Aquaporin 3 is expressed in the basaloid cells of canine sebaceous glands.

The role of aquaporin proteins (AQPs) in tumor biology has attracted attention over the past 20 years. However, the expression profiles of AQPs in canine sebaceous gland tumors remain obscure. This study was performed to clarify the expression of AQP1, 3, 5, the most studied AQPs in tumor biology, in sebaceous adenoma and sebaceous epithelioma. Among these AQPs, only AQP3 was expressed in normal tissue and both tumor types and located to only undifferentiated sebocytes (basaloid cells). A cellular proliferation marker, Ki67, was detected only in the area including basaloid cells in both tumor types. These findings suggest that AQP3 is useful for clarifying the origin of sebaceous gland tumors, and that AQP3 may be related to sebaceous gland development.

Potential of cannabidiol as acne and acne scar treatment: novel insights into molecular pathways of pathophysiological factors.

Cannabidiol (CBD), which is derived from hemp, is gaining recognition because of its anti-inflammatory and lipid-modulating properties that could be utilized to treat acne. We conducted experiments to quantitatively assess the effects of CBD on acne-related cellular pathways. SEB-1 sebocytes and HaCaT keratinocytes were exposed to various CBD concentrations. CBD exhibited a concentration-dependent impact on cell viability and notably reduced SEB-1 viability; furthermore, it induced apoptosis and a significant increase in the apoptotic area at higher concentrations. Additionally, CBD remarkably reduced pro-inflammatory cytokines, including CXCL8, IL-1α, and IL-1ß. Additionally, it inhibited lipid synthesis by modulating the AMPK-SREBP-1 pathway and effectively reduced hyperkeratinization-related protein keratin 16. Simultaneously, CBD stimulated the synthesis of elastin, collagen 1, and collagen 3. These findings emphasize the potential of CBD for the management of acne because of its anti-inflammatory, apoptotic, and lipid-inhibitory effects. Notably, the modulation of the Akt/AMPK-SREBP-1 pathway revealed a novel and promising mechanism that could address the pathogenesis of acne.

TRPV3 promotes sebocyte inflammation via transcriptional modulating TLR2 in acne.

Acne is a common chronic inflammatory disease of the pilosebaceous unit. Transient receptor potential vanilloid 3 (TRPV3) is an ion channel that is involved in inflammatory dermatosis development. However, the involvement of TRPV3 in acne-related inflammation remains unclear. Here, we used acne-like mice and human sebocytes to examine the role of TRPV3 in the development of acne. We found that TRPV3 expression increased in the skin lesions of Propionibacterium acnes (P. acnes)-injected acne-like mice and the facial sebaceous glands (SGs) of acne patients. TRPV3 promoted inflammatory cytokines and chemokines secretion in human sebocytes and led to neutrophil infiltration surrounding the SGs in acne lesions, further exacerbating sebaceous inflammation and participating in acne development. Mechanistically, TRPV3 enhanced TLR2 level by promoting transcriptional factor phosphorylated-FOS-like antigen-1 (p-FOSL1) expression and its binding to the TLR2 promoter, leading to TLR2 upregulation and downstream NF-κB signaling activation. Genetic or pharmacological inhibition of TRPV3 both alleviated acne-like skin inflammation in mice via the TLR2-NF-κB axis. Thus, our study revealed the critical role of TRPV3 in sebaceous inflammation and indicated its potential as an acne therapeutic target.

Alcohol Promotes Lipogenesis in Sebocytes-Implications for Acne.

The oral consumption of alcohol (ethanol) has a long tradition in humans and is an integral part of many cultures. The causal relationship between ethanol consumption and numerous diseases is well known. In addition to the well-described harmful effects on the liver and pancreas, there is also evidence that ethanol abuse triggers pathological skin conditions, including acne. In the present study, we addressed this issue by investigating the effect of ethanol on the energy metabolism in human SZ95 sebocytes, with particular focus on qualitative and quantitative lipogenesis. It was found that ethanol is a strong trigger for lipogenesis, with moderate effects on cell proliferation and toxicity. We identified the non-oxidative metabolism of ethanol, which produced fatty acid ethyl esters (FAEEs), as relevant for the lipogenic effect-the oxidative metabolism of ethanol does not contribute to lipogenesis. Correspondingly, using the Seahorse extracellular flux analyzer, we found an inhibition of the mitochondrial oxygen consumption rate as a measure of mitochondrial ATP production by ethanol. The ATP production rate from glycolysis was not affected. These data corroborate that ethanol-induced lipogenesis is independent from oxygen. In sum, our results give a causal explanation for the prevalence of acne in heavy drinkers, confirming that alcoholism should be considered as a systemic disease. Moreover, the identification of key factors driving ethanol-dependent lipogenesis may also be relevant in the treatment of acne vulgaris.

ALA-PDT promotes IL-1ß 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-1ß release following ALA-PDT by ELISA. Western blotting helped identify the levels of proteins associated with pyroptosis (NLRP3, caspase-1, and IL-1ß). 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-1ß). 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-1ß secretion. This cascade may amplify the local inflammatory response to break chronic inflammation in acne vulgaris treatment.

Nucleotide-binding oligomerization domain protein-1 is expressed and involved in the inflammatory response in human sebocytes.

Sebocytes express Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), which participate in the innate immune response of the skin. Although the roles of TLRs and NLR family pyrin domain-containing 3 (NLRP3) in inflammatory responses in sebocytes have been reported, the expression and functions of other NLR members, such as NOD protein-1 and -2 (NOD1 and NOD2, respectively), remain unclear. In this study, we showed that, in sebocytes, the expression of NOD1 is higher than that of NOD2, and that NOD1 is involved in inflammatory responses, such as the secretion of proinflammatory cytokines. A NOD1 agonist, L-alanyl-γ-D-glutamyl-meso-diaminopimelic acid (Tri-DAP) induced the expression and secretion of interleukin-8 (IL-8) and activated the nuclear factor-kappa B and mitogen-activated protein kinase signaling pathways. On the other hand, a NOD2 agonist, muramyl dipeptide, did not. Either inhibition with a NOD1 inhibitor, ML130, or knockdown of NOD1 expression abolished Tri-DAP-induced inflammatory responses, suggesting that NOD1 is involved in the immunogenic signaling system of sebocytes. Furthermore, Tri-DAP and an agonist of TLR2 or TLR4 additively increased IL-8 expression compared with each agonist alone. Our results reveal the role of NOD1 in the inflammatory responses of sebocytes and may provide a novel therapeutic target for sebaceous gland inflammatory diseases, such as acne vulgaris.

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.

Eruptive Sebaceous Hyperplasia: A Case Report and Review of the Literature.

Introduction: Eruptive sebaceous hyperplasia (ESH) is a benign process characterized by the acute onset and rapid proliferation of sebaceous glands, typically on the face. Although historically attributed to cyclosporine therapy, the preponderance of reports over the past 2 decades suggests a more complex etiology. There is increasing thought a combination of multiple medications as well as a genetic component contribute to ESH's clinical presentation. Despite these theories, the exact cause of ESH in immunosuppressive therapy is poorly understood. Case Presentation: To our knowledge, we report the third case of ESH arising in multimodality immunosuppressive therapy, consisting of tacrolimus, mycophenolate mofetil, and prednisone, affecting a renal transplant patient. Our patient began cyclosporine monotherapy at an early age but did not see eruption of lesions until years later after following a multimodal therapy. Conclusion: We discuss the association of ESH with other medical conditions and treatments. We hope this case sheds light on a possible complication of multimodal immunosuppressive therapy in renal transplant patients. This will allow patients and providers to be better informed of the pros and cons of different treatment options for immunosuppressive therapy in renal transplant patients.

The World's First Acne Dysbiosis-like Model of Human 3D Ex Vivo Sebaceous Gland Colonized with Cutibacterium acnes and Staphylococcus epidermidis.

Acne-prone skin is associated with dysbiosis involving Cutibacterium acnes (C. acnes) and Staphylococcus epidermidis (S. epidermidis) causing increased seborrhea in sebaceous glands (SG) and inflammation. Human primary sebocytes were cultivated using 1.106 UFC/mL C. acnes Type IA (facial acne, ATCC6919) and/or 1.105 UFC/mL S. epidermidis (unknown origin, ATCC12228) for 48 h in our SEB4GLN-optimized media without antibiotics. Bacteria and sebocytes were enumerated and assessed to determine their viability. Lipid production was imaged and quantified via Nile Red staining. SG with hair follicles were microdissected from healthy skin and cultured using 1.105 UFC/mL C. acnes Type 1A and/or 1.104 UFC/mL S. epidermidis (wild-type facial skin strain) through prior fixation and immunostaining for MC5R, C. acnes and nuclei (DAPI) via Z-stack confocal microscopy bioimaging (Leica SP5X & FIJI software, Version 2.9.0). C. acnes growth was not impacted when co-cultivated with sebocytes (2D) or SG (3D) models. Phylotype IA stimulated sebocyte lipid production, which had no impact on viability. The S. epidermidis reference strain overproliferated, inducing sebocyte mortality. For 3D SG model, culture conditions were optimized using a wild-type facial skin strain at a lower concentration, 1:10 ratio to C. acnes, reduced contact time, sequential inoculation and rinsing step. Bioimaging revealed strong C. acnes labeling in the active areas of the pilosebaceous unit. S. epidermidis formed biofilm, which was distributed across the SG via non-specific fluorescence imaging. We developed an innovative model of a sebaceous gland that mimics acne-prone skin with lipid overproduction and virulent phylotype IA C. acnes inoculation.

Linoleic Acid Induced Changes in SZ95 Sebocytes-Comparison with Palmitic Acid and Arachidonic Acid.

Linoleic acid (LA) is an essential omega-6 polyunsaturated fatty acid (PUFA) derived from the diet. Sebocytes, whose primary role is to moisturise the skin, process free fatty acids (FFAs) to produce the lipid-rich sebum. Importantly, like other sebum components such as palmitic acid (PA), LA and its derivative arachidonic acid (AA) are known to modulate sebocyte functions. Given the different roles of PA, LA and AA in skin biology, the aim of this study was to assess the specificity of sebocytes for LA and to dissect the different roles of LA and AA in regulating sebocyte functions. Using RNA sequencing, we confirmed that gene expression changes in LA-treated sebocytes were largely distinct from those induced by PA. LA, but not AA, regulated the expression of genes related to cholesterol biosynthesis, androgen and nuclear receptor signalling, keratinisation, lipid homeostasis and differentiation. In contrast, a set of mostly down-regulated genes involved in lipid metabolism and immune functions overlapped in LA- and AA-treated sebocytes. Lipidomic analyses revealed that the changes in the lipid profile of LA-treated sebocytes were more pronounced than those of AA-treated sebocytes, suggesting that LA may serve not only as a precursor of AA but also as a potent regulator of sebaceous lipogenesis, which may not only influence the gene expression profile but also have further specific biological relevance. In conclusion, we have shown that sebocytes are able to respond selectively to different lipid stimuli and that LA-induced effects can be both AA-dependent and independent. Our findings allow for the consideration of LA application in the therapy of sebaceous gland-associated inflammatory skin diseases such as acne, where lipid modulation and selective targeting of AA metabolism are potential treatment options.

Preservation of epidermal melanocyte integrity in an ex vivo co-culture skin model with sebocytes.

A direct contact co-culture of skin explants to SZ95 sebocytes (3D-SeboSkin) has been shown to preserve the integrity of epidermal keratinocytes and dermis. In this study, the properties of epidermal melanocytes were evaluated in the same 3D SeboSkin ex vivo model. Skin explants (n = 6) were maintained in the 3D-SeboSkin model, in direct contact to fibroblasts and alone in serum-free medium (SFM). Histopathological, immunohistochemical, apoptosis and oil red staining evaluations were performed at Days 0 and 6 of incubation. Results revealed preservation and prominent proliferation of basal keratinocytes of the skin explants in addition to preservation of dermal collagen and vasculature at Day 6 in the 3D-SeboSkin culture model and to a lesser extent in co-culture with fibroblasts but not in SFM alone. Melan-A+/Ki67- epidermal melanocytes remained attached to the dermis even at sites of epidermal detachment in the three skin explant models tested. However, the number of epidermal melanocytes was significantly conserved in 3D-SeboSkin cultures in comparison with skin explants in SFM (p < 0.05), whereas no difference was found in comparison with the co-culture with fibroblasts. Few DAPI/TUNEL+ apoptotic melanocytes could mostly be observed in SFM-incubated skin explants. Furthermore, only SZ95 sebocytes in contact to skin explants in 3D-SeboSkin exhibited increased lipogenesis with accumulation of abundant lipid droplets. These results denote that the 3D-SeboSkin model yielded significant preservation of epidermal melanocytes and hence it is optimal for ex vivo studies of abnormalities of skin pigmentation, melanocyte neoplasms and effects of different hormones, cytokines, carcinogens and various therapeutics in a pattern that recapitulates the in vivo environment.

Krüppel-like factor 4 (KLF4) facilitates lipid production in immortalized human sebocytes via regulating the expression of SREBP1.

BACKGROUND: Acne is associated with the excessive production of sebum, a complex mixture of lipids, in the sebaceous glands. The transcription factor Krüppel-like factor 4 (KLF4) plays an important role in skin morphogenesis, but its role in sebum production by sebocytes is not well known. PURPOSE: In this study, we investigated the possible action mechanism of KLF4 during calcium-induced lipogenesis in immortalized human sebocytes. METHODS: Sebocytes were treated with calcium, and lipid production was confirmed by thin-layer chromatography (TLC) and Oil Red O staining. To investigate the effect of KLF4, sebocytes were transduced with the KLF4-overexpressing adenovirus, and then lipid production was evaluated. RESULTS: Calcium treatment resulted in increased sebum production in terms of squalene synthesis in sebocytes. In addition, calcium increased the expression of lipogenic regulators such as sterol-regulatory element binding protein 1 (SREBP1), sterol-regulatory element binding protein 2 (SREBP2), and stearoyl-CoA desaturase (SCD). Similarly, the expression of KLF4 was increased by calcium in sebocytes. To investigate the effect of KLF4, we overexpressed KLF4 in sebocytes using recombinant adenovirus. As a result, KLF4 overexpression increased the expression of SREBP1, SREBP2, and SCD. Parallel to this result, lipid production was also increased by KLF4 overexpression. Chromatin immunoprecipitation revealed the binding of KLF4 to the SREBP1 promoter, indicating that KLF4 may directly regulate the expression of lipogenic regulators. CONCLUSION: These results suggest that KLF4 is a novel regulator of lipid production in sebocytes.

Explorating the mechanism of Huangqin Tang against skin lipid accumulation through network pharmacology and experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: Huangqin Tang (HQT), a famous prescription with the effect of clearing pathogenic heat and detoxifying, was first recorded in "Treatise on Typhoid and Miscellaneous Diseases". It has proved that HQT has good anti-inflammatory and antioxidant effects and can improve acne symptoms clinically. However, the study on the regulation of HQT on sebum secretion which is one of the inducements of acne is not enough. AIM OF THE STUDY: This paper aimed to investigate the mechanisms of HQT in the treatment of skin lipid accumulation by network pharmacology and validating the results via in vitro experiments. MATERIALS AND METHODS: Network pharmacology was employed to predict the potential targets of HQT against sebum accumulation. Then, the palmitic acid (PA)-induced SZ95 cell model was established to evaluate the effect of HQT on lipid accumulation and anti-inflammation, and the core pathways predicted by network pharmacology were verified in cell studies. RESULTS: 336 chemical compounds and 368 targets in HQT were obtained by network pharmacology, of which 65 targets were related to sebum synthesis. 12 core genes were revealed by protein-protein interaction (PPI) network analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results suggested that AMP-activated protein kinase (AMPK) signaling pathway might play a crucial role in regulating lipogenesis. In vitro experiments, HQT suppressed lipid accumulation, downregulated the expressions of sterol-regulatory element binding protein-1 (SREBP-1) and fatty acid synthase (FAS), and upregulated AMPK phosphorylation. Furthermore, AMPK inhibitor reversed HQT-mediated sebosuppressive effect. CONCLUSION: The results disclosed that HQT ameliorates lipogenesis in PA-induced SZ95 sebocytes partially through the AMPK signaling pathway.

Free Fatty Acids Induce Lipid Accumulation, Autophagy, and Apoptosis in Human Sebocytes.

BACKGROUND: A disruption of sebocyte differentiation and lipogenesis has fatal consequences and can cause a wide spectrum of skin diseases, from acne vulgaris to sebaceous carcinoma, however, the relevant molecular mechanisms have not been fully clarified. OBJECTIVES: The induction of autophagy and apoptosis in human sebocytes in response to biologically relevant fatty acids was investigated. METHODS: Free fatty acids (arachidonic acid, linoleic acid, palmitic acid, and palmitoleic acid) and the pan-caspase inhibitor QVD-Oph were added to the supernatant of cultured human SZ95 sebocytes. Individual relevant proteins were analyzed by Western blotting. Apoptosis and cell viability were determined, and typical autophagy structures were detected through electron microscopy. To obtain cell growth curves, cell confluence was continuously monitored by real-time cell analysis. RESULTS: Fatty acids induced the development of intracellular lipid droplets with subsequent apoptosis, whereas arachidonic acid caused the most rapid effect. Cleavage products of caspase-3 were only detected in arachidonic acid-induced apoptosis. The high basal apoptotic rate of cultured SZ95 sebocytes was strongly suppressed by QVD-Oph. Fatty acid-induced apoptosis was also markedly inhibited by QVD-Oph, whereas intracellular lipid droplets further accumulated. While cell viability after incubation with linoleic acid, palmitic acid, or palmitoleic acid and QVD-Oph was comparable with that of non-treated controls, arachidonic acid significantly reduced cell viability and cell density despite the concomitant pan-caspase inhibitor treatment. Using electron microscopy, typical autophagy structures were detected, such as autophagosomes and autolysosomes, at the basal level, which became more pronounced after treatment with fatty acids. CONCLUSIONS: Our findings contribute to a better understanding of the inflammation-associated mechanisms of lipogenesis and cell death induction in human sebocytes and may help to unveil the effects of fatty acid-rich human nutrition.

Transcriptome Analysis of Particulate Matter 2.5-Induced Abnormal Effects on Human Sebocytes.

Particulate matter 2.5 (PM2.5), an atmospheric pollutant with an aerodynamic diameter of <2.5 µm, can cause serious human health problems, including skin damage. Since sebocytes are involved in the regulation of skin homeostasis, it is necessary to study the effects of PM2.5 on sebocytes. We examined the role of PM2.5 via the identification of differentially expressed genes, functional enrichment and canonical pathway analysis, upstream regulator analysis, and disease and biological function analysis through mRNA sequencing. Xenobiotic and lipid metabolism, inflammation, oxidative stress, and cell barrier damage-related pathways were enriched; additionally, PM2.5 altered steroid hormone biosynthesis and retinol metabolism-related pathways. Consequently, PM2.5 increased lipid synthesis, lipid peroxidation, inflammatory cytokine expression, and oxidative stress and altered the lipid composition and expression of factors that affect cell barriers. Furthermore, PM2.5 altered the activity of sterol regulatory element binding proteins, mitogen-activated protein kinases, transforming growth factor beta-SMAD, and forkhead box O3-mediated pathways. We also suggest that the alterations in retinol and estrogen metabolism by PM2.5 are related to the damage. These results were validated using the HairSkin® model. Thus, our results provide evidence of the harmful effects of PM2.5 on sebocytes as well as new targets for alleviating the skin damage it causes.

Preventative effects of antioxidants on changes in sebocytes, outer root sheath cells, and Cutibacterium acnes-pretreated mice by particulate matter: No significant difference among antioxidants.

OBJECTIVES: Particulate matter (PM) is an air pollutant that can damage human skin; antioxidants have shown some efficacy in alleviating PM-induced skin inflammation. We investigated the antioxidant effects of punicalagin, epigallocatechin-3-gallate (EGCG), and resveratrol on PM-induced changes in cultured human sebocytes, outer root sheath (ORS) cells, and Cutibacterium acnes-pretreated mice. METHODS: Sebocytes and ORS cells were cultured with 100 µg/mL PM10 and 5 µM punicalagin, 1 µM EGCG, or 1 µM resveratrol for 24 h. In C. acnes-pretreated mice, inflammatory nodules were treated with 100 µg/mL PM10 and 5 µM punicalagin, 1 µM EGCG, or 1 µM resveratrol. Cell viability was measured using an MTT assay. Antioxidant effects were analyzed according to RNA expression, using real-time PCR, as well as reactive oxygen species (ROS) and sebum measurements. RESULTS: Antioxidants inhibited the upregulation of inflammatory cytokines, matrix metalloproteinase, aryl hydrocarbon receptor, and NF-kB as well as the production of ROS induced by PM10 in cultured sebocytes and ORS cells. The preventative effects of punicalagin and EGCG on biomarker expression in cultured sebocytes and ORS cells were slightly greater than those of resveratrol, though the difference was not significant. In C. acnes-pretreated mice, the antioxidants inhibited inflammatory cytokine and matrix metalloproteinase expression as well as sebum production. CONCLUSIONS: Antioxidants effectively reduced the expression of inflammatory biomarkers and sebum production in cultured sebocytes, ORS cells, and C. acnes-pretreated mice.

Dieckol Inhibits the Effects of Particulate Matter 10 on Sebocytes, Outer Root Sheath Cells, and Cutibacterium Acnes-Pretreated Mice.

Background: Particulate matter (PM) is an air pollutant that can impair the human skin. Antioxidants have been tested to improve PM-induced skin inflammation. Objective: In this study, we investigated the effects of dieckol on PM-induced inflammation on cultured human sebocytes, outer root sheath (ORS) cells, and mice pretreated with Cutibacterium acnes. Methods: We cultured and treated the sebocytes and ORS cells with 5 µM of dieckol and 100 µg/ml of PM10 for 24 h. The C. acnes-pretreated mice received 5 µM of dieckol and 100 µg/ml of PM10. We measured cell viability using MTT assay. Real-time PCR and measurement of reactive oxygen species (ROS) and sebum production analyzed the effects. Results: Dieckol inhibited the upregulation of the gene expression of the inflammatory cytokines, matrix metalloproteinase (MMP), aryl hydrocarbon receptor, and nuclear factor kappa-light-chain-enhancer of activated B cells by PM10 in the cultured sebocytes and ORS cells and inhibited an increase in ROS production by PM10 in the cultured sebocytes. In addition, dieckol decreased the inflammatory cytokines, MMP, and sebum production in C. acnes-pretreated mice. Conclusion: Dieckol effectively reduced the expression of inflammatory biomarkers and the production of sebum in cultured sebocytes, ORS cells, and C. acnes-pretreated mice.

Effects of <10-µm Particulate Matter on Cultured Human Sebocytes and Outer Root Sheath Cells and Usefulness of Siegesbeckia Herba Extract.

Background: Particulate matter (PM) is one of the air pollutants that can damage human skin; the recent increase in the amount of PM may be detrimental to skin health. Objective: We aimed to investigate the effects of PM on cultured human sebocytes and outer root sheath (ORS) cells and the effects of Siegesbeckia Herba extract (SHE) on PM-treated cultured cells. Methods: Sebocytes and ORS cells were cultured. The cultured cells were treated with various concentrations of PM of <10 µm in size (PM10) (10 µg/ml, 25 µg/ml, 50 µg/ml, and 100 µg/ml) for 24 h. Real-time polymerase chain reaction, measurement of reactive oxygen species (ROS), small interfering (si) RNA transfection, Oil Red O and Nile red staining, and immunofluorescence staining were performed to analyze the presence of inflammatory cytokines, matrix metalloproteinases (MMPs), aryl hydrocarbon receptor (AhR), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), ROS, and lipid production. In addition, PM10 (100 µg/ml)-treated cultured cells were treated with 10 mg/ml of SHE. Results: PM10 upregulates the expression of inflammatory cytokines, MMPs, AhR, NF-κB, and ROS in cultured human sebocytes and ORS cells. The production of ROS was dramatically reduced in AhR siRNA-transfected cells. In addition, PM10 upregulates sebum production in cultured sebocytes. SHE inhibited the upregulation of inflammatory cytokines, MMPs, AhR, NF-κB, ROS, and sebum production in cultured human sebocytes and/or ORS cells by PM10. Conclusion: Effects of PM10 on cultured human sebocytes and ORS cells can be regulated by SH.