Regulation of NADPH oxidase subunit p22(phox) by NF-kB in human aortic smooth muscle cells

Accumulating evidence demonstrates the involvement of oxidative stress in the pathophysiology of cardiovascular diseases. The molecular mechanisms accountable for the increased production of reactive oxygen species remain uncertain. Among others, NADPH oxidase is one of the most important sources of superoxide in vascular cells. Here we investigate the role of NF-kB in the regulation of p22(phox) subunit and NADPH oxidase activity, in human aortic smooth muscle cells. Overexpression of p65/RelA or IKKbeta up-regulated p22(phox) gene promoter activity. Transcription factor pull-down assays demonstrated the physical interaction of p65/RelA protein with predicted NF-kB binding sites. Real time PCR and Western blotting analysis showed that p22(phox) mRNA and protein expression are significantly down-regulated by NF-kB decoy oligodeoxynucleotides and N-alpha-tosyl-l-phenylalanine chloromethyl ketone (TPCK). Lucigenin-enhanced chemiluminescence assay revealed that NF-kB inhibitors reduce the NADPH-dependent superoxide production. Regulation of NADPH oxidase by NF-kB may represent a possible mechanism whereby pro-inflammatory factors induce oxidative stress in atherosclerosis, hypertension, diabetes, stroke or heart failure.

Changes in oxidative balance in rat pericytes exposed to diabetic conditions

Recent data indicate that the oxidative stress plays an important role in the pathogenesis of diabetes and its complications such as retinopathy, nephropathy and accelerated atherosclerosis. In diabetic retinopathy, it was demonstrated a selective loss of pericytes accompanied by capillary basement membrane thickening, increased permeability and neovascularization. This study was designed to investigate the role of diabetic conditions such as high glucose, AGE-Lysine, and angiotensin II in the modulation of antioxidant enzymes activities, glutathione level and reactive oxygen species (ROS) production in pericytes. The activity of antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and total glutathione (GSH) was measured spectrophotometrically. The production of ROS was detected by spectrofluorimetry and fluorescence microscopy after loading the cells with 2'-7' dichlorofluoresceine diacetate; as positive control H2O2 was used. Intracellular calcium was determined using Fura 2 AM assay. The results showed that the cells cultured in high glucose alone, do not exhibit major changes in the antioxidant enzyme activities. The presence of AGE-Lys or Ang II induced the increase of SOD activity. Their combination decreased significantly GPx activity and GSH level. A three times increase in ROS production and a significant impairment of intracellular calcium homeostasis was detected in cells cultured in the presence of the three pro-diabetic agents used. In conclusion, our data indicate that diabetic conditions induce in pericytes: (i) an increase of ROS and SOD activity, (ii) a decrease in GPx activity and GSH level, (iii) a major perturbation of the intracellular calcium homeostasis. The data may explain the structural and functional abnormalities of pericytes characteristic for diabetic retinopathy.

Competitive interactions between established grasses and woody plant seedlings under elevated CO₂ levels are mediated by soil water availability

The expansion of woody plants into grasslands has been observed worldwide and is likely to have widespread ecological consequences. One proposal is that woody plant expansion into grasslands is driven in part by the rise in atmospheric CO2 concentrations. We have examined the effect of CO2 concentration on the competitive interactions between established C4 grasses and woody plant seedlings in a model grassland system. Woody plant seedlings were grown in mesocosms together with established C4 grasses in three competition treatments (root competition, shoot competition and root + shoot competition) under ambient and elevated CO2 levels. We found that the growth of the woody plant seedlings was suppressed by competition from grasses, with root and shoot competition having similar competitive effects on growth. In contrast to expectations, woody plant seedling growth was reduced at elevated CO2 levels compared to that at the ambient CO2 level across all competition treatments, with the most plausible explanation being reduced light and soil water availability in the elevated CO2 mesocosms. Reduced light and soil water availability in the elevated CO2 mesocosms was associated with an increased leaf area index of the grasses which offset the reductions in stomatal conductance and increased rainfall interception. The woody plant seedlings also had reduced 'escapability' (stem biomass and stem height) under elevated compared to ambient CO2 levels. Our results suggest that the expansion of woody plants into grasslands in the future will likely be context-dependent, with the establishment success of woody plant seedlings being strongly coupled to the CO2 response of competing grasses and to soil water availability.

Research on plasma and saliva levels of some bivalent cations in patients with chronic periodontitis (salivary cations in chronic periodontitis)

The purpose of this study was to determine whether chronic periodontitis can stand behind modifications in the salivary and blood concentration of some bivalent cations (Calcium, Magnesium, Zinc and Copper). For this purpose, we formed a group of 30 adult patients with clinically onset chronic periodontitis, and another one of 30 healthy patients as control. Both groups were free from acute oral pathology and general illnesses. The groups were divided again according to the habit of smoking. Total saliva samples were obtained as "first time in the morning", then weighed and processed. Cations were read on Atomic Absorption Spectrophotometer and by Ion Chromatography (Magnesium). The same patients were required to undergo laboratory blood tests for Calcium, Magnesium and Zinc. Data obtained was normalised, then statistically interpreted using two-tailed heteroscedastic t-Student tests. Our data confirmed the existence of a connection between salivary calcium, magnesium, zinc and copper, and of blood magnesium, and chronic periodontitis. Salivary calcium and magnesium are affected by smoking.

Focused ultrasound-induced targeted delivery of miR-155-5p inhibitor employing biomimetic microbubbles reduces NADPH oxidase expression and inflammation in atherosclerotic ApoE-/- mice

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): UEFISCDI

Background

MicroRNAs are important biomarkers and potential therapeutic targets in atherosclerosis. MiR-155-5p amplifies inflammation in atherosclerosis by targeting negative regulators of NF-kB signaling pathway. Inhibition of pro-atherogenic miRNAs or mimicking the function of selected anti-atherogenic miRNAs have emerged as prospective oligonucleotide-base therapeutic interventions in order to correct the expression of key genes that are mechanistically linked to atherosclerotic lesion formation.

Purpose

The aim of this study was to develop a strategy to reduce oxidative stress and inflammation in atherosclerotic mice employing sterically stabilized biomimetic microbubbles (MB) as focused ultrasound-responsive targeted delivery systems of miR-155-5p inhibitor.

Methods

ApoE-/- mice were fed a normal (control) or a high-fat, cholesterol-rich diet for 14 weeks to accelerate de development of aortic atherosclerotic lesions. FAM-labelled miRNA negative control inhibitor, miRNA negative control inhibitor or miR-155-5p inhibitor were charge-coupled to VCAM1-targeted MB. Targeted MB were delivered to mice in a single dose via retro-orbital injection. Ultrasound imaging interrogation of atherosclerotic lesions in ApoE-/- mice was performed using a conventional 30 MHz transducer (Vevo 2100 System). The Sonidel SP100 sonoporator was used for ultrasound-induced targeted release of miRNA inhibitors in mice. The biodistribution of MB was monitored by high-resolution fluorescence imaging. Atherosclerotic lesions were assessed by Oil Red O staining. Real time PCR and Western blot were employed to determine the expression of NADPH oxidase (Nox) subtypes, a major source of oxidative stress, and markers of oxidative stress inflammation (4-HNE-protein adducts, inducible nitric oxide synthase/NOS2, CD68).

Results

Epi-fluorescence analysis demonstrated the enhanced uptake of FAM-labelled miRNA control inhibitor by lungs and the atherosclerotic aorta of ApoE-/- mice following ultrasound wave exposure (1 MHz, 2.0 w/cm2, 50% duty cycles, 15 minutes). The mRNA/protein levels of Nox1-4 subtypes, 4-HNE-protein adducts, NOS2, and macrophage infiltration marker CD68 were found significantly elevated in the atherosclerotic aorta of ApoE-/- mice. The expression levels of Nox isoforms, 4-HNE-protein adducts, NOS2, and CD68 were significantly decreased in the atherosclerotic aorta of ApoE-/- mice 1-week after administration of targeted MB carrying miR-155-5p inhibitor as compared with atherosclerotic ApoE-/- mice treated with targeted MB carrying miRNA negative control inhibitor.

Conclusion

Systemic administration of miR-155-5p inhibitor conjugated with VCAM1-targeted MB reduces the expression of oxidative stress and inflammation-related markers in experimental atherosclerosis. Ultrasound-induced targeted delivery of miRNA-oriented oligonucleotides could become an important theranostic strategy combining imaging and treatment procedures in clinical atherosclerosis.

Life cycle assessment and cost analysis of an innovative automatic system for sorting municipal solid waste: A case study at Milan Malpensa airport

With the recent advancement in artificial intelligence, there are new opportunities to adopt smart technologies for the sorting of materials at the beginning of the recycling value chain. An automatic bin capable of sorting the waste among paper, plastic, glass & aluminium, and residual waste was installed in public areas of Milan Malpensa airport, a context where the separate collection is challenging. First, the airport waste composition was assessed, together with the efficiency of the manual sorting performed by passengers among the conventional bins: paper, plastic, glass & aluminium, and residual waste. Then, the environmental (via the life cycle assessment - LCA) and the economic performances of the current system were compared to those of a system in which the sorting is performed by the automatic bin. Three scenarios were evaluated: i) all waste from public areas, despite being separately collected, is sent to incineration with energy recovery, due to the inadequate separation quality (S0); ii) recyclable fractions are sent to recycling according to the actual level of impurities in the bags (S0R); iii) fractions are sorted by the automatic bin and sent to recycling (S1). According to the results, the current separate collection shows a 62 % classification accuracy. Focusing on LCA, S0 causes an additional burden of 12.4 mPt (milli points) per tonne of waste. By contrast, S0R shows a benefit (-26.4 mPt/t) and S1 allows for a further 33 % increase of benefits. Moreover, the cost analysis indicates potential savings of 24.3 €/t in S1, when compared to S0.

Ursolic acid reduces inflammation and fibrosis in the kidney of diabetic mice

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): UEFISCDI

Background

Diabetic kidney disease (DKD) is arguably the major disabling and life-threatening microvascular-related disorder associated with both type I and type II diabetes. Inflammation of glomerular capillary system and progressive accumulation of glomerular extracellular proteins are important culprit mechanisms leading to glomerulosclerosis and ultimately renal failure in end-stage DKD. Conventional anti-diabetic therapies can only delay the progression of DKD. The naturally-occurring triterpenic acids emerged as important candidate pharmacological compounds for the treatment of cardiometabolic disorders.

Purpose

We aimed at investigating the potential regulatory effects of ursolic acid, a pentacyclic triterpenoid, on the expression of key pro-inflammatory and pro-fibrotic mediators in diabetic kidney.

Methods

Non-diabetic and streptozotocin-induced diabetic C57BL/6J male mice were randomized to receive via intraperitoneal injection 1 mg/kg ursolic acid (UA), or its vehicle (5% DMSO + 95% PBS, pH 7.4), for 4 weeks. Human endothelial cells (EC) were exposed to normal (5 mM) or high (25mM) concentration of glucose in the absence/presence of 1-10 μM UA. Real-time PCR, Western blot, and immunofluorescence microscopy techniques were employed to investigate the expression of selected DKD-relevant pro-inflammatory and pro-fibrotic molecules. Morphological aspects of the kidney and glomeruli were assessed by histochemistry.

Results

The mRNA/protein levels of pro-inflammatory (MCP-1, TNFα, NOS2, ICAM-1, VCAM-1, E-selectin) and pro-fibrotic (collagen IV, fibronectin, laminin, TGFβ) mediators were found significantly elevated in the kidney of diabetic mice as compared to non-diabetic counterparts. Treatment of diabetic mice with UA significantly reduced the up-regulated expression of pro-inflammatory mediators, extracellular matrix proteins, and pro-fibrotic factor TGFβ. Moreover, glomerular hypertrophy and the up-regulation of glomerular collagen IV, fibronectin, and laminin protein levels were significantly reduced in UA-treated diabetic mice. In cultured human EC, UA suppressed the high glucose-induced up-regulation of ICAM-1, VCAM-1, E-selectin and NF-kB signaling.

Conclusion

In experimental diabetes, ursolic acid down-regulates the expression of DKD-relevant pro-inflammatory and pro-fibrotic molecules in the kidney of diabetic mice by potentially targeting NF-kB signaling pathway. The data of this study suggest that triterpenic acids and their chemical derivates could become important pharmacological tools to reduce inflammation and fibrosis associated with DKD.