Voluntary running exercise protects against sepsis-induced early inflammatory and pro-coagulant responses in aged mice

Hydroxychloroquine Mitigates Cytokine Storm and Prevents Critical Illness Neuromyopathy in a Rat Sepsis Model

Background and Objectives: It is known that critical illness and associated neuromuscular problems begin to appear in patients hospitalized in the intensive care unit (ICU) for more than a week. The goal of this study was to research the role of hydroxychloroquine (HCQ) in the treatment of cytokine storm and critical illness neuromyopathy (CINM) in a rat sepsis model. Materials and Methods: Rats were assigned into three groups, and a feces intraperitoneal-injection group (FIP) procedure was carried out on 30 rats to induce a model of sepsis for critical illness polyneuromyopathy (CINM). The study groups were as follows: Group 1: control (nonoperative and orally fed control, n = 10), Group 2: FIP with 0.9% NaCl saline was given as 1 mL/kg/day by oral gavage (n = 10), and Group 3: FIP with 10 mg/kg/day of hydroxychloroquine (Plaquenil 200 mg) administered by oral gavage (n = 10). Electrophysiological recordings (EMG) were conducted six days after surgery. EMG was carried out three times on the right sciatic nerve, which was stimulated with supramaximal intensity utilizing a bipolar needle electrode at the sciatic notch. Tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), lactic acid levels, and interleukin-6 (IL-6) were evaluated. Results: In terms of TNF-α, MDA, lactic acid levels, and IL-6, there was a statistically significant decrease in the CINM + 10 mg/kg HCQ group compared to the CINM and saline group (p < 0.0001, p < 0.05, p < 0.05, and p < 0.05, respectively). Compound muscle action potentials (CMAPs) latency and duration were decreased in the CINM + 10 mg/kg HCQ group compared to other groups (p < 0.01 and p < 0.001). However, CMAP amplitude was significantly higher in the CINM + 10 mg/kg HCQ group unlike the CINM and saline group (p < 0.001). Conclusions: This is the first study to demonstrate the effects of HCQ on CINM in a rat model of sepsis. The findings of our research suggest that hydroxychloroquine may be used as a potential therapeutic agent in the treatment of sepsis. Hydroxychloroquine may have an important effect in the pathogenesis of sepsis-associated CINM by reducing cytokine production and oxidative stress.

Aerobic Exercise Protects against Cardiotoxin-Induced Skeletal Muscle Injury in a DDAH1-Dependent Manner

Dimethylarginine dimethylaminohydrolase 1 (DDAH1) is a critical enzyme that regulates nitric oxide (NO) signaling through the degradation of asymmetric dimethylarginine (ADMA). Previous studies have revealed a link between the beneficial effects of aerobic exercise and the upregulation of DDAH1 in bones and hearts. We previously reported that skeletal muscle DDAH1 plays a protective role in cardiotoxin (CTX)-induced skeletal muscle injury and regeneration. To determine the effects of aerobic exercise on CTX-induced skeletal muscle injury and the role of DDAH1 in this process, wild-type (WT) mice and skeletal muscle-specific Ddah1-knockout (Ddah1MKO) mice were subjected to swimming training for 8 weeks and then injected with CTX. In WT mice, swimming training for 8 weeks significantly promoted skeletal muscle regeneration and attenuated inflammation, oxidative stress, and apoptosis in the gastrocnemius (GA) muscle after CTX injection. These phenomena were associated with increases in the protein expression of PAX7, myogenin, MEF2A, eNOS, SOD2, and peroxiredoxin 5 and decreases in iNOS expression in GA muscles. Swimming training also decreased serum ADMA levels and increased serum nitrate/nitrite (NOx) levels and skeletal muscle DDAH1 expression. Interestingly, swimming training in Ddah1MKO mice had no obvious effect on CTX-induced skeletal muscle injury or regeneration and did not repress the CTX-induced inflammatory response, superoxide generation, or apoptosis. In summary, our data suggest that DDAH1 is important for the protective effect of aerobic exercise on skeletal muscle injury and regeneration.

The Application Potential of the Regulation of Tregs Function by Irisin in the Prevention and Treatment of Immune-Related Diseases

Irisin is a muscle factor induced by exercise, generated through the proteolytic cleavage of the membrane protein fibronectin type III domain-containing protein 5 (FNDC-5). Numerous studies have shown that irisin plays a significant role in regulating glucose and lipid metabolism, inhibiting oxidative stress, reducing systemic inflammatory responses, and providing neuroprotection. Additionally, irisin can exert immunomodulatory functions by regulating regulatory T cells (Tregs). Tregs are a highly differentiated subset of mature T cells that play a key role in maintaining self-immune homeostasis and are closely related to infections, inflammation, immune-related diseases, and tumors. Irisin exerts persistent positive effects on Treg cell functions through various mechanisms, including regulating Treg cell differentiation and proliferation, improving their function, modulating the balance of immune cells, increasing the production of anti-inflammatory cytokines, and enhancing metabolic functions, thereby helping to maintain immune homeostasis and prevent immune-related diseases. As an important myokine, irisin interacts with receptors on the cell membrane, activating multiple intracellular signaling pathways to regulate cell metabolism, proliferation, and function. Although the specific receptor for irisin has not been fully identified, integrins are considered potential receptors. Irisin activates various signaling pathways, including AMPK, MAPK, and PI3K/Akt, through integrin receptors, thereby exerting multiple biological effects. These research findings provide important clues for understanding the mechanisms of irisin's action and theoretical basis for its potential applications in metabolic diseases and immunomodulation. This article reviews the relationship between irisin and Tregs, as well as the research progress of irisin in immune-related diseases such as multiple sclerosis, myasthenia gravis, acquired immune deficiency syndrome, type 1 diabetes, sepsis, and rheumatoid arthritis. Studies have revealed that irisin plays an important role in immune regulation by improving the function of Tregs, suggesting its potential application value in the treatment of immune-related diseases.

Hydroxychloroquine attenuates sepsis-induced acute respiratory distress syndrome in rats

BACKGROUND

This study investigates the effects of hydroxychloroquine (HCQ) on a sepsis-induced acute respiratory distress syndrome (ARDS) model in rats, initiated by a fecal intraperitoneal injection procedure (FIP).

METHODS

Three groups were established: control (n=8), FIP + saline (n=7), and FIP + HCQ (20 mg/kg/day) (n=9). Blood samples were collected for arterial blood gas and biochemical analyses, and bilateral pneumonectomy was performed for histopathologic examination.

RESULTS

In the FIP + saline group, PaO2 decreased and PaCO2 increased, whereas these levels normalized in the FIP + HCQ group compared to the control (p<0.001 and p<0.05, respectively). Histopathological scores for alveolar congestion, perivascular/interstitial edema, hemorrhage in alveolar tissue, leukocyte infiltration or aggregation in air spaces/vascular walls, and alveolar wall/hyaline membrane thickness increased in the FIP + saline group compared to the control group (p<0.01). These scores decreased in the FIP + HCQ group compared to the FIP + saline group (p<0.01). HCQ reversed the sepsis-induced increase in malondialdehyde, tumor necrosis factor-alpha, interleukin-6, and lactic acid.

CONCLUSION

HCQ may be an effective and safe option to mitigate the severe progression of ARDS.

Physical Activity and the incidence of sepsis: A 10-year observational study among 4 million adults

BACKGROUND

As the group at high risk for sepsis is increasing with the aging of the population, physical activity (PA), which has beneficial effects on various diseases, needs to be considered as a personalized prevention strategy for sepsis without direct anti-sepsis drug.

PURPOSE

To examine the association between the amount of PA (based on intensity, duration, and frequency) and the incidence rates of sepsis and mortality after sepsis.

METHODS

This was a large-scale, retrospective, longitudinal cohort study using data from the Korean National Health Insurance Service and the biennial general health screening program. The amount of PA self-reported at the time of the health screening was categorized as non-PA, mild (<500 metabolic equivalents [METs]-Min/Week), moderate (500-1000), severe (1000-1500), and extreme (≥1500). The multivariable regression model was adjusted for age, sex, income, body mass index, smoking, alcohol consumption, diabetes, hypertension, dyslipidemia, and chronic diseases.

RESULTS

From 4,234,415 individuals who underwent a health screening in 2009, 3,929,165 subjects were selected after exclusion for wash-out period and a 1-year lag period, and then observed for the event of sepsis or all-cause death until December 2020. During a median 10.3 years of follow-up, 83,011 incidents of sepsis were detected. The moderate-PA group showed the lowest incidence (1.56/1000 person-years) and risk for sepsis, with an adjusted hazard ratio (aHR) of 0.73 (95% CI, 0.72-0.75, P < 0.001) compared with the non-PA group. The occurrence of sepsis among people aged ≥65 years and ex-smokers were significantly lower in the moderate-PA group (aHR; 0.77, 95% CI; 0.74-0.79; and 0.68, 0.64-0.71, respectively, Ps < 0.001). The long-term all-cause mortality after sepsis was significantly lower in the PA group than in the non-PA group (overall P = 0.003).

CONCLUSIONS

Physical activity is associated with a lower risk of sepsis, especially in elderly people who have the highest incidence of sepsis. The protective effects of aerobic PA on sepsis might need to be incorporated with other interventions in sepsis guidelines through the accumulation of future studies.

Vascular Responses to Acute Induced Inflammation With Aging: Does Fitness Matter?

Acute inflammation impairs vascular function in an age-dependent manner and affects cardiovascular event risk. Regular aerobic exercise preserves vascular function with aging and potentially modifies how acute inflammation affects the vasculature. We hypothesize high cardiorespiratory fitness may accompany greater arterial responsiveness post-acute inflammation in older adults.

Impact of age on the host response to sepsis in a murine model of fecal-induced peritonitis

INTRODUCTION

Despite older adults being more vulnerable to sepsis, most preclinical research on sepsis has been conducted using young animals. This results in decreased scientific validity since age is an independent predictor of poor outcome. In this study, we explored the impact of aging on the host response to sepsis using the fecal-induced peritonitis (FIP) model developed by the National Preclinical Sepsis Platform (NPSP).

METHODS

C57BL/6 mice (3 or 12 months old) were injected intraperitoneally with rat fecal slurry (0.75 mg/g) or a control vehicle. To investigate the early stage of sepsis, mice were culled at 4 h, 8 h, or 12 h to investigate disease severity, immunothrombosis biomarkers, and organ injury. Mice received buprenorphine at 4 h post-FIP. A separate cohort of FIP mice were studied for 72 h (with buprenorphine given at 4 h, 12 h, and then every 12 h post-FIP and antibiotics/fluids starting at 12 h post-FIP). Organs were harvested, plasma levels of Interleukin (IL)-6, IL-10, monocyte chemoattract protein (MCP-1)/CCL2, thrombin-antithrombin (TAT) complexes, cell-free DNA (CFDNA), and ADAMTS13 activity were quantified, and bacterial loads were measured.

RESULTS

In the 12 h time course study, aged FIP mice demonstrated increased inflammation and injury to the lungs compared to young FIP mice. In the 72 h study, aged FIP mice exhibited a higher mortality rate (89%) compared to young FIP mice (42%) (p < 0.001). Aged FIP non-survivors also exhibited a trend towards elevated IL-6, TAT, CFDNA, CCL2, and decreased IL-10, and impaired bacterial clearance compared to young FIP non-survivors.

CONCLUSION

To our knowledge, this is the first study to investigate the impact of age on survival using the FIP model of sepsis. Our model includes clinically-relevant supportive therapies and inclusion of both sexes. The higher mortality rate in aged mice may reflect increased inflammation and worsened organ injury in the early stage of sepsis. We also observed trends in impaired bacterial clearance, increase in IL-6, TAT, CFDNA, CCL2, and decreased IL-10 and ADAMTS13 activity in aged septic non-survivors compared to young septic non-survivors. Our aging model may help to increase the scientific validity of preclinical research and may be useful for identifying mechanisms of age-related susceptibility to sepsis as well as age-specific treatment strategies.

Gallic Acid Protects from Sepsis-Induced Acute Lung Injury

Sepsis, a leading global cause of morbidity and mortality, involves multiple organ dysfunction syndromes driven by free radical-mediated processes. Uncontrolled inflammation in early sepsis stages can lead to acute lung injury (ALI). Activated leukocytes generate reactive oxygen species, contributing to sepsis development. Gallic acid, a phenolic compound, is known for its antimicrobial properties. This study aims to observe gallic acid's protective and restorative effect on the lungs in an experimental sepsis model. Male Wistar albino rats were subjected to a feces intraperitoneal injection procedure (FIP) to induce sepsis. Four groups were formed: normal control, FIP alone, FIP with saline, and FIP with gallic acid. Gallic acid was administered intraperitoneally at 20 mg/kg/day. Blood samples were collected for biochemical analysis, and computed tomography assessed lung tissue histopathologically and radiologically. Gallic acid significantly decreased malondialdehyde, IL-6, IL-1β, TNF-α, CRP levels, oxidative stress, and inflammation indicators. Lactic acid levels decreased, suggesting improved tissue oxygenation. Histopathological examinations revealed reduced lung damage in the gallic-acid-treated group. Computed tomography confirmed lower lung density, indicating less severe inflammation. Arterial blood gas analysis demonstrated improved oxygenation in gallic-acid-treated rats. Gallic acid exhibited anti-inflammatory and antioxidant effects, reducing markers of systemic inflammation and oxidative stress. The findings support its potential to protect against ALI during sepsis. Comparable studies underline gallic acid's anti-inflammatory properties in different tissues. Early administration of gallic acid in sepsis models demonstrated protective effects against ALI, emphasizing its potential as an adjunct therapy to mitigate adverse outcomes. The study proposes gallic acid to reduce mortality rates and decrease the need for mechanical ventilation during sepsis-induced ALI.

Mechanism of exosomes from adipose-derived mesenchymal stem cells on sepsis-induced acute lung injury by promoting TGF-β secretion in macrophages

OBJECTIVE

Acute lung injury (ALI) caused by sepsis is a life-threatening condition characterized by uncontrollable lung inflammation. The current study sought to investigate the mechanism of adipose-derived mesenchymal stem cell-derived exosomes (ADMSC-Exos) in attenuating sepsis-induced ALI through TGF-β secretion in macrophages.

METHODS

Adipose-derived mesenchymal stem cell-derived exosomes (ADMSC-Exos) were extracted from ADMSCs and identified. Septic ALI mouse models were established via cecal ligation and puncture (CLP), followed by administration of ADMSC-Exos or sh-TGF-β lentiviral vector. Mouse macrophages (cell line RAW 264.7) were treated with lipopolysaccharide (LPS), co-cultured with Exos and splenic T cells, and transfected with TGF-β siRNA. The lung injury of CLP mice was evaluated, and levels of inflammatory indicators and macrophage markers were measured. The localization of macrophage markers and TGF-β was determined, and the level of TGF-β in lung tissues was measured. The effect of TGF-β knockdown on sepsis-induced ALI in CLP mice was evaluated, and the percentages of CD4+CD25+Foxp3+ Tregs in mononuclear cells/macrophages and Foxp3 levels in lung tissues/co-cultured splenic T cells were examined.

RESULTS

ADMSC-Exos were found to alleviate sepsis-induced ALI, inhibit inflammatory responses, and induce macrophages to secrete TGF-β in CLP mice. TGF-β silencing reversed the alleviating effect of ADMSC-Exos on sepsis-induced ALI. ADMSC-Exos also increased the number of Tregs in the spleen of CLP mice and promoted M2 polarization and TGF-β secretion in LPS-induced macrophages. After knockdown of TGF-β in macrophages in the co-culture system, the number of Tregs decreased, suggesting that ADMSC-Exos increased the Treg number by promoting macrophages to secrete TGF-β.

CONCLUSION

Our findings suggest ADMSC-Exos can effectively alleviate sepsis-induced ALI in CLP mice by promoting TGF-β secretion in macrophages.

Demonstration of ameliorating effect of papaverine in sepsis-induced acute lung injury on rat model through radiology and histology

BACKGROUND

Our target was to show the role of high mobility group box-1/receptor for (HMGB1/RAGE) interaction in feces intraperitoneal injection procedure (FIP)-induced acute lung injury (ALI) pathophysiology, to investigate the effect of papaverine on RAGE associated NF-κB pathway by determining the level of soluble RAGE (sRAGE) and HMGB1, and to support this hypothesis by evaluating inflammatory biochemical, oxidative stress markers, Hounsfield unit (HU) value in computed tomography (CT), and histo-pathological results.

METHODS

FIP was performed on 37 Wistar rats for creating a sepsis-induced ALI model. The animals were assigned into four groups as follows: Normal control (no treatment), placebo (FIP and saline), and receiving 20 mg/kg and 40 mg/kg per day papaverine. Twenty h after FIP, CT examination was performed for all animals, and HU value of the lung parenchyma was measured. The plasma levels of tumor necrosis factor (TNF)-α, HMGB1, sRAGE, C-reactive protein (CRP) and malondialdehyde (MDA), and lactic acid (LA) were determined and PaO2 and PaCO2 were measured from arterial blood sample. Lung damage was assessed by histopathological.

RESULTS

TNF-, IL-6, CRP, HMGB1, MDA, LA levels, histopathologic scores, and HU values of CT were significantly increased and sRAGE levels were decreased in the saline-treated group against normal group (all P<0.05). Papaverine significantly reversed all results regardless of the dose (all P<0.05) and demonstrated inhibition of HMGB1/RAGE interaction through increasing sRAGE levels and suppresses the pro-inflammatory cytokines.

CONCLUSION

We concluded that papaverine has ameliorating effects in rat model of ALI.

Non-Invasive Pulsatile Shear Stress Modifies Endothelial Activation; A Narrative Review

The monolayer of cells that line both the heart and the entire vasculature is the endothelial cell (EC). These cells respond to external and internal signals, producing a wide array of primary or secondary messengers involved in coagulation, vascular tone, inflammation, and cell-to-cell signaling. Endothelial cell activation is the process by which EC changes from a quiescent cell phenotype, which maintains cellular integrity, antithrombotic, and anti-inflammatory properties, to a phenotype that is prothrombotic, pro-inflammatory, and permeable, in addition to repair and leukocyte trafficking at the site of injury or infection. Pathological activation of EC leads to increased vascular permeability, thrombosis, and an uncontrolled inflammatory response that leads to endothelial dysfunction. This pathological activation can be observed during ischemia reperfusion injury (IRI) and sepsis. Shear stress (SS) and pulsatile shear stress (PSS) are produced by mechanical frictional forces of blood flow and contraction of the heart, respectively, and are well-known mechanical signals that affect EC function, morphology, and gene expression. PSS promotes EC homeostasis and cardiovascular health. The archetype of inducing PSS is exercise (i.e., jogging, which introduces pulsations to the body as a function of the foot striking the pavement), or mechanical devices which induce external pulsations to the body (Enhanced External Pulsation (EECP), Whole-body vibration (WBV), and Whole-body periodic acceleration (WBPA aka pGz)). The purpose of this narrative review is to focus on the aforementioned noninvasive methods to increase PSS, review how each of these modify specific diseases that have been shown to induce endothelial activation and microcirculatory dysfunction (Ischemia reperfusion injury-myocardial infarction and cardiac arrest and resuscitation), sepsis, and lipopolysaccharide-induced sepsis syndrome (LPS)), and review current evidence and insight into how each may modify endothelial activation and how these may be beneficial in the acute and chronic setting of endothelial activation and microvascular dysfunction.

Hypothesis: Enhanced glucose availability and insulin resistance enhances an activated immune system and accounts for the obesity paradox

Many studies have demonstrated an 'obesity paradox' where people with obesity have reduced mortality in the context of acute critical illnesses compared to people of normal weight. In contrast, obesity is associated with reduced life expectancy in the population in general and is associated with an increased risk for type 2 diabetes, cardiovascular disease and other health problems. However, the absence of the metabolic syndrome is associated a lower mortality than when the metabolic syndrome is present regardless of body mass index status and the obesity paradox appears to only occur in association with the metabolic syndrome, but cardiorespiratory fitness modifies these outcomes. Enhanced glucose availability is important when the immune system is activated not only because it has an acute onset, a high consumption of glucose and is substantially an obligate glucose utilizer but also because it has priority over most other tissues and cells for the available glucose. Thus, for vulnerable populations, such as children with severe infections, this increases the risk of hypoglycaemia and death. The obesity paradox may be substantially a consequence of two features associated with obesity. One is endogenous glucose production (EGP). Obesity is associated with an increased capacity for EGP and thus is associated with enhanced glucose availability. Second is insulin resistance that reduces the amount of glucose metabolized by cells that are not obligate glucose utilizers and increases the release of fatty acids and glycerol from adipose stores that are alternative fuels for tissues and cells.

Roles and Molecular Mechanisms of Physical Exercise in Sepsis Treatment

Physical exercise is a planned, purposeful action to keep a healthy lifestyle and improve physical fitness. Physical exercise has been widely used as a non-pharmacological approach to preventing and improving a wide range of diseases, including cardiovascular disease, cancer, metabolic disease, and neurodegenerative disease. However, the effects of physical exercise on sepsis have not been summarized until now. In this review, we discuss the effects of physical exercise on multiple organ functions and the short- and long-time outcomes of sepsis. Furthermore, the molecular mechanisms underlying the protective effects of physical exercise on sepsis are discussed. In conclusion, we consider that physical exercise may be a beneficial and non-pharmacological alternative for the treatment of sepsis.

Protective effect of oxytocin through its anti-inflammatory and antioxidant role in a model of sepsis-induced acute lung injury: Demonstrated by CT and histological findings

Although several studies demonstrate the anti-inflammatory effect of oxytocin in different pathophysiological processes, there are limited data describing the impact of oxytocin on acute respiratory distress syndrome (ARDS). We aimed to elucidate the protective effect of oxytocin in ARDS with histopathological evaluation and radiological imaging in addition to biochemical markers.

Fecal intraperitoneal injection procedure (FIP) was performed on 24 of 32 rats included in the study for creating a sepsis model. Rats were randomly assigned into four groups: control group (no procedure was applied, n = 8), untreated septic group [was operated (FIP) and received no treatment, n = 8], placebo group (FIP, treated with 10 ml/kg of saline at once, n = 8), and treated group (FIP, treated with 0.1 mg/kg of oxytocin at once, n = 8). Chest CT was performed for all rats 20 hours after the procedure and density of the lungs were measured manually by using HU. All animals were sacrificed for histopathological examination of lung damage and blood samples were collected for biochemical analysis.

Plasma malondialdehyde (MDA), lactic acid (LA), C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), interleukin 1-beta (IL 1-β) levels were significantly increased in the placebo (FIP + saline) and the untreated (FIP) groups, and plasma levels of all biomarkers were reversed by oxytocin. Further, the density of the lung parenchyma (Hounsfield unit) on CT images and the histopathological lung damage score values were closer to the control group in the oxytocin-treated group compared to the placebo group.

Our findings suggested that oxytocin could exert anti-inflammatory, antioxidant and protective effects in FIP-induced ARDS.

Endothelial dysfunction: a therapeutic target in bacterial sepsis?

INTRODUCTION

Endothelial cells maintain vascular integrity, tone, and patency and have important roles in hemostasis and inflammatory responses. Although some degree of endothelial dysfunction with increased vascular permeability may be necessary to control local infection, excessive dysfunction plays a central role in the pathogenesis of sepsis-related organ dysfunction and failure as it results in dysregulated inflammation, vascular leakage, and abnormal coagulation. The vascular endothelium has thus been proposed as a potential target for therapeutic intervention in patients with sepsis.

AREAS COVERED

Different mechanisms underlying sepsis-related dysfunction of the vascular endothelium are discussed, including glycocalyx shedding, nitrosative stress, and coagulation factors. Potential therapeutic implications of each mechanism are mentioned.

EXPERT OPINION

Multiple targets to protect or restore endothelial function have been suggested, but endothelium-driven treatments remain a future potential at present. As some endothelial dysfunction and permeability may be necessary to remove infection and repair damaged tissue, targeting the endothelium may be a particular challenge. Ideally, therapies should be guided by biomarkers related to that specific pathway to ensure they are given only to patients most likely to respond. This enrichment based on biological plausibility and theragnostics will increase the likelihood of a beneficial response in individual patients and enable more personalized treatment.

Aerobic exercise improves LPS-induced sepsis via regulating the Warburg effect in mice

We investigated the impact of aerobic exercise (AE) on multiple organ dysfunction syndrome (MODS), aortic injury, pathoglycemia, and death during sepsis. ICR mice were randomized into four groups: Control (Con), Lipopolysaccharide (LPS), Exercise (Ex), and Exercise + LPS (Ex + LPS) groups. Mice were trained with low-intensity for 4 weeks. LPS and Ex + LPS mice received 5 mg/kg LPS intraperitoneally for induction of sepsis. Histopathological micrographs showed the organ morphology and damage. This study examined the effects of AE on LPS-induced changes in systemic inflammation, pulmonary inflammation, lung permeability, and bronchoalveolar lavage fluid (BALF) cell count, oxidative stress-related indicators in the lung, blood glucose levels, plasma lactate levels, serum insulin levels, plasma high-mobility group box 1 (HMGB1) levels, glucose transporter 1 (Glut1) and HMGB1, silent information regulator 1 (Sirt-1), and nuclear factor erythroid 2-related factor 2 (Nrf-2) mRNA expression levels in lung tissue. AE improved sepsis-associated multiple organ dysfunction syndrome (MODS), aortic injury, hypoglycemia, and death. AE prominently decreased pulmonary inflammation, pulmonary edema, and modulated redox balance during sepsis. AE prominently decreased neutrophil content in organ. AE prominently downregulated CXCL-1, CXCL-8, IL-6, TNF-α, Glu1, and HMGB1 mRNA expression but activated IL-1RN, IL-10, Sirt-1, and Nrf-2 mRNA expression in the lung during sepsis. AE decreased the serum levels of lactate and HMGB1 but increased blood glucose levels and serum insulin levels during sepsis. A 4-week AE improves sepsis-associated MODS, aortic injury, pathoglycemia, and death. AE impairs LPS-induced lactate and HMGB1 release partly because AE increases serum insulin levels and decreases the levels of Glut1. AE is a novel therapeutic strategy for sepsis targeting aerobic glycolysis.

The effect of maternal protein restriction during perinatal life on the inflammatory response in pediatric rats

Fetal growth restriction can affect health outcomes in postnatal life. This study tested the hypothesis that the response to an inflammatory pulmonary insult is altered in pediatric fetal growth restricted rats. Using a low-protein diet during gestation and postnatal life, growth-restricted male and female rats and healthy control rats were exposed to an inflammatory insult via the intratracheal instillation of heat-killed bacteria. After 6 h, animal lungs were examined for lung inflammation and status of the surfactant system. The results showed that in response to an inflammatory insult, neutrophil infiltration was decreased in both male and female rats in the growth-restricted animals compared with the control rats. The amount of surfactant was increased in the growth-restricted animals compared with the control rats, regardless of the inflammatory insult. It is concluded that fetal growth restriction results in increased surfactant and altered neutrophil responses following pulmonary insult.

The Relevance of a Physical Active Lifestyle and Physical Fitness on Immune Defense: Mitigating Disease Burden, With Focus on COVID-19 Consequences

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a fast spreading virus leading to the development of Coronavirus Disease-2019 (COVID-19). Severe and critical cases are characterized by damage to the respiratory system, endothelial inflammation, and multiple organ failure triggered by an excessive production of proinflammatory cytokines, culminating in the high number of deaths all over the world. Sedentarism induces worse, continuous, and progressive consequences to health. On the other hand, physical activity provides benefits to health and improves low-grade systemic inflammation. The aim of this review is to elucidate the effects of physical activity in physical fitness, immune defense, and its contribution to mitigate the severe inflammatory response mediated by SARS-CoV-2. Physical exercise is an effective therapeutic strategy to mitigate the consequences of SARS-CoV-2 infection. In this sense, studies have shown that acute physical exercise induces the production of myokines that are secreted in tissues and into the bloodstream, supporting its systemic modulatory effect. Therefore, maintaining physical activity influence balance the immune system and increases immune vigilance, and also might promote potent effects against the consequences of infectious diseases and chronic diseases associated with the development of severe forms of COVID-19. Protocols to maintain exercise practice are suggested and have been strongly established, such as home-based exercise (HBE) and outdoor-based exercise (OBE). In this regard, HBE might help to reduce levels of physical inactivity, bed rest, and sitting time, impacting on adherence to physical activity, promoting all the benefits related to exercise, and attracting patients in different stages of treatment for COVID-19. In parallel, OBE must improve health, but also prevent and mitigate COVID-19 severe outcomes in all populations. In conclusion, HBE or OBE models can be a potent strategy to mitigate the progress of infection, and a coadjutant therapy for COVID-19 at all ages and different chronic conditions.

The impact of maternal protein restriction during perinatal life on the response to a septic insult in adult rats

Although abundant evidence exists that adverse events during pregnancy lead to chronic conditions, there is limited information on the impact of acute insults such as sepsis. This study tested the hypothesis that impaired fetal development leads to altered organ responses to a septic insult in both male and female adult offspring. Fetal growth restricted (FGR) rats were generated using a maternal protein-restricted diet. Male and female FGR and control diet rats were housed until 150-160 d of age when they were exposed either a saline (control) or a fecal slurry intraperitoneal (Sepsis) injection. After 6 h, livers and lungs were analyzed for inflammation and, additionally, the amounts and function of pulmonary surfactant were measured. The results showed increases in the steady-state mRNA levels of inflammatory cytokines in the liver in response to the septic insult in both males and females; these responses were not different between FGR and control diet groups. In the lungs, cytokines were not detectable in any of the experimental groups. A significant decrease in the relative amount of surfactant was observed in male FGR offspring, but this was not observed in control males or in female animals. Overall, it is concluded that FGR induced by maternal protein restriction does not impact liver and lung inflammatory response to sepsis in either male or female adult rats. An altered septic response in male FGR offspring with respect to surfactant may imply a contribution to lung dysfunction.

Exogenous Surfactant as a Pulmonary Delivery Vehicle for Budesonide In Vivo

Background

Lung inflammation is associated with many respiratory conditions. Consequently, anti-inflammatory medications, like glucocorticoids, have become mainstay intrapulmonary therapeutics. However, their effectiveness for treating inflammation occurring in the alveolar regions of the lung is limited by suboptimal delivery. To improve the pulmonary distribution of glucocorticoids, such as budesonide to distal regions of the lung, exogenous surfactant has been proposed as an ideal delivery vehicle for such therapies. It was therefore hypothesized that fortifying an exogenous surfactant (BLES) with budesonide would enhance efficacy for treating pulmonary inflammation in vivo.

Methods

An intratracheal instillation of heat-killed bacteria was used to elicit an inflammatory response in the lungs of male and female rats. Thirty minutes after this initial instillation, either budesonide or BLES combined with budesonide was administered intratracheally. To evaluate the efficacy of surfactant delivery, various markers of inflammation were measured in the bronchoalveolar lavage and lung tissue.

Results

Although budesonide exhibited anti-inflammatory effects when administered alone, delivery with BLES enhanced those effects by lowering the lavage neutrophil counts and myeloperoxidase activity in lung tissue. Combining budesonide with BLES was also shown to reduce several other pro-inflammatory mediators. These results were shown across both sexes, with no observed sex differences.

Conclusion

Based on these findings, it was concluded that exogenous surfactant can enhance the delivery and efficacy of budesonide in vivo.

Papaverine Has Therapeutic Potential for Sepsis-Induced Neuropathy in Rats, Possibly via the Modulation of HMGB1-RAGE Axis and Its Antioxidant Prosperities

AIM

Our aim was to investigate the possible neuroprotective properties of papaverine in sepsis-induced critical illness neuropathy (SCIN) through the evaluation of various inflammatory biochemical markers, including interleukin 6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α), and oxidative stress biomarkers, such as malondialdehyde (MDA) and lactic acid. Additionally, evaluation of the HMGB1/RAGE interactions in SCIN was another target of this research.

METHOD

To create a sepsis model, a procedure involving intraperitoneal injection of feces was performed on 48 rats. The rats were divided into four equal groups: sham operated, controls and those receiving 20 and 40 mg/kg/day papaverine. After five-day treatments, compound muscle action potential (CMAPs) with electroneuromyography (ENMG) was recorded in all rats. Following ENMG evaluations, the plasma levels of sRAGE, HMGB1, TNF-α, IL-6, CRP, MDA and lactic acid were measured.

RESULTS

TNF-α, CRP, IL-6, HMGB1, MDA, and lactic acid levels were significantly elevated in the SCIN group, and sRAGE levels were significantly decreased. In recipients of papaverine (20 and 40 mg/kg) treatment, these biochemical findings were improved. Furthermore, electrophysiological findings also showed significant improvement in both 20 and 40 mg/kg papaverine treated groups.

CONCLUSION

Papaverine demonstrates neuroprotective effects in a rat model of SCIN. Considering its anti-inflammatory and antioxidant properties, papaverine's neuroprotective effects possibly stem from the suppression of the RAGE-HMGB1 axis.

Mechanisms of exercise-induced preconditioning in skeletal muscles

Endurance exercise training promotes numerous biochemical adaptations within skeletal muscle fibers culminating into a phenotype that is safeguarded against numerous perils including doxorubicin-induced myopathy and inactivity-induced muscle atrophy. This exercise-induced protection of skeletal muscle fibers is commonly termed "exercise preconditioning". This review will discuss the biochemical mechanisms responsible for exercise-induced protection of skeletal muscle fibers against these harmful events. The first segment of this report highlights the evidence that endurance exercise training provides cytoprotection to skeletal muscle fibers against several potentially damaging insults. The second and third sections of the review will discuss the cellular adaptations responsible for exercise-induced protection of skeletal muscle fibers against doxorubicin-provoked damage and inactivity-induced fiber atrophy, respectively. Importantly, we also identify gaps in our understanding of exercise preconditioning in hopes of stimulating future research.

Evaluation of 2 Rat Models for Sepsis Developed by Improved Cecal Ligation/Puncture or Feces Intraperitoneal-Injection

Background

The aim of this study was to evaluate the clinical characteristics of 2 rat models of sepsis for improved cecal ligation/puncture (CLP) and feces intraperitoneal-injection (FIP), including systemic inflammation, organ dysfunction, and blood coagulation.

Material/Methods

Sixty-two male SD rats were randomly divided into 3 groups: a normal control group (NC, n=6), a CLP group (n=28), and a FIP group (n=28). Ten rats each in the CLP and FIP groups were observed for 72-h mortality rate. The remaining 18 rats in each group were divided into 3 subgroups (n=6) according to their post-operation period (6, 12, and 24 h). Abdominal arterial blood was collected to determine the lactic acid (Lac) concentration, prothrombin time (PT), active partial prothrombin time (APTT), plasmic interleukin-6 (IL-6) level, and cardiac troponin (cTnI) level. The intestines, lung, and heart were collected for pathological examination.

Results

The 72-h mortality rates in the CLP and FIP groups were 60% and 100%, respectively. The Lac level in both groups was significantly elevated at 6, 12, and 24 h after modeling. Compared with the NC group, PT in the CLP and FIP groups was prolonged at 12 and 24 h, and APTT was significantly prolonged at 6 h. IL-6 levels in the CLP and FIP groups peaked at 6 h. The cTnI level in the FIP group was significantly higher at 12 h after modeling compared with the NC group. The intestines, lung, and heart were pathologically damaged at 6 h, and this damage worsened over time.

Conclusions

Both modeling methods induced sepsis in rats and closely mimicked the clinical conditions, but FIP was easier to establish and was more suitable for standardization.

Effects of Calorie Restriction and Voluntary Exercise on Doxorubicin-Induced Cardiotoxicity

Introduction: Doxorubicin (DOX) is a widely used chemotherapeutic agent with known cardiotoxic properties, while calorie restriction (CR) and exercise have well-documented cardioprotective effects. No studies have investigated the effects of CR alone or the combined effects of CR and exercise on DOX cardiotoxicity. Methods: Rats were divided into 4 groups based on their food intake (ad libitum or CR) and activity (sedentary or voluntary wheel running [WR]). After completing a 16-week treatment, animals received either DOX (15 mg/kg) or saline (SAL) and cardiac function was measured 5 days after treatment. Chromatography was used to quantify left ventricular DOX accumulation. Results: Left ventricular developed pressure (LVDP), end systolic pressure (ESP), and left ventricular maximal rate of pressure development (dP/dt_max) were significantly higher in the CR + DOX group when compared with DOX. Fractional shortening, LVDP, ESP, dP/dt_max, and dP/dt_min were significantly higher in the CR + WR + DOX group compared with the DOX group. In addition, the CR + WR + DOX group showed significantly higher LVDP and ESP compared with the WR + DOX group. DOX accumulation in the heart was 5-fold lower (P < .05) in the CR + WR + DOX group compared with the DOX group. Conclusion: This is the first study to demonstrate that CR can reduce cardiac DOX accumulation, and confirms the protective role of CR against DOX-induced cardiac dysfunction. Our data also show that combining a known cardioprotective intervention, exercise training, with CR results in additive benefits in the protection against DOX cardiotoxicity.

Circulating extracellular vesicle content reveals de novo DNA methyltransferase expression as a molecular method to predict septic shock

Extracellular vesicles (EVs) are mRNA-containing cell fragments shed into circulation during pathophysiological events. DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B) regulate gene expression by modifying DNA methylation and altering transcription. Sepsis is a systemic insult resulting in vascular dysfunction, which can lead to shock and death. We analysed plasma from ICU patients for circulating EV numbers, defined as particles isolated from 1 mL plasma at 21,000xg, and DNMTs mRNA content as prognostic markers of septic shock. Compared to plasma from critically ill patients with or without sepsis, plasma from septic shock patients contained more EVs per mL, expressed as total DNMTs mRNAs over 5 days, and more individual DNMT mRNAs at each day. A comparison of EV-DNMT1 (maintenance methylation) with EV-DNMT3A+DNMT3B (de novo methylation) expression correlated highly with severity, and EVs from septic shock patients carried more total DNMT mRNAs and more DNMT3A+DNMT3B mRNAs than control or sepsis EVs. Total plasma EVs also correlated with sepsis severity. EV-DNMT mRNAs load, when coupled with total plasma EV number, may be a novel method to diagnose septic shock upon ICU admittance and offer opportunities to more precisely intervene with standard therapy or other targeted interventions to regulate EV release and/or specific DNMT activity.

Physiology and technology for the ICU in vivo

This paper discusses the physiological and technological concepts that might form the future of critical care medicine. Initially, we discuss the need for a personalized approach and introduce the concept of personalized physiological medicine (PPM), including (1) assessment of frailty and physiological reserve, (2) continuous assessment of organ function, (3) assessment of the microcirculation and parenchymal cells, and (4) integration of organ and cell function for continuous therapeutic feedback control. To understand the cellular basis of organ failure, we discuss the processes that lead to cell death, including necrosis, necroptosis, autophagy, mitophagy, and cellular senescence. In vivo technology is used to monitor these processes. To this end, we discuss new materials for developing in vivo biosensors and drug delivery systems. Such in vivo biosensors will define the diagnostic platform of the future ICU in vivo interacting with theragnostic drugs. In addition to pharmacological therapeutic options, placement and control of artificial organs to support or replace failing organs will be central in the ICU in vivo of the future. Remote monitoring and control of these biosensors and artificial organs will be made using adaptive physiological mathematical modeling of the critically ill patient. The current state of these developments is discussed.

The effects of aging and exercise on lung mechanics, surfactant and alveolar macrophages

Purpose: Advancing age leads to changes to the respiratory system associated with increased susceptibility to lung diseases, and exercise may counteract this effect. To explore the underlying processes, we investigated the effects of aging and exercise on lung mechanics, alveolar macrophage function, and surfactant pools and activity, in mice. It was hypothesized that aging would impact lung mechanics, macrophage polarization, and the status of the surfactant system, and that these changes would be mitigated by exercise. Methods: Male C57BL/6 mice were housed from 2-3 to 22 months, for the aged group, or until 4 months of age for young mice. Mice in both groups were randomized to voluntarily running exercise or to non-exercise, for a 2-month period. Mice were euthanized and lung mechanics were analyzed using a flexiVent ventilator. Subsequently, the lungs were lavaged to obtain pulmonary surfactant and alveolar macrophages. Pulmonary surfactant was analyzed for pool sizes and activity whereas alveolar macrophages were examined for response to pro and anti-inflammatory stimuli. Results: Changes in lung mechanics, such as increased compliance and decreased airway resistance, were associated with aging but were not affected by exercise. The quantity as well as the biophysical activity of the pulmonary surfactant system was unaffected by either aging or exercise. More alveolar macrophages were recovered from exercising aged mice compared to both the young and non-exercising groups. Macrophages in this aged exercise group were more responsive to an anti-inflammatory stimulus. Conclusions: Our data supports previous literature that suggest the development of emphysema-like alterations to lung mechanics with aging. This effect was independent of exercise. Our data also indicates that surfactant is unaffected by aging and exercise. Alveolar macrophage properties and numbers were affected by exercise in the aging lung and may represent the main, potentially beneficial, effect of exercise on the pulmonary system.

Exercise training modifies gut microbiota with attenuated host responses to sepsis in wild-type mice

This study investigated the effects of exercise preconditioning-induced modification in gut microbiota composition and host responses to cecal ligation and puncture (CLP)-induced sepsis. Four-week-old C57BL/6N male mice were randomly assigned to either CLP ( n = 30) or CLP-exercise (CLP+Exe; n = 30) groups. Prior to CLP-induced sepsis, the CLP+Exe mice were subjected to 8 wk of treadmill running. Fecal samples were collected and analyzed by 16S rRNA amplification sequencing to assess gut microbiota composition. Diversity analyses such as principal coordinates analysis and rarefaction curves showed that exercise preconditioning was associated with differences in gut microbiota community structure and species richness. Exercise preconditioning-induced differences in gut microbiota composition were also evident at the family level of taxonomic analysis, with the dominant phyla being Bacteriodetes, Firmicutes, Verrucomicrobia, and, to a lesser extent, Cyanobacteria. Compared with control mice, preconditioned mice had a higher survival rate and less organ damage during the acute phase of sepsis, secondary to attenuation of the host response to septic shock. The current findings suggest that exercise preconditioning-induced modification in gut microbiota composition may lead to an attenuated host response to CLP-induced sepsis in wild-type mice, as shown by increased survival and less organ damage, as well as the establishment of a balance between pro- and anti-inflammatory responses.-Kim, D., Kang, H. Exercise training modifies gut microbiota with attenuated host responses to sepsis in wild-type mice.

Modelling physical resilience in ageing mice

Geroprotectors, a class of drugs targeting multiple deficits occurring with age, necessitate the development of new animal models to test their efficacy. The COST Action MouseAGE is a European network whose aim is to reach consensus on the translational path required for geroprotectors, interventions targeting the biology of ageing. In our previous work we identified frailty and loss of resilience as a potential target for geroprotectors. Frailty is the result of an accumulation of deficits, which occurs with age and reduces the ability to respond to adverse events (physical resilience). Modelling frailty and physical resilience in mice is challenging for many reasons. There is no consensus on the precise definition of frailty and resilience in patients or on how best to measure it. This makes it difficult to evaluate available mouse models. In addition, the characterization of those models is poor. Here we review potential models of physical resilience, focusing on those where there is some evidence that the administration of acute stressors requires integrative responses involving multiple tissues and where aged mice showed a delayed recovery or a worse outcome then young mice in response to the stressor. These models include sepsis, trauma, drug- and radiation exposure, kidney and brain ischemia, exposure to noise, heat and cold shock.

Age, exercise, and the outcome of sepsis

We report on the increasingly important need to diagnose and care for the elderly with sepsis as a distinct patient population. We share an overview of age-related changes in sepsis physiology and the potential role of exercise.

See related research by Tyml et al., https://ccforum.biomedcentral.com/articles/10.1186/s13054-017-1783-1

Evading sepsis with exercise

Aged mice preconditioned with a running routine were resistant to acute systemic sepsis compared with non-runner.