Specific Gene Expression Patterns Research Articles

Inheritance analysis of major lignan contents in Schisandra chinensis hybrid progeny

Schisandra chinensis (Turcz.) Baill. has been used in traditional Chinese medicine for more than 2000 years and is classified as a superior herb. To examine the inheritance of lignan content traits, we measured the contents of six lignan constituents in the fruit and stem of 142 individuals from the cross ‘Jinwuwei 1’ × ‘Zaohong’ for three successive years. The optimal genetic model for each trait was screened using a mixed major gene + polygene inheritance model. The lignan contents differed in degree of variation, with the annual average coefficient of variation ranging from 22.31% to 79.80% across the three years. Significant transgressive heterosis was observed for schisandrol B content both in the fruit and stem, whereas negative heterosis was detected for γ-schisandrin content both in the fruit and stem. The optimal genetic models were inconsistent among different lignans in the same organ and between different organs for the same lignan, which may be associated with specific gene expression patterns. The additive effects of the lignan contents were mostly positive, whereas the dominance effects were mainly negative. The results of this study provide a theoretical basis for quantitative trait locus mapping and marker-assisted breeding of lignan contents in S. chinensis.

The enriched expression of aquaporin-2 in the renal inner medulla is mediated by increased chromatin accessibility

Introduction: The osmotic gradient between renal cortex (CTX) and renal inner medulla (IM) is important for the generation of a concentrated urine. In addition, the unique hypertonic environment in the IM induces a specific gene expression pattern. For example the expression of aquaporin-2 (Aqp2) is enriched in the IM compared to CTX. We postulated that these changes must be associated with epigenetic mechanisms that could regulate the spatial expression pattern in CTX and IM. We performed assay for transposase-accessible chromatin (ATAC) sequencing to identify genomic regions with differences in accessibility in CTX and IM. Methods: We used kidneys from control mice and collecting duct principal cell specific nuclear factor of activated t cells (Nfat5)-KO mice and dissected CTX and IM. These samples were subjected for ATAC-seq analysis. Accessible genomic regions were identified with MACS2. We next compared differentially accessible regions between CTX and IM in control mice and between control and Nfat5-KO mice. The results were correlated with corresponding gene expression profiles that have been analyzed in a former study. Results: There are massive differences in the accessibility of genomic regions between CTX and IM. In CTX, more than 100,000 regions are differentially accessible compared to IM, with 48,698 regions having higher accessibility and 55,453 regions having lower accessibility. Genes with higher accessibility in CTX show also higher or even specific gene expression in CTX and vice versa. Since loss of NFAT5 is associated with a massive change in gene expression in kidneys from Nfat5-KO mice, we analyzed if this is affected by differences in chromatin accessibility. Our data shows that not only spatial localization in the kidney affects chromatin accessibility, but also the function of NFAT5. Loss of NFAT5 results in 10,456 regions with higher accessibility and 3,858 regions with closed chromatin in the CTX and 16,452 regions losing accessibility and 9,494 regions with increased accessibility in the IM. The accessibility of the Aqp2 gene is higher in IM compared with CTX. The open chromatin of the Aqp2 promoter region correlates with higher expression of Aqp2 in the IM. This suggests that hypertonicity leads to an improvement in the accessibility of the promoter region of Aqp2. In Nfat5-KO IM the accessibility of this region was decreased, which could explain the reduced Aqp2 expression in Nfat5-KO mice. Conclusions: To date, studying hypertonicity-dependent regulation of chromatin accessibility and associated gene expression in CTX and IM in the kidney were missing. Here we show that the differences in gene expression between CTX and IM might be due to changes in accessibility of genomic regions. We also show that the renal expression of Aqp2 might be a result of an epigenetic mechanism. In this context, NFAT5 was found to be an important regulator of chromatin accessibility and gene expression in the kidney. The authors have nothing to disclose. This project was funded by the Deutsche Forschungsgemeinschaft(ED181/9-3). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Bridging Genetic Insights with Neuroimaging in Autism Spectrum Disorder-A Systematic Review.

Autism Spectrum Disorder (ASD) is an early onset neurodevelopmental disorder characterized by impaired social interaction and communication, and repetitive patterns of behavior. Family studies show that ASD is highly heritable, and hundreds of genes have previously been implicated in the disorder; however, the etiology is still not fully clear. Brain imaging and electroencephalography (EEG) are key techniques that study alterations in brain structure and function. Combined with genetic analysis, these techniques have the potential to help in the clarification of the neurobiological mechanisms contributing to ASD and help in defining novel therapeutic targets. To further understand what is known today regarding the impact of genetic variants in the brain alterations observed in individuals with ASD, a systematic review was carried out using Pubmed and EBSCO databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review shows that specific genetic variants and altered patterns of gene expression in individuals with ASD may have an effect on brain circuits associated with face processing and social cognition, and contribute to excitation-inhibition imbalances and to anomalies in brain volumes.

Multi-omics analysis reveals the association between specific solute carrier proteins gene expression patterns and the immune suppressive microenvironment in glioma.

Glioma is the most prevalent malignant brain tumour. Currently, reshaping its tumour microenvironment has emerged as an appealing strategy to enhance therapeutic efficacy. As the largest group of transmembrane transport proteins, solute carrier proteins (SLCs) are responsible for the transmembrane transport of various metabolites and ions. They play a crucial role in regulating the metabolism and functions of malignant cells and immune cells within the tumour microenvironment, making them a promising target in cancer therapy. Through multidimensional data analysis and experimental validation, we investigated the genetic landscape of SLCs in glioma. We established a classification system comprising 7-SLCs to predict the prognosis of glioma patients and their potential responses to immunotherapy and chemotherapy. Our findings unveiled specific SLC expression patterns and their correlation with the immune-suppressive microenvironment and metabolic status. The 7-SLC classification system was validated in distinguishing subgroups within the microenvironment, specifically identifying subsets involving malignant cells and tumour-associated macrophages. Furthermore, the orphan protein SLC43A3, a core member of the 7-SLC classification system, was identified as a key facilitator of tumour cell proliferation and migration, suggesting its potential as a novel target for cancer therapy.

Conserved and specific gene expression patterns in the embryonic development of tardigrades.

Tardigrades, commonly known as water bears, are enigmatic organisms characterized by their remarkable resilience to extreme environments despite their simple and compact body structure. To date, there is still much to understand about their evolutionary and developmental features contributing to their special body plan and abilities. This research provides preliminary insights on the conserved and specific gene expression patterns during embryonic development of water bears, focusing on the species Hypsibius exemplaris. The developmental dynamic expression analysis of the genes with various evolutionary age grades indicated that the mid-conserved stage of H. exemplaris corresponds to the period of ganglia and midgut development, with the late embryonic stage showing a transition from non-conserved to conserved state. Additionally, a comparison with Drosophila melanogaster highlighted the absence of certain pathway nodes in development-related pathways, such as Maml and Hairless, which are respectively the transcriptional co-activator and co-repressor of NOTCH regulated genes. We also employed Weighted Gene Co-expression Network Analysis (WGCNA) to investigate the expression patterns of tardigrade-specific genes during embryo development. Our findings indicated that the module containing the highest proportion of tardigrade-specific genes (TSGs) exhibits high expression levels before the mid-conserved stage, potentially playing a role in glutathione and lipid metabolism. These functions may be associated to the ecdysone synthesis and storage cell formation, which is unique to tardigrades.

Selection of reliable reference genes for gene expression studies involving peripheral blood mononuclear cells in small ruminants

Quantitative PCR (qPCR) is a highly sensitive, cost effective, and routinely used molecular assay for analyzing the gene expression patterns of specific target genes across tissues, pathological conditions, treatment regimes, and physiological states. However, normalization of expression profiles of target genes using stable reference genes (RGs) is a critical step to ensure the accuracy of relative quantification using qPCR. In this study, we evaluated the stability of fourteen potential existing reference genes (ACTB, BACH1, B2M, GAPDH, HMBS, PGK1, PPIA, PPIB, RPLP0, RPL19, RPS9, RPS15, RPS28, and UXT) in the peripheral blood mononuclear cells (PBMCs) of healthy sheep and goats to determine the most stable RGs. These candidate genes belong to different functional classes and were chosen based on published literature on commonly used RGs in different livestock species. Four different analytical approaches (geNorm, NormFinder, BestKeeper, and ΔCt analysis) as well as RefFinder, an online tool which integrates the geometric means of these four prominent stability algorithms were utilized to determine a comprehensive ranking of the investigated genes. Our data indicates that PPIB, BACH1, ACTB, and PPIA are the most suitable RGs, while RPLP0, GAPDH and RPS15 are the most variable and unsuitable genes for normalization of qPCR data in the PBMCs of sheep and goats. The results of this study provide useful resource for researchers engaged in unravelling the transcriptional landscape of PBMCs of small ruminants for various scientific investigations.

Differentially Expressed Genes in Atopic Dermatitis: Bioinformatics analysis of pooled microarray gene expression datasets in Gene Expression Omnibus

Introduction:
 Atopic dermatitis (AD) is a chronic and refractory inflammatory skin disease characterized by relapsing eczematous and pruritic skin lesions. Understanding the specific gene expression patterns associated with AD is crucial for advancing diagnosis and targeted treatment development. Using bioinformatics methods, candidate genes and biological pathways involved in AD pathogenesis were identified based on gene expression profiles in the Gene Expression Omnibus (GEO) database.
 Materials and Methods:
 A comprehensive analysis of four pooled transcriptomic datasets obtained from the Gene Expression Omnibus (GEO) database were conducted. Differential gene expression analysis was performed using the GEO2R. The differentially expressed genes (DEGs) between lesion skin of AD patients and normal skin of individuals were analyzed using the Gene Ontology (GO) term enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein-protein interaction (PPI) network to explore the functional roles of these genes.
 Results:
 Among the patient-level gene expression datasets, we identified 133 shared DEGs, consisting of 48 upregulated genes and 85 downregulated genes. GO analyses revealed these DEGs to be significantly enriched in biological processes including inflammatory responses, cytokine-mediated signaling pathway. These DEGs were also enriched in the KEGG pathway, including viral protein interaction with cytokine and cytokine receptor, C-type lectin receptor signaling pathway, cytokine-cytokine receptor interaction, JAK-STAT signaling pathway, and Adipocytokine signaling pathway.
 Conclusion:
 By comparing with other studies using the same method, we found that in addition to the already confirmed pathways such as inflammatory response, different studies have found changes in different hub genes and metabolic pathways, which prompts us to develop individualized treatments for AD.

General and specific patterns of cortical gene expression as spatial correlates of complex cognitive functioning.

Gene expression varies across the brain. This spatial patterning denotes specialised support for particular brain functions. However, the way that a given gene's expression fluctuates across the brain may be governed by general rules. Quantifying patterns of spatial covariation across genes would offer insights into the molecular characteristics of brain areas supporting, for example, complex cognitive functions. Here, we use principal component analysis to separate general and unique gene regulatory associations with cortical substrates of cognition. We find that the region-to-region variation in cortical expression profiles of 8235 genes covaries across two major principal components: gene ontology analysis suggests these dimensions are characterised by downregulation and upregulation of cell-signalling/modification and transcription factors. We validate these patterns out-of-sample and across different data processing choices. Brain regions more strongly implicated in general cognitive functioning (g; 3 cohorts, total meta-analytic N = 39,519) tend to be more balanced between downregulation and upregulation of both major components (indicated by regional component scores). We then identify a further 29 genes as candidate cortical spatial correlates of g, beyond the patterning of the two major components (|β| range = 0.18 to 0.53). Many of these genes have been previously associated with clinical neurodegenerative and psychiatric disorders, or with other health-related phenotypes. The results provide insights into the cortical organisation of gene expression and its association with individual differences in cognitive functioning.

Transcriptomic Insights and Cytochrome P450 Gene Analysis in Kadsura coccinea for Lignan Biosynthesis.

Kadsura coccinea is a medicinal plant from the Schisandraceae family that is native to China and has great pharmacological potential due to its lignans. However, there are significant knowledge gaps regarding the genetic and molecular mechanisms of lignans. We used transcriptome sequencing technology to analyze root, stem, and leaf samples, focusing on the identification and phylogenetic analysis of Cytochrome P450 (CYP) genes. High-quality data containing 158,385 transcripts and 68,978 unigenes were obtained. In addition, 36,293 unigenes in at least one database, and 23,335 across five databases (Nr, KEGG, KOG, TrEMBL, and SwissProt) were successfully annotated. The KEGG pathway classification and annotation of these unigenes identified 10,825 categorized into major metabolic pathways, notably phenylpropanoid biosynthesis, which is essential for lignan synthesis. A key focus was the identification and phylogenetic analysis of 233 Cytochrome P450 (CYP) genes, revealing their distribution across 38 families in eight clans, with roots showing specific CYP gene expression patterns indicative of their role in lignan biosynthesis. Sequence alignment identified 22 homologous single genes of these CYPs, with 6 homologous genes of CYP719As and 1 of CYP81Qs highly expressed in roots. Our study significantly advances the understanding of the biosynthesis of dibenzocyclooctadiene lignans, offering valuable insights for future pharmacological research and development.

Nitrogen Nutrition Modulates the Response to Alternaria brassicicola Infection via Metabolic Modifications in Arabidopsis Seedlings.

Little is known about the effect of nitrogen nutrition on seedling susceptibility to seed-borne pathogens. We have previously shown that seedlings grown under high nitrate (5 mM) conditions are less susceptible than those grown under low nitrate (0.1 mM) and ammonium (5 mM) in the Arabidopsis-Alternaria brassicicola pathosystem. However, it is not known how seedling metabolism is modulated by nitrogen nutrition, nor what is its response to pathogen infection. Here, we addressed this question using the same pathosystem and nutritive conditions, examining germination kinetics, seedling development, but also shoot ion contents, metabolome, and selected gene expression. Nitrogen nutrition clearly altered the seedling metabolome. A similar metabolomic profile was observed in inoculated seedlings grown at high nitrate levels and in not inoculated-seedlings. High nitrate levels also led to specific gene expression patterns (e.g., polyamine metabolism), while other genes responded to inoculation regardless of nitrogen supply conditions. Furthermore, the metabolites best correlated with high disease symptoms were coumarate, tyrosine, hemicellulose sugars, and polyamines, and those associated with low symptoms were organic acids (tricarboxylic acid pathway, glycerate, shikimate), sugars derivatives and β-alanine. Overall, our results suggest that the beneficial effect of high nitrate nutrition on seedling susceptibility is likely due to nutritive and signaling mechanisms affecting developmental plant processes detrimental to the pathogen. In particular, it may be due to a constitutively high tryptophan metabolism, as well as down regulation of oxidative stress caused by polyamine catabolism.

Spatial transcriptomics reveals alterations in perivascular macrophage lipid metabolism in the onset of Wooden Breast myopathy in broiler chickens

This study aims to use spatial transcriptomics to characterize the cell-type-specific expression profile associated with the microscopic features observed in Wooden Breast myopathy. 1 cm3 muscle sample was dissected from the cranial part of the right pectoralis major muscle from three randomly sampled broiler chickens at 23 days post-hatch and processed with Visium Spatial Gene Expression kits (10X Genomics), followed by high-resolution imaging and sequencing on the Illumina Nextseq 2000 system. WB classification was based on histopathologic features identified. Sequence reads were aligned to the chicken reference genome (Galgal6) and mapped to histological images. Unsupervised K-means clustering and Seurat integrative analysis differentiated histologic features and their specific gene expression pattern, including lipid laden macrophages (LLM), unaffected myofibers, myositis and vasculature. In particular, LLM exhibited reprogramming of lipid metabolism with up-regulated lipid transporters and genes in peroxisome proliferator-activated receptors pathway, possibly through P. Moreover, overexpression of fatty acid binding protein 5 could enhance fatty acid uptake in adjacent veins. In myositis regions, increased expression of cathepsins may play a role in muscle homeostasis and repair by mediating lysosomal activity and apoptosis. A better knowledge of different cell-type interactions at early stages of WB is essential in developing a comprehensive understanding.

Transcriptomic Analysis of Type 2 Diabetes Mellitus Combined with Lower Extremity Atherosclerotic Occlusive Disease.

The pathological damage mechanism of type 2 diabetes (T2D) and macroangiopathy is extremely complex, and T2D and arteriosclerosis obliterans have different biological behaviors and clinical features. To explore the mechanism of lower extremity arteriosclerosis occlusion (LEAOD) in T2D patients, we utilized RNA-seq to identify unique gene expression signatures of T2D and LEAOD through transcriptomic analysis. We obtained blood samples and performed RNA sequencing from four patients with T2D, five of whom had LEAOD. Another six age- and gender-matched blood samples from healthy volunteers were used for control. By exploring the general and specific differential expression analysis after transcriptome sequencing, specific gene expression patterns of T2D and LEAOD were verified. Transcriptome analysis found differentially expressed genes in T2D, and T2D + LEAOD (vs normal) separately, of which 35/486 (T2D/T2D + LEAOD) were up-regulated and 1290/2970 (T2D/T2D + LEAOD) were down-regulated. A strong overlap of 571 genes across T2D, LEAOD, and coexisting conditions was mainly involved in extracellular exosomes and the transcription process. By exploring the sex difference gene expression features between T2D, T2D + LEAOD, and healthy controls, we noticed that sex chromosome-associated genes do not participate in the sexual dimorphism gene expression profiles of T2D and LEAOD. Protein-Protein Interaction Network analysis and drug target prediction provided the drug candidates to treat T2D and LEAOD. This study provides some evidence at the transcript level to uncover the association of T2D with LEAOD. The screened hub genes and predicted target drugs may be therapeutic targets.

Advances in the role of the GADD45 family in neurodevelopmental, neurodegenerative, and neuropsychiatric disorders

The growth arrest and DNA damage inducible protein 45 (GADD45) family comprises stress-induced nuclear proteins that interact with DNA demethylases to facilitate DNA demethylation, thereby regulating diverse cellular processes including oxidative stress, DNA damage repair, apoptosis, proliferation, differentiation, inflammation, and neuroplasticity by modulating the expression patterns of specific genes. Widely expressed in the central nervous system, the GADD45 family plays a pivotal role in various neurological disorders, rendering it a potential therapeutic target for central nervous system diseases. This review presented a comprehensive overview of the expression patterns and potential mechanisms of action associated with each member of GADD45 family (GADD45α, GADD45β, and GADD45γ) in neurodevelopmental, neurodegenerative, and neuropsychiatric disorders, while also explored strategies to harness these mechanisms for intervention and treatment. Future research should prioritize the development of effective modulators targeting the GADD45 family for clinical trials aimed at treating central nervous system diseases.

BiGATAE: a bipartite graph attention auto-encoder enhancing spatial domain identification from single-slice to multi-slices.

Recent advancements in spatial transcriptomics technology have revolutionized our ability to comprehensively characterize gene expression patterns within the tissue microenvironment, enabling us to grasp their functional significance in a spatial context. One key field of research in spatial transcriptomics is the identification of spatial domains, which refers to distinct regions within the tissue where specific gene expression patterns are observed. Diverse methodologies have been proposed, each with its unique characteristics. As the availability of spatial transcriptomics data continues to expand, there is a growing need for methods that can integrate information from multiple slices to discover spatial domains. To extend the applicability of existing single-slice analysis methods to multi-slice clustering, we introduce BiGATAE (Bipartite Graph Attention Auto Encoder) that leverages gene expression information from adjacent tissue slices to enhance spatial transcriptomics data. BiGATAE comprises two steps: aligning slices to generate an adjacency matrix for different spots in consecutive slices and constructing a bipartite graph. Subsequently, it utilizes a graph attention network to integrate information across different slices. Then it can seamlessly integrate with pre-existing techniques. To evaluate the performance of BiGATAE, we conducted benchmarking analyses on three different datasets. The experimental results demonstrate that for existing single-slice clustering methods, the integration of BiGATAE significantly enhances their performance. Moreover, single-slice clustering methods integrated with BiGATAE outperform methods specifically designed for multi-slice integration. These results underscore the proficiency of BiGATAE in facilitating information transfer across multiple slices and its capacity to broaden the applicability and sustainability of pre-existing methods.

Development and validation of epigenetic modification-related signals for the diagnosis and prognosis of colorectal cancer

BackgroundColorectal cancer (CRC) is one of the world's most common malignancies. Epigenetics is the study of heritable changes in characteristics beyond the DNA sequence. Epigenetic information is essential for maintaining specific expression patterns of genes and the normal development of individuals, and disorders of epigenetic modifications may alter the expression of oncogenes and tumor suppressor genes and affect the development of cancer. This study elucidates the relationship between epigenetics and the prognosis of CRC patients by developing a predictive model to explore the potential value of epigenetics in the treatment of CRC.MethodsGene expression data of CRC patients’ tumor tissue and controls were downloaded from GEO database. Combined with the 720 epigenetic-related genes (ERGs) downloaded from EpiFactors database, prognosis-related epigenetic genes were selected by univariate cox and LASSO analyses. The Kaplan–Meier and ROC curve were used to analyze the accuracy of the model. Data of 238 CRC samples with survival data downloaded from the GSE17538 were used for validation. Finally, the risk model is combined with the clinical characteristics of CRC patients to perform univariate and multivariate cox regression analysis to obtain independent risk factors and draw nomogram. Then we evaluated the accuracy of its prediction by calibration curves.ResultsA total of 2906 differentially expressed genes (DEGs) were identified between CRC and control samples. After overlapping DEGs with 720 ERGs, 56 epigenetic-related DEGs (DEERGs) were identified. Combining univariate and LASSO regression analysis, the 8 epigenetic-related genes-based risk score model of CRC was established. The ROC curves and survival difference of high and low risk groups revealed the good performance of the risk score model based on prognostic biomarkers in both training and validation sets. A nomogram with good performance to predict the survival of CRC patients were established based on age, NM stage and risk score. The calibration curves showed that the prognostic model had good predictive performance.ConclusionIn this study, an epigenetically relevant 8-gene signature was constructed that can effectively predict the prognosis of CRC patients and provide potential directions for targeted therapies for CRC.

How Oratosquilla oratoria compound eye response to the polarization of light: In the perspective of vision genes and related proteins

The special rhabdom structure of the mid-band ommatidium in compound eye contributes to the mantis shrimp being the only animal species known to science that can recognize circularly polarized light (CPL). Although the number of mid-band ommatidium of Oratosquilla oratoria is reduced, the mid-band ommatidium still has orthogonal geometric interleaved rhabdom and short oval distal rhabdom, which may mean that the O. oratoria has weakened circular polarized light vision (CPLV). Here we explored the molecular mechanisms of how O. oratoria response to the polarization of light. Based on the specific expression patterns of vision-related functional genes and proteins, we suggest that the order of light response by O. oratoria compound eye was first natural light, then left-circularly polarized light (LCPL), linearly polarized light, right-circularly polarized light (RCPL) and dark. Meanwhile, we found that the expression levels of vision-related functional genes and proteins in O. oratoria compound eye under RCPL were not significantly different from those in DL, which may imply that O. oratoria cannot respond to RCPL. Furthermore, the response of LCPL is likely facilitated by the differential expression of opsin and microvilli - related functional genes and proteins (arrestin and sodium-coupled neutral amino acid transporter). In conclusion, this study systematically illustrated for the first time how O. oratoria compound eye response to the polarization of light at the genetic level, and it can improve the visual ecological theory behind polarized light vision evolution.

Identification of prognostic coagulation-related signatures in clear cell renal cell carcinoma through integrated multi-omics analysis and machine learning

Clear cell renal cell carcinoma is a threat to public health with high morbidity and mortality. Clinical evidence has shown that cancer-associated thrombosis poses significant challenges to treatments, including drug resistance and difficulties in surgical decision-making in ccRCC. However, the coagulation pathway, one of the core mechanisms of cancer-associated thrombosis, recently found closely related to the tumor microenvironment and immune-related pathway, is rarely researched in ccRCC. Therefore, we integrated bulk RNA-seq data, DNA mutation and methylation data, single-cell data, and proteomic data to perform a comprehensive analysis of coagulation-related genes in ccRCC. First, we demonstrated the importance of the coagulation-related gene set by consensus clustering. Based on machine learning, we identified 5 coagulation signature genes and verified their clinical value in TCGA, ICGC, and E-MTAB-1980 databases. It's also demonstrated that the specific expression patterns of coagulation signature genes driven by CNV and methylation were closely correlated with pathways including apoptosis, immune infiltration, angiogenesis, and the construction of extracellular matrix. Moreover, we identified two types of tumor cells in single-cell data by machine learning, and the coagulation signature genes were differentially expressed in two types of tumor cells. Besides, the signature genes were proven to influence immune cells especially the differentiation of T cells. And their protein level was also validated.

A Call for Gene Expression Analysis in Whole Blood of Patients With Rheumatoid Arthritis (RA) as a Biomarker for RA-Associated Interstitial Lung Disease.

Rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) is one of the most common and prognostic organ manifestations of RA. Therefore, to allow effective treatment, it is of crucial importance to diagnose RA-ILD at the earliest possible stage. So far, the gold standard of early detection has been high-resolution computed tomography (HRCT) of the lungs. This procedure involves considerable radiation exposure for the patient and is therefore unsuitable as a routine screening measure for ethical reasons. Here, we propose the analysis of characteristic gene expression patterns as a biomarker to aid in the early detection and initiation of appropriate, possibly antifibrotic, therapy. To investigate unique molecular patterns of RA-ILD, whole blood samples were taken from 12 female patients with RA-ILD (n = 7) or RA (n = 5). The RNA was extracted, sequenced by RNA-Seq, and analyzed for characteristic differences in the gene expression patterns between patients with RA-ILD and those with RA without ILD. The differential gene expression analysis revealed 9 significantly upregulated genes in RA-ILD compared to RA without ILD: arginase 1 (ARG1), thymidylate synthetase (TYMS), sortilin 1 (SORT1), marker of proliferation Ki-67 (MKI67), olfactomedin 4 (OLFM4), baculoviral inhibitor of apoptosis repeat containing 5 (BIRC5), membrane spanning 4-domains A4A (MS4A4A), C-type lectin domain family 12 member A (CLEC12A), and the long intergenic nonprotein coding RNA (LINC02967). All gene products of these genes (except for LINC02967) are known from the literature to be involved in the pathogenesis of fibrosis. Further, for some, a contribution to the development of pulmonary fibrosis has even been demonstrated in experimental studies. Therefore, the results presented here provide an encouraging perspective for using specific gene expression patterns as biomarkers for the early detection and differential diagnosis of RA-ILD as a routine screening test.

DDX41-Low Expression Mimics Germline DDX41-Phenotype in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a complex disease characterized by diverse molecular pathogenesis. Genetic alterations, including germline and somatic variants in the DEAD box helicase 41 gene ( DDX41) located on chromosome 5 play an increasingly recognized role. Recent reports indicate that 5% of intensively treated adult AML patients harbor DDX41 germline mutations ( DDX41MutGL), and their precise impact remains incompletely understood. These studies suggest that DDX41MutGL may define a distinct biological subgroup, associated with e.g. older age, male gender, low blast, and low white blood cell count (WBC). To further elucidate the role of DDX41 in AML, we performed a retrospective analysis of 906 unselected adult AML patients from the AML Cooperative Group (AMLCG) registry (2015-2022), by targeted sequencing. As DDX41MutGL are typically “null mutations”, leading to reduced DDX41 expression, we additionally investigated whether DDX41 gene expression correlates or resembles the observed germline phenotype. Our analysis encompassed >1000 independent gene expression profiles (GSE37642, GSE14468, and GSE106291) of intensively treated adult AML patients. We identified a sub-cohort with low DDX41 ( DDX41-low) expression and re-analyzed them with next-generation sequencing to detect DDX41MutGL. Additionally, we correlated gene expression data with 198 DNA methylation profiles (from patients who had undergone both analyses) to identify potential epigenetic mechanisms underlying DDX41-low expression. Among the 906 patients (median age 61 years; range 18-98 years), we identified 11 unrelated individuals with suspected DDX41MutGL (VAF > 40%). Notably, the overall frequency of DDX41MutGL in the German unselected AML patient population was merely 1%, considerably lower than previously reported (p<0.0001 in comparison to Duployez et al. 2022). Characteristically, DDX41MutGL patients in this cohort were mostly male (73%), with a median age of 67 years displaying low WBC (average 1,3G/l) and a normal karyotype (80%) at initial diagnosis. Remarkably, our analysis of independent large gene expression cohorts revealed a pattern of phenotypic association in patients with decreased DDX41 expression ( DDX41-low) closely resembling those with DDX41MutGL. These associations were consistent across different datasets and included e.g. older age, low WBC, and low blast count. Furthermore, DDX41-low patients had poor overall survival. The DDX41-low subgroup constituted almost 10% of all AML patients, surpassing the reported frequencies of DDX41MutGL. In an exploratory pilot study, we screened 48 patients exhibiting the lowest DDX41 gene expression by sequencing the coding regions for DDX41 mutations but found none, suggesting alternative mechanisms, such as copy number changes, non-coding alterations or aberrant DNA methylation patterns that may replicate the phenotypic effects associated with DDX41MutGL. To further elucidate this mechanism, we correlated the gene expression of DDX41 with all DNA methylation loci (CpG sites covered by the EPIC array) on chromosome 5 using Spearman correlation analysis (GSE106291). We plotted the correlations against the sorted chromosome length, identifying a peak at a specific location corresponding to the PCDH (Protocadherin) cluster (Figure). Thus, DDX41-low was associated with reduced methylation at the PCDH loci and linked to higher PCDH gene expression. Across several data sets, we confirmed the association between higher PCDH cluster gene expression and low DDX41 expression. In summary, our study reveals that the frequency of DDX41MutGL in an unselected population of German AML patients is considerably lower than previously reported. Additionally, we found that apart from DDX41MutGL, DDX41-low exhibits a comparable clinical profile and is linked to specific methylation and gene expression patterns, with a notable emphasis on the PCDH complex located on chromosome 5. Understanding the functional implications of PCDH genes and their interaction with DDX41 in AML may significantly advance our knowledge of AML pathogenesis. Gaining insights into DDX41 alterations may open avenues for personalized therapeutic approaches and further prognostic stratification for AML patients with distinct molecular characteristics.

Expansion of CD4+ cytotoxic T lymphocytes with specific gene expression patterns may contribute to suppression of tumor immunity in oral squamous cell carcinoma: single-cell analysis and in vitro experiments.

Cancer immunotherapy targeting CD8+ T cells has made remarkable progress, even for oral squamous cell carcinoma (OSCC), a heterogeneous epithelial tumor without a substantial increase in the overall survival rate over the past decade. However, the therapeutic effects remain limited due to therapy resistance. Thus, a more comprehensive understanding of the roles of CD4+ T cells and B cells is crucial for more robust development of cancer immunotherapy. In this study, we examined immune responses and effector functions of CD4+ T cells, CD8+ T cells and B cells infiltrating in OSCC lesions using single-cell RNA sequencing analysis, T cell receptor (TCR) and B cell receptor (BCR) repertoire sequencing analysis, and multi-color immunofluorescence staining. Finally, two Kaplan-Meier curves and several Cox proportional hazards models were constructed for the survival analysis. We observed expansion of CD4+ cytotoxic T lymphocytes (CTLs) expressing granzymes, which are reported to induce cell apoptosis, with a unique gene expression patterns. CD4+ CTLs also expressed CXCL13, which is a B cell chemoattractant. Cell-cell communication analysis and multi-color immunofluorescence staining demonstrated potential interactions between CD4+ CTLs and B cells, particularly IgD- CD27- double negative (DN) B cells. Expansion of CD4+ CTLs, DN B cells, and their contacts has been reported in T and B cell-activated diseases, including IgG4-related disease and COVID-19. Notably, we observed upregulation of several inhibitory receptor genes including CTLA-4 in CD4+ CTLs, which possibly dampened T and B cell activity. We next demonstrated comprehensive delineation of the potential for CD8+ T cell differentiation towards dysfunctional states. Furthermore, prognostic analysis revealed unfavorable outcomes of patients with a high proportion of CD4+ CTLs in OSCC lesions. Our study provides a dynamic landscape of lymphocytes and demonstrates a systemic investigation of CD4+ CTL effects infiltrating into OSCC lesions, which may share some pathogenesis reported in severe T and B cell-activated diseases such as autoimmune and infectious diseases.