Hepatic PPARalpha is critical in the metabolic adaptation to sepsis
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE121847 | GEO | 2019/02/01
REPOSITORIES: GEO
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Project description:Hepatic PPARalpha is critical in the metabolic adaptation to sepsis
| PRJNA498629 | ENA
Project description:BACKGROUND & AIMS:Although the role of inflammation to combat infection is known, the contribution of metabolic changes in response to sepsis is poorly understood. Sepsis induces the release of lipid mediators, many of which activate nuclear receptors such as the peroxisome proliferator-activated receptor (PPAR)?, which controls both lipid metabolism and inflammation. We aimed to elucidate the previously unknown role of hepatic PPAR? in the response to sepsis. METHODS:Sepsis was induced by intraperitoneal injection of Escherichia coli in different models of cell-specific Ppara-deficiency and their controls. The systemic and hepatic metabolic response was analyzed using biochemical, transcriptomic and functional assays. PPAR? expression was analyzed in livers from elective surgery and critically ill patients and correlated with hepatic gene expression and blood parameters. RESULTS:Both whole body and non-hematopoietic Ppara-deficiency in mice decreased survival upon bacterial infection. Livers of septic Ppara-deficient mice displayed an impaired metabolic shift from glucose to lipid utilization resulting in more severe hypoglycemia, impaired induction of hyperketonemia and increased steatosis due to lower expression of genes involved in fatty acid catabolism and ketogenesis. Hepatocyte-specific deletion of PPAR? impaired the metabolic response to sepsis and was sufficient to decrease survival upon bacterial infection. Hepatic PPARA expression was lower in critically ill patients and correlated positively with expression of lipid metabolism genes, but not with systemic inflammatory markers. CONCLUSION:During sepsis, Ppara-deficiency in hepatocytes is deleterious as it impairs the adaptive metabolic shift from glucose to FA utilization. Metabolic control by PPAR? in hepatocytes plays a key role in the host defense against infection. LAY SUMMARY:As the main cause of death in critically ill patients, sepsis remains a major health issue lacking efficacious therapies. While current clinical literature suggests an important role for inflammation, metabolic aspects of sepsis have mostly been overlooked. Here, we show that mice with an impaired metabolic response, due to deficiency of the nuclear receptor PPAR? in the liver, exhibit enhanced mortality upon bacterial infection despite a similar inflammatory response, suggesting that metabolic interventions may be a viable strategy for improving sepsis outcomes.
| S-EPMC6774768 | biostudies-literature
Project description:Despite decades of research, sepsis remains one of the most urgent unmet medical needs. Clinical trials in sepsis have mainly focused on targeting the inflammatory pathway, however, recent data indicate that sepsis should also be seen as a metabolic disease. Targeting metabolic dysregulations that take place in sepsis might uncover novel therapeutic opportunities to treat human sepsis patients. The role of PPARα in liver dysfunction during sepsis has recently been described, and restoring PPARα signaling proves to be successful in murine sepsis. To find out whether this therapy might also be helpful in human sepsis patients, we analyzed metabolic perturbations in liver of a porcine fecal peritonitis model. Resuscitation with fluids, antimicrobial therapy and abdominal drainage were applied to the pigs in order to mimic human clinical care. By using RNA-seq, we detected problems with PPARα signaling in the livers of septic pigs and reduced PPARα levels correlated well with disease severity. As PPARα regulates the expression of many genes involved in FA oxidation, reduced expression of these target genes concomitant with increased FFAs in plasma and ectopic lipid deposition in the liver was observed. The results obtained in pigs are in agreement with earlier observations in mice and support the potential of targeting defective PPARα signaling in the clinic.
2022-11-28 | GSE218636 | GEO
Project description:Neonates manifest a unique host response to sepsis even among other children. Preterm neonates may experience sepsis soon after birth or during often protracted birth hospitalizations as they attain physiologic maturity. We examined the transcriptome using genome-wide expression profiling on prospectively collected peripheral blood samples from infants evaluated for sepsis within 24 hours after clinical presentation. Simultaneous plasma samples were examined for alterations in inflammatory mediators. Group designation (sepsis or uninfected) was determined retrospectively based on clinical exam and laboratory results over the next 72 hours from the time of evaluation. Unsupervised analysis showed the major node of separation between groups was timing of sepsis episode relative to birth (early, <3 days or late, >3 days). Principal component analyses revealed significant differences between patients with early or late sepsis despite the presence of similar key immunologic pathway aberrations in both groups. Unique to neonates, the uninfected state and host response to sepsis is significantly affected by timing relative to birth. Future therapeutic approaches may need to be tailored to the timing of the infectious event based on post-natal age. We used human microarrays to detail the molecular profile of the events that occur following sepsis in hospitalized neonates Please note that 'uninfected chorio' represents babies who were not infected but had chorioamnionitis exposure
2015-07-06 | E-GEOD-69686 | biostudies-arrayexpress
Project description:Sepsis is an uncontrolled, systemic response to infection with life-threatening consequences. Our understanding of the pathogenesis of sepsis across organs of the body is rudimentary. Here, using mouse models of sepsis, we generate a dynamic, organism-wide map of the pathogenesis of the disease, revealing the spatiotemporal patterns of well-known and previously unrecognized effects of sepsis on the body. By combining functional perturbations with organism-wide profiling, we discover two interorgan mechanisms that are key to the pathophysiology of sepsis. First, we find that a hierarchical cytokine circuit arising from the pairwise effects of TNF plus IL-18, IFN-γ, or IL-1β suffices to explain a large fraction of the molecular effects of sepsis on the body. Moreover, the effects of these three cytokine pairs on the abundance of nearly two hundred cell types across nine organ types recapitulate half of all the cellular effects of sepsis. Second, we uncover an interorgan pathway whereby a gut-derived, secreted phospholipase, Pla2g5, mediates hemolysis in the blood circulation and contributes to multi-organ failure during sepsis. Thus, a simplifying principle in the systemic behavior of the cytokine network and a lipase misdirected from gut to blood provide fundamental insights to help build a unifying mechanistic framework for the pathophysiological effects of sepsis on the organ systems of the body.
2024-01-11 | GSE253061 | GEO
Project description:Sepsis is a life-threatening organ dysfunction resulting from a dysregulated host response to infection. This is best studied in humans and various mouse models, however finding sof these models to not always translate easy to the clinic. In order to improve this transfer, and because sepsis also plays a significant role in vetrenairy medicine, we use the pig as a model organism in sepsis research. We compare two modes of porcine sepsis iduction: fecal infusion and LPS infusion and also compare thse o wha we can find in mice
2023-12-31 | GSE250039 | GEO
Project description:Despite intensive research and constant medical progress, sepsis remains one of the most urgent unmet medical needs of today. Most studies have been focused on the inflammatory component of the disease, however, recent advances support the notion that sepsis is accompanied by extensive metabolic perturbations. During times of limited caloric intake and high energy needs, the liver acts as the central metabolic hub in which PPARa is crucial to coordinate the breakdown of fatty acids. The role of hepatic PPARa in liver dysfunction during sepsis has hardly been explored. We demonstrate that sepsis leads to a starvation response that is hindered by the rapid decline of hepatic PPARa levels, causing excess free fatty acids, leading to lipotoxicity, and glycerol. In addition, treatment of mice with the PPARa agonist pemafibrate protects against bacterial sepsis by improving hepatic PPARa function, reducing lipotoxicity and tissue damage. Since lipolysis is also increased in sepsis patients and pemafibrate protects after the onset of sepsis, these findings may point towards new therapeutic leads in sepsis.
2019-11-23 | GSE139484 | GEO
Project description:Hepatic PPARα dysfunction in porcine sepsis
| PRJNA904738 | ENA
Project description:In sepsis, limited food intake and increased energy expenditure induce a starvation response, which is compromised by a quick decline in expression of hepatic PPARα, a transcription factor essential in intracellular catabolism of free fatty acids. The mechanism upstream of this PPARα downregulation is unknown. We found that sepsis causes a progressive hepatic loss-of-function of HNF4α, which has strong impact on the expression of several important nuclear receptors, including PPARα. HNF4α depletion in hepatocytes dramatically increases sepsis lethality, steatosis and organ damage and prevents an adequate response towards IL6, which is critical for liver regeneration and survival. An HNF4α agonist protects against sepsis at all possible levels, irrespectively of bacterial loads, suggesting HNF4α is crucial in disease tolerance to sepsis. In conclusion, hepatic HNF4α fails in sepsis, causing PPARα downregulation and metabolic problems and a disturbed IL6-mediated acute phase response. The data open new insights and therapeutic options in sepsis.
2023-10-31 | GSE244821 | GEO
Project description:Neonates manifest a unique host response to sepsis even among other children. Preterm neonates may experience sepsis soon after birth or during often protracted birth hospitalizations as they attain physiologic maturity. We examined the transcriptome using genome-wide expression profiling on prospectively collected peripheral blood samples from infants evaluated for sepsis within 24 hours after clinical presentation. Simultaneous plasma samples were examined for alterations in inflammatory mediators. Group designation (sepsis or uninfected) was determined retrospectively based on clinical exam and laboratory results over the next 72 hours from the time of evaluation. Unsupervised analysis showed the major node of separation between groups was timing of sepsis episode relative to birth (early, <3 days or late, >3 days). Principal component analyses revealed significant differences between patients with early or late sepsis despite the presence of similar key immunologic pathway aberrations in both groups. Unique to neonates, the uninfected state and host response to sepsis is significantly affected by timing relative to birth. Future therapeutic approaches may need to be tailored to the timing of the infectious event based on post-natal age.
2015-07-06 | GSE69686 | GEO