Preconditioning rats with three lipid emulsions prior to acute lung injury affects cytokine production and cell apoptosis in the lung and liver

Omega-3 polyunsaturated fatty acids ameliorate PM2.5 exposure induced lung injury in mice through remodeling the gut microbiota and modulating the lung metabolism

Short-term or long-term exposure to fine particulate matter (PM2.5) is related to increased incidences of respiratory diseases. This study aimed to investigate the influences of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) supplementation on oxidative stress, inflammation, lung metabolic profile, and gut microbiota in PM2.5-induced lung injury mice. Mice were divided into four groups (n = 15, per group): two unsupplemented groups, control group and PM2.5 group, and two supplemented groups with ω-3 PUFAs, ω-3 PUFAs group, and ω-3 PUFAs + PM2.5 group. Mice in the supplemented groups were placed on an ω-3 PUFAs-enriched diet (ω-3 PUFAs, 21 g/kg). During the 5th to 6th week of dietary supplementation, mice were exposed to PM2.5 by intra-tracheal instillation. ω-3 PUFAs ameliorate lung histopathological injury, reduce inflammatory responses and oxidative stress, affect lung metabolite profile, and modulate gut microbiota in PM2.5-induced lung injury mice. Thus, supplementary ω-3 PUFAs showed effectiveness in attenuation of PM2.5-induced lung injury, indicating that the interventions exhibited preventive and therapeutic potential.

Acute arsenic exposure exacerbates lipopolysaccharide-induced lung injury possibly by compromising the integrity of the lung epithelial barrier in rats

Inhalation of large amounts of arsenic can damage the respiratory tract and may exacerbate the development of bacterial pneumonia, but the exact mechanism remains unclear. In this study, male Wistar rats were randomly divided into control, arsenic trioxide (16.0 μg/kg ATO), lipopolysaccharide (0.5 mg/kg LPS), and ATO combined with LPS (16.0 μg/kg ATO + 0.5 mg/kg LPS) groups. Blood and lung tissue samples were collected from each group 12 h after exposure. The results showed that exposure to ATO or LPS alone produced different effects on leukocytes and inflammatory factors, while combined exposure significantly increased serum interleukin-6, interleukin-10, lung water content, lung lavage fluid protein, and p38 protein phosphorylation levels. Alveolar interstitial thickening, alveolar membrane edema, alveolar type I and II cell matrix vacuolization, and nuclear pyknosis were observed in rats exposed to either ATO or LPS. More severe ultrastructural changes were found in the combined exposure group, and chromatin splitting was observed in alveolar type I cells. Lanthanum nitrate particles leaked from the alveolar vascular lumen in the ATO-exposed group, whereas in the combined exposure group, Evans Blue levels were increased and lanthanum nitrate particles were present in the lung parenchyma. Claudin-3 protein expression increased and claudin-4 expression decreased after ATO or LPS exposure, while claudin-18 expression was unchanged. The changes in claudin-3 and claudin-4 protein expression were further exacerbated by combined exposure. In conclusion, these results suggest that inhalation of ATO may exacerbate the development of bacterial pneumonia and that common mechanisms may exist to synergistically disrupt epithelial barrier integrity.

COVID‑19: Main findings after a year and half of unease and the proper scientific progress (Review)

Since the emergence of the disease in late December 2019, numerous studies have been published to date regarding clinical, laboratory and treatment aspects associated with COVID-19. The present study attempts to compare and unify the clinical, para-clinical and therapeutic aspects that have come to light regarding coronavirus disease-19 (COVID 19), mainly in adults. Between April 2020 and September 2021, a comprehensive systematic literature review was performed, which we added to from our own medical experiences. The search was performed on the PubMed, Scopus and Google Scholar databases, comprising studies with analyzable data that were identified alongside studies and documents containing general scientific data. All published studies were written in English, and were from different countries. A 95% confidence interval (CI95) was also calculated for almost each study using the Wilson formula. When compared with preliminary reports between December 2019 and January 2020, the most frequent symptoms were still identified as being fever (68.6%; CI95: 67.5-69.7) and cough (72.7%; CI95: 71.7-73.8). Nevertheless, asymptomatic cases also increased (by 21.4%; CI95: 16.6-27.1). Severe and critical cases accounted for 10.4% (CI95: 9.6-11.1) of all cases. The mean fatality rate was found to be 4% (CI95: 3.6-4.5). The primary co-morbidity found was hypertension (28.9%; CI95: 27-30.8), followed by other underlying cardiovascular diseases (15.4%; CI95: 13.9-16.9) and diabetes (14.5%; CI95: 13.1-16.1). The majority of studies showed lower white blood cell numbers with neutropenia and lymphopenia, and lower platelet levels. The levels of the biomarkers C-reaction protein and erythrocyte sedimentation rate were positive in all studied cases alongside other lab tests, such as examining the D-dimer levels and those of other hepatic, cardiac and renal injury markers. The procalcitonin level was also found to be elevated in many cases, resulting in high usage of antibiotics (83.7%; CI95: 81.2-85.9). Approximately 31.6% (CI95: 29.1-34.1) of the patients required non-invasive ventilation, whereas 9.9% (CI95: 8.1-12.1) of the patients were intubated or placed on extracorporeal membrane oxygenation. The most used antivirals were ribavirin (67.3%; CI95: 63.4-70.9), oseltamivir (52.5%; CI95: 49.4-55.5) and Arbidol™ (34.5%; CI95: 32-37.1). General admittance to the intensive care unit was ~7.2% (CI95: 6.5-7.9) of patients.

Antioxidant-Based Therapy Reduces Early-Stage Intestinal Ischemia-Reperfusion Injury in Rats

Intestinal ischemia-reperfusion injury (i-IRI) is a rare disorder with a high mortality rate, resulting from the loss of blood flow to an intestinal segment. Most of the damage is triggered by the restoration of flow and the arrival of cytokines and reactive oxygen species (ROS), among others. Inactivation of these molecules before tissue reperfusion could reduce intestinal damage. The aim of this work was to analyze the preventive effect of allopurinol and nitroindazole on intestinal mucosal damage after i-IRI. Wag/RijHsd rats were subjected to i-IRI by clamping the superior mesenteric artery (for 1 or 2 h) followed by a 30 min period of reperfusion. Histopathological intestinal damage (HID) was assessed by microscopic examination of histological sections obtained from injured intestine. HID was increased by almost 20% by doubling the ischemia time (from 1 to 2 h). Nitroindazole reduced HID in both the 1 and 2 h period of ischemia by approximately 30% and 60%, respectively (p < 0.001). Our preliminary results demonstrate that nitroindazole has a preventive/protective effect against tissue damage in the early stages of i-IRI. However, to better understand the molecular mechanisms underlying this phenomenon, further studies are needed.

Novel Coronavirus Disease 2019 (COVID-19) and Cytokine Storms for More Effective Treatments from an Inflammatory Pathophysiology

The Novel Coronavirus Disease 2019 (COVID-19) has swept the world and caused a global pandemic. SARS-CoV-2 seems to have originated from bats as their reservoir hosts over time. Similar to SARS-CoV, this new virus also exerts its action on the human angiotensin-converting enzyme 2. This action causes infections in cells and establishes an infectious disease, COVID-19. Against this viral invasion, the human body starts to activate the innate immune system in producing and releasing proinflammatory cytokines such as IL-6, IL-1β, IL-8, TNF-α, and other chemokines, such as G-CSF, IP10 and MCPl, which all develop and increase the inflammatory response. In cases of COVID-19, excessive inflammatory responses occur, and exaggerated proinflammatory cytokines and chemokines are detected in the serum, resulting in cytokine release syndrome or cytokine storm. This causes coagulation abnormalities, excessive oxidation developments, mitochondrial permeability transition, vital organ damage, immune system failure and eventually progresses to disseminated intravascular coagulation and multiple organ failure. Additionally, the excessive inflammatory responses also cause mitochondrial dysfunction due to progressive and persistent stress. This damages cells and mitochondria, leaving products containing mitochondrial DNA and cell debris involved in the excessive chronic inflammation as damage-associated molecular patterns. Thus, the respiratory infection progressively leads to disseminated intravascular coagulation from acute respiratory distress syndrome, including vascular endothelial cell damage and coagulation-fibrinolysis system disorders. This condition causes central nervous system disorders, renal failure, liver failure and, finally, multiple organ failure. Regarding treatment for COVID-19, the following are progressive and multiple steps for mitigating the excessive inflammatory response and subsequent cytokine storm in patients. First, administering of favipiravir to suppress SARS-CoV-2 and nafamostat to inhibit ACE2 function should be considered. Second, anti-rheumatic drugs (monoclonal antibodies), which act on the leading cytokines (IL-1β, IL-6) and/or cytokine receptors such as tocilizumab, should be administered as well. Finally, melatonin may also have supportive effects for cytokine release syndrome, resulting in mitochondrial function improvement. This paper will further explore these subjects with reports mostly from China and Europe.