PGC-1β modulates catabolism and fiber atrophy in the fasting-response of specific skeletal muscle beds

Skeletal muscle is a pivotal organ for the coordination of systemic metabolism, constituting one of the largest storage site for glucose, lipids and amino acids. Tight temporal orchestration of protein breakdown in times of fasting has to be balanced with preservation of muscle mass and function. However, the molecular mechanisms that control the fasting response in muscle are poorly understood.; We now have identified a role for the peroxisome proliferator-activated receptor γ coactivator 1β (PGC-1β) in the regulation of catabolic pathways in this context in muscle-specific loss-of-function mouse models.; Muscle-specific knockouts for PGC-1β experience mitigated muscle atrophy in fasting, linked to reduced expression of myostatin, atrogenes, activation of AMP-dependent protein kinase (AMPK) and other energy deprivation signaling pathways. At least in part, the muscle fasting response is modulated by a negative effect of PGC-1β on the nuclear factor of activated T-cells 1 (NFATC1).; Collectively, these data highlight the complex regulation of muscle metabolism and reveal a new role for muscle PGC-1β in the control of proteostasis in fasting

Molecular control of endurance training adaptation in male mouse skeletal muscle

Skeletal muscle has an enormous plastic potential to adapt to various external and internal perturbations. Although morphological changes in endurance-trained muscles are well described, the molecular underpinnings of training adaptation are poorly understood. We therefore aimed to elucidate the molecular signature of muscles of trained male mice and unravel the training status-dependent responses to an acute bout of exercise. Our results reveal that, even though at baseline an unexpectedly low number of genes define the trained muscle, training status substantially affects the transcriptional response to an acute challenge, both quantitatively and qualitatively, in part associated with epigenetic modifications. Finally, transiently activated factors such as the peroxisome proliferator-activated receptor-γ coactivator 1α are indispensable for normal training adaptation. Together, these results provide a molecular framework of the temporal and training status-dependent exercise response that underpins muscle plasticity in training

Conversational Grammar- Feminine Grammar? A Sociopragmatic Corpus Study

One area in language and gender research that has so far received only little attention is the extent to which the sexes make use of what recent corpus research has termed “conversational grammar.” The author’s initial findings have suggested that the majority of features distinctive of conversational grammar may be used predominantly by female speakers. This article reports on a study designed to test the hypothesis that conversational grammar is “feminine grammar” in the sense that women’s conversational language is more adapted to the conversational situation than men’s. Based on data from the conversational subcorpus of the British National Corpus and following the situational framework for the description of conversational features elaborated in the author’s previous research, features distinctive of conversational grammar are grouped into five functional categories and their normed frequencies compared across the sexes. The functional categories distinguish features that can be seen as adaptations to constraints set by the situational factors of (1) Shared Context, (2) Co-Construction, (3) Real-Time Processing, (4) Discourse Management, and (5) Relation Management. The study’s results, described in detail in relation to the biological category of speaker sex and cultural notions of gender, suggest that the feminine grammar hypothesis is valid