👤 Jack Lu

miRs play critical roles in oxidative stress-related retinopathy pathogenesis. miR-365 was identified in a previously constructed library from glyoxal-treated rat Müller cell. This report explores epigenetic alterations in Müller cells under oxidative stress to develop a novel therapeutic strategy. To examine the miR-365 expression pattern, in situ hybridization and quantitative RT-PCR were performed. Bioinformatical analysis and dual luciferase report assay were applied to identify and confirm target genes. Streptozotocin (STZ)-treated rats were used as the diabetic retinopathy (DR) model. Lentivirus-mediated anti-miR-365 was delivered subretinally and intravitreally into the rats' eyes. The functional and structural changes were evaluated by electroretinogram (ERG), histologically, and through examination of expression levels of metallopeptidase inhibitor 3 (Timp3), glial fibrillary acidic protein (Gfap), recoverin (Rcvrn) and vascular endothelia growth factor A (Vegfa). Oxidative stress factors and pro-inflammatory cytokines were analyzed. miR-365 expression was confirmed in the glyoxal-treated rat Müller cell line (glyoxal-treated rMC-1). In the retina, miR-365 mainly localized in the inner nuclear layer (INL). The increased miR-365 participated in Müller cell gliosis through oxidative stress aggravation, as observed in glyoxal-treated rMC-1 and DR rats before 6 weeks. Timp3 was a target and negatively regulated by miR-365. When miR-365 was inhibited, Timp3 expression was upregulated, Müller cell gliosis was alleviated, and retinal oxidative stress was attenuated. Visual function was also partially rescued as detected by ERG. miR-365 was found to be highly expressed in the retina and the abnormality of miR-365/Timp3 pathway is closely related to the pathology, like Müller gliosis, and the visual injury in DR. The mechanism might be through oxidative stress, and miR-365/Timp3 could be a potential therapeutic target for treating DR. Show less

Mutations in CEP290, a transition zone protein in primary cilia, cause diverse ciliopathies, including Leber congenital amaurosis (LCA) and Joubert-syndrome and related disorders (JSRD). We examined cilia biogenesis and function in cells derived from CEP290-LCA and CEP290-JSRD patients. CEP290 protein was reduced in LCA fibroblasts with no detectable impact on cilia; however, optic cups derived from induced pluripotent stem cells (iPSCs) of CEP290-LCA patients displayed less developed photoreceptor cilia. Lack of CEP290 in JSRD fibroblasts resulted in abnormal cilia and decreased ciliogenesis. We observed selectively reduced localization of ADCY3 and ARL13B. Notably, Hedgehog signaling was augmented in CEP290-JSRD because of enhanced ciliary transport of Smoothened and GPR161. These results demonstrate a direct correlation between the extent of ciliogenesis defects in fibroblasts and photoreceptors with phenotypic severity in JSRD and LCA, respectively, and strengthen the role of CEP290 as a selective ciliary gatekeeper for transport of signaling molecules in and out of the cilium. Show less

We screened variants on an exome-focused genotyping array in >300,000 participants (replication in >280,000 participants) and identified 444 independent variants in 250 loci significantly associated with total cholesterol (TC), high-density-lipoprotein cholesterol (HDL-C), low-density-lipoprotein cholesterol (LDL-C), and/or triglycerides (TG). At two loci (JAK2 and A1CF), experimental analysis in mice showed lipid changes consistent with the human data. We also found that: (i) beta-thalassemia trait carriers displayed lower TC and were protected from coronary artery disease (CAD); (ii) excluding the CETP locus, there was not a predictable relationship between plasma HDL-C and risk for age-related macular degeneration; (iii) only some mechanisms of lowering LDL-C appeared to increase risk for type 2 diabetes (T2D); and (iv) TG-lowering alleles involved in hepatic production of TG-rich lipoproteins (TM6SF2 and PNPLA3) tracked with higher liver fat, higher risk for T2D, and lower risk for CAD, whereas TG-lowering alleles involved in peripheral lipolysis (LPL and ANGPTL4) had no effect on liver fat but decreased risks for both T2D and CAD. Show less

Type 2 diabetes mellitus is often treated with insulin-sensitizing drugs called thiazolidinediones (TZD), which improve insulin resistance and glycemic control. Despite their effectiveness in treating diabetes, these drugs provide little protection from eminent cardiovascular disease associated with diabetes. Here we demonstrate how chiglitazar, a configuration-restricted non-TZD peroxisome proliferator-activated receptor (PPAR) pan agonist with moderate transcription activity, preferentially regulates Show less

Paeoniflorin (PF), an effective composition that is extracted from Radix Paeoniae Alba, plays a role in protecting against various kidney diseases. However, the mechanism of PF on nephrotic syndrome (NS) remains unclear. The aim of this study was to investigate the protective role of PF on Adriamycin (ADR)-induced NS in vivo and vitro as well as its potential mechanism. In animal study, PF significantly decreased the levels of 24-h urine protein, blood urea nitrogen, serum creatinine, total cholesterol and triglycerides in NS rats, but increased the total protein and albumin levels. Hematoxylin-eosin (HE) staining revealed that the kidney lesion was resolved upon PF treatment. After treatment with PF, the morphology and number of podocytes in renal tissue were restored to normal. PF increased expression of synaptopodin and decreased expression of desmin, demonstrating a protective effect in podocyte injury. Further studies revealed that PF upregulated Peroxisome proliferator-activated receptor gamma (PPARγ) and restrained Angiopointin-like 4 (ANGPTL4) in kidney tissue. In vitro study, PF reduced Caspase3 and Bax and increased Bcl-2, indicating that the apoptosis rate of podocytes induced by ADR was reduced by PF. Furthermore, PF ameliorated podocyte injury by upregulating synaptopodin and reducing desmin. In accordance with animal study, PF downregulated ANGPTL4 by activating PPARγ. However, the therapeutic effects of PF were reversed by GW9662 (PPARγ inhibitor), likely by suppressing ANGPTL4 degradation. In general, these results demonstrate that PF has a good therapeutic effect on NS by activating PPARγ and subsequently inhibiting ANGPTL4. Show less

Disappointing results from clinical studies assessing the efficacy of therapies targeting vascular endothelial growth factor (VEGF) for the treatment of pterygia suggest that other angiogenic mediators may also play a role in its development. We therefore explore the relative contribution of VEGF, hypoxia-inducible factor (HIF)-1α (the transcription factor that regulates VEGF expression in ocular neovascular disease), and a second HIF-regulated mediator, angiopoietin-like 4 (ANGPTL4), to the angiogenic phenotype of pterygia. Expression of HIF-1α, VEGF, and ANGPTL4 were examined in surgically excised pterygia, and in immortalized human (ih) and primary rabbit (pr) conjunctival epithelial cells (CjECs). Endothelial cell (EC) tubule formation assays using media conditioned by ihCjECs in the presence or absence of inducers/inhibitors of HIF-1 or RNA interference (RNAi) targeting VEGF, ANGPTL4, or both were used to assess their relative contribution to the angiogenic potential of these cells. HIF-1α and VEGF expression were detected in 6/6 surgically excised pterygia and localized to CjECs. Accumulation of HIF-1α in was confirmed in ihCjECs and prCjECs, including stratified prCjECs grown on collagen vitrigel, and resulted in expression of VEGF and the promotion of EC tubule formation; the latter effect was partially blocked using RNAi targeting VEGF mRNA expression. We demonstrate expression of a second HIF-regulated angiogenic mediator, ANGPTL4, in CjECs in culture and in surgically excised pterygia. RNAi targeting ANGPTL4 inhibited EC tubule formation and was additive to RNAi targeting VEGF. Our results support the development of therapies targeting both ANGPTL4 and VEGF for the treatment of patients with pterygia. Show less

Intratumoral hypoxia promotes the distant metastasis of cancer subclones. The clinical expression level of hypoxia-inducible factor-1α (HIF-1α) reflects the prognosis of a variety of cancers, especially breast cancer. Histone deacetylase (HDAC) inhibitors can target HIF-1α protein due to von Hippel-Lindau (VHL) protein-dependent degradation. Dietary organosulfur compounds, such as those in garlic, have been reported as HDAC inhibitors. The effects of diallyl sulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS) on the ratio of firefly/Renilla luciferase activity in hypoxic MDA-MB-231 cells were determined. The mRNA expressions of HIF-1α target genes ANGPTL4, LOXL4, and LOX in hypoxic MDA-MB-231 cells were significantly down-regulated by DATS. DATS attenuated the metastatic potential of MDA-MB-231 cells in hypoxia-induced embryonic zebrafish, xenograft, and orthotopic tumors. Endothelial cell-cancer cell adhesion, wound healing, transwell, and tube formation assays showed that DATS dose-dependently inhibited the migration and angiogenesis of MDA-MB-231 cells in vitro. The expressions of L1CAM, VEGF-A, and EMT-related proteins (Slug, Snail, MMP-2) were inhibited by DATS. DATS dose-dependently inhibited HIF-1α transcriptional activity and hypoxia-induced hematogenous metastasis of MDA-MB-231 cells. It reduced the protein expression of HIF-1α, which did not involve inhibition of HIF-1α mRNA expression or ubiquitin proteasome degradation. Efficient inhibition of HIF-1α expression was required for DATS to resist breast cancer. Show less

Nonenzymatic glycation of apolipoproteins plays a role in the pathogenesis of the vascular complications of diabetes. This study investigated whether apolipoprotein (apo) A-IV was glycated in patients with type 2 diabetes mellitus (T2DM) and whether apoA-IV glycation was related to coronary artery disease (CAD). The study also determined the biological effects of glycated apoA-IV. The authors consecutively enrolled 204 patients with T2DM without CAD (Group I), 515 patients with T2DM with CAD (Group II), and 176 healthy subjects (control group) in this study. ApoA-IV was precipitated from ultracentrifugally isolated high-density lipoprotein, and its glycation level was determined based on Western blotting densitometry (relative intensity of apoA-IV glycation). ApoA-IV NƐ-(carboxylmethyl) lysine (CML) modification sites were identified by mass spectrometry in 37 control subjects, 63 patients in Group I, and 138 patients in Group II. Saline or glycated apoA-IV (g-apoA-IV) generated by glyoxal culture was injected into apoE The relative intensity and the abundance of apoA-IV glycation were associated with the presence and severity of CAD in patients with T2DM (all p < 0.05). The experiments showed that g-apoA-IV induced proinflammatory reactions in vitro and promoted atherogenesis in apoE ApoA-IV glycation is associated with CAD severity in patients with T2DM, and g-apoA-IV induces atherogenesis through NR4A3 in apoE Show less

Using a proteomic approach, we aimed to identify and compare the urinary excretion of proteins involved in lipid transport and metabolism in children with kidney stones and hypercalciuria (CAL), hypocitraturia (CIT), and normal metabolic work-up (NM), and in healthy controls (HCs). Additionally, we aimed to confirm these results using ELISA, and to examine the relationship between the urinary excretion of selected proteins with demographic, dietary, blood, and urinary parameters. Prospective, controlled, pilot study of pooled urine from CAL, CIT, and NM versus age- and gender-matched HCs, using liquid chromatography-mass spectrometry. Relative protein abundance was estimated using spectral counting. Results were confirmed by ELISA performed on individual samples. Of the 1,813 proteins identified, 230 met the above criteria. Of those, 5 proteins (apolipoprotein A-II [APOA2]; apolipoprotein A-IV [APOA4]; apolipoprotein C-III [APOA3]; fatty acid-binding protein, liver [FABPL]; fatty acid-binding protein, adipocyte [FABP4]) involved in lipid metabolism and transport were found in the CAL group, with significant differences compared with HCs. ELISA analysis indicated statistically significant differences in the urinary excretion of APOC3, APOA4, and FABPL in the CAL group compared with HCs. Twenty-four-hour urinary calcium excretion correlated significantly with concentrations of ApoC3 (r = 0.77, p < 0.001), and FABPL (r = 0.80, p = 0.005). We provide proteomic data showing increased urinary excretion of lipid metabolism/transport-related proteins in children with kidney stones and hypercalciuria. These findings suggest that abnormalities in lipid metabolism might play a role in kidney stone formation. Show less

To investigate the clinical characteristics of patients with hypertriglyceridemic acute pancreatitis (HTGAP), and the molecular foundation contributing to hypertriglyceridemia in such patients. Clinical data from 329 patients with acute pancreatitis (AP) were analyzed. The patients were divided into the HTGAP group, with fasting serum triglyceride (TG) levels ≥500 mg/dL (5.65 mmol/L), and the non-HTGAP (NHTGAP) group. Targeted next-generation sequencing was applied to 11 HTGAP patients to identify the genetic mutations associated with hypertriglyceridemia, including apolipoprotein A-V (APOA5), APOC2, APOC3 and APOE, BLK, LPL, GPIHBP1 and LMF1. Patients in the HTGAP group, compared with those in the NHTGAP group, had a higher mortality rate (7.5% vs 0.7%, P = 0.001), more commonly seen severe AP (17.5% vs 5.2%, P = 0.004) as well as a higher recurrence rate (32.4% vs 19.9%, P = 0.070). DNA sequencing showed that two patients carried the same compound of p.G185C and p.V153M heterozygous mutations located in the APOA5 gene. Two patients carried a homozygous variation of p.C14F, in the GPIHBP1 gene. One patient had a homozygous variation of p.R176C in the APOE gene. And a rare heterozygous LMF1 gene mutation of p.P562R was detected in two patients. HTGAP was significantly severe than NHTGAP, with a high recurrence rate. Genetic information may be useful in the clinical setting for the investigation of the pathogenesis of HTGAP and its interventions. Show less

Axis inhibition protein 1 (AXIN1) is characterized as a tumor suppressor in numerous types of cancer. However, the functional role of AXIN1 in the testicular germ cell tumors (TGCTs) remains unclear. The human embryonal carcinoma-derived cell line NTera2 was transfected with a recombinant AXIN1 expression vector (pcDNA3.1-AXIN1) and/or a small interfering RNA (siRNA) directed against AXIN1 (siAXIN). Following transfection, the mRNA and protein levels of AXIN1 were determined via reverse transcription-quantitative polymerase chain reaction analysis and western blotting, respectively. In addition, cell viability, apoptosis and the expression of apoptosis-associated proteins [apoptosis regulator Bax (Bax) and B-cell lymphoma (Bcl)-2] and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway proteins [phosphorylated (p)-mTOR, mTOR, p-AKT, AKT, P-70S ribosomal protein S6 (S6) and S6] were assessed. AXIN1 mRNA and protein levels were increased following transfection with pcDNA3.1-AXIN1 and decreased following transfection with siAXIN1 compared with their respective control groups. After overexpression of AXIN1, NTera2 cell viability and expression of Bcl-2, p-mTOR p-AKT and p-S6 protein was decreased, while apoptosis and Bax protein levels were increased, compared with the control group. However, there was no significant difference in AXIN1 mRNA expression, apoptosis or Bax/Bcl-2 protein expression when NTera2 cells were simultaneously transfected with pcDNA3.1-AXIN1+siAXIN1. In conclusion, the results of the present study indicate that overexpression of AXIN1 protects against TGCTs via inhibiting the PI3K/AKT/mTOR signaling pathway, suggesting that AXIN1 may be a potential target for gene therapy in TGCTs. Show less

Axin1 is a scaffold protein in the β-catenin destruction complex, which, if disrupted, contributes to pathogenesis of various human diseases, including colorectal carcinogenesis and inflammatory bowel diseases (IBD). We have previously demonstrated that Salmonella infection promotes the degradation and plasma sequestration of Axin1, leading to bacterial invasiveness and inflammatory responses. Vitamin D and the vitamin D receptor (VDR) appear to be important regulators of IBD and colon cancer. Although VDR and Axin1 are all involved in intestinal inflammation, it remains unclear whether these processes are related or function independently. In the current study, we hypothesize that VDR is an important regulator for the maintenance of physiological level of Axin1. Using the intestinal epithelial conditional VDR knockout mouse model (VDR We found that VDR deletion led to lower protein and mRNA levels of Axin1, whereas knockdown of Axin1 did not change the expression level of VDR protein. Immunoprecipitation data did not support physical interaction between VDR and Axin1. The VDR regulation of Axin1 was through a VDR genomic binding site for Axin1 gene on the regulatory region. Fractionation data showed that cytosolic Axin1 was significantly reduced due to VDR deletion, leaving the nuclear fraction unchanged. In ileum, Axin1 was distributed in the cytosol of apical epithelium and crypts. VDR is important for the maintenance of physiological level of Axin1. The discovery of Axin1 as a VDR target gene provides novel and fundamental insights into the interactions between the VDR and β-catenin signaling pathways. Show less

Branched-chain amino acids catabolism plays an important role in human cancers. Colorectal cancer is the third most commonly diagnosed cancer in males and the second in females, and the new global incidence is over 1.2 million cases. The branched-chain α-keto acid dehydrogenase kinase (BCKDK) is a rate-limiting enzyme in branched-chain amino acids catabolism, which plays an important role in many serious human diseases. Here we investigated that abnormal branched-chain amino acids catabolism in colorectal cancer is a result of the disease process, with no role in disease initiation; BCKDK is widely expressed in colorectal cancer patients, and those patients that express higher levels of BCKDK have shorter survival times than those with lower levels; BCKDK promotes cell transformation or colorectal cancer ex vivo or in vivo. Mechanistically, BCKDK promotes colorectal cancer by enhancing the MAPK signaling pathway through direct MEK phosphorylation, rather than by branched-chain amino acids catabolism. And the process above could be inhibited by a BCKDK inhibitor, phenyl butyrate. Show less

Genome-wide association studies have so far identified 56 loci associated with risk of coronary artery disease (CAD). Many CAD loci show pleiotropy; that is, they are also associated with other diseases or traits. This study sought to systematically test if genetic variants identified for non-CAD diseases/traits also associate with CAD and to undertake a comprehensive analysis of the extent of pleiotropy of all CAD loci. In discovery analyses involving 42,335 CAD cases and 78,240 control subjects we tested the association of 29,383 common (minor allele frequency >5%) single nucleotide polymorphisms available on the exome array, which included a substantial proportion of known or suspected single nucleotide polymorphisms associated with common diseases or traits as of 2011. Suggestive association signals were replicated in an additional 30,533 cases and 42,530 control subjects. To evaluate pleiotropy, we tested CAD loci for association with cardiovascular risk factors (lipid traits, blood pressure phenotypes, body mass index, diabetes, and smoking behavior), as well as with other diseases/traits through interrogation of currently available genome-wide association study catalogs. We identified 6 new loci associated with CAD at genome-wide significance: on 2q37 (KCNJ13-GIGYF2), 6p21 (C2), 11p15 (MRVI1-CTR9), 12q13 (LRP1), 12q24 (SCARB1), and 16q13 (CETP). Risk allele frequencies ranged from 0.15 to 0.86, and odds ratio per copy of the risk allele ranged from 1.04 to 1.09. Of 62 new and known CAD loci, 24 (38.7%) showed statistical association with a traditional cardiovascular risk factor, with some showing multiple associations, and 29 (47%) showed associations at p < 1 × 10 We identified 6 loci associated with CAD at genome-wide significance. Several CAD loci show substantial pleiotropy, which may help us understand the mechanisms by which these loci affect CAD risk. 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

To investigate the role of microtubule-actin crosslinking factor 1 (MACF1) in the response of glioma cells to temozolomide (TMZ). TMZ was applied to a human gliomablastoma cell line (U87) and changes in the protein expression and cellular localization were determined with Western blot, RT-PCR, and immunofluorescence. The responses of the cells with MACF1 expression knockdown by RNA interference to TMZ were assessed. TMZ-induced effects on MACF1 expression were also assessed by immunohistochemistry in a nude mouse model bearing human glioblastoma xenografts. TMZ resulted in significantly increased MACF1 expression (by about 2 folds) and changes in its localization in the gliomablastoma cells both in vitro and in vivo (P<0.01). Knockdown of MACF1 reduced the proliferation (by 45%) of human glioma cell lines treated with TMZ (P<0.01). TMZ-induced changes in MACF1 expression was accompanied by cytoskeletal rearrangement. MACF1 may be a potential therapeutic target for glioblastoma. 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

With emerging evidence connecting cholesterol dysregulation with disturbed pulmonary homeostasis, we are wondering if diet induced hypercholesterolemia would influence the susceptibility to chemical induced lung tumorigenesis in mice. Six to eight week-old male C57BL/6J mice were fed with either a high-cholesterol atherogenic diet (HCD) or matching normal diet (ND), respectively. Following 3 weeks diet adapting, a multi-dose intraperitoneal injections of ethyl carbamate (urethane, 1 g/kg body weight) were established and lung tumorigenesis assessments were taken after 15 weeks latency period. Compared to the urethane treated ND-fed mice, the HCD-fed mice exhibited significantly decreased lung tumor multiplicity and attenuated pulmonary inflammation, which including reduced influx of leukocytes and down regulated tumor-promoting cyto-/chemokine profile in bronchoalveolar lavage fluid, decreased TLR2/4 expression and NF-κB activation in the lung. As a sensor regulating intracellular cholesterol homeostasis, nuclear receptor LXR-α was up-regulated significantly in the urethane treated HCD-fed mice lungs compared to the ND-fed mice lungs, accompanied with decreased pulmonary free cholesterol content and suppressed tumor cell proliferation. These results suggested that intrapulmonary cholesterol homeostasis, other than systematic cholesterol level, is important in lung tumorigenesis, and LXR activation might partly contribute to the inhibitory role of atherogenic diet on lung tumorigenesis. Show less

Alzheimer disease (AD) is the most common neurodegenerative disease characterized by the deposition of amyloid plaque in the brain. The autophagy-associated PIK3C3-containing phosphatidylinositol 3-kinase (PtdIns3K) complex has been shown to interfere with APP metabolism and amyloid beta peptide (Aβ) homeostasis via poorly understood mechanisms. Here we report that NRBF2 (nuclear receptor binding factor 2), a key component and regulator of the PtdIns3K, is involved in APP-CTFs homeostasis in AD cell models. We found that NRBF2 interacts with APP in vivo and its expression levels are reduced in hippocampus of 5XFAD AD mice; we further demonstrated that NRBF2 overexpression promotes degradation of APP C-terminal fragments (APP-CTFs), and reduces Aβ Show less

Macroautophagy/autophagy is a cellular defense response to stress conditions and is crucial for cell homeostasis maintenance. However, the precise mechanism underlying autophagy initiation, especially in response to glutamine deprivation and hypoxia, is yet to be explored. We recently discovered that PGK1 (phosphoglycerate kinase 1), a glycolytic enzyme, functions as a protein kinase, phosphorylating BECN1/Beclin 1 to initiate autophagy. Under glutamine deprivation or hypoxia stimulation, PGK1 is acetylated at K388 by NAA10/ARD1 in an MTOR-inhibition-dependent manner, leading to the interaction between PGK1 and BECN1 and the subsequent phosphorylation of BECN1 at S30 by PGK1. This phosphorylation enhances ATG14-associated PIK3C3/VPS34-BECN1-PIK3R4/VPS15 complex activity, thereby increasing phosphatidylinositol-3-phosphate (PtdIns3P) generation in the initiation stage of autophagy. Furthermore, NAA10-dependent PGK1 acetylation and PGK1-dependent BECN1 phosphorylation are required for glutamine deprivation- and hypoxia-induced autophagy and brain tumor formation. Our work reveals the important dual roles of PGK1 as a glycolytic enzyme and a protein kinase in the mutual regulation of cell metabolism and autophagy in maintaining cell homeostasis. Show less

Alternative splicing provides a major mechanism to generate protein diversity. Increasing evidence suggests a link of dysregulation of splicing associated with cancer. Genome-wide alternative splicing profiling in lung cancer remains largely unstudied. We generated alternative splicing profiles in 491 lung adenocarcinoma (LUAD) and 471 lung squamous cell carcinoma (LUSC) patients in TCGA using RNA-seq data, prognostic models and splicing networks were built by integrated bioinformatics analysis. A total of 3691 and 2403 alternative splicing events were significantly associated with patient survival in LUAD and LUSC, respectively, including EGFR, CD44, PIK3C3, RRAS2, MAPKAP1 and FGFR2. The area under the curve of the receiver-operator characteristic curve for prognostic predictor in NSCLC was 0.817 at 2000 days of overall survival which were also over 0.8 in LUAD and LUSC, separately. Interestingly, splicing correlation networks uncovered opposite roles of splicing factors in LUAD and LUSC. We created prognostic predictors based on alternative splicing events with high performances for risk stratification in NSCLC patients and uncovered interesting splicing networks in LUAD and LUSC which could be underlying mechanisms. Show less

Naringin, an essential flavonoid, inhibits inflammatory response and oxidative stress in diabetes. However, whether naringin has beneficial effects on diabetic retinopathy (DR) remains unknown. Streptozotocin (STZ, 65 mg/kg) was intraperitoneally injected into male rats (8 weeks old weighting 200-250 g) to establish diabetic model, then naringin (20, 40 or 80 mg/kg/day) was intraperitoneally injected into the diabetic rats for twelve weeks. Glial fibrillary acidic protein (GFAP) level, thickness of ganglion cell layer (GCL) and ganglion cell counts were assessed in diabetic retina Naringin alleviated DR symptoms as evidenced by the increased retinal ganglion cells and decreased GFAP level in rat retina. Naringin exhibited anti-inflammatory and antioxidative effects as confirmed by the down-regulated pro-inflammatory cytokines, tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), and the up-regulated antioxidants, glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) in DR rats. Moreover, we found that naringin inhibited HG-induced proliferation, abnormal inflammatory response and oxidative stress in rMC1 cells. In addition, the enhanced nuclear translocation of NF-κB p65 in diabetic rat retina and HG-induced rMC1 cells was suppressed by naringin. Naringin attenuates inflammatory response, oxidative stress and NF-κB activation in experimental models of DR. Show less

Glucagon-like peptide-1 (GLP-1) receptor (GLP-1R), glucagon (GCG) receptor (GCGR), and glucose-dependent insulinotropic polypeptide (GIP, also known as gastric inhibitory polypeptide) receptor (GIPR), are three metabolically related peptide hormone receptors. A novel approach to the generation of multifunctional antibody agonists that activate these receptors has been developed. Native or engineered peptide agonists for GLP-1R, GCGR, and GIPR were fused to the N-terminus of the heavy chain or light chain of an antibody, either alone or in pairwise combinations. The fusion proteins have similar in vitro biological activities on the cognate receptors as the corresponding peptides, but circa 100-fold longer plasma half-lives. The GLP-1R mono agonist and GLP-1R/GCGR dual agonist antibodies both exhibit potent effects on glucose control and body weight reduction in mice, with the dual agonist antibody showing enhanced activity in the latter. Show less

Gastric cancer is not a single disease, and its subtype classification is still evolving. Next-generation sequencing studies have identified novel genetic drivers of gastric cancer, but their use as molecular classifiers or prognostic markers of disease outcome has yet to be established. In this study, we integrated somatic mutational profiles and clinicopathologic information from 544 gastric cancer patients from previous genomic studies to identify significantly mutated genes (SMG) with prognostic relevance. Gastric cancer patients were classified into regular (86.8%) and hypermutated (13.2%) subtypes based on mutation burden. Notably, TpCpW mutations occurred significantly more frequently in regular, but not hypermutated, gastric cancers, where they were associated with APOBEC expression. In the former group, six previously unreported (XIRP2, NBEA, COL14A1, CNBD1, ITGAV, and AKAP6) and 12 recurrent mutated genes exhibited high mutation prevalence (≥3.0%) and an unexpectedly higher incidence of nonsynonymous mutations. We also identified two molecular subtypes of regular-mutated gastric cancer that were associated with distinct prognostic outcomes, independently of disease staging, as confirmed in a distinct patient cohort by targeted capture sequencing. Finally, in diffuse-type gastric cancer, CDH1 mutation was found to be associated with shortened patient survival, independently of disease staging. Overall, our work identified previously unreported SMGs and a mutation signature predictive of patient survival in newly classified subtypes of gastric cancer, offering opportunities to stratify patients into optimal treatment plans based on molecular subtyping. Cancer Res; 76(7); 1724-32. ©2016 AACR. Show less

As the start of a new life cycle, activation of the first division of the zygote is a critical event in both plants and animals. Because the zygote in plants is difficult to access, our understanding of how this process is achieved remains poor. Here we report genetic and cell biological analyses of the zygote-arrest 1 (zyg1) mutant in Arabidopsis, which showed zygote-lethal and over-accumulation of cyclin B1 D-box-GUS in ovules. Map-based cloning showed that ZYG1 encodes the anaphase-promoting complex/cyclosome (APC/C) subunit 11 (APC11). Live-cell imaging studies showed that APC11 is expressed in both egg and sperm cells, in zygotes and during early embryogenesis. Using a GFP-APC11 fusion construct that fully complements zyg1, we showed that GFP-APC11 expression persisted throughout the mitotic cell cycle, and localized to cell plates during cytokinesis. Expression of non-degradable cyclin B1 in the zygote, or mutations of either APC1 or APC4, also led to a zyg1-like phenotype. Biochemical studies showed that APC11 has self-ubiquitination activity and is able to ubiquitinate cyclin B1 and promote degradation of cyclin B1. These results together suggest that APC/C-mediated degradation of cyclin B1 in Arabidopsis is critical for initiating the first division of the zygote. Show less

Previously identified common variants explain only a small fraction of the trait heritability and at most loci the identities of the underlying causal genes and their functional variants still remain unknown. To identify the low-frequency and rare coding variants that influence lipid levels, we conducted a meta-analysis of exome-wide association studies in 14,473 Chinese subjects, followed by a joint analysis with 1000 genomes imputed data from 6,534 samples. We replicated 24 previously reported lipid loci with exome-wide significance (P < 3.3 × 10 Show less

Given their association with cardiovascular disease protection, there has been intense interest in understanding the biology of high density lipoproteins (HDL). HDL is actually a family of diverse particle types, each made up of discrete - but as yet undetermined - combinations of proteins drawn from up to 95 lipophilic plasma proteins. The abundant apolipoproteins (apo) of the A class (apoA-I, apoA-II and apoA-IV) have been proposed to act as organizing platforms for auxiliary proteins, but this concept has not been systematically evaluated. We assessed the impact of genetic knock down of each platform protein on the particle size distribution of auxiliary HDL proteins. Loss of apoA-I or apoA-II massively reduced HDL lipids and changed the plasma size pattern and/or abundance of several plasma proteins. Surprisingly though, many HDL proteins were not affected, suggesting they assemble on lipid particles in the absence of apoA-I or apoA-II. In contrast, apoA-IV ablation had minor effects on plasma lipids and proteins, suggesting that it forms particles that largely exclude other apolipoproteins. Overall, the data indicate that distinct HDL subpopulations exist that do not contain, nor depend on, apoA-I, apoA-II or apoA-IV and these contribute substantially to the proteomic diversity of HDL. Plasma levels of high density lipoproteins (HDL) are inversely correlated with cardiovascular disease. These particles are becoming known as highly heterogeneous entities that have diverse compositions and functions that may impact disease. Unfortunately, we know little about the forces that maintain the composition of each particle in plasma. It has been suggested that certain 'scaffold' proteins, such as apolipoprotein (apo) A-I, apoA-II and apoA-IV, may act as organizing centers for the docking of myriad accessory proteins. To test this hypothesis, we took advantage of the genetic tractability of the mouse model and ablated these three proteins individually. We then tracked the abundance and size profile of the remaining HDL proteins by gel filtration chromatography combined with mass spectrometry. The results clearly show that certain cohorts of proteins depend on each scaffold molecule to assemble normal sized HDL particles under wild-type conditions. This work forms the basis for more detailed studies that will define the specific compositions of HDL subspecies with the possibility of connecting them to specific functions or roles in disease. Show less

Genome-wide association studies have identified over 150 loci associated with lipid traits, however, no large-scale studies exist for Hispanics and other minority populations. Additionally, the genetic architecture of lipid-influencing loci remains largely unknown. We performed one of the most racially/ethnically diverse fine-mapping genetic studies of HDL-C, LDL-C, and triglycerides to-date using SNPs on the MetaboChip array on 54,119 individuals: 21,304 African Americans, 19,829 Hispanic Americans, 12,456 Asians, and 530 American Indians. The majority of signals found in these groups generalize to European Americans. While we uncovered signals unique to racial/ethnic populations, we also observed systematically consistent lipid associations across these groups. In African Americans, we identified three novel signals associated with HDL-C (LPL, APOA5, LCAT) and two associated with LDL-C (ABCG8, DHODH). In addition, using this population, we refined the location for 16 out of the 58 known MetaboChip lipid loci. These results can guide tailored screening efforts, reveal population-specific responses to lipid-lowering medications, and aid in the development of new targeted drug therapies. Show less