Combined therapies of antithrombotics and antioxidants delay in silico brain tumor progression

Glioblastoma multiforme, the most frequent type of primary brain tumor, is a rapidly evolving and spatially heterogeneous high-grade astrocytoma that presents areas of necrosis, hypercellularity and microvascular hyperplasia. The aberrant vasculature leads to hypoxic areas and results in an increase of the oxidative stress selecting for more invasive tumor cell phenotypes. In our study we assay in silico different therapeutic approaches which combine antithrombotics, antioxidants and standard radiotherapy. To do so, we have developed a biocomputational model of glioblastoma multiforme that incorporates the spatio-temporal interplay among two glioma cell phenotypes corresponding to oxygenated and hypoxic cells, a necrotic core and the local vasculature whose response evolves with tumor progression. Our numerical simulations predict that suitable combinations of antithrombotics and antioxidants may diminish, in a synergetic way, oxidative stress and the subsequent hypoxic response. This novel therapeutical strategy, with potentially low or no toxicity, might reduce tumor invasion and further sensitize glioblastoma multiforme to conventional radiotherapy or other cytotoxic agents, hopefully increasing median patient overall survival time.Comment: 8 figure

Immigrant IBD Patients in Spain Are Younger, Have More Extraintestinal Manifestations and Use More Biologics Than Native Patients

BackgroundPrevious studies comparing immigrant ethnic groups and native patients with IBD have yielded clinical and phenotypic differences. To date, no study has focused on the immigrant IBD population in Spain. MethodsProspective, observational, multicenter study comparing cohorts of IBD patients from ENEIDA-registry who were born outside Spain with a cohort of native patients. ResultsWe included 13,524 patients (1,864 immigrant and 11,660 native). The immigrants were younger (45 +/- 12 vs. 54 +/- 16 years, p < 0.001), had been diagnosed younger (31 +/- 12 vs. 36 +/- 15 years, p < 0.001), and had a shorter disease duration (14 +/- 7 vs. 18 +/- 8 years, p < 0.001) than native patients. Family history of IBD (9 vs. 14%, p < 0.001) and smoking (30 vs. 40%, p < 0.001) were more frequent among native patients. The most prevalent ethnic groups among immigrants were Caucasian (41.5%), followed by Latin American (30.8%), Arab (18.3%), and Asian (6.7%). Extraintestinal manifestations, mainly musculoskeletal affections, were more frequent in immigrants (19 vs. 11%, p < 0.001). Use of biologics, mainly anti-TNF, was greater in immigrants (36 vs. 29%, p < 0.001). The risk of having extraintestinal manifestations [OR: 2.23 (1.92-2.58, p < 0.001)] and using biologics [OR: 1.13 (1.0-1.26, p = 0.042)] was independently associated with immigrant status in the multivariate analyses. ConclusionsCompared with native-born patients, first-generation-immigrant IBD patients in Spain were younger at disease onset and showed an increased risk of having extraintestinal manifestations and using biologics. Our study suggests a featured phenotype of immigrant IBD patients in Spain, and constitutes a new landmark in the epidemiological characterization of immigrant IBD populations in Southern Europe

Enhanced anti-oxidant protection of liver membranes in long-lived rats fed on a coenzyme Q10-supplemented diet

13 páginas, 6 figuras.Coenzyme Q10 supplementation increases life-span of rats fed on a diet enriched with polyunsaturated fatty acids (Quiles, J.L., Ochoa, J.J., Huertas, J.R., Mataix, J., 2004b. Coenzyme Q supplementation protects from age-related DNA double-strand breaks and increased lifespan in rats fed on a PUFA-rich diet. Exp. Gerontol. 39, 189–194). Our study was set as a first attempt to establish a mechanistic link between life span extension and CoQ10 supplementation. When rats were fed on a PUFAn−6 plus CoQ10 diet, levels of CoQ10 were increased in plasma membrane at every time point compared to control rats fed on a PUFAn-6-alone diet. Ratios of CoQ9 to CoQ10 were significantly lower at every time point in both liver plasma membranes and homogenates of CoQ10-supplemented animals. CoQ10 supplementation did not affect cytosolic NAD(P)H:quinone oxidoreductase 1 (NQO1), which increased significantly with aging, but plasma membrane-bound NQO1 decreased significantly in the CoQ10-supplemented group at 12 months, when maximal incorporation of exogenous CoQ10 was observed. Neither aging nor the diet affected NADH-cytochrome b5 reductase levels. Glutathione-dependent anti-oxidant activities such as cytosolic glutathione-S-transferase (GST) and microsomal Se-independent glutathione peroxidase decreased with aging and supplementation with CoQ10 attenuated this decay. 2,2′ Azobis amidinopropane (AAPH)-induced oxidation of membranes was significantly higher in aged rats, and supplementation with CoQ10 also inhibited this increase. Consistent with higher CoQ10 levels and enhanced anti-oxidant protection, plasma membrane Mg2+-dependent neutral sphingomyelinase was inhibited by dietary CoQ10 in aged rats. Our results support the involvement of thiol-dependent mechanisms in the potentiation of the anti-oxidant capacity of membranes in CoQ10-supplemented rats, further supporting the potentially beneficial anti-oxidative role of dietary CoQ10 during aging. The possibility that a decreased CoQ9/CoQ10 ratio in animals fed on the PUFAn−6-rich plus CoQ10 diet could also influence longevity is also discussed.Supported by Grants No. 1FD97-0457-C02-02 and BMC2002-01078 (Spanish Ministerio de Educación y Cultura and Ministerio de Ciencia y Tecnología), and CVI-276 (Junta de Andalucía). R.I.B. acknowledges financial support by Instituto Danone. C.G.D. was supported by CVI-276.Peer reviewe

Biological Significance of the Protein Changes Occurring in the Cerebrospinal Fluid of Alzheimer’s Disease Patients: Getting Clues from Proteomic Studies

The fact that cerebrospinal fluid (CSF) deeply irrigates the brain together with the relative simplicity of sample extraction from patients make this biological fluid the best target for biomarker discovery in neurodegenerative diseases. During the last decade, biomarker discovery has been especially fruitful for the identification new proteins that appear in the CSF of Alzheimer’s disease (AD) patients together with amyloid-β (Aβ42), total tau (T-tau), and phosphorylated tau (P-tau). Thus, several proteins have been already stablished as important biomarkers, due to an increase (i.e., CHI3L1) or a decrease (i.e., VGF) in AD patients’ CSF. Notwithstanding this, only a deep analysis of a database generated with all the changes observed in CSF across multiple proteomic studies, and especially those using state-of-the-art methodologies, may expose those components or metabolic pathways disrupted at different levels in AD. Deep comparative analysis of all the up- and down-regulated proteins across these studies revealed that 66% of the most consistent protein changes in CSF correspond to intracellular proteins. Interestingly, processes such as those associated to glucose metabolism or RXR signaling appeared inversely represented in CSF from AD patients in a significant manner. Herein, we discuss whether certain cellular processes constitute accurate indicators of AD progression by examining CSF. Furthermore, we uncover new CSF AD markers, such as ITAM, PTPRZ or CXL16, identified by this study

Human amyloid-β enriched extracts: evaluation of in vitro and in vivo internalization and molecular characterization

[Background]: Intracerebral inoculation of extracts from post-mortem human Alzheimer’s disease brains into mice produces a prion-like spreading effect of amyloid-β. The differences observed between these extracts and the synthetic peptide, in terms of amyloid-β internalization and seed and cell-to-cell transmission of cytosolic protein aggregates, suggest that brain extracts contain key contributors that enhance the prion-like effect of amyloid-β. Nevertheless, these potential partners are still unknown due to the complexity of whole brain extracts.[Methods]: Herein, we established a method based on sequential detergent solubilization of post-mortem samples of human brains affected by Alzheimer’s disease that strongly enrich amyloid-β aggregates by eliminating 92% of the remaining proteins. Internalization of Aβ1–42 from the enriched AD extracts was evaluated in vitro, and internalization of fluorescent-labeled AD extracts was also investigated in vivo. Furthermore, we carried out a molecular characterization of the Aβ-enriched fraction using label-free proteomics, studying the distribution of representative components in the amygdala and the olfactory cortex of additional human AD brain samples by immunohistochemistry.[Results]: Aβ1–42 from the enriched AD extracts are internalized into endothelial cells in vitro after 48 h. Furthermore, accumulation of fluorescent-labeled Aβ-enriched extracts into mouse microglia was observed in vivo after 4 months of intracerebral inoculation. Label-free proteomics (FDR < 0.01) characterization of the amyloid-β-enriched fraction from different post-mortem samples allowed for the identification of more than 130 proteins, several of which were significantly overrepresented (i.e., ANXA5 and HIST1H2BK; p < 0.05) and underrepresented (i.e., COL6A or FN1; p < 0.05) in the samples with Alzheimer’s disease. We were also able to identify proteins exclusively observed in Alzheimer’s disease (i.e., RNF213) or only detected in samples not affected by the disease (i.e., CNTN1) after the enrichment process. Immunohistochemistry against these proteins in additional tissues revealed their particular distribution in the amygdala and the olfactory cortex in relation to the amyloid-β plaque.[Conclusions]: Identification and characterization of the unique features of these extracts, in terms of amyloid-β enrichment, identification of the components, in vitro and in vivo cell internalization, and tissue distribution, constitute the best initial tool to further investigate the seeding and transmissibility proposed in the prion-like hypothesis of Alzheimer’s disease.Sponsored by the Spanish Ministry of Economy and Competitiveness-FEDER (grant # SAF2016-75768-R) to AMM, MINECO-RETOS (AEI-FEDER) to MDP, and the Autonomous Government of Castilla-La Mancha/FEDER (grant no. SBPLY/ 17/180501/000430) to AMM and DSS.Peer reviewe

Coenzyme Q₁₀ Protects Human Endothelial Cells from β-Amyloid Uptake and Oxidative Stress-Induced Injury

<div><p>Neuropathological symptoms of Alzheimer's disease appear in advances stages, once neuronal damage arises. Nevertheless, recent studies demonstrate that in early asymptomatic stages, ß-amyloid peptide damages the cerebral microvasculature through mechanisms that involve an increase in reactive oxygen species and calcium, which induces necrosis and apoptosis of endothelial cells, leading to cerebrovascular dysfunction. The goal of our work is to study the potential preventive effect of the lipophilic antioxidant coenzyme Q (CoQ) against ß-amyloid-induced damage on human endothelial cells. We analyzed the protective effect of CoQ against Aβ-induced injury in human umbilical vein endothelial cells (HUVECs) using fluorescence and confocal microscopy, biochemical techniques and RMN-based metabolomics. Our results show that CoQ pretreatment of HUVECs delayed Aβ incorporation into the plasma membrane and mitochondria. Moreover, CoQ reduced the influx of extracellular Ca²⁺, and Ca²⁺ release from mitochondria due to opening the mitochondrial transition pore after β-amyloid administration, in addition to decreasing O₂^.− and H₂O₂ levels. Pretreatment with CoQ also prevented ß-amyloid-induced HUVECs necrosis and apoptosis, restored their ability to proliferate, migrate and form tube-like structures <i>in vitro</i>, which is mirrored by a restoration of the cell metabolic profile to control levels. CoQ protected endothelial cells from Aβ-induced injury at physiological concentrations in human plasma after oral CoQ supplementation and thus could be a promising molecule to protect endothelial cells against amyloid angiopathy.</p></div