No abstract

Long noncoding RNAs (lncRNA) participate in carcinogenesis and tumor progression in lung cancer. Here, we report the identification of a lncRNA signature associated with metastasis of non-small cell lung cancer (NSCLC). In particular, elevated expression of LINC00963 (MetaLnc9) in human NSCLC specimens correlated with poor prognosis, promoted migration and invasion of NSCLC cells , and enhanced lung metastasis formation Mechanistic investigations showed that MetaLnc9 interacted with the glycolytic kinase PGK1 and prevented its ubiquitination in NSCLC cells, leading to activation of the oncogenic AKT/mTOR signaling pathway. MetaLnc9 also interacted with P54nrb/NonO (NONO) to help mediate the activity of CRTC, a coactivator for the transcription factor CREB, reinforcing a positive feedback loop for metastasis. Taken together, our results establish MetaLnc9 as a driver of metastasis and a candidate therapeutic target for treating advanced NSCLC. .

Our previous study showed that high levels of HMGB1 existed in rats following cardiopulmonary bypass (CPB)-induced acute lung injury (ALI) and neutralization of high-mobility group box 1(HMGB1) reduced CPB-induced ALI. However, the mechanism by which CPB increases HMGB1 secretion is unclear. Recent studies have shown that inflammasome-mediated cell pyroptosis promotes HMGB1 secretion. This study aimed to investigate the relationship between inflammasome-mediated pyroptosis and HMGB1 in CPB-related ALI. We employed oxygen-glucose deprivation (OGD)-induced alveolar macrophage (AM) NR8383 pyroptosis to measure HMGB1 secretion. We found that OGD significantly increased the levels of caspase-1 cleaved p10, IL-1β and ASC expression, caspase-1 activity and the frequency of pyroptotic AM, and promoted the cytoplasm transportation and secretion of HMGB1, which were significantly mitigated by ASC silencing or pre-treatment with glyburide (a Nlrp3 inhibitor) in AM. CPB also increased the expression levels of Nlrp3, ASC, caspase-1 P10, and IL-1β, and the percentages of AM pyroptosis in the lungs of experimental rats accompanied by increased levels of serum and bronchoalveolar lavage fluid (BALF) HMGB1. Treatment with glyburide significantly mitigated the CPB-increased ASC, caspase-1 p10 and IL-1β expression, and the percentages of AM pyroptosis in the lungs, as well as the levels of HMGB1 in serum and BALF in rats. Therefore, our data indicated that the Nlrp3/ASC-mediated AM pyroptosis increased HMGB1 secretion in ALI induced by CPB. These findings may provide a therapeutic strategy to reduce lung injury and inflammatory responses during CPB.

Rationale: Ferroptosis, a newly identified form of regulated cell death, can be induced following the inhibition of cystine-glutamate antiporter system X C - because of the impaired uptake of cystine. However, the outcome following the accumulation of endogenous glutamate in lung adenocarcinoma (LUAD) has not yet been determined. Yes-associated protein (YAP) is sustained by the hexosamine biosynthesis pathway (HBP)-dependent O-linked beta-N-acetylglucosaminylation (O-GlcNAcylation), and glutamine-fructose-6-phosphate transaminase (GFPT1), the rate-limiting enzyme of the HBP, can be phosphorylated and inhibited by adenylyl cyclase (ADCY)-mediated activation of protein kinase A (PKA). However, whether accumulated endogenous glutamate determines ferroptosis sensitivity by influencing the ADCY/PKA/HBP/YAP axis in LUAD cells is not understood. Methods: Cell viability, cell death and the generation of lipid reactive oxygen species (ROS) and malondialdehyde (MDA) were measured to evaluate the responses to the induction of ferroptosis following the inhibition of system X C - . Tandem mass tags (TMTs) were employed to explore potential factors critical for the ferroptosis sensitivity of LUAD cells. Immunoblotting (IB) and quantitative RT-PCR (qPCR) were used to analyze protein and mRNA expression. Co-immunoprecipitation (co-IP) assays were performed to identify protein-protein interactions and posttranslational modifications. Metabolite levels were measured using the appropriate kits. Transcriptional regulation was evaluated using a luciferase reporter assay, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA). Drug administration and limiting dilution cell transplantation were performed with cell-derived xenograft (CDX) and patient-derived xenograft (PDX) mouse models. The associations among clinical outcome, drug efficacy and ADCY10 expression were determined based on data from patients who underwent curative surgery and evaluated with patient-derived primary LUAD cells and tissues. Results: The accumulation of endogenous glutamate following system X C - inhibition has been shown to determine ferroptosis sensitivity by suppressing YAP in LUAD cells. YAP O-GlcNAcylation and expression cannot be sustained in LUAD cells upon impairment of GFPT1. Thus, Hippo pathway-like phosphorylation and ubiquitination of YAP are enhanced. ADCY10 acts as a key downstream target and diversifies the effects of glutamate on the PKA-dependent suppression of GFPT1. We also discovered that the protumorigenic and proferroptotic effects of ADCY10 are mediated separately. Advanced-stage LUADs with high ADCY10 expression are sensitive to ferroptosis. Moreover, LUAD cells with acquired therapy resistance are also prone to higher ADCY10 expression and are more likely to respond to ferroptosis. Finally, a varying degree of secondary labile iron ...

NG2 glia, also known as oligodendrocyte precursor cells (OPCs), play an important role in proliferation and give rise to myelinating oligodendrocytes during early brain development. In contrast to other glial cell types, the most intriguing aspect of NG2 glia is their ability to directly sense synaptic inputs from neurons. However, whether this synaptic interaction is bidirectional or unidirectional, or its physiological relevance has not yet been clarified. Here, we report that NG2 glia form synaptic complexes with hippocampal interneurons and that selective photostimulation of NG2 glia (expressing channelrhodopsin-2) functionally drives GABA release and enhances inhibitory synaptic transmission onto proximal interneurons in a microcircuit. The mechanism involves GAD67 biosynthesis and VAMP-2 containing vesicular exocytosis. Further, behavioral assays demonstrate that NG2 glia photoactivation triggers anxiety-like behavior in vivo and contributes to chronic social defeat stress.

Huntington's disease (HD) is a late-onset fatal neurodegenerative disease, characterized by progressive movement disorders, psychiatric symptoms, and cognitive impairment. The cytosine-adenine-guanine (CAG) triplet expansion encoding glutamine present in the protein huntingtin (Htt), produces widespread neuronal and glial pathology. Mutant huntingtin (mHtt) nuclear aggregates are the primary cause of cortical and striatal neuron degeneration, neuronal inflammation, apoptosis and eventual cell loss. The precise mechanisms underlying the pathogenesis of neurodegeneration in HD remain poorly understood and HD patients have no current cure. Potassium channels are widely expressed in most cell types. In neurons, they play a crucial role in setting the resting membrane potential, mediating the rapid repolarization phase of the action potential and controlling sub-threshold oscillations of membrane potentials. In glial cells, their major contributions are maintaining the resting membrane potential and buffering extracellular K . Thus, potassium channels have an essential function in both physiological and pathological brain conditions. This review summarizes recent progress on potassium channels involved in the pathology of HD by using different HD mouse models. Exploring the dysfunction of potassium channels in the brain illustrates new approaches for targeting this channel for the treatment of HD.

With an increasing aging society, China is the world’s fastest growing markets for oral implants. Compared with traditional oral implants, immediate implants cause marginal bone resorption and increase the failure rate of osseointegration, but the mechanism is still unknown. Therefore, it is important to further study mechanisms of tension stimulus on osteoblasts and osteoclasts at the early stage of osseointegration to promote rapid osseointegration around oral implants. The results showed that exosomes containing circ_0008542 from MC3T3-E1 cells with prolonged tensile stimulation promoted osteoclast differentiation and bone resorption. Circ_0008542 upregulated Tnfrsf11a (RANK) gene expression by acting as a miR-185-5p sponge. Meanwhile, the circ_0008542 1916-1992 bp segment exhibited increased m6A methylation levels. Inhibiting the RNA methyltransferase METTL3 or overexpressing the RNA demethylase ALKBH5 reversed osteoclast differentiation and bone resorption induced by circ_0008542. Injection of circ_0008542 + ALKBH5 into the tail vein of mice reversed the same effects in vivo. Site-directed mutagenesis study demonstrated that 1956 bp on circ_0008542 is the m6A functional site with the abovementioned biological functions. In conclusion, the RNA methylase METTL3 acts on the m6A functional site of 1956 bp in circ_0008542, promoting competitive binding of miRNA-185-5p by circ_0008542, and leading to an increase in the target gene RANK and the initiation of osteoclast bone absorption. In contrast, the RNA demethylase ALKBH5 inhibits the binding of circ_0008542 with miRNA-185-5p to correct the bone resorption process. The potential value of this study provides methods to enhance the resistance of immediate implants through use of exosomes releasing ALKBH5.

Background Resistance to ferroptosis, a regulated cell death caused by iron‐dependent excessive accumulation of lipid peroxides, has recently been linked to lung adenocarcinoma (LUAD). Intracellular antioxidant systems are required for protection against ferroptosis. The purpose of the present study was to investigate whether and how extracellular system desensitizes LUAD cells to ferroptosis. Methods Established human lung fibroblasts MRC‐5, WI38, and human LUAD H1650, PC9, H1975, H358, A549, and H1299 cell lines, tumor and matched normal adjacent tissues of LUAD, and plasma from healthy individuals and LUAD patients were used in this study. Immunohistochemistry and immunoblotting were used to analyze protein expression, and quantitative reverse transcription‐PCR was used to analyze mRNA expression. Cell viability, cell death, and the lipid reactive oxygen species generation were measured to evaluate the responses to ferroptosis. Exosomes were observed using transmission electron microscope. The localization of arachidonic acid (AA) was detected using click chemistry labeling followed by confocal microscopy. Interactions between RNAs and proteins were detected using RNA pull‐down, RNA immunoprecipitation and photoactivatable ribonucleoside‐enhanced crosslinking and immunoprecipitation methods. Proteomic analysis was used to investigate RNA‐regulated proteins, and metabolomic analysis was performed to analyze metabolites. Cell‐derived xenograft, patient‐derived xenograft, cell‐implanted intrapulmonary LUAD mouse models and plasma/tissue specimens from LUAD patients were used to validate the molecular mechanism. Results Plasma exosome from LUAD patients specifically reduced lipid peroxidation and desensitized LUAD cells to ferroptosis. A potential explanation is that exosomal circRNA_101093 (cir93) maintained an elevation in intracellular cir93 in LUAD to modulate AA, a poly‐unsaturated fatty acid critical for ferroptosis‐associated increased peroxidation in the plasma membrane. Mechanistically, cir93 interacted with and increased fatty acid‐binding protein 3 (FABP3), which transported AA and facilitated its reaction with taurine. Thus, global AA was reduced, whereas N‐arachidonoyl taurine (NAT, the product of AA and taurine) was induced. Notably, the role of NAT in suppressing AA incorporation into the plasma membrane was also revealed. In pre‐clinical in vivo models, reducing exosome improved ferroptosis‐based treatment. Conclusion Exosome and cir93 are essential for desensitizing LUAD cells to ferroptosis, and blocking exosome may be helpful for future LUAD treatment.