Current issues

Table of contents: 2023

Research Article

The folate cycle is a biochemical pathway that plays an important role in the development and maintenance of the nervous system. Biocompounds synthesized in this cycle must be carefully regulated, since the accumulation of some substances can be neurotoxic and increase susceptibility to neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). The methylenetetrahydrofolate reductase (MTHFR), 5-methyltetrahydrofolate-homocysteine S-methyltransferase (MTR), and solute carrier family 19 member 1 (SLC19A1) genes encode important proteins for this regulation. In this systematic review and meta-analysis, we investigated the association of some polymorphisms in the MTHFR, MTR, and SLC19A1 genes and their associations with ALS and MS. The protocol of this systematic review is registered in the PROSPERO platform (CRD42021232352). We performed a search in EMBASE, Pubmed/NCBI, Scopus, Virtual Health Library (BVS), and Web of Science databases for studies that described polymorphisms in these genes, regardless of statistical association. Thirteen studies were included, and four polymorphisms were identified: C677T (rs1801133) and A1298C (rs1801131) in the MTHFR gene, A2756G (rs1805087) in the MTR gene, and A80G in the SLC19A1 gene. In the meta-analysis, the allelic and genotypic comparison for the C677T polymorphism showed a 1.5-fold increased risk for MS. Despite this significant result, we found a lack of association of most polymorphisms in the MTR, SLC19A1 and MTHFR genes and susceptibility for developing ALS and MS. Further studies are needed to clarify the role of polymorphisms in folate pathway genes in the susceptibility for developing these neurodegenerative diseases.

Genet. Mol. Res. 2023
DOI: 10.4238/gmr19084
Research Article

Amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) are degenerative scleroses with unclear etiology. Vascular endothelial growth factor A (VEGF-A) is a growth factor that plays multiple roles in the central nervous system.  Previous studies indicated a potential association between polymorphisms in this gene and the susceptibility of ALS and MS; however, the results have been inconclusive. Here, we conducted a systematic review and meta-analysis to elucidate the relationship between polymorphisms in the VEGF-A gene and these degenerative scleroses. We searched for observational studies in PubMed, Web of Science, EMBASE, Virtual Health Library (BVS) and SCOPUS, without temporal and language restrictions and 12 studies were included in the systematic review. Six polymorphisms were identified: C-1558T, A-1190G, G-1154A (rs1570360), C-2578A (rs699947), C-634G (rs2010963), and C936T (rs3025039). After a systematic literature search, a pooled odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association of C-2578A, G-1154A, and G-634C polymorphisms and ALS. Due to the small number of articles found in this review for MS, it was not possible to perform a meta-analysis for this disease. The meta-analysis for ALS included 1441 patients and 1978 controls for C-2578A, and 1134 patients and 1629 controls for G-1154A and G-634C polymorphisms. No SNP was significantly associated with risk for ALS. We conclude that polymorphisms in the VEGF-A gene may not be a major risk factor for the development of ALS and MS; However, associated with specific factors, such as sex or haplotype combinations, they may become a strong susceptibility factor. Although we found a lack of association in most VEGF-A polymorphisms and the susceptibility for developing ALS and MS, this review provides a comprehensive understanding for the potential role of this gene in degenerative sclerosis.

Genet. Mol. Res. 2023
DOI: 10.4238/gmr19083
Research Article

The aggressiveness of fungal diseases in oats compromises grain yield. Although fungicides are effective for control, there is a need for productivity with food and environmental safety. Thus, we seek cultivars responsive to more sustainable management. The objective of this study was to identify oat cultivars that are more responsive to reduced fungicide use and a longer application-to-harvest interval with satisfactory yields, and to identify relevant variables in the simulation of grain yield by multiple linear regression. The study was carried out in 2019 and 2020 in Augusto Pestana, RS, a prominent region for oat cultivation in Brazil. The experimental design was randomized blocks, with three replications in a 22 x 4 factorial scheme, for 22 oat cultivars, recommended and no longer suitable for cultivation and four conditions of sequential use of fungicide (no application; one application 60 days after emergence; two applications, 60 and 75 days after emergence; and three applications, 60, 75 and 90 days after emergence). The fungicide used was FOLICUR® CE, at a dosage of 0.75 liters ha-1. The variables analyzed were necrotic leaf area and grain yield. The Stepwise technique was used to identify potential variables for the multiple linear regression model. The cultivars FAEM 4 Carlasul, URS Altiva, URS Charrua and URS Guará show superiority in grain yield in the absence of fungicide. In a single application, 60 days after emergence, FAEM 4 Carlasul and URS Charrua showed productivity above 3000 kg ha-1 with a long interval (around 60 days) from application to harvest. The variables minimum average temperature, necrotic leaf area and number of fungicide applications were found to be suitable for the composition of a multiple linear regression model to simulate grain yield.

Genet. Mol. Res. 2023
DOI: 10.4238/gmr19034
Research Article

Senecavirus A (SVA) is a nonenveloped, single-stranded RNA virusThe icosahedral viral particle is composed of four structural proteins: VP1, VP2, VP3 and VP4, among which VP2 is strongly involved in the antibody immune response. The virus causes vesicles on the snout and feet in pigs, which are clinically indistinguishable from other vesicular diseases such as foot-and-mouth disease. Outbreaks of SVA have been reported worldwide since 2014; however, its prevalence in Brazil remains unknown. In this study, the VP2 structural protein was produced and purified from E. coli, and recombinant VP2 (rVP2), based on the most recent Brazilian strain, was used to develop an indirect ELISA to identify antibodies against SVA in Brazilian swine herds. Sensitivity and specificity values of the rVP2 ELISA were determined using receiver operating characteristic analysis performed on 43 SVA positive and 219 negative serum samples. In addition, serum samples from pigs immunized with eight distinct Brazilian SVA inactivated strains were tested with the rVP2 ELISA. For the specificity of the assay, 17 serum samples from vesicular stomatitis virus (VSV) from naturally infected pigs were tested. The rVP2 ELISA was found to have 100% specificity and 74.4% sensitivity. The performance of the assay using samples collected during the SVA outbreak, had a sensitivity of 100%, and with those collected nine months after the outbreak it had a sensitivity of 73.4%. The rVP2 ELISA developed here was able to detect specific SVA antibodies in acute disease and recovered pigs, and no cross-reactivity with VSV was observed. This assay has potential as a useful tool for monitoring SVA infection and could help to improve disease diagnosis.

Genet. Mol. Res. 2023
DOI: 10.4238/gmr19118
Research Article

We evaluated methylenetetrahydrofolate reductase gene C677T polymorphisms in patients with colorectal cancer in a population-based case-control study in the Azerbaijan population. Genomic DNA was isolated from blood samples taken from 155 patients with colorectal cancer and 155 healthy individuals. The MTHFR gene C677T polymorphism was detected on agarose gel by PCR-RFLP. The frequencies of the CC, CT, and TT genotypes of MTHFR (C677T) were 54, 37, and 9% in the patients with colorectal cancer and 65, 29, and 6% in the healthy control, respectively. Heterozygote CT (OR = 1.422, 95%CI = 0.883–2.289, P = 0.147) and homozygous mutant TT (OR = 1.440, 95% CI = 0.619–3.348, P = 0.395) genotypes were more frequent in colorectal cancer patients compared to controls. No significant associations were observed between genotype and allele frequency of the MTHFR gene and the risk of colorectal cancer. Our findings suggested that MTHFR C677T polymorphism might not be associated with the overall risk of colorectal cancer in an Azerbaijani population. However, these conclusions need to be validated in a larger cohort study.

Genet. Mol. Res. 2023
DOI: 10.4238/gmr19100
Research Article

Valproic acid (VPA) is a drug that is often used to treat epilepsy, seizures, and similar diseases. However, it is known to have serious toxic effects on the liver and the kidney. Oxidative stress and other metabolites of VPA have been suggested to be responsible for VPA induced hepatotoxicity and nephrotoxicity. We evaluated the possible protective role of royal jelly (RJ) against the effects of VPA through toxicity tests on livers and kidneys of rats. Twenty-four male albino rats were separated into three groups; group (1): healthy control received no drug, group (2): administrated VPA (500 mg/kg/day by oral gavage), group (3): received VPA (500 mg/kg/day by oral gavage) one hour prior to RJ (500 mg/kg/day by oral gavage). After two weeks, the rats' livers and kidneys were removed for histopathologic investigation with hematoxylin and eosin staining while biochemical assessment was performed on blood samples. The VPA group had a significant increase in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine and pro-inflammatory cytokines (IL-1a, IL-1b and IL-6). Histopathological observations in liver and kidney tissues also were related with the biochemical parameters. VPA causes hepato-renal damage by promoting inflammation, oxidative stress, and fibrosis. RJ enhanced the functions of the liver and kidneys by reducing ALT, AST, urea and creatinine compared with the VPA treatment group and reduced serum pro-inflammatory cytokines. In addition, the histopathological impairment of liver and kidney tissues were reversed by RJ treatment. In conclusion, RJ can protect hepato-renal functions against VPA acid-induced organ damage.

Genet. Mol. Res. 2023
DOI: 10.4238/gmr19063