Brazilian Journal of Medical and Biological Research最新文献

Endometrial cancer (EC) is the most common pelvic gynecologic malignancy in developed countries, and its incidence is also increasing in developing countries. Endometrioid endometrial carcinoma (EEC) is the most frequent subtype. EEC is often associated with favorable clinicopathological features and a good prognosis, especially when diagnosed in stage I. Although some patients have no signs to predict locally advanced or metastatic disease, they may present tumor relapse in the future. There is no biomarker capable of predicting the relapse of stage I EEC. The present study applied a transcriptome analysis to identify differentially expressed genes in stage I EEC, comparing relapsed with non-relapsed tumors. The estrogen receptor 1 gene (ESR1) was overexpressed in EEC stage I samples from patients who developed relapse by 4.3-fold compared to non-relapsed tumors. Subsequently, an independent set of 64 stage I EEC samples was used to validate ESR1 gene overexpression in relapsed tumors and assess estrogen receptor alpha (ERα) protein levels. ESR1 was confirmed to be overexpressed in samples from relapsed tumors, and its expression level was an independent prognostic variable for disease-free (hazard ratio=7.25) and overall survival (hazard ratio=5.15). In contrast, Erα did not show different values between relapsed and non-relapsed tumors. We concluded that ESR1 overexpression is a biomarker for poor prognosis in stage I EEC.

The primary objective of the present study was to identify differentially expressed genes (DEGs) associated with castration-resistant prostate cancer (CRPC) to verify the potential mechanism of CRPC progression. DEGs from CRPC datasets were filtered with a P<0.05 and Spearman correlation coefficient ≥0.3. Serpin peptidase inhibitor, clade A member 3 (SERPINA3), was uniquely present in three CRPC datasets, and its low expression in CRPC was confirmed in cell lines and tissues. Colony formation, transwell assays, and subcutaneous tumor formation experiments in mice demonstrated that overexpression of SERPINA3 may significantly inhibit the proliferation and invasion of PC3 cells. Mechanistic studies revealed that, in prostate cancer (PCa), SERPINA3 can activate the interleukin (IL)-17 and tumor necrosis factor (TNF)α signaling pathways by promoting the expression of CXC chemokine ligand 2 (CXCL2), thereby increasing the recruitment of M1 macrophages into the tumor microenvironment and inhibiting the progression of PCa. The current results indicated that the expression of SERPINA3 may be negatively correlated with CRPC, and it could promote the M1 polarization of macrophages and inhibit the progression of CRPC by increasing the expression of CXCL2.

The aim of this study was to explore sex differences in neuromuscular fatigue during a severe-intensity cycling exercise. Twenty-four healthy participants (12 women and 12 men) cycled at 80% of the difference between gas exchange threshold and maximal power output to the limit of tolerance. Neuromuscular fatigue was assessed by the decrease in maximal voluntary contraction of the knee extensors before and after exercise, and central and peripheral fatigue was measured by the decrease in voluntary activation and quadriceps potentiated twitch force before and after exercise. Women presented shorter time to task failure (P=0.025) and lower levels of neuromuscular fatigue (P=0.006) and peripheral fatigue (P<0.001) than men. Women and men showed different patterns of muscle activation during exercise, with women presenting greater muscle activation at the beginning of exercise and sustaining this elevated muscle activation throughout exercise, while men increased muscle activation from the beginning to the end of exercise. In conclusion, women had lower levels of neuromuscular fatigue, mainly caused by lower levels of peripheral fatigue, and a different muscle activation pattern in an exhaustive severe-intensity cycling exercise.

Bladder cancer is the most prevalent malignancy of the urinary tract, with significant advancements in treatment achieved over recent decades. Nonetheless, the immunological mechanisms underlying bladder cancer progression remain elusive, and only a limited number of patients derive benefit from current immune checkpoint inhibitors. Here, we conducted a single-cell RNA sequencing analysis of 44,022 cells from peripheral blood mononuclear cell samples of bladder cancer patients and a healthy donor. Our findings indicated that the proportions of T cells and neutrophils are higher in bladder cancer patients than in the healthy donor. LAG3, HAVCR2, and CTLA4 had elevated expression levels in CD8-T2-GZMK cell clusters from patients. CD8-T7-STMN1 cells highly expressed ITGAE, CD38, and STMN1. Furthermore, NK3-CMC1, more prevalent in patients, showed a high expression of TIGIT. Additionally, Bcell2-TCL1A and Bcell3-MS4A1 were characterized by the high expression of inhibitory receptor marker genes. Gene set variation analysis suggested that Mono4-THBS1 may play a role in promoting tumor hypoxia and angiogenesis. Neu-FCGR3B exhibited high levels of IL4R and CD274 expression. Our study indicated that LAG-3 and TIM-3 may serve as novel potential immune checkpoint inhibitors in bladder cancer treatment. The phenotypes of NK3-CMC1, Bcell2-TCL1A, and Bcell3-MS4A1 might be altered by tumor progression. Mono4-THBS1 could potentially be a source of tumor-enriched monocyte-like cells. Neu-FCGR3B may play a detrimental role in the anti-tumor response and could emerge as a predictive marker for bladder cancer. Overall, these high-resolution transcriptomic data offer invaluable insights for identifying new therapeutic targets and biomarkers in bladder cancer immunotherapy.

The objective of the present study was to compare and test the applicability of different protocols for accessing aerobic capacity in Sprague Dawley rats using treadmill running. Fifteen 70-day-old adult Sprague Dawley rats (270-290 g) were used. After 5 days of adaptation to the treadmill, the animals underwent 7 days of evaluations with a 48-h interval between each protocol. On the first two days, they underwent, in random order, a graded exercise test, with (GXT2) or without (GXT1) blood sample collections to determine blood lactate concentrations and the anaerobic threshold. In the subsequent 4 days, they underwent continuous 30-min efforts to determine the maximal lactate steady state (MLSS) with the intensity prescribed in percentages of the maximum speed (MaxS) obtained in GXT1, and on the last day they underwent the minimum lactate (ML) protocol. The MaxS obtained in GXT2 was higher than in GXT1, and there was a moderate correlation (r=0.614, P=0.011) between them. In many cases, lactate and glucose blood concentrations did not show the expected kinetics, making aerobic capacity determination impossible using these protocols. MLSS showed a higher success rate compared to other protocols (MLSS=80%; GXT2=47%; ML=60%). In conclusion, with the MLSS protocol, it is only possible to measure time to exhaustion at each intensity, which does not exactly reflect aerobic capacity, and the use of blood lactate and glucose concentrations to evaluate the aerobic capacity of rats in incremental and ML treadmill running protocols is still discouraged.

Immune checkpoint blockade with anti-programmed cell death protein 1 (PD-1) antibody has become a hot topic for the treatment of human malignancies. Here, we aimed to investigate whether the percentage of PD-1 in CD8+ tumor-infiltrating lymphocytes correlates with the progression of colonic-derived peritoneal adenocarcinoma (PA). Peripheral blood and tissue samples from 40 patients with colonic-derived PA were collected and subjected to multicolor flow cytometry analysis of the percentage of peripheral PD-1+CD8+ T cells. The multiple immunofluorescence method was used to detect the positive percentages of PD-1 and CD8 in the tissues. The enrolled patients were divided into groups by recurrence interval (less than 6 months, greater than two years) and differentiation grade (low, well/moderate). In the colonic-derived PA tissues, the percentages of cells positive for PD-1, CD8, and PD-1+CD8+ were higher in the paracancer tissues compared with cancerous tissues. PD-1+CD8+ T cells had an increased presence in peripheral blood than in tissues. Our data also indicated that colonic-derived PA patients with less than a six-month recurrence interval presented higher levels of PD-1 in CD8+ tumor-infiltrating lymphocytes in than the two-year recurrence group. The level of PD-1+CD8+T cells in the tissue correlated with the clinical outcome of colonic-derived PA. Higher percentages of PD-1+CD8+T cells correlated with a shorter progression-free survival (PFS). PD-1 in CD8+ tumor-infiltrating lymphocytes may have a good predictive value for immunotherapy of colonic-derived PA and act as the prognostic factor for PFS.

Oral tolerance is an immunological phenomenon that results from protein intake and that has systemic effects on inflammation. Previous research has shown that parenteral injection of tolerated proteins reduces inflammatory infiltrate and improves skin wound healing. Herein, we tested whether the injection of tolerated proteins improves the healing of several wounds on different parts of the body, such as on the skin of the back and on the external ear (the auricle). To induce oral tolerance to ovalbumin (OVA), eight-week old C57BL/6 mice drank egg white diluted 1:5 in water for 3 consecutive days. The control mice drank water. Seven days after oral treatment, mice were submitted to excisional injuries on the skin of the back (6 mm) and ears (4 mm). Minutes before the injuries, the mice received an intraperitoneal injection of OVA + Al(OH)3. Seven and 40 days after the injuries, tissue samples were collected and processed for histological analysis of the wounds. The results showed that the injection of OVA in animals that drank OVA reduced the inflammatory infiltrate in all lesions. In addition, injection of OVA in animals that drank OVA promoted better organization of the extracellular matrix, with thicker and intertwined collagen fibers in the neodermis, resulting in smaller scars on the skin. Furthermore, the healing area of the ears of OVA-tolerant animals showed chondrocyte aggregates and less obvious fibrous scar tissue compared with control animals. In conclusion, systemic effects of oral tolerance positively influenced the healing of several lesions on different parts of the body.

Oleanolic acid (OA) is recognized for its anticancer properties, which are similar to those of conventional chemotherapeutic agents used in clinical practice. However, its role in modulating the sensitivity of cancer cells to fluorouracil (5FU) has not yet been documented. This study aimed to examine the effects of OA and 5FU co-administration on hepatocellular carcinoma (HCC) and uncover the mechanisms involved. In this study, the efficacy of combination therapy with OA and 5FU in treating HCC was evaluated using the MTT cell proliferation assay, plate clone formation assay, Hoechst 33342 staining, western blot assay, and Ca2+ fluorescence probe. The results demonstrated that compared with the use of OA or 5FU alone, OA and 5FU combination therapy significantly inhibited the proliferation of HEPG2 cells and enhanced cell apoptosis and Ca2+ levels in HCC. Additionally, the inhibitory effect of OA and 5FU combination therapy on cell proliferation and apoptosis was partially reversed by the calcium channel blocker 2-aminoethyldiphenyl borate (2-APB). In summary, these findings indicated that synergistic treatment with OA and 5FU can enhance cell apoptosis, inhibit cell proliferation, and regulate Ca2+ signaling in HCC, providing new guidance for the clinical treatment of HCC.

Liraglutide (LIRA) is an agonist of the GLP-1 receptor used in the treatment of type 2 diabetes with a cardioprotective effect, although little is known about the effects of LIRA in post-menopause. We aimed to evaluate the effects of LIRA in the cardiovascular system of ovariectomized spontaneously hypertensive rats (SHR). SHR rats were separated into two groups: ovariectomized (saline) and ovariectomized + liraglutide (0.6 and 1.2 mg/kg for 4+4 weeks, respectively). Systolic blood pressure (SBP) was indirectly evaluated at the beginning and end of treatment. Diastolic, systolic, and mean blood pressure were evaluated in the carotid artery of anesthetized animals, while left ventricle systolic blood pressure (LVSBP) and left ventricle derivatives (-dP/dt; +dP/dt) were evaluated in the left ventricle. An oral glucose tolerance test (GTT) was conducted. Antioxidant enzymes and calcium-handling proteins were analyzed in heart tissue by western blot. Treatment with LIRA increased the expression of antioxidant enzymes (superoxide dismutase (SOD2) and catalase). No changes were observed in the GTT, cardiac hemodynamics, blood pressure, and calcium-handling protein expression. A decrease in visceral fat depot was observed without changes in final body weight. LIRA induced an antioxidant subclinical effect in ovariectomized SHR female rats without changing glucose metabolism and cardiac blood pressure.

Axons of dopaminergic neurons projecting from substantia nigra to striatum are severely affected in the early stage of Parkinson's disease (PD), with axonal degeneration preceding the loss of cell bodies. Our previous study indicated that the dysfunctional retrograde axonal transport could lead to the death of dopaminergic neurons resulting in PD (10.1111/j.1471-4159.2008.05526.x). However, dynein, as the main molecule involved in retrograde axonal transport, was not affected. This study aimed to verify the hypothesis that dynactin rather than dynein may be one of the key factors in the retrograde degeneration of dopaminergic neurons in the early stage of PD. Dynactin morpholino was used to inhibit the expression of dynactin in transgenic (Vmat2:GFP) zebrafish, resulting in a significant decrease of diencephalon dopamine neurons and synuclein aggregation in the basal plate region. In the dopaminergic SH-SY5Y cell line, dynactin-siRNA knockdown resulted in the expression of dynein shifting from dispersed distribution to concentration in synapses and cytoplasm near axons, and the fusion rate of dynein to dynactin was decreased, especially in axons, which blocked the retrograde axonal transport of α-synuclein and autophagy flow. Our results linked the knockdown of dynactin gene to the dysfunction of axonal microtubule transport system, suggesting that dynactin may be one of the key factors contributing to the retrograde degeneration of dopaminergic neurons in the early stage of PD.