Impact of Hypoxia on Neutrophil Degranulation and Inflammatory Response in Alpha-1 Antitrypsin Deficiency Patients.

BACKGROUND: Alpha-1 antitrypsin deficiency (AATD) is an inflammatory disorder where neutrophils play a key role. Excessive neutrophil activation leads to local hypoxia and tissue damage. Most research on neutrophil function has been conducted under atmospheric conditions (21% O2), which may not represent physiological or pathological conditions. This study aimed to determine the effects of hypoxia on neutrophil degranulation and cytokine production in AATD patients. METHODS: Neutrophils isolated from 54 AATD patients (31 MZ; 8 SZ; 15 ZZ) and 7 controls (MM) were exposed to hypoxia (1% O2) for 4 h. Neutrophil degranulation was assessed by measuring elastase (NE), myeloperoxidase (MPO), lactoferrin, and matrix metalloproteinase-9 (MMP-9) levels using immunoassay-based methods. Pro-inflammatory (IL-8, IL-1 beta, IL-6, and TNF-alpha) and anti-inflammatory (IL-4 and IL-10) cytokine levels were assessed by a Luminex-based method. RESULTS: Our results indicate a significantly increased release of NE (p = 0.015), MPO (p = 0.042), lactoferrin (p = 0.015), and MMP-9 (p = 0.001) compared to controls. Pro-inflammatory cytokines show a significant rise in IL-8 (p = 0.019), a trend towards increased IL-1 beta (p = 0.3196), no change in IL-6 (p = 0.7329), and reduced TNF-alpha (p = 0.006). Anti-inflammatory cytokines show increased IL-4 (p = 0.057) and decreased IL-10 (p = 0.05703). CONCLUSIONS: Increased neutrophil degranulation and inflammatory phenotype are observed in AATD neutrophils under physiological hypoxia.

Hypoxia Enhances Oxidative Stress in Neutrophils from ZZ Alpha-1 Antitrypsin Deficiency Patients.

Alpha-1 antitrypsin deficiency (AATD) is a neutrophilic inflammatory disorder that may result in local hypoxia, reactive oxygen and nitrogen species (ROS/RNS) production, and increased damage in adjacent tissues. This study aims to determine the impact of hypoxia on neutrophil oxidative stress profile in AATD patients. Neutrophils were isolated from AATD patients and control volunteers and exposed to hypoxia (1% O2 for 4 h), ROS/RNS, mitochondrial parameters, and non-enzymatic antioxidant defenses measured by flow cytometry. The expression of enzymatic antioxidant defenses was determined by qRT-PCR. Our results indicate that ZZ-AATD neutrophils produce higher amounts of hydrogen peroxide, peroxynitrite, and nitric oxide and decreased levels of the antioxidant enzymes catalase, superoxide dismutase, and glutathione reductase. Likewise, our results show a decrease in mitochondrial membrane potential, indicating that this organelle could be involved in the production of the reactive species observed. No decrease in glutathione and thiol levels were observed. The accumulation of substances with high oxidative capacity would explain the greater oxidative damage observed in proteins and lipids. In conclusion, our results indicate that, compared to MM control individuals, ZZ-AATD neutrophils show increased ROS/RNS production under hypoxic conditions opening a new rationale for using antioxidant therapies to treat the disease.

Correction: Magallon et al. Oxidative Stress and Endoplasmic Reticulum Stress in Rare Respiratory Diseases. J. Clin. Med. 2021, 10, 1268.

Sara Pastor was not included as an author in the original publication [...].

Special Issue: Rare Respiratory Diseases: A Personal and Public Health Issue.

In the 1970s, the term "rare disease" was coined to describe a category of inherited metabolic diseases with low prevalence and a wide range of symptoms [...].

Oxidative Stress and Endoplasmic Reticulum Stress in Rare Respiratory Diseases.

Several studies have shown that some rare respiratory diseases, such as alpha-1 antitrypsin deficiency (AATD), idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF), and primary ciliary dyskinesia (PCD) present oxidative stress (OS) and endoplasmic reticulum (ER) stress. Their involvement in these pathologies and the use of antioxidants as therapeutic agents to minimize the effects of OS are discussed in this review.

New Laboratory Protocol to Determine the Oxidative Stress Profile of Human Nasal Epithelial Cells Using Flow Cytometry.

Several studies have shown the importance of oxidative stress (OS) in respiratory disease pathogenesis. It has been reported that the nasal epithelium may act as a surrogate for the bronchial epithelium in several respiratory diseases involving OS. However, the sample yields obtained from nasal biopsies are modest, limiting the number of parameters that can be determined. Flow cytometry has been widely used to evaluate cellular OS profiles. It has the advantage that analyses can be performed using a small amount of sample. Therefore, we aimed to set up a new method based on flow cytometry to assess the oxidative profile of human nasal epithelial cells which could be used in research on respiratory diseases. Levels of total nitric oxide, superoxide anion, peroxynitrite, and intracellular peroxides were measured. Reduced thiol levels, such as antioxidant-reduced glutathione and oxidative damaged lipids and proteins, were also analysed. The intracellular calcium levels, plasma membrane potential, apoptosis, and percentage of live cells were also studied. Finally, a strategy to evaluate the mitochondrial function, including mitochondrial hydrogen peroxide, superoxide anion, mitochondrial mass, and membrane potential, was set up. Using small amounts of sample and a non-invasive sampling technique, the described method enables the measurement of a comprehensive set of OS parameters in nasal epithelial cells, which could be useful in research on respiratory diseases.

Gene Therapy in Rare Respiratory Diseases: What Have We Learned So Far?

Gene therapy is an alternative therapy in many respiratory diseases with genetic origin and currently without curative treatment. After five decades of progress, many different vectors and gene editing tools for genetic engineering are now available. However, we are still a long way from achieving a safe and efficient approach to gene therapy application in clinical practice. Here, we review three of the most common rare respiratory conditions-cystic fibrosis (CF), alpha-1 antitrypsin deficiency (AATD), and primary ciliary dyskinesia (PCD)-alongside attempts to develop genetic treatment for these diseases. Since the 1990s, gene augmentation therapy has been applied in multiple clinical trials targeting CF and AATD, especially using adeno-associated viral vectors, resulting in a good safety profile but with low efficacy in protein expression. Other strategies, such as non-viral vectors and more recently gene editing tools, have also been used to address these diseases in pre-clinical studies. The first gene therapy approach in PCD was in 2009 when a lentiviral transduction was performed to restore gene expression in vitro; since then, transcription activator-like effector nucleases (TALEN) technology has also been applied in primary cell culture. Gene therapy is an encouraging alternative treatment for these respiratory diseases; however, more research is needed to ensure treatment safety and efficacy.

Knowledge of Rare Respiratory Diseases among Paediatricians and Medical School Students.

Alpha-1-antitrypsin deficiency (AATD) and primary ciliary dyskinesia (PCD) are underdiagnosed rare diseases showing a median diagnostic delay of five to ten years, which has negative effects on patient prognosis. Lack of awareness and education among healthcare professionals involved in the management of these patients have been suggested as possible causes. Our aim was to assess knowledge of these diseases among paediatricians and medical school students to determine which knowledge areas are most deficient. A survey was designed with questions testing fundamental aspects of the diagnosis and treatment of AATD and PCD. A score equal to or greater than 50% of the maximum score was set as the level necessary to ensure a good knowledge of both diseases. Our results indicate a profound lack of knowledge of rare respiratory diseases among paediatric professionals and medical students, suggesting that it is necessary to increase rare respiratory diseases training among all physicians responsible for suspecting and diagnosing them; this will allow early diagnosis and the setup of preventive measures and appropriate early-stage treatment. The first step in closing this knowledge gap could be to include relevant material in the medical syllabus.

Oxidative Stress in COPD.

Numerous studies over the years have shown that oxidative stress plays a major role in the development of the disease. Oxidative stress involvement in COPD opens up the possibility of using antioxidant therapies in the treatment of the disease. However, so far, these therapies have shown no clinical benefit indicating that more basic research efforts are needed to understand the underlying mechanisms by which oxidative stress leads to the development of COPD.

Alpha-1 antitrypsin deficiency: outstanding questions and future directions.

BACKGROUND: Alpha-1 antitrypsin deficiency (AATD) is a rare hereditary condition that leads to decreased circulating alpha-1 antitrypsin (AAT) levels, significantly increasing the risk of serious lung and/or liver disease in children and adults, in which some aspects remain unresolved. METHODS: In this review, we summarise and update current knowledge on alpha-1 antitrypsin deficiency in order to identify and discuss areas of controversy and formulate questions that need further research. RESULTS: 1) AATD is a highly underdiagnosed condition. Over 120,000 European individuals are estimated to have severe AATD and more than 90% of them are underdiagnosed. CONCLUSIONS: 2) Several clinical and etiological aspects of the disease are yet to be resolved. New strategies for early detection and biomarkers for patient outcome prediction are needed to reduce morbidity and mortality in these patients; 3) Augmentation therapy is the only specific approved therapy that has shown clinical efficacy in delaying the progression of emphysema. Regrettably, some countries reject registration and reimbursement for this treatment because of the lack of larger randomised, placebo-controlled trials. 4) Alternative strategies are currently being investigated, including the use of gene therapy or induced pluripotent stem cells, and non-augmentation strategies to prevent AAT polymerisation inside hepatocytes.

Anti-angiogenic therapies in prostate cancer.

Prostate cancer (PCa) is the second most common type of cancer among men in Western societies. Once in the castrate-resistant metastatic setting therapeutic options are limited. The importance of angiogenesis in the progression of PCa has been widely reported providing a rationale to test anti-angiogenic compounds for PCa treatment in clinical trials (CTs). However, in spite of the promising results shown in preclinical models and some anti-tumor activity observed in CTs, to date, no angiogenic inhibitor has been approved for use in PCa. This editorial outlines the latest clinical evidence regarding anti-angiogenic therapies in PCa treatment.

Evaluation of the quality of publications on randomized clinical trials using the Consolidated Standards of Reporting Trials (CONSORT) statement guidelines in a Spanish tertiary hospital.

The main reason for conducting a clinical trial (CT) is to test the effect of a drug or medical procedure to improve treatment of a disease. CTs contribute most when they are rigorously conducted and the results are published adequately. The aim of this study is to assess, using the CONSORT statement guidelines, the quality of reporting of completed CTs conducted at a tertiary hospital to determine which sections of the articles should be improved. CTs published between 2002 and 2008 were identified by searching the MEDLINE and Cochrane Library. Forty of 127 completed CTs were published. There was a marked increase in the number of articles and the quality of the journals that published the CTs over time. Although the articles were published in high-impact index journals, the Consolidated Standards of Reporting Trials (CONSORT) score reporting quality of the articles varied substantially, which indicates that they should be improved. The title, abstract, introduction, and discussion sections received the highest CONSORT scores and need little improvement. Poor reporting of methodological details and discussion on limitations and strengths were observed. In conclusion, much improvement remains to be made in the quality of reporting of CTs to allow reliable quality assessment of published trials.