Identification of significant biomarkers for predicting the risk of bipolar disorder with arteriosclerosis based on integrative bioinformatics and machine learning.

Introduction: Increasing evidence has indicated a connection between bipolar disorder (BD) and arteriosclerosis (AS), yet the specific molecular mechanisms remain unclear. This study aims to investigate the hub genes and molecular pathways for BD with AS. Methods: BD-related dataset GSE12649 were downloaded from the Gene Expression Omnibus database and differentially expressed genes (DEGs) and key module genes derived from Limma and weighted gene co-expression network analyses (WGCNA) were identified. AS-related genes were sourced from the DisGeNET database, and the overlapping genes between DEGs and AS-related genes were characterized as differentially expressed arteriosclerosis-related genes (DE-ASRGs). The functional enrichment analysis, protein-protein interaction (PPI) network and three machine learning algorithms were performed to explore the hub genes, which were validated with two external validation sets. Additionally, immune infiltration was performed in BD. Results: Overall, 67 DE-ASRGs were found to be overlapping between the DEGs and AS-related genes. Functional enrichment analysis highlighted the cancer pathways between BD and AS. We identified seven candidate hub genes (CTSD, IRF3, NPEPPS, ST6GAL1, HIF1A, SOX9 and CX3CR1). Eventually, two hub genes (CX3CR1 and ST6GAL1) were identified as BD and AS co-biomarkers by using machine learning algorithms. Immune infiltration had revealed the disorder of immunocytes. Discussion: This study identified the hub genes CX3CR1 and ST6GAL1 in BD and AS, providing new insights for further research on the bioinformatic mechanisms of BD with AS and contributing to the diagnosis and prevention of AS in psychiatric clinical practice.

First-principles study of the electronic structures and optical properties of g-ZnO/CdX (X = S, Se, Te) van der Waals heterostructures.

The stability, electronic structures and optical properties of g-ZnO/CdX (X = S, Se, Te) heterostructures are studied by density functional theory. It is found that the stable monolayers spacing of the corresponding heterostructure decreases with the increase of the X atomic radius in the CdX monolayers. The constructed g-ZnO/CdX heterostructures all belong to direct band gap, 2.12 eV, 2.09 eV and 1.99 eV, respectively. Electrostatic potential results show that the two monolayers form an internal electric field at the heterostructure interface, and can inhibit the recombination of photogenerated electron hole pairs, and effectively extend the carrier lifetime. Charge density difference analysis shows that charge redistribution mainly occurs in the interfacial region. The optical properties show that the absorption of g-ZnO in the visible range is achieved by heterostructure. In general, with the smallest band gap and the strongest built-in electric field, g-ZnO/CdTe could have the best carrier separation efficiency. And the optical property analysis proves that the g-ZnO/CdTe heterostructure system has the highest utilization ratio of visible light. The above results show that the electronic structure and optical properties of g-ZnO/CdTe heterostructure are the best, and it can be inferred that this heterostructure will be the most beneficial to improve the photocatalytic activity of g-ZnO, providing a new direction for its application in the field of photocatalysis.

Shear-Sensitive circRNA-LONP2 Promotes Endothelial Inflammation and Atherosclerosis by Targeting NRF2/HO1 Signaling.

Hemodynamic shear stress is a frictional force that acts on vascular endothelial cells and is essential for endothelial homeostasis. Physiological laminar shear stress (LSS) suppresses endothelial inflammation and protects arteries from atherosclerosis. Herein, we screened differentially expressed circular RNAs (circRNAs) that were significantly altered in LSS-stimulated endothelial cells and found that circRNA-LONP2 was involved in modulating the flow-dependent inflammatory response. Furthermore, endothelial circRNA-LONP2 overexpression promoted endothelial inflammation and atherosclerosis in vitro and in vivo. Mechanistically, circRNA-LONP2 competitively sponged miR-200a-3p and subsequently promoted Kelch-like ECH-associated protein 1, Yes-associated protein 1, and enhancer of zeste homolog 2 expression, thereby inactivating nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling, promoting oxidative stress and endothelial inflammation, and accelerating atherosclerosis. LSS-induced down-regulation of circRNA-LONP2 suppresses endothelial inflammation, at least in part, by activating the miR-200a-3p-mediated nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling pathway. CircRNA-LONP2 may serve as a new therapeutic target for atherosclerosis.

Design Principles of Quinone Redox Systems for Advanced Sulfide Solid-State Organic Lithium Metal Batteries.

The emergence of solid-state battery technology presents a potential solution to the dissolution challenges of high-capacity small molecule quinone redox systems. Nonetheless, the successful integration of argyrodite-type Li6PS5Cl, the most promising solid-state electrolyte system, and quinone redox systems remains elusive due to their inherent reactivity. Here, a library of quinone derivatives is selected as model electrode materials to ascertain the critical descriptors governing the (electro)chemical compatibility and subsequently the performances of Li6PS5Cl-based solid-state organic lithium metal batteries (LMBs). Compatibility is attained if the lowest unoccupied molecular orbital level of the quinone derivative is sufficiently higher than the highest occupied molecular orbital level of Li6PS5Cl. The energy difference is demonstrated to be critical in ensuring chemical compatibility during composite electrode preparation and enable high-efficiency operation of solid-state organic LMBs. Considering these findings, a general principle is proposed for the selection of quinone derivatives to be integrated with Li6PS5Cl, and two solid-state organic LMBs, based on 2,5-diamino-1,4-benzoquinone and 2,3,5,6-tetraamino-1,4-benzoquinone, are successfully developed and tested for the first time. Validating critical factors for the design of organic battery electrode materials is expected to pave the way for advancing the development of high-efficiency and long cycle life solid-state organic batteries based on sulfides electrolytes.

High-Throughput Sorting and Single-Cell Mechanotyping by Hydrodynamic Sorting-Mechanotyping Cytometry.

The existence of many background blood cells hinders the accurate identification of circulating tumor cells (CTCs) in the blood of cancer patients. To unlock this limitation, a hydrodynamic sorting-mechanotyping cytometry (HSMC) integrated with a sorting-concentration chip and a detection chip is proposed for simultaneously achieving the high-throughput cell sorting and the multi-parameter mechanotyping of the sorted tumor cells. The HSMC adopts the spiral inertial microfluidics for label-free sorting of cells in a high-throughput manner, allowing the efficient enrichment of tumor cells from the large background blood cells. Then, the sorted cells are concentrated by the concentration unit and finally passed through the detection unit for hydrodynamic deformation. The HSMC has a high throughput for sorting and detection and can successfully reveal the differences in the cellular mechanical properties. After characterizing and optimizing the single chips, the identification of white blood cells (WBCs) and three types of tumor cells (A549, MCF-7, and MDA-MB-231 cells) is successfully achieved. The identification accuracies for WBCs and different tumor cells are all larger than 94%, while the highest identification accuracy is up to 99.2%. This study envisions that the HSMC will offer an avenue for the analysis of single cell intrinsic mechanics in clinical medicine.

A dicarbonate solvent electrolyte for high performance 5 V-Class Lithium-based batteries.

Rechargeable lithium batteries using 5 V positive electrode materials can deliver considerably higher energy density as compared to state-of-the-art lithium-ion batteries. However, their development remains plagued by the lack of electrolytes with concurrent anodic stability and Li metal compatibility. Here we report a new electrolyte based on dimethyl 2,5-dioxahexanedioate solvent for 5 V-class batteries. Benefiting from the particular chemical structure, weak interaction with lithium cation and resultant peculiar solvation structure, the resulting electrolyte not only enables stable, dendrite-free lithium plating-stripping, but also displays anodic stability up to 5.2 V (vs. Li/Li+), in additive or co-solvent-free formulation, and at low salt concentration of 1 M. Consequently, the Li | |LiNi0.5Mn1.5O4 cells using the 1 M LiPF6 in 2,5-dioxahexanedioate based electrolyte retain >97% of the initial capacity after 250 cycles, outperforming the conventional carbonate-based electrolyte formulations, making this, and potentially other dicarbonate solvents promising for future Lithium-based battery practical explorations.

On-capillary alkylation micro-reactor: a facile strategy for proteo-metabolome profiling in the same single cells.

Single-cell multi-omics analysis can provide comprehensive insights to study cell-to-cell heterogeneity in normal and disease physiology. However, due to the lack of amplification technique, the measurement of proteome and metabolome in the same cell is challenging. Herein, a novel on-capillary alkylation micro-reactor (OCAM) was developed to achieve proteo-metabolome profiling in the same single cells, by which proteins were first covalently bound to an iodoacetic acid functionalized open-tubular capillary micro-reactor via sulfhydryl alkylation reaction, and metabolites were rapidly eluted, followed by on-column digestion of captured proteins. Compared with existing methods for low-input proteome sample preparation, OCAM exhibited improved efficiency, anti-interference ability and recovery, enabling the identification of an average of 1509 protein groups in single HeLa cells. This strategy was applied to single-cell proteo-metabolome analysis of mouse oocytes at different stages, 3457 protein groups and 171 metabolites were identified in single oocytes, which is the deepest coverage of proteome and metabolome from single mouse oocytes to date, achieving complementary characterization of metabolic patterns during oocyte maturation.

Viscoelastic-Sorting Integrated Deformability Cytometer for High-Throughput Sorting and High-Precision Mechanical Phenotyping of Tumor Cells.

The counts and phenotypes of circulating tumor cells (CTCs) in whole blood are useful for disease monitoring and prognostic assessment of cancer. However, phenotyping CTCs in the blood is difficult due to the presence of a large number of background blood cells, especially some blood cells with features similar to those of tumor cells. Herein, we presented a viscoelastic-sorting integrated deformability cytometer (VSDC) for high-throughput label-free sorting and high-precision mechanical phenotyping of tumor cells. A sorting chip for removing large background blood cells and a detection chip for detecting multiple cellular mechanical properties were integrated into our VSDC. Our VSDC has a sorting efficiency and a purity of over 95% and over 81% for tumor cells, respectively. Furthermore, multiple mechanical parameters were used to distinguish tumor cells from white blood cells using machine learning. An accuracy of over 97% for identifying tumor cells was successfully achieved with the highest identification accuracy of 99.4% for MCF-7 cells. It is envisioned that our VSDC will open up new avenues for high-throughput and label-free single-cell analysis in various biomedical applications.

Pyrylium-based derivatization for rapid labeling and enhanced detection of thiol in mass spectrometry imaging.

Many endogenous antioxidants, including glutathione (GSH), cysteine (Cys), cysteinyl-glycine (Cys-Gly) and homocysteine (Hcy) possess free thiol functional groups. In most cases, matrix-assisted laser desorption ionization (MALDI) analyses of trace amounts of thiol compounds are challenging because of their instability and poor ionization properties. We present a mass spectrometry imaging (MSI) approach for mapping of thiol compounds on brain tissue sections. Our derivatization reagents 1-(2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)ethyl)-2,4,6-trimethylpyridinium (MTMP) and 1-(2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)ethyl)-2,4,5-triphenylpyridinium (MTPP) facilitate the covalent charge-tagging of molecules containing free thiol group for the selective and rapid detection of GSH synthesis and metabolic pathway related metabolites by MALDI-MSI. The developed thiol-specific mass spectrometry imaging method realizes the quantitative detection of exogenous N-acetylcysteine tissue sections, and the detection limit in mass spectrometry imaging could reach 0.05 ng. We illustrate the capabilities of the developed method to mapping of thiol compounds on brain tissue from the chronic social defeat stress (CSDS) depression model mice.

Simultaneous Mapping of Amino Neurotransmitters and Nucleoside Neuromodulators on Brain Tissue Sections by On-Tissue Chemoselective Derivatization and MALDI-MSI.

Neurotransmitters (NTs) and neuromodulators (NMs) are two of the most important neurochemicals in the brain, and their imbalances in specific brain regions are thought to underlie certain neurological disorders. We present an on-tissue chemoselective derivatization mass spectrometry imaging (OTCD-MSI) method for the simultaneous mapping of NTs and NMs. Our derivatization system consists of a pyridiniumyl-benzylboronic acid based derivatization reagent and pyrylium salt, which facilitate covalent charge labeling of molecules containing cis-diol and primary amino, respectively. These derivatization systems improved the detection sensitivity of matrix-assisted laser desorption/ionization (MALDI)-MSI and simplified the identification of amino NTs and nucleoside NMs by the innate chemoselectivity of derivatization reagents and the unique isotopic pattern of boron-derivative reagents. We demonstrated the ability of the developed method on brain sections from a hypoxia mouse model and control. The simultaneous imaging of NTs and NMs provided a method for exploring how hypoxic stress and drugs affect specific brain regions through neurotransmitter modulation.

Theory of all-coupling angulon for molecules rotating in many-body environment.

The formation of angulon, stemming from the rotor (molecule or impurity), rotating in the quantum many-body field, adds a new member to the quasi-particles' family and has aroused intense interest in multiple research fields. However, the analysis of the coupling strength between the rotor and its hosting environment remains a challenging task, both in theory and experiment. Here, we develop the all-coupling theory of the angulon by introducing a unitary transformation, where the renormalization of the rotational constants for different molecules in the helium nanodroplets is reproduced, getting excellent agreement with the experimental data collected during the past decades. Moreover, the strength of molecule-helium coupling and the effective radius of the solvation shell co-rotating along with the molecular rotor could be estimated qualitatively. This model not only provides significant enlightenment for analyzing the rotational spectroscopy of molecules in the phononic environment, but also provides a new method to study the transfer of the phonon angular momentum in the angulon frame.

Bimetallic Anionic Organic Frameworks with Solid-State Cation Conduction for Charge Storage Applications.

A new phosphonate-based anionic bimetallic organic framework, with the general formula of A4 -Zn-DOBDP (wherein A is Li+ or Na+ , and DOBDP6- is the 2,5-dioxido-1,4-benzenediphosphate ligand) is prepared and characterized for energy storage applications. With four alkali cations per formula unit, the A4 -Zn-DOBDP MOF is found to be the first example of non-solvated cation conducting MOF with measured conductivities of 5.4×10-8  S cm-1 and 3.4×10-8  S cm-1 for Li4 - and Na4 - phases, indicating phase and composition effects of Li+ and Na+ shuttling through the channels. Three orders of magnitude increase in ionic conductivity is further attained upon solvation with propylene carbonate, placing this system among the best MOF ionic conductors at room temperature. As positive electrode material, Li4 -Zn-DOBDP delivers a specific capacity of 140 mAh g-1 at a high average discharge potential of 3.2 V (vs. Li+ /Li) with 90 % of capacity retention over 100 cycles. The significance of this research extends from the development of a new family of electroactive phosphonate-based MOFs with inherent ionic conductivity and reversible cation storage, to providing elementary insights into the development of highly sought yet still evasive MOFs with mixed-ion and electron conduction for energy storage applications.

An autophagy-inducing stapled peptide induces mitochondria dysfunction and triggers autotic cell death in triple-negative breast cancer.

Autophagy is a lysosome-dependent bulk degradation process essential for cell viability but excessive autophagy leads to a unique form of cell death termed autosis. Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer with notable defect in its autophagy process. In previous studies, we developed stapled peptides that specifically targeted the essential autophagy protein Beclin 1 to induce autophagy and promote endolysosomal trafficking. Here we show that one lead peptide Tat-SP4 induced mild increase of autophagy in TNBC cells but showed potent anti-proliferative effect that could not be rescued by inhibitors of programmed cell death pathways. The cell death induced by Tat-SP4 showed typical features of autosis including sustained adherence to the substrate surface, rupture of plasma membrane and effective rescue by digoxin, a cardioglycoside that blocks the Na+/K+ ATPase. Tat-SP4 also induced prominent mitochondria dysfunction including loss of mitochondria membrane potential, elevated mitochondria reactive oxygen species and reduced oxidative phosphorylation. The anti-proliferative effect of Tat-SP4 was confirmed in a TNBC xenograft model. Our study uncovers three notable aspects of autosis. Firstly, autosis can be triggered by moderate increase in autophagy if such increase exceeds the endogenous capacity of the host cells. Secondly, mitochondria may play an essential role in autosis with dysregulated autophagy leading to mitochondria dysfunction to trigger autosis. Lastly, intrinsic autophagy deficiency and quiescent mitochondria bioenergetic profile likely render TNBC cells particularly susceptible to autosis. Our designed peptides like Tat-SP4 may serve as potential therapeutic candidates against TNBC by targeting this vulnerability.

The potent BECN2-ATG14 coiled-coil interaction is selectively critical for endolysosomal degradation of GPRASP1/GASP1-associated GPCRs.

ABBREVIATIONS: AMBRA1 autophagy and beclin 1 regulator 1; ATG14 autophagy related 14; ATG5 autophagy related 5; ATG7 autophagy related 7; BECN1 beclin 1; BECN2 beclin 2; CC coiled-coil; CQ chloroquine CNR1/CB1R cannabinoid receptor 1 DAPI 4',6-diamidino-2-phenylindole; dCCD delete CCD; DRD2/D2R dopamine receptor D2 GPRASP1/GASP1 G protein-coupled receptor associated sorting protein 1 GPCR G-protein coupled receptor; ITC isothermal titration calorimetry; IP immunoprecipitation; KD knockdown; KO knockout; MAP1LC3/LC3 microtubule associated protein 1 light chain 3; NRBF2 nuclear receptor binding factor 2; OPRD1/DOR opioid receptor delta 1 PIK3C3/VPS34 phosphatidylinositol 3-kinase catalytic subunit type 3; PIK3R4/VPS15 phosphoinositide-3-kinase regulatory subunit 4; PtdIns3K class III phosphatidylinositol 3-kinase; PtdIns3P phosphatidylinositol-3-phosphate; RUBCN rubicon autophagy regulator; SQSTM1/p62 sequestosome 1; UVRAG UV radiation resistance associated; VPS vacuolar protein sorting; WT wild type.

Glucose-induced CRL4COP1-p53 axis amplifies glycometabolism to drive tumorigenesis.

The diabetes-cancer association remains underexplained. Here, we describe a glucose-signaling axis that reinforces glucose uptake and glycolysis to consolidate the Warburg effect and overcome tumor suppression. Specifically, glucose-dependent CK2 O-GlcNAcylation impedes its phosphorylation of CSN2, a modification required for the deneddylase CSN to sequester Cullin RING ligase 4 (CRL4). Glucose, therefore, elicits CSN-CRL4 dissociation to assemble the CRL4COP1 E3 ligase, which targets p53 to derepress glycolytic enzymes. A genetic or pharmacologic disruption of the O-GlcNAc-CK2-CSN2-CRL4COP1 axis abrogates glucose-induced p53 degradation and cancer cell proliferation. Diet-induced overnutrition upregulates the CRL4COP1-p53 axis to promote PyMT-induced mammary tumorigenesis in wild type but not in mammary-gland-specific p53 knockout mice. These effects of overnutrition are reversed by P28, an investigational peptide inhibitor of COP1-p53 interaction. Thus, glycometabolism self-amplifies via a glucose-induced post-translational modification cascade culminating in CRL4COP1-mediated p53 degradation. Such mutation-independent p53 checkpoint bypass may represent the carcinogenic origin and targetable vulnerability of hyperglycemia-driven cancer.

RHOJ as a novel mechanosensitive modulator of endothelial inflammation.

Physiological high shear stress (HSS), a frictional force generated by flowing blood, is essential for endothelial homeostasis under normal physiological conditions. HSS suppresses atherosclerosis by inhibiting endothelial inflammation. However, the molecular mechanisms underlying this process have not been fully elucidated. Here, we report that HSS downregulated the mRNA and protein levels of ras homolog family member J (RHOJ) in endothelial cells (ECs). Silencing endogenous RHOJ expression decreased the mRNA and protein levels of proinflammatory vascular cell adhesion molecule 1 (VCAM-1) and intercellular cell adhesion molecule 1 (ICAM-1) in ECs, leading to a reduction in monocyte adhesion to ECs. Conversely, the overexpression of RHOJ had the opposite effect. RNA-sequencing analysis uncovered several differentially expressed genes (such as yes-associated protein 1 (YAP1),heme oxygenase-1 (HO1), and monocyte chemoattractant protein-1 (MCP1)) and pathways (such as nuclear factor-kappa B (NF-κB), fluid shear stress and atherosclerosis, and cell adhesion pathways) as RHOJ targets. Additionally, HSS was observed to alleviate endothelial inflammation by inhibiting RHOJ expression. Finally, methylated RNA immunoprecipitation sequencing (MeRIP-seq) illustrated that fluid shear stress regulates RHOJ expression in an N6-methyladenosine (m6A)-dependent manner. Mechanistically, the RNA m6A writer, methyltransferase 3 (METTL3), and the RNA m6A readers, YTH N6-methyladenosine RNA-binding protein F 3 (YTHDF3) and YTH N6-methyladenosine RNA-binding protein C 1/2 (YTHDC1/2), are involved in this process. Taken together, our data demonstrate that HSS-induced downregulation of RHOJ contributes to endothelial homeostasis by suppressing endothelial inflammation and that RHOJ inhibition in ECs is a promising therapeutic strategy for endothelial dysfunction.

Perturbation of Autophagy by a Beclin 1-Targeting Stapled Peptide Induces Mitochondria Stress and Inhibits Proliferation of Pancreatic Cancer Cells.

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer, with a dismal five-year survival rate of less than 10%. PDAC possesses prominent genetic alterations in the oncogene KRAS and tumor suppressors p53, SMAD4 and CDKN2A. However, efforts to develop targeted drugs against these molecules have not been successful, and novel therapeutic modalities for PDAC treatment are urgently needed. Autophagy is an evolutionarily conserved self-degradative process that turns over intracellular components in a lysosome-dependent manner. The role of autophagy in PDAC is complicated and context-dependent. Elevated basal autophagy activity has been detected in multiple human PDAC cell lines and primary tumors resected from patients. However, clinical trials using chloroquine (CQ) to inhibit autophagy failed to show therapeutic efficacy. Here we show that a Beclin 1-targeting stapled peptide (Tat-SP4) developed in our lab further enhanced autophagy in multiple PDAC cell lines possessing high basal autophagy activity. Tat-SP4 also triggered faster endolysosomal degradation of EGFR and induced significant mitochondria stress as evidenced by partial loss of Δψ, increased level of ROS and reduced OXPHOS activity. Tat-SP4 exerted a potent anti-proliferative effect in PDAC cell lines in vitro and prohibited xenograft tumor growth in vivo. Intriguingly, excessive autophagy has been reported to trigger a unique form of cell death termed autosis. Tat-SP4 does induce autosis-like features in PDAC cells, including mitochondria stress and non-apoptotic cell death. Overall, our study suggests that autophagy perturbation by a Beclin 1-targeting peptide and the resulting autosis may offer a new strategy for PDAC drug discovery.

Exploration of the potential neuroprotective compounds targeting GluN1-GluN2B NMDA receptors.

The N-methyl-d-aspartic acid (NMDA) receptors belongs to the family of ionotropic glutamate receptors, which could mediate most excitatory synaptic transmission in the brain. It is interesting to know if some available drugs have regulatory effects on the NMDARs. Herein, the present study reports the discovery of drugs targeting NMDAR using virtual screening. In this study, talniflumate with the EC50 value at 61.49 nM was successfully screened. The interaction analysis of this compound was further explored through molecular dynamics simulation. It is indicated that talniflumate could form stable interactions with GluN1-GluN2B NMDA receptors. In particular, H-bond interactions with high occupancies between GluN1-GluN2B NMDA receptors and talniflumate were observed. Compared to de novo drug discovery, this approach could be an alternative choice for development of safety and efficiency NMDAR inhibitors from available drugs.Communicated by Ramaswamy H. Sarma.

An autophagy-inducing stapled peptide promotes c-MET degradation and overrides adaptive resistance to sorafenib in c-MET+ hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) accounts for approximately 90% of primary liver cancer cases and ranks as the second leading cause of cancer related death. Multiple receptor tyrosine kinases such as EGFR, FGFR and c-MET have been shown to drive tumorigenesis and progression of HCC. However, tyrosine kinase inhibitors (TKIs) that target these kinases, including the FDA-approved sorafenib, only offer limited clinical success. Resistance to sorafenib and other TKIs also readily emerge in HCC patients, further limiting the usage of these drugs. Novel therapeutic strategies are needed to address the urgent unmet medical need for HCC patients. Results: Autophagy is an evolutionally conserved lysosome-dependent degradation process that is also functionally implicated in HCC. We previously developed an autophagy-inducing stapled peptide (Tat-SP4) that induced autophagy and endolysosomal degradation of EGFR in lung cancer and breast cancer cells. Here we present data to show that Tat-SP4 also induced significant autophagic response in multiple HCC cell lines and promoted the endolysosomal degradation of c-MET to attenuate its downstream signaling activities although it didn't affect the intrinsically fast turnover of EGFR. Tat-SP4 also overrode adaptive resistance to sorafenib in c-MET+ HCC cells but employed the distinct mechanism of inducing non-apoptotic cell death. Conclusion: With its distinct mechanism of promoting autophagy and endolysosomal degradation of c-MET, Tat-SP4 may serve as a novel therapeutic agent that complement and synergize with sorafenib to enhance its clinical efficacy in HCC patients.

Pyrylium-Based Derivatization for Rapid Labeling and Enhanced Detection of Cholesterol in Mass Spectrometry Imaging.

Cholesterol in the central nervous system has been increasingly found to be closely related to neurodegenerative diseases. Defects in cholesterol metabolism can cause structural and functional disorders of the central nervous system. The detection of abnormal cholesterol is of great significance for the cognition of physiological and pathological states of organisms, and the spatial distribution of cholesterol can also provide more clues for our understanding of the complex mechanism of disease. Here, we developed a novel pyrylium-based derivatization reagent combined with matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to visualize cholesterol in biological tissues. A new class of charged hydroxyl derivatization reagents was designed and synthesized, and finally 1-(carboxymethyl)-2,4,6-trimethylpyridinium (CTMP) was screened for tissue derivatization of cholesterol. Different from the shortcomings of traditional hydroxyl labeling methods such as harsh reaction conditions and long reaction time, in our study, we combined the advantages of CTMP itself and the EDCl/HOBt reaction system to achieve instant labeling of cholesterol on tissues through two-step activation. In addition, we also reported changes in cholesterol content in different stages and different brain regions during disease development in SOD1 mutant mouse model. The cholesterol derivatization method we developed provides an efficient way to explore the distribution and spatial metabolic network of cholesterol in biological tissues.