The therapeutic effect of Interleukin-18 on hypertrophic scar through inducing Fas ligand expression

Deciphering interleukin-18 in diabetes and its complications: Biological features, mechanisms, and therapeutic perspectives

Interleukin-18 (IL-18), a potent and multifunctional pro-inflammatory cytokine, plays a critical role in regulating β-cell failure, β-cell death, insulin resistance, and various complications of diabetes mellitus (DM). It exerts its effects by triggering various signaling pathways, enhancing the production of pro-inflammatory cytokines and nitric oxide (NO), as well as promoting immune cells infiltration and β-cells death. Abnormal alterations in IL-18 levels have been revealed to be strongly associated with the onset and development of DM and its complications. Targeting IL-18 may present a novel and promising approach for DM therapy. An increasing number of IL-18 inhibitors, including chemical and natural inhibitors, have been developed and have been shown to protect against DM and diabetic complications. This review provides a comprehensive understanding of the production, biological functions, action mode, and activated signaling pathways of IL-18. Next, we shed light on how IL-18 contributes to the pathogenesis of DM and its associated complications with links to its roles in the modulation of β-cell failure and death, insulin resistance in various tissues, and pancreatitis. Furthermore, the therapeutic potential of targeting IL-18 for the diagnosis and treatment of DM is also highlighted. We hope that this review will help us better understand the functions of IL-18 in the pathogenesis of DM and its complications, providing novel strategies for DM diagnosis and treatment.

Expression of macrophage activation‑specific factors in hyperplastic scar tissue during hyperplasia phase by antibody array blotting membrane assay and its clinical significance

The expression of macrophage activation-specific factors in hyperplastic scar (HS) tissues during hyperplasia phase was detected by antibody array imprinted membrane method and the role of macrophage activation in the natural evolution of HS was explored. A total of 83 patients with HS admitted to the Affiliated Hospital of Beihua University (Jilin, China) between February 2021 and July 2021 were enrolled. The clinical data of the patients were retrospectively analyzed. These patients were divided into the hyperplasia HS group (n=26) and the decline HS group (the HS tissues ceased to grow and were in regression periods; n=57) according to the time of scar formation and clinical characteristics. The HS tissues were collected from patients in both groups. The contents of IL-12, IL-10, VEGF and basic fibroblast growth factor (bFGF) were detected by antibody array imprinted membrane method and the contents of IL-12, IL-10, VEGF and bFGF in tissues with various groups of tissues and clinical features were compared. The connection between macrophage activation-specific factors with VEGF and bFGF was analyzed using Pearson correlation analysis. The contents of IL-10 (9.48±1.06), VEGF (24.15±2.64) and bFGF (37.48±2.56) were much lower and IL-12 levels (16.45±0.85) were strongly higher in hyperplasia HS group compared with those in the decline HS group (14.56±1.26 for IL-10, 27.85±2.63 for VEGF, 43.15±3.16 for bFGF and 10.46±0.75 for IL-12, P<0.001). In the hyperplasia HS group, the contents of IL-10, VEGF and bFGF were obviously higher and the IL-12 levels were markedly lower in patients with age ≥30 years, protuberance height <2 mm, soft flexibility, low hyperemia degree and no concomitant symptoms than those in the patients with age <30 years, protuberance height ≥2 mm, hard flexibility, high hyperemia degree and concomitant symptoms (P<0.001). Pearson correlation analysis showed that IL-12 was negatively correlated with VEGF and bFGF (r=-0.328, 0.600, P<0.01). IL-10 was positively correlated with VEGF and bFGF (r=0.486, 0.684, respectively, P<0.001). In conclusion, macrophage activation-specific factors were abnormally expressed in hyperplasia HS, mainly M1 macrophages, accompanied by severe inflammatory reaction. The transformation of M1 macrophage into M2 macrophage usually occurred during the declining HS phase, which accelerated scar formation by promoting the formation of fibroblasts and angiogenesis. Detection of macrophage activation-specific factors may contribute to evaluate the clinical stage of HS.

Effectiveness of fractional carbon dioxide laser combined with botulinum toxin type A in a rabbit ear model with the underlying mechanism

BACKGROUND

Hypertrophic scar (HS) is a common disease in plastic and cosmetic surgery, with limited treatment options, and is a challenge for clinicians.

OBJECTIVES

This study aimed to evaluate the efficacy of fractional carbon dioxide (CO₂ ) laser combined with botulinum toxin type A (BTXA) in treating HSs in rabbit ears and to provide new strategies for treating HS.

METHODS

Twenty-four New Zealand white rabbits with induced HSs were randomly divided into one control and three treatment groups. After 4 weeks of modeling, BTXA (2.0 U) was injected into the HS of the BTXA and combination groups, whereas a fractional CO₂ laser (combo mode, deep energy: 12.5 mJ; super energy: 90 mJ) was used in the fractional CO₂ laser and combination groups. The laser treatments were repeated after 2 weeks. The HSs in the rabbit ears were observed and photographed 5 weeks after the first treatment. The scar thickness in each group was measured and compared, and the scar elevation index (SEI) was determined using hematoxylin and eosin staining. Collagen content and alignment were observed using Masson's trichrome staining. Western blotting and immunohistochemistry were performed to analyze scar-related protein levels.

RESULTS

Hypertrophic scars were reduced in all treatment groups compared with the control group. The combination group had lower scar thickness, SEI, and expression of scar-related proteins in HSs, with an appearance similar to that of normal rabbit ear skin. Furthermore, the fibroblast content and collagen deposition decreased significantly in the combination group (p < 0.001).

CONCLUSIONS

Fractional CO₂ laser combined with BTXA more effectively reduced HSs by inhibiting fibroblast proliferation, decreasing transforming growth factor-β1 and α- smooth muscle actin expression, and causing collagen remodeling.

Interleukin-18 and IL-18BP in inflammatory dermatological diseases

Interleukin (IL)-18, an interferon-γ inducer, belongs to the IL-1 family of pleiotropic pro-inflammatory factors, and IL-18 binding protein (IL-18BP) is a native antagonist of IL-18 in vivo, regulating its activity. Moreover, IL-18 exerts an influential function in host innate and adaptive immunity, and IL-18BP has elevated levels of interferon-γ in diverse cells, suggesting that IL-18BP is a negative feedback inhibitor of IL-18-mediated immunity. Similar to IL-1β, the IL-18 cytokine is produced as an indolent precursor that requires further processing into an active cytokine by caspase-1 and mediating downstream signaling pathways through MyD88. IL-18 has been implicated to play a role in psoriasis, atopic dermatitis, rosacea, and bullous pemphigoid in human inflammatory skin diseases. Currently, IL-18BP is less explored in treating inflammatory skin diseases, while IL-18BP is being tested in clinical trials for other diseases. Thereby, IL-18BP is a prospective therapeutic target.

Traditional Chinese medicine for hypertrophic scars—A review of the therapeutic methods and potential effects

Hypertrophic scar (HS) is a typical pathological response during skin injury, which can lead to pain, itching, and contracture in patients and even affect their physical and mental health. The complexity of the wound healing process leads to the formation of HS affected by many factors. Several treatments are available for HS, whereas some have more adverse reactions and can even cause new injuries with exacerbated scarring. Traditional Chinese Medicine (TCM) has a rich source, and most botanical drugs have few side effects, providing new ideas and methods for treating HS. This paper reviews the formation process of HS, the therapeutic strategy for HS, the research progress of TCM with its relevant mechanisms in the treatment of HS, and the related new drug delivery system of TCM, aiming to provide ideas for further research of botanical compounds in the treatment of HS, to promote the discovery of more efficient botanical candidates for the clinical treatment of HS, to accelerate the development of the new drug delivery system and the final clinical application, and at the same time, to promote the research on the anti-HS mechanism of multiherbal preparations (Fufang), to continuously improve the quality control and safety and effectiveness of anti-HS botanical drugs in clinical application.

Therapeutic Strategies by Regulating Interleukin Family to Suppress Inflammation in Hypertrophic Scar and Keloid

Hypertrophic scar (HS) and keloid are fibroproliferative disorders (FPDs) of the skin due to aberrant wound healing, which cause disfigured appearance, discomfort, dysfunction, psychological stress, and patient frustration. The unclear pathogenesis behind HS and keloid is partially responsible for the clinical treatment stagnancy. However, there are now increasing evidences suggesting that inflammation is the initiator of HS and keloid formation. Interleukins are known to participate in inflammatory and immune responses, and play a critical role in wound healing and scar formation. In this review, we summarize the function of related interleukins, and focus on their potentials as the therapeutic target for the treatment of HS and keloid.