Mechanosensitive channel of large conductance enhances the mechanical stretching-induced upregulation of glycolysis and oxidative metabolism in Schwann cells.

BACKGROUND: Physical exercise directly stretching the peripheral nerve promotes nerve regeneration; however, its action mechanism remains elusive. Our present study aimed to investigate the effects of mechanosensitive channel of large conductance (MscL) activated by mechanical stretching on the cultured Schwann cells (SCs) and explore the possible mechanism. METHODS: Primary SCs from neonatal mice at 3-5 days of age were derived and transfected with the lentivirus vector expressing a mutant version of MscL, MscL-G22S. We first detected the cell viability and calcium ion (Ca2+) influx in the MscL-G22S-expressing SCs with low-intensity mechanical stretching and the controls. Proteomic and energy metabolomics analyses were performed to investigate the comprehensive effects of MscL-G22S activation on SCs. Measurement of glycolysis- and oxidative phosphorylation-related molecules and ATP production were respectively performed to further validate the effects of MscL-G22S activation on SCs. Finally, the roles of phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway in the mechanism of energy metabolism modulation of SCs by MscL-G22S activation was investigated. RESULTS: Mechanical stretching-induced MscL-G22S activation significantly increased the cell viability and Ca2+ influx into the SCs. Both the proteomic and targeted energy metabolomics analysis indicated the upregulation of energy metabolism as the main action mechanism of MscL-G22S-activation on SCs. MscL-G22S-activated SCs showed significant upregulation of glycolysis and oxidative phosphorylation when SCs with stretching alone had only mild upregulation of energy metabolism than those without stimuli. MscL-G22S activation caused significant phosphorylation of the PI3K/AKT/mTOR signaling pathway and upregulation of HIF-1α/c-Myc. Inhibition of PI3K abolished the MscL-G22S activation-induced upregulation of HIF-1α/c-Myc signaling in SCs and reduced the levels of glycolysis- and oxidative phosphorylation-related substrates and mitochondrial activity. CONCLUSION: Mechanical stretching activates MscL-G22S to significantly promote the energy metabolism of SCs and the production of energic substrates, which may be applied to enhance nerve regeneration via the glia-axonal metabolic coupling.

Potential benefits and risks of solar photovoltaic power plants on arid and semi-arid ecosystems: an assessment of soil microbial and plant communities.

Exponential increase in photovoltaic installations arouses concerns regarding the impacts of large-scale solar power plants on dryland ecosystems. While the effects of photovoltaic panels on soil moisture content and plant biomass in arid ecosystems have been recognized, little is known about their influence on soil microbial communities. Here, we employed a combination of quantitative PCR, high-throughput sequencing, and soil property analysis to investigate the responses of soil microbial communities to solar panel installation. We also report on the responses of plant communities within the same solar farm. Our findings showed that soil microbial communities responded differently to the shading and precipitation-alternation effects of the photovoltaic panels in an arid ecosystem. By redirecting rainwater to the lower side, photovoltaic panels stimulated vegetation biomass and soil total organic carbon content in the middle and in front of the panels, positively contributing to carbon storage. The shade provided by the panels promoted the co-occurrence of soil microbes but inhibited the abundance of 16S rRNA gene in the soil. Increase in precipitation reduced 18S rRNA gene abundance, whereas decrease in precipitation led to decline in plant aboveground biomass, soil prokaryotic community alpha diversity, and dehydrogenase activity under the panels. These findings highlight the crucial role of precipitation in maintaining plant and soil microbial diversities in dryland ecosystems and are essential for estimating the potential risks of large-scale solar power plants on local and global climate change in the long term.

The traceability method of electronic transformer calibrators based on time series-weighted correlation degree extension integrating Hilbert phase-shift.

The traceability method directly affects the reliability and accuracy of the measurement of electronic transformers. The stability and unreliable traceability performance of analog devices would affect the traditional analog differential method. Thus, we propose a digital differential method combining a time series-weighted correlation degree extension integrating Hilbert phase-shift of four-term continuous third-derivative Nuttall window function, effectively suppressing the end effect problem and realizing the high-precision addition of the differential. Results of simulation experiments showed that the differential's deviation was <10-10, much less than that (1.32 × 10-4) due to the analog differential. The voltage and current ratio difference's combined standard uncertainty was 5.01 × 10-5 and 5.08 × 10-5, respectively, and 0.1718' in the phase error. Finally, an automatic traceability detection system was constructed. Compared with the traditional method, the accuracy and stability of the automatic system were better and could meet the traceability requirements for 0.05-accuracy electronic voltage transformer calibrator.

High-performance liquid chromatography-mass spectrometry and evaporative light-scattering detector to compare phenolic profiles of muscadine grapes.

Evaporative light scattering detector (ELSD) is considered as a universal detector able to detect almost any compound. This study successfully established a HPLC-ELSD method for the simultaneous determination of phenolic acids, flavonoids and anthocyanins in muscadine grape. Twenty-four phenolics, including 5 anthocyanins, were identified by HPLC-UV-MS, ten of them were selected to calibrate the ELSD. Results from the ELSD quantification suggested that gallic acid, proanthocyanidins, and ellagic acid were the main phenolics in muscadines. In addition, antioxidant tests suggested that the extracts of muscadine grapes possessed strong antioxidant activities. All extracts had a high total phenolic content (TPC). High total anthocyanins contents (TAC) were found in Noble muscadine, and high proanthocyanidins content (TPA) in the seed portion.