RESUMO
Lung cancer patients with COVID-19 present an increased risk of developing severe disease and, consequently, have poor outcomes. Determining SARS-CoV-2-host interactome in lung cancer cells and tissues, infected or uninfected with SARS-CoV-2, may reveal molecular mechanisms associated with COVID-19 development and severity in lung cancer patients. Here, we integrated transcriptome data of lung tumors from patients with small- or non-small cell lung cancer (SCLC and NSCLC) and normal lung and lung cancer cells infected with SARS-CoV-2. We aimed to characterize molecular mechanisms potentially associated with COVID-19 development and severity in lung cancer patients and to predict the SARS-CoV-2-host cell interactome. We found that the gene expression profiles of lung cell lines infected with SARS-CoV-2 resemble more primary lung tumors than non-malignant lung tissues. In addition, the transcriptomic-based interactome analysis of SCLC and NSCLC revealed increased expression of cancer genes BRCA1 and CENPF, whose proteins are known or predicted to interact with the SARS-CoV-2 spike glycoprotein and helicase, respectively. We also found that TRIB3, a gene coding a putative host-SARS-CoV-2 interacting protein associated with COVID-19 infection, is co-expressed with the up-regulated genes MTHFD2, ADM2, and GPT2 in all tested conditions. Our analysis identified biological processes such as amino acid metabolism and angiogenesis and 22 host mediators of SARS-CoV-2 infection and replication that may contribute to the development and severity of COVID-19 in lung cancers.
Assuntos
COVID-19 , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Transcriptoma , Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , COVID-19/genética , COVID-19/patologia , Pulmão/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , SARS-CoV-2RESUMO
It has long been hypothesized that hydrogen peroxide (H2O2) may play an essential role in root-to-shoot long-distance signaling during drought conditions. Thus, to better understand the involvement of H2O2 in drought signaling, two experiments were carried out using tomato plants. In the first experiment, a split-root scheme was used, while in the second experiment, the tomato plants were grown in a single pot and subjected to drought stress. In both experiments, H2O2 and catalase were applied together with irrigation. Control plants continued to be irrigated according to the water loss. In the split-root experiment, it was verified that the application of H2O2 to roots induced a clear reduction in plant transpiration compared to untreated or catalase-treated plants. In the second experiment, we observed that H2O2-treated plants exhibited similar transpiration when compared to untreated and catalase-treated plants under drought stress. Similarly, no difference in water use efficiency was observed. Thus, we conclude that the increase in H2O2 in the root system can act as a long-distance signal leading to reduced transpiration even when there is no water limitation in the shoot. But it has little effect when there is a reduction in the shoot water potential.
Assuntos
Secas , Solanum lycopersicum , Peróxido de Hidrogênio/farmacologia , Catalase , Plantas , Estresse FisiológicoRESUMO
Our objectives were to investigate potential changes in the size of steroidogenic large luteal cells (LLC) during partial luteolysis induced by a sub-dose of cloprostenol in early diestrus and to determine transcriptional variations in genes involved in corpus luteum (CL) functions. Cows were subjected to an Ovsynch protocol, with the time of the second GnRH treatment defined as Day 0 (D0). On D6, cows were randomly allocated into three treatments: Control (2 mL saline, im; n = 10), 2XPGF (two doses of 500 µg of cloprostenol, im, 2 h apart; n = 8) or 1/6PGF (single dose of 83.3 µg of cloprostenol, im; n = 10). Before treatments and every 8 h during the 48-h experimental period, blood samples were collected and CL volumes measured. Furthermore, two CL biopsies were obtained at 24 and 40 h post-treatment. The 1/6PGF treatment caused partial luteolysis, characterized by sudden decreases in plasma progesterone (P4) concentrations, luteal volume and LLC size, followed by increases (to pretreatment values) in P4 and luteal volume at 24 and 40 h post-treatment, respectively. However, at the end of the study, P4, luteal volume and LLC size were all significantly smaller than in Control cows. Temporally associated with these phenotypes, there was a lower mRNA abundance of VEGFA at 24 and 40 h, and ABCA1 at 24 h (P < 0.05). In conclusion, a sudden reduction in CL size during partial luteolysis induced by a sub-dose of PGF2α analog on day 6 of the estrous cycle was attributed to a reduction in LLC size, although these changes did not account for the entire phenomenon. In addition to its involvement in reducing CL size, decreased VEGFA mRNA abundance impaired CL development, resulting in a smaller luteal gland and lower plasma P4 concentrations compared to Control cows.
Assuntos
Células Lúteas , Luteólise , Animais , Bovinos , Corpo Lúteo , Diestro , Dinoprosta , Feminino , ProgesteronaRESUMO
CLINICAL RELEVANCE: The photo-initiator system based on an advanced polymerization system may be an alternative that can be used to overcome the disadvantages of radicular dentin, especially for the apical third. SUMMARY: Objectives: The purpose of this study was to evaluate the effects of universal adhesives with different photo-initiator systems applied in etch-and-rinse (ER) and self-etch (SE) modes on dentin interaction (push-out bond strength [PBS], nanoleakage [NL], and degree of conversion [DC] within the hybrid layer) in the different root thirds after fiber post cementation.Methods and Materials: Roots of endodontically prepared human premolars were randomly divided into six groups according to one of three adhesive systems (Scotchbond Universal [SBU], Ambar Universal [AMB], and Ambar Universal APS [AMB-APS]) and two adhesive strategies (ER and SE) for each system. Posts were cemented, and PBS was tested at 0.5 mm/min. The NL was evaluated by scanning electron microscopy. DC was measured using micro-Raman spectroscopy. The data were analyzed by three-way analysis of variance and Tukey tests (α=0.05).Results: AMB-APS showed similar performance in all root thirds (p>0.05) and higher values of DC, especially in the apical third (p<0.0001). AMB and SBU showed the lowest values in the apical third (p<0.0001).Conclusions: The APS photo-initiator system contained in universal adhesives is a feasible alternative for improving radicular bonding procedure.
Assuntos
Colagem Dentária , Adesivos Dentinários , Adesivos , Bis-Fenol A-Glicidil Metacrilato , Cimentos Dentários , Dentina , Humanos , Teste de Materiais , Cimentos de Resina , Resistência à TraçãoRESUMO
Heat stress (HS) has deleterious effects on bovine reproduction, including prolongation of the luteal phase in Holstein cows, perhaps due to compromised luteolysis. The objective was to characterize effects of HS on luteolytic responses of nonlactating Holstein cows given 25 or 12.5 mg of PGF2α on d 7 of the estrous cycle. Cows were randomly distributed into 2 environments: thermoneutral (n = 12; 25°C) or HS (n = 12; 36°C). In each environment, cows were treated with 2 mL of saline, 25 or 12.5 mg of PGF2α (n = 4 cows per group). The HS environment induced a significant increase in rectal temperature and respiratory rate compared with the thermoneutral environment. Heat stress did not have significant effects on luteolytic responses or circulating progesterone concentrations. Rapid and complete luteolysis occurred in all cows given 25 mg of PGF2α and in 4 of 8 cows given 12.5 mg; the other 4 cows given 12.5 mg had partial luteolysis, with circulating progesterone concentrations initially suppressed, but subsequently rebounding. Therefore, we conclude that HS does not change corpus luteum sensitivity to PGF2α.
Assuntos
Bovinos/fisiologia , Corpo Lúteo/efeitos dos fármacos , Dinoprosta/farmacologia , Resposta ao Choque Térmico , Luteólise/efeitos dos fármacos , Animais , Ciclo Estral/efeitos dos fármacos , Feminino , Temperatura Alta , Ocitócicos/farmacologia , Progesterona/farmacologiaRESUMO
This study diagnosed cutaneous wart lesions excised from three rams from a sheep farm in São Paulo State, Brazil. Histopathologically, these cases were diagnosed as papilloma. The amplification by PCR, sequencing and bioinformatics analysis showed that all the lesions presented DNA sequences of bovine papillomavirus type 2. This is the first report confirming the detection of BPV2 in papilloma warts from ovines.
Assuntos
Papillomavirus Bovino 1/isolamento & purificação , Infecções por Papillomavirus/veterinária , Doenças dos Ovinos/virologia , Verrugas/veterinária , Animais , Sequência de Bases , Papillomavirus Bovino 1/genética , Brasil , DNA Viral/genética , Genoma Viral/genética , Masculino , Dados de Sequência Molecular , Papiloma/patologia , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase/veterinária , Ovinos , Verrugas/virologiaRESUMO
AIM: To evaluate, ex vivo, the influence of glass fibre post length and remaining thickness of dentine on the fracture resistance of bovine roots, after thermomechanical ageing. METHODOLOGY: Ninety bovine roots of the same size were root filled and randomly distributed into nine groups (n = 10), according to the root weakening protocol (NW - nonweakened; MW - medium weakened; HW - highly weakened) and post length (7 mm; 9 mm and 12 mm). The weakening of roots was performed using diamond burs, resulting in different thicknesses of remaining dentine. The post spaces were prepared, and in the weakened roots, the glass fibre posts were customized with composite resin, to create posts matching the canal size. Chemically activated resin cement was used to lute the posts. After luting, full crowns made of composite resin were attached to a silicon matrix. To reproduce physiological mobility, the roots were covered with polyether and embedded in polyurethane. The thermomechanical cycling was performed (1 200 000 cycles; 88N; 3,8 Hz; 5 ± 1 °C to 55 ± 1 °C). Then, the specimens were subjected to compressive force in a universal testing machine (1 mm min-1 ; 100 kgf) to analyse the fracture resistance. The specimens were analysed through a stereomicroscope to classify the failure mode (repairable/catastrophic). The values were subjected to statistical analysis (two-way anova and Tukey's test at 5%). The frequencies of failure mode were compared using chi-square test. RESULTS: The association between length and dentine thickness was significant (P > 0.05). The difference was between NW and HW roots for posts of 12 mm in length. There was an association between failure mode and the length and remaining dentine thickness. CONCLUSIONS: Reduced dentine thickness in roots with longer posts had lower fracture resistance values, as catastrophic failure was more predominant.
Assuntos
Dentina/patologia , Técnica para Retentor Intrarradicular , Obturação do Canal Radicular/métodos , Fraturas dos Dentes/prevenção & controle , Animais , Bovinos , Análise do Estresse Dentário , Vidro , Incisivo/lesões , Incisivo/cirurgia , Técnica para Retentor Intrarradicular/efeitos adversos , Obturação do Canal Radicular/efeitos adversos , Fraturas dos Dentes/etiologia , Raiz Dentária/lesões , Raiz Dentária/cirurgiaRESUMO
Bovine papillomavirus (BPV) is an oncogenic virus with mucous and epithelial tropism. Possible productive virus infection in other tissues, such as blood, has been hypothesized. In order to investigate this possibility, three samples of skin papillomas and blood were collected from bovines with BPV infection and five samples of peripheral blood and one sample of normal tissue were collected from a calf without BPV infection. Peripheral blood mononuclear cells (PBMCs) were isolated from whole blood and examined by reverse transcription-polymerase chain reaction, immunofluorescence, in situ hybridization, and electron microscopy. The tissue samples were examined for histopathological and immunohistochemical features. The skin papillomas showed the presence of DNA sequences of BPV-2, BPV-11, and a putative virus type. The blood samples showed DNA sequences of BPV-1, 2, and 4 simultaneously. Immunohistochemistry showed BPV L1 protein in both epithelium and stroma and BPV E2 protein in koilocytes. In situ hybridization confirmed the presence of BPV DNA in PBMCs and immunofluorescence showed nuclear labeling of E2 and L1 BPV proteins in PBMCs. The transcription analysis revealed transcripts of BPV-1 L1, BPV-2 L2, and BPV-4 E7 in blood and papilloma samples of BPV-infected cattle. The comet assay revealed high levels of host cell DNA damage upon BPV infection. Electron microscopy analysis of PBMCs identified the presence of particles in the cytoplasm that are consistent with papillomavirus in size and shape. The productive infection of PBMCs with BPV has been previously discussed and this study provides evidence indicating that PBMCs are a target of BPV.
Assuntos
Papillomavirus Bovino 1/isolamento & purificação , Monócitos/virologia , Papiloma/veterinária , Neoplasias Cutâneas/veterinária , Animais , Papillomavirus Bovino 1/patogenicidade , Bovinos , Epitélio/virologia , Papiloma/sangue , Papiloma/virologia , Neoplasias Cutâneas/sangue , Neoplasias Cutâneas/virologiaRESUMO
The bovine papillomavirus (BPV) causes papillomas that regress spontaneously, but can also progress to malignancy. This study evaluated the role of BPV in oncogenesis. Twenty-four samples from uninfected calves and the papillomas of BPV infected cattle were subjected to molecular diagnosis, as well as histopathological and immunohistochemical analyses. The comet assay (CA) was used to evaluate the clastogenic potential of BPV. The results confirmed the presence of BPV-2, 3, 5, and 9 in infected samples. Histopathological analysis revealed acanthosis, koilocytosis, hypergranulosis, hyperkeratosis, and transformed fibroblasts.E7 and L1 BPV proteins were detected in the epithelium, as well as in the connective tissues, indicating productive infection at different sites. CA results showed that BPV-2, 5, and 9 exhibit the same level of clastogenicity. These findings support the oncogenic action of BPV in establishing a favorable microenvironment for oncogenesis.
Assuntos
Doenças dos Bovinos/patologia , Doenças dos Bovinos/virologia , Papillomaviridae/genética , Infecções por Papillomavirus/veterinária , Animais , Papillomavirus Bovino 1/classificação , Papillomavirus Bovino 1/genética , Carcinogênese , Bovinos , Ensaio Cometa , DNA Viral/genética , Papillomaviridae/classificação , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologiaRESUMO
The bovine papillomavirus (BPV) is the etiological agent of bovine papillomatosis, which causes significant economic losses to livestock, characterized by the presence of papillomas that regress spontaneously or persist and progress to malignancy. Currently, there are 13 types of BPVs described in the literature as well as 32 putative new types. This study aimed to isolate viral particles of BPV from skin papillomas, using a novel viral isolation method. The virus types were previously identified with new primers designed. 77 cutaneous papilloma samples of 27 animals, Simmental breed, were surgically removed. The DNA was extracted and subjected to PCR using Delta-Epsilon and Xi primers. The bands were purified and sequenced. The sequences were analyzed using software and compared to the GenBank database, by BLAST tool. The viral typing showed a prevalence of BPV-2 in 81.81% of samples. It was also detected the presence of the putative new virus type BR/UEL2 in one sample. Virus isolation was performed by ultracentrifugation in a single density of cesium chloride. The method of virus isolation is less laborious than those previously described, allowing the isolation of complete virus particles of BPV-2.
Assuntos
Doenças dos Bovinos/diagnóstico , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/veterinária , Ultracentrifugação/métodos , Virologia/métodos , Animais , Bovinos , Doenças dos Bovinos/virologia , DNA Viral/química , DNA Viral/genética , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Pele/virologia , Vírion/genética , Vírion/isolamento & purificaçãoRESUMO
Bovine papillomavirus (BPV) is an oncogenic virus associated with benign and malignant lesions, which result in notable economic losses. Peripheral blood samples and cutaneous papillomas were obtained from four adult beef cattle. Viral molecular identification was performed using specific primers for BPV-1, -2 and -4 in blood diagnosis and FAP59/FAP64 for skin papillomas. Histopathologic examination was done as a complementary and differential diagnosis. The fragments were purified, sequenced, and compared using BLASTn. The blood diagnosis showed the presence of BPV-2 and the analysis of cutaneous papillomas showed the presence of BPV-4, a new putative virus type BAPV8, and BPV-12, revealing for the first time the presence of BPV-12 and the putative type BAPV8 in beef cattle in Brazil. The sequences were deposited in the GenBank. Histopathology revealed acanthosis, hyperkeratosis, and koilocytosis in all samples analyzed. The presence of BAPV8 and BPV-12 in Brazil emphasizes the ubiquitous dissemination of BPVs in the herds of Brazil.
Assuntos
Doenças dos Bovinos/virologia , Papillomaviridae/genética , Infecções por Papillomavirus/veterinária , Animais , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/patologia , DNA Viral/genética , Dados de Sequência Molecular , Papillomaviridae/classificação , Filogenia , Pele/patologia , Pele/virologiaRESUMO
Bovine papillomaviruses (BPVs) are recognized as causal agents of benign and malignant tumors in cattle. Thirteen types of BPVs have already been described and classified into 3 distinct genera. Divergences in the nucleotide sequence of the L1 gene are used to identify new viral types through the employment of PCR assays with degenerated primers. In the present study, a method for identifying BPVs based on PCR-RFLP and DNA sequencing allowed the identification of a new putative Deltapapillomavirus, designated JN/3SP (JQ280500.1). The analysis of the L1 gene showed that this strain was most closely related to the BPVs -1, -2, -13 , and OaPV1 (71-73% genetic similarity). In this study, we describe the detection of this new putative Deltapapillomavirus type and verify its phylogenetic position within the genus.
Assuntos
Doenças dos Bovinos/virologia , Deltapapillomavirus/genética , Deltapapillomavirus/isolamento & purificação , Filogenia , Sequência de Aminoácidos , Animais , Bovinos , Doenças dos Bovinos/genética , Deltapapillomavirus/classificação , Deltapapillomavirus/patogenicidade , Análise de Sequência de DNARESUMO
THE MAJORITY OF MALIGNANT CELLS PRESENT GENETIC INSTABILITY WITH CHROMOSOME NUMBER CHANGES PLUS SEGMENTAL DEFECTS: these changes involve intact chromosomes and breakage-induced alterations. Some pathways of chromosomal instability have been proposed as random breakage, telomere fusion, and centromere fission. Chromosome alterations in tumor cells have been described in animal models and in vitro experiments. One important question is about possible discrepancies between animal models, in vitro studies, and the real events in cancer cells in vivo. Papillomaviruses are relevant agents in oncogenic processes related to action on host genome. Recently, many reports have discussed the presence of virus DNA in peripheral blood, in humans and in animals infected by papillomaviruses. The meaning of this event is of controversy: possible product of apoptosis occurring in cancer cells, metastasized cancer cells, or active DNA sequences circulating in bloodstream. This study compares chromosome aberrations detected in bovine cells, in peripheral blood cells, and in BPV lesion cells: the literature is poor in this type of study. Comparing chromosome aberrations described in the different cells, a common mechanism in their origin, can be suggested. Furthermore blood cells can be evaluated as an effective way of virus transmission.
RESUMO
Persistent high-risk (HR) human papillomavirus (HPV) infection is necessary for development of precursor lesions and cervical cancer. We investigate persistence and clearance of HPV infections and cofactors in unvaccinated women. Cervical samples of 569 women (18-75 years), received for routine evaluation in the Health Department of Ouro Preto, Brazil, were collected and subjected to PCR (MY09/11 or GP5+/6+ primers), followed by RFLP or sequencing. All women were interviewed to collect sociodemographic and behavioral information. Viral infection persistence or clearance was reevaluated after 24 months and was observed in 59.6% and 40.4% of women, respectively. HPVs 16, 33, 59, 66, 69, and 83 (HR) were the most persistent types whereas HPVs 31, 45, and 58 were less persistent. Clearance or persistence did not differ between groups infected by HPVs 18, 53, and 67. In low-risk (LR) types, HPV 6 infected samples were associated with clearance, while HPV 11, 61, 72, or 81 infected samples were persistent in the follow-up. No statistically significant association was detected between persistent HPV infections and sociodemographic and behavioral characteristics analyzed. To study persistence or clearance in HPV infection allows the identification of risk groups, cofactors, and strategies for prevention of cervical cancer.
Assuntos
Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Adolescente , Adulto , Idoso , Brasil , DNA Viral/isolamento & purificação , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae/classificação , Papillomaviridae/patogenicidade , Infecções por Papillomavirus/virologia , Fatores de Risco , Neoplasias do Colo do Útero/virologiaRESUMO
Bovine papillomavirus (BPV) is an oncogenic virus related to serious livestock diseases. Oncoproteins encoded by BPV are involved in several steps of cellular transformation and have been reported as presenting clastogenic effects in peripheral lymphocytes and primary culture cells. The aim of this study was to evaluate the clastogenic potential of BPV types 1, 2, and 4 by comet assay. Peripheral blood was collected from 37 bovines, 32 infected with different levels of papillomatosis (12 animals have no affection) and five calves, virus free (negative control). The viral identification showed presence of more than one virus type in 59.375% of the infected animals. Comet assay was performed according to alkaline technique. The Kruskal-Wallis test showed statistical difference between the negative control group and infected animals (P = 0.0015). The Dunn post hoc test showed difference comparing the infected animals with calves. Mann-Whitney U test verified no difference between animals infected with only one viral type and animals presenting more than one viral type. The comet assay is considered an efficient tool for assessment of damage in the host chromatin due to viral action, specifically highlighting viral activity in blood cells.
Assuntos
Papillomavirus Bovino 1/isolamento & purificação , Mutagênicos/isolamento & purificação , Proteínas Oncogênicas/isolamento & purificação , Papiloma/genética , Animais , Papillomavirus Bovino 1/genética , Bovinos , Transformação Celular Neoplásica/genética , Ensaio Cometa , Proteínas Oncogênicas/genética , Papiloma/patologia , Papiloma/veterináriaRESUMO
Bovine papillomavirus (BPV) is recognized as a causal agent of benign and malignant tumors in cattle. Thirteen types of BPV are currently characterized and classified into three distinct genera, associated with different pathological outcomes. The described BPV types as well as other putative ones have been demonstrated by molecular biology methods, mainly by the employment of degenerated PCR primers. Specifically, divergences in the nucleotide sequence of the L1 gene are useful for the identification and classification of new papillomavirus types. On the present work, a method based on the PCR-RFLP technique and DNA sequencing was evaluated as a screening tool, allowing for the detection of two relatively rare types of BPV in lesions samples from a six-year-old Holstein dairy cow, chronically affected with cutaneous papillomatosis. These findings point to the dissemination of BPVs with unclear pathogenic potential, since two relatively rare, new described BPV types, which were first characterized in Japan, were also detected in Brazil.
Assuntos
Doenças dos Bovinos/virologia , Coinfecção/veterinária , Deltapapillomavirus/genética , Deltapapillomavirus/isolamento & purificação , Infecções por Papillomavirus/veterinária , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição/genética , Animais , Biópsia , Brasil , Bovinos , Doenças dos Bovinos/genética , Doenças dos Bovinos/patologia , Coinfecção/genética , Coinfecção/patologia , Coinfecção/virologia , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Filogenia , Verrugas/patologia , Verrugas/virologiaRESUMO
Bovine papillomaviruses (BPVs) are recognized as the causal agents of economical relevant diseases in cattle, associated with the development of tumors in skin and mucosa. The oncogenesis process is mainly associated with different viral oncoprotein expressions, which are involved in cell transformation. The expression and characterization of recombinant viral oncoproteins represent an attractive strategy to obtain biotechnological products as antibodies and potential vaccines, Thus, the aim of this work was to clone and express the BPV-1 and BPV-2 E6 recombinant proteins and perform in silico analysis in order to develop a strategy for the systematic study of other papillomaviruses oncoproteins. The results demonstrated that BPV-1 and BPV-2 E6 recombinant proteins were expressed and purified from bacterial system as well as its in silico analysis was performed in order to explore and predict biological characteristics of these proteins.
Assuntos
Clonagem Molecular/métodos , Proteínas Oncogênicas Virais/química , Proteínas Oncogênicas Virais/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Análise de Sequência de Proteína/métodos , Sequência de Aminoácidos , Dados de Sequência Molecular , Proteínas Oncogênicas Virais/biossíntese , Engenharia de Proteínas/métodosRESUMO
The purpose of this study was to determine whether the aerobic training-induced fiber-type transition in different muscles is associated with alterations in NFAT isoforms gene expression. We hypothesized that the aerobic training-induced fiber-type transition would be mediated by NFATc1-c3 isoforms without altering the CaN expression. Male Wistar rats (80 days old) were divided into a trained group (T; n=8) that underwent an 8-wk swimming endurance training program (5 days/week) and a control group (C; n=8). After the experimental period, the animals were sacrificed, and the soleus (SOL) and plantaris (PL) muscles were collected for morphometrical, histochemical and molecular analyses. Aerobic training induced a type I-to-type IIA fiber transition in the SOL muscle and a type IIB-to-type IIA fiber transition in the PL muscle, which were concomitant with a significant (p<0.05) increase in NFATc1-c3 gene expression in both the SOL and PL muscles. In contrast, the expression levels of calcineurin (CaN) and NFATc4 remained unchanged. Therefore, our results showed that fiber type switching induced by aerobic training is mediated by NFATc1-c3 isoforms without altering the CaN expression.
Assuntos
Calcineurina/metabolismo , Fibras Musculares de Contração Rápida/metabolismo , Fibras Musculares de Contração Lenta/metabolismo , Fatores de Transcrição NFATC/metabolismo , Natação/fisiologia , Animais , Biomarcadores/metabolismo , Masculino , Cadeias Pesadas de Miosina/metabolismo , Resistência Física/fisiologia , Isoformas de Proteínas/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Although skeletal muscle atrophy and changes in myosin heavy chain (MyHC) isoforms have often been observed during heart failure, their pathophysiological mechanisms are not completely defined. In this study we tested the hypothesis that skeletal muscle phenotype changes are related to myogenic regulatory factors and myostatin/follistatin expression in spontaneously hypertensive rats (SHR) with heart failure. METHODS: After developing tachypnea, SHR were subjected to transthoracic echocardiogram. Pathological evidence of heart failure was assessed during euthanasia. Age-matched Wistar-Kyoto (WKY) rats were used as controls. Soleus muscle morphometry was analyzed in histological sections, and MyHC isoforms evaluated by electrophoresis. Protein levels were assessed by Western blotting. STATISTICAL ANALYSIS: Student'st test and Pearson correlation. RESULTS: All SHR presented right ventricular hypertrophy and seven had pleuropericardial effusion. Echocardiographic evaluation showed dilation in the left chambers and left ventricular hypertrophy with systolic and diastolic dysfunction in SHR. Soleus weight and fiber cross sectional areas were lower (WKY 3615 ± 412; SHR 2035 ± 224 µm(2); P<0.001), and collagen fractional volume was higher in SHR. The relative amount of type I MyHC isoform was increased in SHR. Myogenin, myostatin, and follistatin expression was lower and MRF4 levels higher in SHR. Myogenin and follistatin expression positively correlated with fiber cross sectional areas and MRF4 levels positively correlated with I MyHC isoform. CONCLUSION: Reduced myogenin and follistatin expression seems to participate in muscle atrophy while increased MRF4 protein levels can modulate myosin heavy chain isoform shift in skeletal muscle of spontaneously hypertensive rats with heart failure.
Assuntos
Insuficiência Cardíaca/patologia , Músculo Esquelético/patologia , Doenças Musculares/metabolismo , Fatores de Regulação Miogênica/antagonistas & inibidores , Fatores de Regulação Miogênica/biossíntese , Animais , Proteínas Relacionadas à Folistatina/antagonistas & inibidores , Proteínas Relacionadas à Folistatina/biossíntese , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/metabolismo , Masculino , Músculo Esquelético/metabolismo , Atrofia Muscular/genética , Atrofia Muscular/metabolismo , Atrofia Muscular/patologia , Doenças Musculares/genética , Doenças Musculares/patologia , Cadeias Pesadas de Miosina/biossíntese , Cadeias Pesadas de Miosina/genética , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Especificidade da EspécieRESUMO
The purpose of this study was to test the hypothesis that skeletal muscle adaptations induced by long-term resistance training (RT) are associated with increased myogenic regulatory factors (MRF) and insulin-like growth factor-I (IGF-I) mRNA expression in rats skeletal muscle. Male Wistar rats were divided into 4 groups: 8-week control (C8), 8-week trained (T8), 12-week control (C12) and 12-week trained (T12). Trained rats were submitted to a progressive RT program (4 sets of 10-12 repetitions at 65-75% of the 1RM, 3 day/week), using a squat-training apparatus with electric stimulation. Muscle hypertrophy was determined by measurement of muscle fiber cross-sectional area (CSA) of the muscle fibers, and myogenin, MyoD and IGF-I mRNA expression were measured by RT-qPCR. A hypertrophic stabilization occurred between 8 and 12 weeks of RT (control-relative % area increase, T8: 29% vs. T12: 35%; p>0.05) and was accompanied by the stabilization of myogenin (control-relative % increase, T8: 44.8% vs. T12: 37.7%, p>0.05) and MyoD (control-relative % increase, T8: 22.9% vs. T12: 22.3%, p>0.05) mRNA expression and the return of IGF-I mRNA levels to the baseline (control-relative % increase, T8: 30.1% vs. T12: 1.5%, p<0.05). Moreover, there were significant positive correlations between the muscle fiber CSA and mRNA expression for MyoD (r=0.85, p=0.0001), myogenin (r=0.87, p=0.0001), and IGF-I (r=0.88, p=0.0001). The significant (p<0.05) increase in myogenin, MyoD and IGF-I mRNA expression after 8 weeks was not associated with changes in the fiber-type frequency. In addition, there was a type IIX/D-to-IIA fiber conversion at 12 weeks, even with the stabilization of MyoD and myogenin expression and the return of IGF-I levels to baseline. These results indicate a possible interaction between MRFs and IGF-I in the control of muscle hypertrophy during long-term RT and suggest that these factors are involved more in the regulation of muscle mass than in fiber-type conversion.