Elevated reactive oxygen species and antioxidant enzyme activities in animal and cellular models of Parkinson's disease

AbstractThe dopaminergic neurotoxin N-methyl,4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) causes a syndrome in primates and humans which mimics Parkinson's disease (PD) in clinical, pathological, and biochemical findings, including diminished activity of complex I in the mitochondrial electron transport chain. Reduced complex I activity is found in sporadic PD and can be transferred through mitochondrial DNA, suggesting a mitochondrial genetic etiology. We now show that MPTP treatment of mice and N-methylpyridinium (MPP+) exposure of human SH-SY5Y neuroblastoma cells increases oxygen free radical production and antioxidant enzyme activities. Cybrid cells created by transfer of PD mitochondria exhibit similar characteristics; however, PD cybrids' antioxidant enzyme activities are not further increased by MPP+ exposure, as are the activities in control cybrids. PD mitochondrial cybrids are subject to metabolic and oxidative stresses similar to MPTP parkinsonism and provide a model to determine mechanisms of oxidative damage and cell death in PD

Применение оксидно-рутениевых титановых анодов, модифицированных сурьмой для очистки воды

Rationale: Unlike conventional dendritic cells, plasmacytoid DCs (PDC) are poor in antigen presentation and critical for type 1 interferon response. Though proposed to be present in human atherosclerotic lesions, their role in atherosclerosis remains elusive. Objective: To investigate the role of PDC in atherosclerosis. Methods and Results: We show that PDC are scarcely present in human atherosclerotic lesions and almost absent in mouse plaques. Surprisingly, PDC depletion by 120G8 mAb administration was seen to promote plaque T-cell accumulation and exacerbate lesion development and progression in LDLr(-/-) mice. PDC depletion was accompanied by increased CD4(+) T-cell proliferation, interferon-gamma expression by splenic T cells, and plasma interferon-gamma levels. Lymphoid tissue PDC from atherosclerotic mice showed increased indoleamine 2,3-dioxygenase (IDO) expression and IDO blockage abrogated the PDC suppressive effect on T-cell proliferation. Conclusions: Our data reveal a protective role for PDC in atherosclerosis, possibly by dampening T-cell proliferation and activity in peripheral lymphoid tissue, rendering PDC an interesting target for future therapeutic interventions. (Circ Res. 2011;109:1387-1395.

Pseudomyxoma peritonei – two novel orthotopic mouse models portray the PMCA-I histopathologic subtype

<p>Abstract</p> <p>Background</p> <p>Pseudomyxoma peritonei (PMP) is a rare malignant disease, most commonly originating from appendiceal lesions and characterized by accumulation of mucinous tumor tissue in the peritoneal cavity. Since the disease is infrequent, the task of carrying out studies of treatment efficacy and disease biology in the clinical setting is challenging, warranting the development of relevant <it>in vitro </it>and <it>in vivo </it>PMP models.</p> <p>Methods</p> <p>Human tumor tissue was implanted in the peritoneal cavity of nude mice to establish two orthotopic models exhibiting noninvasive intraperitoneal growth without metastasis development.</p> <p>Results</p> <p>Xenograft tissues have retained essential properties of the original human tumors, such as macro- and microscopic growth patterns, mucin production as well as expression of carcinoembryonal antigen, cytokeratins 20 and 7 and the proliferation marker pKi67. Upon microscopic examination, the human tumors were categorized as the PMCA-I (peritoneal mucinous carcinomatosis of intermediate features) subtype, which was conserved through 14 examined passages in mice, for the first time modeling this particular histopathologic category.</p> <p>Conclusion</p> <p>In conclusion, two novel orthotopic models of human PMP have been established that consistently portray a distinct histopathologic subtype and reflect essential human tumor properties. Xenografts can easily and reproducibly be transferred to new generations of mice with acceptable passage periods, rendering the models as attractive tools for further studies of PMP biology and treatment.</p

Leukocyte Overexpression of Intracellular NAMPT Attenuates Atherosclerosis by Regulating PPAR gamma-Dependent Monocyte Differentiation and Function

Objective-Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) mediates inflammatory and potentially proatherogenic effects, whereas the role of intracellular NAMPT (iNAMPT), the rate limiting enzyme in the salvage pathway of nicotinamide adenine dinucleotide (NAD)(+) generation, in atherogenesis is largely unknown. Here we investigated the effects of iNAMPT overexpression in leukocytes on inflammation and atherosclerosis. Approach and Results-Low-density lipoprotein receptor-deficient mice with hematopoietic overexpression of human iNAMPT (iNAMPT(hi)), on a western type diet, showed attenuated plaque burden with features of lesion stabilization. This anti-atherogenic effect was caused by improved resistance of macrophages to apoptosis by attenuated chemokine (C-C motif) receptor 2-dependent monocyte chemotaxis and by skewing macrophage polarization toward an anti-inflammatory M2 phenotype. The iNAMPT(hi) phenotype was almost fully reversed by treatment with the NAMPT inhibitor FK866, indicating that iNAMPT catalytic activity is instrumental in the atheroprotection. Importantly, iNAMPT overexpression did not induce any increase in eNAMPT, and eNAMPT had no effect on chemokine (C-C motif) receptor 2 expression and promoted an inflammatory M1 phenotype in macrophages. The iNAMPT-mediated effects at least partly involved sirtuin 1-dependent molecular crosstalk of NAMPT and peroxisome proliferator-activated receptor.. Finally, iNAMPT and peroxisome proliferator-activated receptor. showed a strong correlation in human atherosclerotic, but not healthy arteries, hinting to a relevance of iNAMPT/peroxisome proliferator-activated receptor. pathway also in human carotid atherosclerosis. Conclusions-This study highlights the functional dichotomy of intracellular versus extracellular NAMPT, and unveils a critical role for the iNAMPT-peroxisome proliferator-activated receptor. axis in atherosclerosis

Neil3-dependent base excision repair regulates lipid metabolism and prevents atherosclerosis in Apoe-deficient mice

Increasing evidence suggests that oxidative DNA damage accumulates in atherosclerosis. Recently, we showed that a genetic variant in the human DNA repair enzyme NEIL3 was associated with increased risk of myocardial infarction. Here, we explored the role of Neil3/NEIL3 in atherogenesis by both clinical and experimental approaches. Human carotid plaques revealed increased NEIL3 mRNA expression which significantly correlated with mRNA levels of the macrophage marker CD68. Apoe−/−Neil3−/− mice on high-fat diet showed accelerated plaque formation as compared to Apoe−/− mice, reflecting an atherogenic lipid profile, increased hepatic triglyceride levels and attenuated macrophage cholesterol efflux capacity. Apoe−/−Neil3−/− mice showed marked alterations in several pathways affecting hepatic lipid metabolism, but no genotypic alterations in genome integrity or genome-wide accumulation of oxidative DNA damage. These results suggest a novel role for the DNA glycosylase Neil3 in atherogenesis in balancing lipid metabolism and macrophage function, potentially independently of genome-wide canonical base excision repair of oxidative DNA damage

Birds and bioenergy within the americas: A cross‐national, social–ecological study of ecosystem service tradeoffs

Although renewable energy holds great promise in mitigating climate change, there are socioeconomic and ecological tradeoffs related to each form of renewable energy. Forest‐related bioenergy is especially controversial, because tree plantations often replace land that could be used to grow food crops and can have negative impacts on biodiversity. In this study, we examined public perceptions and ecosystem service tradeoffs between the provisioning services associated with cover types associated with bioenergy crop (feedstock) production and forest habitat‐related supporting services for birds, which themselves provide cultural and regulating services. We combined a social survey‐based assessment of local values and perceptions with measures of bioenergy feedstock production impacts on bird habitat in four countries: Argentina, Brazil, Mexico, and the USA. Respondents in all countries rated birds as important or very important (83–99% of respondents) and showed lower enthusiasm for, but still supported, the expansion of bioenergy feedstocks (48–60% of respondents). Bioenergy feedstock cover types in Brazil and Argentina had the greatest negative impact on birds but had a positive impact on birds in the USA. In Brazil and Mexico, public perceptions aligned fairly well with the realities of the impacts of potential bioenergy feedstocks on bird communities. However, in Argentina and the USA, perceptions of bioenergy impacts on birds did not match well with the data. Understanding people’s values and perceptions can help inform better policy and management decisions regarding land use changes

DNA glycosylase Neil3 regulates vascular smooth muscle cell biology during atherosclerosis development.

BACKGROUND AND AIMS: Atherogenesis involves a complex interaction between immune cells and lipids, processes greatly influenced by the vascular smooth muscle cell (VSMC) phenotype. The DNA glycosylase NEIL3 has previously been shown to have a role in atherogenesis, though whether this is due to its ability to repair DNA damage or to other non-canonical functions is not yet clear. Hereby, we investigate the role of NEIL3 in atherogenesis, specifically in VSMC phenotypic modulation, which is critical in plaque formation and stability. METHODS: Chow diet-fed atherosclerosis-prone Apoe-/- mice deficient in Neil3, and NEIL3-abrogated human primary aortic VSMCs were characterized by qPCR, and immunohistochemical and enzymatic-based assays; moreover, single-cell RNA sequencing, mRNA sequencing, and proteomics were used to map the molecular effects of Neil3/NEIL3 deficiency in the aortic VSMC phenotype. Furthermore, BrdU-based proliferation assays and Western blot were performed to elucidate the involvement of the Akt signaling pathway in the transdifferentiation of aortic VSMCs lacking Neil3/NEIL3. RESULTS: We show that Neil3 deficiency increases atherosclerotic plaque development without affecting systemic lipids. This observation was associated with a shift in VSMC phenotype towards a proliferating, lipid-accumulating and secretory macrophage-like cell phenotype, without changes in DNA damage. VSMC transdifferentiation in Neil3-deficient mice encompassed increased activity of the Akt signaling pathway, supported by cell experiments showing Akt-dependent proliferation in NEIL3-abrogated human primary aortic VSMCs. CONCLUSIONS: Our findings show that Neil3 deficiency promotes atherosclerosis development through non-canonical mechanisms affecting VSMC phenotype involving activation of the Akt signaling pathway

Timed Up-and-Go Dual-Task Testing in the Assessment of Cognitive Function : A Mixed Methods Observational Study for Development of the UDDGait Protocol

New methods to screen for and identify early-stage dementia disorders are highly sought after. The purpose of this pilot study is to develop a study protocol for a dual-task test aimed at aiding the early detection of dementia disorders. We used the Timed Up-and-Go (TUG) test, which is a mobility task involving starting in a sitting position, standing up, walking three meters to cross a line on the floor, turning around, walking back and sitting down again. We combined TUG with the verbal task of naming different animals. Pilot study participants were 43 individuals with and without established dementia diagnoses who attended a clinic for memory assessment. Video-recorded test performances were systematically analysed. Deviant test performances concerning the interplay between test administration and participants' responses to the assessment instructions were revealed and led to refinements being made to the final study protocol. Exploration of the dual-task test outcome measures in a sub-sample of 22 persons, ten with and twelve without dementia, indicated that step-length and number of named animals after the turning point of the dual-task test might constitute appropriate measures for examining this kind of sample. We concluded that the refined study protocol is feasible for testing individuals undergoing initial memory assessments and healthy controls. Follow-up studies with larger samples are being carried out and will bring new knowledge to this area of research. It may also provide an opportunity for further studies exploring possibilities for broad clinical implementation