Search Results (39)

Skin diseases frequently coexist with other disorders, such as metabolic syndrome, diabetes mellitus, depression, psoriatic arthritis, and cardiovascular disease. Altered levels of distinct chemokines, like CCL5/RANTES, CXCL12/SDF-1a, CCL7/MCP-3, CCL2/MCP-1, CXCL1/GROa, and the eotaxin family, contribute to the development and/or exacerbation of inflammation, which is a common feature of numerous skin diseases as well as metabolic syndrome. The pathological and molecular connections between chronic inflammatory skin diseases and metabolic syndrome are increasingly recognized as being driven by shared inflammatory pathways, oxidative stress, and adipokine dysregulation. While systemic inflammation acts as a common thread, the precise mechanisms for some conditions remain partially understood. Nevertheless, the exact pathological and molecular connections between skin diseases (i.e., psoriasis, atopic dermatitis, pemphigus vulgaris, acute and chronic spontaneous urticaria, bullous pemphigoid, squamous cell carcinoma, alopecia areata, systemic sclerosis, discoid lupus erythematosus, diffuse large B-cell lymphoma) and metabolic syndrome are not yet fully understood. This narrative review summarizes the robust association between various chronic inflammatory skin diseases and metabolic syndrome in the context of pro-inflammatory chemokines. Full article

Chemokine CXCL1, also known as Gro-α and MGSA, a ligand of CXCR2, is the best-known CXC chemokine in cancer processes, after CXCL8/IL-8 and CXCL12/SDF-1. This paper is the first review on the role of CXCL1 in general molecular processes associated with cancer. It provides a comprehensive overview that allows for an in-depth understanding of the importance of CXCL1 in tumor-related processes. In this review, however, we did not address the clinical aspects of CXCL1, as these were discussed in our previous review articles. The present paper focuses on the involvement of CXCL1 in cancer processes such as proliferation, cancer stem cell (CSC) function, senescence, angiogenesis, lymphangiogenesis, migration and metastasis, and effects on tumor-associated cells such as neutrophils, tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), mesenchymal stem cells (MSCs), and cancer-associated fibroblasts (CAFs). It also describes the significance of CXCL1 in cancer-associated diseases such as cancer cachexia, cancer-associated immunodeficiency, neuroinflammatory-mediated affective-like behaviors, bone cancer pain, and acute kidney injury. We also present the effects of obesity on CXCL1-related cancer processes. Full article

The history of stromal-derived factor-1 (SDF-1), alias CXCL12, started serendipitously and relatively late in the cytokine cDNA cloning era (1975–2000) and evolved at the biological level from progenitor cell-specific chemokine in the bone marrow to multifunctional cytokine with growth factor-like and tissue-regenerative activities. This evolution was parallelled by the integration of SDF-1/CXCL12 within the protein families of chemokines, cytokines and cell growth-promoting recombinant products having the potential for clinical applications. Here, we use this central position of CXCL12 as small signaling protein as an example for future developments in regenerative medicine. We provide context about SDF-1 biology within the field of skin wound healing research and how this compares with studies of other cytokines and growth factors. We also discuss whether SDF-1 formulations may be exemplary for other cytokines used for tissue regeneration. Normal skin wound healing is fraught with delays and complications in patients with specific underlying diseases, such as diabetes, hypertension and other elderly-related comorbidities, skin infections and accidental physical insults. Except for platelet-derived growth factor (PDGF), many cytokines, including vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF), have failed so far in clinical studies of skin wound healing. This is in part due to the fact that (i) the biology of tissue regeneration is complex and insufficiently studied, (ii) in vitro approaches hardly mimic in vivo situations and (iii) commonly used animal models of acute and chronic wounding do not perfectly match human skin wound regeneration. A review of critical cells and molecules in normal skin and their actions in wounded tissue and a balanced comparison of the recent literature are preambles for progress in wound repair. We define advantages and limitations of recent approaches and appeal for more research. In particular, the possibilities of cellular immunomodulation mediated by endogenous and exogenous SDF-1/CXCL12 as a key molecule for skin regeneration are reviewed. Furthermore, biomaterials and scaffolds for the delivery and use of cytokines in precision medicine and aspects of their biofabrication are outlined with SDF-1 as an example. Finally, we indicate how applications of dermatological SDF-1 formulations for skin wound healing may be tailored for applications in other acute and chronic inflammatory conditions and regenerative medicine. Thereby, SDF-1/CXCL12 is placed at the crossroads between recombinant products, cytokines, chemokines and growth factors and occupies a central position between regenerative biology and medicine. Full article

Lung cancer remains a major public health challenge due to high incidence and mortality. The chemokine receptor CXCR4 and its ligand CXCL12 (SDF-1) constitute a critical axis in tumor biology, influencing tumor cell proliferation, invasion, angiogenesis, and immune evasion. Aberrant CXCR4 expression is frequently observed in lung cancer and is closely associated with adverse prognosis, enhanced metastatic potential, and therapeutic resistance. Mechanistically, CXCR4 activates signaling pathways including PI3K/AKT, MAPK/ERK, JAK/STAT, and FAK/Src, promoting epithelial–mesenchymal transition, stemness, and survival. The CXCL12/CXCR4 axis also orchestrates interactions with the tumor microenvironment, facilitating chemotaxis toward CXCL12-rich niches (e.g., bone marrow and brain) and modulating anti-tumor immunity via regulatory cells. Regulation of CXCR4 occurs at transcriptional, epigenetic, and post-transcriptional levels, with modulation by hypoxia, inflammatory signals, microRNAs, and post-translational modifications. Clinically, high CXCR4 expression correlates with metastasis, poor prognosis, and reduced response to certain therapies, underscoring its potential as a prognostic biomarker and therapeutic target. Therapeutic strategies targeting CXCR4 include small-molecule antagonists (e.g., AMD3100/plerixafor; balixafortide), anti-CXCR4 antibodies, and CXCL12 decoys, as well as imaging probes for patient selection and response monitoring (e.g., 68Ga-pentixafor PET). Preclinical and early clinical studies suggest that CXCR4 blockade can impair tumor growth, limit metastatic spread, and enhance chemotherapy and immunotherapy efficacy, although hematopoietic side effects and infection risk necessitate careful therapeutic design. This review synthesizes the molecular features, regulatory networks, and translational potential of CXCR4 in lung cancer and discusses future directions for precision therapy and biomarker-guided intervention. Full article

Background: The metastasis-promoting G-protein-coupled receptor CXC Receptor 4 (CXCR4) is activated by the chemokine CXCL12, also known as stromal cell-derived factor 1 (SDF-1). The CXCL12/CXCR4 pathway in cancer promotes metastasis but the molecular details of how this pathway cross-talks with oncogenes are understudied. An oncogene pathway known to promote breast cancer metastasis in MDA-MB-231 xenografts is that of Mouse Double Minute 2 and 4 (MDM2 and MDM4, also known as MDMX). MDM2 and MDMX promote circulating tumor cell (CTC) formation and metastasis, and positively correlate with a high expression of CXCR4. Interestingly, this MDMX-associated upregulation of CXCR4 is only observed in cells grown in the tumor microenvironment (TME), but not in MDA-MB-231 cells grown in a tissue culture dish. This suggested a cross-talk signaling factor from the TME which was predicted to be CXCL12 and, as such, we asked if the exogenous addition of the cell non-autonomous CXCL12 ligand would recapitulate the MDMX-dependent upregulation of CXCR4. Methods: We used MDA-MB-231 cells and isolated CTCs, with and without MDMX knockdown, plus the exogenous addition of CXCL12 to determine if MDMX-dependent upregulation of CXCR4 could be recapitulated outside of the TME context. We added exogenous CXCL12 to the culture medium used for growth of MDA-MB-231 cells and isogenic cell lines engineered for MDM2 or MDMX depletion. We carried out immunoblotting, and quantitative RT-PCR to compare the expression of CXCR4, MDM2, MDMX, and AKT activation. We carried out Boyden chamber and wound healing assays to assess the influence of MDMX and CXCL12 on the cells’ migration capacity. Results: The addition of the CXCL12 chemokine to the medium increased the CXCR4 cellular protein level and activated the PI3K/AKT signaling pathway. Surprisingly, we observed that the addition of CXCL12 mediated the upregulation of MDM2 and MDMX at the protein, but not at the mRNA, level. A reduction in MDMX, but not MDM2, diminished both the CXCL12-mediated CXCR4 and MDM2 upregulation. Moreover, a reduction in both MDM2 and MDMX hindered the ability of the added CXCL12 to promote Boyden chamber-assessed cell migration. The upregulation of MDMX by CXCL12 was mediated, at least in part, by a step upstream of the proteasome pathway because CXCL12 did not increase protein stability after cycloheximide treatment, or when the proteasome pathway was blocked. Conclusions: These data demonstrate a positive feed-forward activation loop between the CXCL12/CXCR4 pathway and the MDM2/MDMX pathway. As such, MDMX expression in tumor cells may be upregulated in the primary tumor microenvironment by CXCL12 expression. Furthermore, CXCL12/CXCR4 metastatic signaling may be upregulated by the MDM2/MDMX axis. Our findings highlight a novel positive regulatory loop between CXCL12/CXCR4 signaling and MDMX to promote metastasis. Full article

Background: Active recruitment of osteogenic cells by secreted signaling factors, such as stromal-cell-derived factor 1 (SDF-1), has recently been proposed as a novel strategy to enhance osseointegration. However, the intrinsic importance of the SDF-1/C-X-C chemokine receptor type 4 (CXCR4) axis in promoting osseointegration is unknown. To study the role of SDF-1/CXCR4 in osseointegration, we blocked the SDF-1/CXCR4 pathway in a murine tibial implant model through repeated administrations of an antibody against SDF-1. Methods: Using our previously described murine tibial implant model (N = 24), mice were randomized into an anti-SDF-1 group and a control group (N = 12/group). Intraperitoneal injections of CXCL12/SDF-1 monoclonal antibody (84 µg/mouse) or mouse IgG1 isotype were administered on days 2, 4, 7, 10, 13, 16, 19, 22, and 25 post-surgery. Mice were euthanized 4 weeks post-surgery. Peri-implant bone mass and architecture were determined through microcomputed tomography (µ-CT). Bone implant strength was detected through implant pull-out testing. Results: Inhibition of the SDF-1/CXCR4 pathway significantly reduced host bone–implant interface strength but did not significantly change the cancellous architecture surrounding the implant. Conclusion: SDF-1/CXCR4 is an important pathway to achieve maximum implant osseointegration. However, inhibition of the pathway did not completely eliminate osseointegration. Full article

There is a complex interplay between viral infection and host innate immune response regarding disease severity and outcomes. Neutrophil hyperactivation, including excessive release of neutrophil extracellular traps (NETs), is linked to exacerbated disease in acute COVID-19, notably in hospitalized patients. Delineating protective versus detrimental neutrophil responses is essential to developing targeted COVID-19 therapies and relies on high-quality translational animal models. In this study, we utilize a previously established feline model for COVID-19 to investigate neutrophil dysfunction in which experimentally infected cats develop clinical disease that mimics acute COVID-19. Specific pathogen-free cats were inoculated with SARS-CoV-2 (B.1.617.2; Delta variant) (n = 24) or vehicle (n = 6). Plasma, bronchoalveolar lavage fluid, and lung tissues were collected at various time points over 12 days post-inoculation. Systematic and temporal evaluation of the kinetics of neutrophil activation was conducted by measuring markers of activation including myeloperoxidase (MPO), neutrophil elastase (NE), and citrullinated histone H3 (citH3) in SARS-CoV-2-infected cats at 4 and 12 days post-inoculation (dpi) and compared to vehicle-inoculated controls. Cytokine profiling supported elevated innate inflammatory responses with specific upregulation of neutrophil activation and NET formation-related markers, namely IL-8, IL-18, CXCL1, and SDF-1, in infected cats. An increase in MPO-DNA complexes and cell-free dsDNA in infected cats compared to vehicle-inoculated was noted and supported by histopathologic severity in respiratory tissues. Immunofluorescence analyses further supported correlation of NET markers with tissue damage, especially 4 dpi. Differential gene expression analyses indicated an upregulation of genes associated with innate immune and neutrophil activation pathways. Transcripts involved in activation and NETosis pathways were upregulated by 4 dpi and downregulated by 12 dpi, suggesting peak activation of neutrophils and NET-associated markers in the early acute stages of infection. Correlation analyses conducted between NET-specific markers and clinical scores as well as histopathologic scores support association between neutrophil activation and disease severity during SARS-CoV-2 infection in this model. Overall, this study emphasizes the effect of neutrophil activation and NET release in SARS-CoV-2 infection in a feline model, prompting further investigation into therapeutic strategies aimed at mitigating excessive innate inflammatory responses in COVID-19. Full article

A key step in platelet production is the migration of megakaryocytes to the vascular sinusoids within the bone marrow. This homing is mediated by the chemokine CXCL12 and its receptor CXCR4. CXCR4 is also a positive regulator of platelet activation and thrombosis. Pim-1 kinase has been shown to regulate CXCR4 signalling in other cell types, and we have previously described how Pim kinase inhibitors attenuate platelet aggregation to CXCL12. However, the mechanism by which Pim-1 regulates CXCR4 signalling in platelets and megakaryocytes has yet to be elucidated. Using human platelets, murine bone marrow-derived megakaryocytes, and the megakaryocyte cell line MEG-01, we demonstrate that pharmacological Pim kinase inhibition leads to reduced megakaryocyte and platelet function responses to CXCL12, including reduced megakaryocyte migration and platelet granule secretion. Attenuation of CXCL12 signalling was found to be attributed to the reduced surface expression of CXCR4. The decrease in CXCR4 surface levels was found to be mediated by rapid receptor internalisation, in the absence of agonist stimulation. We demonstrate that pharmacological Pim kinase inhibition disrupts megakaryocyte and platelet function by reducing constitutive CXCR4 surface expression, decreasing the number of receptors available for agonist stimulation and signalling. These findings have implications for the development and use of Pim kinase inhibitors for the treatment of conditions associated with elevated circulating levels of CXCL12/SDF1α and increased thrombotic risk. Full article

Metastasis (Met) largely contributes to the major cause of cancer deaths throughout the world, rather than the growth of the tumor mass itself. The present report brings together several of the pertinent contributors to cancer growth and metastatic processes from an activity standpoint. Such biological activities include the following: (1) cell adherence and detachment; (2) cell-to-cell contact; (3) contact inhibition; (4) the cell interfacing with the extracellular matrix (ECM); (5) tumor cell-to-stroma communication networks; (6) chemotaxis; and (7) cell membrane potential. Moreover, additional biochemical factors that contribute to cancer growth and metastasis have been shown to comprise the following: (a) calcium levels in the extracellular matrix and in intracellular compartments; (b) cation voltage and ATP-regulated potassium channels; (c) selective and non-selective cation channels; and (d) chemokines (cytokines) and their receptors, such as CXCL12 (SDF-1) and its receptor/binding partner, CXCR4. These latter molecular components represent a promising group of an interacting and synchronized set of candidates ideal for peptide therapeutic targeting for cancer growth and metastasis. Such peptides can be obtained from naturally occurring proteins such as alpha-fetoprotein (AFP), an onco-fetal protein and clinical biomarker. Full article

Mesenchymal stem cells (MSCs) have a high tropism for the hypoxic microenvironment of tumors. The combination of nanoparticles in MSCs decreases tumor growth in vitro as well as in rodent models of cancers in vivo. Covalent conjugation of nanoparticles with the surface of MSCs can significantly increase the drug load delivery in tumor sites. Nanoparticle-based anti-angiogenic systems (gold, silica and silicates, diamond, silver, and copper) prevented tumor growth in vitro. For example, glycolic acid polyconjugates enhance nanoparticle drug delivery and have been reported in human MSCs. Labeling with fluorescent particles (coumarin-6 dye) identified tumor cells using fluorescence emission in tissues; the conjugation of different types of nanoparticles in MSCs ensured success and feasibility by tracking the migration and its intratumor detection using non-invasive imaging techniques. However, the biosafety and efficacy; long-term stability of nanoparticles, and the capacity for drug release must be improved for clinical implementation. In fact, MSCs are vehicles for drug delivery with nanoparticles and also show low toxicity but inefficient accumulation in tumor sites by clearance of reticuloendothelial organs. To solve these problems, the internalization or conjugation of drug-loaded nanoparticles should be improved in MSCs. Finally, CXCR4 may prove to be a promising target for immunotherapy and cancer treatment since the delivery of siRNA to knock down this alpha chemokine receptor or CXCR4 antagonism has been shown to disrupt tumor–stromal interactions. Full article

Prolonged thymic involution results in decreased thymopoiesis and thymic output, leading to peripheral T-cell deficiency. Since the thymic-dependent pathway is the only means of generating fully mature T cells, the identification of strategies to enhance thymic regeneration is crucial in developing therapeutic interventions to revert immune suppression in immunocompromised patients. The present study clearly shows that fish collagen peptides (FCPs) stimulate activities of thymic epithelial cells (TECs), including cell proliferation, thymocyte adhesion, and the gene expression of thymopoietic factors such as FGF-7, IGF-1, BMP-4, VEGF-A, IL-7, IL-21, RANKL, LTβ, IL-22R, RANK, LTβR, SDF-1, CCL21, CCL25, CXCL5, Dll1, Dll4, Wnt4, CD40, CD80, CD86, ICAM-1, VCAM-1, FoxN1, leptin, cathepsin L, CK5, and CK8 through the NF-κB signal transduction pathway. Furthermore, our study also revealed the cytoprotective effects of FCPs on TECs against cyclophosphamide-induced cellular injury through the NF-κB signaling pathway. Importantly, FCPs exhibited a significant capability to facilitate thymic regeneration in mice after cyclophosphamide-induced damage via the NF-κB pathway. Taken together, this study sheds light on the role of FCPs in TEC function, thymopoiesis, and thymic regeneration, providing greater insight into the development of novel therapeutic strategies for effective thymus repopulation for numerous clinical conditions in which immune reconstitution is required. Full article

Acute myeloid leukemia (AML) is a type of leukemia known for its unfavorable prognoses, prompting research efforts to discover new therapeutic targets. One area of investigation involves examining extracellular factors, particularly CXC chemokines. While CXCL12 (SDF-1) and its receptor CXCR4 have been extensively studied, research on other CXC chemokine axes in AML is less developed. This study aims to bridge that gap by providing an overview of the significance of CXC chemokines other than CXCL12 (CXCR1, CXCR2, CXCR3, CXCR5, and CXCR6 ligands and CXCL14 and CXCL17) in AML’s oncogenic processes. We explore the roles of all CXC chemokines other than CXCL12, in particular CXCL1 (Gro-α), CXCL8 (IL-8), CXCL10 (IP-10), and CXCL11 (I-TAC) in AML tumor processes, including their impact on AML cell proliferation, bone marrow angiogenesis, interaction with non-leukemic cells like MSCs and osteoblasts, and their clinical relevance. We delve into how they influence prognosis, association with extramedullary AML, induction of chemoresistance, effects on bone marrow microvessel density, and their connection to French–American–British (FAB) classification and FLT3 gene mutations. Full article

Neural crest (NC) is a unique vertebrate cell type arising from the border of the neural plate and epidermis that gives rise to diverse tissues along the entire body axis. Roberto Mayor and colleagues have made major contributions to our understanding of NC induction, delamination, and migration. We report that a truncating mutation of the classical tumor suppressor Adenomatous Polyposis Coli (apc) disrupts craniofacial development in zebrafish larvae, with a marked reduction in the cranial neural crest (CNC) cells that contribute to mandibular and hyoid pharyngeal arches. While the mechanism is not yet clear, the altered expression of signaling molecules that guide CNC migration could underlie this phenotype. For example, apc^mcr/mcr larvae express substantially higher levels of complement c3, which Mayor and colleagues showed impairs CNC cell migration when overexpressed. However, we also observe reduction in stroma-derived factor 1 (sdf1/cxcl12), which is required for CNC migration into the head. Consistent with our previous work showing that APC directly enhances the activity of glycogen synthase kinase 3 (GSK-3) and, independently, that GSK-3 phosphorylates multiple core mRNA splicing factors, we identify 340 mRNA splicing variations in apc mutant zebrafish, including a splice variant that deletes a conserved domain in semaphorin 3f (sema3f), an axonal guidance molecule and a known regulator of CNC migration. Here, we discuss potential roles for apc in CNC development in the context of some of the seminal findings of Mayor and colleagues. Full article

The aim of the study was to determine whether sex-related differences exist in immune response to inhalation lung injury. C57BL/6 mice were exposed to Cl₂ gas (500 ppm for 15, 20, or 30 min). Results showed that male mice have higher rates of mortality and lung injury than females. The binding of the chemokine ligand C-X-C motif chemokine 12 (CXCL12), also called stromal-derived-factor-1 (SDF-1), to the C-X-C chemokine receptor type 4 (CXCR4) on lung cells promotes the migration of leukocytes from circulation to lungs. Therefore, the hypothesis was that elevated SDF-1/CXCR4 signaling mediates exaggerated immune response in males. Plasma, blood leukocytes, and lung cells were collected from mice post-Cl₂ exposure. Plasma levels of SDF-1 and peripheral levels of CXCR4 in lung cells were higher in male vs. female mice post-Cl₂ exposure. Myeloperoxidase (MPO) and elastase activity was significantly increased in leukocytes of male mice exposed to Cl₂. Lung cells were then ex vivo treated with SDF-1 (100 ng/mL) in the presence or absence of the CXCR4 inhibitor, AMD3100 (100 nM). SDF-1 significantly increased migration, MPO, and elastase activity in cells obtained from male vs. female mice post-Cl₂ exposure. AMD3100 attenuated these effects, suggesting that differential SDF-1/CXCR4 signaling may be responsible for sex-based disparities in the immune response to inhalation lung injury. Full article

C-X-C chemokine receptor type 4 (CXCR4), also known as fusin or CD184, is a 7-transmembrane helix G-protein-coupled receptor that is encoded by the CXCR4 gene. Involved in various physiological processes, CXCR4 could form an interaction with its endogenous partner, chemokine ligand 12 (CXCL12), which is also named SDF-1. In the past several decades, the CXCR4/CXCL12 couple has attracted a large amount of research interest due to its critical functions in the occurrence and development of refractory diseases, such as HIV infection, inflammatory diseases, and metastatic cancer, including breast cancer, gastric cancer, and non-small cell lung cancer. Furthermore, overexpression of CXCR4 in tumor tissues was shown to have a high correlation with tumor aggressiveness and elevated risks of metastasis and recurrence. The pivotal roles of CXCR4 have encouraged an effort around the world to investigate CXCR4-targeted imaging and therapeutics. In this review, we would like to summarize the implementation of CXCR4-targeted radiopharmaceuticals in the field of various kinds of carcinomas. The nomenclature, structure, properties, and functions of chemokines and chemokine receptors are briefly introduced. Radiopharmaceuticals that could target CXCR4 will be described in detail according to their structure, such as pentapeptide-based structures, heptapeptide-based structures, nonapeptide-based structures, etc. To make this review a comprehensive and informative article, we would also like to provide the predictive prospects for the CXCR4-targeted species in future clinical development. Full article