MicroRNAs as biomarkers of atrophic scarring in acne: a cross-sectional analysis of 41 patients

A microRNA focus on acne

Acne (syn. acne vulgaris) is a common inflammatory skin disorder associated with puberty and adolescence. The disease is characterized by comedoneous lesions, papules, pustules, and nodules that are mostly found on the face. These lesions are caused by intricate interactions between the pilosebaceous unit and the Cutibacterium acnes (C. acnes) bacteria. Unhealthy acne and its aftereffects, like pigment changes and scarring, have a detrimental impact on one's quality of life. Recent years have seen a sharp increase in the approval of nucleic acid therapies (NATs), such as antisense oligonucleotides and short-interfering RNA medications, for rare diseases for which there are few or no effective treatments. These developments suggest that NATs may be useful in acne treatment plans down the road, as do clinical trials for microRNA (miRNA) modulation in skin contexts. We highlight promising miRNA targets for anti-acne therapy in this review. We outline the pathophysiology of acne in brief and emphasize the functions of C. acnes. Next, we concentrate on the distinct impacts of biofilm and planktonic C. acnes on a Toll-like receptor 2 axis that spans miR-146a-5p, which was recently discovered. Before discussing the potential contributions of miR-21-5p, miR-233-3p, and miR-150-5p to inflammatory axes in acne, we evaluate miR-146a-5p in sebocytes. Finally, we address patient involvement in miRNA-related acne research and translational perspectives.

A Study of FoxO1, mTOR, miR-21, miR-29b, and miR-98 Expression Levels Regarding Metabolic Syndrome in Acne Vulgaris Patients

BACKGROUND

Acne vulgaris (AV) is an inflammatory skin disease caused by the mechanistic target of rapamycin complex 1 (mTORC1). forkhead box protein (Fox) O1 is known to regulate the relationship between the mTORC1 signaling pathway and insulin resistance (IR). Increased mTORC1 signaling is known to predispose one to diseases such as insulin resistance (IR), obesity, and diabetes mellitus. One of the major components of mTORC1 is mTOR. FoxO1 and mTOR play key roles in the onset and progression of metabolic syndrome (MetS). In this study, we aimed to elucidate the relationship between AV and MetS through FoxO1 and mTOR signaling pathways and microRNAs (miRs) associated with these signaling pathways.

METHODS

We examined 20 AV patients without MetS, 16 AV patients with MetS, and 20 healthy controls. The demographic characteristics of the patients, MetS parameters, clinical severity of AV (Global Acne Grading System, GAGS), and the homeostasis model assessment (HOMA) values were compared between the groups. In addition, the expression levels of FoxO1 and mTOR genes, along with the expression levels of miR-21, miR-29b, and miR-98, were assessed in skin biopsy samples from all groups using real-time polymerase chain reaction methods. FoxO1, mTOR, and miRNA expression levels were recorded as fold change.

RESULTS

The mean age of patients with AV without MetS was statistically lower. In AV patients with MetS, those with moderate GAGS scores had statistically significantly higher HOMA values than those with mild GAGS scores. FoxO1 expression was significantly lower in AV patients compared to controls. The mTOR expression levels of AV patients with MetS were significantly higher than the other two groups. The expression levels of miR-21 and miR-29b were significantly increased in the group of AV patients with MetS compared to the group of AV patients without MetS.

CONCLUSIONS

These results suggested that the mTOR pathway may play an important role in explaining the relationship between AV and MetS in acne pathogenesis. They also suggested that miR-21 and miR-29b play a role in the inflammatory process of AV.

Emerging Insights into the Applicability of Essential Oils in the Management of Acne Vulgaris

The occurrence of pustules, comedones, nodules, and cysts defines acne vulgaris, a prevalent chronic inflammatory dermatological condition. In the past few decades, essential oils extracted from varied natural sources have acquired recognition due to their potential medicinal applications in acne therapy. However, there is not yet sufficient medical data to fully characterize this interaction. Multiple factors contribute to the development of acne vulgaris, including excessive sebaceous production, inflammatory processes, hyperkeratinization, and infection with Cutibacterium acnes. Essential oils, including oregano, lavender, lemon grass, myrtle, lemon, thyme, eucalyptus, rosemary, and tea tree, have been found to possess anti-inflammatory, antioxidant, and antimicrobial properties, which may target the multifactorial causes of acne. Analytical methods for determining antioxidant potential (i.e., total phenolic content, diphenyl-1-picrylhydrazyl free radical scavenging assay, reducing power assay, ferrous ion chelating activity, thiobarbituric acid reactive species assay, β-carotene bleaching assay, etc.) are essential for the evaluation of these essential oils, and their method optimization is crucial. Further studies could include the development of novel acne treatments incorporating essential oils and an assessment of their efficacy in large clinical trials. In addition, further research is necessary to ascertain the mechanisms of action of essential oils and their optimal doses and safety profiles for optimal implementation in the management of acne vulgaris.

MicroRNA Cross-Involvement in Acne Vulgaris and Hidradenitis Suppurativa: A Literature Review

Acne Vulgaris (AV) and Hidradenitis suppurativa (HS) are common chronic inflammatory skin conditions that affect the follicular units that often coexist or are involved in differential diagnoses. Inflammation in both these diseases may result from shared pathways, which may partially explain their frequent coexistence. MicroRNAs (miRNAs) are a class of endogenous, short, non-protein coding, gene-silencing or promoting RNAs that may promote various inflammatory diseases. This narrative review investigates the current knowledge regarding miRNAs and their link to AV and HS. The aim is to examine the role of these molecules in the pathogenesis of AV and HS and to identify possible common miRNAs that could explain the similar characteristics of these two diseases. Five miRNA (miR-155 miR-223-, miR-21, and miRNA-146a) levels were found to be altered in both HS and AV. These miRNAs are related to pathogenetic aspects common to both pathologies, such as the regulation of the innate immune response, regulation of the Th1/Th17 axis, and fibrosis processes that induce scar formation. This review provides a starting point for further studies aimed at investigating the role of miRNAs in AV and HS for their possible use as diagnostic-therapeutic targets.