Targeting TSP-1 decreased periodontitis by attenuating extracellular matrix degradation and alveolar bone destruction

Inhibition of fibulin-3 ameliorates periodontal inflammation through reducing M1 macrophage polarization via EGFR/PI3K/AKT pathway

BACKGROUND

This study aimed to evaluate the role of fibulin-3 (FBLN3) in macrophage polarization, its mechanism, and its effect on periodontitis.

METHODS

We conducted studies on periodontitis using both clinical samples and ligature-induced mouse periodontitis model. The inflammatory state was assessed using microcomputed tomography, hematoxylin and eosin staining, immunohistochemical staining, and immunofluorescence staining. In vitro, bone marrow-derived macrophages, and RAW 264.7 macrophages were treated with lipopolysaccharide (LPS) and interleukin (IL)-4 to induce polarization. The role of FBLN3 in macrophage polarization was investigated using overexpression plasmids or siRNAs. Furthermore, local injection of adeno-associated virus was employed to suppress FBLN3 expression in periodontal tissues.

RESULTS

FBLN3 levels were greater in periodontitis tissues. FBLN3 promoted M1 polarization and suppressed M2 polarization in macrophages. The overexpression of FBLN3 promoted M1 polarization via the EGFR/PI3K/AKT signaling pathway, an effect that the epidermal growth factor receptor (EGFR) inhibitor PD153035 reversed. Suppressing FBLN3 expression improved periodontal inflammation and reduced alveolar bone loss in periodontitis.

CONCLUSIONS

FBLN3 suppression can mitigate periodontitis by decreasing the M1 macrophage ratio. FBLN3 regulates M1 macrophage polarization through the EGFR/PI3K/AKT signaling pathway.

PLAIN LANGUAGE SUMMARY

Disruption in the collaboration between extracellular matrix (ECM) and immune system is a significant pathology in periodontitis. Macrophages are a crucial part of the immune system and have unique functions, such as polarization. Fibulin-3, an ECM protein, may play a vital role in this dynamic interplay. Fibulin-3 expression is elevated in periodontitis and is closely related to immune cell function. Inhibiting fibulin-3 can alleviate periodontitis by reducing infiltration of immune cells and M1 macrophage ratio. Furthermore, fibulin-3 promoted macrophage M1 polarization by activating the PI3K/AKT signaling pathway through EGFR binding. Our findings offer a clinically relevant rationale for immune response modulation through fibulin-3.

CD47 and thrombospondin-1 contribute to immune evasion by Porphyromonas gingivalis

Porphyromonas gingivalis is a gram-negative anaerobic bacterium linked to periodontal disease. Remarkably, P. gingivalis thrives in an inflamed environment rich in activated neutrophils. Toll-like receptor 2 (TLR2) recognition is required for P. gingivalis to evade innate immune killing; however, the mechanisms through which P. gingivalis uncouples host inflammation from bactericidal activity are only partially known. Since integrin activation and alternative signaling are implicated in P. gingivalis TLR2-mediated immune escape, we explored the role of CD47, a widely expressed integrin-associated protein known to suppress phagocytosis and implicated as an interacting partner with other innate immune receptors. We found that CD47 associates with TLR2, and blocking CD47 leads to decreased intracellular P. gingivalis survival in macrophages in a manner dependent on the bacterial major fimbria. In vivo, CD47 knock-out mice cleared P. gingivalis more efficiently than wild-type mice. Next, we found increased expression and secretion of the CD47 ligand thrombospondin-1 (TSP-1) following P. gingivalis infection. Secreted TSP-1 broadly protected P. gingivalis and other periodontitis-associated bacterial species from neutrophil bactericidal activity. Therefore, CD47-TLR2 cosignaling in response to P. gingivalis induces TSP-1 that in turn suppresses neutrophil activity, an effect that can explain how species such as P. gingivalis survive in an inflamed environment and cause dysbiosis.

Arrestin beta-2 deficiency exacerbates periodontal inflammation by mediating activating transcription factor 6 activation and abnormal remodelling of the extracellular matrix

AIM

To investigate the specific role of arrestin beta-2 (ARRB2) in the progression of periodontitis and the underlying mechanisms.

MATERIALS AND METHODS

Single-cell RNA sequencing data were used to analyse gene expression in periodontal tissues from healthy controls and patients with periodontitis. Real-time quantitative polymerase chain reaction, Western blotting and immunohistochemical staining were performed to detect the expression of ARRB2. Furthermore, a ligature-induced periodontitis model was created. Using radiographic and histological methods, RNA sequencing and luciferase assay, the role of ARRB2 in periodontitis and the underlying mechanisms were explored. Finally, the therapeutic effect of melatonin, an inhibitor of activating transcription factor 6 (ATF6), on periodontitis in mice was assessed in both in vivo and in vitro experiments.

RESULTS

ARRB2 expression was up-regulated in inflammatory periodontal tissue. In the ligature-induced mouse model, Arrb2 knockout exacerbated alveolar bone loss (ABL) and extracellular matrix (ECM) degradation. ARRB2 exerted a negative regulatory effect on ATF6, an essential targeted gene. Melatonin ameliorated ABL and an imbalance in ECM remodelling in Arrb2-deficient periodontitis mice.

CONCLUSIONS

ARRB2 mediates ECM remodelling via inhibition of the ATF6 signalling pathway, which ultimately exerts a protective effect on periodontal tissues.

Plasma THBS1 as a predictive biomarker for poor prognosis and brain metastasis in patients with HER2-enriched breast cancer

BACKGROUND

Thrombospondin-1 (THBS1) is a secretory adhesive glycoprotein involved in the progression of multiple malignancies, including breast cancer. However, the clinical significance and prognostic role of plasma THBS1 in breast cancer have yet to be clarified.

METHODS

Plasma THBS1 levels in 627 breast cancer patients were analyzed by enzyme-linked immunosorbent assay. Bone marrow blood was drawn from the anterior/posterior superior iliac spine to detect the presence of disseminated tumor cells (DTCs). The effects of plasma THBS1 on the clinicopathological characteristics and survival prediction of breast cancer patients were explored.

RESULTS

Plasma THBS1 did not correlate with overall survival, breast cancer-specific survival (BCSS), and distant disease-free survival (DDFS) in the entire breast cancer cohort. Notably, HER2-enriched patients with high-plasma THBS1 levels had significantly shorter BCSS (P = 0.027) and DDFS (P = 0.011) than those with low levels. Multivariate analyses revealed that plasma THBS1 was an independent prognostic marker of BCSS (P = 0.026) and DDFS (P = 0.007) in HER2-enriched patients. THBS1 levels were 24% higher in positive DTC patients than in negative DTC patients (P = 0.031), and high levels were significantly associated with poor BCSS in positive DTC patients (HR 2.08, 95% CI 1.17-3.71; P = 0.019). Moreover, high-plasma THBS1 levels were specifically associated with an increased occurrence of brain metastasis in HER2-enriched patients (P = 0.041).

CONCLUSION

These findings suggest that plasma THBS1 may be serving as an unfavorable prognosis predictor for HER2-enriched breast cancer and justifies the need for further research.

Targeting Thbs1 reduces bladder remodeling caused by partial bladder outlet obstruction via the FGFR3/p-FGFR3 pathway

BACKGROUND

Partial bladder outlet obstruction (pBOO) may lead to bladder remodeling, including fibrosis and extracellular matrix (ECM) deposition. Despite the extensive research on the mechanisms underlying pBOO, potential therapeutic targets for the treatment of pBOO require further research. Dysregulated expression of thrombospondin-1 (Thbs1) has been reported in various human fibrotic diseases; however, its relationship with pBOO remains unclear.

AIMS

Investigate the effects of Thbs1 on bladder remodeling caused by pBOO.

METHODS

We established a pBOO model in Sprague-Dawley rats and performed urodynamic analyses to estimate functional changes in the bladder, validated the histopathological changes in the bladder by using haematoxylin-eosin and Masson's trichrome staining, identified key target genes by integrating RNA sequencing (RNA-seq) and bioinformatics analyses, validated the expression of related factors using Western blot analysis and RT-qPCR, and used immunofluorescence staining to probe the potential interaction factors of Thbs1.

RESULTS

Urodynamic results showed that pressure-related parameters were significantly increased in rats with pBOO. Compared with the sham group, the pBOO group demonstrated significant increases in bladder morphology, bladder weight, and collagen deposition. Thbs1 was significantly upregulated in the bladder tissues of rats with pBOO, consistent with the RNA-seq data. Thbs1 upregulation led to increased expression of matrix metalloproteinase (MMP) 2, MMP9, and fibronectin (Fn) in normal human urinary tract epithelial cells (SV-HUC-1), whereas anti-Thbs1 treatment inhibited the production of these cytokines in TGF-β1-treated SV-HUC-1. Further experiments indicated that Thbs1 affected bladder remodeling in pBOO via the fibroblast growth factor receptor 3 (FGFR3) pathway.

CONCLUSIONS

Thbs1 plays a crucial role in bladder remodeling caused by pBOO. Targeting Thbs1 might alleviate ECM damage. Mechanistically, Thbs1 may function via the FGFR signaling pathway by regulating the FGFR3 receptor, identified as the most relevant disease target of pBOO, and FGF2 may be a mediator. These findings suggest that Thbs1 plays a role in BOO development and is a therapeutic target for this condition.