Recent advances in understanding inflammatory acne: Deciphering the relationship between Cutibacterium acnes and Th17 inflammatory pathway

Nanoparticle-Encapsulated Plant Polyphenols and Flavonoids as an Enhanced Delivery System for Anti-Acne Therapy

This study conducted a literature review by searching for articles related to the treatment of skin infections/wrinkles using nano-delivery systems containing natural compounds. The search was conducted in various databases for articles published in the last 10 years, with strict inclusion and exclusion criteria. Of the 490 articles found, 40 were considered relevant. Acne vulgaris is a common dermatological disorder characterised by inflammation of the sebaceous glands, often resulting in the development of pimples, cysts, and scarring. Conventional treatments, including antibiotics and topical retinoids, frequently demonstrate limitations such as side effects, resistance, and insufficient skin absorption. Recent advancements in nanotechnology have enabled the creation of innovative drug-delivery systems that enhance the effectiveness and reduce the adverse effects of anti-acne medications. Polyphenols and flavonoids, natural bioactive compounds with notable anti-inflammatory, antioxidant, and antibacterial properties, are recognised for their therapeutic effectiveness in acne treatment. However, their practical application is hindered by insufficient solubility, stability, and bioavailability. The incorporation of these compounds into nanoparticle-based delivery systems has shown promise in resolving these challenges. Various nanoparticle platforms, including lipid-based nanoparticles, polymeric nanoparticles, and solid lipid nanoparticles, are evaluated for their ability to improve the stability, controlled release, and targeted delivery of polyphenols and flavonoids to the skin. The advent of polyphenol and flavonoid-loaded nanoparticles marks a new acne therapy era.

Hypocrellin A-mediated photodynamic antibacterial activity against Cutibacterium acnes: An in vitro study

Skin dysbiosis caused by Cutibacterium acnes contributes greatly to the complex pathogenesis of acne, and antimicrobial photodynamic therapy (PDT) has emerged as a promising treatment option for acne treatment. Hypocrellin, a photosensitizer extracted from a traditional Chinese medicinal fungus, has showed effective antimicrobial activity. This study aimed to evaluate the antibacterial ability of hypocrellin mediated PDT against Cutibacterium acnes. Using modified broth dilution method and morphological observation, the antibacterial effect was tested under a series of experimental conditions. The results showed that hypocrellin initiates type II photodynamic reactions by inducing amount of reactive oxygen species, particularly singlet oxygen. Within a certain concentration range, hypocrellin effectively maintained the antibacterial efficacy with minimal damage to keratinocyte cells. These results provide new insights into the use of PDT for acne treatment.

Network pharmacology, transcriptomics, and biological validation reveal a lipid secretion inhibitory and anti-inflammatory mechanism of tanreqing gel in the treatment of acne

ETHNOPHARMACOLOGICAL RELEVANCE

Acne vulgaris is a common skin disease affecting the pilosebaceous unit, in which abnormal sebum secretion and inflammation play crucial roles. The traditional Chinese medicine Tanreqing has been utilized in dermatology to effectively treat various diseases. However, its effects and underlying mechanisms in acne vulgaris remain unclear.

AIM OF THE STUDY

This study aims to assess the potential benefits of Tanreqing gel (TRQ) in acne treatment and to explore the mechanisms by which TRQ inhibits sebum secretion and reduces inflammation.

MATERIALS AND METHODS

A mouse model of acne induced by Cutibacterium acnes (C. acnes) was established. The impact of TRQ on acne lesions was assessed using optical imaging and histopathology. Network pharmacology and transcriptomics were used to identify significant intervention pathways and targets. Both in vivo and in vitro experiments were conducted to detect the expression of genes and proteins associated with inflammation and sebum metabolism.

RESULTS

TRQ significantly improved pathological changes in the lesion areas of mice, such as redness, vascular dilation, and increased blood flow. It also reduced inflammatory cell infiltration in the dermis and inhibited the accumulation of lipids in the sebaceous glands. Network pharmacology analysis indicated that TRQ might exert anti-inflammatory effects through the IL-17, TOLL-like receptor, and NF-κB signaling pathways. The transcriptomic analysis confirmed the importance of these pathways in the C. acnes-induced acne model. Furthermore, TRQ was found to reduce sebum secretion by inhibiting fatty acid biosynthesis through the suppression of proteins in the PI3K-Akt signaling pathway. Cell experiments confirmed that TRQ could suppress the release of inflammatory factors induced by C. acnes surface structure peptidoglycan (PGN) and metabolite porphyrins. Additionally, it was observed to reverse the elevated porphyrin secretion associated with abnormal sebum production, ultimately relieving acne inflammation.

CONCLUSION

This study demonstrated that TRQ effectively alleviates C. acnes-induced acne symptoms by inhibiting sebum secretion and inflammatory responses through multiple pathways and targets. It provides new insights and directions for acne treatment.

Antibacterial activity and impact on keratinocyte cell growth of Cutibacterium acnes bacteriophages in a Cutibacterium acnes IA1- colonized keratinocyte model

Acne is an inflammatory disease in which microbial disbalance is represented by an augmented population of phylotype IA1 of Cutibacterium acnes. Various treatments for acne can cause side effects, and it has been reported that C. acnes is resistant to prescribed antibiotics. Phage therapy has been proposed as an alternative treatment for acne, given its species-specificity to kill bacteria, its relative innocuity, and its potential to manage antibiotic-resistant pathogens. Moreover, bacteriophages (phages) may modulate the microbiota and immune responses. Some studies have shown the potential use of phages in the treatment of acne. Nevertheless, the capacity to specifically reduce phylotype IA1 and the effect of phage treatment on skin cells are poorly understood. We assessed the capacity of phages to clear C. acnes IA1 and their effects on cell cytotoxicity and growth in HEKa cells- C. acnes IA1 co-culture. Phylotypes IA1 and IB had similar effects on HEKa cells, causing cytotoxicity and diminishing cell growth. Nevertheless, IA1 caused a higher impact on cell doubling time by increasing it 1.8 times more than cell growth control group. Even though there are no phages IA1-specific, we found phages that have a diminished effect on other phylotypes not related to acne. Phage treatment in general reduced IA1-caused cytotoxicity, with differences in efficacy among phages. In addition, phage purification was necessary to restore metabolic activity and growth of HEKa. Overall, phage evaluation as a therapeutic alternative should include phage-bacteria interactions and their impact on skin cells because of the differences that each phage can exhibit.

In vitro and In vivo Activity of a New N-Oxide Derivative for Acne Vulgaris Treatment

INTRODUCTION

Furoxan and benzofuroxan are compounds containing an N-oxide function, known for their diverse pharmacological properties, including antimicrobial and antiinflammatory effects. This study aimed to investigate these activities using an in-house library of N-oxide compounds.

METHOD

Twenty compounds were tested against both Gram-positive and Gram-negative bacteria, including Cutibacterium acnes (C. acnes), a microorganism implicated in the development of acne vulgaris. One compound, (E)-4-(3-((2-(3-hydroxybenzoyl)hydrazone)methyl)phenoxy)-3- (phenylsulfonyl)-1,2,5-oxadiazol-2-N-oxide (compound 15), exhibited selective antimicrobial activity against C. acnes, with a Minimum Inhibitory Concentration (MIC) value of 2 μg/mL. Indirect measurement of Nitric Oxide (NO) release showed that compound 15 and isosorbide dinitrate, when treated with L-cysteine, produced nitrite levels of 20.1% and 9.95%, respectively. Using a NO scavenger (PTIO) in combination with compound 15 in a culture of C. acnes resulted in reduced antimicrobial activity, indicating that NO release is part of its mechanism of action. Cytotoxicity assessments using murine macrophages showed cellular viability above 70% at concentrations up to 0.78 μg/mL.

RESULTS

Measurements of Interleukin-1 beta (IL1-β) and Tumor Necrosis Factor-alpha (TNF-α) indicated that compound 15 did not reduce the levels of these pro-inflammatory cytokines. Sustained NO production by inducible Nitric Oxide Synthase (iNOS) in macrophages or neutrophils has been found to be involved in the inflammatory process in acne vulgaris and lead to toxicity in surrounding tissues. Nitrite levels in the supernatant of murine macrophages were found to be decreased at a concentration of 0.78 μg/mL of compound 15, indicating an anti-inflammatory effect. In vivo studies were conducted using Balb/c nude mice inoculated subcutaneously with C. acnes. Cream and gel formulations of compound 15 were applied to treat the animals, along with commercially available anti-acne drugs, for 14 days. Animals treated with a cream base containing 5% of compound 15 exhibited less acanthosis with mild inflammatory infiltration compared to other groups, highlighting its anti-inflammatory properties.

CONCLUSION

Similar results were observed in the benzoyl peroxide group, demonstrating that compound 15 presented comparable anti-inflammatory activity to the FDA-approved drug. These promising results suggest that compound 15 has a dual mechanism of action, with selective antimicrobial activity against C. acnes and notable anti-inflammatory properties, making it a potential prototype for developing new treatments for acne vulgaris.

A Mixture of Water-Soluble Polysaccharides Reduces Caspase-1 and IL-1β Inflammatory Responses by Cutibacterium acnes in vitro in Reconstructed Human Epidermis (RHE)

Introduction

It is well established that Cutibacterium acnes (C. acnes) is a common skin commensal microorganism that has been linked to acne. In acne flare-ups, C. acnes can be found in abundant levels within the inflammatory lesions (called comedones) associated with the skin disease. Recently, it was reported that 3D reconstructed human epidermis (RHE) treated with viable cultures of C. acnes can elicit β-defensin antimicrobial peptide responses in the skin and can weaken the skin barrier of the RHE after three days of exposure to C. acnes.

Methods

Employing a modification of this in vitro assay, RHE was pretreated with C. acnes for 48 hours, then further treated with a mixture of water-soluble polysaccharides (STRATAPHIX™ POLY, "Polysaccharide Blend") previously shown to reduce inflammasome-mediated inflammatory responses in normal human epidermal keratinocytes (NHEK). Two inflammasome-mediated inflammation markers were tested, including caspase-1, a potent protease enzyme activated by NOD-like receptor protein (NLRP)-induced inflammasome activation, and interleukin-1β (IL-1β), a cytokine which is activated from inactive pro-IL-1β by caspase-1.

Results

The treatment of the RHE tissues with C. acnes for 48 hours elicited an inflammatory response measured with both markers compared against untreated tissues. Treatment of the tissues with 1% and 2% salicylic acid for 24 hours after C. acnes treatment increased the inflammatory response measured with both markers. Application of the water-soluble polysaccharides in combination with 1% and 2% of salicylic acid significantly reduces expression of both active caspase-1 and IL-1β compared against the tissues treated with C. acnes and salicylic acid alone.

Discussion

The results lend further support to previously reported work which was done on NHEKs treated with ultraviolet B (UVB) light and adenosine triphosphate (ATP) and demonstrate that the same mixture of polysaccharides can have a modulating effect against bacterial and chemical induced inflammation in RHE.

A study of granulysin and pentraxin 3 genetic polymorphisms and their contribution to acne susceptibility

This study aims to examine the genetic polymorphisms of the granulysin (GNLY) and pentraxin 3 (PTX3) genes and their association with acne in Egypt. Acne vulgaris is classified as a disorder of the pilosebaceous unit. Clinical, histological, and immunological findings indicate that inflammation is involved in every stage of acne development. GNLY and PTX3 are both involved in the body's immune system and may play a role in the pathophysiology of acne. This case-control study included 180 participants who have acne and 180 healthy controls. Real-time PCR was used to genotype GNLY rs7908 and PTX3 rs2305619 polymorphisms. Genotype occurrence and allelic spreading for both single nucleotide polymorphisms (SNP) are in Hardy-Weinberg equilibrium. Regarding rs7908, no statistical difference was observed in the genotype and allele distributions between acne patients and controls. On the other hand, rs2305619 showed a statistical difference in the genotype and allele distributions between acne patients and controls, with a marked prevalence of the GG group and G allele in acne patients. Our study revealed a significant link between the PTX3 rs2305619 and acne susceptibility in Egypt, with the AG + GG genotype strongly predicting acne. In contrast, the GNYL rs7908 polymorphism was not associated with acne. These results highlight a genetic component to acne and suggest that PTX3 rs2305619 could be a key marker for understanding acne susceptibility.

The synergistic effects of Guaiacum officinale and Rhodomyrtus tomentosa extracts in the treatment of acne vulgaris on sensitive skin

BACKGROUND

Acne vulgaris, a common chronic dermatological condition worldwide, is associated with inflammatory response and Cutibacterium acnes. Individuals with acne vulgaris and sensitive skin have limited suitable treatments due to the skin irritation and side effects exhibited by current hydroxy acidic medications.

AIMS

This study aimed to evaluate the synergistic effects of Guaiacum officinale (GO) and Rhodomyrtus Tomentosa (RT) extracts for treating acne vulgaris on sensitive skin by inhibiting inflammation.

METHODS

The phytochemical constituents and antioxidant activity of GO and RT extracts were determined in vitro. The anti-inflammatory effects were investigated in peptidoglycan (PGN)-induced HaCaT cells. Further, a 28-day clinical trial was conducted involving 30 subjects with both sensitive skin and acne to evaluate the efficacy and subjects' satisfaction.

RESULTS

Total phenolics and flavonoids were detected in GO and RT extracts, the IC50 values for DPPH radical scavenging were 6.15 wt% and 0.76 wt%, respectively. The combination of GO and RT extracts at a 1:1 (v/v) ratio significantly decreased the expression of TLR-2 and TLR-4, as well as the secretion of IL-1α, IL-8, and TNF-α in PGN-induced HaCaT cells, by 2.30-7.93 times compared to GO extract alone (p < 0.05). Moreover, the cream containing 5 wt% the combination significantly improved facial acne and redness (p < 0.05). The number of comedones decreased by 50.00% and papules by 30.65% after 28 days of application. No adverse events were reported and 96.67% of the subjects were satisfied with the treatment.

CONCLUSION

The efficacy of the GO and RT extracts in synergistically suppressing inflammation, improving acne vulgaris, and reducing redness. The study offers an effective and non-irritant treatment for acne vulgaris in individuals with sensitive skin.

Clinical Evaluation of Microbial Communities and Associated Biofilms with Breast Augmentation Failure

The incidence of breast implant illness (BII) and BII-related explant procedures has not decreased with current surgical and treatment techniques. It is speculated the main underlying cause of BII complications is the result of chronic, sub-clinical infections residing on and around the implant. The infection, and subsequent biofilm, produce antagonistic compounds that drive chronic inflammation and immune responses. In this study, the microbial communities in over 600 consecutive samples of infected explant capsules and tissues were identified via next-generation sequencing to identify any commonality between samples. The majority of the bacteria identified were Gram-positive, with Cutibacterium acnes and Staphylococcus epidermidis being the dominant organisms. No correlation between sample richness and implant filling was found. However, there was a significant correlation between sample richness and patient age. Due to the complex nature, breast augmentation failures may be better addressed from a holistic approach than one of limited scope.

Can Gentisic Acid Serve as a High-Performance Antioxidant with Lower Toxicity for a Promising New Topical Application?

Gentisic acid (2,5-dihydroxybenzoic acid) is primarily found naturally in plants and has demonstrated a significant range of biological activities; however, its efficacy and safety as a topical application ingredient are not yet well established. Thus, the compound's potential antioxidant and antimicrobial properties were evaluated for efficacy, while the cytotoxicity was evaluated for safety. The antioxidant activity, measured by the DPPH kinetic method, showed an Efficiency Concentration (EC50) of 0.09 with an antioxidant reducing power (ARP) of 11.1. The minimum inhibitory concentration (MIC) against Staphylococcus aureus was 4.15 mg/mL, Escherichia coli was 4.00 mg/mL, Candida albicans was 3.00 mg/mL, and Cutibacterium acnes was 3.60 mg/mL, and the MIC for C. acnes has remained unpublished until now. The substance showed low cytotoxicity by the neutral red uptake (NRU) methodology against HaCat, HDFa, and HepG2 cells at concentrations of up to 10.0, 7.3, and 4.0 mM, respectively, also representing unpublished data. This evidence demonstrates gentisic acid as a promising active substance for skin topical application in the cosmetic or pharmaceutical industry.

Characterization of the forehead skin microbiome in the early phase of acne

BACKGROUND

The skin microbiota is known to be imbalanced in acne vulgaris, but the changes occurring during the early stages of acne onset remain poorly described.

OBJECTIVES

To characterize the skin microbiome of subclinical stages of acne in adults and adolescents.

METHODS

The composition and diversity of the microbiota from non-lesional skin on the forehead of subjects with mild-to-moderate acne were compared to the ones from non-acne subjects. Analyses of skin swab samples were performed using high-throughput sequencing of the V1-V3 regions of the bacterial 16S ribosomal RNA gene, the tuf gene fragment of Staphylococcus species and the internal transcribed spacer (ITS1) region of the fungal rRNA gene to determine the relative abundance, alpha-diversity and beta-diversity of bacteria and fungi.

RESULTS

Compared with non-acne subjects, acne subjects had a higher abundance of Cutibacterium (72.4% vs. 57.8%) and lower abundances of Corynebacterium (2.8% vs. 4.8%) and Streptococcus (1.4% vs. 3.2%). Bacterial alpha- and beta-diversity indices also differed significantly between the two groups, reflecting differences in richness, evenness, abundance and phylogenetic distance between bacterial populations. Differences were also observed at the level of Staphylococcus species: S. capitis was predominant in skin samples from non-acne subjects (46.7%), whereas S. epidermidis was the most abundant Staphylococcus species in non-lesional forehead skin areas of acne subjects (44.2%). Conversely, no significant between-group differences were found for fungi, with Malasseziales being the predominant order in both subject groups.

CONCLUSION

Dysbiosis was observed very early in subclinical acne stages of the forehead skin, with the overall abundance, richness and evenness of the bacterial population being lower in acne than in non-acne skin samples. Dysbiosis was also found at the level of Staphylococcus species. The development of acne lesions could therefore be prevented by using a skin care product that rebalances facial skin microbiota at very early stages.

vB_CacS-HV1 as a Novel Pahexavirus Bacteriophage with Lytic and Anti-Biofilm Potential against Cutibacterium acnes

Acne vulgaris is a prevalent chronic inflammatory skin disease, most common in adolescence and often persisting into adulthood, leading to severe physical and psychological impacts. The primary etiological factor is Cutibacterium acnes infection. The overuse of antibiotics for acne treatment over recent decades has led to the emergence of antibiotic-resistant Cutibacterium acnes strains. In this study, we isolated and characterized a novel bacteriophage, vB_CacS-HV1, from saliva samples. The average nucleotide identity analysis indicated that vB_CacS-HV1 is a new species within the Pahexavirus genus, enhancing our understanding of this underexplored group. vB_CacS-HV1 demonstrates favorable stability, lacks potentially harmful genetic elements (virulence factors, antibiotic resistance genes, transposons, and integrases), and exhibits potent lytic and anti-biofilm activities against Cutibacterium acnes at low concentrations. These advantages highlight vB_CacS-HV1's potential as a promising antibacterial agent that could possibly be complementary to antibiotics or other treatments for acne therapy.

Integrative bioinformatics and experimental validation of hub genetic markers in acne vulgaris: Toward personalized diagnostic and therapeutic strategies

BACKGROUND

Acne vulgaris is a widespread chronic inflammatory dermatological condition. The precise molecular and genetic mechanisms of its pathogenesis remain incompletely understood. This research synthesizes existing databases, targeting a comprehensive exploration of core genetic markers.

METHODS

Gene expression datasets (GSE6475, GSE108110, and GSE53795) were retrieved from the GEO. Differentially expressed genes (DEGs) were identified using the limma package. Enrichment analyses were conducted using GSVA for pathway assessment and clusterProfiler for GO and KEGG analyses. PPI networks and immune cell infiltration were analyzed using the STRING database and ssGSEA, respectively. We investigated the correlation between hub gene biomarkers and immune cell infiltration using Spearman's rank analysis. ROC curve analysis validated the hub genes' diagnostic accuracy. miRNet, TarBase v8.0, and ChEA3 identified miRNA/transcription factor-gene interactions, while DrugBank delineated drug-gene interactions. Experiments utilized HaCaT cells stimulated with Propionibacterium acnes, treated with retinoic acid and methotrexate, and evaluated using RT-qPCR, ELISA, western blot, lentiviral transduction, CCK-8, wound-healing, and transwell assays.

RESULTS

There were 104 genes with consistent differences across the three datasets of paired acne and normal skin. Functional analyses emphasized the significant enrichment of these DEGs in immune-related pathways. PPI network analysis pinpointed hub genes PTPRC, CXCL8, ITGB2, and MMP9 as central players in acne pathogenesis. Elevated levels of specific immune cell infiltration in acne lesions corroborated the inflammatory nature of the disease. ROC curve analysis identified the acne diagnostic potential of four hub genes. Key miRNAs, particularly hsa-mir-124-3p, and central transcription factors like TFEC were noted as significant regulators. In vitro validation using HaCaT cells confirmed the upregulation of hub genes following Propionibacterium acnes exposure, while CXCL8 knockdown reduced pro-inflammatory cytokines, cell proliferation, and migration. DrugBank insights led to the exploration of retinoic acid and methotrexate, both of which mitigated gene expression upsurge and inflammatory mediator secretion.

CONCLUSION

This comprehensive study elucidated pivotal genes associated with acne pathogenesis, notably PTPRC, CXCL8, ITGB2, and MMP9. The findings underscore potential biomarkers, therapeutic targets, and the therapeutic potential of agents like retinoic acid and methotrexate. The congruence between bioinformatics and experimental validations suggests promising avenues for personalized acne treatments.

Research progress on the role of macrophages in acne and regulation by natural plant products

Acne vulgaris is one of the most common skin diseases. The current understanding of acne primarily revolves around inflammatory responses, sebum metabolism disorders, aberrant hormone and receptor expression, colonization by Cutibacterium acnes, and abnormal keratinization of follicular sebaceous glands. Although the precise mechanism of action remains incompletely understood, it is plausible that macrophages exert an influence on these pathological features. Macrophages, as a constituent of the human innate immune system, typically manifest distinct phenotypes across various diseases. It has been observed that the polarization of macrophages toward the M1 phenotype plays a pivotal role in the pathogenesis of acne. In recent years, extensive research on acne has revealed an increasing number of natural remedies exhibiting therapeutic efficacy through the modulation of macrophage polarization. This review investigates the role of cutaneous macrophages, elucidates their potential significance in the pathogenesis of acne, a prevalent chronic inflammatory skin disorder, and explores the therapeutic mechanisms of natural plant products targeting macrophages. Despite these insights, the precise role of macrophages in the pathogenesis of acne remains poorly elucidated. Subsequent investigations in this domain will further illuminate the pathogenesis of acne and potentially offer guidance for identifying novel therapeutic targets for this condition.

No association between isotretinoin and impulsivity in patients with moderate-to-severe acne vulgaris

BACKGROUND

Acne vulgaris (AV) is one of the common dermatologic diseases that usually affects people during adolescence. Reports have shown that isotretinoin, the first-line therapy option for moderate-to-severe AV, could lead to mood disturbances and suicidality. Impulsivity is the tendency to act prematurely without foresight and is a significant risk factor for suicidality. This study aimed to test the hypothesis that isotretinoin would lead to an increase in impulsivity.

METHODS

Seventeen patients with AV were enrolled. The study was planned as a naturalistic 3-month follow-up study. Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Barratt Impulsiveness Scale (BIS), Go/No-go Task (GNG), and Balloon Analog Risk Task (BART) were administered before and after the isotretinoin treatment.

RESULTS

We found a significant improvement in the severity of anxiety (P = 0.015; t = 2.72) and depression symptoms (P = 0.08; t = 3.04) in AV patients at the end of 3 months. Self-report impulsivity characteristics with BIS stayed unchanged (P = 0.434; t = 0.80). Besides, no statistically significant difference was found in behavioral task results associated with response inhibition with GNG (P = 0.52; t = 0.65) and impulsive decision-making with BART (P = 0.842; t = -0.20). However, there was a significant decrease in omission errors, with GNG suggesting improvement in attention domain (P = 0.020; W = 90.0) after the follow-up.

CONCLUSIONS

It has been demonstrated that isotretinoin treatment improves the severity of depression, anxiety symptoms, and attention performance in AV patients. However, there was no significant change in patients' impulsivity severity based on self-reports and behavioral performances based on GNG and BART.

Acne microbiome: From phyla to phylotypes

Acne vulgaris is a chronic inflammatory skin disease with a complex pathogenesis. Traditionally, the primary pathophysiologic factors in acne have been thought to be: (1) altered sebum production, (2) inflammation, (3) excess keratinization and (4) colonization with the commensal Cutibacterium acnes. However, the role of C. acnes has been unclear, since virtually all adults have C. acnes on their skin yet not all develop acne. In recent years, understanding of the role of C. acnes has expanded. It is still acknowledged to have an important place in acne pathogenesis, but evidence suggests that an imbalance of individual C. acnes phylotypes and an alteration of the skin microbiome trigger acne. In addition, it is now believed that Staphylococcus epidermidis is also an actor in acne development. Together, C. acnes and S. epidermidis maintain and regulate homeostasis of the skin microbiota. Antibiotics, which have long been a staple of acne therapy, induce cutaneous dysbiosis. This finding, together with the long-standing public health edict to spare antibiotic use when possible, highlights the need for a change in acne management strategies. One fertile direction of study for new approaches involves dermocosmetic products that can support epidermal barrier function and have a positive effect on the skin microbiome.

Association of different cell types and inflammation in early acne vulgaris

Acne vulgaris, one of the most common skin diseases, is a chronic cutaneous inflammation of the upper pilosebaceous unit (PSU) with complex pathogenesis. Inflammation plays a central role in the pathogenesis of acne vulgaris. During the inflammatory process, the innate and adaptive immune systems are coordinately activated to induce immune responses. Understanding the infiltration and cytokine secretion of differential cells in acne lesions, especially in the early stages of inflammation, will provide an insight into the pathogenesis of acne. The purpose of this review is to synthesize the association of different cell types with inflammation in early acne vulgaris and provide a comprehensive understanding of skin inflammation and immune responses.

Hsa_circ_0105040 promotes Cutbacterium acnes biofilm induced inflammation via sponge miR-146a in human keratinocyte

Acne is a chronic inflammatory skin disease, and the pathogenesis of acne induced by Cutibacterium acnes (C.acnes) is not well understood. Recently, circular RNAs (circRNAs) have attracted much attention because of its involvement in various diseases. However, the mechanisms by which circRNAs regulated acne have rarely been reported. We identified several differentially expressed circRNAs by sequencing patient-derived acne tissues. Among them, hsa_circ_0105040 was determined to be low expressed in acne tissues and localized in the cytoplasm of human primary keratinocytes. We established a C.acnes biofilms model of acne in vitro and showed that hsa_circ_0105040 promoted inflammation via MAPK and NF-κB pathway. Mechanistically, hsa_circ_0105040 could directly bind to miR-146a and inhibit the expression of miR-146a. Moreover, hsa_circ_0105040 promoted the expression of IRAK1 and TRAF6 by sponging miR-146a, thereby elevating the level of inflammation in acne. Collectively, our data suggested that hsa_circ_0105040- miR-146a -IRAK1/TRAF6 axis was involved in regulating the inflammatory response in acne, which provided a potential therapeutic target for acne and a novel insight into the pathogenesis of inflammatory acne.

Strong infiltrative HHC36 antimicrobial peptide/silver nanoparticles-loaded carboxymethyl chitosan/sodium alginate hydrogel for acne vulgaris therapy

Acne is a common chronic skin inflammatory disease closely related toCutibacterium acnes(C. acnes), which affects the life quality of patients worldwide, especially adolescents and young adults. However, the physical barrier of the skin makes drugs difficult to infiltrate effectively into infected site, causing acne hard to cure and easy to recur. Herein, we developed an antibacterial skin dressing with strong infiltration of antibacterial agents which can co-delivery small-molecular antimicrobial agents through stratum corneum deeply into dermis, achieving high antimicrobial efficacy. The antibacterial dressings were constructed with carboxymethyl chitosan/sodium alginate (CMCS/SA) hydrogel loading with HHC36 (an antimicrobial peptide) and silver nanoparticles (AgNPs) conjugates (Ag-H2/CMCS/SA hydrogel). The released Ag-H2from Ag-H2/CMCS/SA hydrogel can early infiltrate into dermis, co-delivery HHC36 and AgNPs due to the infiltration and targeting of HHC36, presenting the superior antibacterial effect compared to HHC36 or AgNPs alone and killing 100%C. acnesand 100%Staphylococcus epidermidis(S. epidermidis) at a very low concentration of Ag-H2(15μg ml-1A g with 7.1μg ml-1HHC36). Meanwhile, Ag-H2/CMCS/SA hydrogel was biocompatible due to the natural polysaccharides carboxymethyl chitosan and sodium alginate. The HaCaT cells spread well in Ag-H2/CMCS/SA hydrogel. These results indicate that the co-delivery small-molecular antimicrobial agents is a promising strategy and Ag-H2/CMCS/SA hydrogel has a great potential in the therapy of acne.

Emerging Trends and Focus in Human Skin Microbiome Over the Last Decade: A Bibliometric Analysis and Literature Review

Background

Human skin microbiome is the first barrier against exogenous attack and is associated with various skin disease pathogenesis and progression. Advancements in high-throughput sequencing technologies have paved the way for a deeper understanding of this field. Based on the bibliometric analysis, this investigation aimed to identify the hotspots and future research trends associated with human skin microbiomes studied over the past decade.

Methods

The published research on skin microbiome from January 2013 to January 2023 was retrieved from the Web of Science Core Collection. Data cleaning processes to ensure robust data and the bibliometrix packages R, CiteSpace, VOSviewer, Origin, and Scimago Graphica for bibliometric and visual analyses were utilized.

Results

A total of 1629 published documents were analyzed. The overall publication trend steadily increased, with relatively fast growth in 2017 and 2020. The United States of America has the highest number of publications and citations and shows close collaborations with China and Germany. The University of California, San Diego, indicated a higher number of publications than other institutions and the fastest growth rate. The top three most publishing journals on this topic are Microorganisms, Frontiers in Microbiology, and Experimental dermatology. Gallo RL is the most influential author with the highest h- and g-index and most publications in skin microecology, followed by Grice EA and Kong HH. The top 10 most frequently used keywords in recent years included skin microbiome, microbiome, staphylococcus aureus, diversity, atopic dermatitis, skin, bacteria, infections, gut microbiota, and disease.

Conclusion

The skin microbiome is an area of research that requires continuous analysis, and even with much-achieved progress, future research will further be aided as technology develops.

Acneiform Lesions but not Acne after Treatment with Janus Kinase Inhibitors: Diagnosis and Management of Janus Kinase-acne

Abstract is missing (Short communication)

Tea Tree Oil: Properties and the Therapeutic Approach to Acne-A Review

Acne vulgaris is an inflammatory dermatological pathology that affects mostly young people. However, it can also appear in adulthood, mainly in women. It has a high psychosocial impact, not only at the time of active lesions but also due to the consequences of lesions such as scarring and hyperpigmentation. Several factors are involved in the physiopathology of acne and the constant search for active ingredients is a reality, namely phytotherapeutic ingredients. Tea tree oil is an essential oil extracted from Melaleuca alternifolia (Maiden & Betch) Cheel with known antibacterial, anti-inflammatory, and antioxidant properties, making it a candidate for the treatment of acne. This review aims to describe the various properties of tea tree oil that make it a possible ingredient to use in the treatment of acne and to present several human studies that have evaluated the efficacy and safety of using tea tree oil in the treatment of acne. It can be concluded that tea tree oil has good antibacterial, anti-inflammatory, and antioxidant properties that result in a decrease in the number of inflammatory lesions, mainly papules, and pustules. However, given the diversity of study designs, it is not possible to draw concrete conclusions on the efficacy and safety of this oil in the treatment of acne.