bluuebunny/crossref_metadata_2025_split huggingface dataset:
A JNK-dependent switch determines the oncogenic or tumor suppressor activity of ILKs
Authors: Durbin A D , Somers G R , Forrester M , Hannigan G E , Malkin D 
Published: May 2017

Background: Integrin-linked kinase (ILK) is a potent intracellular kinase involved in the regulation of multiple proliferation and survival kinases, including protein kinase B/Akt, glycogen synthase kinase-3β (GSK3β) and extracellular signal-regulated kinases 1 and 2 (ERK1/2). Evidence suggests ILK is overexpressed and acts oncogenically in a wide variety of primary tumors and genetic models, resulting in induction of tumor cell proliferation, migration, adhesion and angiogenic behaviours. Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood. Histological subclassification of RMS yields two major variants, embryonal (ERMS) and alveolar (ARMS). ERMS, as well as multiple other tumors including breast and lung carcinoma, are commonly associated with loss of heterozygosity at 11p15.5, a region harboring the ILK locus.
Methods: We utilized cell culture and primary tumors to examine the expression and function of ILK.
Results: We demonstrate differential expression of ILK between ERMS and ARMS tumors in vitro and in vivo. RNAi to ILK induces potent gene silencing, with decreases in the phosphorylation of multiple ILK targets. ILK silencing induced inhibition of ARMS, and a contrasting potent stimulation of ERMS cell growth in survival and proliferation assays. These effects were reversed by adenoviral overexpression of ILK in multiple RMS and other tumor cell lines. Moreover, ILK silencing has multiple signaling effects, including induction of cell cycle progression through bmi-1and p16INK4a in ERMS with repression in ARMS, and phosphorylation of c-Jun NH2 terminal kinase (JNK) and c-Jun in ERMS and repression in ARMS cells. Coupling of JNK inhibition with ILK knockdown in ERMS cells inverted the ILK knockdown phenotype, resulting in a significant loss of cell proliferation.
Conclusions: Together, these data confirm the oncogenic role of ILK in alveolar rhabdomyosarcoma, and suggest a novel tumor-suppressive role for ILK signaling in embryonal rhabdomyosarcoma, mediated through the novel ILK target axis, JNK-c-Jun.
Targeted deletion of discoidin domain receptor 1 (Ddr1) decreases atherosclerosis, reduces inflammation and accelerates matrix accumulation in LDL receptor deficient mices
Authors: Franco Christopher , Hou Guangpei , Vogel Wolfgang , Bendeck Michelle 
Published: May 2017

Background: Collagens are abundant within the atherosclerotic plaque where they contribute to lesion volume, mechanical stability, and influence cellular behaviour. The discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase that binds multiple collagen subtypes, has been observed in atheromata of non-human primates, but its function during atherogenesis is unclear.
Methods: To examine the role of DDR1 during atherosclerotic plaque development, we generated Ddr1+/+;Ldlr-/- and Ddr1-/-;Ldlr-/- mice and fed them an atherogenic diet for 12 or 24 weeks.
Results: Targeted deletion of Ddr1 resulted in a 50-60% reduction in atherosclerotic lesion area in the descending aorta at both 12 and 24 weeks. Atherosclerotic plaques from Ddr1-/-;Ldlr-/- mice demonstrated a 49% decrease in the area occupied by macrophages at 12 weeks, however, plaque SMC content was unchanged. We also observed accelerated deposition of fibrillar collagen and elastin in Ddr1-/-;Ldlr-/- plaques with a 36% and 45% increase at 12 weeks, respectively. Ddr1-/-;Ldlr-/- mice also demonstrated an early reduction in situ gelatinolytic activity in lesions and gelatin zymography revealed reduced MMP-2 activity at 12 weeks. Finally, mRNA expression analysis of laser microdissected plaques demonstrated enhanced expression of type I collagen and elastin, and reduced collagenase expression at 12 weeks. Moreover, mRNA expression of both MCP-1 and VCAM-1 was reduced in Ddr1-/-;Ldlr-/- plaques suggesting a novel role for DDR1 in the regulation of vascular inflammation.
Conclusion: Our data support a role for DDR1 as a positive regulator of atherosclerosis; capable of influencing both inflammation and matrix turnover early in plaque development, and when inhibited can result in a persistent reduction in atherosclerosis.
A screen for suppressors of apoptosis identifies a novel gain of function mutation in drosphilia RAS1s
Authors: Gafuik C , Agapite J , Steller H 
Published: May 2017

Background: Apoptosis is a morphologically distinct, genetically programmed form of cell death that is evolutionarily highly conserved amongst multi-cellular eukaryotes. Correct regulation of apoptosis is critical for normal development and the prevention of diseases, such as cancer. Genetic analysis of invertebrate model organisms has proven invaluable for the identification and study of key molecules involved in apoptosis. In Drosophila, the proteins Reaper (Rpr), Head involution defective (Hid) and Grim induce cell death in a caspase dependent manner by inhibiting the anti-apoptotic function of diap1.
Methods: To further elucidate the molecular mechanisms underlying the control of apoptosis, we conducted a dominant modifier screen for genes that could suppress the strong eye ablation phenotype caused by expressing hid under the control of an eye-specific promoter.
Results: As previously reported, we identified several loss of function mutants in components of the EGFR/Ras/MAPK pathway that could dominantly suppress hid-induced apoptosis. These mutants proved to be alleles of either sprouty or gap1, two negative regulators of the RTK/Ras1 signaling. Here we report the identification and characterization of the first gain of function mutation in the Drosophila RAS1 gene.
Conclusions: Taken together, these findings provide a molecular paradigm for the anti-apoptotic function of ras oncogenes.
Golgi-bound Rab34 is a novel member of the secretory pathways
Authors: Goldenberg Neil M. , Grinstein Sergio , Silverman Mel 
Published: May 2017

Background: Golgi-localized Rab34 has been implicated in repositioning of lysosomes and activation of macropinocytosis.
Methods: Using HeLa cells we undertook a detailed investigation of Rab34 involvement in intracellular vesicle transport.
Results: Immunoelectron microscopy and immunocytochemistry confirmed that Rab34 is localized to the Golgi stack and that active Rab34 shifts lysosomes to the cell centre. Contrary to a previous report, we found that Rab34 is not concentrated at membrane ruffles and is not involved in macropinocytosis. Also, Rab34 induced repositioning of lysosomes does not affect transport of the mannose 6-phosphate receptor to endosomes. Most strikingly, HeLa cells depleted of Rab34 by transfection with dominant-negative Rab34, or following RNA interference, failed to transport the temperature-sensitive Vesicular Stomatitis Virus G-protein fused to GFP (VSVG-GFP) from the Golgi to the plasma membrane. Transfection with mouse Rab34 rescued this defect. Using endogenous MHC class I (MHC) as a marker, an endoglycosidase H resistance assay showed that ER to medial Golgi traffic remains intact in knock-down cells indicating that Rab34 specifically functions in post-Golgi transport. Further, brefeldin A treatment revealed that Rab34 acts at the Golgi, not the trans-Golgi network.
Conclusion: Collectively, these results define Rab34 as a novel member of the secretory pathway acting at the Golgi.
Relative value of plasma nitrotyrosine for predicting mortality in patients with coronary artery diseases
Authors: Heslop C L , Frohlich J J , Hill J S 
Published: May 2017

Background: Reactive oxygen species (ROS) mediate the signalling of chief inflammatory pathways throughout all stages of atherosclerosis from endothelial dysfunction to plaque rupture. Activated leukocytes within the atherosclerotic lesion produce ROS, causing local and systemic oxidative injury; however, contributions of ROS production to the clinical features atherosclerosis have not yet been clearly established. Markers of oxidative stress include nitrotyrosine (N-tyr), a post-translational modification generated by reactive nitrogen species. N-tyr is enriched in atherosclerotic lesions, where it activates interstitial metalloproteases, which destabilize the lesion and induce plaque rupture. Recent findings associate circulating N-tyr levels with CAD pathogenesis: N-tyr levels are elevated in patients with established CAD, increased by risk factors associated with atherosclerosis, and reduced by statin therapy. The value circulating N-tyr may have for predicting outcome in CAD patients has not yet been determined.
Study Design: We tested the hypothesis that elevated N-tyr predicts mortality in patients with coronary artery disease. Plasma levels of N-tyr were measured using an enzyme-linked immunoassay (Hycult) in a cohort of 619 patients with angiographic evidence of coronary artery disease. After a mean follow-up time of 8.5 years, cases of all-cause mortality (145 cases) and cardiovascular mortality (76 cases) were collected using BC Vital Statistics Agency. The relative value of plasma N-tyr for prediction of mortality was determined using Cox proportional hazards model with adjustment for the following covariates: age, sex, smoking status, hypertension, BMI, LDL-cholesterol, total:HDL-cholesterol, plasma c-reactive protein, personal or known family history of CAD, and reported use of lipid-lowering or antioxidant therapies.
Interpretation: Patients whose plasma N-tyr levels were above the cohort median (71.75 nmol/L) had an increased risk of mortality, however this increased risk did not reach conventional statistical significance after covariate adjustment [HR(CI):1.39(0.96-2.01) p=0.07]. No significant association was observed between N-tyr levels and risk of cardiovascular mortality. While this investigation did not reveal a strong association between elevated N-tyr levels and cardiovascular mortality, the trend for increased risk of all-cause mortality indicates that this marker of oxidative stress could be used to identify patients for whom oxidative processes contribute significantly to disease pathogenesis. Further studies are warranted to establish the clinical value of N-tyr and other oxidative stress biomarkers, with the ultimate goal of improving patient risk assessment, and monitoring primary and secondary cardiovascular risk-reduction strategies.
High affinity IL-2 receptor (CD25) expression among Chronic Lymphocytic leukemia (CLL) patients is independent of mutational status and ZAP-70 positivitys
Authors: Howell J M , Luider J , Wong H , Perrizolo M , Demetrick D , Auer I , Mansoor A 
Published: May 2017

Background: Recent studies have suggested promising roles for immunotherapy through CD40 ligand /IL-2 signaling pathway in CLL patients. Differential expression of the IL-2 receptor (IL-2 R) has been reported in CLL and other B-cell malignancies. Because CLL is divided into two distinct prognostic groups (based on the level of somatic hypermutation or alternatively on the presence or absence of ZAP-70), it is important to determine the correlation of IL-2 R expression with mutational status and/or ZAP-70 positivity in CLL for better patient group stratification in clinical trials.
Methods: In this study, 132 pts (82 M/50F; M: F 1.6) with an age range of 33-91 yrs (median 66 yrs) were included. Of these, 67/132 (51%) were found to be CD25+, 44/132 (33%) CD25- and 16% were CD25 dim (not further analyzed). In terms of ZAP positivity, 19/132 (14%) pts were ZAP-70+ and 113 (86%) were ZAP-70-.
Results: Mutational data (n=93) revealed 60/93 (65%) patients with SHM and 33/ 93 (35%) without. Correlation between ZAP-70+ and absence of SHM was highly significant (p< 0.0001), however, no statistically significant correlation was noted between CD25 expression and SHM (p= 0.331) or ZAP positivity (p= 0.785).
Conclusions: This data suggests that IL-2 R expression, although noted among a significant proportion of patients with B-CLL, is independent of somatic hypermutation or ZAP-70 expression. This observation will be important in evaluation of clinical efficacy of immunotherapy among CLL patients, and points to the existence of another mechanism for the presence of IL-2 R in these patients.

Abbreviations: B-CLL (B-cell Chronic Lymphocytic Leukemia), SHM (Somatic Hypermutation)
Modulation of NMDA receptors by prion proteins
Authors: Khosravani Houman , Zhang Yunfeng , Tsutsui Shigeki , Hameed Shahid , Hamid Jawed , Altier Christophe , Jirik Frank R. , Zamponi Gerald W. 
Published: May 2017

Background: The precise physiological function of endogenous cellular prion protein (PrPC) remains unclear. It has been shown that PrP-null mice exhibit reduced LTP and greater susceptability to seizure mortality in several in vivo (e.g. kainic acid) models of epilepsy. In addition, PrP-null mice exhibit greater exctitotoxic cell death in response to kainic acid exposure. Methods: In our study we investigated the synaptic properties of WT and PrP-null mice.
Results: Recordings in the CA1 layer of adult hippocampal slices showed that PrP-null mice exhibit a reduced threshold to evoked responses and no difference in paired-pulse facilitation relative to WT animals. In addition, greater excitability was observed in PrP-null slices in response to zero-Mg2+ induced seizure-like events. Recordings from mature hippocampal cultures showed slightly altered AMPA and GABAA miniature synaptic currents. NMDA mEPSCs were observed to be increased in amplitude and significantly prolonged in decay time. NMDA-evokved currents also exhibited markedly prolonged deactivation kinetics. This effect on evoked NMDA currents was reproduced in WT neurons by PrP-RNAi transfection, and eliminated by PrPC transfection into PrP-null neurons.
Conclusions: These data suggest enhanced NMDA activity in PrP-null neurons. Consistent with this finding, in vitro and in vivo excitotoxicity assays demonstrated increased neuronal cell death in PrP-null cultures and animals upon transient exposure to NMDA. The prolonged deactivation kinetics were most consistent with functional activity/augmentation of NR2D NMDA receptor subunits, and PrP coimmunoprecipiated with NR2D NMDA receptor subunits. This enhanced NMDA receptor function was paralleleld by increased excitotoxicy in Prp-null mice. Our findings demonstrate a novel functional role for PrP as a modulator of synaptic NMDA currents and attributes a neuroprotective function to PrP.
A genome-wide linkage scan for familial partial lipodystrophy susceptibility genes in a German kindreds
Authors: Lanktree M. , Robinson J. , Creider J. , Cao H. , Carter D. , Horsch D. , Hegele R. 
Published: May 2017

Background: In Dunnigan-type familial partial lipodystrophy (FPLD) patients are born with normal fat distribution, but subcutaneous fat from extremities and gluteal regions are lost during puberty. The abnormal fat distribution leads to the development of metabolic syndrome (MetS), a cluster of phenotypes including hyperglycemia, dyslipidemia, hypertension, and visceral obesity. The study of FPLD as a monogenic model of MetS may uncover genetic risk factors of the common MetS which affects ~30% of adult North Americans. Two molecular forms of FPLD have been identified including FPLD2, resulting from heterozygous mutations in the LMNA gene, and FPLD3, resulting from both heterozygous dominant negative and haploinsufficiency mutations in the PPARG gene. However, many patients with clinically diagnosed FPLD have no mutation in either LMNA or PPARG, suggesting the involvement of additional genes in FPLD etiology.
Methods: Here, we report the results of an Affymetrix 10K GeneChip microarray genome-wide linkage analysis study of a German kindred displaying the FPLD phenotype and no known lipodystrophy-causing mutations.
Results: The investigation identified three chromosomal loci, namely 1q, 3p, and 9q, with non-parametric logarithm of odds (NPL) scores >2.7. While not meeting the criteria for genome-wide significance, it is interesting to note that the 1q and 3p peaks contain the LMNA and PPARG genes respectively.
Conclusions: Three possible conclusions can be drawn from these results: 1) the peaks identified are spurious findings, 2) additional genes physically close to LMNA, PPARG, or within 9q, are involved in FPLD etiology, or 3) alternative disease causing mechanisms not identified by standard exon sequencing approaches, such as promoter mutations, alternative splicing, or epigenetics, are also responsible for FPLD.
Attention and grasping in Parkinson's disease: Effects of treatment and disease stages
Authors: Lu Cathy , Suchowersky Oksana , Kiss Zelma , Haffenden Angela M 
Published: May 2017

Objective: To compare the attentional resources devoted to reach-to-grasp movements at different stages of Parkinson’s disease (PD), on and off treatment, relative to intact controls.
Background: Reach-to-grasp movements are a critical component of activities of daily living. The grasping movements of patients with PD are characterized by a reliance on cues and visual feedback, not seen in the very automatic movements of intact controls (Azulay et al, 2006). PD patients appear to devote significant attentional resources to their movements; dual-task performance is a well-known area of difficulty for PD patients. To date, the role of attention in everyday reach-to-grasp movements has not been examined, though the implications for performance of activities of daily living are clearly considerable.
Methods: The performance of three patient groups [de novo (n=11); moderate (n=24); and surgical (STN DBS; n=14)] was compared with age matched controls (n=24) on a dual task paradigm involving grasping and a concurrent cognitive task designed to consume attention. Attentional resources were measured with standardized tests. Participants reached to grasp functional objects with handles (e.g. a comb). Handles were turned away from participants; an appropriate grasp was scored if they successfully picked up the object by the handle. Between and within group comparisons were made using ANOVA and t-tests.
Results: The control group and the de novo group not yet on medication displayed strong evidence of automaticity in their movements; when performing a challenging spatial imagery task, they made the same number of appropriate grasps as when they picked up the objects without a concurrent task. In contrast, for the moderate and the surgical groups, performing the concurrent task resulted in fewer appropriate grasps, and there was no improvement while on treatment (medication and stimulation, respectively). Only the surgical group showed decreased divided attention on standardized measures (>-0.7 SD below their normative group).
Conclusions: Grasping appears to shift from an automatic to an attention demanding process by the moderate stages of PD. This may be a coping mechanism designed to safely adapt to reduced motor function, or it may reflect pathology in the mechanisms underlying grasping movements.
References:
Azulay JP, Mesure S, and Blin O. 2006. J Neurol Sci, 248(1-2): 192-195.
Memory from one-trial training is resistant to extinction in Lymnaea Stagnaliss
Authors: Murias Kara , Amarell Martin , Lukowiak Ken 
Published: May 2017

Background: Memories that follow a traumatic event or extreme stress have been shown in some cases, to be particularly resistant to therapies meant to reduce their impact on patients. Two methods shown to decrease memories in laboratory tests are disruption after reactivation and extinction training. Newly formed memories undergo a period of stabilization, during which they are susceptible to amnesia treatments. Over a period of time memories become stabilized and can no longer be disrupted. However memories that are retrieved are returned to a labile state that must undergo a process of ‘reconsolidation’. Also, many memories can be occluded by ‘extinction training’, which consists of withholding the training stimulus in the training environment resulting in a new memory that overshadows the original training.
Methods and Results: Using the Lymnaea stagnalis model system we show that memories following an extreme aversive stimulus demonstrate resistance to manipulation by these methods. Lymnaea stagnalis are fresh-water pond snails that can breathe either cutaneously or aerially through an orifice (pneumostome). Snails can form a long-term memory (LTM) to suppress pneumostome opening after operant conditioning consisting of either multiple sessions of repeated tactile stimulation to the orifice area each time the snail attempts to open its pneumostome or a single applications of 25mM KCl stimulus contingent with pneumostome opening (one-trial training; 1TT). The LTM formed following one-trial training has many of the same characteristics as memory formed following repetitive tactile training. Specifically, both are dependent on new mRNA synthesis in the circuit that controls aerial respiration and both can be blocked by cooling immediately after training. However, we show that memories in Lymnaea that form after a single, highly aversive stimulus, unlike LTM after repetitive training, aren’t disrupted after reactivation. We also attempted to extinguish the 1TT memory by placing the snails in the training beaker and not applying the KCl stimulus when they opened their pneumostome. When repetitive training was employed, extinction sessions such as these resulted in naïve levels of aerial respiration i.e. occlusion of the operantly trained memory.
Conclusions: Therefore, memory after 1TT is more resistant to suppression by extinction training than memories formed after less aversive stimuli. Further research will attempt to determine the cellular mechanism that causes the memory to be particularly resilient.