Lies Langouche

Prolonged infusion with the cholesterol precursor, mevalonate, worsened hypocholesterolemia in a mouse model of sepsis-induced critical illness, likely due to increased feedback on hepatic cholesterol synthesis. Loss of muscle force and mass was not further affected, nor did mevalonate affect adrenal gland steroidogenic markers and the loss of adrenocortical lipids. In prolonged sepsis patients, sustained HDL and LDL hypocholesterolemia was observed in the face of high plasma mevalonate concentrations, but did not correlate with plasma cortisol.

Background: Administration of ketone bodies attenuated the severity of sepsis-induced muscle weakness in preclinical studies. Whether lipid-rich emulsions may likewise mitigate such muscle weakness by stimulating the endogenous ketogenic capacity remains uncertain, especially in relation to glucose, a critical suppressor of ketogenesis. This study investigated the ketogenic potential of parenteral nutrition rich in long- and/or medium-chain triglycerides with differing glucose content on sepsis-induced muscle weakness. Methods: We used a parenterally fed murine model of prolonged sepsis-induced muscle weakness to investigate specific lipid mixtures in two consecutive studies. Septic mice receiving standard total parenteral nutrition (TPN) and healthy control (HC) animals were included as references in both studies. In a first study, septic mice received pure long-chain triglycerides (LCT) or long-chain triglycerides supplemented with glucose (gLCT). The second study compared a gLCT mixture to a mixed medium- and long-chain triglyceride emulsion supplemented with glucose (gMCT). After 5 days of sepsis, markers of ketone body metabolism, muscle function, and muscle and liver metabolomics were measured. Results: In study one, ketosis was undetectable with TPN-treatment, but substantially increased with pure LCT (median 1.39 mmol/L, p < 0.001). Supplemental glucose suppressed ketosis sixfold (median 0.24 mmol/L, p < 0.001). The sepsis-induced muscle weakness was exacerbated in LCT mice, while muscle force was comparable between TPN-treated and gLCT mice (TPN 60.9%; gLCT 60.9%; LCT 33.1% of HC 128.7 mN/mm ² , p < 0.001). The decrease in muscle glycolytic metabolites in LCT mice relative to TPN-treated mice was attenuated by supplemental glucose. In study 2, unexpectedly, ketosis was similarly low in gLCT and gMCT mice ( p = 0.1), and muscle force was equally reduced in all septic groups (TPN 68.1%; gLCT 74.0%; gMCT 65.9% of HC 105.9 mN/mm ² , p = 0.5) as compared to HC mice. Protein expression of the rate-limiting enzyme of ketogenesis, Hmgcs2, was suppressed in gMCT as compared to gLCT mice ( p = 0.04). Conclusions: Pure LCT infusion induced ketosis, but aggravated muscle weakness, which was attenuated by providing supplemental glucose. Combined with glucose, neither long-chain triglycerides nor mixed medium- and long-chain triglycerides were able to induce adequate ketosis or attenuate sepsis-induced muscle weakness.

Carnitine deficiency affects mitochondrial and muscle function, but its relevance during critical illness remains unknown. Our aim was to investigate the r

Introduction: Intensive-care-unit-acquired-muscle-weakness is a debilitating complication of sepsis, characterized by loss of muscle mass and functionality. Immobilization is an important trigger, but the role of disturbed mechanical signaling is incompletely understood. In health, the integrin-receptor-complex with key components Kindlin2 (KIND2/ Fermt2 ) and integrin-linked-kinase (ILK/ Ilk1 ) converses mechanical forces into biochemical signals to regulate muscle mass. We hypothesize that this complex, through key elements KIND2 and ILK, plays a role in sepsis-induced-muscle-weakness. Methods: AAV2/9-vectors expressing shRNA-sequences against Ilk1, Fermt2 or noncoding-control-gene were injected in tibialis anterior (TA) muscles of 24w-old male C57BL/6J mice. Two-weeks-post-injection, after knockdown validation, mice were made septic by cecal ligation and puncture. Five-days-post-sepsis muscle force, mass and fiber size were quantified and expression of mechanosensitive elements and downstream pathways of the integrin-receptor-complex was assessed. Results: Two-weeks-post-injection the respective sh-targets were strongly suppressed (mRNA Ilk1 –44%, Fermt2 –76%, protein ILK −34%, KIND2–70%). In rAAV-sh- controls , sepsis induced upregulation across TA and EDL muscle of Ilk1 and Fermt2 and integrin-receptor-complex-related genes Itga 7, ItgB1 , Tln1 , Lims1, Lims2, Parva ( P < 0.001 ), whereas in SOL muscle Lims1, Lims2 and Fermt2 were not and Vcl1 ( P < 0.001 ) was upregulated. In TA and EDL, but not in SOL, rAAV-sh Ilk1 and rAAV-sh Fermt2 attenuated upregulation of respective targets down to healthy controls, but without affecting expression of other integrin-receptor-complex-related genes. TA muscle force or weight were not affected by rAAV-sh Ilk1 or rAAV-sh Fermt2 ( P > 0.05 ), whereas muscle fiber size reduction (−20.7% in Sepsis shControl) was attenuated up to −13.4% (Sepsis sh Ilk1 , P < 0.001 ) and −12.3% (Sepsis sh Fermt2 , P < 0.001 ). Sepsis or sh-treatment did not shift TA fiber types. Expression of markers of atrophy, inflammation, autophagy, protein synthesis and regeneration were affected by sepsis, but not by sh-treatment. Only markers of metabolism Slc2a4 ( P < 0.05) and Rac1 ( P < 0.01 ) were further affected by sh-treatment. Conclusions: Sepsis induced upregulation of integrin-receptor-complex-related genes but attenuating the upregulation of Ilk1 or Fermt2 did not affect the development of muscle weakness, although muscle fiber size was better preserved, arguing against a key role for Ilk1 or Fermt2 .

Background: Suppression of the peroxisome proliferator‐activated receptor alpha (PPARα) has been related to poor outcomes in sepsis and may compromise ketogenesis during critical illness. Infusion of 3‐hydroxybutyrate (3HB) was shown to attenuate muscle weakness in septic mice. We hypothesise that endogenous ketogenesis induced by pharmacological PPARα activation, either alone or combined with ketogenic nutrition, is safe and can also mitigate muscle weakness in septic mice. Methods: In a fluid‐resuscitated, antibiotic‐treated mouse model of prolonged sepsis, we first (Study 1) assessed the safety and effectiveness (impact on ketosis and muscle weakness) of the PPARα agonist pemafibrate (1 mg/kg/d, n = 16), versus placebo ( n = 15) combined with standard balanced parenteral nutrition (PN), composed of glucose, amino acids and long‐chain triglycerides (LCT) (balanced‐TPN). We subsequently (Study 2) evaluated the impact of pemafibrate combined with four types of PN on ketosis and muscle weakness: balanced‐TPN ( n = 18), TPN with extra LCTs (TPN + LCT, n = 18), low‐dose pure LCT emulsion (Low‐LCT, n = 16) and high‐dose pure LCT emulsion (High‐LCT n = 18). Carbohydrates and amino acids were omitted in the pure LCT groups. Healthy control mice (HC, n = 19) served as controls. Ex vivo muscle force was measured as the primary outcome. Metabolic, inflammatory and microstructural parameters were assessed on plasma and in muscle and liver tissue by targeted metabolomics, gene expression analysis, biochemical and metabolite assays and histological assessment. Results: Pemafibrate treatment with balanced‐TPN upregulated hepatic gene expression of PPARα ( Ppara ) and its downstream genes ( Cd36 , Cpt1a , Atgl , Acadl, Hadha, Acox1, and Hmgcs2 ) ( p < 0.0001) and was well tolerated. However, pemafibrate treatment with the use of balanced‐TPN administration did not induce detectable ketosis or improve muscle weakness. In combination with pemafibrate, TPN + LCT also did not induce ketosis, nor did it affect muscle weakness. In contrast, 3‐hydroxybutyrate plasma concentrations increased with High‐LCT (95‐fold) and Low‐LCT (10‐fold) ( p < 0.0001) in combination with pemafibrate, yet muscle force declined further (High‐LCT 25.0%, Low‐LCT 10.7% of HC, p < 0.0001). Blood glucose was lowered with pure High‐LCT and Low‐LCT (High‐LCT 86.9%, Low‐LCT 55.1% of TPN, p < 0.05), while plasma lipids and LC‐carnitines were increased ( p < 0.0001). Markers of hepatic protein catabolism were upregulated with High‐LCT and Low‐LCT ( p < 0.007), while muscle glycolytic intermediates ( p < 0.0001) and ATP levels ( p < 0.0001) were depleted. Conclusions: In septic mice, pemafibrate combined with balanced‐TPN or lipid‐rich TPN induced PPARα activation but did not result in ketosis nor affect muscle weakness. Pemafibrate combined with pure LCTs induced ketosis in sepsis but worsened muscle weakness, possibly explained by muscular bioenergetic failure.

Isoflurane anesthesia is often used to facilitate murine echocardiography, but can suppress cardiac function. Awake imaging avoids pharmacological interference, but can induce sympathetic activation. In this Midazolam sedation. Parameters were compared using repeated‐measures ANOVA. Midazolam enabled imaging without overt stress behavior. Compared to midazolam, heart rate was similar under isoflurane and higher while awake ( p ≤ 0.01). End‐systolic volume was larger under isoflurane and smaller while awake; stroke volumes remained similar across conditions. Global longitudinal and circumferential strain were less negative under isoflurane (p = 0.03) but similar during awake imaging, while radial strain was higher during awake imaging. Peak longitudinal strain rate was less negative under isoflurane ( p ≤ 0.01) and more negative while awake ( p = 0.05). Early diastolic strain rate was similar under isoflurane and lower while awake ( p = 0.02). In conclusion, cardiac function was most depressed under isoflurane and most enhanced during awake imaging, likely stress‐driven. Murine echocardiography under midazolam sedation was feasible, yielding better function than isoflurane anesthesia, closer to awake imaging but without overt handling stress. These findings require further validation across disease models, sexes, and strains.

Background and Aims: Steroid supplementation remains controversial in septic shock, partly due to the heterogeneity of the populations studied. Cirrhotic patients with sepsis frequently develop relative adrenal insufficiency, showing poor response to vasopressors and poor prognosis. Early administration of low‐dose hydrocortisone might facilitate shock reversal and reduce mortality in this population. Methods: Double‐blind, randomised, placebo‐controlled multicentre trial, enrolling adult cirrhotic patients with septic shock. Patients were assigned to receive i.v. hydrocortisone (100 mg followed by a continuous infusion of 200 mg/24 h) or placebo, for at least 3 days, followed by a tapering period of 3–7 days, depending on the time of shock resolution. Primary endpoint was 28‐day all‐cause mortality. Results: After enrolment of 83 patients the trial was stopped early due to slow inclusions. Most patients required low‐to‐moderate doses of vasopressors. There was no difference in 28‐day mortality (35% vs. 39.5%; p = 0.84) between hydrocortisone and placebo groups. Shock resolution (85% vs. 72.1%; p = 0.25) and days to shock resolution [3 days (2.2–4; IQR) vs. 4 (2–7.5; IQR)] were also similar between groups. More patients receiving placebo died of refractory shock (47.6% vs. 8.7%). No significant differences between treatment arms were observed in shock relapse, new shock episodes or bacterial or fungal superinfections during hospital stay. Hypo‐ and hyperglycaemias were more frequent in the hydrocortisone arm. Severity of ACLF at inclusion and inadequacy of empirical antibiotic therapy (HR = 6.40; 95% CI: 3.21–12.79) independently predicted 28‐day mortality. Conclusions: Supplemental hydrocortisone did not improve short‐term survival in cirrhotic patients with septic shock requiring low‐to‐moderate doses of vasopressors. Trial Registration: S‐number University Hospitals Leuven, Belgium: S55168; EUDRACT: 2010–024273‐38; Clinicaltrials.gov id: NCT02602210

Critically ill adults typically develop hypocholesterolemia, associated with poor outcome. Whether similar alterations occur in critically ill children is less clear. In secondary analyses of the PEPaNIC RCT (n = 1440), we first documented the time course of plasma cholesterol and triglyceride concentrations, and the effect of randomization to early-parenteral-nutrition (early-PN) or late-PN hereon, for 96 matched critically ill children staying ≥ 5 days in PICU. Second, for 1165 children with available admission plasma samples, lipid profiles were determined and their independent associations with outcome (time to live PICU discharge, new infection and 90-day mortality) were assessed with Multivariable Cox proportional hazard and logistic regression, adjusting for baseline risk factors. Plasma HDL-cholesterol, LDL-cholesterol, total-cholesterol and triglycerides were low throughout the 5 PICU days, with only HDL-cholesterol further decreasing over time (P < 0.0001) and without effect of randomization to early-PN or late-PN, and with admission values lower in infants than older children and in patients with infection (P < 0.05). Lower admission HDL- and total-cholesterol concentrations were independently associated with a lower likelihood of an earlier live PICU discharge (P < 0.001) and with a higher risk of 90-day mortality (P ≤ 0.01), whereas higher plasma triglycerides were independently associated with higher risk of 90-day mortality (P = 0.004). Low admission plasma HDL-cholesterol was independently associated with a higher risk of acquiring a new infection (P = 0.05). Critically ill children presented with low circulating levels of lipids. Low plasma cholesterol concentrations were associated with poor outcomes, most robustly for HDL-cholesterol. Whether these associations are causal or casual requires further investigation.