PGE2 -EP3 axis promotes brown adipose tissue formation through stabilization of WTAP RNA methyltransferase.

Brown adipose tissue (BAT) functions as a thermogenic organ and is negatively associated with cardiometabolic diseases. N6 -methyladenosine (m6 A) modulation regulates the fate of stem cells. Here, we show that the prostaglandin E2 (PGE2 )-E-prostanoid receptor 3 (EP3) axis was activated during mouse interscapular BAT development. Disruption of EP3 impaired the browning process during adipocyte differentiation from pre-adipocytes. Brown adipocyte-specific depletion of EP3 compromised interscapular BAT formation and aggravated high-fat diet-induced obesity and insulin resistance in vivo. Mechanistically, activation of EP3 stabilized the Zfp410 mRNA via WTAP-mediated m6 A modification, while knockdown of Zfp410 abolished the EP3-induced enhancement of brown adipogenesis. EP3 prevented ubiquitin-mediated degradation of WTAP by eliminating PKA-mediated ERK1/2 inhibition during brown adipocyte differentiation. Ablation of WTAP in brown adipocytes abrogated the protective effect of EP3 overexpression in high-fat diet-fed mice. Inhibition of EP3 also retarded human embryonic stem cell differentiation into mature brown adipocytes by reducing the WTAP levels. Thus, a conserved PGE2 -EP3 axis promotes BAT development by stabilizing WTAP/Zfp410 signaling in a PKA/ERK1/2-dependent manner.

QTLbase2: an enhanced catalog of human quantitative trait loci on extensive molecular phenotypes.

Deciphering the fine-scale molecular mechanisms that shape the genetic effects at disease-associated loci from genome-wide association studies (GWAS) remains challenging. The key avenue is to identify the essential molecular phenotypes that mediate the causal variant and disease under particular biological conditions. Therefore, integrating GWAS signals with context-specific quantitative trait loci (QTLs) (such as different tissue/cell types, disease states, and perturbations) from extensive molecular phenotypes would present important strategies for full understanding of disease genetics. Via persistent curation and systematic data processing of large-scale human molecular trait QTLs (xQTLs), we updated our previous QTLbase database (now QTLbase2, http://mulinlab.org/qtlbase) to comprehensively analyze and visualize context-specific QTLs across 22 molecular phenotypes and over 95 tissue/cell types. Overall, the resource features the following major updates and novel functions: (i) 960 more genome-wide QTL summary statistics from 146 independent studies; (ii) new data for 10 previously uncompiled QTL types; (iii) variant query scope expanded to fit 195 QTL datasets based on whole-genome sequencing; (iv) supports filtering and comparison of QTLs for different biological conditions, such as stimulation types and disease states; (v) a new linkage disequilibrium viewer to facilitate variant prioritization across tissue/cell types and QTL types.

Discovery of novel harmine derivatives as GSK-3ß/DYRK1A dual inhibitors for Alzheimer's disease treatment.

Multitarget-directed ligands (MTDLs) have recently attracted significant interest due to their superior effectiveness in multifactorial Alzheimer's disease (AD). Combined inhibition of two important AD targets, glycogen synthase kinase-3ß (GSK-3ß) and dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A), may be a breakthrough in the treatment of AD. Based on our previous work, we have designed and synthesized a series of novel harmine derivatives, investigated their inhibition of GSK-3ß and DYRK1A, and evaluated a variety of biological activities. The results of the experiments showed that most of these compounds exhibited good activity against GSK-3ß and DYRK1A in vitro. ZLQH-5 was selected as the best compound due to the most potent inhibitory effect against GSK-3ß and DYRK1A. Molecular docking studies demonstrated that ZLQH-5 could form stable interactions with the ATP binding pocket of GSK-3ß and DYRK1A. In addition, ZLQH-5 showed low cytotoxicity against SH-SY5Y and HL-7702, good blood-brain barrier permeability, and favorable pharmacokinetic properties. More importantly, ZLQH-5 also attenuated the tau hyperphosphorylation in the okadaic acid SH-SY5Y cell model. These results indicated that ZLQH-5 could be a promising dual-target drug candidate for the treatment of AD.

Mechanisms of the role of proto-oncogene activation in promoting malignant transformation of mature B cells. / åŽŸç˜¤åŸºå› æ¿€æ´»è¯±å¯¼æˆç†ŸB细胞恶变的作用机制.

Malignant tumors continue to pose a significant threat to human life and safety and their development is primarily due to the activation of proto-oncogenes and the inactivation of suppressor genes. Among these, the activation of proto-oncogenes possesses greater potential to drive the malignant transformation of cells. Targeting oncogenes involved in the malignant transformation of tumor cells has provided a novel approach for the development of current antitumor drugs. Several preclinical and clinical studies have revealed that the development pathway of B cells, and the malignant transformation of mature B cells into tumors have been regulated by oncogenes and their metabolites. Therefore, summarizing the key oncogenes involved in the process of malignant transformation of mature B cells and elucidating the mechanisms of action in tumor development hold significant importance for the clinical treatment of malignant tumors.

Proline promotes proliferation and drug resistance of multiple myeloma by downregulation of proline dehydrogenase.

Amino acids in the bone marrow microenvironment (BMME) are a critical factor for multiple myeloma (MM) progression. Here, we have determined that proline is elevated in BMME of MM patients and links to poor prognosis in MM. Moreover, exogenous proline regulates MM cell proliferation and drug resistance. Elevated proline in BMME is due to bone collagen degradation and abnormal expression of the key enzyme of proline catabolism, proline dehydrogenase (PRODH). PRODH is downregulated in MM patients, mainly as a result of promoter hypermethylation with high expression of DNMT3b. Thus, overexpression of PRODH suppresses cell proliferation and drug resistance of MM and exhibits therapeutic potential for treatment of MM. Altogether, we identify proline as a key metabolic regulator of MM, unveil PRODH governing MM progression and provide a promising therapeutic strategy for MM treatment.

Multimetallic nanoparticles decorated metal-organic framework for boosting peroxidase-like catalytic activity and its application in point-of-care testing.

Metal-organic frameworks (MOFs) are a sort of promising peroxidase-like nanozyme but face the challenge that the inorganic nodes in most of the MOF structures are generally blocked by the organic linkers. Further enhancement or activation of their peroxidase-like activity plays an important role in developing MOF-based nanozymes. Herein, a multimetallic nanoparticle (NP) decorated-MOF, Cu/Au/Pt NP decorated-Cu-TCPP(Fe) nanozyme (CuAuPt/Cu-TCPP(Fe)) was synthesized in situ and served as a peroxidase-like nanozyme. The peroxidase-like activity of this stable CuAuPt/Cu-TCPP(Fe) nanozyme was enhanced due to the decreased potential barriers for *OH generation in the catalytic process. Owing to the remarkable peroxidase-like activity, a CuAuPt/Cu-TCPP(Fe)-based colorimetric assay was established for the sensitive determination of H2O2 and glucose with the limit of detection (LOD) of 9.3 µM and 4.0 µM, respectively. In addition, a visual point-of-care testing (POCT) device was developed by integrating the CuAuPt/Cu-TCPP(Fe)-based test strips with a smartphone and was employed for a portable test of 20 clinical serum glucose samples. The results determined by this method agree well with the values deduced by clinical automatic biochemical analysis. This work not only represents an inspiration for the usage of MNP/MOF composite as a novel nanozyme for POCT diagnosis, but also provides a deeper insight and understanding into the enhanced enzyme-mimic effect of MNP-hybrid MOF composites, which in turn will guide the engineering of MOF-based functional nanomaterials. Graphical Abstract.

High expression of VARS promotes the growth of multiple myeloma cells by causing imbalance in valine metabolism. / VARSé«˜è¡¨è¾¾è‡´ç¼¬æ°¨é ¸ä»£è°¢å¤±è¡¡ä¿ƒè¿›å¤šå‘æ€§éª¨é«“ç˜¤ç»†èƒžç”Ÿé•¿.

OBJECTIVES: Multiple myeloma (MM) is a plasma cell malignancy occurring in middle and old age. MM is still an incurable disease due to its frequent recurrence and drug resistance. However, its pathogenesis is still unclear. Abnormal amino acid metabolism is one of the important characteristics of MM, and the important metabolic pathway of amino acids participates in protein synthesis as basic raw materials. Aminoacyl transfer ribonucleic acid synthetase (ARS) gene is a key regulatory gene in protein synthesis. This study aims to explore the molecular mechanism for ARS, a key factor of amino acid metabolism, in regulating amino acid metabolism in MM and affecting MM growth. METHODS: The corresponding gene number was combined with the gene expression profile GSE5900 dataset and GSE2658 dataset in Gene Expression Omnibus (GEO) database to standardize the gene expression data of ARS. GSEA_4.2.0 software was used to analyze the difference of gene enrichment between healthy donors (HD) and MM patients in GEO database. GraphPad Prism 7 was used to draw heat maps and perform data analysis. Kaplan-Meier and Cox regression model were used to analyze the expression of ARS gene and the prognosis of MM patients, respectively. Bone marrow samples from 7 newly diagnosed MM patients were collected, CD138+ and CD138- cells were obtained by using CD138 antibody magnetic beads, and the expression of ARS in MM clinical samples was analyzed by real-time RT-PCR. Human B lymphocyte GM12878 cells and human MM cell lines ARP1, NCI-H929, OCI-MY5, U266, RPMI 8266, OPM-2, JJN-3, KMS11, MM1.s cells were selected as the study objects. The expression of ARS in MM cell lines was analyzed by real-time RT-PCR and Western blotting. Short hairpin RNA (shRNA) lentiviruses were used to construct gene knock-out plasmids (VARS-sh group). No-load plasmids (scramble group) and gene knock-out plasmids (VARS-sh group) were transfected into HEK 293T cells with for virus packaging, respectively. Stable expression cell lines were established by infecting ARP1 and OCI-MY5 cells, and the effects of knockout valyl-tRNA synthetase (VARS) gene on proliferation and apoptosis of MM cells were detected by cell counting and flow cytometry, respectively. GEO data were divided into a high expression group and a low expression group according to the expression of VARS. Bioinformatics analysis was performed to explore the downstream pathways affected by VARS. Gas chromatography time-of-flight mass spectrometry (GC-TOF/MS) and high performance liquid chromatography (HPLC) were used to detect the valine content in CD138+ cells and ARP1, OCI-MY5 cells and supernatant of knockdown VARS gene in bone marrow samples from patients, respectively. RESULTS: Gene enrichment analysis showed that tRNA processing related genes were significantly enriched in MM compared with HD (P<0.0001). Further screening of tRNA processing-pathway related subsets revealed that cytoplasmic aminoacyl tRNA synthetase family genes were significantly enriched in MM (P<0.0001). The results of gene expression heat map showed that the ARS family genes except alanyl-tRNA synthetase (AARS), arginyl-tRNA synthetase (RARS), seryl-tRNA synthetase (SARS) in GEO data were highly expressed in MM (all P<0.01). With the development of monoclonal gammopathy of undetermined significance (MGUS) to MM, the gene expression level was increased gradually. Kaplan-Meier univariate analysis of survival results showed that there were significant differences in the prognosis of MM patients in methionyl-tRNA synthetase (MARS), asparaginyl-tRNA synthetase (NARS) and VARS between the high expression group and the low expression group (all P<0.05). Cox regression model multivariate analysis showed that the high expression of VARS was associated with abnormal overall survival time of MM (HR=1.83, 95% CI 1.10 to 3.06, P=0.021). The high expression of NARS (HR=0.90, 95% CI 0.34 to 2.38) and MARS (HR=1.59, 95% CI 0.73 to 3.50) had no effect on the overall survival time of MM patients (both P>0.05). Real-time RT-PCR and Western blotting showed that VARS, MARS and NARS were highly expressed in CD138+ MM cells and MM cell lines of clinical patients (all P<0.05). Cell counting and flow cytometry results showed that the proliferation of MM cells by knockout VARS was significantly inhibited (P<0.01), the proportion of apoptosis was significantly increased (P<0.05). Bioinformatics analysis showed that in addition to several pathways including the cell cycle regulated by VARS, the valine, leucine and isoleucine catabolic pathways were upregulated. Non-targeted metabolomics data showed reduced valine content in CD138+ tumor cells in MM patients compared to HD (P<0.05). HPLC results showed that compared with the scramble group, the intracellular and medium supernatant content of ARP1 cells and the medium supernatant of OCI-MY5 in the VARS-shRNA group was increased (all P<0.05). CONCLUSIONS: MM patients with abnormal high expression of VARS have a poor prognosis. VARS promotes the malignant growth of MM cells by affecting the regulation of valine metabolism.

Chronic exposure to low concentration of MC-LR caused hepatic lipid metabolism disorder.

Microcystin-LR (MC-LR), a potent hepatotoxin can cause liver damages. However, research on hepatic lipid metabolism caused by long-term exposure to environmental concentrations MC-LR is limited. In the current study, mice were exposed to various low concentrations of MC-LR (0, 1, 30, 60, 90, 120 µg/L in the drinking water) for 9 months. The general parameters, serum and liver lipids, liver tissue pathology, lipid metabolism-related genes and proteins of liver were investigated. The results show that chronic MC-LR exposure had increased the levels of triglyceride (TG) and total cholesterol (TC) in serum and liver. In addition, histological observation revealed that hepatic lobules were disordered with obvious inflammatory cell infiltration and lipid droplets. More importantly, the mRNA and proteins expression levels of lipid synthesis-related nuclear sterol regulatory element binding protein-1c (nSREBP-1c), SREBP-1c, cluster of differentiation 36 (CD36), acetyl-CoA-carboxylase1 (ACC1), stearoyl-CoA desaturase1 (SCD1) and fatty acid synthase (FASN) were increased in MC-LR treated groups, the expression levels of fatty acids ß-oxidation related genes peroxisomal acyl-coenzyme A oxidase 1 (ACOX1) was decreased after exposure to 60-120 µg/L MC-LR. Furthermore, the inflammatory factors interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) were higher than that in the control group. All the findings indicated that mice were exposed to chronic low concentrations MC-LR caused liver inflammation and hepatic lipid metabolism disorder .

NEK2 promotes the progression of liver cancer by resisting the cellular senescence. / NEK2通过抵抗肝癌细胞衰老促进肝癌进展.

OBJECTIVES: Liver cancer is the sixth most common malignant tumor in the world. Hepatocellular carcinoma (HCC) accounts for 85%-90% of all patients with liver cancer. It possesses the characteristics of insidious onset, rapid progression, early recurrence, easy drug resistance, and poor prognosis. NIMA related kinase 2 (NEK2) is a cell cycle regulating kinases, which regulates cell cycle in mitosis. Cellular senescence is a complex heterogeneous process, and is a stable form of cell cycle arrest that limits the proliferative potential of cells. This study aims to investigate the relationship between the expression level of NEK2 and the senescence in hepatoma cells, and to explore the effect of NEK2 expression on hepatoma cell senescence and the underlying molecular mechanism. METHODS: A total of 581 senescence-relevant genes were obtained from the GenAge website. The gene expression data of tumor tissues of 370 HCC patients were downloaded from the Cancer Genome Atlas database. The co-expression of NEK2 and aging-related genes was analyzed by R-package. KEGG was used to analyze the significant gene enrichment pathway of differentially expressed genes in NEK2 overexpression HEK293. The stable transfected cell lines with overexpression and knockdown of NEK2 were constructed in hepatoma cell line SMMC-7721 and HepG2, and senescence-associated ß-galactosidase (SA-ß-gal) staining was used to detect senescence, the cell proliferation was detected by CCK-8 method and clone formation experiment, the cell cycle was analyzed by flow cytometry, and the expression of proteins related to p53/p21, p16/Rb, and phosphatase and tensin homolog deleted on chromosome ten (PTEN)/Akt signal transduction pathway was detected by Western blotting. RESULTS: There were 320 senescence related genes co-expressed with NEK2. KEGG analysis showed that the senescence signaling pathway was significantly enriched in HEK293 cells with overexpression of NEK2.Compared with SMMC-7721 or HepG2 without knockdown of NEK2, the senescent cells of SMMC-7721 and HepG2 with knockdown of NEK2 were increased, cell proliferation and clone formation were decreased significantly, the percentage of cells in G0/G1 phase was increased, the expression levels of phospho-Akt (p-Akt) and phospho-Rb (p-Rb) protein were decreased significantly, and the expression level of p16 protein was increased significantly (all P<0.05). Compared with SMMC-7721 or HepG2 transfected with blank plasmid, the senescent cells of SMMC-7721 and HepG2 overexpressing NEK2 were decreased, the cell proliferation and clone formation were increased significantly, the percentage of cells in G0/G1 phase were decreased, the expression levels of p-Akt and p-Rb protein were increased significantly, and the expression level of p16 protein was decreased significantly (all P<0.05). CONCLUSIONS: NEK2 may mediate the anti-aging effect of hepatoma cells through p16/Rb and PTEN/Akt signal transduction pathways, which provides a new theoretical basis for NEK2 to promote the progress of liver cancer and a new idea for the targeting treatment for liver cancer.

MBP-activated autoimmunity plays a role in arsenic-induced peripheral neuropathy and the potential protective effect of mecobalamin.

Intake excessive arsenic (As) is related to the occurrence of peripheral neuropathy. However, both the underlying mechanism and the preventive approach remain largely unknown. In the present study, As treatment significantly decreased the mechanical withdrawal threshold and increased the titer of anti-myelin basic protein antibody in rats, accompanied with damaged BNB. The levels of inflammatory cytokines and proteolytic enzymes were also significantly upregulated. However, administration of MeCbl in As-treated rats significantly reversed the decline in hindfoot mechanical withdrawal threshold, as well as BNB failure and sciatic nerve inflammation. Repeated As treatment in athymic nude mice indicated that sciatic nerve inflammation and mechanical hyperalgesia were T cell-dependent. These data implicated that MBP-activated autoimmunity and the related neuroinflammation probably contributed to As-induced mechanical hyperalgesia and MeCbl exerted a protective role probably via maintenance the integrity of BNB and inhibition of neuroinflammation.