Brazilian Journal of Medical and Biological Research最新文献

[This corrects the article doi: 10.1590/1414-431X2023e12894].

This genetic association study including 120 patients with type 2 diabetes mellitus (T2DM) and 166 non-diabetic individuals aimed to investigate the association of polymorphisms in the genes GSTM1 and GSTT1 (gene deletion), GSTP1 (rs1695), ACE (rs4646994), ACE2 (rs2285666), VEGF-A (rs28357093), and MTHFR (rs1801133) with the development of T2DM in the population of Goiás, Brazil. Additionally, the combined effects of these polymorphisms and the possible differences between sexes in susceptibility to the disease were evaluated. Finally, machine learning models were integrated to select the main risk characteristics for the T2DM diagnosis. Risk associations were found for the GSTT1-null genotype in the non-stratified sample and females, and for mutant C allele of the VEGF-A rs28357093 polymorphism in the non-stratified sample. Furthermore, an association of heterozygous (AG) and mutant (GG) GSTP1 genotypes was observed when combined with GSTT1-null. Machine learning approaches corroborated the results found. Therefore, these results suggested that GSTT1 and GSTP1 polymorphisms may contribute to T2DM susceptibility in a Brazilian sample.

Bile acids are closely associated with necrotizing enterocolitis (NEC), and their accumulation has cytotoxic effects on cells. However, the specific bile acid subtype involved in NEC and its underlying mechanisms remains poorly understood, limiting the therapeutic potential of bile acids as treatment targets. In the present study, deoxycholic acid (DCA) accumulation in the intestinal lumen exacerbated NEC-induced intestinal damage. DCA suppressed the expression of mesenchymal-epithelial transition factor (MET), a proto-oncogene located on chromosome 7q31.2 that encodes c-Met, in the mouse intestine through transcription factors and increased nuclear translocation of p-STAT3. MET is a receptor tyrosine kinase that participates in cell proliferation and migration processes. Increasing concentrations of DCA downregulated MET expression and reduced the proliferation and migration of intestinal epithelial cells in vitro. MET knockdown reduced the proliferation and migration of intestinal epithelial cells but increased STAT3 phosphorylation. These findings indicated that MET mediated STAT3 involvement in intestinal epithelial cell proliferation and migration, demonstrating that the inhibitory effect of DCA on MET disrupted this process. These results elucidated the damaging effects and mechanisms of DCA accumulation in NEC, providing new insights into the use of DCA as a therapeutic target for NEC.

The objective of the present randomized trial was to verify the effect of twelve weeks of strength training with self-selected and imposed loads on muscle function, functionality, muscle quality, and perceptual and affective responses in elderly men and women. Twenty-four volunteers were divided into two groups of 12 individuals each: self-selected group (SS) (8 women, 4 men; mean age=66.92±6.18 years) and imposed group (IMP) (8 women, 4 men; mean age=65.33±2.42 years). The strength exercise program lasted 12 weeks (3 d/w). All exercises were performed on machines. The SS group was instructed to select a weight that would allow them to complete three sets of 10 repetitions, while the IMP group had the load imposed by the researchers following the exercise prescription model recommended by American College of Sports Medicine (ACSM). Rated perceived exertion (RPE) and affective responses were recorded at the end of each session. Muscle function, functionality, and muscle quality were assessed before and after the intervention. Both groups demonstrated similar improvements in strength and functional capacity. Furthermore, the SS group reported lower RPE and higher affective responses compared to the IMP group at 8-12 weeks. In summary, the findings from this study highlighted the effectiveness of both IMP and SS intensity resistance training programs in enhancing muscle strength and functional capacity among older adults.

Cystic echinococcosis (CE) is a zoonotic disease caused by the infection of Echinococcus granulosus (E. granulosus) larva. Currently, blocking the pathogenic cycle chain through immunoprophylaxis has become the main research direction. EgG1Y162 protein has good antigenicity and immunogenicity and is therefore a good candidate molecule for E. granulosus vaccine. Mature T cells express CTLA-4 on their surface, and its extracellular IgV region binds efficiently to the B7 molecules on antigen-presenting cells to deliver negative signals. We designed and prepared a recombinant vaccine by fusing CTLA-4IgV to the EgG1Y162 protein to exploit its binding properties. Bioinformatic methods were used to analyze the structure and epitopes of the proposed recombinant vaccine. The placement of 16 amino acids (GTDDDDKAMADIGSEF) between the CTLA-4IgV and EgG1Y162 using the skeleton structure of pET30a plasmid did not affect the correct folding of the proteins. When the recombinant proteins were co-cultured with bone marrow-induced dendritic cells (DC), the protein CTLA-4IgV-EgG1Y162 promoted its binding to DC and increased the percentage of DC maturation compared with protein EgG1Y162 in vitro and in vivo. Compared to EgG1Y162, CTLA-4IgV-EgG1Y162 promoted the proliferation of lymphocytes in spleen and the release of interferon (IFN)-γ and interleukin (IL)-4 by those lymphocytes in vitro, while it also promoted the release of protective antibodies in the serum of immunized mice in vivo. These findings indicated that the designed recombinant vaccine, CTLA-4IgV-EgG1Y162, can provide new ideas for the optimization and improvement of vaccines against E. granulosus.

Personalized therapy in lung cancer (LC) has revolutionized routine histopathology and cytopathology, emphasizing the importance of obtaining adequate material for molecular studies to support oncological decisions. Adaptations of cytologic sample preparations offer benefits for molecular testing, yet their potential remains underutilized. A significant number of LC cases is identified through specimens of aspiration or exfoliative cytology. Improving screening approaches and optimizing tissue utilization for biomarker research are crucial for effective LC management. The utilization of formalin-fixed, paraffin-embedded (FFPE) tumor tissues has become standard practice in clinical and epidemiological genetic research. However, current techniques require not only a standardized sample fixation and storage but also sufficient genetic material to yield reliable results. In this study, we utilized the Qiagen GeneRead® DNA FFPE kit with an adapted protocol for two extraction methods: one involved cutting FFPE blocks and the other involved scraping tissue from slides used for histochemical and cytological analysis. Our findings emphasized the importance of increasing the number of FFPE sections, heat deparaffinization, and adjusting proteinase K digestion time to enhance genomic DNA (gDNA) yields. Notably, scraping tissue from slides yielded superior results compared to the standard FFPE protocol. A median of 2.82 and 4.34 DNA yields for tumor and lymph node, respectively, were obtained. Our results demonstrated the feasibility of this adapted protocol for gDNA extraction in clinical and epidemiological studies. We recommend scraping tissue from slides as a reliable source of gDNA and suggest fine-tuning proteinase K digestion time and heat exposure based on the input tissue volume.

COVID-19, caused by SARS-CoV-2, presents diverse symptoms, including neurological manifestations. This study investigated COVID-19's neurological sequelae, focusing on the central nervous system's involvement through cerebral glycolytic metabolism assessed via PET/CT. Twenty-two patients with mild long COVID cognitive symptoms and 20 healthy volunteers without cognitive, psychiatric, or neurological impairments and no history of COVID-19 infection underwent cerebral PET/CT scans using [18F]FDG to assess cerebral metabolism. The study meticulously evaluated the uptake of [18F]FDG in various brain regions, employing the CortexID Suite software for quantitative analysis. The analysis focused on identifying areas of hypometabolism and hypermetabolism, indicative of altered glucose metabolism possibly related to COVID-19's neurological impact. No statistically significant differences were found between the mild COVID and healthy groups. Although our sample was too small to generate a statistical difference between groups, future studies should explore some findings, such as hypometabolism in 15 regions and hypermetabolism in 11 regions in the mild COVID group. These changes, especially in areas linked to executive functions, sensory perception, and emotional regulation, suggest nuanced alterations in brain function. Our study did not find significant glycolytic metabolic changes in patients with mild long COVID. However, areas of glycolytic hypometabolism and hypermetabolism found in some patients showed biological plausibility with the cognitive and affective symptoms they presented. Future investigations with a larger sample size should be correlated with neuropsychological and neuropsychiatric examinations to confirm this relationship.

Gastric cancer (GC) remains a global health challenge due to its heterogeneity and diverse regional epidemiology. Treatment for advanced GC often requires chemotherapy, whose effects are closely associated with the cell cycle. This association highlights the critical need to understand cell cycle regulators that can influence the effectiveness of chemotherapy. Bioinformatics analyses were performed on transcriptome data from a hospital cohort and on a publicly available database. Flow cytometry was used for cell cycle analysis. The interaction of PMEPA1 with 14-3-3σ was confirmed by coimmunoprecipitation and immunofluorescence staining. Western blot analysis was performed following inhibition of protein synthesis and degradation to assess 14-3-3σ protein stability, while ubiquitination was evaluated after treatment with the proteasome inhibitor MG132. High PMEPA1 expression was detected in GC tissues and was correlated with poor prognosis. In vitro overexpression of PMEPA1 promoted GC cell proliferation, while knockdown of PMEPA1 inhibited cell proliferation and induced G2/M arrest. In vivo study showed that overexpressing PMEPA1 promoted tumor growth, while knocking down PMEPA1 inhibited tumor growth, as indicated by the level of the proliferation marker Ki67. 14-3-3σ was identified as a downstream target of PMEPA1. PMEPA1 binds to 14-3-3σ and promoted its degradation by facilitating its ubiquitination. Overexpression of PMEPA1 increased its interactions with TTC3 and 14-3-3σ, increased 14-3-3σ ubiquitination, and reduced 14-3-3σ stability, and the opposite effects were observed after PMEPA1 knockdown. PMEPA1 recruited TTC3, allowing the ubiquitination of 14-3-3σ and leading to its degradation, thus promoting cell cycle progression in GC.

Pyroptosis has attracted attention due to its role in various cancers. Recently, gasdermins (GSDMs) involved in pyroptosis have been reported to be associated with several types of cancers. However, the role of GSDMs expression in the diagnosis and prognosis of gastric cancer (GC) is still not well understood. We analyzed the transcriptional and prognostic information and the role of GSDMs in patients with GC from TIMER, UALCAN, Human Protein Atlas (HPA), GEPIA, and Kaplan-Meier Plotter databases. The cBioPortal platform was used to discover the genetic alterations, significance, and networks of GSDMs. Furthermore, STRING, Cytoscape, and TIMER were used to explore functional enrichment and immunomodulation. GSDMB, GSDMC, GSDMD, and GSDME were more highly expressed in GC than in normal tissues in the TIMER database. Moreover, survival analyses in two databases showed that high expression of GSDME was related to shorter overall survival (OS) in patients with GC. Additionally, functional enrichment revealed that GSDMs may be involved in endopeptidase activity, peptidase regulatory activity, and cysteine peptidase activity. GSDMs correlated with infiltration levels of immune cells in GC, and GSDME correlated with the infiltrating level of CD4+ T, CD8+ T, neutrophils, macrophages, and dendritic cells. This study indicated the potential diagnostic and prognostic value of GSDMs in GC. Our results showed that GSDME could play a significant oncogenic role in GC diagnosis and prognosis. However, our bioinformatics analyses should be validated in further prospective studies.

Renal fibrosis is a common manifestation in the progression of chronic kidney disease (CKD) to kidney failure. Currently, there is no available therapy to prevent the progression of renal fibrosis. Poricoic acid A (PAA) isolated from Poria cocos shows notable antifibrotic effects. However, its potential mechanism is still unclear. This study aimed to evaluate the effects and the potential mechanisms of PAA against renal fibrosis. A mouse model of renal fibrosis was established using unilateral ureteral obstruction (UUO). We showed that PAA administration significantly alleviated renal lesions and collagen deposition in UUO mice. Mice with UUO resulted in epithelial-to-mesenchymal transition (EMT) and the activation of endoplasmic reticulum stress (ERS) in the renal tissues, while PAA treatment significantly inhibited EMT and ERS activation. Additionally, PAA markedly alleviated ERS-mediated apoptosis in UUO mice. Molecular docking results indicated that PAA stably combined to GRP78 and ATF4. In conclusion, these results demonstrated that PAA possesses a significant bioactivity against renal fibrosis and its treatment mechanism might be the inhibition of ERS-mediated apoptosis.