Salivary chemokines and growth factors in patients with ischemic stroke

Abstract

Stroke is a serious health problem that affects an increasing number of people. As a result of the blockage of blood flow, tissue necrosis occurs in areas of the brain supplied by the damaged vessel, and leads to the development of inflammation. Changes that occur in the brain allow molecules to enter the blood, and it has been suggested that some can also penetrate the saliva. This study is the first to assess the profile of 25 chemokines and growth factors in the saliva of stroke survivors compared to a control group. 22 stroke survivors and 22 individuals matched by age and gender were enrolled in the study. Salivary chemokines and growth factors were assessed using the multiplex ELISA method. In the unstimulated saliva of stroke patients, we demonstrated significantly higher levels of chemotactic factors (CTACK/CCL27, IL-8/CXCL8, MIG/CXCL9, MIF) and growth factors (basic FGF, G-CSF, HGF, LIF, VEGF) compared to controls. The levels of MCP-3/CCL7, eotaxin/CCL11, IP-10/CXCL10, IL-3/MCGF, and PDGF-BB were lower in the saliva of the study group. The concentration of basic FGF negatively correlated with cognitive function as measured by the Addenbrooke's Cognitive Examination (ACE) scale (p = 0.007 r = - 0.56), while salivary IL-3 and LIF levels positively correlated with scores on the Functional Independence Measure (FIM) scale (p = 0.019 r = 0.53; p = 0.033 r = 0.47, respectively). Receiver Operating Characteristic (ROC) analysis showed that salivary basic FGF, HGF, IL-3 and LIF can distinguish ischemic stroke patients from the control group with high sensitivity and specificity. In conclusion, disruptions in chemokine and growth factor levels in saliva may suggest an inflammatory etiology of ischemic stroke. Salivary basic FGF, HGF, IL-3 and LIF could serve as potential biomarkers for stroke. Further research is needed to illuminate the differences in salivary inflammatory mediator profiles in stroke and to evaluate the diagnostic utility of chemokines and growth factors in clinical practice.

Keywords: Biomarkers; Chemokines; Growth factors; Saliva; Salivary diagnostics; Stroke.

Fig. 1

Patient selection flow chart.

Fig. 2

Concentration of chemokines in non-stimulated saliva of stroke patients compared to controls. MCP-1/CCL2: monocyte chemoattractant protein-1/chemokine ligands 2; MIP-1α/CCL3: macrophage inflammatory protein 1alpha/chemokine ligands 3; MIP-1β/ CCL4: macrophage inflammatory protein 1beta/chemokine ligands 4; MCP-3/CCL7: monocyte chemoattractant protein-3/chemokine ligands 7; eotaxin/CCL11: eotaxin/chemokine ligand 11; CTACK/CCL27: cutaneous T-cell-attracting chemokine/chemokine ligands 27; GRO-α/ CXCL1: growth-regulated alpha protein/chemokine (C-X-C motif) ligand 1; IL-8/CXCL8: interleukin 8/chemokine (C-X-C motif) ligand 8; MIG/CXCL9: monokine induced by gamma interferon/chemokine (C-X-C motif) ligand 9; IP-10/CXCL10: interferon gamma-induced protein 10/chemokine (C-X-C motif) ligand 10; SDF-1alpha/CXCL12: stromal cell-derived factor 1/chemokine (C-X-C motif) ligand 12; MIF: macrophage migration inhibitory factor; **p < 0.01; ***p < 0.001; ****p < 0.0001.

Fig. 3

Concentration of growth factors in non-stimulated saliva of stroke patients compared to controls. Basic FGF: fibroblast growth factor; G-CSF: granulocyte colony-stimulating factor, HGF: hepatocyte growth factor; IL-3/MCGF: interleukin-3/mast cell growth factor; LIF: leukemia inhibitory factor; M-CSF: macrophage colony-stimulating factor, PDGF-BB; platelet-derived growth factor isoform BB; VEGF: vascular endothelial growth factor; *p < 0.05; ****p < 0.0001.

Fig. 4

Correlations between the studied biomarkers. MCP-1/CCL2: monocyte chemoattractant protein-1/chemokine ligands 2; MIP-1α/CCL3: macrophage inflammatory protein 1alpha/chemokine ligands 3; MIP-1β/CCL4: macrophage inflammatory protein 1beta/chemokine ligands 4; MCP-3/CCL7: monocyte chemoattractant protein-3/chemokine ligands 7; eotaxin/CCL11: eotaxin/chemokine ligand 11; CTACK/CCL27: cutaneous T-cell-attracting chemokine/chemokine ligands 27; GRO-α/CXCL1: growth-regulated alpha protein/chemokine (C-X-C motif) ligand 1; IL-8/CXCL8: interleukin 8/chemokine (C-X-C motif) ligand 8; MIG/CXCL9: monokine induced by gamma interferon/chemokine (C-X-C motif) ligand 9; IP-10/CXCL10: interferon gamma-induced protein 10/chemokine (C-X-C motif) ligand 10; SDF-1α/CXCL12: stromal cell-derived factor 1/chemokine (C-X-C motif) ligand 12; MIF: macrophage migration inhibitory factor; basic FGF: fibroblast growth factor; G-CSF: granulocyte colony-stimulating factor; HGF: hepatocyte growth factor; IL-3/MCGF: interleukin-3/mast cell growth factor; LIF: leukemia inhibitory factor; M-CSF: macrophage colony-stimulating factor; PDGF-BB; platelet-derived growth factor isoform BB; VEGF: vascular endothelial growth factor; ACE-R: Addenbrooke’s Cognitive Examination Revised; BI: Barthel Index; FIM: The Functional Independence Measure; SBS: Sitting Balance Scale.

Fig. 5

Graphical conclusions of the study (generated using canva.com and biorender.com). In the unstimulated saliva of stroke patients, a significantly higher content of chemotactic factors (CTACK/CCL27, IL-8/CXCL8, MIG/CXCL9, MIF) and growth factors (basic FGF, G-CSF, HGF, LIF, VEGF) was found compared to individuals from the control group. The content of MCP-3/CCL7, eotaxin/CCL11, IP-10/CXCL10, IL-3/MCGF and PDGF-BB was significantly lower in the saliva of patients from the study group. MCP-3/CCL7: monocyte chemoattractant protein-3/chemokine ligands 7; Eotaxin/CCL11: eotaxin/chemokine ligand 11; CTACK/CCL27: cutaneous T-cell-attracting chemokine/chemokine ligands 27; IL-8/CXCL8: interleukin 8/chemokine (C-X-C motif) ligand 8; MIG/CXCL9: monokine induced by gamma interferon/chemokine (C-X-C motif) ligand 9; IP-10/CXCL10: interferon gamma-induced protein 10/chemokine (C-X-C motif) ligand 10; MIF: Macrophage migration inhibitory factor; Basic FGF: fibroblast growth factor; G-CSF: granulocyte colony-stimulating factor, HGF: Hepatocyte growth factor; IL-3/MCGF: Interleukin-3/Mast cell growth factor; LIF: Leukemia inhibitory factor; PDGF-BB; platelet-derived growth factor isoform BB; VEGF: vascular endothelial growth factor.