Search bioRxiv⌕ Search

Biology subjects

Du, M.

Publications and source records attributed to Du, M..

At least 37 records · Page 2Linked to original sources

Common Signatures of Neutrophils in Diverse Disease Conditions

Neutrophils are traditionally recognized for their pro-inflammatory roles. However, accumulating evidence has begun to highlight the plasticity of transcriptional states of neutrophils during pathological insults. Whether such unconventional neutrophils may share commonality across diverse disease conditions is incompletely understood. Here, we systematically profile over 500,000 neutrophils in key immune compartments and disease-inflicted tissues of the mouse models of metabolic disorder, autoimmunity, tissue damage, peripheral cancers, and intracranial gliomas. Of importance, we observe two distinct neutrophil clusters with unique immune features. The first cluster, characterized by Cd274, Vegfa, and antigen presentation, is highly enriched within the diseased tissues. In contrast, the second cluster with elevated Cd244 and type 2 immune response but reduced maturation markers primarily emerges in the peripheral blood and spleens of specific disease scenarios. These results have elucidated the common signatures of neutrophils in response to various pathological conditions, providing a valuable reference for diagnostic and therapeutic applications.

immunology↗

Establishing a Digital PCR-Based Reference Measurement Procedure for Monkeypox Virus: An Inter-laboratory Assessment and Standardization Study

The accurate detection of monkeypox virus (MPXV) is crucial for effective viral diagnosis and epidemic prevention. Currently, the field lacks standardized reference methods for MPXV quantification, as well as reliable pseudovirus reference materials (RMs) to ensure quality control throughout the detection process. To address this, we developed a droplet digital PCR (ddPCR) reference measurement procedure (RMP) for precise quantification of MPXV genes B6R, which demonstrates excellent performance with a wide dynamic range (11-1.24x104 copies/L), strong linearity (R2=0.9984), and a low limit of quantitation (11 copies/L, CV[&le;]25%). Repeatability tests confirmed high precision, with inter-laboratory CVs <10% across nine labs using different dPCR platforms. recovery efficiencies for B6R and F3L were [~]69%, with uncertainties incorporated into final measurements. The homogeneity assessment showed good results (CV=2.94%), and stability studies confirmed the stability of the sample during -70 {degrees}C and short-term storage (4 {degrees}C/-20 {degrees}C). Mandels statistical data shows that the reproducibility between laboratories is consistent. This validated ddPCR RMP provides metrological traceability, ensuring reliable and comparable results for MPXV diagnosis and supporting public health efforts.

molecular biology↗

Transposable elements drive species-specific and tissue-specific transcriptomes in human development

BackgroundTransposable elements (TEs) are an abundant and crucial regulatory resource in the human genome. Serving as alternative promoters, TEs can be reactivated and produce TE-initiated transcripts, which play importance roles in early development and differentiated tissues. However, the prevalence and function of TE-initiated transcription in human development are poorly characterized. ResultsWe identified 12,918 TE-initiated transcripts across 40 human body sites and embryonic stem cells. Among TE-initiated transcripts, 80% were activated in a tissue-specific manner. TEs with tissue-specific transcription factor binding motifs were enriched in particular tissues. Additionally, approximately half of TE-derived TSSs were primates-specific. Notably, 375 primates-specific TE-derived TSSs were found to create novel tissue-specific gene expression patterns during evolution. ConclusionsOur results characterize the global profile of TE-initiated transcription and enhance our understanding of TE contribution to the primate-specific gene regulatory networks in human development.

bioinformatics↗

TEITbase: a database for transposable element (TE)-initiated transcripts in human cancers

Transposable elements (TEs) are abundant and play a crucial regulatory role in the human genome. Functioning as alternative promoters, TEs can be reactivated to produce TE-initiated transcripts. In cancer, TE-initiated transcription may upregulate oncogene expression and generate novel tumor-specific antigens, which could serve as potential targets for immunotherapy. However, there remains a lack of comprehensive databases that systematically investigate TE-initiated transcription in cancer. To address this gap, we developed a deep learning-based method and identified 38,995 TE-initiated transcripts across 33 cancer types from The Cancer Genome Atlas. Among these, 6,203 were tumor-specific expressed and strongly associated with the tumorigenesis. Using these annotations, we created TEITbase (http://teitbase.medbioinfo.org/), a user-friendly database that provides researchers with tools to conduct various downstream analyses and investigations for TE-initiated transcripts, including 546 novel onco-exaptation events. The establishment of TEITbase provides new insights into transcriptional reprogramming in cancers and enables further investigation into the potential roles of TE-initiated transcripts in cancer diagnostics and therapeutic strategies.

bioinformatics↗

LC-MS analysis of RNA through hydrogen bonding of alkylamines

Nucleic acid oligonucleotides represent a promising therapy for treating disease. Production of these biopolymers happens synthetically which can produce impurities concomitant with the desired product. The use of liquid chromatography coupled to high resolution mass spectrometry is a robust analytical technique for determination of sample purity. Traditionally, ion pairing reagents are used to facilitate chromatography separation before sampling with the mass spectrometer. The choice of reagent for analysis can impact the analysis as the length of the oligonucleotide increases. This is in part due to the thermodynamics of transitioning the oligonucleotide from the liquid phase to the gas phase. Here we show that the use of a hydrogen bond donating alkylamine assists with overcoming the energy barrier of phase transition by bonding to the nucleobase as well as the phosphodiester backbone. By increasing the relative hydrophobicity of the oligonucleotide, the transition to the gas phase is increased producing a cleaner mass spectrum. Furthermore, we show that by using a hydrogen bond donating alkylamine, we can remove the fluoroalcohol reagent commonly used in ion pairing mass spectrometry of nucleic acids.

biochemistry↗

cxcl18b-defined transitional state-specific nitric oxide drives injury-induced Müller glia cell-cycle re-entry in the zebrafish retina

In lower vertebrates, retinal Muller glia (MG) exhibit a life-long capacity of cell-cycle re-entry to regenerate neurons following the retinal injury. However, the mechanism driving such injury-induced MG cell-cycle re-entry remains incompletely understood. Combining single-cell transcriptomic analysis and in-vivo clonal analysis, we identified previously undescribed cxcl18b-defined MG transitional states as essential routes towards MG proliferation following green/red cone (G/R cone) ablation. Inflammation blockage abolished the triggering of these transitional states, which expressed the gene modules shared by cells of the ciliary marginal zone (CMZ), where life-long adult neurogenesis takes place. Functional studies of the redox properties of these transitional states further demonstrated the regulatory role of nitric oxide (NO) produced by Nos2b in injury-induced MG proliferation. Finally, we developed a viral-based strategy to specifically disrupt nos2b in cxcl18b-defined MG transitional states and revealed the effect of transitional state-specific NO signaling. Our findings elucidate the precision redox mechanism underlying injury-induced MG cell-cycle re-entry, providing insights into species-specific mechanisms for vertebrate retina regeneration.

neuroscience↗

Single-cell RNA sequencing analysis reveals new insights for intersex gonad initiation and early sex differentiation of goats

Polled intersex syndrome in goats severely impacts productivity and economic benefits, serving as a potential model for human reproductive defects. However, its specific molecular and cellular regulatory mechanisms remain unclear. This study combined single-cell RNA-sequencing (scRNA-seq) with tissue morphology and immunofluorescence detection to investigate the cellular heterogeneity, pseudo-time differentiation trajectory, differentially expressed genes, and regulatory networks of female, intersex, and male gonads during the 55-65 days embryonic stage of goats. The results indicated significant heterogeneity and cell fate transition in the somatic and germ cells of female, intersex, and male gonads at different developmental stages. Stromal cells may initiate female and intersexual gonad development, and epithelial cells may be the source of gonad cells in male fetuses. The abnormal expression of FOXL2, SOX9, AMH, DMRT1, RSPO1, INSL3, TCF21 and CSF1R may cause female-to-male sex reversal. The new candidate genes like PHLDB2, ZNRF3 and TEAD1 may contribute to the gender differentiation. Additionally, TREM2+ macrophages analogous to those in humans were identified in male gonads, while genes such as CSF1R and TYROBP potentially regulate macrophage immune privilege mechanisms. Early gonadal development in goats may also be regulated by circadian rhythm mechanisms similar to humans, with genes such as NR1D1, LGR4, and ATG5 involved in granulosa cell development, while genes such as ATG5, NRIP1, and FBXW11 may affect intersex trait development. In general, this study provided an important reference for exploring molecular and cellular mechanisms of intersex initiation during early embryonic development in goats and also for modelling human reproductive defects. Author summaryIn this study, we investigated the cell fate trajectory and key gene expression profile of goat fetus gonads using scRNA-seq. The analysis revealed cellular heterogeneity among normal male, normal female, and intersex gonadal somatic and germ cells, alongside their dynamic fate transitions across various developmental states. Pseudo-time trajectory analysis suggested that stromal cells might act as the initiation signal for female and intersexual gonad development, while epithelial cells could serve as the primary source of gonadal cells in male fetal goats. GO functional enrichment and KEGG analyses confirmed that abnormal expression of FOXL2, SOX9, AMH, DMRT1 and RSPO1 was linked to the emergence of intersexual gonads. Newly identified candidate genes including LRP2, PITX2, ARX, LHX9, PHLDB2, ZNRF3 and TEAD1 may contribute to sex-specific differences, while INSL3 and TCF21 could be linked to intersexual gonads. We identified TREM2+ macrophages analogous to those in humans, which could regulate immune privilege mechanisms. Circadian rhythmic changes were observed during early goat gonadal development.

developmental biology↗

Functional diversification of the MADS-box gene family in fine-tuning the dimorphic transition of Talaromyces marneffei

The dynamic transition between yeast and hypha is a crucial adaptive mechanism for many human pathogenic fungi, including Talaromyces marneffei, a thermodimorphic fungus responsible for causing fatal talaromycosis. In the current study, we elucidated the roles of the MADS-box gene family in fine-tuning the dimorphic transition in T. marneffei through functional diversification. Utilizing adaptive laboratory evolution, we identified an enrichment of MADS-box genes in mutants deficient in yeast-to- mycelium transition. Further phylogenetic analyses revealed a significant expansion of MADS-box gene family within T. marneffei. Functional genetic manipulations revealed that overexpression of mads9, as opposed to its paralog mads10, effectively impeded the hyphal-to-yeast transition. Through integrating RNA sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq), we demonstrated that mads9 and the previously characterized madsA modulated the rate of hyphal-to-yeast conversion by orchestrating metabolic pathways and membrane dynamics, respectively, with mutual regulation via shared target genes. Our findings illuminated the distinct functional roles of the MADS-box family in regulating dimorphic transitions in T. marneffei, offering new insights into fungal adaptability.

microbiology↗

Species-specific circular RNA circDS-1 enhances adaptive evolution in Talaromyces marneffei through regulation of dimorphic transition and virulence

Thermal adaptability is a crucial characteristic for mammalian pathogenic fungi that originally inhabit natural ecosystems. Thermally dimorphic fungi have evolved a unique ability to respond to host body temperature by shifting from mycelium to yeast. The high similarity of protein-coding genes between these fungi and their relatives suggests the indispensable but often overlooked roles of non-coding elements in fungal thermal adaptation. Here, we systematically delineated the landscape of full-length circRNAs in both mycelial and yeast conditions of Talaromyces marneffei, a typical thermally dimorphic fungus causing fatal Talaromycosis, by optimizing an integrative pipeline for circRNA detection utilizing next- and third-generation sequencing. We found T. marneffei circRNA demonstrated features such as shorter length, lower abundance, and circularization-biased splicing. We then identified and validated that circDS-1, independent of its parental gene, promotes the hyphae-to-yeast transition, maintains yeast morphology, and is involved in virulence regulation. Further analysis and experiments among Talaromyces confirmed that the generation of circDS-1 is driven by a T. marneffei-specific region in the flanking intron of circDS-1. Together, our findings not only provide fresh insights into the role of circRNA in fungal thermal adaptation but also reveal a novel molecular mechanism for the adaptive evolution of functional circRNAs derived from intronic mutations. Author SummaryIt is an essential characteristic for human pathogens to survive under human body temperature, which is obviously higher than environmental temperature. The morphology transformation between mycelia and yeasts of thermally dimorphic fungi are tightly associated with temperature. The limited divergences of protein-coding genes among their closest relatives are not able to explain these fungi thermal dimorphism. CircRNAs are non-coding RNAs that distribute ubiquitously across eukaryotes. However, lower eukaryotes have been relatively neglected in circRNA research, either from the biological function level or from the evolutionary level. Our study focused on the typical thermally dimorphic fungus, Talaromyces marneffei. We combined next-generation and third-generation sequencing technologies to map the full-length circRNA profile in both the saprophytic mycelial and pathogenic yeast forms of T. marneffei to identify functional circRNAs. Gene manipulation experiments were performed to evaluate the functional impact of the target circRNA circDS-1. We uncovered unique characteristics of T. marneffei circRNAs, such as shorter lengths, reduced abundance, and a preference for circularization-biased splicing events. CircDS-1, which functions independently from its host gene to promote the transition from hyphae to yeast form, maintain yeast morphology, and modulate virulence. Our study not only offers fresh perspectives on the role of circRNAs in fungal thermal adaptation, but also enhances our understanding of the adaptive evolution of pathogenic fungi as they transform from environmental to host environments.

microbiology↗

Divergent and Convergent TMEM106B Pathology in Murine Models of Neurodegeneration and Human Disease

TMEM106B is a lysosomal/late endosome protein that is a potent genetic modifier of multiple neurodegenerative diseases as well as general aging. Recently, TMEM106B was shown to form insoluble aggregates in postmortem human brain tissue, drawing attention to TMEM106B pathology and the potential role of TMEM106B aggregation in disease. In the context of neurodegenerative diseases, TMEM106B has been studied in vivo using animal models of neurodegeneration, but these studies rely on overexpression or knockdown approaches. To date, endogenous TMEM106B pathology and its relationship to known canonical pathology in animal models has not been reported. Here, we analyze histological patterns of TMEM106B in murine models of C9ORF72-related amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD), SOD1-related ALS, and tauopathy and compare these to postmortem human tissue from patients with C9-ALS/FTD, Alzheimers disease (AD), and AD with limbic-predominant age-related TDP-43 encephalopathy (AD/LATE). We show that there are significant differences between TMEM106B pathology in mouse models and human patient tissue. Importantly, we also identified convergent evidence from both murine models and human patients that links TMEM106B pathology to TDP-43 nuclear clearance specifically in C9-ALS. Similarly, we find a relationship at the cellular level between TMEM106B pathology and phosphorylated Tau burden in Alzheimers disease. By characterizing endogenous TMEM106B pathology in both mice and human postmortem tissue, our work reveals considerations that must be taken into account when analyzing data from in vivo mouse studies and elucidates new insights supporting the involvement of TMEM106B in the pathogenesis and progression of multiple neurodegenerative diseases.

neuroscience↗

BDNF augmentation reverses cranial radiation therapy-induced cognitive decline and neurodegenerative consequences

Cranial radiation therapy (RT) for brain cancers is often associated with the development of radiation-induced cognitive dysfunction (RICD). RICD significantly impacts the quality of life for cancer survivors, highlighting an unmet medical need. Previous human studies revealed a marked reduction in plasma brain-derived neurotrophic factor (BDNF) post-chronic chemotherapy, linking this decline to a substantial cognitive dysfunction among cancer survivors. Moreover, riluzole (RZ)-mediated increased BDNF in vivo in the chemotherapy-exposed mice reversed cognitive decline. RZ is an FDA-approved medication for ALS known to increase BDNF in vivo. In an effort to mitigate the detrimental effects of RT-induced BDNF decline in RICD, we tested the efficacy of RZ in a cranially irradiated (9 Gy) adult mouse model. Notably, RT-exposed mice exhibited significantly reduced hippocampal BDNF, accompanied by increased neuroinflammation, loss of neuronal plasticity-related immediate early gene product, cFos, and synaptic density. Spatial transcriptomic profiling comparing the RT+Veh with the RT+RZ group showed gene expression signatures of neuroprotection of hippocampal excitatory neurons post-RZ. RT-exposed mice performed poorly on learning and memory, and memory consolidation tasks. However, irradiated mice receiving RZ (13 mg/kg, drinking water) for 6-7 weeks showed a significant improvement in cognitive function compared to RT-exposed mice receiving vehicle. Dual-immunofluorescence staining, spatial transcriptomics, and biochemical assessment of RZ-treated irradiated brains demonstrated preservation of synaptic integrity and neuronal plasticity but not neurogenesis and reduced neuroinflammation concurrent with elevated BDNF levels and transcripts compared to vehicle-treated irradiated brains. In summary, oral administration of RZ represents a viable and translationally feasible neuroprotective approach against RICD.

neuroscience↗

Crystal structure and catalytic mechanism of PL35 family glycosaminoglycan lyases with an ultrabroad substrate spectrum

Recently, a new class of glycosaminoglycan (GAG) lyases (GAGases) belonging to PL35 family has been discovered with an ultrabroad substrate spectrum that can degrade three types of uronic acid-containing GAGs (hyaluronic acid, chondroitin sulfate and heparan sulfate) or even alginate. In this study, the structures of GAGase II from Spirosoma fluviale and GAGase VII from Bacteroides intestinalis DSM 17393 were determined at 1.9 and 2.4 [A] resolution, respectively, and their catalytic mechanism was investigated by the site-directed mutant of their crucial residues and molecular docking assay. Structural analysis showed that GAGase II and GAGase VII consist of an N-terminal (/)6 toroid multidomain and a C-terminal two-layered {beta}-sheet domain with Mn2+. Notably, although GAGases share similar folds and catalytic mechanisms with some GAG lyases and alginate lyases, they exhibit higher structural similarity with alginate lyases than GAG lyases, which may present a crucial structural evidence for the speculation that GAG lyases with (/)n toroid and antiparallel {beta}-sheet structures arrived by a divergent evolution from alginate lyases with the same folds. Overall, this study not only solved the structure of PL35 GAG lyases for the first time and investigated their catalytic mechanism, especially the reason why GAGase III can additionally degrade alginate, but also provided a key clue in the divergent evolution of GAG lyases that originated from alginate lyases.

biochemistry↗

Head dopaminergic and serotonergic neurons monitor alterations in gut bacterial activity through a gut-brain-gut axis

The brain is suggested to monitor gut microbial changes to critically maintain health, whereas the particular bacterial alterations and the mechanisms involved are largely unclear. Here, through a genome-wide screen, we identified 29 E. coli genes whose inactivation can be surveilled by C. elegans head dopaminergic and serotonergic neurons through increasing host neuronal dopamine and serotonin biosynthesis. Mechanistically, we found that these head neurons respond to the E. coli lack of respiratory chain genes by detecting the bacteria-caused reductions in host labile iron levels that impair intestinal mitochondria, and the intestine-expressed mitochondrial stress sensor ATFS-1 is critically involved. Furthermore, this neuronal response in turn promotes intestinal ferritin-1 expression to counteract bacteria-caused labile iron reduction and thereby maintaining mitochondrial function. Our findings systematically identify bacterial activity changes that elevate brain dopamine and serotonin levels and unveil an unexpected gut-brain-gut axis in which the head neurons inspect bacterial activity-mediated changes in host iron metabolism and mitochondrial function, enlightening crucial roles and mechanisms of brain in surveilling microbial activity alterations.

developmental biology↗

ProLLM: Protein Chain-of-Thoughts Enhanced LLM for Protein-Protein Interaction Prediction

The prediction of protein-protein interactions (PPIs) is crucial for understanding biological functions and diseases. Previous machine learning approaches to PPI prediction mainly focus on direct physical interactions, ignoring the broader context of nonphysical connections through intermediate proteins, thus limiting their effectiveness. The emergence of Large Language Models (LLMs) provides a new opportunity for addressing this complex biological challenge. By transforming structured data into natural language prompts, we can map the relationships between proteins into texts. This approach allows LLMs to identify indirect connections between proteins, tracing the path from upstream to downstream. Therefore, we propose a novel framework ProLLM that employs an LLM tailored for PPI for the first time. Specifically, we propose Protein Chain of Thought (ProCoT), which replicates the biological mechanism of signaling pathways as natural language prompts. ProCoT considers a signaling pathway as a protein reasoning process, which starts from upstream proteins and passes through several intermediate proteins to transmit biological signals to downstream proteins. Thus, we can use ProCoT to predict the interaction between upstream proteins and downstream proteins. The training of ProLLM employs the ProCoT format, which enhances the models understanding of complex biological problems. In addition to ProCoT, this paper also contributes to the exploration of embedding replacement of protein sites in natural language prompts, and instruction fine-tuning in protein knowledge datasets. We demonstrate the efficacy of ProLLM through rigorous validation against benchmark datasets, showing significant improvement over existing methods in terms of prediction accuracy and generalizability. Our results highlight the potential of LLMs to transform the field of PPI, serving as a robust potential tool for various categories of biological and medical research. The code is available at: https://github.com/MingyuJ666/ProLLM.

bioinformatics↗

Lateral cell polarization drives organization of epithelia in sea anemone embryos and embryonic cell aggregates

One of the first organizing processes during animal development is the assembly of embryonic cells into epithelia. In certain animals, including Hydra and sea anemones, epithelia also emerge when cells from dissociated tissues are aggregated back together. Although cell adhesion is required to keep cells together, it is not clear whether cell polarization plays a role as epithelia emerge from disordered aggregates. Here, we demonstrate that lateral cell polarization is essential for epithelial organization in both embryos and aggregates of the sea anemone Nematostella vectensis. Specifically, knock down of the lateral polarity protein Lgl disrupts epithelia in developing embryos and impairs the capacity of dissociated cells to epithelialize from aggregates. Cells in lgl mutant epithelia lose their columnar shape and have mispositioned mitotic spindles and ciliary basal bodies. Together, our data suggest that in Nematostella, Lgl is required to establish lateral cell polarity and position cytoskeletal organelles in cells of embryos and aggregates during de novo epithelial organization.

developmental biology↗

The Genomes of Nematode-Trapping Fungi Provide Insights into the Origin and Diversification of Fungal Carnivorism

Nematode-trapping fungi (NTF), most of which belong to a monophyletic lineage in Ascomycota, cannibalize nematodes and other microscopic animals, raising questions regarding the types and mechanisms of genomic changes that enabled carnivorism and adaptation to the carbon-rich and nitrogen-poor environment created by the Permian-Triassic extinction event. Here, we conducted comparative genomic analyses of 21 NTF and 21 non-NTF to address these questions. Carnivorism-associated changes include expanded genes for nematode capture, infection, and consumption (e.g., adhesive proteins, CAP superfamily, eukaryotic aspartyl proteases, and serine-type peptidases). Although the link between secondary metabolite (SM) production and carnivorism remains unclear, we found that the numbers of SM gene clusters among NTF are significantly lower than those among non-NTF. Significantly expanded cellulose degradation gene families (GH5, GH7, AA9, and CBM1) and contracted genes for carbon-nitrogen hydrolases (enzymes that degrade organic nitrogen to ammonia) are likely associated with adaptation to the carbon-rich and nitrogen-poor environment. Through horizontal gene transfer events from bacteria, NTF acquired the Mur gene cluster (participating in synthesizing peptidoglycan of the bacterial cell wall) and Hyl (a virulence factor in animals). Disruption of MurE reduced NTFs ability to attract nematodes, supporting its role in carnivorism. This study provides new insights into how NTF evolved and diversified after the Permian-Triassic mass extinction event.

evolutionary biology↗

Novel Ser74 of NF-kappaB/CgIkappaBalpha Phosphorylated by MAPK/ERK Regulates Temperature Adaptation in Oysters

Phosphorylation of I{kappa}B at Ser32 and Ser36 by IKKs during biotic stress triggers its ubiquitin-proteasome degradation, causing to the nuclear translocation of REL, representing a key cascade mechanism in metazoans conserved and immune core signaling pathway, NF-{kappa}B. However, studies on its response to abiotic stress and signal transduction by phosphorylation in mollusks are lacking. Here, we firstly report a novel heat-induced phosphorylation site (Ser74) at the major NF-{kappa}B/CgI{kappa}B of oysters, phosphorylated by MAPK/CgERK1/2, which independently mediated the subsequent ubiquitin-proteasome degradation without phosphorylation at Ser32 and Ser36 and decreased thermal stability. The degradation of CgI{kappa}B promoted CgREL nuclear translocation, which stimulated cell survival related gene expression to defend against thermal stress. The MAPK and NF-{kappa}B pathways exhibited stronger activation patterns in higher environmental temperature and in the warm-adapted Crassostrea angulata than those in the cold-adapted C. gigas-two allopatric congeneric oyster species with differential habitat temperatures. These findings unveil the complex and unique phosphorylation-mediated signal transduction mechanisms in marine invertebrates, and further expand our understanding of the evolution and function of established classical pathway crosstalk mechanisms.

cell biology↗

Air-liquid interface exposure of A549 human lung cells to characterize the hazard potential of a gaseous bio-hybrid fuel blend

Gaseous and semi-volatile organic compounds emitted by the transport sector contribute to air pollution and have adverse effects on human health. To reduce harmful effects to the environment as well as to humans, renewable and sustainable bio-hybrid fuels are explored and investigated in the cluster of excellence "The Fuel Science Center" at RWTH Aachen University. However, data on the effects of bio-hybrid fuels on human health is scarce, leaving a data gap regarding their hazard potential. To help close this data gap, this study investigates potential toxic effects of a Ketone-Ester-Alcohol-Alkane (KEAA) fuel blend on A549 human lung cells. Experiments were performed using a commercially available air-liquid interface exposure system which was optimized beforehand. Then, cells were exposed at the air-liquid interface to 50-2000 ppm C3.7 of gaseous KEAA for 1 h. After a 24 h recovery period in the incubator metabolic activity and cytotoxicity of cells were assessed. Our data support the international occupational exposure limits of the single KEAA constituents and moreover indicate no adverse effect to A549 cells when exposed to a fuel mixture. This finding applies only to the exposure scenario tested in this study and is difficult to extrapolate to the complex in vivo situation.

pharmacology and toxicology↗