sirolimus and Endotoxemia

Plant-based diets are becoming more popular for many reasons, and epidemiological as well as clinical data also suggest that a well-balanced vegan diet can be adopted for the prevention, and in some cases, in the treatment of many diseases. In this narrative review, we provide an overview of the relationships between these diets and various conditions and their potential biochemical background. As whole plant foods are very rich in food-derived antioxidants and other phytochemicals, they have many positive physiological effects on different aspects of health. In the background of the beneficial health effects, several biochemical processes could stand, including the reduced formation of trimethylamine oxide (TMAO) or decreased serum insulin-like growth factor 1 (IGF-1) levels and altered signaling pathways such as mechanistic target of rapamycin (mTOR). In addition, the composition of plant-based diets may play a role in preventing lipotoxicity, avoiding N-glycolylneuraminic acid (Neu5Gc), and reducing foodborne endotoxin intake. In this article, we attempt to draw attention to the growing knowledge about these diets and provide starting points for further research.

Topics: Animals; Antioxidants; Biochemical Phenomena; Diet; Diet, Vegan; Endotoxemia; Humans; Insulin-Like Growth Factor I; Methylamines; Neoplasms; Sirolimus; TOR Serine-Threonine Kinases; Vegans

Here, the regulatory role of autophagy is examined in both an LPS-induced lethal endotoxic shock mouse model and cecal ligation and puncture (CLP) mouse model. Autophagy-inhibitor 3-methyladenine (3-MA) and autophagy-enhancer rapamycin were administrated to mice challenged with LPS or CLP. Animals challenged with LPS or CLP combined with 3-MA displayed increased survival after endotoxemia, but LPS combined with rapamycin worsened the endotoxic shock of the mice. Among the different organs studied, the lungs and intestines exhibited significant differences among LPS alone, LPS combined with 3-MA and LPS combined with rapamycin. LPS combined with 3-MA attenuated the inflammatory damages of these organs as compared with LPS alone. In contrast, LPS combined with rapamycin increased damage in these organs. Consistently, serum inflammatory mediators TNF-α and IL-6 were decreased by the treatment of LPS combined with 3-MA as compared with LPS alone, while administration of LPS combined with rapamycin increased the serum TNF-α and IL-6 levels. Similar results were found in mouse bone marrow-derived macrophages exposed to LPS. Moreover, the regulatory effect of autophagy to endotoxic shock is dependent on the TLR4 signaling pathway. Our results demonstrate the central role of autophagy in the regulation of endotoxic shock and its potential modulation for endotoxic shock treatment.

Topics: Adenine; Animals; Autophagy; Carrier Proteins; Endotoxemia; Interleukin-6; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Sepsis; Shock, Septic; Signal Transduction; Sirolimus; Tumor Necrosis Factor-alpha

Macroautophagy/autophagy is a central mechanism by which cells maintain integrity and homeostasis, and endotoxin-induced autophagy plays important roles in innate immunity. Although TLR4 stimulation mediated by lipopolysaccharide (LPS) also upregulates autophagy in hepatocytes and liver, its physiological role remains elusive. The objective of this study was to determine the role of LPS-induced autophagy in the regulation of liver lipid metabolism. LPS treatment (5 mg/kg) increased autophagy, as detected by LC3 conversion and transmission electron microscopy (TEM) analysis in C57BL6 mouse livers. AC2F hepatocytes also showed increased autophagic flux after LPS treatment (1 μg/ml). To investigate the role of LPS-induced autophagy further, liver lipid metabolism changes in LPS-treated mice and fasted controls were compared. Interestingly, LPS-treated mice showed less lipid accumulation in liver than fasted mice despite increased fatty acid uptake and lipid synthesis-associated genes. In vitro analysis using AC2F hepatocytes demonstrated LPS-induced autophagy influenced the degradation of lipid droplets. Inhibition of LPS-induced autophagy using bafilomycin A

Topics: Age Factors; Animals; Autophagy; Chloroquine; Class III Phosphatidylinositol 3-Kinases; Endotoxemia; Fasting; Hepatitis, Animal; Hepatocytes; Lipid Metabolism; Lipopolysaccharides; Liver; Mice; Mice, Inbred C57BL; p38 Mitogen-Activated Protein Kinases; Sirolimus

Adiponectin (APN), an adipose-derived adipokine, alleviates lipopolysaccharide (LPS)-induced injury in multiple organs including hearts although the underlying mechanism in endotoxemia remains elusive. This study was designed to examine the role of adiponectin in LPS-induced cardiac anomalies and inflammation as well as the underlying mechanism with a focus on autophagy - a conserved machinery for bulk degradation of intracellular components.. Wild-type (WT) and APN(-/-) mice were challenged with LPS (4mg/kg) or saline for 6h. Echocardiography, cardiomyocyte contractile and intracellular Ca(2+) properties were evaluated. Markers of autophagy, apoptosis and inflammation including LC3B, p62, Beclin1, AMPK, mTOR, ULK, Caspase 3, Bcl-2, Bax, TLR4, TRAF6, MyD88, IL-1B, TNFα, HMGB1, JNK and IκB were examined using Western blot or RT-PCR. Our results showed that LPS challenge reduced fractional shortening, compromised cardiomyocyte contractile capacity, intracellular Ca(2+) handling properties, apoptosis and inflammation, which were accentuated by adiponectin ablation. Adiponectin ablation unmasked the LPS-induced cardiac remodeling (left ventricular end systolic diameter) and prolongation of cell shortening. The detrimental effects of adiponectin ablation were associated with dampened autophagy in response to LPS through an AMPK-mTOR-ULK1-dependent mechanism. In vivo administration of AMPK activator AICAR or the autophagy inducer rapamycin effectively attenuated or obliterated LPS-induced and adiponectin deficiency-accentuated responses without affecting TLR4, TRAF6 and MyD88.. The findings suggest that AMPK and autophagy may play a permissive role in the adiponectin deficiency-exacerbated cardiac dysfunction, apoptosis and inflammation under LPS challenge possibly at the post-TLR4 receptor level.

Topics: Adiponectin; Aminoimidazole Carboxamide; AMP-Activated Protein Kinases; Animals; Autophagy; Autophagy-Related Protein-1 Homolog; Calcium; Calcium-Calmodulin-Dependent Protein Kinase Kinase; Cell Death; Disease Models, Animal; Endotoxemia; Lipopolysaccharides; Male; Mice; Mice, Knockout; Myocarditis; Myocardium; Myocytes, Cardiac; Ribonucleotides; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Ventricular Dysfunction

Septic kidney injury is one of the most common complications in critically ill patients with a high risk of developing chronic kidney disease (CKD). Emerging data indicate that mammalian target of rapamyci (mTOR) signaling plays a major role in septic inflammation by regulating the immune response of macrophage. This study was designed to evaluate the role of mTOR signaling in kidney macrophages during endotoxemia-induced chronic kidney injury and subsequent fibrogenesis.. Male C57BL/6 mice were used for all animal studies (n=9 for each group). Lipopolysaccharide (LPS) was injected intraperitoneally (1 mg/kg) every 2 days to induce persistent endotoxemia. Rapamycin (1 mg/kg·day) was administered to a subgroup of mice 1 day prior to LPS treatment and continued to termination of the experiment. In ex-vivo experiment, RAW264.7 cells were cultured and treated with LPS (2 µg/ml) for 48 h while a subgroup of cells were incubated in the presence of rapamycin (50 nmol) for 2 h.. Continuous administration of LPS resulted in progressive macrophage infiltration, tubular injury and collagen deposition in mice kidneys. Rapamycin markedly ameliorated LPS-induced kidney pathological changes. Expression of pS6K was rarely observed in normal kidney macrophages, but significantly increased with time by LPS treatment. In ex-vivo study, LPS induced prominent production of IL-1β and MCP-1 in cultured RAW264.7 cells, which was significantly suppressed by rapamycin.. Taken together, our findings show that endotoxemia results in activation of mTOR signaling in macrophages, leading to progressive kidney inflammatory injuries and subsequent fibrosis. Our study may reveal a mechanism involved in the development of sepsis-associated CKD and kidney fibrosis.

Topics: Animals; Blotting, Western; Cell Line; Chemokine CCL2; Collagen; Endotoxemia; Fibrosis; Fluorescent Antibody Technique; Immunohistochemistry; Immunosuppressive Agents; Injections, Intraperitoneal; Interleukin-1beta; Kidney; Kidney Tubules; Lipopolysaccharides; Macrophages; Male; Mice; Mice, Inbred C57BL; Real-Time Polymerase Chain Reaction; Renal Insufficiency, Chronic; RNA, Messenger; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

To determine that 1) an age-dependent loss of inducible autophagy underlies the failure to recover from AKI in older, adult animals during endotoxemia, and 2) pharmacologic induction of autophagy, even after established endotoxemia, is of therapeutic utility in facilitating renal recovery in aged mice.. Murine model of endotoxemia and cecal ligation and puncture (CLP) induced acute kidney injury (AKI).. Academic research laboratory.. C57Bl/6 mice of 8 (young) and 45 (adult) weeks of age.. Lipopolysaccharide (1.5 mg/kg), Temsirolimus (5 mg/kg), AICAR (100 mg/kg).. Herein we report that diminished autophagy underlies the failure to recover renal function in older adult mice utilizing a murine model of LPS-induced AKI. The administration of the mTOR inhibitor temsirolimus, even after established endotoxemia, induced autophagy and protected against the development of AKI.. These novel results demonstrate a role for autophagy in the context of LPS-induced AKI and support further investigation into like interventions that have potential to alter the natural history of disease.

Topics: Acute Kidney Injury; Aminoimidazole Carboxamide; Animals; Autophagy; Class III Phosphatidylinositol 3-Kinases; Endotoxemia; Lipopolysaccharides; Male; Mice; Protein Kinase Inhibitors; Ribonucleotides; Sirolimus; TOR Serine-Threonine Kinases

Bacterial infection of the kidney is associated with renal tubule dysfunction and dysregulation of systemic electrolyte balance. Whether bacterial molecules directly affect renal tubule transport is unknown. We examined the effects of LPS on HCO3(-) absorption in the isolated rat and mouse medullary thick ascending limb (MTAL). LPS decreased HCO3(-) absorption when added to bath or lumen. The MEK/ERK inhibitor U0126 eliminated inhibition by bath LPS but had no effect on inhibition by lumen LPS. Conversely, the mammalian target of rapamycin (mTOR) inhibitor rapamycin eliminated inhibition by lumen LPS but had no effect on inhibition by bath LPS. Inhibiting basolateral Na(+)/H(+) exchange with amiloride eliminated inhibition of HCO3(-) absorption by lumen but not bath LPS. Confocal immunofluorescence showed expression of TLR4 in basolateral and apical membrane domains. Inhibition of HCO3(-) absorption by bath and lumen LPS was eliminated in MTALs from TLR4(-/-) mice. Thus LPS inhibits HCO3(-) absorption through distinct TLR4-dependent pathways in basolateral and apical membranes. These results establish that bacterial molecules can directly impair the transport function of renal tubules, identifying a new mechanism contributing to tubule dysfunction during bacterial infection. The LPS-induced reduction in luminal acidification may contribute to Gram-negative pathogenicity by promoting bacterial adherence and growth and impairing correction of infection-induced systemic acid-base disorders.

Topics: Amiloride; Animals; Bicarbonates; Butadienes; Disease Progression; Endotoxemia; Escherichia coli Infections; Escherichia coli K12; Immunity, Innate; In Vitro Techniques; Kidney Tubules; Lipid A; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitriles; Rats; Rats, Sprague-Dawley; Serum; Signal Transduction; Sirolimus; Toll-Like Receptor 4; Urinary Tract Infections