Hernández‐Tejero, María

Liver macrophages are central in maintaining hepatic homeostasis and mediating immune responses during liver injury, including fibrosis. Macrophages may have proinflammatory or antiinflammatory properties, but which properties influence fibrosis remains unclear. To explore the role of macrophages in liver fibrosis, we performed single-cell RNA-seq in a mouse model of liver injury and found that macrophage diversity was increased. Marco was among the most significantly upregulated genes, and a population of Marco hi macrophages increased with injury and spatially segregated to nonfibrotic areas. The macrophage receptor with collagenous structure (MARCO) protein is a scavenger receptor expressed by specific subsets of macrophages, and its role in liver fibrosis is unclear. In vitro induction of Marco in bone marrow–derived macrophages decreased proinflammatory gene expression, increased antiinflammatory and antifibrotic gene expression, and enhanced phagocytosis, indicating a restorative phenotype. Adoptive transfer of MARCO + macrophages in a mouse model of liver fibrosis reduced the expression of extracellular matrix–associated (ECM-associated) genes in hepatic stellate cells (HSCs) and reduced collagen deposition, which did not occur with the transfer of MARCO – macrophages. Therefore, MARCO + macrophages have a tissue restorative role in the liver and attenuate fibrogenesis through interaction with HSCs, thereby providing a potential therapeutic pathway for liver fibrosis.

ABSTRACT 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