Intricate signaling cascades involving chemokines and their cognate receptors on neoplastic and immune constituents within tumor microenvironment have garnered substantial research interest. Our investigation delineates the contribution of Chemokine (C-C motif) ligand 16 (CCL16) to the clinico-pathological features and tumorigenesis of hepatocellular carcinoma (HCC). Analysis of 237 pairs of HCC specimens unraveled a significant association between CCL16 expression and vascular invasion, early-stage clinicopathological features, and diminished recurrence-free survival among HCC patients. Immunohistochemical (IHC) assays of the clinical HCC specimens indicated elevated CCL16 in tumorous versus normal hepatic tissues. Our in vivo experiments demonstrated CCL16 overexpression fostered tumor proliferation, whereas in vitro assays elucidated that CCL16-mediated chemotactic recruitment of monocytes and M2 macrophages was orchestrated via CCR1 and CCR5. In contrast to previous claims that CCL16 is physiologically irrelevant and has minimal affinity for its receptors (CCR1, CCR2, CCR5, CCR8), our findings unravel that inhibition of CCL16/CCR1 and CCL16/CCR5 interactions through receptor-specific antagonists markedly impeded CCL16-directed chemotaxis, migration, adhesion, and leukocyte recruitment. Moreover, CCL16-overexpression in HCCs significantly augmented levels of several cytokines implicated in tumor progression, namely IL-6, IL-10 and VEGFA. IHC analysis of CCL16-overexpressing xenografts elicited greatly enhanced levels of VEGFA and IL-6, while assessments of HCC specimens confirmed a positive correlation between CCL16 expression and IL-6 and VEGFA levels. Collectively, our study highlights oncogenic role of CCL16 in hepatocarcinogenesis and provides a foundational basis for novel therapeutic interventions targeting the CCL16/CCR1/CCR5 axis.

BACKGROUND: Increased proinflammatory molecules are a main reason for severe symptoms in patients infected with SARS-CoV-2. This study evaluated mutations in the S gene of SARS-CoV-2 and the expression of hsa-miR-223-5p, interleukin 2 receptor α (IL-2Rα), and CCL16 chemokine in hospitalized SARS-CoV-2 infected patients.
METHODS: This is a cross-sectional study.
METHODS: This study included 75 SARS-CoV-2-infected patients with severe symptoms and 75 age-sex-matched healthy controls. Real-time polymerase chain reaction techniques were used to evaluate the expression levels of hsa-miR-223-5p, IL-2Rα, and CCL16 chemokine. The Sanger technique was used to sequence the S gene of SARS-CoV-2 from positions 23,274 to 23,641.
RESULTS: The relative expression of hsa-miR-223-5p was significantly increased whereas that of IL-2Rα was significantly decreased in the SARS-CoV-2 infected patients. Two mutations were found in the S gene of SARS-CoV-2 at positions 23,403 (p.Asp23403Gly) and 23,525 (p.His23525Tyr) of the S gene of SARS-CoV-2.
CONCLUSIONS: Increased hsa-miR-223-5p may be a main cause for the downregulation of IL-2Rα, which is a main developer of T-regulatory lymphocytes. The mutations in the S gene of SARS-CoV-2-infected patients may affect immune responses to the molecule and alter the avidity of virus-human cell interactions.

The heterogeneity of the tumor microenvironment significantly influences the prognosis of hepatocellular carcinoma (HCC) patients, with cell communication through ligand-receptor complexes playing a central role.
We conducted single-cell transcriptomic analysis on ten HCC tissues to identify ligand-receptor genes involved in malignant HCC cell communication using CellChat. Leveraging RNA-Seq data from the TCGA Liver Cancer (TCGA-LIHC) and Liver Cancer - RIKEN, JP (LIRI-JP) cohorts, we employed Cox regression analysis to screen for prognosis-related genes. Prognostic risk models were constructed through unsupervised clustering and differential gene expression analysis. Subsequently, a co-culture system involving tumor cells and macrophages was established. A series of experiments, including Transwell assays, immunofluorescence staining, immunoprecipitation, flow cytometry, and immunohistochemistry, were conducted to elucidate the mechanism through which HCC cells recruit macrophages via the CCL16-CCR1 axis.
Single-cell analysis unveiled significant interactions between malignant HCC cells and macrophages, identifying 76 related ligand-receptor genes. Patients were classified into three subtypes based on the expression patterns of eight prognosis-related ligand-receptor genes. The subtype with the worst prognosis exhibited reduced infiltration of T cell-related immune cells, downregulation of immune checkpoint genes, and increased M2-like tumor-associated macrophage scores. In vitro experiments confirmed the pivotal role of the CCL16-CCR1 axis in the recruitment and M2 polarization of tumor-associated macrophages. Clinical samples demonstrated a significant association between CCL16 protein expression levels and advanced stage, lymph node metastasis, and distant metastasis. Immunohistochemistry and immunofluorescence staining further confirmed the correlation between CCL16 and CCR1, CD68, and CD206, as well as CD68+CCR1+ macrophage infiltration.
Our study identified molecular subtypes, a prognostic model, and immune microenvironment features based on ligand-receptor interactions in malignant HCC cell communication. Moreover, we revealed the pro-tumorigenic role of HCC cells in recruiting M2-like tumor-associated macrophages through the CCL16-CCR1 axis.

Considering the crucial role of long non-coding RNAs (lncRNAs) in non-small cell lung cancer (NSCLC), we tried to analyze the role of extracellular vesicle (EV)-derived LINC00482 in the occurrence of brain metastasis in NSCLC. LINC00482 expression was quantified in EVs isolated from serum samples of NSCLC patients (serum-EVs). Ectopic expression and depletion assays were conducted in the microglial cell line HMC3 co-cultured with serum-EVs and in xenograft mouse models of NSCLC to explore the roles of EV-carried LINC00482. LINC00482 was enriched in serum-EVs and induced M2 polarization of microglial cells HMC3 in vitro. LINC00482 competitively bound to miR-142-3p and upregulated the expression of miR-142-3p target gene TGF-β1 in HMC3 cells, thus promoting microglial M2 polarization. EV-derived LINC00482-induced M2 microglia promoted the malignant properties of NSCLC cells. In vivo data demonstrated that EVs transmitted LINC00482 to regulate the miR-142-3p/TGF-β1 axis, induce microglial M2 polarization and affect the pre-metastatic niche, thus enhancing brain metastasis of NSCLC. Overall, suppression of the expression of tumor-derived LINC00482 or LINC00482-containing EVs, may serve as an effective target for contributing to the reduction of brain metastasis of NSCLC.

BACKGROUND: Circular RNA (circRNA) has been found to play an important role in the progression of many diseases, including infantile pneumonia. However, the role of circ_0044411 in infantile pneumonia progression is still unclear.
METHODS: MRC-5 cells were incubated with lipopolysaccharide (LPS) for 12 h to establish the in vitro cellular model for infantile pneumonia. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the levels of circ_0044411, miR-141-3p (micoRNA-141-3p) and CCL16 (CC motif chemokine ligand 16). Cell viability and proliferation was assessed by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay and 5-ethynyl-2\'-deoxyuridine (EdU) assay. The levels of inflammatory factors IL-1β, IL-6 and TNF-α were determined by enzyme-linked immunosorbent assay kits. Cell apoptosis and caspase-3 activity were detected by flow cytometry analysis and caspase-3 activity assay kit. The target interaction was confirmed by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay.
RESULTS: Circ_0044411 was highly repressed in the serum of infantile pneumonia patients and LPS-induced MRC-5 cells. Circ_0044411 could promote the cell viability and proliferation, inhibit inflammatory response and apoptosis in LPS-induced MRC-5 cells. Circ_0044411 could serve as a sponge of miR-141-3p, and miR-141-3p could reverse the function of circ_0044411 on LPS-induced MRC-5 cell injury. In addition, miR-141-3p could target CCL16, and miR-141-3p could protect MRC-5 cells from LPS-induced cell injury by targeting CCL16. Furthermore, circ_0044411 sponged miR-141-3p to positively regulate CCL16 expression.
CONCLUSIONS: Circ_0044411 knockdown promoted cell viability and proliferation, inhibited inflammatory response and apoptosis by regulating miR-141-3p/CCL16 axis, indicating that circ_0044411 might be a potential therapeutic target for IP.

Human C-C motif ligand 16 (CCL16) is a chemokine that is distinguished by a large cleavable C-terminal extension of unknown significance. Conflicting data have been reported concerning its tissue distribution and modulation of expression, rendering the biological function of CCL16 enigmatic. Here, we report an integrated approach to the characterisation of this chemokine, including a re-assessment of its expression characteristics as well as a biophysical investigation with respect to its structure and dynamics. Our data indicate that CCL16 is chiefly synthesised by hepatocytes, without an appreciable response to mediators of inflammation, and circulates in the blood as a full-length protein. While the crystal structure of CCL16 confirms the presence of a canonical chemokine domain, molecular dynamics simulations support the view that the C-terminal extension impairs the accessibility of the glycosaminoglycan binding sites and may thus serve as an intrinsic modulator of biological activity.

Multiple studies have investigated the role of blood circulating proteins in COVID-19 disease using the Olink affinity proteomics platform. However, study inclusion criteria and sample collection conditions varied between studies, leading to sometimes incongruent associations. To identify the most robust protein markers of the disease and the underlying pathways that are relevant under all conditions, it is essential to identify proteins that replicate most widely. Here we combined the Olink proteomics profiles of two newly recruited COVID-19 studies (N=68 and N=98) with those of three previously published COVID-19 studies (N=383, N=83, N=57). For these studies, three Olink panels (Inflammation and Cardiovascular II & III) with 253 unique proteins were compared. Case/control analysis revealed thirteen proteins (CCL16, CCL7, CXCL10, CCL8, LGALS9, CXCL11, IL1RN, CCL2, CD274, IL6, IL18, MERTK, IFNγ, and IL18R1) that were differentially expressed in COVID-19 patients in all five studies. Except CCL16, which was higher in controls, all proteins were overexpressed in COVID-19 patients. Pathway analysis revealed concordant trends across all studies with pathways related to cytokine-cytokine interaction, IL18 signaling, fluid shear stress and rheumatoid arthritis. Our results reaffirm previous findings related to a COVID-19 cytokine storm syndrome. Cross-study robustness of COVID-19 specific protein expression profiles support the utility of affinity proteomics as a tool and for the identification of potential therapeutic targets.

UNASSIGNED: Emerging evidence shows that long noncoding RNA (lncRNA) has been a novel insight in various diseases, including pneumonia. Even though lncRNA X-inactive-specific transcript (XIST) is well studied, its role in pneumonia remains to be largely unrevealed.
UNASSIGNED: Expression of XIST, miRNA-30b-5p (miR-30b-5p), and CC chemokine ligand 16 (CCL16) was detected using reverse transcriptase quantitative polymerase chain reaction and western blotting; their interaction was confirmed by dual-luciferase reporter assay. Apoptosis, inflammation, and toll-like receptor 4 (TLR4)/NF-κB signaling pathway were measured using methyl thiazolyl tetrazolium assay, flow cytometry, western blotting, and enzyme-linked immunosorbent assay.
UNASSIGNED: Lipopolysaccharide (LPS) stimulation decreased cell viability and B cell lymphoma (Bcl)-2 expression, and increased cell apoptosis rate and expression of Bcl-2-associated X protein (Bax), cleaved-caspase-3, interleukin (IL)-6, IL-1β, and tumor necrosis factor α (TNF-α) in WI-38 cells. Expression of XIST and CCL16 was upregulated in the serum of patients with pneumonia and LPS-induced WI-38 cells, respectively; silencing XIST and CCL16 could suppress LPS-induced apoptosis and inflammation in WI-38 cells, and this protection was abolished by miR-30b-5p downregulation. Moreover, XIST and CCL16 could physically bind to miR-30b-5p, and XIST regulated CCL16 expression via sponging miR-30b-5p. TLR4 and phosphorylated P65 (p-P65) and p-IκB-α were highly induced by LPS treatment, and this upregulation was diminished by blocking XIST, accompanied with CCL16 downregulation and miR-30b-5p upregulation.
UNASSIGNED: Silencing XIST could alleviate LPS-induced inflammatory injury in human lung fibroblast WI-38 cells through modulating miR-30b-5p/CCL16 axis and inhibiting TLR4/NF-κB signaling pathway.

Rationale: Considerable evidence suggests that breast cancer metastasis and recurrence occur due to emergence of cancer stem cells (CSCs). In our previous study, we designed a high-throughput siRNA screening platform that identifies inflammation genes involved in the regulation of cancer cell stemness. We reported that CCL16 protein decreases OCT4 expression and reduces the ALDH+ subpopulation. However, the mechanism by which CCL16 maintains stem cell-like properties remains unclear. Methods: Tissue microarrays were used to evaluate CCL16 expression. Cancer stemness assays were performed in CCL16 knockdown and overexpressing cells in vitro and in a xenograft model in vivo. Human phosphokinase array, immunofluorescence and chromatin immunoprecipitation assays were performed to explore the underlying mechanism. Results: We report that CCL16 was overexpressed in breast tumors and significantly correlated with clinical progression. We found that silencing CCL16 in MDA-MB-231 and BT549 cells diminished CSC properties including ALDH+ subpopulation, side population, chemo-resistance, and sphere formation. Furthermore, mice bearing CCL16-silenced MDA-MB-231 xenografts had lower tumorigenic frequency and developed smaller tumors. Exploration of the underlying mechanism found that CCL16 selects CCR2 to activate p-AKT/GSK3β signaling and facilitate β-catenin nuclear translocation. Further, CCL16 binds to the OCT4 promoter and promotes OCT4 expression. In addition, shRNAs targeting CCR2 and XAV939 targeting β-catenin abolished CCL16-mediated cancer stemness. Upstream, IL10 mediates STAT3 activation, which binds to the CCL16 promoter and enhances its expression. The STAT3-targeted inhibitor Stattic suppressed CCL16 expression in vitro and restrained tumor progression in vivo. Conclusions: We identified a potential CSC regulator and suggest a novel mechanism for how CCL16 governs cancer cell stemness. We propose that CCL16 could be an effective target for breast cancer therapy.

OBJECTIVE: The aim of this study was to investigate the effect of the medical and the surgical treatment on the olfactory functions, clinical scoring systems and inflammation markers in patients with nasal polyposis. In addition, the secondary aim was to investigate the correlation between those investigated parameters.
METHODS: A total of 30 patients, who completed the standardized medical and surgical treatment and also came to 3 months of follow-ups regularly after the surgery, were included in the study. The Sniffin\' Sticks olfactory tests, radiological and the endoscopic stagings, liver-expressed chemokine (CCL16) and endothelin (ET) levels and sino-nasal outcome test-22 (SNOT-22) were performed at the initial and at the end of the study.
RESULTS: The current study had four major findings: (1) significant improvement in odor functions after treatment was determined; however, the majority of the patients had been already hyposmic. (2) In addition, significant improvement was found in ET and CCL16 levels, SNOT-22 results, and radiologic and endoscopic stagings at the end of the study. (3) However, there was no correlation between the olfactory functions and the investigated parameters. (4) There was a positive correlation between polyp recurrence and ET levels.
CONCLUSIONS: The standardized medical and surgical treatment provided a significant improvement in the olfactory functions. However, only one patient (3.3%) had become normosmic at the end of the study.