Breast capsule contracture: is fibroblast activity associated with severity?

The activation of FPR3/PKA/Rap1/ERK1/2 and FPR3/p-IκB/NF-κB axis in fibroblasts promote capsular contracture after rhinoplasty

BACKGROUND

Capsular contracture may occur after rhinoplasty due to rejection of silicone implants by the immune system. Our previous high-throughput sequencing of RNA in nasal capsular contracture tissue revealed that FPR3 was significantly increased in grade IV capsular contracture tissue, compared with grade II.

OBJECTIVE

This study aimed to elucidate the effect and specific mechanism of FPR3 on capsular formation and contracture following rhinoplasty.

METHODS

Using the GeneMANIA Database, the genes involved with FPR3 expression were searched, and the Gene Ontology analysis was performed to annotate the biological functions of the aforementioned genes. The mRNA and protein expressions of related genes in fibroblasts and capsular contracture tissues were analyzed using quantitative real-time PCR, western blot, and immunohistochemical staining. CCK-8 was used to determine the viability of cells. The migration capacity of fibroblasts was assessed using a wound healing assay. ELISA was used to detect levels of IL-1β, TNF-α, and IL-6.

RESULTS

After rhinoplasty, the expression of FPR3 in the capsular tissue increased in proportion to the degree of contracture. By activating the PKA/Rap1/ERK1/2 axis, overexpression of FPR3 can significantly increase the cell viability of fibroblasts and promote their transformation into myofibroblasts. Moreover, FPR3 phosphorylates IκB to decrease NF-κB inhibition, thereby promoting the synthesis and release of the inflammatory cytokines IL-1β, TNF-α, and IL-6.

CONCLUSION

FPR3 is a crucial molecule that causes capsular development and contracture following rhinoplasty. In the future, local suppression of FPR3 may be an effective treatment for relieving capsular contracture.

Morphologic Features of Magnetic Resonance Imaging as a Surrogate of Capsular Contracture in Breast Cancer Patients With Implant-based Reconstructions

PURPOSE

Capsular contracture (CC) is a serious complication in patients receiving implant-based reconstruction for breast cancer. Currently, no objective methods are available for assessing CC. The goal of the present study was to identify image-based surrogates of CC using magnetic resonance imaging (MRI).

METHODS AND MATERIALS

We analyzed a retrospective data set of 50 patients who had undergone both a diagnostic MRI scan and a plastic surgeon's evaluation of the CC score (Baker's score) within a 6-month period after mastectomy and reconstructive surgery. The MRI scans were assessed for morphologic shape features of the implant and histogram features of the pectoralis muscle. The shape features, such as roundness, eccentricity, solidity, extent, and ratio length for the implant, were compared with the Baker score. For the pectoralis muscle, the muscle width and median, skewness, and kurtosis of the intensity were compared with the Baker score. Univariate analysis (UVA) using a Wilcoxon rank-sum test and multivariate analysis with the least absolute shrinkage and selection operator logistic regression was performed to determine significant differences in these features between the patient groups categorized according to their Baker's scores.

RESULTS

UVA showed statistically significant differences between grade 1 and grade ≥2 for morphologic shape features and histogram features, except for volume and skewness. Only eccentricity, ratio length, and volume were borderline significant in differentiating grade ≤2 and grade ≥3. Features with P<.1 on UVA were used in the multivariate least absolute shrinkage and selection operator logistic regression analysis. Multivariate analysis showed a good level of predictive power for grade 1 versus grade ≥2 CC (area under the receiver operating characteristic curve 0.78, sensitivity 0.78, and specificity 0.82) and for grade ≤2 versus grade ≥3 CC (area under the receiver operating characteristic curve 0.75, sensitivity 0.75, and specificity 0.79).

CONCLUSIONS

The morphologic shape features described on MR images were associated with the severity of CC. MRI has the potential to further improve the diagnostic ability of the Baker score in breast cancer patients who undergo implant reconstruction.

Effect of the inhibitor peptide of the transforming growth factor beta (p144) in a new silicone pericapsular fibrotic model in pigs

BACKGROUND

Capsular contracture is the most common complication associated with silicone prostheses. It may take the form of anything from slight hardening to obvious deformity. The role of transforming growth factor beta (TGF-beta) in the scar physiopathology of any fibrotic process has been demonstrated. The effects of inhibition of TGF-beta have also been demonstrated in experimental models of fibrosis, which opens the way for new therapeutic alternatives in the treatment of capsular contracture. The aim of this study was to evaluate periprosthetic fibrosis with a newly synthesized TGF-beta peptide inhibitor (p144).

METHODS

Three experimental groups were formed: Group I, subcutaneous and submuscular textured silicone prostheses were left untreated; Group 2, the prostheses were left after being immersed in the vehicle; Group 3, the same protocol was followed as in Group 2, but the solution contained the vehicle with the inhibitor peptide of TGF-beta, p144 (15 mg/prosthesis). The animals were sacrificed 24 weeks after implantation, and the capsules were assessed both macroscopically and histologically.

RESULTS

The results obtained showed that the inhibition of capsular thickness and soluble collagen content in pericapsular fibrosis did not significantly decrease in the group of animals treated with the TGF-beta inhibitor peptide in comparison with control cases.

CONCLUSIONS

We detected no statistically significant reduction in fibrosis in the periprosthetic capsule after treating the implants with the inhibitor peptide p144, but we feel that the influence of trauma around the prosthesis is critical in impeding the antifibrotic activity of the inhibitor peptide.

Flector tissugel used to treat capsular contracture after breast augmentation surgery

Capsular contracture constitutes the main postoperative complication after breast augmentation by implant placement. To date, no systemic treatment known allows for improvement that does not simultaneously put the patient at risk for secondary complications of a more general nature. Flector Tissugel is the sole locally active antiinflammatory patch. Its durable local antiinflammatory effect is associated only with a risk for rare and highly limited side effects. After approximately 3 weeks of treatment, a high frequency of change from capsular contracture Baker 2 or 3 to Baker 1 occurs, provided the application was started no later than 3 months after the onset of capsular contracture.

Breast Implant Capsules Are Partially Composed of Bone Marrow–Derived Cells

Capsular contracture is the most common complication following breast augmentation or reconstruction with implants. We recently demonstrated that bone marrow-derived cells provide fibroblasts to murine skin during wound healing. To determine if bone marrow-derived cells were the cellular source of periprosthetic capsules, we created chimeric C57BL mice containing bone marrow cells from isogeneic enhanced green fluorescent protein (EGFP) mice and implanted with a textured silicone shell implant. We found that none of the mice developed infection or capsular contracture, but day 30 capsules were composed of 26.4 +/- 6.1% EGFP cells, and day 60 capsules had 21.8 +/- 10.3% EGFP cells. Immunohistochemistry revealed a small population of EGFP cells in the capsules that were myofibroblasts. Thus, breast implant capsules are partially composed of bone marrow-derived cells and, given the potential of these cells to become myofibroblasts, may explain the cellular source of capsular contracture when it develops.

Use of the Transforming Growth Factor-??1 Inhibitor Peptide in Periprosthetic Capsular Fibrosis: Experimental Model with Tetraglycerol Dipalmitate

BACKGROUND

Capsular contracture is the most common specific complication associated with silicone prostheses. It is thought to be caused by the gradual retraction of the fibrous scar tissue that forms around the prosthesis. Molecular biology has made it possible to determine the role of transforming growth factor beta (TGF-beta) in the scar physiopathology of any fibrotic process, including periprosthetic capsular fibrosis. The effects on the inhibition of TGF-beta have also been demonstrated in experimental models of scar formation and fibrosis, which opens the way for new therapeutic alternatives in the treatment of capsular contracture.

METHODS

Three experimental groups of 10 rats each were formed to evaluate periprosthetic fibrosis after its modulation with a newly synthesized TGF-beta1 peptide inhibitor in a tetraglycerol dipalmitate matrix. In the first group, subcutaneously and submuscularly placed, smooth, solid silicone prostheses were left untreated; in the second group, the prostheses were left after being immersed in a solution of tetraglycerol dipalmitate; and in the third group, following the same protocol as in the second group, the solution contained tetra-glycerol dipalmitate mixed with the inhibitor peptide of TGF-beta1. The animals were euthanized 8 weeks after implantation, and the capsules were assessed both macroscopically and histologically.

RESULTS

Inhibition of capsular thickness and cellularity was significantly more effective in the group of animals treated with the inhibitor peptide of TGF-beta1.

CONCLUSIONS

The TGF-beta1 inhibitor peptide applied in a matrix with tetraglycerol dipalmitate is significantly effective in achieving a reduction in periprosthetic fibrosis after placement of silicone implants, either subcutaneously or submuscularly. This result suggests new therapeutic approaches.