Disruption of metabolic, sleep, and sensorimotor functional outcomes in a female transgenic mouse model of Alzheimer's disease

Alzheimer's Disease (AD) is the most prevalent form of dementia globally, and the number of individuals with AD diagnosis is expected to double by 2050. Numerous preclinical AD studies have shown that AD neuropathology accompanies alteration in learning and memory. However, less attention has been given to alterations in metabolism, sleep, and sensorimotor functional outcomes during AD pathogenesis. The objective of this study was to elucidate the extent to which metabolic activity, sleep-wake cycle, and sensorimotor function is impaired in APPSwDI/Nos2^-/- (CVN-AD) transgenic mice. Female mice were used in this study because AD is more prevalent in women compared to men. We hypothesized that the presence of AD neuropathology in CVN-AD mice would accompany alterations in metabolic activity, sleep, and sensorimotor function. Our results showed that CVN-AD mice had significantly decreased energy expenditure compared to wild-type (WT) mice. An examination of associated functional outcome parameters showed that sleep activity was elevated during the awake (dark) cycle and as well as an overall decrease in spontaneous locomotor activity. An additional functional parameter, the nociceptive response to thermal stimuli, was also impaired in CVN-AD mice. Collectively, our results demonstrate CVN-AD mice exhibit alterations in functional parameters that resemble human-AD clinical progression.

Association between immunotherapy biomarkers and glucose metabolism from F-18 FDG PET

OBJECTIVE

To assess associations between parameters derived from F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and mRNA expression levels of immune checkpoint biomarkers such as programmed death receptor 1 (PD-1), programmed death-ligand 1 (PD-L1), cytotoxic T-lymphocyte antigen 4 (CTLA-4) as well as tumor mutation burden (TMB) in non-small cell lung cancer (NSCLC) patients.

PATIENTS AND METHODS

Integrated data were downloaded from Genomic Data Common Data Portal. Clinical, mRNA-seq, and whole exome-seq data of lung adenocarcinoma and squamous cell carcinoma from The Cancer Genome Atlas (TCGA) database were analyzed. TMB was defined as the total number of somatic missense mutations per megabase of the genome examined. Expression levels of PD-1, PD-L1, CTLA4 mRNA and TMB were collected. Correlations between imaging parameters of glucose metabolism and the expression levels of genomic biomarkers from cancers were evaluated. Bonferroni correction (adjusted p<0.0027) was applied to reduce type 1 error.

RESULTS

Of 31 NSCLC cases, 11 cases were adenocarcinoma (LUAD) and 20 were squamous cell carcinoma (LUSC). In linear regression analysis, texture parameters such as low gray-level run emphasis (LGRE, R2=0.48, p<0.0001), short run low gray-level emphasis (SRLGE, R2=0.45, p<0.0001) and long run low gray-level emphasis (LRLGE, R2=0.41, p=0.0001) derived from gray-level run length matrix (GLRLM) showed remarkable correlation with PD-L1 mRNA expression. Expression of PD-1, CTLA-4, and TMB failed to show any significant correlation with parameters of the F-18 FDG PET/CT.

CONCLUSIONS

Texture parameters derived from PET, known to indicate glucose uptake distribution, were correlated with expression of PD-L1 mRNA but not with expression of PD-1, CTLA-4 and TMB. Thus, tumoral heterogeneity could be a surrogate marker for the identification of PD-L1 level in NSCLC.

Loss of tissue-nonspecific alkaline phosphatase (TNAP) enzyme activity in cerebral microvessels is coupled to persistent neuroinflammation and behavioral deficits in late sepsis

Sepsis is a host response to systemic inflammation and infection that may lead to multi-organ dysfunction and eventual death. While acute brain dysfunction is common among all sepsis patients, chronic neurological impairment is prevalent among sepsis survivors. The brain microvasculature has emerged as a major determinant of sepsis-associated brain dysfunction, yet the mechanisms that underlie its associated neuroimmune perturbations and behavioral deficits are not well understood. An emerging body of data suggests that inhibition of tissue-nonspecific alkaline phosphatase (TNAP) enzyme activity in cerebral microvessels may be associated with changes in endothelial cell barrier integrity. The objective of this study was to elucidate the connection between alterations in cerebrovascular TNAP enzyme activity and brain microvascular dysfunction in late sepsis. We hypothesized that the disruption of TNAP enzymatic activity in cerebral microvessels would be coupled to the sustained loss of brain microvascular integrity, elevated neuroinflammatory responses, and behavioral deficits. Male mice were subjected to cecal ligation and puncture (CLP), a model of experimental sepsis, and assessed up to seven days post-sepsis. All mice were observed daily for sickness behavior and underwent behavioral testing. Our results showed a significant decrease in brain microvascular TNAP enzyme activity in the somatosensory cortex and spinal cord of septic mice but not in the CA1 and CA3 hippocampal regions. Furthermore, we showed that loss of cerebrovascular TNAP enzyme activity was coupled to a loss of claudin-5 and increased perivascular IgG infiltration in the somatosensory cortex. Analyses of whole brain myeloid and T-lymphoid cell populations also revealed a persistent elevation of infiltrating leukocytes, which included both neutrophil and monocyte myeloid derived suppressor cells (MDSCs). Regional analyses of the somatosensory cortex, hippocampus, and spinal cord revealed significant astrogliosis and microgliosis in the cortex and spinal cord of septic mice that was accompanied by significant microgliosis in the CA1 and CA3 hippocampal regions. Assessment of behavioral deficits revealed no changes in learning and memory or evoked locomotion. However, the hot plate test uncovered a novel anti-nociceptive phenotype in our septic mice, and we speculate that this phenotype may be a consequence of sustained GFAP astrogliosis and loss of TNAP activity in the somatosensory cortex and spinal cord of septic mice. Taken together, these results demonstrate that the loss of TNAP enzyme activity in cerebral microvessels during late sepsis is coupled to sustained neuroimmune dysfunction which may underlie, in part, the chronic neurological impairments observed in sepsis survivors.

Systemic inhibition of tissue-nonspecific alkaline phosphatase alters the brain-immune axis in experimental sepsis

Tissue-nonspecific alkaline phosphatase (TNAP) is a ubiquitous enzyme present in many cells and tissues, including the central nervous system. Yet its functions at the brain-immune axis remain unclear. The goal of this study was to use a novel small molecular inhibitor of TNAP, SBI-425, to interrogate the function of TNAP in neuroimmune disorders. Following intraperitoneal (IP) administration of SBI-425, mass spectrometry analysis revealed that the SBI-425 does not cross the blood-brain barrier (BBB) in healthy mice. To elucidate the role of TNAP at the brain-immune axis, mice were subjected to experimental sepsis and received either vehicle or SBI-425 (25 mg/kg, IP) daily for 7 days. While SBI-425 administration did not affect clinical severity outcomes, we found that SBI-425 administration suppressed CD4 + Foxp3+ CD25- and CD8 + Foxp3+ CD25- splenocyte T-cell populations compared to controls. Further evaluation of SBI-425's effects in the brain revealed that TNAP activity was suppressed in the brain parenchyma of SBI-425-treated mice compared to controls. When primary brain endothelial cells were treated with a proinflammatory stimulus the addition of SBI-425 treatment potentiated the loss of barrier function in BBB endothelial cells. To further demonstrate a protective role for TNAP at endothelial barriers within this axis, transgenic mice with a conditional overexpression of TNAP were subjected to experimental sepsis and found to have increased survival and decreased clinical severity scores compared to controls. Taken together, these results demonstrate a novel role for TNAP activity in shaping the dynamic interactions within the brain-immune axis.

Intraspinal Paragonimiasis in Children: MRI Findings and Suggestions for Pathogenesis

BACKGROUND AND PURPOSE

Intraspinal paragonimiasis is a rare entity for which imaging findings have seldom been described. The present study investigated the MR imaging features of spinal paragonimiasis, thus providing diagnostic imaging evidence and exploring the possible pathogenesis of intraspinal paragonimiasis.

MATERIALS AND METHODS

The clinical and imaging findings of spinal paragonimiasis in 6 children were analyzed retrospectively. Spinal MR imaging was performed in all patients, 5 of whom also underwent enhanced MR imaging. The diagnosis was confirmed by enzyme-linked immunosorbent assay in all cases and postoperative pathology in 4 cases.

RESULTS

All cases manifested as fusiform-shaped or beanlike masses in the extradural space in the thoracic spine. The extradural masses were connected with pleural lesions through the intervertebral foramen. The plain MR imaging scan showed mixed signals with predominant isointensity on T1WI and hyperintensity on T2WI, among which 5 (5/6) masses presented as patchy hemorrhage with hyperintensity on T1WI. On enhanced scans, all masses (5/5) showed heterogeneous marked enhancement, with thickening and enhancement in the adjacent spinal meninges (5/5). Various degrees of spinal cord compression and edema were found in 5 cases (5/6).

CONCLUSIONS

MR imaging is sensitive for detecting and characterizing spinal paragonimiasis. The MR imaging features of intraspinal granulomas included localization to the extradural space and thoracic segment, connections between intraspinal lesions and pleural lesions through the intervertebral foramen, and hemorrhagic foci within the mass. These findings support an intraspinal mode of paragonimiasis pathogenesis: The Paragonimus larvae migrate from the chest into the extradural space through the intervertebral foramen.

Hypoxia-reoxygenation of primary astrocytes results in a redistribution of mitochondrial size and mitophagy

Astrocytes serve to maintain proper neuronal function and support neuronal viability, but remain largely understudied in research of cerebral ischemia. Astrocytic mitochondria are core participants in the metabolic activity of astrocytes. The objective of this study is to assess astrocyte mitochondrial competence during hypoxia and post-hypoxia reoxygenation and to determine cellular adaptive and pathological changes in the mitochondrial network. We hypothesize that during metabolic distress in astrocytes; mitochondrial networks undergo a shift in fission-fusion dynamics that results in a change in the morphometric state of the entire mitochondrial network. This mitochondrial network shift may be protective during metabolic distress by priming mitochondrial size and facilitating mitophagy. We demonstrated that hypoxia and post-hypoxia reoxygenation of rat primary astrocytes results in a redistribution of mitochondria to smaller sizes evoked by increased mitochondrial fission. Excessive mitochondrial fission corresponded to Drp-1 dephosphorylation at Ser 637, which preceded mitophagy of relatively small mitochondria. Reoxygenation of astrocytes marked the initiation of elevated mitophagic activity primarily reserved to the perinuclear region where a large number of the smallest mitochondria occurred. Although, during hypoxia astrocytic ATP content was severely reduced, after reoxygenation ATP content returned to near normoxic values and these changes mirrored mitochondrial superoxide production. Concomitant with these changes in astrocytic mitochondria, the number of astrocytic extensions declined only after 10-hours post-hypoxic reoxygenation. Overall, we posit a drastic mitochondrial network change that is triggered by a metabolic crisis during hypoxia; these changes are followed by mitochondrial degradation and retraction of astrocytic extensions during reoxygenation.

Extracellular Vesicles Secreted in Response to Cytokine Exposure Increase Mitochondrial Oxygen Consumption in Recipient Cells

Extracellular vesicles (EVs) are small, membrane-bound nanoparticles released from most, if not all cells, and can carry functionally active cargo (proteins, nucleic acids) which can be taken up by neighboring cells and mediate physiologically relevant effects. In this capacity, EVs are being regarded as novel cell-to-cell communicators, which may play important roles in the progression of neurodegenerative diseases, like Alzheimer’s disease (AD). Aside from the canonical physical hallmarks of this disease [amyloid β (Aβ) plaques, neurofibrillary tangles, and widespread cell death], AD is characterized by chronic neuroinflammation and mitochondrial dysfunction. In the current study, we sought to better understand the role of tumor necrosis factor-alpha (TNF-α), known to be involved in inflammation, in mediating alterations in mitochondrial function and EV secretion. Using an immortalized hippocampal cell line, we observed significant reductions in several parameters of mitochondrial oxygen consumption after a 24-h exposure period to TNF-α. In addition, after TNF-α exposure we also observed significant upregulation of two microRNAs (miRNAs; miR-34a and miR-146a) associated with mitochondrial dysfunction in secreted EVs. Despite this, when naïve cells are exposed to EVs isolated from TNF-α treated cells, mitochondrial respiration, proton leak, and reactive oxygen species (ROS) production are all significantly increased. Collectively these data indicate that a potent proinflammatory cytokine, TNF-α, induces significant mitochondrial dysfunction in a neuronal cell type, in part via the secretion of EVs, which significantly alter mitochondrial activity in recipient cells.

The impact of lipids, lipid oxidation, and inflammation on AMD, and the potential role of miRNAs on lipid metabolism in the RPE

The accumulation of lipids within drusen, the epidemiologic link of a high fat diet, and the identification of polymorphisms in genes involved in lipid metabolism that are associated with disease risk, have prompted interest in the role of lipid abnormalities in AMD. Despite intensive investigation, our understanding of how lipid abnormalities contribute to AMD development remains unclear. Lipid metabolism is tightly regulated, and its dysregulation can trigger excess lipid accumulation within the RPE and Bruch's membrane. The high oxidative stress environment of the macula can promote lipid oxidation, impairing their original function as well as producing oxidation-specific epitopes (OSE), which unless neutralized, can induce unwanted inflammation that additionally contributes to AMD progression. Considering the multiple layers of lipid metabolism and inflammation, and the ability to simultaneously target multiple pathways, microRNA (miRNAs) have emerged as important regulators of many age-related diseases including atherosclerosis and Alzheimer's disease. These diseases have similar etiologic characteristics such as lipid-rich deposits, oxidative stress, and inflammation with AMD, which suggests that miRNAs might influence lipid metabolism in AMD. In this review, we discuss the contribution of lipids to AMD pathobiology and introduce how miRNAs might affect lipid metabolism during lesion development. Establishing how miRNAs contribute to lipid accumulation in AMD will help to define the role of lipids in AMD, and open new treatment avenues for this enigmatic disease.

Abstract TP254: Effects of Inducible Nitric Oxide Synthase on Behavior and Functional Outcomes in a Novel “Humanized” Transgenic Mouse Model of Ischemic Stroke

Introduction: Inducible nitric oxide synthase (iNOS) is a critical regulator of brain and systemic inflammatory responses in many neurological disorders. Intriguingly, iNOS null mice have produced equivocal outcomes in mouse models of ischemic stroke, a result that may be due, in part, to species-specific differences between the mouse and human iNOS genes. Due to numerous differences at the gene regulatory level, mouse iNOS naturally produces much higher levels of nitric oxide (NO) than the human gene. To resolve the functional differences between mouse and human iNOS in ischemic stroke, we employed a novel mouse that expresses human iNOS on a mouse iNOS null genetic background, termed the HN mouse. Our study objective was to compare functional and behavioral outcomes following ischemic stroke between wildtype (WT) and HN mice.

Hypothesis: We hypothesized that post-stroke functional outcomes would be more severe in HN male mice than in WT mice.

Methods: Male C57BL/6J (WT) and HN mice (4-6 months) were subjected to 60 minutes of transient middle cerebral artery occlusion (tMCAO) followed by reperfusion and behavioral assessments at seven-day intervals for 30 days. Laser-Doppler flowmetry pre- and post-tMCAO was used to assess the effect of iNOS on blood flow. A comprehensive neurological battery was used to assess sensorimotor ability, reflexes, and balance, followed by open field, wire hang, and rotarod testing to evaluate locomotor activity, limb strength, and coordination.

Results and Conclusion: Blood flow was significantly decreased in the ipsilateral hemisphere of both WT and HN mice following acute ischemic stroke; however, HN mice exhibited a sustained global decrease in blood flow following reperfusion. HN mice also demonstrated decreased locomotor activity and coordination, as well as greater neurological deficits compared to WT mice. Overall, these results suggest that the HN mouse model recapitulates more neurological deficits associated with human ischemic stroke than WT mice. Thus, the HN mouse may represent a more “humanized” model of ischemic stroke than more commonly used mouse models that express the mouse iNOS gene.

Expression of microRNA-34a in Alzheimer's disease brain targets genes linked to synaptic plasticity, energy metabolism, and resting state network activity

Polygenetic risk factors and reduced expression of many genes in late-onset Alzheimer's disease (AD) impedes identification of a target(s) for disease-modifying therapies. We identified a single microRNA, miR-34a that is over expressed in specific brain regions of AD patients as well as in the 3xTg-AD mouse model. Specifically, increased miR-34a expression in the temporal cortex region compared to age matched healthy control correlates with severity of AD pathology. miR-34a over expression in patient's tissue and forced expression in primary neuronal culture correlates with concurrent repression of its target genes involved in synaptic plasticity, oxidative phosphorylation and glycolysis. The repression of oxidative phosphorylation and glycolysis related proteins correlates with reduced ATP production and glycolytic capacity, respectively. We also found that miR-34a overexpressed neurons secrete miR-34a containing exosomes that are taken up by neighboring neurons. Furthermore, miR-34a targets dozens of genes whose expressions are known to be correlated with synchronous activity in resting state functional networks. Our analysis of human genomic sequences from the tentative promoter of miR-34a gene shows the presence of NFκB, STAT1, c-Fos, CREB and p53 response elements. Together, our results raise the possibilities that pathophysiology-induced activation of specific transcription factor may lead to increased expression of miR-34a gene and miR-34a mediated concurrent repression of its target genes in neural networks may result in dysfunction of synaptic plasticity, energy metabolism, and resting state network activity. Thus, our results provide insights into polygenetic AD mechanisms and disclose miR-34a as a potential therapeutic target for AD.

A new method for segmentation of FDG PET metabolic tumour volume using the peritumoural halo layer and a 10-step colour scale. A study in patients with papillary thyroid carcinoma

AIM

We observed a layer between tumour activity and background on FDG PET/CT with the 10-step colour scale and the window level set properly. We named the layer peritumoral halo layer (PHL). We performed this study to establish the reliability of metabolic tumor volume (MTV) segmentation using PHL (MTV(PHL)) in patients with papillary thyroid carcinoma.

PATIENTS, METHODS

Of a total of 140 papillary thyroid carcinoma (PTC) patients, 70 (50.0%) had FDG-avid PTC. In these patients, MTV(PHL), MTV segmented according to fixed 50% SUVmax (MTV(50%)), and fixed SUV with 2.5 to 4.0 (MTV(2.5) to MTV(4.0)) were compared with pathologic tumour volume (PTV). The absolute percentage difference between MTV(PHL) and PTV was compared in micropapillary carcinoma (MPTC) and non-micropapillary carcinoma (non-MPTC) subgroups. The % SUVmax and SUV thresholds of MTV(PHL) were compared with tumour SUVmax.

RESULTS

Among the MTVs, MTV(50%) was not correlated with PTV (r = -0.16, p = 0.182) and was not reliable according to the Bland-Altman plot. Although MTV(2.5), MTV(3.0), MTV(3.5), and MTV(4.0) correlated with PTV (r = 0.85, 0.86, 0.87, and 0.87, respectively; p < 0.001), these MTVs were not reliable on Bland-Altman analyses. MTV(PHL) was significantly correlated with PTV (r = 0.80, p < 0.001), and the Bland-Altman plot did not show systemic error. The MTV(PHL) was more accurate in non-MPTC than in MPTC (p < 0.001), and the absolute % difference was smaller as PTV became larger (σ = -0.65, p < 0.001). The MTV(PHL) thresholds had correlations with SUVmax (% SUVmax threshold: σ = -0.87, p < 0.001; SUV threshold: r = 0.88, p < 0.001).

CONCLUSIONS

MTV(PHL) was more reliable than MTV(%SUVmax) or MTV(SUV). The reliability of MTV(PHL) improved with larger PTVs. The threshold of the MTV(PHL) was naturally altered by PHL according to SUVmax.

Estrogen amelioration of Aβ-induced defects in mitochondria is mediated by mitochondrial signaling pathway involving ERβ, AKAP and Drp1

Perturbations in dynamic properties of mitochondria including fission, fusion, and movement lead to disruption of energy supply to synapses contributing to neuropathology and cognitive dysfunction in Alzheimer׳s disease (AD). The molecular mechanisms underlying these defects are still unclear. Previously, we have shown that ERβ is localized in the mitochondria and ERβ knock down disrupts mitochondrial functions. Because a selective ERβ modulator (DPN) can activate PKA, and localized PKA signaling in the mitochondrial membrane regulates mitochondrial structure and functions, we reasoned that ERβ signaling in the mitochondrial membrane rescues many of the mitochondrial defects caused by soluble Aβ oligomer. We now report that DPN treatment in primary hippocampal neurons attenuates soluble Aβ-oligomer induced dendritic mitochondrial fission and reduced mobility. Additionally, Aβ treatment reduced the respiratory reserve capacity of hippocampal neuron and inhibited phosphorylation of Drp1 at its PKA site, which induces excessive mitochondrial fission, and DPN treatment ameliorates these inhibitions. Finally, we discovered a direct interaction of ERβ with a mitochondrial resident protein AKAP1, which induces the PKA-mediated local signaling pathway involved in increased oxidative phosphorylation and inhibition of mitochondrial fission. Taken together, our findings highlight the possibility that ERβ signaling pathway may be a useful mitochondria-directed therapeutic target for AD.

Differential Protein Expression between Type 1 Diabetic Cataract and Age-Related Cataract Patients

Diabetes has become one of the major diseases affecting human health. Diabetic cataracts (DCs) are considered a common complication in diabetic patients. The present study investigated differences in lens proteomic profiles between DCs and age-related cataracts (ACs) to determine the mechanism underlying the formation of DCs. Intrasurgical samples were collected from eight DC patients and 12 AC patients, and lens proteins were extracted by lysis and separated using two-dimensional gel electrophoresis (2-DE). The electrophoretic bands were analysed using PD-Quest software 8.0.1. Differentially expressed proteins were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and peptide mass fingerprinting combined with protein database searching. In the 2-DE maps, the DC and AC lens proteins migrated in the region of pH 5-9 with a relative molecular weight (RMW) of 14-97 kDa, whereas the RMW of more abundant crystallin was 20-31 kDa. Approximately three protein spots with differential intensity were detected. Two crystallin proteins (αB and βB1) were identified using MALDI-TOF-MS. Proteomic analysis of the crystalline humour is feasible, and the proteins can be well separated; moreover, differentially expressed lens proteins can be analysed using 2-DE and mass spectrometry to compare DC and AC. The present results indicate that the αB and βB1 crystallins may accelerate the development of DCs. These techniques offer new avenues for mechanistic evaluation and future prevention or therapy of DCs.

Extracellular superoxide dismutase impairs neutrophil function and clearance of Listeria monocytogenes (118.4)

It is well established that reactive oxygen species (ROS) play a critical role during immune responses against pathogens. Extracellular superoxide dismutase (ecSOD) regulates extracellular concentrations of ROS and protects tissues during non-infectious inflammatory insults. However, how ecSOD activity impacts immune responses directed against pathogenic microorganisms has not been thoroughly investigated. We utilized mice with varying levels of ecSOD activity to investigate the involvement of this enzyme in innate immune responses against Listeria monocytogenes. Our data demonstrate that ecSOD activity negatively impacted host survival and bacterial clearance from the spleen and liver. Paradoxically, ecSOD activity was associated with increased percentages of neutrophils in the livers of mice prior to, and during infection. Neutrophils from livers of mice with high ecSOD activity were altered in their ability to produce various molecules important for bacterial clearance. Additionally, ecSOD activity was associated with a higher percentage of neutrophils that phenotypically resembled myeloid-derived suppressor cells. Neutrophil depletion studies revealed that high ecSOD activity resulted in neutrophils with no protective capacity, whereas neutrophils from mice lacking ecSOD provided superior protection compared to neutrophils from wild-type mice. Collectively, our data demonstrate that ecSOD activity inhibits innate immune responses, thus impairing bacterial clearance.

Foam consolidation and drainage

A theoretical model of foam as a consolidating continuum is proposed. The general model is applied to foam in a gravity settler. It is predicted that liquid drainage from foam in a gravity settler begins with a slow drainage stage. Next, a stage with faster drainage occurs where the drainage rate doubles compared to the initial stage. The experiments conducted within the framework of this work confirmed the theoretical predictions and allowed measurements of foam characteristics. Foams of three different concentrations of Pantene Pro-V Classic Care Solutions shampoo were studied, as well as the addition of polyethylene oxide (PEO) in one case. The shampoo's main foaming components are sodium lauryl sulfate and sodium laureth sulfate. It is shown to what extent foam drainage is slowed down by using higher shampoo concentrations and how it is further decreased by adding polymer (PEO).

Extracellular superoxide dismutase inhibits innate immune responses and clearance of an intracellular bacterial infection

Reactive oxygen species and reactive nitrogen species play important roles during immune responses to bacterial pathogens. Extracellular superoxide dismutase (ecSOD) regulates extracellular concentrations of reactive oxygen species and reactive nitrogen species and contributes to tissue protection during inflammatory insults. The participation of ecSOD in immune responses seems therefore intuitive, yet is poorly understood. In the current study, we used mice with varying levels of ecSOD activity to investigate the involvement of this enzyme in immune responses against Listeria monocytogenes. Surprisingly, our data demonstrate that despite enhanced neutrophil recruitment to the liver, ecSOD activity negatively affected host survival and bacterial clearance. Increased ecSOD activity was accompanied by decreased colocalization of neutrophils with bacteria, as well as increased neutrophil apoptosis, which reduced overall and neutrophil-specific TNF-α production. Liver leukocytes from mice lacking ecSOD produced equivalent NO· compared with liver leukocytes from mice expressing ecSOD. However, during infection, there were higher levels of peroxynitrite (NO(3)·(-)) in livers from mice lacking ecSOD compared with livers from mice expressing ecSOD. Neutrophil depletion studies revealed that high levels of ecSOD activity resulted in neutrophils with limited protective capacity, whereas neutrophils from mice lacking ecSOD provided superior protection compared with neutrophils from wild-type mice. Taken together, our data demonstrate that ecSOD activity reduces innate immune responses during bacterial infection and provides a potential target for therapeutic intervention.

Allele-specific effects of ecSOD on asbestos-induced fibroproliferative lung disease in mice

Previous work by others suggests that there is a strain-dependent variation in the susceptibility to inflammatory lung injury in mice. Specifically, the 129/J mice appear to be more resistant to asbestos-induced pulmonary fibrosis than the C57BL/6 strain. A separate line of evidence suggests that extracellular superoxide dismutase (ecSOD) may play an important role in protecting the lung from such injuries. We have recently reported that the 129/J strain of mice has an ecSOD genotype and phenotype distinctly different from those of the C57BL/6 mice. In order to identify ecSOD as a potential "asbestos-injury resistance" gene, we bred congenic mice, on the C57BL/6 background, carrying the wild type (sod3wt) or the 129/J (sod3129) allele for ecSOD. This allowed us to examine the role of ecSOD polymorphism in susceptibility to lung injury in an otherwise identical genetic background. Interestingly, asbestos treatment induces a significant (~40%) increase in plasma ecSOD activity in the sod3129 mice, but not in the sod3wt mice. Asbestos administration results in a loss of ecSOD activity and protein from lung tissue of both congenic strains, but the lung ecSOD activity remains significantly higher in sod3129 mice. As expected, asbestos treatment results in a significant recovery of ecSOD protein in bronchoalveolar lavage fluid (BALF). The BALF of sod3129 mice also have significantly lower levels of proteins and inflammatory cells, especially neutrophils, accompanied by a significantly lower extent of lung injury, as measured by a pathology index score or hydroxyproline content. Immunohistochemistry reveals a significant loss of ecSOD from the tips of the respiratory epithelial cells in response to asbestos treatment and that the loss of immunodetectable ecSOD is compensated for by enzyme expression by infiltrating cells, especially in the sod3wt mice. Our studies thus identify ecSOD as an important anti-inflammatory gene, responsible for most, if not all of the resistance to asbestos-induced lung injury reported for the 129/J strain of mice. The data further suggest allele-specific differences in the regulation of ecSOD expression. These congenic mice therefore represent a very useful model to study the role of this enzyme in all inflammatory diseases. Polymorphisms in human ecSOD have also been reported and it appears logical to assume that such variations may have a profound effect on disease susceptibility.

Extracellular superoxide dismutase polymorphism in mice: Allele-specific effects on phenotype

Extracellular superoxide dismutase (ecSOD) protects the extracellular matrix from oxidative stress. We previously reported a new allele for ecSOD, expressed in 129P3/J mice (129), which differs from the wild type (wt), expressed in C57BL/6J and other strains, by two amino acid substitutions and a 10-bp deletion in the 3' UTR of the mRNA (A. Pierce et al., 2003, Arterioscler. Thromb. Vasc. Biol.23:1820-1825). The newly discovered allele is associated with a phenotype of significantly increased circulating and heparin-releasable enzyme activities and levels. To examine the properties of the two forms of ecSOD in an identical environment we generated, by extensive backcrossing of ecSOD heterozygous progeny to C57BL/6J females, a congenic C57 strain with the 129 (or wt) allele of ecSOD. These mice are homozygous for nearly 5000 SNPs across all chromosomes, as determined by the Affymetrix Parallele Mouse 5K SNP panel. This study describes the generation of the congenic mice (genetically >99.8% identical) and their ecSOD phenotype. The congenic mouse plasma ecSOD activity before and after heparin administration recapitulates the differences reported in the founder mice. Tissue enzyme distribution is similar in both congenic groups, although the 129 allele is associated with higher levels of enzyme expression despite lower levels of enzyme mRNA. In these characteristics the phenotype is allele driven, with little impact from the rest of the genome. The congenic mice carrying the 129 allele have mRNA levels that are in between those in the founder 129P3/J and C57BL/6J strains. We conclude that the ecSOD phenotype in most aspects of enzyme expression is allele driven, with the exception of tissue mRNA levels, for which a significant contribution by the surrounding (host) genome is observed. These results also suggest potential allele-specific differences in the regulation of ecSOD synthesis and intracellular processing/secretion of ecSOD, independent of the genotype context. Most importantly, the congenic mice offer an excellent model to examine the regulatory mechanisms of ecSOD expression and the role of ecSOD in various diseases involving oxidative stress.

Effect of denosumab on bone mineral density (BMD) in women with breast cancer (BC) and men with prostate cancer (PC) undergoing hormone ablation therapy

9520

Background: Hormone ablation therapies, including adjuvant aromatase inhibitor (AI) therapy and androgen deprivation therapy (ADT), improve recurrence-free survival in patients (pts) with BC and PC, respectively. However, these treatments increase bone resorption, leading to bone loss and fractures. RANKL is a key mediator of osteoclast-mediated bone resorption. In this 24 month (mo) comparison, we investigated the effects of denosumab, a fully human monoclonal antibody against RANKL, on preserving BMD across both populations. Methods: Two trials were conducted: a 24-mo BC study and a 36-mo PC study. Postmenopausal women with low BMD receiving AI therapy for nonmetastatic BC and men receiving ADT for nonmetastatic PC (with low BMD or history of osteoporotic fracture if < 70 yrs) were randomized to receive placebo or denosumab 60mg subcutaneously every 6 mos. All pts in both studies were prescribed calcium and vitamin D supplements. The primary endpoint was % change from baseline in lumbar spine (LS) BMD at 12 mos for the BC study and at 24 mos for the PC study. Herein, we present changes in BMD at 24 mos at LS, total hip (TH), and 1/3 radius from both studies. Power calculations were based on enrollment of at least 208 patients in the BC study (for primary endpoint only) and 1226 in the PC study (for primary and key secondary endpoints). The actual numbers randomized were 252 and 1468, respectively. Results: Denosumab increased BMD of the LS, TH, and 1/3 radius compared with placebo at 24 mos in both pt populations ( Table ). In both studies, differences between denosumab and placebo at each skeletal site were consistent, and the effects of denosumab were statistically significantly different from placebo as early as 1 month at the LS in both studies. The overall safety profile was similar to placebo in each study. Conclusions: Denosumab consistently increased BMD at all 3 skeletal sites compared with placebo in both women with BC undergoing AI therapy and in men with PC undergoing ADT.

[Table: see text]

[Table: see text]

RIPK1 gene polymorphism as a prognostic marker for survival in patients with colorectal cancer

e15078

Background: Since apoptosis plays a key role in cancer progression, we hypothesized that single nucleotide polymorphisms (SNPs) of apoptosis-related gene can affect survival after curative resection in patients with colorectal cancer. Patients and Methods: Three hundred and ninety seven patients with colorectal cancer who underwent surgery with curative intent were enrolled in the present study. The genomic DNA was extracted from fresh colorectal mucosal tissue, and the 19 SNPs of 15 apoptosis-related genes (CASP3, CASP6–10, FAS, FAS ligand [FASLG], TNSFR1A, TNSFR10B, RIPK1, BCL2, BCL2 ligand [BCL2L], TP53, and PTGS2) were determined using a PCR-RFLP assay. Results: The median age of the patients was 63 years (range, 21–85), and 218 (54.9%) patients had colon cancer and 179 (45.1%) patients rectal cancer. Pathologic stages after surgery were as follows: stage 0/I (n=86, 21.7%), stage II (n=146, 36.8%), stage III (n=145, 36.5%), and stage IV (n=20, 5.0%). Multivariate survival analysis including pathologic stage, differentiation, age, and CEA level showed that relapse-free survival for the patients with the GA+AA genotype of RIPK1 (Receptor interacting serine/threonine kinase 1) +83G>A (rs2272990) was worse than for the patients with the GG genotype (hazard ratio [HR]=1.66, 95% confidence interval [CI]=1.03–2.68, p=0.038). However, no associations were observed between the polymorphisms and overall survival (OS) in a multivariate analysis. Conclusions: RIPK1 gene polymorphism can be considered as a possible prognostic marker for survival after curative resection in patient with colorectal cancer.

No significant financial relationships to disclose.

Denosumab for the treatment of giant cell tumor (GCT) of bone: Final results from a proof-of-concept, phase II study

10510

Background: GCT of bone is a primary osteolytic bone tumor with low metastatic potential that is associated with significant skeletal morbidity. GCT is rich in stromal cells that express RANKL, a key mediator of osteoclast activation. In this open-label, study, we investigated whether denosumab, a fully human monoclonal antibody against RANKL, could have a potential therapeutic effect on giant cell histology for patients with GCT. Methods: In this single-arm study, 37 patients with measurable or unresectable GCT received denosumab 120 mg subcutaneously once monthly with loading doses on days 8 and 15 of month 1. The primary endpoint was the proportion of patients with a tumor response (≥90% elimination of giant cells or no radiographic progression of the target lesion) at week 25 as assessed by histology and CT or MRI. A sample size of 35 patients was planned. All 37 enrolled patients were evaluated for safety; 35 were eligible for efficacy evaluation (2 had insufficient histology or radiology data). Results: Thirty of 35 patients (86%; 95% CI 70%-95%) had a tumor response: 20 of 20 by histology and 10 of 15 by radiology. Of 31 patients with data for assessments of clinical benefit, 26 (84%%; 95% CI 66%-95%) reported reduced pain or improvement in functional status. Bone repair was reported in 9 patients (29%; 95% CI 14%-48%). Suppression of the bone turnover markers urinary N-telopeptide and serum C-telopeptide was seen as early as 28 days after the first dose and sustained for the duration of the study. Adverse events (AEs) were reported in 33 patients (89%). One death due to surgical complications (not treatment-related) occurred on-study. No patient experienced treatment-related serious AEs or developed anti-denosumab antibodies. Conclusions: In this study, 86% of patients with measurable or unresectable GCT experienced a tumor response with denosumab. Further clinical trials of denosumab as a new therapy for GCT are warranted.

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Effects of denosumab treatment in breast cancer patients with bone metastases and elevated bone resorption levels after therapy with intravenous bisphosphonates: results of a phase 2 randomized trial

Abstract #1155

Background: Patients with breast cancer-induced bone disease and elevated urine-N-telopeptide (uNTx), a marker of bone resorption, are at increased risk for skeletal complications, disease progression, and death. Receptor activator of NF-kB ligand (RANKL) mediates osteoclastic bone resorption. Denosumab, a fully human monoclonal antibody, inhibits bone destruction by binding and neutralizing RANKL. Denosumab efficacy and safety were assessed in a phase 2, randomized, open-label, active-controlled trial in patients with bone metastases and elevated levels of uNTx after at least 8 weeks of intravenous (IV) bisphosphonate (BP) therapy. We report results in a subset of patients with breast cancer.&#x2028; Methods: Cancer patients with bone metastases and uNTx &gt;50 nM/mM creatinine [Cr] following at least 8 weeks of IV BP therapy were randomized to continue IV BP therapy every 4 weeks (Q4W) or switch to subcutaneous (SC) denosumab injection (180 mg) Q4W or every 12 weeks (Q12W). The primary endpoint was the proportion of patients who achieved uNTx &lt;50 nM/mM at week 13. Safety was also assessed.&#x2028; Results: The study population (N = 111) included 46 patients (41%) with breast cancer; the median time since diagnosis of bone metastases was approximately 1 year in both groups. At week 13, 76% of denosumab-treated patients and 33% of IV BP-treated patients had uNTx &lt; 50 nM/mM. Denosumab-induced suppression of uNTx was rapid (as early as 2 weeks after initial treatment), sustained through week 25, and unaffected by baseline uNTx (Table). In the total study population, adverse events of grade 3, 4, or 5 were reported in 25 (71%) IV BP-treated patients and 40 (55%) denosumab-treated patients.&#x2028; &#x2028; Discussion: Denosumab reduced bone turnover in breast cancer patients with bone metastases and elevated uNTx despite prior IV BP therapy. Phase 3 trials of denosumab in cancer patients with bone metastases are in progress.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1155.

Burden of hospitalizations associated with skeletal related events in patients with breast cancer or lung cancer and bone metastases or multiple myeloma

17083

Background: Patients with bone metastases secondary to cancer often experience skeletal related events (SREs) including pathological fracture, spinal cord compression, hypercalcemia, bone surgery or radiotherapy, or initiation of opioid analgesic use. These SREs result in major morbidity and reduced quality of life. This research examines hospitalizations associated with SREs. Methods: Data for this study were obtained from i3 LabRx Database (05/01/2000 to 03/31/2005). Individuals were included in the analyses if they had at least two diagnoses of breast cancer (based upon an ICD-9 code of 174.xx), lung cancer (162.xx), or multiple myeloma (203.0x) and had at least two diagnoses of bone metastases (198.5x) after the first diagnosis of cancer. In addition, individuals were required to have at least one SRE (based upon a previously published algorithm) on or after their initial diagnosis of bone metastases (their index date). Individuals were required to be continuously insured for at least 6 months prior to, and at least one month post their index date. Data were analyzed until 03/31/2005 or until the end of their continuous coverage, whichever occurred first. Descriptive statistics for each of these cohorts are provided. Results: A total of 1,204 individuals with breast cancer, 1,094 with lung cancer, and 258 with multiple myeloma were included in the study. The vast majority of individuals with breast cancer (96.5%), lung cancer (95.9%), or multiple myeloma (96.8%) were hospitalized. All three patient groups were likely to have SRE-related hospitalizations; multiple myeloma 43.4%, breast cancer 36.2% and lung cancer 35.6%. The average number of days per patient year that patients were hospitalized related to a diagnosis or procedure for a SRE was 6.75 days for patients with lung cancer, 6.56 days for patients with multiple myeloma, and 3.75 days for patients with breast cancer. Conclusion: Hospitalizations related to SREs are common and the number of days per year is substantial.

No significant financial relationships to disclose.