👤 Xiaoqian Feng

Chronic pain is one of the serious conditions that affect human health and remains cure still remains a serious challenge as the molecular mechanism remains largely unclear. Here, we used label-free proteomics to identify potential target proteins that regulate peripheral inflammatory pain and reveal its mechanism of action. Inflammation in peripheral tissue was induced by injecting complete Freund's adjuvant (CFA) into rat hind paw. A proteomic method was adopted to compare the spinal dorsal horn (SDH) in peripheral inflammatory pain (PIP) model rats with controls. Differential proteins were identified in SDH proteome by label-free quantification. The role of screened target proteins in the PIP was verified by small interfering RNA (siRNA). A total of 3072 and 3049 proteins were identified in CFA and normal saline (NS) groups, respectively, and 13 proteins were identified as differentially expressed in the CFA group. One of them, neurexin-2, was validated for its role in the inflammatory pain. Neurexin-2 was up-regulated in the CFA group, which was confirmed by quantitative PCR. Besides, intrathecal siRNA-mediated knock-down of neurexin-2 attenuated CFA-induced mechanical and thermal hyperalgesia and reduced the expression of SDH membrane glutamate receptors (eg mGlu receptor 1, AMPA receptor) and postsynaptic density (eg PSD-95, DLG2). These findings increased the understanding of the role of neurexin-2 in the inflammatory pain, implicating that neurexin-2 acts as a potential regulatory protein of inflammatory pain through affecting synaptic plasticity in the SDH of rats. Show less

Nerve damage can lead to movement and sensory dysfunction, with high morbidity and disability rates causing severe burdens on patients, families, and society. DNA methylation is a kind of epigenetics, and a great number of previous studies have demonstrated that DNA methylation plays an important role in the process of nerve regeneration and remodeling. However, compared with the central nervous system, the peripheral nervous system shows stronger recovery after injury, which is related to the complex microenvironment and epigenetic changes occurring at the site of injury. Therefore, what common epigenetic changes between the central and peripheral nervous systems remain to be elucidated. We first screened differential methylation genes after spinal cord injury and sciatic nerve injury using whole-genome bisulfite sequencing and methylated DNA immunoprecipitation sequencing, respectively. Subsequently, a total of 16 genes had the same epigenetic changes after spinal cord injury and sciatic nerve injury. The Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were performed to identify the critical biological processes and pathways. Furthermore, a protein-protein interaction network analysis indicated that Dnm3, Ntrk3, Smurf1, Dpysl2, Kalrn, Shank1, Dlg2, Arsb, Reln, Bmp5, Numbl, Prickle2, Map6, and Htr7 were the core genes. These outcomes may provide novel insights into the molecular mechanism of the subacute phase of nerve injury. These verified genes can offer potential diagnostic and therapeutic targets for nerve injury. Show less

Numerous evidences have shown that circular RNAs (circRNAs) play a key role in regulating the pathogenesis of cancer. However, the mechanism of circRNAs in urothelial carcinoma of bladder (UCB) remains largely unclear. In this study, we found circFAM114A2 was significantly downregulated both in UCB tissue specimens and cell lines, and the expression level was highly correlated with pathological TNM stage and grade. Functionally, overexpression of circFAM114A2 dramatically inhibited the migration, invasion and proliferation of UCB cells in vitro, and suppressed tumor growth in vivo. Mechanistically, we confirmed miR-762 was copiously pulled down by circFAM114A2 in 5637 and T24 cells. Fluorescence in situ hybridization (FISH) further indicated the cytoplasmic interactions between circFAM114A2 and miR-762. By using luciferase reporter assay, we found that miR-762 could directly target TP63. Subsequently, we found that circFAM114A2 might increase the expression of ∆NP63 (main isoform of TP63 in UCB) by sponging miR-762. Taken together, our results demonstrated that circFAM114A2 might serve as a competing endogenous RNA (ceRNA) of miR-762 in regulating the expression of ∆NP63, thus suppressed UCB progression through circFAM114A2/miR-762/∆NP63 axis. Show less

Chronic overconsumption of a high-carbohydrate diet leads to steatosis and its associated metabolic disorder and, eventually, to non-alcoholic fatty liver disease. Carbohydrate-responsive element binding protein (ChREBP) and insulin regulate de novo lipogenesis from glucose. Herein, we studied the effect of reticulon-4 (Nogo) expression on diet-induced metabolic disorders in mice. Nogo-deficient (Nogo HGD/HFrD induced steatosis and its associated metabolic disorders in WT mice by activating ChREBP and impairing insulin sensitivity. They also activated Nogo-B expression, which in turn inhibited insulin activity. In response to HGD/HFrD feeding, Nogo deficiency enhanced insulin sensitivity and energy metabolism to reduce the expression of ChREBP and lipogenic molecules, activated AMP-activated catalytic subunit α, peroxisome proliferator activated receptor α and fibroblast growth factor 21, and reduced endoplasmic reticulum (ER) stress and inflammation, thereby blocking HGD/HFrD-induced hepatic lipid accumulation, insulin resistance and other metabolic disorders. Injection of Nogo siRNA protected C57BL/6J mice against HFrD-induced metabolic disorders by ameliorating insulin sensitivity, ChREBP activity, ER stress and inflammation. Our study identified Nogo as an important mediator of insulin sensitivity and ChREBP activity. Reduction of Nogo expression is a potential strategy for the treatment of high-carbohydrate diet-induced metabolic complications. Nogo deficiency blocks high-carbohydrate diet-induced glucose intolerance and insulin resistance, while increasing glucose/lipid utilisation and energy expenditure. Thus, reduction of Nogo expression protects against high-carbohydrate diet-induced body-weight gain, hepatic lipid accumulation and the associated metabolic disorders, indicating that approaches inhibiting Nogo expression can be applied for the treatment of diseases associated with metabolic disorders. Show less

Arsenic poisoning and induced potential lesion is a global concern. However, the exact mechanisms underlying its toxicity especially in male reproductive system still remain unclear. Hence, this study aimed to explore the roles of mTOR and Beclin1-Vps34/PI3K complex during As-induced-toxicity using Rapamycin (mTOR inhibitor), Beclin1 siRNA and 3-methyladenine (3-MA, Vps34/PI3K inhibitor) in testicular stromal cells. For this, mouse testis Leydig Tumor Cell lines (MLTC-1) were challenged with As Show less

Deoxynivalenol (DON) is a major mycotoxin from the trichothecene family of mycotoxins produced by Fusarium fungi. It can cause a variety of adverse effects on human and farm animal health. Here, we determined the effect of DON on the Class III phosphatidylinositol 3-kinase (PIK3C3)/beclin 1/B cell lymphoma-2 (Bcl-2) pathway in PC12 cells and the relationship between autophagy and apoptosis. The effects of DON were evaluated based on the apoptosis ratio; the typical indicators of autophagy, including cellular morphology, acridine orange- and monodansylcadaverine-labeled vacuoles, green fluorescent protein-microtubule associated protein 1 light chain 3 (LC3) localization, and LC3 immunofluorescence; and the expression of key autophagy-related genes and proteins, that is, PIK3C3, beclin 1, Bcl-2, LC3, and p62. The relationship between autophagy and apoptosis was analyzed by western blot analysis and flow cytometry. DON-induced PC12 cell morphological changes and autophagy significantly. PIK3C3, beclin 1, and LC3 increased in tandem with the DON concentration used; Bcl-2 and p62 expression decreased as DON concentrations increased. Moreover, the PIK3C3/beclin 1/Bcl-2 signaling pathway played a role in DON-induced autophagy. Our findings suggest that DON can induce autophagy by activating the PIK3C3/beclin 1/Bcl-2 signaling pathway and that autophagy may play a positive role in reducing DON-induced apoptosis. Show less

Esophageal squamous cell carcinoma (ESCC) is the main subtype of esophageal cancer in China, and the prognosis of patients remains poor mainly due to the occurrence of lymph node and distant metastasis. The long non‑coding RNA (lncRNA) maternally expressed gene 3 (MEG3) has been shown to have tumor‑suppressive properties and to play an important role in epithelial‑to‑mesenchymal transition (EMT) in some solid tumors. However, whether MEG3 is involved in EMT in ESCC remains unclear. In the present study, the MEG3 expression level and its association with tumorigenesis were determined in 43 tumor tissues of patients with ESCC and in ESCC cells using reverse transcription‑quantitative PCR analysis. Gene microarray analysis was performed to detect differentially expressed genes (DEGs). Based on the functional annotation results, the effects of ectopic expression of MEG3 on cell growth, migration, invasion and EMT were assessed. MEG3 expression level was found to be markedly lower in tumor tissues and cells. Statistical analysis revealed that MEG3 expression was significantly negatively associated with lymph node metastasis and TNM stage in ESCC. Fluorescence in situ hybridization assay demonstrated that MEG3 was expressed mainly in the nucleus. Ectopic expression of MEG3 inhibited cell proliferation, migration, invasion and cell cycle progression in EC109 cells. Gene microarray results demonstrated that 177 genes were differentially expressed ≥2.0 fold in MEG3‑overexpressing cells, including 23 upregulated and 154 downregulated genes. Functional annotation revealed that the DEGs were mainly involved in amino acid biosynthetic process, mitogen‑activated protein kinase signaling, and serine and glycine metabolism. Further experiments indicated that the ectopic expression of MEG3 significantly suppressed cell proliferation, migration, invasion and EMT by downregulating phosphoserine aminotransferase 1 (PSAT1). In pathological tissues, PSAT1 and MEG3 were significantly negatively correlated, and high expression of PSAT1 predicted poor survival. Taken together, these results suggest that MEG3 may be a useful prognostic biomarker and may suppress EMT by inhibiting the PSAT1‑dependent glycogen synthase kinase‑3β/Snail signaling pathway in ESCC. Show less

Endoplasmic reticulum (ER) stress is associated with liver inflammation and hepatocellular carcinoma (HCC). However, how ER stress links inflammation and HCC remains obscure. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress-inducible secretion protein that inhibits inflammation by interacting with the key subunit of nuclear factor kappa light chain enhancer of activated B cells (NF-κB) p65. We hypothesized that MANF may play a key role in linking ER stress and inflammation in HCC. Here, we found that MANF mRNA and protein levels were lower in HCC tissues versus adjacent noncancer tissues. Patients with high levels of MANF had better relapse-free survival and overall survival rates than those with low levels. MANF levels were also associated with the status of liver cirrhosis, advanced tumor-node-metastasis (TNM) stage, and tumor size. In vitro experiments revealed that MANF suppressed the migration and invasion of hepatoma cells. Hepatocyte-specific deletion of MANF accelerated N-nitrosodiethylamine (DEN)-induced HCC by up-regulating Snail1+2 levels and promoting epithelial-mesenchymal transition (EMT). MANF appeared in the nuclei and was colocalized with p65 in HCC tissues and in tumor necrosis factor alpha (TNF-α)-treated hepatoma cells. The interaction of p65 and MANF was also confirmed by coimmunoprecipitation experiments. Consistently, knockdown of MANF up-regulated NF-κB downstream target genes TNF-α, interleukin (IL)-6 and IL-1α expression in vitro and in vivo. Finally, small ubiquitin-related modifier 1 (SUMO1) promoted MANF nuclear translocation and enhanced the interaction of MANF and p65. Mutation of p65 motifs for SUMOylation abolished the interaction of p65 and MANF. MANF plays an important role in linking ER stress and liver inflammation by inhibiting the NF-κB/Snail signal pathway in EMT and HCC progression. Therefore, MANF may be a cancer suppressor and a potential therapeutic target for HCC. Show less

E3 ubiquitin ligase gene, WWP2, is associated with acute kidney injury (AKI). This research was conducted to explore the role of WWP2 in AKI. AKI cell model was produced in human renal proximal tubular epithelial cell line (HK-2) by ischemia-reperfusion (IR) injury. CCK8 and flow cytometry assay were performed to explore the influence of WWP2 overexpression on cell proliferation and apoptosis of IR-induced HK-2 cells. Quantitative real-time PCR and immunoblotting (IB) were performed to assess the gene and protein expression. Then, the influence of WWP2 on p53 ubiquitylation and degradation was estimated by immunoprecipitation assay. Our data indicated that WWP2 was down-regulated and p53 was up-regulated in IR-induced HK-2 cells. WWP2 overexpression promoted proliferation and inhibited apoptosis of IR-induced HK-2 cells. And WWP2 interacted with p53 and regulated p53 ubiquitylation and degradation. Furthermore, the influence of WWP2 on cell proliferation and apoptosis was rescued by MG132 (proteasome inhibitor) treatment. In conclusion, our work described for the first time the role of WWP2 in AKI, showing that WWP2 ameliorated AKI by mediating p53 ubiquitylation and degradation. Moreover, the study offers some important insights into the occurrence of AKI and WWP2 may be a novel target of AKI treatment. SIGNIFICANCE OF THE STUDY: Our data elaborates that WWP2 has protective effect against AKI by mediating p53 ubiquitylation and degradation. Thus, WWP2 might be a therapeutic target for AKI. Show less

Our research group has showed that the LIM homeobox transcription factor 1 alpha (LMX1A) is inactivated in gastric cancers. Overexpression of LMX1A inhibits tumor growth. However, the mechanisms remains unclear. Considering LMX1A as a transcription factor, a comparison of RNA-seq between gastric cancer cells (GCCs) and GCCs with LMX1A overexpressed was performed to identify genes transcriptionally activated by LMX1A. Among the potential LMX1A target genes, angiopoietin-like 4 (ANGPTL4) has been reported to be an important tumor suppressor and thus was selected for further validation and research. Both LMX1A and ANGPTL4 showed downregulated expression in gastric cancer samples. More importantly, the expression of LMX1A is positively correlated with ANGPTL4, without including other family members in gastric cancer cell lines. What's more, knockdown of ANGPTL4 rescued the tumor suppressive phenotype of LMX1A overexpression, which indicated that LMX1A upregulates ANGPTL4 to exert its role. Mechanistically, we found that LMX1A inhibited the expression of the oncogene C-Myc, which is alleviated by ANGPTL4 knockdown. In general, our results showed that LMX1A exerts its tumor suppressive role by activating ANGPTL4 to inhibit C-Myc. Show less

Apolipoprotein A-IV (ApoA-IV) exists in relatively high levels in the circulation systems of animals, but its roles are not fully elucidated. It is known that the Age-matched knockout rats and their wild-type littermate controls maintained on a standard rodent diet were studied and blood metabolic parameters were measured. Glucose, insulin, olive oil, and intralipid tolerance tests were performed to study the glucose and lipid metabolism of rats. Quantitative real-time PCR and RNA-seq analysis in liver and inguinal white adipose tissue (iWAT) of rats at three ages (18 weeks, 45 weeks and 90 weeks) were performed to identify the genes altered by ApoA-IV knockout. ApoA-IV knockout rats were apparently normal and fertile, but exhibited improved glucose clearance when challenged with glucose tolerance test. In addition, fasting-induced hepatic steatosis was more pronounced in ApoA-IV knockout rats. Further analysis identified that a set of hepatic genes involved in glycolysis, gluconeogenesis and ApoA-IV functions in an age-independent manner in the modulation of glucose and lipid metabolism of rats, and may serve as a potential linker between hepatic glucose and lipid metabolism. Show less

Nitidine chloride (NC) has been demonstrated to have an anticancer effect in hepatocellular carcinoma (HCC). However, the mechanism of action of NC against HCC remains largely unclear. In this study, three pairs of NC-treated and NC-untreated HCC xenograft tumour tissues were collected for circRNA sequencing analysis. In total, 297 circRNAs were differently expressed between the two groups, with 188 upregulated and 109 downregulated, among which hsa_circ₀₀₈₈₃₆₄ and hsa_circ₀₀₉₀₀₄₉ were validated by real-time quantitative polymerase chain reaction. The in vitro experiments showed that the two circRNAs inhibited the malignant biological behaviour of HCC, suggesting that they may play important roles in the development of HCC. To elucidate whether the two circRNAs function as "miRNA sponges" in HCC, we identified circRNA-miRNA and miRNA-mRNA interactions by using the CircInteractome and miRwalk, respectively. Subsequently, 857 miRNA-associated differently expressed genes in HCC were selected for weighted gene co-expression network analysis. Module Eigengene turquoise with 423 genes was found to be significantly related to the survival time, pathology grade and TNM stage of HCC patients. Gene functional enrichment analysis showed that the 423 genes mainly functioned in DNA replication- and cell cycle-related biological processes and signalling cascades. Eighteen hubgenes (SMARCD1, CBX1, HCFC1, RBM12B, RCC2, NUP205, ECT2, PRIM2, RBM28, COPS7B, PRRC2A, GPR107, ANKRD52, TUBA1B, ATXN7L3, FUS, MCM8 and RACGAP1) associated with clinical outcomes of HCC patients were then identified. These findings showed that the crosstalk between hsa_circ₀₀₈₈₃₆₄ and hsa_circ₀₀₉₀₀₄₉ and their competing mRNAs may play important roles in HCC, providing interesting clues into the potential of circRNAs as therapeutic targets of NC in HCC. Show less

Carbamoyl phosphate synthetase-1 (CPS1) is the major mitochondrial urea cycle enzyme in hepatocytes. It is released into mouse and human blood during acute liver injury, where is has a short half-life. The function of CPS1 in blood and the reason for its short half-life in serum are unknown. We show that CPS1 is released normally into mouse and human bile, and pathologically into blood during acute liver injury. Other cytoplasmic and mitochondrial urea cycle enzymes are also found in normal mouse bile. Serum, bile, and purified CPS1 manifest sedimentation properties that overlap with extracellular vesicles, due to the propensity of CPS1 to aggregate despite being released primarily as a soluble protein. During liver injury, CPS1 in blood is rapidly sequestered by monocytes, leading to monocyte M2-polarization and homing to the liver independent of its enzyme activity. Recombinant CPS1 (rCPS1), but not control r-transferrin, increases hepatic macrophage numbers and phagocytic activity. Notably, rCPS1 does not activate hepatic macrophages directly; rather, it activates bone marrow and circulating monocytes that then home to the liver. rCPS1 administration prevents mouse liver damage induced by Fas ligand or acetaminophen, but this protection is absent in macrophage-deficient mice. Moreover, rCPS1 protects from acetaminophen-induced liver injury even when given therapeutically after injury induction. In summary, CPS1 is normally found in bile but is released by hepatocytes into blood upon liver damage. We demonstrate a nonenzymatic function of CPS1 as an antiinflammatory protective cytokine during acute liver injury. Show less

To explore the molecular mechanism of insulin on proliferation and differentiation of MC3T3-E1 cell under high glucose conditions. We first investigated the effect of different concentrations of insulin on the osteoblast cell proliferation and cell differentiation at various time points by MTT analysis, cell cycle analysis, and expression detection of differentiation genes. Then, we used 200 ng/mL of insulin to treat the osteoblast cell at different time points for identifying the common differentially expressed mRNAs among various time points by RNA sequencing. Thirdly, we performed the gene ontology (GO) and the Kyoto Encyclopaedia of Genes and Genomes (KEGG) analysis to explore the biological function of these common differentially expressed mRNAs. The results showed that insulin promoted the cell proliferation and differentiation of osteoblast cell. In RNA sequencing, a total of 31 common differentially expressed mRNAs were identified between different time points. Mt1, Tmem135, Avp, and Dlg2 were found to be associated with the new bone formation. In addition, three important signalling pathways, namely, lysosome, glutamatergic synapse, and chemokine signalling pathways, were found in the KEGG enrichment analysis. Our work demonstrated that insulin could promote the osteoblast cell proliferation and cell differentiation, which may play a key role in bone formation. SIGNIFICANCE OF THE STUDY: Our result showed that insulin could promote the proliferation and differentiation of osteoblast at both cellular and molecular levels, which may promote the new bone formation in the osteoblasts. Show less

The direct conversion of accessible cells such as human fibroblasts to inaccessible cells, particularly neurons, opens up many opportunities for using the human model system to study diseases and discover therapies. Previous studies have indicated that the neuronal conversion of adult human skin fibroblasts is much harder than that for human lung fibroblasts, which are used in many experiments. Here we formally report this differential plasticity of human skin versus lung fibroblasts in their transdifferentiation to induced neurons. Using RNAseq of isogenic and non-isogenic pairs of human skin and lung fibroblasts at different days in their conversion to neurons, we found that several master regulators (TWIST1, TWIST2, PRRX1 and PRRX2) in the fibroblast Gene Regulatory Network were significantly downregulated in lung fibroblasts, but not in skin fibroblasts. By knocking down each of these genes and other genes that suppress the neural fate, such as REST, HES1 and HEY2, we found that the combined attenuation of HEY2 and PRRX2 significantly enhanced the transdifferentiation of human skin fibroblasts induced by ASCL1 and p53 shRNA. The new method, which overexpressed ASCL1 and knocked down p53, HEY2 and PRRX2 (ApH2P2), enabled the efficient transdifferentiation of adult human skin fibroblasts to MAP2 Show less

Megacystis-microcolon-intestinal-hypoperistalsis syndrome (MMIHS) is a rare and severe disorder characterized by functional obstruction in the urinary and gastrointestinal tract. The molecular basis of this condition has been defined recently. Heterozygous variants in ACTG2, homozygous mutations in LMOD1, MYLK, and MYH9 were related to the pathogenesis of the syndrome, which encodes proteins involved in the process of smooth muscle contraction, supporting a myopathic basis for the disease. Recent studies have identified homozygous or compound heterozygous variants in MYH11 as a candidate gene of MMIHS. In this report, we described a nonconsanguineous Chinese family with three male fetuses affected with megacystis. Trio-targeted exome sequencing identified compound heterozygous variants, c.2051 G > A (p.R684H) and c.3540₃₅₄₁delinsTT (p.(E1180D, Q1181Ter)), in MYH11 (NM₀₀₁₀₄₀₁₁₄₎. The variants were inherited from the parents, respectively. Western blotting showed a marked decrease in MYH11 protein in the proband's umbilical cord tissue compared with the control sample. The study's results confirmed that MYH11 is a candidate gene for MMIHS with autosomal recessive (AR) inheritance and expanded the mutation spectrum for this clinical condition. Combining clinical phenotype with molecular diagnosis may enable the identification of candidate genes for potential monogenic diseases and facilitate accurate genetic counseling, informed decision-making, and prenatal diagnosis. Show less

Intracranial aneurysm (IA) represents a cerebrovascular disorder that featured by dilation or bulging of the weakened blood vessel wall. When it ruptures, an IA leads to subarachnoid hemorrhage with high disability and mortality rates. Despite the numerous studies focusing on IA ruptures, little research on IA pathogenesis has been reported. In this study, we aimed to reveal key genes related to IA formation. Four datasets from Gene Expression Omnibus data were downloaded, normalized, and separated into the IA group and the normal vessel control group for analyses. We screened for differentially expressed genes (DEGs) between groups and conducted functional enrichment, pathway enrichment, and gene set enrichment analysis analyses among significant DEGs. according to our analyses, significant DEGs majorly associate with smooth muscle system and the complement system. Among all DEGs, 5 down-regulated genes (MYH11, CNN1, MYOCD, ACTA1, and LMOD1) and 3 up-regulated genes (C1QB, C3AR1, and VSIG4) are most relevant in IA formation. Key DEGs identified in this study are related to IA pathogenesis. Among identified DEGs, LMOD1 is the most significant and merits more attention. Show less

Although the genotype-phenotype for familial medullary thyroid carcinoma (FMTC) is well studied, only few low susceptibility risk loci were identified for familial non-medullary thyroid carcinoma (FNMTC). The aim of this study is to screen and identify high-penetrate genes for FNMTC. A total of 34 families with more than two first-degree relatives diagnosed as papillary thyroid cancer without other familial syndrome were recruited. Whole exome and target gene sequencing were performed for candidate variants. These variants were screened and analyzed with ESP6500, ExAC, 1000 genomes project, and the Cancer Genome Atlas (TCGA) with SIFT score and Polyphen2 prediction. Finally, we identified recurrent genetic mutation of MAP2K5 variants c.G961A and c.T1100C (p. A321T and p.M367 T) as susceptibility loci for FNMTC. The frequencies of MAP2K5 c.G961A and c.T1100C were found, 0.0385 and 0.0259 in FNMTC and 0 and 0.00022523 in healthy Chinese controls (n = 2200, P < 0.001), respectively. Both variants were located in the protein kinase domain. The functional study showed that MAP2K5 A321T or M367 T could consistently phosphorylate downstream protein ERK5 on site Ser731 + Thr733 or Ser496, promoting nuclear translocation and subsequently altering target gene expressions. Our data revealed that MAP2K5 variants A321T or M367 T can activate MAP2K5-ERK5 pathway, alter downstream gene expression, and subsequently induce thyroid epithelial cell malignant transformation. While classic MAP2K1/2(MEK1/2)-ERK1/2 signaling is well known for driving sporadic NMTC, our research indicated that MAP2K5 (MEK5) is a susceptibility gene for FNMTC. These findings highlight the potential application of MAP2K5 for molecular diagnosis as well as early prevention. Show less

High fructose feeding changes fibroblast growth factor 21 (FGF21) regulation. Lactobacillus rhamnosus GG (LGG) supplementation reduces fructose-induced non-alcoholic fatty liver disease (NAFLD). The aim of this study was to determine the role of FGF21 and underlying mechanisms in the protective effects of LGG. FGF21 knockout (KO) mice and C57BL/6 wild type (WT) mice were fed 30% fructose for 12 weeks. LGG was administered to the mice in the last 4 weeks during fructose feeding. FGF21-adiponectin (ADPN)-mediated hepatic lipogenesis and inflammation were investigated. FGF21 expression was robustly increased after 5-weeks of feeding and significantly decreased after 12-weeks of feeding in fructose-induced NAFLD mice. LGG administration reversed the depressed FGF21 expression, increased adipose production of ADPN, and reduced hepatic fat accumulation and inflammation in the WT mice but not in the KO mice. Hepatic nuclear carbohydrate responsive-element binding protein (ChREBP) was increased by fructose and reduced by LGG, resulting in a reduction in the expression of lipogenic genes. The methylated form of protein phosphatase 2A (PP2A) C, which dephosphorylates and activates ChREBP, was upregulated by fructose and normalized by LGG. Leucine carboxyl methyltransferase-1, which methylates PP2AC, was also increased by fructose and decreased by LGG. However, those beneficial effects of LGG were blunted in the KO mice. Hepatic dihydrosphingosine-1-phosphate, which inhibits PP2A, was markedly increased by LGG in the WT mice but attenuated in the KO mice. LGG decreased adipose hypertrophy and increased serum levels of ADPN, which regulates sphingosine metabolism. This beneficial effect was decreased in the KO mice. LGG administration increases hepatic FGF21 expression and serum ADPN concentration, resulting in a reduced ChREBP activation through dihydrosphingosine-1-phosphate-mediated PP2A deactivation, and subsequently reversed fructose-induced NAFLD. Thus, our data suggest that FGF21 is required for the beneficial effects of LGG in reversal of fructose-induced NAFLD. Show less

The glucose-responsive transcription factor carbohydrate response element-binding protein (ChREBP) critically promotes aerobic glycolysis and cell proliferation in colorectal cancer cells. It has been reported that ubiquitination may be important in the regulation of ChREBP protein levels and activities. However, the ChREBP-specific E3 ligase and molecular mechanism of ChREBP ubiquitination remains unclear. Using database exploration and expression analysis, we found here that levels of the E3 ligase SMURF2 (Smad-ubiquitination regulatory factor 2) negatively correlate with those of ChREBP in cancer tissues and cell lines. We observed that SMURF2 interacts with ChREBP and promotes ChREBP ubiquitination and degradation via the proteasome pathway. Interestingly, ectopic SMURF2 expression not only decreased ChREBP levels but also reduced aerobic glycolysis, increased oxygen consumption, and decreased cell proliferation in colorectal cancer cells. Moreover, SMURF2 knockdown increased aerobic glycolysis, decreased oxygen consumption, and enhanced cell proliferation in these cells, mostly because of increased ChREBP accumulation. Furthermore, we identified Ser/Thr kinase AKT as an upstream suppressor of SMURF2 that protects ChREBP from ubiquitin-mediated degradation. Taken together, our results indicate that SMURF2 reduces aerobic glycolysis and cell proliferation by promoting ChREBP ubiquitination and degradation via the proteasome pathway in colorectal cancer cells. We conclude that the SMURF2-ChREBP interaction might represent a potential target for managing colorectal cancer. Show less

Various cancer stem cell (CSC) biomarkers have been identified for hepatocellular carcinoma (HCC), but little is known about the implications of heterogeneity and shared molecular networks within the CSC population. Through miRNA profile analysis in an HCC cohort ( Show less

UVRAG (UV radiation resistance associated) is an important regulator of mammalian macroautophagy/autophagy by interacting with BECN1, PIK3C3, and RUBCN. Phosphorylation of UVRAG by MTORC1 negatively regulates autophagosome maturation under nutrient-enriched conditions. However, how UVRAG ubiquitination is regulated is still unknown. Here we report that UVRAG is ubiquitinated by SMURF1 at lysine residues 517 and 559, which decreases the association of UVRAG with RUBCN and promotes autophagosome maturation. However, the deubiquitinase ZRANB1 specifically cleaves SMURF1-induced K29 and K33-linked polyubiquitin chains from UVRAG, thereby increasing the binding of UVRAG to RUBCN and inhibiting autophagy flux. We also demonstrate that CSNK1A1-mediated UVRAG phosphorylation at Ser522 disrupts the binding of SMURF1 to UVRAG through PPxY motif and blocks UVRAG ubiquitination-mediated autophagosome maturation. Interestingly, ZRANB1 is phosphorylated at Thr35, and Ser209 residues by CSNK1A1, and this phosphorylation activates its deubiquitinating activity. Importantly, we provide Show less

Phosphatase and tensin homolog (PTEN), one of the most frequently mutated tumor suppressor genes in human cancer, is pivotal in the progression of colorectal cancer. Therefore, the regulation of PTEN has emerged as a theme of intense research in tumor biology. This study aims to show that long noncoding RNA (lncRNA) Linc02023 aberrant downregulation in colorectal cancer correlates positively with the expression of PTEN and CDKN2B but negatively with the tumor size in patients and xenografted mouse models. The gain- and loss-of-function investigation reveals that Linc02023 suppresses the proliferation of colorectal cancer cells in vitro and in vivo with apoptosis promotion and cell cycle rearrangement. Mechanistically, Linc02023 specifically binds to PTEN and blocks its interaction with and ubiquitination by WWP2, stabilizing it and suppressing its downstream expression. In conclusion, this study demonstrates that lncRNA Linc02023 may serve as a novel therapeutic target by restoring the PTEN tumor suppressor activity. Show less

Genome-wide association studies (GWAS) have identified >250 loci for body mass index (BMI), implicating pathways related to neuronal biology. Most GWAS loci represent clusters of common, noncoding variants from which pinpointing causal genes remains challenging. Here we combined data from 718,734 individuals to discover rare and low-frequency (minor allele frequency (MAF) < 5%) coding variants associated with BMI. We identified 14 coding variants in 13 genes, of which 8 variants were in genes (ZBTB7B, ACHE, RAPGEF3, RAB21, ZFHX3, ENTPD6, ZFR2 and ZNF169) newly implicated in human obesity, 2 variants were in genes (MC4R and KSR2) previously observed to be mutated in extreme obesity and 2 variants were in GIPR. The effect sizes of rare variants are ~10 times larger than those of common variants, with the largest effect observed in carriers of an MC4R mutation introducing a stop codon (p.Tyr35Ter, MAF = 0.01%), who weighed ~7 kg more than non-carriers. Pathway analyses based on the variants associated with BMI confirm enrichment of neuronal genes and provide new evidence for adipocyte and energy expenditure biology, widening the potential of genetically supported therapeutic targets in obesity. Show less

To investigate whether angiopoietin-like 3 (ANGPTL3) and angiopoietin-like 4 (ANGPTL4) are differentially associated with the severity of retinopathy in patients with type 2 diabetes mellitus (T2DM). Cross-sectional study. Serum levels of ANGPTL3, ANGPTL4, high-sensitivity C-reactive protein (CRP), vascular adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), and vascular endothelial growth factor (VEGF) were quantified by ELISA. Retinal images were recorded to assess the grade of diabetic retinopathy (DR). Multivariable-adjusted logistic analysis was performed to estimate the association of each biomarker and DR stage. Among 1192 T2DM patients, 426 (35.7%) had nonproliferative diabetic retinopathy (NPDR) and 56 (4.5%) had proliferative diabetic retinopathy (PDR). After adjusting for covariables, the odds ratios expressing the risk of having DR vs no DR (n = 710 vs 482) were 1.23 (95% confidence interval [CI], 1.08-1.40, P = .002) for ANGPTL3; 0.90 (95% CI, 0.79-1.02; P = .095) for ANGPTL4; and 1.14 (95% CI, 1.00-1.29; P = .044) for VEGF. The risk of having no DR vs NPDR (n = 710 vs 426) was 1.16 (95% CI, 1.01-1.32; P = .036) for ANGPTL3; 0.90 (95% CI, 0.79-1.04; P = .15) for ANGPTL4; and 1.14 (95% CI, 1.00-1.31; P = .045) for VEGF. The odds ratios of having NPDR vs PDR (n = 426 vs 56) was 1.47 (95% CI, 1.03-2.10; P = .035) for serum ANGPTL3; 0.96 (95% CI, 0.69-1.35; P = .83) for ANGPTL4; and 1.05 (95% CI, 0.77-1.45; P = .74) for VEGF. ANGPTL3 is independently and strongly associated with DR progression in all stages. Blockade of ANGPTL3 signal in retina might postpone the onset and development of DR in T2DM patients. Show less

High altitude pulmonary edema (HAPE) is a life threatening condition occurring in otherwise healthy individuals who rapidly ascend to high altitude. However, the molecular mechanisms of its pathophysiology are not well understood. The objective of this study is to evaluate differential gene expression in patients with HAPE during acute illness and subsequent recovery. Twenty-one individuals who ascended to an altitude of 3780 m were studied, including 12 patients who developed HAPE and 9 matched controls without HAPE. Whole-blood samples were collected during acute illness and subsequent recovery for analysis of the expression of hypoxia-related genes, and physiologic and laboratory parameters, including mean pulmonary arterial pressure (mPAP), heart rate, blood pressure, and arterial oxygen saturation (SpO Compared with control subjects, numerous hypoxia-related genes were up-regulated in patients with acute HAPE. Gene network analyses suggested that HIF-1α played a central role in acute HAPE by affecting a variety of hypoxia-related genes, including BNIP3L, VEGFA, ANGPTL4 and EGLN1. Transcriptomic profiling revealed the expression of most HAPE-induced genes was restored to a normal level during the recovery phase except some key hypoxia response factors, such asBNIP3L, EGR1, MMP9 and VEGF, which remained persistently elevated. Differential expression analysis of hypoxia-related genes revealed distinct molecular signatures of HAPE during acute and recovery phases. This study may help us to better understand HAPE pathogenesis and putative targets for further investigation and therapeutic intervention. Show less

The traditional Chinese medicine (TCM) Yuanshi Shengmai Chenggu Tablet is used for treating the common orthopedic disease, hormone‑induced avascular necrosis of the femoral head (ANFH) in China. However, its underlying mechanism and the changes induced in the treatment of ANFH remain to be fully elucidated. In the present study, through the use of isobaric Tag for Relative and Absolute Quantitation and multiple reaction monitoring quantifications, corticosteroid‑induced femoral head necrosis and the effects of treatment with Yuanshi Shengmai Chenggu Tablet were examined. The aim was to identify serum proteins, which may be potential serum markers for the early clinical diagnosis of ANFH, and maybe used to develop more rapid and convenient detection strategies. A total of five proteins were identified, comprising Ig mu chain C region, keratin, type I cytoskeletal 9, properdin, apolipoprotein A‑IV, and IQ and AAA domain‑containing protein 1. The expression levels of all five proteins were lower in ANFH and were higher following TCM treatment. These findings were confirmed using ELISA and western blot analysis. Show less