2,756 research outputs found
HIV-1 induces in vivo platelet activation by enhancing platelet NOX2 activity.
OBJECTIVES: HIV-1 patients show increased platelet activation, but the mechanisms involved are not completely clarified. We speculated that HIV-1 might induce in vivo platelet activation by enhancing platelet NOX2-related oxidative stress. METHODS: We measured soluble CD40 Ligand (sCD40L), a systemic marker of platelet activation, in 36 HIV-1 patients under effective combined antiretroviral therapy (cART) and in 10 naïve HIV-1 subjects. As control, 20 healthy subjects (HS) were included. Platelet oxidative stress was measured by platelet NOX2-derived peptide (sNOX2-dp), p47(phox) translocation to platelet membrane and platelet prostaglandin F2α (8-iso-PGF2α). RESULTS: sCD40L was increased both in HIV-1 naïve and cART patients compared to HS (p < 0.001). Platelet sNOX2-dp and 8-iso-PGF2α were significantly higher in HIV-1 naïve subjects compared to those on cART and to HS, and both were mutually correlated (R = 0.734, p < 0.001). A stepwise multivariable linear regression analysis showed that platelet sNOX2-dp (β: 0.803, p < 0.001), HIV-1 infection (β: 0.146, p = 0.014) and age (β: 0.166, p = 0.001) were independently associated to sCD40L levels. CONCLUSIONS: HIV-1 infection is associated with increased platelet oxidative stress, which was related to the activation of NOX2. The independent association between platelet NOX2 activation and plasma levels of sCD40L suggest that in vivo platelet activation may be dependent upon platelet oxidative stress
Metformin increases APP expression and processing via oxidative stress, mitochondrial dysfunction and NF-κB activation: Use of insulin to attenuate metformin's effect
AbstractClinical and experimental biomedical studies have shown Type 2 diabetes mellitus (T2DM) to be a risk factor for the development of Alzheimer's disease (AD). This study demonstrates the effect of metformin, a therapeutic biguanide administered for T2DM therapy, on β-amyloid precursor protein (APP) metabolism in in vitro, ex vivo and in vivo models. Furthermore, the protective role of insulin against metformin is also demonstrated. In LAN5 neuroblastoma cells, metformin increases APP and presenilin levels, proteins involved in AD. Overexpression of APP and presenilin 1 (Pres 1) increases APP cleavage and intracellular accumulation of β-amyloid peptide (Aβ), which, in turn, promotes aggregation of Aβ. In the experimental conditions utilized the drug causes oxidative stress, mitochondrial damage, decrease of Hexokinase-II levels and cytochrome C release, all of which lead to cell death. Several changes in oxidative stress-related genes following metformin treatment were detected by PCR arrays specific for the oxidative stress pathway. These effects of metformin were found to be antagonized by the addition of insulin, which reduced Aβ levels, oxidative stress, mitochondrial dysfunction and cell death. Similarly, antioxidant molecules, such as ferulic acid and curcumin, are able to revert metformin's effect. Comparable results were obtained using peripheral blood mononuclear cells. Finally, the involvement of NF-κB transcription factor in regulating APP and Pres 1 expression was investigated. Upon metformin treatment, NF-κB is activated and translocates from the cytoplasm to the nucleus, where it induces increased APP and Pres 1 transcription. The use of Bay11-7085 inhibitor suppressed the effect of metformin on APP and Pres 1 expression
How water-soluble saccharides drive the metabolism of lactic acid bacteria during fermentation of brewers' spent grain
We proposed a novel phenomic approach to track the effect of short-term exposures of Lactiplantibacillus plantarum and Leuconostoc pseudomesenteroides to environmental pressure induced by brewers' spent grain (BSG)-derived saccharides. Water-soluble BSG-based medium (WS-BSG) was chosen as model system. The environmental pressure exerted by WS-BSG shifted the phenotypes of bacteria in species- and strains-dependent way. The metabolic drift was growth phase-dependent and likely underlay the diauxic profile of organic acids production by bacteria in response to the low availability of energy sources. Among pentosans, metabolism of arabinose was preferred by L. plantarum and xylose by Leuc. pseudomesenteroides as confirmed by the overexpression of related genes. Bayesian variance analysis showed that phenotype switching towards galactose metabolism suffered the greatest fluctuation in L. plantarum. All lactic acid bacteria strains utilized more intensively sucrose and its plant-derived isomers. Sucrose-6-phosphate activity in Leuc. pseudomesenteroides likely mediated the increased consumption of raffinose. The increased levels of some phenolic compounds suggested the involvement of 6-phospho-beta-glucosidases in beta-glucosides degradation. Expression of genes encoding beta-glucoside/cellobiose-specific EII complexes and phenotyping highlighted an increased metabolism for cellobiose. Our reconstructed metabolic network will improve the understanding of how lactic acid bacteria may transform BSG into suitable food ingredients.Peer reviewe
Dolphin Morbillivirus in Eurasian Otters, Italy
We report biomolecular evidence of dolphin morbillivirus in 4 wild Eurasian otters (Lutra lutra) from southern Italy; 2 animals showed simultaneous immunohistochemical reactivity against morbilliviral antigen. These cases add further concern and support to the progressively expanding host range of dolphin morbillivirus in the western Mediterranean Sea
Data concerning the proteolytic resistance and oxidative stress in LAN5 cells after treatment with BSA hydrogels
AbstractProteolytic resistance is a relevant aspect to be tested in the formulation of new nanoscale biomaterials. The action of proteolytic enzymes is a very fast process occurring in the range of few minutes. Here, we report data concerning the proteolytic resistance of a heat-set BSA hydrogel obtained after 20-hour incubation at 60°C prepared at the pH value of 3.9, pH at which the hydrogel presents the highest elastic character with respect to gel formed at pH 5.9 and 7.4 “Heat-and pH-induced BSA conformational changes, hydrogel formation and application as 3D cell scaffold” (G. Navarra, C. Peres, M. Contardi, P. Picone, P.L. San Biagio, M. Di Carlo, D. Giacomazza, V. Militello, 2016) [1]. We show that the BSA hydrogel produced by heating treatment is protected by the action of proteinase K enzyme. Moreover, we show that LAN5 cells cultured in presence of BSA hydrogels formed at pH 3.9, 5.9 and 7.4 did not exhibit any oxidative stress, one of the first and crucial events causing cell death “Are oxidative stress and mitochondrial dysfunction the key players in the neurodegenerative diseases?” (M. Di Carlo, D. Giacomazza, P. Picone, D. Nuzzo, P.L. San Biagio, 2012) [2] “Effect of zinc oxide nanomaterials induced oxidative stress on the p53 pathway” (M.I. Setyawati, C.Y. Tay, D.T. Leaong, 2013) [3]
Aphanizomenon flos-aquae (AFA) Extract Prevents Neurodegeneration in the HFD Mouse Model by Modulating Astrocytes and Microglia Activation
Obesity and related metabolic dysfunctions are associated with neurodegenerative diseases, such as Alzheimer's disease. Aphanizomenon flos-aquae (AFA) is a cyanobacterium considered a suitable supplement for its nutritional profile and beneficial properties. The potential neuroprotective effect of an AFA extract, commercialized as KlamExtra®, including the two AFA extracts Klamin® and AphaMax®, in High-Fat Diet (HFD)-fed mice was explored. Three groups of mice were provided with a standard diet (Lean), HFD or HFD supplemented with AFA extract (HFD + AFA) for 28 weeks. Metabolic parameters, brain insulin resistance, expression of apoptosis biomarkers, modulation of astrocytes and microglia activation markers, and Aβ deposition were analyzed and compared in the brains of different groups. AFA extract treatment attenuated HFD-induced neurodegeneration by reducing insulin resistance and loss of neurons. AFA supplementation improved the expression of synaptic proteins and reduced the HFD-induced astrocytes and microglia activation, and Aβ plaques accumulation. Together, these outcomes indicate that regular intake of AFA extract could benefit the metabolic and neuronal dysfunction caused by HFD, decreasing neuroinflammation and promoting Aβ plaques clearanc
Early retinal flow changes after vitreoretinal surgery in idiopathic epiretinal membrane using swept source optical coherence tomography angiography
(1) Background: The aim of this observational cross-sectional work was to investigate early retinal vascular changes in patients undergoing idiopathic epiretinal membrane (iERM) surgery using swept source optical coherence tomography angiography (SS-OCTA); (2) Methods: 24 eyes of 24 patients who underwent vitrectomy with internal limiting membrane (ILM) peeling were evaluated pre- and postoperatively using SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). For each eye, five 6x6-mm OCTA volume scans were acquired by two observers independently. The en face images of superficial capillary plexus (SCP) were then exported to imageJ and a semi-automated algorithm was used for subsequent quantitative analysis. Perfusion density (PD), vessel length density (VLD), vessel diameter index (VDI) and vessel tortuosity (VT) of SCP were evaluated in both the parafoveal (2.5 mm diameter) and perifoveal areas (5.5 mm diameter); (3) Results: At OCTA analysis statistically significant differences were found between controls and diseased eyes for all parameters in parafoveal and perifoveal regions (p < 0.001; p < 0.05) except for perifoveal VLD. During 6-month follow up, both anatomical/perfusion and functional parameters showed a statistically significant improvement if compared to preoperative values. In detail, at one-month post vitrectomy, VLD and VT significantly changed in parafoveal region (p = 0.043; p = 0.045), while PD and VDI showed a trend of increase in both parafoveal and perifoveal region. At 6 months after surgery, PD, VLD and VT of parafoveal region significantly improved (p = 0.021, p = 0.018, p = 0.047 respectively). (4) Conclusions: SS-OCTA provides a quantitative and qualitative analysis of the superficial capillary plexus allowing for early vascular changes assessment after vitrectomy with iERM and ILM peeling
Galectin-3 Serum Levels Are Independently Associated With Microalbuminuria in Chronic Heart Failure Outpatients
Background: Galectin-3 (Gal-3) is a novel biomarker reflecting inflammation status and fibrosis involving worsening of both cardiac and renal functions.
Objectives: The aim of this study was to evaluate the relationship between Gal-3 serum levels and microalbuminuria in a group of chronic heart failure (CHF) outpatients.
Patients and Methods: We enrolled CHF outpatients having stable clinical conditions and receiving conventional therapy. All patients underwent clinical evaluation, routine chemistry analysis, echocardiography, and evaluation of the urinary albumin/creatinine ratio (UACR).
Results: Among the patients enrolled, 61 had microalbuminuria (UACR, 30-299) and 133 normoalbuminuria (UACR, < 30). Patients with normoalbuminuria showed significantly higher levels of Gal-3 than those without (19.9 ± 8.8 vs. 14.6 ± 5.5 ng/mL). The stepwise regression analysis indicated that Gal-3 was the first determinant of microalbuminuria (odds ratio [OR]: 1.08; 95% confidence interval [CI]: 1.02 - 1.14, P = 0.012), followed by diabetes (OR 2.14; 95% CI: 1.00 - 4.57; P = 0.049) and high central venous pressure (OR 2.80; 95% CI: 1.04 - 7.58; P= 0.042).
Conclusions: Our findings indicate an independent association between Gal-3 levels and microalbuminuria, an early marker of altered renal function. This suggests the possible role of Gal-3 in the progression of cardiorenal syndrome in CHF outpatients
Growth hormone-releasing hormone attenuates cardiac hypertrophy and improves heart function in pressure overload-induced heart failure
It has been shown that growth hormone-releasing hormone (GHRH) reduces cardiomyocyte (CM) apoptosis, prevents ischemia/reperfusion injury, and improves cardiac function in ischemic rat hearts. However, it is still not known whether GHRH would be beneficial for life-threatening pathological conditions, like cardiac hypertrophy and heart failure (HF). Thus, we tested the myocardial therapeutic potential of GHRH stimulation in vitro and in vivo, using GHRH or its agonistic analog MR-409. We show that in vitro, GHRH(1-44)NH2attenuates phenylephrine-induced hypertrophy in H9c2 cardiac cells, adult rat ventricular myocytes, and human induced pluripotent stem cell-derived CMs, decreasing expression of hypertrophic genes and regulating hypertrophic pathways. Underlying mechanisms included blockade of Gq signaling and its downstream components phospholipase Cβ, protein kinase Ce, calcineurin, and phospholamban. The receptor-dependent effects of GHRH also involved activation of Gαsand cAMP/PKA, and inhibition of increase in exchange protein directly activated by cAMP1 (Epac1). In vivo, MR-409 mitigated cardiac hypertrophy in mice subjected to transverse aortic constriction and improved cardiac function. Moreover, CMs isolated from transverse aortic constriction mice treated with MR-409 showed improved contractility and reversal of sarcolemmal structure. Overall, these results identify GHRH as an antihypertrophic regulator, underlying its therapeutic potential for HF, and suggest possible beneficial use of its analogs for treatment of pathological cardiac hypertrophy
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