Fluorescent Cationic Conjugated Polymer-Based Adaptive Developing Strategy for Both Sebaceous and Blood Fingerprints.

Both latent sebaceous and blood fingerprints may provide valuable information for forensic investigation. To detect both types of fingerprints with no need to predistinguish them, a new adaptive developing strategy was proposed. A cationic conjugated polymer with poly[p-(phenylene ethylene)-alt-(thienylene ethynylene)] backbone (PPETE-NMe3+) was synthesized, which was dissolved in N,N-dimethylformamide (DMF) to form the developing solution. Fingerprints were developed by a simple dropping and incubating process without any pre-/post-treatments. Fluorescent photographs of the developed fingerprints on various substrates demonstrated that this developing strategy was effective for both types of fingerprints on nonporous substrates. Gray value analysis further confirmed the enhancement of the legibility of the fingerprint images. The preliminary mechanism exploration suggested that certain weak interactions, such as hydrophobic interaction and electrostatic interaction, may synergistically contribute to the interaction between the polymer and fingerprint components. The molecular design of the polymer combined with an appropriate solvent endowed the developing system the adaptiveness toward different types of fingerprints. This adaptive developing strategy made the fingerprint-developing process more efficient and may be further extended to more practical application scenes.

Detection of endogenous lipids in chicken feathers distinct from preen gland constituents.

Bird feather lipids are usually attributed to the oily secretion product of the uropygial (preen) gland. We have observed, however, that feathers exhibit a strong reaction with osmium tetroxide (OsO4), even after treatment with detergents. This leads us to postulate the existence of endogenous feather lipids distinct from preen gland lipids. In order to substantiate our hypothesis, we investigated down feathers from a 1-day-old chicken as their uropgygial gland is not functionally active. The results confirmed the osmiophilic reaction, which was concentrated in the center of barbs and strongly reduced after lipid extraction. In these lipid extracts, we identified using thin layer chromatography, cholesterol, various ceramides, glycolipids, phospholipids, and fatty acids, which closely resembled the lipid composition of the water barrier in the chicken-cornified epidermal envelope. This composition is clearly distinct from chicken uropygeal gland secretion (UGS) known to consist of fatty alcohols as part of aliphatic monoester waxes and of free, predominantly saturated, fatty acids. A filter assay showed a strong reactivity between OsO4 and the fatty acids C18:1 and C18:2 and with feather lipid extracts, but not with UGS. These observations were confirmed by gas chromatography detecting unsaturated fatty acids including C18:1 and C18:2 as well as cholesterol exclusively in chicken feathers. Our results indicate that (1) endogenous lipids are detectable in chicken feathers and distinct from UGS and (2) in analogy to the morphogenesis of the cornified envelope of chicken feather lipids that may have derived from cellular feather-precursors, apparently enduring the specific cell death during developmental feather cornification.

The Latoia consocia Caterpillar Induces Pain by Targeting Nociceptive Ion Channel TRPV1.

Accidental contact with caterpillar bristles causes local symptoms such as severe pain, intense heat, edema, erythema, and pruritus. However, there is little functional evidence to indicate a potential mechanism. In this study, we analyzed the biological characteristics of the crude venom from the larval stage of Latoia consocia living in South-West China. Intraplantar injection of the venom into the hind paws of mice induced severe acute pain behaviors in wild type (WT) mice; the responses were much reduced in TRPV1-deficit (TRPV1 KO) mice. The TRPV1-specific inhibitor, capsazepine, significantly attenuated the pain behaviors. Furthermore, the crude venom evoked strong calcium signals in the dorsal root ganglion (DRG) neurons of WT mice but not those of TRPV1 KO mice. Among the pain-related ion channels we tested, the crude venom only activated the TRPV1 channel. To better understand the venom components, we analyzed the transcriptome of the L. consocia sebaceous gland region. Our study suggests that TRPV1 serves as a primary nociceptor in caterpillar-induced pain and forms the foundation for elucidating the pain-producing mechanism.

Global Monitoring of Persistent Organic Pollutants (POPs) Using Seabird Preen Gland Oil.

Situated at high positions on marine food webs, seabirds accumulate high concentrations of persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), and hexachlorocyclohexanes (HCHs). Our previous studies proposed the usefulness of seabirds preen gland oil as a nondestructive biomonitoring tool. The present study applied this approach to 154 adult birds of 24 species collected from 11 locations during 2005-2016 to demonstrate the utility of preen gland oil as a tool for global monitoring POPs, i.e., PCBs, DDTs, and HCHs. Concentrations of the POPs were higher in the Northern Hemisphere than in the Southern Hemisphere. In particular, ∑20PCBs and∑DDTs were highly concentrated in European shags (Phalacrocorax aristotelis) and Japanese cormorants (Phalacrocorax capillatus), explainable by a diet of benthic fishes. Higher concentrations of γ-HCH were detected in species from the polar regions, possibly reflecting the recent exposure and global distillation of ∑HCHs. We examined the relationship between age and POP concentrations in preen gland oil from 20 male European shags, aged 3-16 years old. Concentrations and compositions of POPs were not related to age. We also examined sex differences in the POP concentrations from 24 streaked shearwaters (Calonectris leucomelas) and did not detect a sex bias. These results underline the importance of the geographic concentration patterns and the dietary behavior as determinants species-specific POPs concentrations in preen gland oil.

Is Human Sebum the Source of Skin Follicular Ultraviolet-Induced Red Fluorescence? A Cellular to Histological Study.

BACKGROUND: The ultraviolet-induced red fluorescence (UVRF) from human skin follicles was suggested to be a result of Propionibacterium acnes and was used for the monitoring of acne. More recent studies suggested that the UVRF may be more related to sebum rather than to microorganisms. OBJECTIVE: To clarify whether human sebum or follicular microorganisms are the source of UVRF. METHODS: We examined the fluorescence of human-derived SZ95 sebocytes, human sebaceous glands, sebum extracted from the sebaceous glands, and bacteria isolated from human hair follicles under ultraviolet light. RESULTS: SZ95 sebocytes, human sebaceous glands, and sebum do not emit UVRF. Two types of UVRF peaking at about 635 nm and at about 620 nm were detected in P. acnes and Staphylococcus epidermidis, respectively. This is the first report that S. epidermidis emits UVRF when it is anaerobically cultured and then exposed to air. CONCLUSION: Human follicular UVRF is emitted by resident bacteria, not by sebum. Therefore, UVRF may be used to monitor certain species of skin microorganisms.

Sebaceous lipids are essential for water repulsion, protection against UVB-induced apoptosis and ocular integrity in mice.

Sebocytes, which are characterized by lipid accumulation that leads to cell disruption, can be found in hair follicle-associated sebaceous glands (SGs) or in free SGs such as the Meibomian glands in the eyelids. Because genetic tools that allow targeting of sebocytes while maintaining intact epidermal lipids are lacking, the relevance of sebaceous lipids in health and disease remains poorly understood. Using Scd3, which is expressed exclusively in mature sebocytes, we established a mouse line with sebocyte-specific expression of Cre recombinase. Both RT-PCR analysis and crossing into Rosa26-lacZ reporter mice and Kras(G12D) mice confirmed Cre activity specifically in SGs, with no activity in other skin compartments. Importantly, loss of SCD3 function did not cause detectable phenotypical alterations, endorsing the usefulness of Scd3-Cre mice for further functional studies. Scd3-Cre-induced, diphtheria chain A toxin-mediated depletion of sebaceous lipids resulted in impaired water repulsion and thermoregulation, increased rates of UVB-induced epidermal apoptosis and caused a severe pathology of the ocular surface resembling Meibomian gland dysfunction. This novel mouse line will be useful for further investigating the roles of sebaceous lipids in skin and eye integrity.

Ghrelin in the pilosebaceous unit: alteration of ghrelin in patients with acne vulgaris.

BACKGROUND: Ghrelin in the pilosebaceous tissues of human skin and ghrelin levels in patients with acne vulgaris have not yet been investigated. OBJECTIVE: The purpose of this study was to screen ghrelin immunoreactivity by immunohistochemistry in human pilosebaceous tissues of human skin and also to determine the quantities of ghrelin in the serum of the patients with acne vulgaris. METHODS: 30 patients presenting with acne vulgaris and 30 control subjects participated in this study. Ghrelin levels were determined by enzyme linked immunosorbent assay (ELISA). Human hair follicles and sebaceous glands were immunohistochemically examined. RESULTS: Immunohistochemistry results showed that there is a strong ghrelin immunoreactivity in the hair follicles and sebaceous glands in sections of human skin. The mean serum ghrelin levels (27.58 ・} 15.44 pg/mL) in patients with acne vulgaris was significantly lower than those of controls (35.62・}20.46 pg/mL). CONCLUSIONS: Ghrelin produced in hair follicles and sebaceous glands of the skin might participate in the pathogenesis of acne vulgaris and also acne vulgaris in humans might be associated with decreased serum ghrelin.

Aryl Hydrocarbon Receptor Activation in Acne Vulgaris Skin: A Case Series from the Region of Naples, Italy.

BACKGROUND: Dioxins are persistent organic pollutants present in the environment. They exert their biological effects by binding to an intracellular receptor, the aryl hydrocarbon receptor (AhR). Activation of AhR leads to the induction of cytochrome p450 1A1 (CYP1A1). Expression of CYP1A1 in human skin is a key marker for AhR activation, and it may induce comedogenesis resulting in acne-like lesions known as chloracne/metabolising acquired dioxin-induced skin hamartomas (MADISH). The contribution of this pathway in patients seen in a busy acne clinic is unknown. MATERIALS AND METHODS: We explored the expression of CYP1A1 by immunohistochemistry in the acne lesions of 16 patients living in the region of Naples, Italy, where epidemiological studies have suggested a possibly increased exposure to environmental dioxins. A composite score to outline potential components of the chloracne/MADISH histological pattern was used. RESULTS: CYP1A1 expression was observed in 11 lesions (69%) and was distributed in sebaceous glands, follicular epithelium, cystic wall and endothelial cells. The histological score for chloracne/MADISH was 'likely' in 3 cases and 'possible' in 11 cases. Compared to current data on CYP1A1 expression in the skin of 67 patients with proven exposure to AhR agonists, these data indicate a high incidence of AhR activation in this series. CONCLUSION: This is the first study analysing AhR activation in skin in a series of patients from a hospital-based acne clinic. It provides information for future controlled prospective studies. The significance of CYP1A1 expression in terms of AhR ligand exposure is discussed.

Neuro-folliculo-sebaceous cystic hamartoma is a unique entity.

Folliculosebaceous cystic hamartoma (FSCH) is a distinct type of cutaneous hamartoma of pilosebaceous origin that usually occurs on the face. For FSCH, other parts have been reported such as the genital area, and the trunk. A 50-year-old woman presented with an asymptomatic dome-shaped scalp nodule. The clinical diagnosis was pilar cyst or tumor. Histopathological assessment showed FSCH with absolute neural component as the only mesenchymal stroma, leading to the diagnosis of folliculosebaceous cystic neural hamartoma. To the best of our knowledge, absolute neural stroma in FSCH has not been reported previously in the literature.

Age-associated skin changes in innate immunity markers reflect a complex interaction between aging mechanisms in the sebaceous gland.

Skin aging is the most apparent form of senescence and could reflect the aging of inner organs. Molecular changes involved in innate immunity signaling, tumorigenesis, and inflammation were studied. Protein levels were evaluated based on the immunohistochemistry of the skin of 42 young and old individuals. The investigated molecules (peroxisome proliferator-activated receptors-α and -γ, Toll-like receptor 4, and interleukin-6 and 8) were expressed in almost all skin compartments and exhibited significant aging-associated downregulation in epithelial tissues, mostly in the sebaceous glands, the sweat glands, and the epidermis. With the exception of interleukin-6 in the dermal tissue, no upregulation was detected in the aged group. The results obtained indicate an interesting interaction between different pathways of aging, namely defective stress responses, downregulated innate immunity responses, and activation of the tumorigenesis pathway, which was especially apparent in the sebaceous glands.

Preferential expression of OVOL1 in inner root sheath of hair, sebaceous gland, eccrine duct and their neoplasms in human skin.

OVOL1 is an important transcription factor for epidermal keratinization, which suppresses proliferation and switches on the differentiation of keratinocytes. A recent genome-wide association study has revealed that OVOL1 is one of the genes associated with susceptibility to atopic dermatitis. Although it is known to be expressed in murine skin and hair follicles, no investigations have focused on its localization in human skin. In the present study, we thus immunolocalized the expression of OVOL1 in normal and diseased human skin. In normal human skin, OVOL1 was preferentially expressed in the suprabasal layer of the epidermis, inner root sheath of hair, mature sebocytes and the ductal portion of the eccrine glands. Compared to this, no remarkable change in the expression of OVOL1 was observed among inflammatory skin diseases. The expression of OVOL1 was evident in eccrine poroma and hidradenoma. Moreover, it was overexpressed in Bowen's disease and sebaceous adenoma, in sharp contrast to its downregulation in their more malignant counterparts, squamous cell carcinoma and sebaceous carcinoma. OVOL1 may play an important role in human skin morphogenesis and tumorigenesis.

Toker cells of the nipple are commonly associated with underlying sebaceous glands but not with lactiferous ducts.

AIMS: Toker cells are clear cells present in the squamous epithelium of the nipple of some women. In contrast to squamous epithelium, they are cytokeratin 7 (CK7) positive. The origin of these cells is not completely understood. It has been suggested that they may represent abortive glands or migratory ductal cells; and may be precursors of Paget's disease of the nipple. Our aim was to investigate the incidence and distribution of Toker cells and their relationship with lactiferous ducts. METHODS: We examined nipple sections from 100 consecutive mastectomies performed at Charing Cross hospital. New sections were stained for CK7 using the immunoperoxidase technique. RESULTS: Toker cells were identified in 11 cases. They were always clustered within the squamous epithelium superficial to sebaceous glands with no relationship with lactiferous ducts. Two cases in the study had Paget's disease and these were not associated with underlying sebaceous glands. CONCLUSIONS: This study suggests that Toker cells are more likely to be developmentally related to sebaceous glands rather than lactiferous ducts. This raises doubts about the presence of a relationship between Toker cells and the common forms of Paget's disease, as the latter are commonly seen in association with ductal carcinoma in situ (DCIS) involving underlying lactiferous ducts. Toker cells, however, may be related to a less common form of Paget's disease which is not associated with underlying DCIS.

Markers of epidermal stem cell subpopulations in adult mammalian skin.

The epidermis is the outermost layer of mammalian skin and comprises a multilayered epithelium, the interfollicular epidermis, with associated hair follicles, sebaceous glands, and eccrine sweat glands. As in other epithelia, adult stem cells within the epidermis maintain tissue homeostasis and contribute to repair of tissue damage. The bulge of hair follicles, where DNA-label-retaining cells reside, was traditionally regarded as the sole epidermal stem cell compartment. However, in recent years multiple stem cell populations have been identified. In this review, we discuss the different stem cell compartments of adult murine and human epidermis, the markers that they express, and the assays that are used to characterize epidermal stem cell properties.

Expression of caspase-14 and keratin-19 in the human epidermis and appendages during fetal skin development.

Caspase-14 is a seemingly non-apoptotic caspase involved in keratinocyte differentiation and cornification of the skin. Keratin-19 is an epithelial marker and a potential marker of epidermal stem cells that is expressed during human fetal skin development. We examined the immunohistochemical expression of caspase-14 in relation to CK-19 in the human fetal skin during development and perinatally, to assess their role in human skin maturation. Skin samples were received at autopsy. In the fetal epidermis, caspase-14 was predominantly expressed in the more differentiated layers, gradually disappearing from the basal layer toward term. By contrast, keratin-19 expression gradually decreased with epidermal maturation through gestation (rho = -0.949; p = 0.0001) and was a marker of the germinative layers. Keratin-19 was preserved in scarce basal cell nests at term and postnatally. Caspase-14 and keratin-19 were inversely expressed in the differentiating epidermal layers through gestation (p < 0.0001). Concerning the appendages, in hair follicles and sebaceous glands, caspase-14 located preferentially in the more differentiated layers of the inner root sheath, whereas keratin-19 was expressed in the outer sheath. Eccrine sweat glands showed a variable pattern of caspase-14 and keratin-19 expression. In conclusion, caspase-14 emerged as a marker of human skin differentiation during development, while keratin-19 marked the germinative epithelial layers in the fetal epidermis and appendages and possibly the nests of epidermal stem cells.

Microbiological and biochemical origins of human axillary odour.

The generation of malodour on various sites of the human body is caused by the microbial biotransformation of odourless natural secretions into volatile odorous molecules. On the skin surface, distinctive odours emanate, in particular, from the underarm (axilla), where a large and permanent population of microorganisms thrives on secretions from the eccrine, apocrine and sebaceous glands. Traditional culture-based microbiological studies inform us that this resident microbiota consists mainly of Gram-positive bacteria of the genera Staphylococcus, Micrococcus, Corynebacterium and Propionibacterium. Among the molecular classes that have been implicated in axillary malodour are short- and medium-chain volatile fatty acids, 16-androstene steroids and, most recently, thioalcohols. Most of the available evidence suggests that members of the Corynebacterium genus are the primary causal agents of axillary odour, with the key malodour substrates believed to originate from the apocrine gland. In this article, we examine, in detail, the microbiology and biochemistry of malodour formation on axillary skin, focussing on precursor-product relationships, odour-forming enzymes and metabolic pathways and causal organisms. As well as reviewing the literature, some relevant new data are presented and considered alongside that already available in the public domain to reach an informed view on the current state-of-the-art, as well as future perspectives.