AB1450 CHARACTERISTICS, OUTCOME AND FACTORS ASSOCIATED WITH EVOLUTION TO MULTIPLE MYELOMA AND SURVIVAL IN PATIENTS WITH SOLITARY BONE PLASMACYTOMA

Background

Solitary bone plasmacytoma (SPB) is a rare malignancy whose main risk is progression to multiple myeloma (MM).

Objectives

To describe the characteristics and outcome of patients treated for SBP and to identify factors associated with progression to MM and death.

Methods

This retrospective study was conducted between 1992 and 2020. Patients were included if they met the International Myeloma Working Group (IMWG) criteria for the diagnosis of SBP (1). Treatment response was assessed according to the IMWG criteria (2) for patients with detectable monoclonal protein and according to radiological response only for non-secretory SBP. Hazard ratios (HR) and their 95% confidence intervals (CI) were estimated by Cox proportional hazards models, adjusted for potential confounders. When available, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) were reviewed by two experienced nuclear physicians.

Results

A total of 77 patients diagnosed with SBP were included. The median age was 59 years [range: 27-89]. Median follow-up duration was 87.1 months [range: 1.6-306.8]. At the end of the follow-up, 45 (58.4%) patients had developed a MM and 13 (16.9%) deaths occurred, including 10 patients with progression to MM. Five-year myeloma-free survival and overall survival were 47.9% and 86.8% respectively. All patients received radiotherapy with a median dose of 45 Grays [range: 30-55]. Chemotherapy was prescribed in 32 (41.6%) patients, concomitant to radiotherapy in 8, because of high risk of local extension, or adjuvant in 24 because of persistent disease after radiotherapy. Chemotherapy included mainly immunomodulatory drugs (28/32 (87.5%)) and/or proteasome inhibitors (11/32 (34.4%)) based combinations. Adjuvant chemotherapy after radiotherapy was associated with a reduced risk of MM compared to patients treated by radiotherapy alone, in a multivariate model adjusted for potential confounding factors, including response after radiotherapy alone (adjuvant chemotherapy versus no chemotherapy, HR 0.30, 95%CI [0.14-0.64]). Response to the first line of treatment (radiotherapy +/- chemotherapy) was the main factor associated with progression to MM (complete response versus partial response or progressive disease, HR 0.25, 95%CI [0.11-0.59]) and death (HR 0.22, 95%CI [0.05-0.99]). A non-significant trend between bone marrow plasmacytosis ≥ 5% at diagnosis and higher risk of MM was observed (≥ 5% versus <5%, HR 2.40, 95%CI [1.00-5.74]). 18F-FDG PET/CT images were available for review in only 36/77 patients. A significant decrease of 18F-FDG uptake after treatment was observed whereas the lesion size was unchanged. No association was observed with the risk of MM but the limited available images may have resulted in underpowered analyses.

Conclusion

In this large study of patients with SBP, we observed that even though mostly prescribed for insufficient response to radiotherapy alone, treatment with adjuvant chemotherapy was associated with a decreased risk of evolution to MM, suggesting that this treatment might be systematically prescribed in addition to radiotherapy alone. These observations need to be confirmed and justify conduction of a prospective trial evaluating adjuvant chemotherapy in patients with SBP.

References

[1]Rajkumar SV, Dimopoulos MA, Palumbo A, Blade J, Merlini G, Mateos M-V, et al. International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma. Lancet Oncol. nov 2014;15(12):e538-548.

[2]Kumar S, Paiva B, Anderson KC, Durie B, Landgren O, Moreau P, et al. International Myeloma Working Group consensus criteria for response and minimal residual disease assessment in multiple myeloma. Lancet Oncol. août 2016;17(8):e328‑46.

Acknowledgements

The authors are indebted to all participants for their continued participation.

Disclosure of Interests

None declared

Team Interdependence as a Substitute for Empowering Leadership Contribution to Team Meaningfulness and Performance

This study uses a relational work design perspective to explore substitutes for leadership behaviors that promote team meaningfulness and performance. We propose that team task interdependence, a structural feature facilitating interaction among team members, can be a substitute for the contributions of empowering leadership. Data were collected from 47 R&D and technology implementation teams across three organizations in a cross-sectional field study. The results revealed that high task interdependence attenuated the contributions of empowering leadership concerning team meaningfulness and, indirectly, to team performance. These findings highlight that the importance of leaders as generators of team meaningfulness is contingent on team relational work design.

ETS1, ELK1, and ETV4 Transcription Factors Regulate Angiopoietin-1 Signaling and the Angiogenic Response in Endothelial Cells

Background

Angiopoietin-1 (Ang-1) is the main ligand of Tie-2 receptors. It promotes endothelial cell (EC) survival, migration, and differentiation. Little is known about the transcription factors (TFs) in ECs that are downstream from Tie-2 receptors.

Objective

The main objective of this study is to identify the roles of the ETS family of TFs in Ang-1 signaling and the angiogenic response.

Methods

In silico enrichment analyses that were designed to predict TF binding sites of the promotors of eighty-six Ang-1-upregulated genes showed significant enrichment of ETS1, ELK1, and ETV4 binding sites in ECs. Human umbilical vein endothelial cells (HUVECs) were exposed for different time periods to recombinant Ang-1 protein and mRNA levels of ETS1, ELK1, and ETV4 were measured with qPCR and intracellular localization of these transcription factors was assessed with immunofluorescence. Electrophoretic mobility shift assays and reporter assays were used to assess activation of ETS1, ELK1, and ETV4 in response to Ang-1 exposure. The functional roles of these TFs in Ang-1-induced endothelial cell survival, migration, differentiation, and gene regulation were evaluated by using a loss-of-function approach (transfection with siRNA oligos).

Results

Ang-1 exposure increased ETS1 mRNA levels but had no effect on ELK1 or ETV4 levels. Immunostaining revealed that in control ECs, ETS1 has nuclear localization whereas ELK1 and ETV4 are localized to the nucleus and the cytosol. Ang-1 exposure increased nuclear intensity of ETS1 protein and enhanced nuclear mobilization of ELK1 and ETV4. Selective siRNA knockdown of ETS1, ELK1, and ETV4 showed that these TFs are required for Ang-1-induced EC survival and differentiation of cells, while ETS1 and ETV4 are required for Ang-1-induced EC migration. Moreover, ETS1, ELK1, and ETV4 knockdown inhibited Ang-1-induced upregulation of thirteen, eight, and nine pro-angiogenesis genes, respectively.

Conclusion

We conclude that ETS1, ELK1, and ETV4 transcription factors play significant angiogenic roles in Ang-1 signaling in ECs.

P2733Prognostic value of cardiac dysautonomia in AL amyloidosis

Introduction

Cardiac involvement is the major prognostic factor in patients with light chain amyloidosis (AL). Cardiac dysautonomia can occur early in amyloidosis and can be assess by Iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy. Its prognostic value has been shown in TTR amyloidosis but is unknown in AL amyloidosis. We aimed to evaluate the prognosis impact of cardiac dysautonomia in patients with AL amyloidosis.

Methods

We carried out a prospective study in consecutive patients with biopsy-proven AL amyloidosis. All patients underwent clinical examination, EKG, echocardiography, cardiac MRI and biological tests. The 2012 Mayo clinic prognostic classification was calculated by using blood levels of NT-proBNP, cardiac T troponin and the differential of free light chains as recommended. The sympathetic cardiac innervation was assessed by using 123I-MIBGscintigraphy and measurement of the heart-to-mediastinum uptake ratio (late H/M) in the anterior view of the chest. A cardiac denervation was defined by late H/M <1.8 4h after injection of 3 MBq/kg of 123I-MIBG. The primary end-point was all-cause mortality during follow-up.

Results

Fifty consecutive patients with AL amyloidosis were included. The median age was 68 years old [58–73]. By using both echocardiography and MRI, cardiac involvement was diagnosed in 33 patients (66%) and thirteen of these patients were NYHA class III or IV. By using Mayo clinic classification, patients were I, II, III and IV classes in 9 (18%), 14 (28%), 16 (32%) and 11 (22%) cases respectively. According to echocardiographic data, the median wall thickness of left ventricle was 13 mm [12–15]. The late H/M was 1.51 [1.33–1.67]. Cardiac denervation was found in 44 patients (88%). The 6 patients (12%) with a normal late H/M had no cardiac amyloidosis involvement.

During a median follow-up of 24 months, 9 patients (18%) died. The area under the ROC curve of late H/M for predicting death was 0.74 (CI 95% 0.58–0.86). According to this curve, the best threshold was 1.44 and 7 of the 9 patients who died had late H/M ≤1.44. The figure shows the 2 year-survival according to late H/M. Late H/M ≤1.44 predicted all-cause death irrespective of the Mayo clinic classification: HR 8.0 (CI 95% 2.1–63) after adjustment on the Mayo clinic score (p=0.005). In addition, unplanned hospitalization for heart failure occurred in 8 patients with late H/M ≤1.44 versus 3 patients with late H/M >1.44 (p=0.03).

Survival according to late H/M

Conclusion

Late H/M ≤1.44 is predictive of adverse outcomes in patients with AL amyloidosis, independently of the Mayo Clinic prognostic classification.

Forced expression of microRNA-146b reduces TRAF6-dependent inflammation and improves ischemia-induced neovascularization in hypercholesterolemic conditions

BACKGROUND AND AIMS

MicroRNA (miR)-146 is a key regulator of inflammation, endothelial activation and atherosclerosis. This study sought to define its potential role for the modulation of ischemia-induced neovascularization in atherosclerotic conditions.

METHODS

Next generation sequencing and qRT-PCR analyses were used to compare microRNA expression in the ischemic muscles of hypercholesterolemic ApoE-deficient (ApoE^-/-) mice vs. wild type mice, and in HUVECs exposed or not to oxLDL. Neovascularization was investigated in a mouse model of hindlimb ischemia and the functional activities of HUVECs and pro-angiogenic cells (PACs) were assessed in vitro.

RESULTS

We found that miR-146b (but not miR-146a) is significantly reduced in the ischemic muscles of ApoE^-/- mice, and in HUVECs exposed to oxLDL. Inhibition of miR-146b reduces angiogenesis in vitro, whereas forced expression of miR-146b rescues oxLDL-mediated impairment of endothelial cell proliferation and tube formation. Mechanistically, miR146b directly targets tumor necrosis factor-alpha (TNFa) Receptor Associated Factor 6 (TRAF6) to inhibit inflammation. We found that hypercholesterolemia and oxLDL exposure are associated with higher levels of TRAF6, and increased expression of TNFa. However, forced expression of miR-146b in high cholesterol conditions reduces the expression of these inflammatory factors. In vivo, intramuscular injection of miR-146b mimic reduces ischemic damages and restores blood flow recuperation and capillary density in the ischemic muscles of ApoE^-/- mice. Treatment with miR-146b also increases the number and functional activities of pro-angiogenic cells (PACs).

CONCLUSIONS

Hypercholesterolemia is associated with reduced expression of miR-146b, which increases TRAF6-dependent inflammation and is associated with poor neovascularization in response to ischemia. Forced expression of miR-146b using a miR mimic could constitute a novel therapeutic strategy to improve ischemia-induced neovascularization in atherosclerotic conditions.

Negative regulation of angiogenesis by novel micro RNAs

Angiopoietin-1 (Ang-1) is a ligand of Tie-2 receptors that promotes survival, migration, and differentiation of endothelial cells (ECs). Recent studies have identified several microRNA (miRNA) families that either promote or inhibit angiogenesis. To date, the nature and functional importance of miRNAs in Ang-1-induced angiogenesis are unknown. Microarray screening of known miRNAs in human umbilical vein endothelial cells (HUVECs) revealed that the expressions of miR-103b, miR-330-5p, miR-557, miR-575, miR-1287-5p, and miR-1468-5p significantly decrease following exposure to Ang-1 for 24 h. Exposure to the angiogenesis factors angiopoietin-2 (Ang-2), vascular endothelial growth factor, fibroblast growth factor 2, and transforming growth factor β also inhibits miR-103b expression, but exerts varying effects on the other miRNAs. By overexpressing miR-103b, miR-330-5p, miR-557, miR-575, miR-1287-5p, and miR-1468-5p with selective mimics, we demonstrated that the pro-survival effects of Ang-1 are eliminated, Caspase-3 activity increases, and cell migration, proliferation, and capillary-like tube formation decreases. Conversely, transfection with selective miRNA inhibitors increases cell survival, inhibits Caspase-3 activity, and stimulates migration, proliferation and tube formation. miRNet miRNA-target gene network analyses revealed that miR-103, miR-330-5p, miR-557, miR-575, miR-1287-5p, and miR-1468-5p directly interact with 47, 95, 165, 108, 49, and 16 gene targets, respectively. Since many of these genes are positive regulators of angiogenic processes, we conclude that these miRNAs function as anti-angiogenic miRNAs and that their downregulation may be essential for Ang-1-induced angiogenesis to occur.

Effect of the KF post-deposition treatment on grain boundary properties in Cu(In, Ga)Se2 thin films

Significant power conversion efficiency improvements have recently been achieved for thin-film solar cells based on a variety of polycrystalline absorbers, including perovskites, CdTe, and Cu(In,Ga)Se₂ (CIGS). The passivation of grain boundaries (GBs) through (post-deposition) treatments is a crucial step for this success. For the case of CIGS, the introduction of a potassium fluoride post-deposition treatment (KF-PDT) has boosted their power conversion efficiency to the best performance of all polycrystalline solar cells. Direct and indirect effects of potassium at the interface and interface-near region in the CIGS layer are thought to be responsible for this improvement. Here, we show that also the electronic properties of the GBs are beneficially modified by the KF-PDT. We used Kelvin probe force microscopy to study the effect of the KF-PDT on the CIGS surface by spatially resolved imaging of the surface potential. We find a clear difference for the GB electronic properties: the KF-PDT increases the band bending at GBs by about 70% and results in a narrower distribution of work function values at the GBs. This effect of the KF-PDT on the GB electronic properties is expected to contribute to the improved efficiency values observed for CIGS thin-film solar cells with KF-PDT.

Evaluation of different buffer materials for solar cells with wide-gap Cu2ZnGeSxSe4−x absorbers

In this work kesterite-type Cu₂ZnGeS_xSe_4−x (CZGSSe) absorbers were coated with four different buffer layer materials: CdS, In₂S₃, Zn(O,S) and CdIn₂S₄.

Tele-rehabilitation service delivery journey from prototype to robust in-home use

PURPOSE

The purpose of this study is to present a retrospective study on clients with Acquired Brain Injury (ABI) enrolled in a tele-motion-rehabilitation service program for two or more months.

METHODS

Data from 82 clients (46 males; 74 with ABI), aged 22-85 years, are reported. The Kinect-based CogniMotion System (ReAbility Online, Gertner Institute, Tel Hashomer, Israel) provided services that included 30-min biweekly sessions. Participants were evaluated prior to and 2 months following the commencement of service with clinical assessments that measured movements and function of the weaker upper extremity and cognitive abilities.

RESULTS

Clients enrolled in the service had intact or mild cognitive impairment, mild-moderate motor impairment but little use of their weak upper extremity for daily activities. They were satisfied with the service and reported high levels of system usability. Post-intervention clinical assessments were performed on about half of the participants after 2 months; significant improvements in active movements of the weak upper extremity, shoulder flexion range of motion and in the Trail Making Test were found (p < 0.05).

CONCLUSIONS

The service appears to be feasible for people with ABI and effective in important clinical outcomes related to improvements in upper extremity function. Implications for Rehabilitation Tele-rehabilitation provided with Microsoft Kinect 3D sensor virtual reality tracking system is feasible for people with Acquired Brain Injury. People with Acquired Brain Injury in the chronic stage were satisfied with the tele-rehabilitation service and perceived it as beneficial to improve their motor and cognitive abilities The CogniMotion System service appears to be effective in important clinical outcomes related to improvements in upper extremity function.

Angiopoietin-1 inhibits toll-like receptor 4 signalling in cultured endothelial cells: role of miR-146b-5p

AIMS

Bacterial lipopolysaccharides (LPS) induce innate immune inflammatory responses in endothelial cells by activating toll-like receptor 4 (TLR4) signalling. Here, we investigate the effects of angiopoietin-1 (Ang-1) on LPS-induced TLR4 signalling and the role of the miR-146 family of micro RNAs in the effects of Ang-1 on TRL4 signalling.

METHODS AND RESULTS

Leucocyte adhesion to human umbilical vein endothelial cells (HUVECs) was detected using fluorescence microscopy. Adhesion molecule, pro-inflammatory cytokine, miR-146a, and miR-146b-5p expressions in HUVECs were quantified using real-time PCR. TLR4 signalling protein levels were measured using immunoblotting. Exposure of HUVECs to LPS for 4-6 h induces robust inflammatory responses, including enhanced leucocyte adhesion, up-regulation of adhesion molecule expression (VCAM1, ICAM1, E-SELECTIN), enhanced cytokine production (TNFα, IL1β, IL6, and IL8), and increased NFκB luciferase reporter activity. Addition of Ang-1 to the culture medium for 24 h prior to LPS exposure significantly attenuates these responses. Prolonged Ang-1 exposure significantly decreases IRAK1 and TRAF6 protein levels but has no effect on TLR4, MYD88, IRAK4, or TAK1 expressions. Ang-1 triggers significant up-regulation of miR-146b-5p levels but has no effect on miR-146a or miR-146b-3p expressions. Transfection of HUVECs with a miR-146b-5p mimic significantly attenuates LPS-induced inflammatory responses and IRAK1 and TRAF6 expressions. In HUVECs transfected with a miR-146b-5p inhibitor, Ang-1 has no effect on LPS-induced inflammatory responses or IRAK1 and TRAF6 expressions.

CONCLUSION

Ang-1 disrupts TLR4 signalling, resulting in inhibition of LPS-induced inflammatory responses in endothelial cells. This inhibition occurs through selective targeting of IRAK1 and TRAF6 proteins by miR-146b-5p.

Angiopoietin-1 enhances skeletal muscle regeneration in mice

Activation of muscle progenitor cell myogenesis and endothelial cell angiogenesis is critical for the recovery of skeletal muscle from injury. Angiopoietin-1 (Ang-1), a ligand of Tie-2 receptors, enhances angiogenesis and skeletal muscle satellite cell survival; however, its role in skeletal muscle regeneration after injury is unknown. We assessed the effects of Ang-1 on fiber regeneration, myogenesis, and angiogenesis in injured skeletal muscle (tibialis anterior, TA) in mice. We also assessed endogenous Ang-1 levels and localization in intact and injured TA muscles. TA fiber injury was triggered by cardiotoxin injection. Endogenous Ang-1 mRNA levels immediately decreased in response to cardiotoxin then increased during the 2 wk. Ang-1 protein was expressed in satellite cells, both in noninjured and recovering TA muscles. Positive Ang-1 staining was present in blood vessels but not in nerve fibers. Four days after the initiation of injury, injection of adenoviral Ang-1 into injured muscles resulted in significant increases in in situ TA muscle contractility, muscle fiber regeneration, and capillary density. In cultured human skeletal myoblasts, recombinant Ang-1 protein increased survival, proliferation, migration, and differentiation into myotubes. The latter effect was associated with significant upregulation of the expression of the myogenic regulatory factors MyoD and Myogenin and certain genes involved in cell cycle regulation. We conclude that Ang-1 strongly enhances skeletal muscle regeneration in response to fiber injury and that this effect is mediated through induction of the myogenesis program in muscle progenitor cells and the angiogenesis program in endothelial cells.

pix-1 controls early elongation in parallel with mel-11 and let-502 in Caenorhabditis elegans

Cell shape changes are crucial for metazoan development. During Caenorhabditis elegans embryogenesis, epidermal cell shape changes transform ovoid embryos into vermiform larvae. This process is divided into two phases: early and late elongation. Early elongation involves the contraction of filamentous actin bundles by phosphorylated non-muscle myosin in a subset of epidermal (hypodermal) cells. The genes controlling early elongation are associated with two parallel pathways. The first one involves the rho-1/RHOA-specific effector let-502/Rho-kinase and mel-11/myosin phosphatase regulatory subunit. The second pathway involves the CDC42/RAC-specific effector pak-1. Late elongation is driven by mechanotransduction in ventral and dorsal hypodermal cells in response to body-wall muscle contractions, and involves the CDC42/RAC-specific Guanine-nucleotide Exchange Factor (GEF) pix-1, the GTPase ced-10/RAC and pak-1.

In this study, pix-1 is shown to control early elongation in parallel with let-502/mel-11, as previously shown for pak-1. We show that pix-1, pak-1 and let-502 control the rate of elongation, and the antero-posterior morphology of the embryos. In particular, pix-1 and pak-1 are shown to control head, but not tail width, while let-502 controls both head and tail width. This suggests that let-502 function is required throughout the antero-posterior axis of the embryo during early elongation, while pix-1/pak-1 function may be mostly required in the anterior part of the embryo. Supporting this hypothesis we show that low pix-1 expression level in the dorsal-posterior hypodermal cells is required to ensure high elongation rate during early elongation.

Reactive oxygen species regulation of autophagy in skeletal muscles

OBJECTIVE

To evaluate the effects of physiological levels of mitochondrial-derived reactive oxygen species (ROS) on skeletal muscle autophagy, a proteolytic pathway designed to regulate contractile and myofilament homeostasis and to recycle long-lived proteins and damaged organelles.

RESULTS

Basal levels of autophagy and autophagy triggered by 1.5 to 4 h of acute nutrient deprivation, rapamycin treatment, or leucine deprivation were measured in differentiated C2C12 myotubes using long-lived protein degradation assays, LC3B lipidation, autophagy-related gene expression, and electron microscopy. Preincubation with the general antioxidants tempol (superoxide dismutase mimic) and N-acetyl cysteine (NAC) or the mitochondria-specific antioxidants mito-tempol and SS31 significantly decreased the rates of long-lived protein degradation and LC3B flux and blocked the induction of autophagy-related gene expression. Mitochondrial ROS levels significantly increased in response to acute nutrient deprivation and rapamycin treatment. Mito-tempol and tempol blocked this response. Antioxidants decreased AMP-activated protein kinase (AMPK) phosphorylation by 40% and significantly increased protein kinase B (AKT) phosphorylation, but exerted no effects on mTORC1-dependent ULK1 phosphorylation on Ser(555). NAC significantly decreased basal LC3B autophagic flux in skeletal muscles of mice.

INNOVATION

We report for the first time that endogenous ROS promote skeletal muscle autophagy at the basal level and in response to acute nutrient starvation and mTORC1 inhibition. We also report for the first time that mitochondrial-derived ROS promote skeletal muscle autophagy and that this effect is mediated, in part, through regulation of autophagosome initiation and AKT inhibition.

CONCLUSION

Mitochondrial-derived ROS promote skeletal muscle autophagy and this effect is mediated, in part, through activation of AMPK and inhibition of AKT.

Angiogenesis-related factors in skeletal muscles of COPD patients: roles of angiopoietin-2

The role of angiogenesis factors in skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD) is unknown. The first objective of this study was to assess various pro- and antiangiogenic factor and receptor expressions in the vastus lateralis muscles of control subjects and COPD patients. Preliminary inquiries revealed that angiopoietin-2 (ANGPT2) is overexpressed in limb muscles of COPD patients. ANGPT2 promotes skeletal satellite cell survival and differentiation. Factors that are involved in regulating muscle ANGPT2 production are unknown. The second objective of this study was to evaluate how oxidants and proinflammatory cytokines influence muscle-derived ANGPT2 expression. Angiogenic gene expressions in human vastus lateralis biopsies were quantified with low-density real-time PCR arrays. ANGPT2 mRNA expressions in cultured skeletal myoblasts were quantified in response to proinflammatory cytokine and H2O2 exposure. Ten proangiogenesis genes, including ANGPT2, were significantly upregulated in the vastus lateralis muscles of COPD patients. ANGPT2 mRNA levels correlated negatively with forced expiratory volume in 1 s and positively with muscle wasting. Immunoblotting confirmed that ANGPT2 protein levels were significantly greater in muscles of COPD patients compared with control subjects. ANGPT2 expression was induced by interferon-γ and -β and by hydrogen peroxide, but not by tumor necrosis factor. We conclude that upregulation of ANGPT2 expression in vastus lateralis muscles of COPD patients is likely due to oxidative stress and represents a positive adaptive response aimed at facilitating myogenesis and angiogenesis.

Angiopoietin-1 and vascular endothelial growth factor regulation of leukocyte adhesion to endothelial cells: role of nuclear receptor-77

OBJECTIVE

Vascular endothelial growth factor (VEGF) promotes leukocyte adhesion to endothelial cells (ECs). Angiopoietin-1 (Ang-1) inhibits this response. Nuclear receptor-77 (Nur77) is a proangiogenic nuclear receptor. In the present study, we assessed the influence of Ang-1 and VEGF on Nur77 expression in ECs, and evaluated its role in Ang-1/VEGF-mediated leukocyte adhesion.

METHODS AND RESULTS

Expression of Nur77 was evaluated with real-time polymerase chain reaction and immunoblotting. Adhesion of leukocytes to ECs was monitored with inverted microscopy. Nur77 expression or activity was inhibited using adenoviruses expressing dominant-negative form of Nur77, retroviruses expressing Nur77 in the antisense direction, and small interfering RNA oligos. Both Ang-1 and VEGF induce Nur77 expression, by >5- and 30-fold, respectively. When combined, Ang-1 potentiates VEGF-induced Nur77 expression. Ang-1 induces Nur77 through the phosphoinositide 3-kinase and extracellular signal-regulated protein kinase 1/2 pathways. VEGF induces Nur77 expression through the protein kinase D/histone deacetylase 7/myocyte enhancer factor 2 and extracellular signal-regulated protein kinase 1/2 pathways. VEGF induces nuclear factor-kappaB transcription factor, vascular cell adhesion molecule-1, and E-selectin expressions, and promotes leukocyte adhesion to ECs. Ang-1 inhibits these responses. This inhibitory effect of Ang-1 disappears when Nur77 expression is disrupted, restoring the inductive effects of VEGF on adhesion molecule expression, and increased leukocyte adhesion to ECs.

CONCLUSIONS

Nur77 promotes anti-inflammatory effects of Ang-1, and functions as a negative feedback inhibitor of VEGF-induced EC activation.

Inhibition of mammalian target of rapamycin augments lipopolysaccharide-induced lung injury and apoptosis

Acute lung injury during bacterial infection is associated with neutrophilic inflammation, epithelial cell apoptosis, and disruption of the alveolar-capillary barrier. TLR4 is required for lung injury in animals exposed to bacterial LPS and initiates proinflammatory responses in part via the transcription factor NF-κB. Ligation of TLR4 also initiates a proapoptotic response by activating IFN-β and STAT1-dependent genes. We recently demonstrated that mammalian target of rapamycin (mTOR), a key controller of cell growth and survival, can physically interact with STAT1 and suppress the induction of STAT1-dependent apoptosis genes. We therefore hypothesized that the mTOR inhibitor rapamycin would increase LPS-induced apoptosis and lung injury in vivo. Rapamycin increased lung injury and cellular apoptosis in C57BL/6J mice exposed to intratracheal LPS for 24 h. Rapamycin also augmented STAT1 activation, and the induction of STAT1-dependent genes that mediate cellular apoptosis (i.e., Fas, caspase-3). LPS-induced lung injury was attenuated in STAT1 knockout mice. In addition, LPS and IFN-β-induced apoptosis was absent in cultured cells lacking STAT1, and, unlike in wild-type cells, a permissive effect of rapamycin was not observed. In contrast to its effect on STAT1, rapamycin inhibited NF-κB activation in vivo and reduced selected markers of inflammation (i.e., neutrophils in the bronchoalveolar lavage fluid, TNF-α). Therefore, although it inhibits NF-κB and neutrophilic inflammation, rapamycin augments LPS-induced lung injury and apoptosis in a mechanism that involves STAT1 and the induction of STAT1-dependent apoptosis genes.

[Curing mental retardation: searching for balance]

Mental retardation (MR) occurs in 2 to 3 % of the general population and is still not therapeutically addressed. Milder forms of MR result from deficient synaptogenesis and/or impaired synaptic plasticity during childhood. These alterations would result from disequilibrium in signalling pathways regulating the balance between long term potentiation (LTP) and long term depression (LTD) in certain neurons such as hippocampus neurons. To provide mentally retarded children with increased cognitive abilities, novel experimental approaches are currently being developed to characterize signalling status associated with MR and to identify therapeutic targets that would restore lost equilibrium. Several studies also highlighted the major role played by molecular switches like kinases, phosphatases, small G proteins and their regulators in the coordination and integration of signalling pathways associated with synaptic plasticity. These proteins may therefore constitute promising therapeutic targets for a number of cognitive deficiencies.

Searching for signaling balance through the identification of genetic interactors of the Rab guanine-nucleotide dissociation inhibitor gdi-1

Background

The symptoms of numerous diseases result from genetic mutations that disrupt the homeostasis maintained by the appropriate integration of signaling gene activities. The relationships between signaling genes suggest avenues through which homeostasis can be restored and disease symptoms subsequently reduced. Specifically, disease symptoms caused by loss-of-function mutations in a particular gene may be reduced by concomitant perturbations in genes with antagonistic activities.

Methodology/Principal Findings

Here we use network-neighborhood analyses to predict genetic interactions in Caenorhabditis elegans towards mapping antagonisms and synergisms between genes in an animal model. Most of the predicted interactions are novel, and the experimental validation establishes that our approach provides a gain in accuracy compared to previous efforts. In particular, we identified genetic interactors of gdi-1, the orthologue of GDI1, a gene associated with mental retardation in human. Interestingly, some gdi-1 interactors have human orthologues with known neurological functions, and upon validation of the interactions in mammalian systems, these orthologues would be potential therapeutic targets for GDI1-associated neurological disorders. We also observed the conservation of a gdi-1 interaction between different cellular systems in C. elegans, suggesting the involvement of GDI1 in human muscle degeneration.

Conclusions/Significance

We developed a novel predictor of genetic interactions that may have the ability to significantly streamline the identification of therapeutic targets for monogenic disorders involving genes conserved between human and C. elegans.

Verbal short-term memory span in children: long-term modality dependent effects of intrauterine growth restriction

BACKGROUND

Recent reports showed that children born with intrauterine growth restriction (IUGR) are at greater risk of experiencing verbal short-term memory span (STM) deficits that may impede their learning capacities at school. It is still unknown whether these deficits are modality dependent.

METHODS

This long-term, prospective design study examined modality-dependent verbal STM functions in children who were diagnosed at birth with IUGR (n = 138) and a control group (n = 64). Their STM skills were evaluated individually at 9 years of age with four conditions of the Visual-Aural Digit Span Test (VADS; Koppitz, 1981): auditory-oral, auditory-written, visuospatial-oral and visuospatial-written. Cognitive competence was evaluated with the short form of the Wechsler Intelligence Scales for Children--revised (WISC-R95; Wechsler, 1998).

RESULTS

We found IUGR-related specific auditory-oral STM deficits (p < .036) in conjunction with two double dissociations: an auditory-visuospatial (p < .014) and an input-output processing distinction (p < .014). Cognitive competence had a significant effect on all four conditions; however, the effect of IUGR on the auditory-oral condition was not overridden by the effect of intelligence quotient (IQ).

CONCLUSIONS

Intrauterine growth restriction affects global competence and inter-modality processing, as well as distinct auditory input processing related to verbal STM functions. The findings support a long-term relationship between prenatal aberrant head growth and auditory verbal STM deficits by the end of the first decade of life. Empirical, clinical and educational implications are presented.

Tyrosine kinase B receptor and its activated neurotrophins in ovaries from human fetuses and adults

The signals initiating the growth of primordial follicles are unknown. Growth factors such as neurotrophin 4/5 (NT-4/5) and brain-derived neurotrophic factor (BDNF) may play a role in this process. To investigate the expression of NT-4/5 and BDNF and their receptor tyrosine kinase B (TrkB) in the early developing follicles, we fixed and froze 12 ovarian samples from adolescents/adults and 31 ovaries from human fetuses. The fixed samples were prepared for immunohistochemical staining for NT-4/5, BDNF and the TrkB receptor. Total RNA was extracted from the frozen ovarian samples, and the expression of NT-4/5, BDNF and the TrkB receptor (full length and two truncated isoforms) was investigated by RT-PCR. Products were resolved by 1% agarose gel electrophoresis and image analysis. Immunohistochemical staining revealed the expression of NT-4/5 and BDNF mainly in oocytes and, in a minority of samples, also in the granulosa cells (GCs); TrkB receptor was identified in oocytes and GCs. Transcripts of NT-4/5, BDNF and all forms of TrkB receptor were identified in the samples. To elucidate whether indeed NT-4/5 and BDNF are involved in growth initiation of human primordial follicles, they should be added to the culture medium.

Deficits in spatial orientation of children with intrauterine growth retardation

The spatial orientation of intrauterine growth retarded (IUGR) children versus age-matched controls was examined using two spatial tests. The first test was the radial arm maze (RAM), a navigational test frequently used in animal models. The second test was a subtest from the Kaufman assessment battery for children (K-ABC). The IUGR group comprised 28 children aged 6 years. The control group comprised 29 appropriate-for-gestational age children. The performance of the IUGR children was significantly inferior to controls in both tests. In the RAM test, the ratio between the correct entrances to the total entrances was significantly lower in the IUGR group than in the control group (P<0.001). In the K-ABC, the IUGR group could not perform as well as control children (P<0.001). These results suggest that spatial orientation in IUGR children is inferior to their age-matched controls, possibly contributing to their potential learning difficulties. The present results also suggest that the RAM can be potentially used to test spatial orientation of children at-risk.

The effect of intrauterine growth restriction on the development and health of children

The neurodevelopmental and cognitive outcome of long-term Intrauterine Growth Restriction (IUGR) has been followed up from pregnancy to school age at the Tel Aviv Child Development Centre.

Blood pressure values in children with intrauterine growth retardation

BACKGROUND

Low birth weight has been shown to be strongly related to hypertension in adult life.

OBJECTIVES

To determine whether blood pressure is higher in children with intrauterine growth retardation than in control subjects.

METHODS

Blood pressure was measured in 58 children aged 4-6 years with IUGR and in 58 age-matched controls. The control children, whose birth weight was appropriate for gestational age, were also matched for gestational age.

RESULTS

The children with IUGR had significantly higher mean values of systolic (P < 0.05) and diastolic blood pressures (P < 0.05) and mean arterial pressure (P < 0.05). Significant differences in blood pressure values were found between preterm IUGR (n = 21) and preterm controls (P < 0.05).

CONCLUSIONS

These data indicate that children with IUGR may be at higher risk of hypertension already in childhood.

Betalains--a new class of dietary cationized antioxidants

Antioxidant nutrients from fruits and vegetables are believed to be a class of compounds that exert their effects in humans by preventing oxidative processes which contribute to the onset of several degenerative diseases. This study found a new class of dietary cationized antioxidants in red beets (Beta vulgaris L.). These antioxidants are betalains, and the major one, betanin, is a betanidin 5-O-beta-glucoside. Linoleate peroxidation by cytochrome c was inhibited by betanin, betanidin, catechin, and alpha-tocopherol with IC(50) values of 0.4, 0.8, 1.2, and 5 microM, respectively. In addition, a relatively low concentration of betanin was found to inhibit lipid peroxidation of membranes or linoleate emulsion catalyzed by the "free iron" redox cycle, H(2)O(2)-activated metmyoglobin, or lipoxygenase. The IC(50) inhibition of H(2)O(2)-activated metmyoglobin catalysis of low-density lipoprotein oxidation by betanin was <2.5 microM and better than that of catechin. Betanin and betanidin at very small concentrations were found to inhibit lipid peroxidation and heme decomposition. During this reaction, betanidin was bleached completely, but betanin remained unchanged in its absorption. This difference seems to derive from differing mechanisms of protection by these two compounds. The high affinity of betanin and betanidin for membranes was demonstrated by determining the rate of migration of the compounds through a dialysis tube. Betanin bioavailability in humans was demonstrated with four volunteers who consumed 300 mL of red beet juice, containing 120 mg of the antioxidant. The betacyanins were absorbed from the gut and identified in urine after 2-4 h. The calculated amount of betacyanins found in the urine was 0.5-0.9% of that ingested. Red beet products used regularly in the diet may provide protection against certain oxidative stress-related disorders in humans.

Prognostic significance of hyperechogenic lesions in the basal ganglia and thalamus in neonates

Neonatal cranial ultrasonography at times reveals hyperechogenic lesions in the basal ganglia and thalamus. These lesions have been attributed to a wide variety of pathologic states, among them toxoplasmosis, rubella, cytomegalovirus, and herpes simplex (TORCH) infections, chromosomal abnormalities, and asphyxia. The clinical significance in terms of the neurodevelopmental outcome of this radiologic abnormality is unknown. We performed a developmental evaluation on 16 children aged 2 to 6 years in whom neonatal cranial ultrasonography had demonstrated hyperechogenic lesions in the basal ganglia or thalamus and had no other neurodevelopmental risk factors. There was no significant difference between the average Developmental Quotient of the target population and the normal population in regard to developmental status. We conclude that in our population, an isolated finding of hyperechogenic lesions in the basal ganglia is probably not a predictor of poor neurodevelopmental outcome.

Transient oromotor deficits in children with benign childhood epilepsy with central temporal spikes

PURPOSE

To describe transient oromotor deficits in benign childhood epilepsy with centrotemporal spikes (BCECTS), an idiopathic age-specific epileptic syndrome with a benign course.

METHODS

Five children with BCECTS and intermittent dysarthria and drooling not in the context of typical clinical seizures are presented.

RESULTS

The periods of oromotor deficits correlated with increased seizure frequency in all children. Concomitant EEGs that were recorded during periods of dysarthria in four of the children revealed focal electrographic seizures. The reported children did not differ from other patients with BCECTS in any other respect.

CONCLUSIONS

Transient oromotor dysfunction is a rare ictal phenomenon that occurs in children with BCECTS with no other unique clinical features.