Differential Gene Expression in Circulating CD14+ Monocytes Indicates the Prognosis of Critically Ill Patients with Sepsis

Abstract

Critical illness and sepsis are characterized by drastic changes in the systemic innate immune response, particularly involving monocytes. The exact monocyte activation profile during sepsis, however, has remained obscure. Therefore, we prospectively analyzed the gene expression profile of circulating CD14+ monocytes from healthy volunteers (n = 54) and intensive care unit (ICU) patients (n = 76), of which n = 36 had sepsis. RNA sequencing of selected samples revealed that monocytes from septic ICU patients display a peculiar activation pattern, which resembles characteristic functional stages of monocyte-derived macrophages and is distinct from controls or non-sepsis ICU patients. Focusing on 55 highly variable genes selected for further investigation, arachidonate 5-lipoxygenase-activating protein (ALOX5AP) was highly upregulated in monocytes of ICU patients and only normalized during 7 days in the ICU in non-sepsis patients. Strikingly, low monocytic guanine nucleotide exchange factor 10-like protein (ARHGEF10L) mRNA expression was associated with the disease severity and mortality of ICU patients. Collectively, our comprehensive analysis of circulating monocytes in critically ill patients revealed a distinct activation pattern, particularly in ICU patients with sepsis. The association with disease severity, the longitudinal recovery or lack thereof during the ICU stay, and the association with prognosis indicate the clinical relevance of monocytic gene expression profiles during sepsis.

Differences in monocyte subsets are associated with short‐term survival in patients with septic shock

“…As we mainly focused to analyse phenotype of the dynamically changing monocytes subsets, the 12 hours time-point of analysis provided an important advantage comparing to other reports focused to monocytes where authors used later sampling (1-5 days after admission to ICU). 13,14,21 The prompt risk stratification of patients with septic shock, is a key information for adjusting the care and later improvement of the therapeutics outcomes remain a key research focus. 21,25 Unlike published studies 21,25 comparing healthy volunteers, or critically ill non-septic patients with septic patients, we used a more appropriate way to assess markers of septic shock prognosis dividing the cohort of septic shock patients to survivors and early deceased patients.…”

“…13,14,21 The prompt risk stratification of patients with septic shock, is a key information for adjusting the care and later improvement of the therapeutics outcomes remain a key research focus. 21,25 Unlike published studies 21,25 comparing healthy volunteers, or critically ill non-septic patients with septic patients, we used a more appropriate way to assess markers of septic shock prognosis dividing the cohort of septic shock patients to survivors and early deceased patients. We showed that shift in monocyte subsets can serve as predictive marker of early survival first five days of septic shock.…”

Induction of a regulatory myeloid program in bacterial sepsis and severe COVID-19

“…Sepsis is associated with profound alterations in the peripheral immune compartment, including marked reduction in lymphocyte counts [10][11][12] and phenotypic alteration of myeloid cells [13][14][15] . Monocytes from sepsis patients have decreased responsiveness to stimuli [15][16][17] and have lower expression of HLA-DR [18][19][20][21][22][23] characteristic of monocytic MDSCs.…”

Reference Genes for Quantitative qPCR Analyses in Monocytes of Septic Patients

“…Another study with monocytes from critically ill patients and septic patients used the geometric mean of ve targets genes that had the smallest variation among them as reference genes [12]. As mentioned, the majority of these studies used in vitro LPS-stimulated monocytes, which differ from the condition of cells obtained from septic patients.…”

“…Only six studies reported monocyte/macrophage gene expression results in septic conditions using different experimental approaches mostly in in vitro studies using murine bone marrow-derived macrophages and J774A1 murine macrophage cell line [11][12][13][14][15][16]. The followings were used as reference genes in the mentioned studies: 18S (18S RNA ribosomal), ACTB (beta actin), B2M (beta 2-microglobulin), GAPDH (glyceraldehyde 3-phosphate dehydrogenase), GUSB (glucuronidase beta), HMBS (hydroxymethylbilane synthase), HNRNPAB (heterogeneous nuclear ribonucleoprotein A/B), HPRT1 (hypoxanthine phosphoribosyltransferase 1), MAU2 (MAU2 chromatid cohesion factor homolog), PGK1 (phosphoglycerate kinase 1), PPIA (peptidylprolyl isomerase A), PPIB (peptidylprolyl cis-trans isomerase B), RPL13A (ribosomal protein L13a), STX5A (syntaxin 5), YWHAZ (14-3-3 protein zeta/delta).…”