-
Experimental Dermatology Jul 2019Acne vulgaris is a prevalent cutaneous disease characterized by a multifactorial pathogenic process including hyperseborrhea, inflammation, over-keratinization of...
Acne vulgaris is a prevalent cutaneous disease characterized by a multifactorial pathogenic process including hyperseborrhea, inflammation, over-keratinization of follicular keratinocytes and Propionibacterium acnes (P acnes) overgrowth. Salicylic acid (SA), a beta-hydroxy acid, is frequently used in the treatment of acne. SA has been found to decrease skin lipids and to possess anti-inflammatory properties. However, few studies have elucidated the mechanisms and pathways involved in such treatment of acne. In this study, we initially investigated the anti-acne properties of SA in human SEB-1 sebocytes. Treatment with SA decreased sebocyte lipogenesis by downregulating the adenosine monophosphate-activated protein kinase (AMPK)/sterol response element-binding protein-1 (SREBP-1) pathway and reduced inflammation by suppressing the NF-κB pathway in these cells. Salicylic acid also decreased the cell viability of SEB-1 by increasing apoptosis via the death signal receptor pathway. Subsequently, histopathological analysis of a rabbit ear acne model after application of SA for three weeks confirmed that SA suppressed the levels of cytokines and major pathogenic proteins around acne lesions, which supports the mechanisms suggested by our in vitro experiments. These results initially clarified that therapeutic activities of SA in acne vulgaris treatment could be associated with the regulation of SREBP-1 pathway and NF-κB pathway in human SEB-1 sebocytes.
Topics: AMP-Activated Protein Kinases; Acne Vulgaris; Apoptosis; Cell Line; Computational Biology; Down-Regulation; Humans; Keratinocytes; Lipid Metabolism; Propionibacterium acnes; Salicylic Acid; Sebaceous Glands; Sebum; Signal Transduction; Sterol Regulatory Element Binding Protein 1
PubMed: 30972839
DOI: 10.1111/exd.13934 -
Biological Reviews of the Cambridge... Jun 2020The nervous system communicates with peripheral tissues through nerve fibres and the systemic release of hypothalamic and pituitary neurohormones. Communication between... (Review)
Review
The nervous system communicates with peripheral tissues through nerve fibres and the systemic release of hypothalamic and pituitary neurohormones. Communication between the nervous system and the largest human organ, skin, has traditionally received little attention. In particular, the neuro-regulation of sebaceous glands (SGs), a major skin appendage, is rarely considered. Yet, it is clear that the SG is under stringent pituitary control, and forms a fascinating, clinically relevant peripheral target organ in which to study the neuroendocrine and neural regulation of epithelia. Sebum, the major secretory product of the SG, is composed of a complex mixture of lipids resulting from the holocrine secretion of specialised epithelial cells (sebocytes). It is indicative of a role of the neuroendocrine system in SG function that excess circulating levels of growth hormone, thyroxine or prolactin result in increased sebum production (seborrhoea). Conversely, growth hormone deficiency, hypothyroidism, and adrenal insufficiency result in reduced sebum production and dry skin. Furthermore, the androgen sensitivity of SGs appears to be under neuroendocrine control, as hypophysectomy (removal of the pituitary) renders SGs largely insensitive to stimulation by testosterone, which is crucial for maintaining SG homeostasis. However, several neurohormones, such as adrenocorticotropic hormone and α-melanocyte-stimulating hormone, can stimulate sebum production independently of either the testes or the adrenal glands, further underscoring the importance of neuroendocrine control in SG biology. Moreover, sebocytes synthesise several neurohormones and express their receptors, suggestive of the presence of neuro-autocrine mechanisms of sebocyte modulation. Aside from the neuroendocrine system, it is conceivable that secretion of neuropeptides and neurotransmitters from cutaneous nerve endings may also act on sebocytes or their progenitors, given that the skin is richly innervated. However, to date, the neural controls of SG development and function remain poorly investigated and incompletely understood. Botulinum toxin-mediated or facial paresis-associated reduction of human sebum secretion suggests that cutaneous nerve-derived substances modulate lipid and inflammatory cytokine synthesis by sebocytes, possibly implicating the nervous system in acne pathogenesis. Additionally, evidence suggests that cutaneous denervation in mice alters the expression of key regulators of SG homeostasis. In this review, we examine the current evidence regarding neuroendocrine and neurobiological regulation of human SG function in physiology and pathology. We further call attention to this line of research as an instructive model for probing and therapeutically manipulating the mechanistic links between the nervous system and mammalian skin.
Topics: Animals; Brain; Dopamine; Growth Hormone; Humans; Hypothalamo-Hypophyseal System; Neurosecretory Systems; Peripheral Nervous System; Prolactin; Sebaceous Glands; Sebum; Skin; Skin Physiological Phenomena; Somatomedins; Stem Cells; Thyroid Gland
PubMed: 31970855
DOI: 10.1111/brv.12579 -
Pharmaceutics Jul 2023Acne vulgaris is a common skin disease characterized by increased sebum production, inflammation, and (CA: formerly ) hyperproliferation in pilosebaceous follicles....
Acne vulgaris is a common skin disease characterized by increased sebum production, inflammation, and (CA: formerly ) hyperproliferation in pilosebaceous follicles. This study evaluated the efficacy of FRO, a formula composed of fermented Stokes and , against acne pathogenesis via antimicrobial assessment and an in vitro analysis. Stimulated model cells treated with hormones, CA, or lipopolysaccharide (LPS) were designed based on the characteristics of acne pathogenesis, including inflammation and sebum hypersecretion. High-performance liquid chromatography, disc diffusion, MTS, and western blotting assays were used to examine potential anti-acne effects. FRO was determined to contain phenolics such as gallic acid, fisetin, quercetin, and kaempferol. FRO exerted antimicrobial activity against CA and inhibited reactive oxygen species production that was otherwise increased by LPS or CA in HaCaT cells. Additionally, FRO exerted anti-inflammatory effects by inhibiting iNOS, TNF-α, IL-6, p-STAT-3, and p-NF-κB, which were previously upregulated by LPS or CA in THP-1 and HaCaT cells. FRO inhibited lipogenesis induced by steroid hormones and CA by decreasing FAS and SREBP-1 levels in sebocytes. Additionally, FRO down-regulated the androgen receptor, 5α-reductase, SREBP-1, and FAS levels, which were upregulated by steroid hormone in LNCaP cells. Taken together, our findings suggest that FRO alleviates acne by inhibiting the growth of CA, inflammation, and excess sebum and could be used for functional cosmetics or acne treatments.
PubMed: 37514071
DOI: 10.3390/pharmaceutics15071885 -
Dermato-endocrinology 2017The major role of sebaceous glands in mammals is to produce sebum, which coats the epidermis and the hair providing waterproofing, thermoregulation and photoprotection.... (Review)
Review
The major role of sebaceous glands in mammals is to produce sebum, which coats the epidermis and the hair providing waterproofing, thermoregulation and photoprotection. However, as the need for these functions decreased along the evolutionary changes in humans, a relevant question has been raised: are sebaceous glands and sebum the remnants of our mammalian heritage or do they have overtaken a far more complex role in human skin biology? Trying to provide answers to this question, this review introduces the evolving field of sebaceous immunobiology and puts into the focus the pathways that sebum lipids use to influence the immune milieu of the skin. By introducing possible modifiers of sebaceous lipogenesis and discussing the - human-specific - alterations in composition and amount of sebum, the attribute of sebum as a sensitive tool, which is capable of translating multiple signalling pathways into the dermal micro environment is presented. Further their interaction with macrophages and keratinocytes involves sebum lipid fractions into disease pathogenesis, which could lead - on the other side - to the development of novel sebum-based therapeutic strategies.
PubMed: 29484100
DOI: 10.1080/19381980.2017.1375636 -
The Journal of Allergy and Clinical... Dec 2023The cytokine TSLP promotes type 2 immune responses and can induce adipose loss by stimulating lipid loss from the skin through sebum secretion by sebaceous glands, which...
BACKGROUND
The cytokine TSLP promotes type 2 immune responses and can induce adipose loss by stimulating lipid loss from the skin through sebum secretion by sebaceous glands, which enhances the skin barrier. However, the mechanism by which TSLP upregulates sebaceous gland function is unknown.
OBJECTIVES
This study investigated the mechanism by which TSLP stimulates sebum secretion and adipose loss.
METHODS
RNA-sequencing analysis was performed on sebaceous glands isolated by laser capture microdissection and single-cell RNA-sequencing analysis was performed on sorted skin T cells. Sebocyte function was analyzed by histological analysis and sebum secretion in vivo and by measuring lipogenesis and proliferation in vitro.
RESULTS
This study found that TSLP sequentially stimulated the expression of lipogenesis genes followed by cell death genes in sebaceous glands to induce holocrine secretion of sebum. TSLP did not affect sebaceous gland activity directly. Rather, single-cell RNA-sequencing revealed that TSLP recruited distinct T-cell clusters that produce IL-4 and IL-13, which were necessary for TSLP-induced adipose loss and sebum secretion. Moreover, IL-13 was sufficient to cause sebum secretion and adipose loss in vivo and to induce lipogenesis and proliferation of a human sebocyte cell line in vitro.
CONCLUSIONS
This study proposes that TSLP stimulates T cells to deliver IL-4 and IL-13 to sebaceous glands, which enhances sebaceous gland function, turnover, and subsequent adipose loss.
PubMed: 38157943
DOI: 10.1016/j.jaci.2023.11.923 -
Current Opinion in Allergy and Clinical... Oct 2018To summarize the current knowledge on the morphology, functionality and biochemical composition of the skin in allergic reactions. We address novel noninvasive... (Review)
Review
PURPOSE OF REVIEW
To summarize the current knowledge on the morphology, functionality and biochemical composition of the skin in allergic reactions. We address novel noninvasive techniques that promise to disclose intimate mechanisms of skin allergy in vivo. Epidermal barrier is not just a static wrap of the organism but rather a dynamic field for immunological, biophysical and biochemical processes and serves as a bio-sensor for exogenous danger signals.
RECENT FINDINGS
Classical biophysical methods are amended by novel in-vivo techniques, such as Raman spectroscopy, analysing the skin microcomposition and develop epidermal profiles. Visualization techniques, such as reflectance spectroscopy and optical coherence tomography (OCT) are employed in studying the micro-morphological changes in the skin of allergic patients.
SUMMARY
The noninvasive assessment of skin functions, micro-morphology and biochemical as well as immunological pathways will help to better understand skin allergies. They will allow to detect subtypes, for example in atopic dermatitis and to develop specific treatment modalities.
Topics: Dermatitis, Atopic; Eccrine Glands; Humans; Hydrogen-Ion Concentration; Laser-Doppler Flowmetry; Lipids; Microcirculation; Permeability; Sebum; Skin; Spectrum Analysis; Spectrum Analysis, Raman; Tomography, Optical Coherence
PubMed: 30113329
DOI: 10.1097/ACI.0000000000000476 -
Journal of Microbiology and... May 2021is the most abundant genus in the fungal microflora found on human skin, and it is associated with various skin diseases. Among the 18 different species of that have... (Review)
Review
is the most abundant genus in the fungal microflora found on human skin, and it is associated with various skin diseases. Among the 18 different species of that have been identified to date, and are the most predominant fungal species found on human skin. Several studies have suggested a possible link between and skin disorders. However, our knowledge on the physiology and pathogenesis of in human body is still limited. is unable to synthesize fatty acids; hence, it uptakes external fatty acids as a nutrient source for survival, a characteristic compensated by the secretion of lipases and degradation of sebum to produce and uptake external fatty acids. Although it has been reported that the activity of secreted lipases may contribute to pathogenesis of , majority of the data were indirect evidences; therefore, enzymes' role in the pathogenesis of infections is still largely unknown. This review focuses on the recent advances on in the context of an emerging interest for lipases and summarizes the existing knowledge on , diseases associated with the fungus, and the role of the reported lipases in its physiology and pathogenesis.
Topics: Dermatomycoses; Fungal Proteins; Humans; Lipase; Lipid Metabolism; Malassezia; Sebum; Skin; Virulence
PubMed: 33526754
DOI: 10.4014/jmb.2012.12048 -
Journal of Cosmetic Dermatology Aug 2020Seborrhea is linked to several medical and mental conditions. Although it is common, effective agents and the standardized sebum level for seborrhea are not elucidated. (Clinical Trial)
Clinical Trial
BACKGROUND
Seborrhea is linked to several medical and mental conditions. Although it is common, effective agents and the standardized sebum level for seborrhea are not elucidated.
AIMS
To determine the efficacy of chitosan particles (CP) formulation on controlling sebum secretion, its extended effects on skin redness and texture after combining with proretinal nanoparticles (CP-PRN), and a correlation of the clinical grading with sebum levels that affect mental health.
PATIENTS/METHODS
A four-week clinical trial with forty subjects was conducted. Subjects applied either CP formulation or CP-PRN during nighttime. Objective measurements including sebum levels, transepidermal water loss (TEWL), skin corneometry, skin redness, and texture were analyzed. Subjects completed a self-assessment clinical grading of skin oiliness at every visit.
RESULTS
Both CP and CP-PRN significantly decreased sebum levels (P ≤ .01) at week 4 compared to baseline. CP also resulted in significant decreases in TEWL (P ≤ .05) and skin corneometry (P ≤ .05) throughout the study. A significant improvement in skin redness was observed with CP-PRN (P ≤ .01). A moderate correlation between the clinical grading and sebum levels was detected (coefficient of 0.5, P ≤ .001), with a sebum level of 106 μg cm indicating emotional discomfort. One subject experienced local irritation with the CP-PRN. Mild pruritic symptoms were reported in both groups.
CONCLUSIONS
Chitosan particles exhibited an interesting anti-sebum effect. It could be combined with PRN to extend benefits without losing the sebum controlling effect. The clinical grading may be useful in practice due to a modest correlation with sebum levels.
Topics: Chitosan; Humans; Nanoparticles; Sebum; Skin; Skin Physiological Phenomena
PubMed: 31904190
DOI: 10.1111/jocd.13274 -
Experimental Cell Research Jan 2016Mammalian skin is characterized by the presence of sebaceous glands (SGs), which develop with the hair follicle and whose predominant cell type is the sebocyte.... (Review)
Review
Mammalian skin is characterized by the presence of sebaceous glands (SGs), which develop with the hair follicle and whose predominant cell type is the sebocyte. Sebocytes are epithelial cells that progressively accumulate lipids and eventually release their content (sebum) by holocrine secretion as cells disrupt. In addition to thermoregulatory and pheromonal actions, numerous additional functions have been demonstrated or postulated for sebum, including antimicrobial and antioxidant activities. The SG has also been involved in the pathogenesis of skin diseases as acne vulgaris and some forms of alopecia. Although lipid accumulation culminating in cell disruption and content release is the hallmark of sebocyte differentiation, only a surprisingly low number of studies have so far focused on sebocyte lipid droplets and their associated proteins.
Topics: Animals; Epithelial Cells; Humans; Lipid Droplets; Lipids; Sebaceous Glands; Sebum; Skin
PubMed: 26571075
DOI: 10.1016/j.yexcr.2015.11.008 -
International Journal of Cosmetic... Dec 2022A critical and often-overlooked factor that may give rise to dandruff and oily hair is the intrinsic quality of the scalp stratum corneum (SC), which is often unbalanced... (Review)
Review
OBJECTIVE
A critical and often-overlooked factor that may give rise to dandruff and oily hair is the intrinsic quality of the scalp stratum corneum (SC), which is often unbalanced and susceptible to external aggressions. Addressing the inflammation element of unhealthy scalp plays an important role in promoting healthy-looking and feeling hair. Although specialized pro-resolving lipid mediators (SPMs) have been studied in the skin to end the inflammation process and promote tissue regeneration, no studies have been provided in the scalp. This study aims to investigate SPMs expression and its role in improving scalp integrity and consequently improving hair appearance using an Anetholea anisita extract.
METHODS
The effect of Anetholea anisita extract was investigated in vitro on human follicle dermal papilla cells (HFDPC), evaluating its antioxidant and anti-inflammatory properties by fluorescence staining and ELISA, respectively. Ex vivo measurement of the volume of human scalp sebaceous glands was performed using X-ray microtomography (micro-CT). The extract was then clinically tested on a population of dandruff sufferers presenting oily hair. Volunteers' sebum was collected on the scalp and analysed by LC-MS/MS or ELISA to identify SPMs and pro-inflammatory markers. Scalp integrity was assessed by measuring the pH and the TEWL. Sebum production, dandruff and hair gloss were also evaluated.
RESULT
Anetholea anisita extract reduced IL-8 and reactive oxygen species (ROS) generation in HFDPC. Interestingly, this extract also decreased the volume of sebaceous glands as revealed by micro-CT. This result was confirmed in vivo by a decrease in sebum production in volunteers. Moreover, SPMs were analysed and detected in the scalp for the first time. An increase in Lipoxin B4 (LxB4) and Resolvin D1 and D2 (RvD1 and RvD2) was observed after Anetholea anisita treatment as well as decrease in pro-inflammatory sebum mediators expression such as PGE2, LTB4 and IL-8. Consequently, the scalp barrier was reinforced as observed through improved transepidermal water loss (TEWL) and skin surface pH, reducing dandruff and improving hair health.
CONCLUSION
The present results suggest the potential of cosmetic applications of Anetholea anisita extract to improve scalp health by targeting inflammation pathways to decrease dandruff and improve hair condition.
Topics: Humans; Dandruff; Scalp; Chromatography, Liquid; Interleukin-8; Tandem Mass Spectrometry; Dermatitis, Seborrheic; Inflammation; Inflammation Mediators; Plant Extracts
PubMed: 35979727
DOI: 10.1111/ics.12813