Effect of captopril on collagen metabolisms in keloid fibroblast cells

Natural products - Dawn of keloid treatment

Keloids are prevalent pathological scars, often leading to cosmetic deformities and hindering joint mobility.They cause discomfort, including burning and itching, while gradually expanding and potentially posing a risk of cancer.Developing effective drugs and treatments for keloids has been a persistent challenge in the medical field. Natural products are an important source of innovative drugs and a breakthrough for many knotty disease.Herein, keywords of "natural, plant, compound, extract" were combined with "keloid" and searched in PubMed and Google Scholar, respectively. A total of 32 natural products as well as 9 extracts possessing the potential for treating keloids were ultimately identified.Current research in this field faces a significant challenge due to the lack of suitable animal models, resulting in a predominant reliance on in vitro studies.In vivo and clinical studies are notably scarce as a result.Moreover, there is a notable deficiency in research focusing on the role of nutrients in keloid formation and treatment.The appropriate dosage form (oral, topical, injectable) is crucial for the development of natural product drugs. Finally, the conclusion was hereby made that natural products, when used as adjuncts to other treatments, hold significant potential in the management of keloids.By summarizing the natural products and elucidating their mechanisms in keloid treatment, the present study aims to stimulate further discoveries and research in drug development for effectively addressing this challenging condition.

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.

Acne-induced pathological scars: pathophysiology and current treatments

Acne is a common chronic inflammatory dermatosis that can lead to pathological scars (PSs, divided into hypertrophic scars and keloids). These kinds of abnormal scars seriously reduce the quality of life of patients. However, their mechanism is still unclear, resulting in difficult clinical prevention, unstable treatment effects and a high risk of recurrence. Available evidence supports inflammatory changes caused by infection as one of the keys to abnormal proliferation of skin fibroblasts. In acne-induced PSs, increasing knowledge of the immunopathology indicates that inflammatory cells directly secrete growth factors to activate fibroblasts and release pro-inflammatory factors to promote the formation of PSs. T helper cells contribute to PSs via the secretion of interleukin (IL)-4 and IL-13, the pro-inflammatory factors; while regulatory T cells have anti-inflammatory effects, secrete IL-10 and prostaglandin E2, and suppress fibrosis production. Several treatments are available, but there is a lack of combination regimens to target different aspects of acne-induced PSs. Overall, this review indicates that the joint involvement of inflammatory response and fibrosis plays a crucial role in acne-induced PSs, and also analyzes the interaction of current treatments for acne and PS.

Progress in the clinical treatment of keloids

Keloid is a pathological scar that is higher than the skin surface following skin damage. Its lesion range often extends beyond the original damage boundary and does not naturally subside over time. Its pathogenesis is very complex, currently the main causes include fibroblast excessive proliferation, collagen and extracellular matrix (Extracellular matrix, ECM) excessive deposition, excessive angiogenesis, and so on. The traditional treatment method primarily involves surgical intervention, but it is associated with a high recurrence rate post-surgery. Consequently, many treatment methods are derived according to the different clinical characteristics of keloid. This paper will review the therapeutic progress in recent years from surgical treatment, physiotherapy, drug therapy, and biological therapy, with the goal of offering valuable insights for the clinical treatment of keloids.

Angiotensin converting enzyme and angiotensin converting enzyme inhibitors in dermatology: a narrative review

INTRODUCTION

Angiotensin converting enzyme inhibitors (ACEI) are commonly used for cardiovascular diseases. The evidence supporting the use of ACEI in dermatology is limited.

AREAS COVERED

This review article was divided into three parts. The first part discusses ACEI in clinical use in dermatology. The second part reveals the relationship between angiotensin converting enzyme (ACE) and immune diseases, and further discusses the possible relationship between ACEI in clinical use in these diseases and ACE. The third part focuses on cutaneous adverse reactions of ACEI.

EXPERT OPINION

The use of ACEI in dermatology is mainly based on its properties as regulation of renin angiotensin system (RAS), but currently, with limited clinical use. The association of ACE and several diseases are well discussed, including COVID-19, psoriasis, sarcoidosis, systemic lupus erythematosus and vitiligo. The main cutaneous adverse effects of ACEI include angioedema, psoriasis and pemphigus. Plausible factors for these adverse reactions include accumulation of vasoactive mediators, preventing angiotension from binding to AT₁ receptor and AT₂ receptor and presence of circulating antibodies.

Keloids: Current and emerging therapies

Keloids are pathological scars that grow over time and extend beyond the initial site of injury after impaired wound healing. These scars frequently recur and rarely regress. They are aesthetically disfiguring, can cause pain, itching, discomfort as well as psychological stress, often affecting quality of life. Many treatment modalities, including surgical and non-surgical, have been explored and have been reported to be beneficial; however, none have been absolutely satisfactory or optimal for the treatment of all keloid subtypes to date. This poses a major challenge to clinicians. Often, a combinational therapeutic approach appears to offer the best results with higher patient satisfaction compared to monotherapy. The aetiopathogenesis of keloids is not fully elucidated; however, with recent advances in molecular biology and genetics, insight is being gained on the complex process of scar formation and hence new therapeutic and management options for keloids. In this paper, we explore the literature and summarise the general concepts surrounding keloid development and review both current (corticosteroids, surgical excision, silicone-based products, pressure therapy, radiotherapy, cryotherapy, laser therapy, imiquimod and 5-fluorouracil) and emerging (stem cell therapy, mitomycin C, verapamil, interferons, bleomycin, botulinum toxin type A and angiotensin-converting enzyme inhibitors) treatments. Increased knowledge and understanding in this area may potentially lead to the discovery and development of novel therapeutic options that are more efficacious for all keloid types.

LAY SUMMARY

Keloids are problematic scars that are difficult to treat and manage. The aetiopathogenesis of keloids is not clear; however, recent advances in molecular biology and genetics are beginning to shed light on the underlying mechanisms implicated in keloid scar formation which will hopefully lead to the development of treatment options for all keloid types. This review summarises current and emerging therapies.

Expression of Cathepsins B, D, and G by the Embryonic Stem Cell-Like Population within Human Keloid Tissues and Keloid-Derived Primary Cell Lines

BACKGROUND

The authors have previously shown that an embryonic stem cell-like population within keloid-associated lymphoid tissues in keloid lesions expresses components of the renin-angiotensin system that may be dysregulated. The authors hypothesized that cathepsins B, D, and G are present within the embryonic stem cell-like population in keloid lesions and contribute to bypass loops of the renin-angiotensin system.

METHODS

3,3'-Diaminobenzidine immunohistochemical staining for cathepsins B, D, and G was performed on formalin-fixed paraffin-embedded sections in keloid tissue samples of 11 patients. Immunofluorescence immunohistochemical staining was performed on three of these keloid tissue samples, by co-staining with CD34, tryptase, and OCT4. Western blotting, reverse transcription quantitative polymerase chain reaction, and enzyme activity assays were performed on five keloid tissue samples and four keloid-derived primary cell lines to investigate protein and mRNA expression, and functional activity, respectively.

RESULTS

3,3'-Diaminobenzidine immunohistochemical staining demonstrated expression of cathepsins B, D, and G in all 15 keloid tissue samples. Immunofluorescence immunohistochemical staining showed localization of cathepsins B and D to the endothelium of microvessels within the keloid-associated lymphoid tissues and localization of cathepsin G to the tryptase-positive perivascular cells. Western blotting confirmed semiquantitative levels of cathepsins B and D in keloid tissue samples and keloid-derived primary cell lines. Reverse transcription quantitative polymerase chain reaction showed quantitative transcriptional activation of cathepsins B and D in keloid tissue samples and keloid-derived primary cell lines and cathepsin G in keloid tissue samples. Enzyme activity assays demonstrated functional activity of cathepsins B and D.

CONCLUSION

Cathepsins B, D, and G are expressed by the embryonic stem cell-like population within the keloid-associated lymphoid tissues of keloid lesions and may act to bypass the renin-angiotensin system, suggesting a potential therapeutic target using renin-angiotensin system modulators and cathepsin inhibitors.

The Plethora of Angiotensin-Converting Enzyme-Processed Peptides in Mouse Plasma

Angiotensin-converting enzyme (ACE) converts angiotensin I into the potent vasoconstrictor angiotensin II, which regulates blood pressure. However, ACE activity is also essential for other physiological functions, presumably through processing of peptides unrelated to angiotensin. The goal of this study was to identify novel natural substrates and products of ACE through a series of mass-spectrometric experiments. This included comparing the ACE-treated and untreated plasma peptidomes of ACE-knockout (KO) mice, validation with select synthetic peptides, and a quantitative in vivo study of ACE substrates in mice with distinct genetic ACE backgrounds. In total, 244 natural peptides were identified ex vivo as possible substrates or products of ACE, demonstrating high promiscuity of the enzyme. ACE prefers to cleave substrates with Phe or Leu at the C-terminal P2' position and Gly in the P6 position. Pro in P1' and Iso in P1 are typical residues in peptides that ACE does not cleave. Several of the novel ACE substrates are known to have biological activities, including a fragment of complement C3, the spasmogenic C3f, which was processed by ACE ex vivo and in vitro. Analyses with N-domain-inactive (NKO) ACE allowed clarification of domain selectivity toward substrates. The in vivo ACE-substrate concentrations in WT, transgenic ACE-KO, NKO, and CKO mice correspond well with the in vitro observations in that higher levels of the ACE substrates were observed when the processing domain was knocked out. This study highlights the vast extent of ACE promiscuity and provides a valuable platform for further investigations of ACE functionality.

Managing keloid scars: From radiation therapy to actual and potential drug deliveries

The aetiology of keloids is becoming clearer, but many questions remain, including about the most optimal treatment. Current therapies include surgical excision, radiotherapy, and various pharmaceutical drugs. However, none of these drugs are keloid-specific. Moreover, all current interventions are associated with high recurrence rates. Here, we review the pharmaceutical interventions that are currently available. All are based on the fact that keloids are an expanding solid mass with intense chronic inflammation at its advancing edges. Consequently, current pharmaceuticals aim to reduce the mass and/or symptoms of keloids, similar to surgery and radiotherapy. They include chemotherapies, immunotherapies, volume-reducing therapies, and anti-inflammatory therapies. We also describe new advances in keloid pharmaceuticals. They include drugs that were designed to treat systemic diseases such as hypertension or breast cancer but were found to also treat keloids. Furthermore, recent progress in genetic, epigenetic, and stem cell therapies suggests that they could become useful in the keloid field. This review of pharmaceutical advances will hopefully promote additional research and the development of effective and specific pharmaceuticals for keloids.

Comparison of Enalapril, Candesartan and Intralesional Triamcinolone in Reducing Hypertrophic Scar Development: An Experimental Study

BACKGROUND

The purpose of this study was to compare the effects of oral enalapril, an angiotensin-converting enzyme inhibitor (ACE-I), oral candesartan, an angiotensin receptor blocker (ARB), and intralesional corticosteroid treatments in reducing scar formation.

METHODS

Twenty male rabbits were divided into five study groups: A (sham), B (control), C (ACE-I), D (ARB) and E (intralesional corticosteroid). The rabbit ear hypertrophic scar model was used. The hypertrophic scars were photographed and analyzed with the program ImageJ quantitatively to determine the degree of collagen fibers. The scar elevation index (SEI) was calculated at the end of the 40th day. Tissue samples were stained with hematoxylin and eosin and Masson's trichrome and examined under light microscopy for the determination of fibroblast number, epithelization, vascularization, inflammation and fibrosis.

RESULTS

The SEI was the highest in the control group with the highest number of fibroblasts under the epithelium. In the steroid group, the SEI was significantly lower than both the ACE-I (p: 0.02) and ARB (p: 0.001) groups. The density of type 1 collagen fibers was the lowest in the control group, whereas type 3 collagen fibers were highest in that group. The ACE-I and ARB groups were similar regarding densities of type 1 and type 3 collagen fibers. The density of type 1 collagen fibers was the highest in the steroid group, whereas the density of type 3 collagen fibers was the lowest in that group.

CONCLUSIONS

Enalapril, candesartan and intralesional steroid therapies were all effective in reducing scar tissue development; however, enalapril and steroid groups revealed better results.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

HSP47 is associated with the prognosis of laryngeal squamous cell carcinoma by inhibiting cell viability and invasion and promoting apoptosis

Heat shock protein 47 (HSP47) is a 47 kDa collagen binding protein that has a close relationship with the development and progression of tumours. However, little is known concerning the expression profile of HSP47 in laryngeal squamous cell carcinoma (LSCC) patients and there is still insufficient data concerning the underlying mechanisms. The aim of the present study was to explore the expression of HSP47 in LSCC and provide an overview of its association with tumourigenicity and clinical prognosis. The expression of HSP47 in LSCC and adjacent non-cancerous laryngeal tissues was assessed via western blotting and immunohistochemical studies. The prognostic significance of HSP47 expression was analysed using a Kaplan-Meier survival curve. To investigate the influence of HSP47 on the viability, invasion and apoptosis of a LSCC cell line, we performed an in vitro analysis with plasmid vectors and small interfering RNA (siRNA). Our results showed that HSP47 protein expression in the LSCC tissues was markedly decreased compared to that noted in the adjacent non-cancerous tissues, and low expression of HSP47 was correlated with poor prognosis in LSCC patients. Upregulation of HSP47 via plasmid vectors inhibited the proliferation, reduced the invasive ability, increased the sensitivity to cisplatin chemotherapy, promoted apoptosis, and induced the G1 phase arrest of LSCC cells in vitro. The expression of apoptosis-regulating proteins was also altered when HSP47 was upregulated, involving increased expression of cleaved caspase-7/-8/-9, PARP, and Bax and decreased expression of Bcl-2. Our present data suggest that HSP47 is an important prognostic factor and an attractive therapeutic target in LSCC due to its influence on the biological behaviour of LSCC cells.