👤 Joanna Guo

Chinese medicine has been proposed as a novel strategy for the prevention of metabolic disorders such as obesity. The present study tested 17 Chinese medicinal herbs were tested for their potential anti-obesity effects. The herbs were evaluated in terms of their abilities to stimulate the transcription of Apolipoprotein A-IV (ApoA-IV) in cultured Caco-2/TC7 enterocytes. The herbs that showed stimulating effects on ApoA-IV transcription were further evaluated in terms of their abilities to reduce the formation of triglyceride in differentiated 3T3-L1 adipocytes. ApoA-IV transcription was stimulated by Rhizoma Alismatis and Radix Angelica Sinensis in a dose- and time-dependent manner in cultured Caco-2/TC7 cells. Moreover, these two herbs reduced the amount of triglyceride in differentiated 3T3-L1 adipocytes. The results suggest that Rhizoma Alistmatis and Radix Angelica Sinensis may have potential anti-obesity effects as they stimulate ApoA-IV transcription and reduce triglyceride formation. Show less

Obesity is a major public health problem in most developed countries and a major risk factor for diabetes and cardiovascular disease. Emerging evidence indicates that ciliary dysfunction can contribute to human obesity but the underlying molecular and cellular mechanisms are unknown. Bardet-Biedl syndrome (BBS) is a genetically heterogeneous human obesity syndrome associated with ciliary dysfunction. BBS proteins are thought to play a role in cilia function and intracellular protein/vesicle trafficking. Here, we show that BBS proteins are required for leptin receptor (LepR) signaling in the hypothalamus. We found that Bbs2(-/-), Bbs4(-/-) and Bbs6(-/-) mice are resistant to the action of leptin to reduce body weight and food intake regardless of serum leptin levels and obesity. In addition, activation of hypothalamic STAT3 by leptin is significantly decreased in Bbs2(-/-), Bbs4(-/-) and Bbs6(-/-) mice. In contrast, downstream melanocortin receptor signaling is unaffected, indicating that LepR signaling is specifically impaired in Bbs2(-/-), Bbs4(-/-) and Bbs6(-/-) mice. Impaired LepR signaling in BBS mice was associated with decreased Pomc gene expression. Furthermore, we found that BBS1 protein physically interacts with the LepR and that loss of BBS proteins perturbs LepR trafficking. Our data indicate that BBS proteins mediate LepR trafficking and that impaired LepR signaling underlies energy imbalance in BBS. These findings represent a novel mechanism for leptin resistance and obesity. Show less

Reduced retrograde transport of neurotrophins (NT) and their receptors has been hypothesized to contribute directly to retinal ganglion cell (RGC) loss in glaucoma. However, strategies of supplementing NT and NT receptors have failed to avert ultimate RGC death in experimental glaucoma. This study examines the response of major components of the NT system and their interacting proteins in a rat glaucoma model. Unilateral chronic intraocular pressure (IOP) elevation was produced by episcleral vein injection of hypertonic saline (N = 99). Retinas were collected and grouped by extent of optic nerve injury. Quantitative reverse transcription PCR, western blot analysis and immunohistochemistry were used to determine mRNA and protein levels and protein localization. Out of three RGC-specific Brn3 proteins (Brn3a, b, and c), only Brn3a was significantly downregulated at the message level to 35 +/- 4% of fellow values with the severest nerve injury. With IOP elevation, no significant alterations were found in retinal mRNA levels for BDNF, NGF, NT-4/5 or NT-3. The abundance of mature retinal BDNF protein was not significantly affected by elevated IOP, while proBDNF protein decreased linearly with increasing injury grade (r(2) = 0.50). In retinas with the severest nerve injury, TrkB and TrkC receptor mRNA levels significantly declined to 67 +/- 9% and 44 +/- 5% of fellow values, respectively. However, the levels of TRKB protein and its phosphorylated form were unchanged. Message level for p75(NTR) was linearly upregulated up to 219 +/- 26% with increasing injury (r(2) = 0.46), but no alteration was detected at protein level. The mRNA expression of p75(NTR) apoptosis adaptor proteins NADE, NRIF, and Lingo1 were significantly downregulated in retinas with the greatest nerve injury. A positive correlation was found between injury extent and message levels for Jun (r(2) = 0.23) as well as Junb (r(2) = 0.27), and RGC labeling of activated JUN protein increased. Atf3 mRNA levels demonstrated a positive linear correlation to the extent of injury (r(2) = 0.53), resulting in a nearly five-fold increase (482 +/- 76%) in eyes with the greatest nerve damage. Among downstream pro-survival signaling components, Erk5 mRNA expression was linearly upregulated (r(2) = 0.32) up to 157 +/- 15% of fellow values in retinas with the severest nerve injury (p < 0.01). A slight positive correlation was found between NF-kappaB message levels and injury extent (r(2) = 0.12). Bcl-xl mRNA levels in the most severely injured retinas were significantly reduced to 83 +/- 7% by elevated IOP exposure. Message levels for Erk1/2, Akt1-3 or Bcl2 appeared unaffected. Elevated IOP did not alter mRNA levels of pro-apoptotic Bim, Bax, or p53. This study demonstrates that elevated IOP exposure does not result in a dramatic decrease in retinal levels of either BDNF or its receptor, TrkB. It shows that the responses of NT pathways to elevated IOP are complex, particularly with regard to the role of p75(NTR) and Atf3. A better understanding of the roles of these proteins in IOP-induced injury is likely to suggest informed strategies for neuroprotection in glaucoma. Show less

To investigate the gene expression profiles of adipose tissue of obese rats after central administration of neuropeptide Y-Y5 receptor antisense oligodeoxynucleotides (ODNs), Y5 receptor antisense, mismatched ODNs or vehicle was intracerebroventricularly injected and cDNA microarrays were undertaken. Central administration of NPY-Y5 receptor antisense ODNs decreased food intake, body weight and serum insulin compared with both vehicle and mismatched ODNs. The average area of adipocytes both at retroperitoneal and epididymal adipose tissue were fall in antisense group while only the weight of the retroperitoneal fat pats was reduced in antisense group. cDNA microarrays containing 18,000 genes/Ests were used to investigate gene expression of adipose tissue. Autoradiographic analysis showed that 404, 81, and 34 genes were differently expressed over twofold, threefold, and fivefold, respectively. The analysis of gene expression profiles indicated that 332 genes were up-regulated and 187 genes were down-regulated in response to Y5 receptor antisense ODNs treatment. Different clusters of genes associated with apoptosis, signal transduction, energy metabolism, lipid metabolism, etc., such as FXR1, PHLDA1, MAEA, PIK3R1, ICAM2, PITPN, CALM2, CAMK2D, PKIA, DRD2, SLC25A14, CKB, AADAC, LIPA, ACOX3, FADS1, were concerned. Analysis of differentially expressed genes will help to understand the effects of Y5 receptor antisense ODNs therapy. Show less

Anthocyanins belong to a large and widespread group of water-soluble phytochemicals and exhibit potent antioxidative and anti-inflammatory properties; however, the molecular mechanisms of these biochemical actions mediated by anthocyanins remain unclear. In this study, our data show that pretreatment of THP-1 macrophages with Cyanidin-3-O-beta-glucoside (C3G) for 12 h can enhance the expression and transcriptional activities of the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) and liver X receptor alpha (LXRalpha). Furthermore, pretreatment of these cells with C3G for 12 h causes dose-dependent inhibition of lipopolysaccharide (LPS)-induced nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at both the mRNA and protein levels together with a decrease in nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production. Consequently, addition of geranylgeranyl pyrophosphate ammonium salt (GGPP), an LXRalpha antagonist, significantly downregulates the inhibitory effect of C3G on LPS-induced iNOS and COX-2 expression in THP-1 macrophages, whereas the PPARgamma antagonist GW9662 has no effect. Further investigation revealed that LXRalpha might interfere with LPS-induced iNOS and COX-2 expression by suppressing the functional activation of nuclear factor-kappaB (NF-kappaB), not - as was previously proposed - by reducing NF-kappaB nuclear translocation. Taken together, these results indicate that LXRalpha activation has an essential role in the anti-inflammatory property of C3G. Moreover, they provide new insight into the molecular basis for the anti-inflammatory property of anthocyanins. Show less

The purpose of this study was to explore the frequency of apolipoprotein A5 (APOA5) -1131T/C polymorphism in Zhenjiang and its effects on lipid metabolism and insulin resistance in type II diabetes mellitus(DM) patients. The genotypes of APOA5 -1131T/C polymorphism were determined in 152 healthy individuals and 71 type II DM patients by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum levels of lipids, glucose and insulin in these subjects were also estimated by biochemical methods. The frequency of the APOA5-1131C allele in DM patients was significantly higher than that of the control group (0.430 vs 0.296, P = 0.006). When compared with the TT genotype, CC homozygotes had a significantly increased DM risk (OR=3.75, 95% CI: 1.57-8.92). In the DM group, the serum levels of triglyceride (TG) of C carriers (TC+CC) were significantly higher than those of non-C carriers (TT) (P 0.01), and serum levels of total cholesterol (TC) and low density lipoprotein cholesterol(LDL-c) in subjects with the CC genotype were also significantly higher than those with the TT genotype (P 0.05). However, there was no significance in profiles of insulin resistance in various genotypes in both groups. The APOA5 single nucleotide polymorphism was associ-ated with serum TG level in the population. The -1131C allele contributed to the increase of serum levels of TG, TC and LDL-c and but had no effect on profiles of insulin resistance in DM patients. The APOA5 -1131C allele may be associated with increased susceptibility to type II diabetes mellitus. Show less

To investigate the effects of 2-methoxyestradiol (2-ME) on 2 myeloid leukemia cell lines HL-60 and U937, and to explore its mechanisms. Human myeloid leukemia cells HL-60 and U937 were used. Measurement of mitochondrial membrane potential (Dym) was performed using 5,5',6,6'-Tetrachloro-1,1',3,3'- tetraethylbenzimidazolylcarbocyanine iodide ( JC-1). Apoptosis and cellular nitric oxide (NO) were detected by flow cytometry using Annexin V and NO sensor dye. Superoxide anion was measured with a fluorescent plate reader by dihydroethidium (DHE). Cytotoxicity was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assay. 2-ME resulted in viability decrease in a dose-dependent manner. 2-ME treatment also generated reactive oxygen species (ROS), including NO and superoxide anions, which resulted in mitochondria damage. 2-ME-induced apoptosis was correlated with an increase in ROS. The quenching of ROS with N-acetyl-L-cysteine protected leukemia cells from 2-ME cytotoxicity and prevented apoptosis induction by 2-ME. Furthermore, the addition of manumycin, a farnesyltransferase inhibitor, significantly enhanced apoptosis induced by 2-ME. Cellular ROS generation plays an important role in the cytotoxic effect of 2-ME. It is possible to use ROS generation agents, such as manumycin, to enhance the antileukemic effect. The combination strategy needs further in vivo justification and may have potential clinical application. Show less

Demyelinating diseases, such as multiple sclerosis, are characterized by the loss of the myelin sheath around neurons, owing to inflammation and gliosis in the central nervous system (CNS). Current treatments therefore target anti-inflammatory mechanisms to impede or slow disease progression. The identification of a means to enhance axon myelination would present new therapeutic approaches to inhibit and possibly reverse disease progression. Previously, LRR and Ig domain-containing, Nogo receptor-interacting protein (LINGO-1) has been identified as an in vitro and in vivo negative regulator of oligodendrocyte differentiation and myelination. Here we show that loss of LINGO-1 function by Lingo1 gene knockout or by treatment with an antibody antagonist of LINGO-1 function leads to functional recovery from experimental autoimmune encephalomyelitis. This is reflected biologically by improved axonal integrity, as confirmed by magnetic resonance diffusion tensor imaging, and by newly formed myelin sheaths, as determined by electron microscopy. Antagonism of LINGO-1 or its pathway is therefore a promising approach for the treatment of demyelinating diseases of the CNS. Show less

Rhabdastrellic acid-A is an isomalabaricane triterpenoid isolated from the sponge Rhabdastrella globostellata from South China Sea. Our previous study indicated that rhabdastrellic acid-A can inhibit the proliferation of many types of tumor cells with minor toxicity. This study was to investigate the apoptosis of human leukemia HL-60 cells induced by rhabdastrellic acid-A and its possible mechanisms. Inhibitory effect of rhabdastrellic acid-A on the proliferation of HL-60 cells was evaluated by MTT assay. DNA fragmentation was analyzed by agarose electrophoresis. Cell morphology was observed under fluorescent microscope. The protein levels of Caspase-3, poly(ADP-ribose) polymerase (PARP), P73, Bcl-2 and Bax were analyzed by Western blot. The expression profile of apoptosis-related genes was analyzed by gene microarray. Reverse transcription-polymerase chain reaction (RT-PCR) was conducted to confirm some altered genes identified by gene microarray. Rhabdastrellic acid-A inhibited the proliferation of HL-60 cells and the 50% inhibition concentration (IC50) was (0.64+/-0.21) microg/ml. When treated with 1 microg/ml rhabdastrellic acid-A for 36 h, condensation of nuclear chromatin of HL-60 cells was observed under fluorescent microscope and DNA fragmentation was observed by agarose electrophoresis. Also, rhabdastrellic acid-A induced cleavage of PARP and Caspase-3. The mRNA levels of 44 genes, including p73, JunD, TNFAIP3 and GADD45A, were up-regulated and the mRNA levels of 16 genes, including MAP2K5 and IGF2R, were down-regulated. The results were further confirmed by RT-PCR. The protein level of P73 was up-regulated after rhabdastrellic acid-A treatment. Rhabdastrellic acid-A could induce the apoptosis of HL-60 cells which may be related to the up-regulation of apoptosis-related genes such as p73 and JunD, and the down-regulation of MAP2K5 and IGF2R. Show less

Several independent population studies have reported that c.553G>T polymorphism of the apolipoprotein A5 gene (APOA5) is associated with hypertriglyceridaemia. The aim of this study is to investigate the association between this genetic variation and the risk of type 2 diabetes mellitus. In this study, APOA5 c.553G>T polymorphisms in 152 healthy individuals and 71 type 2 diabetes mellitus patients were detected by PCR-restriction fragment length polymorphism and agarose electrophoresis methods, and serum levels of lipids were also estimated by biochemical methods. The frequency of T alleles in the diabetes and control groups was 0.085 and 0.049, respectively. Compared with controls, there was no significant difference in the distribution of genotype and allele frequencies of c.553G>T polymorphic sites in diabetic patients (p=0.27 and p=0.15, respectively). However, the frequency of GT and TT genotypes and the T allele in the subgroup with hypertriglyceridaemia was significantly higher than that in the subgroup with normal triglyceridaemia in both the control group (p=0.034 and p=0.014, respectively) and the diabetes group (p=0.037 and p=0.007, respectively). In the diabetes and control groups, triglyceride levels in (GT+TT) genotype individuals were significantly higher than in GG genotype individuals (p=0.001 and p=0.003, respectively), and levels of low-density lipoprotein cholesterol were also significantly higher (p=0.044 and p=0.022, respectively). APOA5 c.553G>T polymorphism is not significantly associated with susceptibility to type 2 diabetes mellitus, but is associated with plasma triglyceride and low-density lipoprotein cholesterol levels. Show less

Elevation in plasma triglycerides (TG) has been widely accepted as a coronary artery disease (CAD) risk predictor. Recently, a new apolipoprotein playing an important role in TG metabolism named apolipoprotein AV (apoAV) was discovered, which is encoded by the APOA5 gene. Several single nucleotide polymorphisms (SNPs) of APOA5 associated with increased TG concentrations have been identified. We here report that a recently identified genetic variant, c.553G>T in the APOA5 gene which causes a substitution of a cysteine for a glycine residue at amino acid residue 185(G185C) is also associated with increased TG levels. To investigate the association between this genetic variation and the risk of CAD, a case-control study comprising 232 patients with CAD and 302 controls from the same area of China was performed. The minor allele frequencies of c.553G > T for the CAD and control groups were 7.76 and 3.97%, respectively (P = 0.008). In both the CAD and control groups, the T allele carriers had higher serum TG levels than homozygous carriers of the major G allele (CAD group: 2.67 +/- 1.48 mmol/l versus 1.95 +/- 1.02 mmol/l, P = 0.021; controls: 2.31 +/- 1.20 mmol/l versus 1.68 +/- 0.95 mmol/l, P = 0.002). After adjustment for age, gender, body mass index, smoking status, glucose and presence of hypertension, the odds ratio (OR) for CAD in the T allele carriers was 2.089 (95% CI = 1.140-3.830, P = 0.017), in comparison to the individuals without the T allele. These results suggest that the APOA5 c.553G > T polymorphism is an important predictor for hypertriglyceridemia and CAD. Show less

The Saccharomyces cerevisiae Hym1p, Mob2p, Tao3p, Cbk1p, Sog2p and Kic1p proteins are thought to function together in the RAM signaling network, which controls polarized growth, cell separation and cell integrity. Whether these proteins also function as a network to affect cell proliferation is not clear. Here we examined cells lacking or over-expressing RAM components, and evaluated the timing of initiation of DNA replication in each case. Our results suggest opposing roles of RAM proteins, where only Hym1p can promote the transition from the G1 to S phase of the cell cycle. We also uncovered additive growth defects in strains lacking several pair-wise combinations of RAM proteins, possibly arguing for multiple roles of RAM components in the overall control of cell proliferation. Finally, our findings suggest that Hym1p requires the Dcr2p phosphatase to promote the G1/S transition, but it does not require the G1 cyclin Cln3p or the RAS pathway. Taken together, our results point to a complex regulation of cell proliferation by RAM proteins, in a non-uniform manner that was not previously anticipated. Show less

To investigate the relationship between apolipoprotein A5(apoA5) - 1131T > C polymorphism and the susceptibility of coronary artery disease (CAD) in Chinese. The restriction fragment length polymorphism of apoA5 gene - 1131T > C was studied using PCR in a case-control study which enrolled 235 patients with CAD diagnosed by angiography and 262 healthy controls from Jiangsu province. The frequencies of T, C allele were 59.57%ì40.43% and 65.65%, 34.35% in CAD group and control group respectively. There was statistically significant difference in allele frequencies between CAD group and control group (P < 0.05). The susceptibility to CAD for the CC genotype was much higher than that for wild type TT (OR = 1.872, 95% CI = 1.039 - 3.376, P = 0.037), even after the use of Logistic regression models (OR = 2.285, 95% CI = 1.222 - 4.274, P = 0.012). In control group, there was significant difference in TG levels among different genotypes, the C allele carriers had higher serum TG concentration (P = 0.007). apoA5 - 1131T > C polymorphism is associated with an increased risk of CAD and is also in strong association with serum TG levels. Show less

In order to clarify the relationship of apolipoprotein CIII (APOC3) polymorphism and sporadic Alzheimer's disease (AD) in Chinese, 165 sporadic AD patients and 174 age-matched elderly individuals were genotyped for the APOC3 SstI and apolipoprotein E (APOE) HhaI polymorphisms. As the result, the APOC3 3017G allele was found to be associated with AD in APOE epsilon4 allele noncarriers (chi2=4.433, P=0.035), and the risk estimate of allele C versus G resulted in an OR of 1.56 (95% CI: 1.03-2.37), although in total no significant differences of allelic or genotypic frequencies between patients and controls were found. Assessment of interaction between APOE epsilon4 and APOC3 3017G status presented an adjusted odds ratio of 0.62 (95% CI: 0.37-1.03) with a borderline significant P-value (P=0.066). Therefore, we conclude that the rare APOC3 G allele may offer some protection against the development of sporadic AD in APOE epsilon4 noncarriers in Chinese. Show less

Bardet-Biedl syndrome (BBS) is a heterogeneous multisystemic disorder characterized primarily by five cardinal features of retinal degeneration, obesity, polydactyly, hypogenitalism and mental retardation. To date, six distinct BBS loci that have been identified on different chromosomes. BBS4 gene is mapped to 15q22.2-23, which when mutated can cause BBS4. Its protein shows strong homology to O-linked N-acetylglucosamine (O-GlcNAc) transferase. Here we report a splice variant of BBS4, which is 2556 bp in length and has an open reading frame coding a predicted 527 amino-acids protein. RT-PCR shows that the cDNA is widely expressed while it has higher expression levels in pancreas, liver and prostate. Show less

How cells determine when to initiate DNA replication is poorly understood. Here we report that in Saccharomyces cerevisiae overexpression of the dosage-dependent cell cycle regulator genes DCR2 (YLR361C) and GID8 (DCR1/YMR135C) accelerates initiation of DNA replication. Cells lacking both GID8 and DCR2 delay initiation of DNA replication. Genetic analysis suggests that Gid8p functions upstream of Dcr2p to promote cell cycle progression. DCR2 is predicted to encode a gene product with phosphoesterase activity. Consistent with these predictions, a DCR2 allele carrying a His338 point mutation, which in known protein phosphatases prevents catalysis but allows substrate binding, antagonized the function of the wild-type DCR2 allele. Finally, we report genetic interactions involving GID8, DCR2, and CLN3 (which encodes a G(1) cyclin) or SWI4 (which encodes a transcription factor of the G(1)/S transcription program). Our findings identify two gene products with a probable regulatory role in the timing of initiation of cell division. Show less

The Saccharomyces cerevisiae HYM1 gene is conserved among eukaryotes. The mammalian orthologue (called MO25) mediates signaling through the AMP-activated protein kinase and other related kinases, implicated in cell proliferation. In yeast, Hym1p plays a role in cellular morphogenesis and also promotes the daughter cell-specific localization of the Ace2p transcription factor. Here, we report that increased dosage of HYM1 apparently shortens the G1 phase of the cell cycle. In the absence of HYM1 or ACE2, mother and daughter cells divide with the same generation times. Genetic analysis of HYM1, ACE2 and CLN3 mutants suggests that these genes together contribute to the establishment of asynchronous mother-daughter cell divisions, but probably not in a linear pathway. Our overall data suggest that Hym1p has a regulatory role in cell cycle progression. Show less

NogoA, a myelin-associated component, inhibits neurite outgrowth. Nogo66, a portion of NogoA, binds to Nogo66 receptor (NgR) and induces the inhibitory signaling. LINGO-1 and p75 neurotrophin receptor (p75), the low-affinity nerve growth factor receptor, are also required for NogoA signaling. However, signaling mechanisms downstream to Nogo receptor remain poorly understood. Here, we observed that NgR and p75 were colocalized in low-density membrane raft fractions derived from forebrains and cerebella as well as from cerebellar granule cells. NgR interacted with p75 in lipid rafts. In addition, disruption of lipid rafts by beta-methylcyclodextrin, a cholesterol-binding reagent, reduced the Nogo66 signaling. Our results suggest an important role of lipid rafts in facilitating the interaction between NgRs and provide insight into mechanisms underlying the inhibition of neurite outgrowth by NogoA. Show less

The activation of the APC/beta-catenin signalling pathway due to beta-catenin mutations has been implicated in the development of a subset of endometrial carcinomas (ECs). However, up to 25% of ECs have beta-catenin nuclear accumulation without evidence of beta-catenin mutations, suggesting alterations of other molecules that can modulate the Wnt pathway, such as APC, gamma-catenin, AXIN1 and AXIN2. We investigated the expression pattern of beta- and gamma-catenin in a group of 128 endometrial carcinomas, including 95 endometrioid endometrial carcinomas (EECs) and 33 non-endometrioid endometrial carcinomas (NEECs). In addition, we evaluated the presence of loss of heterozygosity and promoter hypermethylation of the APC gene and mutations in the APC, beta- and gamma-catenin, AXIN1, AXIN2, and RAS genes, and phospho-Akt expression. No APC mutations were detected but LOH at the APC locus was found in 24.3% of informative cases. APC promoter 1A hypermethylation was observed in 46.6% of ECs, and was associated with the endometrioid phenotype (P=0.034) and microsatellite instability (P=0.008). Neither LOH nor promoter hypermethylation of APC was associated with nuclear catenin expression. Nuclear beta-catenin expression was found in 31.2% of EECs and 3% of NEECs (P=0.002), and was significantly associated with beta-catenin gene exon 3 mutations (P<0.0001). beta-catenin gene exon 3 mutations were associated with the endometrioid phenotype, and were detected in 14 (14.9%) EECs, but in none of the NEECs (P=0.02). gamma-catenin nuclear expression was found in 10 ECs; it was not associated with the histological type but was associated with more advanced stages (P=0.042). No mutations in gamma-catenin, AXIN1 and 2 genes were detected in this series. Neither RAS mutations nor phospho-Akt expression, which were found in 16 and 27.6% of the cases, respectively, were associated with beta-catenin nuclear expression. Our results demonstrated a high prevalence of alterations in molecules of the APC/beta-catenin pathway, but only mutations in beta-catenin gene are associated with aberrant nuclear localization of beta-catenin. Show less

Juvenile Batten disease is a neurodegenerative disease caused by accelerated apoptotic death of photoreceptors and neurons attributable to defects in the CLN3 gene. CLN3 is antiapoptotic when overexpressed in NT2 neuronal precursor cells. CLN3 negatively modulates endogenous ceramide levels in NT2 cells and acts upstream of ceramide generation. Because defects in regulation of apoptosis are involved in the development of cancer, we evaluated the expression of CLN3 on both mRNA and protein levels in a variety of cancer cell lines and solid colon cancer tissue. We also observed the effect of the blocking of CLN3 protein expression on cancer cell growth, survival, ceramide production, and apoptosis by using an adenovirus-bearing antisense CLN3 construct. We show that CLN3 mRNA and protein are overexpressed in glioblastoma (U-373G and T98g), neuroblastoma (IMR-32 and SK-N-MC), prostate (Du145, PC-3, and LNCaP), ovarian (SK-OV-3, SW626, and PA-1), breast (BT-20, BT-549, and BT-474), and colon (SW1116, SW480, and HCT 116) cancer cell lines but not in pancreatic (CAPAN and As-PC-1) or lung (A-549 and NCI-H520) cancer cell lines. CLN3 is also up-regulated in mouse melanoma and breast carcinoma cancer cell lines. We found CLN3 expression is 22-330% higher than in corresponding normal colon control tissue in 8 of 10 solid colon tumors. An adenovirus-expressing antisense CLN3 (Ad-AS-CLN3) blocks CLN3 protein expression in DU-145, BT-20, SW1116, and T98g cancer cell lines as seen by Western blot. Blocking of CLN3 expression using Ad-AS-CLN3 inhibits growth and viability of cancer cells. It also causes elevation in endogenous ceramide production through de novo ceramide synthesis and results in increased apoptosis as shown by propidium iodide and JC-1 staining. This suggests that Ad-AS-CLN3 may be an option for therapy in some cancers. More importantly these results suggest that CLN3 is a novel molecular target for cancer drug discovery. Show less

To evaluate the relationship between plasma apoA-IV levels and coronary atherosclerosis and to explore its relation to other risk factors. Using ELISA techniques, plasma apoA-IV levels were quantified in 181 patients who underwent coronary angiography (CAG). Patients were divided according to their coronary status into a coronary heart disease (CHD) group (stenotic lesion on CAG, n = 118) and a control group (normal CAG, n = 63). The severity of atherosclerosis was assessed by stenosis scoring of the different lesions. Other parameters, including apoA-I, apoB, Lp(a), HDL-C, LDL-C, TG, and TC, were measured as well. Univariate, logistic regression analyses were used to define the relationship between coronary atherosclerosis and plasma apoA-IV levels. When compared with the control group, plasma apoA-IV levels were found to be lower in the CHD group. There was a weak negative correlation between plasma apoA-IV levels and the severity of coronary atherosclerosis. ApoA-IV was found to be a relatively independent risk factor for CHD. We also found a positive correlation between apoA-IV and triglyceride levels. ApoA-IV may be important in the prediction of CHD and coronary atherosclerosis severity. It may also play an important role in the metabolism of triglycerides. Show less

1. In order to investigate the biological function of the human CLN3 gene that is defective in Batten disease, we created a yeast strain by PCR-targeted disruption of the yeast gene (YHC3), which is a homologue of the human CLN3 gene. 2. The phenotypic characterization revealed that the yhc3 delta mutants are more sensitive to combined heat and alkaline stress than the wild-type strains as determined by inhibition of cell proliferation. 3. This suggests that the yhc3 delta mutant is a good model to investigate the biological function of human CLN3 gene in mammalian cells and to understand the pathophysiology of juvenile Batten disease. Show less

Juvenile neuronal ceroid lipofuscinosis or Batten disease (JNCL) is a neurodegenerative disorder characterized by blindness, seizures, cognitive decline and early death. Brain atrophy and retinitis pigmentosa ensue because of neuronal and photoreceptor apoptosis. The CLN3 gene defective in JNCL encodes a novel 438 amino acid protein. Most affected genes harbor a deletion resulting in a truncated protein. CLN3 overexpression in NT2 cells enhances growth, reverses growth inhibition induced by serum starvation and protects from apoptosis induced by vincristine, staurosporine, and etoposide but not from death caused by ceramide. CLN3 modulates endogenous and vincristine-activated ceramide, and therefore suppresses apoptosis by impacting generation of ceramide. Show less

The onset of leukaemia caused by type C retroviruses (MLV) in mice is accelerated by the emergence of recombinant polytropic or mink cell focus-forming (MCF) viruses. Susceptibility to infection by polytropic/MCF and also by closely related xenotropic MLV has been mapped to Rmc1 on mouse chromosome 1 (refs 5-7). To identify this gene, we introduced an expression cDNA library prepared from mouse NIH3T3 fibroblasts into nonpermissive hamster cells and screened these cells for acquired susceptibility to MCF viruses encoding beta-galactosidase and G418 resistance. From hamster cell clones identified in the screen, we recovered a mouse cDNA that maps to Rmc1 and confers MCF MLV infection when expressed in nonpermissive cell lines. It encodes a membrane protein related to Syg1p (suppressor of yeast G alpha deletion; ref. 8). The receptor-binding domain of the MCF MLV envelope protein binds specifically to Xenopus laevis oocytes that express mouse Syg1, suggesting it functions as a receptor that mediates virus entry. We also obtained the cDNA encoding human SYG1. When expressed in hamster cells, it establishes infectivity by MCF MLV as well as xenotropic MLV, which do not infect laboratory mice. Show less