Protective effects of aerobic exercise on acute lung injury induced by LPS in mice

Effect of exercise on postoperative recovery of patients with non-small cell lung cancer: a systematic review and meta-analysis

Patients with non-small cell lung cancer (NSCLC) in the postoperative recovery period often experience reduced exercise capacity and impaired lung function, which affects their overall quality of life. This paper investigated the effect of exercise interventions on exercise capacity, lung function, quality of life, and symptoms in these patients.

METHODS

We performed a literature search across Cochrane, Embase, PubMed, Web of Science, and EBSCO databases were comprehensively searched for randomized controlled trials (RCTs) from inception to September 2023, all English RCTs were eligible if they assessed the effects of exercise interventions on postoperative NSCLC patients.

RESULTS

Twelve articles met our inclusion criteria, evidencing that exercise interventions could significantly improve the functional capacity of NSCLC patients in postoperative recovery. Notably, Forced Expiratory Volume in 1 s (FEV1) was improved, indicating enhanced lung function. Furthermore, exercise improved the physical and mental health scores of SF-36, along with increased quadriceps strength and relieved dyspnea. However, fatigue levels were not significantly changed.

CONCLUSIONS

Exercise interventions of NSCLC patients in the postoperative recovery are associated with improved functional capacity, lung function, quality of life, and quadriceps strength, as well as alleviated symptoms of dyspnea. These findings underscore the potential benefits of incorporating exercise into postoperative care for NSCLC patients. Nonetheless, further large-scale RCTs are required to solidify the evidence base on the clinical outcomes of exercise following pneumonectomy.

Aerobic physical training reduces severe asthma phenotype involving kinins pathway

INTRODUCTION

Aerobic physical training (APT) reduces eosinophilic airway inflammation, but its effects and mechanisms in severe asthma remain unknown.

METHODS

An in vitro study employing key cells involved in the pathogenesis of severe asthma, such as freshly isolated human eosinophils, neutrophils, and bronchial epithelial cell lineage (BEAS-2B) and lung fibroblasts (MRC-5 cells), was conducted. Additionally, an in vivo study using male C57Bl/6 mice, including Control (Co; n = 10), Trained (Exe; n = 10), house dust mite (HDM; n = 10), and HDM + Trained (HDM + Exe; n = 10) groups, was carried out, with APT performed at moderate intensity, 5x/week, for 4 weeks.

RESULTS

HDM and bradykinin, either alone or in combination, induced hyperactivation in human neutrophils, eosinophils, BEAS-2B, and MRC-5 cells. In contrast, IL-10, the primary anti-inflammatory molecule released during APT, inhibited these inflammatory effects, as evidenced by the suppression of numerous cytokines and reduced mRNA expression of the B1 receptor and ACE-2. The in vivo study demonstrated that APT decreased bronchoalveolar lavage levels of bradykinin, IL-1β, IL-4, IL-5, IL-17, IL-33, TNF-α, and IL-13, while increasing levels of IL-10, klotho, and IL-1RA. APT reduced the accumulation of polymorphonuclear cells, lymphocytes, and macrophages in the peribronchial space, as well as collagen fiber accumulation, epithelial thickness, and mucus accumulation. Furthermore, APT lowered the expression of the B1 receptor and ACE-2 in lung tissue and reduced bradykinin levels in the lung tissue homogenate compared to the HDM group. It also improved airway resistance, tissue resistance, and tissue damping. On a systemic level, APT reduced total leukocytes, eosinophils, neutrophils, basophils, lymphocytes, and monocytes in the blood, as well as plasma levels of IL-1β, IL-4, IL-5, IL-17, TNF-α, and IL-33, while elevating the levels of IL-10 and IL-1RA.

CONCLUSION

These findings indicate that APT inhibits the severe asthma phenotype by targeting kinin signaling.

High-intensity intermittent training ameliorates methotrexate-induced acute lung injury

Inflammation and oxidative stress are recognized as two primary causes of lung damage induced by methotrexate, a drug used in the treatment of cancer and immunological diseases. This drug triggers the generation of oxidants, leading to lung injury. Given the antioxidant and anti-inflammatory effects of high-intensity intermittent training (HIIT), our aim was to evaluate the therapeutic potential of HIIT in mitigating methotrexate-induced lung damage in rats. Seventy male Wistar rats were randomly divided into five groups: CTL (Control), HIIT (High-intensity intermittent training), ALI (Acute Lung Injury), HIIT+ALI (pretreated with HIIT), and ALI + HIIT (treated with HIIT).HIIT sessions were conducted for 8 weeks. At the end of the study, assessments were made on malondialdehyde, total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (Gpx), myeloperoxidase (MPO), interleukin 10 (IL-10), tumor necrosis factor-alpha (TNF-α), gene expression of T-bet, GATA3, FOXP3, lung wet/dry weight ratio, pulmonary capillary permeability, apoptosis (Caspase-3), and histopathological indices.Methotrexate administration resulted in increased levels of TNF-α, MPO, GATA3, caspase-3, and pulmonary edema indices, while reducing the levels of TAC, SOD, Gpx, IL-10, T-bet, and FOXP3. Pretreatment and treatment with HIIT reduced the levels of oxidant and inflammatory factors, pulmonary edema, and other histopathological indicators. Concurrently, HIIT increased the levels of antioxidant and anti-inflammatory factors.

Lung molecular and histological changes in type 2 diabetic rats and its improvement by high-intensity interval training

BACKGROUND

Type 2 diabetes (T2D) leads to serious respiratory problems. This study investigated the effectiveness of high-intensity interval training (HIIT) on T2D-induced lung injuries at histopathological and molecular levels.

METHODS

Forty-eight male Wistar rats were randomly allocated into control (CTL), Diabetes (Db), exercise (Ex), and Diabetes + exercise (Db + Ex) groups. T2D was induced by a high-fat diet plus (35 mg/kg) of streptozotocin (STZ) administration. Rats in Ex and Db + Ex performed HIIT for eight weeks. Tumor necrosis factor-alpha (TNFα), Interleukin 10 (IL-10), BAX, Bcl2, Lecithin, Sphingomyelin (SPM) and Surfactant protein D (SPD) levels were measured in the bronchoalveolar lavage fluid (BALF) and malondialdehyde (MDA) and total antioxidant capacity (TAC) levels were measured in lung tissue. Lung histopathological alterations were assessed by using H&E and trichrome mason staining.

RESULTS

Diabetes was significantly associated with imbalance in pro/anti-inflammatory, pro/anti-apoptosis and redox systems, and reduced the SPD, lecithin sphingomyelin and alveolar number. Performing HIIT by diabetic animals increased Bcl2 (P < 0.05) and IL10 (P < 0.01) levels as well as surfactants components and TAC (P < 0.05) but decreased fasting blood glucose (P < 0.001), TNFα (P < 0.05), BAX (P < 0.05) and BAX/Bcl2 (P < 0.001) levels as well as MDA (P < 0.01) and MDA/TAC (P < 0.01) compared to the diabetic group. Furthermore, lung injury and fibrosis scores were increased by T2D and recovered in presence of HIIT.

CONCLUSION

These findings suggested that the attenuating effect of HIIT on diabetic lung injury mediated by reducing blood sugar, inflammation, oxidative stress, and apoptosis as well as improving pulmonary surfactants components.

Role of Enhancing Aerobic Capacity in Countering COVID-19-induced Liver Injury in Elderlies

COVID-19 is still a world disaster; however, its vaccination is globally available. Liver and gastrointestinal disturbances occur in patients infected with COVID-19 at varying incidences. Aging decreases the functions of the liver. Thus, the elderly have a weaker response to the COVID-19 virus. The COVID-19 virus affects the liver directly through direct and indirect mechanisms. It directly affects the renin-angiotensin system or indirectly causes sepsis, uncontrolled immune reactions, drug-related hepatic injury, and cytokine storm. Also, COVID-19 vaccines and anti-drugs have adverse effects on the liver too. Thus, this review explores the effect of enhancing aerobic capacity as a nonpharmacological intervention on decreasing COVID- 19-induced liver injury. Enhancing aerobic capacity decreases COVID-19-induced liver injury through the following: 1) downregulating systemic and tissue ACE/ANG II/AT1R axis, upregulating ACE2/ANG 1-7/Mas axis, and moving the renin-angiotensin system to the direction of the ACE2/ANG (1-7)/Mas axis, 2) Improving mitochondrial function and oxygenation to body and lung tissues, causing a decrease in harmful oxidative reactions, 3) Increasing the processing of accumulated free radicals and inhibiting the acute respiratory distress syndrome, 4) Acting as an antioxidant to protect the liver from oxidative stress, 5) Increasing the effect of antiviral drugs and COVID-19 vaccines, which improves the function of immune biomarkers, decreases the viral load, and increases the body's defense against the virus, 6) Decreasing coagulation abnormalities and thrombosis. In conclusion, enhancing aerobic capacity may be an efficient nonpharmacological intervention to decrease COVID-19-induced liver injury in elderlies and regenerate the liver to its normal status after being infected by the COVID-19 virus. It also helps to strengthen the body's immunity for better effects of both COVID-19 vaccination and drugs.

Exercise improves cardiac function and attenuates myocardial inflammation and apoptosis by regulating APJ/STAT3 in mice with stroke

Stroke can induce cardiac dysfunction without a primary cardiac disease. Exercise can promote the overall rehabilitation of stroke patients and be beneficial for all kinds of heart diseases. However, the mechanisms underlying the protective effects of exercise in stroke-induced cardiac dysfunction are poorly understood. Hence, we aimed to distinguish the different effects of acute and long-term exercise and further study the mechanism of protection against cardiomyopathy caused by stroke. Mice underwent a single acute session or long-term exercise for 30 days, followed by middle cerebral artery occlusion surgery. The expression of apoptosis-related proteins and proinflammatory factors in the heart was evaluated. Then, overexpression of apelin peptide jejunum (APJ) transfected adeno-associated virus type 9 (AAV9) and inhibition of signal transducer and activator of transcription 3 (STAT3) by Stattic were used in stroke mice or hypoxic cardiomyocytes. ML221 were used to inhibit APJ activity in exercise mouse. Thereafter, changes in apoptotic and proinflammatory factors were evaluated. The results demonstrated that chronic exercise prevented myocardial inflammation, apoptosis and cardiac dysfunction after stroke. However, acute exercise did not have similar effects. Exercise maintained the levels of APJ expression and decreased phosphorylated-STAT3 (p-STAT3) activation to protect cardiomyocytes. Moreover, APJ overexpression promoted cardiomyocyte survival and reduced p-STAT3 levels. STAT3 inhibition also reduced apoptosis and proinflammatory factors in mice hearts. Conversely, the protective effect of exercise was eliminated by APJ inhibition. This study showed that exercise can maintain APJ expression and inhibit p-STAT3, thus, conferring protection against myocardial inflammation and apoptosis induced by stroke.

Aerobic exercise alleviates ventilator-induced lung injury by inhibiting NLRP3 inflammasome activation

BACKGROUND

Ventilator-induced lung injury (VILI) is caused by stretch stimulation and other factors related to mechanical ventilation (MV). NOD-like receptor protein 3 (NLRP3), an important innate immune component, is strongly associated with VILI. This study aimed to investigate the effect and mechanisms of aerobic exercise (EX) on VILI.

METHODS

To test the effects of the PKC inhibitor bisindolylmaleimide I on PKC and NLRP3, male C57BL/6 mice (7 weeks old, 19 ~ 23 g) were randomly divided into four groups: control group(C), bisindolylmaleimide I-pretreated group(B), MV group, and bisindolylmaleimide I-pretreated + MV (B + MV) group. The mice were pretreated with bisindolylmaleimide I through intraperitoneal injection (0.02 mg/kg) 1 h before MV. MV was performed at a high tidal volume (30 ml/kg). To explore the ameliorative effect of EX on VILI, the mice were randomly divided into C group, MV group, EX group and EX + MV group and subjected to either MV or 5 weeks of EX training. After ventilation, haematoxylin-eosin (HE) staining and wet/dry weight ratio was used to assess lung pathophysiological changes. PKCɑ, P-PKCɑ, ASC, procaspase-1, caspase-1, pro-IL-1β, IL-1β, NLRP3 and occludin (tight junction protein) expression in lung tissues was determined by Western blotting. The level of IL-6 in alveolar lavage fluid was determined by ELISA.

RESULTS

NLRP3, P-PKCɑ, and PKCɑ levels were inceased in MV group, but bisindolylmaleimide I treatment reversed these changes. Inhibition of PKC production prevented NLRP3 activation. Moreover, MV increased ASC, procaspase-1, caspase-1, pro-IL-1β, and IL1β levels and decreased occludin levels, but EX alleviated these changes. HE staining and lung injury scoring confirmed an absence of obvious lung injury in C group and EX group. Lung injury was most severe in MV group but was improved in EX + MV group. Overall, these findings suggest that MV activates the NLRP3 inflammasome by activating PKCɑ and inducing occludin degradation, while Exercise attenuates NLRP3 inflammasome and PKCɑ activation. Besides, exercise improves cyclic stretch-induced degradation of occludin.

CONCLUSION

PKC activation can increase the level of NLRP3, which can lead to lung injury. Exercise can reduce lung injury by inhibiting PKCɑ and NLRP3 activation. Exercise maybe a potential measure for clinical prevention of VILI.

Inhibitory effects and mechanisms of the anti-covid-19 traditional Chinese prescription, Keguan-1, on acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Keguan-1, a new traditional Chinese medicine (TCM) prescription contained seven Chinese herbs, is developed to treat coronavirus disease 19 (COVID-19). The first internationally registered COVID-19 randomised clinical trial on integrated therapy demonstrated that Keguan-1 significantly reduced the incidence of ARDS and inhibited the severe progression of COVID-19.

AIM OF THE STUDY

To investigate the protective mechanism of Keguan-1 on ARDS, a lipopolysaccharide (LPS)-induced acute lung injury (ALI) model was used to simulate the pathological state of ARDS in patients with COVID-19, focusing on its effect and mechanism on ALI.

MATERIALS AND METHODS

Mice were challenged with LPS (2 mg/kg) by intratracheal instillation (i.t.) and were orally administered Keguan-1 (low dose, 1.25 g/kg; medium dose, 2.5 g/kg; high dose, 5 g/kg) after 2 h. Bronchoalveolar lavage fluid (BALF) and lung tissue were collected 6 h and 24 h after i.t. administration of LPS. The levels of inflammatory factors tumour necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1β, keratinocyte-derived chemokine (KC or mCXCL1), macrophage inflammatory protein 2 (MIP2 or mCXCL2), angiotensin II (Ang II), and endothelial cell junction-associated proteins were analysed using ELISA or western blotting.

RESULTS

Keguan-1 improved the survival rate, respiratory condition, and pathological lung injury; decreased the production of proinflammatory factors (TNF-α, IL-6, IL-1β, KC, and MIP2) in BALF and the number of neutrophils in the lung tissues; and ameliorated inflammatory injury in the lung tissues of the mice with LPS-induced ALI. Keguan-1 also reduced the expression of Ang II and the adhesion molecule ICAM-1; increased tight junction proteins (JAM-1 and claudin-5) and VE-cadherin expression; and alleviated pulmonary vascular endothelial injury in LPS-induced ALI.

CONCLUSION

These results demonstrate that Keguan-1 can improve LPS-induced ALI by reducing inflammation and pulmonary vascular endothelial injury, providing scientific support for the clinical treatment of patients with COVID-19. Moreover, it also provides a theoretical basis and technical support for the scientific use of TCMs in emerging infectious diseases.

Effect of Aerobic Exercise on Oxidative Stress and Inflammatory Response During Particulate Matter Exposure in Mouse Lungs

Regular exercise provides several health benefits that can improve the cardiovascular and musculoskeletal systems, but clear evidence on the effect of exercise-induced hyperventilation in particulate matter (PM) exposure is still lacking. This study aimed to investigate the effects of exercise in PM exposure on reactive oxygen species (ROS) generation, inflammatory response, and mitochondrial integrity in human lung epithelial cells (A549), as well as in mouse lung tissue. In in vitro experiments, PM treatment was shown to significantly increased ROS production, and reduced cell viability and mitochondrial function in A549 cells. The mice were divided into four groups for an in vivo exercise experiment: control (CON), PM inhalation (PI), PM inhalation during exercise (PIE), and exercise (EX) groups. The PI and PIE groups were exposed to 100 μg/m³ of PM for 1 h per day for a week. The PIE and EX groups performed treadmill exercises every day for 1 h at 20 m/min for a week. The levels of pro-inflammatory markers (IL-6 and TNF-α) were significantly higher in the PI group than in the CON group (P < 0.001 and P < 0.01, respectively). The carbonyl protein level was decreased in EX vs. PI (P < 0.001). Mitochondrial fission (Drp1) content was significantly decreased in the EX vs. CON group (P < 0.01), but anti-mitochondrial fission (P-Drp1 Ser637) was increased in the EX vs. PI group (P < 0.05). Mitochondrial autophagy (mitophagy), which is an assessment of mitochondrial integrity, was markedly increased in PI vs. CON (P < 0.001), but the level was reversed in PIE (P < 0.05). Lung fibrosis was increased in PI vs. CON group (P < 0.001), however, the cells were rescued in the PIE (P < 0.001). The number of apoptotic cells was remarkably increased in the PI vs. CON group (P < 0.001), whereas the level was decreased in the PIE (P < 0.001). Taken together, these results showed that short-term exposure to PM triggers oxidative stress, pro-inflammatory responses, and apoptosis in the lungs, but the PM-induced adverse effects on the lung tissue are not exacerbated by exercise-induced PM hyperventilation but rather has a protective effect.

The effects of exercise training on the lungs and cardiovascular function of animals exposed to diesel exhaust particles and gases

Air pollution has been identified as one of the main environmental risks to health. Since exercise training seems to act as an anti-inflammatory modulator, our hypothesis is that exercise training prevents damage to respiratory and cardiovascular function caused by diesel exhaust particle (DEP) exposure. This study aimed to evaluate whether aerobic exercise training prior to DEP exposure prevents inflammatory processes in the pulmonary and cardiovascular systems. Therefore, BALB/C male mice were or were not submitted to a 10-week exercise training protocol (5×/week, 1 h/d), and after four weeks, they were exposed to DEP in a chamber with 24 μg/m³ PM2.5 or filtered air. Heart rate variability, lung mechanics and bronchoalveolar lavage fluid, cytokines and polymorphonuclear cells in the lung parenchyma were evaluated. Exposure to DEPs reduced heart rate variability and the elastance of the respiratory system and increased the number of cells in bronchoalveolar lavage fluid, as well as macrophages, neutrophils and lymphocytes, the density of polymorphonuclear cells and the proportion of collagen fibres in the lung parenchyma. Additionally, DEP-exposed animals showed increased expression of IL-23 and IL-12p40 (proinflammatory cytokines) and inducible nitric oxide synthase. Exercise training avoided the increases in all these inflammatory parameters, except the elastance of the respiratory system, the amount of collagen fibres and the expression of inducible nitric oxide synthase. Additionally, trained animals showed increased expression of the anti-inflammatory cytokine IL-1ra. Although our data showed a reduction in proinflammatory markers and an increase in markers of the anti-inflammatory pathway, these changes were not sufficient to prevent damage to the lung and cardiovascular function induced by DEPs. Based on these data, we propose that aerobic exercise training prevents the lung inflammatory process induced by DEPs, although it was not sufficient to avoid chronic damage, such as a loss of lung function or cardiovascular events.

Effects of aerobic exercise on lipopolysaccharide-induced experimental acute lung injury in the animal model of type 1 diabetes mellitus

NEW FINDINGS

What is the central question of this study? We evaluated the effects of diabetes and exercise on lipopolysaccharide-induced acute lung injury. By providing a comprehensive analysis of redox status, blood gases and histological parameters, we aimed to contribute to the ongoing debate in the literature. What are the main findings and its importance? We demonstrated the preventive effect of exercise, but diabetes did not alter the severity of acute lung injury.

ABSTRACT

Acute lung injury (ALI) is a life-threatening respiratory condition. Diabetes (DM) is a metabolic disease characterized by hyperglycaemia. There is an ongoing debate concerning whether there is a protective effect of diabetes in ALI. Exercise is a special type of physical activity that has numerous beneficial effects. The aim of our study was to investigate the effects of diabetes and exercise on the prognosis of ALI. Male Wistar albino rats were divided into two groups (sedentary and exercise). Both groups were divided into four subgroups: Control, ALI, DM, DM+ALI (n = 6 each). Diabetes was induced by injection of streptozotocin (50 mg/kg i.p.). The maximal exercise capacity was determined with the incremental load test. Animals were exercised on a treadmill for 45 min at 70% of maximal exercise capacity, 5 days a week for 12 weeks. Acute lung injury was induced by intratracheal injection of lipopolysaccharide (100 μg/100 g body weight) 24 h before the end of the experiment. We performed arterial blood gas analysis. Redox status was measured in both plasma and lung tissue. Malondialdehyde and 8-hydroxy-2'-deoxyguanosine levels were measured in lung tissue. Lung tissue was evaluated histologically. Acute lung injury caused significant damage in the lung tissue, which was verified histologically, with an increase in oxidative stress parameters. Exercise prevented the lung damage induced by ALI and reduced oxidative stress in the lung tissue. Diabetes did not alter the magnitude of damage done by ALI. Exercise showed a protective effect against DM and ALI in rats. The effect of DM was insignificant for the prognosis of ALI.

The effect of aerobic exercise on immune biomarkers and symptoms severity and progression in patients with COVID-19: A randomized control trial

BACKGROUND

The World Health Organization in March 2020 has announced that COVID-19 is a world pandemic because the number of infected cases increases rapidly. however, there are several available vaccines, their protection is limited to a certain period. Thus, the role of modalities that improve immune functions should be performed to counter COVID-19 viral load and decrease mortality rates.

OBJECTIVE

To investigate the effect of aerobic exercise on immune biomarkers, disease severity, and progression in patients with COVID-19.

DESIGN

A randomized controlled study.

PARTICIPANTS

Thirty patients with COVID-19 participated in this study. Participants' age ranged from 24 to 45 years old. Participants had a mild or moderate COVID-19. Participants were assigned randomly into two groups, exercise and control groups. There were two main dependent variables including blood immune markers and severity of respiratory symptoms.

INTERVENTIONS

All participants performed 2 weeks of moderate-intensity aerobic exercise for 40 min/session, 3 sessions/week. The measurements were performed at baseline, and after 2-weeks.

RESULTS

At baseline measurements, there were non-significant differences between both groups in the Wisconsin scale total score, Leucocytes, Lymphocytes, Interleukin-6, Interleukin-10, Immunoglobulin-A, and TNF-α (P > .05). After the intervention, the Wisconsin scale (patient-oriented illness-specific quality-of-life) total score significantly decreased in the intervention group (P < .05); while, Leucocytes, Lymphocytes, and Immunoglobulin-A significantly increased in the intervention group (P < .05).

CONCLUSION

The current study indicated that 2 weeks of moderate-intensity aerobic exercise decreased the severity and progression of COVID-19 associated disorders and quality of life. Also, a 2-weeks of aerobic exercise positively affected immune function by increasing the amounts of Leucocytes, Lymphocytes, Immunoglobulin A.

Exercise duration modulates upper and lower respiratory fluid cellularity, antiviral activity, and lung gene expression

Exercise has substantial health benefits, but the effects of exercise on immune status and susceptibility to respiratory infections are less clear. Furthermore, there is limited research examining the effects of prolonged exercise on local respiratory immunity and antiviral activity. To assess the upper respiratory tract in response to exercise, we collected nasal lavage fluid (NALF) from human subjects (1) at rest, (2) after 45 min of moderate-intensity exercise, and (3) after 180 min of moderate-intensity exercise. To assess immune responses of the lower respiratory tract, we utilized a murine model to examine the effect of exercise duration on bronchoalveolar lavage (BAL) fluid immune cell content and lung gene expression. NALF cell counts did not change after 45 min of exercise, whereas 180 min significantly increased total cells and leukocytes in NALF. Importantly, fold change in NALF leukocytes correlated with the post-exercise fatigue rating in the 180-min exercise condition. The acellular portion of NALF contained strong antiviral activity against Influenza A in both resting and exercise paradigms. In mice undergoing moderate-intensity exercise, BAL total cells and neutrophils decreased in response to 45 or 90 min of exercise. In lung lobes, increased expression of heat shock proteins suggested that cellular stress occurred in response to exercise. However, a broad upregulation of inflammatory genes was not observed, even at 180 min of exercise. This work demonstrates that exercise duration differentially alters the cellularity of respiratory tract fluids, antiviral activity, and gene expression. These changes in local mucosal immunity may influence resistance to respiratory viruses, including influenza or possibly other pathogens in which nasal mucosa plays a protective role, such as rhinovirus or SARS-CoV-2.

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.

Potential Physiological and Cellular Mechanisms of Exercise That Decrease the Risk of Severe Complications and Mortality Following SARS-CoV-2 Infection

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has unmasked mankind's vulnerability to biological threats. Although higher age is a major risk factor for disease severity in COVID-19, several predisposing risk factors for mortality are related to low cardiorespiratory and metabolic fitness, including obesity, cardiovascular disease, diabetes, and hypertension. Reaching physical activity (PA) guideline goals contribute to protect against numerous immune and inflammatory disorders, in addition to multi-morbidities and mortality. Elevated levels of cardiorespiratory fitness, being non-obese, and regular PA improves immunological function, mitigating sustained low-grade systemic inflammation and age-related deterioration of the immune system, or immunosenescence. Regular PA and being non-obese also improve the antibody response to vaccination. In this review, we highlight potential physiological, cellular, and molecular mechanisms that are affected by regular PA, increase the host antiviral defense, and may determine the course and outcome of COVID-19. Not only are the immune system and regular PA in relation to COVID-19 discussed, but also the cardiovascular, respiratory, renal, and hormonal systems, as well as skeletal muscle, epigenetics, and mitochondrial function.

Enhancing oxygenation of patients with coronavirus disease 2019: Effects on immunity and other health-related conditions

Coronavirus disease 2019 (COVID-19) distresses the pulmonary system causing acute respiratory distress syndrome, which might lead to death. There is no cure for COVID-19 infection. COVID-19 is a self-limited infection, and the methods that can enhance immunity are strongly required. Enhancing oxygenation is one safe and effective intervention to enhance immunity and pulmonary functions. This review deliberates the probable influences of enhancing oxygenation on immunity and other health-connected conditions in patients with COVID-19. An extensive search was conducted through Web of Science, Scopus, Medline databases, and EBSCO for the influence of enhancing oxygenation on immunity, pulmonary functions, psycho-immune hormones, and COVID-19 risk factors. This search included clinical trials and literature and systematic reviews. This search revealed that enhancing oxygenation has a strong effect on improving immunity and pulmonary functions and psycho-immune hormones. Also, enhancing oxygenation has a self-protective role counter to COVID-19 risk factors. Lastly, this search revealed the recommended safe and effective exercise protocol to enhance oxygenation in patients with COVID-19. Enhancing oxygenation should be involved in managing patients with COVID-19 because of its significant effects on immunity, pulmonary functions, and COVID-19 risk factors. A mild to moderate cycling or walking with 60%-80% Vo2max for 20-60 min performed 2-3 times per week could be a safe and effective aerobic exercise program in patients with COVID-19 to enhance their immunity and pulmonary functions.

Aerobic exercise ameliorates survival, clinical score, lung inflammation, DNA and protein damage in septic mice

BACKGROUND AND OBJECTIVE

Sepsis is a potentially deadly organic dysfunction, and one of the main causes of mortality in intensive care units (ICU). Aerobic exercise (AE) is a preventive intervention in the establishment of inflammatory conditions, such as chronic lung diseases, but its effects on sepsis remain unclear. Therefore, this study aimed to evaluate the effects of AE on health condition, mortality, inflammation, and oxidative damage in an experimental model of pneumosepsis induced by Klebsiella pneumoniae (K.p).

METHODS

Animals were randomly allocated to Control; Exercise (EXE); Pneumosepsis (PS) or Exercise + Pneumosepsis (EPS) groups. Exercised animals were submitted to treadmill exercise for 2 weeks, 30 min/day, prior to pneumosepsis induced by K.p tracheal instillation.

RESULTS

PS produced a striking decrease in the health condition leading to massive death (85%). AE protected mice, as evidenced by better clinical scores and increased survival (70%). AE alleviated sickness behavior in EPS mice as evaluated in the open field test, and inflammation (nitrite + nitrate, TNF-α and IL-1β levels) in broncoalveolar fluid. Catalase activity, oxidative damage to proteins and DNA was increased by sepsis and prevented by exercise.

CONCLUSION

Overall, the beneficial effects of exercise in septic animals encompassed a markedly improved clinical score and decreased mortality, along with lower inflammation markers, less DNA and protein damage, as well as preserved antioxidant enzyme activity. Neural network risk analysis revealed exercise had a considerable effect on the overall health condition of septic mice.

Exercise Improves Lung Inflammation, but Not Lung Remodeling and Mechanics in a Model of Bleomycin-Induced Lung Fibrosis

Introduction

Moderate aerobic exercise training accelerates the resolution of lung fibrosis in a model of bleomycin-induced pulmonary fibrosis. However, whether it can inhibit the development of lung fibrosis is unknown.

Materials and Methods

C57Bl/6 mice were distributed into four groups: Control (Co), Exercise (Exe), Bleomycin (Bleo), and Bleomycin+Exercise (Bleo+Exe). A single bleomycin dose (1.5 UI/kg) was administered orotracheally and treadmill exercise started in the same day, enduring for 4 weeks, 5x/week, 60 minutes/session, at moderate intensity. Lung mechanics, systemic and pulmonary inflammation, and lung remodeling were evaluated. Lung homogenates were used to evaluate the antioxidant status.

Results

Total cells, macrophages, lymphocytes, and neutrophils numbers, in agreement with IL-6 levels, were higher in the BAL and serum of Bleo group, compared to other groups. In addition, lung levels of LTB4 in Bleo were higher than other groups, whereas SOD activity and nitric oxide levels in exercised groups (Exe and Exe+Bleo) compared to the Bleo group. Lung GPX activity was lower in Bleo and Exe+Bleo groups compared to others. Exe and Exe+Bleo groups also showed higher IL-10 expression by lung macrophages than other groups, whereas TGF-β expression was higher in Exe, Bleo, and Exe+Bleo groups compared to control. CCR7 expression was induced only in the Exe group. However, exercise did not improve lung remodeling and mechanics, or serum and pulmonary levels of VEGF, IGF-1, and TGF-β.

Conclusion

Aerobic exercise training initiated concomitantly with induction of pulmonary fibrosis reduces lung and systemic inflammation but fails to inhibit lung fibrosis and mechanics impairment.

Chronic alteration of circadian rhythm is related to impaired lung function and immune response

BACKGROUND

Alterations of the circadian rhythm negatively impact several aspects of the health, including the lung function. Chronic shiftwork scale classically induces alterations in the circadian rhythm. However, its effects on pulmonary immune response are unknown.

AIMS

To evaluate the impact of chronic alteration of circadian rhythm on pulmonary function and immune response.

METHODS

In this context, a 12 × 24 hours and 12 × 48 hours work scale in shiftwork scale policemen (n = 25; 38.73 ± 6.92 years old) were compared with fixed work scale (8 h/d) civil men (n = 25; 34.00 ± 9.60 years old) who were evaluated for perceived stress, sleepiness, physical activity levels, anthropometric characteristics, lung function, pulmonary and systemic cellular and humoral immune response.

RESULTS

Policemen presented increased levels of perceived stress (P < .0008), impaired sleepiness (P < .04) and lung function as demonstrated by reduced forced vital capacity (FVC) (P < .053) and FEV1 (P < .043) when compared with civil men. In addition, increased levels of exhaled nitric oxide (P < .037) and of IL-2 (P < .0046) in the breath condensate revealed that policemen presented chronic lung inflammation compared with civil men. Although the whole blood analysis did not showed any differences between the two groups concerning the number of leucocytes, the humoral response revealed that policemen presented increased levels of IL-2 (P < .002) and lower levels of IL-10 (P < .001), clearly displaying a clinical status of low-grade inflammation.

CONCLUSIONS

Chronic alteration of circadian rhythm in shiftwork scale policemen results in impaired lung function, beyond to impair pulmonary and systemic immune function.

Role of increasing the aerobic capacity on improving the function of immune and respiratory systems in patients with coronavirus (COVID-19): A review

BACKGROUND AND AIMS

COVID-19 is a public world crisis, however, it is a self-limited infection. In COVID-19, the strength of immune and respiratory systems is a critical element. Thus, this review was conducted to demonstrate the short and long term effects of increasing the aerobic capacity on increasing the function and strength of immune and respiratory systems, particularly those essential for overcoming COVID-19 infections and associated disorders.

METHODS

This review was carried out by searching in Web of Science, Scopus, EBSCO, Medline databases. The search was conducted over clinical trials and literature and systematic reviews on the effects of increasing the aerobic capacity on the function and strength of specific immune and respiratory elements essential for overcoming COVID-19 infections.

RESULTS

This review found that increasing the aerobic capacity could produce short-term safe improvements in the function of immune and respiratory systems, particularly those specific for COVID-19 infections. This could be mainly produced through three mechanisms. Firstly, it could improve immunity by increasing the level and function of immune cells and immunoglobulins, regulating CRP levels, and decreasing anxiety and depression. Secondly, it could improve respiratory system functions by acting as an antibiotic, antioxidant, and antimycotic, restoring normal lung tissue elasticity and strength. Lastly, it could act as a protective barrier to decrease COVID-19 risk factors, which helps to decrease the incidence and progression of COVID-19.

CONCLUSION

This review summarizes that increasing the aerobic capacity is recommended because it has potential of improving immune and respiratory functions which would help counter COVID-19.

Protective effect of MOTS-c on acute lung injury induced by lipopolysaccharide in mice

MOTS-c (mitochondrial open-reading-frame of the twelve S rRNA-c), a mitochondrial-derived 16-amino acid peptide, targets the methionine-folate cycle, increases 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) levels, and eventually activates AMP-activated protein kinase (AMPK). AMPK activation can attenuate neutrophil pro-inflammatory activity and attenuates lipoteichoic acid (LTA) and lipopolysaccharide (LPS) induced acute lung injury (ALI) in mice. However, to our knowledge, the role of MOTS-c in LPS-induced ALI remains unclear. Hence, we investigated the potential effectiveness and underlying mechanism of MOTS-c against LPS-induced ALI in mice. The intraperitoneal administration of MOTS-c (5 mg/kg, i.p., bid, 6 days) before intratracheal LPS instillation attenuated body weight loss and pulmonary edema, inhibited neutrophilic tissue infiltration in lung tissue, downregulated the expression of cytokine-induced neutrophil chemoattractant-1 (CINC-1) and intercellular cell adhesion molecule-1 (ICAM-1) in lung tissues, decreased the levels of TNF-α, IL-1β, and IL-6, and increased the expression of IL-10 and SOD in serum, lung tissue, and bronchoalvelolar lavage fluid (BALF). Moreover, MOTS-c treatment significantly promoted p-AMPKα and SIRT1 expression and suppressed LPS-induced ERK, JNK, p38, p65, and STAT3 activation in the mouse lung tissues. Collectively, these findings suggest that MOTS-c plays important roles in protecting the lungs from the inflammatory effects of LPS-induced ALI. The effects of MOTS-c are probably orchestrated by activating AMPK and SIRT1, inhibiting ERK, JNK, p65, and STAT3 signaling pathways. Thus, MOTS-c appears to be a novel and promising candidate for the treatment of ALI.

Impacts of exercise interventions on different diseases and organ functions in mice

Background

In recent years, much evidence has emerged to indicate that exercise can benefit people when performed properly. This review summarizes the exercise interventions used in studies involving mice as they are related to special diseases or physiological status. To further understand the effects of exercise interventions in treating or preventing diseases, it is important to establish a template for exercise interventions that can be used in future exercise-related studies.

Methods

PubMed was used as the data resource for articles. To identify studies related to the effectiveness of exercise interventions for treating various diseases and organ functions in mice, we used the following search language: (exercise [Title] OR training [Title] OR physical activity [Title]) AND (mice [title/abstract] OR mouse [title/abstract] OR mus [title/abstract]). To limit the range of search results, we included 2 filters: one that limited publication dates to "in 10 years" and one that sorted the results as "best match". Then we grouped the commonly used exercise methods according to their similarities and differences. We then evaluated the effectiveness of the exercise interventions for their impact on diseases and organ functions in 8 different systems.

Results

A total of 331 articles were included in the analysis procedure. The articles were then segmented into 8 systems for which the exercise interventions were used in targeting and treating disorders: motor system (60 studies), metabolic system (45 studies), cardio-cerebral vascular system (58 studies), nervous system (74 studies), immune system (32 studies), respiratory system (7 studies), digestive system (1 study), and the system related to the development of cancer (54 studies). The methods of exercise interventions mainly involved the use of treadmills, voluntary wheel-running, forced wheel-running, swimming, and resistance training. It was found that regardless of the specific exercise method used, most of them demonstrated positive effects on various systemic diseases and organ functions. Most diseases were remitted with exercise regardless of the exercise method used, although some diseases showed the best remission effects when a specific method was used.

Conclusion

Our review strongly suggests that exercise intervention is a cornerstone in disease prevention and treatment in mice. Because exercise interventions in humans typically focus on chronic diseases, national fitness, and body weight loss, and typically have low intervention compliance rates, it is important to use mice models to investigate the molecular mechanisms underlying the health benefits from exercise interventions in humans.

Montelukast, Leukotriene Inhibitor, Reduces LPS-Induced Acute Lung Inflammation and Human Neutrophil Activation

OBJECTIVES

Some pro-inflammatory lipids derived from 1 lipooxygenase enzyme are potent neutrophil chemoattractant, a cell centrally involved in acute respiratory distress syndrome (ARDS); a syndrome lacking effective treatment. Considering the beneficial effects of the leukotriene receptor inhibitor, montelukast, on other lung diseases, whether montelukast attenuates inflammation in a mouse model of ARDS, and whether it reduces LPS stimulated activation of human neutrophils was investigated.

METHODS

Thirty-five C57Bl/6 mice were distributed into control (PBS)+24h, LPS+24h (10μg/mouse), control+48h, LPS+48h, and LPS 48h+Montelukast (10mg/kg). In addition, human neutrophils were incubated with LPS (1μg/mL) and treated with montelukast (10μM).

RESULTS

Oral-tracheal administration of montelukast significantly attenuated total cells (P<.05), macrophages (P<.05), neutrophils (P<.01), lymphocytes (P<.001) and total protein levels in BAL (P<.05), as well as IL-6 (P<.05), CXCL1/KC (P<.05), IL-17 (P<.05) and TNF-α (P<.05). Furthermore, montelukast reduced neutrophils (P<.001), lymphocytes (P<.01) and macrophages (P<.01) in the lung parenchyma. In addition, montelukast restored BAL VEGF levels (P<.05). LTB4 receptor expression (P<.001) as well as NF-κB (P<.001), a downstream target of LPS, were also reduced in lung parenchymal leukocytes. Furthermore, montelukast reduced IL-8 (P<.001) production by LPS-treated human neutrophils.

CONCLUSION

In conclusion, montelukast efficiently attenuated both LPS-induced lung inflammation in a mouse model of ARDS and in LPS challenged human neutrophils.

Creatine supplementation impairs airway inflammation in an experimental model of asthma involving P2 × 7 receptor

Creatine (Cr) is a substrate for adenosine triphosphate synthesis, and it is the most used dietary supplement among professional and recreative athletes and sportsmen. Creatine supplementation may increase allergic airway response, but the cellular and molecular mechanisms are unknown. We used murine model of OVA-induced chronic asthma and showed that Cr supplementation increased total proteins, ATP level, lymphocytes, macrophages, and IL-5 levels in BALF, as well as IL-5 in the supernatant of re-stimulated mediastinal lymph nodes. IL-5 and IL-13 expression by epithelial cells and by peribronchial leukocytes were increased by Cr. Cr augmented the expression of P2 × 7 receptor by peribronchial leukocytes and by epithelial cells, and increased the accumulation of eosinophils in peribronchial space and of collagen fibers in airway wall. In human cells, while Cr induced a release of ATP, IL-6, and IL-8 from BEAS-2B cells, whole blood cells, such as eosinophils, and CD4⁺ T cells, P2 × 7 receptor inhibitor (A740003) reduced such effects, as denoted by reduced levels of ATP, IL-6, and IL-8. Therefore, Cr supplementation worsened asthma pathology due to activation of airway epithelial cells and peribronchial leukocytes, involving purinergic signaling.

Extracellular ATP is a danger signal activating P2X7 receptor in a LPS mediated inflammation (ARDS/ALI)

Acute respiratory distress syndrome (ARDS) is a life-threating lung condition resulting from a direct and indirect injury to the lungs [1, 2]. Pathophysiologically it is characterized by an acute alveolar damage, an increased permeability of the microvascular-barrier, leading to protein-rich pulmonary edema and subsequent impairment of arterial oxygenation and respiratory failure [1]. This study examined the role of extracellular ATP in recruiting inflammatory cells to the lung after induction of acute lung injury with lipopolysaccharide (LPS). However, the precise mechanism is poorly understood. Our objective was to investigate the functional role of the P2X7 receptor in the pathogenesis of acute respiratory distress syndrome (ARDS/ acute lung injury (ALI)) in vitro and in vivo. We show that intratracheally applied LPS causes an acute accumulation of ATP in the BALF (bronchoalveolar lavage) and lungs of mice. Prophylactic and therapeutic inhibition of P2X7R signalling by a specific antagonist and knock-out experiments was able to ameliorate the inflammatory response demonstrated by reduced ATP-levels, number of neutrophils and concentration of pro-inflammatory cytokine levels in the BALF. Experiments with chimeric mice showed that P2X7R expression on immune cells was responsible for the observed effect. Consistently, the inflammatory response is diminished only by a cell-type specific knockdown of P2X7 receptor on non-stationary immune cells. Since the results of BALF from patients with acute ARDS or pneumonia simulated the in vivo data after LPS exposure, the P2X7 receptor may be a new therapeutic target for treatment in acute respiratory distress syndrome (ARDS/ALI).

Aerobic Exercise Protects from Pseudomonas aeruginosa-Induced Pneumonia in Elderly Mice

BACKGROUND

Pseudomonas aeruginosa (PS) infection results in severe morbidity and mortality, especially in immune-deficient populations. Aerobic exercise (AE) modulates the immune system, but its effects on the outcomes of pulmonary PS infection in elderly mice are unknown.

METHODS

BALB/c mice (24 weeks old) were randomized to sedentary, exercise (EX), PS, and PS + EX groups for the acute experimental setting, and PS and PS + EX groups for the chronic setting. Low-intensity AE was performed for 5 weeks, 60 min/day; 24 h after the final AE session, mice were inoculated with 5 × 104 colony-forming units (CFU) of PS, and 24 h and 14 days after PS inoculation, mice were studied.

RESULTS

AE inhibited PS colonization (p < 0.001) and lung inflammation (total cells, neutrophils, lymphocytes [p < 0.01] in bronchoalveolar lavage [BAL]), with significant differences in BAL levels of IL-1β (p < 0.001), IL-6 (p < 0.01), CXCL1 (p < 0.001), and TNF-α (p < 0.001), as well as parenchymal neutrophils (p < 0.001). AE increased BAL levels of IL-10 and parenchymal (p < 0.001) and epithelial (p < 0.001) IL-10 expression, while epithelial (p < 0.001) and parenchymal (p < 0.001) NF-κB expression was decreased. AE diminished pulmonary lipid peroxidation (p < 0.001) and increased glutathione peroxidase (p < 0.01). Pre-incubation of BEAS-2B with IL-10 inhibited PS-induced epithelial cell expression of TNF-α (p < 0.05), CD40 (p < 0.01), and dichlorodihydrofluorescein diacetate (p < 0.05).

CONCLUSIONS

AE inhibits PS-induced lung inflammation and bacterial colonization in elderly mice, involving IL-10/NF-κB, and redox signaling.

Effect of a 12-week submaximal swimming training in rats exposed to tobacco- derived nitrosamine ketone

Background

Tobacco contains carcinogens such as NNK (nicotine-derived nitrosamine ketone) that makes induction of lung cancer by changing the stimulation of IL-10 expression. The aim of this study was to investigate changes in resting levels of IL-10 in lung tissues of rats exposed to NNK after a 12-week aerobic submaximal swimming training.

Methods

For this purpose, 46 Wistar rats were randomly divided into five groups consisting training, training + NNK, NNK, saline and control. NNK-induced groups received NNK subcutaneously one day per week at a rate of 12/5 mg per kg body weight and the training groups performed submaximal swimming training for 12 weeks. The levels of IL-10 in homogenized lung tissue were measured by ELISA.

Results

Findings indicated that a period of swimming training increased the IL-10 levels significantly in lung tissue of training group when compared to control (P=0.00) and NNK groups (P=0.00). Also, a significant increase of IL-10 level was observed in exercise + NNK group when compared to NNK group (p≤0/02). Furthermore, it was observed that IL-10 levels of NNK group had a significant decrease when compared to training group (P=0/00), training + NNK group (p≤0/02), but had insignificant increase when compared to saline group (p≤0/85).

Conclusions

Generally, it could be confirmed that regular submaximal aerobic training plays an important role in the inhibition of the effects of lung inflammation induced by NNK via increasing IL-10 activity.

The effects of exercise on depressive- and anxiety-like behaviors as well as lung and hippocampus oxidative stress in ovalbumin-sensitized juvenile rats

Allergic asthma during early life period has been reported to be associated with neurochemical and behavioral disorders, including anxiety and depression. We aimed to determine the effects of exercise on depressive- and anxiety-like behaviors as well as lung and hippocampus oxidative stress in ovalbumin (OVA)-sensitized juvenile rats. Animals were divided into 4 groups including control (non-exercised and non-sensitized), Exe (exercise and non-sensitized); OVA (non-exercised and OVA-sensitized); and OVA+Exe (exercised and OVA-sensitized). The rats were subjected to chronic OVA sensitization followed by 4 weeks of treadmill exercise training. Compared to the control group, the OVA group had an increase in anxiety- and depressive-like behavior, lung inflammation, and oxidative stress index in the lung and hippocampus. Compared to the OVA group, the OVA+Exe group had a decline in anxiety- and depressive-like behavior, lung inflammation, and oxidative stress index in the lung and hippocampus. No significant difference in terms of the above-mentioned parameters, were found between the control group and the Exe group. Exercise decreased depressive- and anxiety-like behaviors in OVA-sensitized juvenile rats; this effect might have been mainly mediated by improvement in antioxidant system.

Muscle-derived extracellular superoxide dismutase inhibits endothelial activation and protects against multiple organ dysfunction syndrome in mice

Multiple organ dysfunction syndrome (MODS) is a detrimental clinical complication in critically ill patients with high mortality. Emerging evidence suggests that oxidative stress and endothelial activation (induced expression of adhesion molecules) of vital organ vasculatures are key, early steps in the pathogenesis. We aimed to ascertain the role and mechanism(s) of enhanced extracellular superoxide dismutase (EcSOD) expression in skeletal muscle in protection against MODS induced by endotoxemia. We showed that EcSOD overexpressed in skeletal muscle-specific transgenic mice (TG) redistributes to other peripheral organs through the circulation and enriches at the endothelium of the vasculatures. TG mice are resistant to endotoxemia (induced by lipopolysaccharide [LPS] injection) in developing MODS with significantly reduced mortality and organ damages compared with the wild type littermates (WT). Heterogenic parabiosis between TG and WT mice conferred a significant protection to WT mice, whereas mice with R213G knock-in mutation, a human single nucleotide polymorphism leading to reduced binding EcSOD in peripheral organs, exacerbated the organ damages. Mechanistically, EcSOD inhibits vascular cell adhesion molecule 1 expression and inflammatory leukocyte adhesion to the vascular wall of vital organs, blocking an early step of the pathology in organ damage under endotoxemia. Therefore, enhanced expression of EcSOD in skeletal muscle profoundly protects against MODS by inhibiting endothelial activation and inflammatory cell adhesion, which could be a promising therapy for MODS.

A murine model of elastase- and cigarette smoke-induced emphysema

Objective:

To describe a murine model of emphysema induced by a combination of exposure to cigarette smoke (CS) and instillation of porcine pancreatic elastase (PPE).

Methods:

A total of 38 C57BL/6 mice were randomly divided into four groups: control (one intranasal instillation of 0.9% saline solution); PPE (two intranasal instillations of PPE); CS (CS exposure for 60 days); and CS + PPE (two intranasal instillations of PPE + CS exposure for 60 days). At the end of the experimental protocol, all animals were anesthetized and tracheostomized for calculation of respiratory mechanics parameters. Subsequently, all animals were euthanized and their lungs were removed for measurement of the mean linear intercept (Lm) and determination of the numbers of cells that were immunoreactive to macrophage (MAC)-2 antigen, matrix metalloproteinase (MMP)-12, and glycosylated 91-kDa glycoprotein (gp91phox) in the distal lung parenchyma and peribronchial region.

Results:

Although there were no differences among the four groups regarding the respiratory mechanics parameters assessed, there was an increase in the Lm in the CS + PPE group. The numbers of MAC-2-positive cells in the peribronchial region and distal lung parenchyma were higher in the CS + PPE group than in the other groups, as were the numbers of cells that were positive for MMP-12 and gp91phox, although only in the distal lung parenchyma.

Conclusions:

Our model of emphysema induced by a combination of PPE instillation and CS exposure results in a significant degree of parenchymal destruction in a shorter time frame than that employed in other models of CS-induced emphysema, reinforcing the importance of protease-antiprotease imbalance and oxidant-antioxidant imbalance in the pathogenesis of emphysema.

Exercise Reduces Lung Fibrosis Involving Serotonin/Akt Signaling

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is a chronic fibrosing interstitial pneumonia, which involves aberrant serotonin (5-hydroxytryptamine [5-HT]) and Akt signaling. As protective effects of chronic aerobic training (AT) have been demonstrated in the context of lung injury, this study investigated whether AT attenuates bleomycin-induced lung fibrosis partly via a reduction of 5-HT and AKT signaling.

METHODS

Seventy-two C57BL/6 male mice were distributed in Control (Co), Exercise (Ex), Fibrosis (Fi), and Fibrosis + Exercise (Fi + Ex) groups. Bleomycin (1.5 UI·kg) was administered on day 1 and treadmill AT began on day 15 and continued for 60 min·d, 5 d·wk for 4 wk. We evaluated total and differential cell counts in bronchoalveolar lavage (BAL), interleukin (IL)-1β, IL-6, CXCL1/KC, IL-10, tumor necrosis factor α, and transforming growth factor β levels in BAL, collagen content in lung parenchyma, 5-HT levels in BAL fluid and in serum, the expression of 5-HT2B receptor, and Akt phosphorylation in lung tissue.

RESULTS

AT reduced bleomycin-increased number of total cells (P < 0.001), neutrophils (P < 0.01), macrophages (P < 0.01), and lymphocytes (P < 0.05) in BAL. It also reduced the levels of IL-1β (P < 0.01), IL-6 (P < 0.05), CXCL1/KC (P < 0.001), tumor necrosis factor α (P < 0.001), and transforming growth factor β (P < 0.001). It increased expression of ant-inflammatory cytokine IL-10 (P < 0.001). It reduced bleomycin-increased 5-HT levels in BAL (P < 0.001) and in serum (P < 0.05). Reductions in collagen fiber deposition (P < 0.01), 5-HT2B receptor expression (P < 0.01), and Akt phosphorylation in lung tissue were observed.

CONCLUSIONS

AT accelerates the resolution of lung inflammation and fibrosis in a model of bleomycin-induced lung fibrosis partly via attenuation of 5-HT/Akt signaling.

Short-Term Preoperative High-Intensity Interval Training in Patients Awaiting Lung Cancer Surgery: A Randomized Controlled Trial

INTRODUCTION

Impairment in aerobic fitness is a potential modifiable risk factor for postoperative complications. In this randomized controlled trial, we hypothesized that a high-intensity interval training (HIIT) program enhances cardiorespiratory fitness before lung cancer surgery and therefore reduces the risk of postoperative complications.

METHODS

Patients with operable lung cancer were randomly assigned to usual care (UC) (n = 77) or preoperative rehabilitation based on HIIT (Rehab) (n = 74). Maximal cardiopulmonary exercise testing and the 6-minute walk test were performed twice before surgery. The primary outcome measure was a composite of death and in-hospital postoperative complications.

RESULTS

The groups were well balanced in terms of patient characteristics. During the preoperative waiting period (median 25 days), the peak oxygen consumption and the 6-minute walking distance increased (median +15%, interquartile range, 25th to 75 percentile [IQR25%-75%, %] = +9% to +22%, p = 0.003 and +15%, IQR25%-75% = +8% to +28%, p < 0.001, respectively) in the Rehab group, whereas peak oxygen consumption declined in the UC group (median -8%, IQR25%-75% = -16% to 0%], p = 0.005). The primary end point did not differ significantly between the two groups: at least one postoperative complication developed in 27 of the 74 patients (35.5%) in the Rehab group and 39 of 77 patients (50.6%) in the UC group (p = 0.080). Notably, the incidence of pulmonary complications was lower in the Rehab compared with in the UC group (23% versus 44%, p = 0.018), owing to a significant reduction in atelectasis (12.2% versus 36.4%, p < 0.001), and this decrease was accompanied by a shorter length of stay in the postanesthesia care unit (median -7 hours, IQR25%-75% = -4 to -10).

CONCLUSIONS

In this randomized controlled trial, preoperative HIIT resulted in significant improvement in aerobic performances but failed to reduce early complications after lung cancer resection.

Choline Triggers Exacerbations of Chronic Obstructive Pulmonary Disease in Patients Infected with Pseudomonas aeruginosa

Background

Although exacerbations of chronic obstructive pulmonary disease produced by Pseudomonas aeruginosa infections are a major cause of death, the molecular mechanism that produces them is not well known. Here we focused on the energetic basis of dyspnoea, hypercapnia and acidosis symptoms.

Methods and Findings

We used an in vivo exacerbation model exposing mice to cigarette smoke and LPS, to mimic emphysema and infections, and choline challenges to trigger exacerbations, that showed 31% increased in the airway resistance for naïve mice and 250% for smoke/LPS treatment. Tissue resistance was increased 32%, in naïve mice, and 169% for smoke/LPS treatment. A decreased tissue elastance, was confirmed by decreased collagen content and increased alveoli chord length. Consequently, the O₂ demanded was 260% greater for smoke/LPS treated mice, to provide the energy required to pump the same volume of air then for naïve mice. The extra CO₂ produced per ml of air pumped caused hypercapnia and acidosis by 4% decrease in pH.In addition, the bacteria grown with choline had a decrease of 67% in phosphate, 23% ATP and 85% phospholipids with an increase of 57% in polyphosphates, 50% carbohydrates, 100% LPS, consuming 45% less energy relative to the bacteria grown with succinate.

Conclusion

choline, released by P. aeruginosa, triggers exacerbation symptoms by increasing lung resistance, O₂ consumption and producing more pCO₂ in blood with dyspnea, hypercapnia and acidosis. The energetic shift of decreased O₂ bacterial demand and increased lung demand benefits the infection, thus restoring the energetic balance on the host will favor P. aeruginosa eradication.

The Potential Role of 8-Oxoguanine DNA Glycosylase-Driven DNA Base Excision Repair in Exercise-Induced Asthma

Asthma is characterized by reversible airway narrowing, shortness of breath, wheezing, coughing, and other symptoms driven by chronic inflammatory processes, commonly triggered by allergens. In 90% of asthmatics, most of these symptoms can also be triggered by intense physical activities and severely exacerbated by environmental factors. This condition is known as exercise-induced asthma (EIA). Current theories explaining EIA pathogenesis involve osmotic and/or thermal alterations in the airways caused by changes in respiratory airflow during exercise. These changes, along with existing airway inflammatory conditions, are associated with increased cellular levels of reactive oxygen species (ROS) affecting important biomolecules including DNA, although the underlying molecular mechanisms have not been completely elucidated. One of the most abundant oxidative DNA lesions is 8-oxoguanine (8-oxoG), which is repaired by 8-oxoguanine DNA glycosylase 1 (OGG1) during the base excision repair (BER) pathway. Whole-genome expression analyses suggest a cellular response to OGG1-BER, involving genes that may have a role in the pathophysiology of EIA leading to mast cell degranulation, airway hyperresponsiveness, and bronchoconstriction. Accordingly, this review discusses a potential new hypothesis in which OGG1-BER-induced gene expression is associated with EIA symptoms.

Muscles provide protection during microbial infection by activating innate immune response pathways in Drosophila and zebrafish

Muscle contraction brings about movement and locomotion in animals. However, muscles have also been implicated in several atypical physiological processes including immune response. The role of muscles in immunity and the mechanism involved has not yet been deciphered. In this paper, using Drosophila indirect flight muscles (IFMs) as a model, we show that muscles are immune-responsive tissues. Flies with defective IFMs are incapable of mounting a potent humoral immune response. Upon immune challenge, the IFMs produce anti-microbial peptides (AMPs) through the activation of canonical signaling pathways, and these IFM-synthesized AMPs are essential for survival upon infection. The trunk muscles of zebrafish, a vertebrate model system, also possess the capacity to mount an immune response against bacterial infections, thus establishing that immune responsiveness of muscles is evolutionarily conserved. Our results suggest that physiologically fit muscles might boost the innate immune response of an individual.

Summary: Using fruit fly and zebrafish models, we show that skeletal muscles are immune responsive tissues; they mount innate immune responses during bacterial infection – an evolutionarily conserved defense mechanism.

Gut Microbiota Modification: Another Piece in the Puzzle of the Benefits of Physical Exercise in Health?

Regular physical exercise provides many health benefits, protecting against the development of chronic diseases, and improving quality of life. Some of the mechanisms by which exercise provides these effects are the promotion of an anti-inflammatory state, reinforcement of the neuromuscular function, and activation of the hypothalamic-pituitary-adrenal (HPA) axis. Recently, it has been proposed that physical exercise is able to modify gut microbiota, and thus this could be another factor by which exercise promotes well-being, since gut microbiota appears to be closely related to health and disease. The purpose of this paper is to review the recent findings on gut microbiota modification by exercise, proposing several mechanisms by which physical exercise might cause changes in gut microbiota.

Immune Function: Impact of Exercise and Nutritional Interventions

This article provides a brief commentary on the accompanying article, "Nutrition and Physical Activity Interventions to Improve Immunity" by Davison, Kehaya, and Jones. The article reviews the evidence on physical exercise and/or nutrition in modulating immune response, with a specific focus on the prevention of respiratory infection. Given the large scope of the review, an overview of current findings is presented, rather than in-depth discussions, and the nutritional strategies discussed tend to focus on the strategies that have been studied in the context of exercise. Some further insight is provided in the commentary on potential mechanisms that may explain the benefits of exercise, a brief discussion on the impact of obesity and host defense, and future directions for research. In general, the article sufficiently describes the current evidence, and draws appropriate conclusions based on the evidence presented. The article is recommended for audiences that have limited background on these topics, and for those who are familiar with this line of research.

C1P Attenuates Lipopolysaccharide-Induced Acute Lung Injury by Preventing NF-κB Activation in Neutrophils

Recently, ceramide-1-phosphate (C1P) has been shown to modulate acute inflammatory events. Acute lung injury (Arnalich et al. 2000. Infect. Immun. 68: 1942-1945) is characterized by rapid alveolar injury, lung inflammation, induced cytokine production, neutrophil accumulation, and vascular leakage leading to lung edema. The aim of this study was to investigate the role of C1P during LPS-induced acute lung injury in mice. To evaluate the effect of C1P, we used a prophylactic and therapeutic LPS-induced ALI model in C57BL/6 male mice. Our studies revealed that intrapulmonary application of C1P before (prophylactic) or 24 h after (therapeutic) LPS instillation decreased neutrophil trafficking to the lung, proinflammatory cytokine levels in bronchoalveolar lavage, and alveolar capillary leakage. Mechanistically, C1P inhibited the LPS-triggered NF-κB levels in lung tissue in vivo. In addition, ex vivo experiments revealed that C1P also attenuates LPS-induced NF-κB phosphorylation and IL-8 production in human neutrophils. These results indicate C1P playing a role in dampening LPS-induced acute lung inflammation and suggest that C1P could be a valuable candidate for treatment of ALI.

Update on the Mechanisms of Pulmonary Inflammation and Oxidative Imbalance Induced by Exercise

The mechanisms involved in the generation of oxidative damage and lung inflammation induced by physical exercise are described. Changes in lung function induced by exercise involve cooling of the airways, fluid evaporation of the epithelial surface, increased contact with polluting substances, and activation of the local and systemic inflammatory response. The present work includes evidence obtained from the different types of exercise in terms of duration and intensity, the effect of both acute performance and chronic performance, and the influence of special conditions such as cold weather, high altitude, and polluted environments. Levels of prooxidants, antioxidants, oxidative damage to biomolecules, and cellularity, as well as levels of soluble mediators of the inflammatory response and its effects on tissues, are described in samples of lung origin. These samples include tissue homogenates, induced sputum, bronchoalveolar lavage fluid, biopsies, and exhaled breath condensate obtained in experimental protocols conducted on animal and human models. Finally, the need to simultaneously explore the oxidative/inflammatory parameters to establish the interrelation between them is highlighted.

Inflammation and its genesis in cystic fibrosis

The host inflammatory response in cystic fibrosis (CF) lung disease has long been recognized as a central pathological feature and an important therapeutic target. Indeed, many believe that bronchiectasis results largely from the oxidative and proteolytic damage comprised within an exuberant airway inflammatory response that is dominated by neutrophils. In this review, we address the longstanding argument of whether or not the inflammatory response is directly attributable to impairment of the cystic fibrosis transmembrane conductance regulator or only secondary to airway obstruction and chronic bacterial infection and challenge the importance of this distinction in the context of therapy. We also review the centrality of neutrophils in CF lung pathophysiology and highlight more recent data that suggest the importance of other cell types and signaling beyond NF-κB activation. We discuss how protease and redox imbalance are critical factors in CF airway inflammation and end by reviewing some of the more promising therapeutic approaches now under development.

Collagenase mRNA Overexpression and Decreased Extracellular Matrix Components Are Early Events in the Pathogenesis of Emphysema

To describe the progression of parenchymal remodeling and metalloproteinases gene expression in earlier stages of emphysema, mice received porcine pancreatic elastase (PPE) instillation and Control groups received saline solution. After PPE instillation (1, 3, 6 hours, 3 and 21 days) we measured the mean linear intercept, the volume proportion of types I and III collagen, elastin, fibrillin and the MMP-1, -8, -12 and -13 gene expression. We observed an initial decrease in type I (at the 3rd day) and type III collagen (from the 6th hour until the 3rd day), in posterior time points in which we detected increased gene expression for MMP-8 and -13 in PPE groups. After 21 days, the type III collagen fibers increased and the type I collagen values returned to similar values compared to control groups. The MMP-12 gene expression was increased in earlier times (3 and 6 hours) to which we detected a reduced proportion of elastin (3 days) in PPE groups, reinforcing the already established importance of MMP-12 in the breakdown of ECM. Such findings will be useful to better elucidate the alterations in ECM components and the importance of not only metalloelastase but also collagenases in earlier emphysema stages, providing new clues to novel therapeutic targets.

Therapeutic exercise attenuates neutrophilic lung injury and skeletal muscle wasting

Early mobilization of critically ill patients with the acute respiratory distress syndrome (ARDS) has emerged as a therapeutic strategy that improves patient outcomes, such as the duration of mechanical ventilation and muscle strength. Despite the apparent efficacy of early mobility programs, their use in clinical practice is limited outside of specialized centers and clinical trials. To evaluate the mechanisms underlying mobility therapy, we exercised acute lung injury (ALI) mice for 2 days after the instillation of lipopolysaccharides into their lungs. We found that a short duration of moderate intensity exercise in ALI mice attenuated muscle ring finger 1 (MuRF1)-mediated atrophy of the limb and respiratory muscles and improved limb muscle force generation. Exercise also limited the influx of neutrophils into the alveolar space through modulation of a coordinated systemic neutrophil chemokine response. Granulocyte colony-stimulating factor (G-CSF) concentrations were systemically reduced by exercise in ALI mice, and in vivo blockade of the G-CSF receptor recapitulated the lung exercise phenotype in ALI mice. Additionally, plasma G-CSF concentrations in humans with acute respiratory failure (ARF) undergoing early mobility therapy showed greater decrements over time compared to control ARF patients. Together, these data provide a mechanism whereby early mobility therapy attenuates muscle wasting and limits ongoing alveolar neutrophilia through modulation of systemic neutrophil chemokines in lung-injured mice and humans.