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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Effect of growth differentiation factor-15 secreted by human umbilical cord blood-derived mesenchymal stem cells on amyloid beta levels in in vitro and in vivo models of Alzheimer's disease

Highlights: • Paracrine action of hUCB-MSCs enhances Aβ clearance through microglial modulation. • GDF-15 secreted from hUCB-MSCs promotes the decrease of Aβ levels via enhancing IDE expression in microglia. • TGFβRII is involved in GDF-15-enhanced IDE expression in microglia. Alzheimer's disease (AD), which is the most common progressive neurodegenerative disease, causes learning and memory impairment. The pathological progress of AD can derive from imbalanced homeostasis of amyloid beta (Aβ) in the brain. In such cases, microglia play important roles in regulating the brain Aβ levels. In the present study, we found that human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) can increase, through paracrine action, the ability of microglial cells to clear Aβ. In order to identify the associated paracrine factors, a secretome of hUCB-MSCs co-cultured with Aβ-treated BV2 microglial cells was analyzed using a human cytokine protein array. As a result, growth differentiation factor-15 (GDF-15) was identified as a predominant candidate, and its association with Aβ clearance by microglial cells was investigated in vitro and in a 5XFAD mouse model. When Aβ-treated BV2 cells were treated with exogenous recombinant GDF-15, the Aβ levels in the culture medium decreased. Moreover, GDF-15 injection in the brain parenchyma of 5XFAD mice also led to decrease in Aβ plaques. In contrast, co-culture of BV2 cells and hUCB-MSCs treated with GDF-15-specific siRNA did not influence the Aβ levels in the culture medium. To elucidate how these phenomena are related, we confirmed that GDF-15 specifically increases insulin-degrading enzyme (IDE) expression in microglial cells through TGFβ receptor type II (TGFβRII), both in vitro and in vivo. These findings suggest that hUCB-MSCs promote the Aβ clearance ability of microglial cells through regulation of GDF-15 secretion, thus elucidating a therapeutic mechanism for AD.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Systemic inflammatory markers associated with cardiovascular disease and acute and chronic exposure to fine particulate matter air pollution (PM2.5) among US NHANES adults with metabolic syndrome

Highlights: • A cross sectional study of the effect of PM{sub 2.5} AP on inflammatory biomarkers among NHANES participants was conducted. • Participants’ Census tract of residence was linked to USEPA downscaler modeled air pollution for the continental US. • Goal was the assessment of susceptibility of adults with metabolic syndrome to PM2.5 exposure and levels of CRP and WBC. • There was a significant effect of PM2.5 at lag day 0; a 10 µg/m3 rise was associated with a 10.1% increase in CRP level. • There were no significant associations with CRP or WBC for those without metabolic syndrome. There has been no investigation to date of adults with metabolic syndrome examining the association of short and long-term exposure to fine particulate matter (PM{sub 2.5}) air pollution with cardiovascular-disease related inflammatory marker (WBC and CRP) levels in a nationally representative sample. The goal of this study is to assess the susceptibility of adults with metabolic syndrome to PM{sub 2.5} exposure as suggested by increased cardiovascular-disease related inflammatory marker levels.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Assessing the recent estimates of the global burden of disease for ambient air pollution: Methodological changes and implications for low- and middle-income countries

Highlights: • From 2013 to 2015, the Global Burden of Disease estimates for ambient air pollution increased by over one million deaths. • We reconstructed the global estimates to quantify the impact of changes in model inputs. • Much of the change was due to new studies and improved methods in calculating dose response functions. • For certain low-income countries the improved air pollution exposure assessment had a significant impact. • Complete documentation and implications of future input changes are essential. The Global Burden of Disease (GBD) is a comparative assessment of the health impact of the major and well-established risk factors, including ambient air pollution (AAP) assessed by concentrations of PM2.5 (particles less than 2.5 µm) and ozone. Over the last two decades, major improvements have emerged for two important inputs in the methodology for estimating the impacts of PM2.5: the assessment of global exposure to PM2.5 and the development of integrated exposure risk models (IERs) that relate the entire range of global exposures of PM2.5 to cause-specific mortality. As a result, the estimated annual mortality attributed to AAP increased from less than 1 million in 2000 to roughly 3 million for GBD in years 2010 and 2013, to 4.2 million for GBD 2015. However, the magnitude of the recent change and uncertainty regarding its rationale have resulted, in some cases, in skepticism and reduced confidence in the overall estimates. To understand the underlying reasons for the change in mortality, we examined the estimates for the years 2013 and 2015 to determine the quantitative implications of alternative model input assumptions. We calculated that the year 2013 estimates increased by 8% after applying the updated exposure data used in GBD 2015, and increased by 23% with the application of the updated IERs from GBD 2015. The application of both upgraded methodologies together increased the GBD 2013 estimates by 35%, or about one million deaths. We also quantified the impact of the changes in demographics and the assumed threshold level. Since the global estimates of air pollution-related deaths will continue to change over time, a clear documentation of the modifications in the methodology and their impacts is necessary. In addition, there is need for additional monitoring and epidemiological studies to reduce uncertainties in the estimates for low- and medium-income countries, which contribute to about one-half of the mortality.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Brain in situ hybridization maps as a source for reverse-engineering transcriptional regulatory networks: Alzheimer's disease insights

Microarray data have been a valuable resource for identifying transcriptional regulatory relationships among genes. As an example, brain region-specific transcriptional regulatory events have the potential of providing etiological insights into Alzheimer Disease (AD). However, there is often a paucity of suitable brain-region specific expression data obtained via microarrays or other high throughput means. The Allen Brain Atlas in situ hybridization (ISH) data sets (Jones et al., 2009) represent a potentially valuable alternative source of high-throughput brain region-specific gene expression data for such purposes. In this study, Allen BrainAtlasmouse ISH data in the hippocampal fields were extracted, focusing on 508 genes relevant to neurodegeneration. Transcriptional regulatory networkswere learned using three high-performing network inference algorithms. Only 17% of regulatory edges from a network reverse-engineered based on brain region-specific ISH data were also found in a network constructed upon gene expression correlations inmousewhole brain microarrays, thus showing the specificity of gene expression within brain sub-regions. Furthermore, the ISH data-based networks were used to identify instructive transcriptional regulatory relationships. Ncor2, Sp3 and Usf2 form a unique three-party regulatory motif, potentially affecting memory formation pathways. Nfe2l1, Egr1 and Usf2 emerge among regulators of genes involved in AD (e.g. Dhcr24, Aplp2, Tia1, Pdrx1, Vdac1, andSyn2). Further, Nfe2l1, Egr1 and Usf2 are sensitive to dietary factors and could be among links between dietary influences and genes in the AD etiology. Thus, this approach of harnessing brain region-specific ISH data represents a rare opportunity for gleaning unique etiological insights for diseases such as AD.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

Radiation Therapy to Sites of Metastatic Disease as Part of Consolidation in High-Risk Neuroblastoma: Can Long-term Control Be Achieved?

As part of consolidative therapy in high-risk neuroblastoma, modern protocols recommend radiation therapy (RT) both to the primary site and to sites of metastatic disease that persist after induction chemotherapy. Although there are abundant data showing excellent local control (LC) with 21 Gy directed at the primary site, there are few data describing the feasibility and efficacy of RT directed at metastatic sites of disease as part of consolidation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

APOE effect on Alzheimer's disease biomarkers in older adults with significant memory concern

This study assessed apolipoprotein E (APOE) ε4 carrier status effects on Alzheimer's disease imaging and cerebrospinal fluid (CSF) biomarkers in cognitively normal older adults with significant memory concerns (SMC). Cognitively normal, SMC, and early mild cognitive impairment participants from Alzheimer's Disease Neuroimaging Initiative were divided by APOE ε4 carrier status. Diagnostic and APOE effects were evaluated with emphasis on SMC. Additional analyses in SMC evaluated the effect of the interaction between APOE and [ 18 F]Florbetapir amyloid positivity on CSF biomarkers. SMC ε4+ showed greater amyloid deposition than SMC ε4-, but no hypometabolism or medial temporal lobe (MTL) atrophy. SMC ε4+ showed lower amyloid beta 1-42 and higher tau/p-tau than ε4-, which was most abnormal in APOE ε4+ and cerebral amyloid positive SMC. Lastly, SMC APOE ε4+ show abnormal changes in amyloid and tau biomarkers, but no hypometabolism or MTL neurodegeneration, reflecting the at-risk nature of the SMC group and the importance of APOE in mediating this risk.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Comparison of multiple tau-PET measures as biomarkers in aging and Alzheimer's disease

The recent development of tau-specific positron emission tomography (PET) tracers enables in vivo quantification of regional tau pathology, one of the key lesions in Alzheimer's disease (AD). Tau PET imaging may become a useful biomarker for clinical diagnosis and tracking of disease progression but there is no consensus yet on how tau PET signal is best quantified. The goal of the current paper was to evaluate multiple whole-brain and region-specific approaches to detect clinically relevant tau PET signal. Two independent cohorts of cognitively normal adults and amyloid-positive (Aβ + ) patients with mild cognitive impairment (MCI) or AD-dementia underwent [ 18 F]AV-1451 PET. Methods for tau tracer quantification included: (i) in vivo Braak staging, (ii) regional uptake in Braak composite regions, (iii) several whole-brain measures of tracer uptake, (iv) regional uptake in AD-vulnerable voxels, and (v) uptake in a priori defined regions. Receiver operating curves characterized accuracy in distinguishing Aβ - controls from AD/MCI patients and yielded tau positivity cutoffs. Clinical relevance of tau PET measures was assessed by regressions against cognition and MR imaging measures. Key tracer uptake patterns were identified by a factor analysis and voxel-wise contrasts. Braak staging, global and region-specific tau measures yielded similar diagnostic accuracies, which differed between cohorts. While all tau measures were related to amyloid and global cognition, memory and hippocampal/entorhinal volume/thickness were associated with regional tracer retention in the medial temporal lobe. Key regions of tau accumulation included medial temporal and inferior/middle temporal regions, retrosplenial cortex, and banks of the superior temporal sulcus. Finally, our data indicate that whole-brain tau PET measures might be adequate biomarkers to detect AD-related tau pathology. However, regional measures covering AD-vulnerable regions may increase sensitivity to early tau PET signal, atrophy and memory decline.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Deep learning for Alzheimer's disease: Mapping large-scale histological tau protein for neuroimaging biomarker validation

Abnormal tau inclusions are hallmarks of Alzheimer's disease and predictors of clinical decline. Several tau PET tracers are available for neurodegenerative disease research, opening avenues for molecular diagnosis in vivo. However, few have been approved for clinical use. Understanding the neurobiological basis of PET signal validation remains problematic because it requires a large-scale, voxel-to-voxel correlation between PET and (immuno) histological signals. Large dimensionality of whole human brains, tissue deformation impacting co-registration, and computing requirements to process terabytes of information preclude proper validation. We developed a computational pipeline to identify and segment particles of interest in billion-pixel digital pathology images to generate quantitative, 3D density maps. The proposed convolutional neural network for immunohistochemistry samples, IHCNet, is at the pipeline's core. We have successfully processed and immunostained over 500 slides from two whole human brains with three phospho-tau antibodies (AT100, AT8, and MC1), spanning several terabytes of images. Our artificial neural network estimated tau inclusion from brain images, which performs with ROC AUC of 0.87, 0.85, and 0.91 for AT100, AT8, and MC1, respectively. Introspection studies further assessed the ability of our trained model to learn tau-related features. We present an end-to-end pipeline to create terabytes-large 3D tau inclusion density maps co-registered to MRI as a means to facilitate validation of PET tracers.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Uncompetitive, adduct-forming SARM1 inhibitors are neuroprotective in preclinical models of nerve injury and disease

Axon degeneration is an early pathological event in many neurological diseases. The identification of the nicotinamide adenine dinucleotide (NAD) hydrolase SARM1 as a central metabolic sensor and axon executioner presents an exciting opportunity to develop novel neuroprotective therapies that can prevent or halt the degenerative process, yet limited progress has been made on advancing efficacious inhibitors. Here we describe a class of NAD-dependent active-site SARM1 inhibitors that function by intercepting NAD hydrolysis and undergoing covalent conjugation with the reaction product adenosine diphosphate ribose (ADPR). The resulting small-molecule ADPR adducts are highly potent and confer compelling neuroprotection in preclinical models of neurological injury and disease, validating this mode of inhibition as a viable therapeutic strategy. Additionally, we show that the most potent inhibitor of CD38, a related NAD hydrolase, also functions by the same mechanism, further underscoring the broader applicability of this mechanism in developing therapies against this class of enzymes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Tau covariance patterns in Alzheimer's disease patients match intrinsic connectivity networks in the healthy brain

According to the network model of neurodegeneration, the spread of pathogenic proteins occurs selectively along connected brain regions. We tested in vivo whether the distribution of filamentous tau (measured with [ 18 F]flortaucipir-PET), fibrillar amyloid-β ([ 11 C]PIB-PET) and glucose hypometabolism ([ 18 F]FDG-PET) follows the intrinsic functional organization of the healthy brain. We included 63 patients with Alzheimer's disease (AD; 30 male, 63 ± 8 years) who underwent [ 18 F]flortaucipir, [ 11 C]PIB and [ 18 F]FDG PET, and 1000 young adults (427 male, 21 ± 3 years) who underwent task-free fMRI. We selected six predefined disease epicenters as seeds for whole-brain voxelwise covariance analyses to compare correlated patterns of tracer uptake across AD patients against fMRI intrinsic connectivity patterns in young adults. We found a striking convergence between [18F]flortaucipir covariance patterns and intrinsic connectivity maps (range Spearman rho's: 0.32-0.78, p < .001), which corresponded with expected functional networks (range goodness-of-fit: 3.8-8.2). The topography of amyloid-β covariance patterns was more diffuse and less network-specific, while glucose hypometabolic patterns were more spatially restricted than tau but overlapped with functional networks. These findings suggest that the spatial patterns of tau and glucose hypometabolism observed in AD resemble the functional organization of the healthy brain, supporting the notion that tau pathology spreads through circumscribed brain networks and drives neurodegeneration.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Solvents and Parkinson disease: A systematic review of toxicological and epidemiological evidence

Parkinson disease (PD) is a debilitating neurodegenerative motor disorder, with its motor symptoms largely attributable to loss of dopaminergic neurons in the substantia nigra. The causes of PD remain poorly understood, although environmental toxicants may play etiologic roles. Solvents are widespread neurotoxicants present in the workplace and ambient environment. Case reports of parkinsonism, including PD, have been associated with exposures to various solvents, most notably trichloroethylene (TCE). Animal toxicology studies have been conducted on various organic solvents, with some, including TCE, demonstrating potential for inducing nigral system damage. However, a confirmed animal model of solvent-induced PD has not been developed. Numerous epidemiologic studies have investigated potential links between solvents and PD, yielding mostly null or weak associations. An exception is a recent study of twins indicating possible etiologic relations with TCE and other chlorinated solvents, although findings were based on small numbers, and dose–response gradients were not observed. At present, there is no consistent evidence from either the toxicological or epidemiologic perspective that any specific solvent or class of solvents is a cause of PD. Future toxicological research that addresses mechanisms of nigral damage from TCE and its metabolites, with exposure routes and doses relevant to human exposures, is recommended. Improvements in epidemiologic research, especially with regard to quantitative characterization of long-term exposures to specific solvents, are needed to advance scientific knowledge on this topic. -- Highlights: ► The potential for organic solvents to cause Parkinson's disease has been reviewed. ► Twins study suggests etiologic relations with chlorinated solvents and Parkinson's. ► Animal studies with TCE showed potential to cause damage to dopaminergic neurons. ► Need to determine if effects in animals are relevant to human exposure levels.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Osthole promotes neuronal differentiation and inhibits apoptosis via Wnt/β-catenin signaling in an Alzheimer's disease model

Neurogenesis is the process by which neural stem cells (NSCs) proliferate and differentiate into neurons. This is diminished in several neurodegenerative disorders such as Alzheimer's disease (AD), which is characterized by the deposition of amyloid (A)β peptides and neuronal loss. Stimulating NSCs to replace lost neurons is therefore a promising approach for AD treatment. Our previous study demonstrated that osthole modulates NSC proliferation and differentiation, and may reduce Aβ protein expression in nerve cells. Here we investigated the mechanism underlying the effects of osthole on NSCs. We found that osthole enhances NSC proliferation and neuronal differentiation while suppressing apoptosis, effects that were exerted via activation of Wnt/β-catenin signaling. These results provide evidence that osthole can potentially be used as a therapeutic agent in the treatment of AD and other neurodegenerative disorders. - Highlights: • An Alzheimer's disease model was successfully established by transfecting APP gene into neural stem cells in vitro. • Roles of osthole in experimental AD cells were studied. • Osthole promotes proliferation and differentiation into neurons and inhibits accumulation of Aβ{sub 1–42} peptide and apoptosis. • Osthole exerts protection via Wnt/β-catenin signaling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Bisphenol A sulfonation is impaired in metabolic and liver disease

Background: Bisphenol A (BPA) is a widely used industrial chemical and suspected endocrine disruptor to which humans are ubiquitously exposed. The liver metabolizes and facilitates BPA excretion through glucuronidation and sulfonation. The sulfotransferase enzymes contributing to BPA sulfonation (detected in human and rodents) is poorly understood. Objectives: To determine the impact of metabolic and liver disease on BPA sulfonation in human and mouse livers. Methods: The capacity for BPA sulfonation was determined in human liver samples that were categorized into different stages of metabolic and liver disease (including obesity, diabetes, steatosis, and cirrhosis) and in livers from ob/ob mice. Results: In human liver tissues, BPA sulfonation was substantially lower in livers from subjects with steatosis (23%), diabetes cirrhosis (16%), and cirrhosis (18%), relative to healthy individuals with non-fatty livers (100%). In livers of obese mice (ob/ob), BPA sulfonation was lower (23%) than in livers from lean wild-type controls (100%). In addition to BPA sulfonation activity, Sult1a1 protein expression decreased by 97% in obese mouse livers. Conclusion: Taken together these findings establish a profoundly reduced capacity of BPA elimination via sulfonation in obese or diabetic individuals and in those with fatty or cirrhotic livers versus individuals with healthy livers. - Highlights: • Present study demonstrates that hepatic SULT 1A1/1A3 are primarily sulfonate BPA in mouse and human. • Hepatic BPA sulfonation is profoundly reduced steatosis, diabetes and cirrhosis. • With BPA-S detectable in urine under low or common exposures, these findings are novel and important.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

A cellular model to study drug-induced liver injury in nonalcoholic fatty liver disease: Application to acetaminophen

Obesity and nonalcoholic fatty liver disease (NAFLD) can increase susceptibility to hepatotoxicity induced by some xenobiotics including drugs, but the involved mechanisms are poorly understood. For acetaminophen (APAP), a role of hepatic cytochrome P450 2E1 (CYP2E1) is suspected since the activity of this enzyme is consistently enhanced during NAFLD. The first aim of our study was to set up a cellular model of NAFLD characterized not only by triglyceride accumulation but also by higher CYP2E1 activity. To this end, human HepaRG cells were incubated for one week with stearic acid or oleic acid, in the presence of different concentrations of insulin. Although cellular triglycerides and the expression of lipid-responsive genes were similar with both fatty acids, CYP2E1 activity was significantly increased only by stearic acid. CYP2E1 activity was reduced by insulin and this effect was reproduced in cultured primary human hepatocytes. Next, APAP cytotoxicity was assessed in HepaRG cells with or without lipid accretion and CYP2E1 induction. Experiments with a large range of APAP concentrations showed that the loss of ATP and glutathione was almost always greater in the presence of stearic acid. In cells pretreated with the CYP2E1 inhibitor chlormethiazole, recovery of ATP was significantly higher in the presence of stearate with low (2.5 mM) or high (20 mM) concentrations of APAP. Levels of APAP-glucuronide were significantly enhanced by insulin. Hence, HepaRG cells can be used as a valuable model of NAFLD to unveil important metabolic and hormonal factors which can increase susceptibility to drug-induced hepatotoxicity. - Highlights: • Nonalcoholic fatty liver disease (NAFLD) is frequent in obese individuals. • NAFLD can favor hepatotoxicity induced by some drugs including acetaminophen (APAP). • A model of NAFLD was set up by using HepaRG cells incubated with stearate or oleate. • Stearate-loaded HepaRG cells presented higher cytochrome P450 2E1 (CYP2E1) activity. • APAP cytotoxicity was stronger in steatotic HepaRG cells with higher CYP2E1 activity.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

A silk peptide fraction restores cognitive function in AF64A-induced Alzheimer disease model rats by increasing expression of choline acetyltransferase gene

This study investigated the effects of a silk peptide fraction obtained by incubating silk proteins with Protease N and Neutrase (SP-NN) on cognitive dysfunction of Alzheimer disease model rats. In order to elucidate underlying mechanisms, the effect of SP-NN on the expression of choline acetyltransferase (ChAT) mRNA was assessed in F3.ChAT neural stem cells and Neuro2a neuroblastoma cells; active amino acid sequence was identified using HPLC-MS. The expression of ChAT mRNA in F3.ChAT cells increased by 3.79-fold of the control level by treatment with SP-NN fraction. The active peptide in SP-NN was identified as tyrosine-glycine with 238.1 of molecular weight. Male rats were orally administered with SP-NN (50 or 300 mg/kg) and challenged with a cholinotoxin AF64A. As a result of brain injury and decreased brain acetylcholine level, AF64A induced astrocytic activation, resulting in impairment of learning and memory function. Treatment with SP-NN exerted recovering activities on acetylcholine depletion and brain injury, as well as cognitive deficit induced by AF64A. The results indicate that, in addition to a neuroprotective activity, the SP-NN preparation restores cognitive function of Alzheimer disease model rats by increasing the release of acetylcholine. - Highlights: • Cognition-enhancing effects of SP-NN, a silk peptide preparation, were investigated. • SP-NN enhanced ChAT mRNA expression in F3.ChAT neural stem cells and Neuro-2a neuroblastoma cells. • Active molecule was identified as a dipeptide composed of tyrosine-glycine. • SP-NN reversed cognitive dysfunction elicited by AF64A. • Neuroprotection followed by increased acetylcholine level was achieved with SP-NN.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Comparison of self-processing of foot-and-mouth disease virus leader proteinase and porcine reproductive and respiratory syndrome virus leader proteinase nsp1α

The foot-and-mouth disease virus leader proteinase (Lb{sup pro}) cleaves itself off the nascent viral polyprotein. NMR studies on the monomeric variant Lb{sup pro} L200F provide structural evidence for intramolecular self-processing. {sup 15}N-HSQC measurements of Lb{sup pro} L200F showed specifically shifted backbone signals in the active and substrate binding sites compared to the monomeric variant sLb{sup pro}, lacking six C-terminal residues. This indicates transient intramolecular interactions between the C-terminal extension (CTE) of one molecule and its own active site. Contrastingly, the porcine reproductive and respiratory syndrome virus (PRRSV) leader proteinase nsp1α, with a papain-like fold like Lb{sup pro}, stably binds its own CTE. Parts of the β-sheet domains but none of the α-helical domains of Lb{sup pro} and nsp1α superimpose; consequently, the α-helical domain of nsp1α is oriented differently relative to its β-sheet domain. This provides a large interaction surface for the CTE with the globular domain, stabilising the intramolecular complex. Consequently, self-processing inactivates nsp1α but not Lb{sup pro}. - Highlights: • We examine self-processing of the leader protease of foot-and-mouth disease virus. • NMR analysis strongly supports intramolecular self-processing. • Self-processing is a dynamic process with no stable complex. • Structural comparison with nsp1α of PRRSV which forms stable intramolecular complex. • Subdomain orientation explains differences in stability of intramolecular complexes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Disordered glycometabolism involved in pathogenesis of Kashin–Beck disease, an endemic osteoarthritis in China

Kashin–Beck disease (KBD) is a chronic endemic osteoarthritis in China. Previous studies have suggested a role of metabolic dysfunction in causation of this disease. In this investigation, the metabolomics approach and cell experiments were used to discover the metabolic changes and their effects on KBD chondrocytes. Nuclear magnetic resonance ({sup 1}H NMR) spectroscopy was used to examine serum samples from both the KBD patients and normal controls. The pattern recognition multivariate analysis (OSC–PLS) and quantitative analysis (QMTLS iterator) revealed altered glycometabolism in KBD, with increased glucose and decreased lactate and citrate levels. IPA biological analysis showed the centric location of glucose in the metabolic network. Massive glycogen deposits in chondrocytes and increased uptake of glucose by chondrocytes further confirmed disordered glycometabolism in KBD. An in vitro study showed the effects of disordered glycometabolism in chondrocytes. When chondrocytes were treated with high glucose, expression of type II collagen and aggrecan were decreased, while TNF-α expression, the level of cellular reactive oxygen species and cell apoptosis rates all were increased. Therefore, our results demonstrated that disordered glycometabolism in patients with KBD was linked to the damage of chondrocytes. This may provide a new basis for understanding the pathogenesis of KBD. - Highlights: • Disordered glycometabolism in KBD was demonstrated by combining serum metabolomics and chondrocyte studies. • Glucose and TNF-α were key molecules linked to altered metabolism and inflammation in the pathophysiology of KBD. • The glycometabolism disorder was linked to expression of type II collagen and aggrecan, ROS and apoptosis of KBD chondrocytes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Binding of 3,4,5,6-Tetrahydroxyazepanes to the Acid-[beta]-glucosidase Active Site: Implications for Pharmacological Chaperone Design for Gaucher Disease

Pharmacologic chaperoning is a therapeutic strategy being developed to improve the cellular folding and trafficking defects associated with Gaucher disease, a lysosomal storage disorder caused by point mutations in the gene encoding acid-{beta}-glucosidase (GCase). In this approach, small molecules bind to and stabilize mutant folded or nearly folded GCase in the endoplasmic reticulum (ER), increasing the concentration of folded, functional GCase trafficked to the lysosome where the mutant enzyme can hydrolyze the accumulated substrate. To date, the pharmacologic chaperone (PC) candidates that have been investigated largely have been active site-directed inhibitors of GCase, usually containing five- or six-membered rings, such as modified azasugars. Here we show that a seven-membered, nitrogen-containing heterocycle (3,4,5,6-tetrahydroxyazepane) scaffold is also promising for generating PCs for GCase. Crystal structures reveal that the core azepane stabilizes GCase in a variation of its proposed active conformation, whereas binding of an analogue with an N-linked hydroxyethyl tail stabilizes GCase in a conformation in which the active site is covered, also utilizing a loop conformation not seen previously. Although both compounds preferentially stabilize GCase to thermal denaturation at pH 7.4, reflective of the pH in the ER, only the core azepane, which is a mid-micromolar competitive inhibitor, elicits a modest increase in enzyme activity for the neuronopathic G202R and the non-neuronopathic N370S mutant GCase in an intact cell assay. Our results emphasize the importance of the conformational variability of the GCase active site in the design of competitive inhibitors as PCs for Gaucher disease.

59 BASIC BIOLOGICAL SCIENCES↗