Overexpression Of CXCL12 Research Articles

Bioinformatics study of the TNFRSF1A mechanism involved in acute liver injury in sepsis through the mTOR signaling pathway.

This study analyzed potential key genes involved in the mechanism of acute liver injury induced by sepsis through bioinformatics techniques, aiming to provide novel insights for the identification of early-stage sepsis-induced acute liver injury and its diagnosis. Gene chip data sets containing samples from acute liver injury induced by sepsis and control groups (GSE22009 and GSE60088) were selected from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) with |log fold change| >1 and p<0.05 were screened with the GEO2R tool, which was also used for the selection of upregulated DEGs in the chips with p<0.05. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, Gene Ontology, and protein-protein interaction (PPI) analyses were then conducted. Results were visualized using R language packages, including volcano plots, Venn diagrams, and boxplots. The intersection of candidate genes with relevant genes in the Comparative Toxicogenomics Database (CTD) was performed, and the clinical significance of these genes was explored through a literature review. A rat model of acute liver injury was developed by inducing sepsis with the cecum ligation and puncture method. Real-time PCR was performed to determine the gene expression in rat liver tissues. A total of 646 upregulated DEGs were determined in GSE22009 and 146 in GSE60088. A Venn diagram was used to find the intersection of the upregulated DEGs between the two data sets, and 67 DEGs associated with sepsis-mediated acute liver damage were obtained. Enrichment analysis from the KEGG pathway showed that DEG upregulation was primarily associated with various pathways: TNF, NF-κB, IL-17, ferroptosis, mTOR, and JAK-STAT signaling pathways. DEGs resulted in three clusters and 15 candidate genes, as revealed by the PPI network and module analyses. Intersection with sepsis-induced acute liver injury-related genes in the CTD resulted in the identification of three significant differentially co-expressed genes: CXCL1, ICAM1, and TNFRSF1A. Sepsis-induced liver tissue indicated the overexpression of CXCL1, ICAM1, and TNFRSF1A mRNA, as compared with the control group (p<0.05). The key genes identified and related signaling pathways provided insights into the molecular mechanisms of sepsis-induced acute liver injury. In vivo studies revealed the overexpression of CXCL1, ICAM1, and TNFRSF1A mRNA in sepsis-mediated injured liver tissues, providing a theoretical basis for early diagnosis and targeted treatment research.

Instructive interaction between myelodysplastic hematopoiesis and the bone marrow microenvironment at the single-cell level

AbstractMyelodysplastic neoplasms (MDS) are hypothesized to remodel their bone marrow (BM) microenvironment to reinforce conditions for their propagation. In this study, we investigated interactions between MDS cells and the BM niche at single-cell level. In a patient-derived xenograft (PDX) model, we analyzed 13 000 cells from different murine niche cell populations after long-term (>24 weeks) exposure to MDS vs healthy human grafts. Subsequently, we analyzed over 24 000 primary human BM cells enriched for the nonhematopoietic compartment by using whole bone fragments from n = 8 patients with MDS and n = 7 healthy, age-matched donors. In PDX who received MDS transplantation, mesenchymal cell (MSC) subpopulations were forced to overexpress hematopoietic factors such as Cxcl12 and Il7 upon contact with hematopoietic MDS cells as compared with healthy grafts. Single-cell analyses of primary in situ BM cells from patients with MDS showed highly heterogeneous MSC subpopulations on a patient-individual level. We identified inflammatory gene expression profiles as well as overexpression of C-X-C Motif Chemokine Ligand 12, KIT ligand, and Interleukin 7 in MDS MSCs and endothelial cells. In conclusion, we demonstrate reprogramming of the BM microenvironment by MDS cells, pointing to altered MSC subpopulations with increased growth factor expression profiles in a subgroup of patients with MDS.

Abstract 3591: Upregulation of CXCL8 is an early step in the oncogenic transition of human thyroid cells by BRAFV600E

Abstract Introduction: BRAFV600E is one of the most common oncogenic mutations in human thyroid cancers, especially in papillary thyroid carcinoma (PTC). However, the early molecular changes caused by this mutation have not been studied previously in human thyrocytes in vitro. Methods: Primary cultures of cells derived from noncancerous thyroid tissue of patients (at least n=3) were infected with BRAFV600E adenovirus to mimic the mutated condition. Changes induced by the infection were measured at early times (&amp;lt;24h). Transcriptome analysis was performed on infected thyrocytes (n=6) to determine the highest differentially expressed genes between the control and infected groups, which were then verified at the gene and protein levels. RNAi downregulation experiments were performed to determine the cross-regulatory function of the genes. Results: The induction of BRAFV600E mutation, confirmed at the protein level, increased proliferation of the cells, and morphological changes were observed at approximately 24h post-infection. The decreased expression of thyroid-specific genes, viz. TSHR, TG, and TPO were observed after &amp;gt;72h post-introduction of BRAFV600E mutation. Transcriptome and protein expression analysis of BRAFV600E-positive thyrocytes showed the overexpression of chemokines CXCL8 and CXCL12, and upregulation of endothelial cell-specific molecule 1 (ESM1). These molecules are known to be associated with increased neoangiogenesis and proliferation. Functional studies showed that siRNA knockdown of CXCL8 decreased the expressions of CXCL12 and ESM1, whereas knockdown of either CXCL12 or ESM1 did not decrease the expression of CXCL8. Conclusion: Increased proliferation, de-differentiation, upregulation of chemokines, and endothelial-specific factor are effects associated with BRAFV600E-driven thyroid carcinogenesis. CXCL8 appears to play an important early regulatory role in this process. Citation Format: Rhitajit Sarkar, Priyanka Bolel, Joanna Klubo-Gwiezdzinska, Marvin C. Gershengorn. Upregulation of CXCL8 is an early step in the oncogenic transition of human thyroid cells by BRAFV600E [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3591.

Prevention of severe lung immunopathology associated with influenza infection through adeno-associated virus vector administration

BackgroundInfluenza A viruses (IAVs) have long posed a threat to humans, occasionally causing significant morbidity and mortality. The initial immune response is triggered by infected epithelial cells, alveolar macrophages and dendritic cells. However, an exaggerated innate immune response can result in severe lung injury and even host mortality. One notable pathology observed in hosts succumbing to severe influenza is the excessive influx of neutrophils and monocytes into the lung. In this study, we investigated a strategy for controlling lung immunopathology following severe influenza infection.ResultsTo evaluate the impact of innate immunity on influenza-associated lung injury, we employed CB17.SCID and NOD.SCID mice. NOD.SCID mice exhibited slower weight loss and longer survival than CB17.SCID mice following influenza infection. Lung inflammation was reduced in NOD.SCID mice compared to CB17.SCID mice. Bulk RNA sequencing analysis of lung tissue showed significant downregulation of 827 genes, and differentially expressed gene analysis indicated that the cytokine-cytokine receptor interaction pathway was predominantly downregulated in NOD.SCID mice. Interestingly, the expression of the Cxcl14 gene was higher in the lungs of influenza-infected NOD.SCID mice than in CB17.SCID mice. Therefore, we induced overexpression of the Cxcl14 gene in the lung using the adeno-associated virus 9 (AAV9)-vector system for target gene delivery. However, when we administered the AAV9 vector carrying the Cxcl14 gene or a control AAV9 vector to BALB/c mice from both groups, the morbidity and mortality rates remained similar. Both groups exhibited lower morbidity and mortality than the naive group that did not receive the AAV9 vector prior to IAV infection, suggesting that the pre-administration of the AAV9 vector conferred protection against lethal influenza infection, irrespective of Cxcl14 overexpression. Furthermore, we found that pre-inoculation of BALB/c mice with AAV9 attenuated the infiltration of trans-macrophages, neutrophils and monocytes in the lungs following IAV infection. Although there was no difference in lung viral titers between the naive group and the AAV9 pre-inoculated group, pre-inoculation with AAV9 conferred lung injury protection against lethal influenza infection in mice.ConclusionsOur study demonstrated that pre-inoculation with AAV9 prior to IAV infection protected mouse lungs from immunopathology by reducing the recruitment of inflammatory cells.

Importance of metabolic and immune profile as a prognostic indicator in patients with diabetic clear cell renal cell carcinoma.

ccRCC, also known as clear cell renal cell carcinoma, is a cancer that is highly metabolically active and has a strong connection with the immune system. The objective of this research was to investigate the correlation between pathways associated with metabolism, diabetes, immune infiltration, and their impact on the prognosis of ccRCC. We conducted an extensive examination utilizing ssGSEA, ESTIMATE algorithm, WGCNA, and GSVA for gene set enrichment analysis, gene co-expression network analysis, and gene set variation analysis. An established prognostic model, utilizing immune-related WGCNA findings, was evaluated for its association with clinical characteristics and the tumor microenvironment (TME). The ssGSEA effectively categorized ccRCC into groups based on low and high metabolism. Strong associations were observed between scores related to metabolism and immune scores, ESTIMATE scores, stromal scores, and gene expression related to HLA. The analysis conducted by WGCNA revealed a module called the 'yellow module' that exhibited a significant correlation with the infiltration of immune cells and the survival rates of patients. A risk model was developed, demonstrating reliable predictive performance for patient survival outcomes. The risk model also correlated significantly with immune scores and HLA-related gene expressions, suggesting potential immune evasion mechanisms. The analysis of mutations in TCGA data revealed the mutational patterns of ccRCC, and there was a significant correlation between the risk score and clinical characteristics. The GSVA analysis revealed a notable enrichment of pathways associated with cancer in patients at high risk. Finally, in order to evaluate the role of CX3CL1 in renal cell carcinoma cells, we then performed the cell proliferation assays. The results demonstrated that the over expression of CXCL1 could promote the cell proliferation ability in renal cell carcinoma cells. Our findings provide a novel perspective on the interactions between diabetes, metabolic pathways, and the immune landscape in ccRCC. The predictive value of the prognostic model established in this research has the potential to guide the development of new therapeutic and prognostic approaches for patients with ccRCC.

CXCL12/CXCR4/CXCR7 axis in placenta tissues of patients with placenta previa.

CXCR4 and CXCR7 have been revealed to be receptors of CXCL12. This research was designed to probe the expression of chemokine CXCL12 and its receptors CXCR4 and CXCR7 in placental tissues of patients with placenta previa and the effect of CXCL12/CXCR4/CXCR7 axis on the biological functions of human trophoblast cells. CXCL12, CXCR4, and CXCR7 expression in placental tissue from patients with placenta previa and healthy puerperae was detected. CXCL12, CXCR4, and CXCR7 expression in human trophoblast cell lines (HTR8/SVneo cells) was assessed after suppression or overexpression of CXCL12, CXCR4, and CXCR7. The cell proliferative, invasive, and migratory capacities were also evaluated in HTR8/SVneo cells after suppression or overexpression of CXCL12, CXCR4, and CXCR7. CXCL12, CXCR4, and CXCR7 expression was elevated in placental tissues from patients with placenta previa. Downregulation of CXCL12, CXCR4, and CXCR7 could lead to decreased mRNA levels of CXCL12, CXCR4, and CXCR7 in HTR-8/SVneo cells, which was accompanied by diminished cell proliferative, migratory, and invasive capabilities. Overexpression of CXCL12, CXCR4, and CXCR7 genes presented an opposite tendency. CXCL12, CXCR4, and CXCR7 are highly expressed in placental tissues of patients with placenta previa and induce the biological activities of HTR8/SVneo cells.

CXCR4 and CXCL12 signaling regulates the development of extrinsic innervation to the colorectum.

The gastrointestinal tract is innervated by an intrinsic neuronal network, known as the enteric nervous system (ENS), and by extrinsic axons arising from peripheral ganglia. The nerve of Remak (NoR) is an avian-specific sacral neural crest-derived ganglionated structure that extends from the cloaca to the proximal midgut and, similar to the pelvic plexus, provides extrinsic innervation to the distal intestine. The molecular mechanisms controlling extrinsic nerve fiber growth into the gut is unknown. In vertebrates, CXCR4, a cell-surface receptor for the CXCL12 chemokine, regulates migration of neural crest cells and axon pathfinding. We have employed chimeric tissue recombinations and organ culture assays to study the role of CXCR4 and CXCL12 molecules in the development of colorectal innervation. CXCR4 is specifically expressed in nerve fibers arising from the NoR and pelvic plexus, while CXCL12 is localized to the hindgut mesenchyme and enteric ganglia. Overexpression of CXCL12 results in significantly enhanced axonal projections to the gut from the NoR, while CXCR4 inhibition disrupts nerve fiber extension, supporting a previously unreported role for CXCR4 and CXCL12 signaling in extrinsic innervation of the colorectum.

Effect of CXCL1 on the NF-κB/P300 signaling pathway and colon cancer progression.

236 Background: The upregulated expression of CXCL1 has been validated in colorectal cancer patients. As a potential biotherapeutic target for colorectal cancer, the mechanism by which CXCL1 affects the development of colorectal cancer is not clear. Methods: Expression data of CXCL1 in colorectal cancer were obtained from the GEO database and verified using the GEPIA database and the TIMER 2.0 database. Knockout and overexpression of CXCL1 in colorectal cancer cells by CRISPR/Cas and "Sleeping Beauty" transposon-mediated gene editing techniques. Cell biological function was demonstrated by CCK-8, transwell chamber and Colony formation assay. RT-qPCR and Western Blot assays measured RNA and protein expression. Protein localization and expression were measured by immunohistochemistry and immunofluorescence. Results: Bioinformatics analysis showed significant overexpression of CXCL1 in the colorectal cancer tissues compared to normal human tissues, and identified CXCL1 as a potential therapeutic target for colorectal cancer. We demonstrate that CXCL1 promotes the proliferation and migration of colon cancer cells and has a facilitative effect on tumor angiogenesis. Furthermore, CXCL1 elevation promoted the migration of M2-tumor associated macrophages (TAMs) while disrupting the aggregation of CD4+ and CD8+ T cells at tumor sites. Mechanistic studies suggested that CXCL1 activates the NF-κB pathway. In the in vivo colon cancer transplantation tumor model, treatment with the P300 inhibitor C646 significantly inhibited the growth of CXCL1-overexpressing colon cancer. Conclusions: CXCL1 promotes colon cancer development through activation of NF-κB/P300, and that CXCL1-based therapy is a potential novel strategy to prevent colon cancer development.

DNA Methylation-Mediated Overexpression of CXCL1 in Helicobacter pylori-Induced Gastric Cancer: In Silico- and In Vitro-Based Identification of a Potential Biomarker for Carcinogenesis.

Given the high global prevalence and mortality associated with gastric cancer, and its known causal link with Helicobacter pylori infection, it is important to have a biomarker to identify malignant transformation at early stages. Previously, we, and others, have reported that H. pylori-induced epigenetic changes could mediate carcinogenic transformation of the gastric cells. Also, CXCL1 secreted by gastric cancer cells was reported as a key diagnostic and prognostic biomarker for the pathogenic progression of gastric cancer. In this study, for the first time, we aimed to investigate the role of H. pylori-induced DNA methylation-based epigenetic regulation of CXCL1. In silico analysis of publicly available datasets and in vitro experiments were performed. Our results showed that CXCL1 is highly expressed in both gastric cancer tissues and gastric cancer cells infected with H. pylori. Further, we showed and confirmed that H. pylori-mediated overexpression of CXCL1 is due to hypomethylation of its promoter region. Since epigenetic events such as DNA methylation happen early in the sequence; H. pylori-induced CXCL1 hypomethylation could likely be detected at an early stage of gastric cancer development. Epigenetic modifications, such as CXCL1 hypomethylation, are reversible and could potentially be a therapeutic target using demethylation drugs.

CXCL1 promotes colon cancer progression through activation of NF-κB/P300 signaling pathway

BackgroundThe upregulated expression of CXCL1 has been validated in colorectal cancer patients. As a potential biotherapeutic target for colorectal cancer, the mechanism by which CXCL1 affects the development of colorectal cancer is not clear.MethodsExpression data of CXCL1 in colorectal cancer were obtained from the GEO database and verified using the GEPIA database and the TIMER 2.0 database. Knockout and overexpression of CXCL1 in colorectal cancer cells by CRISPR/Cas and "Sleeping Beauty" transposon-mediated gene editing techniques. Cell biological function was demonstrated by CCK-8, transwell chamber and Colony formation assay. RT-qPCR and Western Blot assays measured RNA and protein expression. Protein localization and expression were measured by immunohistochemistry and immunofluorescence.ResultsBioinformatics analysis showed significant overexpression of CXCL1 in the colorectal cancer tissues compared to normal human tissues, and identified CXCL1 as a potential therapeutic target for colorectal cancer. We demonstrate that CXCL1 promotes the proliferation and migration of colon cancer cells and has a facilitative effect on tumor angiogenesis. Furthermore, CXCL1 elevation promoted the migration of M2-tumor associated macrophages (TAMs) while disrupting the aggregation of CD4+ and CD8+ T cells at tumor sites. Mechanistic studies suggested that CXCL1 activates the NF-κB pathway. In the in vivo colon cancer transplantation tumor model, treatment with the P300 inhibitor C646 significantly inhibited the growth of CXCL1-overexpressing colon cancer.ConclusionCXCL1 promotes colon cancer development through activation of NF-κB/P300, and that CXCL1-based therapy is a potential novel strategy to prevent colon cancer development.

CXCL14 Attenuates Triple-Negative Breast Cancer Progression by Regulating Immune Profiles of the Tumor Microenvironment in a T Cell-Dependent Manner.

Triple-negative breast cancer (TNBC) is aggressive and has a poor overall survival due to a lack of therapeutic targets compared to other subtypes. Chemokine signature revealed that TNBC had low levels of CXCL14, an orphan homeostatic chemokine to regulate the immune network. Here, we investigated if CXCL14 plays a critical role in TNBC progression, focusing on survival rates, tumor growth and metastasis, and immune profiles in the tumor microenvironment. Analysis of human breast-cancer datasets showed that low CXCL14 expression levels were associated with poor survival rates in patients with breast cancer, particularly for TNBC subtypes. Overexpression of CXCL14 in TNBC 4T1 orthotopic mouse model significantly reduced tumor weights and inhibited lung metastasis. Furthermore, the CXCL14 overexpression altered immune profiles in the tumor microenvironment as follows: decreased F4/80+ macrophages and CD4+CD25+ Treg cells, and increased CD8+T cells in primary tumors; decreased Ly6C+ myeloid cells and CD4+CD25+ Treg cells and increased CD4+ and CD8+T cells in lung metastatic tumors. CXCL14-induced reduction of tumor growth and metastasis was diminished in T cell-deficient nude mice. Taken together, our data demonstrate that CXCL14 inhibits TNBC progression through altering immune profiles in the tumor microenvironment and it is mediated in a T cell-dependent manner. Thus, CXCL14 could be used as a biomarker for prognosis.

MicroRNA-103a-3p enhances sepsis-induced acute kidney injury via targeting CXCL12

ABSTRACT Acute kidney injury (AKI) is a common and fatal complication in inflammatory sepsis. Several microRNAs (miRNAs or miRs) have been identified to control sepsis. MiR-103a-3p has been reported to take part in the various inflammatory response. However, its role in AKI remains unclear. The present research aimed to explore the role and mechanisms of miR-103a-3p in AKI. Neurogenic sepsis mouse model and lipopolysaccharide-induced HK-2 and 293 cell models were established. The renal functions in each group of mice were measured. After evaluating the biological functions of C-X-C motif chemokine 12 (CXCL12) and miR-103a-3p on HK-2 and HEK-293 T cells, their interaction was determined. Detection of CXCL12 and apoptosis and inflammation-related factors in renal tissue was done. MiR-103a-3p was significantly repressed in the sepsis model, while CXCL12 was elevated. Furthermore, miR-103a-3p inversely controlled CXCL12. Knockdown of miR-103a-3p or overexpression of CXCL12 could significantly inhibit the progression of HK-2 and HEK293 cells, whereas elevated miR-103a-3p or knockdown of CXCL12 showed the opposite effects. Collectively, miR-103a-3p heightens renal cell damage caused by sepsis by targeting CXCL12.

A Role of CXCL1 Drives Osteosarcoma Lung Metastasis via VCAM-1 Production.

Osteosarcoma, a common aggressive and malignant cancer, appears in the musculoskeletal system among young adults. The major cause of mortality in osteosarcoma was the recurrence of lung metastases. However, the molecular mechanisms of metastasis involved in osteosarcomas remain unclear. Recently, CXCL1 and CXCR2 have been crucial indicators for lung metastasis in osteosarcoma by paracrine releases, suggesting the involvement of directing neutrophils into tumor microenvironment. In this study, overexpression of CXCL1 has a positive correlation with the migratory and invasive activities in osteosarcoma cell lines. Furthermore, the signaling pathway, CXCR2/FAK/PI3K/Akt, is activated through CXCL1 by promoting vascular cell adhesion molecule 1 (VCAM-1) via upregulation of nuclear factor-kappa B (NF-κB) expression and nuclear translocation. The in vivo animal model further demonstrated that CXCL1 serves as a critical promoter in osteosarcoma metastasis to the lung. The correlated expression of CXCL1 and VCAM-1 was observed in the immunohistochemistry staining from human osteosarcoma specimens. Our findings demonstrate the cascade mechanism regulating the network in lung metastasis osteosarcoma, therefore indicating that the CXCL1/CXCR2 pathway is a worthwhile candidate to further develop treatment schemas.

Aberrant ROS Mediate Cell Cycle and Motility in Colorectal Cancer Cells Through an Oncogenic CXCL14 Signaling Pathway.

Background: Reactive oxygen species (ROS) act as signal mediators to induce tumorigenesis. Objective: This study aims to explore whether chemokine CXCL14 is involved in the proliferation and migration of ROS-induced colorectal cancer (CRC) cells. Methods: The proliferative and migratory capacities of CRC cells treated with or without H2O2 were measured by various methods, including the CKK-8 assay, colony formation assay, flow cytometry, wounding healing assay, and migration assay. Results: The results revealed that H2O2 promoted the proliferation and migration of CRC cells by regulating the cell cycle progression and the epithelial to mesenchymal transition (EMT) process. Furthermore, we noted that the expression level of CXCL14 was elevated in both HCT116 cells and SW620 cells treated with H2O2. An antioxidant N-Acetyl-l-cysteine (NAC) pretreatment could partially suppress the CXCL14 expression in CRC cells treated with H2O2. Next, we constructed CRC cell lines stably expressing CXCL14 (HCT116/CXCL14 and SW620/CXCL14) and CRC cell lines with empty plasmid vectors (HCT116/Control and SW620/Control) separately. We noted that both H2O2 treatment and CXCL14 over-expression could up-regulate the expression levels of cell cycle-related and EMT-related proteins. Moreover, the level of phosphorylated ERK (p-ERK) was markedly higher in HCT116/CXCL14 cells when compared with that in HCT116/Control cells. CXCL14-deficiency significantly inhibited the phosphorylation of ERK compared with control (i.e., scrambled shNCs). H2O2 treatment could partially restore the expression levels of CXCL14 and p-ERK in HCT116/shCXCL14 cells. Conclusion: Our studies thus suggest that aberrant ROS may promote colorectal cancer cell proliferation and migration through an oncogenic CXCL14 signaling pathway.

Megakaryocyte progenitor cell function is enhanced upon aging despite the functional decline of aged hematopoietic stem cells.

SummaryAge-related morbidity is associated with a decline in hematopoietic stem cell (HSC) function, but the mechanisms of HSC aging remain unclear. We performed heterochronic HSC transplants followed by quantitative analysis of cell reconstitution. Although young HSCs outperformed old HSCs in young recipients, young HSCs unexpectedly failed to outcompete the old HSCs of aged recipients. Interestingly, despite substantial enrichment of megakaryocyte progenitors (MkPs) in old mice in situ and reported platelet (Plt) priming with age, transplanted old HSCs were deficient in reconstitution of all lineages, including MkPs and Plts. We therefore performed functional analysis of young and old MkPs. Surprisingly, old MkPs displayed unmistakably greater regenerative capacity compared with young MkPs. Transcriptome analysis revealed putative molecular regulators of old MkP expansion. Collectively, these data demonstrated that aging affects HSCs and megakaryopoiesis in fundamentally different ways: whereas old HSCs functionally decline, MkPs gain expansion capacity upon aging.

CDX2 enhances natural killer cell-mediated immunotherapy against head and neck squamous cell carcinoma through up-regulating CXCL14.

(NK) cells are at the first line of defence against tumours, but their anti‐tumour mechanisms are not fully understood. We aimed to investigate the mechanism by which NK cells can mediate immunotherapy against head and neck squamous cell carcinoma (HNSCC). We collected fifty‐two pairs of HNSCC tissues and corresponding adjacent normal tissues; analysis by RT‐qPCR showed underexpression of CXCL14 in HNSCC tissues. Primary NK cells were then isolated from the peripheral blood of HNSCC patients and healthy donors. CXCL14 was found to be consistently under‐expressed in the primary NK cells from the HNSCC patients. However, CXCL14 expression was increased in IL2‐activated primary NK cells and NK‐92 cells. We next evaluated NK cell migration, IFN‐γ and TNF‐α expression, cytotoxicity and infiltration in response to CXCL14 overexpression or knockdown using gain‐ and loss‐of‐function approach. The results exhibited that CXCL14 overexpression promoted NK cell migration, cytotoxicity and infiltration. Subsequent in vivo experiments revealed that CXCL14 suppressed the growth of HNSCC cells via activation of NK cells. ChIP was applied to study the enrichment of H3K27ac, p300, H3K4me1 and CDX2 in the enhancer region of CXCL14, which showed that CDX2/p300 activated the enhancer of CXCL14 to up‐regulate its expression. Rescue experiments demonstrated that CDX2 stimulated NK cell migration, cytotoxicity and infiltration through up‐regulating CXCL14. In vivo data further revealed that CDX2 suppressed tumorigenicity of HNSCC cells through enhancement of CXCL14. To conclude, CDX2 promotes CXCL14 expression by activating its enhancer, which promotes NK cell–mediated immunotherapy against HNSCC.

Chemokine signaling is required for homeostatic and injury-induced neurogenesis in the olfactory epithelium.

The olfactory epithelium (OE) possesses unique lifelong neuroregenerative capacities and undergoes constitutive neurogenesis throughout mammalian lifespan. Two populations of stem cells, frequently dividing globose basal cells (GBCs) and quiescent horizontal basal cells (HBCs), readily replace olfactory neurons throughout lifetime. Although lineage commitment and neuronal differentiation of stem cells has already been described in terms of transcription factor expression, little is known about external factors balancing between differentiation and self-renewal. We show here that expression of the CXC-motif chemokine receptor 4 (CXCR4) distinguishes both types of stem cells. Extensive colocalization analysis revealed exclusive expression of CXCR4 in proliferating GBCs and their neuronal progenies. Moreover, only neuronal lineage cells were derived from CXCR4-CreER-tdTomato reporter mice in the OE. Furthermore, Cre-tdTomato mice specific for HBCs (Nestin+ and Cytokeratin14+) did not reduce CXCR4 expression when bred to mice bearing floxed CXCR4 alleles, and did not show labeling of the neuronal cells. CXCR4 and its ligand CXCL12 were markedly upregulated upon induction of GBC proliferation during injury-induced regeneration. in vivo overexpression of CXCL12 did downregulate CXCR4 levels, which results in reduced GBC maintenance and neuronal differentiation. We proved that these effects were caused by CXCR4 downregulation rather than over-activation by showing that the phenotypes of CXCL12-overexpressing mice were highly similar to the phenotypes of CXCR4 knockout mice. Our results demonstrate functional CXCR4 signaling in GBCs regulates cell cycle exit and neural differentiation. We propose that CXCR4/CXCL12 signaling is an essential regulator of olfactory neurogenesis and provide new insights into the dynamics of neurogenesis in the OE.

Malignant cell-specific CXCL14 promotes tumor lymphocyte infiltration in oral cavity squamous cell carcinoma.

ObjectivesTo explore lymphocyte infiltration as a potential mechanism behind CXCL14-mediated tumor growth suppression in oral cavity squamous cell carcinoma (OSCC).MethodsWe analyzed single cell RNA-sequencing (scRNA-seq) data from OSCC to identify expression changes among malignant cells in lymph nodes (LN) versus primary tumors. CXCL14 expression in murine OSCC cell lines was quantified using qRT-PCR. Short hairpin RNA knockdown of CXCL14 was performed in mouse oral cavity (MOC)1 cells, and CXCL14 overexpression was performed in MOC2 cells. Cells in each condition were injected into C57BL/6 mice with and without T cell depletion, and tumor volume was measured. At 30 days, tumors were dissociated and analyzed by flow cytometry for CD45+CD3+ T cells. CXCL14 expression was correlated with gene expression signatures of tumor infiltrating lymphocytes (TIL) in scRNA-seq data, as well as TCGA tumors.ResultsscRNA-seq revealed CXCL14 as the most significantly downregulated gene among malignant cells in LNs relative to primary tumor, supporting a role in preventing invasion and/or metastasis. In a murine immunocompetent model, CXCL14 expression was higher in indolent MOC1 cells than in more aggressive MOC2 cells. Tumor growth in vivo was significantly increased by CXCL14 knockdown in MOC1 cells relative to control, with a corresponding decrease in TIL. In MOC2 cells, tumor growth was significantly reduced by CXCL14 overexpression relative to control and TIL were increased. Both effects were lost with T cell depletion. In a human tumor scRNA-seq cohort, we found that only malignant cell CXCL14, but not non-malignant cell or fibroblast CXCL14, was associated with TIL. Bulk CXCL14 from the TCGA cohort had no association with TIL.ConclusionsHigher CXCL14 expression by tumor cells is associated with reduced tumor growth and increased TIL, supporting immune-mediated suppression of tumor growth in OSCC. Given that CXCL14 is downregulated in LN metastases compared with primary tumors, our data raise the possibility that CXCL14-mediated immune infiltration may discourage invasion and metastasis. In human scRNA-seq data, only malignant cell-specific CXCL14 was associated with TIL, suggesting a critical context-dependent effect of CXCL14 expression.

Protective and Detrimental Roles of p38α Mitogen-Activated Protein Kinase in Different Stages of Nonalcoholic Fatty Liver Disease.

Neutrophil infiltration is a hallmark of nonalcoholic steatohepatitis (NASH), but how this occurs during the progression from steatosis to NASH remains obscure. Human NASH features hepatic neutrophil infiltration and up-regulation of major neutrophil-recruiting chemokines (e.g., chemokine [C-X-C motif] ligand 1 [CXCL1] and interleukin [IL]-8). However, mice fed a high-fat diet (HFD) only develop fatty liver without significant neutrophil infiltration or elevation of chemokines. The aim of this study was to determine why mice are resistant to NASH development and the involvement of p38 mitogen-activated protein kinase (p38) activated by neutrophil-derived oxidative stress in the pathogenesis of NASH. Inflamed human hepatocytes attracted neutrophils more effectively than inflamed mouse hepatocytes because of the greater induction of CXCL1 and IL-8 in human hepatocytes. Hepatic overexpression of Cxcl1 and/or IL-8 promoted steatosis-to-NASH progression in HFD-fed mice by inducing liver inflammation, injury, and p38 activation. Pharmacological inhibition of p38α/β or hepatocyte-specific deletion of p38a (a predominant form in the liver) attenuated liver injury and fibrosis in the HFD+Cxcl1 -induced NASH model that is associated with strong hepatic p38α activation. In contrast, hepatocyte-specific deletion of p38a in HFD-induced fatty liver where p38α activation is relatively weak exacerbated steatosis and liver injury. Mechanistically, weak p38α activation in fatty liver up-regulated the genes involved in fatty acid β-oxidation through peroxisome proliferator-activated receptor alpha phosphorylation, thereby reducing steatosis. Conversely, strong p38α activation in NASH promoted caspase-3 cleavage, CCAAT-enhancer-binding proteins homologous protein expression, and B cell lymphoma 2 phosphorylation, thereby exacerbating hepatocyte death. Genetic ablation of hepatic p38a increases simple steatosis but ameliorates oxidative stress-driven NASH, indicating that p38α plays distinct roles depending on the disease stages, which may set the stage for investigating p38α as a therapeutic target for the treatment of NASH.

CXCL12-CXCR4 Interplay Facilitates Palatal Osteogenesis in Mice.

Cranial neural crest cells (CNCCs), identified by expression of transcription factor Sox9, migrate to the first branchial arch and undergo proliferation and differentiation to form the cartilage and bone structures of the orofacial region, including the palatal bone. Sox9 promotes osteogenic differentiation and stimulates CXCL12-CXCR4 chemokine-receptor signaling, which elevates alkaline phosphatase (ALP)-activity in osteoblasts to initiate bone mineralization. Disintegration of the midline epithelial seam (MES) is crucial for palatal fusion. Since we earlier demonstrated chemokine-receptor mediated signaling by the MES, we hypothesized that chemokine CXCL12 is expressed by the disintegrating MES to promote the formation of an osteogenic center by CXCR4-positive osteoblasts. Disturbed migration of CNCCs by excess oxidative and inflammatory stress is associated with increased risk of cleft lip and palate (CLP). The cytoprotective heme oxygenase (HO) enzymes are powerful guardians harnessing injurious oxidative and inflammatory stressors and enhances osteogenic ALP-activity. By contrast, abrogation of HO-1 or HO-2 expression promotes pregnancy pathologies. We postulate that Sox9, CXCR4, and HO-1 are expressed in the ALP-activity positive osteogenic regions within the CNCCs-derived palatal mesenchyme. To investigate these hypotheses, we studied expression of Sox9, CXCL12, CXCR4, and HO-1 in relation to palatal osteogenesis between E15 and E16 using (immuno)histochemical staining of coronal palatal sections in wild-type (wt) mice. In addition, the effects of abrogated HO-2 expression in HO-2 KO mice and inhibited HO-1 and HO-2 activity by administrating HO-enzyme activity inhibitor SnMP at E11 in wt mice were investigated at E15 or E16 following palatal fusion. Overexpression of Sox9, CXCL12, CXCR4, and HO-1 was detected in the ALP-activity positive osteogenic regions within the palatal mesenchyme. Overexpression of Sox9 and CXCL12 by the disintegrating MES was detected. Neither palatal fusion nor MES disintegration seemed affected by either HO-2 abrogation or inhibition of HO-activity. Sox9 progenitors seem important to maintain the CXCR4-positive osteoblast pool to drive osteogenesis. Sox9 expression may facilitate MES disintegration and palatal fusion by promoting epithelial-to-mesenchymal transformation (EMT). CXCL12 expression by the MES and the palatal mesenchyme may promote osteogenic differentiation to create osteogenic centers. This study provides novel evidence that CXCL12-CXCR4 interplay facilitates palatal osteogenesis and palatal fusion in mice.