To clarify the relationship between myosin heavy chain (MyHC) isoforms and tropomyosin (TPM) isoforms in single fibers, 64 single fibers were isolated from each of bovine three muscles (masseter, ...semispinalis and semitendinosus). mRNA expressions of MyHC and TPM isoforms were analyzed by real-time PCR. All single fibers from the masseter expressed MyHC-slow. The fibers from the semispinalis expressed both MyHC-slow and 2a. The fibers from the semitendinosus expressed MyHC-slow, 2a and 2x. TPM-1 and TPM-2 were co-expressed in 2a and 2x type fibers, and TPM-2 and TPM-3 were co-expressed in slow type fibers. The expression pattern of TPM isoforms in each fiber type was similar between fibers isolated from different muscles. These results suggest that TPM-1 and TPM-3 isoforms correspond to the function of 2a or 2x type fibers and slow type fibers, respectively, with TPM-2 in common. Furthermore, the patterns of MyHC and TPM isoform combinations did not vary among single fibers isolated from the individual muscles examined.
We aimed to clarify the mechanisms affecting postmortem thiamine and its phosphoester contents in major edible pork muscles, namely the longissimus lumborum (LL) in addition to vastus intermedius ...(VI). Metabolomic analysis by capillary electrophoresis-time of flight mass spectrometry revealed that the level of thiamine triphosphate (ThTP), approximately 1.8-fold higher in LL than in VI muscle at 0h postmortem, declined in the first 24hrs, resulting in an undetectable level at 168h postmortem in both muscles. In contrast, the thiamine content in both muscles increased after 24h postmortem during the aging process. The thiamine accumulation and ThTP decline progressed in parallel with a drastic reduction of the ATP level. The intermuscular differences in pH at 24h and in expression of thiamine transporter and thiamine pyrophosphokinase might result in delayed thiamine generation in LL. These results suggest that postmortem ATP exhaustion forced ThTP hydrolysis and further depyrophosphorylation of thiamine diphosphate in the porcine muscles, which resulted in thiamine accumulation.
•Levels of ThTP and ATP decline in parallel during postmortem pig longissimus muscle.•Thiamine level in pig longissimus and vastus intermedius increases in the duration.•Changes in thiamine and its phosphate levels were different between the muscles.•Expressions of genes related to thiamine metabolism differ between the two muscles.
Abstract
Grazing alters skeletal muscle physiological properties in cattle. We hypothesized that changes in circulating microRNA (c-miRNA) levels are attributed to release and/or uptake of exosomal ...miRNA at adipose and liver tissues. In this study, to determine grazing-induced mRNA and miRNA transcriptomic changes at those tissues, we conducted microarray analyses in biceps femoris muscle (BF), subcutaneous fat (ScF), and liver tissues of Japanese Shorthorn steers. Three steers (aged 20–22 mo) were allocated to each of grazing and housed groups; grazing steers were fed on pasture for 3 months from middle of May, when the other steers were housed and fed in a free-stall barn with grass harvested every morning. The samples were collected at 3 mo of grazing period, with surgical biopsy in case of solid tissues. Plasma exosomes (pEX) were prepared from the blood samples, using ultracentrifugation. Total RNAs were prepared from the tissues and pooled within each tissue, and finally applied to both mRNA and miRNA expression microarray analyses. The number of changed genes was the highest in BF (52 increased and 1088 decreased genes). On the other hand, the number of genes showing more than 2-fold increase (INC) and decrease (DEC) compared to the housed was the highest in ScF and the lowest in liver. Especially in ScF, we observed 169 INC and 249 DEC genes, indicating dominance of DEC genes over INC genes in ScF of the grazing steers. Using the list of INC and DEC genes, we conducted gene ontology analyses and extracted the term ‘extracellular exosome’ from the DEC genes in ScF, as a term associated with changes in ScF of the grazing steers. This was coincident with greater number of the decreased miRNAs than the increased in pEX. These results suggest an association of grazing-induced changes in c-miRNAs with ScF transcriptome in the steers.
MicroRNA (miRNA) are highly conserved, noncoding small RNA involved in post-transcriptional gene regulation in a variety of biological processes. To elucidate roles of miRNA in bovine muscle type ...specification and maintenance, we sought to determine differentially expressed miRNA between semitendinosus (STD) and masseter (MS) muscles from 3 Japanese black cattle by massively parallel sequencing. Differential gene expression of myosin heavy chain (MyHC) isoforms confirmed that STD and MS were MyHC-2x- and MyHC-1-abundant muscles, respectively. In total, 192 known miRNA and 20 potential new bovine miRNA were obtained from the sequencing. The differentially expressed miRNA with more than 2-fold difference in each muscle were identified. In particular, miR-196a and miR-885 were exclusively expressed in STD muscle, which was validated by quantitative reverse transcription-PCR (P=0.045 and P<0.001, respectively), whereas a slow type-directing miR-208b was highly expressed in MS compared with STD (false discovery rate<0.05). In addition, 16 potential novel miRNA were mapped and confirmed for their precursor structures by computational analyses. The results of functional annotation combined with in silico target analysis showed that the predicted target genes of miR-196a/b and miR-885 enriched gene ontology (GO) terms related to skeletal system development and regulation of transcription, respectively. Moreover, GO terms enriched from predicted targets miRNA suggested that STD-abundant- and MS-abundant-miRNA were associated with embryonic body planning and organ/tissue pattern formation, respectively. The present results revealed that the differentially expressed miRNA between the STD and MS muscles may play key roles to determine muscle type-specific tissue formation and maintenance in cattle thorough attenuating putative target genes involved in different developmental events.
Here we characterized gene expressions in subcutaneous adipose tissue and blood metabolites of pigs with genetically low backfat (Landrace) and high backfat (Meishan). As pigs aged from 1 wk-to 3-mo ...old, mRNA levels of adipose-specific genes increased, although their gene expressions coding for major enzymes involved in lipid metabolism (lipoprotein lipase, fatty acid synthase, and hormone-sensitive lipase) did not differ between lean and fat pigs. Instead, there were significant effects for adiponectin and its receptor AdipoR1 mRNA levels between the two breeds of which respective expressions were lower and higher in Meishan by 3 mo of age. Contrary to changes in gene expressions, the concentrations of blood glucose, triglyceride (TG), and NEFA in both breeds decreased during growth, and 3-mo-old Meishan evidenced lower glucose with higher TG than the Landrace. The homeostasis model assessment insulin resistance (HOMA-IR) index was also calculated from the measurements of fasting glucose and insulin concentration, and Meishan showed a higher value than the Landrace. We next examined these differences in Landrace and Meishan crossbreds, which were phenotypically distinguishable by the backfat thickness as the former lean type and the latter fat type. As with the purebreds, high backfat Meishan crosses showed the characteristics of lower glucose and higher TG in circulating levels and also lower adiponectin transcripts in subcutaneous adipose tissue. Collectively, our results demonstrate that levels of adiponectin and its receptor gene expressions, blood glucose, blood lipids, and HOMA-IR in pigs vary between lean and fat. These observations strongly suggest the possibility that overall metabolic differences rather than adipocyte ability itself contribute to the fatness of genetically high backfat pigs.
•The major lipogenic and lipolytic gene expressions did not differ between low and high backfat pigs.•High backfat pigs expressed lower adiponectin transcripts in subcutaneous adipose tissue.•High backfat pigs expressed higher AdipoR1 transcripts in subcutaneous adipose tissue.•High backfat pigs showed higher concentrations in blood lipids but lower blood glucose.•Fasting treatment did not affect circulating levels of glucose and insulin in high backfat pigs.
A ceiling radiant cooling system (CRCS) can provide comfortable environment with less energy consumption. It has been reported that the amount of heat removed by only radiant panels increases ...compared to one removed by only air handling units (AHUs) due to the existence of a plenum. However, few studies have focused on installation conditions of CRCS and surface temperature of radiant panels. Therefore, we proposed a new calculation flow to decide cooling system specifications, where we considered an impact of a plenum and the surface temperature of panels. In the conventional flow, the amount of heat covered by AHUs and the equipment capacity are determined by subtracting the assumed capacity of radiant panels from the load without radiant panels. On the other hand, in the proposed flow, the amount of heat covered by radiant panels and AHUs and the capacity of them are simultaneously calculated by using a thermal network model considering the impact of radiant panels on the wall surface temperature. In this study, we carried out case studies for different installation conditions of CRCS and examined the cooling loads and the equipment specifications. As a result, regardless of the laying area of radiant panels, the entire cooling load removed by both radiant panels and AHUs in the proposed flow was higher than that in the conventional flow. Furthermore, depending on installation conditions, we found that there is a possibility that the equipment capacity of AHUs is underestimated in the conventional flow. In addition, through the proposed flow, supply water temperature can be slightly raised when the heat capacity of the building is larger. This study will contribute to the establishment of the correct design method of CRCS. From now on, we need to study about the design of CRCS considering the energy-saving performance including heat source system.
'Nudge', which is a framework of altering people's behaviour in a predictable way without large penalty or economic incentives, is applied to energy saving measures of buildings in several papers. ...However, most of them focus on energy saving in a private space such as home, and little research has been done for energy saving in a public space. In this research, field experiments were conducted with the aim of energy saving in a public space by offering information. Focusing on individual behavior in a public space, we provided information directly to an individual, not to a public. By using power taps and thermal sensors, the individual equipment electricity consumption during absence, which is considered as the amount of energy wasted, is calculated. The subjects were divided into three groups. Through the information provision, some people changed their behavior and reduced energy consumption by approximately 70%. Furthermore, it was founded that those who originally consumed much energy even when absent might tend not to change behavior by receiving information. The results from this experiment will provide fresh insight into information provision such as data visualization for energy saving of a public space and be useful for life management of occupants.
The objective of this study was to investigate the differences in the muscle proteome of grass-fed and grain-fed cattle. Eight Japanese Black Cattle 10 mo of age were separated randomly into 2 ...groups: 1) grazing (grass-fed) and 2) concentrate (grain-fed) groups. All cattle were first housed individually in a stall barn and fed a combination of concentrate ad libitum and Italian ryegrass hay until 21 mo of age. After this control period, the 4 grass-fed cattle were placed on outdoor pasture, whereas the other 4 grain-fed cattle continued on the concentrate diet. The cattle were slaughtered at 27 mo of age, and tissues from the semitendinosus muscle were obtained for use in proteome analysis. Differential expression of muscle proteins in the 2 groups was carried out using 2-dimensional gel electrophoresis (2DE) and Western blot analyses, with subsequent mass spectrometry. Approximately 200 individual protein spots were detected and compared in each group using 2DE, of which 20 and 9 spots, respectively, showed differences in the spot intensity for the sarcoplasmic fraction and myofibrillar fraction. In the grazing group, the relative intensity of spots was significantly greater for adenylate kinase 1 and myoglobin in the sarcoplasmic fraction, and for slow-twitch myosin light chain 2 in the myofibrillar fraction (P < 0.05), than the concentrate group. The relative spot intensity of several glycolytic enzymes was significantly greater in the grazing group, such as β-enolase 3, fructose-1,6-bisphosphate aldolase A, triosephosphate isomerase, and heat shock 27 kDa protein (P < 0.05). Moreover, significantly greater slow twitch of troponin T, troponin I, and myosin heavy chain of semitendinosus muscle was detected in the grazing group than in the concentrate group using Western blot analysis (P < 0.05). Several previous reports have described that the slow-twitch muscle contents affect elements of nutrition, flavor, and food texture of meat. This study revealed muscle fiber type conversion to slow-twitch tissues from fast-twitch tissues occurring with change in the energy metabolic enzyme when cattle were grazed in the latter fattening period. Although analyses of the influence on elements of nutrition, flavor, and food texture were not done for this study, these results show that slow-twitch converted muscle resulting from the grazing of cattle might modify several meat characteristics.
The efficacy of the combination of the rapid-acting insulin secretagogue mitiglinide and the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin was explored in ...streptozotocin-nicotinamide-induced type 2 diabetic (STZ-NA) rats and in Zucker fatty (ZF) rats. The STZ-NA rats were prepared at 8 weeks of age. At 9 weeks of age, the combination study was conducted by oral glucose tolerance test (OGTT). At 13 weeks of age, ZF rats were dosed orally with dapagliflozin once daily up to the 22(nd) day. At days 15 and 22, the combination study was conducted by OGTT. In 2 different animal models, plasma glucose levels were strongly suppressed by the combination of mitiglinide and dapagliflozin as compared with either drug alone. The urinary glucose excretion was drastically elevated in the dapagliflozin group, but the combination with mitiglinide suppressed it about 50%. In STZ-NA rats, the plasma insulin secretion by the combination of both drugs was about at the same level as in the mitiglinide group. In ZF rats, the plasma insulin secretion by the combination of both drugs was less than mitiglinide group. Thus, in 2 different animal models, the combination of mitiglinide and dapagliflozin showed stronger antihyperglycemic action accompanied by less insulin secretion than mitiglinide alone, and reduced the urinary glucose excretion as compared with dapagliflozin used alone. These results indicate that the combination of mitiglinide and dapagliflozin can be a promising combination for the treatment of diabetic patients.
MicroRNA (miRNA) are highly conserved, noncoding small RNA involved in post-transcriptional gene regulation in a variety of biological processes. To elucidate roles of miRNA in bovine muscle type ...specification and maintenance, we sought to determine differentially expressed miRNA between semitendinosus (STD) and masseter (MS) muscles from 3 Japanese black cattle by massively parallel sequencing. Differential gene expression of myosin heavy chain (MyHC) isoforms confirmed that STD and MS were MyHC-2x- and MyHC-1-abundant muscles, respectively. In total, 192 known miRNA and 20 potential new bovine miRNA were obtained from the sequencing. The differentially expressed miRNA with more than 2-fold difference in each muscle were identified. In particular, miR-196a and miR-885 were exclusively expressed in STD muscle, which was validated by quantitative reverse transcription-PCR (P = 0.045 and P < 0.001, respectively), whereas a slow type-directing miR-208b was highly expressed in MS compared with STD (false discovery rate < 0.05). In addition, 16 potential novel miRNA were mapped and confirmed for their precursor structures by computational analyses. The results of functional annotation combined with in silico target analysis showed that the predicted target genes of miR-196a/b and miR-885 enriched gene ontology (GO) terms related to skeletal system development and regulation of transcription, respectively. Moreover, GO terms enriched from predicted targets miRNA suggested that STD-abundant- and MS-abundant-miRNA were associated with embryonic body planning and organ/ tissue pattern formation, respectively. The present results revealed that the differentially expressed miRNA between the STD and MS muscles may play key roles to determine muscle type-specific tissue formation and maintenance in cattle thorough attenuating putative target genes involved in different developmental events. PUBLICATION ABSTRACT
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