The mediating role of psychological flexibility in the relationship between psychotic symptom severity and depression in individuals diagnosed with schizophrenia.

WHAT IS KNOWN ABOUT THE SUBJECT?: Psychotic symptoms and depression are common problems in people diagnosed with schizophrenia. Psychological flexibility is a skill that facilitates coping with difficulties. There is limited research on the role of psychological flexibility in the relationship between psychotic symptoms and depression in people diagnosed with schizophrenia. WHAT DOES THE ARTICLE ADD TO EXISTING KNOWLEDGE?: This article investigates the role of psychological flexibility in the link between psychotic symptom severity and depression in people diagnosed with schizophrenia. The article shows that psychological flexibility partially mediates the relationship between psychotic symptom severity and depression. The article suggests that interventions aimed at improving psychological flexibility may be beneficial in reducing depressive symptoms in people diagnosed with schizophrenia. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Mental health nurses should consider psychotic symptom severity and psychological flexibility when assessing and intervening for depressive symptoms in people diagnosed with schizophrenia. Mental health nurses should receive training to improve psychological flexibility and pass this skill on to their patients. Mental health nurses should continue to research the effectiveness and outcomes of interventions aimed at improving psychological flexibility. ABSTRACT: INTRODUCTION: Psychological flexibility may help people diagnosed with schizophrenia (PWS) cope with their psychotic symptoms and reduce their depressive symptoms, but the mechanism of this effect is unclear. AIM: To investigate whether psychological flexibility mediates the relationship between psychotic symptom severity and depression in PWS. METHOD: A cross-sectional study was conducted, in which a total of 111 PWS were assessed with DSM-5 Clinician-Rated Dimensions of Psychosis Symptom Severity, Calgary Depression Scale for Schizophrenia and Acceptance and Action Questionnaire. Data analysis was performed using SPSS 25 and PROCESS macro. RESULTS: Significant correlations were found between psychotic symptoms, depression and psychological flexibility. Psychological flexibility partially mediated the relationship between psychotic symptom severity and depression. DISCUSSION: Psychological flexibility could weaken the impact of psychotic symptom severity on depression in PWS. Higher psychotic symptoms were associated with lower psychological flexibility and higher depression. IMPLICATIONS FOR PRACTICE: Interventions to improve psychological flexibility may prevent depressive symptoms in PWS. Psychiatric nurses can use psychological flexibility as a goal for evaluation and intervention.

Clitocybe nebularis extract and 5­fluorouracil synergistically inhibit the growth of HT-29 colorectal cancer cells by inducing the S phase arrest.

Although 5-fluorouracil (5-FU) is an important anticancer agent for the treatment of colorectal cancer, drug resistance, and dose-related side effects limit the effectiveness of the treatment. Therefore, developing new pharmaceuticals with effective and low toxicity is critically necessary for cancer therapy. This study aimed to investigate the cytotoxic activity of the Clitocybe nebularis mushroom extract (CN) on HT-29 human colon cancer cells. A series of in vitro experiments were performed on the HT-29, Caco-2, and HEK-293 cells, which includes cytotoxicity, drug interaction, colony formation, cell cycle, and migration assays. In addition, qRT-PCR experiment was also performed to investigate the potential molecular mechanisms of action of CN on the proliferation of colon cancer cell line. Our results show that CN exhibited selective cytotoxic activity on HT-29 and Caco-2 colon cancer cells, whereas no cytotoxic effect was observed on normal HEK-293 cells. With the combination of CN and 5­FU, their cytotoxic activity on HT-29 cells was significantly increased compared to their use alone. In addition, the combination of CN and 5-FU also showed synergistic anticancer activity through cell cycle arrest in the S phase. The results also show that p21, p27, and p53 expression levels increased as a result of CN treatment. Our in vitro findings show that CN has a synergistic effect with 5-FU by inhibiting cell proliferation of colon cancer cells and inducing cell cycle arrest in the S phase.

Multigene Panel Testing in Turkish Hereditary Cancer Syndrome Patients.

Objective: Hereditary cancer syndromes (HCSs) are a heterogenous group of disorders caused by germline pathogenic variations in various genes that function in cell growth and proliferation. This study aimed to describe the germline variations in patients with hereditary cancer using multigene panels. Methods: The molecular and clinical findings of 218 patients with HCS were evaluated. In addition, 25 HCS-related genes were sequenced using a multigene panel, and variations were classified according to the American College of Medical Genetics and Genomics (ACMG) criteria. In total, 218 HCS patients predominantly with breast, colorectal, ovarian, gastric, and endometrium cancers were included. Results: Pathogenic variations in 12 distinct genes were detected in 36 of 218 (16.5%) cases. In this study, the most affected gene was the ATM gene, in which pathogenic variations were detected in 8 of 218 cases, followed by CHEK2 (3.2%), MUTYH (3.2%), BRIP1 (1.8%), BARD1 (0.9%), TP53 (0.9%), PALB2 (0.4%), MLH1 (0.4%), MSH2 (0.4%), PMS2 (0.4%), RAD50 (0.4%), and RAD51C (0.4%). Conclusions: This study contributes to genotype-phenotype correlation in HCSs and expands the variation spectrum by introducing three novel pathogenic variations. The wide spectrum of the gene pathogenic variations detected and the presence of multiple gene defects in the same patient make the multigene panel testing a valuable tool in detecting the hereditary forms of cancer and providing effective genetic counseling and family specific screening strategies. Amaç: Herediter kanser sendromlari (HCS) hücre büyümesi ve proliferasyonunda görevli genlerde saptanan germline mutasyonlardan kaynaklanan heterojen bir grup hastaliktir. Bu çalismada kalitimsal kanser sendrom ön tanisiyla degerlendirilen olgularda çoklu gen paneli ile germ hatti varyasyonlarinin degerlendirilmesi planlanmistir. Yöntemler: Kalitimsal kanser sendromu düsünülen 218 olgudan periferik kandan DNA izolasyonu sonrasi HCS ile iliskili 25 gen multigen panel kullanilarak dizilendi ve varyasyonlar American College of Medical Genetics and Genomics (ACMG) kriterlerine göre degerlendirildi. Bulgular: Meme, kolorektal, over, gastrik ve endometriyum kanseri basta olmak üzere toplam 218 herediter kanser sendromlu olgu degerlendirildi. Tüm çalisma grubu incelendiginde en sik ATM gen varyasyonlari (8/218, %3,6) tespit edildi ve bunu siklik sirasina göre CHEK2 (%3,2), MUTYH (%3,2), BRIP1 (%1,8), BARD1 (%0,9), TP53 (%0,9), PALB2 (%0,4), MLH1 (%0,4), MSH2 (%0,4), PMS2 (%0,4), RAD50 (%0,4), RAD51C (%0,4) varyasyonlari takip etmekteydi. Sonuçlar: Bu çalismada farkli kanser türlerinde kalitimsal kansere yol açan genler analiz edilmis ve fenotiple iliskisi degerlendirilmistir. Ayrica bu çalismada ilk kez saptanan üç yeni varyasyon ile literatüre katki saglanmaktadir. Patojenik varyasyon tespit edilen genlerin genis dagilimi ve ayni hastada birden fazla genetik varyasyonun varligi düsünüldügünde, uygun genetik danisma ve aileye özgü tarama planlamasi yapmak için çoklu gen taramasi kalitimsal kanser hastalarinin degerlendirilmesinde hizli ve etkin bir yöntem olarak görünmektedir.

The Remarkable Antibiofilm Activity of the Sweet Tooth Mushroom, Hydnum repandum (Agaricomycetes), Displaying Synergetic Interactions with Antibiotics.

This study examines the antioxidant, anticancer, antimicrobial, and antibiofilm activities of Hydnum repandum, an edible and medicinal mushroom known as sweet tooth or wood hedgehog. H. repandum ethanolic extract had a high amount of myricetin and apigenin and displayed antiproliferative effects against the MCF-7 and HT-29 cell lines. Moreover, the extract displayed antimicrobial and antibiofilm activities against methicillin-resistant Staphylococcus aureus ATCC 43300, S. epidermidis ATCC 35984, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853. Synergetic interactions have been observed when antibiotics such as kanamycin and ampicillin are used together with mushroom extract. The minimum biofilm eradication concentration values were lower for H. repandum extract than for antibiotics. This study demonstrates that H. repandum has antibiofilm potential against biofilms and confronts antibiotic resistance.

Comparison of the chemical composition and biological effects of Clitocybe nebularis and Infundibulicybe geotropa.

Clitocybe mushrooms have long been recognized for their various therapeutic potential and medicinal properties. A few members of the genus are considered edible and many others are poisonous. This study investigated the ethanolic extracts obtained from C. nebularis (CN) and I. geotropa (IG) mushrooms for phenolic content and antioxidant, antiproliferative, antimicrobial, and antibiofilm activities. The data from ultra-performance liquid chromatography and Fourier transform infrared spectroscopy analysis of the mushrooms were presented for the first time. According to the results, both ethanolic extracts contain high levels of phenolic (catechin, myricetin, quercetin, rutin, gallic acid, vanillic acid) compounds. Fourier transform infrared spectroscopy results may suggest the presence of clitopycin in CN extract. The ethanol extract of CN scavenged about 79% and the IG 78% of the free 2,2-diphenyl-1-picrylhydrazyl radicals. Additionally, the CN and IG extracts inhibited glutathione-S-transferase by 10%-18% at all concentrations. The CN extract effectively inhibited aldose reductase by 30%-80% at all concentrations. Besides, the CN extract showed promising antiproliferative activity on HT-29 and MCF-7 cell lines. On the other hand, CN and IG extracts displayed inhibitory effects on some multidrug-resistant Gram-positive bacteria and effectively inhibited biofilm production. The obtained results showed that C. nebularis and I. geotropa extracts presented inhibition of biofilm production. Therefore, C. nebularis was demonstrated to be a potential source of natural medicine.

Genetic and Clinical Characterization of Patients with Maturity-Onset of Diabetes of the Young (MODY): Identification of Novel Variations.

BACKGROUND: Maturity-onset diabetes of the young (MODY) is a rare monogenic type of diabetes, and accounts for 2-5% of all diabetes cases. An early age of onset, a family history supporting autosomaldominant inheritance, insulin resistance, and the absence of autoimmunity are the major characteristics of MODY. However, genetic testing is crucial for diagnosis. AIMS: To investigate the 7 MODY-related genes and clinical findings of patients with a preliminary clinical diagnosis of MODY. STUDY DESIGN: Retrospective cross-sectional study. METHODS: In this study, 7 genes (KCNJ11, ABCC8, INS, GCK, HNF4A, HNF1A, and HNF1B) related to MODY were screened via targeted sequencing in 182 cases with a confirmed pre-diagnosis of MODY. The clinical characteristics of the patients were evaluated retrospectively. RESULTS: A total of 182 patients, 48% of whom were women, between the ages of 18-62 were included in the study. In 30 cases (16.4%), 28 different pathogenic variations were found, of which 20 were previously reported and 8 were novel variations segregated by disease within the family. Pathogenic variations were detected in the following genes in order of mutation frequency; GCK, HNF1A, ABCC8, HNF4A, HNF1B and KCNJ11. Interestingly, six of the 30 cases (20%) carried a pathogenic variation in the ABCC8 gene. No mutation was detected in the INS gene. A family history of vertically transmitted diabetes and elevated HbA1C at the time of diagnosis were found in 20 (66%) and 16 (52%) cases, respectively. CONCLUSION: In this series, 28 different pathogenic variations are identified, 8 of which are novel. The rate of pathogenic variation in the ABCC8 gene is unexpectedly high. Two-thirds of cases have a family history of vertically transmitted diabetes.

Secondary findings in 622 Turkish clinical exome sequencing data.

CES (Clinical Exome Sequencing) is a method that we use to diagnose rare diseases with nonspesific clinical features. Besides primary indication for testing genetic information may be detected about diseases which have not yet emerged. ACMG guidelines recommend to report pathogenic variations in medically actionable 59 genes. In this study we evaluated CES data of 622 cases which were tested for various indications. According to ACMG recommendations 59 genes were screened for reportable variations. The detected variations were reviewed using distinct databases and ACMG variation classification guidelines. Among 622 cases 13 (2.1%) had reportable variations including oncogenetic, cardiogenetic disorders, and malignant hyperthermia susceptibility-related genes. In 15 cases (2.4%) heterozygous pathogenic and likely pathogenic variations were detected in genes showing autosomal recessive inheritance. Ten novel variations causing truncated protein or splicing defect were reported. We detected 11 variations having conflicting interpretations in databases and 30 novel variations, predicted as likely pathogenic via insilico analysis tools which further evaluations are needed. As to our knowledge this is the first study investigating secondary findings in Turkish population. To extract the information that may lead to prevent severe morbidities and mortalities from big data is a valuable and lifesaving effort. Results of this study will contrbute to existing knowledge about secondary findings in exome sequencing and will be a pioneer for studies in Turkish population.

Relationship Between Final Visual Acuity and Optical Coherence Tomography Findings in Patients with Diabetic Macular Edema Undergoing Anti-VEGF Therapy

Objectives: To identify the prevalence of findings in optical coherence tomography (OCT) sections before intravitreal anti-VEGF treatment in patients with diabetic macular edema (DME), and to evaluate the relationship between these findings and final visual acuity and number of injections. Materials and Methods: This retrospective study included 296 eyes of 191 patients (104 male, 87 female) who started intravitreal ranibizumab treatment after being diagnosed with DME in the retina unit between January 2013 and April 2017 were included the study. Spectral domain OCT findings at the time of presentation such as presence of serous macular detachment (SD), vitreomacular traction (VMT), and epiretinal membrane (ERM) were recorded. In addition, the regularity of the ellipsoid zone (EZ) and inner retinal layers was also studied. Results: The mean central retinal thickness measured in SD-OCT was 449±81 µm before treatment and 350±96 µm after treatment (p<0.001). SD was detected in 155 eyes (52.4%), ERM in 67 eyes (22.6%), and VMT in 9 eyes (3%). Thirty eyes (10.1%) had disorganization of the retinal inner layers (DRIL) and 54 eyes (18.2%) had EZ deterioration. The presence of ERM, EZ irregularity, and DRIL were associated with significantly lower final visual acuity (p<0.0001), while there was no relationship between pre-treatment SD and final visual acuity (p=0.11). Injection number was higher in eyes with SD and ERM compared to those without, but this difference was statistically significant only in the presence of SD (p=0.01 and p=0.59, respectively). There was no difference in injection number according to EZ irregularity or presence of DRIL. Conclusion: The coexistence of SD with DME was associated with increased need for treatment but not with final visual acuity. EZ irregularities, DRIL, and ERM are findings that negatively affect visual acuity.

S-phase Enriched Non-coding RNAs Regulate Gene Expression and Cell Cycle Progression.

Many proteins that are needed for progression through S-phase are produced from transcripts that peak in the S-phase, linking temporal expression of those proteins to the time that they are required in cell cycle. Here, we explore the potential roles of long non-coding RNAs in cell cycle progression. We use a sensitive click-chemistry approach to isolate nascent RNAs in a human cell line, and we identify more than 900 long non-coding RNAs (lncRNAs) whose synthesis peaks during the S-phase. More than 200 of these are long intergenic non-coding RNAs (lincRNAs) with S-phase-specific expression. We characterize three of these lincRNAs by knockdown and find that all three lincRNAs are required for appropriate S-phase progression. We infer that non-coding RNAs are key regulatory effectors during the cell cycle, acting on distinct regulatory networks, and herein, we provide a large catalog of candidate cell-cycle regulatory RNAs.

Antioxidant, Anticancer, Antimicrobial, and Antibiofilm Properties of the Culinary-Medicinal Fairy Ring Mushroom, Marasmius oreades (Agaricomycetes).

This study is based on the phenolic composition and the antioxidant, anticancer, antimicrobial, and antibiofilm activities of the edible mushroom Marasmius oreades from Turkey. The phenolic composition of an M. oreades ethanol extract was measured by using the Folin-Ciocalteu method, aluminium chloride colorimetry, and ultraperformance liquid chromatography. The antioxidant activity was evaluated on the basis of DPPH radical scavenging activity. The effect of the M. oreades ethanol extract was also screened in order to determine glutathione-S-transferase, glutathione peroxidase, catalase, and superoxide dismutase enzyme activities. The antimicrobial activity of the mushroom extract was evaluated by using well diffusion and was based on the minimum inhibitory concentration. In addition, the antibiofilm potential of M. oreades was analyzed against Gram-positive and -negative bacteria. Finally, the anticancer effects of the mushroom extract were tested on colon (HT-29) and breast (MCF-7 and MDA-MB-231) cancer cell lines by using the MTT assay. The results revealed that the total amount of phenolics in the ethanol extract of M. oreades was 10.990 ± 0.0007 mg gallic acid equivalent/100 g, and the total amount of flavonoids was 1.139 ± 0.0052 mg quercetin equivalent/100 g. The ultraperformance liquid chromatography results indicated that the M. oreades ethanol extract contained various phenolic compounds: catechin, ferulic, gallic acid, and vanillic acid. The M. oreades ethanol extract scavenged about 80% of DPPH free radicals. It did not show any effect on the glutathione-S-transferase, glutathione peroxidase, and catalase enzyme activities, but its maximal concentration (10 mg/mL) increased superoxide dismutase activity (8%). The ethanol extract of M. oreades showed a moderate anticancer effect on the HT-29, MCF-7, and MDA-MB-231 cell lines. Although the ethanolic extract of the mushroom did not show sufficient antibacterial activity, it presented a strong antibiofilm effect against all studied pathogenic strains at the tested concentrations.

Antimicrobial screening of some selected Turkish medicinal plants.

For many years, plants are used for treatment of various diseases. In general, plants have rather more therapeutic benefits and fewer adverse effects compared with the synthetic drugs. The purpose of this study was to determine the in vitro antimicrobial potentials of fifteen plant species from Anatolia region of Turkey against some selected bacteria and a yeast strain. The extracts from belong to nine families were examined against Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 43300 (MRSA), Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231 using disc diffusion and micro dilution methods. According to the obtained results, all plant extracts showed different ranges of antibacterial activity against S. aureus ATCC 43300 and S. aureus ATCC 25923 strains. Flower and leaves extracts of R. lutea, leaves extract of E. ritro, flower and leaves extracts of H. europaeum, leaves extract of E. macroclada, fruit and leaves extracts of Z. fabago, flower extract of C.crupinastrum, leaves extract of D. tenuifolia showed different ranges of antifungal activity against C. albicans.

Investigation of the Polyphenol Composition, Biological Activities, and Detoxification Properties of Some Medicinal Mushrooms from Turkey.

OBJECTIVES: Ethanolic extracts of the mushroom species Ganoderma adspersum, Inonotus hispidus, Russula chloroides, and Sarcodon imbricatus were investigated for their polyphenolic contents and biological activities. MATERIALS AND METHODS: The radical scavenging activity of the extracts was evaluated by 2,2-diphenyl-1-(2,4,6-trinitrophenyl) (DPPH) method and their polyphenolic compounds were determined by high performance liquid chromatography (HPLC) analysis. Furthermore, the activity effects of mushroom extracts on the enzyme glutathione-S-transferase (GST) were also examined. Additionally, the antimicrobial activity of mushroom extracts was evaluated by disc diffusion method. RESULTS: Ethanolic extract of I. hispidus demonstrated the highest total phenolic content and total flavonoid contents, with 227.23±4.96 mg gallic acid equivalent/g and 42.14±0.20 quercetin equivalent/g, respectively. The highest DPPH radical scavenging activity was observed for ethanolic extracts of I. hispidus, with 10.687±1.643 µg/mL IC50. HPLC analysis demonstrated that R. chloroides was composed of ferulic acid, gallic acid, and myricetin compounds. The highest GST enzyme activity effect was detected with the ethanol extracts of I. hispidus and S. imbricatus. None of the mushroom extracts demonstrated significant inhibition of the bacterial strains used. CONCLUSION: These results indicate that I. hispidus may be proposed as a new potential source of natural medicine and its potential may be related to its polyphenolic content, which needs further investigation.

Optimization of Immobilized Aldose Reductase Isolated from Bovine Liver.

OBJECTIVES: Isolation of enzymes and experiments on them require great effort and cost and are time-consuming. Therefore, it is important to extend the usability of the enzymes by immobilizing them. In this study our purpose was to immobilize the enzyme aldose reductase (AR) and to optimize the experimental conditions of the immobilized AR and compare them to those of free AR. MATERIALS AND METHODS: AR was isolated from bovine liver and the enzyme immobilized in photographic gelatin by cross-linking with glutaraldehyde. Then the optimum conditions for free and immobilized AR in terms of pH, temperature, and storage were characterized by determining the enzyme activity. RESULTS: Following immobilization, the optimum pH and temperature levels for free AR, which were pH 7.0 and 60°C, slightly altered to pH 7.5 and 50°C. The enzyme activity of the immobilized AR was maintained at about 65% after reusing 15 times. Moreover, immobilized AR maintained 95% of its original activity after 20 days of storage at 4°C, while the retained activity of the free AR was 85% of the original. CONCLUSION: Our experiments indicated that the conditions that affect enzyme activity might alter following immobilization. Once the optimum experimental conditions are fixed, the immobilized AR can be stored and reused with efficiency higher than that of free AR. Moreover, this study provides an insight into the advantages of using immobilized AR in enzyme assays rather than free AR.

Screening Effects of Methanol Extracts of Diplotaxis tenuifolia and Reseda lutea on Enzymatic Antioxidant Defense Systems and Aldose Reductase Activity.

OBJECTIVES: The aim of the study was to investigate the effects of methanol extracts from the flowers and leaves of Diplotaxis tenuifolia and Reseda lutea on the activity of AR, CAT, GST, and GPx. MATERIALS AND METHODS: Total phenolic and flavonoid contents of the plant samples were evaluated using Folin-Ciocalteu reagent and aluminum chloride colorimetric methods. Also, the effects of extracts on CAT, GST, GPx, and AR enzyme activities were investigated using kinetic assays. RESULTS: The highest phenolic and flavonoid contents were detected in the methanol extract of D. tenuifolia leaves with 144.49±0.29 mg gallic acid equivalent/L and 250.485±0.002 quercetin equivalent/L, respectively. The best activity profile for GST and GPx were observed in the extract of leaves belonging to D. tenuifolia with IC50 values of 121±0.05 and 140±0.001 ng/mL, respectively. According to the results, methanol extracts from leaves of R. lutea and D. tenuifolia showed no significant activity potential on AR. Moreover, none of the studied extracts demonstrated any reasonable CAT activation potential. CONCLUSION: The results indicated that leaves of D. tenuifolia had good effect on the antioxidant enzymatic defense system, which it makes it a good constituent of the daily diet.

Expression of prostaglandin E2 receptor subtypes in human pterygium and normal conjunctiva: immunohistochemical study.

PURPOSE: In the present study, we aimed to evaluate the expression of EP receptors in primary and recurrent human pterygium tissues. METHODS: Pterygium samples were collected from 65 patients with primary pterygium and 16 patients with recurrent pterygium. Normal conjunctival tissues were collected from nasal interpalpebral area from 17 patients without systemic and any other ocular pathology. Expression of EP receptors was evaluated by immunohistochemistry. The median value for each receptor staining score (RSS) was determined in normal conjunctival specimens. In this study, RSS of > median value was defined as positive staining or high expression and ≤ median value as negative staining or weak expression in specimens. Chi-square test was used for statistical analysis, and p value of less than 0.05 was considered significant. RESULTS: Stromal expression of EP1 was significantly higher in primary and recurrent pterygium specimens compared to normal conjunctival tissues (p = 0.007 and p = 0.002, respectively). Epithelial expressions of EP2 and EP3 were significantly lower in primary pterygium specimens compared to normal conjunctival tissues (p = 0.005 and p < 0.0001, respectively), and stromal expressions were insignificant. Stromal expression of EP4 was significantly higher in primary and recurrent pterygium specimens compared to normal conjunctival tissues (p = 0.002 and p = 0.012, respectively). CONCLUSIONS: Expression of EP receptors has been up- or downregulated in primary and recurrent pterygium tissues, and these receptors may play a role in formation and recurrence of pterygium.

[Investigating the role of ceramide metabolism-associated CERS5 (LASS5) gene in atherosclerosis pathogenesis in endothelial cells]. / Seramid metabolizmasi ile iliskili CERS5 (LASS5) geninin endotel hücrelerinde ateroskleroz patogenezindeki rolünün arastirilmasi.

OBJECTIVE: Ceramide, the backbone of sphingolipids, is the key component affecting atherosclerotic changes through its important second-messenger role. Previous studies have demonstrated protective role of AMP-activated protein kinase (AMPK) genes in regulating atherosclerosis and hypertension. Ceramide synthase 5 (LASS5 or CERS5) gene has function in de novo synthesis of ceramide, and has indirect effect on AMPK gene. Aim of the present study was to identify role of LASS5 gene in atherosclerosis. METHODS: LASS5 gene-specific small interfering RNA (siRNA)-mediated gene silencing was performed in human umbilical vein endothelial cells (HUVEC) and differential expression of LASS5, AMPK-alpha and AMPK-alpha target genes were analyzed. HUVEC cells were then treated with AMPK activator in order to examine relationship of change in gene expression levels to AMPK activity. RESULTS: Novel physiological function of LASS5 was identified. Downregulation of LASS5 was found to attenuate ceramide production and increase expression of some AMPK target genes in HUVEC. CONCLUSION: This is the first study to demonstrate that LASS5 was involved in negative regulation of atherosclerosis-related genes, such as AMPK-alpha. These preliminary findings provide insight into molecular mechanism of atherosclerosis and are important for development of potential therapeutic agents in the treatment of atherosclerosis.