Leukocyte Chemotaxis Research Articles

Structural Basis for Chemerin Recognition and Signaling Through Its Receptors

Chemerin is a chemotactic adipokine that participates in a multitude of physiological processes, including adipogenesis, leukocyte chemotaxis, and neuroinflammation. Chemerin exerts biological functions through binding to one or more of its G protein-coupled receptors (GPCRs), namely chemokine-like receptor 1 (CMKLR1), G protein-coupled receptor 1 (GPR1), and CC-motif receptor-like 2 (CCRL2). Of these receptors, CMKLR1 and GPR1 have been confirmed as signaling receptors of chemerin, whereas CCRL2 serves as a chemerin-binding protein without transmembrane signaling. High-resolution structures of two chemerin receptors are now available thanks to recent advancements in structure biology. This review focuses on the structural perspectives of the chemerin receptors with an emphasis on the structure–activity correlation, including key components of the two receptors for ligand recognition and conformational changes induced by chemerin and its derivative peptides for G protein activation. There are also comparisons between the two chemerin receptors and selected GPCRs with peptide ligands for better appreciation of the shared and distinct features of the chemerin receptors in ligand recognition and transmembrane signaling, and in the evolution of this subclass of GPCRs.

Unravel novel therapeutic targets in heart failure and associated pulmonary hypertension

Abstract Background Heart Failure (HF) is a complex clinical syndrome with poor prognosis. Pulmonary hypertension (PH) often complicates HF but can hardly be addressed therapeutically. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) improve cardiovascular outcomes in patients with HF. Whether SGLT2i positively impact on HF-associated PH is poorly understood. Omics offer great promise in the discovery of novel biomarkers and therapeutic targets for HF and PH. Aims We investigated novel markers associated with HF and PH, as well as how these biomarkers vary in response to HF-modyfing therapies, including SGLT2i. We also explored the impact of SGLT2i, compared with conventional anti-HF therapy, on HF-associated PH and right ventricular function. Methods Seventy-four patients with HF and reduced ejection fraction (HFrEF) with/without diabetes were divided into a gliflozin (G)-group receiving 10 mg/day empagliflozin or dapagliflozin, and a control (C)-group receiving conventional anti-HF therapy. Resting echocardiography, analyses on senescence markers [leucocyte telomere length (LTL), mitochondrial DNA copy number (mtDNAcn)], as well as measurement of two microRNAs (miRNA-21 and miRNA-92, recently implicated in response to treatment in HFpEF patients), were performed. Shotgun proteomic analyses were conducted on peripheral blood mononuclear cells. Results Compared to group C, group G had a significantly higher ejection fraction (EF, 42±13 vs 33±8, p=0.001), reduced left ventricular filling pressures (11±3 vs 15±5, p=0.001), reduced pulmonary artery systolic pressure (PAPs, 31±11 vs 46±15, p=0.001), better right ventricular-pulmonary artery coupling index (0.64±0.31 vs 0.44±0.22, p=0.002), increased LTL (Figure 1 A), higher mtDNAcn (Figure 1 B), reduced miRNA-21 levels (Figure 1 C) and no significant changes of miRNA-92 (Figure 1 D). Functional proteomic analysis showed that, compared with the C-group, the protein cargo from the G-group was able to trigger several biological pathways, showing a significant activation of T lymphocytes immune response (p-value=9.67x10-06, z-score=2.21) chemotaxis of monocytes (p-value=9.39x10-07, z-score=2.0), leukocytes (p-value=9.67x10-10, z-score=2.0)and phagocytes (p-value)=3.10x10-10, z-score=2.03) (Figure 2). Compared with the C-group, the G-group showed a downregulation of activin signaling pathway (z-score=-2.12), which is a novel therapeutic target in pulmonary arterial hypertension (PAH). Conclusions In HF patients, SGLT2i therapy is associated with improved left ventricular function and improved pulmonary hemodynamics. Activin is overactive in HF patients and its serum levels may be reduced by SGLT2i. SGLT2i may preserve LTL and mtDNA-cn as well as modulate the expression of specific miRNA implied in the regulation of endothelial function. SGLT2i may represent an additional therapeutic tool in patients with HF-associated PH, an area with no approved treatment options beyond traditional HF therapy.Figure 1:genomic analysesFigure 2:proteomic analyses

Computational Identification of Migrating T cells in Spatial Transcriptomics Data.

T cells are the central players in antitumor immunity, and effective tumor killing depends on their ability to infiltrate into the tumor microenvironment (TME) while maintaining normal cytotoxicity. However, late-stage tumors develop immunosuppressive mechanisms that impede T cell movement and induce exhaustion. Investigating T cell migration in human tumors in vivo could provide novel insights into tumor immune escape, although it remains a challenging task. In this study, we developed ReMiTT, a computational method that leverages spatial transcriptomics data to track T cell migration patterns within tumor tissue. Applying ReMiTT to ovarian tumor samples, we identified key genes and pathways that enriched on algorithm-identified T cell migration trails, including leukocyte chemotaxis, cell-cell adhesion, and ECM remodeling. We also characterized the phenotypes of T cells on the migrating trails, suggesting that regulatory T cells may accompany cytotoxic T cells during migration. Our findings provide a novel approach to studying T cell migration and interactions within the TME, offering new insights into tumor-immune dynamics.

Extracellular vesicles in sepsis plasma mediate neuronal inflammation in the brain through miRNAs and innate immune signaling

BackgroundNeuroinflammation reportedly plays a critical role in the pathogenesis of sepsis-associated encephalopathy (SAE). We previously reported that circulating plasma extracellular vesicles (EVs) from septic mice are proinflammatory. In the current study, we tested the role of sepsis plasma EVs in neuroinflammation.MethodsTo track EVs in cells and tissues, HEK293T cell-derived EVs were labeled with the fluorescent dye PKH26. Cecal ligation and puncture (CLP) was conducted to model polymicrobial sepsis in mice. Plasma EVs were isolated by ultracentrifugation and their role in promoting neuronal inflammation was tested following intracerebroventricular (ICV) injection. miRNA inhibitors (anti-miR-146a, -122, -34a, and -145a) were applied to determine the effects of EV cargo miRNAs in the brain. A cytokine array was performed to profile microglia-released protein mediators. TLR7- or MyD88-knockout (KO) mice were utilized to determine the underlying mechanism of EVs-mediated neuroinflammation.ResultsWe observed the uptake of fluorescent PKH26-EVs inside the cell bodies of both microglia and neurons. Sepsis plasma EVs led to a dose-dependent cytokine release in cultured microglia, which was partially attenuated by miRNA inhibitors against the target miRNAs and in TLR7-KO cells. When administered via the ICV, sepsis plasma EVs resulted in a marked increase in the accumulation of innate immune cells, including monocyte and neutrophil and cytokine gene expression, in the brain. Although sepsis plasma EVs had no direct effect on cytokine production or neuronal injury in vitro, the conditioned media (CM) of microglia treated with sepsis plasma EVs induced neuronal cell death as evidenced by increased caspase-3 cleavage and Annexin-V staining. Cytokine arrays and bioinformatics analysis of the microglial CM revealed multiple cytokines/chemokines and other factors functionally linked to leukocyte chemotaxis and migration, TLR signaling, and neuronal death. Moreover, sepsis plasma EV-induced brain inflammation in vivo was significantly dependent on MyD88.ConclusionsCirculating plasma EVs in septic mice cause a microglial proinflammatory response in vitro and a brain innate immune response in vivo, some of which are in part mediated by TLR7 in vitro and MyD88 signaling in vivo. These findings highlight the importance of circulating EVs in brain inflammation during sepsis.

Leveraging single-cell transcriptomic data to uncover immune suppressive cancer cell subsets in triple-negative canine breast cancers.

Single-cell RNA sequencing (scRNA-seq) has become an essential tool for uncovering the complexities of various physiological and immunopathological conditions in veterinary medicine. However, there is currently limited information on immune-suppressive cancer subsets in canine breast cancers. In this study, we aimed to identify and characterize immune-suppressive subsets of triple-negative canine breast cancer (TNBC) by utilizing integrated scRNA-seq data from published datasets. Published scRNA-seq datasets, including data from six groups of 30 dogs, were subjected to integrated bioinformatic analysis. Immune modulatory TNBC subsets were identified through functional enrichment analysis using immune-suppressive gene sets, including those associated with anti-inflammatory and M2-like macrophages. Key immune-suppressive signaling, such as viral infection, angiogenesis, and leukocyte chemotaxis, was found to play a role in enabling TNBC to evade immune surveillance. In addition, interactome analysis revealed significant interactions between distinct subsets of cancer cells and effector T cells, suggesting potential T-cell suppression. The present study demonstrates a versatile and scalable approach to integrating and analyzing scRNA-seq data, which successfully identified immune-modulatory subsets of canine TNBC. It also revealed potential mechanisms through which TNBC promotes immune evasion in dogs. These findings are crucial for advancing the understanding of the immune pathogenesis of canine TNBC and may aid in the development of new immune-based therapeutic strategies.

Differential expression of plasma cytokines in sepsis patients and their clinical implications.

Sepsis, which is characterized by acute systemic inflammation and is associated with high rates of morbidity and mortality, presents a significant challenge in health care. Some scholars have found that the sequential organ failure assessment (SOFA) and quick SOFA scores are not ideal for predicting severe sepsis and mortality. Microbial culture takes a long time (2-3 d) and provides no information for early diagnosis and treatment. Therefore, new diagnostic methods for sepsis need to be explored. To assess cytokine levels in the plasma of sepsis patients and identify potential biomarkers for diagnosing sepsis. Ten sepsis patients admitted to the emergency department within 24 h of onset were enrolled as the observation group, whereas ten noninfected patients served as the control group. Of the 10 noninfected patients, 9 hypertension combined with cerebral infarction, 1 patients with vertiginous syndrome. Plasma Cytokines were measured using the Bio-Plex Pro™ Human Chemokine Panel 40-plex. Differentially expressed cytokines in plasma of sepsis and nonsepsis patients were analyzed using Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Interleukin (IL)-16, granulocyte-macrophage granulocyte-macrophage colony-stimulating factor (GM-CSF), CX3CL1, CXCL9, CXCL16, CCL25, and CCL23 plasma levels were significantly increased in sepsis patients. GO analysis revealed that these cytokines were mainly associated with cellular structures such as intermediates, nuclear plaques, adhesion plaques, lateral plasma membranes, and cell matrix junctions. These genes were involved in various molecular functions, such as cytokine activity, receptor ligand activity, and signal receptor activator activity, contributing to various biological functions, such as leukocyte chemotaxis, migration, and chemotaxis. KEGG analysis indicated involvement in cytokine cytokine receptor interactions, chemokine signaling pathways, virus-protein interactions with cytokines and cytokine receptors, and the tumor necrosis factor signaling pathway. Elevated serum levels of IL-16, GM-CSF, CX3CL1, CXCL9, CXCL16, CCL25, and CCL23 in sepsis patients suggest their potential as diagnostic biomarkers for sepsis.

The Complex Immunological Alterations in Patients with Type 2 Diabetes Mellitus on Hemodialysis.

It is widely known that diabetes mellitus negatively impacts both the innate immunity (the inflammatory response) and the acquired immunity (the humoral and cellular immune responses). Many patients with diabetes go on to develop chronic kidney disease, which will necessitate hemodialysis. In turn, long-term chronic hemodialysis generates an additional chronic inflammatory response and impairs acquired immunity. The purpose of this paper is to outline and compare the mechanisms that are the basis of the constant aggression towards self-components that affects patients with diabetes on hemodialysis, in order to find possible new therapeutic ways to improve the functionality of the immune system. Our study will take a detailed look at the mechanisms of endothelial alteration in diabetes and hemodialysis, at the mechanisms of inflammatory generation and signaling at different levels and also at the mechanisms of inflammation-induced insulin resistance. It will also discuss the alterations in leukocyte chemotaxis, antigen recognition and the dysfunctionalities in neutrophils and macrophages. Regarding acquired immunity, we will outline the behavioral alterations of T and B lymphocytes induced by diabetes mellitus and chronic hemodialysis.

Dissecting thrombus-directed chemotaxis and random movement in neutrophil near-thrombus motion in flow chambers.

Thromboinflammation is caused by mutual activation of platelets and neutrophils. The site of thromboinflammation is determined by chemoattracting agents release by endothelium, immune cells, and platelets. Impaired neutrophil chemotaxis contributes to the pathogenesis of Shwachman-Diamond syndrome (SDS). In this hereditary disorder, neutrophils are known to have aberrant chemoattractant-induced F-actin properties. Here, we aim to determine whether neutrophil chemotaxis could be analyzed using our previously developed ex vivo assay of the neutrophils crawling among the growing thrombi. Adult and pediatric healthy donors, alongside with pediatric patients with SDS, were recruited for the study. Thrombus formation and granulocyte movement in hirudinated whole blood were visualized by fluorescent microscopy in fibrillar collagen-coated parallel-plate flow chambers. Alternatively, fibrinogen, fibronectin, vWF, or single tumor cells immobilized on coverslips were used. A computational model of chemokine distribution in flow chamber with a virtual neutrophil moving in it was used to analyze the observed data. The movement of healthy donor neutrophils predominantly occurred in the direction and vicinity of thrombi grown on collagen or around tumor cells. For SDS patients or on coatings other than collagen, the movement was characterized by randomness and significantly reduced velocities. Increase in wall shear rates to 300-500 1/s led to an increase in the proportion of rolling neutrophils. A stochastic algorithm simulating leucocyte chemotaxis movement in the calculated chemoattractant field could reproduce the experimental trajectories of moving neutrophils for 72% of cells. In samples from healthy donors, but not SDS patients, neutrophils move in the direction of large, chemoattractant-releasing platelet thrombi growing on collagen.

Association Between Sleep Apnea Syndrome and Osteoarthritis: Insights from Bidirectional Mendelian Randomization and Bioinformatics Analysis.

Sleep apnea syndrome(SAS) and osteoarthritis (OA) are two prevalent diseases that often coexist, but the causal relationship between them remains unclear. In light of this, our team utilizes Mendelian Randomization and bioinformatics analysis methods to investigate the potential association between the two diseases. In this study, we utilized GWAS data pertaining to SAS and OA to assess the causal relationship between the two diseases through Mendelian randomization (MR) analysis. We then employed transcriptomic data to perform differential gene identification, WGCNA, shared gene determination, functional enrichment analysis, and colocalization analysis, all designed to further elucidate the mechanisms underlying the association between the two diseases. In the end, we utilized Mendelian randomization (MR) analysis again to delve deeper into the relationship between the two diseases and immune cells. Our research findings indicate that SAS is a risk factor for OA (p = 0.000004), knee OA (p = 0.0000001) and hip OA(p = 0.001). Furthermore, OA (p = 0.000195), knee OA (p = 0.001) are significant risk factors for SAS. However, there is no clear evidence that hip OA (p = 0.892) is a risk factor for SAS. Interestingly, the genes shared between OA and SAS are significantly enriched in leukocyte migration, leukocyte chemotaxis. Moreover, colocalization analysis suggests that the genes JUNB, COL8A1, FOSB, and IER2 may be key genes associated with both diseases. Furthermore, 57 immune cell phenotypes are associated with SAS, 95 with OA, and 6 shared between both diseases. This research confirmed the bidirectional causal relationship between SAS and OA. Notably, the 4 genes (JUNB, COL8A1, FOSB, IER2) and 6 immune phenotypes are crucial for both diseases, these provide hopeful targets for future interventions against these two diseases.

Proteomics-Derived Biomarker Panel Facilitates Distinguishing Primary Lung Adenocarcinomas With Intestinal or Mucinous Differentiation From Lung Metastatic Colorectal Cancer

The diagnosis of primary lung adenocarcinomas with intestinal or mucinous differentiation (PAIM) remains challenging due to the overlapping histomorphological, immunohistochemical (IHC), and genetic characteristics with lung metastatic colorectal cancer (lmCRC). This study aimed to explore the protein biomarkers that could distinguish between PAIM and lmCRC. To uncover differences between the two diseases, we used tandem mass tagging–based shotgun proteomics to characterize proteomes of formalin-fixed, paraffin-embedded tumor samples of PAIM (n = 22) and lmCRC (n = 17).Then three machine learning algorithms, namely support vector machine (SVM), random forest, and the Least Absolute Shrinkage and Selection Operator, were utilized to select protein features with diagnostic significance. These candidate proteins were further validated in an independent cohort (PAIM, n = 11; lmCRC, n = 19) by IHC to confirm their diagnostic performance. In total, 105 proteins out of 7871 proteins were significantly dysregulated between PAIM and lmCRC samples and well-separated two groups by Uniform Manifold Approximation and Projection. The upregulated proteins in PAIM were involved in actin cytoskeleton organization, platelet degranulation, and regulation of leukocyte chemotaxis, while downregulated ones were involved in mitochondrial transmembrane transport, vasculature development, and stem cell proliferation. A set of ten candidate proteins (high-level expression in lmCRC: CDH17, ATP1B3, GLB1, OXNAD1, LYST, FABP1; high-level expression in PAIM: CK7 (an established marker), NARR, MLPH, S100A14) was ultimately selected to distinguish PAIM from lmCRC by machine learning algorithms. We further confirmed using IHC that the five protein biomarkers including CDH17, CK7, MLPH, FABP1 and NARR were effective biomarkers for distinguishing PAIM from lmCRC. Our study depicts PAIM-specific proteomic characteristics and demonstrates the potential utility of new protein biomarkers for the differential diagnosis of PAIM and lmCRC. These findings may contribute to improving the diagnostic accuracy and guide appropriate treatments for these patients.

Single-cell RNA sequencing explores the evolution of the ecosystem from leukoplakia to head and neck squamous cell carcinoma

It has been found that progression from leukoplakia to head and neck squamous cell carcinoma (HNSCC) is a long-term process that may involve changes in the multicellular ecosystem. We acquired scRNA-seq samples information from gene expression omnibus and UCSC Xena database. The BEAM function was used to construct the pseudotime trajectory and analyze the differentially expressed genes in different branches. We used the ssGSEA method to explore the correlation between each cell subgroup and survival time, and obtained the cell subgroup related to prognosis. During the progression from leukoplakia to HNSCC, we found several prognostic cell subgroups, such as AURKB + epithelial cells, SFRP1 + fibroblasts, SLC7A8 + macrophages, FCER1A + CD1C + dendritic cells, and TRGC2 + NK/T cells. All cell subgroups had two different fates, one tending to cell proliferation, migration, and enhancement of angiogenesis capacity, and the other tending to inflammatory immune response, leukocyte chemotaxis, and T cell activation. Tumor-promoting genes such as CD163 and CD209 were highly expressed in the myeloid cells, and depletion marker genes such as TIGIT, LAG3 were highly expressed in NK/T cells. Our study may provide a reference for the molecular mechanism of HNSCC and theoretical basis for the development of new therapeutic strategies.

Transcriptomic responses of cumulus granulosa cells to SARS-CoV-2 infection during controlled ovarian stimulation.

Cumulus granulosa cells (CGCs) play a crucial role in follicular development, but so far, no research has explored the impact of SARS-CoV-2 infection on ovarian function from the perspective of CGCs. In the present study, we compared the cycle outcomes between infected and uninfected female patients undergoing controlled ovarian stimulation, performed bulk RNA-sequencing of collected CGCs, and used bioinformatic methods to explore transcriptomic changes. The results showed that women with SARS-CoV-2 infection during stimulation had significantly lower number of oocytes retrieved and follicle-oocyte index, while subsequent fertilization and embryo development were similar. CGCs were not directly infected by SARS-CoV-2, but exhibited dramatic differences in gene expression (156 up-regulated and 65 down-regulated). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses demonstrated a high enrichment in antiviral, immune and inflammatory responses with necroptosis. In addition, the pathways related to telomere organization and double strand break repair were significantly affected by infection in gene set enrichment analysis. Further weighted gene co-expression network analysis identified a key module associated with ovarian response traits, which was mainly enriched as a decrease of leukocyte chemotaxis and migration in CGCs. For the first time, our study describes how SARS-CoV-2 infection indirectly affects CGCs at the transcriptional level, which may impair oocyte-CGC crosstalk and consequently lead to poor ovarian response during fertility treatment.

Integrated transcriptomic analysis systematically reveals the heterogeneity and molecular characterization of cancer-associated fibroblasts in osteosarcoma

BackgroundOsteosarcoma (OS), with a peak incidence during the adolescent growth spurt, is correlated with poor prognosis for its high malignancy. The tumor microenvironment (TME) is highly complicated, with frequent interactions between tumor and stromal cells. The cancer-associated fibroblasts (CAFs) in the TME have been considered to actively involve in the progression, metastasis, and drug resistance of OS. This study aimed to characterize cellular heterogeneity and molecular characterization in CAFs subtypes and explore the potential targeting therapeutic strategies to improve the prognosis of OS patients. MethodsThe single-cell atlas of human OS tumor lesions were constructed from the GEO database. Then significant marker genes and potential biological functions for each CAFs subtype were identified and explored using the Seurat R package. Next, by performing the survival analyses and constructing the risk scores for CAFs subtypes, we aimed to identify and characterize the prognostic values of specific marker genes and different CAFs subtypes. Furthermore, we explored the therapeutic targets and innovative drugs targeting different CAFs subtypes based on the GDSC database. Finally, prognoses related CAFs subtypes were further validated through immunohistochemistry (IHC) on clinical OS specimens. ResultsOverall, nine main cell clusters and five subtypes of CAFs were identified. The differentially expressed marker genes for each CAFs clusters were then identified. Moreover, through Gene Ontology (GO) enrichment analysis, we defined the CAFs_2 (upregulated CXCL14 and C3), which was closely related to leukocyte migration and chemotaxis, as inflammatory CAFs (iCAFs). Likewise, we defined the CAFs_4 (upregulated CD74, HLA-DRA and HLA-DRB1), which was closely related to antigen process and presentation, as antigen-presenting CAFs (apCAFs). Furthermore, Kaplan-Meier analyses showed that CAFs_2 and CAFs_4 were correlated with poor clinical prognosis of OS patients. Meanwhile, therapeutic drugs targeting CAFs_2 and CAFs_4, such as 17-AAG/Docetaxel/Bleomycin and PHA-793887/NG-25/KIN001-102, were also explored, respectively. Finally, IHC assay confirmed the abundant CAFs_2 and CAFs_4 subtypes infiltration in the OS microenvironment compared with adjacent tissues. ConclusionOur study revealed the diversity, complexity, and heterogeneity of CAFs in OS, and complemented the single-cell atlas in OS TME.

Acute stress transiently activates macrophages and chemokines in cervical lymph nodes.

Acute restraint stress (RS) is routinely used to study the effects of psychological and/or physiological stress. We evaluated the impact of RS on cervical lymph nodes in rats at molecular and cellular levels. Male Sprague-Dawley rats were subjected to stress by immobilization for 30, 60, and 120 min (RS30, RS60, and RS120, respectively) and compared with rats of a no-stress control (C) group. The expression of genes encoding chemokines CXCL1/CXCL2 (Cxcl1 and Cxcl2) and their receptor CXCR2 (Cxcr2) was analyzed using reverse transcription-quantitative PCR (RT-qPCR) and microarray analyses. Immunohistochemistry and in situ hybridization were performed to determine the expression of these proteins and the macrophage biomarker CD68. Microarray analysis revealed that the expression of 514 and 496 genes was upregulated and downregulated, respectively, in the RS30 group. Compared with the C group, the RS30 group exhibited a 23.0-, 13.0-, and 1.6-fold increase in Cxcl1, Cxcl2, and Cxcr2 expression. Gene Ontology analysis revealed the involvement of these three upregulated genes in the cytokine network, inflammation, and leukocyte chemotaxis and migration. RT-qPCR analysis indicated that the mRNA levels of Cxcl1 and Cxcl2 were significantly increased in the RS30 group but were reverted to normal levels in the RS60 and RS120 groups. Cxcr2 mRNA level was significantly increased in the RS30 and RS120 groups compared with that in the C group. RS-induced CXCL1-immunopositive cells corresponded to B/plasma cells, whereas CXCL2-immunopositive cells corresponded to endothelial cells of the high endothelial venules. Stress-induced CXCR2-immunopositive cells corresponded to macrophages. Psychological and/or physiological stress induces an acute stress response and formation of an immunoreactive microenvironment in cervical lymph nodes, with the CXCL1/CXCL2-CXCR2 axis being pivotal in the acute stress response.

Nicotinamide Riboside Regulates Chemotaxis to Decrease Inflammation and Ameliorate Functional Recovery Following Spinal Cord Injury in Mice.

Changes in intracellular nicotinamide adenine dinucleotide (NAD+) levels have been observed in various disease states. A decrease in NAD+ levels has been noted following spinal cord injury (SCI). Nicotinamide riboside (NR) serves as the precursor of NAD+. Previous research has demonstrated the anti-inflammatory and apoptosis-reducing effects of NR supplements. However, it remains unclear whether NR exerts a similar role in mice after SCI. The objective of this study was to investigate the impact of NR on these changes in a mouse model of SCI. Four groups were considered: (1) non-SCI without NR (Sham), (2) non-SCI with NR (Sham +NR), (3) SCI without NR (SCI), and (4) SCI with NR (SCI + NR). Female C57BL/6J mice aged 6-8 weeks were intraperitoneally administered with 500 mg/kg/day NR for a duration of one week. The supplementation of NR resulted in a significant elevation of NAD+ levels in the spinal cord tissue of mice after SCI. In comparison to the SCI group, NR supplementation exhibited regulatory effects on the chemotaxis/recruitment of leukocytes, leading to reduced levels of inflammatory factors such as IL-1β, TNF-α, and IL-22 in the injured area. Moreover, NR supplementation notably enhanced the survival of neurons and synapses within the injured area, ultimately resulting in improved motor functions after SCI. Therefore, our research findings demonstrated that NR supplementation had inhibitory effects on leukocyte chemotaxis, anti-inflammatory effects, and could significantly improve the immune micro-environment after SCI, thereby promoting neuronal survival and ultimately enhancing the recovery of motor functions after SCI. NR supplementation showed promise as a potential clinical treatment strategy for SCI.

Cronkhite‒Canada syndrome as inflammatory hamartomatous polyposis: new evidence from whole transcriptome sequencing of colonic polyps

BackgroundCronkhite-Canada syndrome (CCS) is a rare, nonhereditary disease characterized by diffuse gastrointestinal polyposis and ectodermal abnormalities. Although it has been proposed to be a chronic inflammatory condition, direct evidence of its pathogenesis is lacking. This study aims to investigate the pathophysiology of CCS by analyzing transcriptomic changes in the colonic microenvironment.MethodsNext-generation sequencing-based genome-wide transcriptional profiling was performed on colonic hamartomatous polyps from four CCS patients and normal colonic mucosa from four healthy volunteers. Analyses of differential expression and multiple enrichment analyses were conducted from the molecular level to the cellular level. Quantitative real-time PCR (qRT-PCR) was carried out to validate the sequencing accuracy in samples from six CCS patients and six healthy volunteers.ResultsA total of 543 differentially expressed genes were identified, including an abundance of CC- and CXC-chemokines. Innate immune response-related pathways and processes, such as leukocyte chemotaxis, cytokine production, IL-17, TNF, IL-1 and NF-kB signaling pathways, were prominently enhanced in CCS colonic polyps. Upregulation of wound healing, epithelial-mesenchymal transition, Wnt, and PI3K-Akt signaling pathways were also observed. Enrichment analyses at different levels identified extracellular structure disorganization, dysfunction of the gut mucosal barrier, and increased angiogenesis. Validation by qRT-PCR confirmed increased expression of the LCN2, IL1B, CXCL1, and CXCL3 genes in CCS colonic polyps.ConclusionsThis case-control whole transcriptome analysis of active CCS colonic hamartomatous polyps revealed intricate molecular pathways, emphasizing the role of the innate immune response, extracellular matrix disorganization, inflammatory cell infiltration, increased angiogenesis, and potential epithelial to mesenchymal transition. These findings supports CCS as a chronic inflammatory condition and sheds light on potential therapeutic targets, paving the way for more effective and personalized management of CCS in the future.

Exploring the comorbidity mechanisms between psoriasis and obesity based on bioinformatics.

Psoriasis is a chronic, recurrent, immune-mediated inflammatory skin disease characterized by erythematous scaly lesions. Obesity is currently a major global health concern, increasing the risk of diseases such as cardiovascular diseases and diabetes. Since the correlation between psoriasis and obesity, as well as hypertension, diabetes, and cardiovascular diseases, has been clinically evidenced, it is of certain clinical significance to explore the mechanisms underlying the comorbidity of psoriasis with these conditions. Gene targets for both diseases were obtained from the Gene Expression Omnibus (GEO) comprehensive gene expression database. Differential gene analysis, intersection gene analysis, construction and visualization of protein-protein interaction networks (PPI) using R software, Cytoscape 3.8.2 software, online tools such as String, and enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed, with relevant graphics generated. Analysis identified 29 intersecting genes between the two diseases, with 10 key targets such as S100A7 and SERPINB4. Enrichment analysis indicated their involvement in regulating biological processes such as leukocyte chemotaxis, migration, and chronic inflammatory responses through cellular structures such as intracellular vesicles and extracellular matrix. Molecular functions, including RAGE receptor binding, Toll-like receptor binding, and fatty acid binding, were found to simultaneously regulate psoriasis and obesity. Psoriasis and obesity may mutually influence each other through multiple targets and pathways, emphasizing the importance of considering comorbidity treatment and daily care in clinical practice.

Comprehensive Analysis of Immune Infiltration and Key Genes in Peri-Implantitis Using Bioinformatics and Molecular Biology Approaches.

BACKGROUND Peri-implantitis is the main cause of failure of implant treatment, and there is little research on its molecular mechanism. This study aimed to identify key biomarkers and immune infiltration of peri-implantitis using a bioinformatics method. MATERIAL AND METHODS Three Gene Ontology (GO) gene expression profiles were selected from the Gene Expression Omnibus. Differentially expressed genes (DEGs) were identified by the LIMMA package, and functional correlations of DEGs were analyzed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. Information on immune-related genes was obtained from ImmPort (https://www.immport.org) and InnateDB (http://www.innatedb.com). Immune-related DEGs were screened by least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE). The single-sample Gene Set Enrichment Analysis algorithm was used to analyze immune cell infiltration in gingival tissue between peri-implantitis and normal controls. Finally, results of bioinformatics analysis were verified by qPCR. RESULTS A total of 398 DEGs were identified, of which 96 were immune-related. Enrichment analysis showed these genes were enriched in inflammatory response, leucocyte chemotaxis, immune response-regulating signaling pathway, and cell activation. Seven key genes were selected by LASSO and SVM-RFE. Receiver operating characteristic curve results showed these genes had excellent diagnostic efficacy. Results of qPCR showed significant differences in the expression of these genes. CONCLUSIONS Differences in key genes and immune infiltration between peri-implantitis and gingival tissues of normal controls may provide new insights into the development of peri-implantitis. Elucidating the difference in immune infiltration between peri-implantitis tissues and normal tissues will help to understand the development of peri-implantitis.

Diacylglycerols and Lysophosphatidic Acid, Enriched on Lipoprotein(a), Contribute to Monocyte Inflammation.

Oxidized phospholipids play a key role in the atherogenic potential of lipoprotein(a) (Lp[a]); however, Lp(a) is a complex particle that warrants research into additional proinflammatory mediators. We hypothesized that additional Lp(a)-associated lipids contribute to the atherogenicity of Lp(a). Untargeted lipidomics was performed on plasma and isolated lipoprotein fractions. The atherogenicity of the observed Lp(a)-associated lipids was tested ex vivo in primary human monocytes by RNA sequencing, ELISA, Western blot, and transendothelial migratory assays. Using immunofluorescence staining and single-cell RNA sequencing, the phenotype of macrophages was investigated in human atherosclerotic lesions. Compared with healthy individuals with low/normal Lp(a) levels (median, 7 mg/dL [18 nmol/L]; n=13), individuals with elevated Lp(a) levels (median, 87 mg/dL [218 nmol/L]; n=12) demonstrated an increase in lipid species, particularly diacylglycerols (DGs) and lysophosphatidic acid (LPA). DG and the LPA precursor lysophosphatidylcholine were enriched in the Lp(a) fraction. Ex vivo stimulation with DG(40:6) demonstrated a significant upregulation in proinflammatory pathways related to leukocyte migration, chemotaxis, NF-κB (nuclear factor kappa B) signaling, and cytokine production. Functional assessment showed a dose-dependent increase in the secretion of IL (interleukin)-6, IL-8, and IL-1β after DG(40:6) and DG(38:4) stimulation, which was, in part, mediated via the NLRP3 (NOD [nucleotide-binding oligomerization domain]-like receptor family pyrin domain containing 3) inflammasome. Conversely, LPA-stimulated monocytes did not exhibit an inflammatory phenotype. Furthermore, activation of monocytes by DGs and LPA increased their transendothelial migratory capacity. Human atherosclerotic plaques from patients with high Lp(a) levels demonstrated colocalization of Lp(a) with M1 macrophages, and an enrichment of CD68+IL-18+TLR4+ (toll-like receptor) TREM2+ (triggering receptor expressed on myeloid cells) resident macrophages and CD68+CASP1+ (caspase) IL-1B+SELL+ (selectin L) inflammatory macrophages compared with patients with low Lp(a). Finally, potent Lp(a)-lowering treatment (pelacarsen) resulted in a reduction in specific circulating DG lipid subspecies in patients with cardiovascular disease with elevated Lp(a) levels (median, 82 mg/dL [205 nmol/L]). Lp(a)-associated DGs and LPA have a potential role in Lp(a)-induced monocyte inflammation by increasing cytokine secretion and monocyte transendothelial migration. This DG-induced inflammation is, in part, NLRP3 inflammasome dependent.

OP30 Endothelial cell-mediated smooth muscle hyperplasia in Crohn’s disease intestinal strictures: Caveolin 1 as a potential therapeutic target

Abstract Background Intestinal stricture is a severe and common complication of Crohn’s disease (CD). Current therapies offer limited success and surgery is often needed. Smooth muscle hyperplasia and hypertrophy play a key role in CD stricture development. This study explores the transcriptomic features of fibrostenotic CD, focusing on the endothelial contribution to smooth muscle changes within intestinal strictures. Methods 9 CD patients undergoing surgery for fibrotic strictures were prospectively enrolled. Dissected samples from the stricture and the adjacent proximal and distal non-strictured areas were obtained from fresh specimens collected directly from the operating theatre. RNA was extracted from all samples for bulk-transcriptomic analysis. Differentially expressed genes (adj. p-value <0.05) were identified and pathway enrichment analysis pinpointed relevant pathways. Subsequently, single-cell RNA sequencing (scRNAseq) analysis was performed using the 10x Chromium Controller® platform. A total of 31.195 cells were sequenced and bioinformatic analysis revealed 13 distinct clusters based on the expression of key lineage target genes. To better characterise the nature of clusters expressing stromal like markers and positioned closely in the UMAP plot, a further subclustering was performed. This resulted in 5 groups, including plasma cells, endothelial cells, fibroblasts, epithelial cells and dendritic like cells. Results Bulk-transcriptomic analysis identified 81 genes differentially expressed in strictures compared to both proximal and distal regions. Notably, genes associated with leukocyte and macrophage recruitment and chemotaxis, namely Platelet and Endothelial Cell Adhesion Molecule 1 (PECAM1), C-C motif Chemokine Ligand 2 (CCL2), and Endothelin Receptor Type B (EDNRB), resulted overexpressed in strictures. scRNAseq identified a distinct subset of endothelial cells (CD34+, PECAM1+). Caveolin 1 (CAV1), a gene encoding for a structural protein predominantly expressed in smooth muscle cell plasma membrane invaginations, was exclusively up-regulated in endothelial cells of ileal stricture samples. Previous research linked CAV1 to smooth muscle proliferation and fibrosis in various organs. Conclusion This study highlights the pivotal role of endothelial cells in CD strictures. The transcriptomic analysis shows the involvement of inflammatory targets featured genes involved in transendothelial immune cell migration. Furthermore, the up-regulation of CAV1 in endothelial cells within stricture segments suggests a mechanistic connection between endothelial cells and smooth muscle hyperplasia in intestinal strictures. CAV1 holds promise as a potential therapeutic target in fibrostenotic CD.