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Journal of Smooth Muscle Research =... 2023Vascular smooth muscle cell (VSMC) migration plays an important role in cardiovascular diseases, including atherosclerotic plaque formation and restenosis after vascular... (Review)
Review
Vascular smooth muscle cell (VSMC) migration plays an important role in cardiovascular diseases, including atherosclerotic plaque formation and restenosis after vascular intervention. The mechanisms involved in VSMC migration are complex and have not been fully elucidated. Recently, we discovered a novel interaction, direct binding of active Fyn-paxillin at focal adhesions, which plays an important role in actin stress fiber formation and migration in VSMCs. In this review, we highlight paxillin as an intermediate signaling molecule that mediates actin stress fiber formation and VSMC migration through the Fyn/paxillin/Rho-kinase signaling pathway by directly binding to active Fyn. We also discuss the inhibition of VSMC migration by blocking the active Fyn-paxillin interaction and the potential of this interaction as a therapeutic target for cardiovascular diseases.
Topics: Humans; Paxillin; Muscle, Smooth, Vascular; Actins; Cardiovascular Diseases; Cell Movement
PubMed: 37438114
DOI: 10.1540/jsmr.59.58 -
Journal of Hematology & Oncology Feb 2017Paxilllin is a multifunctional and multidomain focal adhesion adapter protein which serves an important scaffolding role at focal adhesions by recruiting structural and... (Review)
Review
Paxilllin is a multifunctional and multidomain focal adhesion adapter protein which serves an important scaffolding role at focal adhesions by recruiting structural and signaling molecules involved in cell movement and migration, when phosphorylated on specific Tyr and Ser residues. Upon integrin engagement with extracellular matrix, paxillin is phosphorylated at Tyr31, Tyr118, Ser188, and Ser190, activating numerous signaling cascades which promote cell migration, indicating that the regulation of adhesion dynamics is under the control of a complex display of signaling mechanisms. Among them, paxillin disassembly from focal adhesions induced by extracellular regulated kinase (ERK)-mediated phosphorylation of serines 106, 231, and 290 as well as the binding of the phosphatase PEST to paxillin have been shown to play a key role in cell migration. Paxillin also coordinates the spatiotemporal activation of signaling molecules, including Cdc42, Rac1, and RhoA GTPases, by recruiting GEFs, GAPs, and GITs to focal adhesions. As a major participant in the regulation of cell movement, paxillin plays distinct roles in specific tissues and developmental stages and is involved in immune response, epithelial morphogenesis, and embryonic development. Importantly, paxillin is also an essential player in pathological conditions including oxidative stress, inflammation, endothelial cell barrier dysfunction, and cancer development and metastasis.
Topics: Animals; Cell Movement; Focal Adhesions; Humans; Pathology, Molecular; Paxillin; Phosphorylation; Signal Transduction
PubMed: 28214467
DOI: 10.1186/s13045-017-0418-y -
The Journal of Clinical Investigation Nov 2023Solid cancers like pancreatic ductal adenocarcinoma (PDAC), a type of pancreatic cancer, frequently exploit nerves for rapid dissemination. This neural invasion (NI) is...
Solid cancers like pancreatic ductal adenocarcinoma (PDAC), a type of pancreatic cancer, frequently exploit nerves for rapid dissemination. This neural invasion (NI) is an independent prognostic factor in PDAC, but insufficiently modeled in genetically engineered mouse models (GEMM) of PDAC. Here, we systematically screened for human-like NI in Europe's largest repository of GEMM of PDAC, comprising 295 different genotypes. This phenotype screen uncovered 2 GEMMs of PDAC with human-like NI, which are both characterized by pancreas-specific overexpression of transforming growth factor α (TGF-α) and conditional depletion of p53. Mechanistically, cancer-cell-derived TGF-α upregulated CCL2 secretion from sensory neurons, which induced hyperphosphorylation of the cytoskeletal protein paxillin via CCR4 on cancer cells. This activated the cancer migration machinery and filopodia formation toward neurons. Disrupting CCR4 or paxillin activity limited NI and dampened tumor size and tumor innervation. In human PDAC, phospho-paxillin and TGF-α-expression constituted strong prognostic factors. Therefore, we believe that the TGF-α-CCL2-CCR4-p-paxillin axis is a clinically actionable target for constraining NI and tumor progression in PDAC.
Topics: Humans; Animals; Mice; Transforming Growth Factor alpha; Paxillin; Pancreatic Neoplasms; Carcinoma, Pancreatic Ductal; Phenotype; Cell Line, Tumor
PubMed: 37607005
DOI: 10.1172/JCI166333 -
Frontiers in Cell and Developmental... 2022Focal adhesions are specialized integrin-dependent adhesion complexes, which ensure cell anchoring to the extracellular matrix. Focal adhesions also function as... (Review)
Review
Focal adhesions are specialized integrin-dependent adhesion complexes, which ensure cell anchoring to the extracellular matrix. Focal adhesions also function as mechano-signaling platforms by perceiving and integrating diverse physical and (bio)chemical cues of their microenvironment, and by transducing them into intracellular signaling for the control of cell behavior. The fundamental biological mechanism of creating intracellular signaling in response to changes in tensional forces appears to be tightly linked to paxillin recruitment and binding to focal adhesions. Interestingly, the tension-dependent nature of the paxillin binding to adhesions, combined with its scaffolding function, suggests a major role of this protein in integrating multiple signals from the microenvironment, and accordingly activating diverse molecular responses. This minireview offers an overview of the molecular bases of the mechano-sensitivity and mechano-signaling capacity of core focal adhesion proteins, and highlights the role of paxillin as a key component of the mechano-transducing machinery based on the interaction of cells to substrates activating the 3 integrin-talin1-kindlin.
PubMed: 35450290
DOI: 10.3389/fcell.2022.852016 -
Oncotarget May 2016Pancreatic ductal adenocarcinoma (PDAC) is a devastating cancer in large part due to late diagnosis and a lack of effective screening tests. In spite of recent progress... (Review)
Review
Pancreatic ductal adenocarcinoma (PDAC) is a devastating cancer in large part due to late diagnosis and a lack of effective screening tests. In spite of recent progress in imaging, surgery and new therapeutic options for pancreatic cancer, the overall five-year survival still remains unacceptably low. Numerous studies have shown that focal adhesion kinase (FAK) is activated in many cancers including PDAC and promotes cancer progression and metastasis. Paxillin, an intracellular adaptor protein that plays a key role in cytoskeletal organization, connects integrins to FAK and plays a key role in assembly and disassembly of focal adhesions. Here, we have reviewed evidence in support of FAK as a potential therapeutic target and summarized related combinatorial therapies.
Topics: Biomarkers, Tumor; Carcinoma, Pancreatic Ductal; Focal Adhesion Kinase 1; Humans; Models, Biological; Molecular Targeted Therapy; Pancreatic Neoplasms; Paxillin; Protein Kinase Inhibitors; Signal Transduction
PubMed: 26980710
DOI: 10.18632/oncotarget.8040 -
Journal of Oral and Maxillofacial... 2023Cell adhesion molecules (CAMs) are found on the surface of all cells, where they allow dynamic processes to take place. These include cadherins, integrins, selectins and... (Review)
Review
BACKGROUND
Cell adhesion molecules (CAMs) are found on the surface of all cells, where they allow dynamic processes to take place. These include cadherins, integrins, selectins and Immunoglobulin superfamily. Directly associated with β-integrin tails is a multidomain protein known as paxillin. However, CAMs participate in cell-cell and extracellular matrix-cell interactions during histomorphogenesis in the various phases of odontogenesis. Some tumours or cysts like ameloblastoma (AB) or odontogenic keratocyst (OKC) having odontogenic origin show disturbance in the interaction of these CAMs. Hence, the assessment of paxillin expression in AB and OKC was carried out.
MATERIALS AND METHODS
The present observational study comprised 30 clinically and histologically confirmed cases of AB and OKC. All the slides were stained immunohistochemically using a paxillin antibody.
RESULTS
Upon comparison of staining intensity of paxillin among AB and OKC showed statistically significant result, whereas quantitative staining and final summation showed non-significant result. Gender-wise comparison of paxillin staining intensity, quantitative staining and final summation among OKC showed significant result; however, in AB, staining intensity showed non-significant result, whereas quantitative staining and final summation showed significant result.
CONCLUSION
Paxillin has the greatest influence on tissue morphogenesis and development. The regulation of cell mobility is aided by the multiple roles that paxillin plays in a range of cells and tissues. However, further studies using a large sample size, along with other molecular analytical methods, may be essential to draw a definite conclusion about the association of paxillin and its exact function in OKC and AB.
PubMed: 38304525
DOI: 10.4103/jomfp.jomfp_312_23 -
Proceedings of the National Academy of... Aug 2023Integrin adhesion complexes are essential membrane-associated cellular compartments for metazoan life. The formation of initial integrin adhesion complexes is a dynamic...
Integrin adhesion complexes are essential membrane-associated cellular compartments for metazoan life. The formation of initial integrin adhesion complexes is a dynamic process involving focal adhesion proteins assembled at the integrin cytoplasmic tails and the inner leaflet of the plasma membrane. The weak multivalent protein interactions within the complex and with the plasma membrane suggest that liquid-liquid phase separation could play a role in the nascent adhesion assembly. Here, we report that solid-supported lipid membranes supplemented with phosphoinositides induce the phase separation of minimal integrin adhesion condensates composed of integrin 1 tails, kindlin, talin, paxillin, and FAK at physiological ionic strengths and protein concentrations. We show that the presence of phosphoinositides is key to enriching kindlin and talin on the lipid membrane, which is necessary to further induce the phase separation of paxillin and FAK at the membrane. Our data demonstrate that lipid membrane surfaces set the local solvent conditions for steering the membrane-localized phase separation even in a regime where no condensate formation of proteins occurs in bulk solution.
Topics: Animals; Integrins; Paxillin; Talin; Cell Membrane; Integrin beta1; Phosphatidylinositols; Cell Adhesion
PubMed: 37494400
DOI: 10.1073/pnas.2301881120 -
ACS Applied Materials & Interfaces Feb 2024The complex interplay between cells and materials is a key focus of this research, aiming to develop optimal scaffolds for regenerative medicine. The need for tissue...
The complex interplay between cells and materials is a key focus of this research, aiming to develop optimal scaffolds for regenerative medicine. The need for tissue regeneration underscores understanding cellular behavior on scaffolds, especially cell adhesion to polymer fibers forming focal adhesions. Key proteins, paxillin and vinculin, regulate cell signaling, migration, and mechanotransduction in response to the extracellular environment. This study utilizes advanced microscopy, specifically the AiryScan technique, along with advanced image analysis employing the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) cluster algorithm, to investigate protein distribution during osteoblast cell adhesion to polymer fibers and glass substrates. During cell attachment to both glass and polymer fibers, a noticeable shift in the local maxima of paxillin and vinculin signals is observed at the adhesion sites. The focal adhesion sites on polymer fibers are smaller and elliptical but exhibit higher protein density than on the typical glass surface. The characteristics of focal adhesions, influenced by paxillin and vinculin, such as size and density, can potentially reflect the strength and stability of cell adhesion. Efficient adhesion correlates with well-organized, larger focal adhesions characterized by increased accumulation of paxillin and vinculin. These findings offer promising implications for enhancing scaffold design, evaluating adhesion to various substrates, and refining cellular interactions in biomedical applications.
Topics: Paxillin; Vinculin; Focal Adhesions; Mechanotransduction, Cellular; Cell Adhesion; Polymers; Phosphoproteins; Focal Adhesion Protein-Tyrosine Kinases
PubMed: 38354103
DOI: 10.1021/acsami.3c19035 -
The Role of Paxillin Aberrant Expression in Cancer and Its Potential as a Target for Cancer Therapy.International Journal of Molecular... May 2023Paxillin is a multi-domain adaptor protein. As an important member of focal adhesion (FA) and a participant in regulating cell movement, paxillin plays an important role... (Review)
Review
Paxillin is a multi-domain adaptor protein. As an important member of focal adhesion (FA) and a participant in regulating cell movement, paxillin plays an important role in physiological processes such as nervous system development, embryonic development, and vascular development. However, increasing evidence suggests that paxillin is aberrantly expressed in many cancers. Many scholars have also recognized that the abnormal expression of paxillin is related to the prognosis, metastases, invasion, survival, angiogenesis, and other aspects of malignant tumors, suggesting that paxillin may be a potential cancer therapeutic target. Therefore, the study of how aberrant paxillin expression affects the process of tumorigenesis and metastasis will help to develop more efficacious antitumor drugs. Herein, we review the structure of paxillin and its function and expression in tumors, paying special attention to the multifaceted effects of paxillin on tumors, the mechanism of tumorigenesis and progression, and its potential role in tumor therapy. We also hope to provide a reference for the clinical prognosis and development of new tumor therapeutic targets.
Topics: Humans; Paxillin; Neoplasms; Cell Movement; Antineoplastic Agents; Carcinogenesis; Cell Line, Tumor
PubMed: 37175948
DOI: 10.3390/ijms24098245 -
Journal of Cell Science Apr 2022Integrin-mediated adhesions are convergence points for multiple signaling pathways. Their inner structure and diverse functions can be studied with super-resolution...
Integrin-mediated adhesions are convergence points for multiple signaling pathways. Their inner structure and diverse functions can be studied with super-resolution microscopy. Here, we examined the spatial organization within focal adhesions by analyzing several adhesion proteins with structured illumination microscopy (SIM). Paxillin (Pax) serves as a scaffold protein and signaling hub in focal adhesions, and focal adhesion kinase (FAK, also known as PTK2) regulates the dynamics of adhesions. We found that their phosphorylated forms, pPax and pFAK, form spot-like, spatially defined clusters within adhesions in several cell lines and confirmed these findings with additional super-resolution techniques. These clusters showed a more regular separation from each other compared with more randomly distributed signals for FAK or paxillin. Mutational analysis indicated that the active (open) FAK conformation is a prerequisite for the pattern formation of pFAK. Live-cell super-resolution imaging revealed that organization in clusters is preserved over time for FAK constructs; however, distance between clusters is dynamic for FAK, while paxillin is more stable. Combined, these data introduce spatial clusters of pPax and pFAK as substructures in adhesions and highlight the relevance of paxillin-FAK binding for establishing a regular substructure in focal adhesions.
Topics: Focal Adhesion Kinase 1; Focal Adhesion Protein-Tyrosine Kinases; Focal Adhesions; Paxillin; Phosphoproteins; Phosphorylation; Signal Transduction
PubMed: 35343568
DOI: 10.1242/jcs.258764