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BioRxiv : the Preprint Server For... Apr 2023The host-microbiota relationship has evolved to shape mammalian processes, including immunity, metabolism, and development . Host phenotypes change in direct response...
The host-microbiota relationship has evolved to shape mammalian processes, including immunity, metabolism, and development . Host phenotypes change in direct response to microbial exposures by the individual. Here we show that the microbiota induces phenotypic change not only in the individual but also in their succeeding generations of progeny. We found that germ-free mice exhibit a robust sebum secretion defect and transcriptional changes in various organs, persisting across multiple generations despite microbial colonization and breeding with conventional mice. Host-microbe interactions could be involved in this process, since T cell-deficient mice, which display defective sebum secretion , also transgenerationally transmit their phenotype to progeny. These phenotypes are inherited by progeny conceived during fertilization using germ-free sperm and eggs, demonstrating that epigenetic information in the gametes is required for phenotypic transmission. Accordingly, small non-coding RNAs that can regulate embryonic gene expression were strikingly and similarly altered in gametes of germ-free and T cell-deficient mice. Thus, we have uncovered a novel mechanism whereby the microbiota and immune system induce phenotypic changes in successive generations of offspring. This epigenetic form of inheritance could be advantageous for host adaptation to environmental perturbation, where phenotypic diversity can be introduced more rapidly than by genetic mutation.
PubMed: 37066207
DOI: 10.1101/2023.04.06.535940 -
Cureus Sep 2021A variety of skin measurements are routinely made in various clinical and research settings to evaluate the skin's biophysical properties for diagnostic and research... (Review)
Review
A variety of skin measurements are routinely made in various clinical and research settings to evaluate the skin's biophysical properties for diagnostic and research purposes. Such measurements include transepidermal water loss (TEWL), skin pH, sebum, skin blood flow (SBF), and tissue dielectric constant (TDC) as a measure of skin water. Given the various reported circadian, diurnal, and possible ultradian and other temporal variations in skin physiological processes, it is of value to have clarity as to possible temporal variations in skin's biophysical properties associated with such processes. It was thus the purpose of this investigation to review and detail key elements of what is currently known regarding such variations and to provide a characterization that will permit informed judgments as to the sensitivity of the timing of measurements to optimize measurement reproducibility. Understanding these variations and their possible oscillatory effects on skin biophysical properties may aid physicians in providing optimal treatment timing for dermatological conditions and offer researchers insight into optimal measurement timing. The major findings of the present investigation that systematically searched multiple databases and critically examined pertinent findings, revealed that of the several skin parameters reviewed, which included TEWL, pH, sebum, SBF, TDC, and thickness, each had at least one study describing a statistically significant within-a-day temporal change. The magnitude of these changes varied and may be large enough to be seriously considered when assessing these parameters in clinical and research settings. However, inconsistencies in reported temporal variations suggest that further systematic research is well warranted especially with respect to temporal within-a-day and day-to-day variabilities of TEWL, TDC, and mechanical properties. At present, the impact of this type of confounding variability on reported values for skin biophysical parameters is unclear and worthy of further clarification.
PubMed: 34650847
DOI: 10.7759/cureus.17665 -
PeerJ 2023Diseases vary among and within species but the causes of this variation can be unclear. Immune responses are an important driver of disease variation, but mechanisms on... (Review)
Review
Diseases vary among and within species but the causes of this variation can be unclear. Immune responses are an important driver of disease variation, but mechanisms on how the body resists pathogen establishment before activation of immune responses are understudied. Skin surfaces of mammals are the first line of defense against abiotic stressors and pathogens, and skin attributes such as pH, microbiomes, and lipids influence disease outcomes. Sebaceous glands produce sebum composed of multiple types of lipids with species-specific compositions. Sebum affects skin barrier function by contributing to minimizing water loss, supporting thermoregulation, protecting against pathogens, and preventing UV-induced damage. Sebum also affects skin microbiome composition both via its antimicrobial properties, and by providing potential nutrient sources. Intra- and interspecific variation in sebum composition influences skin disease outcomes in humans and domestic mammal species but is not well-characterized in wildlife. We synthesized knowledge on sebum function in mammals in relation to skin diseases and the skin microbiome. We found that sebum composition was described for only 29 live, wild mammalian species. Sebum is important in dermatophilosis, various forms of dermatitis, demodicosis, and potentially white-nose syndrome. Sebum composition likely affects disease susceptibility, as lipid components can have antimicrobial functions against specific pathogens. It is unclear why sebum composition is species-specific, but both phylogeny and environmental effects may drive differences. Our review illustrates the role of mammal sebum function and influence on skin microbes in the context of skin diseases, providing a baseline for future studies to elucidate mechanisms of disease resistance beyond immune responses.
Topics: Humans; Animals; Sebum; Skin Diseases; Mammals; Lipids; Microbiota; Anti-Infective Agents
PubMed: 38144187
DOI: 10.7717/peerj.16680 -
Indian Journal of Dermatology,... 2013Underlying hormone imbalances may render acne unresponsive to conventional therapy. Relevant investigations followed by initiation of hormonal therapy in combination... (Review)
Review
Underlying hormone imbalances may render acne unresponsive to conventional therapy. Relevant investigations followed by initiation of hormonal therapy in combination with regular anti-acne therapy may be necessary if signs of hyperandrogenism are present. In addition to other factors, androgen-stimulated sebum production plays an important role in the pathophysiology of acne in women. Sebum production is also regulated by other hormones, including estrogens, growth hormone, insulin, insulin-like growth factor-1, glucocorticoids, adrenocorticotropic hormone, and melanocortins. Hormonal therapy may also be beneficial in female acne patients with normal serum androgen levels. An understanding of the sebaceous gland and the hormonal influences in the pathogenesis of acne would be essential for optimizing hormonal therapy. Sebocytes form the sebaceous gland. Human sebocytes express a multitude of receptors, including receptors for peptide hormones, neurotransmitters and the receptors for steroid and thyroid hormones. Various hormones and mediators acting through the sebocyte receptors play a role in the orchestration of pathogenetic lesions of acne. Thus, the goal of hormonal treatment is a reduction in sebum production. This review shall focus on hormonal influences in the elicitation of acne via the sebocyte receptors, pathways of cutaneous androgen metabolism, various clinical scenarios and syndromes associated with acne, and the available therapeutic armamentarium of hormones and drugs having hormone-like actions in the treatment of acne.
Topics: Acne Vulgaris; Hormones; Humans; Hyperandrogenism; Hypoglycemic Agents; Metformin; Sebaceous Glands
PubMed: 23619437
DOI: 10.4103/0378-6323.110765 -
Turkish Journal of Medical Sciences Jun 2020Atopic dermatitis (AD) is a chronic, inflammatory skin disorder characterized by dry skin, pruritus and eczematous lesions. The aim of this study is to evaluate the skin...
BACKGROUND/AIM
Atopic dermatitis (AD) is a chronic, inflammatory skin disorder characterized by dry skin, pruritus and eczematous lesions. The aim of this study is to evaluate the skin moisture and sebum content of the infants with AD and its relationship between the disease severity.
MATERIALS AND METHODS
For this cross-sectional and case-control study we included 49 infants with AD aged between 2 and 24 months and 34 healthy infants with the same age and sex as a control group. Skin moisture and sebum content were measured by the bio- impedance method and recorded. Skin prick tests, total IgE levels and food-specific (milk, egg) IgE levels were performed.
RESULTS
There was a significant difference between the groups in terms of mean skin moisture and sebum content percentage (P < 0.001, both). The mean skin moisture and sebum content were correlated with CRP in patients with AD (P < 0.01, r = –1.00, both), but we did not find any correlation between these parameters with the disease severity.
CONCLUSION
We found that skin moisture and sebum content were low even in unaffected areas in AD. The skin structure of these patients may contribute to the pathogenesis of the disease.
Topics: C-Reactive Protein; Case-Control Studies; Dermatitis, Atopic; Female; Food Hypersensitivity; Humans; Immunoglobulin E; Infant; Male; Sebum; Severity of Illness Index; Skin Tests
PubMed: 32283889
DOI: 10.3906/sag-1912-56 -
Biomedical Optics Express Jun 2016We report a method on quantitative and simultaneous non-contact in-vivo hydration and sebum measurements of the skin using an infrared optical spectroscopic set-up. The...
We report a method on quantitative and simultaneous non-contact in-vivo hydration and sebum measurements of the skin using an infrared optical spectroscopic set-up. The method utilizes differential detection with three wavelengths 1720, 1750, and 1770 nm, corresponding to the lipid vibrational bands that lay "in between" the prominent water absorption bands. We have used an emulsifier containing hydro- and lipophilic components to mix water and sebum in various volume fractions which was applied to the skin to mimic different oily-dry skin conditions. We also measured the skin sebum and hydration values on the forehead under natural conditions and its variations to external stimuli. Good agreement was found between our experimental results and reference values measured using conventional biophysical methods such as Corneometer and Sebumeter.
PubMed: 27375946
DOI: 10.1364/BOE.7.002311 -
Experimental Dermatology Dec 2011Scalp pruritus is a common complaint that is considered a diagnostically and therapeutically challenging situation. Scalp skin has a unique neural structure that... (Review)
Review
Scalp pruritus is a common complaint that is considered a diagnostically and therapeutically challenging situation. Scalp skin has a unique neural structure that contains densely innervated hair follicles and dermal vasculature. In spite of the recent advances in our understanding of itch pathophysiology, scalp itching has not been studied as yet. In this review, we summarize the current knowledge on the neurobiology of scalp and hair follicles as well as itch mediators and provide a putative mechanism for scalp itch with special emphasis on neuroanatomy and pathophysiology.
Topics: Animals; Humans; Pruritus; Scalp; Sebum
PubMed: 22092575
DOI: 10.1111/j.1600-0625.2011.01389.x -
The Journal of Clinical and Aesthetic... Aug 2017One of the most common dermatologic concerns is oily skin, and the demand for effective treatment options is ever apparent. This review article addresses numerous... (Review)
Review
One of the most common dermatologic concerns is oily skin, and the demand for effective treatment options is ever apparent. This review article addresses numerous topical treatment options such as retinoids, olumacostat glasaretil, and various cosmeceutical agents. several systemic and procedural techniques that incorporate isotretinoin, spironolactone, oral contraceptives, botulinum toxin, photodynamic therapy, and lasers are reviewed as well. Each treatment option is analyzed in terms of the proposed mechanism of action, efficacy reported in the literature, and potential adverse effects.
PubMed: 28979664
DOI: No ID Found -
Acta Dermato-venereologica Feb 2023Dandruff is a common scalp disorder with multiple microbial and host-related factors contributing to its aetiology, including alterations in scalp sebum. Despite...
Dandruff is a common scalp disorder with multiple microbial and host-related factors contributing to its aetiology, including alterations in scalp sebum. Despite existing evidence that the yeast Malassezia restricta plays a key role in the onset of dandruff, the interplay of these factors is poorly understood. Recently, squalene monohydroperoxide and malondialdehyde were established as biomarkers of dandruff-afflicted scalp, highlighting the role of sebum lipoperoxidation in the triggering and maintenance of dandruff, although its mechanism of action is unknown. The current study provides evidence that M. restricta mediates sebum peroxidation, leading to production of squalene monohydroperoxide and malondialdehyde. Furthermore, in vitro data show that these lipoperoxidation products act on epidermal cells and alter the skin barrier. These results support the role of Malassezia restricta-induced lipoperoxides as triggers of dandruff, which suggests that blocking their production could be a novel anti-dandruff treatment approach.
Topics: Humans; Dandruff; Malassezia; Malondialdehyde
PubMed: 36789756
DOI: 10.2340/actadv.v103.4808 -
Molecules (Basel, Switzerland) Feb 2022Oily skin from overactive sebaceous glands affects self-confidence and personality. There is report of an association between steroid 5-alpha reductase gene ()...
Oily skin from overactive sebaceous glands affects self-confidence and personality. There is report of an association between steroid 5-alpha reductase gene () expression and facial sebum production. There is no study of the effect of Willd. root extract on the regulation of mRNA expression and anti-sebum efficacy. This study extracted using the supercritical carbon dioxide fluid technique with ethanol and investigated its biological compounds and activities. The root extract had a high content of polyphenolic compounds, including quercetin, naringenin, and -coumaric acid, and DPPH scavenging activity comparable to that of the standard L-ascorbic acid. root extract showed not only a significant reduction in and mRNA expression by about 45.45% and 90.86%, respectively, but also a reduction in the in vivo anti-sebum efficacy in male volunteers, with significantly superior percentage changes in facial sebum production and a reduction in the percentages of pore area after 15 and 30 days of treatment. It can be concluded that root extract with a high content of polyphenol compounds, great antioxidant effects, promising downregulation of and , and predominant facial sebum reduction and pore-minimizing efficacy could be a candidate for an anti-sebum and pore-minimizing active ingredient to serve in functional cosmetic applications.
Topics: 3-Oxo-5-alpha-Steroid 4-Dehydrogenase; Asparagus Plant; Carbon Dioxide; Humans; Male; Membrane Proteins; Plant Extracts; RNA, Messenger; Sebum
PubMed: 35268636
DOI: 10.3390/molecules27051535