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• Endogenous FGF activity negatively regulates myogenesis. • Inhibition of FGF activity enhances vitamin C-induced myogenesis. • Vitamin C and FGF inhibition upregulate myogenin expression. • DNA demethylation mediates vitamin C and FGF inhibition-induced myogenesis. [ABSTRACT FROM AUTHOR]

BACKGROUND Magnesium (Mg) is highly bioavailable in kombu compared with other edible seaweeds. However, a considerable amount of Mg is lost during industrial processing and cooking of kombu. We hypothesized that thinly shaved kombu (TSK), a traditional Japanese kombu product, is a suitable Mg source for daily diets because TSK hardly loses Mg during processing. Rats were fed diets containing TSK or magnesium oxide (MgO) to satisfy 25%, 50%, 75%, or 100% of their Mg requirements. We determined the relative Mg bioavailability of TSK compared to MgO and examined factors affecting Mg bioavailability in TSK. RESULTS: The relative bioavailability of Mg in TSK compared with MgO was calculated as 92.3%, 111.4%, and 87.2% from apparent absorption, urinary excretion, and femoral concentration of Mg, respectively. The ultrafiltrable Mg concentration was lower in the cecal content of rats given TSK than those given MgO. However, the mRNA expression of TRPM6, an Mg channel responsible for Mg absorption, was higher in the cecum of rats given TSK than those given MgO. CONCLUSION: Enhancement of TRPM6 expression in the large intestine negates the low bioaccessibility of Mg in TSK, and thus TSK shows Mg bioavailability comparable with MgO. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: Long‐distance transportation has negative impacts on production and health in cattle. Feed and water are routinely deprived from cattle during transportation. We investigated whether niacin supplementation could improve niacin nutrition and mitigate the adverse effect of transportation with feed and water deprivation in steer calves. We also studied the adverse effect of feed and water deprivation in nontransported steer calves. Twelve calves were assigned to feed and water deprivation for 2 days, or full access to feed and water in experiment 1. Ten calves were assigned to 2‐day transportation with feed and water deprivation, or the transportation with feed and water deprivation, but with supplementation of rumen‐protected niacin at 100 g/day per head in experiment 2. Bodyweight was measured and blood was collected for 32 days in each experiment. Feed and water deprivation temporarily decreased serum glucose concentrations and bodyweight gain. Transportation with deprivation of feed and water caused a temporal decrease in bodyweight gain and serum albumin concentration, and a continuous decrease in serum glucose and total cholesterol concentrations, which was suppressed by niacin supplementation. Niacin supplementation increased blood niacin concentration. These results suggest that niacin supplementation mitigates adverse effects of transportation with feed and water deprivation in steer calves. [ABSTRACT FROM AUTHOR]

Abstract: The relationship between mineral concentrations, and the relationship of mineral concentrations with physicochemical characteristics in muscles were investigated using the Longissimus thoracis (LT) muscle of 44 Japanese Black steers. We determined moisture content, fat content, meat color, fatty acid composition and mineral concentrations in the LT muscle. Magnesium (Mg), potassium (K) and zinc (Zn) concentrations had negative correlations with fat content, but sodium (Na), manganese (Mn), copper (Cu) and molybdenum (Mo) concentrations were not correlated with fat content. The concentrations of Mg, Mn, Fe, Cu and Zn largely and positively contributed to the first principal component of mineral concentrations. Because the red muscle was rich in these minerals compared to the white muscle, the variation of these minerals probably results from the abundance of red fibers in the LT muscle. The concentration of K was positively correlated with moisture content but Na concentration was not related to moisture content, suggesting that the intracellular fluid volume can largely affect moisture content. The results of the present experiment suggest that mineral concentrations reflect some traits such as not only fat content but also the composition of myofiber type and the intracellular fluid volume in the LT muscle of Japanese Black cattle. [ABSTRACT FROM AUTHOR]

Microphthalmia-associated transcription factor (MITF) is a transcription factor that is expressed in limited types of cells, including osteoclasts, but the expression and role of MITF during osteoclastogenesis have not been fully elucidated. The expression of the MITF-E isoform but not that of the MITF-A isoform was induced in response to differentiation stimulation towards osteoclasts by receptor activator of NF- κB ligand (RANKL) in both RAW264.7 cells and primary bone marrow cells. The RANKL-induced formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells was inhibited in RAW264.7 cells expressing siRNA for MITF-E. Transforming growth factor-β (TGF-β) enhanced RANKL-induced MITF-E expression and -TRAP positive multinucleated cell formation. In particular, TGF-β potentiated the formation of larger osteoclasts. The expression levels of NFATc1, TRAP and CtsK, genes related to osteoclast development and activity, were concurrently enhanced by TGF-β in the presence of RANKL. Furthermore, the expression of dendritic cell-specific transmembrane protein (DC-STAMP), Itgav, Itga2, Itga5, Itgb1, Itgb3 and Itgb5, genes related to cell adhesion and fusion, were up-regulated by co-treatment with TGF-β. In particular, the regulatory expression of Itgav and Itgb5 in response to RANKL with or without TGF-β resembled that of MITF-E. Because MITF is involved in cell fusion in some cell systems, these results imply a role for MITF-E as an enhancer of osteoclastogenesis and that RANKL-induced levels of both MITF-E mRNA and of MITF-dependent gene expression are enhanced by treatment with TGF-β. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) deficiency induces the production of free radicals, increases cytosolic ionized calcium concentration, and modulates the function of skeletal muscle in rats. The present study examined the effects of Mg deficiency on the gene expression of molecules related to myogenesis in the gastrocnemius muscle as well as in C2C12 myogenic cells. Ingestion of an Mg-deficient diet resulted in a lower weight of the gastrocnemius muscle and higher concentration of muscular TBARSs, an index of oxidative stress. Mg deficiency also enhanced the expression of Myod and myogenin. In vivo effects of Mg deficiency on myogenic gene expression were partially reproduced in in vitro C2C12 cells; expression of Myod was up-regulated by a mixed culture of myoblasts and myotubes with Mg-deficient medium, which related to the simultaneous up-regulation of Myhc IIb, a myotube-specific protein. The culture with Mg-deficient medium did not increase the gene transcript level of HO-1, another marker of oxidative stress, suggesting that Mg deficiency-induced Myod expression does not result from oxidative stress. Furthermore, oxidative stress induced by hydrogen peroxide did not increase Myod expression, whereas the expression of Myod, myogenin and Myhc IIb was decreased by oxidative stress from the initial phase of differentiation. The effects of Mg deficiency depended on the stages of myogenesis; myoblast culture in Mg-deficient differentiation medium did not affect the expression of Myod and Myhc IIb. The present study revealed stage-dependent effects of Mg deficiency on myogenesis. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The transforming growth factor-β (TGF-β) family is involved in a variety of physiological processes, and transmits signals through phosphorylation of Smad by the receptor complexes. In the present study, effects of blocking solution in Western blot analyses on detection of phosphorylated Smad1/5/8 and Smad2 were examined. When EzBlock was used as a blocking reagent, phosphorylated Smad1/8 and Smad2 were most efficiently detected. The anti-phospho-Smad2 antibody specifically recognized the phosphorylated form of Smad2, whereas the anti-phospho-Smad1/5/8 antibody also reacted to the unphosphorylated form. These antibodies did not react with the other Smads. [Copyright &y& Elsevier]

Abstract: Factors affecting struvite, a magnesium–ammonium–phosphate complex (MgNH4PO4 6H2O), in feline urine were evaluated. Incubation of just “urine mineral (UM)” solution, in which mineral concentrations are compatible with those in feline urine, for 4 h at 37 °C did not induce the formation of crystals. Similarly, incubation of urine alone did not produce crystals. However, struvite crystals were formed by the addition of urine to UM solution. Mg, NH3 and P were all required for urine-induced struvite crystallization. The lower molecular weight (LMW) fraction of urine was essential for struvite crystal formation, and the higher molecular weight (HMW) fraction enhanced formation of LMW-induced struvite crystals. The effects of urine proteins further fractionated by column chromatography were examined. A protein at >250 kDa and cauxin, a major urine protein recently identified as a regulator of felinine production, potentiated struvite crystal formation induced by the LMW fraction. In contrast, Tamm–Horsfall glycoprotein, a urine protein thought to promote struvite crystallization, did not have this activity. The present study reveals a novel mechanism of feline struvite crystallization. [Copyright &y& Elsevier]

Abstract: Transforming growth factor-β (TGF-β) modulates functions of bone marrow-derived cultured mast cells (BMMCs); cell maturation (up-regulation of mouse mast cell proteases (mmcps)), growth arrest and migration. We investigated the roles of p38 MAP kinase and Smad3 in TGF-β-mediated cell responses in BMMCs. Treating BMMCs with TGF-β induced the phosphorylation of p38 within 2 h and persisted for 24 h. The involvement of p38 in TGF-β-induced cell responses depended upon mast cell functions; it was necessary for up-regulation of mmcp-1 and migration, but not for up-regulation of mmcp-7 and inhibition of metabolic activity. New protein synthesis was required for the up-regulation of mmcp-1 but not mmcp-7 in response to TGF-β treatment, and stabilization of mRNA was partially responsible for the increase in gene transcript of mmcp-1. The decrease in metabolic activity in response to TGF-β treatment was smaller in Smad3-deficient BMMCs compared to wild-type BMMCs. Maximal migration was detected at a TGF-β concentration of 40 fM in wild-type BMMCs, whereas TGF-β-induced migration was absent in Smad3-deficient BMMCs. Thus, the roles of p38 and Smad3 are different among TGF-β-mediated cell responses in BMMCs. [Copyright &y& Elsevier]

Abstract: Previous studies have demonstrated that treatment with activin A and TGF-β1, members of the TGF-β family, stimulated maturation of mouse bone marrow-derived cultured mast cells (BMMC), which was characterized by morphology and gene expression of mouse mast cell proteases (mmcps). In order to gain a better understanding of activin A- and TGF-β1-induced maturation in mast cells, we investigated the genes that were up-regulated in response to treatment with these two members of the TGF-β family. The cDNA microarray analyses indicated that in BMMC, five genes were induced by treatment with 4 nM activin A for 2 h. Tocopherol-associated protein (Tap) was one of the induced genes, and the Tap induction in response to activin A treatment was confirmed by real-time RT-PCR analyses. Treatment with TGF-β1 at 200 pM but not BMP-2 at 4 nM also increased Tap gene transcript in BMMC. Activin A-induced Tap expression was detected in BMMC but not in RAW264 macrophage-like cells, B16 melanoma cells or P19 embryonic carcinoma cells. Treatment with >1 μM SB431542, an inhibitor of activin and TGF-β type I receptors ALK4/5, reduced responsiveness of Tap expression to TGF-β1, whereas <0.5 μM SB431542 effectively reduced TGF-β1-induced expression of mmcp-1 and mmcp-7. These results suggest that inhibitory effects of SB431542 are different between TGF-β-induced genes. Reporter assays indicated that Tap expression enhances transcription mediated by the activin/TGF-β pathway. Thus, the present results suggest that Tap induction in response to activin/TGF-β occurs predominantly in mast cells and serves as a positive regulator in activin/TGF-β signaling. [Copyright &y& Elsevier]

Abstract: The involvement of the TGF-β family in cell growth of bone marrow-derived mast cells (BMMC) cultured with medium containing pokeweed mitogen-stimulated spleen cell-conditioned medium (PWM-SCM) was examined. Doubling time of BMMC from Smad3-null mice was longer than that from wild-type (WT) mice, and the differences tended to be larger with time of culture. Consistent with the results, uptake and reduction of [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt; MTS] was lower in Smad3-deficient BMMC. Cell cycle analyses revealed no apparent differences between WT BMMC and Smad3-deficient BMMC, suggesting that longer doubling time in Smad3-deficient BMMC resulted from increased cell death. TGF-β and activin A were supplied by PWM-SCM rather than by self-production by BMMC. Blocking the TGF-β pathway by anti-TGF-β neutralizing antibody or an inhibitor for the type I receptors for ligands including TGF-β and activin, SB431542, inhibited MTS uptake and reduction in WT BMMC, whereas anti-activin A antibody and SB431542 tended to inhibit them in Smad3-deficient BMMC. The present results suggest that TGF-β-induced and Smad3-mediated signaling is essential for maximal cell growth in mast cells, and that the activin pathway may be required for it when mast cell context is modulated by Smad3 depletion. [Copyright &y& Elsevier]

Abstract: Mouse mast cell protease-7 (mmcp-7) is a tryptase predominantly expressed in differentiated connective tissue-type mast cells. Previous study revealed that transforming growth factor-β (TGF-β) increases gene transcript of mmcp-7 in mast cells. The present study explored molecular mechanism of the up-regulation of mmcp-7 by TGF-β. Luciferase-based reporter assays using deletion and point mutations of mmcp-7 promoter showed a critical region spanning nt −126 to −122 relative to the transcriptional start site, a Smad-binding element, for transcriptional activation by the TGF-β pathway. In addition, a region from nt −104 to −98, a TPA-responsive element, was also necessary for the transactivation. Consistent with the current model for the TGF-β signaling, Smad4 was required for the transcription of mmcp-7 by Smad3, a signal mediator of TGF-β. Treatment with TGF-β in mast cells resulted in the differential gene induction of the AP-1 components, i.e., transient induction of c-fos but not of c-jun and junB. Expression of c-fos further enhanced Smad3 and Smad4-induced transcription of mmcp-7, whereas c-jun expression inhibited the transcription. Our results suggest that TGF-β stimulates mmcp-7 transcription through the Smad3-Smad4 pathway as well as c-fos induction, and that the AP-1 components distinctly related with the TGF-β pathway. [Copyright &y& Elsevier]

Previous studies have revealed that members of the transforming growth factor-β (TGF-β) including TGF-β1 and activin A modulate the function of mast cells. Here we show the up-regulation of mouse mast cell protease-6 (mMCP-6), which is expressed in differentiated mast cells, by TGF-β1 and activin A in bone marrow-derived cultured mast cell progenitors (BMCMCs). Quantitative real time RT-PCR analyses revealed that the mRNA level of mMCP-6 was slightly but reproducibly increased by treatment with TGF-β1 or activin A, which was regulated at the transcription level. Reporter assays showed that Smad3, a signal mediator of the TGF-β/activin pathway, was responsible for the transcription. The TGF-β response element is located at −153 bp relative to the transcription initiation site, CAGA. Microphthalmia-associated transcription factor (MITF), a tissue-specific transcription factor predominantly expressed in mast cells, melanocytes, the heart and skeletal muscle, also stimulated the transcription of mMCP-6. The region at −166 bp, GACCTG, was responsible for MITF-induced transcription. Mutations of the CAGA motif and the MITF responsive site indicated that the MITF site of mMCP-6 promoter is indispensable for the transcriptional activation by a constitutively active TGF-β receptor (ALK5-TD), whereas the CAGA motif is dispensable for transcription by MITF. Transcriptional activation of mMCP-6 by the TGF-β pathway was differently interacted with that by MITF isoform; ALK5-TD further enhanced MITF-E-induced transcription, whereas MITF-M-induced transcription abolished responsiveness to ALK5-TD. The positive regulation of mMCP-6 by the TGF-β/activin pathway and the differential regulation by the MITF isoform suggest a rigorous regulation of mast cell function as effector cells of immune response. [Copyright &y& Elsevier]

Objective--To evaluate effects of dietary carbohydrate on urine volume; struvite crystal formation; and calcium, phosphorus, and magnesium balance in clinically normal cats. Animals--21 healthy adult cats (15 sexually intact males and 6 sexually intact females). Procedure--Diets containing no carbohydrate source (control diet), control plus starch, or control plus fiber were given in a 3 X 3 Latin-square design. The diets were available ad libitum in study 1 (n = 12) and given under restrictions in study 2 (9) to equalize daily intakes of crude protein among the 3 groups. Formation of struvite crystals and balance of calcium, phosphorus, and magnesium were measured. Results--Urine volume was lower in the starch group and fiber group in study 1, whereas no differences were detected among the groups in study 2. Urinary pH and struvite activity product were higher in the starch group in both studies, and the fiber group also had higher struvite activity product in study 2. In both studies, urinary concentrations of HCl-insoluble sediment were higher in the starch group and fiber group. In the fiber group, a net loss of body calcium, phosphorus, and magnesium was detected in study 2. Conclusions and Clinical Relevance--Starch and fiber in diets potentially stimulate formation of struvite crystals. Hence, reducing dietary carbohydrate is desirable to prevent struvite urolith formation. In addition, a net loss of body calcium, phosphorus, and magnesium during feeding of the fiber diet suggests that dietary inclusion of insoluble fiber could increase macromineral requirements of cats. [ABSTRACT FROM AUTHOR]

Previous studies have revealed that activin A and transforming growth factor-β[sub 1] (TGF-β[sub 1]) induced migration and morphological changes toward differentiation in bone marrow-derived cultured mast cell progenitors (BMCMCs). Here we show up-regulation of mouse mast cell protease-7 (mMCP-7), which is expressed in differentiated mast cells, by activin A and TGF-β[sub 1] in BMCMCs, and the molecular mechanism of the gene induction of mmcp-7. Smad3, a signal mediator of the activin/TGF-β pathway, transcriptionally activated mmcp-7. Microphthalmia-associated transcription factor (MITF), a tissue-specific transcription factor predominantly expressed in mast cells, melanocytes, and heart and skeletal muscle, inhibited Smad3-mediated mmcp-7 transcription. MITF associated with Smad3, and the C terminus of MITF and the MH1 and linker region of Smad3 were required for this association. Complex formation between Smad3 and MITF was neither necessary nor sufficient for the inhibition of Smad3 signaling by MITF. MITF inhibited the transcriptional activation induced by the MH2 domain of Smad3. In addition, MITF-truncated N-terminal amino acids could associate with Smad3 but did not inhibit Smad3mediated transcription. The level of Smad3 was decreased by co-expression of MITF but not of dominantnegative MITF, which resulted from proteasomal protein degradation. The changes in the level of Smad3 protein were paralleled by those in Smad3-mediated signaling activity. These findings suggest that MITF negatively regulates Smad-dependent activin/TGF-β signaling in a tissue-specific manner. [ABSTRACT FROM AUTHOR]

Involvement of the calmodulin pathway in Ca2+-induced degranulation was evaluated in RBL-2H3 mast cells. Pretreatment of RBL-2H3 cells with a calmodulin antagonist, W-13, blocked ionomycin-dependent release of β-hexosaminidase into the supernatant, although W-13 treatment alone slightly but significantly increased the release. Ca2+/calmodulin activates various protein kinases and phosphatases including myosin-light chain kinase (MLCK), calmodulin-dependent protein kinases (CaMKs), and calcineurin. When RBL-2H3 cells were pretreated with a MLCK inhibitor, ML-7, or a CaMKs inhibitor, KN-93, the ionomycin-dependent release of β-hexosaminidase into the supernatant was inhibited. In addition, pretreatment with calcineurin inhibitors, cyclosporin A and FR901725, resulted in blockage of the ionomycin-dependent release of β-hexosaminidase into the supernatant. Our results indicate that Ca2+/calmodulin, activated calmodulin, is indispensable for Ca2+-induced degranulation, and that within the calmodulin pathways, at least MLCK, CaMKs and calcineurin positively regulate the release of granules initiated by increasing cytosolic Ca2+concentrations in RBL-2H3 cells. [Copyright &y& Elsevier]

Provides information on a study that evaluated the effects of a high-protein diet versus dietary supplementation with ammonium chloride on struvite crystal formation in the urine of clinically normal cats by measuring the urine concentration of hydrochloric acid-insoluble sediment, urine potential of hydrogen ions, struvite activity product, number of struvite crystals in urine and urine volume. Methodology of the study; Results and discussion on the study; Conclusions.

Toll-like receptors (TLRs) recognize and signal the presence of bacterial components such as lipopolysaccharide (LPS) and peptidoglycan (PG) as a part of innate immunity. Our previous studies revealed that mast cells function as effector cells in the protection of mice against lethal enterobacterial infections. In this study, we examined both the gene expression of molecules involved in TLR signaling and the effects of LPS and PG in bone marrow-derived cultured mast cells (BMCMCs). The mRNA expression of TLR2, TLR4 and TLR6 was detected in BMCMCs. CD14, MD-2 and MyD88, which are also involved in TLR pathway, were also expressed. Neither LPS nor PG affected degranulation in BMCMCs, but release of tumor necrosis factor increased slightly in response to LPS and PG. Both LPS and PG enhanced expression of pro-matrix metalloproteinase 9 (pro-MMP-9) in a dose-dependent manner, and DNA fragmentation was induced by LPS, but not by PG. These results suggest that mast cells are the targets of LPS and PG, and that the functions of these molecules produced exclusively by bacteria partly overlap, but are distinct. [Copyright &y& Elsevier]

The present study examined the regulatory expression of activin A, a potent growth and differentiation factor, in rat basophilic leukemia (RBL-2H3) mast cells. Treatment of RBL-2H3 cells sensitized with anti-dinitrophenyl IgE with multivalent dinitrophenyl led to a clear increase in RT-PCR products of inhibin/activin βA. The steady-state mRNA of inhibin/activin βA was also induced by increasing cytosolic Ca2+ concentration with ionomycin, which required de novo protein synthesis, and was regulated at the transcriptional level. Pretreatment of RBL-2H3 cells with antagonists or inhibitors for the calmodulin pathway blocked ionomycin-dependent inhibin/activin βA transcription and mRNA induction, suggesting the involvement of calmodulin-dependent kinase (CaMK) and calcineurin. The ionomycin-dependent inhibin/activin βA induction was also partially blocked by preincubation with c-Jun NH2-terminal kinase (JNK) and p38 kinase inhibitors, but not with MEK1 inhibitor. These results suggest that inhibin/activin βA gene activation is achieved by the JNK and p38 kinase activation through the calmodulin pathway in mast cells. [Copyright &y& Elsevier]

Hepcidin negatively regulates the circulating iron levels by inhibiting the intestinal absorption of iron as well as iron release from macrophages. Hepcidin activity is largely determined by its expression, which is regulated at the transcriptional level. Hepcidin transcription is induced not only by the iron status‐related bone morphogenetic protein (BMP)‐2/6, but also by inflammatory cytokines, such as interleukin (IL)‐1β and IL‐6. The present study reveals that the microphthalmia (MiT)/transcription factor E (TFE) family members are novel regulators of hepcidin transcription. Melanocyte‐inducing transcription factor (MITF)‐A, a member of the MiT/TFE family, was identified as a positive regulator of hepcidin transcription via stimulus screening for transcription regulators. An E‐box (5′‐CATGTG‐3′) spanning nt‐645 to nt‐640 of the murine hepcidin promoter was identified as an MITF‐A‐responsive element. Responsiveness to MITF‐A on hepcidin transcription decreased when the cells were stimulated with BMP2 or IL‐1β. These results suggest a functional interaction between the MITF pathway and BMP‐ or IL‐1β‐mediated signaling. TFEB and TFE3, members of the MiT/TFE family, also stimulated hepcidin transcription, but the main region responsible for hepcidin transcription was distinct from that induced by MITF‐A. The region spanning nt‐581 to nt‐526 was involved in TFEB/TFE3‐mediated hepcidin transcription. Considering that members of the MiT/TFE family act as regulators of starvation‐induced lysosomal biogenesis, hepcidin expression may be controlled by additional pathways apart from those identified so far. Significance statement: Systemic iron levels are negatively regulated by hepatic transcription of hepcidin. Hepcidin transcription has been shown to be mainly regulated by iron levels and inflammation, but recent evidence suggested the involvement of the other factors in hepcidin transcription. The present study identified novel inducers of hepcidin transcription; melanocyte‐inducing transcription factor (MITF)‐A, TFEB, and TFE3, members of the MiT/TFE family, stimulated hepcidin transcription. MITF‐A modified the bone morphogenetic protein‐ or interleukin‐1β‐mediated hepcidin transcription. Furthermore, region responsible for MITF‐mediated hepcidin transcription was distinct from that induced by TFEB/TFE3. Considering that members of the microphthalmia/transcription factor E (TFE) family act as regulators of starvation‐induced lysosomal biogenesis, hepcidin expression may be controlled by additional pathways apart from those identified so far. [ABSTRACT FROM AUTHOR]

Presents a study on bone growth and myofibrillar protein degradation, after early weaning in calves. Experimental methods use; Detrimental effects on nitrogen and calcium retention.

Estimates age-related changes in duodenal flow of microbial nitrogen in calves after weaning by determining endogenous excretion of purine derivatives and the ratio of excretion into urine as PD to duodenal flow of purine bases. Experimental design; Administration of acid-free milk replacer; Administration of purine bases into the abomasum.

Myogenesis is a complex process that is regulated by a variety of factors. We have previously shown that vitamin C and mild endoplasmic reticulum stress synergistically enhance myogenesis. The present study evaluated the effects of vitamin C (ascorbic acid (AsA) and AsA 2-phosphate (AsAp)) and extracellular signal-regulated kinase (ERK) 1/2 pathway on myogenesis. Treatment with U0126, an inhibitor of MEK1/2 that phosphorylates and activates ERK1/2, during the differentiation, increased the mRNA levels of Myod and Myog with an increase in the protein level of myosin heavy chain (MYH)1/2. Treatment with AsA or AsAp alone had minimal effects on myogenesis in C2C12 cells. However, combination treatment with vitamin C and U0126 greatly enhanced myogenesis; the number of thick and long myotubes was increased, and the expression of MYH1/2 was also increased. PD98059, another MEK1/2 inhibitor, also enhanced myogenesis in combination with vitamin C. These results indicate that relief of endogenous ERK1/2 activity enhances vitamin C-mediated myogenesis, suggesting a functional interaction between endogenous ERK1/2 activity and vitamin C. In addition, inhibition of p38 mitogen-activated protein kinase repressed myogenesis in the presence of vitamin C. Thus, vitamin C is a conditional factor that modulates myogenesis. • Endogenous ERK1/2 activity negatively regulates myogenesis. • Inhibition of ERK activity greatly enhances vitamin C-stimulated myogenesis. • Inhibition of p38 MAP kinase represses myogenesis in the presence of vitamin C. • The role of endogenous JNK activity is similar to that of endogenous ERK1/2 activity. [ABSTRACT FROM AUTHOR]

No Abstract available [ABSTRACT FROM AUTHOR]

Activin B, a homodimer of the inhibin βB subunit, acts as a regulator of gonadal function and as an adipokine. To clarify the role of activin B in dogs, we characterized the canine inhibin βB gene and signalling pathways regulated by the canine inhibin βB. Using 5′‐ and 3′‐rapid amplification of cDNA end (RACE) and RT‐PCR on RNA isolated from the ovary of dogs, we identified short and long forms of the inhibin βB gene. Immunoreactive inhibin βB molecules were detected at ~25 and ~14 kDa under nonreducing and reducing conditions, respectively, in culture supernatants from HEK293 cells transfected with a plasmid containing the long form of the inhibin βB gene, indicating activin B production and secretion. Similar to human and murine activin B, the canine activin B‐stimulated transcriptions of reporter genes, CAGA‐luc and Hepcidin‐luc, regulated by the canonical activin/transforming growth factor‐β (TGF‐β) and bone morphogenetic protein (BMP) pathway, respectively. Activin B‐induced CAGA‐luc transcription was not detected in ALK7‐deficient MDCK canine‐derived cells; however, the forced expression of ALK7 resulted in the activin B‐dependent expression in MDCK cells. Unexpectedly, the activin B‐induced activation of the BMP pathway was partially blocked by the inhibition of endogenous activin/TGF‐β receptor activity. The present study identified an experimentally isolated long form of the canine inhibin βB gene producing activin B that transactivates BMP‐ and activin/TGF‐β‐regulated gene expression. [ABSTRACT FROM AUTHOR]

Myogenesis is a complex process regulated by several factors. This study evaluated the functional interaction between vitamin C and a high dose of capsaicin (a potential endoplasmic reticulum (ER) stress inducer) on myogenesis. After the induction of differentiation, treatment with ascorbic acid or ascorbic acid phosphate (AsAp) alone had minimal effects on myogenesis in C2C12 cells. However, treatment with capsaicin (300 μM) in undifferentiated C2C12 cells increased the expression levels of genes related to ER stress as well as oxidative stress. Myogenesis was effectively enhanced in C2C12 cells treated with a combination of capsaicin (300 μM) for one day before differentiation stimulation and AsAp for four days post-differentiation; subsequently, thick and long myotubes formed, and the expression levels of myosin heavy chain (MYH) 1/2 and Myh1, Myh4, and Myh7 increased. Considering that mild ER stress stimulates myogenesis, AsAp may elicit myogenesis through the alleviation of oxidative stress-induced negative effects in capsaicin-pretreated cells. The enhanced expression of Myh1 and Myh4 coincided with the expression of Col1a1 , a type I collagen, suggesting that the fine-tuning of the myogenic cell microenvironment is responsible for efficient myogenesis. Our results indicate that vitamin C is a potential stimulator of myogenesis in cells, depending on the cell context. • High-dose capsaicin induces ER stress in undifferentiated myogenic cells. • Vitamin C enhances myogenesis in capsaicin-pretreated cells. • Modulation of extracellular matrix may be involved in vitamin C-induced myogenesis. [ABSTRACT FROM AUTHOR]

A metabolomic study was performed on the kidneys and skeletal muscles of rats fed diets containing varying contents of Mg for 4 weeks. The kidneys are divided into two parts, the aerobic cortex and the anaerobic medulla, that differ in metabolism. The relative contents of 3-phosphoglyceric acid, 2-phosphoglyceric acid, and phosphoenolpyruvic acid increased with Mg restriction in both renal regions. In contrast, pyruvic acid content decreased with Mg restriction in the diets, suggesting an inhibitory conversion of phosphoenolpyruvic acid to pyruvic acid. The lactic acid content increased in both regions of the kidneys of Mg-restricted rats, implying changes towards a more glycolytic metabolism, possibly resulting from the impairment of mitochondrial function. There are two types of muscle fibers: glycolytic fast and oxidative slow muscle fibers. The soleus muscle consists of slow muscle fibers, whereas the gastrocnemius muscle consists of a combination of fast and slow muscle fibers. Similar to the changes in the kidneys, the contents of 3-phosphoglyceric acid, 2-phosphoglyceric acid, phosphoenolpyruvic acid, and lactic acid increased in the soleus and gastrocnemius muscles with dietary Mg restriction. Unlike in the kidney, pyruvic acid content increased in the soleus muscle in response to Mg restriction. Severe Mg restriction decreased contents of carnosine and its constituent β-alanine and increased the levels of purine derivatives such as xanthine and uric acid in the gastrocnemius muscle. The present study suggests a region-dependent sensitivity to dietary restriction of Mg, which may lead to the onset of various metabolic disorders. [ABSTRACT FROM AUTHOR]

Three types of adipocytes, white, brown, and beige, regulate the systemic energy balance through the storage and expenditure of chemical energy. In addition, adipocytes produce various bioactive molecules known as adipokines. In contrast to white adipocyte‐derived molecules, less information is available on the adipokines produced by brown adipocytes (batokine). This study explored the regulatory expression of interleukin (IL)‐6 in cell culture studies. Norepinephrine or a nonselective β‐adrenergic receptor agonist increased the expression of IL‐6 in primary brown adipocytes and HB2 brown adipocytes. Treatment with forskolin (Fsk), an activator of the cAMP‐dependent protein kinase (PKA) pathway (downstream signaling of the β‐adrenergic receptor), efficiently stimulated IL‐6 expression in brown adipocytes and myotubes. Phosphorylated CREB and phosphorylated p38 MAP kinase levels were increased in Fsk‐treated brown adipocytes within 5 min. In contrast, a long‐term (∼60 min and ∼4 h) treatment with Fsk was required for increase in STAT3 phosphorylation and C/EBPβ expression, respectively. The PKA, p38 MAP kinase, STAT3, and C/EBPβ pathways are required for the maximal IL‐6 expression induced by Fsk, which were verified by use of various inhibitors of these signal pathways. Vitamin C enhanced Fsk‐induced IL‐6 expression through the extracellular signal‐regulated kinase activity. The present study provides basic information on the regulatory expression of IL‐6 in activated brown adipocytes. Significance statement: White adipocytes accumulate excess energy as fat, whereas brown adipocytes consume the chemical energy of fat and carbohydrates as heat. Adipocytes also secrete bioactive molecules called adipokine. Interleukin‐6 (IL‐6) is produced not only in white adipocytes but also brown adipocytes, but the regulation of IL‐6 expression in brown adipocytes is unclear. We explored the mechanisms underlying IL‐6 gene induction in activated brown adipocytes. Forskolin increased IL‐6 expression in brown adipocytes through stimulated phosphorylation of CREB, p38 MAP kinase, and STAT3. In addition, C/EBPβ induction was required for the enhancement of IL‐6 induction. Vitamin C also promoted forskolin‐induced IL‐6 expression. The present study provides basic information on the regulatory expression of IL‐6 in activated brown adipocytes. [ABSTRACT FROM AUTHOR]

Hepcidin negatively regulates systemic iron levels by inhibiting iron entry into the circulation. Hepcidin production is increased in response to an increase in systemic iron via the activation of the bone morphogenetic protein (BMP) pathway. Regulation of hepcidin expression by iron status has been proposed on the basis of evidence mainly from rodents and humans. We evaluated the effect of iron administration on plasma hepcidin concentrations in calves and the expression of bovine hepcidin by the BMP pathway in a cell culture study. Hematocrit as well as levels of blood hemoglobin and plasma iron were lower than the reference level in calves aged 1–4 weeks. Although intramuscular administration of iron increased iron‐related parameters, plasma hepcidin concentrations were unaffected. Treatment with BMP6 increased hepcidin expression in human liver‐derived cells but not in bovine liver‐derived cells. A luciferase‐based reporter assay revealed that Smad4 was required for hepcidin reporter transcription induced by Smad1. The reporter activity of hepcidin was lower in the cells transfected with bovine Smad4 than in those transfected with murine Smad4. The lower expression levels of bovine Smad4 were responsible for the lower activity of the hepcidin reporter, which might be due to the instability of bovine Smad4 mRNA. In fact, the endogenous Smad4 protein levels were lower in bovine cells than in human and murine cells. Smad4 also confers TGF‐β/activin‐mediated signaling. Induction of TGF‐β‐responsive genes was also lower after treatment with TGF‐β1 in bovine hepatocytes than in human hepatoma cells. We revealed the unique regulation of bovine hepcidin expression and the characteristic TGF‐β family signaling mediated by bovine Smad4. The present study suggests that knowledge of the regulatory expression of hepcidin as well as TGF‐β family signaling obtained in murine and human cells is not always applicable to bovine cells. [ABSTRACT FROM AUTHOR]

Long-distance transportation is sometimes inevitable in the beef industry because of the geographic separation of major breeding and fattening areas. Long-distance transportation negatively impacts production and health of cattle, which may, at least partly, result from the disturbance of metabolism during and after transportation. However, alteration of metabolism remains elusive in transported cattle. We investigated the effects of transportation on the metabolomic profiles of Holstein steer calves. Non-targeted analysis of serum concentrations of low molecular weight metabolites was performed by gas chromatography mass spectrometry. Transportation affected 38 metabolites in the serum. A pathway analysis suggested that 26, 10, and 10 pathways were affected immediately after transportation, and 3 and 7 days after transportation, respectively. Some pathways were disturbed only immediately after transportation, likely because of feed and water withdrawal during transit. Nicotinate and nicotinamide metabolism, and citric acid cycle were affected for 3 days after transportation, whereas propionate metabolism, phenylalanine and tyrosine metabolism were affected throughout the experiment. Four pathways were not affected immediately after transportation, but were altered thereafter. These results suggested that many metabolic pathways had marked perturbations during transportation. Metabolites such as citric acid, propionate, tyrosine and niacin can be candidate supplements for mitigating transportation-induced adverse effects. [ABSTRACT FROM AUTHOR]

A previous study revealed that the expression of the Borna disease virus (BDV)-encoding phosphoprotein in glial cells was sufficient to induce neurobehavioral abnormalities resembling Borna disease. To evaluate the involvement of the TGF-β family in BDV-induced changes in cell responses by C6 glial cells, we examined the expression levels of the TGF-β family and effects of inhibiting the TGF-β family pathway in BDV-infected C6 (C6BV) cells. The expression of activin βA and BMP7 was markedly increased in BDV-infected cells. Expression of Smad7, a TGF-β family-inducible gene, was increased by BDV infection, and the expression was decreased by treatment with A-83-01 or LDN-193189, inhibitors of the TGF-β/activin or BMP pathway, respectively. These results suggest autocrine effects of activin A and BMP7 in C6BV cells. IGFBP-3 expression was also induced by BDV infection; it was below the detection limit in C6 cells. The expression level of IGFBP-3 was decreased by LDN-193189 in C6BV cells, suggesting that endogenous BMP activity is responsible for IGFBP-3 gene induction. Our results reveal the regulatory expression of genes related to the TGF-β family, and the role of the enhanced BMP pathway in modulating cell responses in BDV-infected glial cells. [ABSTRACT FROM AUTHOR]

Abstract: Background: The roles of microphthalmia-associated transcription factor (Mitf) in the skeletal muscle and during myogenesis are unclear. Methods: Expression of Mitf in mouse tissues and during myogenesis was evaluated. Effects of Mitf knockdown on myogenesis and gene expression related to myogenesis were subsequently explored. Furthermore, effects of p21, a cyclin-dependent kinase inhibitor, and integrin α9 (Itga9) were examined. Results: Mitf was highly expressed in the skeletal muscle; Mitf-A and -J were expressed. Mitf expression increased after differentiation stimulation in C2C12 myogenic cells. Down-regulation of Mitf expression by transfection of siRNA for common Mitf inhibited myotube formation, which was reproduced by Mitf-A knockdown. Morphometric analyses indicated that both multinucleated cell number and the proportion of myotubes with more than 6 nuclei were decreased in Mitf-knockdown cells, suggesting that Mitf is required for not only the formation of nascent myotubes but also their maturation. Searching for genes positively regulated by Mitf revealed p21 and Itga9; decreasing Mitf expression inhibited up-regulation of p21 expression after differentiation stimulation and blocked the induction of Itga9 expression in response to differentiation. Knockdown of p21 decreased the number of multinucleated cells, whereas Itga9 knockdown did not affect the myotube number. Both p21 knockdown and Itga9 knockdown decreased the proportion of myotubes with more than 6 nuclei. General significance: Mitf positively regulates skeletal muscle formation; Mitf is significantly expressed during myogenesis, and is required for efficient myotube formation through expression of p21 and Itga9. [Copyright &y& Elsevier]

ABSTRACT We determined the true absorption and endogenous fecal loss of zinc (Zn) in goats using its stable isotope. Three goats were fed with the diet containing 50 mg/kg Zn twice a day for 17 days. In the morning of day 11, the goats were given a meal labeled by 67Zn as the tracer with dysprosium as the unabsorbed marker. Then the goats were given unlabeled diet as the rest of the morning feed. We measured dietary and fecal Zn concentration, 67Zn abundance and dysprosium concentration in feces. The excretion pattern of the tracer Zn into feces differed from that of dysprosium. Therefore, we directly calculated the true absorption of Zn from Zn concentration and 67Zn abundance in fecal samples collected after the labeled diet was given. The apparent absorption of Zn was -0.009 ± 0.016 mg/kg bodyweight (fractional absorption, −1.07 ± 1.85%). The true absorption of Zn was 0.162 ± 0.018 mg/kg bodyweight (fractional absorption, 18.25 ± 2.01%). The endogenous fecal loss of Zn was 0.172 ± 0.004 mg/kg bodyweight and the intestinal secretion of Zn was 0.210 ± 0.009 mg/kg bodyweight. The present experiment indicates that stable isotopic Zn is a powerful tool for examining Zn metabolism in ruminants. [ABSTRACT FROM AUTHOR]

Changes in gene expression of TGF- β family members and their receptors in response to treatment with H2O2 and a calcium ionophore, A23187, were examined in C2C12 myoblasts and myotubes. The expression of Myf5, an initial regulator of myogenesis, was increased by A23187, and H2O2 inhibited the up-regulation of Myf5. Treatment with H2O2 decreased the expression of MHC IIb, a protein component of the myofibrils, irrespective of the presence of A23187, suggesting an inhibitory role of oxidative stress for myogenesis. Expression of ligands and receptors for the TGF- β family was modulated in response to H2O2 and A23187. Treatment with H2O2 decreased expression of TGF-β3, BMP-4, ALK4, ALK5, and ActRIIB, and increased expression of inhibin α and inhibin βA in either the myoblast stage or the myotube stage, or both. A23187 potentiated down-regulation of BMP-4 and ALK4 expression, and up-regulation of TGF-β1, TGF-β2, inhibin α, inhibin βA, ALK2, and ALK3 expression. These results indicate that oxidative stress and Ca2+ influx affect expression of the TGF- β family in C2C12 myoblasts and myotubes. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

While analyzing the role of c-Jun NH2-terminal kinase (JNK) in neurogenesis in P19 embryonal carcinoma cells, we noticed that treatment with SP600125, a JNK inhibitor, increased the cell size markedly. SP600125-induced enlargement of P19 cells was time- and dose-dependent. The increased cell size in response to SP600125 was also detected in B6mt-1 embryonic stem cells. SP600125 treatment inhibited cell growth and increased DNA contents, indicating the inhibition of cell proliferation resulting from endoreduplication. Concurrently, the gene expression of p21, a regulator of G2/M arrest as well as G1 arrest, was increased in cells treated with SP600125. The increased cell size in response to SP600125 was detected even in P19 cells treated with colcemide, an inhibitor of cell cycle progression at the metaphase. The present study suggests that treatment with SP600125 progresses the cell cycle, skipping cytokinesis in P19 cells. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Microbes such as yeast and Aspergillus are known to produce phytase, and Aspergillus phytase has been used as a feed additive for improving phytate-phosphorus bioavailability in monogastric animals. We measured phytase activity in some by-products from fermented food and beverage productions by yeast and Aspergillus. The phytase activity was as high as 3577 and 2225 PU/kg DM in raw and dried brewer's yeasts, respectively. On the other hand, the phytase activity was approximately 400 PU/kg DM in white-wine yeast and red-wine yeast. The phytase activity was further low in natto (fermented soybean) residue, soy sauce cake, rice brewer's grain and the activity was not detected in dried corn-barley distiller's grain with soluble and sweet-potato distiller's residue. The stability of phytase against pepsin was much lower in the brewer's yeast than in an Aspergillus phytase preparation. On the other hand, the addition of raw brewer's yeast effectively degraded phytate phosphorus in a corn-soybean meal diet during soaking. These results suggest that phytase in the examined by-products is not suitable for the phytase source of conventional diets, but that the soaking treatment with a raw brewer's yeast is an alternative method for improving phytate-phosphorus bioavailability in corn-soybean meal diets for pigs. [ABSTRACT FROM AUTHOR]

Abstract: Mouse TGF-β type I receptor, Alk5, encodes two types of mRNA generated by alternative splicing of four amino acids in the extracellular region. In the present study, the expression and function of alternative splice variants of Alk5, i.e., Alk5-L (Alk5 with the four amino acids) and Alk5-S (Alk5 without the four amino acids), were examined. Expression of Alk5 was detected in all examined tissues, and no significant differences in the ratio of Alk5-S to Alk5-L were detected between tissues. Expression of Alk5 was also detected in various cells, with Alk5-L being especially abundant in A-6 ES cells when it was examined by RT-PCR and subsequent image analyses. No clear difference in Smad2 phosphorylation in response to treatment with TGF-β1 was detected between L17 cells expressing Alk5-S and those expressing Alk5-L. Consistent with these results, transcription mediated by Alk5-S in L17 cells treated with TGF-β1 was comparable to that mediated by Alk5-L. In addition, alternative splicing had no effect on transcriptional activation induced by GDF-8, a member of the TGF-β family. The present results indicate ubiquitous expression of Alk5 isoforms in mouse tissues and cells, and insignificant effects of alternative splicing on signaling induced by TGF-β1 and GDF-8. [Copyright &y& Elsevier]

Three methods to quantify gene transcript levels in mast cells, real-time RT-PCR, competitive RT-PCR and conventional RT-PCR analyses, were compared. Linear regression analysis on five gene transcripts revealed that the mRNA levels measured by real-time RT-PCR analysis were minimally correlated with those by conventional RT-PCR analysis. In addition, differences in the mRNA level between samples measured by conventional RT-PCR analysis were smaller than those by real-time RT-PCR analysis, suggesting that conventional RT-PCR analysis is less sensitive at measuring mRNA levels. Results from competitive RT-PCR analysis correlated closely with those from real-time RT-PCR analysis. When the differences in mRNA level between samples are relatively smaller, however, the correlation tended to be weaker. Real-time RT-PCR analysis has higher reliability, but is expensive. In contrast, competitive RT-PCR analysis is inexpensive, but is weaker at detecting smaller differences in gene transcript level between samples. Therefore, the most appropriate analytical method to measure mRNA levels should be chosen, depending on the experimental conditions. [Copyright &y& Elsevier]

Identifies limiting amino acids in weanling calves fed a corn and soybean meal (SBM) diet. Materials and methods used; Information on some free amino acids (AA) immediately before and after morning feeding; Results and discussion of the study.

Uncoupling protein 1 (UCP1) is responsible for non‐shivering thermogenesis, with restricted expression in brown/beige adipocytes in humans and rodents. We have previously shown an unexpected expression of UCP1 in bovine skeletal muscles. This study evaluated factors affecting Ucp1 gene expression in cultured bovine myogenic cells. Myosatellite cells, which were isolated from the bovine musculus longissimus cervicis, were induced to differentiate into myotubes in the presence of 2% horse serum. Previous studies using murine brown/beige adipocytes revealed that Ucp1 expression levels are directly increased by forskolin and all‐trans retinoic acid (RA). The transforming growth factor‐β (TGF‐β)/activin pathway negatively regulated Ucp1 expression, whereas activation of the bone morphogenetic protein (BMP) pathway indirectly increases Ucp1 expression through the stimulation of brown/beige adipogenesis. Neither forskolin nor RA significantly affected Ucp1 mRNA levels in bovine myogenic cells. A‐83‐01, an inhibitor of the TGF‐β/activin pathway, stimulated myogenesis in these cells. A‐83‐01 significantly increased the expression of some brown fat signature genes such as Pgc‐1α, Cox7a1, and Dio2, with a quantitative but not significant increase in the expression of Ucp1. Treatment with LDN‐193189, an inhibitor of the BMP pathway, did not affect the differentiation of bovine myosatellite cells. Rather, LDN‐193189 increased Ucp1 mRNA levels without modulating the levels of other brown/beige adipocyte‐related genes. The current results indicate that the regulation of Ucp1 expression in bovine myogenic cells is distinct from that in murine brown/beige adipocytes, which has been more intensely characterized. Significance of the study: We previously reported unexpected expression of Ucp1 in bovine muscle tissues; Ucp1 expression has been known to be detected predominantly in brown/beige adipocytes. This study examined regulatory expression of bovine Ucp1 in myogenic cells. Consistent with the changes in expression levels of brown/beige adipocyte‐selective genes, Ucp1 expression tended to be increased by inhibition of endogenous TGF‐β activity. In contrast, inhibition of endogenous BMP significantly increased Ucp1 expression without affecting brown/beige adipocyte‐selective gene expression. The current results indicate that regulatory expression of Ucp1 in bovine myogenic cells is distinct from that in murine brown/beige adipocytes that is more intensely characterized. [ABSTRACT FROM AUTHOR]

Beige adipocytes and brown adipocytes can generate heat by using mitochondrial uncoupling protein 1 (Ucp1), a thermogenic protein. Browning/beiging is the emergence of beige adipocytes in white adipose tissues (WAT) for cold acclimatization. Here we show the existence of brown/beige adipocytes in retro-orbital WAT in mice. Histologically, Ucp1-positive cells with multilocular lipid droplets were abundant in retro-orbital WAT of immature mice; those cells decreased in number with age. However, Ucp1-positive adipocytes with multilocular lipid droplets emerged in retro-orbital WAT in adult mice, due to cold exposure as short as 3 h. Consistent with this observation, the expression level of Ucp1 mRNA was enhanced in tissues upon cold exposure. Furthermore, eye surface temperature remained within a physiological range during cold challenge. RT-qPCR suggested a mixed phenotype of brown and beige adipocytes in retro-orbital WAT. Transmission electron microscopic observation showed multiple lipid droplets and numerous mitochondria with high cristae density in retro-orbital WAT cells from both control and cold-exposed mice. Our results suggest that warming of the orbital cavity by browning/beiging in retro-orbital WAT is a protective mechanism against cold cataract caused by lowered lens temperature. • Retro-orbital WAT has Ucp1 positive adipocytes in juvenile mice, while the cells decrease in number in adult mice. • Consistently, the eye surface temperature was decreased with aging. • The Ucp1 positive adipocytes in retro-orbital WAT were inducible by cold exposure. • The Ucp1 positive adipocytes exhibited mixed signature of brown/beige adipocytes. [ABSTRACT FROM AUTHOR]

Dietary vitamin A status affects energy metabolism. The present study explored the effect of all‐trans retinoic acid (ATRA) on the expression levels of molecules and metabolites of brown adipocytes. Chronic ATRA treatment was initiated during the early stage (days 0‐8) or late stage (days 8‐12) of adipogenesis. Treatment with ATRA during the early and late stage of adipogenesis resulted in an increase in the expression level of Ucp1 and Cidea, genes highly expressed in brown adipocytes, on day 8 and day 12, respectively, whereas expression of Pgc‐1α, another gene expressed during brown adipogenesis, was unaffected by ATRA. Non‐targeted metabolomic analyses indicated that the pathways related to the glucose metabolism were affected by ATRA, irrespective of the differentiation stage. Cellular levels of glucose 6‐phosphate, fructose 6‐phosphate, citric acid, and succinic acid decreased after ATRA treatment on days 8 and 12. In contrast, glucose level was higher in ATRA‐treated cells on day 8, but it was lower on day 12. ATRA decreased the cellular level of aconitic acid, fumaric acid, and malic acid on day 12 but not on day 8. Furthermore, ATRA increased the expression level of Hxk2 and downregulated the expressions of G6pdh and Pfkl/Pfkp on day 8 but not on day 12. Together, the results indicate that the chronic treatment with ATRA stimulated the formation of activated brown adipocytes, eventually leading to alterations in the levels of cellular metabolites related to glucose metabolism. Significance of the study: Significance of the study treatment with all‐trans retinoic acid (ATRA) during the early and late stage of adipogenesis increased the expression of Ucp1 and Cidea, genes highly expressed in brown adipocytes, on day 8 and day 12. Cellular levels of glucose 6‐phosphate, fructose 6‐phosphate, citric acid, and succinic acid decreased after ATRA treatment on days 8 and 12. In contrast, glucose level was higher in ATRA‐treated cells on day 8, but it was lower on day 12. The present results indicate that ATRA stimulated the formation of activated brown adipocytes, eventually leading to alterations in the levels of cellular metabolites related to glucose metabolism. [ABSTRACT FROM AUTHOR]

Activity of brown/beige adipocytes is higher in women than in men. The expression level of uncoupling protein 1 (UCP1) is largely consistent with the thermogenic activity in brown/beige adipocytes. The present study examined the direct effects of sex hormones on Ucp1 expression in brown adipocytes and beige adipocytes, which were differentiated from HB2 brown preadipocytes and 3T3‐L1 white preadipocytes, respectively; treatment with estradiol or testosterone was used during the early (days 0‐8) or late stage (days 8‐12) of brown adipogenesis and beige adipogenesis. On day 8 or day 12, cells were treated with or without isoproterenol (Iso), an agonist for the β‐adrenergic receptor, for 4 hours. Furthermore, the sex of cells was examined; the sex‐determining region y gene, which is located on the y chromosome, was present in HB2 cells, but not in 3T3‐L1 cells, suggesting that HB2 cells and 3T3‐L1 cells are male and female cells, respectively. Treatment with 17β‐estradiol during the early stage of brown adipogenesis enhanced the responsiveness to Iso on Ucp1 induction, whereas treatment during the late stage of brown adipogenesis decreased Ucp1 expression in unstimulated brown adipocytes. Estradiol decreased Iso‐induced Ucp1 expression during the early stage of beige adipogenesis. Treatment with testosterone during the early stage of brown adipogenesis did not affect Ucp1 expression but increased the responsiveness to Iso on Ucp1 induction by the treatment during the late stage of brown adipogenesis. The present results suggest that sex hormones modulate the expression level of Ucp1 in brown/beige adipocytes in a stage‐dependent manner. Direct effects of sex hormones in brown/beige adipogenesis were evaluated. Treatment with 17β‐estradiol during the early stage of brown adipogenesis enhanced the responsiveness to isoproterenol (Iso), an agonist for the β‐adrenergic receptor, on Ucp1 induction, whereas treatment during the late stage of brown adipogenesis decreased Ucp1 expression in unstimulated brown adipocytes. Estradiol decreased Iso‐induced Ucp1 expression during the early stage of beige adipogenesis. Testosterone during the late stage of brown adipogenesis increased the responsiveness to Iso on Ucp1 induction. Sex hormones modulate the expression level of Ucp1 in brown/beige adipocytes in a stage‐dependent manner. [ABSTRACT FROM AUTHOR]

Highlights • IL-1β stimulates hepcidin transcription and phosphorylation of JNK and JunB. • IL-1β-induced JunB activation is required for hepcidin transcription. • JunB stimulates hepcidin transcription via CRE site B on the hepcidin promoter. • Binding of JunB to hepcidin promotor is increased by IL-1β. Abstract Hepcidin, a liver-derived hormone, negatively regulates circulating iron levels through an increase in its expression in response to iron overload. Inflammation also increases production of hepcidin, potentially leading to inflammatory anemia. We previously revealed that proinflammatory cytokine interleukin (IL)-1β increased hepcidin expression through its transcriptional stimulation in hepatocytes. Induction of CCAAT-enhancer-binding protein (C/EBP) δ and IL-6 in response to IL-1β treatment stimulated hepcidin transcription via the C/EBP-binding site (C/EBP-BS) and signal transducer and activator of transcription (STAT)-BS on the hepcidin promoter, respectively. Here, we show an additional pathway responsible for IL-1β-induced hepcidin transcription. IL-1β stimulated phosphorylation of c-Jun N-terminal kinase (JNK) and its substrates c-Jun and JunB. SP600125, a JNK inhibitor, blocked IL-1β-induced phosphorylation of c-Jun and JunB as well as IL-1β-induced expression and transcription of hepcidin. Reporter assays for hepcidin transcription revealed that reporters with mutations of cAMP response element (CRE) site B, a putative Jun binding element, decreased responsiveness to IL-1β, and that activated JunB, but not c-Jun, conferred IL-1β-induced hepcidin transcription. Furthermore, binding of JunB to hepcidin promoter was increased by IL-1β. The present study indicated that IL-1β activates JNK and subsequently stimulates JunB activation, leading to hepcidin transcription via CRE site B on the hepcidin promoter. The present experiment provides novel insights into the molecular mechanisms underlying induction of hepcidin by inflammation and alteration of iron homeostasis. [ABSTRACT FROM AUTHOR]

With longevity, the prevalence of osteoporosis, which occurs when the activity of osteoclast surpasses that of osteoblasts, has increased in dogs. However, limited information is available on canine osteoclastogenesis. We herein described culture conditions to induce osteoclasts from canine bone marrow cells, and identified factors affecting canine osteoclastogenesis. Tartrate-resistant acid phosphatase-positive multinucleated cells were efficiently formed in a culture of bone marrow mononuclear cells with macrophage colony-stimulating factor (M-CSF 25 ng/mL) for 3 days and a subsequent culture in the presence of M-CSF (25 ng/mL) and soluble receptor activator of NF-κB ligand (RANKL 50 ng/mL) for 4 days. We previously reported in a murine cell system that gene induction of the E isoform of microphthalmia-associated transcription factor (Mitf-E) was required and sufficient for osteoclastogenesis, while transforming growth factor-β (TGF-β) enhanced RANKL-induced Mitf-E expression and osteoclastogenesis. Mitf-E expression also increased during RANKL-induced osteoclastogenesis in canine cells; however, TGF-β down-regulated Mitf-E expression and osteoclastogenesis, indicating a species-dependent response. The results of the present study show that, consistent with murine cells, M-CSF and soluble RANKL enable canine bone marrow cells to differentiate into osteoclasts, and Mitf-E expression is induced during osteoclastogenesis. However, the role of TGF-β in osteoclast formation is distinct between murine and canine cells, suggesting the necessity of analyses using canine cells to examine the factors affecting canine osteoclastogenesis. [ABSTRACT FROM AUTHOR]

Brown/beige adipocytes dissipate energy as heat. We previously showed that brown/beige adipocytes are present in white adipose tissue (WAT) of fattening cattle. The present study examined the effect of vitamin A restriction on mRNA expression of brown/beige adipocyte-related genes. In Japan, fattening cattle are conventionally fed a vitamin A-restricted diet to improve beef marbling. Twelve Japanese Black steers aged 10 mo were fed control feed (n = 6) or vitamin A-restricted feed (n = 6) for 20 mo. Subcutaneous WAT (scWAT) and mesenteric WAT (mesWAT) were collected, and mRNA expression levels of molecules related to the function of brown/beige adipocytes (Ucp1, Cidea, Dio2, Cox7a, and Cox8b) as well as transcriptional regulators related to brown/beige adipogenesis (Zfp516, Nfia, Prdm16, and Pgc-1a) were evaluated. The vitamin A restriction significantly increased or tended to increase expression levels of Cidea and Pgc-1a in scWAT, and Cidea, Dio2, and Nfia in mesWAT. Previous studies revealed that the bone morphogenetic protein (Bmp) pathway was responsible for commitment of mesenchymal stem cells to brown/beige adipocyte-lineage cells. The vitamin A restriction increased expression of Bmp7 and some Bmp receptors in WAT. The interrelationship between gene expression levels indicated that expression levels of Nfia, Prdm16, and Pgc-1a were closely related to those of genes related to the function of brown/beige adipocytes in scWAT. Also, expression levels of Nfia, Prdm16, and Pgc- 1a were highly correlated with those of Alk3 in scWAT. In summary, the present results suggest that the vitamin A restriction increases the number or activity of brown/beige adipocytes through regulatory expression of transcriptional regulators to induce brown/beige adipogenesis, especially in scWAT of fattening cattle, which may be governed by the Bmp pathway. [ABSTRACT FROM AUTHOR]

The liver is the organ that responds to nutritional disturbances including magnesium deficiency. The present study evaluated cellular responses to magnesium deficiency using model cells of the liver, namely, HepG2 cells as hepatocytes, RAW264.7 cells as Kupffer cells and human umbilical vein endothelial cells (HUVECs) as vascular endothelial cells; we examined effects of culture with magnesium deficient medium on cell responses in individual types of cells as well as interactive responses among cells. Metabolomic analyses indicated that magnesium deficiency differentially affected the cellular content of metabolites among HepG2 cells, RAW264.7 cells and HUVECs. The cellular content of the metabolites in HepG2 cells and HUVECs was also affected by the conditioned medium from RAW264.7 cells cultured with the magnesium-deficient media. The changes in HUVECs partly resembled those of the livers of magnesium-deficient rats previously described. RNA-seq analyses indicated that magnesium deficiency modulated the expression levels of molecules related to the ubiquitin-proteasome pathway and oxidative stress/antioxidant response in HepG2 cells and RAW264.7 cells, respectively. Furthermore, when HUVECs were co-cultured with RAW264.7 cells, lipopolysaccharide-induced expression of interleukin (IL)-1β and IL-6 was enhanced by magnesium deficiency, depending on the presence of RAW264.7 cells. The present study reveals that magnesium deficiency affects cellular metabolism in HepG2 liver cells, RAW264.7 macrophages and HUVECs, and that the modulation of cellular responses to extracellular magnesium deficiency in HUVECs depends on the presence of RAW264.7 cells. The complex responses in individual cells and through cell interactions partly explain the regulatory reaction to magnesium deficiency in the liver. [ABSTRACT FROM AUTHOR]

Hepcidin plays a central role in systemic iron metabolism. The bone morphogenetic protein (BMP) pathway regulates expression of hepcidin through transcriptional activation via BMP-responsive elements (REs) 1 and 2 on the promoter. Previous studies also revealed that the BMP pathway stimulates transcription of its target genes via GC-rich sequences on the promoter. A search for GC-rich sequences on the hepcidin promoter indicated 13 regions across the distal (A to F), middle (G to I), and proximal (J to M) areas; among them, mutations of the GC-rich element found in regions B to D exhibited decreased responsiveness to ALK3(QD) expression in the presence of BMP-RE1 mutations, indicating necessity of the elements for full expression of hepcidin by the BMP pathway. [ABSTRACT FROM AUTHOR]

Four Japanese Black steers (16 months of age) were assigned to a 4 × 4 Latin square design to investigate the effect of graded levels of sweet-potato condensed distillers solubles (SCDS) in their diets on intake and urinary excretion of minerals. The four diets consisted of 0%, 10%, 20% and 30% (dry matter (DM) basis) SCDS, with SCDS replacing commercial concentrate (CC). Intake of K, Cl, S, P and Mg increased linearly with increasing SCDS content. Urinary pH increased linearly with increasing dietary SCDS content. SCDS feeding increased urinary K concentrations (linear and quadratic effects). Urinary concentrations of Cl increased linearly with increasing SCDS content. In contrast, urinary concentrations of Mg decreased with increasing SCDS content. Feeding of SCDS did not apparently affect urinary NH3,P, Na or Ca concentrations. These results suggest that high SCDS feeding is not a risk for crystallization of minerals leading to the formation of magnesium-phosphate type calculi: although SCDS contains large amounts of P and Mg, high SCDS feeding decreased the Mg concentration and did not affect the P concentration in urine. Additionally, high SCDS feeding had no apparent effects on plasma concentrations of Na, K, Cl, Ca or inorganic P. [ABSTRACT FROM AUTHOR]