Kaufman, Kenneth M. | Zhao, Jian | Kelly, Jennifer A. | Hughes, Travis | Adler, Adam | Sanchez, Elena | Ojwang, Joshua O. | Langefeld, Carl D. | Ziegler, Julie T. | Williams, Adrienne H. | Comeau, Mary E. | Marion, Miranda C. | Glenn, Stuart B. | Cantor, Rita M. | Grossman, Jennifer M. | Hahn, Bevra H. | Song, Yeong Wook | Yu, Chack-Yung | James, Judith A. | Guthridge, Joel M. | Brown, Elizabeth E. | Alarcón, Graciela S. | Kimberly, Robert P. | Edberg, Jeffrey C. | Ramsey-Goldman, Rosalind | Petri, Michelle A. | Reveille, John D. | Vilá, Luis M. | Anaya, Juan-Manuel | Boackle, Susan A. | Stevens, Anne M. | Freedman, Barry I. | Criswell, Lindsey A. | Pons-Estel, Bernardo A. | Lee, Joo-Hyun | Lee, Ji-Seon | Chang, Deh-Ming | Scofield, R Hal | Gilkeson, Gary S. | Merrill, Joan T. | Niewold, Timothy B. | Vyse, Timothy J. | Bae, Sang-Cheol | Alarcón-Riquelme, Marta E. | Jacob, Chaim O. | Sivils, Kathy Moser | Gaffney, Patrick M. | Harley, John B. | Sawalha, Amr H. | Tsao, Betty P.
Objectives
The Xq28 region containing IRAK1 and MECP2 has been identified as a risk locus for systemic lupus erythematosus (SLE) in previous genetic association studies. However, due to the strong linkage disequilibrium between IRAK1 and MECP2, it remains unclear which gene is affected by the underlying causal variant(s) conferring risk of SLE.
Methods
We fine-mapped ≥136 SNPs in a ~227kb region on Xq28, containing IRAK1, MECP2 and 7 adjacent genes (L1CAM, AVPR2, ARHGAP4, NAA10, RENBP, HCFC1 and TMEM187), for association with SLE in 15,783 case-control subjects derived from 4 different ancestral groups.
Results
Multiple SNPs showed strong association with SLE in European Americans, Asians and Hispanics at P<5×10−8 with consistent association in subjects with African ancestry. Of these, 6 SNPs located in the TMEM187-IRAK1-MECP2 region captured the underlying causal variant(s) residing in a common risk haplotype shared by all 4 ancestral groups. Among them, rs1059702 best explained the Xq28 association signals in conditional testings and exhibited the strongest P value in trans-ancestral meta-analysis (Pmeta=1.3×10−27, OR=1.43), and thus was considered to be the most-likely causal variant. The risk allele of rs1059702 results in the amino acid substitution S196F in IRAK1 and had previously been shown to increase NF-κB activity in vitro. We also found that the homozygous risk genotype of rs1059702 was associated with lower mRNA levels of MECP2, but not IRAK1, in SLE patients (P=0.0012) and healthy controls (P=0.0064).
Conclusion
These data suggest contributions of both IRAK1 and MECP2 to SLE susceptibility.
doi:10.1136/annrheumdis-2012-201851
PMCID: PMC3567234
PMID: 22904263
Systemic Lupus Erythematosus; Gene Polymorphism; Xq28; IRAK1; MECP2
Alzheimer's disease (AD) is a progressive and complex neurodegenerative disease in which the γ-secretase-mediated amyloid-β (Aβ) pathology plays an important role. We found that a multifunctional protein, β-arrestin1, facilitated the formation of NCT/APH-1 (anterior pharynx-defective phenotype 1) precomplex and mature γ-secretase complex through its functional interaction with APH-1. Deficiency of β-arrestin1 or inhibition of binding of β-arrestin1 with APH-1 by small peptides reduced Aβ production without affecting Notch processing. Genetic ablation of β-arrestin1 diminished Aβ pathology and behavioral deficits in transgenic AD mice. Moreover, in brains of sporadic AD patients and transgenic AD mice, the expression of β-arrestin1 was upregulated and correlated well with neuropathological severity and senile Aβ plaques. Thus, our study identifies a regulatory mechanism underlying both γ-secretase assembly and AD pathogenesis, and indicates that specific reduction of Aβ pathology can be achieved by regulation of the γ-secretase assembly.
doi:10.1038/cr.2012.167
PMCID: PMC3587707
PMID: 23208420
Alzheimer's disease; β-arrestin1; APH-1; γ-secretase
Deng, Yun | Zhao, Jian | Sakurai, Daisuke | Kaufman, Kenneth M. | Edberg, Jeffrey C. | Kimberly, Robert P. | Kamen, Diane L. | Gilkeson, Gary S. | Jacob, Chaim O. | Scofield, R. Hal | Langefeld, Carl D. | Kelly, Jennifer A. | Ramsey-Goldman, Rosalind | Petri, Michelle A. | Reveille, John D. | Vilá, Luis M. | Alarcón, Graciela S. | Vyse, Timothy J. | Pons-Estel, Bernardo A. | Freedman, Barry I. | Gaffney, Patrick M. | Sivils, Kathy Moser | James, Judith A. | Gregersen, Peter K. | Anaya, Juan-Manuel | Niewold, Timothy B. | Merrill, Joan T. | Criswell, Lindsey A. | Stevens, Anne M. | Boackle, Susan A. | Cantor, Rita M. | Chen, Weiling | Grossman, Jeniffer M. | Hahn, Bevra H. | Harley, John B. | Alarcόn-Riquelme, Marta E. | Brown, Elizabeth E. | Tsao, Betty P. | McCarthy, Mark I.
We previously reported that the G allele of rs3853839 at 3′untranslated region (UTR) of Toll-like receptor 7 (TLR7) was associated with elevated transcript expression and increased risk for systemic lupus erythematosus (SLE) in 9,274 Eastern Asians [P = 6.5×10−10, odds ratio (OR) (95%CI) = 1.27 (1.17–1.36)]. Here, we conducted trans-ancestral fine-mapping in 13,339 subjects including European Americans, African Americans, and Amerindian/Hispanics and confirmed rs3853839 as the only variant within the TLR7-TLR8 region exhibiting consistent and independent association with SLE (Pmeta = 7.5×10−11, OR = 1.24 [1.18–1.34]). The risk G allele was associated with significantly increased levels of TLR7 mRNA and protein in peripheral blood mononuclear cells (PBMCs) and elevated luciferase activity of reporter gene in transfected cells. TLR7 3′UTR sequence bearing the non-risk C allele of rs3853839 matches a predicted binding site of microRNA-3148 (miR-3148), suggesting that this microRNA may regulate TLR7 expression. Indeed, miR-3148 levels were inversely correlated with TLR7 transcript levels in PBMCs from SLE patients and controls (R2 = 0.255, P = 0.001). Overexpression of miR-3148 in HEK-293 cells led to significant dose-dependent decrease in luciferase activity for construct driven by TLR7 3′UTR segment bearing the C allele (P = 0.0003). Compared with the G-allele construct, the C-allele construct showed greater than two-fold reduction of luciferase activity in the presence of miR-3148. Reduced modulation by miR-3148 conferred slower degradation of the risk G-allele containing TLR7 transcripts, resulting in elevated levels of gene products. These data establish rs3853839 of TLR7 as a shared risk variant of SLE in 22,613 subjects of Asian, EA, AA, and Amerindian/Hispanic ancestries (Pmeta = 2.0×10−19, OR = 1.25 [1.20–1.32]), which confers allelic effect on transcript turnover via differential binding to the epigenetic factor miR-3148.
Author Summary
Systemic lupus erythematosus (SLE) is a debilitating autoimmune disease contributed to by excessive innate immune activation involving toll-like receptors (TLRs, particularly TLR7/8/9) and type I interferon (IFN) signaling pathways. TLR7 responds against RNA–containing nuclear antigens and activates IFN-α pathway, playing a pivotal role in the development of SLE. While a genomic duplication of Tlr7 promotes lupus-like disease in the Y-linked autoimmune accelerator (Yaa) murine model, the lack of common copy number variations at TLR7 in humans led us to identify a functional single nucleotide polymorphism (SNP), rs3853839 at 3′ UTR of the TLR7 gene, associated with SLE susceptibility in Eastern Asians. In this study, we fine-mapped the TLR7-TLR8 region and confirmed rs3853839 exhibiting the strongest association with SLE in European Americans, African Americans, and Amerindian/Hispanics. Individuals carrying the risk G allele of rs3853839 exhibited increased TLR7 expression at the both mRNA and protein level and decreased transcript degradation. MicroRNA-3148 (miR-3148) downregulated the expression of non-risk allele (C) containing transcripts preferentially, suggesting a likely mechanism for increased TLR7 levels in risk-allele carriers. This trans-ancestral mapping provides evidence for the global association with SLE risk at rs3853839, which resides in a microRNA–gene regulatory site affecting TLR7 expression.
doi:10.1371/journal.pgen.1003336
PMCID: PMC3585142
PMID: 23468661
Aberrant cellular responses to pro-inflammatory cytokines, such as TNF-α, are pathogenic features in most chronic inflammatory diseases. A variety of extracellular and intracellular feedback pathways have evolved to prevent an inappropriate cellular reaction to these pro-inflammatory cytokines. Here, we report that TNF-α treatment of human and mouse cholangiocytes and hepatocytes downregulated expression of p300/CBP-associated factor (PCAF), a co-activator and an acetyltransferase that promotes histone acetylation and gene transcription. Of these upregulated microRNAs (miRNAs) in TNF-α-treated cells, miR-181a/b (miR-181a and miR-181b) suppressed translation of PCAF mRNA. Functional manipulation of miR-181a/b caused reciprocal alterations in PCAF protein expression in cultured cholangiocytes and hepatocytes. Inhibition of miR-181a/b function with anti-miRs blocked TNF-α-induced suppression of PCAF expression. Promoter recruitment of PCAF was shown to be associated with TNF-α-induced transcription of inflammatory genes. Intriguingly, pretreatment of cells with TNF-α inhibited transcription of inflammatory genes in response to subsequent TNF-α stimulation. Overexpression of PCAF or inhibition of miR-181a/b function with anti-miRs attenuated the inhibitory effects of TNF-α pretreatment on epithelial inflammatory response to subsequent TNF-α stimulation. Downregulation of PCAF and the inhibitory effects of TNF-α pretreatment on liver epithelial inflammatory response were further confirmed in a mouse model of TNF-α intraperitoneal injection. These data suggest that PCAF is a target for miR-181a/b, and downregulation of PCAF by TNF-α provides negative feedback regulation to inflammatory reactions in liver epithelial cells, a process that may be relevant to the epigenetic fine-tuning of epithelial inflammatory processes in general.
doi:10.4049/jimmunol.1101976
PMCID: PMC3262895
PMID: 22219331
miRNAs; PCAF; Negative feedback; Epithelial cells; Inflammation; TNF-α
Zhao, Guangyi | Cai, Chengkui | Yang, Tongtao | Qiu, Xiuchun | Liao, Bo | Li, Wei | Ji, Zhenwei | Zhao, Jian | Zhao, Haien | Guo, Mingjun | Ma, Qiong | Xiao, Chun | Fan, Qingyu | Ma, Baoan | Cheng, Jin Q.
Background
MicroRNAs are short regulatory RNAs that negatively modulate protein expression at a post-transcriptional and/or translational level and are deeply involved in the pathogenesis of several types of cancers. Specifically, microRNA-221 (miR-221) is overexpressed in many human cancers, wherein accumulating evidence indicates that it functions as an oncogene. However, the function of miR-221 in human osteosarcoma has not been totally elucidated. In the present study, the effects of miR-221 on osteosarcoma and the possible mechanism by which miR-221 affected the survival, apoptosis, and cisplatin resistance of osteosarcoma were investigated.
Methodology/Principal Findings
Real-time quantitative PCR analysis revealed miR-221 was significantly upregulated in osteosarcoma cell lines than in osteoblasts. Both human osteosarcoma cell lines SOSP-9607 and MG63 were transfected with miR-221 mimic or inhibitor to regulate miR-221 expression. The effects of miR-221 were then assessed by cell viability, cell cycle analysis, apoptosis assay, and cisplatin resistance assay. In both cells, upregulation of miR-221 induced cell survival and cisplatin resistance and reduced cell apoptosis. In addition, knockdown of miR-221 inhibited cell growth and cisplatin resistance and induced cell apoptosis. Potential target genes of miR-221 were predicted using bioinformatics. Moreover, luciferase reporter assay and western blot confirmed that PTEN was a direct target of miR-221. Furthermore, introduction of PTEN cDNA lacking 3′-UTR or PI3K inhibitor LY294002 abrogated miR-221-induced cisplatin resistance. Finally, both miR-221 and PTEN expression levels in osteosarcoma samples were examined by using real-time quantitative PCR and immunohistochemistry. High miR-221 expression level and inverse correlation between miR-221 and PTEN levels were revealed in osteosarcoma tissues.
Conclusions/Significance
These results for the first time demonstrate that upregulation of miR-221 induces the malignant phenotype of human osteosarcoma whereas knockdown of miR-221 reverses this phenotype, suggesting that miR-221 could be a potential target for osteosarcoma treatment.
doi:10.1371/journal.pone.0053906
PMCID: PMC3553141
PMID: 23372675
Objectives
This updated meta-analysis was conducted to assess the association between coffee consumption and breast cancer risk.
Methods
We conducted a systematic search updated July 2012 to identify observational studies providing quantitative estimates for breast cancer risk in relation to coffee consumption. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model, and generalized least square trend estimation was used to assess dose–response relationships.
Results
A total of 26 studies (16 cohort and 10 case–control studies) on coffee intake with 49497 breast cancer cases were included in the meta-analysis. The pooled RR showed a borderline significant influence of highest coffee consumption (RR = 0.96; 95% CI 0.93–1.00), low-to moderate coffee consumption (RR = 0.99; 95% CI 0.95–1.04), or an increment of 2 cups/day of coffee consumption (RR = 0.98; 95% CI 0.97–1.00) on the risk of breast cancer. In stratified analysis, a significant inverse association was observed in ER-negative subgroup. However, no significant association was noted in the others.
Conclusions
Our findings suggest that increased coffee intake is not associated with a significantly reduced risk of breast cancer, but we observe an inverse association in ER-negative subgroup analysis. More large studies are needed to determine subgroups to obtain more valuable data on coffee drinking and breast cancer risk.
doi:10.1371/journal.pone.0052681
PMCID: PMC3537715
PMID: 23308117
Guerrero, Miguel | Urbano, Mariangela | Zhao, Jian | Crisp, Melissa | Chase, Peter | Hodder, Peter | Schaeffer, Marie-Therese | Brown, Steven | Rosen, Hugh | Roberts, Edward
High affinity and selective small molecule agonists of the S1P4 receptor (S1P4-R) may have significant therapeutic utility in diverse disease areas including autoimmune diseases, viral infections and thrombocytopenia. A high-throughput screening (HTS) of the Molecular Libraries-Small Molecule Repository library identified 3-(2-(2,4-dichlorophenoxy)ethoxy)-6-methyl-2-nitropyridine as a moderately potent and selective S1P4-R hit agonist. Design, synthesis and systematic structure-activity relationships study of the HTS-derived hit led to the development of novel potent S1P4-R agonists exquisitely selective over the remaining S1P1–3,5–Rs family members. Remarkably, the molecules herein reported provide novel pharmacological tools to decipher the biological function and assess the therapeutic utility of the S1P4–R.
doi:10.1016/j.bmcl.2011.10.096
PMCID: PMC3248976
PMID: 22119461
S1P4 receptor; selective small molecule S1P4–R agonists; autoimmune diseases; viral infections; thrombocytopenia
Background and Aim: Neutropenia is a serious adverse event for patients who are treated with cetuximab, an inhibitor of endothelial growth factor receptor. However, there is no consistent result of the relationship between cetuximab and neutropenia in randomized controlled trials (RCTs). We did a systematic review and meta-analysis of published RCTs to assess the overall risk of neutropenia associated with cetuximab.
Methods: PubMed, Cochrane Central Register of Controlled Trials, EMBASE, and American Society of Clinical Oncology conferences were searched for relevant RCTs. Quantitative and qualitative analyses were carried out to evaluate the association between neutropenia and cetuximab. Both the fixed-effect model and random-effects model were used.
Results: A total of 7186 patients with a variety of advanced cancers from 14 trials were included in our analysis. The overall incidence of neutropenia in patients receiving cetuximab was 33% (95% CI 26, 43). Patients treated with cetuximab had a significantly increased risk of neutropenia compared with patients treated with control medication, with a relative risk (RR) of 1.12 (95% CI 1.05, 1.19; fixed-effect model). Risk varied with tumor type. Higher risks were observed in patients with colorectal carcinoma (RR 1.17; 95% CI 1.04, 1.32; fixed-effect model) and non-small cell lung cancer (RR 1.07; 95% CI 0.99, 1.16; fixed-effect model).
Conclusion: Cetuximab is associated with a significant risk of neutropenia in patients with advanced cancer receiving concurrent chemotherapy.
doi:10.2165/11598190-000000000-00000
PMCID: PMC3586098
PMID: 22133387
Previous studies document Nukuleka in the Kingdom of Tonga as a founder colony for first settlement of Polynesia by Lapita peoples. A limited number of radiocarbon dates are one line of evidence supporting this claim, but they cannot precisely establish when this event occurred, nor can they afford a detailed chronology for sequent occupation. High precision U/Th dates of Acropora coral files (abraders) from Nukuleka give unprecedented resolution, identifying the founder event by 2838±8 BP and documenting site development over the ensuing 250 years. The potential for dating error due to post depositional diagenetic alteration of ancient corals at Nukuleka also is addressed through sample preparation protocols and paired dates on spatially separated samples for individual specimens. Acropora coral files are widely distributed in Lapita sites across Oceania. U/Th dating of these artifacts provides unparalleled opportunities for greater precision and insight into the speed and timing of this final chapter in human settlement of the globe.
doi:10.1371/journal.pone.0048769
PMCID: PMC3492438
PMID: 23144962
Dong, Li | Liu, Meng | Fang, Yuan-Yuan | Zhao, Jian-Hua | He, Xiang-Feng | Ying, Xiao-Bao | Zhang, Yi-Yue | Xie, Qi | Chua, Nam-Hai | Guo, Hui-Shan
Summary
In plants, exogenous transgene transcribing inverted-repeat (exo-IR) sequences produces double-stranded RNAs that are processed by DCL4. The generated 21-nt siRNAs function as mobile signals to trigger non-cell-autonomous silencing of target endogene in neighboring 10-15 cells. The potential involvement of nuclear silencing pathway components in signal spreading or sensing in target cells is not clear. Here, we demonstrate that the exo-IR silencer (exo-Pdsi) is negatively auto-regulated through methylation spreading, which acts in cis to reinforce self-silencing of the silencer. Mutations affecting nuclear proteins DRD1 and Pol V (NRPE1 or NRPD2) relieved exo-Pdsi self-silencing resulting in higher levels of Pdsi transcripts which increased non-cell-autonomous silencing of endo-PDS. Our results suggest that in an experimental silencing pathway, methylation spreading on a silencer transgene may not have a direct endogenous plant counterpart when protein-encoding gene is the target. DRD1-Pol V-dependent de novo methylation, by acting in cis to reinforce self-silencing of exo-IR may play a role in restraining inappropriate silencing of active protein-coding genes in plants.
doi:10.1111/j.1365-313X.2011.04714.x
PMCID: PMC3204326
PMID: 21771120
exo-IR; non-cell-autonomous silencing; PTGS; TGS; methylation spreading
Background
Androgen receptor (AR) signalling is critical to the initiation and progression of prostate cancer (PCa). Transcriptional activity of AR involves chromatin recruitment of co-activators, including the p300/CBP-associated factor (PCAF). Distinct miRNA expression profiles have been identified in PCa cells during the development and progression of the disease. Whether miRNAs regulate PCAF expression in PCa cells to regulate AR transcriptional activity is still unclear.
Methods
Expression of PCAF was investigated in several PCa cell lines by qRT-PCR, Western blot, and immunocytochemistry. The effects of PCAF expression on AR-regulated transcriptional activity and cell growth in PCa cells were determined by chromatin immunoprecipitation, reporter gene construct analysis, and MTS assay. Targeting of PCAF by miR-17-5p was evaluated using the luciferase reporter assay.
Results
PCAF was upregulated in several PCa cell lines. Upregulation of PCAF promoted AR transcriptional activation and cell growth in cultured PCa cells. Expression of PCAF in PCa cells was associated with the downregulation of miR-17-5p. Targeting of the 3’-untranslated region of PCAF mRNA by miR-17-5p caused translational suppression and RNA degradation, and, consequently, modulation of AR transcriptional activity in PCa cells.
Conclusions
PCAF is upregulated in cultured PCa cells, and upregulation of PCAF is associated with the downregulation of miR-17-5p. Targeting of PCAF by miR-17-5p modulates AR transcriptional activity and cell growth in cultured PCa cells.
doi:10.1186/1471-2407-12-492
PMCID: PMC3519561
PMID: 23095762
Reed is a widespread-growing, inexpensive, and readily available lignocellulosic material source in northeast China. The objective of this study is to evaluate the liquid hot water (LHW) pretreatment efficiency of reed based on the enzymatic digestibility and ethanol fermentability of water-insoluble solids (WISs) from reed after the LHW pretreatment. Several variables in the LHW pretreatment and enzymatic hydrolysis process were optimized. The conversion of glucan to glucose and glucose concentrations are considered as response variables in different conditions. The optimum conditions for the LHW pretreatment of reed area temperature of 180°C for 20min and a solid-to-liquid ratio of 1 : 10. These optimum conditions for the LHW pretreatment of reed resulted in a cellulose conversion rate of 82.59% in the subsequent enzymatic hydrolysis at 50°C for 72 h with a cellulase loading of 30 filter paper unit per gram of oven-dried WIS. Increasing the pretreatment temperature resulted in a higher enzymatic digestibility of the WIS from reed. Separate hydrolysis and fermentation of WIS showed that the conversion of glucan to ethanol reached 99.5% of the theoretical yield. The LHW pretreatment of reed is a suitable method to acquire a high recovery of fermentable sugars and high ethanol conversion yield.
doi:10.1155/2012/276278
PMCID: PMC3477588
PMID: 23118503
Recent evidence suggests an innovative application of chemical modulators targeting the S1P4 receptor as novel mechanism-based drugs for the treatment of influenza virus infection. Modulation of the S1P4 receptor may also represent an alternative therapeutic approach for clinical conditions where reactive thrombocytosis is an undesired effect or increased megakaryopoiesis is required. With the exception of our recent research program disclosure, we are not aware of any selective S1P4 antagonists reported in the literature to date. Herein, we describe complementary structure-activity relationships (SAR) of the high-throughput screening (HTS)-derived hit 5-(2,5-dichlorophenyl)-N-(2,6-dimethylphenyl)furan-2-carboxamide and its 2,5-dimethylphenyl analog. Systematic structural modifications of the furan ring showed that both steric and electronic factors in this region have a significant impact on the potency. The furan moiety was successfully replaced with a thiophene or phenyl ring maintaining potency in the low nanomolar range and high selectivity against the other S1P receptor subtypes. By expanding the molecular diversity within the hit-derived class, our SAR study provides innovative small molecule potent and selective S1P4 antagonists suitable for in vivo pharmacological validation of the target receptor.
doi:10.1016/j.bmcl.2011.06.132
PMCID: PMC3159836
PMID: 21783362
S1P4 receptor antagonists; S1P1-3,5 receptor family; megakaryocyte differentiation; viral infections
Background
Bone morphogenic proteins (BMPs) play a key role in bone formation. Consequently, it was expected that topical application of recombinant human (rh)BMP-2 and rhBMP-7 would improve the healing of complex fractures. However, up to 36% of fracture patients do not respond to this therapy. There are hints that a systemic increase in transforming growth factor β1 (TGFβ1) interferes with beneficial BMP effects. Therefore, in the present work we investigated the influence of rhTGFβ1 on rhBMP signaling in primary human osteoblasts, with the aim of more specifically delineating the underlying regulatory mechanisms.
Methods
BMP signaling was detected by adenoviral Smad-binding-element-reporter assays. Gene expression was determined by reverse transcription polymerase chain reaction (RT-PCR) and confirmed at the protein level by western blot. Histone deacetylase (HDAC) activity was determined using a test kit. Data sets were compared by one-way analysis of variance.
Results
Our findings showed that Smad1/5/8-mediated rhBMP-2 and rhBMP-7 signaling is completely blocked by rhTGFβ1. We then investigated expression levels of genes involved in BMP signaling and regulation (for example, Smad1/5/8, TGFβ receptors type I and II, noggin, sclerostin, BMP and activin receptor membrane bound inhibitor (BAMBI), v-ski sarcoma viral oncogene homolog (Ski), Ski-related novel protein N (SnoN) and Smad ubiquitination regulatory factors (Smurfs)) and confirmed the expression of regulated genes at the protein level. Smad7 and SnoN were significantly induced by rhTGFβ1 treatment while expression of Smad1, Smad6, TGFβRII and activin receptor-like kinase 1 (Alk1) was reduced. Elevated SnoN expression was accompanied by increased HDAC activity. Addition of an HDAC inhibitor, namely valproic acid, fully abolished the inhibitory effect of rhTGFβ1 on rhBMP-2 and rhBMP-7 signaling.
Conclusions
rhTGFβ1 effectively blocks rhBMP signaling in osteoblasts. As possible mechanism, we postulate an induction of SnoN that increases HDAC activity and thereby reduces the expression of factors required for efficient BMP signaling. Thus, inhibition of HDAC activity may support bone healing during rhBMP therapy in patients with elevated TGFβ serum levels.
doi:10.1186/1741-7015-10-101
PMCID: PMC3523027
PMID: 22958403
alkaline phosphatase; mineralized matrix; osteoblasts; rhBMPs; TGFβ
Tan, Wenfeng | Sunahori, Katsue | Zhao, Jian | Deng, Yun | Kaufman, Kenneth M. | Kelly, Jennifer A. | Langefeld, Carl D. | Williams, Adrienne H. | Comeau, Mary E. | Ziegler, Julie T. | Marion, Miranda C. | Bae, Sang-Cheol | Lee, Joo Hyun | Lee, Ji-Seon | Chang, Deh-Ming | Song, Yeong Wook | Yu, Chack-Yung | Kimberly, Robert P. | Edberg, Jeffrey C. | Brown, Elizabeth E. | Petri, Michelle A. | Ramsey-Goldman, Rosalind | Vilá, Luis M. | Reveille, John D. | Alarcón-Riquelme, Marta E. | Harley, John B. | Boackle, Susan A. | Stevens, Anne M. | Scofield, R. Hal | Merrill, Joan T. | Freedman, Barry I. | Anaya, Juan-Manuel | Criswell, Lindsey A. | Jacob, Chaim O. | Vyse, Timothy J. | Niewold, Timothy B. | Gaffney, Patrick M. | Moser, Kathy L. | Gilkeson, Gary S. | Kamen, Diane L. | James, Judith A. | Grossman, Jennifer M. | Hahn, Bevra H. | Tsokos, George C. | Tsao, Betty P.
Objective
T cells from patients with SLE express increased amounts of PP2Ac which contribute to decreased production of IL-2. Because IL-2 is important in the regulation of several aspects of the immune response, it has been proposed that PP2Ac contributes to the expression of SLE. This study was designed to determine whether genetic variants of PPP2AC are linked to the expression of SLE and specific clinical manifestations and account for the increased expression of PP2Ac.
Methods
We conducted a trans-ethnic study consisting of 8,695 SLE cases and 7,308 controls from four different ancestries. Eighteen single-nucleotide polymorphisms (SNPs) across the PPP2CA were genotyped using an Illumina custom array. PPP2CA expression in SLE and control T cells was analyzed by real-time PCR.
Results
A 32-kb haplotype comprised of multiple SNPs of PPP2CA showed significant association with SLE in Hispanic Americans (HA), European Americans (EA) and Asians but not in African-Americans (AA). Conditional analyses revealed that SNP rs7704116 in intron 1 showed consistently strong association with SLE across Asian, EA and HA populations (pmeta=3.8×10−7, OR=1.3[1.14–1.31]). In EA, the largest ethnic dataset, the risk A allele of rs7704116 was associated with the presence of renal disease, anti-dsDNA and anti-RNP antibodies. PPP2CA expression was approximately 2-fold higher in SLE patients carrying the rs7704116 AG genotype than those carrying GG genotype (p = 0.008).
Conclusion
Our data provide the first evidence for an association between PPP2CA polymorphisms and elevated PP2Ac transcript levels in T cells, which implicates a new molecular pathway for SLE susceptibility in EA, HA and Asians.
doi:10.1002/art.30452
PMCID: PMC3163110
PMID: 21590681
The extremely acidophilic, chemolithoautotrophic Acidithiobacillus ferrooxidans is an important bioleaching bacterium of great value in the metallurgical industry and environmental protection. In this report, a mutagenesis system based on the homing endonuclease I-SceI was developed to produce targeted, unmarked gene deletions in the strain A. ferrooxidans ATCC 23270. A targeted phosphofructokinase (PFK) gene (pfkB) mutant of A. ferrooxidans ATCC 23270 was constructed by homologous recombination and identified by PCR with specific primers as well as Southern blot analysis. This potential pfkB gene (AFE_1807) was also characterized by expression in PFK-deficient Escherichia coli cells, and heteroexpression of the PFKB protein demonstrated that it had functional PFK activity, though it was significantly lower (about 800-fold) than that of phosphofructokinase-2 (PFK-B) expressed by the pfkB gene from E. coli K-12. The function of the potential PFKB protein in A. ferrooxidans was demonstrated by comparing the properties of the pfkB mutant with those of the wild type. The pfkB mutant strain displayed a relatively reduced growth capacity in S0 medium (0.5% [wt/vol] elemental sulfur in 9K basal salts solution adjusted to pH 3.0 with H2SO4), but the mutation did not completely prevent A. ferrooxidans from assimilating exogenous glucose. The transcriptional analysis of some related genes in central carbohydrate metabolism in the wild-type and mutant strains with or without supplementation of glucose was carried out by quantitative reverse transcription-PCR. This report suggests that the markerless mutagenesis strategy could serve as a model for functional studies of other genes of interest from A. ferrooxidans and multiple mutations could be made in a single A. ferrooxidans strain.
doi:10.1128/AEM.07230-11
PMCID: PMC3298148
PMID: 22210219
Fan, Biao | Zhang, Lian-Hai | Jia, Yong-ning | Zhong, Xi-Yao | Liu, Yi-Qiang | Cheng, Xiao-Jing | Wang, Xiao-Hong | Xing, Xiao-Fang | Hu, Ying | Li, Ying-Ai | Du, Hong | Zhao, Wei | Niu, Zhao-Jian | Lu, Ai-Ping | Li, Ji-You | Ji, Jia-Fu
Background
S100A9 was originally discovered as a factor secreted by inflammatory cells. Recently, S100A9 was found to be associated with several human malignancies. The purpose of this study is to investigate S100A9 expression in gastric cancer and explore its role in cancer progression.
Methods
S100A9 expression in gastric tissue samples from 177 gastric cancer patients was assessed by immunohistochemistry. The expression of its dimerization partner S100A8 and the S100A8/A9 heterodimer were also assessed by the same method. The effect of exogenous S100A9 on motility of gastric cancer cells AGS and BGC-823 was then investigated.
Results
S100A9 was specifically expressed by inflammatory cells such as macrophages and neutrophils in human gastric cancer and gastritis tissues. Statistical analysis showed that a high S100A9 cell count (> = 200) per 200x magnification microscopic field in cancer tissues was predictive of early stage gastric cancer. High S100A9-positive cell count was negatively correlated with lymph node metastasis (P = 0.009) and tumor invasion (P = 0.011). S100A9 was identified as an independent prognostic predictor of overall survival of patients with gastric cancer (P = 0.04). Patients with high S100A9 cell count were with favorable prognosis (P = 0.021). Further investigation found that S100A8 distribution in human gastric cancer tissues was similar to S100A9. However, the number of S100A8-positive cells did not positively correlate with patient survival. The inflammatory cells infiltrating cancer were S100A8/A9 negative, while those in gastritis were positive. Furthermore, exogenous S100A9 protein inhibited migration and invasion of gastric cancer cells.
Conclusions
Our results suggested S100A9-positive inflammatory cells in gastric cancer tissues are associated with early stage of gastric cancer and good prognosis.
doi:10.1186/1471-2407-12-316
PMCID: PMC3476982
PMID: 22838504
Gastric cancer; S100A9; Inflammatory cells; Tumor staging; Survival
In eukaryotic cells, the shape of mitochondria can be tuned to various physiological conditions by a balance of fusion and fission processes termed mitochondrial dynamics. Mitochondrial dynamics controls not only the morphology but also the function of mitochondria, and therefore is crucial in many aspects of a cell’s life. Consequently, dysfunction of mitochondrial dynamics has been implicated in a variety of human diseases including cancer. Several proteins important for mitochondrial fusion and fission have been discovered over the past decade. However, there is emerging evidence that there are as yet unidentified proteins important for these processes and that the fusion/fission machinery is not completely conserved between yeast and vertebrates. The recent characterization of several mammalian proteins important for the process that were not conserved in yeast, may indicate that the molecular mechanisms regulating and controlling the morphology and function of mitochondria are more elaborate and complex in vertebrates. This difference could possibly be a consequence of different needs in the different cell types of multicellular organisms. Here, we review recent advances in the field of mitochondrial dynamics. We highlight and discuss the mechanisms regulating recruitment of cytosolic Drp1 to the mitochondrial outer membrane by Fis1, Mff, and MIEF1 in mammals and the divergences in regulation of mitochondrial dynamics between yeast and vertebrates.
doi:10.1007/s00018-012-1066-6
PMCID: PMC3578726
PMID: 22806564
Mitochondria; Mitochondrial dynamics; Mitochondrial fusion/fission; Yeast; Vertebrates
Selective S1P4 receptor antagonists could be novel therapeutic agents for the treatment of influenza infection in addition to serving as a useful tool for understanding S1P4 receptor biological functions. 5-(2,5-dichlorophenyl)-N-(2,6-dimethylphenyl)furan-2-carboxamide was identified from screening the Molecular Libraries-Small Molecule Repository (MLSMR) collection and selected as a promising S1P4 antagonist hit with moderate in vitro potency and high selectivity against the other family receptor subtypes (S1P1–3,5). Rational chemical modifications of the hit allowed the disclosure of the first reported highly selective S1P4 antagonists with low nanomolar activity and adequate physicochemical properties suitable for further lead-optimization studies.
doi:10.1016/j.bmcl.2011.04.097
PMCID: PMC3107912
PMID: 21570287
S1P4 receptor antagonists; S1P1–3,5 receptor family; 5-aryl furan-2-arylcarboxamide
The asymmetric unit of the title compound, C15H13FN2O, contains two independent molecules with different conformations; the two aromatic rings in the independent molecules form dihedral angles of 85.3 (2) and 10.0 (2)°. In the crystal, N—H⋯O hydrogen bonds link the molecules into chains along [100].
doi:10.1107/S1600536812025548
PMCID: PMC3393891
PMID: 22798756
AIM: To investigate the effect of intensive vs conventional insulin therapy on perioperative nutritional substrates metabolism in patients undergoing radical distal gastrectomy.
METHODS: Within 24 h of intensive care unit management, patients with gastric cancer were enrolled after written informed consent and randomized to the intensive insulin therapy (IIT) group to keep glucose levels from 4.4 to 6.1 mmol/L or the conventional insulin therapy (CIT) group to keep levels less than 10 mmol/L. Resting energy expenditure (REE), respiratory quotient (RQ), resting energy expenditure per kilogram (REE/kg), and the lipid oxidation rate were monitored by the indirect calorimeter of calcium citrate malate nutrition metabolism investigation system. The changes in body composition were analyzed by multi-frequency bioimpedance analysis. Blood fasting glucose and insulin concentration were measured for assessment of Homeostasis model assessment of insulin resistance.
RESULTS: Sixty patients were enrolled. Compared with preoperative baseline, postoperative REE increased by over 22.15% and 11.07%; REE/kg rose up to 27.22 ± 1.33 kcal/kg and 24.72 ± 1.43 kcal/kg; RQ decreased to 0.759 ± 0.034 and 0.791 ± 0.037; the lipid oxidation ratio was up to 78.25% ± 17.74% and 67.13% ± 12.76% supported by parenteral nutrition solutions from 37.56% ± 11.64% at the baseline; the level of Ln-HOMA-IR went up dramatically (P < 0.05, respectively) on postoperative days 1 and 3 in the IIT group. Meanwhile the concentration of total protein, albumin and triglyceride declined significantly on postoperative days 1 and 3 compared with pre-operative levels (P < 0.05, respectively). Compared with the CIT group, IIT reduced the REE/kg level (27.22 ± 1.33 kcal/kg vs 29.97 ± 1.47 kcal/kg, P = 0.008; 24.72 ± 1.43 kcal/kg vs 25.66 ± 1.63 kcal/kg, P = 0.013); and decreased the Ln-HOMA-IR score (P = 0.019, 0.028) on postoperative days 1 and 3; IIT decreased the level of CRP on postoperative days 1 and 3 (P = 0.017, 0.006); the total protein and albumin concentrations in the IIT group were greater than those in the CIT group (P = 0.023, 0.009). Postoperative values of internal cell fluid (ICF), fat mass, protein mass (PM), muscle mass, free fat mass and body weight decreased obviously on postoperative 7th day compared with the preoperative baseline in the CIT group (P < 0.05, respectively). IIT reduced markedly consumption of fat mass, PM and ICF compared with CIT (P = 0.009 to 0.026).
CONCLUSION: There were some benefits of IIT in decreasing the perioperative insulin resistance state, reducing energy expenditure and consumption of proteins and lipids tissue in patients undergoing gastrectomy.
doi:10.3748/wjg.v18.i21.2695
PMCID: PMC3370008
PMID: 22690080
Intensive insulin therapy; Resting energy expenditure; Respiratory quotient; Insulin resistance; Free fat acids; Body composition
Bone-tendon junction (BTJ) injury is difficult to cure due to its special anatomical structure. Most methods applied for BTJ injury treatment cannot lead to the perfect restoration of the fibrocartilage zone and perfect vascular regeneration, which are two important facets of BTJ reconstruction. Based on current research, hypoxia, which has been discovered to induce chondrogenesis and angiogenesis in vivo, plays an essential role in the tissue repair process. Consequently, it is reasonable to confirm that a hypoxic environment is the prerequisite condition to obtain physiological healing of BTJ injury. In this paper, the potential relationship between hypoxia and BTJ healing is discussed. Moreover, an operation model and possible drug application to obtain hypoxic conditions are delineated.
doi:10.1007/s00264-010-1157-7
PMCID: PMC3103969
PMID: 21127862
Fu, Qiong | Zhao, Jian | Qian, Xiaoxia | Wong, Jonathan LH | Kaufman, Kenneth M | Yu, C. Yung | Mok, Mo Yin | Harley, John B | Guthridge, Joel M | Song, Yeong Wook | Cho, Soo-Kyung | Bae, Sang-Cheol | Grossman, Jennifer M | Hahn, Bevra H | Arnett, Frank C | Shen, Nan | Tsao, Betty P
Objective
Previous genome wide association study conducted in a population of European ancestry identified rs4963128, a KIAA1542 SNP 23kb telomeric to IRF7, in strong association with SLE. This study was undertaken to investigate whether genetic polymorphism within IRF7 is a risk factor for the development of SLE.
Methods
We genotyped one KIAA1542 SNP rs4963128 and one IRF7 SNP rs1131665 (Q412R) in an Asian population (cases vs. controls: 1302 vs.1479) to assess their association with SLE using custom-designed Beadstation Infinium II platform (Illumina). Subsequently, rs1131665 was further genotyped in independent panels of Chinese (528 vs.527), European American (EA) (446 vs.461) and African American (AA) (159 vs.115) by Taqman genotyping assay to seek confirmation of association in various ethnic groups. Luciferase reporter assay was used to assess the effect of Q412R polymorphism on the activation of IRF7.
Results
Consistent association of rs1131665 (Q412R) with SLE was identified in Asian, EA and AA populations (case vs. control: 2435 vs. 2582; Pmeta = 6.18×10−6, OR = 1.42[1.22–1.65]). Expression of IRF7 412Q risk allele resulted in a 2-fold increase in ISRE transcriptional activity compared with expression of IRF7 412R (P = 0.0003), suggesting IRF7 412Q confers elevated IRF7 activity and may therefore affect downstream IFN pathway.
Conclusion
We showed that the major allele of a nonsynonymous SNP rs1131665 (412Q) in IRF7 confers elevated IRF7 activation and predisposes to the development of SLE in multiple ethnic groups. This result provides direct genetic evidence supporting IRF7 may be a risk gene for human SLE.
doi:10.1002/art.30193
PMCID: PMC3063317
PMID: 21360504
Xu, Ning | Li, Yan | Zhao, Ying-Tao | Guo, Li | Fang, Yuan-Yuan | Zhao, Jian-Hua | Wang, Xiu-Jie | Huang, Li | Guo, Hui-Shan | Rusche, Laura N.
The term RNA silencing (RNA interference, RNAi) describes a set of mechanisms that regulate gene expression in eukaryotes. Small interfering RNAs (siRNA) and microRNAs (miRNAs) are two major types of RNAi-associated small RNAs (smRNAs) found in most eukaryotic organisms. Despite the presence of a plethora of non-coding RNAs longer than 50-nucleotide (nt) in length in various species of Archaea, little is known about smRNAs in archaea that resemble the 20–24-nt long smRNAs found in eukaryotes, which have been implicated in the post-transcriptional control of gene expression. Here, we report the finding of a large number of smRNAs approximatelly 20-nt in length, including phased smRNAs and potential miRNAs, from the hyperthermophilic archaeon Sulfolobus solfataricus p2 (Ssp2) based on deep sequencing. The expression of some of the miRNA candidates in Ssp2 was confirmed. Consistent with the Ssp2 hyperthermophilic properties, we found that higher temperatures more efficiently induced the production of the miRNA candidates in an in vitro system using the putative foldback precursor transcripts incubated with Ssp2 extract. Although we initially predicted putative target genes of some miRNA candidates, further analysis mapped the cleavage sites downstream of the miRNA candidate complementary regions, similar to those involved in plant miRNA-mediated TAS transcript cleavage. We also identified smRNAs from clustered, regularly interspaced, short palindromic repeat (CRISPR) loci, which play important roles in prokaryotic microbial defense systems. Archaea represent a unique life form next to Bacteria and Eukarya, and our results may provide a useful resource for further in-depth study on the regulation and evolution of smRNAs in this special organism.
doi:10.1371/journal.pone.0035306
PMCID: PMC3325985
PMID: 22514725
Zhao, Jian-Yuan | Sun, Jing-Wei | Gu, Zhuo-Ya | Wang, Jue | Wang, Er-Li | Yang, Xue-Yan | Qiao, Bin | Duan, Wen-Yuan | Huang, Guo-Ying | Wang, Hong-Yan | Sun, Qi
Background
Clinical research indicates that periconceptional administration of folic acid can reduce the occurrence of congenital cardiac septal defects (CCSDs). The vital roles of folate exhibits in three ways: the unique methyl donor for DNA expression regulation, the de novo biosynthesis of purine and pyrimidine for DNA construction, and the serum homocysteine removal. Thymidylate synthase (TYMS) is the solo catalysis enzyme for the de novo synthesis of dTMP, which is the essential precursor of DNA biosynthesis and repair process. To examine the role of TYMS in Congenital Cardiac Septal Defects (CCSDs) risk, we investigated whether genetic polymorphisms in the TYMS gene associated with the CCSDs in a Han Chinese population.
Method
Polymorphisms in the noncoding region of TYMS were identified via direct sequencing in 32 unrelated individuals composed of half CCSDs and half control subjects. Nine SNPs and two insertion/deletion polymorphisms were genotyped from two independent case-control studies involving a total of 529 CCSDs patients and 876 healthy control participants. The associations were examined by both single polymorphism and haplotype tests using logistic regression.
Result
We found that TYMS polymorphisms were not related to the altered CCSDs risk, and even to the changed risk of VSDs subgroup, when tested in both studied groups separately or in combination. In the haplotype analysis, there were no haplotypes significantly associated with risks for CCSDs either.
Conclusion
Our results show no association between common genetic polymorphisms of the regulatory region of the TYMS gene and CCSDs in the Han Chinese population.
doi:10.1371/journal.pone.0031644
PMCID: PMC3285645
PMID: 22384047