Cerium Nitrate Stiffens In Vitro Skin Models and Reduces Pseudomonas aeruginosa Pathogenicity and Penetration Through Skin Models.

Objective: Cerium nitrate (CeN) plus silver sulfadiazine (SSD) cream has been used for 40-plus years to manage burns. CeN produces a hardened eschar believed to resist bacterial colonization/infection. To evaluate this potential mechanism, we treated in vitro skin models or Pseudomonas aeruginosa with CeN and measured mechanical properties of the models and bacterial virulence, respectively. Approach: We treated three-dimensional-collagen matrix and ex-vivo-burned porcine skin with CeN and evaluated stiffness and P. aeruginosa penetration. In addition, we treated P. aeruginosa with CeN and evaluated the bacteria's motility, skin model penetration, susceptibility to be phagocytized by the human monocytic cell line THP-1, and ability to stimulate this cell line to produce cytokines. Results: CeN treatment of skin models stiffened them and made them resistant to P. aeruginosa penetration. Inversely, CeN treatment of P. aeruginosa reduced their motility, penetration through skin models (ex-vivo-burned porcine skin), and ability to stimulate cytokine production (tumor necrosis factor-α [TNF-α] and interleukin 8 [IL-8]) by THP-1 cells. In addition, CeN-treated Pseudomonas was more readily phagocytized by THP-1 cells. Finally, P. aeruginosa inoculated on CeN-treated ex-vivo-burned porcine skin was more susceptible to killing by a silver dressing. Innovation: In vitro skin models offer a platform for screening drugs that interfere with bacterial penetration into wounded tissue. Conclusion: CeN treatment reduced P. aeruginosa virulence, altered the mechanical properties of ex-vivo-burned porcine skin and collagen matrix, retarded penetration of P. aeruginosa through the skin models, and resulted in increased vulnerability of P. aeruginosa to killing by antimicrobial wound dressings. These data support the use of CeN in burn management.

Quercitrin neutralizes sPLA2IIa activity, reduces the inflammatory IL-6 level in PC3 cell lines, and exhibits anti-tumor activity in the EAC-bearing mice model.

Human phospholipase A2 group IIa (sPLA2IIa) is an inflammatory enzyme that plays a significant role in tumorigenesis. Inhibiting the sPLA2IIa enzyme with an effective molecule can reduce the inflammatory response and halt cancer progression. The present study evaluates quercitrin, a biflavonoid, for sPLA2IIa inhibition and anticancer activity. Quercitrin inhibited sPLA2IIa activity to a greater extent-at 86.24% ± 1.41 with an IC50 value of 8.77 µM ± 0.9. The nature of sPLA2IIa inhibition was evaluated by increasing calcium concentration from 2.5 to 15 µM and substrate from 20 to 120 nM, which did not alter the level of inhibition. Intrinsic fluorescence and far UV-CD studies confirmed the direct interaction of quercitrin with the sPLA2IIa enzyme. This significantly reduced the sPLA2IIa-induced hemolytic activity and mouse paw edema from 97.32% ± 1.23-16.91% ± 2.03 and 172.87% ± 1.9-118.41% ± 2.53, respectively. As an anticancer activity, quercitrin reduced PC-3 cell viability from 98.66% ± 2.51-18.3% ± 1.52 and significantly decreased the IL-6 level in a dose-dependent manner from 98.35% ± 2.2-37.12% ± 2.4. It increased the mean survival time (MST) of EAC-bearing Swiss albino mice from 30 to 35 days. It obeyed Lipinski's rule of five, suggesting a druggable property. Thus, all the above experimental results were promising and encouraged further investigation into developing quercitrin as a therapeutic drug for both inflammatory diseases and cancers.

A guide to senolytic intervention in neurodegenerative disease.

Cellular senescence is a potential tumor-suppressive mechanism that generally results in an irreversible cell cycle arrest. Senescent cells accumulate with age and actively secrete soluble factors, collectively termed the 'senescence-associated secretory phenotype' (SASP), which has both beneficial and detrimental effects. Although the contribution of senescent cells to age-related pathologies has been well-established outside the brain, emerging evidence indicates that brain cells also undergo cellular senescence and contribute to neuronal loss in the context of age-related neurodegenerative diseases. Contribution of senescent cells in the pathogenesis of neurological disorders has led to the possibility of eliminating senescence cells via pharmacological compounds called senolytics. Recently several senolytics have been demonstrated to elicit improved cognitive performance and healthspan in mouse models of neurodegeneration. However, their translation for use in the clinic still holds several potential challenges. This review summarizes available senolytics, their purported mode of action, and possible off-target effects. We also discuss possible alternative strategies that may help minimize potential side-effects associated with the senolytics approach.

Dysregulated iron metabolism in C. elegans catp-6/ATP13A2 mutant impairs mitochondrial function.

Mutations in the human ATP13A2 gene are associated with an early-onset form of Parkinson's disease (PD) known as Kufor Rakeb Syndrome (KRS). Patients with KRS show increased iron deposition in the basal ganglia, suggesting iron toxicity-induced neurodegeneration as a potential pathogenesis associated with the ATP13A2 mutation. Previously we demonstrated that functional losses of ATP13A2 disrupt the lysosomes ability to store excess iron, leading to reduce survival of dopaminergic neuronal cells. To understand the possible mechanisms involved, we studied a Caenorhabditis elegans mutant defective in catp-6 function, an ortholog of human ATP13A2 gene. Here we show that catp-6 mutant worms have defective autophagy and lysosomal function, demonstrate characteristic PD phenotypes including reduced motor function and dysregulated iron metabolism. Additionally, these mutants have defective mitochondrial health, which is rescuable via iron chelation or mitophagy induction.

Cerium Nitrate Treatment Provides Eschar Stabilization through Reduction in Bioburden, DAMPs, and Inflammatory Cytokines in a Rat Scald Burn Model.

In this study, we used a clinically relevant rat scald burn model to determine the treatment effects of cerium nitrate (CN) for stabilizing burn eschars through reduction of damage-associated molecular patterns (DAMPs), inflammatory cytokines, and bioburden. Forty-two male Sprague-Dawley rats were anesthetized before undergoing a scald burn at 99°C for 6 seconds to create a 10% full-thickness burn. The test groups included sham burn, burn with water bathing, and burn with CN bathing. End point parameters included circulating DAMPs, proinflammatory cytokines, tissue myeloperoxidase activity, and quantification of resident flora in burn skin. The high mobility group protein box 1 was found to be elevated in burn animals at postoperative days (POD) 1 and 7. CN significantly alleviated the increase (P < .05 at POD 1 and P < .01 at POD 7). CN also lessened the heightened levels of hyaluronan in burn animals (P < .05 at POD 7). Additionally, CN significantly reduced the burn-induced increases in interleukin-1ß, growth-regulated oncogene/keratinocyte chemoattractant, and macrophage inflammatory protein-1α in burn wounds. The anti-inflammatory effect of CN was also demonstrated in its ability to mitigate the upregulated circulatory xanthine oxidase/dehydrogenase and increased tissue neutrophil infiltration in burn animals. Last, CN suppressed postburn proliferation of resident skin microbes, resulting in a significant 2-log reduction by POD 7. In conclusion, these results suggest that CN attenuates the burn-induced DAMPs, tissue inflammatory responses, and regrowth of resident skin flora, all of which collectively could improve the quality of burn eschar when applied at the point of injury in prolonged field care situations.

Antitumor effects of chitin specific lectin from Praecitrullus fistulosus by targeting angiogenesis and apoptosis.

In the present study, chitin specific lectin was purified from fruit exudates of Praecitrullus fistulosus. The lectin was purified and analyzed using affinity chromatography, RP-HPLC and electrophoretic studies. Furthermore, protein was identified by MALDI-MS/MS and peptide mass fingerprinting. Purified lectin (PfL) effectively agglutinates RBC, lymphocytes and displayed strong cytotoxicity against colon cancer (line HT29) cells among screened cells. PfL induced apoptosis by altering the expression of apoptotic proteins via caspadse-3 dependent pathway. In vivo studies using EAC mice model proves the efficacy of PfL by activating apoptosis and inhibiting the tumor neovasculature by targeting the MVD, VEGF and MMP's secretion. More importantly, the PfL treatment leads to effective inhibition of tumor growth and a ∼2.71 fold increase in the lifespan of EAC mice. Collectively, our study provides comprehensive evidence that the role of dietary lectins with significant cytotoxic potential by targeting tumor angiogenesis and activating apoptosis in cancer study models.

A randomized trial of endovascular versus surgical management of ruptured intracranial aneurysms: Interim results from ISAT2.

BACKGROUND AND PURPOSE: Appropriate management of ruptured intracranial aneurysm (RIA) in patients eligible for surgical clipping but under-represented in or excluded from previous randomized trials remains undetermined. METHODS: The International Subarachnoid Aneurysm Trial-2 (ISAT-2) is a randomized care trial comparing surgical versus endovascular treatment (EVT) of RIA. All patients considered for surgical clipping but eligible for endovascular treatment can be included. The primary endpoint is death or dependency on modified Rankin score (mRS>2) at 1 year. Secondary endpoints are 1 year angiographic results and length of hospital stay. RESULTS: An interim analysis was performed after 103 patients were treated from November 2012 to July 2017 in 4 active centers. Fifty-two of the 55 patients allocated to surgery were treated by clipping, and 45 of the 48 allocated to EVT were treated by coiling, with 3 crossovers in each arm. The main endpoint (1 year mRS>2), available for 76 patients, was reached in 16/42 patients allocated to clipping (38%; 95%CI: 25%-53%), and 10/34 patients allocated to coiling (29%; 17%-46%). One year imaging results were available in 54 patients: complete aneurysm occlusion was found in 23/27 patients allocated to clipping (85%; 67%-94%), and 18/27 patients allocated to coiling (67%; 47%-81%). Hospital stay exceeding 20 days was more frequent in surgery (26/55 [47%; 34%-60%]) than EVT (9/48 [19%; 10%-31%]). CONCLUSION: Ruptured aneurysm patients for whom surgical clipping may still be best can be managed in a randomized care trial, which is feasible in some centers. More participating centers are needed.

Cellular Senescence Is Induced by the Environmental Neurotoxin Paraquat and Contributes to Neuropathology Linked to Parkinson's Disease.

Exposure to the herbicide paraquat (PQ) is associated with an increased risk of idiopathic Parkinson's disease (PD). Therapies based on PQ's presumed mechanisms of action have not, however, yielded effective disease therapies. Cellular senescence is an anticancer mechanism that arrests proliferation of replication-competent cells and results in a pro-inflammatory senescence-associated secretory phenotype (SASP) capable of damaging neighboring tissues. Here, we demonstrate that senescent cell markers are preferentially present within astrocytes in PD brain tissues. Additionally, PQ was found to induce astrocytic senescence and an SASP in vitro and in vivo, and senescent cell depletion in the latter protects against PQ-induced neuropathology. Our data suggest that exposure to certain environmental toxins promotes accumulation of senescent cells in the aging brain, which can contribute to dopaminergic neurodegeneration. Therapies that target senescent cells may constitute a strategy for treatment of sporadic PD, for which environmental exposure is a major risk factor.

The interactome of metabolic enzyme carbonic anhydrase IX reveals novel roles in tumor cell migration and invadopodia/MMP14-mediated invasion.

Carbonic anhydrase IX (CAIX) is a hypoxia inducible factor 1-induced, cell surface pH regulating enzyme with an established role in tumor progression and clinical outcome. However, the molecular basis of CAIX-mediated tumor progression remains unclear. Here, we have utilized proximity dependent biotinylation (BioID) to map the CAIX 'interactome' in breast cancer cells in order to identify physiologically relevant CAIX-associating proteins with potential roles in tumor progression. High confidence proteins identified include metabolic transporters, ß1 integrins, integrin-associated protein CD98hc and matrix metalloprotease 14 (MMP14). Biochemical studies validate the association of CAIX with α2ß1 integrin, CD98hc and MMP14, and immunofluorescence microscopy demonstrates colocalization of CAIX with α2ß1 integrin and MMP14 in F-actin/cofilin-positive lamellipodia/pseudopodia, and with MMP14 to cortactin/Tks5-positive invadopodia. Modulation of CAIX expression and activity results in significant changes in cell migration, collagen degradation and invasion. Mechanistically, we demonstrate that CAIX associates with MMP14 through potential phosphorylation residues within its intracellular domain, and that CAIX enhances MMP14-mediated collagen degradation by directly contributing hydrogen ions required for MMP14 catalytic activity. These findings establish hypoxia-induced CAIX as a novel metabolic component of cellular migration and invasion structures, and provide new mechanistic insights into its role in tumor cell biology.

Debio 0617B Inhibits Growth of STAT3-Driven Solid Tumors through Combined Inhibition of JAK, SRC, and Class III/V Receptor Tyrosine Kinases.

Tumor survival, metastases, chemoresistance, and escape from immune responses have been associated with inappropriate activation of STAT3 and/or STAT5 in various cancers, including solid tumors. Debio 0617B has been developed as a first-in-class kinase inhibitor with a unique profile targeting phospho-STAT3 (pSTAT3) and/or pSTAT5 in tumors through combined inhibition of JAK, SRC, ABL, and class III/V receptor tyrosine kinases (RTK). Debio 0617B showed dose-dependent inhibition of pSTAT3 in STAT3-activated carcinoma cell lines; Debio 0617B also showed potent antiproliferative activity in a panel of cancer cell lines and in patient-derived tumor xenografts tested in an in vitro clonogenic assay. Debio 0617B showed in vivo efficacy by inhibiting tumor growth in several mouse xenograft models. To increase in vivo efficacy and STAT3 inhibition, Debio 0617B was tested in combination with the EGFR inhibitor erlotinib in a non-small cell lung cancer xenograft model. To evaluate the impact of in vivo STAT3 blockade on metastases, Debio 0617B was tested in an orthotopic tumor model. Measurement of primary tumor weight and metastatic counts in lung tissue demonstrated therapeutic efficacy of Debio 0617B in this model. These data show potent activity of Debio 0617B on a broad spectrum of STAT3-driven solid tumors and synergistic activity in combination with EGFR inhibition. Mol Cancer Ther; 15(10); 2334-43. ©2016 AACR.

Regulation of ATP13A2 via PHD2-HIF1α Signaling Is Critical for Cellular Iron Homeostasis: Implications for Parkinson's Disease.

We previously reported that pharmacological inhibition of a class of enzymes known as prolyl hydroxylase domain proteins (PHDs) has neuroprotective effects in various in vitro and in vivo models of Parkinson's disease (PD). We hypothesized that this was due to inhibition of the PHD2 isoform, preventing it from hydroxylating the transcription factor hypoxia inducible factor 1 α (HIF1α), targeting it for eventual proteasomal degradation. HIF1α itself induces the transcription of various cellular stress genes, including several involved in iron metabolism. Although all three isoforms of PHD are expressed within vulnerable dopaminergic (DAergic) substantia nigra pars compacta neurons, only select downregulation of the PHD2 isoform was found to protect against in vivo neurodegenerative effects associated with the mitochondrial neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. These findings were corroborated in induced pluripotent stem cell-derived neurons, providing validation in a pertinent human cell model. PHD2 inhibition was found to result in increased expression of ATP13A2, mutation of which is responsible for a rare juvenile form of PD known as Kufor-Rakeb syndrome. Knockdown of ATP13A2 expression within human DAergic cells was found to abrogate restoration of cellular iron homeostasis and neuronal cell viability elicited by inhibition of PHD2 under conditions of mitochondrial stress, likely via effects on lysosomal iron storage. These data suggest that regulation of ATP13A2 by the PHD2-HIF1α signaling pathway affects cellular iron homeostasis and DAergic neuronal survival. This constitutes a heretofore unrecognized process associated with loss of ATP13A2 function that could have wide-ranging implications for it as a therapeutic target for PD and other related conditions. SIGNIFICANCE STATEMENT: Reductions in PHD2 activity within dopaminergic neurons in vivo and in cultured human induced pluripotent stem cell-derived neurons protects against mitochondrial stress-induced neurotoxicity. Protective effects are dependent on downstream HIF-1α expression. Knockdown of ATP13A2, a gene linked to a rare juvenile form of Parkinson's disease and recently identified as a novel HIF1α target, was found to abrogate maintenance of cellular iron homeostasis and neuronal viability elicited by PHD2 inhibition in vivo and in cultured dopaminergic cells under conditions of mitochondrial stress. Mechanistically, this was due to ATP13A2's role in maintaining lysosomal iron stores. This constitutes a novel mechanism by which alterations in ATP13A2 activity may be driving PD-related neuropathology.

Impact of an Interdisciplinary Deep Brain Stimulation Screening Model on Post-Surgical Complications in Essential Tremor Patients.

OBJECTIVE: To investigate the relationship of our interdisciplinary screening process on post-operative unintended hospitalizations and quality of life. BACKGROUND: There are currently no standardized criteria for selection of appropriate Deep Brain Stimulation candidates and little hard data exists to support the use of any singular method. METHODS: An Essential Tremor cohort was selected from our institutional Deep Brain Stimulation database. The interdisciplinary model utilized seven specialties who pre-operatively screened all potential Deep Brain Stimulation candidates. Concerns for surgery raised by each specialty were documented and classified as none, minor, or major. Charts were reviewed to identify unintended hospitalizations and quality of life measurements at 1 year post-surgery. RESULTS: Eighty-six percent (44/51) of the potential screened candidates were approved for Deep Brain Stimulation. Eight (18%) patients had an unintended hospitalization during the follow-up period. Patients with minor or major concerns raised by any specialty service had significantly more unintended hospitalizations when compared to patients without concerns (75% vs. 25%, p < 0.005). The rate of hospitalization revealed a direct relationship to the "level of concern"; ranging from 100% if major concerns, 42% if minor concerns, and 7% if no concerns raised, p = 0.001. Quality of life scores significantly worsened in patients with unintended hospitalizations at 6 (p = 0.046) and 12 months (p = 0.027) when compared to baseline scores. No significant differences in tremor scores between unintended and non-unintended hospitalizations were observed. CONCLUSIONS: The number and level of concerns raised during interdisciplinary Deep Brain Stimulation screenings were significantly related to unintended hospitalizations and to a reduced quality of life. The interdisciplinary evaluation may help to stratify risk for these complications. However, data should be interpreted with caution due to the limitations of our study. Further prospective comparative and larger studies are required to confirm our results.

Aspergillus flavus induces granulomatous cerebral aspergillosis in mice with display of distinct cytokine profile.

Aspergillus flavus is one of the leading Aspergillus spp. resulting in invasive aspergillosis of central nervous system (CNS) in human beings. Immunological status in aspergillosis of central nervous system remains elusive in case of both immunocompetent and immunocompromised patients. Since cytokines are the major mediators of host response, evaluation of disease pathology along with cytokine profile in brain may provide snapshots of neuro-immunological response. An intravenous model of A. flavus infection was utilized to determine the pathogenicity of infection and cytokine profile in the brain of male BALB/c mice. Enumeration of colony forming units and histopathological analyses were performed on the brain tissue at distinct time periods. The kinetics of cytokines (TNF-α, IFN-γ, IL-12/IL-23p40, IL-6, IL-23, IL-17A and IL-4) was evaluated at 6, 12, 24, 48, 72 and 96h post infection (hPI) in brain homogenates using murine cytokine specific enzyme linked immunosorbent assay. Histological analysis exhibited the hyphae with leukocyte infiltrations leading to formation of granulomata along with ischemia and pyknosis of neurons in the brain of infected mice. Diseased mice displayed increased secretion of IFN-γ, IL-12p40 and IL-6 with a concomitant reduction in the secretion of Th2 cytokine IL-4, and Th17 promoting cytokine, IL-23 during the late phase of infection. A.flavus induced inflammatory granulomatous cerebral aspergillosis in mice, characterized by a marked increase in the Th1 cytokines and neurons undergoing necrosis. A marked increase in necrosis of neurons with concurrent inflammatory responses might have led to the host mortality during late phase of infection.

Cellular senescence and the aging brain.

Cellular senescence is a potent anti-cancer mechanism that arrests the proliferation of mitotically competent cells to prevent malignant transformation. Senescent cells accumulate with age in a variety of human and mouse tissues where they express a complex 'senescence-associated secretory phenotype' (SASP). The SASP includes many pro-inflammatory cytokines, chemokines, growth factors and proteases that have the potential to cause or exacerbate age-related pathology, both degenerative and hyperplastic. While cellular senescence in peripheral tissues has recently been linked to a number of age-related pathologies, its involvement in brain aging is just beginning to be explored. Recent data generated by several laboratories suggest that both aging and age-related neurodegenerative diseases are accompanied by an increase in SASP-expressing senescent cells of non-neuronal origin in the brain. Moreover, this increase correlates with neurodegeneration. Senescent cells in the brain could therefore constitute novel therapeutic targets for treating age-related neuropathologies.

Pharmacological prolyl hydroxylase domain inhibition as a therapeutic target for Parkinson's disease.

Previously published data from our laboratory demonstrated that pharmacological inhibition of a family of enzymes known as prolyl hydroxylase domain proteins prevents neurotoxicity associated with the acute 1-methyl-4- phenyl-1,2,3,6-tetrahydropyridine intoxication model of Parkinson's disease in young animals. In this study, we assessed whether prolyl hydroxylase domain inhibition was neuroprotective in an inducible genetic dopaminergic glutathione depletion model previously characterized by our laboratory that more closely recapitulates the age-related and progressive nature of the human disease. Pharmacological prolyl hydroxylase domain inhibition via 3,4-dihydroxybenzoate was found to significantly attenuate hallmark mitochondrial dysfunction and loss of dopaminergic substantia nigral pars compacta neurons associated with this model. These studies further validate the possibility that prolyl hydroxylase domain inhibition may constitute a viable therapy for Parkinson's disease.

Catecholamine metabolism drives generation of mitochondrial DNA deletions in dopaminergic neurons.

Accumulation of mitochondrial DNA deletions is observed especially in dopaminergic neurons of the substantia nigra during ageing and even more in Parkinson's disease. The resulting mitochondrial dysfunction is suspected to play an important role in neurodegeneration. However, the molecular mechanisms involved in the preferential generation of mitochondrial DNA deletions in dopaminergic neurons are still unknown. To study this phenomenon, we developed novel polymerase chain reaction strategies to detect distinct mitochondrial DNA deletions and monitor their accumulation patterns. Applying these approaches in in vitro and in vivo models, we show that catecholamine metabolism drives the generation and accumulation of these mitochondrial DNA mutations. As in humans, age-related accumulation of mitochondrial DNA deletions is most prominent in dopaminergic areas of mouse brain and even higher in the catecholaminergic adrenal medulla. Dopamine treatment of terminally differentiated neuroblastoma cells, as well as stimulation of dopamine turnover in mice over-expressing monoamine oxidase B both induce multiple mitochondrial DNA deletions. Our results thus identify catecholamine metabolism as the driving force behind mitochondrial DNA deletions, probably being an important factor in the ageing-associated degeneration of dopaminergic neurons.

Monocytes mediate metastatic breast tumor cell adhesion to endothelium under flow.

Endothelial adhesion is necessary for the hematogenous dissemination of tumor cells. However, the metastatic breast tumor cell MDA-MB-231 does not bind to the endothelium under physiological flow conditions, suggesting alternate mechanisms of adhesion. Since monocytes are highly represented in the tumor microenvironment, and also bind to endothelium during inflammation, we hypothesized that the monocytes assist in the arrest of MDA-MB-231 on the endothelium. Using in vitro models of the dynamic shear environment of the vasculature, we show that TNF-α-activated THP1/primary human monocytes and MDA-MB-231 cells form stable aggregates, and that the monocytes in these aggregates mediate the adhesion of otherwise nonadherent MDA-MB-231 cells to inflamed endothelium under flow (55±2.4 vs. 1.7±0.82 at a shear stress of 0.5 dyn/cm(2), P<0.01). We also show that the hydrodynamic forces determine the size and orientation of aggregates adhered to the endothelium, and strongly favor the attachment of small aggregates with tumor cells downstream of flow (74-86% doublets at 0.5-2 dyn/cm(2), P<0.01). The 5-fold up-regulation of ICAM-1 on TNF-α-activated MDA-MB-231 cells through the Nf-κB pathway was found to be critical in MDA-MB-231-monocyte aggregation and endothelial adhesion. Our results demonstrate that, under inflammatory conditions, monocytes may serve to disseminate tumor cells through circulation, and the tumor-monocyte-endothelial axis may represent a new therapeutic target to reduce cancer metastasis.

Selective binding of nuclear alpha-synuclein to the PGC1alpha promoter under conditions of oxidative stress may contribute to losses in mitochondrial function: implications for Parkinson's disease.

Alpha-synuclein has been reported to be present in the nucleus and levels enhanced by oxidative stress. Herein, we sought to investigate the mechanistic role of nuclear alpha-synuclein. We found that alpha-synuclein nuclear localization coincided with enhanced chromatin binding both in an in vitro and a corresponding in vivo brain oxidative stress model previously characterized by our laboratory as well as in PD brain tissues. Genome-wide chromatin immunoprecipitation (ChIP)-on-chip analysis of alpha-synuclein:promoter binding in response to oxidative stress in vitro revealed that binding occurs at several promoters belonging to a range of functional categories including transcriptional regulation. Interestingly, given the important role of mitochondrial dysfunction in PD, this included binding to the promoter for the master mitochondrial transcription activator, PGC1alpha in vitro, in vivo, and in human brain tissue with age and PD. To test the possible mechanistic impact of alpha-synuclein PGC1alpha promotor binding, we assessed PGC1alpha promoter activity, mRNA, and protein levels and expression of candidate PGC1alpha target genes in our in vitro model. All were found to be reduced in conjunction with increased levels of aberrant mitochondrial morphology and impaired mitochondrial function. Exogenous PGC1alpha expression was found to attenuate alpha-synuclein-mediated mitochondrial dysfunction and subsequent neurotoxicity in vitro. Our data suggest that nuclear alpha-synuclein localization under conditions of oxidative stress may impact on mitochondrial function in part via the protein's capacity to act as a transcriptional modulator of PGC1alpha. This represents a novel role for alpha-synuclein as it relates to mitochondrial dysfunction in PD.

Amplatzer vascular plug for occlusion of parent artery in carotid blowout with active extravasation.

Carotid blowout is a devastating complication in patients with head and neck malignancy. Various treatments including high risk surgery, carotid stenting or carotid occlusion using either coils or detachable balloons have been described. The key for any treatment is the rapidity at which it can be performed. We describe treatment of common carotid blowout secondary to neoplastic infiltration using four Amplatzer vascular plugs deployed in less than ten minutes.