PPARγ/Pgc-1α-Fndc5 pathway up-regulation in gastrocnemius and heart muscle of exercised, branched chain amino acid diet fed mice.

BACKGROUND: Previous studies have revealed the inductive effect of branched-chain amino acids (BCAAs) catabolism on fatty acid oxidation and metabolism, especially in muscle cells. In the present investigation, we have attempted to address whether a combination of BCAAs supplement consumption with aerobic exercise could elaborate the expression of PPARγ, Pgc-1α and Fndc5 genes in gastrocnemius muscle and heart tissue of male C57BL/6 mice. METHODS: Thirty-six young male mice with an average weight of 18 ± 2 g were selected. Mice were randomly assigned to 6 groups: 20 mg/mL of BCAAs consumption with simultaneous exercise-training, 60 mg/mL of BCAAs consumption with simultaneous exercise-training, exercise-trained with no BCAAs consumption group, 20 mg/mL BCAAs without exercise-training, 60 mg/mL BCAAs without exercise-training, and untrained mice without BCAAs consumption. RESULTS: The findings showed a combination of 20 mg/mL BCAAs with aerobic exercise significantly increased Fndc5, PPARγ, Pgc-1α gene expression in skeletal muscles although, circulating Irisin levels remained unchanged (p < 0.05). Interestingly, plasma urea and lactate levels were significantly increased in 60 mg/mL BCAAs administrated mice which performed exercised (p < 0.05). Two-way analysis of variance (ANOVA) was used to examine significant difference between groups and sedentary group. CONCLUSIONS: Results showed inductive effect of 20 mg/mL BCAAs on expression levels of Fndc5, PPARγ, Pgc-1α in gastrocnemius muscle similar with counterparts in heart tissue. Of note, higher serum irisin levels were detected after 20 mg/mL BCAAs supplementation coincided with the exercise. GRAPHICAL ABSTRACT: An Overview on supplemantaion of branched chain amoinoacids on metablism of skeletal muscle and heart.

Identification, cloning, and functional analysis of the TATA-less mouse FNDC5 promoter during neural differentiation.

FNDC5 (also termed PEP) gene encodes a type I membrane protein which is cleaved and secreted as Irisin hormone. We have identified mouse putative core promoter of FNDC5 and characterized its activity. FNDC5 is located within mouse chromosome 4, spans about 7,534 bp, and consists of 6 exons. The mouse FNDC5 promoter is TATA-less and lacks a consensus initiator sequence. In silico analyses revealed that the core promoter (-561/+101 with respect to translation start site) is located in a GC-rich domain (approximately 70.01 %) with one CpG island as a promoter index and several GC box factors including GC/SP1 which is necessary for transcription of TATA-less promoters. The core promoter showed a lower activity than CMV promoter in CHO and P19 cell lines when located upstream of EGFP CDS in an appropriate expression vector. Data implicated that both exon 1 and intron 1 of the gene are included in the core promoter. Upon treating with retinoic acid, FNDC5 expression was upregulated during embryoid body formation and decreased slowly at final stage of neural differentiation when neurospheres emerged. However, Noggin induction induced up regulation of FNDC5 expression at final stage of neural differentiation. In conclusion, stage dependent expression of FNDC5 is affected by neural induction method used for neural differentiation.

Amplification of GC-rich Putative Mouse PeP Promoter using Betaine and DMSO in Ammonium Sulfate Polymerase Chain Reaction Buffer.

BACKGROUND: Recently, we have shown that peroxisomal protein expression was induced upon retinoic acid treatment in mouse embryonic stem cells during the process of neurogenesis. Thus, characterization of the respective promoter could elucidate the molecular aspects of transcriptional regulation of this gene. METHODS: Using the conventional software programs for promoter prediction, a putative promoter region was identified approximately 561 bp upstream of the peroxisomal protein coding sequence. In order to clone this region with a GC-content of 71.01%, a cocktail of ammonium sulfate buffer supplied with two additive components, betaine and dimethyl sulfoxide, and a high concentration of MgCl(2) was used. RESULTS: The modulated polymerase chain reaction composition significantly improved the amplification of GC-rich DNA target sequences. Improved amplification of this region was due to reduction in the formation of secondary structures by the GC-rich region. CONCLUSION: Therefore, this polymerase chain reaction composition could be generally used to facilitate the amplification of other GC-rich DNA sequences as verified by amplification of different GC rich regions.