👤 Yingjie Jiang

Long non-coding RNAs (lncRNAs) are expressed in tissue-specific pattern, but it is not clear how these are regulated. We aimed to identify squamous cell carcinoma (SCC)-specific lncRNAs and investigate mechanisms that control their expression and function. We studied expression patterns and functions of 4 SCC-specific lncRNAs. We obtained 113 esophageal SCC (ESCC) and matched non-tumor esophageal tissues from a hospital in Shantou City, China, and performed quantitative reverse transcription polymerase chain reaction assays to measure expression levels of LINC01503. We collected clinical data from patients and compared expression levels with survival times. LINC01503 was knocked down using small interfering RNAs and oligonucleotides in TE7, TE5, and KYSE510 cell lines and overexpressed in KYSE30 cells. Cells were analyzed by chromatin immunoprecipitation sequencing, luciferase reporter assays, colony formation, migration and invasion, and mass spectrometry analyses. Cells were injected into nude mice and growth of xenograft tumors was measured. LINC01503 interaction with proteins was studied using fluorescence in situ hybridization, RNA pulldown, and RNA immunoprecipitation analyses. We identified a lncRNA, LINC01503, which is regulated by a super enhancer and is expressed at significantly higher levels in esophageal and head and neck SCCs than in non-tumor tissues. High levels in SCCs correlated with shorter survival times of patients. The transcription factor TP63 bound to the super enhancer at the LINC01503 locus and activated its transcription. Expression of LINC01503 in ESCC cell lines increased their proliferation, colony formation, migration, and invasion. Knockdown of LINC01503 in SCC cells reduced their proliferation, colony formation, migration, and invasion, and the growth of xenograft tumors in nude mice. Expression of LINC01503 in ESCC cell lines reduced ERK2 dephosphorylation by DUSP6, leading to activation of ERK signaling via MAPK. LINC01503 disrupted the interaction between EBP1 and the p85 subunit of PI3K, increasing AKT signaling. We identified an lncRNA, LINC01503, which is increased in SCC cells compared with non-tumor cells. Increased expression of LINC01503 promotes ESCC cell proliferation, migration, invasion, and growth of xenograft tumors. It might be developed as a biomarker of aggressive SCCs in patients. Show less

Genome-wide association studies (GWASs) have shown that genetic variants are important determinants of free fatty acid levels. The mechanisms underlying the associations between genetic variants and free fatty acid levels are incompletely understood. Here, we aimed to identify genetic markers that could influence diverse fatty acid levels in a Chinese population and uncover the molecular mechanisms in terms of DNA methylation and gene expression. We identified strong associations between single-nucleotide polymorphisms (SNPs) in the fatty acid desaturase (FADS) region and multiple polyunsaturated fatty acids. Expression quantitative trait locus (eQTL) analysis of rs174570 on FADS1 and FADS2 mRNA levels proved that minor allele of rs174570 was associated with decreased FADS1 and FADS2 expression levels (P < 0.05). Methylation quantitative trait locus (mQTL) analysis of rs174570 on DNA methylation levels in three selected regions of FADS region showed that the methylation levels at four CpG sites in FADS1, one CpG site in intragenic region, and three CpG sites in FADS2 were strongly associated with rs174570 (P < 0.05). Then, we demonstrated that methylation levels at three CpG sites in FADS1 were negatively associated with FADS1 and FADS2 expression, while two CpG sites in FADS2 were positively associated with FADS1 and FADS2 expression. Using mediation analysis, we further show that the observed effect of rs174570 on gene expression was tightly correlated with the effect predicted through association with methylation. Our findings suggest that genetic variants in the FADS region are major genetic modifiers that can regulate fatty acid metabolism through epigenetic gene regulation. Show less

Polyunsaturated fatty acids (PUFAs) are associated with a lower risk of multiple diseases. Fatty acid desaturase 1 gene (FADS1) polymorphisms and dietary PUFA intake are both established determinants of circulating PUFA proportions. We explored the joint effects of FADS1 polymorphisms and dietary PUFA intake on circulating PUFA proportions. We studied 2288 participants from a nested case-control study of coronary artery disease among participants who provided blood samples in the Nurses' Health Study and the Health Professionals Follow-Up Study. Dietary PUFA intake was obtained from semiquantitative food-frequency questionnaires. FADS1 rs174546 was genotyped by using the Affymetrix 6.0 platform, and circulating PUFA proportions were measured with gas-liquid chromatography. Linear regression models were used to examine the associations between rs174546 and circulating proportions of each fatty acid. Gene-diet interactions were tested by including a cross-product term of dietary intake of each PUFA by rs174546 genotype in the linear regression models. After adjustment for sex and ancestry, each copy of the C allele of rs174546 was associated with higher circulating proportions of arachidonic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and lower proportions of linoleic acid and α-linolenic acid. The magnitude of positive association between higher consumption of dietary EPA or DHA and circulating proportions of EPA increased with each copy of the rs174546_T allele (P-interaction = 0.01 and 0.007, respectively). Each 1-SD increment in EPA intake was associated with an average 3.7% increase in circulating EPA proportions among participants with the rs174546_CC genotype and an average 7.8% increase among participants with the TT genotype. Carriers of the T allele at FADS1 rs174546 may need higher doses of dietary EPA and DHA to achieve the same circulating proportions of EPA as carriers of the C allele. The implications of these findings on disease risk and dietary guidelines require further study. Show less

Mammary epithelial cells (MECs) affect milk production capacity during lactation and are critical for the maintenance of tissue homeostasis. Our previous studies have revealed that the expression of miR-152 was increased significantly in MECs of cows with high milk production. In the present study, bioinformatics analysis identified ACAA2 and HSD17B12 as the potential targets of miR-152, which were further validated by dual-luciferase repoter assay. In addition, the expressions of miR-152 was shown to be negatively correlated with levels of mRNA and protein of ACAA2, HSD17B12 genes by qPCR and western bot analysis. Furthermore, transfection with miR-152 significantly up-regulated triglyceride production, promoted proliferation and inhibited apoptosis in MECs. Furthermore, overexpression of ACAA2 and HSD17B12 could inhibit triglyceride production, cells proliferation and induce apoptosis; but sh234-ACAA2-181/sh234-HSD17B12-474 could reverse the trend. These findings suggested that miR-152 could significantly influence triglyceride production and suppress apoptosis, possibly via the expression of target genes ACAA2 and HSD17B12. Show less

Non-small-cell lung cancer (NSCLC) has been recognized as a highly heterogeneous disease with phenotypic and genotypic diversity in each subgroup. While never-smoker patients with NSCLC have been well studied through next generation sequencing, we have yet to recognize the potentially unique molecular features of young never-smoker patients with NSCLC. In this study, we conducted whole genome sequencing (WGS) to characterize the genomic alterations of 36 never-smoker Chinese patients, who were diagnosed with lung adenocarcinoma (LUAD) at 45 years or younger. Besides the well-known gene mutations (e.g., TP53 and EGFR), our study identified several potential lung cancer-associated gene mutations that were rarely reported (e.g., HOXA4 and MST1). The lung cancer-related copy number variations (e.g., EGFR and CDKN2A) were enriched in our cohort (41.7%, 15/36) and the lung cancer-related structural variations (e.g., EML4-ALK and KIF5B-RET) were commonly observed (22.2%, 8/36). Notably, new fusion partners of ALK (SMG6-ALK) and RET (JMJD1C-RET) were found. Furthermore, we observed a high prevalence (63.9%, 23/36) of potentially targetable genomic alterations in our cohort. Finally, we identified germline mutations in BPIFB1 (rs6141383, p.V284M), CHD4 (rs74790047, p.D140E), PARP1 (rs3219145, p.K940R), NUDT1 (rs4866, p.V83M), RAD52 (rs4987207, p.S346*), and MFI2 (rs17129219, p.A559T) were significantly enriched in the young never-smoker patients with LUAD when compared with the in-house noncancer database (p < 0.05). Our study provides a detailed mutational portrait of LUAD occurring in young never-smokers and gives insights into the molecular pathogenesis of this distinct subgroup of NSCLC. Show less

Seizure-induced brain damage is age-dependent, as evidenced by the different alterations of neural physiopathology in developing and mature brains. However, little is known about the age-dependent characteristics of myelinated fiber injury induced by seizures. Considering the critical functions of oligodendrocyte progenitor cells (OPCs) in myelination and Lingo-1 signaling in regulating OPCs' differentiation, the present study aimed to explore the effects of Lingo-1 on myelin and axon in immature and adult rats after status convulsion (SC) induced by lithium-pilocarpine, and the differences between immature and adult brains. Dynamic variations in electrophysiological activity and spontaneous recurrent seizures were recorded by electroencephalogram monitoring after SC. The impaired microstructures of myelin sheaths and decrease in myelin basic protein caused by SC were observed through transmission electron microscopy and western blot analysis respectively, which became more severe in adult rats, but improved gradually in immature rats. Aberrant axon sprouting occurred in adult rats, which was more prominent than in immature rats, as shown by a Timm stain. This damage was improved or negatively affected after down or upregulating Lingo-1 expression. These results demonstrated that in both immature and adult brains, Lingo-1 signaling plays important roles in seizure-induced damage to myelin sheaths and axon growth. The plasticity of the developing brain may provide a potential window of opportunity to prevent the brain from damage. Show less

The carbohydrate response element-binding protein (ChREBP), also referred to as MLXIPL, plays a crucial role in the regulation of glucose and lipid metabolism. Existing studies have shown an association between genetic variations of the ChREBP gene and lipid levels, such as triglycerides and high-density lipoprotein cholesterol. However, mechanistic studies of this association are limited. In this study, bioinformatic analysis revealed that the polymorphism rs1051943A occurs in the complementary binding sequence of miR-1322 in the ChREBP 3'-untranslated region (UTR). Studies of potential mechanisms showed that the A allele could facilitate miR-1322 binding, and luciferase activity significantly decreased when co-transfected with a ChREBP 3'-UTR luciferase reporter vector and miR-1322 mimics in HepG2 cells. Furthermore, miR-1322 significantly regulated the expression of ChREBP downstream genes and reduced the synthesis of lipids. The expression of miR-1322 was up-regulated by glucose and palmitic acid stimulation. Population studies showed that rs1051943-A allele was only found in the Han Chinese and Uighur ethnic groups, different from European populations (G allele frequency = 0.07). In summary, we provide evidence that the rs1051943 A allele creates a functional miR-1322 binding site in ChREBP 3'-UTR and post-transcriptionally down-regulates its expression, possibly associated with levels of plasma lipids and glucose. Show less

Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide-dependent protein deacetylase. Recent studies have demonstrated that enhancing SIRT1 expression or activity may modulate cholesterol and lipid metabolism. However, pharmacological and molecular regulators for SIRT1 are scarce. Here, we aimed to find novel small molecule modulators of SIRT1 to regulate cholesterol and lipid metabolism. A high-throughput screening assay was established to identify SIRT1 activators. Surface plasmon resonance and immunoprecipitation were performed to confirm the interaction of E1231 with SIRT1. Cholesterol assay was performed to demonstrate the in vitro effect of E1231. The in vivo effect of E1231 was evaluated in experimental models. E1231, a piperazine 1,4-diamide compound, was identified as a SIRT1 activator with EC We identified a novel SIRT1 activator E1231 and elucidated its beneficial effects on lipid and cholesterol metabolism. Our study suggests that E1231 might be developed as a novel drug for treating atherosclerosis. Show less

During mouse preimplantation development, blastomeres are equipotent until polarity establishment at compacted 8-cell stage. The intrinsic nature of polarity is the asymmetric distribution of polarity proteins between inside and outside blastomeres along the direction of apical-basal axis. This study investigated the early developmental temporal and spatial expression of the main CRUMBS polarity complex proteins in the mouse preimplantation embryo. We observed that Crb3, Pals1, Patj and Mpdz are transcribed in the mouse preimplantation embryo. However, the asymmetric distribution of these polarity proteins is not established until the compacted 8-cell stage. From compaction and thereafter, CRB3 and PALS1 are progressively enriched in the apical membrane, while PATJ and MPDZ are discretely localized at both tight junctions and the apical membrane adjacent to tight junctions. These temporal and spatial distribution patterns suggest that CRUMBS polarity complex might be involved in the cell polarity establishment in the early mouse embryo and reinforce the viewpoint that developmentally spatial asymmetries are first set up at the compaction stage. The present study provides a foundation for further investigation on the functions of CRUMBS polarity complex in trophectoderm specification and blastocyst morphogenesis. Show less

Nasopharyngeal carcinoma (NPC) is a poorly differentiated malignant tumor, and 5-fluorouracil (5-FU) is one of the most effective chemotherapeutic drugs used for the treatment of NPC. Abnormal expression of RGS17 had been shown to improve the sensitivity of many cancers to chemotherapy; however, the effects of RGS17 on NPC remain unclear. We cultured NPC cell lines and altered the RGS17 expression with vector. Subsequently colony formation assays and CCK8 cell viability assay was used to test the proliferation of NPC cells, flow cytometry was used to determine the percentage of apoptotic cells, MMP kit and flow cytometry was used to measure the mitochondrial membrane potential, and a xenograft tumour model was attached to investigate the effects of RGS17 on the growth of NPC cells in vivo. Additionally, RT-PCR and western blot was induced to examine the expression of RGS17 and the mechanism. Here, we report for the first time that RGS17 is downregulated in NPC cell lines and that RGS17 overexpression significantly reduces cell proliferation, decreases the mitochondrial membrane potential, and induces cell apoptosis in NPC cells. In vivo, RGS17 also inhibits the tumorigenicity of NPC. In addition, RGS17 could significantly improve the sensitivity of NPC cells to 5-FU. Furthermore, investigation into the underlying mechanisms showed that RGS17 upregulated the levels of IRE1α, p53, and active caspase-3 and cleaved PARP. These results indicate that RGS17 could play important roles in the proliferation, apoptosis, and chemotherapeutic sensitivity of NPC cells. Show less

N-Hydroxysuccinimide (NHS)-esters are widely used to label proteins nonselectively on free amino groups. Such broad labeling can be disadvantageous because it can interfere with protein structure or function and because stoichiometry is poorly controlled. Here we describe a simple method to transform NHS-esters into site-specific protein labeling on N-terminal Cys residues. MESNA addition converts NHS-esters to chemoselective thioesters for N-Cys modification. This labeling strategy was applied to clarify mechanistic features of the ubiquitin E3 ligase WWP2 including its interaction with one of its substrates, the tumor suppressor PTEN, as well as its autoubiquitination molecularity. We propose that this convenient protein labeling strategy will allow for an expanded application of NHS-esters in biochemical investigation. Show less

Zinc finger protein 668 (ZNF668) is a recently discovered protein and its expression levels, as well as its involvement in the invasion and metastasis of non-small cell lung cancer (NSCLC), are largely unknown. In the present study, immunohistochemical analysis demonstrated that ZNF668 protein expression was decreased in lung tumors (51/167, 30.5%) compared with adjacent normal lung tissues (43/62, 69.4%; P<0.001). Subsequent statistical analysis revealed that ZNF668 expression was negatively associated with increased tumor-node-metastasis stage (P=0.019) and lymph node metastasis (P=0.002). Following ZNF668 downregulation by transfection of a Show less

Coronary heart disease (CHD) is the most common cause of death worldwide. This study aimed to validate the association of the rs964184 polymorphism with the CHD risk and included 874 CHD patients and 776 controls. rs964184 polymorphism genotyping was performed using Tm-shift polymerase chain reaction. A strong association of the rs964184 polymorphism with CHD was found (genotype: X Our results indicate that both gender and age have great impacts on the association of the rs964184 polymorphism with CHD among Chinese. Show less

We aim to validate the effects of glucose-dependent insulinotropic polypeptide (GIP) on fat distribution and glucose metabolism in Han Chinese populations. We genotyped six tag single-nucleotide polymorphisms (SNPs) of GIP and four tag SNPs of glucose-dependent insulinotropic polypeptide receptor (GIPR) among 2884 community-based individuals from Han Chinese populations. Linear analysis was applied to test the associations of these variants with visceral fat area (VFA) and subcutaneous fat area (SFA) quantified by magnetic resonance imaging as well as glucose-related traits. We found that the C allele of rs4794008 of GIP tended to increase the VFA and the VFA/SFA ratio in all subjects (P=0.050 and P=0.054, respectively), and rs4794008 was associated with the VFA/SFA ratio in males (P=0.041) after adjusting for the BMI. The VFA-increasing allele of rs4794008 was not related to any glucose metabolism traits. However, rs9904288 of GIP was associated with the SFA in males as well as glucose-related traits in all subjects (P range, 0.004-0.049), and the GIPR variants displayed associations with both fat- and glucose-related traits. The results could provide the evidence that GIP might modulate visceral fat accumulation via incretin function or independent of incretin. Show less

Recently single-cell whole-exome sequencing (scWES) has deeply expanded and sharpened our knowledge of cancer evolution and subclonality. Herein, with scWES and matched bulk whole-exome sequencing (bulk WES) on two colorectal cancer (CRC) patients with normal or adenomatous polyps, we found that both the adenoma and cancer were of monoclonal origin, and both shared partial mutations in the same signaling pathways, but each showed a specific spectrum of heterogeneous somatic mutations. In addition, the adenoma and cancer further developed intratumor heterogeneity with the accumulation of nonrandom somatic mutations specifically in GPCR, PI3K-Akt and FGFR signaling pathways. We identified novel driver mutations that developed during adenoma and cancer evolution, particularly in OR1B1 (GPCR signaling pathway) for adenoma evolution, and LAMA1 (PI3K-Akt signaling pathway) and ADCY3 (FGFR signaling pathway) for CRC evolution. In summary, we demonstrated that both colorectal adenoma and CRC are monoclonal in origin, and the CRCs further diversified into different subclones with heterogeneous mutation profiles accumulating in GPCR, PI3K-Akt and FGFR signaling pathways. ScWES provides evidence for the importance of mutations in certain pathways that would not be as apparent from bulk sequencing of tumors, and can potentially establish whether specific mutations are mutually exclusive or occur sequentially in the same subclone of cells. Show less

Peroxisome proliferator-activated receptor γ (PPARγ) has been shown to be a therapeutic target for preeclampsia (PE). Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional secretory protein involved in regulating lipid metabolism and angiogenesis in various tissues. However, the expression of PPARγ and ANGPTL4 and their interaction in PE remain elusive. Here we showed that PPARγ agonist rosiglitazone upregulated the expression and secretion of ANGPTL4 in a dose-dependent manner in HTR8/SVneo cells, human umbilical vein endothelial cells (HUVECs) and placental explants. More importantly, we confirmed that the PPARγ/retinoid X receptor α heterodimer specifically binds to the ANGPTL4 promoter region and enhances its transcriptional activity. In addition, the levels of ANGPTL4 and PPARγ activators in the serum and their expression in placental tissues were significantly reduced in preeclamptic patients compared with normal pregnant subjects. Furthermore, functional studies demonstrated that ANGPTL4 mediates the facilitative effects of the PPARγ agonist on the survival, proliferation, migration and invasion of HTR8/SVneo cells, placental explants outgrowth and angiogenesis in HUVECs. Taken together, our results suggest that ANGPTL4 is a potential target gene for PPARγ and mediates the protective role of PPARγ activators in the pathogenesis of PE. Show less

Urea cycle disorders (UCDs) are genetic conditions characterized by nitrogen accumulation in the form of ammonia and caused by defects in the enzymes required to convert ammonia to urea for excretion. UCDs include a spectrum of enzyme deficiencies, namely n-acetylglutamate synthase deficiency (NAGS), carbamoyl phosphate synthetase I deficiency (CPS1), ornithine transcarbamylase deficiency (OTC), argininosuccinate lyase deficiency (ASL), citrullinemia type I (ASS1), and argininemia (ARG). Currently, sodium phenylbutyrate and glycerol phenylbutyrate are primary medications used to treat patients with UCDs, and long-term monitoring of these compounds is critical for preventing drug toxic levels. Therefore, a fast and simple ultra-performance liquid chromatography (UPLC-MS/MS) method was developed and validated for quantification of phenylbutyrate (PB), phenylacetate (PA), and phenylacetylglutamine (PAG) in plasma and urine. The separation of all three analytes was achieved in 2min, and the limits of detection were <0.04μg/ml. Intra-precision and inter-precision were <8.5% and 4% at two quality control concentrations, respectively. Average recoveries for all compounds ranged from 100% to 106%. With the developed assay, a strong correlation between PA and the PA/PAG ratio and an inverse correlation between PA/PAG ratio and plasma glutamine were observed in 35 patients with confirmed UCDs. Moreover, all individuals with a ratio ≥0.6 had plasma glutamine levels<1000μmol/l. Our data suggest that a PA/PAG ratio in the range of 0.6-1.5 will result in a plasma glutamine level<1000μmol/l without reaching toxic levels of PA. Show less

The evidence supporting an association between traffic-related air pollution exposure and incident childhood asthma is inconsistent and may depend on genetic factors. To identify gene-environment interaction effects on childhood asthma using genome-wide single-nucleotide polymorphism (SNP) data and air pollution exposure. Identified loci were further analyzed at epigenetic and transcriptomic levels. We used land use regression models to estimate individual air pollution exposure (represented by outdoor NO In the European cohorts, 186 SNPs had an interaction P < 1 × 10 Our results indicated that gene-environment interactions are important for asthma development and provided supportive evidence for interaction with air pollution for ADCY2, B4GALT5, and DLG2. Show less

Endometrial cancer is a prevalent cancer, and its metastasis causes low survival rate. This study aims to utilize DNA methylation data to investigate the mechanism of the development and metastasis of endometrial cancer. Methylation profiling data were down-loaded from Gene Expression Omnibus, including 8 hyperplasias, 33 primary and 53 metastatic endometrial cancers. COHCAP package and annotation files were utilized to identify differentially methylated genes (DMGs) and CpG islands between the three different endometrial diseases. STRING database and Cytoscape were used to analyze and visualize protein-protein interactions (PPIs) between DMGs. CytoNCA plugin was utilized to identify key nodes in PPI network. A total of 610, 1076, and 501 DMGs were identified between primary endometrial cancer and hyperplasia, metastatic endometrial cancer and hyperplasia, as well as metastatic and primary endometrial cancers, respectively. For the three DMG sets, 53 common hypermethylated DMGs (e.g. PAX6 and INSR) and 6 common hypomethylated DMGs (e.g. PRDM8, KLHL14, and DUSP6) were found. For primary-hyperplasia DMG set and metastasis-hyperplasia DMG set, 527 common DMGs were found. For these common DMGs, a PPI network involving 692 PPIs was constructed. For DMGs between metastatic and primary endometrial cancers, a PPI network involving 673 PPIs was established, with PAX6 and INSR in the top 20 DMGs in both networks. PRDM8, KLHL14, and DUSP6 had hypomethylated CpG islands. DMGs comparison, PPI network analysis, and analysis of differentially methylated CpG islands indicated that PAX6, INSR, PRDM8, KLHL14, and DUSP6 might participate in the development and metastasis of endometrial cancer. Show less

Dual specificity phosphatase 6 (DUSP6), a member of the dual specificity protein phosphatase subfamily, can inactivate ERK1/2. However, its possible role in glutamate-induced oxidative cytotoxicity effects is not clear.Here, we aimed to investigate whether DUSP6 was neuroprotective against glutamate-induced cytotoxicity in HT22 mouse hippocampal cells and primary cultured hippocampal neurons (pc-HNeu). HT22 and pc-HNeu cells were treated with varying concentrations of glutamate (from 0.05mM to 5.0mM) and DUSP6 protein expression were detected by western blotting. DUSP6-overexpressing HT22 and pc-HNeu cells were generated by transfection with DUSP6-overexpressing plasmid. The effects of DUSP6 overexpression on glutamate-induced cytotoxicity, cell death, cell apoptosis, and cell autophagy were determined by cell proliferation assays, flow cytometry, transmission electron microscopy, and western blotting. Glutamate treatment from 0.5mM to 5.0mM downregulated DUSP6 protein expression in both HT22 and pc-HNeu cells. DUSP6 overexpression ameliorated glutamate-induced cell death, apoptosis, and autophagy in both HT22 and pc-HNeu cells. Furthermore, ERK1/2 phosphorylation was decreased by DUSP6 overexpression. In conclusion, DUSP6 has neuroprotective effects against glutamate-induced cytotoxicity in HT22 and pc-HNeu cells. Targeting DUSP6 may be a useful strategy to prevent neuronal death in neurodegenerative diseases including AD. Show less

Maternal obesity increases fetal adiposity which may adversely affect metabolic health of the offspring. Choline regulates lipid metabolism and thus may influence adiposity. This study investigates the effect of maternal choline supplementation on fetal adiposity in a mouse model of maternal obesity. C57BL/6J mice were fed either a high-fat (HF) diet or a control (NF) diet and received either 25 mM choline supplemented (CS) or control untreated (CO) drinking water for 6 weeks before timed-mating and throughout gestation. At embryonic day 17.5, HF feeding led to higher ( Show less

Vascular smooth muscle cell proliferation, migration, and dedifferentiation are critical for vascular diseases. Recently, it was demonstrated that Notch receptors have opposing effects on intima formation after vessel injury. Therefore, it is important to investigate the specific regulatory pathways that activate the different Notch receptors. There was a time- and dose-dependent activation of Notch1 by angiotensin II and platelet-derived growth factor in vascular smooth muscle cells. When phospholipase Cγ1 (PLCγ1) expression was reduced by small interfering RNA, Notch1 activation and Hey2 expression (Notch target gene) induced by angiotensin II or platelet-derived growth factor were remarkably inhibited, while Notch2 degradation was not affected. Mechanistically, we observed an association of PLCγ1 and Akt, which increased after angiotensin II or platelet-derived growth factor stimulation. PLCγ1 knockdown significantly inhibited Akt activation. Importantly, PLCγ1 phospholipase site mutation (no phospholipase activity) did not affect Akt activation. Furthermore, PLCγ1 depletion inhibited platelet-derived growth factor-induced vascular smooth muscle cell proliferation, migration, and dedifferentiation, while it increased apoptosis. In vivo, PLCγ1 and control small interfering RNA were delivered periadventitially in pluronic gel and complete carotid artery ligation was performed. Morphometric analysis 21 days after ligation demonstrated that PLCγ1 small interfering RNA robustly attenuated intima area and intima/media ratio compared with the control group. PLCγ1-Akt-mediated Notch1 signaling is crucial for intima formation. This effect is attributable to PLCγ1-Akt interaction but not PLCγ1 phospholipase activity. Specific inhibition of the PLCγ1 and Akt interaction will be a promising therapeutic strategy for preventing vascular remodeling. Show less

A lack of sufficient oligodendrocyte myelination contributes to remyelination failure in demyelinating disorders. miRNAs have been implicated in oligodendrogenesis; however, their functions in myelin regeneration remained elusive. Through developmentally regulated targeted mutagenesis, we demonstrate that miR-219 alleles are critical for CNS myelination and remyelination after injury. Further deletion of miR-338 exacerbates the miR-219 mutant hypomyelination phenotype. Conversely, miR-219 overexpression promotes precocious oligodendrocyte maturation and regeneration processes in transgenic mice. Integrated transcriptome profiling and biotin-affinity miRNA pull-down approaches reveal stage-specific miR-219 targets in oligodendrocytes and further uncover a novel network for miR-219 targeting of differentiation inhibitors including Lingo1 and Etv5. Inhibition of Lingo1 and Etv5 partially rescues differentiation defects of miR-219-deficient oligodendrocyte precursors. Furthermore, miR-219 mimics enhance myelin restoration following lysolecithin-induced demyelination as well as experimental autoimmune encephalomyelitis, principal animal models of multiple sclerosis. Together, our findings identify context-specific miRNA-regulated checkpoints that control myelinogenesis and a therapeutic role for miR-219 in CNS myelin repair. Show less

Hepatic de novo lipogenesis (DNL) converts carbohydrates into triglycerides and is known to influence systemic lipid homoeostasis. Here, we demonstrate that the zinc finger protein Zbtb20 is required for DNL. Mice lacking Zbtb20 in the liver exhibit hypolipidemia and reduced levels of liver triglycerides, along with impaired hepatic lipogenesis. The expression of genes involved in glycolysis and DNL, including that of two ChREBP isoforms, is decreased in livers of knockout mice. Zbtb20 binds to and enhances the activity of the ChREBP-α promoter, suggesting that altered metabolic gene expression is mainly driven by ChREBP. In addition, ChREBP-β overexpression largely restores hepatic expression of genes involved in glucose and lipid metabolism, and increases plasma and liver triglyceride levels in knockout mice. Finally, we show that Zbtb20 ablation protects from diet-induced liver steatosis and improves hepatic insulin resistance. We suggest ZBTB20 is an essential regulator of hepatic lipogenesis and may be a therapeutic target for the treatment of fatty liver disease. Show less

Allicin, a major component of garlic, is regarded as a cardioprotective agent and is associated with increased endothelial function. The effects of allicin on lipopolysaccharide (LPS)-induced vascular oxidative stress and inflammation in cultured human umbilical vein endothelial cells (HUVECs) and the mechanisms underlying these effects were studied. The protective effects were measured using cell viability, a lactate dehydrogenase (LDH) assay and cell apoptosis as indicators, and the anti-oxidative activity was determined by measuring reactive oxygen species (ROS) generation, oxidative products and endogenous antioxidant enzyme activities. HUVEC mitochondrial function was assessed by determining mitochondrial membrane potential (MMP) collapse, cytochrome c production and mitochondrial ATP release. To investigate the potential underlying mechanisms, we also measured the expression of dynamic mitochondrial proteins using western blotting. Furthermore, we evaluated the Nrf2 antioxidant signaling pathway using an enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that allicin enhanced HUVEC proliferation, which was suppressed by LPS exposure, and LDH release. Allicin ameliorated LPS-induced apoptosis, suppressed ROS overproduction, reduced lipid peroxidation and decreased the endogenous antioxidant enzyme activities in HUVECs. These protective effects were associated with the inhibition of mitochondrial dysfunction as indicated by decreases in the MMP collapse, cytochrome c synthesis and mitochondrial ATP release. In addition, allicin attenuated the LPS-induced inflammatory responses, including endothelial cell adhesion and TNF-α and IL-8 production. Furthermore, allicin increased the expression of LXRα in a dose-dependent manner. Allicin-induced attenuation of inflammation was inhibited by LXRα siRNA treatment. Finally, allicin activated NF-E2-related factor 2 (Nrf2), which controls the defense against oxidative stress and inflammation. Taken together, the present data suggest that allicin attenuated the LPS-induced vascular injury process, which may be closely related to the oxidative stress and inflammatory response in HUVECs. Allicin modulated Nrf2 activation and protected the cells against LPS-induced vascular injury. Our findings suggest that allicin attenuated the LPS-induced inflammatory response in blood vessels. Show less

Hepatocellular carcinoma (HCC) ranks as the third leading cause of cancer-related mortality in China with increasing incidence. This study is designed to explore early genetic changes implicated in HCC tumorigenesis and progression by whole-exome sequencing. We firstly sequenced the whole exomes of 5 paired hepatitis B virus-related early-stage HCC and peripheral blood samples, followed by gene ontological analysis and pathway analysis of the single-nucleotide variants discovered. Then, the mutations of high frequency were further confirmed by Sanger sequencing. We identified a mutational signature of dominant T:A>A:T transversion in early HCC and significantly enriched pathways including ECM-receptor interaction, axon guidance, and focal adhesion and enriched biological processes containing cell adhesion, axon guidance, and regulation of pH. Eight genes, including MUC16, UNC79, USH2A, DNAH17, PTPN13, TENM4, PCLO, and PDE1C, were frequently mutated. This study reveals a mutational profile and a distinct mutation signature of T:A>A:T transversion in early-stage HCC with HBV infection, which will enrich our understanding of genetic characteristics of the early-stage HCC. Show less

The HECT E3 ligases ubiquitinate numerous transcription factors and signaling molecules, and their activity must be tightly controlled to prevent cancer, immune disorders, and other diseases. In this study, we have found unexpectedly that peptide linkers tethering WW domains in several HECT family members are key regulatory elements of their catalytic activities. Biochemical, structural, and cellular analyses have revealed that the linkers can lock the HECT domain in an inactive conformation and block the proposed allosteric ubiquitin binding site. Such linker-mediated autoinhibition of the HECT domain can be relieved by linker post-translational modifications, but complete removal of the brake can induce hyperactive autoubiquitination and E3 self destruction. These results clarify the mechanisms of several HECT protein cancer associated mutations and provide a new framework for understanding how HECT ubiquitin ligases must be finely tuned to ensure normal cellular behavior. Show less

Spinal muscular atrophy (SMA) is caused by the low levels of survival motor neuron (SMN) protein and is characterized by motor neuron degeneration and muscle atrophy. Respiratory failure causes death in SMA but the underlying molecular mechanism is unknown. The zinc finger protein ZPR1 interacts with SMN. ZPR1 is down regulated in SMA patients. We report that ZPR1 functions downstream of SMN to regulate HoxA5 levels in phrenic motor neurons that control respiration. Spatiotemporal inactivation of Zpr1 gene in motor neurons down-regulates HoxA5 and causes defects in the function of phrenic motor neurons that results in respiratory failure and perinatal lethality in mice. Modulation in ZPR1 levels directly correlates and influences levels of HoxA5 transcription. In SMA mice, SMN-deficiency causes down-regulation of ZPR1 and HoxA5 that result in degeneration of phrenic motor neurons. Identification of ZPR1 and HoxA5 as potential targets provides a paradigm for developing strategies to treat respiratory distress in SMA. Show less