Comparative analysis of two L-carnitine preparations and their concentration effects on CAT expression in healthy human peripheral blood lymphocyte cultures

CAT gene encodes catalase, a key antioxidant enzyme in the body against oxidative stress. This enzyme plays an important role in the molecular mechanisms of inflammation, apoptosis, mutagenesis and tumorigenesis. Anti-oxidant L-carnitine is used in food supplementation, medical co-treatment and bodyweight regulation. We aimed to investigate molecular basis of L-carnitine commercial preparations supplementation in reducing oxidative stress with customized CAT gene assay in vitro. Human lymphocytes cell culture was established using standard procedure and treated with range of concentrations of L-carnitine in two preparations. We tested two preparations: 500 mg tablets of L-carnitine and liquid L-carnitine with vitamin B6. L-carnitine significantly reduced the expression of CAT gene in cultured lymphocytes at concentrations of 50 μmol/l and 250 μmol/l compared to negative control, (p = 0,001; p = 0,001; respectively). The L-carnitine liquid supplement with vitamin B6 also reduced the transcription of CAT gene at concentrations of 50 μmol/l and 250 μmol/l as compared to the negative control (p = 0,018; p = 0,006; respectively). Selected L-carnitine preparations modulated the transcriptional activity of the antioxidant enzyme gene in human lymphocyte culture, indicating its possible effects in inhibition of pro-inflammatory processes that involve catalase activity.

A secreted catalase contributes to Puccinia striiformis resistance to host-derived oxidative stress

Plants can produce reactive oxygen species (ROS) to counteract pathogen invasion, and pathogens have also evolved corresponding ROS scavenging strategies to promote infection and pathogenicity. Catalases (CATs) have been found to play pivotal roles in detoxifying H2O2 formed by superoxide anion catalyzed by superoxide dismutases (SODs). However, few studies have addressed H2O2 removing during rust fungi infection of wheat. In this study, we cloned a CAT gene PsCAT1 from Puccinia striiformis f. sp. tritici (Pst), which encodes a monofunctional heme-containing catalase. PsCAT1 exhibited a high degree of tolerance to pH and temperature, and forms high homopolymers.Heterologous complementation assays in Saccharomyces cerevisiae reveal that the signal peptide of PsCAT1 is functional. Overexpression of PsCAT1 enhanced S. cerevisiae resistance to H2O2. Transient expression of PsCAT1 in Nicotiana benthamiana suppressed Bax-induced cell death. Knockdown of PsCAT1 using a host-induced gene silencing (HIGS) system led to the reduced virulence of Pst, which was correlated to H2O2 accumulation in HIGS plants. These results indicate that PsCAT1 acts as an important pathogenicity factor that facilitates Pst infection by scavenging host-derived H2O2.

Quercetin Alleviates the Immunotoxic Impact Mediated by Oxidative Stress and Inflammation Induced by Doxorubicin Expo-Sure in Rats

Doxorubicin (DOX) is a chemotherapeutic agent against hematogenous and solid tumors with undesirable side effects including immunosuppression. Quercetin (QUR), a natural flavonoid abundant in fruits and vegetables, has a potent antioxidant activity. The aim of the current study was to assess the impact of QUR on DOX-induced hematological and immunological dysfunctions in a rodent model. Randomly grouped rats were treated as follows: control, QUR alone (50 mg/kg for 15 days per os), DOX alone (2.5 mg/kg I/P, three times a week, for two weeks), and co-treated rats with QUR for 15 days prior to and concomitantly with DOX (for two weeks), at the doses intended for groups two and three. DOX alone significantly disrupted the erythrogram and leukogram variables. Serum immunoglobulin (IgG, IgM, and IgE) levels and the activities of catalase (CAT) and superoxide dismutase (SOD) and in spleen were declined. The DNA damage traits in spleen were elevated with an upregulation of the expression of the apoptotic markers (p53 and Caspase-3 genes) and the proinflammatory cytokines (IL-6 and TNF-α genes), while the expression of CAT gene was downregulated. These biochemical changes were accompanied by morphological changes in the spleen of DOX-treated rats. Co-treatment with QUR abated most of the DOX-mediated alterations in hematological variables, serum immunoglobulins, and spleen antioxidant status, pro-inflammatory and apoptotic responses, and histopathological alterations. In essence, these data suggest that QUR alleviated DOX-induced toxicities on the bone marrow, spleen, and antibody-producing cells. Supplementation of chemotherapy patients with QUR could circumvent the DOX-induced inflammation and immunotoxicity, and thus prevent chemotherapy failure.

Catalase (CAT) Gene Family in Rapeseed (Brassica napus L.): Genome-Wide Analysis, Identification and Expression Pattern in Response to Multiple Hormones and Abiotic Stress Conditions

Catalase (CAT) is an antioxidant enzyme expressed by the CAT gene family and exists in almost all aerobic organisms. Environmental stresses induce the generation of reactive oxygen species (ROS) that eventually hinder plant growth and development. The CAT enzyme translates the hydrogen peroxide (H2O2) to water (H2O) and reduce the ROS levels to shelter the cells' death. So far, the CAT gene family has not been reported in rapeseed (Brassica napus L.). Therefore, a genome-wide comprehensive analysis was conducted to classify the CAT genes in the rapeseed genome. The current study identified 14 BnCAT genes in the rapeseed genome. Based on phylogenetic and synteny analysis, the BnCATs belong to four groups (Groups I–IV). A gene structure and conserved motif analysis showed that Group I, Group II, and Group IV possess almost the same intron/exon pattern, and an equal number of motifs, while Group III contains diverse structures and contain 15 motifs. By analyzing the cis-elements in the promoters, we identified five hormone-correlated responsive elements and four stress-related responsive elements. Further, six putative bna-miRNAs were also identified, targeting three genes (BnCAT4, BnCAT6, and BnCAT8). Gene ontology (GO) enrichment analysis showed that the BnCAT genes were largely related to cellular organelles, ROS response, stimulus response, stress response, and antioxidant enzymes. Almost 10 BnCAT genes showed higher expression levels in different tissues, i.e., root, leaf, stem, and silique. The expression analysis showed that BnCAT1–BnCAT3 and BnCAT11–BnCAT13 were significantly upregulated by cold, salinity, abscisic acid (ABA), and gibberellic acid (GA) treatment, but not by drought and methyl jasmonate (MeJA). Notably, most of the genes were upregulated by waterlogging stress, except BnCAT6, BnCAT9, and BnCAT10. Our results opened new windows for future investigations and provided insights into the CAT family genes in rapeseed.

AsaGEI2d: a new variant of a genomic island identified in a group of Aeromonas salmonicida subsp. salmonicida isolated from France, which bears the pAsa7 plasmid

Genomic islands (Aeromonas salmonicida genomic islands, AsaGEIs) are found worldwide in many isolates of Aeromonas salmonicida subsp. salmonicida, a fish pathogen. To date, five variants of AsaGEI (1a, 1b, 2a, 2b and 2c) have been described. Here, we investigate a sixth AsaGEI, which was identified in France between 2016 and 2019 in 20 A. salmonicida subsp. salmonicida isolates recovered from sick salmon all at the same location. This new AsaGEI shares the same insertion site in the chromosome as the other AsaGEI2s as they all have a homologous integrase gene. This new AsaGEI was thus named AsaGEI2d, and has 5 unique genes compared to the other AsaGEIs. The isolates carrying AsaGEI2d also bear the plasmid pAsa7, which was initially found in an isolate from Switzerland. This plasmid provides resistance to chloramphenicol thanks to a cat gene. This study reveals more about the diversity of the AsaGEIs.

The Association of Antioxidants Gene Polymorphisms (SOD2 Ala16Val, GPx1 Pro198Leu, GSTP1 Ile105Val, and Cat −21 A/T) and Risk of Type 2 Diabetes Mellitus

BACKGROUND: Antioxidant gene polymorphism is one of the genetic risk factors associated with type 2 diabetes mellitus (T2DM) incidence. AIM: This study was to analyze the association of superoxide dismutase 2 (SOD2) Ala16VAl, glutathione peroxidase (GPx1) Pro198Leu, glutathione S-transferase Pi1 (GSTP1) Ile105Val, and Cat −21 A/T gene polymorphisms and risk of T2DM. METHODS: We genotyped deoxyribonucleic acid of 120 T2DM patients and 80 healthy control by polymerase chain reaction and restriction fragment length polymorphism method, using a specific restriction enzyme. RESULTS: This study showed that the Val/Val of SOD2 was significantly associated with an increased risk of T2DM compared to the Ala/Ala+Ala/Val (p = 0.011; odds ratio [OR] = 2.220; confidence interval [CI] = 1.234–3.992). The TT genotype of Cat gene was also significantly associated with an increased risk of T2DM compared to the AA genotype (p = 0.027; OR = 5.000; CI = 1.079–23.176) and TT genotype to the AA+AT genotype (p = 0,030; OR = 4.738; CI = 1.039–21.600). However, there was no difference in all genetic models of GPx1 Pro198Leu and GSTP1 Ile105Val gene polymorphisms (p > 0.05). CONCLUSION: This study indicates that the Val/Val under the recessive model of SOD2 gene also TT genotype under the co-dominant model of Cat gene and TT genotype under the recessive model of Cat gene were associated with risk factors for T2DM occurrence.