Common Pathogenesis of Acne Vulgaris and Atherosclerosis

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.

Exploring the association between rosacea and acne by integrated bioinformatics analysis

Clinically, rosacea occurs frequently in acne patients, which hints the existence of shared signals. However, the connection between the pathophysiology of rosacea and acne are not yet fully understood. This study aims to unveil molecular mechanism in the pathogenesis of rosacea and acne. We identified differentially expressed genes (DEGs) by limma and weighted gene co-expression network analysis and screened hub genes by constructing a protein-protein interaction network. The hub genes were verified in different datasets. Then, we performed a correlation analysis between the hub genes and the pathways. Finally, we predicted and verified transcription factors of hub genes, performed the immune cell infiltration analysis using CIBERSORT, and calculated the correlation between hub genes and immune cells. A total of 169 common DEGs were identified, which were mainly enriched in immune-related pathways. Finally, hub genes were identified as IL1B, PTPRC, CXCL8, MMP9, CCL4, CXCL10, CD163, CCR5, CXCR4, and TLR8. 9 transcription factors that regulated the expression of hub genes were identified. The infiltration of γδT cells was significantly increased in rosacea and acne lesions and positively linked with almost all hub genes. These identified hub genes and immune cells may play a crucial role in the development of rosacea and acne.

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.

DNA methylation profiling and integrative multi-omics analysis of skin samples reveal important contribution of epigenetics and immune response in the pathogenesis of acne vulgaris

The regulatory effect of DNA methylation on the pathogenesis of acne vulgaris is completely unknown. Herein we analyzed the DNA methylation profile in skin samples of acne vulgaris and further integrated it with gene expression profiles and single-cell RNA-sequencing data. Finally, 31,134 differentially methylated sites and 770 differentially methylated and expressed genes (DMEGs) were identified. The multi-omics analysis suggested the importance of DNA methylation in inflammation and immunity in acne. And DMEGs were verified in an external dataset and were closely related to early inflammatory acne. Additionally, we conducted experiments to verify the mRNA expression and DNA methylation level of DMEGs. This study supports the significant contribution of epigenetics to the pathogenesis of acne vulgaris and may provide new ideas for the molecular mechanisms of and potential therapeutic strategies for acne vulgaris.

Exploring the mechanism of action of Hedyotis diffusa Willd on acne using network analysis

In this study, we used a network pharmacological method to explore the active ingredients of Hedyotis diffusa Willd (HDW) in the treatment of acne and elucidated the physiological mechanisms in the human body in which they are involved. We identified the active compounds of HDW that are expected to act effectively in the human body using the Traditional Chinese Medicine Systems Pharmacology database and analysis platform and extracted potential interacting proteins for each active compound using the Swiss Target Prediction platform. Next, we analyzed the potential mechanisms of action of the protein targets shared by HDW and each standard drug on acne and assessed the possibility of spontaneous occurrence of the binding between proteins and active compounds through the molecular docking process. Seven active compounds were selected according to the oral bioavailability and drug-likeness criteria of the Traditional Chinese Medicine Systems Pharmacology database and analysis platform. Subsequently, 300 protein targets were collected from the Swiss Target Prediction. Using the Search Tool for the Retrieval of Interacting Genes/Proteins database, a protein-protein interaction network was constructed by analyzing the relationship between HDW, acne, and each standard drug. By analyzing the gene ontology terms and Kyoto Encyclopedia of Genes and Genomes pathway, the "positive regulation of lipid metabolic process" was found to be the most involved pathway shared by HDW, acne, and isotretinoin. An analysis of the protein targets shared by the antibiotic agents with HDW and acne found that "cholesterol storage" in tetracycline, "icosacoid transport" in azithromycin, "steroid hydroxylase activity" in erythromycin, "positive regulation of leukocyte tethering or rolling" in clindamycin, "response to UV-A" in minocycline, "steroid 11-beta-monooxygenase activity" in doxycycline, and "neutrophil-mediated immunity" in trimethoprim were the most involved. Virtual molecular docking analysis showed that all proteins spontaneously bound to their corresponding active compounds. Our analysis suggests that HDW can, directly and indirectly, suppress sebum secretion and exert antiinflammatory effects on acne. Further, HDW may regulate free radicals and suppress apoptosis. Therefore, HDW can be used as an alternative or supplement to standard drugs for acne treatment in patients who cannot use standard treatments due to side effects.

TREM2 macrophages induced by human lipids drive inflammation in acne lesions

Acne affects 1 in 10 people globally, often resulting in disfigurement. The disease involves excess production of lipids, particularly squalene, increased growth of Cutibacterium acnes, and a host inflammatory response with foamy macrophages. By combining single-cell and spatial RNA sequencing as well as ultrahigh-resolution Seq-Scope analyses of early acne lesions on back skin, we identified TREM2 macrophages expressing lipid metabolism and proinflammatory gene programs in proximity to hair follicle epithelium expressing squalene epoxidase. We established that the addition of squalene induced differentiation of TREM2 macrophages in vitro, which were unable to kill C. acnes. The addition of squalene to macrophages inhibited induction of oxidative enzymes and scavenged oxygen free radicals, providing an explanation for the efficacy of topical benzoyl peroxide in the clinical treatment of acne. The present work has elucidated the mechanisms by which TREM2 macrophages and unsaturated lipids, similar to their involvement in atherosclerosis, may contribute to the pathogenesis of acne.

Polyphyllin I Inhibits Propionibacterium acnes-Induced IL-8 Secretion in HaCaT Cells by Downregulating the CD36/NOX1/ROS/NLRP3/IL-1β Pathway

Acne vulgaris (AV) is a chronic skin disease involving inflammation of the pilosebaceous units. Propionibacterium acnes (P. acnes) hypercolonization is one pathogenic factor for AV. P. acnes that triggers interleukin-1β (IL-1β) by activating the pyrin domain-containing 3 protein (NLRP3) inflammasome of the NOD-like receptor family in human monocytes. Reactive oxygen species (ROS) acts as a trigger for the production of IL-8 and activates theNLRP3 inflammasome. IL-8 promotes the metastasis and multiplication of different cancerous cells, whereas keratinocyte proliferation and migration contribute to the progression of AV. A steroidal saponin called polyphyllin I (PPI) that is extracted from Paris polyphylla's rhizomes has anti-inflammatory properties. This study investigates the regulatory role of P. acnes in the secretion of IL-8 mediated by the CD36/NADPH oxidase 1 (NOX1)/ROS/NLRP3/IL-1β pathway and the effects of PPI on the CD36/NOX1/ROS/NLRP3/IL-1β/IL-8 pathway and human keratinocyte proliferation and migration. HaCaT cells were cultured and stimulated with 10⁸ CFU/ml of P. acnes for 0, 6, 12, 18, 24, 30, and 36 hours. P. acnes induced IL-8 secretion from HaCaT cells via the CD36/NOX1/ROS/NLRP3/IL-1β pathway. PPI inhibited the CD36/NLRP3/NOX1/ROS/IL-8/IL-1β pathway and HaCaT cell proliferation and migration. PPI alleviates P. acnes-induced inflammatory responses and human keratinocyte proliferation and migration, implying a novel potential therapy for AV.

The Association between Adiponectin Single Nucleotide Polymorphisms and Side Effects of Isotretinoin in Acne Patients

Background

Acne is a common condition of pilosebaceous follicle especially among young. Clinically, the most used medication in the treatment of moderate to severe acne is oral isotretinoin. However, interindividual variability in therapeutic response to isotretinoin and many side effects such as musculoskeletal pain, headache, and alteration in lipid profile can be seen with this treatment.

Aim

In this study, the effect of genetic polymorphisms, rs2241766 and rs1501299, of the adiponectin gene was investigated in relation to the side effects of isotretinoin-treated young adult acne patients (n = 230).

Methods

Several biochemical parameters were measured at baseline and after treatments with isotretinoin. The ADIPOQ gene SNPs, rs2241766 and rs1501299, were genotyped in 230 patients.

Results

Alterations in lipid profile with a significant increase of ALT (P=0.007) were detected after isotretinoin treatment. Moreover, percentage change in HDL following isotretinoin treatment was significantly associated with rs1501299 (P=0.008). On the other hand, no associations between examined SNPs and side effects of isotretinoin and other lipid parameters (total cholesterol, LDL, and triglycerides) or liver function enzymes (ALT and AST) were detected.

Conclusions

Current findings showed that rs1501299 of the ADIPOQ gene might be associated with changes in HDL level in acne patients following treatment with isotretinoin.

The implications of vitamin content in the plasma in reference to the parameters of carbohydrate metabolism and hormone and lipid profiles in PCOS

So far, there have been no analyses of correlations between the level of water-soluble vitamins in women with polycystic ovary syndrome (PCOS) and hormone and lipid profiles as well as carbohydrate metabolism. The unpopular concept that PCOS may also be conditioned by a chronic infection leads to a suspicion that water-soluble vitamins may be involved in the struggle against PCOS. This is why the aim of this research was to determine whether there are any indications that could confirm this hypothesis. The study included 64 women of Caucasian race: 50 patients aged 29.52 ± 7.01 years with PCOS, diagnosed according to the Rotterdam criteria. The control group consisted of 14 women aged 30.23 ± 6.3 years with correct BMI. HPLC Infinity1260 Binary LC (Agilent Technologies, Waldbronn, Germany) was used to analyze nine vitamins. The vitamins were separated using the gradient method, a buffer of 25 mM HK2PO4 with pH equal to 7.0, and 100 % methanol buffer. The acquired results were compared using Statistica 12.0 (Statsoft, Tulsa, Oklahoma, USA). Non-parametric tests were used: Mann-Whitney tests for comparisons between groups (PCOS and control group, CG), in which p < 0.05 was considered statistically significant. Subsequently, we performed a correlation matrix of the biochemical parameters of blood with vitamins at p ≤ 0.05. Higher concentrations of ascorbic acid were observed in PCOS. The content of the remaining vitamins was higher in the control group, and the statistical differences were significant in reference to thiamine, riboflavin, pyridoxine and folic acid in comparison to the control group. A significant positive correlation was observed between vitamin C and testosterone/insulin, another between riboflavin and androstenedione/testosterone, next between biotin and thyrotropic hormone (TSH), between pantothenic acid and dehydroepiandrosteron (DHEA-SO4), and finally between pyridoxine and androstenedione. A negative correlation was observed in the case of niacin with sex hormone binding protein (SHBG) and high density lipoprotein (HDL). Water-soluble vitamins play an important role in the therapy of women with PCOS through the reduction of antioxidative stress and low-intensity inflammation caused by various factors, including chronic infection.