Nonalcoholic fatty liver disease (NAFLD) including nonalcoholic steatohepatitis (NASH) has reached epidemic proportions with no pharmacological therapy approved. Lower circulating glycine is ...consistently reported in patients with NAFLD, but the causes for reduced glycine, its role as a causative factor, and its therapeutic potential remain unclear. We performed transcriptomics in livers from humans and mice with NAFLD and found suppression of glycine biosynthetic genes, primarily alanine-glyoxylate aminotransferase 1 (
). Genetic (
mice) and dietary approaches to limit glycine availability resulted in exacerbated diet-induced hyperlipidemia and steatohepatitis, with suppressed mitochondrial/peroxisomal fatty acid β-oxidation (FAO) and enhanced inflammation as the underlying pathways. We explored glycine-based compounds with dual lipid/glucose-lowering properties as potential therapies for NAFLD and identified a tripeptide (Gly-Gly-L-Leu, DT-109) that improved body composition and lowered circulating glucose, lipids, transaminases, proinflammatory cytokines, and steatohepatitis in mice with established NASH induced by a high-fat, cholesterol, and fructose diet. We applied metagenomics, transcriptomics, and metabolomics to explore the underlying mechanisms. The bacterial genus
sensu stricto was markedly increased in mice with NASH and decreased after DT-109 treatment. DT-109 induced hepatic FAO pathways, lowered lipotoxicity, and stimulated de novo glutathione synthesis. In turn, inflammatory infiltration and hepatic fibrosis were attenuated via suppression of NF-κB target genes and TGFβ/SMAD signaling. Unlike its effects on the gut microbiome, DT-109 stimulated FAO and glutathione synthesis independent of NASH. In conclusion, impaired glycine metabolism may play a causative role in NAFLD. Glycine-based treatment attenuates experimental NAFLD by stimulating hepatic FAO and glutathione synthesis, thus warranting clinical evaluation.
Reactive oxygen species (ROS) play an important role in the maintenance of cardiovascular homeostasis. The present study sought to determine whether nuclear factor erythroid-2 related factor 2 ...(Nrf2), a master gene of the endogenous antioxidant defense system, is a critical regulator of the cardiac hypertrophic response to pathological stress.
Cardiac hypertrophy and dysfunction were established in mice by transverse aortic constriction (TAC). Nrf2 expression was transiently increased and then declined to the basal level while impairment of cardiac function proceeded. The knockout of Nrf2 (Nrf2(-/-)) did not cause any apparent structural and functional abnormalities in the unstressed heart. However, Nrf2(-/-) mice after TAC developed pathological cardiac hypertrophy, significant myocardial fibrosis and apoptosis, overt heart failure, and increased mortality, which were associated with elevated myocardial levels of 4-hydroxy-2-nonenal and 8-hydroxydeoxyguanosine and a complete blockade of the myocardial expression of several antioxidant genes. Overexpression of Nrf2 dramatically inhibited hypertrophic factor-induced ROS production and growth in both cardiomyocytes and cardiac fibroblasts, whereas knockdown of Nrf2 exerted opposite effects in both cells.
These findings demonstrate that activation of Nrf2 provides a novel mechanism to protect the murine heart against pathological cardiac hypertrophy and heart failure via suppressing oxidative stress.
ABSTRACT The application of edible coatings containing natural antimicrobials is a postharvest conservation technology in fruits that have generated interest. This research aimed the determination of ...the edible coating composition and the concentration of essential oil that allows optimizing the physical-mechanical characteristics for its application in the conservation of blueberries. The antimicrobial activity of the essential oils of cinnamon and lemon was determined, resulting in a minimum inhibitory concentration of 0.3% in both cases. After applying the Box Behnken design of the Response Surface Methodology (RSM), the optimal treatment for edible coating with cinnamon essential oil 0.3% was determined: aloe vera gel 18.40%, gelatin 2%, and glycerol 0.055% obtaining values of 27.95% solubility, 0.90 mm of deformation and 3.34 N of breaking strength. Likewise, the same procedure was followed for the coating with lemon essential oil 0.3%, determining as optimal 23.94% aloe vera gel, 2% gelatin, and 0.05% glycerol, getting values of 28.06% solubility, 0.45 mm deformation, and 4.53 N of breaking strength. Finally, their applications in Biloxi blueberries were validated, preserving the main physicochemical and microbiological quality attributes during 28 days of storage at 2 °C, compared, to a control sample.
RESUMO A aplicação de revestimentos comestíveis com antimicrobianos naturais é uma tecnologia de conservação pós-colheita em frutas de interesse. O objetivo da pesquisa foi determinar os componentes da cobertura comestível e concentração de óleo essencial que permitem otimizar as características físico-mecânicas para aplicação na conservação de mirtilos. A atividade antimicrobiana dos óleos essenciais de canela e limão foi determinada, encontrando uma concentração inibitória mínima de 0,3% em ambos os casos. Após a aplicação do desenho Box Behnken da Metodologia de Superfície de Resposta (MSR), determinou-se o tratamento ótimo para cobertura comestível com óleo essencial de 0,3% de canela, 18,40% de gel de aloe vera, 2% de gelatina e 0,055% de glicerol obtendo valores de 27,95% de solubilidade, 0,90 mm de deformação e 3,34 N de resistência à ruptura. Da mesma forma, foi feito um trabalho de cobertura com 0,3% de óleo essencial de limão, determinando como valores, 23,94% de gel de aloe vera, 2% de gelatina e 0,05% de glicerol obtendo valores de 28,06% de solubilidade, 0,45 mm de deformação e 4,53 N de quebra força. Por fim, a aplicação foi validada em mirtilos da variedade Biloxi, conservando seus principais atributos de qualidade físico-química e microbiológica em alto nível durante 28 dias de armazenamento a 2 °C, em comparação, com uma amostra controle.
Fatty acid binding protein 4 (FABP4) is a member of the intracellular lipid-binding protein family, responsible for the transportation of fatty acids. It is considered to express mainly in adipose ...tissues, and be strongly associated with inflammation, obesity, diabetes and cardiovasculardiseases. Here we report that FABP4 is also expressed in cardiomyocytes and plays an important role in regulating heart function under pressure overload. We generated heart-specific transgenic FABP4 (FABP4-TG) mice using α myosin-heavy chain (α-MHC) promoter and human FABP4 sequence, resulting in over-expression of FABP4 in cardiomyocytes. The FABP4-TG mice displayed normal cardiac morphology and contractile function. When they were subjected to the transverse aorta constriction (TAC) procedure, the FABP4-TG mice developed more cardiac hypertrophy correlated with significantly increased ERK phosphorylation, compared with wild type controls. FABP4 over-expression in cardiomyocytes activated phosphor-ERK signal and up-regulate the expression of cardiac hypertrophic marker genes. Conversely, FABP4 induced phosphor-ERK signal and hypertrophic gene expressions can be markedly inhibited by an ERK inhibitor PD098059 as well as the FABP4 inhibitor BMS309403. These results suggest that FABP4 over-expression in cardiomyocytes can aggravate the development of cardiac hypertrophy through the activation of ERK signal pathway.
Conjugated linoleic acid (CLA) is a prime substrate for intra-gastric nitration giving rise to the formation of nitro-conjugated linoleic acid (NO2-CLA). Herein, NO2-CLA generation is demonstrated ...within the context of acute inflammatory responses both in vitro and in vivo. Macrophage activation resulted in dose- and time-dependent CLA nitration and also in the production of secondary electrophilic and non-electrophilic derivatives. Both exogenous NO2-CLA as well as that generated in situ, attenuated NF-κB-dependent gene expression, decreased pro-inflammatory cytokine production and up-regulated Nrf2-regulated proteins. Importantly, both CLA nitration and the corresponding downstream anti-inflammatory actions of NO2-CLA were recapitulated in a mouse peritonitis model where NO2-CLA administration decreased pro-inflammatory cytokines and inhibited leukocyte recruitment. Taken together, our results demonstrate that the formation of NO2-CLA has the potential to function as an adaptive response capable of not only modulating inflammation amplitude but also protecting neighboring tissues via the expression of Nrf2-dependent genes.
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Stimulator of Interferon Genes (STING) is essential for the inflammatory response to cytosolic DNA. Despite that aberrant activation of STING is linked to an increasing number of inflammatory ...diseases, the development of inhibitors has been challenging, with no compounds in the pipeline beyond the preclinical stage. We previously identified endogenous nitrated fatty acids as novel reversible STING inhibitors. With the aim of improving the specificity and efficacy of these compounds, we developed and tested a library of nitroalkene-based compounds for in vitro and in vivo STING inhibition. The structure-activity relationship study revealed a robustly improved electrophilicity and reduced degrees of freedom of nitroalkenes by conjugation with an aromatic moiety. The lead compounds CP-36 and CP-45, featuring a β-nitrostyrene moiety, potently inhibited STING activity in vitro and relieved STING-dependent inflammation in vivo. This validates the potential for nitroalkene compounds as drug candidates for STING modulation to treat STING-driven inflammatory diseases, providing new robust leads for preclinical development.
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Purpose
Abdominal aortic aneurysm (AAA) is one of the leading causes of death in the developed world and is currently undertreated due to the complicated nature of the disease. Herein, we aimed to ...address the therapeutic potential of a novel class of pleiotropic mediators, specifically a new drug candidate, nitro-oleic acid (NO
2
-OA), on AAA, in a well-characterized murine AAA model.
Methods
We generated AAA using a mouse model combining AAV.PCSK9-D377Y induced hypercholesterolemia with angiotensin II given by chronic infusion. Vehicle control (PEG-400), oleic acid (OA), or NO
2
-OA were subcutaneously delivered to mice using an osmotic minipump. We characterized the effects of NO
2
-OA on pathophysiological responses and dissected the underlying molecular mechanisms through various in vitro and ex vivo strategies.
Results
Subcutaneous administration of NO
2
-OA significantly decreased the AAA incidence (8/28 mice) and supra-renal aorta diameters compared to mice infused with either PEG-400 (13/19,
p =
0.0117) or OA (16/23,
p
= 0.0078). In parallel, the infusion of NO
2
-OA in the AAA model drastically decreased extracellular matrix degradation, inflammatory cytokine levels, and leucocyte/macrophage infiltration in the vasculature. Administration of NO
2
-OA reduced inflammation, cytokine secretion, and cell migration triggered by various biological stimuli in primary and macrophage cell lines partially through activation of the peroxisome proliferator-activated receptor-gamma (PPARγ). Moreover, the protective effect of NO
2
-OA relies on the inhibition of macrophage prostaglandin E2 (PGE
2
)-induced PGE
2
receptor 4 (EP4) cAMP signaling, known to participate in the development of AAA.
Conclusion
Administration of NO
2
-OA protects against AAA formation and multifactorial macrophage activation. With NO
2
-OA currently undergoing FDA approved phase II clinical trials, these findings may expedite the use of this nitro-fatty acid for AAA therapy.
Nitro-oleic acid (OA-NO(2)) is a bioactive, nitric-oxide derived fatty acid with physiologically relevant vasculoprotective properties in vivo. OA-NO(2) exerts cell signaling actions as a result of ...its strong electrophilic nature and mediates pleiotropic cell responses in the vasculature.
The present study sought to investigate the protective role of OA-NO(2) in angiotensin (Ang) II-induced hypertension.
We show that systemic administration of OA-NO(2) results in a sustained reduction of Ang II-induced hypertension in mice and exerts a significant blood pressure lowering effect on preexisting hypertension established by Ang II infusion. OA-NO(2) significantly inhibits Ang II contractile response as compared to oleic acid (OA) in mesenteric vessels. The improved vasoconstriction is specific for the Ang II type 1 receptor (AT(1)R)-mediated signaling because vascular contraction by other G-protein-coupled receptors is not altered in response to OA-NO(2) treatment. From the mechanistic viewpoint, OA-NO(2) lowers Ang II-induced hypertension independently of peroxisome proliferation-activated receptor (PPAR)gamma activation. Rather, OA-NO(2), but not OA, specifically binds to the AT(1)R, reduces heterotrimeric G-protein coupling, and inhibits IP(3) (inositol-1,4,5-trisphosphate) and calcium mobilization, without inhibiting Ang II binding to the receptor.
These results demonstrate that OA-NO(2) diminishes the pressor response to Ang II and inhibits AT(1)R-dependent vasoconstriction, revealing OA-NO(2) as a novel antagonist of Ang II-induced hypertension.
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