Trace metals in fluids lining the respiratory system of patients with idiopathic pulmonary fibrosis and diffuse lung diseases

Copper homeostasis dysregulation in respiratory diseases: a review of current knowledge

Cu is an essential micronutrient for various physiological processes in almost all human cell types. Given the critical role of Cu in a wide range of cellular processes, the local concentrations of Cu and the cellular distribution of Cu transporter proteins in the lung are essential for maintaining a steady-state internal environment. Dysfunctional Cu metabolism or regulatory pathways can lead to an imbalance in Cu homeostasis in the lungs, affecting both acute and chronic pathological processes. Recent studies have identified a new form of Cu-dependent cell death called cuproptosis, which has generated renewed interest in the role of Cu homeostasis in diseases. Cuproptosis differs from other known cell death pathways. This occurs through the direct binding of Cu ions to lipoylated components of the tricarboxylic acid cycle during mitochondrial respiration, leading to the aggregation of lipoylated proteins and the subsequent downregulation of Fe-S cluster proteins, which causes toxic stress to the proteins and ultimately leads to cell death. Here, we discuss the impact of dysregulated Cu homeostasis on the pathogenesis of various respiratory diseases, including asthma, chronic obstructive pulmonary disease, idiopathic interstitial fibrosis, and lung cancer. We also discuss the therapeutic potential of targeting Cu. This study highlights the intricate interplay between copper, cellular processes, and respiratory health. Copper, while essential, must be carefully regulated to maintain the delicate balance between necessity and toxicity in living organisms. This review highlights the need to further investigate the precise mechanisms of copper interactions with infections and immune inflammation in the context of respiratory diseases and explore the potential of therapeutic strategies for copper, cuproptosis, and other related effects.

Development of a protocol of isolation of nanoparticles from patients' broncho-alveolar lavages for their in vitro toxicity assessment

To investigate potential correlations between human exposure to inhaled particles and pathological effects, the biological monitoring of nanoparticles in broncho-alveolar lavages (BAL) from patients has been proposed. To better understand the underlying mechanisms of toxicity, we propose to couple this biomonitoring of nanoparticles to their in vitro toxicity assessment. However, BAL obtained from regular clinical practice are conditioned with sodium hypochlorite solution (in a 50% v/v ratio), which is toxic to cells. The aim of this study was to develop a protocol to neutralize sodium hypochlorite, allowing to properly investigate the toxicity of the nanoparticles BAL contain. We first tried to neutralize chemically the sodium hypochlorite using H2O2, ascorbic acid or sodium ascorbate but this approach was unsuccessful. In addition, standard toxicology assays (MTT, LDH) could not be used because of interference with neutralizing solutions. We thus changed strategy and used ultracentrifugation to isolate nanoparticles from the sodium hypochlorite solution, with satisfactory extraction yields (88 to 100%). We then incubated the extracted nanoparticles with macrophages from the RAW264.7 cell line and assessed the cell viability and pro-inflammatory response. This study can be used as a proof-of-concept for further study of the biological impact of nanoparticles. This approach paves the way for studies aiming at a better understanding of the aetiology of some idiopathic diseases and underlying mechanisms.

The influence of trace elements on the therapeutic success of suprachoroidal draining devices

PURPOSE

The therapeutic success of minimal invasive glaucoma surgery (MIGS) is challenging due to many factors including fibrotic or occlusive events. Recent clinical data show sudden peaks of intraocular pressure (IOP) in the postoperative care of glaucoma patients after suprachoroidal draining stents. Yet, the reasons for the IOP peaks are speculative. As a link between trace elements and fibrosis had been previously observed in systemic disorders, the present study aimed to investigate the impact of trace elements on the therapeutic success of the suprachoroidal draining stents in patients with open-angle glaucoma (OAG).

MATERIAL AND METHODS

An analysis of a prospective single-center study was done: fifty-five eyes of patients with OAG (29 female, 26 male) underwent Cypass Micro-Stent implantation either as a stand-alone procedure or combined with cataract surgery. All patients underwent pre-operatively an ophthalmological examination which included slit lamp biomicroscopy and fundoscopy. IOP was measured by Goldmann applanation tonometry. Functional and morphometric data were assessed by Octopus G1-perimetry, which included measurement of retinal nerve fiber layer thickness (Spectralis OCT). Data of the patients' follow-ups were recorded during 18 months post-operatively. The therapeutic success of CyPass Micro-Stent was classified as 'success' (IOP reduction ≥20% compared to a pre-operative baseline without any medication), 'qualified success' (IOP reduction ≥20 % with same or lower additional eye medication), and 'failure' (IOP reduction ≤20 % or additional surgical treatment necessary). Aqueous humour was extracted once during surgery for analysis of the level of 14 trace elements: Copper (Cu), Cadmium (Cd), Cobalt (Co), Chromium (Cr), Iron (Fe), Lithium (Li), Magnesium (Mg), Manganese (Mn), Phosphorus (P), Lead (Pb), Titanium (Ti), Uranium (U), Vanadium (V), and Zinc (Zn). Analysis of the trace elements was done using an ELEMENT 2, ICP-sf-MS instrument (Thermo-Fisher Scientific, Bremen, Germany). Analysis of levels of trace elements was done across the patients' groups of the three subclasses of therapeutic success. Statistical investigations for substantial differences were conducted using the method of least squares to fit general linear models and mixed models. The last one for the repeated measurements of IOP.

RESULTS

Levels of Mg were significantly lower one month postoperatively in the success group (LS-Mean 1.30 mg/L) compared to the qualified success group (LS-Mean 1.22 mg/L; p-value = 0.04). Fe was significantly increased in the failure group (LS-Mean 2.07 µg/L) compared to the qualified success group (LS-Mean 1.64 µg/L; p-value = 0.019) after 3 months of follow-up. Additionally, Fe levels were significantly lower in the success group (LS-Mean 1.47 µg/L) compared to the failure cohort (LS-Mean 2.07 µg/L; p-value = 0.009). After a period of 18 months, significantly higher levels of Mn were observed in the success group (LS-Mean 1.24 µg/L) than in the failure group (LS Mean 0.30 µg/L, p-value = 0.019).

CONCLUSION

The present data might suggest that trace elements can influence therapeutic success of suprachoroidal draining devices postoperatively and thus offer first hints for potential novel therapeutic options.

Experimental and Computational Nanotoxicology-Complementary Approaches for Nanomaterial Hazard Assessment

The growing development and applications of nanomaterials lead to an increasing release of these materials in the environment. The adverse effects they may elicit on ecosystems or human health are not always fully characterized. Such potential toxicity must be carefully assessed with the underlying mechanisms elucidated. To that purpose, different approaches can be used. First, experimental toxicology consisting of conducting in vitro or in vivo experiments (including clinical studies) can be used to evaluate the nanomaterial hazard. It can rely on variable models (more or less complex), allowing the investigation of different biological endpoints. The respective advantages and limitations of in vitro and in vivo models are discussed as well as some issues associated with experimental nanotoxicology. Perspectives of future developments in the field are also proposed. Second, computational nanotoxicology, i.e., in silico approaches, can be used to predict nanomaterial toxicity. In this context, we describe the general principles, advantages, and limitations especially of quantitative structure–activity relationship (QSAR) models and grouping/read-across approaches. The aim of this review is to provide an overview of these different approaches based on examples and highlight their complementarity.

Comparison of the Content of Several Elements in Seawater, Sea Cucumber Eupentacta fraudatrix and Its High-Molecular-Mass Multiprotein Complex

Metal ions and other elements play many different critical roles in all biological processes. They can be especially important in high concentrations for the functioning of organisms living in seawater. It is important to understand how much the concentrations of different trace elements in such organisms can be higher than in seawater. Some marine organisms capable of rapid recovery after different injuries are fascinating in this regard. Sea cucumbers Eupentacta fraudatrix can completely restore all organs and the whole body within several weeks after their division into two parts. Here, for the first time, a comparison of the content of different elements in seawater, sea cucumber, and its very stable multiprotein complex (2000 kDa) was performed using two-jet plasma atomic emission spectrometry. Among the 18 elements we found in sea cucumbers, seawater contained only six elements in detectable amounts, and their content decreased in the following order: Mg > Ca > B > Sr ≈ Si > Cr (0.13−930 µg/g of seawater). The content of these elements in sea cucumbers was higher compared with seawater (-fold): Ca (714) > Sr (459) > Cr (75) > Si (42)> B (12) > Mg (6.9). Only four of them had a higher concentration in the protein complex than in seawater (-fold): Si (120.0) > Cr (31.5) > Ca (9.1) > Sr (8.8). The contents of Mg and B were lower in the protein complex than in seawater. The content of elements additionally found in sea cucumbers decreased in the order (µg/g of powder) of P (1100) > Fe (47) > Mn (26) > Ba (15) > Zn (13) > Al (9.3) > Mo (2.8) > Cu (1.4) > Cd (0.3), and in the protein complex, in the order of P (290) > Zn (51) > Fe (23) > Al (14) ≈ Ni (13) > Cu (7.5) > Ba (2.5) ≈ Co (2.0) ≈ Mn (1.6) > Cd (0.7) >Ag (0.2). Thus, sea cucumbers accumulate various elements, including those contained in very low concentrations in seawater. The possible biological roles of these elements are discussed here.

Relationship between Occupational Exposure to Airborne Nanoparticles, Nanoparticle Lung Burden and Lung Diseases

The biomonitoring of nanoparticles in patients’ broncho-alveolar lavages (BAL) could allow getting insights into the role of inhaled biopersistent nanoparticles in the etiology/development of some respiratory diseases. Our objective was to investigate the relationship between the biomonitoring of nanoparticles in BAL, interstitial lung diseases and occupational exposure to these particles released unintentionally. We analyzed data from a cohort of 100 patients suffering from lung diseases (NanoPI clinical trial, ClinicalTrials.gov Identifier: NCT02549248) and observed that most of the patients showed a high probability of exposure to airborne unintentionally released nanoparticles (>50%), suggesting a potential role of inhaled nanoparticles in lung physiopathology. Depending on the respiratory disease, the amount of patients likely exposed to unintentionally released nanoparticles was variable (e.g., from 88% for idiopathic pulmonary fibrosis to 54% for sarcoidosis). These findings are consistent with the previously performed mineralogical analyses of BAL samples that suggested (i) a role of titanium nanoparticles in idiopathic pulmonary fibrosis and (ii) a contribution of silica submicron particles to sarcoidosis. Further investigations are necessary to draw firm conclusions but these first results strengthen the array of presumptions on the contribution of some inhaled particles (from nano to submicron size) to some idiopathic lung diseases.

Iron deposition-induced ferroptosis in alveolar type II cells promotes the development of pulmonary fibrosis

Ferroptosis is a newly discovered type of regulated cell death, characterized by the iron-dependent accumulation of lipid reactive oxygen species, which has been implicated in numerous human diseases. However, its role in pulmonary fibrosis, a fatal lung disease with unknown etiology, is largely unknown. Here, we investigated the role of ferroptosis in pulmonary fibrosis. We found a large amount of iron deposition in the lung tissue of patients with pulmonary fibrosis. We observed ferroptosis in alveolar type II (ATII) cells, fibrotic lung tissues of BLM-induced pulmonary fibrosis mice. BLM-induced increase in iron level was accompanied by pathological changes, collagen deposition, and ferroptosis in ATII cells, indicating iron deposition-induced ferroptosis, which promoted the development of pulmonary fibrosis. Moreover, deferoxamine (DFO) completely prevented the pro-fibrosis effects of BLM by reducing iron deposition and ferroptosis in ATII cells. Genes associated with intracellular iron metabolism and homeostasis, such as transferrin receptor 1, divalent metal transporter 1, and ferroportin-1, and showed abnormal expression levels in animal tissues and lung epithelial MLE-12 cells, which responded to BLM stimulation. Overall, we demonstrated that BLM-induced iron deposition in MLE-12 cells is prone to both mitochondrial dysfunction and ferroptosis and that DFO reverses this phenotype. In the future, understanding the role of ferroptosis may shed new light on the etiology of pulmonary fibrosis. Ferroptosis inhibitors or genetic engineering of ferroptosis-related genes might offer potential targets to treat pulmonary fibrosis.

The levels of trace elements in sputum as biomarkers for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a rare lung disease that quickly leads to death. This paper addressed the issue of whether the levels of trace elements in sputum samples are suitable biomarkers for IPF disease. The sputum Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn concentrations were measured by sector field inductively coupled plasma mass spectrometry in populations sampled in Sardinia Island (Italy) including 31 patients with IPF, 31 patients with other lung-related diseases and 30 age- and gender-matched healthy controls. Risk factors in the disease as gender, age, severity and duration of the disease were assessed. Results showed that IPF patients had significantly increased sputum levels of Cd, Cr, Cu and Pb respect to controls. In males, but not in females, sputum levels of Cd, Cr and Cu were significantly higher in IPF cases respect to controls. In addition, Cr and Pb were increased in male patients with IPF compared to male patients with other lung diseases. Regarding Zn, it was found higher with the more serious stage of disease. Moreover, the ratios Cu/Zn, Fe/Mn and Cu/Mn were significantly increased in IPF patients and in non-IPF patients than in control subjects. These data showed clear increases in the concentration of some trace elements in sputum from patients with IPF and patients with other lung-related diseases that may contribute to the injury. The non-invasiveness of the sputum analysis is beneficial for its use as biomarker of trace element status in diseased patients for both the researcher and the clinic.

Nutritional immunity: the impact of metals on lung immune cells and the airway microbiome during chronic respiratory disease

Nutritional immunity is the sequestration of bioavailable trace metals such as iron, zinc and copper by the host to limit pathogenicity by invading microorganisms. As one of the most conserved activities of the innate immune system, limiting the availability of free trace metals by cells of the immune system serves not only to conceal these vital nutrients from invading bacteria but also operates to tightly regulate host immune cell responses and function. In the setting of chronic lung disease, the regulation of trace metals by the host is often disrupted, leading to the altered availability of these nutrients to commensal and invading opportunistic pathogenic microbes. Similarly, alterations in the uptake, secretion, turnover and redox activity of these vitally important metals has significant repercussions for immune cell function including the response to and resolution of infection. This review will discuss the intricate role of nutritional immunity in host immune cells of the lung and how changes in this fundamental process as a result of chronic lung disease may alter the airway microbiome, disease progression and the response to infection.

Copper-Associated Oxidative Stress Contributes to Cellular Inflammatory Responses in Cystic Fibrosis

Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF Transmembrane Conductance Regulator (CFTR), an apical chloride channel. An early inflammation (EI) in the lung of CF patients occurring in the absence of any bacterial infection has been reported. This EI has been proposed to be associated with oxidative stress (OX-S), generated by deregulations of the oxidant/antioxidant status. Recently, we demonstrated that copper (Cu), an essential trace element, mediates OX-S in bronchial cells. However, the role of this element in the development of CF-EI, in association with OX-S, has never been investigated. Using healthy (16HBE14o-; HBE), CF (CFBE14o-; CFBE), and corrected-wild type CFTR CF (CFBE-wt) bronchial cells, we characterized the inflammation and OX-S profiles in relation to the copper status and CFTR expression and function. We demonstrated that CFBE cells exhibited a CFTR-independent intrinsic inflammation. These cells also exhibited an alteration in mitochondria, UPR (Unfolded Protein Response), catalase, Cu/Zn- and Mn-SOD activities, and an increase in the intracellular content of iron, zinc, and Cu. The increase in Cu concentration was associated with OX-S and inflammatory responses. These data identify cellular Cu as a key factor in the generation of CF-associated OX-S and opens new areas of investigation to better understand CF-associated EI.

Levels of serum trace elements in patients with Peyronie

Aim: The etiology of the disease of Peyronie is not certainly known. However, penile micro traumas are thought to be important in the pathogenesis of Peyronie's disease (PD) in genetically predisposed individuals. In this study, we aimed to determine the relationship of some trace element and heavy metals with PD.Material and methods: Thirty Peyronie patients and 26 healthy volunteers were included in the study. In individuals in both groups, levels of serum trace elements (Manganese [Mn], Cu, Cobalt (Co), zinc [Zn], Cd, and iron [Fe]) were determined separately by Atomic Absorption Spectrophotometer method in Yüzüncü Yıl University Central Research Laboratory.Results: Mn, Cu, Zn, and Fe levels in Peyronie patients were statistically significantly lower when compared to the healthy control group (p < .05). Cd and Co levels were similar for both groups but not statistically significant (p > .05).Conclusions: The changes in trace element levels are related to the etiopathogenesis of PD. We think that our study is the first from this aspect.

Comparison of Trace Elements in High-Molecular-Mass Multiprotein Complex and in Female Milk from Which It Was Obtained

Background

Many biological processes are performed by different protein complexes. During the association of proteins and enzymes forming specific complexes, the latter can include ions of various metal ions, which may be important for their formation and biological function.

Objective of the Studies

However, to date in the literature there are no data on metal ions that are part of any protein complexes.

Methods

A very stable multiprotein complex (~1000±100 kDa) was separated from other proteins of nine samples of female milk by gel filtration on Sepharose 4B. The content of microelements in the stable multiprotein complex and milk was analyzed using two-jet plasma atomic emission spectrometry.

Results

The content of different elements in milk on average decreased in the order: Ca>P>Mg>Al≥Zn≥Fe>Cu >B (0.76–3500 μg/g of dry milk powder), while the content of some elements was very low (Sr>Mn>Cr>Ba>Pb>Ag>Ni>Cd, <0.03–0.5 μg/g). The content of eight elements in stable multiprotein complex was 1.2-9.6-fold higher than in milk and increased in the order: Ca≈Mg<P<Al<Fe<Pb<Ba<Cr<Cd<Zn, while content of SPC eight metals was 12.3-110-fold higher: Cu (12.3)>B (19.7)>Ag (28.7)>Ni (38)≥Sr (110).

Conclusions

The analysis of the relative content of sixteen elements in human milk and oligomeric complexes of proteins was performed for the first time. Data on the content of metals indicate that during the formation of protein which associates the increase in the content of metal ions bound with proteins of the complex can occur. Such metal ions can be important for the formation and biological function of protein complexes.

Twenty Element Concentrations in Human Organs Determined by Two-Jet Plasma Atomic Emission Spectrometry

In this paper, we have performed determination of the concentration of twenty elements in seven human organs (spleen, liver, kidney, muscle, heart, lungs, and brain) using two-jet plasma atomic emission spectrometry. The method allows multielemental analysis of solid samples without wet acid digestion. Before analysis, all human organs were first dried, ground to powders, and carbonized. The relative content of elements in each of the seven organs was very different depending on the donor. The average content of twenty elements in various organs varied in the following ranges (μg/g of dry weight): Ag (<0.02–0.2), Al (2.1–263), B (<0.5–2.5), Ca (323–1650), Cd (<0.1–114), Co (<0.2–1.0), Cr (<0.5–4.0), Cu (4.2–47), Fe (156–2900), Mg (603–1305), Mn (0.47–8.5), Mo (<0.2–4.9), Ni (<0.3–3.1), Pb (<0.3–1.9), Si (31.6–2390), Sn (<0.3–3.2), Sr (0.2–1.0), Ti (<2–31, mainly in lungs), and Zn (120–292). The concentration range of Ba in organs of five donors was <0.2–6.9 and 2.0–5600 for one donor with pneumoconiosis (baritosis). The maximum element contents were found, respectively, in the following organs: Al, B, Cr, Ni, Si, Sn, Sr, Ti (lungs), Fe (lungs and spleen), Mn (liver and kidney), Ag and Mo (liver), Ca (lungs and kidney), Cu (brain), Cd (kidney), Pb (brain), and Zn (liver, kidney, and muscle). The minimal content of elements was observed, respectively, in the following organs: Ag (all organs except liver), Ba (spleen, muscles, and brain), Ca and Mg (liver), Si (liver, muscle, and brain), Cd and Sr (heart and brain), Al, Cu, Fe, and Mn (muscle), and Zn (spleen and brain). The analysis of possible biological role and reasons for the increased content of some elements in the organs analyzed was carried out.

Downregulation of microRNA‑30a in bronchoalveolar lavage fluid from idiopathic pulmonary fibrosis patients

MicroRNAs (miRs) are short, highly conserved small noncoding RNA molecules with fundamental roles in regulating gene expression. To identify miR biomarkers associated with idiopathic pulmonary fibrosis (IPF), the expression pattern of miRs in exosomes from bronchoalveolar lavage fluid (BALF) of elderly patients with IPF were evaluated. High‑throughput quantitative detection of miR expression using a microarray indicated that miR‑125b, miR‑128, miR‑21, miR‑100, miR‑140‑3p and miR‑374b were upregulated in patients with IPF, while let‑7d, miR‑103, miR‑26 and miR‑30a‑5p were downregulated. The expression level of miR‑30a‑5p was further examined, and its potential target genes were predicted using target gene prediction analysis software. A direct regulatory association was confirmed between miR‑30a‑5p and TGF‑β activated kinase 1/MAP3K7 binding protein 3 (TAB3) via a dual‑luciferase reporter assay. Overexpression of miR‑30a‑5p decreased TAB3, α‑smooth muscle actin and fibronectin expression in A549 cells with or without transforming growth factor‑β1 treatment. The decreased expression of miR‑30a in the BALF of patients with IPF, along with the consequential increase in TAB3 expression, may be a crucial factor in IPF progression.