Brazilian Journal of Medical and Biological Research最新文献

Cancer is the second leading cause of death worldwide. Cancer cachexia is a multifactorial catabolic syndrome responsible for almost one third of cancer-related deaths. Drug repurposing has been used in oncological research and drugs like clenbuterol and metformin seem to be reasonable candidates in the context of cancer cachexia, because the former is a β2-agonist that stimulates muscle gain and the latter has anti-inflammatory properties. The aim of this study was to assess the effects of a short-term treatment with metformin and clenbuterol, isolated or combined, on tumor growth and cancer cachexia parameters in Walker 256 tumor-bearing rats, a model of cancer cachexia. To this end, Wistar rats were separated into 8 groups and 4 of them were injected with Walker 256 tumor cells (W groups). Control (C) and W groups received the following treatments: metformin (M), clenbuterol (Cb), or metformin combined with clenbuterol (MCb). Body and tumor weight, metabolic parameters, and oxidative damage in the tumor were assessed. Compared to the C group, the W group showed body weight loss, hypoglycemia, hyperlactatemia, and hypertriacylglycerolemia. None of the treatments could reverse body weight loss, although they reversed the alterations of the assessed plasma metabolic parameters. Surprisingly, only clenbuterol alone reduced tumor weight. Hydrogen peroxide production and lipid peroxidation in tumor tissue was increased in this group. In conclusion, metformin and clenbuterol ameliorated metabolic cachexia parameters in Walker tumor-bearing rats, but only clenbuterol reduced the tumor weight, probably, through a lipid peroxidation-dependent cell death.

This systematic review of inception prospective cohort studies aimed to investigate whether autoantibodies are potential prognostic factors for short- and long-term clinical outcomes of COVID-19. Searches were conducted in MEDLINE, EMBASE, AMED, GLOBAL HEALTH, and COCHRANE databases from 2019 to 2022. When possible, meta-analysis was conducted, otherwise findings from individual studies were reported using odds ratios (OR) with 95% confidence intervals (CI). Quality of evidence was summarized using the GRADE criteria. We identified 2292 references, 18 inception prospective cohort studies (3178 patients) were included in the systematic review, and 12 studies reached criteria for meta-analysis. Studies achieved, in general, low to moderate risk of bias. Moderate quality of evidence showed that anti-interferon (IFN) was associated with increased risk of severity (OR=7.75; CI=1.79-33.61) and mechanical ventilation (OR=4.19; CI=2.06-8.53), but not with COVID-19 mortality (OR=1.68; CI=0.63-4.44). Antiphospholipids were not associated with COVID-19 mortality (OR=1.42; CI=0.85-2.37; P=0.18; I2=3.21) nor with thrombosis risk (OR=1.41; CI: 0.71-2.8; P=0.33). Antinuclear antibody level was not associated with risk of mortality or severity (risk for mortality: OR=3.8; CI=0.78-18.6; P=0.1; I2: 32.3; severity: OR=1.74; CI=0.96-3.16; P=0.07). Evidence currently available is insufficient for a quantitative analysis of autoantibodies association with long COVID-19. Anti-IFN measurement should be considered in COVID-19 follow-up. In a population-based rational, optimized vaccination strategies should be considered for individuals with anti-IFN antibodies since it could represent a risk for a worse prognosis. High-quality prospective studies for short- and long-term disease effects and autoantibody evaluation are still needed.

Sirtuins (SIRTs) are key regulators of cellular metabolism, involved in a wide range of physiological and pathological processes. However, there is scarce knowledge about the effect of sugar consumption and physical activity on SIRTs in kidney disorders. Here, we evaluated the impact of prolonged consumption of an isocaloric high-sugar diet (HSD) and physical training on the modulation of renal Sirts and the link between these alterations and possible obesity-associated kidney damage. Newly weaned male Wistar rats were fed a standard chow diet (STD) or HSD ad libitum and then subjected or not to regular workload swimming training for 18 weeks. Morphometric and biochemical parameters were analyzed, and the kidneys were removed for lipid quantification, histological analysis, and for Sirts1-7 expression. HSD led to the development of obesity, increased serum triglyceride levels, and glucose intolerance, regardless of higher caloric consumption. However, training was able to partially inhibit the HSD-induced obesogenic effect. No changes were identified in kidney mass, lipid content, histology, and creatinine clearance among the groups; these results were associated with a decrease in the renal expression of Sirt2-3 and Sirt7; however, training was able to reverse this modulation. The interaction between HSD and training led to an increase in Sirt4-7. However, Sirt1 remained constant among experimental groups. In conclusion, our results indicated that the transcriptional modulation of Sirts precedes HSD-induced damage and loss of kidney function, as well as a possible protective adaptive response of physical exercise on long-term Sirts expression.

Necrotizing enterocolitis (NEC) is a severe intestinal disease of multifactorial origin that primarily affects premature infants. Approximately 27% of NEC babies develop short gut (SG) secondary to extensive intestinal resection, and 10% will have chronic dependence on total parenteral nutrition. We evaluated the Botox treatment in SG model rats. Twenty-day-old weanling male rats (weight range 38-70 g, n=72) were divided into four groups (n=18 each): 1) Control (fed a regular liquid diet); 2) Botox (Control submitted to laparotomy and intestinal injection of Botox®); 3) SG (short gut); and 4) SG and Botox (SG+Botox®). After seven post-operative days, samples were collected for biometrics [body weight (BW), intestine weight (IW) and IW/BW ratio (IBR), and intestine length (IL) and height (IH)], histometric analysis [villous height (VH), crypt depth (CD), muscular thickness (MT), and PCNA index)], and intestinal transit time (ITT). BW, IW, and IL decreased in SG (P<0.05). IH, VH, and PCNA index increased in Botox groups [Control = SG < Botox and SG+Botox (P<0.05)], CD increased in Botox, SG, and SG+Botox (P<0.005), and MT was higher in SG and SG+Botox. Botox groups had lower ITT (P<0.05). Botox provided dilatation and histological changes in SG. These findings suggested that Botox improved adaptation and might be applied in SG with promising results.

[This retracts the article doi: 10.1590/1414-431X20209346].

Phosphodiesterase 2A (PDE2A) plays a pivotal role in modulating cyclic nucleotide metabolism. Recent studies have shown that PDE2A is associated with some tumors, but its expression profiles, prognostic significance, and immunological roles in diverse cancer types remain unclear. Utilizing advanced bioinformatics tools, we performed a comprehensive analysis of PDE2A gene expression in multiple human cancers. Our study revealed that PDE2A expression was significantly reduced in the majority of cancer types and clinicopathological stages (I to IV) compared to normal tissues. Additionally, PDE2A expression was closely related to the prognosis of cancers such as stomach adenocarcinoma (STAD), ovarian serous cystadenocarcinoma (OV), and liver hepatocellular carcinoma (LIHC). Cox regression analyses indicated that PDE2A can act as an independent prognostic factor for these cancers. The level of PDE2A DNA methylation was significantly decreased in most cancers. Genetic alterations in PDE2A predominantly manifest in the form of amplifications. Moreover, infiltrating cells and immune checkpoint genes, including PDCD1, exhibited notable correlations with PDE2A expression. Significant associations were observed between PDE2A expression and tumor mutation burden as well as microsatellite instability. Single cell sequencing revealed PDE2A's crucial role in regulating differentiation and angiogenesis of cancer cells. Functional enrichment analysis emphasized the important role of PDE2A in synaptic transmission and tumor development. Aberrant expression of PDE2A influenced the sensitivity of various antitumor and chemotherapy drugs. This research provided a comprehensive analysis of PDE2A in human cancers, highlighting its potential as both a prognostic marker and an immunotherapy target for future research.

Both embryonic stem cells (ESCs) and the successful reprogramming of induced pluripotent stem cells (iPSCs) offer an unprecedented therapeutic potential for Parkinson's disease (PD), allowing for the replacement of depleted neurons in PD-affected brain regions, thereby achieving therapeutic goals. This study explored the differences in cell types between iPSCs and ESCs in the PD brain to provide a feasible theoretical basis for the improved use of iPSCs as a replacement for ESCs in treating PD. Signal cell RNA sequencing data and microarray data of ESCs and iPSCs were collected from the GEO database. scRNA-seq data were subjected to quality control, clustering, and identification using the Seurat R package to determine cell types and proportions in ESCs and iPSCs. Differential expression analysis was performed to identify differentially expressed genes between ESCs and iPSCs, and PPI network analysis was conducted using String. Based on scRNA-seq data, we identified 13 cell clusters in ESCs and 13 cell clusters in iPSCs. iPSCs were predominantly composed of immune cells and lacked astrocytes, neurons, and dopamine neurons compared to ESCs. iPSCs also exhibited lower cell type diversity compared to ESCs. At the gene level, iPSCs lacked key genes, such as TH and GAP43 for nerve growth and development. At the metabolic level, the difference between ESCs and iPSC was mainly reflected in nerve cells and was closely related to the tumor-proliferation signature. iPSCs can be promoted to differentiate into cell types closer to or even replace ESCs, providing a better therapeutic option for PD treatment.

Chronobiology and sleep medicine are pivotal disciplines for understanding human health. Additionally, the lack of training in medical schools exacerbates the underdiagnosis and undertreatment of sleep disorders. This study investigated the exposure of Brazilian medical students to chronobiology and sleep medicine during their undergraduate education and assessed their knowledge in these areas. The study was conducted between December 2021 and June 2022 through the administration of an online questionnaire (Google Forms) to medical students in the final two years of undergraduate studies. The questionnaire gathered student data (i.e., sex, age, and educational institution), research data (stage in the medical program with exposure to chronobiology or sleep medicine), and responses to a questionnaire on basic knowledge of sleep medicine and chronobiology (adapted from Assessing Sleep Knowledge in Medical Education - ASKME). A total of 240 students from medical schools in Brazil participated, 4.6% of whom reported no exposure to either subject, with exposure declining as students progressed through the curriculum. Only 3.7% reported specific disciplines covering these topics. Over half of the students encountered learning barriers, such as limited curriculum time. Despite these challenges, the accuracy rate in responses regarding chronobiology and sleep medicine was 79.75%, positively correlating with exposure level and knowledge retention. This study underscores the urgent need for enhanced education in sleep medicine and chronobiology within Brazilian medical schools. It offers insights into the current landscape of sleep medicine education in Brazil and lays groundwork for future efforts to integrate these essential subjects into medical school curricula.

[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.