bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of Chemical Diversity in Echinocandin Lipopeptide Antifungal Metabolites
Authors: Yue Qun , Chen Li , Zhang Xiaoling , Li Kuan , Sun Jingzu , Liu Xingzhong , An Zhiqiang , Bills Gerald F.
Published: May 2015

The echinocandins are a class of antifungal drugs that includes caspofungin, micafungin, and anidulafungin. Gene clusters encoding most of the structural complexity of the echinocandins provided a framework for hypotheses about the evolutionary history and chemical logic of echinocandin biosynthesis. Gene orthologs among echinocandin-producing fungi were identified. Pathway genes, including the nonribosomal peptide synthetases (NRPSs), were analyzed phylogenetically to address the hypothesis that these pathways represent descent from a common ancestor. The clusters share cooperative gene contents and linkages among the different strains. Individual pathway genes analyzed in the context of similar genes formed unique echinocandin-exclusive phylogenetic lineages. The echinocandin NRPSs, along with the NRPS from the
inp
gene cluster in
Aspergillus nidulans
and its orthologs, comprise a novel lineage among fungal NRPSs. NRPS adenylation domains from different species exhibited a one-to-one correspondence between modules and amino acid specificity that is consistent with models of tandem duplication and subfunctionalization. Pathway gene trees and Ascomycota phylogenies are congruent and consistent with the hypothesis that the echinocandin gene clusters have a common origin. The disjunct Eurotiomycete-Leotiomycete distribution appears to be consistent with a scenario of vertical descent accompanied by incomplete lineage sorting and loss of the clusters from most lineages of the
Ascomycota
. We present evidence for a single evolutionary origin of the echinocandin family of gene clusters and a progression of structural diversification in two fungal classes that diverged approximately 290 to 390 million years ago. Lineage-specific gene cluster evolution driven by selection of new chemotypes contributed to diversification of the molecular functionalities.
Using Concept Maps in Teaching Microbiology
Authors: Kaiser Gary E.
Published: May 2015

This article is intended for faculty teaching microbiology and other biological science courses, and is applicable to both the classroom and the laboratory.

Concept maps are graphical tools for presenting knowledge concepts and the relationship between these concepts in a graphical, hierarchical fashion. Cross-links are further used to illustrate the relationships between the various segments of the concept map.
An Eco-friendly, Scaled-down Gram Stain Protocol
Authors: Gyure Ruth A.
Published: May 2015

Currently, flushing large volumes of Gram stain reagents into sanitary sewage systems is no longer acceptable. These chemical wastes are highly regulated and must be collected, labeled, and disposed of in a responsible manner, usually by paying a commercial service to remove them to an authorized off-site facility. Such services are costly and, as expected, costs are proportional to volume of collected waste. This “old” method of Gram staining, even if effluent is collected, generates a high volume of liquid waste which is unnecessarily diluted with additional large volumes of water from the rinsing steps.

The purpose of using this scaled-down and eco-friendly protocol is to dramatically reduce the amount of liquid waste produced without sacrificing quality of results. This protocol is flexible, practical, and easy to implement. It does not require students to work at a bench sink, reduces user cost, and lowers environmental impact overall.
A Web-Based Comparative Genomics Tutorial for Investigating Microbial Genomes
Authors: STRONG MICHAEL , CASCIO DUILIO , EISENBERG DAVID
Published: May 2015

As the number of completely sequenced microbial genomes continues to rise at an impressive rate, it is important to prepare students with the skills necessary to investigate microorganisms at the genomic level. As a part of the core curriculum for first-year graduate students in the biological sciences, we have implemented a web-based tutorial to introduce students to the fields of comparative and functional genomics. The tutorial focuses on recent computational methods for identifying functionally linked genes and proteins on a genome-wide scale and was used to introduce students to the Rosetta Stone, Phylogenetic Profile, conserved Gene Neighbor, and Operon computational methods. Students learned to use a number of publicly available web servers and databases to identify functionally linked genes in the
Escherichia coli
genome, with emphasis on genome organization and operon structure. The overall effectiveness of the tutorial was assessed based on student evaluations and homework assignments. The tutorial is available to other educators at
http://www.doe-mbi.ucla.edu/~strong/m253.php
.
Intracellular Signalling Pathways Associated with the Glucose-Lowering Effect of St36 Electroacupuncture in Streptozotocin-Induced Diabetic Rats
Authors: Tzeng Chung-Yuh , Lee Yu-Chen , Ho Tin-Yun , Chen Ying-I , Hsu Tai-Hao , Lin Jaung-Geng , Lee Kuan-Rong , Chang Shih-Liang
Published: May 2015

Background and Aim

Previous animal studies have reported a glucose-lowering effect of electroacupuncture (EA) and suggested that the mechanisms are closely related to intracellular signalling pathways. The aim of this study was to screen for potential intracellular signalling pathways that are upregulated by EA at ST36 bilaterally in rats with diabetes mellitus (DM) using microarray analysis.

Methods

Streptozotocin (STZ)-induced diabetic rats were randomly assigned to experimental (EA, n=8) or control (non-EA, n=8) groups. Plasma glucose levels were measured at baseline and after 30 and 60 min, and microarray analysis was performed on samples of gastrocnemius muscle.

Results

Relative to baseline values, EA significantly reduced plasma levels of glucose at 30 and 60 min. The microarray pathway analysis showed that cell adhesion molecules and type 1 DM gene sets were both upregulated in EA versus non-EA groups (p<0.05).

Conclusions

Cell adhesion molecules might be related to the glucose-lowering effect induced by EA in rats with STZ-induced type 1 diabetes. Further research will be required to examine the involvement of related intracellular signalling pathways.
Electroacupuncture plus Metformin Lowers Glucose Levels and Facilitates Insulin Sensitivity by Activating Mapk in Steroid-Induced Insulin-Resistant Rats
Authors: Liao Hsien-Yin , Sun Mao-Feng , Lin Jaung-Geng , Chang Shih-Liang , Lee Yu-Chen
Published: May 2015

Background

Type 2 diabetes mellitus is the predominant form of diabetes. Although metformin is the preferred first-line drug for treatment of the disease, it is associated with a risk of secondary failure. Electroacupuncture (EA) can enhance insulin sensitivity and reduce blood glucose levels.

Objectives

To examine, in an animal study, whether EA combined with metformin (EA–metformin) results in a better glucose-lowering effect and greater insulin sensitivity than metformin alone in steroid-induced insulin-resistant rats.

Methods

Adult Wistar rats were injected with dexamethasone to induce diabetes and subsequently treated with EA plus metformin or metformin alone. Variations in plasma glucose, plasma insulin, and plasma free fatty acid levels were studied at the midpoint and end of the experimental course. Insulin receptor substrate 1 (IRS-1) and peroxisome proliferator-activated receptor γ (PPAR-γ), which are associated with glucose transporter type 4 (GLUT4) translocation, and mitogen-activated protein kinase (MAPK), which is related to GLUT4 activation, were measured after EA treatment.

Results

We found that EA–metformin resulted in a better glucose-lowering effect, greater insulin sensitivity, lower plasma free fatty acid levels and higher levels of MAPK than metformin alone (p<0.05). There were no significant differences between treatment groups in expression of IRS-1 or PPAR-γ.

Conclusions

The glucose-lowering effect and increased insulin sensitivity associated with EA–metformin administration is governed, at least in part, by its ability to stimulate the activation of GLUT4 via upregulation of MAPK expression.
Transcutaneous Electrical Acupuncture Stimulation as a Countermeasure against Cardiovascular Deconditioning during 4 days of Head-Down Bed Rest in Humans
Authors: Sun Jing , Li Xiaotao , Yang Changbin , Wang Yongchun , Shi Fei , Gao Yuan , Luan Qi , Zhu Yongsheng , Sun Xiqing
Published: May 2015

Objective

Spaceflight is associated with cardiovascular deregulation. However, the influence of microgravity on the cardiovascular system and its mechanisms and countermeasures remain unknown. Our previous studies have demonstrated that transcutaneous electrical acupuncture stimulation (TEAS) is effective in improving orthostatic tolerance (OT). The purpose of this study was to determine if TEAS treatment can attenuate cardiovascular deconditioning induced by a 4-day −6° head-down bed rest (HDBR).

Methods

Fourteen healthy male subjects were randomly allocated to a control group (control, n=6, 4 days HDBR without countermeasures) and a TEAS treatment group (TEAS, n=8, 4 days HDBR with TEAS at Neiguan (PC6) for 30 min each day for 4 consecutive days during HDBR). OT, plasma hormones, plasma volume and heart rate variability were assessed before and after HDBR. Cardiac function and cerebral blood flow were measured before, during and after HDBR.

Results

The data showed that TEAS treatment mitigated the decrease in OT that was observed in the control group and cardiac function, alleviated autonomic dysfunction, and partially prevented plasma volume reduction after HDBR. Angiotensin II and aldosterone were significantly increased by 129.3% and 133.3% after HDBR in the TEAS group (p<0.05).

Conclusions

These results indicate that 30 min of daily TEAS treatment at PC6 is partially effective in maintaining OT, probably due to increased plasma volume-regulating hormones and activation of the peripheral sympathetic nervous system. TEAS treatment appears effective at reducing cardiovascular deconditioning induced by HDBR for 4 days.

Trial Registration Number

NCT02300207.
Influence of renal complications on the efficacy and adverse events of tacrolimus combination therapy in patients with systemic lupus erythematosus (SLE) during a maintenance phase: a single-centre, prospective study
Authors: Ishii Sho , Miwa Yusuke , Otsuka Kumiko , Nishimi Shinichiro , Nishimi Airi , Saito Mayu , Miura Yoko , Oguro Nao , Tokunaga Takahiro , Takahashi Ryo , Kasama Tsuyoshi
Published: May 2015

Objectives

The study investigated whether renal complications affected the efficacy and safety of tacrolimus combination therapy in patients with systemic lupus erythematosus (SLE) during a maintenance phase.

Methods

Fifty-seven patients with SLE (A: 30 cases with renal complication, B: 27 cases without renal complications) were included. The presence of renal complications was defined as proteinuria ≥0.5 g/day and lupus nephritis on renal biopsy. Major outcome measures included SLE disease activity index (SLEDAI), steroid dose, serum anti-dsDNA Ab, C3 and creatinine (Cr) levels and estimated glomerular filtration rate (eGFR). The patient's background factors included age, gender, disease duration and ACE-I/angiotensin II receptor blocker and statin therapies. We compared these outcome measures pre treatment and after 1 year of treatment.

Results

The SLEDAI and serum C3 levels improved in both groups from pretreatment period to post-treatment period: from 7.2±5.0 to 2.8±2.3 in A and 6.4±3.8 to 2.4±2.2 in B, p<0.001, and from 65.9±24.6 to 77.7±18.2 mg/dL in A and 81.8±23.0 to 90.6±19.4 mg/dL in B, p=0.002, respectively. The anti-dsDNA antibody level was reduced, and the serum Cr and eGFR levels were slightly elevated. No patients developed end-stage renal failure that required artificial dialysis.

Conclusions

Tacrolimus combination therapy had additive beneficial effects on reduced proteinuria and increased serum C3 levels in patients with SLE with renal complications during a maintenance phase.
Initial experience with a new distal intermediate and aspiration catheter in the treatment of acute ischemic stroke: clinical safety and efficacy
Authors: Stampfl Sibylle , Kabbasch Christoph , Müller Marguerite , Mpotsaris Anastasios , Brockmann Marc , Liebig Thomas , Wiesmann Martin , Bendszus Martin , Möhlenbruch Markus A
Published: May 2015

Purpose

To describe our initial experience with the novel 5 F SOFIA (Soft Torqueable catheter Optimized For Intracranial Access) intermediate and aspiration catheter for endovascular treatment of patients with acute ischemic stroke.

Methods

A retrospective review was performed in three centers of prospectively collected data of all stroke patients who underwent endovascular therapy using the SOFIA catheter. Patients were enrolled between November 2013 and December 2014. The primary endpoint of the study was accessibility of the thrombus with the SOFIA catheter. As a secondary endpoint, the study assessed recanalization success (Thrombolysis In Cerebral Infarction (TICI) ≥2b). Clinical presentation on admission and discharge was also documented. In addition, catheter- and procedure-related complications (particularly thromboembolic complications) were recorded.

Results

The SOFIA catheter was used in 115 acute stroke procedures. In 110 cases (96%) the catheter could be advanced to the occlusion site. After mechanical thrombectomy, successful recanalization (TICI ≥2b) was documented in 86.9%. There were no complications related to positioning of the catheter. Distal thrombus migration into a new vascular territory occurred in three patients following thrombectomy with a stent retriever (2.6%). The mean NIH Stroke Scale (NIHSS) score on admission was 16.8±6 and at discharge the mean NIHSS score was 8.2±7.7. Sixteen patients died.

Conclusions

The SOFIA catheter is a safe and efficient catheter for endovascular stroke therapy.
Incidental findings on chest CT imaging are associated with increased COPD exacerbations and mortality
Authors: Jairam Pushpa M , van der Graaf Yolanda , Lammers Jan-Willem J , Mali Willem P Th M , de Jong Pim A
Published: May 2015

Background

This study aimed to evaluate whether incidental CT findings of emphysema, airway thickening and bronchiectasis, as seen on CT scans performed for other non-pulmonary clinical indications, are associated with future acute exacerbations of COPD resulting in hospitalisation or death.

Methods

This multicentre prospective case–cohort study comprised 6406 subjects who underwent routine diagnostic chest CT for non-pulmonary indications. Using a case–cohort approach, we visually graded CT scans from cases and a random sample of ∼10% of the baseline cohort (n=704) for emphysema severity (range 0–20), airway thickening (range 0–5) and bronchiectasis (range 0–5). We used weighted Cox proportional hazards analysis to assess the independent association between CT findings and hospitalisation or death due to COPD exacerbation.

Results

During a median follow-up of 4.4 years (maximum 5.2 years), 338 COPD events were identified. The risk of experiencing a future acute exacerbation of COPD resulting in hospitalisation or death was significantly increased in subjects with severe emphysema (score ≥7) and severe airway thickening (score ≥3). The respective HRs were 4.6 (95% CI 3.0 to 7.1) and 5.9 (95% CI 3.4 to 10.5). Severe bronchiectasis (score ≥3) was not significantly associated with increased risk of adverse events (HR 1.5; 95% CI 0.9 to 2.5).

Conclusions

Morphological correlates of COPD such as emphysema and airway thickening detected on CT scans obtained for other non-pulmonary indications are strong independent predictors of subsequent development of acute exacerbations of COPD resulting in hospitalisation or death.
Longitudinal shape irregularity of airway lumen assessed by CT in patients with bronchial asthma and COPD
Authors: Oguma Tsuyoshi , Hirai Toyohiro , Fukui Motonari , Tanabe Naoya , Marumo Satoshi , Nakamura Hajime , Ito Hisao , Sato Susumu , Niimi Akio , Ito Isao , Matsumoto Hisako , Muro Shigeo , Mishima Michiaki
Published: May 2015

Background

Airway remodelling in bronchial asthma (BA) and COPD has been quantitatively assessed by analysing the airway wall area and the luminal area on cross-sectional CT images. To date, there have been no reports on assessment of the longitudinal structure of the airway lumen.

Methods

Quantitative airway analysis using CT was performed on three groups consisting of 29 patients with BA, 58 patients with COPD and 59 healthy controls. To assess the longitudinal shape irregularity of the airway lumen, new quantitative CT parameters, validated by a phantom study, were established. The internal radii of imaginary inscribed spheres in the airway lumen were measured as a function of distance from the level of the carina to the fifth-order branches of the right posterior basal bronchus. The gaps of these radii from the regression line were calculated as parameters to reflect the longitudinal airway lumen shape irregularity. These new parameters were compared among the study groups as well as with the conventional parameters of airway wall thickening and luminal area.

Results

Longitudinal airway lumen shape irregularity was significantly greater in patients with COPD than in those with BA and healthy controls. Wall thickening was significantly greater, and luminal area smaller, in patients with BA than in those with COPD and healthy controls. These results were consistent even among the BA and COPD subgroups with similar airflow limitation.

Conclusions

The combination of cross-sectional and longitudinal airway structure analyses using CT images may suggest differences in the characteristics of airway remodelling between COPD and asthma.
Glacial dispersal of gahnite from the Izok Lake Zn-Cu-Pb-Ag VMS deposit, northern Canada
Authors: McClenaghan M.B. , Paulen R.C. , Layton-Matthews D. , Hicken A.K. , Averill S.A.
Published: May 2015

The Izok Lake Zn–Cu–Pb–Ag volcanogenic massive sulphide (VMS) deposit in the Arctic region of Canada is one of the largest undeveloped Zn–Cu VMS resources in North America. In 2009, the Geological Survey of Canada initiated a detailed glacial dispersal study of the deposit focused on documenting its associated indicator mineral and till geochemical signatures. Glacial dispersal from the deposit is fan-shaped and was formed by an older SW ice flow and younger NW ice flow phases. Till samples contain chalcopyrite, sphalerite, galena, and pyrite up to 1.3 km down-ice and gahnite at least 40 km down-ice. Gahnite (ZnAl
2
O
4
) is an ideal indicator mineral in till because of its visually distinctive bluish green colour combined with its high specific gravity (4–4.6) for recovery using density-based separation methods, moderate hardness (physical durability during glacial transport), chemical stability in oxidizing surficial environments (resistance to post-glacial weathering), and its occurrence in highly metamorphosed VMS deposits such as Izok Lake. Most gahnite grains in till down-ice are 0.25–0.5 mm in size. Coarser gahnite (0.5–2.0 mm) occurs only in till proximal to the deposit (<3 km down-ice) and thus is an indicator of proximity to a gahnite-bearing bedrock source. Ore (Cu, Pb, Zn, Ag) and pathfinder element (As, Cd, Bi, Hg, In, Sb, Sb, Tl) contents in the <0.063 mm fraction of till reflect glacial dispersal up to a maximum of 6 km down-ice. A 15–20 km till indicator mineral sample spacing is sufficient to detect a gahnite glacial dispersal train such as that from the Izok Lake VMS deposit.
Estimating barrier shale extent and optimizing well placement in heavy oil reservoirs
Authors: Lajevardi Saina , Babak Olena , Deutsch Clayton V.
Published: May 2015

Shale barriers within the bituminous oil sand deposits of the McMurray Formation have a detrimental effect on the steam-assisted gravity-drainage chamber growth and oil recovery. Typically, the non-net shale barrier lateral extents are too small to be detected with a few widely spaced delineation wells. The information on net reservoir and shale interval thicknesses collected from wells, along with a vertical indicator variogram, provide limited information about the horizontal extent and connectivity of these intervals. In this paper, a novel quantitative approach for predicting the lateral extents of the barriers, using thickness information provided by well log data, is proposed. The proposed approach is based on moments of inertia (MOI) applied to the shale objects to determine their effective size. The MOI calculation is aimed to simplify the almost infinite complexity of shale bodies into summary size parameters that can be readily understood and calibrated to production parameters. A case study is presented for optimal well placement accounting for uncertainty in the shale barrier sizes.
Myocardial ATP hydrolysis rates in vivo: a porcine model of pressure overload-induced hypertrophy
Authors: Xiong Qiang , Zhang Pengyuan , Guo Jing , Swingen Cory , Jang Albert , Zhang Jianyi
Published: May 2015

Left ventricular (LV) hypertrophy (LVH) and congestive heart failure are accompanied by changes in myocardial ATP metabolism. However, the rate of ATP hydrolysis cannot be measured in the in vivo heart with the conventional techniques. Here, we used a double-saturation phosphorous-31 magnetic resonance spectroscopy-magnetization saturation transfer protocol to monitor ATP hydrolysis rate in swine hearts as the hearts became hypertrophic in response to aortic banding (AOB). Animals that underwent AOB ( n = 22) were compared with animals that underwent sham surgery ( n = 8). AOB induced severe LVH (cardiac MRI). LV function (ejection fraction and systolic thickening fraction) declined significantly, accompanied by deferent levels of pericardial effusion, and wall stress increased in aorta banded animals at week 1 after AOB, suggesting acute heart failure, which recovered by week 8 when concentric LVH restored LV wall stresses. Severe LV dysfunction was accompanied by corresponding declines in myocardial bioenergetics (phosphocreatine-to-ATP ratio) and in the rate of ATP production via creatine kinase at week 1. For the first time, the same linear relationships of the rate increase of the constants of the ATP hydrolysis rate ( kATP→Pi) vs. the LV rate-pressure product increase during catecholamine stimulation were observed in vivo in both normal and LVH hearts. Collectively, these observations demonstrate that the double-saturation, phosphorous-31 magnetic resonance spectroscopy-magnetization saturation transfer protocol can accurately monitor myocardial ATP hydrolysis rate in the hearts of living animals. The severe reduction of LV chamber function during the acute phase of AOB is accompanied by the decrease of myocardial bioenergetic efficiency, which recovers as the compensated LVH restores the LV wall stresses.
Neural control of circulation and exercise: a translational approach disclosing interactions between central command, arterial baroreflex, and muscle metaboreflex
Authors: Michelini Lisete C. , O'Leary Donal S. , Raven Peter B. , Nóbrega Antonio C. L.
Published: May 2015

The last 100 years witnessed a rapid and progressive development of the body of knowledge concerning the neural control of the cardiovascular system in health and disease. The understanding of the complexity and the relevance of the neuroregulatory system continues to evolve and as a result raises new questions. The purpose of this review is to articulate results from studies involving experimental models in animals as well as in humans concerning the interaction between the neural mechanisms mediating the hemodynamic responses during exercise. The review describes the arterial baroreflex, the pivotal mechanism controlling mean arterial blood pressure and its fluctuations along with the two main activation mechanisms to exercise: central command (parallel activation of central somatomotor and autonomic descending pathways) and the muscle metaboreflex, the metabolic component of exercise pressor reflex (feedback from ergoreceptors within contracting skeletal muscles). In addition, the role of the cardiopulmonary baroreceptors in modulating the resetting of arterial baroreflex is identified, and the mechanisms in the central nervous system involved with the resetting of baroreflex function during dynamic exercise are also described. Approaching a very relevant clinical condition, the review also presents the concept that the impaired arterial baroreflex function is an integral component of the metaboreflex-mediated exaggerated sympathetic tone in subjects with heart failure. This increased sympathetic activity has a major role in causing the depressed ventricular function observed during submaximal dynamic exercise in these patients. The potential contribution of a metaboreflex arising from respiratory muscles is also considered.
Shear stress-induced mitochondrial biogenesis decreases the release of microparticles from endothelial cells
Authors: Kim Ji-Seok , Kim Boa , Lee Hojun , Thakkar Sunny , Babbitt Dianne M. , Eguchi Satoru , Brown Michael D. , Park Joon-Young
Published: May 2015

The concept of enhancing structural integrity of mitochondria has emerged as a novel therapeutic option for cardiovascular disease. Flow-induced increase in laminar shear stress is a potent physiological stimulant associated with exercise, which exerts atheroprotective effects in the vasculature. However, the effect of laminar shear stress on mitochondrial remodeling within the vascular endothelium and its related functional consequences remain largely unknown. Using in vitro and in vivo complementary studies, here, we report that aerobic exercise alleviates the release of endothelial microparticles in prehypertensive individuals and that these salutary effects are, in part, mediated by shear stress-induced mitochondrial biogenesis. Circulating levels of total (CD31+/CD42a−) and activated (CD62E+) microparticles released by endothelial cells were significantly decreased (∼40% for both) after a 6-mo supervised aerobic exercise training program in individuals with prehypertension. In cultured human endothelial cells, laminar shear stress reduced the release of endothelial microparticles, which was accompanied by an increase in mitochondrial biogenesis through a sirtuin 1 (SIRT1)-dependent mechanism. Resveratrol, a SIRT1 activator, treatment showed similar effects. SIRT1 knockdown using small-interfering RNA completely abolished the protective effect of shear stress. Disruption of mitochondrial integrity by either antimycin A or peroxisome proliferator-activated receptor-γ coactivator-1α small-interfering RNA significantly increased the number of total, and activated, released endothelial microparticles, and shear stress restored these back to basal levels. Collectively, these data demonstrate a critical role of endothelial mitochondrial integrity in preserving endothelial homeostasis. Moreover, prolonged laminar shear stress, which is systemically elevated during aerobic exercise in the vessel wall, mitigates endothelial dysfunction by promoting mitochondrial biogenesis.
Cyclic stretch stimulates mitochondrial reactive oxygen species and Nox4 signaling in pulmonary artery smooth muscle cells
Authors: Wedgwood Stephen , Lakshminrusimha Satyan , Schumacker Paul T. , Steinhorn Robin H.
Published: May 2015

This study was designed to determine whether cyclic stretch induces a persistent pulmonary hypertension of the newborn (PPHN) phenotype of increased NADPH oxidase (Nox) 4 signaling in control pulmonary artery smooth muscle cells (PASMC), and to identify the signal transduction molecules involved. To achieve this, PPHN was induced in lambs by antenatal ligation of the ductus arteriosus at 128 days gestation. After 9 days, lungs and PASMC were isolated from control (twin) and PPHN lambs. Control PASMC were exposed to cyclic stretch at 1 Hz and 15% elongation for 24 h. Stretch-induced Nox4 expression was attenuated by inhibition of mitochondrial complex III and NF-κB, and stretch-induced protein thiol oxidation was attenuated by Nox4 small interfering RNA and complex III inhibition. NF-κB activity was increased by stretch in a complex III-dependent fashion, and stretch-induced cyclin D1 expression was attenuated by complex III inhibition and Nox4 small interfering RNA. This is the first study to show that cyclic stretch increases Nox4 expression via mitochondrial complex III-induced activation of NF-κB in fetal PASMC, resulting in ROS signaling and increased cyclin D1 expression. Targeting these signaling molecules may attenuate pulmonary vascular remodeling associated with PPHN.
Longitudinal in vivo microcomputed tomography of mouse lungs: No evidence for radiotoxicity
Authors: Vande Velde Greetje , De Langhe Ellen , Poelmans Jennifer , Bruyndonckx Peter , d'Agostino Emiliano , Verbeken Erik , Bogaerts Ria , Lories Rik , Himmelreich Uwe
Published: May 2015

Before microcomputed tomography (micro-CT) can be exploited to its full potential for longitudinal monitoring of transgenic and experimental mouse models of lung diseases, radiotoxic side effects such as inflammation or fibrosis must be considered. We evaluated dose and potential radiotoxicity to the lungs for long-term respiratory-gated high-resolution micro-CT protocols. Free-breathing C57Bl/6 mice underwent four different retrospectively respiratory gated micro-CT imaging schedules of repeated scans during 5 or 12 wk, followed by ex vivo micro-CT and detailed histological and biochemical assessment of lung damage. Radiation exposure, dose, and absorbed dose were determined by ionization chamber, thermoluminescent dosimeter measurements and Monte Carlo calculations. Despite the relatively large radiation dose delivered per micro-CT acquisition, mice did not show any signs of radiation-induced lung damage or fibrosis when scanned weekly during 5 and up to 12 wk. Doubling the scanning frequency and once tripling the radiation dose as to mimic the instant repetition of a failed scan also stayed without detectable toxicity after 5 wk of scanning. Histological analyses confirmed the absence of radiotoxic damage to the lungs, thereby demonstrating that long-term monitoring of mouse lungs using high-resolution micro-CT is safe. This opens perspectives for longitudinal monitoring of (transgenic) mouse models of lung diseases and therapeutic response on an individual basis with high spatial and temporal resolution, without concerns for radiation toxicity that could potentially influence the readout of micro-CT-derived lung biomarkers. This work further supports the introduction of micro-CT for routine use in the preclinical pulmonary research field where postmortem histological approaches are still the gold standard.
Airway epithelial cell PPARγ modulates cigarette smoke-induced chemokine expression and emphysema susceptibility in mice
Authors: Solleti Siva Kumar , Simon Dawn M. , Srisuma Sorachai , Arikan Meltem C. , Bhattacharya Soumyaroop , Rangasamy Tirumalai , Bijli Kaiser M. , Rahman Arshad , Crossno Joseph T. , Shapiro Steven D. , Mariani Thomas J.
Published: May 2015

Chronic obstructive pulmonary disease (COPD) is a highly prevalent, chronic inflammatory lung disease with limited existing therapeutic options. While modulation of peroxisome proliferator-activating receptor (PPAR)-γ activity can modify inflammatory responses in several models of lung injury, the relevance of the PPARG pathway in COPD pathogenesis has not been previously explored. Mice lacking Pparg specifically in airway epithelial cells displayed increased susceptibility to chronic cigarette smoke (CS)-induced emphysema, with excessive macrophage accumulation associated with increased expression of chemokines, Ccl5, Cxcl10, and Cxcl15. Conversely, treatment of mice with a pharmacological PPARγ activator attenuated Cxcl10 and Cxcl15 expression and macrophage accumulation in response to CS. In vitro, CS increased lung epithelial cell chemokine expression in a PPARγ activation-dependent fashion. The ability of PPARγ to regulate CS-induced chemokine expression in vitro was not specifically associated with peroxisome proliferator response element (PPRE)-mediated transactivation activity but was correlated with PPARγ-mediated transrepression of NF-κB activity. Pharmacological or genetic activation of PPARγ activity abrogated CS-dependent induction of NF-κB activity. Regulation of NF-κB activity involved direct PPARγ-NF-κB interaction and PPARγ-mediated effects on IKK activation, IκBα degradation, and nuclear translocation of p65. Our data indicate that PPARG represents a disease-relevant pathophysiological and pharmacological target in COPD. Its activation state likely contributes to NF-κB-dependent, CS-induced chemokine-mediated regulation of inflammatory cell accumulation.
Minor Changes in Expression of the Mismatch Repair Protein MSH2 Exert a Major Impact on Glioblastoma Response to Temozolomide
Authors: McFaline-Figueroa José L. , Braun Christian J. , Stanciu Monica , Nagel Zachary D. , Mazzucato Patrizia , Sangaraju Dewakar , Cerniauskas Edvinas , Barford Kelly , Vargas Amanda , Chen Yimin , Tretyakova Natalia , Lees Jacqueline A. , Hemann Michael T. , White Forest M. , Samson Leona D.
Published: May 2015

Glioblastoma (GBM) is often treated with the cytotoxic drug temozolomide, but the disease inevitably recurs in a drug-resistant form after initial treatment. Here, we report that in GBM cells, even a modest decrease in the mismatch repair (MMR) components MSH2 and MSH6 have profound effects on temozolomide sensitivity. RNAi-mediated attenuation of MSH2 and MSH6 showed that such modest decreases provided an unexpectedly strong mechanism of temozolomide resistance. In a mouse xenograft model of human GBM, small changes in MSH2 were sufficient to suppress temozolomide-induced tumor regression. Using The Cancer Genome Atlas to analyze mRNA expression patterns in tumors from temozolomide-treated GBM patients, we found that MSH2 transcripts in primary GBM could predict patient responses to initial temozolomide therapy. In recurrent disease, the absence of microsatellite instability (the standard marker for MMR deficiency) suggests a lack of involvement of MMR in the resistant phenotype of recurrent disease. However, more recent studies reveal that decreased MMR protein levels occur often in recurrent GBM. In accordance with our findings, these reported decreases may constitute a mechanism by which GBM evades temozolomide sensitivity while maintaining microsatellite stability. Overall, our results highlight the powerful effects of MSH2 attenuation as a potent mediator of temozolomide resistance and argue that MMR activity offers a predictive marker for initial therapeutic response to temozolomide treatment. Cancer Res; 75(15); 3127–38. ©2015 AACR.
Does It MEK a Difference? Understanding Immune Effects of Targeted Therapy
Authors: Cooper Zachary A. , Reuben Alexandre , Austin-Breneman Jacob , Wargo Jennifer A.
Published: May 2015

BRAF inhibitor (BRAFi) treatment enhances antitumor immunity, but is associated with increased intratumoral PD-L1 expression. MEK inhibitors (MEKi) may alter T-cell function; however, recent studies demonstrate preserved T-cell infiltrate during treatment with BRAFi/MEKi. These data have important implications for combining BRAFi/MEKi and checkpoint blockade in the treatment of melanoma. Clin Cancer Res; 21(14); 3102–4. ©2015 AACR.

See related article by Kakavand et al., p. 3140
The TMPRSS2–ERG Gene Fusion Blocks XRCC4-Mediated Nonhomologous End-Joining Repair and Radiosensitizes Prostate Cancer Cells to PARP Inhibition
Authors: Chatterjee Payel , Choudhary Gaurav S. , Alswillah Turkeyah , Xiong Xiahui , Heston Warren D. , Magi-Galluzzi Cristina , Zhang Junran , Klein Eric A. , Almasan Alexandru
Published: May 2015

Exposure to genotoxic agents, such as ionizing radiation (IR), produces DNA damage, leading to DNA double-strand breaks (DSB); IR toxicity is augmented when the DNA repair is impaired. We reported that radiosensitization by a PARP inhibitor (PARPi) was highly prominent in prostate cancer cells expressing the TMPRSS2–ERG gene fusion protein. Here, we show that TMPRSS2–ERG blocks nonhomologous end-joining (NHEJ) DNA repair by inhibiting DNA-PKcs. VCaP cells, which harbor TMPRSS2–ERG and PC3 cells that stably express it, displayed γH2AX and 53BP1 foci constitutively, indicating persistent DNA damage that was absent if TMPRSS2–ERG was depleted by siRNA in VCaP cells. The extent of DNA damage was enhanced and associated with TMPRSS2–ERG's ability to inhibit DNA-PKcs function, as indicated by its own phosphorylation (Thr2609, Ser2056) and that of its substrate, Ser1778-53BP1. DNA-PKcs deficiency caused by TMPRSS2–ERG destabilized critical NHEJ components on chromatin. Thus, XRCC4 was not recruited to chromatin, with retention of other NHEJ core factors being reduced. DNA-PKcs autophosphorylation was restored to the level of parental cells when TMPRSS2–ERG was depleted by siRNA. Following IR, TMPRSS2–ERG-expressing PC3 cells had elevated Rad51 foci and homologous recombination (HR) activity, indicating that HR compensated for defective NHEJ in these cells, hence addressing why TMPRSS2–ERG alone did not lead to radiosensitization. However, the presence of TMPRSS2–ERG, by inhibiting NHEJ DNA repair, enhanced PARPi-mediated radiosensitization. IR in combination with PARPi resulted in enhanced DNA damage in TMPRSS2–ERG-expressing cells. Therefore, by inhibiting NHEJ, TMPRSS2–ERG provides a synthetic lethal interaction with PARPi in prostate cancer patients expressing TMPRSS2–ERG. Mol Cancer Ther; 14(8); 1896–906. ©2015 AACR.
Structure-Based Screen Identifies a Potent Small Molecule Inhibitor of Stat5a/b with Therapeutic Potential for Prostate Cancer and Chronic Myeloid Leukemia
Authors: Liao Zhiyong , Gu Lei , Vergalli Jenny , Mariani Samanta A. , De Dominici Marco , Lokareddy Ravi K. , Dagvadorj Ayush , Purushottamachar Puranik , McCue Peter A. , Trabulsi Edouard , Lallas Costas D. , Gupta Shilpa , Ellsworth Elyse , Blackmon Shauna , Ertel Adam , Fortina Paolo , Leiby Benjamin , Xia Guanjun , Rui Hallgeir , Hoang David T. , Gomella Leonard G. , Cingolani Gino , Njar Vincent , Pattabiraman Nagarajan , Calabretta Bruno , Nevalainen Marja T.
Published: May 2015

Bypassing tyrosine kinases responsible for Stat5a/b phosphorylation would be advantageous for therapy development for Stat5a/b-regulated cancers. Here, we sought to identify small molecule inhibitors of Stat5a/b for lead optimization and therapy development for prostate cancer and Bcr-Abl–driven leukemias. In silico screening of chemical structure databases combined with medicinal chemistry was used for identification of a panel of small molecule inhibitors to block SH2 domain–mediated docking of Stat5a/b to the receptor-kinase complex and subsequent phosphorylation and dimerization. We tested the efficacy of the lead compound IST5-002 in experimental models and patient samples of two known Stat5a/b-driven cancers, prostate cancer and chronic myeloid leukemia (CML). The lead compound inhibitor of Stat5-002 (IST5-002) prevented both Jak2 and Bcr-Abl–mediated phosphorylation and dimerization of Stat5a/b, and selectively inhibited transcriptional activity of Stat5a (IC50 = 1.5μmol/L) and Stat5b (IC50 = 3.5 μmol/L). IST5-002 suppressed nuclear translocation of Stat5a/b, binding to DNA and Stat5a/b target gene expression. IST5-002 induced extensive apoptosis of prostate cancer cells, impaired growth of prostate cancer xenograft tumors, and induced cell death in patient-derived prostate cancers when tested ex vivo in explant organ cultures. Importantly, IST5-002 induced robust apoptotic death not only of imatinib-sensitive but also of imatinib-resistant CML cell lines and primary CML cells from patients. IST5-002 provides a lead structure for further chemical modifications for clinical development for Stat5a/b-driven solid tumors and hematologic malignancies. Mol Cancer Ther; 14(8); 1777–93. ©2015 AACR.
Inhibition of mTORC2 Induces Cell-Cycle Arrest and Enhances the Cytotoxicity of Doxorubicin by Suppressing MDR1 Expression in HCC Cells
Authors: Chen Bryan Wei , Chen Wei , Liang Hui , Liu Hao , Liang Chao , Zhi Xiao , Hu Li-qiang , Yu Xia-Zhen , Wei Tao , Ma Tao , Xue Fei , Zheng Lei , Zhao Bin , Feng Xin-Hua , Bai Xue-li , Liang Ting-bo
Published: May 2015

mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0–G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027–induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. Mol Cancer Ther; 14(8); 1805–15. ©2015 AACR.
STAT3 in CD8+ T Cells Inhibits Their Tumor Accumulation by Downregulating CXCR3/CXCL10 Axis
Authors: Yue Chanyu , Shen Shudan , Deng Jiehui , Priceman Saul J. , Li Wenzhao , Huang Austin , Yu Hua
Published: May 2015

One of the obstacles for cancer immunotherapy is the inefficiency of CD8+ T-cell recruitment to tumors. STAT3 has been shown to suppress CD8+ T-cell antitumor functions in various cancer models, in part by restricting accumulation of CD8+ T cells. However, the underlying molecular mechanism by which STAT3 in CD8+ T cells inhibits their accumulation in tumors remains to be defined. Here, we show that STAT3 signaling in CD8+ T cells inhibits chemokine CXCL10 production by tumor-associated myeloid cells by reducing IFNγ expression by T cells. We further demonstrate that ablating STAT3 in T cells allows expression of CXCR3, the receptor of CXCL10, on CD8+ T cells, resulting in efficient accumulation of CD8+ T cells at tumor sites. Blocking IFNγ or CXCR3 impairs the accumulation of STAT3-deficient CD8+ T cells in tumor and their antitumor effects. Together, our study reveals a negative regulation by STAT3 signaling in T cells on cross-talk between myeloid cells and T cells through IFNγ/CXCR3/CXCL10, which is important for CD8+ T cells homing to tumors. Our results thus provide new insights applicable to cancer immunotherapy and adoptive T-cell strategies. Cancer Immunol Res; 3(8); 864–70. ©2015 AACR.
Inhibition of Fatty Acid Oxidation Modulates Immunosuppressive Functions of Myeloid-Derived Suppressor Cells and Enhances Cancer Therapies
Authors: Hossain Fokhrul , Al-Khami Amir A. , Wyczechowska Dorota , Hernandez Claudia , Zheng Liqin , Reiss Krzystoff , Valle Luis Del , Trillo-Tinoco Jimena , Maj Tomasz , Zou Weiping , Rodriguez Paulo C. , Ochoa Augusto C.
Published: May 2015

Myeloid-derived suppressor cells (MDSC) promote tumor growth by inhibiting T-cell immunity and promoting malignant cell proliferation and migration. The therapeutic potential of blocking MDSC in tumors has been limited by their heterogeneity, plasticity, and resistance to various chemotherapy agents. Recent studies have highlighted the role of energy metabolic pathways in the differentiation and function of immune cells; however, the metabolic characteristics regulating MDSC remain unclear. We aimed to determine the energy metabolic pathway(s) used by MDSC, establish its impact on their immunosuppressive function, and test whether its inhibition blocks MDSC and enhances antitumor therapies. Using several murine tumor models, we found that tumor-infiltrating MDSC (T-MDSC) increased fatty acid uptake and activated fatty acid oxidation (FAO). This was accompanied by an increased mitochondrial mass, upregulation of key FAO enzymes, and increased oxygen consumption rate. Pharmacologic inhibition of FAO blocked immune inhibitory pathways and functions in T-MDSC and decreased their production of inhibitory cytokines. FAO inhibition alone significantly delayed tumor growth in a T-cell–dependent manner and enhanced the antitumor effect of adoptive T-cell therapy. Furthermore, FAO inhibition combined with low-dose chemotherapy completely inhibited T-MDSC immunosuppressive effects and induced a significant antitumor effect. Interestingly, a similar increase in fatty acid uptake and expression of FAO-related enzymes was found in human MDSC in peripheral blood and tumors. These results support the possibility of testing FAO inhibition as a novel approach to block MDSC and enhance various cancer therapies. Cancer Immunol Res; 3(11); 1236–47. ©2015 AACR.
Loss of Function Mutations in
NNT
Are Associated With Left Ventricular Noncompaction
Authors: Bainbridge Matthew N. , Davis Erica E. , Choi Wen-Yee , Dickson Amy , Martinez Hugo R. , Wang Min , Dinh Huyen , Muzny Donna M. , Pignatelli Ricardo , Katsanis Nicholas , Boerwinkle Eric , Gibbs Richard A. , Jefferies John L.
Published: May 2015

Background—

Left ventricular noncompaction (LVNC) is an autosomal-dominant, genetically heterogeneous cardiomyopathy with variable severity, which may co-occur with cardiac hypertrophy.

Methods and Results—

Here, we generated whole exome sequence data from multiple members from 5 families with LVNC. In 4 of 5 families, the candidate causative mutation segregates with disease in known LVNC genes
MYH7
and
TPM1
. Subsequent sequencing of
MYH7
in a larger LVNC cohort identified 7 novel likely disease causing variants. In the fifth family, we identified a frameshift mutation in
NNT
, a nuclear-encoded mitochondrial protein, not implicated previously in human cardiomyopathies. Resequencing of
NNT
in additional LVNC families identified a second likely pathogenic missense allele. Suppression of
nnt
in zebrafish caused early ventricular malformation and contractility defects, probably driven by altered cardiomyocyte proliferation. In vivo complementation studies showed that mutant human
NNT
failed to rescue
nnt
morpholino-induced heart dysfunction, indicating a probable haploinsufficiency mechanism.

Conclusions—

Together, our data expand the genetic spectrum of LVNC and demonstrate how the intersection of whole exome sequence with in vivo functional studies can accelerate the identification of genes that drive human genetic disorders.