Light control of Arabidopsis development entails coordinated regulation of genome expression and cellular pathways

An expressed sequence tag-based microarray was used to profile genome expression underlying light control of Arabidopsis development. Qualitatively similar gene expression profiles were observed among seedlings grown in different light qualities, including far-red, red, and blue light, which are mediated primarily by phytochrome A, phytochrome B, and the cryptochromes, respectively. Furthermore, light/dark transitions also triggered similar differential genome expression profiles. Most light treatments also resulted in distinct expression profiles in small fractions of the expressed sequence tags examined. The similarly regulated genes in all light conditions were estimated to account for approximately one-third of the genome, with three-fifths upregulated and two-fifths downregulated by light. Analysis of those light-regulated genes revealed more than 26 cellular pathways that are regulated coordinately by light. Thus, light controls Arabidopsis development through coordinately regulating metabolic and regulatory pathways.

Use of quantitative competitive PCR to measure Epstein-Barr virus genome load in the peripheral blood of pediatric transplant patients with lymphoproliferative disorders

A quantitative competitive PCR (QC-PCR) assay for Epstein-Barr virus (EBV) has been developed to provide accurate measurement of EBV genome load in pediatric transplant recipients at risk for developing posttransplant lymphoproliferative disorder (PTLD). The assay quantifies between 8 and 5,000 copies of the EBV genome in 10(5) lymphocytes after a 30-cycle amplification reaction. For 14 pediatric patients diagnosed with PTLD, the median EBV genome load was 4,000, and 13 of the 14 patients had values of >500 copies per 10(5) lymphocytes. Only 3 of 12 control transplant recipients not diagnosed with PTLD had detectable viral genome loads (median value, 40). This median was calculated by using the highest value obtained by PCR testing on each of these patients posttransplantation. PCR values of >500 copies per 10(5) lymphocytes appear to correlate with a diagnosis of PTLD. By a modified protocol, the EBV genome copy number in latently infected adults was estimated to be <0.1 copy per 10(5) lymphocytes.

Epstein-Barr virus latent gene expression in uncultured peripheral blood lymphocytes

In this study of Epstein-Barr virus (EBV) latency, the polymerase chain reaction was used in modified form for amplification and detection of viral mRNA sequences in peripheral blood lymphocytes from healthy seropositive adults. Six known promoters for latent gene expression and eight known gene products were identified in in vitro-immortalized lymphocytes and in the cell lines established spontaneously from seropositive adults. We examined whether mRNA expression in uncultured B cells from four seropositive adults was the same as that which occurred in spontaneously established EBV-positive B-cell lines from the same individuals. A minimum of 17 polymerase chain reaction targets was required to circumscribe the known latent mRNA structures. Expression of the C promoter for the EBNA genes was detected in B-cell RNA from three of the four subjects. Transcripts initiated from the alternative W promoter for EBNA expression were not detected. The spliced transcripts detected in the B cells contained only the C2-to-W1 alternative splice, which was nonproductive for EBNA4 gene expression. None of the other EBNA open reading frames were detected spliced onto the 3' ends of the C promoter-initiated RNAs. Spliced RNA from the TP gene was detected in all four subjects. Expression of the TP gene was restricted to TP1 promoter-initiated RNAs, as no TP2 promoter-initiated transcripts were detected. Expression of RNA from the LMP gene was not detected. The F promoter which is active in the restricted expression latency that occurs in Burkitt's lymphoma cells was not detected being expressed in peripheral blood B cells. This pattern of latent gene expression is unique to uncultured B cells, indicating that there are profound differences between viral latent states in vitro and in situ and suggesting a central role for the TP gene in the latency of EBV.

Serial measurement of Epstein-Barr viral load in peripheral blood in pediatric liver transplant recipients during treatment for posttransplant lymphoproliferative disease

BACKGROUND

Few data are available describing the natural history of the Epstein-Barr virus (EBV) viral load after the diagnosis of EBV-associated posttransplant lymphoproliferative disease (PTLD). Accordingly, we prospectively followed the EBV viral load after the diagnosis of EBV/PTLD in seven pediatric orthotopic liver transplant recipients.

METHODS

EBV viral loads were serially measured by quantitative competitive polymerase chain reaction of the peripheral blood from pediatric patients with PTLD and correlated with the clinical course of these children. Viral loads >200 genome copies/10(5) peripheral blood lymphocytes were considered consistent with an increased risk of PTLD. Viral loads <200 obtained during treatment for PTLD were considered evidence of "clearance" of EBV; subsequent loads >200 were considered evidence of virologic "rebound."

RESULTS

The mean EBV viral load at the time of diagnosis of PTLD was 1029. All patients "cleared" their EBV viral load during the treatment of PTLD; patient and graft survival in this series was 100%. The mean time to clearance of EBV from the peripheral blood (18.8 days) was similar to the mean time to onset of first rejection (13.8 days). EBV viral load at the time of diagnosis of rejection after PTLD was always <100. A rebound in the EBV viral load to >200 was noted in five of seven patients a median of 3.5 months (range 2.3-13 months) after the diagnosis of EBV/PTLD. However, none of these children has had any evidence of PTLD recurrence.

CONCLUSIONS

Clearance of the EBV viral load from the peripheral blood seems to correlate with restoration of the host's immune response as noted both by the regression of the PTLD and the onset of rejection. Late rebound of the EBV viral load is common and does not seem to predict disease recurrence.

Light control of Arabidopsis development entails coordinated regulation of genome expression and cellular pathways

An expressed sequence tag-based microarray was used to profile genome expression underlying light control of Arabidopsis development. Qualitatively similar gene expression profiles were observed among seedlings grown in different light qualities, including far-red, red, and blue light, which are mediated primarily by phytochrome A, phytochrome B, and the cryptochromes, respectively. Furthermore, light/dark transitions also triggered similar differential genome expression profiles. Most light treatments also resulted in distinct expression profiles in small fractions of the expressed sequence tags examined. The similarly regulated genes in all light conditions were estimated to account for approximately one-third of the genome, with three-fifths upregulated and two-fifths downregulated by light. Analysis of those light-regulated genes revealed more than 26 cellular pathways that are regulated coordinately by light. Thus, light controls Arabidopsis development through coordinately regulating metabolic and regulatory pathways.

Predictive negative value of persistent low Epstein-Barr virus viral load after intestinal transplantation in children

BACKGROUND

The correlation between an elevated Epstein-Barr virus (EBV) viral load in the peripheral blood and the subsequent development of EBV-associated posttransplant lymphoproliferative disease (PTLD) is the basis for strategies using serial measurements of the EBV viral load to guide preemptive therapy (PT). Neither the frequency, duration of monitoring, nor the predictive negative value of viral load monitoring for asymptomatic patients with persistent low or nondetectable viral loads against the development of PTLD has been established.

METHODS

Since April 1994, children undergoing intestinal transplantation (ITx) underwent serial monitoring of the EBV viral load in their peripheral blood using a quantitative competitive EBV polymerase chain reaction assay (PCR). Samples were obtained every 2 weeks for the first 3 months and then every 1-3 months depending on the patients clinical condition. EBV viral loads > or =40 (for patients who were EBV seronegative pre-ITx) and > or =200 (for those who were seropositive) genome copies/10(5) peripheral blood lymphocytes were felt to identify patients at increased risk for PTLD and generally prompted PT.

RESULTS

A total of 30 ITx recipients were compliant with our monitoring protocol; 23/30 are alive 6-59 months post-ITx. A total of 12/30 never had a viral load >40 and did not receive PT. In contrast, 18/30 had > or =1 high viral load (> or =200); the first high viral load was measured a median of 59 days post-ITx (range 1-440). A late rise (>6 months post-ITx) was seen in only 2/18 children. A total of 0/12 patients with persistently low viral loads received PT and none developed PTLD. In contrast, 5/18 with > or =1 one high viral load (including 2/14 who received and 3/4 who did not receive PT) developed PTLD. All five children with PTLD were EBV seropositive pre-ITx and experienced their first high EBV PCR within the first 3 months after ITx.

CONCLUSIONS

The predictive negative value of persistently low or nondetectable EBV viral loads was 100% in this study. Patients with nondetectable or low viral loads for the first 6 months after ITx did not develop PTLD regardless of their pretransplant EBV serological status. The frequency of viral load monitoring can be safely decreased for patients whose viral loads remain low for the first 6 months ITx.

Prevalence and characteristics of psoriatic arthritis in Chinese patients with psoriasis

BACKGROUND

The prevalence and clinical characteristics of psoriatic arthritis (PsA) in patients with psoriasis vary widely in different countries and studies on Chinese population are rarely reported.

OBJECTIVE

The aim of this study was to evaluate the prevalence and clinical characteristics of PsA in a Chinese population of patients with psoriasis.

METHODS

A large cross-sectional observational study was conducted in our outpatient dermatology department and consecutive psoriatic patients were evaluated for PsA according to Classification of Psoriatic arthritis (CASPAR) criteria. Demographic and medical parameters were recorded.

RESULTS

Among 1928 patients with psoriasis, 112 patients (5.8%) had PsA, of which 92% was newly diagnosed. Oligoarthritis (48.2%) was the most common manifestation pattern, followed by spondylitis (26.8%), polyarthritis (19.6%) and classic distal interphalangeal (DIP) arthritis (5.4%). Enthesitis was present in 26.8% and dactylitis in 13.4% of the patients. Compared with patients without PsA, patients with PsA had more severe skin disease (mean PASI 9.7 vs. 6.0), higher frequency of nail changes (46.4% vs. 21.0%) and scalp involvement (90.2% vs. 76.4%).

CONCLUSION

The findings are consistent with a low prevalence of PsA among patients with psoriasis in Asia and confirm a high percentage of undiagnosed cases with active arthritis among PsA patients in dermatologist's office. Dermatologists should screen for PsA in their patients, especially those with risk characteristics and early signs.

Enhancement of docosahexaenoic acid production by Schizochytrium sp. using a two-stage oxygen supply control strategy based on oxygen transfer coefficient

AIMS

To improve the yield and productivity of docosahexaenoic acid (DHA) by Schizochytrium sp. in terms of the analysis of microbial physiology.

METHODS AND RESULTS

A two-stage oxygen supply control strategy, aimed at achieving high concentration and high productivity of DHA, was proposed. At the first 40 h, K(L) a was controlled at 150·1 h(-1) to obtain high μ for cell growth, subsequently K(L) a was controlled at 88·5 h(-1) to maintain high q(p) for high DHA accumulation. Finally, the maximum lipid, DHA content and DHA productivity reached 46·6, 17·7 g l(-1) and 111 mg l(-1) h(-1), which were 43·83%, 63·88% and 32·14% over the best results controlled by constant K(L) a.

CONCLUSIONS

This paper described a two-stage oxygen supply control strategy based on the kinetic analysis for efficient DHA fermentation by Schizochytrium sp.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study showed the advantage of two-stage control strategy in terms of microbial physiology. As K(L) a is a scaling-up parameter, the idea developed in this paper could be scaled-up to industrial process and applied to other industrial biotechnological processes to achieve both high product concentration and high productivity.

Isolation and characterization of noncytopathic pestivirus mutants reveals a role for nonstructural protein NS4B in viral cytopathogenicity

Isolates of bovine viral diarrhea virus (BVDV), the prototype pestivirus, are divided into cytopathic (cp) and noncytopathic (ncp) biotypes according to their effect on cultured cells. The cp viruses also differ from ncp viruses by the production of viral nonstructural protein NS3. However, the mechanism by which cp viruses induce cytopathic effect in cell culture remains unknown. Here we used a genetic approach to isolate ncp variants that arose from a cp virus at low frequency. A bicistronic BVDV (cp strain NADL) was created that expressed puromycin acetyltransferase as a dominant selectable marker. This bicistronic virus exhibited slightly slower growth kinetics and smaller plaques than NADL but remained cp. A number of independent ncp variants were isolated by puromycin selection. Remarkably, these ncp variants produced NS3 and viral RNA at levels comparable to those of the cp parent. Sequence analyses uncovered no change in NS3, but for all ncp variants a Y2441C substitution at residue 15 of NS4B was found. Introduction of the Y2441C substitution into the NADL or bicistronic cp viruses reconstituted the ncp phenotype. Y2441 is highly conserved among pestiviruses and is located in a region of NS4B predicted to be on the cytosolic side of the endoplasmic reticulum membrane. Other engineered substitutions for Y2441 also affected viral cytopathogenicity and viability, with Y2441V being cp, Y2441A being ncp, and Y2441D rendering the virus unable to replicate. The ncp substitutions for Y2441 resulted in slightly increased levels of NS2-3 relative to NS3. We also showed that NS3, NS4B, and NS5A could be chemically cross-linked in NADL-infected cells, indicating that they are associated as components of a multiprotein complex. Although the mechanism remains to be elucidated, these results demonstrate that mutations in NS4B can attenuate BVDV cytopathogenicity despite NS3 production.

Quantum dots based molecular beacons for in vitro and in vivo detection of MMP-2 on tumor

Matrix metalloproteinase-2 (MMP-2) is a protease related to tumor invasion and metastasis. It is heavily secreted by malignant tumor cells, allowing the protease to serve as an imaging biomarker of cancer. In this study, a novel sensing system based on fluorescence resonance energy transfer (FRET) from quantum dot (QD, the donor) to organic dye (the acceptor) was constructed for the in vitro and in vivo detection of matrix metalloproteinases-2 via a MMP-2-specific peptide substrate (GPLGVRGKGG). Specifically, 535 nm-emitting CdTe QD were bound to Rhodamine B (RB) through the peptide for in vitro detection of MMP-2, while 720 nm-emitting CdTeS QDs was linked to near infrared dye ICG-Der-02 (MPA) by the peptide for measurement in vivo. When these probes were exposed to MMP-2, the selective cleavage of the peptide resulted in the recovery of fluorescence from QDs. By using the produced 540QD-peptide-RB and 720QD-peptide-MPA probes, we successfully examined MMP-2 in live cells and tumor on nude mouse, respectively. Due to the tunable fluorescence of Qds, this nanosensor can be fine-tuned for a wide range of applications such as the detection of different biomarkers and early diagnosis of disease.

Epstein-Barr virus gene expression in the peripheral blood of transplant recipients with persistent circulating virus loads

Pediatric solid organ transplant recipients are at risk for Epstein-Barr virus (EBV)-driven lymphoproliferative disease. The expression of 5 sentinel EBV genes (EBNA1, EBNA2a, LMP1, LMP2a, and ZEBRA) was examined in solid organ transplant recipients who developed persistent virus loads in their peripheral blood lymphocytes after transplantation. Two distinct groups were identified. LMP2a gene expression alone was detected among 12 of 14 patients carrying EBV loads < or =100 copies/10(5) lymphocytes. The other 2 low-load carriers made LMP2a RNA but also expressed LMP1 RNA. In contrast, LMP2a and LMP1 gene expression was detected among 11 of 13 patients carrying a virus load >100 copies/10(5) lymphocytes. Two high-load carriers made LMP1 RNA but not the RNA for LMP2a or any of the other viral genes. Therefore, persistent low-load carriers appear to maintain an apparently normal state of latent viral infection, whereas high-load carriers display a unique LMP1:LMP2a pattern of viral gene expression that has not been previously described.

Astragaloside IV synergizes with ferulic acid to inhibit renal tubulointerstitial fibrosis in rats with obstructive nephropathy

BACKGROUND AND PURPOSE

The combination of Chinese herbs, Astragali Radix and Angelicae Sinensis Radix, could alleviate renal interstitial fibrosis. Astragaloside IV (AS-IV) and ferulic acid (FA) are the two major active constituents in this combination. In this study, we employed rats with unilateral ureteral obstruction to determine whether AS-IV and FA have the same renoprotective effects and investigated the mechanisms of this action.

EXPERIMENTAL APPROACH

Renal pathological changes were evaluated after treatment with AS-IV, FA or AS-IV + FA (AF) for 10 days. Meanwhile, the expression of transforming growth factor β₁ (TGF-β₁), fibronectin, α-smooth muscle actin (α-SMA), phosphorylation of c-Jun NH₂-terminal kinase (p-JNK) and nitric oxide (NO) production in kidney were determined. The expressions of fibronectin, α-SMA, mitogen-activated protein kinases [JNK, extracellular signal-regulated kinases (ERK), P38] in TGF-β₁-treated NRK-49F cells or interleukin-1-treated HK-2 cells after AS-IV, FA or AF were assessed.

KEY RESULTS

AF alleviated the infiltration of mononuclear cells, tubular atrophy and interstitial fibrosis; reduced the expression of fibronectin, α-SMA, TGF-β₁ and p-JNK; and dramatically increased the production of NO in obstructed kidneys. Neither AS-IV nor FA alone improved renal damage, but both increased NO production. AF inhibited α-SMA and fibronectin expression in NRK-49F or HK-2 cells. Furthermore, AF significantly inhibited IL-1β-induced JNK phosphorylation, without affecting ERK or P38 phosphorylation. Neither AS-IV nor FA alone had any effect on the cells.

CONCLUSIONS AND IMPLICATIONS

AS-IV synergizes with FA to alleviate renal tubulointerstitial fibrosis; this was associated with inhibition of tubular epithelial–mesenchymal transdifferentiation (EMT) and fibroblast activation, as well as an increase in NO production in the kidney.

The epidemiology of adolescent acne in North East China

BACKGROUND

Adolescent acne impacts self-esteem and quality of life in adolescents and its aetiology is not fully clarified.

OBJECTIVE

The aim of this study was to describe the epidemiological features of adolescent acne in North East China and determine the impact of genetic and environmental factors on the pathogenesis of acne.

METHODS

Data were collected from 5696 undergraduates (2920 patients and 2776 controls) using questionnaire. The survey data were analysed using spss version 13.0 and heritability of adolescent acne was calculated using Falconer's method.

RESULTS

Total prevalence of adolescent acne was 51.30% (52.74% in males, 49.65% in females). The difference between genders was statistically significant (P < 0.05). Adolescents with a family history of acne had earlier age of onset (P < 0.001). The prevalence of acne in first- and second-degree relatives of acne patients was 22.5% and 7.19%, respectively, significantly higher than in controls (P < 0.001). Heritability of adolescent acne was 78.47 +/- 2.05% in first-degree relatives and 75.05 +/- 3.18% in second-degree relatives. Risk factors to the acne suffers include (in descending order of occurrence), acne family history, mental stress, menstrual disorder, frequent insomnia, high fat diet, being male, dysmenorrhoea, anxiety, sleeping < 8 h per day, depression, fried food, study pressure, spicy food, oily skin and mixed type skin. Protective factors include (presented in descending order of occurrence) dry skin, neutral skin, frequent fruit consumption and computer access time < 2 h daily.

CONCLUSION

Adolescent acne includes a familial genetic predisposition. Additional environmental factors of psychological stress, skin oiliness and high caloric diets may also contribute to the onset of acne in Chinese adolescents.

InDels within caprine IGF2BP1 intron 2 and the 3'-untranslated regions are associated with goat growth traits

Insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) is involved in the Hedgehog pathway and has been shown to regulate the RNA stability of several growth-related target genes. It is located in a quantitative trait locus showing a strong association with traits related to body size in ducks. Fibroblast growth factor receptor 1 (FGFR1) also participates in Hedgehog signaling pathways and has been reported to be associated with organic growth and development. FGFR1-knockout mice have been shown to have severe postnatal growth defects, including an approximately 50% reduction in body weight and bone mass. Meanwhile, nonsense-mediated mRNA decay factor (SMG6) can maintain genomic stability, which is associated with organic growth and development. Therefore, we hypothesized that IGF2BP1, FGFR1 and SMG6 genes may play important roles in the growth traits of goats. In this study, the existence of two insertion/deletion (InDel) variants within IGF2BP1, one InDel within FGFR1 and two InDels within SMG6 was verified and their correlation with growth traits was analyzed in 2429 female Shaanbei white cashmere goats. Results showed both the 15 bp InDel in intron 2 and the 5 bp InDel in the 3' regulatory region within IGF2BP1 were significantly associated with growth traits (P < 0.05) and goats with the combinatorial homozygous insertion genotypes of these two loci had the highest body weight (P = 0.046). The other InDels within FGFR1 and SMG6 were not obviously associated with growth traits (P > 0.05). Therefore, the two InDels in IGF2BP1 were vital mutations affecting goat growth traits.

Videodensitometric determination of minimum coronary artery luminal diameter before and after angioplasty

Quantitative measurements of coronary stenoses were made from digital coronary angiograms in 19 patients before and after percutaneous transluminal coronary angioplasty (PTCA). Two methods of measurement were compared. Mean stenosis before PTCA was 67 +/- 10% by the edge detection method and 67 +/- 12% by videodensitometry (difference not significant). After PTCA, the mean stenosis was 32 +/- 14% by edge detection and 30 +/- 13% by videodensitometry (difference not significant). In addition, a new method was developed to rapidly calculate the absolute minimum luminal area and diameter by videodensitometry. The minimum luminal diameter before PTCA was 1.0 +/- 0.5 mm and after PTCA increased to 2.4 +/- 0.5 mm (p less than 0.001). The validity of the videodensitometric method was analyzed in a series of Lucite phantom studies, which suggested that when there is an irregular angiographic appearance, the densitometric method may be more accurate than standard edge detection methods. Digital acquisition of coronary angiograms provides a means for rapid application of quantitative analysis during coronary interventional procedures.

Tacrolimus versus cyclophosphamide as treatment for diffuse proliferative or membranous lupus nephritis: a non-randomized prospective cohort study

Treatment of lupus nephritis (LN) with cyclophosphamide (CYC) is effective but retains a certain severe adverse effect. Tacrolimus (TAC) may be a suitable treatment for LN. Forty patients with diffuse proliferative or membranous LN were recruited for this non-randomized open-label study — 67.5% (27/40) had nephrotic proteinuria (>3.5 g/day) and 50.0% (20/40) had low estimated glomerular filtration rate (eGFR) (<60 mL/min/1.73m2). We compared the efficacy and adverse effects of TAC (0.04–0.08 mg/kg/d)/prednisone for 12 months (TAC group, n = 20) with intravenous CYC (750 mg/m2 per month)/prednisone for six months followed by azathioprine (Aza) (100 mg/day)/prednisone for six months (CYC group, n = 20). The TAC target concentration was 6–8 ng/mL or 4–6 ng/mL, respectively, when induction or maintenance therapy was required and 4.0 ng/mL for patient with renal insufficiency. In the TAC group, mean urinary protein excretion decreased significantly from 5.00 ± 1.91 g/day at baseline to 2.54 ± 1.68 g/day after two weeks of therapy ( P < 0.001), compared with the CYC group (4.9 ± 19.4 g/day), P = 0.001, and 65.0% (13/20) achieved partial remission at one month, compared with the CYC group (0/20), P < 0.001. The incidence of complete remission (CR) was significantly higher in the TAC group than in the CYC group (55.0% vs.15.0% by five months, P = 0.008, and 75.0% vs.40.0% by 12 months, P = 0.025, respectively). The significant improvement in serum anti-dsDNA and systemic lupus erythematosus (SLE) disease activity index (DAI) was in the TAC group relative to the CYC group at 12 months ( P = 0.031, P = 0.003, respectively). The eGFR improved in the TAC group from 59.90 ± 23.64 mL/min/1.73m2 at baseline to 93.75 ± 28.52 mL/min/1.73m2 after 12 months, P = 0.001. In the CYC group, two patients developed end-stage renal disease (ESRD), three patients experienced serious pneumonia, and one patient died. Our preliminary study showed TAC is a safe and effective treatment for LN with severe renal disease, and with less-severe adverse events compared with CYC followed Aza therapy. Further larger sample studies are needed to confirm our conclusion.

Investigation of 20 non-HLA (human leucocyte antigen) psoriasis susceptibility loci in Chinese patients with psoriatic arthritis and psoriasis vulgaris

BACKGROUND

Recently, a number of non-HLA (human leucocyte antigen) psoriasis genetic susceptibility loci have been identified through genome-wide association studies, but data on their association with psoriatic arthritis (PsA) are lacking.

OBJECTIVES

To investigate recently identified psoriasis susceptibility loci in a cohort of Chinese patients with PsA, psoriasis vulgaris (PsV) and healthy controls.

METHODS

Twenty single-nucleotide polymorphisms (SNPs) from 20 loci were selected for genotyping in 379 patients with PsA, 595 patients with PsV and 1181 healthy controls using the MassARRAY platform (Sequenom, San Diego, CA, U.S.A.). Data handling, quality control and association were performed using PLINK software, v. 1.07. The Cochran-Armitage trend test was used to test the genotype-phenotype association.

RESULTS

PsA showed a significant association with markers at TNIP1 (rs17728338, P = 2.20 × 10(-8)), IL28RA (rs4649203, P = 5.04 × 10(-6)), IL12B (rs2082412, P = 3.82 × 10(-5)), ERAP1 (rs27524, P = 1.25 × 10(-3)), PTTG1 (rs2431697, P = 1.22 × 10(-3)) and GJB2 (rs3751385, P = 1.48 × 10(-3)) when compared with the control group. In PsV a significant association was found for IL28RA (rs4649203, P = 9.53 × 10(-7)), TNIP1 (rs17728338, P = 1.21 × 10(-4)) and ERAP1 (rs27524, P = 1.17 × 10(-3)). The allele frequencies were not statistically different between PsA and PsV except for SNPs at IL12B and ZNF816A with a nominal P-value of 0.04 and 0·01, respectively.

CONCLUSIONS

This study provides evidence for the involvement of ERAP1, IL28RA, GJB2 and PTTG1 loci in PsA susceptibility and confirmed the previously reported association with PsA and PsV. These results support the hypothesis that genetic aetiology of psoriasis is the same in both PsA and PsV and also support the higher genetic component of PsA than PsV.

Structure of the Forkhead Domain of FOXA2 Bound to a Complete DNA Consensus Site

FOXA2, a member of the forkhead family of transcription factors, plays essential roles in liver development and bile acid homeostasis. In this study, we report a 2.8 Å co-crystal structure of the FOXA2 DNA-binding domain (FOXA2-DBD) bound to a DNA duplex containing a forkhead consensus binding site (GTAAACA). The FOXA2-DBD adopts the canonical winged-helix fold, with helix H3 and wing 1 regions mainly mediating the DNA recognition. Although the wing 2 region was not defined in the structure, isothermal titration calorimetry assays suggested that this region was required for optimal DNA binding. Structure comparison with the FOXA3-DBD bound to DNA revealed more major groove contacts and fewer minor groove contacts in the FOXA2 structure than in the FOXA3 structure. Structure comparison with the FOXO1-DBD bound to DNA showed that different forkhead proteins could induce different DNA conformations upon binding to identical DNA sequences. Our findings provide the structural basis for FOXA2 protein binding to a consensus forkhead site and elucidate how members of the forkhead protein family bind different DNA sites.