Characterization of Pectobacterium carotovorum subsp. carotovorum Bacteriophage PP16 Prospective for Biocontrol of Potato Soft Rot

Microbiology - Phages of the phytopathogenic Pectobacteriaceae species causing black leg and soft rot of potato were investigated. These phages are promising as biocontrol agents to prevent the...     

Heme metabolism and oxidative stress

The role of heme metabolism in oxidative stress development and defense reactions formation in mammals under different stress factors are discussed in the article. Heme metabolism is considered as the totality of synthesis, degradation, transport and exchange processes of exogenous heme and heme liberated from erythrocyte hemoglobin under erythrocyte aging and hemolysis. The literature data presented display normal heme metabolism including mammals heme-binding proteins and intracellular free heme pool and heme metabolism alterations under oxidative stress development. The main attention is focused to the prooxidant action of heme, the interaction of heme transport and lipid exchange, and to the heme metabolism key enzymes (delta-aminolevulinate synthase and heme oxygenase), serum heme-binding protein hemopexin and intracellular heme-binding proteins participating in metabolism adaptation under the action of factors, which cause oxidative stress.     

Long non‐coding RNAs in melanoma

Melanoma is the most lethal cutaneous cancer with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have shed new insights into the mechanism of melanoma development, the involvement of regulatory non‐coding RNAs remain unclear. Long non‐coding RNAs (lncRNAs) are a group of endogenous non‐protein‐coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidences have shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration and invasion. In the melanoma, deregulation of a number of lncRNAs, such as HOTAIR, MALAT1, BANCR, ANRIL, SPRY‐IT1 and SAMMSON, have been reported. Our review summarizes the functional role of lncRNAs in melanoma and their potential clinical application for diagnosis, prognostication and treatment.     

Protective effect of bixin on carbon tetrachloride-induced hepatotoxicity in rats

Background

The liver is an important organ for its ability to transform xenobiotics, making the liver tissue a prime target for toxic substances. The carotenoid bixin present in annatto is an antioxidant that can protect cells and tissues against the deleterious effects of free radicals. In this study, we evaluated the protective effect of bixin on liver damage induced by carbon tetrachloride (CCl₄) in rats.

Results

The animals were divided into four groups with six rats in each group. CCl₄ (0.125 mL kg^-1 body wt.) was injected intraperitoneally, and bixin (5.0 mg kg^-1 body wt.) was given by gavage 7 days before the CCl₄ injection. Bixin prevented the liver damage caused by CCl₄, as noted by the significant decrease in serum aminotransferases release. Bixin protected the liver against the oxidizing effects of CCl₄ by preventing a decrease in glutathione reductase activity and the levels of reduced glutathione and NADPH. The peroxidation of membrane lipids and histopathological damage of the liver was significantly prevented by bixin treatment.

Conclusion

Therefore, we can conclude that the protective effect of bixin against hepatotoxicity induced by CCl₄ is related to the antioxidant activity of the compound.     

The influence of phenothiazines on the sarcoplasmic reticulum Ca-ATPase from skeletal and cardiac muscles

Phenothiazines--trifluoperazine, chloropromazine and ethmozine-- inhibit the sarcoplasmic reticulum Ca-ATPase from skeletal and cardiac muscles of the rabbit. The inhibition constants for both preparations are of the same order of magnitude. The experimental data suggest that the effect of phenothiazine on the sarcoplasmic reticulum Ca-ATPase is not mediated by CaM, but is directed toward the enzyme molecule.     

A new DNA diagnostic system for the detection of human <Emphasis Type="Italic">CYP21</Emphasis> gene mutations associated with adrenal cortex hyperplasia

Congenital Adrenal Hyperplasia (CAH) is one of the most widespread severe autosomal recessive hereditary diseases. CAH is caused by the impaired biosynthesis of the key human hormones cortisol and aldosterone and is accompanied by the excess synthesis of androgens. Over 90% of CAH cases are caused by a deficiency of the steroid 21-hydrohylase (P450c21). The degree of damage in this enzyme is responsible for the severity of the clinical manifestation of CAH from potentially lethal to mild symptoms. Various mutations of the gene encoding this enzyme are the main source of the reduced activity of the steroid-21-hydrolase. The location of the highly homological pseudogene CYP21P in close proximity to the functional gene impedes the DNA diagnostics of CAH. To detect the eight most frequent CYP21 gene mutations associated with CAH, we developed a new real-time PCR-based system of DNA diagnostics using new allele-specific primers and TaqMan probes for the analyzed mutations. The method was primarily tested on artificial DNA templates, where the analyzed mutations were introduced by site-directed mutagenesis. Then, it was tested on DNA samples from 43 patients with clinical and biochemical manifestations of CAH; seven patients were used as a control. Two mutant alleles were detected in two different individuals: the nonsense Q318X and the missense V281L mutations.     

Free heme pool and activity of key enzyme of heme synthesis in the rat liver under action of agents affecting reduced glutathione level

The decrease of GSH level in the rat liver was found to be accompanied by an increase of tryptophan 2,3-dioxygenase (TDO) heme saturation during first hours after HgCl2, phenylhydrazine (Ph) injection or rhabdomyolysis (the coefficient of correlation -0.978). The activity of the key enzyme of heme synthesis--5-aminolevulinate synthase (ALAS) was 2.5-fold increased in the first hours after Ph injection and rhabdomyolysis. Glutathione injection in vivo as well as CdCl2 caused the increase of GSH content and the inhibition of ALAS. The coefficient of correlation for GSH content and ALAS activity under the action of agents altering both these parameters (CdCl2, Ph, GSH injection and rhabdomyolysis) is 0.938. Taking into account the presence of heme regulatory motif with conserved cystein in many proteins, including ALAS and TDO (accession number in SwissProt database AAH61793 and P21643, respectively), the link between alterations of GSH content, ALAS activity and heme saturation of TDO in the rat liver could be proposed. The further experiments should be performed in order to elucidate the mechanisms of GSH level influence on free heme pool formation in the liver cells.     

Unique polymorphism of the CYP21A2 gene encoding 21-hydroxylase in female patients with the signs of hyperandrogenism

Hyperandrogenism is a pathological condition characterized by a high level of male sex hormones (andogens) in a female organism. One of the main causes of hyperandrogenism is the autosomal recessive disease, congenital adrenal hyperplasia (CAH). More than 90% of all cases of this disease arise due to a mutation-induced decrease in the activity of the enzyme steroid-21-hydroxylase encoded by the CYP21A2 gene. In the present work, the sequencing of the full-size CYP21A2 gene from 16 female patients with well-pronounced signs of hyperandrogenism was performed; preliminarily the patients were tested for the presence in the CYP21A2 gene of nine most widespread mutations causing CAH (seven point mutations and 8-bp and ??30-kb deletions). The preliminary examination of the patients revealed no genotype that could lead to the development of the pathological phenotype. During the sequencing, 26 single nucleotide polymorphisms (SNP) were identified in the gene of which 25 were described in the literature (database dbSNP, NCBI). The gene of each patient had a unique combination of polymorphisms inherent only in this very woman. The novel SNP was localized in the 3??-terminal part of exon 8 and represented a synonymous C ?? T substitution. The SNPs were not uniformly distributed along the gene, but were arranged in clusters in the vicinity of the initiation and termination codons and near the boundaries of introns 2, 6, and 8. It was assumed that clinically neutral SNPs in unique combinations can, by themselves, affect either the spatial structure of CYP21A2 mRNA or the efficiency of pre-mRNA splicing and decrease the level of gene expression, which may lead to the development of the pathological phenotype in the patients.     

Study of bromthymol blue binding with plasma membranes

It has been established that sorption of bromthymol blue by membranes is due to interaction with integral proteins. The value of the bond is ascribed both to the structural state and electrochemical property of membranes.     

Metabolism of heme and hemoproteins in rat liver upon administration of mercuric chloride

Rat liver delta-aminolevulinate synthase (delta-ALAS) activity in the early period after mercury chloride administration (0.7 mg per 100 g body weight) was found to be followed by free heme level increase, which was registered by the increase of heme saturation of the heme-binding protein tryptophan-2,3-dioxygenase (T-2,3-DO). delta-ALAS and heme oxygenase activity increase was observed 24 h after action. Microsomal cytochromes P450 and b5 levels decrease. Heme saturation of the T-2,3-DO returned to control level. Heme oxygenase and T-2,3-DO induction promoted hepatocytes free heme level normalization. Heme oxygenase and delta-ALAS induction role in the liver cells defense from the oxidative damage is discussed.