Triamcinolone Acetonide Suppresses Keloid Formation Through Enhancing Apoptosis in a Nude Mouse Model

Development and validation of novel keloid-derived immortalized fibroblast cell lines

Keloids are a common connective tissue disorder with an ill-understood etiopathogenesis and no effective treatment. This is exacerbated because of the absence of an animal model. Patient-derived primary keloid cells are insufficient as they age through passaging and have a limited supply. Therefore, there is an unmet need for development of a cellular model that can consistently and faithfully represent keloid's pathognomic features. In view of this, we developed keloid-derived immortalized fibroblast (KDIF) cell lines from primary keloid fibroblasts (PKF) by transfecting the human telomerase reverse transcriptase (hTERT) gene. The TERT gene encodes the catalytic subunit of the telomerase enzyme, which is responsible for maintaining the cellular replicative potential (cellular immortalization). Primary fibroblasts from keloid-specific lesional (peripheral, middle, and top) as well as extralesional sites were isolated and evaluated for cell line development and comparative cellular characteristics by employing qRT-PCR and immunofluorescence staining. Moreover, the immortalized behavior of KDIF cell lines was evaluated by comparing with cutaneous fibrosarcoma and dermatofibrosarcoma protuberans cell lines. Stable KDIF cell lines with elevated expression of hTERT exhibited the cellular characteristics of site-specific keloid fibroblasts. Histochemical staining for β-galactosidase revealed a significantly lower number of β-gal-positive cells in all three KDIF cell lines compared with that in PKFs. The cell growth curve pattern was studied over 10 passages for all three KDIF cell lines and was compared with the control groups. The results showed that all three KDIF cell lines grew significantly faster and obtained a fast growing characteristic as compared to primary keloid and normal fibroblasts. Phenotypic behavior in growth potential is an indication of hTERT-mediated immortalized transformation. Cell migration analysis revealed that the top and middle KDIF cell lines exhibited similar migration trend as site-specific PKFs. Notably, peripheral KDIF cell line showed significantly enhanced cell migration in comparison to the primary peripheral fibroblasts. All KDIF cell lines expressed Collagen I protein as a keloid-associated fibrotic marker. Functional testing with triamcinolone inhibited cell migration in KDIF. ATCC short tandem repeat profiling validated the KDIF as keloid representative cell line. In summary, we provide the first novel KDIF cell lines. These cell lines overcome the limitations related to primary cell passaging and tissue supply due to immortalized features and present an accessible and consistent experimental model for keloid research.

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Insights into How Plant-Derived Extracts and Compounds Can Help in the Prevention and Treatment of Keloid Disease: Established and Emerging Therapeutic Targets

Keloid is a disease in which fibroblasts abnormally proliferate and synthesize excessive amounts of extracellular matrix, including collagen and fibronectin, during the healing process of skin wounds, causing larger scars that exceed the boundaries of the original wound. Currently, surgical excision, cryotherapy, radiation, laser treatment, photodynamic therapy, pressure therapy, silicone gel sheeting, and pharmacotherapy are used alone or in combinations to treat this disease, but the outcomes are usually unsatisfactory. The purpose of this review is to examine whether natural products can help treat keloid disease. I introduce well-established therapeutic targets for this disease and various other emerging therapeutic targets that have been proposed based on the phenotypic difference between keloid-derived fibroblasts (KFs) and normal epidermal fibroblasts (NFs). We then present recent studies on the biological effects of various plant-derived extracts and compounds on KFs and NFs. Associated ex vivo, in vivo, and clinical studies are also presented. Finally, we discuss the mechanisms of action of the plant-derived extracts and compounds, the pros and cons, and the future tasks for natural product-based therapy for keloid disease, as compared with existing other therapies. Extracts of Astragalus membranaceus, Salvia miltiorrhiza, Aneilema keisak, Galla Chinensis, Lycium chinense, Physalis angulate, Allium sepa, and Camellia sinensis appear to modulate cell proliferation, migration, and/or extracellular matrix (ECM) production in KFs, supporting their therapeutic potential. Various phenolic compounds, terpenoids, alkaloids, and other plant-derived compounds could modulate different cell signaling pathways associated with the pathogenesis of keloids. For now, many studies are limited to in vitro experiments; additional research and development are needed to proceed to clinical trials. Many emerging therapeutic targets could accelerate the discovery of plant-derived substances for the prevention and treatment of keloid disease. I hope that this review will bridge past, present, and future research on this subject and provide insight into new therapeutic targets and pharmaceuticals, aiming for effective keloid treatment.

Triamcinolone acetonide induces the autophagy of Ag85B-treated WI-38 cells via SIRT1/FOXO3 pathway

BACKGROUND

Tracheobronchial stenosis due to tuberculosis (TSTB) seriously threatens the health of tuberculosis patients. The inflammation and autophagy of fibroblasts affect the development of TSTB. Triamcinolone acetonide (TA) can regulate the autophagy of fibroblasts. Nevertheless, the impact of TA on TSTB and underlying mechanism has remained unclear.

OBJECTIVE

To study the impact of TA on TSTB and underlying mechanism.

MATERIAL AND METHODS

In order to simulate the TSTB-like model in vitro, WI-38 cells were exposed to Ag85B protein. In addition, the cell counting kit (CCK)-8 assay was applied to assess the function of TA in Ag85B-treated WI-38 cells. Quantitative real-time polymerase chain reaction was applied to detect the mRNA level of sirtuin 1 (SIRT1) and forkhead box O3 (FOXO3a), and autophagy-related proteins were evaluated by Western blot analysis. Vascular endothelial growth factor (VEGF) level was investigated by immunohistochemical staining. Enzyme-linked immunosorbent serologic assay was applied to detect the secretion of inflammatory cytokines. Furthermore, hematoxylin and eosin staining was applied to observe tissue injuries.

RESULTS

Ag85B affected WI-38 cell viability in a limited manner, while TA notably suppressed Ag85B-treated WI-38 cell viability. TA induced the apoptosis of Ag85B-treated WI-38 cells in a dose-dependent manner. In addition, Ag85B-treated WI-38 cells demonstrated the upregulation of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), interferon gamma (IFN-γ), and fibrotic proteins (transforming growth factor-beta [TGF-β] and vascular endothelial growth factor [VEGF]), which can be significantly destroyed by the TA. Meanwhile, TA reversed Ag85-induced inhibition of cell autophagy by mediation of p62, LC3, and Beclin1. Furthermore, silencing of SIRT1/FOXO3a pathway could reverse the effect of TA on the autophagy of Ag85B-treated cells.

CONCLUSION

TA significantly induced the autophagy of fibroblasts in Ag85B-treated cells by mediation of SIRT1/FOXO3 pathway. This study established a new theoretical basis for exploring strategies against TSTB.

Targeting the Akt/PI3K/mTOR signaling pathway for complete eradication of keloid disease by sunitinib

Keloid disease is a nodular lesion, tumor-like but not cancerous, and characterized of excessive proliferation of fibroblasts and deposition of extracellular matrix (ECM) components. This condition often causes itching, pain and cosmetic disfigurement, significantly reducing patient quality of life. To date, no universally effective therapies are available, possibly due to inadequate understanding of keloid pathogenesis. As an oral small-molecule inhibitor of certain tyrosine kinase receptors, sunitinib has shown significant therapeutic effects in renal cell carcinoma (RCC) and gastrointestinal stromal tumor (GIST). However, it has never been tested if keloid therapy can be effective for the management of keloids. This study thus aims to explore the potential of sunitinib for keloid treatment. Keloid-derived fibroblasts (KFs) were successfully isolated and demonstrated proliferative advantage to normal skin-derived fibroblasts (NFs). Additionally, sunitinib showed specific cytotoxicity and inhibition of invasion, and induced cell cycle arrest and significant apoptosis in KFs. These effects were accompanied by complete suppression of ECM component expression, including collagen types 1 and 3, upregulation of autophagy-associated LC3B and significant suppression of the Akt/PI3K/mTOR pathway. Moreover, a keloid explant culture model was successfully established and used to test the therapeutic efficacy of sunitinib on keloid formation in nude mice. Sunitinib was found to induce complete regression of keloid explant fragments in nude mice, showing significantly higher therapeutic efficacy than the most commonly used intralesional drug triamcinolone acetonide (TAC). These data suggest that sunitinib effectively inhibits keloid development through suppression of the Akt/PI3K/mTOR pathway and thus can be potentially developed as a monotherapy or combination therapy for the effective treatment of keloid disease.

Effect of the combination of photobiomodulation therapy and the intralesional administration of corticoid in the preoperative and postoperative periods of keloid surgery: A randomized, controlled, double-blind trial protocol study

Keloid scars are characterized by the excessive proliferation of fibroblasts and an imbalance between the production and degradation of collagen, leading to its buildup in the dermis. There is no “gold standard” treatment for this condition, and the recurrence is frequent after surgical procedures removal. In vitro studies have demonstrated that photobiomodulation (PBM) using the blue wavelength reduces the proliferation speed and the number of fibroblasts as well as the expression of TGF-β. There are no protocols studied and established for the treatment of keloids with blue LED. Therefore, the purpose of this study is to determine the effects of the combination of PBM with blue light and the intralesional administration of the corticoid triamcinolone hexacetonide on the quality of the remaining scar by Vancouver Scar Scale in the postoperative period of keloid surgery. A randomized, controlled, double-blind, clinical trial will be conducted involving two groups: 1) Sham (n = 29): intralesional administration of corticoid (IAC) and sham PBM in the preoperative and postoperative periods of keloid removal surgery; and 2) active PBM combined with IAC (n = 29) in the preoperative and postoperative periods of keloid removal surgery. Transcutaneous PBM will be performed on the keloid region in the preoperative period and on the remaining scar in the postoperative period using blue LED (470 nm, 400 mW, 4J per point on 10 linear points). The patients will answer two questionnaires: one for the assessment of quality of life (Qualifibro-UNIFESP) and one for the assessment of satisfaction with the scar (PSAQ). The team of five plastic surgeons will answer the Vancouver Scar Scale (VSS). All questionnaires will be administered one, three, six, and twelve months postoperatively. The keloids will be molded in silicone prior to the onset of treatment and prior to excision to assess pre-treatment and post-treatment size. The same will be performed for the remaining scar at one, three, six, and twelve months postoperatively. The removed keloid will be submitted to histopathological analysis for the determination of the quantity of fibroblasts, the organization and distribution of collagen (picrosirius staining), and the genic expression of TGF-β (qPCR). All data will be submitted to statistical analysis.

Trial registration: This study is registered in ClinicalTrials.gov (ID: NCT04824612).