Heterogeneous osteoimmune profiles via single-cell transcriptomics in osteoporotic patients who fail bisphosphonate treatment

Postmenopausal osteoporosis arises from imbalanced osteoclast and osteoblast activity, and mounting evidence suggests a role for the osteoimmune system in bone homeostasis. Bisphosphonate (BP) is an antiresorptive agent, but its treatment failure rate can be as high as 40%. Here, we performed single-cell RNA sequencing on peripheral immune cells from carefully selected postmenopausal women: non-osteoporotic, osteoporosis improved after BP treatment, and BP-failed cases. We found an increase in myeloid cells in patients with osteoporosis (specifically, T cell receptor+ macrophages). Furthermore, lymphoid lineage cells varied significantly, notably elevated natural killer cells (NKs) in the BP-failed group. Moreover, we provide fruitful lists of biomarkers within the immune cells that exhibit condition-dependent differences. The existence of osteoporotic- and BP-failure-specific cellular information flows was revealed by cell-cell interaction analysis. These findings deepen our insight of the osteoporosis pathology enhancing comprehension of the role of immune heterogeneity in postmenopausal osteoporosis and BP treatment failure.

Mepolizumab improves sense of smell in severe chronic rhinosinusitis with nasal polyps: SYNAPSE

BACKGROUND

Loss of smell is one of the most bothersome and difficult-to-treat symptoms in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODOLOGY

SYNAPSE was a 52-week Phase III study of 4-weekly mepolizumab (100 mg subcutaneously) plus standard of care in adults with severe bilateral CRSwNP. This post hoc analysis assessed changes from baseline to study end in loss of smell visual analogue scale (VAS) symptom score, in patients stratified by several baseline clinical characteristics. SinoNasal Outcomes Test (SNOT)-22 sense of smell/taste item and University of Pennsylvania Smell Identification Test (UPSIT) scores were also assessed.

RESULTS

SYNAPSE enrolled 407 patients (mepolizumab=206; placebo=201) with impaired sense of smell at baseline. Improvements from baseline to study end in loss of smell VAS score were greater with mepolizumab versus placebo (treatment difference: -0.37) and most notable in patients with fewer or more recent prior surgeries (treatment difference: 1 vs 2 vs >2 prior surgeries,-1.29 vs -0.23 vs -0.07.

Two-year outcomes of radiofrequency device treatment of the nasal valve for nasal airway obstruction

BACKGROUND

Temperature-controlled radiofrequency (TCRF) device treatment of nasal valve dysfunction (NVD) was superior to a sham procedure control in reducing the symptoms of nasal airway obstruction (NAO) in this randomised controlled trial (RCT).

METHODOLOGY

Two-year outcomes for 108 patients actively treated in a prospective, multicenter, patient-blinded RCT were used to determine treatment effect durability and changes in medication/nasal dilator usage. A responder was defined as ≥20% reduction in NOSE score or ≥1 reduction in severity class.

RESULTS

The mean (SD) age of patients was 48.5 (12.3) years; 66 (61.1%) women. Baseline NOSE score was 76.3. The 2-year responder rate was 90.4% and NOSE score treatment effect was -41.7; 54.7% improvement. Of 57 patients using medications/nasal dilators at baseline, 45 (78.9%) either stopped all use (33.3%) or stopped/decreased (45.6%) use in ≥1 class at 2 years. Concurrent septal deviation, septal swell body, or turbinate enlargement did not significantly affect the odds of exhibiting a NOSE score of ≤25 at 2 years.

CONCLUSIONS

TCRF device treatment of NVD resulted in significant and sustained improvements in the symptoms of NAO at 2 years, accompanied by a substantial reduction in medication/nasal dilator use.

Comparison of nasal valve dysfunction treatment outcomes for temperature-controlled radiofrequency and functional rhinoplasty surgery: a systematic review and meta-analyses

BACKGROUND

Nasal valve dysfunction (NVD) is a substantial contributor to nasal airway obstruction. Minimally-invasive temp-erature-controlled radiofrequency (TCRF) treatment of the nasal valve is available and comparison with surgical techniques is warranted.

METHODOLOGY

Databases: Medline (PubMed), Embase, Cochrane Library.

POPULATION

adults with preprocedural nasal obstruction symptom evaluation (NOSE) score ≥45. Treatment effects were derived from a random effects model and reported as weighted mean difference in NOSE score between baseline; 3, 6, and 12 months postprocedure.

RESULTS

Of 2529 initial articles, 5 studies describing TCRF treatment and 63 studies describing functional rhinoplasty were included. Pooled effect sizes for TCRF treatment and functional rhinoplasty were comparable in all analyses.

CONCLUSIONS

TCRF treatment of the internal nasal valve for NVD was associated with sustained effects comparable to functional rhinoplasty addressing the nasal valve only, rhinoplasty without concomitant turbinate treatment, and all rhinoplasty.

Mepolizumab improves sense of smell in severe chronic rhinosinusitis with nasal polyps: SYNAPSE

BACKGROUND

Loss of smell is one of the most bothersome and difficult-to-treat symptoms in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODOLOGY

SYNAPSE was a 52-week Phase III study of 4-weekly mepolizumab (100 mg subcutaneously) plus standard of care in adults with severe bilateral CRSwNP. This post hoc analysis assessed changes from baseline to study end in loss of smell visual analogue scale (VAS) symptom score, in patients stratified by several baseline clinical characteristics. SinoNasal Outcomes Test (SNOT)-22 sense of smell/taste item and University of Pennsylvania Smell Identification Test (UPSIT) scores were also assessed.

RESULTS

SYNAPSE enrolled 407 patients (mepolizumab=206; placebo=201) with impaired sense of smell at baseline. Improvements from baseline to study end in loss of smell VAS score were greater with mepolizumab versus placebo (treatment difference: −0.37) and most notable in patients with fewer or more recent prior surgeries (treatment difference: 1 vs 2 vs more than 2 prior surgeries,−1.29 vs −0.23 vs −0.07; =3 years since last surgery, −0.89 vs 0.22). Approximately 25% of patients had baseline UPSIT scoresavailable; among those scoring =19 by study end. The SNOT-22 sense of smell/taste item score improved with mepolizumab versus placebo.

CONCLUSIONS

Mepolizumab treatment improved patients' perceived sense of smell, as measured by loss of smell VAS score and SNOT-22 sense of smell/taste item score in patients with severe refractory CRSwNP.

Comparison of nasal valve dysfunction treatment outcomes for temperature-controlled radiofrequency and functional rhinoplasty surgery: a systematic review and meta-analyses

BACKGROUND

Nasal valve dysfunction (NVD) is a substantial contributor to nasal airway obstruction. Minimally-invasive temp-erature-controlled radiofrequency (TCRF) treatment of the nasal valve is available and comparison with surgical techniques is warranted.

METHODOLOGY

Databases: Medline (PubMed), Embase, Cochrane Library.

POPULATION

adults with preprocedural nasal obstruction symptom evaluation (NOSE) score ≥45. Treatment effects were derived from a random effects model and reported as weighted mean difference in NOSE score between baseline; 3, 6, and 12 months postprocedure.

RESULTS

Of 2529 initial articles, 5 studies describing TCRF treatment and 63 studies describing functional rhinoplasty were included. Pooled effect sizes for TCRF treatment and functional rhinoplasty were comparable in all analyses.

CONCLUSIONS

TCRF treatment of the internal nasal valve for NVD was associated with sustained effects comparable to functional rhinoplasty addressing the nasal valve only, rhinoplasty without concomitant turbinate treatment, and all rhinoplasty.

RNF2 regulates Wnt/ß-catenin signaling via TCF7L1 destabilization

The Wnt signaling pathway is a crucial regulator of various biological processes, such as development and cancer. The downstream transcription factors in this pathway play a vital role in determining the threshold for signaling induction and the length of the response, which vary depending on the biological context. Among the four transcription factors involved in canonical Wnt/ß-catenin signaling, TCF7L1 is known to possess an inhibitory function; however, the underlying regulatory mechanism remains unclear. In this study, we identified the E3 ligase, RNF2, as a novel positive regulator of the Wnt pathway. Here, we demonstrate that RNF2 promotes the degradation of TCF7L1 through its ubiquitination upon activation of Wnt signaling. Loss-of-function studies have shown that RNF2 consistently destabilizes nuclear TCF7L1 and is required for proper Wnt target gene transcription in response to Wnt activation. Furthermore, our results revealed that RNF2 controls the threshold, persistence, and termination of Wnt signaling by regulating TCF7L1. Overall, our study sheds light on the previously unknown degradation mechanism of TCF7L1 by a specific E3 ligase, RNF2, and provides new insights into the variability in cellular responses to Wnt activation.

Probing strongly exchange coupled magnetic behaviors in soft/hard Ni/CoFe2O4 core/shell nanoparticles

Exchange coupling in a model core-shell system is demonstrated as a step on the path to 3d exchange spring magnets. Employing a model system of Ni@CoFe2O4, high quality core-shell nanoparticles were fabricated using a simple two-step method. The microstructural quality was validated using TEM, confirming a well-defined interface between the core and the shell. A strongly temperature dependent two-phase magnetic hysteresis loop was measured, wherein an analysis of step heights indicates coupling of roughly 50% between the core and the shell. Element-specific XMCD hysteresis confirms the presence of exchange coupling, suppressing the superparamagnetism of the Ni core at room temperature, and reaching a coercivity of >6 kOe at 80 K. These results provide a pathway to the development of heterostructured metal-oxide exchange coupled nanoparticles with improved maximum energy product.

Transmembrane protein 150b attenuates BMP signaling in the Xenopus organizer

The vertebrate organizer is a specified embryonic tissue that regulates dorsoventral patterning and axis formation. Although numerous cellular signaling pathways have been identified as regulators of the organizer's dynamic functions, the process remains incompletely understood, and as-yet unknown pathways remain to be explored for sophisticated mechanistic understanding of the vertebrate organizer. To identify new potential key factors of the organizer, we performed complementary DNA (cDNA) microarray screening using organizer-mimicking Xenopus laevis tissue. This analysis yielded a list of prospective organizer genes, and we determined the role of six-transmembrane domain containing transmembrane protein 150b (Tmem150b) in organizer function. Tmem150b was expressed in the organizer region and induced by Activin/Nodal signaling. In X. laevis, Tmem150b knockdown resulted in head defects and a shortened body axis. Moreover, Tmem150b negatively regulated bone morphogenetic protein (BMP) signaling, likely via physical interaction with activin receptor-like kinase 2 (ALK2). These findings demonstrated that Tmem150b functions as a novel membrane regulatory factor of BMP signaling with antagonistic effects, contributing to the understanding of regulatory molecular mechanisms of organizer axis function. Investigation of additional candidate genes identified in the cDNA microarray analysis could further delineate the genetic networks of the organizer during vertebrate embryogenesis.

Identification of protein phosphatase 4 catalytic subunit as a Wnt promoting factor in pan-cancer and Xenopus early embryogenesis

Protein Phosphatase 4 Catalytic Subunit (PPP4C) is an evolutionarily conserved protein involved in multiple biological and pathological events, including embryogenesis, organogenesis, cellular homeostasis, and oncogenesis. However, the detailed mechanisms underlying these processes remain largely unknown. Thus, we investigated the potential correlation between PPP4C and biological processes (BPs) and canonical Wnt signaling using pan-cancer analysis and Xenopus laevis (X. laevis) embryo model. Our results indicate that PPP4C is a potential biomarker for specific cancer types due to its high diagnostic accuracy and significant prognostic correlation. Furthermore, in multiple cancer types, PPP4C-related differentially expressed genes (DEGs) were significantly enriched in pattern specification, morphogenesis, and canonical Wnt activation. Consistently, perturbation of Ppp4c in X. laevis embryos interfered with normal embryogenesis and canonical Wnt responses. Moreover, biochemical analysis of X. laevis embryos demonstrated that both endogenous and exogenous Ppp4c negatively regulated AXIN1 (Wnt inhibitor) abundance. This study provides novel insights into PPP4C roles in pattern specification and Wnt activation. The similarities in BPs and Wnt signaling regulation regarding PPP4C support the intrinsic link between tumorigenesis and early embryogenesis.

EPOS/EUFOREA update on indication and evaluation of Biologics in Chronic Rhinosinusitis with Nasal Polyps 2023

Severe chronic rhinosinusitis with nasal polyps (CRSwNP) is a debilitating disease with a significant impact on the quality of life (QoL). It is typically characterized by a type 2 inflammatory reaction and by comorbidities such as asthma, allergies and NSAID-Exacerbated Respiratory Disease (N-ERD). Here, the European Forum for Research and Education in Allergy and Airway diseases discusses practical guidelines for patients on biologic treatment. Criteria for the selection of patients who would benefit from biologics were updated. Guidelines are proposed concerning the monitoring of the drug effects that provide recognition of responders to the therapy and, subsequently, the decision about continuation, switching or discontinuation of a biologic. Furthermore, gaps in the current knowledge and unmet needs were discussed.

The EUFOREA pocket guide for chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is known to affect around 5 % of the total population, with major impact on the quality of life of those severely affected (1). Despite a substantial burden on individuals, society and health economies, CRS often remains underdiagnosed, under-estimated and under-treated (2). International guidelines like the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) (3) and the International Consensus statement on Allergy and Rhinology: Rhinosinusitis 2021 (ICAR) (4) offer physicians insight into the recommended treatment options for CRS, with an overview of effective strategies and guidance of diagnosis and care throughout the disease journey of CRS.

Evaluating treatment response to mepolizumab in patients with severe CRSwNP

BACKGROUND

The SYNAPSE study (NCT03085797) demonstrated that mepolizumab decreased nasal polyp (NP) size and nasal obstruction in patients with chronic rhinosinusitis with NP (CRSwNP).

METHODS

SYNAPSE, a randomized, double-blind study, included patients with recurrent, refractory, severe CRSwNP, eligible for repeated surgery despite receiving standard of care (SoC). Patients received 4-weekly mepolizumab 100 mg or placebo subcutaneously plus SoC for 52 weeks. This post hoc analysis further characterized treatment responses and association with patient characteristics. The proportion of patients meeting any and each of five response criteria indicating improvement in disease-specific quality of life, NP size, nasal obstruction, loss of smell, and overall symptoms at Weeks 24 and 52, were assessed in subgroups: 1) no surgery; 2) neither surgery nor systemic corticosteroids (SCS).

RESULTS

Of 407 patients in the intention-to-treat population, 381 and 343 patients had no sinus surgery by Weeks 24 and 52, respectively. More mepolizumab- versus placebo-treated patients without surgery by Weeks 24 and 52 met each response criteria. Of the mepolizumab-treated patients without surgery by Week 24, 109 (55%) responded across ≥ 3 criteria, increasing to 126 (67%) by Week 52. Similar response trends were seen for patients with neither surgery nor SCS by Weeks 24 and 52. At either timepoint, there were no major differences in baseline characteristics between mepolizumab-treated full- (5/5 categories) and non-responders (0/5 categories).

CONCLUSIONS

Most patients who completed SYNAPSE required neither surgery nor SCS use and in addition achieved a progressive and sustained clinical response to mepolizumab underscoring the therapeutic benefits of mepolizumab in severe CRSwNP.

Prasugrel-based de-escalation vs. conventional therapy after percutaneous coronary intervention in ACS patients according to the renal function

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): A consortium of six companies in Korea (Daiichi Sankyo, Boston Scientific, Terumo, Biotronik, Qualitech Korea, and Dio).

Background

Patients with coronary artery disease and impaired renal function are at higher risk for both bleeding and ischemic adverse events after percutaneous coronary intervention (PCI).

Purpose

We assessed the efficacy and safety of a prasugrel based de-escalation strategy in patients with impaired renal function.

Methods

We conducted a post-hoc analysis of the HOST-REDUCE-POLYTECH-ACS study. Patients with available estimated glomerular filtration rate (eGFR) (n=2,311) were categorized into three groups. (high eGFR: ≥90 mL/min; intermediate eGFR: ≥60 and <90 mL/min; low eGFR: <60 mL/min). The endpoints were bleeding outcomes (Bleeding Academic Research Consortium type 2, or higher), ischemic outcomes (cardiovascular death, myocardial infarction, stent thrombosis, repeat revascularization, and ischemic stroke), and net adverse clinical events (all cause death, BARC 2 or greater bleeding, MI, stent thrombosis, repeat revascularization, and ischemic stroke) at 1 year follow-up. The hazard ratio (HR) and 95% Confidence interval (CI) were calculated from the multivariate Cox proportional hazard regression analysis. Covariates that were considered clinically meaningful were included. The probability risk ratio was obtained by dividing ischemic hazard function from the bleeding hazard function.

Results

With respect to net adverse clinical events, prasugrel de-escalation was beneficial regardless of baseline renal function (p for interaction = 0.508). The relative reduction in bleeding risk from prasugrel de-escalation was higher in the low eGFR group compared with that from both the intermediate and high eGFR groups (relative reduction: 64% [HR 0.36, 95% CI 0.15–0.83] vs. 50% [HR 0.50, 95% CI 0.28-0.90] and 52% [HR 0.48, 95% CI 0.21-1.13] for low, intermediate, and high eGFR groups, p for interaction=0.646). Ischemic risk from prasgurel de-escalation was not significant in all eGFR groups ([HR 1.18, 95% CI 0.47-2.98], [HR 0.95, 95% CI 0.53-1.69], and [HR 0.61, 95% CI 0.26-1.39)], respectively, p for interaction=0.119). The probability risk ratio was highest in low eGFR group (1.06 vs. 1.26 vs. 1.36, for high, intermediate, and low eGFR groups, respectively, p for trend<0.001), suggesting higher relative bleeding risk above ischemic risk. Within those randomized to the de-escalation strategy, the mean probability risk ratio was not significantly different according to renal function (0.89, vs. 0.84 vs. 0.80 respectively, p for trend = 0.053), which was in contrast to those randomized to the conventional strategy where the mean probability risk ratio increased significantly as renal function decreased (1.24 vs. 1.67 vs. 1.94 respectively, p for trend<0.001).

Conclusion

The beneficial effect of prasugrel-based de-escalation strategy was consistent regardless of the baseline renal function, which was mostly driven by a reduction in bleeding risk which was greatest in those with low eGFR.

[Analysis of current status and influencing factors of inflammatory factors among electrical workers in Hainan province]

Objective: To analyze the level and influence factors of inflammatory factors among electrical workers in Hainan Province. Methods: A total of 509 electrical workers were selected as the research subjects with random cluster sampling in September 2020. Basic information was collected by questionnaire, the serum IL-6, IL-8 and TNF-α levels of the subjects were detected by Luminex.Mann-Whitney U test and Kruskal-wallis H test were used for univariate analysis. Ordinal logistic regression analysis was used for potential influencing factors of the level of inflammatory factors. Results: The median concentrations of IL-6, IL-8 and TNF-α in serum were 2.78, 9.77 and 8.18 pg/ml. Compared with women, male was a risk factor for the increase of IL-6 levels (OR=1.80, 95%CI: 1.08~3.00, P=0.024) . Compared with 51-60 years old, 21-31 years old (OR=0.27, 95%CI: 0.18~0.42, P<0.001) , 31-41 years old (OR=0.27, 95%CI: 0.17~0.43, P<0.001) and 41-51 years old (OR=0.64, 95%CI: 0.41~0.99, P=0.043) were protective factors for the increase of IL-8 level. Compared with day shift workers, shift work was a risk factor for the increase of IL-8 level (OR=1.73, 95%CI: 1.21~2.48, P=0.003) . Compared with women, male was a risk factor for the increase of TNF-α levels (OR=2.87, 95%CI: 1.70~4.86, P<0.001) . Compared with workers who exposed to 7 or more occupational hazard factors, exposed to 1~3 (OR=0.53, 95%CI: 0.30~0.92, P=0.024) occupational hazard factors were protective factors for the increase of TNF-α levels. Conclusion: The level of inflammatory factors was related to sex, age, work system and occupational environment, which can provide basic data for follow-up research on occupational population.

Aspirin vs. Clopidogrel as a Chronic maintenance monotherapy after PCI in patients with high ischemic risk and high bleeding risk: Subgroup analysis of the HOST-EXAM trial

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

on behalf of the HOST-EXAM investigators

Background

The HOST-EXAM randomized clinical trial recently performed a comparison of clopidogrel monotherapy vs. aspirin monotherapy in patients requiring indefinite antiplatelet monotherapy after percutaneous coronary intervention (PCI). This study randomized 5,438 patients who maintained dual antiplatelet therapy without clinical events for 6–18 months after PCI with drug-eluting stents (DES) to receive a monotherapy agent of clopidogrel 75 mg once daily or aspirin 100 mg once daily for 24 months. During the 24-month follow-up, the primary outcome (a composite of all-cause death, non-fatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and Bleeding Academic Research Consortium (BARC) bleeding type 3 or greater) rate was significantly lower in the clopidogrel group (hazard ratio [HR] 0.73 [95% CI 0.59–0.90]; p = 0.0035). However, it is uncertain whether the beneficial effect of clopidogrel will be consistent in patients with high ischemic risk or those with high bleeding risk.

Methods

This is a post-hoc analysis of the HOST-EXAM trial. A high ischemic risk was defined as those who had at least 1 of the following procedural features: 3 vessels treated, ≥3 stents implanted, ≥3 lesions treated, bifurcation PCI, total stent length &gt;60 mm, or left main PCI. Patients with high bleeding risk were defined according to the Academic Research Consortium for High Bleeding Risk (ARC-HBR) criteria. The co-primary outcome were thrombotic endpoints (a composite of cardiac death, non-fatal myocardial infarction, ischemic stroke, readmission due to acute coronary syndrome, and definite or probable stent thrombosis) and bleeding endpoints (BARC type ≥2 bleeding events) at 24-month follow-up.

Results

 Among the total population, 22.1% had high ischemic risk and 21.4% had high bleeding risk. Complex PCI was not associated with a higher risk of thrombotic endpoints, nor bleeding endpoints. For patients with a high bleeding risk, these patients had a higher risk of both thrombotic endpoints (HR 1.545, 95% CI 0.141-2.092, p = 0.005) and bleeding endpoints (HR 3.418, 95% CI 2.413-4.840, p &lt; 0.001). The primary results focusing on the interaction between high ischemic risk, high bleeding and the antiplatelet regimen will be presented.

Conclusion

The current post-hoc analysis of the HOST-EXAM trial will evaluate the efficacy of clopidogrel monotherapy vs. aspirin monotherapy during the chronic maintenance period after PCI, in patients with high ischemic risk or those with high bleeding risk.

A novel index reflecting both anatomical and physiologic parameters in coronary artery disease, the FFR adjusted SYNTAX score (FaSs)

Background

Various physiology-based indices have been proposed to predict adverse clinical events in patients with coronary artery disease (CAD), such as the sum of three vessel-fractional flow reserve (3v-FFR), and the functional SYNTAX score (fSS). However, these values could not fully reflect the anatomical factors, which remains as a barrier for clinical application of these indices.

Purpose

To propose a novel index which can reflect both anatomical and physiologic features in CAD patients, and evaluate the additional predictive value for cardiovascular adverse events compared to previous indices.

Methods

For an index which can reflect both anatomical and physiologic features, we proposed the FFR adjusted SYNTAX score (FaSs). The FaSs is calculated by adding the product of the SYNTAX score and `1-FFR', for all three major coronary arteries. Among the 1136 patients who enrolled at 3V FFR-FRIENDS study, we investigated 866 patients, after excluding those who had missing variables. The 3v-FFR, fSS and FaSs were calculated, derived from the baseline FFR and SYNTAX score. Patients were divided into two groups according to the median value of each index. The primary endpoint was major adverse cardiac events (MACE, a composite of cardiac death, myocardial infarction and ischemia-driven revascularization) at 2 years follow-up.

Results

Among the total population, MACE occurred in 35 (4.04%) patients. Using the median value in a multivariable COX regression model, only FaSs was associated with an increased risk of MACE, (Hazard Ratio [HR] 5.256, 95% confidence interval [CI] 2.014–13.720), while 3v-FFR (HR 1.383, 95% CI 0.685–2.790) and fSS (HR 1.640, 95% CI 0.830–3.243) were not significantly associated with a higher risk of MACE. This was also observed in the Kaplan Meier survival curve analysis (log-rank p value: p&lt;0.001 for FaSs, 0.153 for 3v-FFR, and 0.061 for fSS; Figure 1) The sensitivity and specificity of the FaSs was 85.7% and 51.6%, which was higher compared to the 3v-FFR (62.9% and 49.3%, respectively) and fSS (57.1% and 58.5%, respectively). When these indices were combined with clinical risk factors (age, sex, hypertension, diabetes, hyperlipidemia, chronic renal failure, LVEF&lt;40%), FaSs was superior compared with 3v-FFR and fSS assessed in regards of the predictive accuracy for MACE (Figure 2).

Conclusion

The FaSs, which is a novel index calculated by a formula using the SYNTAX score and FFR, showed a superior predictive value for MACE compared to previous indices. Our results confirm the importance of considering both anatomical and physiologic parameters in evaluating the patient's risk for cardiovascular adverse outcomes.

Funding Acknowledgement

Type of funding sources: None.

Dupilumab reduces systemic corticosteroid use and sinonasal surgery rate in CRSwNP

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease with a high symptom burden and poor quality of life. Treatment options include recurrent surgeries and/or frequent systemic corticosteroids (SCS). Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2-mediated inflammation. We report results of pooled analyses from 2 randomised, double-blind, placebo-controlled phase 3 studies (SINUS 24 [NCT02912468]; SINUS-52 [NCT02898454]) to evaluate dupilumab effect versus placebo in adults with CRSwNP with/without SCS use and sinonasal surgery.

METHODOLOGY

SINUS-24 patients were randomised 1:1 to subcutaneous dupilumab 300 mg (n=143) or placebo (n=133) every 2 weeks (q2w) for 24 weeks. SINUS-52 patients were randomised 1:1:1 to 52 weeks of subcutaneous dupilumab 300 mg q2w (n=150), 24 weeks q2w followed by 28 weeks of dupilumab 300 mg every 4 weeks (n=145) or 52 weeks of placebo q2w (n=153).

RESULTS

Dupilumab reduced the number of patients undergoing sinonasal surgery (82.6%), the need for in-study SCS use (73.9%), and SCS courses (75.3%). Significant improvements were observed with dupilumab vs placebo regardless of prior sinonasal surgery or SCS use in nasal polyp, nasal congestion, Lund-MacKay, and Sinonasal Outcome Test (22-items) scores, and the University of Pennsylvania Smell Identification Test.

CONCLUSIONS

Dupilumab demonstrated significant improvements in disease signs and symptoms and reduced the need for sino-nasal surgery and SCS use versus placebo in patients with severe CRSwNP, regardless of SCS use in the previous 2 years, or prior sinonasal surgery.

Sclerostin inhibits Wnt signaling through tandem interaction with two LRP6 ectodomains

Low-density lipoprotein receptor-related protein 6 (LRP6) is a coreceptor of the β-catenin-dependent Wnt signaling pathway. The LRP6 ectodomain binds Wnt proteins, as well as Wnt inhibitors such as sclerostin (SOST), which negatively regulates Wnt signaling in osteocytes. Although LRP6 ectodomain 1 (E1) is known to interact with SOST, several unresolved questions remain, such as the reason why SOST binds to LRP6 E1E2 with higher affinity than to the E1 domain alone. Here, we present the crystal structure of the LRP6 E1E2–SOST complex with two interaction sites in tandem. The unexpected additional binding site was identified between the C-terminus of SOST and the LRP6 E2 domain. This interaction was confirmed by in vitro binding and cell-based signaling assays. Its functional significance was further demonstrated in vivo using Xenopus laevis embryos. Our results provide insights into the inhibitory mechanism of SOST on Wnt signaling.

The low-density lipoprotein receptor-related protein 6 (LRP6) is a co-receptor of the β-catenin-dependent Wnt signaling pathway and interacts with the Wnt inhibitor sclerostin (SOST). Here the authors present the crystal structure of SOST in complex with the LRP6 E1E2 ectodomain construct, which reveals that the SOST C-terminus binds to the LRP6 E2 domain, and further validate this binding site with in vitro and in vivo experiments.

The mechanistic insight of a specific interaction between 15d-Prostaglandin-J2 and eIF4A suggests an evolutionary conserved role across species

15-deoxy-delta 12,14-prostaglandin J2 (15d-PGJ2) is an anti-inflammatory/anti-neoplastic prostaglandin that functions through covalent binding to cysteine residues of various target proteins. We previously showed that 15d-PGJ2 mediated anti-inflammatory responses are dependent on the translational inhibition through its interaction with eIF4A (Kim et al., 2007). Binding of 15d-PGJ2 to eIF4A specifically blocks the interaction between eIF4G and eIF4A, which leads to the formation of stress granules (SGs), which then cluster mRNAs with inhibited translation. Here, we show that the binding between 15d-PGJ2 and eIF4A specifically blocks the interaction between the MIF4G domain of eIF4G and eIF4A. To reveal the mechanism of this interaction, we used computational simulation-based docking studies and identified that the carboxyl tail of 15d-PGJ2 could stabilize the binding of 15d-PGJ2 to eIF4A through arginine 295 of eIF4A, which is the first suggestion that the 15d-PGJ2 tail plays a physiological role. Interestingly, the putative 15d-PGJ2 binding site on eiF4A is conserved across many species, suggesting a biological role. Our data propose that studying 15d-PGJ2 and its targets may uncover new therapeutic approaches in anti-inflammatory drug discovery.

Comparative lipidomic profiling of the human commensal bacterium Propionibacterium acnes and its extracellular vesicles

Propionibacterium acnes is a lipophilic commensal bacterium mainly found on the skin and in the gastrointestinal tract. Pathophysiological effects of P. acnes have recently been reported not only in acne progression but in various diseases. As an emerging mode of bacterial communication, extracellular vesicles (EVs) have been demonstrated to conduct critical pathophysiological functions. To provide information on P. acnes lipid composition for the first time, we conducted a comparative lipidomic analysis of P. acnes and P. acnes EVs and identified 214 lipids with high confidence using triplicated liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses. P. acnes EVs contained substantially more PCs, DGs, PAs, PEs, LPAs, LPCs, and MGs than P. acnes, and contained fewer PSs, SO1Ps, SA1Ps, LPGs, LPIs, and LPSs. Distinctively, P. acnes EVs possessed a markedly reduced amount of TG. These findings will provide useful clues for understanding the biological and pathophysiological mechanisms of P. acnes and for clinical applications such as vaccine development, diagnostics and therapeutics.

March2 is required for head formation by mediating Dishevelled degradation in concert with Dapper1

Dishevelled (Dvl/Dsh) is a key scaffold protein that propagates Wnt signaling essential for embryogenesis and homeostasis. However, whether antagonism of Wnt signaling necessary for vertebrate head formation can be achieved through regulation of Dsh protein stability is unclear. Here we show that membrane-associated RING-CH2 (March2), a RING-type E3 ubiquitin ligase, antagonizes Wnt signaling by regulating the turnover of Dsh protein via ubiquitin-mediated lysosomal degradation in prospective head region of Xenopus. We further found that March2 acquires regional and functional specificities for head formation from the Dsh-interacting protein Dapper1 (Dpr1). Dpr1 stabilizes interaction between March2 and Dsh for mediating ubiquitination and subsequent degradation of Dsh protein only in the dorso-animal region of Xenopus embryo. These results suggest that March2 restricts cytosolic pools of Dsh protein and leads to subsequent limitation of Wnt signaling for the precise vertebrate head development.

Tbx2 regulates anterior neural specification by repressing FGF signaling pathway

During early embryogenesis, FGF signals regulate the antero-posterior (AP) patterning of the neural plate by promoting posterior cell fates. In particular, BMP signal-mediated attenuation of FGF pathway plays a critical role in the determination of the anterior neural region. Here we show that Tbx2, a T-box transcriptional repressor regulates anterior neural specification by suppressing FGF8 signaling pathway in Xenopus embryo. Tbx2 is expressed in the anterior edge of the neural plate in early neurulae. Overexpression and knockdown of Tbx2 induce expansion and reduction in the expression of anterior neural markers, respectively. It also suppresses FGF8-induced ERK phosphorylation and neural caudalization. Tbx2, which is a target gene of BMP signal, down-regulates FGF8 signaling by inhibiting the expression of Flrt3, a positive regulator of this pathway. We found that Tbx2 binds directly to the T-box element located in the promoter region of Flrt3 gene, thereby interfering with the activity of the promoter. Consistently, Tbx2 augmentation of anterior neural formation is inhibited by co-expression of Flrt3. Furthermore, disruption of the anterior-most structures such as eyes in Tbx2-depleted embryos can be rescued by inhibition of Flrt3 function or FGF signaling. Taken together, our results suggest that Tbx2 mediates BMP signal to down-regulate FGF signaling pathway by repressing Flrt3 expression for anterior tissue formation.

Interactions between Transmembrane Helices within Monomers of the Aquaporin AtPIP2;1 Play a Crucial Role in Tetramer Formation

Aquaporin (AQP) is a water channel protein found in various subcellular membranes of both prokaryotic and eukaryotic cells. The physiological functions of AQPs have been elucidated in many organisms. However, understanding their biogenesis remains elusive, particularly regarding how they assemble into tetramers. Here, we investigated the amino acid residues involved in the tetramer formation of the Arabidopsis plasma membrane AQP AtPIP2;1 using extensive amino acid substitution mutagenesis. The mutant proteins V41A/E44A, F51A/L52A, F87A/I91A, F92A/I93A, V95A/Y96A, and H216A/L217A, harboring alanine substitutions in the transmembrane (TM) helices of AtPIP2;1 polymerized into multiple oligomeric complexes with a variable number of subunits greater than four. Moreover, these mutant proteins failed to traffic to the plasma membrane, instead of accumulating in the endoplasmic reticulum (ER). Structure-based modeling revealed that these residues are largely involved in interactions between TM helices within monomers. These results suggest that inter-TM interactions occurring both within and between monomers play crucial roles in tetramer formation in the AtPIP2;1 complex. Moreover, the assembly of AtPIP2;1 tetramers is critical for their trafficking from the ER to the plasma membrane, as well as water permeability.

Abstract B12: March E3 ubiquitin ligase is required for head formation by mediating Dishevelled degradation during Xenopus development

Wnt signaling controls numerous biological events including vertebrate development, adult tissue homeostasis and organogenesis. In addition, dysregulation of Wnt itself or its downstream signaling components causes human birth defects and cancer. Dishevelled (Dvl) is a crucial scaffolding protein that exerts activation of Wnt signaling pathway. Recently, several Dvl-interacting proteins have been suggested to mediate the stability of Dvl. However, the molecular mechanisms by which Dvl undergoes degradation remain to be elucidated. Here we identify March, a RING domain-containing ubiquitin ligase, targeting Dvl protein and show that it regulates canonical Wnt signaling in Xenopus. During Xenopus embryogenesis, March transcripts were ubiquitously expressed. We intriguingly found that March depletion by microinjection of morpholino oligonucleotide caused defects in the anterior head formation, including loss of the forebrain, cement gland and eye structures. We also found that these defective phenotypes were caused by the Wnt antagonistic function of March in the head organizer region. Knockdown of March suppressed expression of head organizer genes Gsc, Chd and Otx2 at the dorsal marginal region of the gastrula embryo. Wnt reporter assay, western blot analysis measuring phosphorylation of LRP6 and activation of β-catenin, RT-PCR and axis duplication assay in Xenopus revealed that March inhibits canonical Wnt signaling pathway. Furthermore, we identified that March protein associates with Dvl and mediates its poly-ubiquitination for lysosomal degradation in Xenopus embryos. Taken together, these results suggest that March retains cytosolic pools of Dvl protein and leads subsequent limitation of Wnt signaling for vertebrate head development.

Citation Format: Hyeyoon Lee, Seong-Moon Cheong, Jin-Kwan Han. March E3 ubiquitin ligase is required for head formation by mediating Dishevelled degradation during Xenopus development. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr B12.

PLD1 regulates Xenopus convergent extension movements by mediating Frizzled7 endocytosis for Wnt/PCP signal activation

Phospholipase D (PLD) is involved in the regulation of receptor-associated signaling, cell movement, cell adhesion and endocytosis. However, its physiological role in vertebrate development remains poorly understood. In this study, we show that PLD1 is required for the convergent extension (CE) movements during Xenopus gastrulation by activating Wnt/PCP signaling. Xenopus PLD1 protein is specifically enriched in the dorsal region of Xenopus gastrula embryo and loss or gain-of-function of PLD1 induce defects in gastrulation and CE movements. These defective phenotypes are due to impaired regulation of Wnt/PCP signaling pathway. Biochemical and imaging analysis using Xenopus tissues reveal that PLD1 is required for Fz7 receptor endocytosis upon Wnt11 stimulation. Moreover, we show that Fz7 endocytosis depends on dynamin and regulation of GAP activity of dynamin by PLD1 via its PX domain is crucial for this process. Taken together, our results suggest that PLD1 acts as a new positive mediator of Wnt/PCP signaling by promoting Wnt11-induced Fz7 endocytosis for precise regulation of Xenopus CE movements.

Switching bipolar hepatic radiofrequency ablation using internally cooled wet electrodes: comparison with consecutive monopolar and switching monopolar modes

OBJECTIVE

To evaluate whether switching bipolar radiofrequency ablation (SB-RFA) using three internally cooled wet (ICW) electrodes can induce coagulations >5 cm in porcine livers with better efficiency than consecutive monopolar (CM) or switching monopolar (SM) modes.

METHODS

A total of 60 coagulations were made in 15 in vivo porcine livers using three 17-gauge ICW electrodes and a multichannel radiofrequency (RF) generator. RF energy (approximately 200 W) was applied in CM mode (Group A, n = 20) for 24 min, SM mode for 12 min (Group B, n = 20) or switching bipolar (SB) mode for 12 min (Group C, n = 20) in in vivo porcine livers. Thereafter, the delivered RFA energy, as well as the shape and dimension of coagulations were compared among the groups.

RESULTS

Spherical- or oval-shaped ablations were created in 30% (6/20), 85% (17/20) and 90% (18/20) of coagulations in the CM, SM and SB groups, respectively (p = 0.003). SB-RFA created ablations >5 cm in minimum diameter (Dmin) in 65% (13/20) of porcine livers, whereas SM- or CM-RFA created ablations >5 cm in only 25% (5/20) and 20% (4/20) of porcine livers, respectively (p = 0.03). The mean Dmin of coagulations was significantly larger in Group C than in Groups A and B (5.1 ± 0.9, 3.9 ± 1.2 and 4.4 ± 1.0 cm, respectively, p = 0.002) at a lower delivered RF energy level (76.8 ± 14.3, 120.9 ± 24.5 and 114.2 ± 18.3 kJ, respectively, p < 0.001).

CONCLUSION

SB-RFA using three ICW electrodes can create coagulations >5 cm in diameter with better efficiency than do SM- or CM-RFA.

ADVANCES IN KNOWLEDGE

SB-RFA can create large, regular ablation zones with better time-energy efficiency than do CM- or SM-RFA.

Inhibition of CYP4A reduces hepatic endoplasmic reticulum stress and features of diabetes in mice

BACKGROUND & AIMS

Endoplasmic reticulum (ER) stress is implicated in the development of type 2 diabetes mellitus. ER stress activates the unfolded protein response pathway, which contributes to apoptosis and insulin resistance. We investigated the roles of cytochrome P450 4A (CYP4A) in the regulation of hepatic ER stress, insulin resistance, and the development of diabetes in mice.

METHODS

We used mass spectrometry to compare levels of CYP450 proteins in livers from C57BL/6J and C57BL/KsJ-db/db (db/db) mice; findings were confirmed by immunoblot and real-time PCR analyses. To create a model of diet-induced diabetes, C57BL/6J mice were placed on high-fat diets. Mice were given intraperitoneal injections of an inhibitor (HET0016) or an inducer (clofibrate) of CYP4A, or tail injections of small hairpin RNAs against CYP4A messenger RNA; liver tissues were collected and analyzed for ER stress, insulin resistance, and apoptosis. The effect of HET0016 and CYP4A knockdown also were analyzed in HepG2 cells.

RESULTS

Levels of the CYP4A isoforms were highly up-regulated in livers of db/db mice compared with C57BL/6J mice. Inhibition of CYP4A in db/db and mice on high-fat diets reduced features of diabetes such as insulin hypersecretion, hepatic steatosis, and increased glucose tolerance. CYP4A inhibition reduced levels of ER stress, insulin resistance, and apoptosis in the livers of diabetic mice; it also restored hepatic functions. Inversely, induction of CYP4A accelerated ER stress, insulin resistance, and apoptosis in livers of db/db mice.

CONCLUSIONS

CYP4A proteins are up-regulated in livers of mice with genetically induced and diet-induced diabetes. Inhibition of CYP4A in mice reduces hepatic ER stress, apoptosis, insulin resistance, and steatosis. Strategies to reduce levels or activity of CYP4A proteins in liver might be developed for treatment of patients with type 2 diabetes.

Cholesterol selectively activates canonical Wnt signalling over non-canonical Wnt signalling

Wnt proteins control diverse biological processes through β-catenin-dependent canonical signalling and β-catenin-independent non-canonical signalling. The mechanisms by which these signalling pathways are differentially triggered and controlled are not fully understood. Dishevelled (Dvl) is a scaffold protein that serves as the branch point of these pathways. Here, we show that cholesterol selectively activates canonical Wnt signalling over non-canonical signalling under physiological conditions by specifically facilitating the membrane recruitment of the PDZ domain of Dvl and its interaction with other proteins. Single-molecule imaging analysis shows that cholesterol is enriched around the Wnt-activated Frizzled and low-density lipoprotein receptor-related protein 5/6 receptors and plays an essential role for Dvl-mediated formation and maintenance of the canonical Wnt signalling complex. Collectively, our results suggest a new regulatory role of cholesterol in Wnt signalling and a potential link between cellular cholesterol levels and the balance between canonical and non-canonical Wnt signalling activities.

Meteorin regulates mesendoderm development by enhancing nodal expression

During gastrulation, distinct lineage specification into three germ layers, the mesoderm, endoderm and ectoderm, occurs through an elaborate harmony between signaling molecules along the embryonic proximo-distal and anterior-posterior axes, and Nodal signaling plays a key role in the early embryonic development governing embryonic axis formation, mesoderm and endoderm specification, and left-right asymmetry determination. However, the mechanism by which Nodal expression is regulated is largely unknown. Here, we show that Meteorin regulates Nodal expression and is required for mesendoderm development. It is highly expressed in the inner cell mass of blastocysts and further in the epiblast and extra-embryonic ectoderm during gastrulation. Genetic ablation of the Meteorin gene resulted in early embryonic lethality, presumably due to impaired lineage allocation and subsequent cell accumulation. Embryoid body culture using Meteorin-null embryonic stem (ES) cells showed reduced Nodal expression and concomitant impairment of mesendoderm specification. Meteorin-null embryos displayed reduced levels of Nodal transcripts before the gastrulation stage, and impaired expression of Goosecoid, a definitive endoderm marker, during gastrulation, while the proximo-distal and anterior-posterior axes and primitive streak formation were preserved. Our results show that Meteorin is a novel regulator of Nodal transcription and is required to maintain sufficient Nodal levels for endoderm formation, thereby providing new insights in the regulation of mesendoderm allocation.

Role of Sp5 as an essential early regulator of neural crest specification in xenopus

BACKGROUND

The neural crest (NC) is a multipotent embryonic cell population, which is induced by an integration of secreted signals including BMP, Wnt, and FGF and, subsequently, NC cell fates are specified by a regulatory network of specific transcription factors. This study was undertaken to identify a role of Sp5 transcription factor in vertebrates.

RESULTS

Xenopus Sp5 is expressed in the prospective neural crest regions from gastrulation through the tadpole stages in early development. Knockdown of Sp5 caused severe defects in craniofacial cartilage, pigmentation, and dorsal fin. Gain- and loss-of-function of Sp5 led to up- and down-regulation of the expression of NC markers in the neural fold, respectively. In contrast, Sp5 had no effect on neural induction and patterning. Sp5 regulated the expression of neural plate border (NPB) specifiers, Msx1 and Pax3, and these regulatory factors recovered the expression of NC marker in the Sp5-deficient embryos. Depletion of Sp5 impaired NC induction by Wnt/β-catenin or FGF signal, whereas its co-expression rescued NC markers in embryos in which either signal was blocked.

CONCLUSIONS

These results suggest that Sp5 functions as a critical early factor in the genetic cascade to regulate NC induction downstream of Wnt and FGF pathways.

β-Arrestin 1 mediates non-canonical Wnt pathway to regulate convergent extension movements

β-Arrestins are multifaceted proteins that play critical roles in termination of G protein-coupled receptor (GPCR) signaling by inducing its desensitization and internalization as well as in facilitation of many intracellular signaling pathways. Here, we examine using Xenopus embryos whether β-arrestin 1 might act as a mediator of β-catenin-independent Wnt (non-canonical) signaling. Xenopus β-arrestin 1 (xβarr1) is expressed in the tissues undergoing extensive cell rearrangements in early development. Gain- and loss-of-function analyses of xβarr1 revealed that it regulates convergent extension (CE) movements of mesodermal tissue with no effect on cell fate specification. In addition, rescue experiments showed that xβarr1 controls CE movements downstream of Wnt11/Fz7 signal and via activation of RhoA and JNK. In line with this, xβarr1 associated with key Wnt components including Ryk, Fz, and Dishevelled. Furthermore, we found that xβarr1 could recover CE movements inhibited by xβarr2 knockdown or its endocytosis defective mutant. Overall, these results suggest that β-arrestin 1 and 2 share interchangeable endocytic activity to regulate CE movements downstream of the non-canonical Wnt pathway.

Dual-source, dual-energy multidetector CT for the evaluation of pancreatic tumours

OBJECTIVE

To investigate the potential diagnostic value of dual-energy CT (DECT) with virtual non-enhanced (VNE) and iodine-only images, and to determine the optimal mixed ratio of blended images for evaluation of pancreatic diseases.

METHODS

Multiphasic DECT was performed in 44 patients with focal pancreatic disease. DECT was used during the pancreatic and hepatic venous phases, and a peak kilovoltage of 120 kVp was used for both non-contrast phases. For qualitative analysis of the CT images, two radiologists assessed three image sets (VNE, iodine-only and blended images) in order to determine the acceptability of VNE in replacing true non-enhanced (TNE) images, the added value of iodine-only images and the preferred blending ratio. For quantitative analyses, the CT numbers and image noise of the pancreatic parenchyma, lesions, aorta and psoas muscle were measured. The contrast-to-noise ratio of the lesion was calculated on the pancreatic phase images. The effective radiation dose for DECT and TNE images was calculated. Statistical comparisons were made using the Friedman test, the Wilcoxon test, the paired t-test and repeated measures of analysis of variation with Bonferroni correction for multiple comparisons.

RESULTS

The level of acceptance of the VNE images in replacing TNE images was 90.9%. Regarding the iodine-only images, 50% of the cases were found to have an added value. The linear-blended images with a weighting factor of 0.5 were preferred.

CONCLUSIONS

DECT was able to provide high-quality VNE images that could replace TNE images and iodine-only images showing an added value. Blended images with a weighting factor of 0.5 were preferred by the reviewers.

Enhancement patterns of hepatocellular carcinomas on multiphasicmultidetector row CT: comparison with pathological differentiation

OBJECTIVE

The objective of this study was to determine the incidence of typical and atypical enhancement patterns of hepatocellular carcinomas (HCCs) on multiphasic multidetector row CT (MDCT) and to correlate the enhancement patterns and morphological image findings of HCC with the degree of tumour differentiation.

METHODS

MDCT images of 217 patients with 243 surgically proven HCCs were evaluated through consensus reading by two radiologists. Our MDCT protocol was composed of precontrast, arterial, portal and delayed phases. The reviewers analysed the CT images for degree of attenuation; relative timing of washout; presence of dysmorphic intratumoral vessels, aneurysms and necrosis; tumour size; tumour margin; presence of pseudocapsule; intratumoral heterogeneity; and determined enhancement pattern. The imaging features were correlated with tumour differentiation using Fisher's exact test or the χ(2) test.

RESULTS

Among 243 HCCs, 137 (56.4%) showed the typical enhancement pattern of HCC, which is arterial enhancement and washout on portal or equilibrium phase images. In the arterial phase, 190 of 243 (78.2%) HCCs showed hypervascularity, with approximately three quarters of poorly differentiated (PD) (34 of 45, 75.6%) and moderately differentiated (MD) HCCs (92 of 123, 74.8%) showing washout during the portal or delayed phases, vs only 50% of well-differentiated (WD) HCCs (11 of 22; p<0.048). The presence of intratumoral vessels and aneurysms, tumour necrosis, attenuation of precontrast, the relative timing of washout, intratumoral attenuation heterogeneity, tumour margin and tumour size were correlated with the pathological differentiation of HCCs (p<0.05).

CONCLUSION

A typical enhancement of HCCs on MDCT was not unusual (43.6%) and WD and PD HCCs account for most of the atypical enhancement patterns. Early washout favoured MD and PD HCCs rather than WD HCCs, whereas in our study the presence of intratumoral aneurysm was a highly specific finding for PD HCC.

Multiple-electrode radiofrequency ablations using Octopus® electrodes in an in vivo porcine liver model

OBJECTIVES

The objective of this study was to determine the in vivo efficacy of radiofrequency ablation (RFA) in porcine liver using Octopus® electrodes for creating a large coagulation compared with RFA using clustered electrodes.

METHODS

A total of 39 coagulations were created using a 200-W generator and clustered electrodes or Octopus electrodes during laparotomy in 19 pigs. Radiofrequency was applied to the livers using four protocols: (1) Group A-1, monopolar mode using a clustered electrode (n=11); (2) Group A-2, monopolar mode using an Octopus electrode (n=11); (3) Group B-1, consecutive monopolar mode using three, clustered electrodes (n=8); and (4) Group B-2, switching monopolar mode using two Octopus electrodes (n=9). The energy efficiency, shape, diameters (D) and volume (V) of the coagulation volume were compared in each of the two groups.

RESULTS

The mean maximum D and V of the coagulations in Group A-2 (4.7 cm and 33.1 cm(3), respectively) were significantly larger than those in Group A-1 (4.1 cm and 20.3 cm(3), respectively) (p<0.05). Furthermore, the mean minimum D, maximum D and V of the coagulations in Group B-2 were significantly larger than those in Group B-1, i.e. 5.3 vs 4.0 cm, 6.6 vs 4.9 cm and 66.9 vs 30.2 cm(3), respectively (p<0.05). The energy efficiencies were also significantly higher in Groups A-2 and B-2 than in Groups A-1 and B-1 (p<0.05).

CONCLUSION

The Octopus electrodes were more efficient for creating a large ablation zone than clustered electrodes, and the efficacy of RFA with Octopus electrodes can be amplified in the switching monopolar mode.

Dab2 is pivotal for endothelial cell migration by mediating VEGF expression in cancer cells

Although angiogenesis is crucial for tumor growth and metastasis, the molecular mechanisms controlling this process are not clearly understood. Here, we explore the role of Dab2 in tumor angiogenesis. We found that Dab2 is expressed in several cancer cells, including A549 lung cancer cells, but it is hardly detectable in SW480 colon cancer cells. Migration and Erk phosphorylation were enhanced in human umbilical vein endothelial cells (HUVECs) treated with the conditioned medium obtained from Dab2-overexpressing SW480 stable cells. In addition, vascular endothelial growth factor (VEGF) protein was strongly detected in conditioned medium derived from Dab2-overexpressing SW480 cells, and Erk phosphorylation enhanced by Dab2(+) CM was restored by VEGF inhibition. Moreover, Dab2 depletion in A549 cells led to a decrease in HUVEC migration and Erk phosphorylation. Furthermore, we show that Dab2 is required for the TGFβ-induced gene expression of angiogenic factors such as VEGF and FGF2. Taken together, these results suggest that Dab2, which is expressed in cancer cells, is pivotal for endothelial cell migration by affecting VEGF expression.

Small molecule-based disruption of the Axin/β-catenin protein complex regulates mesenchymal stem cell differentiation

The Wnt/β-catenin pathway plays important roles in the differentiation of multiple cell types, including mesenchymal stem cells. Using a cell-based chemical screening assay with a synthetic chemical library of 270 000 compounds, we identified the compound SKL2001 as a novel agonist of the Wnt/β-catenin pathway and uncovered its molecular mechanism of action. SKL2001 upregulated β-catenin responsive transcription by increasing the intracellular β-catenin protein level and inhibited the phosphorylation of β-catenin at residues Ser33/37/Thr41 and Ser45, which would mark it for proteasomal degradation, without affecting CK1 and GSK-3β enzyme activities. Biochemical analysis revealed that SKL2001 disrupted the Axin/β-catenin interaction, which is a critical step for CK1- and GSK-3β-mediated phosphorylation of β-catenin at Ser33/37/Thr41 and Ser45. The treatment of mesenchymal stem cells with SKL2001 promoted osteoblastogenesis and suppressed adipocyte differentiation, both of which were accompanied by the activation of Wnt/β-catenin pathway. Our findings provide a new strategy to regulate mesenchymal stem cell differentiation by modulation of the Wnt/β-catenin pathway.

Rab3d is required for Xenopus anterior neurulation by regulating Noggin secretion

Rab3d is a member of the Ras-related small GTPase family of secretory Rab, Rab3. In this study, we showed that Xenopus Rab3d is expressed specifically in the anterior border of the neural plate when the neural plate converges and folds to initiate neural tube formation. Morpholino-mediated knockdown of Rab3d resulted in neurulation defects both in neural plate convergence and folding. Interestingly, perturbation of BMP signaling rescued neurulation defects of Rab3d morphants, suggesting that Rab3d inhibits BMP signaling during neurulation. By secretion assay in the Xenopus animal cap, we found that Rab3d specifically regulates secretion of a BMP antagonist, Noggin, but not Chordin and Wnts. We also found that Rab3d is co-localized with Noggin and that this interaction is dependent on the GTP/GDP cycle of Rab3d. Collectively, these findings suggest that Rab3d-mediated secretion regulation of a BMP antagonist, Noggin, is one of the mechanisms of BMP antagonism during Xenopus anterior neurulation.

Role of Tbx2 in defining the territory of the pronephric nephron

Despite extensive study of the development of the nephron, which is the functional unit of the kidney, the molecular mechanisms underlying the determination of nephron size remain largely unknown. Using the Xenopus pronephros, we demonstrate here that Tbx2, a T-box transcriptional repressor, functions to demarcate the territory of the pronephric nephron. Tbx2 is specifically expressed around three distinct components of the pronephric nephron: the tubule, duct and glomus. Gain of function of Tbx2 inhibits nephric mesoderm formation. Conversely, Tbx2 loss of function expands the boundary of each component of the pronephric nephron, resulting in an enlarged pronephros. BMP signals induce Tbx2 in the non-nephric mesoderm, which inhibits the expression of the nephric markers Hey1 and Gremlin. Importantly, these pronephric molecules repress Tbx2 expression by antagonizing BMP signals in the nephric mesoderm. These results suggest that the negative regulatory loops between BMP/Tbx2 and Gremlin or Hey1 are responsible for defining the territory of the pronephric nephron.

Negative feedback regulation of Wnt signaling by Gbetagamma-mediated reduction of Dishevelled

Wnt signaling is known to be important for diverse embryonic and post-natal cellular events and be regulated by the proteins Dishevelled and Axin. Although Dishevelled is activated by Wnt and involved in signal transduction, it is not clear how Dishevelled-mediated signaling is turned off. We report that guanine nucleotide binding protein beta 2 (Gnb2; Gbeta2) bound to Axin and Gbeta2 inhibited Wnt mediated reporter activity. The inhibition involved reduction of the level of Dishevelled, and the Gbeta2gamma2 mediated reduction of Dishevelled was countered by increased expression of Axin. Consistent with these effects in HEK293T cells, injection of Gbeta2gamma2 into Xenopus embryos inhibited the formation of secondary axes induced either by XWnt8 or Dishevelled, but not by beta-catenin. The DEP domain of Dishevelled is necessary for both interaction with Gbeta2gamma2 and subsequent degradation of Dishevelled via the lysosomal pathway. Signaling induced by Gbeta2gamma2 is required because a mutant of Gbeta2, Gbeta2 (W332A) with lower signaling activity, had reduced ability to downregulate the level of Dishevelled. Activation of Wnt signaling by either of two methods, increased Frizzled signaling or transient transfection of Wnt, also led to increased degradation of Dishevelled and the induced Dishevelled loss is dependent on Gbeta1 and Gbeta2. Other studies with agents that interfere with PLC action and calcium signaling suggested that loss of Dishevelled is mediated through the following pathway: Wnt/Frizzled-->Gbetagamma-->PLC-->Ca(+2)/PKC signaling. Together the evidence suggests a novel negative feedback mechanism in which Gbeta2gamma2 inhibits Wnt signaling by degradation of Dishevelled.

XPteg (Xenopus proximal tubules-expressed gene) is essential for pronephric mesoderm specification and tubulogenesis

Retinoic acid (RA) signaling is important for the early steps of nephrogenic cell fate specification. Here, we report a novel target gene of RA signaling named XPteg (Xenopus proximal tubules-expressed gene) which is critical for pronephric development. XPteg starts to be expressed at the earliest stage of embryonic kidney specification and was restricted to the pronephric proximal tubules during kidney development. Anti-sense morpholino (MO)-mediated knockdown of XPteg perturbed formation of pronephros as demonstrated by reduced expression of pronephric tubule markers. Conversely, overexpression of XPteg promoted endogenous and ectopic expression of those markers and expanded pronephric tubules. Treatment of retinoic acid induced the expression of XPteg in the pronephric field without protein synthesis. Furthermore, we found that the pronephric defects caused by a dominant negative RA receptor could be rescued by coexpression of XPteg. Taken together, these results suggest that XPteg functions as a direct transcriptional target of RA signaling to regulate pronephric tubulogenesis in Xenopus early development.