Search Results (449)

We investigated the role of the intermediate-conductance, Ca²⁺-activated K⁺ channel K_Ca3.1 and volume-regulatory anion channel LRRC8A in regulating C-C motif chemokine ligand 2 (CCL2) expression in THP-1-differentiated M₂ macrophages (M₂-MACs), which serve as a useful model for studying tumor-associated macrophages (TAMs). CCL2 is a potent chemoattractant involved in the recruitment of immunosuppressive cells and its expression is regulated through intracellular signaling pathways such as ERK, JNK, and Nrf2 in various types of cells including macrophages. The transcriptional expression of CCL2 was suppressed in M₂-MACs following treatment with a K_Ca3.1 activator or an LRRC8A inhibitor via distinct signaling pathways: ERK–CREB2 and JNK–c-Jun pathways for K_Ca3.1, and the NOX2–Nrf2–CEBPB pathway for LRRC8A. Under in vitro conditions mimicking the elevated extracellular K⁺ concentration ([K⁺]_e) characteristic of the tumor microenvironment (TME), CCL2 expression was markedly upregulated, and this increase was reversed by treatment with them in M₂-MACs. Additionally, the WNK1–AMPK pathway was, at least in part, involved in the high [K⁺]_e-induced upregulation of CCL2. Collectively, modulating K_Ca3.1 and LRRC8A activities offers a promising strategy to suppress CCL2 secretion in TAMs, potentially limiting the CCL2-induced infiltration of immunosuppressive cells (TAMs, T_regs, and MDSCs) in the TME. Full article

Background and Objectives: Patients with GG rs738409 patatin-like phospholipase domain-containing protein 3 (PNPLA3) genotype (148M variant) have greater risk to develop end-stage liver disease and its associated clinical complications, including hepatocellular carcinoma (HCC). We aimed to analyze the association between the PNPLA3 genotype and augmented inflammatory response in transplant candidates with end-stage alcoholic liver disease (ALD). Materials and Methods: Concentrations of 13 cytokines were measured in 106 end-stage ALD patients without HCC (40 with CC, 40 with CG, and 26 with GG genotype), 35 end-stage ALD patients with HCC, and 19 control patients by cytometric bead array. Results: We found significantly higher concentrations of IL-1, IFN-α, IFN-γ, TNF-α, IL-6, CXCL8, IL-10, IL-12, IL-32, and IL-33 in patients with ALD compared to controls, while the concentration of CCL2 was significantly lower. No differences were observed in the concentration of IL-17 and IL-18. ALD patients with and without HCC had similar cytokine concentrations (p > 0.05 for all comparisons). End-stage ALD patients without HCC of the GG genotype had significantly higher CCL2 concentrations (212.6 [135.9–264.9] pg/mL) compared to end-stage ALD patients without HCC carrying the CC/CG genotypes (141.3 [104.1–201.6] pg/mL, p = 0.002, Mann–Whitney). No significant differences across the genotypes were found for the remaining measured cytokines (p > 0.05). GG carriers also had significantly higher levels of AST and ALT, and lower platelet counts. Conclusions: End-stage ALD patients without HCC who carry the PNPLA3 GG genotype have relatively higher CCL2 levels compared to those with the CC or CG genotypes. Relatively elevated CCL2 concentrations in GG patients might contribute to their increased risk of developing clinical complications compared to CC/CG patients. Full article

Ovarian cancer, the most lethal form of gynecological cancer worldwide with a poor prognosis, is largely driven by an immunosuppressive tumor microenvironment. In this study, we investigated the anticancer effects of hydnocarpin, a natural flavonolignan derived from the flowers of Pueraria lobata, focusing on its effects on ovarian cancer and tumor-associated immune cells, including ovarian cancer-stimulated macrophages (MQs) and T cells. Hydnocarpin exhibited potent cytotoxicity against multiple ovarian cancer cell lines but only minimal toxicity against normal ovarian surface epithelial cells. Mechanistically, hydnocarpin triggered caspase-dependent apoptosis, as evidenced by the activation of caspase-9 and -3, with limited involvement of caspase-8, indicating the activation of the intrinsic apoptotic pathway. Experimental data implicated reactive oxygen species generation as a key mediator of hydnocarpin cytotoxicity, and reactive oxygen species inhibition significantly inhibited this cytotoxicity. In addition to its direct tumoricidal effects, hydnocarpin reprogrammed the tumor-associated immune cells, ovarian cancer-stimulated macrophages and T cells, by downregulating the levels of M2 MQ markers and pro-tumoral factors (matrix metalloproteinase-2/9, C–C motif chemokine ligand 5, transforming growth factor-β, and vascular endothelial growth factor) and enhancing MQ phagocytosis. Additionally, hydnocarpin promoted T-cell activation (interferon-γ and interleukin-2) and reduced the expression levels of immune evasion markers (CD80, CD86, and VISTA). Overall, this study demonstrated the dual anti-tumor effects of hydnocarpin on both ovarian cancer cells and immunosuppressive immune components in the tumor microenvironment, highlighting its potential as a novel therapeutic candidate for ovarian cancer. Full article

Compelling evidence has demonstrated a bidirectional relationship between Sjögren’s syndrome (SS) and periodontitis (PD). Nevertheless, the underlying mechanisms driving their co-occurrence remain unclear, highlighting the need for finding the hub gene. This study sought to examine the common genes and any connections between SS and PD. Differently expressed genes (DEGs) were analyzed by means of gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and least absolute shrinkage and selection operator (LASSO) methods. The test and validation sets were used to depict the receiver operating characteristic (ROC) curves. The immune cell infiltration was performed via the cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) methodology. The relationships between immune infiltrating cells and the common gene were examined. Ninety-five common genes with similar expression trends were obtained after DEGs analysis, which were enriched in cytokine—cytokine receptor interaction, chemokine signaling pathway, proteasome, intestinal immune network for IgA production, and cytosolic DNA sensing pathway. Thirty-nine common genes were obtained after WGCNA. Sixteen shared genes of DEGs analysis and WGCNA were incorporated into the LASSO model to obtain the unique shared gene, C-C motif chemokine receptor 1 (CCR1), which overexpressed and owned predictable ROC curves in test and validation sets. The examination of immune cell infiltration underscored its crucial roles in the disturbance of immune homeostasis and the emergence of pathogenic circumstances with the simultaneous occurrence of SS and PD. CCR1 overexpresses and serves as a critical pathogenic hub linking SS and PD, which may play a role through immune cell infiltration. Full article

Psoriasis is a chronic inflammatory skin disease characterized by erythema, infiltration, and scaling, which is mainly caused by interleukin (IL)-17. The use of molecular targeted drugs in specific therapies offers high efficacy; however, high medical costs and a significant risk of side effects highlight the need for novel therapeutic agents. We previously observed that Morus alba extract (MAE) suppressed IL-17-induced CCL20 mRNA expression in normal human epidermal keratinocytes (NHEKs). In this study, we focused on the IL-17 signaling pathway and investigated the effects of pentacyclic triterpenoids, betulinic acid (BA), and ursolic acid (UA), which are present in MAE, on NHEK cells. Real-time reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) revealed that both BA and UA suppressed CCL20 expression, while only UA alone inhibited CCL20 release. ELISA using specific inhibitors demonstrated that both the p38 and extracellular-signal-regulated kinase 1/2 (ERK1/2) pathways were crucial for IL-17-induced CCL20 release in NHEK. UA effectively suppressed ERK1/2 nuclear localization and moderately affected p38 phosphorylation. These results indicated that UA is a potential seed compound for psoriasis treatment through its targeting of the IL-17 pathway. Full article

While there are many postulates for the etiology of post-viral chronic fatigue and other symptomatology, little is known. We draw on our past experience of these syndromes to devise means which can expose the primary players of this malady in terms of a panoply participating biomolecules and the state of the stool microbiome. Using databases established from a large dataset of patients at risk of colorectal cancer who were followed longitudinally over 3 decades, and a smaller database dedicated to building a Long PASC cohort (Post-Acute Sequelae of COVID-19), we were able to ascertain factors that predisposed patients to (and resulted in) significant changes in various biomarkers, i.e., the stool microbiome and serum cytokine levels, which we verified by collecting stool and serum samples. There were significant changes in the stool microbiome with an inversion from the usual Bacillota and Bacteroidota species. Serum cytokines showed significant differences in MIP-1β versus TARC (CC chemokine ligand 17) in patients with either PASC or COVID-19 (p < 0.02); IL10 versus IL-12p70a (p < 0.02); IL-1b versus IL-6 (p < 0.01); MCP1 versus TARC (p < 0.03); IL-8 versus TARC (p < 0.002); and Eotaxin3 versus TARC (p < 0.004) in PASC. Some changes were seen solely in COVID-19, including MDC versus MIP-1α (p < 0.01); TNF-α versus IL-1-β (p < 0.06); MCP4 versus TARC (p < 0.0001). We also show correlates with chronic fatigue where an etiology was not identified. These findings in patients with positive criteria for PASC show profound changes in the microbiome and serum cytokine expression. Patients with chronic fatigue without clear viral etiologies also have common associations, including a history of tonsillectomy, which evokes a likely immune etiology. Full article

Metabolic syndrome (MetS), characterized by obesity, insulin resistance, and dyslipidemia, is a major risk factor for renal injury. Oxidative stress (OxS) plays a pivotal role in its progression; however, the underlying molecular mechanisms are not fully understood. In this study, we established a rat model of MetS using a high-fat diet combined with a single-dose streptozotocin injection in male Wistar rats. MetS rats exhibited systemic OxS, evidenced by elevated circulating levels of free oxygen radicals and decreased antioxidant defense capacity, as well as hypertension, renal lipid peroxidation, glomerular hyperfiltration, and renal tubular injury. Transcriptomic profiling of renal tissue revealed significant downregulation of six OxS-related genes: C-C motif chemokine ligand 5 (CCL5), glutamate-cysteine ligase catalytic subunit, glutathione peroxidase 6, recombination activating gene 2, NAD(P)H: quinone oxidoreductase 1, and selenoprotein P-1. Among these downregulated genes, CCL5 was further confirmed to be repressed at both mRNA and protein levels across intrarenal and systemic compartments. Given its documented functions in immune signaling and redox homeostasis, CCL5 downregulation may contribute to enhanced oxidative damage in MetS-associated renal injury. These findings highlight the role of redox gene dysregulation in the pathogenesis of MetS-related kidney disease and support the potential of CCL5 as a biomarker for oxidative renal injury. Full article

Hepatitis B virus (HBV) infection is one of the most dangerous viral diseases, with innate immunity representing the first line of defense against the virus. In this branch of the immune system, neutrophils are considered key cellular mediators. To better understand the implication of neutrophils in the distinct stages of the disease, HBV-infected patients were enrolled in this study and categorized into three groups: patients with acute infection, chronic infection under treatment, and at early cirrhotic stage. To elucidate the role of inflammatory mediators and cellular mechanisms of neutrophilic origin in the course of the infection, both ex vivo and in vitro studies were performed. Increased levels of C-C motif chemokine ligand 2 (CCL2), interleukin (IL)-18, IL-33, and citrullinated histone H3 (CitH3)—an accurate marker of neutrophil extracellular traps (NETs)—were detected in the circulation of patients with acute infection or early cirrhosis. In parallel, sera from the aforementioned patient groups induced the formation of IL-1b-bearing NETs in neutrophils from healthy individuals. These inflammatory NETs affected primary fibroblasts towards acquiring a pro-fibrotic phenotype. These results suggest that NETs could be regarded as mediators in hepatitis B manifestations, while their therapeutic targeting could enhance the management of early-stage cirrhotic patients. Full article

Mogamulizumab is a humanized monoclonal antibody that targets C-C chemokine receptor 4 (CCR4) present on certain T cells in lymphomas and leukemias. This antibody-based therapy has demonstrated efficacy in treating various cutaneous T cell lymphomas (CTCLs), including mycosis fungoides and Sézary syndrome, through the depletion of CCR4-expressing T cells by antibody-dependent cellular cytotoxicity (ADCC). However, the precise epitope and binding mode of mogamulizumab responsible for its augmented ADCC activity remain undisclosed. Here, X-ray crystallographic studies of mogamulizumab in complex with a 28-residue N-terminal peptide indicated that SIYSNYYLYES (residues 14–24) would constitute the antibody epitope. Another high-resolution structure, using a short core peptide of these 11 residues, has elucidated unambiguous electron density for the bound peptide, confirming consistent binding for both peptides. This linear epitope is located in the membrane-proximal region of CCR4, facilitating the Fc-mediated effector functions, including ADCC. The structures also provide insights into the molecular basis for the resistance of the CCR4 L21V variant to mogamulizumab, which is due to a lack of structural complementarity with mogamulizumab binding. Understanding the structural basis for the mechanism of action of mogamulizumab is crucial for optimizing anti-CCR4 therapeutics to improve treatment outcomes for patients with these challenging diseases. Full article

Background/Objectives: Cellular aging represents a crucial element in the progression of musculoskeletal diseases, contributing to muscle atrophy, functional decline, and alterations in bone turnover, which promote fragility fractures. However, knowledge about expression patterns of factors potentially involved in aging and senescence at the tissue level remains limited. Our pilot study aimed to characterize the expression profile of cell cycle regulators, factors released by aged cells, and sirtuin 1 (SIRT1) in the muscle tissue of 26 elderly patients undergoing hip arthroplasty, including 13 with low-energy fracture and 13 with osteoarthritis (OA). Methods: The mRNA expression levels of cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin-dependent kinase inhibitor 1B (CDKN1B), cyclin-dependent kinase inhibitor 2A (CDKN2A), p53, tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-15 (IL-15), chemokine (C-C motif) ligand 2 (CCL2), chemokine (C-C motif) ligand 3 (CCL3), growth differentiation factor 15 (GDF15), and SIRT1 were evaluated in muscle tissue by qRT-PCR. In addition, immunohistochemistry and Western blotting analysis were conducted to measure the protein levels of SIRT1. Results: A marked muscle atrophy was observed in fractured patients compared to the OA group, in association with an up-regulation of cell cycle regulators and factors released by the aged cells. The expression of matrix metallopeptidase 3 (MMP3), plasminogen activator inhibitor 1 (PAI-1), and fas cell surface death receptor (FAS) was also investigated, although no significant differences were observed between the two experimental groups. Notably, SIRT1 expression was significantly higher in OA patients, confirming its role in maintaining muscle health during aging. Conclusions: Further studies will be needed to clarify the role of SIRT1 in the senescence characteristic of age-related musculoskeletal disorders, counteracting the muscle atrophy that predisposes to fragility fractures. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease worldwide, contributing to metabolic dysfunction and increased healthcare costs. The green Mediterranean diet reduces intrahepatic fat and elevates the plasma levels of 2,5-dihydroxybenzoic acid (2,5-DHBA), suggesting a mechanistic role for 2,5-DHBA in hepatic lipid metabolism. This study aimed to evaluate the therapeutic potential of 2,5-DHBA in MASLD and elucidate its molecular mechanism. Methods: Lipid accumulation was assessed in oleic acid-treated HepG2 cells and a high-fat diet (HFD)-induced MASLD mouse model. RNA sequencing, molecular docking, and immunohistochemical staining were performed to investigate the molecular mechanisms, focusing on the chemokine (C-C motif) ligand 2 (CCL2)–CCL2 receptor (CCR2) axis. Results: 2,5-DHBA significantly reduced hepatic lipid accumulation in both HepG2 cells and HFD-fed mice in a dose-dependent manner. RNA sequencing revealed the marked downregulation of CCL2, a key proinflammatory mediator in MASLD pathogenesis. Molecular docking predicted that 2,5-DHBA competed with CCL2 for binding at the CCR2 axis. Immunohistochemistry further confirmed that 2,5-DHBA treatment lowered hepatic CCL2 expression, suppressed nuclear factor-κB activation, and reduced inflammatory cell infiltration. These findings suggest that 2,5-DHBA exerted anti-steatotic effects by modulating the CCL2-CCR2 signaling pathway. Conclusions: This is the first study to demonstrate that 2,5-DHBA attenuates hepatic steatosis via targeting the CCL2-CCR2 axis. These findings highlight its potential as a novel nutraceutical strategy for MASLD treatment. Full article

Background. Despite the high transmissibility of SARS-CoV-2, some individuals remain uninfected despite prolonged exposure to a high viral load, suggesting the involvement of an innate resistance mechanism, possibly underpinned by the host’s genetic factors. The angiotensin-converting enzyme-1 (ACE1), ACE2, and C-C Chemokine Receptor 5 (CCR5) polymorphisms have been shown to influence susceptibility to the infection. In this study, the role of ACE1, ACE2, and CCR5 gene polymorphisms in modulating susceptibility to SARS-CoV-2 infection within the context of intimate contact was evaluated. Methods. A cohort of heterosexual couples from Northern Sardinia, characterized by a homogenous genetic background, was recruited during the initial pandemic wave (March–June 2020). In each couple, one partner (index case) tested positive for SARS-CoV-2 by at least two consecutive independent molecular tests (real-time polymerase chain reaction: RT-PCR) on nasopharyngeal swabs. Bed-sharing partners of SARS-CoV-2 positive index cases, resistant and susceptible to the infection, were genotyped for ACE1 287 bp Alu repeat insertion/deletion (I/D) polymorphism, ACE2 G8790A (rs2285666) variant, and a 32-base pair deletion (Δ32) of CCR5. Resistant and susceptible partners to the infection were compared for polymorphisms. Results. Out of 63 couples, 30 partners acquired SARS-CoV-2 infection, while 33 remained uninfected despite intimate exposure. Clinical history was minimal for current or past illnesses. SARS-CoV-2-infected index spouses and partners who acquired the infection developed a mild disease, not requiring hospitalization. The observed distribution of ACE1 I/D and ACE2 G8790A genotypes was consistent with previously reported frequencies in Sardinia and across European populations. None of the study participants carried the CCR5-Δ32 variant. No statistically significant differences (p > 0.05) in the allelic or genotypic frequencies of these polymorphisms were observed between the infected and resistant partners. Conclusions. No differences in the distribution of ACE1, ACE2, and CCR5 polymorphisms between the two groups were detected. These findings suggest that resistance is likely multifactorial, involving a complex interplay of genetic, immunological, and environmental factors. Full article

Background/Objectives: We reported previously that antagonists at chemokine receptors CCR2 and CCR3 have fluid-sparing effects during resuscitation from hemorrhagic shock. Because CCR1 shares several chemokine ligands with CCR2/3, we tested whether the CCR1 antagonist BX471 also reduces fluid requirements to maintain hemodynamics. Methods: Sprague Dawley rats were hemorrhaged for 30 min, followed by fluid resuscitation to maintain blood pressure for 60 min (series 1) and 180 min (series 2). Series 1: Animals received vehicle (n = 5), 0.05 μmol/kg (n = 5), or 0.5 μmol/kg (n = 4) BX471 at t = 30 min. Series 2: Animals received vehicle (n = 8) or 0.5 μmol/kg (n = 7) BX471 at t = 30 min. Hemodynamics, fluid requirements, blood gases, and lactate were monitored. Serum concentrations of CCR1 ligands (CCL3/4/5/7) were determined at baseline and at the conclusion of the experiments. Tissue (small/large intestine, lung) wet/dry (W/D) weight ratios, lung myeloperoxidase activity, and a panel of inflammation markers in tissue extracts were measured. Results: All animals could be resuscitated to target blood pressures. Series 1: A total of 0.5 μmol/kg BX471 reduced fluid requirements by more than 60% (p < 0.05 vs. vehicle and 0.05 μmol/kg BX471). Series 2: Systemic CCL3/5/7 levels increased during the experiment (p < 0.05). BX471-treatment reduced fluid requirements by more than 60% (p < 0.05) and prevented increases in CCL3/7. W/D ratios of large intestine and of the sum of all tissues were lower with BX471 treatment (p < 0.05). BX471-treatment reduced TNFα and IL6 concentrations in large intestine extracts (p < 0.05). Conclusions: Our findings suggest CCR1 as a new therapeutic target to reduce fluid requirements during resuscitation from hemorrhagic shock. Full article

C-C motif ligand 11 (CCL11) is a multifunctional chemokine that regulates immunity, angiogenesis, and tissue remodeling. In addition to its allergic inflammation role, CCL11 exhibits context-dependent dual functions in relation to cancer progression. In liver diseases, it mediates injury, fibrosis, and inflammation while serving as a disease biomarker. This review systematically examines CCL11–receptor interactions and their immunomodulatory mechanisms in cancers and hepatic pathologies. We highlight CCL11’s therapeutic potential as both a prognostic marker and immunotherapeutic target. By integrating molecular and clinical insights, this work advances the understanding of CCL11’s pathophysiological roles and facilitates targeted therapy development. Full article

Tissue-resident macrophages (TRMs) play a crucial role in maintaining tissue homeostasis and regulating immune responses. In recent years, an increasing number of studies have highlighted their central role in cardiovascular diseases. This review provides a comprehensive overview of TRMs, with a particular emphasis on cardiac resident macrophages (CRMs), discussing their origin, heterogeneity, and functions in various cardiovascular diseases. We conduct an in-depth analysis of macrophage subpopulations based on C-C Chemokine Receptor Type 2 (CCR2) receptor expression, elucidating the role of CCR2⁺ macrophages in promoting fibrosis and cardiac remodeling, while highlighting the protective functions of CCR2⁻ macrophages in suppressing inflammation and promoting tissue repair. In atherosclerosis, we focus on the role of metabolic reprogramming in regulating macrophage polarization, revealing how metabolic pathways influence the balance between pro-inflammatory M1 and anti-inflammatory M2 macrophages, thereby affecting plaque stability and disease progression. By summarizing the roles of these macrophage subpopulations in myocardial infarction, heart failure, and other diseases, we propose potential therapeutic strategies aimed at modulating different macrophage subtypes. These include targeting the CCR2 signaling pathway to mitigate inflammation and fibrosis, and metabolic reprogramming to restore the balance between M1 and M2 macrophages. Finally, we highlight the need for future research to focus on the functional diversity and molecular mechanisms of human TRMs to develop novel immunotherapeutic strategies and improve the prognosis of cardiovascular diseases. Full article