Association of sex hormones with non-alcoholic fatty liver disease: An observational and Mendelian randomization study.

BACKGROUND AND AIMS: Sex-specific associations of sex hormone-binding globulin (SHBG) and bioavailable testosterone (BAT) with NAFLD remain indeterminate. We aimed to explore observational and genetically determined relationships between each hormone and NAFLD. METHODS: We included 187 395 men and 170 193 women from the UK Biobank. Linear and nonlinear Cox regression models and Mendelian randomization (MR) analysis were used to test the associations. RESULTS: During 12.49 years of follow-up, 2209 male and 1886 female NAFLD cases were documented. Elevated SHBG levels were linearly associated with a lower risk of NAFLD in women (HR (95% CI), .71 (.63, .79)), but not in men (a "U" shape, pnon-linear < .001). Higher BAT levels were associated with a lower NAFLD risk in men (HR (95% CI), .81 (.71, .93)) but a higher risk in women (HR (95% CI): 1.25 (1.15, 1.36)). Genetically determined SHBG and BAT levels were linearly associated with NAFLD risk in women (OR (95% CI): .57 (.38, .87) and 2.21 (1.41, 3.26) respectively); in men, an "L-shaped" MR association between SHBG levels and NAFLD risk was found (pnon-linear = .016). The bidirectional MR analysis further revealed the effect of NAFLD on SHBG and BAT levels in both sexes. CONCLUSIONS: Consistently, linear associations of lower SHBG and higher BAT levels with increased NAFLD risk were both conventionally and genetically found in women, while in men, SHBG acts in a nonlinear manner. In addition, NAFLD may affect SHBG and BAT levels.

Support Pore Structure and Composition Strongly Influence the Direct Air Capture of CO2 on Supported Amines.

A variety of amine-impregnated porous solid sorbents for direct air capture (DAC) of CO2 have been developed, yet the effect of amine-solid support interactions on the CO2 adsorption behavior is still poorly understood. When tetraethylenepentamine (TEPA) is impregnated on two different supports, commercial γ-Al2O3 and MIL-101(Cr), they show different trends in CO2 sorption when the temperature (-20 to 25 °C) and humidity (0-70% RH) of the simulated air stream are varied. In situ IR spectroscopy is used to probe the mechanism of CO2 sorption on the two supported amine materials, with weak chemisorption (formation of carbamic acid) being the dominant pathway over MIL-101(Cr)-supported TEPA and strong chemisorption (formation of carbamate) occurring over γ-Al2O3-supported TEPA. Formation of both carbamic acid and carbamate species is enhanced over the supported TEPA materials under humid conditions, with the most significant enhancement observed at -20 °C. However, while equilibrium H2O sorption is high at cold temperatures (e.g., -20 °C), the effect of humidity on a practical cyclic DAC process is expected to be minimal due to slow H2O uptake kinetics. This work suggests that the CO2 capture mechanisms of impregnated amines can be controlled by adjusting the degree of amine-solid support interaction and that H2O adsorption behavior is strongly affected by the properties of the support materials. Thus, proper selection of solid support materials for amine impregnation will be important for achieving optimized DAC performance under varied deployment conditions, such as cold (e.g., -20 °C) or ambient temperature (e.g., 25 °C) operations.

Humans combine value learning and hypothesis testing strategically in multi-dimensional probabilistic reward learning.

Realistic and complex decision tasks often allow for many possible solutions. How do we find the correct one? Introspection suggests a process of trying out solutions one after the other until success. However, such methodical serial testing may be too slow, especially in environments with noisy feedback. Alternatively, the underlying learning process may involve implicit reinforcement learning that learns about many possibilities in parallel. Here we designed a multi-dimensional probabilistic active-learning task tailored to study how people learn to solve such complex problems. Participants configured three-dimensional stimuli by selecting features for each dimension and received probabilistic reward feedback. We manipulated task complexity by changing how many feature dimensions were relevant to maximizing reward, as well as whether this information was provided to the participants. To investigate how participants learn the task, we examined models of serial hypothesis testing, feature-based reinforcement learning, and combinations of the two strategies. Model comparison revealed evidence for hypothesis testing that relies on reinforcement-learning when selecting what hypothesis to test. The extent to which participants engaged in hypothesis testing depended on the instructed task complexity: people tended to serially test hypotheses when instructed that there were fewer relevant dimensions, and relied more on gradual and parallel learning of feature values when the task was more complex. This demonstrates a strategic use of task information to balance the costs and benefits of the two methods of learning.

Minimal cross-trial generalization in learning the representation of an odor-guided choice task.

There is no single way to represent a task. Indeed, despite experiencing the same task events and contingencies, different subjects may form distinct task representations. As experimenters, we often assume that subjects represent the task as we envision it. However, such a representation cannot be taken for granted, especially in animal experiments where we cannot deliver explicit instruction regarding the structure of the task. Here, we tested how rats represent an odor-guided choice task in which two odor cues indicated which of two responses would lead to reward, whereas a third odor indicated free choice among the two responses. A parsimonious task representation would allow animals to learn from the forced trials what is the better option to choose in the free-choice trials. However, animals may not necessarily generalize across odors in this way. We fit reinforcement-learning models that use different task representations to trial-by-trial choice behavior of individual rats performing this task, and quantified the degree to which each animal used the more parsimonious representation, generalizing across trial types. Model comparison revealed that most rats did not acquire this representation despite extensive experience. Our results demonstrate the importance of formally testing possible task representations that can afford the observed behavior, rather than assuming that animals' task representations abide by the generative task structure that governs the experimental design.

Improvement of Distance Measurement Based on Dispersive Interferometry Using Femtosecond Optical Frequency Comb.

Since the dispersive interferometry (DPI) based on optical frequency combs (OFCs) was proposed, it has been widely used in absolute distance measurements with long-distance and high precision. However, it has a serious problem for the traditional DPI based on the mode-locked OFC. The error of measurements caused by using the fast Fourier transform (FFT) algorithm to process signals cannot be overcome, which is due to the non-uniform sampling intervals in the frequency domain of spectrometers. Therefore, in this paper, we propose a new mathematical model with a simple form of OFC to simulate and analyze various properties of the OFC and the principle of DPI. Moreover, we carry out an experimental verification, in which we adopt the Lomb-Scargle algorithm to improve the accuracy of measurements of DPI. The results show that the Lomb-Scargle algorithm can effectively reduce the error caused by the resolution, and the error of absolute distance measurement is less than 12 µm in the distance of 70 m based on the mode-locked OFC.

Nonlinear calibration of frequency modulated continuous wave LIDAR based on a microresonator soliton comb.

Traditional frequency modulated continuous wave (FMCW) LIDAR ranging is based on heterodyne detection, calculating unknown distance by extracting the frequency of the interference signal, while the main error source is frequency modulation (FM) nonlinearity. In this paper, a ranging system based on a microresonator soliton comb is demonstrated to correct the nonlinearity by sampling the ranging signals at equal frequency intervals, producing a ranging error lower than 20 µm, while at the range of 2 m. Advantages of fast data acquisition, light computation requirements, and a simple optical path, without long optical fiber, give this method a high practical value in precision manufacturing.

Exploring Diverse-Ring Analogues on Combretastatin A4 (CA-4) Olefin as Microtubule-Targeting Agents.

Combretastatin-4 (CA-4) as a tubulin polymerization inhibitor draws extensive attentions. However, due to its weak stability of cis-olefin and poor metabolic stability, structure modifications on cis-configuration are being performed. In this work, we constructed a series of novel CA-4 analogues with linkers on olefin containing diphenylethanone, cis-locked dihydrofuran, α-substituted diphenylethanone, cyclobutane and cyclohexane on its cis-olefin. Cytotoxic activity of all analogues was measured by an SRB assay. Among them, compound 6b, a by-product in the preparation of diphenylethanone analogues, was found to be the most potent cytotoxic agents against HepG2 cells with IC50 values of less than 0.5 µM. The two isomers of 6b induced cellular apoptosis tested by Annexin V-FITC and propidium iodide (PI) double staining, arrested cells in the G2/M phase by PI staining analysis, and disrupted microtubule network by immunohistochemistry study in HepG2 cells. Moreover, 6b-(E) displayed a dose-dependent inhibition effect for tubulin assembly in in vitro tubulin polymerization assay. In addition, molecular docking studies showed that two isomers of 6b could bind efficiently at colchicine binding site of tubulin similar to CA-4.

Constructing novel dihydrofuran and dihydroisoxazole analogues of isocombretastatin-4 as tubulin polymerization inhibitors through [3+2] reactions.

[3+2] reactions play a key role in constructing various pharmaceutical moleculars. In this study, using Mn(OAc)3 mediated and 1,3-dipolar [3+2] cyclization reactions, 38 novel dihydrofuran and dihydroisoxazole analogues of isoCA-4 were synthesized as inhibitors of tubulin polymerization. Among them, compound 6g was found to be the most potent cytotoxic agents against PC-3 cells with IC50 value of 0.47µM, and compound 5p exhibted highest activity on HeLa cells with IC50 vaule of 2.32µM. Tubulin polymerization assay revealed that 6g was a dose-dependent and effective inhibitor of tubulin assembly. Immunohistochemistry studies and cell cycle distribution analysis indicated that 6g severely disrupted microtubule network and significantly arrested most cells in the G2/M phase of the cell cycle in PC-3 cells. In addition, molecular docking studies showed that two chiral isomers of 6g can bind efficiently and similarly at colchicine binding site of tubulin.

Effects of electromagnetic fields on bone loss in hyperthyroidism rat model.

Optimal therapeutics for hyperthyroidism-induced osteoporosis are still lacking. As a noninvasive treatment, electromagnetic fields (EMF) have been proven to be effective for treating osteoporosis in non-hyperthyroidism conditions. We herein systematically evaluated the reduced effects of EMF on osteoporosis in a hyperthyroidism rat model. With the use of Helmholtz coils and an EMF stimulator, 15 Hz/1 mT EMF was generated. Forty-eight 5-month-old male Sprague-Dawley rats were randomly divided into four different groups: control, levothyroxine treated (L-T4), EMF exposure + levothyroxine (EMF + L-T4), and EMF exposure without levothyroxine administration (EMF). All rats were treated with L-T4 (100 mg/day) except those in control and EMF groups. After 12 weeks, the results obtained from bone mineral density analyses and bone mechanical measurements showed significant differences between L-T4 and EMF + L-T4 groups. Micro CT and bone histomorphometric analyses indicated that trabecular bone mass and architecture in distal femur and proximal tibia were augmented and restored partially in EMF + L-T4 group. In addition, bone thyroid hormone receptors (THR) expression of hyperthyroidism rats was attenuated in EMF + L-T4 group, compared to control group, which was not observed in L-T4 group. According to these results, we concluded that 15 Hz/1 mT EMF significantly inhibited bone loss and micro architecture deterioration in hyperthyroidism rats, which might occur due to reduced THR expression caused by EMF exposure. Bioelectromagnetics. 38:137-150, 2017. © 2016 Wiley Periodicals, Inc.

Effects of electromagnetic fields on the metabolism of lubricin of rat chondrocytes.

Electromagnetic fields (EMFs) can improve pain, stiffness and physical function in osteoarthritis (OA) patients and have been proposed for the treatment of OA. However, the precise mechanisms involved in this process are still not fully understood. In the present study, we investigated the effects of exposure for different durations with 75 Hz, 2.3 mT sinusoidal EMFs (SEMFs) on the metabolism of lubricin of rat chondrocytes cultured in vitro. Our results showed that SEMFs exposure promoted lubricin synthesis in a time-dependent manner, and the expression of transforming growth factor (TGF)-ß1 was also enhanced after SEMFs treatment. The up-regulation effect of the expression of lubricin under SEMF was partly reduced by SB431542, an inhibitor of TGF-RI kinase. The Smad pathway was also investigated in our study. Smad2 synthesis was higher in EMF-exposed condition than in controls, whereas no effects were observed on inhibitory Smads (Smad6 and Smad7) production. Altogether, these data suggest that SEMF exposure can promote lubricin synthesis of rat chondrocytes in a time-dependent manner and that the TGF-ß/Smads signaling pathway plays a partial role.

Role of P2 × 7 receptor in the differentiation of bone marrow stromal cells into osteoblasts and adipocytes.

Imbalance in osteogenesis and adipogenesis of bone marrow stromal cells is a crucial pathological process of osteoporosis. P2 × 7-deficient mice were previously shown to exhibit an osteopenic phenotype and abnormal fat distribution, leading us to hypothesize that P2 × 7R activation was involved in the differentiation of BMSCs. Consequently, we investigated the effect of P2 × 7R activation on osteogenic and adipogenic differentiation of BMSCs in vitro, and established an ovariectomized (OVX) osteoporosis model to test P2 × 7R activation on adipocytes formation, trabecular and cortical bone parameters in vivo. Our results showed that activation of P2 × 7R by BzATP resulted in increase in the gene expression of osteoblastic markers, the activity of alkaline phosphatase and bone mineralization, and decrease in the gene expression of adipogenic markers and the number of adipocytes generated by BMSCs. MicroCT analysis showed that BzATP treatment ameliorated the micro-architecture of trabecular bones in OVX mice, while cortical bone parameters were unaffected. H&E staining analysis showed that was increase in the volume of trabecular bone and number of trabecular bone, and decrease in bone marrow adipocytes in BzATP-treated OVX mice compared with OVX mice. Also, activation of P2 × 7R transduced to ERK1/2 and JNK signaling pathways. This transduction was prevented by BBG, U0126, and SP600125. U0126 and SP600125 prevented BzATP-induced up-regulation of osteogenic-related genes expression and down-regulation of adipogenic-related genes expression. These data suggest that BzATP activates the differentiation of BMSCs into osteoblasts but not adipocytes by stimulating ERK1/2 and JNK signaling pathways in a P2 × 7R-dependent way.

Effects of electromagnetic fields on osteoporosis: A systematic literature review.

Electromagnetic fields (EMFs) as a safe, effective and noninvasive treatment have been researched and used for many years in orthopedics, and the common use clinically is to promote fracture healing. The effects of EMFs on osteoporosis have not been well concerned. The balance between osteoblast and osteoclast activity as well as the balance between osteogenic differentiation and adipogenic differentiation of bone marrow mesenchymal stem cells plays an important role in the process of osteoporosis. A number of recent reports suggest that EMFs have a positive impact on the balances. In this review, we discuss the recent advances of EMFs in the treatment of osteoporosis from basic research to clinical study and introduce the possible mechanism. In addition, we presented future perspectives of application of EMFs for osteoporosis.

Roles of Rho guanine nucleotide triphosphatases in hippocampal mossy fiber sprouting in the pentylenetetrazole kindling model.

BACKGROUND: One unique feature of chronic human and experimental epilepsy is hippocampal dentate granule cell axon (mossy fiber) sprouting which creates an aberrant positive-feedback circuit that may be epileptogenic. However, the mechanism underlying this process remains unclear. Rho guanine nucleotide triphosphatases (RhoGTP ases) Rac1 and RhoA are important regulators of axon growth and synaptic plasticity and can be blocked by treatment with fasudil. We hypothesized that Rac1 and RhoA are involved in aberrant mossy fiber sprouting (MFS). METHODS: A temporal lobe epilepsy model was established by intraperitoneal pentylenetetrazole (PTZ) injection for animals in PTZ group, and fasudil was injected 30 minutes prior to PTZ injection for animals in PTZ + Fas group. The expression of Rac1 and RhoA in the rat hippocampus was tested at different time points by immunohistochemistry, Western blot and quantitative real-time PCR. Mossy fiber sprouting in the hippocampus was evaluated by Timm staining. RESULTS: Rac1 and RhoA were significantly up-regulated in the PTZ group, and as predicted, the degree of aberrant MFS was correspondingly increased. However, the expression of Rac1 and RhoA was not inhibited in the PTZ + Fas group, and the epileptiform activity, EEG and aberrant MFS were not suppressed following PTZ + Fas treatment. CONCLUSIONS: RhoGTPases play a role in MFS but fasudil is not sufficient to inhibit RhoGTPases and MFS in the PTZ kindling model.

Expression of SOCSs and TLRs in the hippocampus of pentylenetetrazole kindling model.

BACKGROUND: Epilepsy is one of the most common neurological disorders, and approximately one-third of patients with epilepsy are resistant to anti-epileptic drugs (AEDs). Recent emerging evidence has demonstrated the roles of innate immunity and the associated inflammatory processes in epilepsy. Toll-like receptors (TLRs) are a type of pattern-recognition receptor that promote innate immune defense. The SOCS proteins as negative-feedback regulators in cytokine signaling are involved in the regulation of TLR-mediated immune responses. However, few studies investigating the role of TLRs and SOCSs in epilepsy have been reported. METHODS: To explore the role of innate immunity in the mechanism of epilepsy, the pentylenetetrazole (PTZ) kindling rat model was established using intraperitoneal injection of PTZ. The expression levels of TLR2, TLR4, and STAT molecules in rat hippocampi were analyzed using qRT-PCR and western blotting techniques. The expression levels of SOCS-1 and SOCS-3 in rat hippocampi were analyzed using qRT-PCR. RESULTS: Our data demonstrated that both the mRNA and protein expression of TLR2 and TLR4 were significantly upregulated in the rat hippocampus with PTZ injection, which was accompanied by an inhibition of SOCS-1 and SOCS-3 and an upregulation of STAT3. CONCLUSIONS: Our study suggested that SOCSs and TLRs contribute to the development of epilepsy which may lead to therapeutic interventions that limit epileptogenesis.

The effect of electromagnetic fields on the proliferation and the osteogenic or adipogenic differentiation of mesenchymal stem cells modulated by dexamethasone.

Although glucocorticoids provide benefits for inflammation or autoimmune disorders, high-dose and long-term use could cause osteonecrosis or osteoporosis as adverse effect for patients. Electromagnetic field (EMF) treatments have been clinically used for many years to promote fracture healing, but whether EMF can attenuate the deleterious effects of glucocorticoids is not clear. In this study, the effects of different concentrations of dexamethasone (DEX) on proliferation and adipogenic or osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) were detected and compared, and the effects of EMF treatment (15 Hz, 1 mT, 4 h/day) on 0.1 µM DEX-modulated BMSCs' proliferation and adipogenic or osteogenic differentiation were investigated. Higher concentrations of DEX (0.1 and 1 µM) inhibited proliferation of BMSCs but promoted expression of adipogenic-related genes, increasing the number of lipid droplets. In the early stage of differentiation, DEX restrained expression of RUNX2 and alkaline phosphatase (ALP), but amplified expression of ALP and osteopontin (OPN) in the late stage. EMF treatment of BMSCs influenced by 0.1 µM DEX inhibited the high expression of adipogenic-related genes, stimulated the expression of RUNX2, ALP, OPN, and osteocalcin, and increased the activity of ALP. EMF exposure augmented the expression of p-ERK, which DEX reduced. After using mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK signaling pathway inhibitor, U0126, the effect of EMF was reduced. In conclusion, EMF exposure accelerates BMSCs proliferation, inhibits adipogenic differentiation, and promotes osteogenic differentiation of BMSCs modulated by DEX, and these effects are mediated at least in part by MEK/ERK signaling pathway.

Osteogenic differentiation of bone mesenchymal stem cells regulated by osteoblasts under EMF exposure in a co-culture system.

This study examined the osteogenic effect of electromagnetic fields (EMF) under the simulated in vivo conditions. Rat bone marrow mesenchymal stem cells (BMSCs) and rat osteoblasts were co-cultured and exposed to 50 Hz, 1.0 mT EMF for different terms. Unexposed single-cultured BMSCs and osteoblasts were set as controls. Cell proliferation features of single-cultured BMSCs and osteoblasts were studied by using a cell counting kit (CCK-8). For the co-culture system, cells in each group were randomly chosen for alkaline phosphatase (ALP) staining on the day 7. When EMF exposure lasted for 14 days, dishes in each group were randomly chosen for total RNA extraction and von Kossa staining. The mRNA expression of osteogenic markers was detected by using real-time PCR. Our study showed that short-term EMF exposure (2 h/day) could obviously promote proliferation of BMSCs and osteoblasts, while long-term EMF (8 h/day) could promote osteogenic differentiation significantly under co-cultured conditions. Under EMF exposure, osteogenesis-related mRNA expression changed obviously in co-cultured and single-cultured cells. It was noteworthy that most osteogenic indices in osteoblasts were increased markedly after co-culture except Bmp2, which was increased gradually when cells were exposed to EMF. Compared to other indices, the expression of Bmp2 in BMSCs was increased sharply in both single-cultured and co-cultured groups when they were exposed to EMF. The mRNA expression of Bmp2 in BMSCs was approximately four times higher in 8-h EMF group than that in the unexposed group. Our results suggest that Bmp2-mediated cellular interaction induced by EMF exposure might play an important role in the osteogenic differentiation of BMSCs.

Cold Temperature Direct Air CO2 Capture with Amine-Loaded Metal-Organic Framework Monoliths.

Zeolites, silica-supported amines, and metal-organic frameworks (MOFs) have been demonstrated as promising adsorbents for direct air CO2 capture (DAC), but the shaping and structuring of these materials into sorbent modules for practical processes have been inadequately investigated compared to the extensive research on powder materials. Furthermore, there have been relatively few studies reporting the DAC performance of sorbent contactors under cold, subambient conditions (temperatures below 20 °C). In this work, we demonstrate the successful fabrication of adsorbent monoliths composed of cellulose acetate (CA) and adsorbent particles such as zeolite 13X and MOF MIL-101(Cr) by a 3D printing technique: solution-based additive manufacturing (SBAM). These monoliths feature interpenetrated macroporous polymeric frameworks in which microcrystals of zeolite 13X or MIL-101(Cr) are evenly distributed, highlighting the versatility of SBAM in fabricating monoliths containing sorbents with different particle sizes and density. Branched poly(ethylenimine) (PEI) is successfully loaded into the CA/MIL-101(Cr) monoliths to impart CO2 uptakes of 1.05 mmol gmonolith-1 at -20 °C and 400 ppm of CO2. Kinetic analysis shows that the CO2 sorption kinetics of PEI-loaded MIL-101(Cr) sorbents are not compromised in the monoliths compared to the powder sorbents. Importantly, these monoliths exhibit promising working capacities (0.95 mmol gmonolith-1) over 14 temperature swing cycles with a moderate regeneration temperature of 60 °C. Dynamic breakthrough experiments at 25 °C under dry conditions reveal a CO2 uptake capacity of 0.60 mmol gmonolith-1, which further increases to 1.05 and 1.43 mmol gmonolith-1 at -20 °C under dry and humid (70% relative humidity) conditions, respectively. Our work showcases the successful implementation of SBAM in making DAC sorbent monoliths with notable CO2 capture performance over a wide range of sorption temperatures, suggesting that SBAM can enable the preparation of efficient sorbent contactors in various form factors for other important chemical separations.

BMSC-derived exosomal miR-148b-3p attenuates OGD/R-induced HMC3 cell activation by targeting DLL4 and Notch1.

Bone mesenchymal stem cell (BMSC)-derived exosome (BMSC-Exo) could be a treatment method for ischemic injury. In ischemic cerebrovascular disease (IC), microglia is pivotal in neuronal damage and remodeling. This study explores the mechanisms of BMSC-Exo miR-148b-3p in regulating oxygen-glucose deprivation/reoxygenation (OGD/R)-induced human microglial clone 3 (HMC3) cell activation. Transmission electron microscopy (TEM) and qNano were used to assess BMSC-Exo features. The functions of BMSC-Exo miR-148 b-3p in OGD/R-induced HMC3 cell activation were explored via MTT assay, flow cytometry, scratch, transwell, and enzyme-linked immunosorbent assay (ELISA) assays. A dual-luciferase reporter assay was performed to determine the relationship between miR-148b-3p and Delta-like ligand 4(DDL4) or neurogenic locus notch homolog protein 1 (Notch1). OGD/R decreased miR-148b-3p expression in HMC3 cells. After BMSC-Exo treatment, miR-148b-3p expression was upregulated, cell viability and migration were inhibited, cell cycles remained in the G0/G1 phase, and proinflammatory cytokines were decreased in OGD/R-induced HMC3 cells. More importantly, BMSC-Exo miR-148b-3p could further strengthen BMSC-Exo effects. DDL4 and Notch1 are direct targets of miR-148b-3p, respectively. Moreover, the knockdown of DLL4 or Notch1 could inhibit OGD/R-induced HMC3 cell activation. BMSC-Exo miR-148b-3p inhibited OGD/R-induced HMC3 cell activation via inhibiting DLL4 and Notch1 expression, which provided a new strategy for treating cerebral ischemia.

USP18 Stabilized FTO Protein to Activate Mitophagy in Ischemic Stroke Through Repressing m6A Modification of SIRT6.

Ischemic stroke (IS) is a dangerous cerebrovascular disorder with a significant incidence and death rate. Ubiquitin-specific peptidase 18 (USP18) has been proven to mitigate ischemic brain damage; however, its potential regulatory mechanisms remain unclear. In vivo and in vitro models of IS were established by middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation/reoxygenation (OGD/R). Neurocyte injury was detected by MTT, LDH, ROS level, mitochondrial membrane potential (Δψm), and flow cytometry. Molecular expression was evaluated by qPCR, Western blotting, and immunofluorescence staining. Molecular mechanisms were determined by Co-IP, RIP, and MeRIP. IS injury was determined by neurological behavior score and TTC staining. Mitophagy was observed by TEM. USP18 and fat mass and obesity-associated protein (FTO) expression declined after OGD/R. Dysfunctional mitochondrial and apoptosis in OGD/R-stimulated neurocytes were eliminated by USP18/FTO overexpression via mitophagy activation. USP18-mediated de-ubiquitination was responsible for increasing FTO protein stability. Up-regulation of FTO protein restrained m6A modification of sirtuin6 (SIRT6) in a YTHDF2-dependent manner to enhance SIRT6 expression and subsequent activation of AMPK/PGC-1α/AKT signaling. FTO induced mitophagy to ameliorate nerve cell damage through SIRT6/AMPK/PGC-1α/AKT pathway. Finally, USP18/FTO overexpression relieved IS in rats via triggering SIRT6/AMPK/PGC-1α/AKT axis-mediated mitophagy. USP18 increased FTO protein stability to trigger SIRT6-induced mitophagy, thus mitigating IS. Our data unravel the novel neuroprotective mechanism of USP18 and suggest its potential as a promising treatment target for IS.

Influenza a Neuraminidase-Based Bivalent mRNA Vaccine Induces Th1-Type Immune Response and Provides Protective Effects in Mice.

Vaccines are one of the most effective means of preventing influenza A, typically containing the hemagglutinin (HA) of the influenza A virus. However, antigenic drift and shift of the influenza A virus can lead to instability in vaccine efficacy. Compared to HA, the antigenic variation rate of neuraminidase (NA) is slower. In traditional inactivated influenza vaccines, although they contain a certain amount of NA, there are significant differences between different batches, which cannot consistently induce NA-based immune responses. Therefore, NA is often overlooked in vaccine development. In this study, we report an mRNA vaccine encoding the NA of two strains of influenza A virus. The experimental results demonstrated that when matched with the viral strain, this mRNA vaccine induced high levels of neutralizing antibodies, providing a protective effect to mice in viral challenge experiments, and this immune response was shown to be biased towards the Th1 type. In summary, this study demonstrates that NA is a promising potential antigen, providing new insights for the development of influenza A virus vaccines.