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Rationale: The mechanistic basis for cardiac and renal dysfunction in sepsis is unknown. In particular, the degree and type of cell death is undefined. Objectives: To evaluate the degree of sepsis-induced cardiomyocyte and renal tubular cell injury and death. Methods: Light and electron microscopy and immunohistochemical staining for markers of cellular injury and stress, including connexin-43 and kidney-injury-molecule-1 (Kim-1), were used in this study. Measurements and Main Results: Rapid postmortem cardiac and renal harvest was performed in 44 septic patients. Control hearts were obtained from 12 transplant and 13 brain-dead patients. Control kidneys were obtained from 20 trauma patients and eight patients with cancer. Immunohistochemistry demonstrated low levels of apoptotic cardiomyocytes (,1-2 cells per thousand) in septic and control subjects and revealed redistribution of connexin-43 to lateral membranes in sepsis (P , 0.020). Electron microscopy showed hydropic mitochondria only in septic specimens, whereas mitochondrial membrane injury and autophagolysosomes were present equally in control and septic specimens. Control kidneys appeared relatively normal by light microscopy; 3 of 20 specimens showed focal injury in approximately 1% of renal cortical tubules. Conversely, focal acute tubular injury was present in 78% of septic kidneys, occurring in 10.3 6 9.5% and 32.3 6 17.8% of corticomedullary-junction tubules by conventional light microscopy and Kim-1 immunostains, respectively (P , 0.01). Electron microscopy revealed increased tubular injury in sepsis, including hydropic mitochondria and increased autophagosomes. Conclusions: Cell death is rare in sepsis-induced cardiac dysfunction, but cardiomyocyte injury occurs. Renal tubular injury is common in sepsis but presents focally; most renal tubular cells appear normal. The degree of cell injury and death does not account for severity of sepsis-induced organ dysfunction.Keywords: sepsis; apoptosis; necrosis; autophagy; kidney Sepsis causes profound myocardial depression, and echocardiography frequently reveals severe biventricular dysfunction (1-5). Sepsis also induces renal insufficiency in 30 to 60% of patients, up to half of whom require dialysis (6-10). The mechanistic basis for cardiac and renal dysfunction occurring in sepsis is controversial (1,5,7,9,(11)(12)(13)(14)(15)(16). The degree to which apoptosis, necrosis, or autophagy contribute to cardiac and renal dysfunction in sepsis is unresolved (2,3,(16)(17)(18)(19).Although a few well controlled studies have been performed, extensive cell death in hearts or kidneys in patients dying of sepsis has not been described, leading investigators to postulate that cellular "hibernation" or metabolic suppression and not cell death is the basis of sepsis-induced organ failure (11,13,14,16,18,(20)(21)(22). Cardiac dysfunction in sepsis is reversible, and the majority of renal failure patients who survive sepsis recover baseline renal function; these observations are consistent with organ "hibernation" (1, ...

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Autophagy is the regulated process cells use to recycle non-essential, redundant, or inefficient components and is an adaptive response during times of stress. In addition to its role in enabling the cell to gain vital nutrients in times of stress, autophagy can also be involved in elimination of intracellular microorganisms, tumor suppression, and antigen presentation. Because of difficulty in diagnosing autophagy, few clinical studies have been performed. This study examined whether autophagy occurs in hepatocytes during sepsis. Electron microscopy (EM) was performed on liver samples obtained from both an observational clinical cohort of 6 septic patients and 4 control patients as well as liver specimens from mice with surgical sepsis (via cecal ligation and puncture (CLP)) or sham operation. EM demonstrated increased autophagic vacuoles in septic versus non-septic patients. Randomly selected fields (3,000 square microns) from control and septic patients contained 1.2 ± 1.5 versus 5.3 ± 3.3 (mean ± SD) complex lysosomal/autophagolysosomal structures per image respectively (P<0.001). In rare instances, hepatocytes with autophagic vacuoles appeared to be unequivocally committed to death. Membrane alterations (membrane vacuoles, invagination into adjacent organelles and myelin figure-like changes) occur in a subpopulation of mitochondria in sepsis, but other hepatocyte organelles showed no consistent ultrastructural injury. Findings in murine sepsis paralleled those of patients, with 7.2 ± 1.9 versus 38.7 ± 3.9 lysosomal/autophagolysosomal structures in sham and septic mice, respectively (P =0.002). Quantitative RT-PCR demonstrated that sepsis-induced the upregulation of select apoptosis and cytokine gene expression with minimal changes in the core autophagy genes in liver. In conclusion, hepatocyte autophagic vacuolization increases during sepsis and is associated with mitochondrial injury. However, it is not possible to determine whether the increase in autophagic vacuolization is an adaptive response or a harbinger of cell death.

Background Little information is available about the geo-economic variations in demographics, management, and outcomes of patients with acute respiratory distress syndrome (ARDS). We aimed to characterise the effect of these geo-economic variations in patients enrolled in the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE). Methods LUNG SAFE was done during 4 consecutive weeks in winter, 2014, in a convenience sample of 459 intensivecare units in 50 countries across six continents. Inclusion criteria were admission to a participating intensive-care unit (including transfers) within the enrolment window and receipt of invasive or non-invasive ventilation. One of the trial's secondary aims was to characterise variations in the demographics, management, and outcome of patients with ARDS. We used the 2016 World Bank countries classification to define three major geo-economic groupings, namely European high-income countries (Europe-High), high-income countries in the rest of the world (rWORLD-High), and middle-income countries (Middle). We compared patient outcomes across these three groupings. LUNG SAFE is registered with ClinicalTrials.gov, number NCT02010073. Findings Of the 2813 patients enrolled in LUNG SAFE who fulfilled ARDS criteria on day 1 or 2, 1521 (54%) were recruited from Europe-High, 746 (27%) from rWORLD-High, and 546 (19%) from Middle countries. We noted significant geographical variations in demographics, risk factors for ARDS, and comorbid diseases. The proportion of patients with severe ARDS or with ratios of the partial pressure of arterial oxygen (PaO 2) to the fractional concentration of oxygen in inspired air (F I O 2) less than 150 was significantly lower in rWORLD-High countries than in the two other regions. Use of prone positioning and neuromuscular blockade was significantly more common in Europe-High countries than in the other two regions. Adjusted duration of invasive mechanical ventilation and length of stay in the intensive-care unit were significantly shorter in patients in rWORLD-High countries than in Europe-High or Middle countries. High gross national income per person was associated with increased survival in ARDS; hospital survival was significantly lower in Middle countries than in Europe-High or rWORLD-High countries. Interpretation Important geo-economic differences exist in the severity, clinician recognition, and management of ARDS, and in patients' outcomes. Income per person and outcomes in ARDS are independently associated.

IntroductionIt is not well understood whether the process of autophagy is accelerated or blocked in sepsis, and whether it is beneficial or harmful to the immune defense mechanism over a time course during sepsis. Our aim was to determine both the kinetics and the role of autophagy in sepsis.MethodsWe examined autophagosome and autolysosome formation in a cecal ligation and puncture (CLP) mouse model of sepsis (in C57BL/6N mice and GFP-LC3 transgenic mice), using western blotting, immunofluorescence, and electron microscopy. We also investigated the effect of chloroquine inhibition of autophagy on these processes.ResultsAutophagy, as demonstrated by increased LC3-II/LC3-I ratios, is induced in the liver, heart, and spleen over 24 h after CLP. In the liver, autophagosome formation peaks at 6 h and declines by 24 h. Immunofluorescent localization of GFP-LC3 dots (alone and with lysosome-associated membrane protein type 1 (LAMP1)), as well as electron microscopic examination, demonstrate that both autophagosomes and autolysosomes are increased after CLP, suggesting that intact autophagy mechanisms operate in the liver in this model. Furthermore, inhibition of autophagy process by chloroquine administration immediately after CLP resulted in elevated serum transaminase levels and a significant increase in mortality.ConclusionsAll autophagy-related processes are properly activated in the liver in a mouse model of sepsis; autophagy appears to play a protective role in septic animals.

Ebolavirus (EBOV) is a member of the filovirus family and causes severe hemorrhagic fever, resulting in death in up to 90% of infected humans. EBOV infection induces massive bystander lymphocyte apoptosis; however, neither the cellular apoptotic pathway(s) nor the systemic implications of lymphocyte apoptosis in EBOV infection are known. In this study, we show data suggesting that EBOV-induced lymphocyte apoptosis in vivo occurs via both the death receptor (extrinsic) and mitochondrial (intrinsic) pathways, as both Fas-associated death domain dominant negative transgenic mice and mice overexpressing bcl-2 were resistant to EBOV-induced lymphocyte apoptosis. Surprisingly, inhibiting lymphocyte apoptosis during EBOV infection did not result in improved animal survival. Furthermore, we show for the first time that hepatocyte apoptosis likely occurs in EBOV infection, and that mice lacking the proapoptotic genes Bim and Bid had reduced hepatocyte apoptosis and liver enzyme levels postinfection. Collectively, these data suggest that EBOV induces multiple proapoptotic stimuli and that blocking lymphocyte apoptosis is not sufficient to improve survival in EBOV infection. These data suggest that hepatocyte apoptosis may play a role in the pathogenesis of EBOV infection, whereas lymphocyte apoptosis appears to be nonessential for EBOV disease progression.

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