RESUMO
Physical exercise has profound effects on quality of life and susceptibility to chronic disease; however, the regulation of skeletal muscle function at the molecular level after exercise remains unclear. We tested the hypothesis that the benefits of exercise on muscle function are linked partly to microtraumatic events that result in accumulation of circulating heme. Effective metabolism of heme is controlled by Heme Oxygenase-1 (HO-1, Hmox1), and we find that mouse skeletal muscle-specific HO-1 deletion (Tam-Cre-HSA-Hmox1fl/fl) shifts the proportion of muscle fibers from type IIA to type IIB concomitant with a disruption in mitochondrial content and function. In addition to a significant impairment in running performance and response to exercise training, Tam-Cre-HSA-Hmox1fl/fl mice show remarkable muscle atrophy compared to Hmox1fl/fl controls. Collectively, these data define a role for heme and HO-1 as central regulators in the physiologic response of skeletal muscle to exercise.
Assuntos
Heme Oxigenase-1/genética , Heme/metabolismo , Proteínas de Membrana/genética , Fibras Musculares Esqueléticas/metabolismo , Atrofia Muscular/genética , Condicionamento Físico Animal/fisiologia , 5-Aminolevulinato Sintetase/genética , 5-Aminolevulinato Sintetase/metabolismo , Animais , Ferroquelatase/genética , Ferroquelatase/metabolismo , Regulação da Expressão Gênica , Heme Oxigenase-1/deficiência , Isoenzimas/genética , Isoenzimas/metabolismo , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Masculino , Proteínas de Membrana/deficiência , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Atrofia Muscular/metabolismo , Atrofia Muscular/fisiopatologia , Proteína MyoD/genética , Proteína MyoD/metabolismo , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Transdução de Sinais , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
The aim of this study was to characterize the breast meat of turkeys affected by different degrees of severity (normal [NORM], moderate [MOD], and severe [SEV]) of the white striping (WS) myopathy, as well as to evaluate the influence of this myopathy on meat quality. Twenty-nine samples of the pectoralis major muscles of each treatment were obtained from Nicholas breed male and female turkeys, reared and slaughtered in the center-west region of Brazil. The whole breasts of the turkeys were used for macroscopic classification, weight evaluation, and morphometric measurements. Then, the pectoralis major muscle was separated for histological evaluation and qualitative physicochemical analyses, namely ventral and dorsal color (L∗, a∗, and b∗), pH value, water holding capacity (WHC), cooking loss (CL), shear force (SF) (Meullenet-Owens Razor Shear [MORS] and Warner-Bratzler), sarcomere length, total, soluble, and insoluble collagen contents, proximate composition (protein, lipids, moisture, and ash), cholesterol content, and fatty acid profile. The results showed that muscles affected by myopathy, both MOD and SEV, exhibited larger weights (around 2.8 kg) compared to NORM muscles (1.3 kg) and a significant increase (P < 0.05) in the diameter of the fibers. The increase in the degree of severity of the myopathy increased (P < 0.05) the value of L∗ of the dorsal part and ventral part of the muscle. No differences (P > 0.05) were observed in the pH, CL, and WHC values of the muscles, whereas the MORS and Warner-Bratzler SF of the SEV fillets resulted in significantly lower shear values (P < 0.05) compared to the NORM fillets. In addition, the MOD and SEV fillets presented lower values of protein (P < 0.05) than NORM fillets. No significant differences (P > 0.05) were observed for moisture and lipid and cholesterol contents. Meat with MOD and SEV severity of WS myopathy had higher (P < 0.05) concentrations of total and insoluble collagen. Thus, the presence of WS myopathy in MOD and SEV degrees affected a large part of the histological and quality characteristics evaluated.
Assuntos
Doenças Musculares , Perus , Animais , Brasil , Galinhas , Feminino , Masculino , Carne/análise , Doenças Musculares/etiologia , Doenças Musculares/veterinária , Músculos PeitoraisRESUMO
The development of efficient catalytic systems is a fundamental aspect for the straightforward production of chemicals. During the last years, covalent organic frameworks (COFs) emerged as an exciting class of organic nanoporous materials. Due to their pre-designable structure, they can be prepared with distinct physicochemical characteristics, specific pore sizes, and tunable functional groups. Moreover, associated with their stability in different media, these materials are considered promising supports for enzyme immobilization. Herein, it is highlighted the recent literature of enzyme immobilization in COFs, the main immobilization strategies, and the catalytic applications of these composites.
Assuntos
Enzimas Imobilizadas/metabolismo , Estruturas Metalorgânicas/química , Biocatálise , NanoestruturasRESUMO
Sustainability in chemistry heavily relies on heterogeneous catalysis. Enzymes, the main catalyst for biochemical reactions in nature, are an elegant choice to catalyze reactions due to their high activity and selectivity, although they usually suffer from lack of robustness. To overcome this drawback, enzyme-decorated nanoporous heterogeneous catalysts were developed. Three different approaches for Candida antarctica lipaseâ B (CAL-B) immobilization on a covalent organic framework (PPF-2) were employed: physical adsorption on the surface, covalent attachment of the enzyme in functional groups on the surface and covalent attachment into a linker added post-synthesis. The influence of the immobilization strategy on the enzyme uptake, specific activity, thermal stability, and the possibility of its use through multiple cycles was explored. High specific activities were observed for PPF-2-supported CAL-B in the esterification of oleic acid with ethanol, ranging from 58 to 283â U mg-1 , which was 2.6 to 12.7â times greater than the observed for the commercial Novozyme 435.
Assuntos
Enzimas Imobilizadas/química , Proteínas Fúngicas/química , Lipase/química , Estruturas Metalorgânicas/química , Adsorção , Biocatálise , Candida/enzimologia , Esterificação , Modelos Moleculares , Nanoporos/ultraestrutura , Ácido Oleico/químicaRESUMO
Tuberculosis (TB) remains a serious public health problem aggravated by the emergence of M. tuberculosis (Mtb) strains resistant to multiple drugs (MDR). Delay in TB treatment, common in the MDR-TB cases, can lead to deleterious life-threatening inflammation in susceptible hyper-reactive individuals, encouraging the discovery of new anti-Mtb drugs and the use of adjunctive therapy based on anti-inflammatory interventions. In this study, a series of forty synthetic chalcones was evaluated in vitro for their anti-inflammatory and antimycobacterial properties and in silico for pharmacokinetic parameters. Seven compounds strongly inhibited NO and PGE2 production by LPS-stimulated macrophages through the specific inhibition of iNOS and COX-2 expression, respectively, with compounds 4 and 5 standing out in this respect. Four of the seven most active compounds were able to inhibit production of TNF-α and IL-1ß. Chalcones that were not toxic to cultured macrophages were tested for antimycobacterial activity. Eight compounds were able to inhibit growth of the M. bovis BCG and Mtb H37Rv strains in bacterial cultures and in infected macrophages. Four of them, including compounds 4 and 5, were active against a hypervirulent clinical Mtb isolate as well. In silico analysis of ADMET properties showed that the evaluated chalcones displayed satisfactory pharmacokinetic parameters. In conclusion, the obtained data demonstrate that at least two of the studied chalcones, compounds 4 and 5, are promising antimycobacterial and anti-inflammatory agents, especially focusing on an anti-tuberculosis dual treatment approach.
Assuntos
Anti-Inflamatórios/farmacologia , Antituberculosos/farmacologia , Chalconas/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Animais , Linhagem Celular , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Óxido Nítrico Sintase Tipo II/metabolismo , Óxidos de Nitrogênio/metabolismo , Tuberculose/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Spent birds are usually used in the industry to make processed foods. This occurs due to the advanced age of these birds and the small price per kilogram of them. As well, the consumer is not used to buy meat of spent birds, thinking that this meat has a lower quality then the commercial one, found at the markets. Today, in Brazil, white spent males are sold for R$ 0.55/kg and red ones for R$ 0.65/kg. According to these, the aim of this study was to compare the chemical composition of birds with the ideal age to slaughter and birds in a spent age. It was used the Pectoralis major muscle from ten deboned carcasses of slow growth lineage at the ideal age to slaughter (85 days) and ten of spent birds (70 weeks) obtained from a commercial slaughterhouse. After the slaughter and rigor mortis process, they were carried to the Laboratory of Animal Products Technology. The breasts were crushed in a compact industrial mill and the meat was placed (100g of average weight) in an aluminum pot (or aluminum lunch box). These pots were carried to a forced ventilation heater with temperature of 65ºC and took off 72 hours later. The dried meat was crushed again in a ball mill, the dusted meat placed in porcelain crucibles and carried to a new dry at 105ºC in other heater to determine the humidity percentage. After this process, 0.1g of the sample dried was weighed in triplets to total nitrogen
O artigo não apresenta resumo em português.
RESUMO
Freezing has been widely used as the safest and most economical preservation method for poultry meat because on the frozen meat the microbial activity is paralyzed, the enzymatic and the speed of chemical reactions are substantially reduced. So, the aim of this current study was to analyze the efficiency of different methods of freezing over the maintenance of quality of frozen meat when it is compared to in natura meat intend for laboratory tests. It was used 50 Pectoralis major muscles from deboned chicken breasts, which was submitted to four different methods of freezing (domestic freezer, freezer -20C, freezer -70C and liquid nitrogen). The samples were previously weighed, individually packed in vacuum or with aluminum foil (in the case of the samples that would be frozen with liquid nitrogen) and storage in low temperature for 30 days. The samples frozen with liquid nitrogen were kept on freezer -20ºC after fast freezing. The following parameters were analyzed: water holding capacity (WHC), cooking weight loss (CWL) and shear force (SF). The WHC was evaluated using the compression method and its determination was given by the difference between the initial weight and the final weight. The CWL was determined in samples of deboned muscles packed in plastic bags and cooked in water bath (85ºC) for 30 minutes. The CWL determination was given by the difference between the ini
O artigo não apresenta resumo em português.
RESUMO
Freezing has been widely used as the safest and most economical preservation method for poultry meat because on the frozen meat the microbial activity is paralyzed, the enzymatic and the speed of chemical reactions are substantially reduced. So, the aim of this current study was to analyze the efficiency of different methods of freezing over the maintenance of quality of frozen meat when it is compared to in natura meat intend for laboratory tests. It was used 50 Pectoralis major muscles from deboned chicken breasts, which was submitted to four different methods of freezing (domestic freezer, freezer -20C, freezer -70C and liquid nitrogen). The samples were previously weighed, individually packed in vacuum or with aluminum foil (in the case of the samples that would be frozen with liquid nitrogen) and storage in low temperature for 30 days. The samples frozen with liquid nitrogen were kept on freezer -20ºC after fast freezing. The following parameters were analyzed: water holding capacity (WHC), cooking weight loss (CWL) and shear force (SF). The WHC was evaluated using the compression method and its determination was given by the difference between the initial weight and the final weight. The CWL was determined in samples of deboned muscles packed in plastic bags and cooked in water bath (85ºC) for 30 minutes. The CWL determination was given by the difference between the ini
O artigo não apresenta resumo em português.
RESUMO
Spent birds are usually used in the industry to make processed foods. This occurs due to the advanced age of these birds and the small price per kilogram of them. As well, the consumer is not used to buy meat of spent birds, thinking that this meat has a lower quality then the commercial one, found at the markets. Today, in Brazil, white spent males are sold for R$ 0.55/kg and red ones for R$ 0.65/kg. According to these, the aim of this study was to compare the chemical composition of birds with the ideal age to slaughter and birds in a spent age. It was used the Pectoralis major muscle from ten deboned carcasses of slow growth lineage at the ideal age to slaughter (85 days) and ten of spent birds (70 weeks) obtained from a commercial slaughterhouse. After the slaughter and rigor mortis process, they were carried to the Laboratory of Animal Products Technology. The breasts were crushed in a compact industrial mill and the meat was placed (100g of average weight) in an aluminum pot (or aluminum lunch box). These pots were carried to a forced ventilation heater with temperature of 65ºC and took off 72 hours later. The dried meat was crushed again in a ball mill, the dusted meat placed in porcelain crucibles and carried to a new dry at 105ºC in other heater to determine the humidity percentage. After this process, 0.1g of the sample dried was weighed in triplets to total nitrogen
O artigo não apresenta resumo em português.
RESUMO
Lecitase Ultra was immobilized on Amberlites XAD2 and XAD4, through physical entrapping under conventional stirring or ultrasound irradiation, and characterized by standard techniques. The resulting immobilized biocatalysts were utilized in the valorization of an acidic food-derived residue from a palm oil refining process to produce monoacylglycerols from isopropylidene glycerol under batch and continuous flow conditions. Results indicated that the immobilized biocatalysts could moderately convert the food waste residue (max. conversion 50-60 %), exhibiting interesting stability under continuous flow conditions.
Assuntos
Enzimas Imobilizadas/química , Lipase/química , Monoglicerídeos/química , Óleos de Plantas , Resíduos , Esterificação , Indústria de Processamento de Alimentos , Óleo de Palmeira , Poliestirenos/química , Polivinil/químicaRESUMO
Myonecrosis with permanent loss of muscle mass is a relevant local toxic effect following envenomation with Bothrops jararacussu snake venom. Regeneration of adult skeletal muscle involves the activation of satellite cells, a process regulated by myogenic regulatory factors (MRF). MyoD is an MRF involved in both proliferation and differentiation of satellite cells. Androgens are modulators of skeletal muscle, known to increase muscle mass and strength. This study examined the hypothesis that anabolic androgens improve the muscle regeneration process in mice following envenomation by Bothrops jararacussu snake venom. Myonecrosis was induced by venom injection (30 microg/50 microl in physiological solution) over the extensor digitorum longus (EDL) muscles of mice. Nandrolone (ND) (6 mg/kg, sc) was administered after 12 h, 7 d, and 14 d following venom injection. The histological changes in EDL muscle at 1, 3, 7, and 21 d after muscle injury were analyzed by light microscopy. Cross-sectional areas of fibers were measured. MyoD was evaluated by immunofluorescence technique. Histological examination revealed the presence of a regeneration process in ND-treated animals, characterized by the appearance of some myotubes at 3 d, and numerous myotubes at 7 d from venom injection. Nandrolone treatment reduced the frequency of small fibers at 7 and 21 d after venom administration, and increased the frequency of large fibers at 7 d postinjury. Nandrolone also significantly augmented the expression of MyoD-positive cells at 7 and 21 d after envenomation. These results suggest that ND accelerates muscle regeneration and indicate the involvement of MyoD in this process.