Rat Long Chain Acyl-CoA Synthetase 5, but Not 1, 2, 3, or 4, Complements Escherichia coli fadD

Long chain fatty acids are converted to acyl-CoAs by acyl-CoA synthetase (fatty acid CoA ligase: AMP forming, E.C. 6.2.1.3; ACS). Escherichia coli has a single ACS, FadD, that is essential for growth when fatty acids are the sole carbon and energy source. Rodents have five ACS isoforms that differ in substrate specificity, tissue expression, and subcellular localization and are believed to channel fatty acids toward distinct metabolic pathways. We expressed rat ACS isoforms 1-5 in an E. coli strain that lacked FadD. All rat ACS isoforms were expressed in E. coli fadD or fadDfadR and had ACS specific activities that were 1.6-20-fold higher than the wild type control strain expressing FadD. In the fadD background, the rat ACS isoforms 1, 2, 3, 4 and 5 oxidized [(14)C]oleate at 5 to 25% of the wild type levels, but only ACS5 restored growth on oleate as the sole carbon source. To ensure that enzymes of beta-oxidation were not limiting, assays of ACS activity, beta-oxidation, fatty acid transport, and phospholipid synthesis were also examined in a fadD fadR strain, thereby eliminating FadR repression of the transporter FadL and the enzymes of beta-oxidation. In this strain, fatty acid transport levels were low but detectable for ACS1, 2, 3, and 4 and were nearly 50% of wild type levels for ACS5. Despite increases in beta-oxidation, only ACS5 transformants were able to grow on oleate. These studies show that although ACS isoforms 1-4 variably supported moderate transport activity, beta-oxidation, and phospholipid synthesis and although their in vitro specific activities were greater than that of chromosomally encoded FadD, they were unable to substitute functionally for FadD regarding growth. Thus, membrane composition and protein-protein interactions may be critical in reconstituting bacterial ACS function

CCL20 mediates lipopolysaccharide induced liver injury and is a potential driver of inflammation and fibrosis in alcoholic hepatitis

OBJECTIVE: Chemokines are known to play an important role in the pathophysiology of alcoholic hepatitis (AH), a form of acute-on-chronic liver injury frequently mediated by gut derived lipopolysaccharide (LPS). In our study, we hypothesise that chemokine CCL20, one of the most upregulated chemokines in patients with AH, is implicated in the pathogenesis of AH by mediating LPS induced liver injury. DESIGN: CCL20 gene expression and serum levels and their correlation with disease severity were assessed in patients with AH. Cellular sources of CCL20 and its biological effects were evaluated in vitro and in vivo in chronic, acute and acute-on-chronic experimental models of carbon tetrachloride and LPS induced liver injury. RNA interference technology was used to knockdown CCL20 in vivo. RESULTS: CCL20 hepatic and serum levels were increased in patients with AH and correlated with the degree of fibrosis, portal hypertension, endotoxaemia, disease severity scores and short term mortality. Moreover, CCL20 expression was increased in animal models of liver injury and particularly under acute-on-chronic conditions. Macrophages and hepatic stellate cells (HSCs) were identified as the main CCL20 producing cell types. Silencing CCL20 in vivo reduced LPS induced aspartate aminotransferase and lactate dehydrogenase serum levels and hepatic proinflammatory and profibrogenic genes. CCL20 induced proinflammatory and profibrogenic effects in cultured primary HSCs. CONCLUSIONS: Our results suggest that CCL20 upregulation is strongly associated with LPS and may not only represent a new potential biomarker to predict outcome in patients with AH but also an important mediator linking hepatic inflammation, injury and fibrosis in AH

CCL20 mediates lipopolysaccharide induced liver injury and is a potential driver of inflammation and fibrosis in alcoholic hepatitis

Chemokines are known to play an important role in the pathophysiology of alcoholic hepatitis (AH), a form of acute-on-chronic liver injury frequently mediated by gut derived lipopolysaccharide (LPS). In our study, we hypothesise that chemokine CCL20, one of the most upregulated chemokines in patients with AH, is implicated in the pathogenesis of AH by mediating LPS induced liver injury

Promotion of Hepatocellular Carcinoma by the Intestinal Microbiota and TLR4

Increased translocation of intestinal bacteria is a hallmark of chronic liver disease and contributes to hepatic inflammation and fibrosis. Here we tested the hypothesis that the intestinal microbiota and Toll-like receptors (TLRs) promote hepatocellular carcinoma (HCC), a long-term consequence of chronic liver injury, inflammation and fibrosis. Hepatocarcinogenesis in chronically injured livers depended on the intestinal microbiota, and TLR4 activation in non-bone marrow-derived resident liver cells. TLR4 and the intestinal microbiota were not required for HCC initiation but for HCC promotion, mediating increased proliferation, expression of the hepatomitogen epiregulin, and prevention of apoptosis. Gut sterilization restricted to late stages of hepatocarcinogenesis reduced HCC suggesting that the intestinal microbiota and TLR4 represent therapeutic targets for HCC prevention in advanced liver disease

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Prueba oral de tolerancia al almidón del grano de avena en ponies

Resumen: Se efectuó una Prueba Oral de Tolerancia al Almidón del grano de Avena en ponies, para desarrollar una curva de glucemia propia de estas razas, compararla con las curvas de glucemia de equinos de mayor alzada, consumiendo pasturas o dietas mixtas de forrajes y concentrados, y observar si algún pony pudiera ser considerado un valor atípico. Estos animales, aún sin síntomas clínicos, podrían ser resistentes a la insulina. Los ponies consumían heno de alfalfa, por lo que se esperaba encontrar una respuesta glucémica, similar a caballos alimentados con pasturas. Sin embargo, la glucemia de los ponies era similar (p < 0,05) a la glucemia de los caballos alimentados con dietas mixtas, probablemente por el consumo previo de alfalfa. La curva obtenida en esta experiencia es la que debe ser utilizada en ponies consumiendo este alimento. Al ejecutar esta prueba, se pudo comprobar que existen ponies que ante la descarga de almidón, desarrollan una intolerancia a la glucosa, que podría deberse a una resistencia a la insulina. Se considera que esta prueba puede ser de utilidad para detectar ponies predispuestos a sufrir enfermedades tales como infosuras, obesidad, rhabdomiolisis, etc.Abstract: An oral oats grain starch tolerance test in ponies was carried out to develop a glycaemic curve specific to these breeds, compared it with glycaemic curves of larger height horses, pasture fed or forage and concentrates fed, and see if any pony could be considered outlier. These animals, even without clinical signs, may be insulin resistant. The ponies were fed on alfalfa hay, so it was expected to find a glycaemic response similar to pasture-fed horses. However, the ponies glycaemia was similar (p <0.05) to glycaemia of horses fed mixed diets, probably because they were previously eating alfalfa. So, the curve obtained in this experiment is to be used in ponies eating this last food. When this test was run, some ponies, when starch discharged, developed glucose intolerance, which could be due to insulin resistance. This test may be useful for detecting ponies predisposed to suffer diseases such as laminitis, obesity, rhabdomiolysis, etc

Influencia de la dieta previa sobre una prueba de sensibilidad a la insulina en caballos

Resumen: Se utilizó una prueba de sensibilidad a la insulina (In) para determinar si existe una diferente respuesta de los tejidos a la misma, debido a la adaptación a diferentes dietas. Se utilizaron 10 caballos en dos ensayos. En el primer ensayo, los animales consumieron solo forrajes (pasturas naturales y 4 kg heno de alfalfa). En el segundo ensayo, se agregó grano de avena (3 kg diarios) a la dieta durante los dos meses previos. En cada ensayo, se administró una dosis de 0,1 U/kg de In y se extrajeron 13 muestras, al minuto (T1), a los 5 minutos (T5), cada 10 minutos hasta los 45 minutos (T5 a T45) y cada 15 minutos hasta los 150 minutos (T45 a T150) y se determinó la glucemia en cada tiempo. Solo seis animales finalizaron la prueba, debido a que los restantes animales sufrieron shocks hipoglucémicos sin complicaciones posteriores. Para cada animal se determinó el área bajo la curva (ABC) mediante el método trapezoidal. Los dos tratamientos fueron comparados en relación al ABC mediante la prueba t para muestras pareadas. El nivel de significación empleado fue de 0,05. Se empleó el software NCSS 8 (Utah, USA). No fue posible observar diferencias entre tratamientos (p = 0,36), probablemente por haber finalizado ambos ensayos con un tamaño muestral insuficienteSummary: A sensitivity insulin test (In) was used to determine if there is a different tissue response to it, due to adaptation to different diets. Ten horses were used in two trials. In the first trial, the animals consumed only forage (natural pastures and 4 kg alfalfa hay). In the second trial, oats grain (3 kg daily) was added to the diet during the two previous months. In each trial, a dose of 0.1 U/kg of In was administered and the horses were sampled at one minute (T1), 5 minutes (T5), every 10 minutes up to 45 minutes (T5 to T45) and every 15 minutes up to 150 minutes (T45 to T150) and blood glucose was measures at each time. Only six animals finished the test, since the other animals suffered hypoglycaemic shocks without complications. The area under the curve (ABC) using the trapezoidal method was determined for each animal. The two treatments were compared in relation to the ABC by the t-test for paired samples. Significance level was 0.05. The NCSS 8 (Utah, USA) software was used. It was not possible to observe differences between treatments (p = 0.36), probably by having completed both trials with an insufficient sample siz