The spatiotemporal matching pattern of Ezrin/Periaxin involved in myoblast differentiation and fusion and Charcot-Marie-Tooth disease-associated muscle atrophy.

BACKGROUND: Clinically, Charcot-Marie-Tooth disease (CMT)-associated muscle atrophy still lacks effective treatment. Deletion and mutation of L-periaxin can be involved in CMT type 4F (CMT4F) by destroying the myelin sheath form, which may be related to the inhibitory role of Ezrin in the self-association of L-periaxin. However, it is still unknown whether L-periaxin and Ezrin are independently or interactively involved in the process of muscle atrophy by affecting the function of muscle satellite cells. METHOD: A gastrocnemius muscle atrophy model was prepared to mimic CMT4F and its associated muscle atrophy by mechanical clamping of the peroneal nerve. Differentiating C2C12 myoblast cells were treated with adenovirus-mediated overexpression or knockdown of Ezrin. Then, overexpression of L-periaxin and NFATc1/c2 or knockdown of L-periaxin and NFATc3/c4 mediated by adenovirus vectors were used to confirm their role in Ezrin-mediated myoblast differentiation, myotube formation and gastrocnemius muscle repair in a peroneal nerve injury model. RNA-seq, real-time PCR, immunofluorescence staining and Western blot were used in the above observation. RESULTS: For the first time, instantaneous L-periaxin expression was highest on the 6th day, while Ezrin expression peaked on the 4th day during myoblast differentiation/fusion in vitro. In vivo transduction of adenovirus vectors carrying Ezrin, but not Periaxin, into the gastrocnemius muscle in a peroneal nerve injury model increased the numbers of muscle myosin heavy chain (MyHC) I and II type myofibers, reducing muscle atrophy and fibrosis. Local muscle injection of overexpressed Ezrin combined with incubation of knockdown L-periaxin within the injured peroneal nerve or injection of knockdown L-periaxin into peroneal nerve-injured gastrocnemius muscle not only increased the number of muscle fibers but also recovered their size to a relatively normal level in vivo. Overexpression of Ezrin promoted myoblast differentiation/fusion, inducing increased MyHC-I+ and MyHC-II + muscle fiber specialization, and the specific effects could be enhanced by the addition of adenovirus vectors for knockdown of L-periaxin by shRNA. Overexpression of L-periaxin did not alter the inhibitory effects on myoblast differentiation and fusion mediated by knockdown of Ezrin by shRNA in vitro but decreased myotube length and size. Mechanistically, overexpressing Ezrin did not alter protein kinase A gamma catalytic subunit (PKA-γ cat), protein kinase A I alpha regulatory subunit (PKA reg Iα) or PKA reg Iß levels but increased PKA-α cat and PKA reg II α levels, leading to a decreased ratio of PKA reg I/II. The PKA inhibitor H-89 remarkably abolished the effects of overexpressing-Ezrin on increased myoblast differentiation/fusion. In contrast, knockdown of Ezrin by shRNA significantly delayed myoblast differentiation/fusion accompanied by an increased PKA reg I/II ratio, and the inhibitory effects could be eliminated by the PKA reg activator N6-Bz-cAMP. Meanwhile, overexpressing Ezrin enhanced type I muscle fiber specialization, accompanied by an increase in NFATc2/c3 levels and a decrease in NFATc1 levels. Furthermore, overexpressing NFATc2 or knocking down NFATc3 reversed the inhibitory effects of Ezrin knockdown on myoblast differentiation/fusion. CONCLUSIONS: The spatiotemporal pattern of Ezrin/Periaxin expression was involved in the control of myoblast differentiation/fusion, myotube length and size, and myofiber specialization, which was related to the activated PKA-NFAT-MEF2C signaling pathway, providing a novel L-Periaxin/Ezrin joint strategy for the treatment of muscle atrophy induced by nerve injury, especially in CMT4F.

Engineering of triterpene metabolism and overexpression of the lignin biosynthesis gene PAL promotes ginsenoside Rg3 accumulation in ginseng plant chassis.

The ginsenoside Rg3 found in Panax species has extensive pharmacological properties, in particular anti-cancer effects. However, its natural yield in Panax plants is limited. Here, we report a multi-modular strategy to improve yields of Rg3 in a Panax ginseng chassis, combining engineering of triterpene metabolism and overexpression of a lignin biosynthesis gene, phenylalanine ammonia lyase (PAL). We first performed semi-rational design and site mutagenesis to improve the enzymatic efficiency of Pq3-O-UGT2, a glycosyltransferase that directly catalyzes the biosynthesis of Rg3 from Rh2 . Next, we used clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing to knock down the branch pathway of protopanaxatriol-type ginsenoside biosynthesis to enhance the metabolic flux of the protopanaxadiol-type ginsenoside Rg3 . Overexpression of PAL accelerated the formation of the xylem structure, significantly improving ginsenoside Rg3 accumulation (to 6.19-fold higher than in the control). We combined overexpression of the ginsenoside aglycon synthetic genes squalene epoxidase, Pq3-O-UGT2, and PAL with CRISPR/Cas9-based knockdown of CYP716A53v2 to improve ginsenoside Rg3 accumulation. Finally, we produced ginsenoside Rg3 at a yield of 83.6 mg/L in a shake flask (7.0 mg/g dry weight, 21.12-fold higher than with wild-type cultures). The high-production system established in this study could be a potential platform to produce the ginsenoside Rg3 commercially for pharmaceutical use.

PEG300 Protects Mitochondrial Function By Upregulating PGC-1α to Delay Central Nervous System Oxygen Toxicity in Mice.

Central nervous system oxygen toxicity (CNS-OT) is a complication of hyperbaric oxygen (HBO) treatment, with limited prevention and treatment options available. In this study, we aimed to explore the effect of polyethylene glycol 300 (PEG300) on CNS-OT and underlying mechanisms. Motor and cognitive functions of mice in normobaric conditions were evaluated by Morris water maze, passive active avoidance, and rotarod tests. HBO was applied at 6 atmospheres absolute (ATA) for 30 min after drug administration. The latency period of convulsion in mice was recorded, and hippocampal tissues were extracted for biochemical experiments. Our experimental results showed that PEG300 extended the convulsion latencies in CNS-OT mice, reduced oxidative stress and inflammation levels in hippocampal tissues. Furthermore, PEG300 preserved mitochondrial integrity and maintained mitochondrial membrane potential in hippocampal tissue by upregulating Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha (PGC-1α). This protective effect was enhanced following the administration of ZLN005, an agonist of PGC-1a. Hence, our study suggests that PEG300 might exert protective effects by upregulating PGC-1α expression and preserving mitochondrial health, offering promising prospects for CNS-OT treatment.

Evolutionary change in the brain size of bats.

It has been widely recognized that mammal brain size predominantly increases over evolutionary time. Safi et al. [Biol Lett 2005;1:283-286] questioned the generality of this trend, arguing that brain size evolution among bats involved reduction in multiple lineages as well as enlargement in others. Our study explored the direction of change in the evolution of bat brain size by estimating brain volume in fossil bats, using synchrotron radiation X-ray tomographic microscopy. Virtual endocasts were generated from 2 Hipposideros species: 3 specimens of Oligocene Hipposideros schlosseri (∼35 Ma) and 3 of Miocene Hipposideros bouziguensis (∼20 Ma). Upper molar tooth dimensions (M(2) length × width) collected for 43 extant insectivorous bat species were used to derive empirical formulae to estimate body mass in the fossil bats. Brain size was found to be relatively smaller in the fossil bats than in the average extant bat both with raw data and after allowing for phylogenetic inertia. Phylogenetic modeling of ancestral relative brain size with and without fossil bats confirmed a general trend towards evolutionary increase in this bat lineage.

Facile preparation of lignin-containing cellulose nanofibrils from sugarcane bagasse by mild soda-oxygen pulping.

Lignin-containing cellulose nanofibrils (LCNFs) with tunable lignin contents from sugarcane bagasse were directly prepared by low-temperature soda­oxygen pulping combined with simple mechanical treatment. The residual lignin structure, morphology and physical dimensions of LCNFs, and properties of the relevant cellulose nanopapers (CNPs) were investigated. In situ 2D Heteronuclear Single Quantum Coherence (HSQC) NMR spectra showed ß-O-4 linkages, ferulate, and para-coumarate were well preserved in the LCNFs. Compared with the cellulose nanofibrils (CNFs), LCNFs displayed a more uniform size and narrow diameter distribution. The corresponding CNPs exhibited outstanding mechanical properties (tensile strength reached 152.9 MPa), and excellent combined optical properties both in the UV blocking and visible light transparency. Moreover, the water contact angles (50.0-80.2°) of LCNFs were much higher than that of CNFs (21.7°). Direct preparation of LCNFs under mild condition would unlock the full potential of cellulosic materials and provide enhanced opportunities for cellulose to fabricate multi-functional and high-value materials.

Quantifying the Carbon Reduction Potential of Recycling Construction Waste Based on Life Cycle Assessment: A Case of Jiangsu Province.

The recycling of construction waste is key to reducing waste generation and CO2 emissions. This study aimed to develop a quantitative model for analyzing the carbon reduction potential of recycling construction, demolition, and renovation waste (CDRW) in Jiangsu province. The waste generation rate calculation method and nonlinear autoregressive artificial neural network model were used to estimate and predict CDRW generation. The life cycle assessment was performed to calculate the carbon reduction potential of recycling CDRW. In quantifying the carbon reduction potential, not only construction and demolition waste, but also renovation waste was considered for the first time. The results showed that the total carbon reduction potential of recycling CDRW increased from 3.94 Mt CO2e in 2000 to 58.65 Mt CO2e in 2020. Steel and concrete were the main contributors. By scenario analysis, the carbon reduction potential of fully recycling CDRW in 2020 increased by 37.79 Mt CO2e, a growth rate of 64%. The study further predicts future CDRW generation and the corresponding carbon reduction potential. Our conclusions indicate that 245.45 Mt of CDRW will be generated in 2030, and carbon reduction potential may reach 82.36 Mt CO2e. These results will help the government manage construction waste better and reach early achievement of the carbon peak target.

Effectiveness of liposome bupivacaine for postoperative pain control in total knee arthroplasty: A PRISMA-compliant meta-analysis of randomized controlled trials.

BACKGROUND: Adequate pain control after total knee arthroplasty (TKA) enables quicker recovery and reduces readmissions and treatment costs. The aim of this study was to determine the effect of liposomal bupivacaine (LB) for postoperative pain control in patients prepared for TKA. METHODS: We searched for the reports that evaluating the effect of liposomal bupivacaine for postoperative pain control in patients prepared for TKA between March 1983 and May 2017 in the electronic database Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, Web of Science, and Ovid. The main outcomes were visual analog scale (VAS) at 24, 48, and 72 hours. The secondary outcomes were total morphine consumption, the length of hospital stay, range of motion, and the occurrence of nausea. RESULTS: Seven randomized controlled trials (RCTs) enrolling 825 patients, with 413 in the LB group and 412 in the control group, were included in this meta-analysis. Our results suggested that administration LB was associated with a reduction of VAS by 4.22 points at 72 hours after TKA (WMD = -4.22, 95% CI -7.47, -0.97, P = .011) on a 100-point VAS. What's more, LB can decrease the occurrence of nausea when compared with traditional bupivacaine by 18.3% (risk ratio  = 0.70, 95% confidence interval 0.55, 0.89, P = .003). LB was associated with an increase of the range of motion than traditional bupivacaine (P < .05). There was no significant difference between the VAS at 24, 48 hours, total morphine consumption and the length of hospital stay. CONCLUSIONS: Administration with LB was associated with pain-relieving effects and reduces the morphine-related complications (nausea). Due the limited number of the included RCTs, large number and high quality RCTs are still need to identify the effects of LB for pain control after TKA.

Enhancement of ß-crystalline phase of poly(vinylidene fluoride) in the presence of hyperbranched copolymer wrapped multiwalled carbon nanotubes.

Many efforts have been performed on the poly(vinylidene fluoride), PVDF, due to its piezoelectric, pyroelectric and ferroelectric potentials. In this regard, how to fabricate the PVDF with high content of ß-phase, which is also the direct contribution to PVDF's prominent property, becomes a critical issue. In this study, starting with the α-phase dominated sample, the PVDF with extremely high content of ß-crystalline phase was obtained by the incorporation of multiwalled carbon nanotubes (MWCNTs) modified by hyperbranched copolymers (HBCs). We proved that, via XRD, DSC as well as the structural characterizations from the polarized optical microscopy and transmission electron microscopy (TEM), the success of this strategy was ascribed to the enhanced dispersibility and stability of MWCNTs endowed by the HBCs, which significantly favors the formation of the ß-crystalline phase of PVDF.

Preparation and catalytic ability to reduce hydrogen peroxide of Ag nanoparticles highly dispersed via hyperbranched copolymer.

Highly dispersed Ag nanoparticles, stabilized by hyperbranched copolymers (HPCs), were prepared by chemical reduction in toluene. These Ag NPs were used further for the fabrication of a hydrogen peroxide (H2O2) sensor, by which a good catalytic ability for the reduction of H2O2 was found.