cancer cells appear to have an altered lipid metabolism as evidenced by modulated lipogenic enzymes. The aim of this study is to investigate differences in tissue fat composition between malignant and adjacent normal urinary bladder tissue. Normal-appearing and malignant bladder tissues were collected from 31 patients with high-grade (Ta) urothelial carcinoma during transurethral resection (TUR). The fatty acid composition in the tissue was determined by gas liquid chromatography. In the bladder cancer tissue, levels of stearic acid (18:0; P = 0.01) and oleic acid (18:1n-9; P = 0.03) were higher, and the level of arachidonic aid (20:4n-6; P < 0.001) was lower than that in the normal-appearing bladder. Overall, bladder cancer tissue showed a significant reduction in total n-6 polyunsaturated fatty acid (-15.1%; P < 0.001). The change in the fatty acid composition may be regarded as an indicator of altered lipid metabolism occurring in vivo during human bladder tumourigenesis.

Tissue fatty acid composition in obstructive sleep apnea and recurrent tonsillitis

OBJECTIVE

Tonsillar hypertrophy cells appear to have an altered lipid metabolism as evidenced by modulated inflammatory cytokines that affect tissue lipid metabolism. The aim of this study was to investigate differences in tissue fat composition between obstructive sleep apnea (OSA) and recurrent infective tonsillitis (RT) in children.

METHODS

Tonsillar tissues were collected from 114 patients with OSA and 92 patients with RT, aged 4-10 years, during tonsillectomy. The tissue lipid extracts were analyzed by gas liquid chromatography for a comprehensive fatty acid profile.

RESULTS

In the tonsillitis tissue, the levels of palmitoleic acid (16:1n-7; P=0.002) and oleic acid (18:1n-9; P=0.003) were higher, and the level of stearic acid (18:0; P=0.004) was lower than that in the hyperplastic tonsillar tissue. Overall, tonsillar tissue of patients with RT had a significant increase in the total monounsaturated fatty acids (+9.9%; P<0.001) and the fatty acid desaturation index (+20.5%; P<0.001). Furthermore, oleic acid content of tonsillar tissue was positively correlated with BMI (r=0.20, P=0.004), snoring (r=0.16, P=0.022) and hypertrophy grade (r=0.18, P=0.023), which remain significant in the subgroup analysis by hypertrophy type.

CONCLUSIONS

The change in the fatty acid composition may be regarded as an indicator of altered lipid metabolism occurring in vivo during human tonsillar hypertrophy, which might be linked to the severity or type of the tissue damage.

PPARγ agonist-induced alterations in Δ6-desaturase and stearoyl-CoA desaturase 1: Role of MEK/ERK1/2 pathway

AIM

To investigate the effect of MEK/ERK1/2 pathway on peroxisome proliferator-activated receptors (PPARγ) agonist-induced alterations in Δ6-desaturase (Δ6D) and stearoyl-CoA desaturase 1 (SCD1) in hepatocellular carcinoma cell line HepG2.

METHODS

HepG2 cells cultured in RPMI-1640 were exposed to the commonly used ERK1/2 pathway inhibitor PD98059 and PPARγ agonist, pioglitazone. Total RNA was isolated and reverse transcribed from treated cells. Changes in gene expression and metabolites ratio, as activity index for Δ6D and SCD1, were then determined using reverse transcription-polymerase chain reaction and gas liquid chromatography, respectively.

RESULTS

The expression of both Δ6D (P = 0.03) and SCD1 (P = 0.01) increased following PD98059 treatment, with a higher impact on SCD1 (24.5% vs 62.5%). Although pioglitazone increased the mRNA level (1.47 ± 0.10 vs 0.88 ± 0.02, P = 0.006) and activity index (1.40 ± 0.07 vs 0.79 ± 0.11, P < 0.001) of Δ6D, no such changes have been observed for SCD1 activity index in pioglitazone-treated cells. SCD1 gene expression (+26.4%, P = 0.041) and activity index (+52.8%, P = 0.035) were significantly increased by MEK inhibition in the presence of pioglitazone, as compared with pioglitazone alone and control cells. However, the response of Δ6D expression and activity index to pioglitazone was unaffected by incubation with PD98059.

CONCLUSION

PPARγ and ERK1/2 signaling pathway affect differentially and may have inhibitory crosstalk effects on the genes expression of ∆6D and SCD1, and subsequently on their enzymatic activities.

Inhibition of MEK/ERK1/2 Signaling Affects the Fatty Acid Composition of HepG2 Human Hepatic Cell Line

INTRODUCTION

The extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase pathway, also known as the MEK/ERK1/2 kinase cascade, has recently been implicated in the regulation of lipid metabolism and fatty liver disease. However, its functional effect on cellular fatty acid composition is unknown. Herein, we examined the effect of a pharmacological inhibitor of MEK, the upstream kinase activator of ERK1/2, on fatty acid composition of hepatocellular carcinoma cell line HepG2.

METHODS

HepG2 cells cultured in RPMI-1640 were exposed to the commonly used ERK1/2 pathway inhibitor PD98059 and were investigated with respect to fatty acid composition by gas-liquid chromatography.

RESULTS

Exposure of cells to the ERK1/2 pathway inhibitor induced an increase in monounsaturated fatty acids and the fatty acid desaturation index and a decrease in polyunsaturated fatty acid content. Specifically, we showed a significant increase of oleic acid (18:1n-9; +29%, P=0.003) and arachidonic acid (20:4n-6)/linoleic acid (18:2n-6) ratio (3.5-fold; P<0.001) in HepG2 cells.

CONCLUSION

Cellular fatty acid composition of HepG2 cells appeared to be differentially regulated by ERK1/2 pathway, thus suggesting related metabolic pathways as potential mediators of the effects of ERK1/2 signaling on hepatic fatty acid composition.

Bioinformatics study of the 3-hydroxy-3-methylglotaryl-coenzyme A reductase (HMGR) gene in Gramineae

Isoprenoids or terpenoids are synthesized by two important units' including dimethylallyl diphosphate and isopentenyl diphosphate (IPP). Plants use two different methods for formation of IPP, which is a cytosolic and a plastidial method. The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR, EC 1.1.1.34) catalyzes the conversion of HMG-CoA to mevalonate, which is the first stage in the cytosolic pathway for biosynthesis of isoprenoid in plants. In this study, a total of fifty HMGR protein sequences from Gramineae and three animal samples including human, mouse and fruit fly were aligned and analyzed by computational tools to predict the protein properties, such as molecular mass, pI, signal peptide, transmembrane and conserved domains, secondary and spatial structures. Sequence comparison analysis revealed that there is high identity between plants and animals. Three catalytic regions including L domain, N domain and S domain were detected by structural modeling of HMGR. The tertiary structure model of Oryza sativa HMGR (Accession Number: NP_001063541) was further checked by PROCHECK algorithm, and showed that 90.3 % of the amino acid residues were located in the most favored regions in Ramachandran plot, indicating that the simulated three-dimensional structure was reliable. Phylogenetic analysis indicated that there is a relationship among species of Gramineae and other organisms. According to these results, HMGRs should be derived from a common ancestor.

Circulating phospholipase-A2 activity in obstructive sleep apnea and recurrent tonsillitis

OBJECTIVE

Phospholipase A2 (PLA2) plays a major part in growth regulation, differentiation and inflammation. It has been proposed as an evaluating marker for infection and inflammation. The aim of this study was to investigate activity of serum type II secretory PLA2 (sPLA2 IIa) in obstructive sleep apnea (OSA) and recurrent infective tonsillitis (RT) in children.

METHODS

Activity of serum sPLA2 IIa was determined in children who underwent tonsillectomy, including OSA in 126 cases and RT in 60. Serum enzyme activities were measured using the standard assay with Diheptanoyl Thio-Phosphatidylcholin as substrate.

RESULTS

The sPLA2 IIa activity of serum was significantly higher in RT than in OSA (P<0.01). Serum sPLA2 IIa activity in the RT patients was positively correlated with BMI (r=0.26; P=0.02), which was not apparent in OSA (r=0.14; P=0.09).

CONCLUSION

This study suggests that serum sPLA2 IIa activity may be considered as a supportive diagnostic marker in suspected or clinically unclear cases of RT children.

Increased leukocyte ABCA1 gene expression in post-menopausal women on hormone replacement therapy

OBJECTIVE

The ATP binding cassette A1 (ABCA1) is a key participant in the reverse cholesterol process whereby mediates cholesterol efflux directly to HDL particles. The aim of this study was to investigate whether long-term treatment with conventional hormone replacement therapy (HRT) in post-menopausal women could affect their leukocytes ABCA1 expression. Changes in various serum lipids and lipoprotein fractions were also investigated.

MATERIAL AND METHODS

A total of 60 non-obese normolipidaemic post-menopausal women treated with oral oestrogen together with progestin therapy for 3 months were selected. Leukocytes ABCA1 gene expression and serum lipid and lipoprotein concentrations were measured at the start and end of the HRT.

RESULTS

HRT led to significant increases in HDL cholesterol (P = 0.001) and apoA-I (P = 0.046) and significant decrease in apoB (P = 0.049) and LDL cholesterol (P = 0.022) when compared with the baseline levels. Analysis of leukocytes ABCA1 mRNA showed a significant increase in ABCA1 gene expression after HRT (P = 0.001). There was also a significant inverse association (r =  -0.28, P = 0.03) between ABCA1 gene expression and log TG/HDL cholesterol changes related to HRT.

CONCLUSION

The beneficial cardiovascular effects of HRT could be explained, at least in part, by increasing the ABCA1 gene expression.

Occupational dose assessment and National Dose Registry System in Iran

This report presents status of external and internal dose assessment of workers and introducing the structure of National Dose Registry System of Iran (NDRSI). As well as types of individual dosemeters in use, techniques for internal dose assessment are presented. Results obtained from the International Atomic Energy Agency intercomparison programme on measurement of personal dose equivalent H(p) (10) and consistency of the measured doses with the delivered doses are shown. Also, implementation of dosimetry standards, establishment of quality management system, authorisation and approval procedure of dosimetry service providers are discussed.

Effect of estrogen receptor β A1730G polymorphism on ABCA1 gene expression response to postmenopausal hormone replacement therapy

The estrogen receptor β (ERβ) mediates the action of estrogen on metabolism of lipids and lipoprotein. Therefore, its gene is a promising candidate gene for cardiovascular disease. The aim of the present study was to investigate whether the ERβ A1730G polymorphism modifies the metabolic response to hormone replacement therapy (HRT) in postmenopausal women. The population included 60 normolipidemic postmenopausal women with equal numbers of each A1730G genotype followed during a 90-day experimental period. All subjects received oral estrogen together with a progestin therapy during the HRT. ABCA1 gene expression and serum lipid and lipoprotein concentrations were measured at the beginning and end of the HRT trial. At baseline, ABCA1 gene expression, lipid or lipoprotein concentrations were not significantly different among the ERβ A1730G genotype groups. After HRT, however, subjects with GG genotype had a greater increase in ABCA1 gene expression (p = 0.002) and a trend toward greater increase in apoA-I (p = 0.058) than subjects carrying the A allele. An interaction effect between genotype and HRT effect was observed on ABCA1 gene expression. In conclusion, the positive changes of ABCA1 gene expression and apoA-I were affected by the ERβ A1730G polymorphism in women taking estrogen-progesterone therapy.

Effect of hormone replacement therapy on total serum anti-oxidant potential and oxidized LDL/β2-glycoprotein I complexes in postmenopausal women

Oxidative stress and consequent oxidized lipoprotein production is thought to play a central role in both the initiation and progression of atherosclerosis. Oxidized low-density lipoprotein (oxLDL)/β2-glycoprotein I (β2GPI) complexes are etiologically important in the development of atherosclerosis. The aim of the present study was to investigate whether long-term treatment with conventional hormone replacement therapy (HRT) in postmenopausal women could affect total serum antioxidant capacity (TAC) and serum levels of oxLDL/β2GPI complexes. A total of 60 normolipidemic postmenopausal women treated with oral estrogen together with progestin therapy for 3 months were selected. TAC and serum levels of oxLDL/β2GPI complexes were measured at the beginning and end of the HRT. HRT led to a significant increase in TAC (15%, P=0.02) and a minor but statistically nonsignificant decrease of oxLDL/β2GPI complexes (3%, P=0.30) when compared with the baseline control levels. There was also no significant association between TAC and oxLDL/β2GPI complexes changes related to HRT. This study indicates that, HRT in postmenopausal women leads to an increase in TAC without an equivalent change in serum levels of oxLDL/β2GPI complexes. It is concluded that beneficial effects of HRT could be explained, at least in part, by improving antioxidant status, but may not be directly associated with a change in oxidized lipoprotein production.

Fatty acid composition of epicardial and subcutaneous human adipose tissue

BACKGROUND

Epicardial adipose tissue has special properties that distinguish it from the more widely studied depots of adipose tissue.

OBJECTIVES

We undertook this study to investigate regional differences between epicardial and subcutaneous adipose tissue fat composition, as well as associations between these measures and metabolic variables.

METHODS

Epicardial and subcutaneous peripheral adipose tissue were collected during coronary artery bypass grafting from 42 patients (ages 37-65) with coronary artery disease (CAD). The fatty acid composition of adipose tissue was determined by gas liquid chromatography (GLC).

RESULTS

The saturated fatty acids, including myristic acid (14:0), palmitic acid (16:0), and stearic acid (18:0), were higher, and the unsaturated fatty acids, including palmitoleic acid (16:1n-7), oleic acid (18:1n-9), linoleic acid (18:2n-6), and linolenic acid (18:3n-3), were lower than the subcutaneous adipose tissue. The presence of hypertension was positively correlated with the 16:1n-7 (r = 0.407, P = 0.032) and 18:1n-11(r = 0.370, P = 0.027), and negatively correlated with 18:1n-9 (r = -0.367, P = 0.036) and 18:2n-6 (r = -0.446, P = 0.006) contents of epicardial adipose tissue after adjustment for body mass index.

CONCLUSIONS

Regional differences may be observed in fatty acid composition, suggesting a depot specific impact of stored fatty acids on adipocyte function and metabolism.

Cholesteryl ester transfer protein I405V polymorphism influences apolipoprotein A-I response to a change in dietary fatty acid composition

The aim of the present study was to investigate whether the cholesteryl ester transfer protein (CETP) I405V polymorphism modifies the response to changes in the dietary ratio of polyunsaturated to saturated fat (P:S). The population included 85 healthy subjects with the different I405V genotypes (35 II, 36 IV, and 14 VV) assigned to two consecutive 28-day experimental period. All subjects consumed a high-P:S with P:S of 1.2 for the first period and a low-P:S with a P:S of 0.3 for the next 28-day period. At the first and end of each dietary period, serum lipid, lipoprotein, and CETP concentrations were measured. At screening, lipid or lipoprotein concentrations were not significantly different among CETP I405V genotype groups. After the low-P:S diet, subjects carrying V allele had greater reduction in apoA-I and HDL cholesterol (HDL-C) than subjects with II genotype. A genotype-by-diet interaction effect was observed on apoA-I (p=0.016) concentrations. In conclusion, the CETP I405V polymorphism contributes to the unfavorable changes of apoA-I and HDL-C when a high-P:S diet was replaced with a low-P:S diet.

Fatty acid composition of HDL phospholipids and coronary artery disease

BACKGROUND

The phospholipid fatty acid content of high-density lipoprotein (HDL) partially reflects that of the diet and has been reported to be associated with several important biological functions that might serve as risk markers for coronary heart disease.

OBJECTIVE

To investigate whether fatty acid composition of HDL phospholipids correlates with angiographically documented coronary artery disease (CAD).

METHODS

The population included 212 patients who underwent clinically indicated coronary angiography. The patients were classified with significantly diseased arteries (SDA) if one or more coronary arteries had a stenosis >50% and with minimally diseased arteries (MDA) if there was no significant stenosis (<40%) in any artery. The severity of CAD was expressed by the number of affected vessels. The fatty acid composition of HDL phospholipids was determined by gas liquid chromatography. Multivariate analyses were used to test the independence of associations between the presence and severity of CAD as outcome variables and fatty acid composition of HDL phospholipids.

RESULTS

Patients with SDA showed significantly lower levels of linoleic acid (P = .041), eicosapentaenoic acid (EPA) (P = .027), and docosahexaenoic acid (DHA) (P = .026) than patients with MDA in univariate analyses. The association of linoleic acid (odds ratio [OR] .90, P < .05), EPA (OR, 0.41, P < .02), and DHA (OR, 0.48, P < .02) remained statistically significant in the multivariate analyses. The content of EPA (β = -0.23, P < .01) and DHA (β = -0.17, P < .05) remained inversely significantly associated with the severity of CAD.

CONCLUSIONS

This study shows that polyunsaturated fatty acids, including EPA and DHA content of HDL particles, are independently associated with the presence and severity of angiographically documented CAD.

Effect of opium addiction on lipid profile and atherosclerosis formation in hypercholesterolemic rabbits

In some Asian and Middle Eastern societies, opium consumption has traditionally been regarded as a way to lower blood lipids and to prevent heart diseases. This could eventually lead to addiction. In this study, the effect of oral opium consumption on serum lipids and atherogenesis in rabbits was investigated. Twenty-eight male New Zealand white rabbits were divided into control, hypercholesterolemic, addicted, and hypercholesterolemic-addicted groups and were studied for 3 months. Serum lipid profile was determined at the beginning of the study and at 1 month intervals thereafter. At the end of the study period, aortic plaque formation was assessed. Compared with control, in the hypercholesterolemic and hypercholesterolemic-addicted groups, cholesterol, triglycerides, and low-density lipoprotein cholesterol levels were significantly increased (P<0.01). The increases in lipids and lesion areas in the aorta were higher in hypercholesterolemic-addicted than hypercholesterolemic group (P<0.05). Our findings suggest that opium consumption can have aggravating effects in atherosclerosis formation related with hypercholesterolemia, mainly affecting lipid profile.