Cerium compounds have been used as a fuel-borne catalyst to lower the generation of diesel exhaust particles (DEPs), but are emitted as cerium oxide nanoparticles (CeO2) along with DEP in the diesel ...exhaust. The present study investigates the effects of the combined exposure to DEP and CeO2 on the pulmonary system in a rat model. Specific pathogen-free male Sprague–Dawley rats were exposed to CeO2 and/or DEP via a single intratracheal instillation and were sacrificed at various time points post-exposure. This investigation demonstrated that CeO2 induces a sustained inflammatory response, whereas DEP elicits a switch of the pulmonary immune response from Th1 to Th2. Both CeO2 and DEP activated AM and lymphocyte secretion of the proinflammatory cytokines IL-12 and IFN-γ, respectively. However, only DEP enhanced the anti-inflammatory cytokine IL-10 production in response to ex vivo LPS or Concanavalin A challenge that was not affected by the presence of CeO2, suggesting that DEP suppresses host defense capability by inducing the Th2 immunity. The micrographs of lymph nodes show that the particle clumps in DEP+CeO2 were significantly larger than CeO2 or DEP, exhibiting dense clumps continuous throughout the lymph nodes. Morphometric analysis demonstrates that the localization of collagen in the lung tissue after DEP+CeO2 reflects the combination of DEP-exposure plus CeO2-exposure. At 4weeks post-exposure, the histological features demonstrated that CeO2 induced lung phospholipidosis and fibrosis. DEP induced lung granulomas that were not significantly affected by the presence of CeO2 in the combined exposure. Using CeO2 as diesel fuel catalyst may cause health concerns.
•DEP induced acute lung inflammation and switched immune response from Th1 to Th2.•DEP induced lung granulomas were not affected by the presence of CeO2.•CeO2 induced sustained lung inflammation, phospholipidosis, and fibrosis.•After the combined exposure, CeO2 and DEP are co-localized in the lung tissues.•CeO2+DEP induced lung inflammation, phospholipidosis, granulomas, and fibrosis.
Objectives
Due to the maternally‐inherited nature of mitochondrial DNA (mtDNA), there is a lack of information regarding fetal mtDNA in the plasma of pregnant women. We aim to explore the presence ...and topologic forms of circulating fetal and maternal mtDNA molecules in surrogate pregnancies.
Methods
Genotypic differences between fetal and surrogate maternal mtDNA were used to identify the fetal and maternal mtDNA molecules in plasma. Plasma samples were obtained from the surrogate pregnant mothers. Using cleavage‐end signatures of BfaI restriction enzyme, linear and circular mtDNA molecules in maternal plasma could be differentiated.
Results
Fetal‐derived mtDNA molecules were mainly linear (median: 88%; range: 80%–96%), whereas approximately half of the maternal‐derived mtDNA molecules were circular (median: 51%; range: 42%–60%). The fetal DNA fraction of linear mtDNA was lower (median absolute difference: 9.8%; range: 1.1%–27%) than that of nuclear DNA (median: 20%; range: 9.7%–35%). The fetal‐derived linear mtDNA molecules were shorter than the maternal‐derived ones.
Conclusion
Fetal mtDNA is present in maternal plasma, and consists mainly of linear molecules. Surrogate pregnancies represent a valuable clinical scenario for exploring the biology and potential clinical applications of circulating mtDNA, for example, for pregnancies conceived following mitochondrial replacement therapy.
Cerium compounds have been used as a diesel engine catalyst to lower the mass of diesel exhaust particles, but are emitted as cerium oxide (CeO2) nanoparticles in the diesel exhaust. In a previous ...study, we have demonstrated a wide range of CeO2-induced lung responses including sustained pulmonary inflammation and cellular signaling that could lead to pulmonary fibrosis. In this study, we investigated the fibrogenic responses induced by CeO2 in a rat model at various time points up to 84days post-exposure. Male Sprague Dawley rats were exposed to CeO2 by a single intratracheal instillation. Alveolar macrophages (AM) were isolated by bronchial alveolar lavage (BAL). AM-mediated cellular responses, osteopontin (OPN) and transform growth factor (TGF)-β1 in the fibrotic process were investigated. The results showed that CeO2 exposure significantly increased fibrotic cytokine TGF-β1 and OPN production by AM above controls. The collagen degradation enzymes, matrix metalloproteinase (MMP)-2 and -9 and the tissue inhibitor of MMP were markedly increased in the BAL fluid at 1day- and subsequently declined at 28days after exposure, but remained much higher than the controls. CeO2 induced elevated phospholipids in BAL fluid and increased hydroxyproline content in lung tissue in a dose- and time-dependent manner. Immunohistochemical analysis showed MMP-2, MMP-9 and MMP-10 expressions in fibrotic regions. Morphological analysis noted increased collagen fibers in the lungs exposed to a single dose of 3.5mg/kg CeO2 and euthanized at 28days post-exposure. Collectively, our studies show that CeO2 induced fibrotic lung injury in rats, suggesting it may cause potential health effects.
► Cerium oxide exposure significantly affected the following parameters in the lung. ► Induced fibrotic cytokine OPN and TGF-β1 production and phospholipidosis. ► Caused imbalance of the MMP-9/ TIMP-1 ratio that favors fibrosis. ► Cerium oxide particles were detected in lung tissue and AM. ► Cerium oxide caused lung fibrosis in a dose- and time-dependent manner.
Abstract Sepsis is a life threatening disease that is associated with high mortality. Existing treatments have failed to improve survivability in septic patients. The purpose of this present study is ...to evaluate whether cerium oxide nanoparticles (CeO2 NPs) can prevent lipopolysaccharide (LPS) induced severe sepsis mortality by preventing hepatic dysfunction in male Sprague Dawley rats. Administration of a single dose (0.5 mg/kg) of CeO2 NPs intravenously to septic rats significantly improved survival rates and functioned to restore body temperature, respiratory rate and blood pressure towards baseline. Treatment-induced increases in animal survivability were associated with decreased hepatic damage along with reductions in serum cytokines/chemokines, and diminished inflammatory related signaling. Kupffer cells and macrophage cells exposed to CeO2 NPs exhibited decreases in LPS-induced cytokine release (TNF-α, IL-1β, IL-6, HMGB1) which were associated with diminished cellular ROS, reduced levels of nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and decreased nuclear factor-kappa light chain enhancer of activated B cells (NF-kB) transcriptional activity. The findings of this study indicate that CeO2 NPs may be useful as a therapeutic agent for sepsis.
Abstract
The use of cerium compounds as diesel fuel catalyst results in the emission of cerium oxide nanoparticles (CeO2) in the exhaust. This study characterized the potential effects of CeO2 ...exposure on lung toxicity. Male Sprague Dawley rats were exposed to CeO2 by a single intratracheal instillation at 0.15, 0.5, 1, 3.5 or 7 mg/kg body weight. At 1 day after exposure, CeO2 significantly reduced NO production, but increased IL-12 production, by alveolar macrophages (AM) in response to ex vivo lipopolysacchride (LPS) challenge, and caused AM apoptosis, through activation of caspases 9 and 3. CeO2 exposure markedly increased suppressor of cytokine signaling-1 at 1-day and elevated arginase-1 at 28-day post exposure in lung cells, while osteopontin was significantly elevated in lung tissue at both time points. CeO2 induced inflammation, cytotoxicity, air/blood barrier damage, and phospholipidosis with enlarged AM. Thus, CeO2 induced lung inflammation and injury in lungs which may lead to fibrosis.
Cell-free DNA (cfDNA) fragmentation is nonrandom, at least partially mediated by various DNA nucleases, forming characteristic cfDNA end motifs. However, there is a paucity of tools for deciphering ...the relative contributions of cfDNA cleavage patterns related to underlying fragmentation factors. In this study, through non-negative matrix factorization algorithm, we used 256 5' 4-mer end motifs to identify distinct types of cfDNA cleavage patterns, referred to as "founder" end-motif profiles (F-profiles). F-profiles were associated with different DNA nucleases based on whether such patterns were disrupted in nuclease-knockout mouse models. Contributions of individual F-profiles in a cfDNA sample could be determined by deconvolutional analysis. We analyzed 93 murine cfDNA samples of different nuclease-deficient mice and identified six types of F-profiles. F-profiles I, II, and III were linked to deoxyribonuclease 1 like 3 (DNASE1L3), deoxyribonuclease 1 (DNASE1), and DNA fragmentation factor subunit beta (DFFB), respectively. We revealed that 42.9% of plasma cfDNA molecules were attributed to DNASE1L3-mediated fragmentation, whereas 43.4% of urinary cfDNA molecules involved DNASE1-mediated fragmentation. We further demonstrated that the relative contributions of F-profiles were useful to inform pathological states, such as autoimmune disorders and cancer. Among the six F-profiles, the use of F-profile I could inform the human patients with systemic lupus erythematosus. F-profile VI could be used to detect individuals with hepatocellular carcinoma, with an area under the receiver operating characteristic curve of 0.97. F-profile VI was more prominent in patients with nasopharyngeal carcinoma undergoing chemoradiotherapy. We proposed that this profile might be related to oxidative stress.
Recently cerium compounds have been used in a variety of consumer products, including diesel fuel additives, to increase fuel combustion efficiency and decrease diesel soot emissions. However, cerium ...oxide (CeO2) nanoparticles have been detected in the exhaust, which raises a health concern. Previous studies have shown that exposure of rats to nanoscale CeO2 by intratracheal instillation (IT) induces sustained pulmonary inflammation and fibrosis. In the present study, male Sprague–Dawley rats were exposed to CeO2 or CeO2 coated with a nano layer of amorphous SiO2 (aSiO2/CeO2) by a single IT and sacrificed at various times post-exposure to assess potential protective effects of the aSiO2 coating. The first acellular bronchoalveolar lavage (BAL) fluid and BAL cells were collected and analyzed from all exposed animals. At the low dose (0.15mg/kg), CeO2 but not aSiO2/CeO2 exposure induced inflammation. However, at the higher doses, both particles induced a dose-related inflammation, cytotoxicity, inflammatory cytokines, matrix metalloproteinase (MMP)-9, and tissue inhibitor of MMP at 1day post-exposure. Morphological analysis of lung showed an increased inflammation, surfactant and collagen fibers after CeO2 (high dose at 3.5mg/kg) treatment at 28days post-exposure. aSiO2 coating significantly reduced CeO2-induced inflammatory responses in the airspace and appeared to attenuate phospholipidosis and fibrosis. Energy dispersive X-ray spectroscopy analysis showed Ce and phosphorous (P) in all particle-exposed lungs, whereas Si was only detected in aSiO2/CeO2-exposed lungs up to 3days after exposure, suggesting that aSiO2 dissolved off the CeO2 core, and some of the CeO2 was transformed to CePO4 with time. These results demonstrate that aSiO2 coating reduce CeO2-induced inflammation, phospholipidosis and fibrosis.
•Both CeO2 and aSiO2/CeO2 particles were detected in the respective particle-exposed lungs.•The dissolution of aSiO2 coating from CeO2 particle core with time was demonstrated in the particle-exposed lungs.•aSiO2 coating significantly protected CeO2-induced pulmonary inflammatory responses.•aSiO2 coating showed a protective effect on CeO2-induced lung fibrosis.
Requests for pathological demand avoidance diagnoses have increased over recent years but pathological demand avoidance remains a controversial issue. We undertook a systematic review of ...peer-reviewed studies of pathological demand avoidance, using standardised appraisal and synthesis methods, to assess how pathological demand avoidance is identified and to explore the relationships between pathological demand avoidance, autism and other developmental/psychiatric disorders. A search of PsycINFO/PubMed/MEDLINE/Embase identified 13 studies meeting inclusion criteria. Narrative synthesis was chosen due to methodological heterogeneity of the identified studies. Autistic children/adolescents constituted the majority of participants in most studies. Most studies provided clearly defined inclusion criteria together with adequate descriptions of participants and study settings. Almost all studies relied on the parental report of pathological demand avoidance symptoms/diagnosis. Identification of pathological demand avoidance in all studies seemed to be, directly or indirectly, based on the criteria developed by Newson et al. While eight studies used objective criteria for the identification of pathological demand avoidance, the measures used have methodological limitations. Though associations with anxiety have been reported, few studies took account of possible relationships between pathological demand avoidance and other conditions, such as anxiety. Methodological limitations restrict current conclusions regarding the uniformity or stability of the constellation of behaviours associated with pathological demand avoidance or the characteristics of individuals displaying them. Clinical implications of current research are discussed.
Lay Abstract
Requests for diagnoses of pathological demand avoidance have increased over recent years, but pathological demand avoidance remains a controversial issue. The concept of pathological demand avoidance has been criticised for undermining the self-advocacy of autistic people and neglecting the potential role of anxiety as a possible underlying or contributing cause. The current study was undertaken to summarise and review the methodological quality and findings from current research into pathological demand avoidance in children and adolescents. Further aims were to describe how pathological demand avoidance has been identified and to explore the relationships with autism and other developmental and psychiatric disorders. After a comprehensive search, 13 relevant studies using a wide range of methods were identified and systematic quality assessments were undertaken. All the studies had based the identification of pathological demand avoidance, directly or indirectly, on descriptions from the original study by Newson and colleagues. However, the methods used to develop these criteria were not clearly described. Most studies relied exclusively on parental report for data, and there was a general failure to take account of alternative explanations for the behaviours under study. No studies explored the views of individuals with pathological demand avoidance themselves. Problems concerning definition and measurement in the reviewed studies currently limit any conclusions regarding the uniformity or stability of the behaviours described, or the characteristics of individuals displaying them. Relationships between pathological demand avoidance and other emotional and behavioural difficulties should be explored in future research, as should the perspectives of individuals with pathological demand avoidance themselves.
Nuclear-derived cell-free DNA (cfDNA) molecules in blood plasma are nonrandomly fragmented, bearing a wealth of information related to tissues of origin. DNASE1L3 (deoxyribonuclease 1 like 3) is an ...important player in shaping the fragmentation of nuclear-derived cfDNA molecules, preferentially generating molecules with 5 CC dinucleotide termini (i.e., 5 CC-end motif). However, the fragment end properties of microbial cfDNA and its clinical implication remain to be explored.
We performed end motif analysis on microbial cfDNA fragments in plasma samples from patients with sepsis. A sequence context-based normalization method was used to minimize the potential biases for end motif analysis.
The end motif profiles of microbial cfDNA appeared to resemble that of nuclear cfDNA (Spearman correlation coefficient: 0.82, P value 0.001). The CC-end motif was the most preferred end motif in microbial cfDNA, suggesting that DNASE1L3 might also play a role in the fragmentation of microbe-derived cfDNA in plasma. Of note, differential end motifs were present between microbial cfDNA originating from infection-causing pathogens (enriched at the CC-end) and contaminating microbial DNA potentially derived from reagents or the environment (nearly random). The use of fragment end signatures allowed differentiation between confirmed pathogens and contaminating microbes, with an area under the receiver operating characteristic curve of 0.99. The performance appeared to be superior to conventional analysis based on microbial cfDNA abundance alone.
The use of fragmentomic features could facilitate the differentiation of underlying contaminating microbes from true pathogens in sepsis. This work demonstrates the potential usefulness of microbial cfDNA fragmentomics in metagenomics analysis.
Cellular mitochondrial DNA (mtDNA) is organized as circular, covalently closed and double-stranded DNA. Studies have demonstrated the presence of short mtDNA fragments in plasma. It is not known ...whether circular mtDNA might concurrently exist with linear mtDNA in plasma.
We elucidated the topology of plasma mtDNA using restriction enzyme
I cleavage signatures on mtDNA fragment ends to differentiate linear and circular mtDNA. mtDNA fragments with both ends carrying
I cleavage signatures were defined as circular-derived mtDNA, whereas those with no cleavage signature or with 1 cleavage signature were defined as linear-derived mtDNA. An independent assay using exonuclease V to remove linear DNA followed by restriction enzyme
I digestion was used for confirming the conclusions based on
I cleavage analysis. We analyzed the presence of
I cleavage signatures on plasma DNA ends in nonhematopoietically and hematopoietically derived DNA molecules by sequencing plasma DNA of patients with liver transplantation and bone marrow transplantation.
Both linear and circular mtDNA coexisted in plasma. In patients with liver transplantation, donor-derived (i.e., liver) mtDNA molecules were mainly linear (median fraction, 91%; range, 75%-97%), whereas recipient-derived (i.e., hematopoietic) mtDNA molecules were mainly circular (median fraction, 88%; range, 77%-93%). The proportion of linear mtDNA was well correlated with liver DNA contribution in the plasma DNA pool (
= 0.83;
value = 0.0008). Consistent data were obtained from a bone marrow transplantation recipient in whom the donor-derived (i.e., hematopoietic) mtDNA molecules were predominantly circular.
Linear and circular mtDNA molecules coexist in plasma and may have different tissue origins.
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