mTORC1 underlies ageâ related muscle fiber damage and loss by inducing oxidative stress and catabolism

Aging leads to skeletal muscle atrophy (i.e., sarcopenia), and muscle fiber loss is a critical component of this process. The mechanisms underlying these ageâ related changes, however, remain unclear. We show here that mTORC1 signaling is activated in a subset of skeletal muscle fibers in aging mouse and human, colocalized with fiber damage. Activation of mTORC1 in TSC1 knockout mouse muscle fibers increases the content of morphologically abnormal mitochondria and causes progressive oxidative stress, fiber damage, and fiber loss over the lifespan. Transcriptomic profiling reveals that mTORC1’s activation increases the expression of growth differentiation factors (GDF3, 5, and 15), and of genes involved in mitochondrial oxidative stress and catabolism. We show that increased GDF15 is sufficient to induce oxidative stress and catabolic changes, and that mTORC1 increases the expression of GDF15 via phosphorylation of STAT3. Inhibition of mTORC1 in aging mouse decreases the expression of GDFs and STAT3’s phosphorylation in skeletal muscle, reducing oxidative stress and muscle fiber damage and loss. Thus, chronically increased mTORC1 activity contributes to ageâ related muscle atrophy, and GDF signaling is a proposed mechanism.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149208/1/acel12943-sup-0002-TableS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149208/2/acel12943.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149208/3/acel12943-sup-0001-FigS1-S14.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149208/4/acel12943_am.pd

Result of a year-long animal survey in a state-owned forest farm in Beijing, China

BackgroundArtificial forest can have great potential in serving as habitat to wildlife, depending on different management methods. As the state-owned forest farms now play a new role in ecological conservation in China, the biological richness of this kind of land-use type is understudied. Once owned by a mining company, a largest state-owned forest farm, Jingxi Forest Farm, has been reformed to be a state-owned forest farm with the purpose of conservation since 2017. Although this 116.4 km2 forest farm holds a near-healthy montaine ecosystem very representative in North China, a large proportion of artificial coniferous forest in the forest farm has been proven to hold less biodiversity than natural vegetation. This situation, however, provides a great opportunity for ecological restoration and biodiversity conservation. Therefore, from November 2019 to December 2020, we conducted a set of biodiversity surveys, whose results will serve as a baseline for further restoration and conservation.New informationHere, we report the result of a multi-taxa fauna diversity survey conducted in Jingxi Forest Farm mainly in year 2020 with explicit spatial information. It is the first survey of its kind conducted in this area, revealing a total of 19 species of mammals, 86 birds, four reptiles, two amphibians and one fish species, as well as 101 species of insects. Four species of mammals are identified as data-poor species as they have less than 100 occurrence records with coordination in the GBIF database. One species of insect, representing one new provincial record genus of Beijing, is reported

Climate change : strategies for mitigation and adaptation

The sustainability of life on Earth is under increasing threat due to humaninduced climate change. This perilous change in the Earth's climate is caused by increases in carbon dioxide and other greenhouse gases in the atmosphere, primarily due to emissions associated with burning fossil fuels. Over the next two to three decades, the effects of climate change, such as heatwaves, wildfires, droughts, storms, and floods, are expected to worsen, posing greater risks to human health and global stability. These trends call for the implementation of mitigation and adaptation strategies. Pollution and environmental degradation exacerbate existing problems and make people and nature more susceptible to the effects of climate change. In this review, we examine the current state of global climate change from different perspectives. We summarize evidence of climate change in Earth’s spheres, discuss emission pathways and drivers of climate change, and analyze the impact of climate change on environmental and human health. We also explore strategies for climate change mitigation and adaptation and highlight key challenges for reversing and adapting to global climate change

Terlipressin for septic shock patients: a meta-analysis of randomized controlled study

Abstract Background Catecholamines are commonly used in septic shock but face limitations of their hypo-responsiveness and adverse events due to high dose. Terlipressin is a synthetic vasopressin analog with greater selectivity for the V1-receptor. A meta-analysis was conducted to evaluate the efficacy and safety of terlipressin in septic shock. Methods We searched for relevant studies in PubMed, Embase, and the Cochrane database from inception up to July 15, 2018. Randomized controlled trials (RCTs) were included if they reported data on any of the predefined outcomes in patients with septic shock and managed with terlipressin or any catecholamines. Results were expressed as risk ratio (RR) or mean difference (MD) with accompanying 95% confidence interval (CI). Heterogeneity, subgroup analysis, sensitivity analysis, and publication bias were explored. Results Ten studies with 928 patients were included. Despite the shorter duration of mechanical ventilation, use of terlipressin did not reduce the risk of mortality (RR = 0.94; 95% CI, 0.85 to 1.05; I 2 = 0%; P = 0.28) when compared with control. This finding was confirmed by further subgroup and sensitivity analyses. In addition, lactate clearance, length of stay in ICU or hospital, total adverse events, digital ischemia, and arrhythmia were also similar between groups, while terlipressin was associated with shorter duration of mechanical ventilation and less norepinephrine requirements. Conclusions Current results suggest terlipressin did not show added survival benefit in septic shock therapy when compared with catecholamines