Rationale: In septic animal models mesenchymal stem (stromal) cells (MSCs) modulate inflammation, enhance tissue repair and pathogen clearance, and reduce death. Objectives: To conduct a phase I dose escalation trial of MSCs in septic shock with the primary objective of examining the safety and tolerability of MSCs. Methods: We enrolled nine participants within 24 hours of admission to the ICU. A control cohort of 21 participants was enrolled before starting the MSC interventional cohort to characterize expected adverse events (AEs) and to serve as a comparator for the intervention cohort. Three separate MSC dose cohorts, with three participants per cohort, received a single intravenous dose of 0.3, 1.0, and 3.0 × 106 cells/kg. A prespecified safety plan monitored participants for the occurrence of AEs; cytokines were collected at prespecified time points. Measurements and Main Results: Ages of participants in the interventional versus observational cohorts were median of 71 (range, 38–91) and 61 (range, 23–95). Acute Physiology and Chronic Health Evaluation scores were median of 25 (range, 11–28) and 26 (range, 17–32). MSC doses ranged from 19 to 250 million cells. There were no prespecified MSC infusion–associated or serious unexpected AEs, nor any safety or efficacy signals for the expected AEs or the measured cytokines between the interventional and observational cohorts. Conclusions: The infusion of freshly cultured allogenic bone marrow–derived MSCs, up to a dose of 3 million cells/kg (250 million cells), into participants with septic shock seems safe. Clinical trial registered with www.clinicaltrials.gov (NCT02421484).

In this review, we seek to highlight how critical illness and critical care affect longer-term outcomes, to underline the contribution of ICU delirium to cognitive dysfunction several months after ICU discharge, to give new insights into ICU acquired weakness, to emphasize the importance of value-based healthcare, and to delineate the elements of family-centered care. This consensus of 29 also provides a perspective and a research agenda about post-ICU recovery.

Due to their anti-inflammatory, antiapoptotic, antimicrobial, and antifibrotic properties, mesenchymal stromal cells (MSCs) have been considered a promising alternative for treatment of respiratory diseases. Nevertheless, even though MSC administration has been demonstrated to be safe in clinical trials, to date, few studies have shown evidence of MSC efficacy in respiratory diseases. The present review describes strategies to enhance the beneficial effects of MSCs, including preconditioning (under hypoxia, oxidative stress, heat shock, serum deprivation, and exposure to inflammatory biological samples) and genetic manipulation. These strategies can variably promote increases in MSC survival rates, by inducing expression of cytoprotective genes, as well as increase MSC potency by improving secretion of reparative factors. Furthermore, these strategies have been demonstrated to enhance the beneficial effects of MSCs in preclinical lung disease models. However, there is still a long way to go before such strategies can be translated from bench to bedside.

The diagnostic and prognostic potential of the vast quantity of publicly-available microarray data has driven the development of methods for integrating the data from different microarray platforms. Cross-platform integration, when appropriately implemented, has been shown to improve reproducibility and robustness of gene signature biomarkers. Microarray platform integration can be conceptually divided into approaches that perform early stage integration (cross-platform normalization) versus late stage data integration (meta-analysis). A growing number of statistical methods and associated software for platform integration are available to the user, however an understanding of their comparative performance and potential pitfalls is critical for best implementation. In this review we provide evidence-based, practical guidance to researchers performing cross-platform integration, particularly with an objective to discover biomarkers.

Rationale: Ventilator-induced lung injury (VILI) contributes to the mortality in patients with acute lung injury by increasing inflammation. Recent evidence suggests that stimulation of the cholinergic antiinflammatory pathway may be an attractive way to attenuate inflammatory injury. Objectives: To determine the role of vagus nerve signaling in VILI and establish whether stimulation of the vagus reflex can mitigate VILI. Methods: We performed bilateral vagotomy in a mouse model of high-tidal volume–induced lung injury. We performed pharmacological and electrical vagus nerve stimulation in a rat model of VILI following ischemia/reperfusion injury. To determine the contribution of the alpha 7 acetylcholine nicotinic receptor to pulmonary cell injury, we exposed human bronchial epithelial cells to cyclic stretch in the presence of specific agonist or antagonist of the alpha 7 receptor. Measurements and Main Results: Vagotomy exacerbates lung injury from VILI in mice as demonstrated by increased wet-to-dry ratio, infiltration of neutrophils, and increased IL-6. Vagal stimulation attenuates lung injury in rats after ischemia/reperfusion injury ventilated with high-volume strategies. Treatment of both mice and rats with the vagus mimetic drug semapimod resulted in decreased lung injury. Vagotomy also increased pulmonary apoptosis, whereas vagus stimulation (electrical and pharmacological) attenuated VILI-induced apoptosis. In vitro studies suggest that vagus-dependent effects on inflammation and apoptosis are mediated via the α7 nicotinc acetylcholine receptor–dependent effects on cyclic stretch–dependent signaling pathways c-jun N-terminal kinase and tumor necrosis factor receptor superfamily, member 6. Conclusions: Stimulation of the cholinergic antiinflammatory reflex may represent a promising alternative for the treatment of VILI.

Objectives: Recent evidence from the fields of microbiology and immunology, as well as a small number of human sepsis studies, suggest that epigenetic regulation may play a central role in the pathogenesis of sepsis. The term “epigenetics” refers to regulatory mechanisms that control gene expression but are not related to changes in DNA sequence. These include DNA methylation, histone modifications, and regulation of transcription via non-coding RNAs. Epigenetic modifications, occurring in response to external stressors, lead to changes in gene expression, and thus lie at the intersection between genetics and the environment. In this review, we examine data from in vitro studies, animal studies, and the existing human sepsis studies in epigenetics to demonstrate that epigenetic mechanisms are likely central to the pathogenesis of sepsis and that epigenetic therapies may have potential in the treatment of sepsis and its associated organ failures. Data Sources: Online search of published scientific literature via Pubmed using the term “epigenetics” in combination with the terms “sepsis”, “infection”, “bacterial infection”, “viral infection”, “critical illness”, “acute respiratory distress syndrome”, and “acute lung injury”. Study Selection: Articles were chosen for inclusion based on their relevance to sepsis, acute inflammation, sepsis-related immune suppression, and sepsis-related organ failure. Reference lists were reviewed to identify additional relevant articles. Data Extraction: Relevant data was extracted and synthesized for narrative review. Data Synthesis: Epigenetic regulation is a key determinant of gene expression in sepsis. At the onset of infection, host-pathogen interactions often result in epigenetic alterations to host cells that favor pathogen survival. In parallel, the host inflammatory response is characterized by epigenetic modifications in key regulatory genes, including tumor necrosis factor and interleukin-1β. In human sepsis patients, multiple epigenetic modifying enzymes show differential expression in early sepsis, suggesting a role for epigenetics in coordinating the response to infection. In the later stages of sepsis, epigenetic modifications accompany endotoxin tolerance and the immune-suppressed state. In animal models, treatment with epigenetic modifiers can mitigate the effects of sepsis and improve survival as well as reverse sepsis-associated organ injury. Conclusions: Epigenetic modifications are associated with key phases of sepsis, from the host-pathogen interaction, to acute inflammation, to immune suppression. Epigenetic markers show promise in the diagnosis and prognosis of sepsis and epigenetic modifying agents show promise as therapeutic tools in animal models of sepsis. Human studies in the area of epigenetics are sorely lacking and should be a priority for sepsis researchers.