1.
Cigarette Smoke Extract Disturbs Mitochondria-Regulated Airway Epithelial Cell Responses to Pneumococci.
Aghapour, M, Tulen, CBM, Abdi Sarabi, M, Weinert, S, Müsken, M, Relja, B, van Schooten, FJ, Jeron, A, Braun-Dullaeus, R, Remels, AH, et al
Cells. 2022;11(11)
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Cigarette smoking can affect airway epithelial cells, causing overproduction of mucus, damage, and inflammation, which may result in the progression of airway diseases. Airway epithelial cells (AEC) rely on mitochondria for energy, and mitochondrial dysfunction may affect innate immunity and the integrity of the airway epithelium. Cigarette smoking is found to accelerate mitochondrial damage within AEC. Maintaining a normal microbial composition within the respiratory tract is essential for maintaining immunity. There is evidence that smoking cigarettes disrupts the microbial composition and increases the spread of pathogenic bacteria such as Streptococcus pneumoniae (Sp) which causes inflammation. By exposing 16HBE cells to Sp and cigarette smoke extract (CSE), this study investigated the effect of cigarette smoking on mitochondrial dysfunction in ACE in an in vitro model. Additionally, the study examined the direct and indirect pathways involved in cigarette smoking-induced mitochondrial dysfunction and altered innate immune response to Sp infection. CSE exposure decreases mitochondrial complex protein levels and mitochondrial membrane potential, which affects energy production. It also increases mitochondrial oxidative stress and mitochondrial degradation. All these factors lead to mitochondrial dysfunction in ACE. CSE exposure to ACE was associated with altered gene expression in the tight and adherence junctions that serve as a protective barrier against pathogens and pollutants and reduced type I interferon immune responses to Sp. Using the results of this study, healthcare professionals can gain a better understanding of the impact of cigarette smoking on mitochondrial dysfunction and how it increases susceptibility to Sp-related immune responses. It is necessary to conduct further studies to evaluate the effects of cigarette smoking on mitochondrial dysfunction, microbial composition disruption, and the interaction between AECs and elevated immune responses.
Abstract
Mitochondrial functionality is crucial for the execution of physiologic functions of metabolically active cells in the respiratory tract including airway epithelial cells (AECs). Cigarette smoke is known to impair mitochondrial function in AECs. However, the potential contribution of mitochondrial dysfunction in AECs to airway infection and airway epithelial barrier dysfunction is unknown. In this study, we used an in vitro model based on AECs exposed to cigarette smoke extract (CSE) followed by an infection with Streptococcus pneumoniae (Sp). The levels of oxidative stress as an indicator of mitochondrial stress were quantified upon CSE and Sp treatment. In addition, expression of proteins associated with mitophagy, mitochondrial content, and biogenesis as well as mitochondrial fission and fusion was quantified. Transcriptional AEC profiling was performed to identify the potential changes in innate immune pathways and correlate them with indices of mitochondrial function. We observed that CSE exposure substantially altered mitochondrial function in AECs by suppressing mitochondrial complex protein levels, reducing mitochondrial membrane potential and increasing mitochondrial stress and mitophagy. Moreover, CSE-induced mitochondrial dysfunction correlated with reduced enrichment of genes involved in apical junctions and innate immune responses to Sp, particularly type I interferon responses. Together, our results demonstrated that CSE-induced mitochondrial dysfunction may contribute to impaired innate immune responses to Sp.
2.
Vitamin C and Immunity - NED Infobite
BANT's scientific NED InfoBites are designed to provide key elements of the latest research using plain language. They provide quick overviews on particular health issues and nutrition topics for a speedy introduction to the science. Visually attractive and easily shareable with clients and social media followers.
2021
Abstract
Since the early 20th century, it has been known that Vitamin C plays a role in human health and susceptibility to infections. Studies show that for specific population groups, the duration of the common cold can be reduced with increased Vitamin C intake. It has also been shown to reduce the length of stay in intensive care units and use of mechanical ventilation by 8% with administration of 1-3g of Vitamin C daily. This NED Infobite highlights some of the latest research into Vitamin C and the immune system, focusing in particular on infections, ICU stays and need for mechanical ventilation.
3.
Vitamin C in Pneumonia and Sepsis
Anitra C. Carr
2020
Abstract
This chapter exert from 'Vitamin C in Health and Disease' by Anitra Carr and Jens Lykkesfeldt focuses on Vitamin C in pneumonia and sepsis. It provides details of acute lung dysfunction, the role of neutrophils and the mechanisms of action of Vitamin C in infections, including those of the respiratory tract. The complete book is available free for on-line reading from our supporter, MDPI Nutrients at this link https://www.mdpi.com/books/pdfview/book/690.
4.
Clinical Impact of Supplementation of Vitamins B1 and C on Patients with Sepsis-Related Acute Respiratory Distress Syndrome.
Yoo, JW, Kim, RB, Ju, S, Lee, SJ, Cho, YJ, Jeong, YY, Lee, JD, Kim, HC
Tuberculosis and respiratory diseases. 2020;83(3):248-254
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Acute respiratory distress syndrome (ARDS) is a life-threatening condition that commonly develops in patients with sepsis. Patients with ARDS require admission to intensive care and invasive mechanical ventilation. Vitamin B1 and C deficiencies have been reported in critically ill patients with sepsis. Vitamin B1 is involved in aerobic metabolism, and vitamin C has anti-inflammatory and anti-oxidative effects. The aim of this Korean retrospective cohort study was to evaluate the clinical impact of vitamin B1 and C supplementation in patients with sepsis-related ARDS. Patients with ARDS requiring invasive mechanical ventilation, admitted to an intensive care unit (ICU) were included in this study. Clinical outcomes were compared between patients administered with vitamin B1 (200 mg/day) and C (2 g/day) between June 2018-May 2019 (the supplementation group) and those who did not receive vitamin B1 and C administration between June 2017-May 2018 (the control group). Seventy-nine patients were included. Thirty-three patients received vitamin B1 and C, and 46 patients did not. There were no significant differences in the number of deaths between the patients who received vitamin B1 and C and those who did not. The mean number of days not requiring ICU admission or ventilation was greater in patients supplemented with vitamin B1 and C than that in the control patients, but the difference was not statistically significant. Steroid administration was more frequent in patients receiving vitamin B1 and C supplementation than in those without it. The authors concluded that Vitamin B1 and C supplementation at the doses used in this study did not reduce the death rates in ARDS patients.
Abstract
BACKGROUND Although few studies have reported improved clinical outcomes with the administration of vitamin B1 and C in critically ill patients with septic shock or severe pneumonia, its clinical impact on patients with sepsis-related acute respiratory distress syndrome (ARDS) remains unclear. The purpose of this study was to evaluate the association with vitamin B and C supplementation and clinical outcomes in patients with ARDS. METHODS Patients with ARDS requiring invasive mechanical ventilation, admitted to the medical intensive care unit (ICU) were included in this study. Clinical outcomes were compared between patients administered with vitamin B1 (200 mg/day) and C (2 g/day) June 2018-May 2019 (the supplementation group) and those who did not receive vitamin B1 and C administration June 2017-May 2018 (the control group). RESULTS Seventy-nine patients were included. Thirty-three patients received vitamin B1 and C whereas 46 patients did not. Steroid administration was more frequent in patients receiving vitamin B1 and C supplementation than in those without it. There were no significant differences in the mortality between the patients who received vitamin B1 and C and those who did not. There were not significant differences in ventilator and ICU-free days between each of the 21 matched patients. CONCLUSION Vitamin B1 and C supplementation was not associated with reduced mortality rates, and ventilator and ICU-free days in patients with sepsis-related ARDS requiring invasive mechanical ventilation.
5.
Vitamin C Can Shorten the Length of Stay in the ICU: A Meta-Analysis.
Hemilä, H, Chalker, E
Nutrients. 2019;11(4)
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For centuries, Vitamin C has been known as an important part of human health. Initially, deficiency was associated with scurvy, however subsequent research has found links between administration of Vitamin C and a number of conditions, including lowering blood pressure, decreasing blood glucose levels in Type 2 diabetes and shortening the duration of the common cold. This meta-analysis of 18 controlled trials examined the effect of Vitamin C on the length of ICU stay or the duration of mechanical ventilation. Doses varied from 1-3g daily orally and 0.5-110g daily intravenously and from 1-4 days in duration. The authors found that in 12 of the trials (1766 patients), Vitamin C shortened the length of ICU stay by 8%. 6 trials reported that Vitamin C shortened the length of mechanical ventilation by 8%. Given the significant price difference between Vitamin C supplementation and ICU stay, the authors suggest that further research is justified on the basis of these findings.
Abstract
A number of controlled trials have previously found that in some contexts, vitamin C can have beneficial effects on blood pressure, infections, bronchoconstriction, atrial fibrillation, and acute kidney injury. However, the practical significance of these effects is not clear. The purpose of this meta-analysis was to evaluate whether vitamin C has an effect on the practical outcomes: length of stay in the intensive care unit (ICU) and duration of mechanical ventilation. We identified 18 relevant controlled trials with a total of 2004 patients, 13 of which investigated patients undergoing elective cardiac surgery. We carried out the meta-analysis using the inverse variance, fixed effect options, using the ratio of means scale. In 12 trials with 1766 patients, vitamin C reduced the length of ICU stay on average by 7.8% (95% CI: 4.2% to 11.2%; p = 0.00003). In six trials, orally administered vitamin C in doses of 1⁻3 g/day (weighted mean 2.0 g/day) reduced the length of ICU stay by 8.6% (p = 0.003). In three trials in which patients needed mechanical ventilation for over 24 hours, vitamin C shortened the duration of mechanical ventilation by 18.2% (95% CI 7.7% to 27%; p = 0.001). Given the insignificant cost of vitamin C, even an 8% reduction in ICU stay is worth exploring. The effects of vitamin C on ICU patients should be investigated in more detail.
