Genomic Analysis of the Glutathione S-Transferase Family in Pear (Pyrus communis) and Functional Identification of PcGST57 in Anthocyanin Accumulation

Anthocyanin accumulation in vacuoles results in red coloration in pear peels. Glutathione S-transferase (GST) proteins have emerged as important regulators of anthocyanin accumulation. Here, a total of 57 PcGST genes were identified in the European pear ‘Bartlett’ (Pyrus communis) through comprehensive genomic analysis. Phylogenetic analysis showed that PcGST genes were divided into 10 subfamilies. The gene structure, chromosomal localization, collinearity relationship, cis-elements in the promoter region, and conserved motifs of PcGST genes were analyzed. Further research indicated that glutamic acid (Glu) can significantly improve anthocyanin accumulation in pear peels. RNA sequencing (RNA-seq) analysis showed that Glu induced the expression of most PcGST genes, among which PcGST57 was most significantly induced. Further phylogenetic analysis indicated that PcGST57 was closely related to GST genes identified in other species, which were involved in anthocyanin accumulation. Transcript analysis indicated that PcGST57 was expressed in various tissues, other than flesh, and associated with peel coloration at different developmental stages. Silencing of PcGST57 by virus-induced gene silencing (VIGS) inhibited the expression of PcGST57 and reduced the anthocyanin content in pear fruit. In contrast, overexpression of PcGST57 improved anthocyanin accumulation. Collectively, our results demonstrated that PcGST57 was involved in anthocyanin accumulation in pear and provided candidate genes for red pear breeding.

Antioxidant Defense during Recovery of Resurrection Plant Haberlea rhodopensis from Drought- and Freezing-Induced Desiccation

In this study, the contribution of nonenzymatic (ascorbate, glutathione) and enzymatic antioxidants (superoxide dismutase, catalase, glutathione reductase, glutathione S-transferase) in the first hours of recovery of the resurrection plant Haberlea rhodopensis from drought- and freezing-induced desiccation was assessed. The initial stage of recovery after desiccation is critical for plants, but less investigated. To better understand the alterations in the activity of antioxidant enzymes, their isoenzyme patterns were determined. Our results showed that ascorbate content remained high during the first 9 h of rehydration of desiccated plants and declined when the leaves′ water content significantly increased. The glutathione content remained high at the first hour of rehydration and then strongly decreased. The changes in ascorbate and glutathione content during recovery from drought- and freezing-induced desiccation showed great similarity. At the beginning of rehydration (1–5 h), the activities of antioxidant enzymes were significantly increased or remained as in dry plants. During 7–24 h of rehydration, certain differences in the enzymatic responses between the two plant groups were registered. The maintenance of a high antioxidant activity and upregulation of individual enzyme isoforms indicated their essential role in protecting plants from oxidative damage during the onset of recovery.

The role of genes of the second phase of detoxification of xenobiotics in the pathogenesis of multifactorial diseases

The genetic status of a person is currently assigned a major role in the pathogenesis, diagnosis and treatment of various diseases. The most important genetic factors that have been attached great importance to are the genes of the glutathione-S-transferase family (GSTs). The genes of the glutathione-S-transferase family belong to the second phase of detoxification of xenobiotics and their altered activity leads to the development of many pathological conditions. GSTM, GSTT, GSTP are considered to be the most polymorphic. The issues of the participation of polymorphic GSTs in the development of infectious, allergic and oncological diseases, disorders of the reproductive system, as well as in the development of Alzheimer's disease are discussed in the article.

Immunization Trials with Recombinant Major Sperm Protein of the Bovine Lungworm Dictyocaulus viviparus

The lungworm Dictyocaulus viviparus is one of the most economically important bovine parasites in temperate climate regions. Following infection, D. viviparus induces a temporary protective immunity, and a vaccine based on attenuated, infective larvae is commercially available. However, due to several disadvantages of the live vaccine, the development of a recombinant subunit vaccine is highly desirable. Therefore, the major sperm protein (MSP), which is essential for the parasite’s reproduction, was tested as a recombinantly Escherichia coli-expressed glutathione-S-transferase (GST)-fused vaccine antigen in immunization trials with two different adjuvants, Quil A and Al(OH)3. Calves (N = 4 per group) were immunized on study day (SD) 0, 21 and 42 and given a challenge infection on SD 63–65. The two control groups received only the respective adjuvant. Based on geometric means (GM), a 53.64% reduction in larvae per female worm was observed in the rMSP Quil A group vs. its control group (arithmetic means (AM): 54.43%), but this difference was not statistically significant. In the rMSP Al(OH)3 group, the mean number of larvae per female worm was even higher than in the respective control group (GM: 9.24%, AM: 14.14%). Furthermore, male and female worm burdens and the absolute number of larvae did not differ significantly, while the Al(OH)3 control group harbored significantly longer worms than the vaccinated group. Vaccinated animals showed a rise in rMSP-specific antibodies, particularly IgG and its subclass IgG1, and the native protein was detected by immunoblots. Although rMSP alone did not lead to significantly reduced worm fecundity, it might still prove useful as part of a multi-component vaccine.

Characteristics of lipid peroxidation processes and factors of the antioxidant defense system in chronic atrophic gastritis and gastric cancer

Background. The problem of gastric cancer remains unresolved throughout the world, while chronic atrophic gastritis (CAG) increases the likelihood of its development by 15 times. In the Russian Federation, the incidence of gastric cancer (GC) is among the highest, with it prevailing among males. One of the leading mechanisms in molecular pathology of membranes is lipid peroxidation (LPO). The severity of oxidative membrane damage depends on concomitant diseases, contributing to emergence and progression of pathological processes and development of cancer. Currently, the problem of LPO is unsolved in biological systems.The aim of this study was to investigate the state of LPO and antioxidant defense system in CAG and GC. Materials and methods. The parameters were studied in 45 patients with CAG and 50 patients with GC. The control group included 50 practically healthy volunteers without gastrointestinal complaints, who did not have changes in the gastric mucosa according to the fibroesophagogastroduodenoscopy (FEGDS) findings.Results. In patients with CAG, an increase in malondialdehyde, superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase was found in the blood plasma compared with the control group. In patients with CAG, lipid peroxidation was activated, and the malondialdehyde level increased by 3.5 times relative to normal values. At the same time, the body fought against oxidative stress by increasing the activity of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase. All patients with GC showed pronounced oxidative stress in the blood plasma in the form of a 45-fold increase in malondialdehyde. The activity of the main antioxidant enzyme superoxide dismutase was reduced in GC. Catalase was activated, which indicated pronounced oxidative stress, significant damage to blood vessels, and massive cell death. Glutathione-related enzymes (glutathione S-transferase and glutathione peroxidase) and the antioxidant protein ceruloplasmin were activated, which also indicated significant oxidative stress and severe intoxication in patients with GC.Conclusion. Depending on the stage and type of cancer, an in-depth study of lipid peroxidation and factors of the antioxidant defense system can be used to correct therapy and prevent cancer and can serve as markers of progression and prognosis in gastric cancer.