Homeostasis of the sebaceous gland and mechanisms of acne pathogenesis

Unveiling the mechanism of photothermal therapy in acne man-agement: targeting sebaceous gland ferroptosis via umbilical cord mesenchymal stem cell membrane-encapsulated Au-Ag-PDA

Background

Branched gold and silver nanoparticles coated with polydopamine (Au-Ag-PDA) demonstrate high photothermal conversion efficiency. Utilizing umbilical cord mesenchymal stem cell membranes (MSCM) as an effective drug delivery system, our preliminary studies investigated the suppression of sebum secretion in sebaceous glands using MSCM-coated Au-Ag-PDA nano-particles (Au-Ag-PDA@MSCM) combined with 808 nm laser irradiation, showing potential for dermatological applications in acne treatment.

Methods

This study employs proteomic analysis, complemented by subsequent techniques such as Western blotting (WB), small interfering RNA (siRNA), and transmission electron microscopy, to further investigate the differential mechanisms by which Au-Ag-PDA and Au-Ag-PDA@MSCM-mediated photothermal therapy (PTT) suppress sebum secretion.

Results

Our proteomic analysis indicated mitochondrial respiratory chain damage in sebaceous gland tissues post-PTT, with further validation revealing ferroptosis in sebaceous cells and tissues. Acyl-CoA Synthetase Long-Chain Family Member 4 (Acsl4) has been identified as a critical target, with Au-Ag-PDA@MSCM demonstrating enhanced ferroptotic effects.

Conclusion

These findings significantly advance our understanding of how PTT mediated by Au-Ag-PDA@MSCM nanoparticles reduces sebum secretion and underscore the pivotal role of MSCM in inducing ferroptosis in sebaceous glands, thus providing a robust theoretical foundation for employing PTT via specific molecular pathways in acne treatment.

A novel H‑tert immortalized human sebaceous gland cell line (XL-i-20) for the investigation of photodynamic therapy

BACKGROUND

Acne vulgaris is a species-specific human disease. To date, there has been no established human sebocyte cell line of Asian origin. Our previous study has demonstrated the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in the treatment of acne vulgaris, primarily attributed to its cytotoxic properties; however, its regulatory mechanism remains largely unknown.

OBJECTIVES

To establish an immortalized human sebocyte cell line derived from Chinese population and investigate the underlying mechanism of ALA-PDT.

METHODS

Human primary sebocytes were transfected with the human tert gene (h‑tert). The biological characteristics, including cell proliferation, cell markers, and sebum secretion function, were compared between primary sebocytes and the immortalized sebocytes (XL-i-20). Stimulations such as ALA-PDT, were applied respectively to both primary sebocytes and XL-i-20 cells to assess changes in their cellular functions. The transcriptome differences between primary sebocytes and XL-i-20 sebocytes were investigated using RNA-seq analysis. The XL-i-20 cell line was used to establish a sebaceous gland (SG) organoid culture, serving as a representative model of SG for the investigation of ALA-PDT.

RESULTS

The h‑tert immortalized sebocyte cell line exhibited the ability to be consecutively cultured for more than fifty passages. Both primary and immortalized cells expressed sebocyte markers such as epithelial membrane antigens (EMA, or MUC-1), Cytokeratin 7 (CK7) and adipose differentiation-related protein associated antigens (ADRP), and maintained sebum secretion function. The proliferative capacity of XL-i-20 was found to be significantly higher than that of primary sebocytes. The responses of XL-i-20 to ALA-PDT were indistinguishable from those elicited by primary sebocytes. Cell viability and sebum secretion were decreased after ALA-PDT in both two cell lines, and lipid-related proteins (SREBP-1/PPARγ) were down-regulated. The transcriptome data consistently demonstrated upregulation of genes related to inflammatory responses and downregulation of genes involved in lipid metabolism in both cell types following PDT. The analysis of common differential genes of primary sebocytes and XL-i-20 sebocytes post ALA-PDT showed that TNF signaling pathways, MAPK signaling pathways and JAK-STAT signaling pathways were activated. The SG organoids were spherical, which expressed markers of FANS and PLET1. Ki-67 was down-regulated after ALA-PDT.

CONCLUSIONS

We have developed an h‑tert immortalized sebocyte cell line from an Asian population. The cell line, XL-i-20, maintains the essential characteristics of its parent primary sebocytes. Moreover, XL-i-20 sebocyte exhibited a significant respond to ALA-PDT, demonstrating comparable phenotypic and molecular changes to primary sebocytes. Therefore, XL-i-20 and its derived SG organoid serve as appropriate in vitro models for investigating the efficacy and mechanisms of ALA-PDT in SG-related diseases.

Metformin Therapy for Acne Vulgaris: A Meta-Analysis

Acne vulgaris is a common disease, which occurs in adolescents as well as adults and has a significant influence on the patient's quality of life (QoL) in every aspect. Due to resistance to standard therapies, it has become necessary to prospect for new treatment strategies. It is important to highlight that the diagnosis and treatment of the underlying cause of acne such as metabolic and hormonal disorders may significantly improve the effectiveness of acne treatment. The correlation between Insulin Resistance (IR) and acne has been proven. Both disorders share many common occurrence factors and activation pathways. Metformin, an antihyperglycemic agent, seems to be a possible therapy option, not only because of its insulin sensitizing ability but also via plenty of additional effects of this medicine. While the efficiency of metformin therapy in patients with acne and Polycystic Ovary Syndrome (PCOS) is well explored, it is still necessary to evaluate it in patients without any endocrinopathies. This meta-analysis aimed to estimate the effectiveness of oral metformin as a monotherapy in acne patients without PCOS or other endocrinopathies. Study selection was performed with included criteria such as no PCOS and other endocrinopathies diagnosed, oral administration of metformin, and metformin in monotherapy. Selected studies contained comparisons in the Global Acne Grading System (GAGS) before and after metformin therapy. Statistical analysis detected significant improvement in skin condition after treatment with metformin.

Nuclear receptors for epidermal lipid barrier: Advances in mechanisms and applications

The skin plays an essential role in preventing the entry of external environmental threats and the loss of internal substances, depending on the epidermal permeability barrier. Nuclear receptors (NRs), present in various tissues and organs including full-thickness skin, have been demonstrated to exert significant effects on the epidermal lipid barrier. Formation of the lipid lamellar membrane and the normal proliferation and differentiation of keratinocytes (KCs) are crucial for the development of the epidermal permeability barrier and is regulated by specific NRs such as PPAR, LXR, VDR, RAR/RXR, AHR, PXR and FXR. These receptors play a key role in regulating KC differentiation and the entire process of epidermal lipid synthesis, processing and secretion. Lipids derived from sebaceous glands are influenced by NRs as well and participate in regulation of the epidermal lipid barrier. Furthermore, intricate interplay exists between these receptors. Disturbance of barrier function leads to a range of diseases, including psoriasis, atopic dermatitis and acne. Targeting these NRs with agonists or antagonists modulate pathways involved in lipid synthesis and cell differentiation, suggesting potential therapeutic approaches for dermatosis associated with barrier damage. This review focuses on the regulatory role of NRs in the maintenance and processing of the epidermal lipid barrier through their effects on skin lipid synthesis and KC differentiation, providing novel insights for drug targets to facilitate precision medicine strategies.

Exosomes from adipose-derived stem cells activate sebocytes through the PI3K/AKT/SREBP-1 pathway to accelerate wound healing

Sebocyte regeneration after injury is considered a key element of functional skin repair. Exosomes from adipose-derived stem cells (ADSCs-EXO) accelerate wound healing by promoting the proliferation of fibroblasts. However, the effects of ADSCs-EXO on sebocytes are largely unknown. In this study, the effects of ADSCs-EXO on sebocyte proliferation and migration were evaluated. The levels of phosphorylated AKT (p-AKT), AKT, sterol regulatory-element binding protein (SREBP), and perilipin-1 (PLIN-1) were detected with immunofluorescence, quantitative PCR, and western blot analysis. RNA-Seq was used to analyze the differential gene expression between the ADSCs-EXO group and the control group under anaerobic conditions. Lipogenesis was assessed with Nile red staining. In animal studies, full-thickness skin wounds in BALB/c mice were treated with gelatin methacrylate (GelMA) hydrogel-loaded sebocytes alone or in combination with ADSCs-EXO. Histopathological assessments of the wound tissues were performed Masson Trichrome staining, Immunohistochemical staining and so on. The phosphatidylinositol 3-kinase (PI3K)/AKT pathway blocker LY294002 inhibited the effects of ADSCs-EXO on p-AKT and sebocytes proliferation. ADSCs-EXO also regulated the expression of SREBP-1 and PLIN-1 through the PI3K/AKT pathway in an oxygen level-dependent manner. In BALB/c mice, ADSCs-EXO accelerated sebocyte-assisted wound healing and regeneration. These in vitro and in vivo results supported that ADSCs-EXO can promote the regeneration of fully functional skin after injury through the PI3K/AKT-dependent activation of sebocytes.

Sebaceous gland organoid engineering

Sebaceous glands (SGs), as holocrine-secreting appendages, lubricate the skin and play a central role in the skin barrier. Large full-thickness skin defects cause overall architecture disruption and SG loss. However, an effective strategy for SG regeneration is lacking. Organoids are 3D multicellular structures that replicate key anatomical and functional characteristics of in vivo tissues and exhibit great potential in regenerative medicine. Recently, considerable progress has been made in developing reliable procedures for SG organoids and existing SG organoids recapitulate the main morphological, structural and functional features of their in vivo counterparts. Engineering approaches empower researchers to manipulate cell behaviors, the surrounding environment and cell-environment crosstalk within the culture system as needed. These techniques can be applied to the SG organoid culture system to generate functionally more competent SG organoids. This review aims to provide an overview of recent advancements in SG organoid engineering. It highlights some potential strategies for SG organoid functionalization that are promising to forge a platform for engineering vascularized, innervated, immune-interactive and lipogenic SG organoids. We anticipate that this review will not only contribute to improving our understanding of SG biology and regeneration but also facilitate the transition of the SG organoid from laboratory research to a feasible clinical application.

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.

Antibacterial activity and mechanism of cell-free supernatants of Lacticaseibacillus paracasei against Propionibacterium acnes

Propionibacterium acnes (P. acnes) is an anaerobic and gram-positive bacterium involved in the pathogenesis and inflammation of acne vulgaris. This study particularly focuses on the antimicrobial effect of Lacticaseibacillus paracasei LPH01 against P. acnes, a bacterium that causes acne vulgaris. Fifty-seven Lactobacillus strains were tested for their ability to inhibit P. acnes growth employing the Oxford Cup and double dilution methods. The cell-free supernatant (CFS) of L. paracasei LPH01 demonstrated a strong inhibitory effect, with an inhibition zone diameter of 24.65 ± 0.27 mm and a minimum inhibitory concentration of 12.5 mg/mL. Among the CFS, the fraction over 10 kDa (CFS-10) revealed the best antibacterial effect. Confocal laser scanning microscopes and flow cytometry showed that CFS-10 could reduce cell metabolic activity and cell viability and destroy the integrity and permeability of the cell membrane. A scanning electron microscope revealed that bacterial cells exhibited obvious morphological and ultrastructural changes, which further confirmed the damage of CFS-10 to the cell membrane and cell wall. Findings demonstrated that CFS-10 inhibited the conversion of triglycerides, decreased the production of free fatty acids, and down-regulated the extracellular expression of the lipase gene. This study provides a theoretical basis for the metabolite of L. paracasei LPH01 as a potential antibiotic alternative in cosmeceutical skincare products.

ALA-PDT promotes IL-1β secretion from human SZ95 sebocytes via activation of the NLRP3 inflammasome

BACKGROUND

5-Aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective treatment for pilosebaceous inflammatory diseases, such as acne vulgaris. In this study, we explored ALA-PDT's mechanisms against acne in vitro.

METHODS

We treated human SZ95 sebocytes with ALA (0.2 mM) and subjected them to varied PDT doses (0, 5, 10, 20 J/cm²) over 12 h. We assessed cell viability post-treatment using the Annexin V FITC/PI apoptosis kit. ROS accumulation in the sebocytes was detected with a DCFDA probe. We quantified NLRP3 and caspase-1 mRNA via quantitative PCR and determined IL-1β release following ALA-PDT by ELISA. Western blotting helped identify the levels of proteins associated with pyroptosis (NLRP3, caspase-1, and IL-1β). To elucidate the mechanisms, we re-evaluated these parameters after administering various concentrations of NAC antioxidants (0, 0.4, 2, 10 mM) and the caspase inhibitor Z-VAD-FMK (0, 5, 10, 20 μM).

RESULTS

Increasing PDT dose inversely affected SZ95 sebocyte survival, with a corresponding rise in ROS and pyroptosis-related proteins (NLRP3, caspase-1, and IL-1β). Furthermore, NAC and Z-VAD-FMK modulated the expression and secretion of these molecules in a dose-responsive manner.

CONCLUSION

Our findings suggest ALA-PDT's potential mechanism of action on sebaceous glands could involve ROS induction, leading to NLRP3 inflammasome assembly, thereby heightening caspase-1 activation and IL-1β secretion. This cascade may amplify the local inflammatory response to break chronic inflammation in acne vulgaris treatment.

Deciphering the molecular mechanisms of stem cell dynamics in hair follicle regeneration

Hair follicles, which are connected to sebaceous glands in the skin, undergo cyclic periods of regeneration, degeneration, and rest throughout adult life in mammals. The crucial function of hair follicle stem cells is to maintain these hair growth cycles. Another vital aspect is the activity of melanocyte stem cells, which differentiate into melanin-producing melanocytes, contributing to skin and hair pigmentation. Sebaceous gland stem cells also have a pivotal role in maintaining the skin barrier by regenerating mature sebocytes. These stem cells are maintained in a specialized microenvironment or niche and are regulated by internal and external signals, determining their dynamic behaviors in homeostasis and hair follicle regeneration. The activity of these stem cells is tightly controlled by various factors secreted by the niche components around the hair follicles, as well as immune-mediated damage signals, aging, metabolic status, and stress. In this study, we review these diverse stem cell regulatory and related molecular mechanisms of hair regeneration and disease conditions. Molecular insights would provide new perspectives on the disease mechanisms as well as hair and skin disorder treatment.

Die Bedeutung von Mikrokomedonen bei der Akne: Von der Beschreibung bis zum Behandlungsansatz?: The role of microcomedones in acne: Moving from a description to treatment target?

Ein wichtiger Faktor in der Pathogenese der Akne vulgaris ist die duktale Hyperproliferation der Talgdrüsen. Diese beginnt mit der Bildung unsichtbarer Mikrokomedonen und führt im weiteren Verlauf zur Ausbildung sowohl entzündlicher als auch nicht‐entzündlicher klinischer Läsionen. Die Mikrokomedonen stehen am Anfang der zyklischen Entwicklung einer Akne, die als Komedogenese bezeichnet wird. Mikrokomedonen können mithilfe von Cyanoacrylat‐Hautablösungen, Elektronenmikroskopie, konfokaler Reflexionsmikroskopie und anderen Techniken nachgewiesen werden. Es wird angenommen, dass die Dichte und Größe von Mikrokomedonen positiv mit dem Schweregrad der Akne korreliert. Ziel dieser Übersichtsarbeit ist es, die Ursachen der Akne zusammenzufassen und darauf hinzuweisen, dass die Behandlung von Mikrokomedonen zumindest teilweise Akneläsionen beseitigen und Rückfälle verhindern könnte.

The role of microcomedones in acne: Moving from a description to treatment target?

A major factor in the pathogenesis of acne is ductal hyperproliferation in the pilosebaceous glands. This takes the form of invisible microcomedones and leads to the subsequent formation of both inflammatory and non-inflammatory clinical lesions. Microcomedones are the initial stage in the cyclical development of acne, so called comedogenesis. Microcomedones can be detected using cyanoacrylate skin surface stripping, electron microscopy, reflection confocal microscopy and other techniques. It has been proposed that the density and the size of microcomedones are positively correlated with acne severity. Thus, the purpose of this review is to summarize the root causes of acne, and suggest that treatment of microcomedones could, at least in part, resolve acne lesions and prevent relapse.

1927nm fractional thulium fiber laser combined with 30% salicylic acid for the treatment of acne and acne scars: A prospective, randomized, and split-face study

OBJECTIVES

Patients with acne usually develops acne scars subsequently, early intervention of scars is crucial in acne management. 1927nm fractional thulium fiber laser (TFL) is effective in scars improvement and chemical peels with 30% supramolecular salicylic acid (SSA) can be applied for the treatment of acne. The purpose of this study is to evaluate and compare the efficacy and safety of TFL monotherapy versus the concomitant application of TFL and 30% SSA on acne and acne scars.

MATERIALS AND METHODS

Thirty-three patients with acne and acne scars were enrolled, and two sides of the face were randomly divided to receive either TFL and SSA chemical peeling or TFL. Four sessions of TFL treatments were applied with 4-week intervals for both sides, SSA combined treatment side received eight SSA chemical peels with 2-week intervals additionally. GAGS, ECCA score, the number of acne lesions, melanin index (MI) and erythema index (EI), transepidermal water loss (TEWL), and side effects were recorded at Weeks 0, 4, 8, 12, and 18. Satisfaction of patients was recorded on both sides at the end of the study.

RESULTS

Thirty patients completed the study. Both control group (TFL monotherapy) and SSA group (TFL combined with SSA chemical peeling) significantly improved GAGS and ECCA score. SSA group showed higher efficacy in terms of GAGS and ECCA score, acne lesion count, TEWL, MI, EI, and satisfaction than control group. All the side effects were temporary and tolerable, no adverse effects were observed.

CONCLUSIONS

Both TFL and the TFL combined with 30% SSA chemical peeling are safe and effective for the treatment and prevention of acne and acne scars, though the combined group has higher efficacy.

Combining superpulse dynamic CO2 laser and supramolecular salicylic acid in the treatment of dense comedones with higher clearance in a shorter time: A prospective, randomized, split-face clinical trial

OBJECTIVES

Dense comedones are common in patients with acne vulgaris, and promoting treatment can prevent the progression of acne lesions. However, the efficacy-time conflict makes the treatment challenging and the medication options are limited by the side effects.

MATERIALS AND METHODS

Thirty-five patients with symmetrical dense comedones were enrolled and the two sides of the face were randomly assigned to receive 30% supramolecular salicylic acid (SSA) combined with CO2 laser or CO2 laser monotherapy at an interval of 2 weeks for six treatment sessions. Comedones count, porphyrin index (PI), texture index (TI), melanin index, erythema index, hydration index (HI), transepidermal water loss (TEWL), and side effects were recorded at each visit till the 12th week.

RESULTS

Thirty-one patients completed the study. Comedones on the combined-SSA side were reduced more after six treatments, that the mean reduction rate of the combined-SSA side was 85.76%, and that of the CO2 laser-treated side was 62.32% (Pbetween  < 0.001). Combining SSA also showed a better effect on reducing PI and TI than CO2 laser singly (Pbetween  < 0.001). TEWL and HI between the two sides showed no significant differences after treatments. No permanent or severe side effects were observed on both side.

CONCLUSIONS

The treatment combined CO2 laser with 30% SSA dealt with the efficacy-time conflict while significantly reducing comedones and improving skin texture in 12 weeks and no serious adverse reactions occurred.

LIMITATIONS

It is a single-center study and the number of subjects was small.

Near-infrared radiation causes sebaceous gland enlargement along with an ROS-dependent augmentation of epidermal growth factor receptor expression in hamsters

As near-infrared radiation (NIR), which is a composition of sunlight with an 780-1400 nm wavelength, is associated with skin aging such as wrinkles and slacks, the biological actions of NIR with high dermal penetration remains unclear. In the present study, we found that NIR irradiation (40 J/cm2 ) at different levels of irradiance (95-190 mW/cm2 ) using a laboratory device with a xenon flash lamp (780-1700 nm) caused sebaceous gland enlargement concomitantly with skin thickening in the auricle skin of hamsters. The sebaceous gland enlargement resulted from the proliferation of sebocytes due to an increase in the number of proliferating cell nuclear antigen (PCNA)- and lamin B1-positive cells in vivo. In addition, NIR irradiation transcriptionally augmented the production of epidermal growth factor receptor (EGFR) accompanied with an increase in the reactive oxygen species (ROS) level in hamster sebocytes in vitro. Furthermore, the administration of hydrogen peroxide increased the level of EGFR mRNA in the sebocytes. Therefore, these results provide novel evidence that NIR irradiation causes the hyperplasia of sebaceous glands in hamsters by mechanisms in which EGFR production is transcriptionally augmented through ROS-dependent pathways in sebocytes.

Insulin and the sebaceous gland function

Insulin affects metabolic processes in different organs, including the skin. The sebaceous gland (SG) is an important appendage in the skin, which responds to insulin-mediated signals, either directly or through the insulin growth factor 1 (IGF-1) axis. Insulin cues are differently translated into the activation of metabolic processes depending on several factors, including glucose levels, receptor sensitivity, and sebocyte differentiation. The effects of diet on both the physiological function and pathological conditions of the SG have been linked to pathways activated by insulin and IGF-1. Experimental evidence and theoretical speculations support the association of insulin resistance with acne vulgaris, which is a major disorder of the SG. In this review, we examined the effects of insulin on the SG function and their implications in the pathogenesis of acne.

Development of skin diseases following systemic exposure: example of dioxins

Most skin manifestations of exposure to toxic compounds are a consequence of a direct contact with the toxicants. However, some toxicants may reach the skin following systemic exposure, and promote skin diseases. Good examples of such chemicals are dioxin-like compounds. This family of lipophilic molecules comprises polychlorinated (dibenzodioxins, dibenzofurans and biphenyls). The most potent member of this family is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Following oral ingestion of as little as a few mg TCDD, skin lesions appear in a couple of weeks, starting from the face and diffuse then on the trunk and limbs. This syndrome was historically called "chloracne" and the skin lesions have now been shown to be skin hamartoma induced by TCDD. Sweat glands release their lipid content on the surface of the skin by a holocrine secretion, and so any lost sebocyte should be transmitted to progenitor cells to differentiate and migrate to the sebaceous gland to replace the lost sebocyte. TCDD acts by inducing a switch in this signal and skin hamartoma develop in place of new sebocytes.

Effect of Janus Kinase 3 Inhibitor on Sebaceous Gland Regeneration during Skin Wound Healing

BACKGROUND

Janus kinase (Jak) 3 has recently been shown as a beneficial target for the treatment of chronic inflammatory diseases, such as psoriasis and alopecia areata. The role of Jak3 in tissue repair and remodeling is emerging.

OBJECTIVE

This study aimed to investigate the role of Jak3 signaling in the remodeling of the sebaceous gland (SG) during skin wound repair, and the development of in vitro SGs.

METHODS

Mouse skin tissue (ICR mouse) was obtained from the recovered skin eight days after a 4 mm biopsy punch wound. To observe the role of Jak3, the selective inhibitors WHI-p131 and PF06651600 was administered. Formation of in vitro SG was examined using primary sebocyte cultures obtained postnatally from 3-day-old mice.

RESULTS

The data showed that SGs showed highly positive signals with anti-isolectin B4, which also used for detection of angiogenetic vessels and the basal epidermis. Isolectin B4 could be a good indicator of SGs. The Jak3 inhibitors significantly reduced the area and volume of SG remodeling with reduced expression of p-Jak3. In addition, the area of cultured intact SG in vitro was significantly decreased in a concentration-dependent manner by Jak3 inhibition.

CONCLUSION

These data showed that Jak3 signaling is a potent regulator to develop SGs. Jak3 inhibition did not decrease the number of sebocytes in SGs but decreased the area and volume of SG remodeling. Therefore, Jak3 inhibition may be a potential target for the treatment of SG hyperplasia and associated skin diseases.

Exploring the Pathogenesis and Mechanism-Targeted Treatments of Rosacea: Previous Understanding and Updates

Rosacea is a chronic inflammatory skin disease characterized by recurrent erythema, flushing, telangiectasia, papules, pustules, and phymatous changes in the central area of the face. Patients with this condition often experience a significant negative impact on their quality of life, self-esteem, and overall well-being. Despite its prevalence, the pathogenesis of rosacea is not yet fully understood. Recent research advances are reshaping our understanding of the underlying mechanisms of rosacea, and treatment options based on the pathophysiological perspective hold promise to improve patient outcomes and reduce incidence. In this comprehensive review, we investigate the pathogenesis of rosacea in depth, with a focus on emerging and novel mechanisms, and provide an up-to-date overview of therapeutic strategies that target the diverse pathogenic mechanisms of rosacea. Lastly, we discuss potential future research directions aimed at enhancing our understanding of the condition and developing effective treatments.

Isotretinoin treatment upregulates the expression of p53 in the skin and sebaceous glands of patients with acne vulgaris

The transcriptomic regulation induced by isotretinoin (13-cis retinoic acid) is still a matter of debate as short-term exposures of immortalized sebocytes with isotretinoin produced conflicting results. Based on translational evidence, it has been hypothesized that oral isotretinoin treatment upregulates the expression of the transcription factor p53. Twenty-five patients suffering from acne vulgaris were treated with isotretinoin (0.6 mg/kg body weight) for 6 weeks. Biopsies from back skin were taken before and after isotretinoin treatment for the determination of p53 expression by immunohistochemical staining, quantification of p53 protein concentration by enzyme-linked immunosorbent assay and TP53 gene expression by quantitative reverse transcription real time PCR. Fifteen socio-demographically cross-matched healthy volunteers served as controls. Isotretinoin treatment significantly increased the nuclear expression of p53 in sebaceous glands of treated patients compared to pre-treatment levels and p53 levels of untreated controls. Furthermore, the p53 protein and gene expression significantly increased in the skin after treatment. The magnitude of p53 expression showed an inverse correlation to acne severity score and body mass index. Under clinical conditions, isotretinoin induced the expression of p53, which controls multiple transcription factors involved in the pathogenesis of acne vulgaris including FoxO1, androgen receptor and critical genes involved in the induction of autophagy and apoptosis. Increased p53-FoxO1 signalling enhanced by systemic isotretinoin treatment explains the underlying transcriptomic changes causing sebum suppression but also the adverse effects associated with systemic isotretinoin therapy.

The Activation of PPARγ by (2Z,4E,6E)-2-methoxyocta-2,4,6-trienoic Acid Counteracts the Epithelial–Mesenchymal Transition Process in Skin Carcinogenesis

Cutaneous squamous cell carcinoma (cSCC) is the most common UV-induced keratinocyte-derived cancer, and its progression is characterized by the epithelial–mesenchymal transition (EMT) process. We previously demonstrated that PPARγ activation by 2,4,6-octatrienoic acid (Octa) prevents cutaneous UV damage. We investigated the possible role of the PPARγ activators Octa and the new compound (2Z,4E,6E)-2-methoxyocta-2,4,6-trienoic acid (A02) in targeting keratinocyte-derived skin cancer. Like Octa, A02 exerted a protective effect against UVB-induced oxidative stress and DNA damage in NHKs. In the squamous cell carcinoma A431 cells, A02 inhibited cell proliferation and increased differentiation markers’ expression. Moreover, Octa and even more A02 counteracted the TGF-β1-dependent increase in mesenchymal markers, intracellular ROS, the activation of EMT-related signal transduction pathways, and cells’ migratory capacity. Both compounds, especially A02, counterbalanced the TGF-β1-induced cell membrane lipid remodeling and the release of bioactive lipids involved in EMT. In vivo experiments on a murine model useful to study cell proliferation in adult animals showed the reduction of areas characterized by active cell proliferation in response to A02 topical treatment. In conclusion, targeting PPARγ may be useful for the prevention and treatment of keratinocyte-derived skin cancer.

Genome-wide meta-analysis identifies novel loci conferring risk of acne vulgaris

Acne vulgaris is a common chronic skin disorder presenting with comedones, cystic structures forming within the distal hair follicle, and in most cases additionally with inflammatory skin lesions on the face and upper torso. We performed a genome-wide association study and meta-analysis of data from 34,422 individuals with acne and 364,991 controls from three independent European-ancestry cohorts. We replicated 19 previously implicated genome-wide significant risk loci and identified four novel loci [11q12.2 (FADS2), 12q21.1 (LGR5), 17q25.3 (FASN), and 22q12.1 (ZNRF3-KREMEN1)], bringing the total number of reported acne risk loci to 50. Our meta-analysis results explain 9.4% of the phenotypic variance of acne. A polygenic model of acne risk variants showed that individuals in the top 5% of the risk percentiles had a 1.62-fold (95% CI 1.47-1.78) increased acne risk relative to individuals with average risk (20-80% on the polygenic risk score distribution). Our findings highlight the Wnt and MAPK pathways as key factors in the genetic predisposition to acne vulgaris, together with the effects of genetic variation on the structure and maintenance of the hair follicle and pilosebaceous unit. Two novel loci, 11q12.2 and 17q25.3, contain genes encoding key enzymes involved in lipid biosynthesis pathways.

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

Acne vulgaris is a common chronic inflammatory skin disease of the pilosebaceous units. Four factors contribute to acne: hyperseborrhea and dysseborrhea, follicular hyperkeratinisation, skin microbiome dysbiosis and local immuno-inflammation. Recent key studies have highlighted a better understanding of the important role of Cutibacterium acnes (C. acnes) in the development of acne. Three major findings in the last decade include: (1) the ability of C. acnes to self-organize in a biofilm associated with a more virulent activity, (2) the loss of the C. acnes phylotype diversity and (3) the central role of the Th17 pathway in acne inflammation. Indeed, there is a close link between C. acnes and the activation of the Th17 immuno-inflammatory pathway at the initiation of acne development. These mechanisms are directly linked to the loss of C. acnes phylotype diversity during acne, with a predominance of the pro-pathogenic phylotype IA1. This specifically contributes to the induction of the Th17-mediated immuno-inflammatory response involving skin cells, such as keratinocytes, monocytes and sebocytes. These advancements have led to new insights into the underlying mechanisms which can be harnessed to develop novel treatments and diagnostic biomarkers. A major disadvantage of traditional treatment with topical antibiotics is that they induce cutaneous dysbiosis and antimicrobial resistance. Thus, future treatments would no longer aim to 'kill' C. acnes, but to maintain the skin microbiota balance allowing for tissue homeostasis, specifically, the restoration of C. acnes phylotype diversity. Here, we provide an overview of some of the key processes involved in the pathogenesis of acne, with a focus on the prominent role of C. acnes and the Th17-inflammatory pathways involved.

Hyaluronic acid-FGF2-derived peptide bioconjugates for suppression of FGFR2 and AR simultaneously as an acne antagonist

Acne is a chronic skin condition that has serious consequences for mental and social well-being because it frequently occurs on the face. Several acne treatment approaches have commonly been used but have been hampered by side effects or weak activity. Thus, the investigation of the safety and efficacy of anti-acne compounds is of considerable medical importance. Herein, an endogenous peptide (P5) derived from fibroblast growth factors 2 (FGF2) was conjugated to the polysaccharide hyaluronic acid (HA) to generate the bioconjugate nanoparticle HA-P5, which suppresses fibroblast growth factor receptors (FGFRs) to significantly rehabilitate acne lesions and reduce sebum accumulation in vivo and in vitro. Moreover, our results show that HA-P5 inhibits both fibroblast growth factor receptor 2 (FGFR2) and androgen receptor (AR) signalling in SZ95 cells, reverses the acne-prone transcriptome, and decreases sebum secretion. Furthermore, the cosuppression mechanism revealed that HA-P5 blocks FGFR2 activation, as well as the YTH N6-methyladenosine RNA binding protein F3 (YTHDF3) downstream molecules, including an N6-methyladenosine (m6A) reader that facilitates AR translation. More importantly, a significant difference between HA-P5 and the commercial FGFR inhibitor AZD4547 is that HA-P5 does not trigger the overexpression of aldo-keto reductase family 1 member C3 (AKR1C3), which blocks acne treatment by catalyzing the synthesis of testosterone. Overall, we demonstrate that a polysaccharide-conjugated and naturally derived oligopeptide HA-P5 can alleviate acne and act as an optimal FGFR2 inhibitor and reveal that YTHDF3 plays a crucial role in signalling between FGFR2 and AR.

The effect of the ketogenic diet on Acne: Could it be a therapeutic tool?

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinization, inflammation, and bacterial colonization of the hair follicles of the face, neck, chest and back by Propionibacterium acnes. Overall, inflammation and immune responses are strongly implicated in the pathogenesis of acne. Although early colonization with Propionibacterium acnes and family history may play an important role in the disease, it remains unclear exactly what triggers acne and how treatment affects disease progression. The influence of diet on acne disease is a growing research topic, yet few studies have examined the effects of diet on the development and clinical severity of acne disease, and the results have often been contradictory. Interestingly, very low-calorie ketogenic diet (VLCKD) has been associated with both significant reductions in body weight and inflammatory status through the production of ketone bodies and thus it has been expected to reduce the exacerbation of clinical manifestations or even block the trigger of acne disease. Given the paucity of studies regarding the implementation of VLCKD in the management of acne, this review aims to provide evidence from the available scientific literature to support the speculative use of VLCKD in the treatment of acne.

Lipidomic Analysis of Hand Skin Surface Lipids Reveals Smoking-Related Skin Changes

Smoking contributes to the formation of skin wrinkles and reduces skin function, but the mechanism is not yet fully proven. This study aims to compare and analyze the effects of smoking on skin lipids and to further investigate the harmful effects of smoking on the skin. A total of 40 subjects (20 male smokers and 20 healthy control males) were recruited for this study. Measurement of hand skin-surface lipids (SSLs) in smoking and healthy control groups was undertaken using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Multivariate data analysis was used to investigate the differences in SSLs between the two groups. There were 1230 lipids detected in the two groups and significant differences in SSLs' composition were observed between them. Under selected conditions, 26 types of lipid with significant differences were observed between the two groups (p < 0.05). Sphingolipids (SP) and glycerolipids (GL) were significantly increased, and sterol lipids (ST) were significantly reduced. Smoking causes changes in skin lipids that disrupt skin homeostasis, making the skin more fragile and more susceptible to skin aging and diseases.

Stimulation with THBS4 activates pathways that regulate proliferation, migration and inflammation in primary human keratinocytes

As in other mammalian tissues, the extracellular matrix (ECM) of skin functions as mechanical support and regulative environment that guides the behavior of the cells. ECM is a gel-like structure that is primarily composed of structural and nonstructural proteins. While the content of structural proteins is stable, the level of nonstructural ECM proteins, such as thrombospondin-4 (THBS4), is dynamically regulated. In a previous work we demonstrated that THBS4 stimulated cutaneous wound healing. In this work we discovered that in addition to proliferation, THBS4 stimulated the migration of primary keratinocytes in 3D. By using a proteotransciptomic approach we found that stimulation of keratinocytes with THBS4 regulated the activity of signaling pathways linked to proliferation, migration, inflammation and differentiation. Interestingly, some of the regulated genes (eg IL37, TSLP) have been associated with the pathogenesis of atopic dermatitis (AD). We concluded that THBS4 is a promising candidate for novel wound healing therapies and suggest that there is a potential convergence of pathways that stimulate cutaneous wound healing with those active in the pathogenesis of inflammatory skin diseases.

Lactoferrin regulates sebogenesis and inflammation in SZ95 human sebocytes and mouse model of acne

BACKGROUND

The aim of this study was to explore the anti-inflammatory and anti-lipid effects of lactoferrin on SZ95 human sebaceous gland cells and mouse model of acne.

METHODS

SZ95 cells were co-cultured with different concentrations of lactoferrin, and cell viability was determined using the 2,5-diphenyl-2H-tetrazolium bromide method. Oil red O and Nile red staining were performed to determine the lipid content. The mRNA expression of genes related to lipid metabolism (sterol regulatory element-binding protein-1 [SREBP-1], fatty acid synthase [FAS], stearoyl-CoA desaturase-1 [SCD-1], fatty acid desaturase 2 [FADS2]) and inflammation (interleukin-8 [IL-8]) was determined by reverse transcription-polymerase chain reaction. An acne mouse model was established using injection of P. acnes on the backs of mice. The proliferation and apoptosis of sebaceous gland cells were examined by immunohistochemistry against proliferating cell nuclear antigen (PCNA) and TUNEL staining, respectively. Western blotting was used to detect FADS2 and CXCL15 protein expression.

RESULTS

Lactoferrin treatment at 10-500 μg/ml significantly decreased the lipid content, as revealed by the oil red O and Nile red staining. It also attenuated the increase of mRNA expression of SREBP-1, FAS, SCD-1, FADS2, and IL-8 in insulin-treated SZ95 cells. Moreover, lactoferrin treatment at the doses of 1-50 mg/mouse significantly reduced the inflammation and lipid production in the mouse model of acne. Also, the number of sebaceous gland cells was significantly reduced, and apoptosis was significantly increased by lactoferrin treatment in the mice. Mechanically, the levels of FADS2 and CXCL15 proteins in tissues were significantly decreased after lactoferrin treatment in the model mice.

CONCLUSION

Our results demonstrate the potential of lactoferrin against sebogenesis, sebaceous gland inflammation in acne.

Long-Term Use of Silybum marianum fruit extract Contributes to Homeostasis in Acne-Prone Skin-A 12-Month Follow-Up International "Real Life" Cohort Study

BACKGROUND

Homeostasis in the differentiation programme of sebaceous stem cells has been identified as a key step in comedogenesis and should be a target for acne-prone skin care.

OBJECTIVE

To report on a multicentre, year-long/real-life use study of a patented natural product containing S. marianum fruit extract proven to modulate molecular actors in the initial steps of comedogenesis.

METHODS

An open-label multicentric international study, with a 12 month follow-up, included 54 teenage and young adult subjects with mild to moderate facial acne. The study was aimed at reproducing a real-life use context.

RESULTS

Total lesion count mean was 88.3 at inclusion. There was a sustained, highly significant decrease over the months of clinical lesion counts (45.6% improvement after 6 months and 59.6% at 12 months) and on other efficacy markers, associated with a significant decrease in global microcomedone quantity on cyanoacrylate superficial skin surface biopsies. Importantly, the study protocol allowed the dermatologist to prescribe, if needed as in real life, any of the acne drugs registered in the acne guidelines. The exposure to these acne drugs during the whole year was calculated as a percentage of S. marianum fruit extract/352 days of use and happened to be very limited at less than 4%, which indicates a marginal contribution to the sustained clinical improvement. (Oral and local acne treatments: Lymecycline 1.46%; Doxycycline 0.24%; Adapalene 0.16% or gel association with Benzoyl peroxide 1.17%; Clindamycin 0.04%; Benzoyl peroxide 1.5%; Erythromycin 0.75%). The tolerance with daily S. marianum fruit extract long-term use was good.

LIMITATIONS

The association with routine prescription acne drugs when needed, even if limited, does not allow a full evaluation of the intrinsic quantitative efficacy of S. marianum fruit extract in lesion reduction.

CONCLUSION

This open, real-life, year-long multicentre study confirms a previous 48-week proof of concept study and qualifies the use of S. marianum fruit extract as a "field-dermo cosmetic" contributing to homeostasis of acne-prone skin in association with acne drugs.

The Effects of Synthetic SREBP-1 and PPAR-γ Decoy Oligodeoxynucleotide on Acne-like Disease In Vivo and In Vitro via Lipogenic Regulation

Acne vulgaris has a pathogenesis that involves increased sebum production and perifollicular inflammation. Sterol regulatory element-binding protein-1 (SREBP-1) and peroxisome proliferator activated receptor-γ (PPAR-γ) are transcription factors that regulate numerous genes involved in lipid biosynthesis. To improve a new therapeutic approach, we designed the SREBP/PPAR decoy oligodeoxynucleotide (ODN), a synthetic short DNA containing complementary sequences for the SREBP and PPAR transcription factors. We aim to investigate the beneficial functions and the molecular mechanisms of the synthetic SREBP/PPAR decoy ODN in lipogenic models. C. acnes was intradermally injected with a 1.0 × 10⁷ colony forming unit/20 μL. The synthetic SREBP/PPAR decoy ODN or scrambled decoy ODN (10 μg) was transferred via the mouse tail vein injection. SZ95 cells were transfected with 2 μg of synthetic ODNs. After transfection, the SZ95 cells were cultured in serum-free medium containing 20 ng/μL of insulin-like growth factor-1 (IGF)-1 for 24 h. To investigate the expression of gene and signaling pathways, we performed Western blotting. The distribution of the chimeric decoy ODN was confirmed by EMSA. Lipid levels were assessed by Nile red and Oil Red O staining. The cytokine levels were measured by ELISA kit. This study showed that C. acnes-injected mice and IGF-1-stimulated SZ95 cells exhibited increased expression of SREBP-1 and PPAR-γ compared to the normal controls. In contrast, the administration of the SREBP/PPAR chimeric decoy ODN significantly suppressed the upregulation of lipogenic genes. Furthermore, the SREBP/PPAR decoy ODN decreased the plasma cytokines and cytokine levels of total protein. These results suggested that the SREBP/PPAR decoy ODN exerts its anti-lipogenic effects by regulating lipid metabolism and by inhibiting lipogenesis through the inactivation of the SREBP and PPAR pathways. Therefore, the synthetic SREBP/PPAR ODN demonstrates substantial therapeutic feasibility for the treatment of acne vulgaris.

Skin Microbiome, Metabolome and Skin Phenome, from the Perspectives of Skin as an Ecosystem

Skin is a complex ecosystem colonized by millions of microorganisms, including bacteria, fungi, and viruses. Skin microbiota is believed to exert critical functions in maintaining host skin health. Profiling the structure of skin microbial community is the first step to overview the ecosystem. However, the community composition is highly individualized and extremely complex. To explore the fundamental factors driving the complexity of the ecosystem, namely the selection pressures, we review the present studies on skin microbiome from the perspectives of ecology. This review summarizes the following: (1) the composition of substances/nutrients in the cutaneous ecological environment that are derived from the host and the environment, highlighting their proposed function on skin microbiota; (2) the features of dominant skin commensals to occupy ecological niches, through self-adaptation and microbe-microbe interactions; (3) how skin microbes, by their structures or bioactive molecules, reshape host skin phenotypes, including skin immunity, maintenance of skin physiology such as pH and hydration, ultraviolet (UV) protection, odor production, and wound healing. This review aims to re-examine the host-microbe interactions from the ecological perspectives and hopefully to give new inspiration to this field.

Therapeutic potential of adipose tissue-derivatives in modern dermatology

Stem cell-mediated therapies in combination with biomaterial and growth factor-based approaches in regenerative medicine are rapidly evolving with increasing application beyond the dermatologic field. Adipose-derived stem cells (ADSCs) are the more frequently used adult stem cells due to their abundance and easy access. In the case of volumetric defects, adipose tissue can take the shape of defects, restoring the volume and enhancing the regeneration of receiving tissue. When regenerative purposes prevail on volume restoration, the stromal vascular fraction (SVF) rich in staminal cells, purified mesenchymal stem cells (MSCs) or their cell-free derivatives grafting are favoured. The therapeutic efficacy of acellular approaches is explained by the fact that a significant part of the natural propensity of stem cells to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines and extracellular matrix components. Therefore, the secretome's ability to modulate multiple targets simultaneously demonstrated preclinical and clinical efficacy in reversing pathological mechanisms of complex conditions such atopic dermatitis (AD), vitiligo, psoriasis, acne and Lichen sclerosus (LS), non-resolving wounds and alopecia. This review analysing both in vivo and in vitro models gives an overview of the clinical relevance of adipose tissue-derivatives such as autologous fat graft, stromal vascular fraction, purified stem cells and secretome for skin disorders application. Finally, we highlighted the major disease-specific limitations and the future perspective in this field.

Sebaceous immunobiology - skin homeostasis, pathophysiology, coordination of innate immunity and inflammatory response and disease associations

This review presents several aspects of the innovative concept of sebaceous immunobiology, which summarizes the numerous activities of the sebaceous gland including its classical physiological and pathophysiological tasks, namely sebum production and the development of seborrhea and acne. Sebaceous lipids, which represent 90% of the skin surface lipids in adolescents and adults, are markedly involved in the skin barrier function and perifollicular and dermal innate immune processes, leading to inflammatory skin diseases. Innovative experimental techniques using stem cell and sebocyte models have clarified the roles of distinct stem cells in sebaceous gland physiology and sebocyte function control mechanisms. The sebaceous gland represents an integral part of the pilosebaceous unit and its status is connected to hair follicle morphogenesis. Interestingly, professional inflammatory cells contribute to sebocyte differentiation and homeostasis, whereas the regulation of sebaceous gland function by immune cells is antigen-independent. Inflammation is involved in the very earliest differentiation changes of the pilosebaceous unit in acne. Sebocytes behave as potent immune regulators, integrating into the innate immune responses of the skin. Expressing inflammatory mediators, sebocytes also contribute to the polarization of cutaneous T cells towards the Th17 phenotype. In addition, the immune response of the perifollicular infiltrate depends on factors produced by the sebaceous glands, mostly sebaceous lipids. Human sebocytes in vitro express functional pattern recognition receptors, which are likely to interact with bacteria in acne pathogenesis. Sex steroids, peroxisome proliferator-activated receptor ligands, neuropeptides, endocannabinoids and a selective apoptotic process contribute to a complex regulation of sebocyte-induced immunological reaction in numerous acquired and congenital skin diseases, including hair diseases and atopic dermatitis.

The influence of cosmetics dedicated to oily and acne-prone skin on skin parameters

INTRODUCTION

Patient compliance with care recommendations is closely related to the role of cosmetics in delaying or preventing the side effects of medications used to treat acne.

METHODS

A total of 33 volunteers with symptoms of acne vulgaris were qualified for the study. The skin parameters were measured before the experiment, after the 4 and at the 8 weeks of use. The measurements were subject to moisturizing the skin and secretion of sebum and skin color. A skin acoustic parameters using high-frequency ultrasound (33 MHz) was also performed. The recorded images were used to determine the epidermal entrance echo thickness and echo density of dermis.

RESULTS

The results show a change in the value of skin parameters during the 8-week application of a specific skin care procedure. The secretion of sebum did not change significantly, there was a decrease in hydration, and the level of melanin and hemoglobin remained at the same level. The thickness of the epidermis entrance echo in the ultrasound image was thinned.

CONCLUSION

For many mild/moderate acne patients, cosmetics proven to be effective and well tested in clinical trials can offer a real benefit in reducing both inflammation, sebum production, melanin, and irritation, but should also be moisturizing.

Biofabrication of Human Skin with Its Appendages

Much effort has been made to generate human skin organ in the laboratory. Yet, the current models are limited due to the lack of many critical biological and structural features of the skin. Importantly, these in vitro models lack appendages and fail to recapitulate the whole human skin construction. Thus, engineering a human skin with the capacity to generate all components, including appendages, is a major challenge. This review intends to provide an update on the recent efforts underway to regenerate appendage-bearing skin organs based on scaffold-free and scaffold-based bioengineering approaches. Although the mouse skin equivalents containing hair follicles, sebaceous glands, and sweat glands have been established in vitro, there has been limited success in humans. A combination of biofabricated matrices and cell aggregates, such as organoids, can pave the way for generating skin substitutes with human-like biological, structural, and physical features. Accordingly, the formation of human skin organoids and reconstruction of vascularized skin equipped with immune cells prompt calls for more scientific research. The generation of appendage-bearing skin substitutes can be applied in practice for wound healing, hair restoration, and scar treatment.

Honokiol Improves Acne-like Lesions in a Rabbit Ear Model by Alleviating Hyperkeratosis and Sebum Secretion

The prevalence of acne vulgaris is high, but the topical retinoids used as the foundation of treatment have teratogenic and photosensitivity properties. Previous studies have suggested that honokiol, a small-molecule compound extracted from Magnolia officinalis, could effectively inhibit Cutibacterium acnes ( C acnes) and inflammation in vitro. However, the effect in vivo is unclear. The rabbit ear acne model that we created showed obvious comedones and hyperkeratosis. These lesions were repeatedly measured and recorded by dermatoscopy (ultraviolet light). Compared with the control group, topical 2.5% honokiol cream obviously improved the comedones and hyperkeratosis and effectively reduced sebum secretion, as shown by Oil Red O staining. The effects were equivalent to those of adapalene gel without local side effects. We added honokiol's other functions to acne treatment in addition to antiinflammation, but further studies are needed.

Efficacy and safety of low-level light therapy by delicate pulsed light combined with low-dose oral isotretinoin for the treatment of acne vulgaris: a randomized split-face study

Acne vulgaris (AV) is a common dermatosis that causes psychological problems. Isotretinoin is the first-line treatment for moderate-to-severe AV, but its onset of effect is delayed. Although light-based therapy is widely used in the treatment of AV, there is a lack of reports on delicate pulsed light (DPL) which has a narrow therapeutic spectrum (500-600 nm). Low-level light therapy (LLLT) has shown an emerging role in anti-inflammatory effects and skin repair. This study investigates the efficacy and safety of low-dose oral isotretinoin combined with LLLT using DPL in patients with moderate-to-severe AV. Thirty-six patients with moderate-to-severe AV were enrolled and received low-dose oral isotretinoin (10-20 mg/day). The two sides of the face were randomly assigned to receive DPL (6-9 J/cm²) or not at an interval of 2 weeks for 4 treatment sessions (weeks 0, 2, 4, 6). Photos, GAGS score, counts of papules, pustules, comedones, TEWL, melanin and erythema index, side effects, efficacy, and satisfactory score were recorded at each visit and at 4 weeks after the final treatment (week 10). Thirty-three patients completed the study. DPL and oral isotretinoin combined therapy exhibited significantly improved GAGS score as well as the number of the lesions from week 2 and maintained until week 10. At the end of the observation, the improvement of GAGS was 70.88% on the DPL and isotretinoin combined side versus 62.12% on the side with isotretinoin monotherapy (p = 0.0009). The improvement for papule number was 61.58% on the DPL combined side versus 43.33% on the control side (p < 0.0001), for comedone was 63.15% versus 43.30% (p = 0.0008). TEWL and indexes of melanin and erythema also had better outcomes with DPL combined therapy at week 10. All the side effects were temporary and tolerable; no adverse effects were observed. Oral low-dose isotretinoin combined with LLLT by DPL offers a combination with reduced side effects and better outcomes within a limited treatment duration, which advances the onset of effect of isotretinoin monotherapy and improves lesion clearance.

Skin microbiome reconstruction and lipid metabolism profile alteration reveal the treatment mechanism of Cryptotanshinone in the acne rat

BACKGROUND

Acne has become one of the most prevalent skin disorders, affecting mostly young people's physical and mental health globally. Cryptotanshinone (CPT) is a potential drug for acne, but its mechanism of acne treatment has not been thoroughly studied on the microbiota. Till date, only a few studies are directed to the impact of acne therapy on skin microbiota and lipid metabolites.

PURPOSE

The action mechanism of CPT treatment of acne was investigated by the strategy of microbiome integration with lipidomics.

METHODS

The 16Sr DNA sequencing was used to detect skin microbiota composition, and absolute quantitative lipidomics was utilized to identify lipid metabolites profiles levels. Four key proteins of the glycolysis pathway were detected with the immunochemistry method. Antibacterial analysis was used to evaluate CPT treatment of acne.

RESULTS

CPT significantly inhibited Staphylococcus epidermidis and Staphylococcus aureus. Combination of the skin microbiome and lipidomics analysis, 29 types of differentially expressed flora (DEFs) and 782 differentially expressed lipid metabolites (DELMs) were significantly altered, especially Staphylococcus, Corynebacterium, Ralstonia, Enhydrobacter, Burkholderia, and Streptococcus. Cer was mainly regulated by Staphylococcus and Corynebacterium, whereas TG and DG were mainly regulated by Ralstonia, Enhydrobacter, Burkholderia, and Streptococcus. The glycolysis pathway was significantly regulated by Staphylococcus on CPT treatment of acne. The energy metabolism, lipid metabolism, immune system, glycan biosynthesis, and metabolism could be reversed by CPT.

CONCLUSION

CPT might help acne rats rebuild their skin microbiota and alter lipid metabolism signatures. Furthermore, since skin microbes and skin lipid metabolites have a close correlation and are both regulated by CPT, the findings potentially provide a research foundation for the discovery of biomarkers of skin microbiome imbalance and targeted treatment of acne development mechanisms.

The Role of Herbal Medicine in the Treatment of Acne Vulgaris: A Systematic Review of Clinical Trials

Over the past few decades, interest in medicinal plants and phytochemicals for the treatment of skin disorders, including acne vulgaris, has progressively increased. Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit, which mainly occurs in adolescents and young adults. The treatment focuses on the four main factors involved in its pathogenesis: increased sebum production, hyperkeratinization, overgrowth of Cutibacterium acnes, and inflammation. The treatment includes topical retinoids, benzoyl peroxide, antibiotics, and oral isotretinoin. In this regard, the use of herbal medicine as a complementary and alternative medicine is a promising strategy. The main objective of this study was to systematically evaluate the efficacy and safety of medicinal plants and phytochemicals in the treatment of acne vulgaris. Three scientific databases (PubMed, Web of Science, and Scopus) were searched from inception to January 2021. Clinical trials comparing herbal therapies with placebo or other medicines for the treatment of acne vulgaris were included and analyzed. Outcome measures of interest comprised acne lesions (inflammatory and noninflammatory), sebum production, acne severity, and quality of life. The risk of bias in the included randomized controlled trials (RCTs) was assessed using the Cochrane risk-of-bias tool. A total of 34 clinical trials involving 1753 participants met the inclusion criteria for this systematic review. Most trials showed that herbal medicine significantly reduces inflammatory and noninflammatory acne lesions and has a relevant effect on acne severity. Some medicinal plants revealed equal or higher efficacy to standard treatments. No significant difference between groups in sebum production and quality of life was observed and no severe adverse events were reported. This systematic review provides evidence that medicinal plants and phytochemicals are promising treatments for mild to moderate acne vulgaris. However, more quality of evidence and standardized methodologies are needed to support their effectiveness and safety claims.

A composite of hepatocyte growth factor and 5α-dihydrotestosterone-gelatin microspheres with adipose-derived stem cells enhances wound healing

INTRODUCTION

Reconstructing sebaceous glands is one goal of functionally healing patients who have suffered severe burns, instead of the simple pursuit of wound closure. Effective regeneration of skin appendages remains a challenge in skin wound management and research.

OBJECTIVE

The aim of this study was to evaluate the differentiation of ADSC into sebaceous glands, and clarified the involvement of HGF and 5α-DHT in this process.

METHODS

This study used hepatocyte growth factor (HGF)- and 5α-dihydrotestosterone (5α-DHT)-gelatin microspheres to treat human adipose-derived stem cells (ADSCs) and investigated the reconstruction of sebaceous glands. HGF- and 5α-DHT-gelatin microspheres were constructed using microcapsule slow-release technology. Mice full-thickness skin-wound model was established to evaluate wound healing and hematoxylin-eosin staining was utilized to determine the skin structure.

RESULTS

In vitro analyses found that HGF- and 5α-DHT-gelatin microspheres promoted migration of and tube formation by ADSCs. Furthermore, AKT/ERK signaling, which is related to sebocyte and sweat gland epithelial cell growth, were activated after HGF and 5α-DHT treatment. An in vivo wound healing model demonstrated that ADSCs primed with amnion-loaded HGF- and 5α-DHT-gelatin microspheres promoted wound healing and increased sebaceous gland formation compared to the control group.

CONCLUSIONS

This study confirms the efficacy of ADSCs treated with amnion and HGF- and 5α-DHT-gelatin microspheres in accelerating wound healing and effectively restoring sebaceous glands. This engineered tissue provides insight into and a novel therapeutic material for burns and full-thickness skin wounds.¬¬.

Hair Follicle-Related MicroRNA-34a Serum Expression and rs2666433A/G Variant in Patients with Alopecia: A Cross-Sectional Analysis

Alopecia areata (AA) is a type of immune-mediated alopecia. Recent studies have suggested microRNAs’ (miRNAs) implication in several cellular processes, including epidermal and hair follicle biology. Single nucleotide polymorphisms (SNPs) can modify gene expression levels, which may induce an autoimmune response. This case−control study included 480 participants (240 for each case/control group). MicroRNA-34a gene (MIR-34A) rs2666433A/G variant was genotyped using real-time allelic discrimination polymerase chain reaction (PCR). Additionally, circulatory miR-34a levels were quantified by quantitative reverse transcription PCR (qRT-PCR). On comparing between alopecia and non-alopecia cohorts, a higher frequency of A variant was noted among patients when compared to controls—A allele: 28 versus 18% (p < 0.001); A/A genotype: 9 versus 2%; A/G genotype: 39 versus 32% (p < 0.001). A/A and A/G carriers were more likely to develop alopecia under heterozygote comparison (OR = 1.83, 95% CI = 1.14−2.93), homozygote comparison (OR = 4.19, 95% CI = 1.33−13.1), dominant (OR = 2.0, 95% CI = 1.27−3.15), recessive (OR = 3.36, 95% CI = 1.08−10.48), over-dominant (OR = 1.65, 95% CI = 1.04−32.63), and log additive (OR = 1.91, 95% CI = 1.3−2.82) models. Serum miR-34a expression levels were upregulated in alopecia patients with a median and quartile fold change of 27.3 (1.42−2430). Significantly higher levels were more pronounced in A/A genotype patients (p < 0.01). Patients carrying the heterozygote genotype (rs2666433 * A/G) were two times more likely to develop more severe disease grades. Stratified analysis by sex revealed the same results. A high expression level was associated with concomitant autoimmune comorbidities (p = 0.001), in particular SLE (p = 0.007) and vitiligo (p = 0.049). In conclusion, the MIR34A rs2666433 (A/G) variant is associated with AA risk and severity in the studied population. Furthermore, high miR-34a circulatory levels could play a role in disease pathogenesis.

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.

Female Adult Acne and Androgen Excess: A Report From the Multidisciplinary Androgen Excess and PCOS Committee

In endocrine and reproductive endocrine literature, adult female acne is considered as a possible clinical expression of hyperandrogenism, with most polycystic ovary syndrome (PCOS) guidelines considering acne as a condition of androgen excess. Adult female acne, however, in the dermatological literature is considered as an inflammatory skin disease and new guidelines on adult female acne have been produced by dermatological societies, with little perspective from any endocrine or reproductive endocrine points of view. An expert task force was appointed by the AE-PCOS society to determine the current state of knowledge and provide evidence-based recommendations that could be valid for all specialists taking care of female adult acne. The following are the recommendations (level of evidence A or B): (1) diagnosis of female adult acne is mainly clinical, but a grading tool is needed for optimizing the treatment; (2) measurement of serum androgen values (total testosterone, free testosterone, and dehydroepiandrosterone sulfate) by high-quality assays is recommended in all women with adult acne; (3) in women with adult acne and proven hyperandrogenism, oral combined estroprogestins should be added to the topical or systemic treatment of acne, independently of severity of acne; (4) all second- and third-generation estroprogestins may be used, independently of the estrogen dose and progestin component; (5) spironolactone may be added to estroprogestins in women with moderate or severe hyperandrogenic adult acne, not responding to usual treatments; (6) estroprogestins may be used in nonhyperandrogenic patients with adult acne as second-line therapy.

The Efficacy of Pulsed Dye Laser Treatment for Acne Vulgaris: A Systemic Review and Meta-Analysis

BACKGROUND

Previous reports have shown that pulsed dye laser (PDL) is promising for the treatment of acne; however, results provide conflicting evidence.

OBJECTIVE

To determine the efficacy of PDL in treating acne vulgaris.

METHODS

A systematic review and meta-analysis of studies published before March 31, 2020 was conducted. Randomized controlled trials and case series were analyzed. The meta-analysis estimated the standardized mean difference (SMD) in acne severity score changes in patients treated by PDL versus control and also the SMD of the acne severity scores and comedone counts changes before and after PDL treatment.

RESULTS

Eleven studies were included in this systematic review. Six studies were included in the meta-analysis. Pulsed dye laser treatment was not found to be superior to the control group in treating acne vulgaris (SMD: -0.285; 95% confidence interval [CI], -0.886 to 0.317). However, single-arm studies revealed a significantly improved acne severity score after PDL therapy (SMD, -1.321; 95% CI, -2.057 to -0.586), especially when a multiple-session treatment and a longer pulse duration were employed. The comedone counts were significantly decreased after PDL therapy (SMD, -0.596; 95% CI, -1.137 to -0.054).

CONCLUSION

When treatment consisted of 4 or more sessions or longer pulse duration, PDL could significantly decrease the acne severity score.

ABERRANT WNT SIGNALING INDUCES COMEDO-LIKE CHANGES IN THE MURINE UPPER HAIR FOLLICLE

Stem cell proliferation and differentiation must be carefully balanced to support tissue maintenance and growth. Defective stem cell regulation may underpin diseases in many organs, including the skin. Lrig1-expressing stem cells residing in the HF junction zone (JZ) support sebaceous gland (SG) homeostasis. An emerging hypothesis from observations in both mouse and human holds that imbalances in key stem cell regulatory pathways such as Wnt signaling may lead to abnormal fate determination of these Lrig1^+ve cells. They accumulate and form cystic structures in the JZ that are similar to the comedones found in human acne. To test the possible involvement of Wnt signals in this scenario, we used the Lrig1-CreERT2 mouse line to modulate Wnt signaling in JZ stem cells. We observed that persistent activation of Wnt signaling leads to JZ cyst formation with associated SG atrophy. The cysts strongly express stem cell markers and can be partially reduced by all-trans retinoic acid treatment as well as by Hedgehog signaling inhibition. Conversely, loss of Wnt signaling leads to enlargement of JZ, infundibulum and SGs. These data implicate abnormal Wnt signaling in the generation of mouse pathologies that resemble human acne and respond to acne treatments.

Red Seaweed-Derived Compounds as a Potential New Approach for Acne Vulgaris Care

Acne vulgaris (AV) is a chronic skin disease of the pilosebaceous unit affecting both adolescents and adults. Its pathophysiology includes processes of inflammation, increased keratinization, sebum production, hormonal dysregulation, and bacterial Cutibacterium acnes proliferation. Common AV has been treated with antibiotics since the 1960s, but strain resistance has emerged and is of paramount concern. Macroalgae are known producers of substances with bioactive properties, including anti-viral, antibacterial, antioxidant, and anti-inflammatory properties, among several others. In particular, red algae are rich in bioactive compounds such as polysaccharides, phenolic compounds, lipids, sterols, alkaloids, and terpenoids, conferring them antioxidant, antimicrobial, and anti-inflammatory activities, among others. Thus, the exploration of compounds from marine resources can be an appealing approach to discover new treatment options against AV. The aim of this work is to provide an overview of the current knowledge of the potentialities of red macroalgae in the treatment of AV by reviewing the main therapeutic targets of this disease, and then the existence of compounds or extracts with bioactive properties against them.

Transcriptional Differences in Lipid-Metabolizing Enzymes in Murine Sebocytes Derived from Sebaceous Glands of the Skin and Preputial Glands

Sebaceous glands are adnexal structures, which critically contribute to skin homeostasis and the establishment of a functional epidermal barrier. Sebocytes, the main cell population found within the sebaceous glands, are highly specialized lipid-producing cells. Sebaceous gland-resembling tissue structures are also found in male rodents in the form of preputial glands. Similar to sebaceous glands, they are composed of lipid-specialized sebocytes. Due to a lack of adequate organ culture models for skin sebaceous glands and the fact that preputial glands are much larger and easier to handle, previous studies used preputial glands as a model for skin sebaceous glands. Here, we compared both types of sebocytes, using a single-cell RNA sequencing approach, to unravel potential similarities and differences between the two sebocyte populations. In spite of common gene expression patterns due to general lipid-producing properties, we found significant differences in the expression levels of genes encoding enzymes involved in the biogenesis of specialized lipid classes. Specifically, genes critically involved in the mevalonate pathway, including squalene synthase, as well as the sphingolipid salvage pathway, such as ceramide synthase, (acid) sphingomyelinase or acid and alkaline ceramidases, were significantly less expressed by preputial gland sebocytes. Together, our data revealed tissue-specific sebocyte populations, indicating major developmental, functional as well as biosynthetic differences between both glands. The use of preputial glands as a surrogate model to study skin sebaceous glands is therefore limited, and major differences between both glands need to be carefully considered before planning an experiment.