Blimp1+ cells generate functional mouse sebaceous gland organoids in vitro.

Most studies on the skin focus primarily on the hair follicle and interfollicular epidermis, whereas little is known regarding the homeostasis of the sebaceous gland (SG). The SG has been proposed to be replenished by different pools of hair follicle stem cells and cells that resides in the SG base, marked by Blimp1. Here, we demonstrate that single Blimp1+ cells isolated from mice have the potential to generate SG organoids in vitro. Mimicking SG homeostasis, the outer layer of these organoids is composed of proliferating cells that migrate inward, undergo terminal differentiation and generating lipid-filled sebocytes. Performing confocal microscopy and mass-spectrometry, we report that these organoids exhibit known markers and a lipidomic profile similar to SGs in vivo. Furthermore, we identify a role for c-Myc in sebocyte proliferation and differentiation, and determine that SG organoids can serve as a platform for studying initial stages of acne vulgaris, making this a useful platform to identify potential therapeutic targets.

Morphological description of smell glands in Cyclopes didactylus.

A macroscopic and microscopic study of the mandibular organ of the silky anteater (Cyclopes didactylus) was carried out. The organ extends from below the zygomatic bone line to the middle of the mandible body, between the skin and the masseter muscle, on both sides of the animal. It has an average length of 11.7 mm and a width of 6.3 mm. In the mesoscopic analysis, it was observed that the organ presents in yellowish color due to the high amount of sebaceous content. In the histological analysis, the mandibular organ was observed to be composed of innumerable alveoli of the specialized sebaceous gland, surrounded by a layer of adventitia tunica. Scanning electron microscopy (SEM), revealed an apparent alveolar division with what appeared to be a sulcus at its center. The information here presented regarding the constitution and location of this structure has not been previously explored for other species and differs with respect to other descriptions for anteaters. Based on the present study, it is suggested that the mandibular organ is involved in social interaction in this species.

Effects of Extracellular Calcium and 1,25 dihydroxyvitamin D3 on Sebaceous Gland Cells In vitro and In vivo.

Calcium and 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) are promoters of epithelial cell functions; however their effects on sebaceous glands are unknown. In this study, morphology, ultrastructure, cell numbers, lipid synthesis and apoptosis of SZ95 sebocytes were assessed in vitro under different concentrations of extracellular calcium with or without 1,25(OH)2D3. Moreover, serum calcium and 1,25(OH)2D3 levels were assessed in acne and non-acne patients (controls). Under conditions of low extracellular calcium, lipogenesis and cell detachment were observed. Increasing extracellular calcium enhanced sebocyte numbers, induced epithelial morphology and reduced lipogenesis. Moreover, a reduction in extracellular calcium reduced E-cadherin and enhanced caspase 3/7 activity (apoptosis), whereas calcium chelation by EGTA (ethylene glycol-bis(ß-aminoethyl ether)-N,N,N',N'-tetraacetic acid) resulted in enhanced lipogenesis. 1,25(OH)2D3 decreased sebaceous lipogenesis, but also induced signs of autophagy. In the clinical study, patients and controls exhibited normal serum calcium levels. Younger acne patients presented lower 1,25(OH)2D3 levels than did older ones. In conclusion, extracellular calcium and 1,25(OH)2D3 regulate sebocyte morphology, increase cell numbers, decrease sebaceous lipogenesis and induce cell autophagy in vitro. The increased ionized calcium and the reduced 1,25(OH)2D3 levels detected in the serum of younger patients with acne may contribute respectively to increased sebaceous gland volume and enhanced lipogenesis.

Immunohistochemical localization of fatty acid transporters and MCT1 in the sebaceous glands of mouse skin.

The sebaceous glands secrete sebum to protect the epidermis and hairs by the oily products. The glands express several transporters and binding proteins for the production of fatty acids and uptake of their sources. The present immunohistochemical study examined the expression and localization of CD36, MCT1, FATP4, and E-FABP in the sebaceous glands, including the meibomian and preputial glands of mice. CD36 and MCT1 in sebaceous glands were largely co-localized along the plasma membrane of secretory cells, while they were separately expressed in the glandular portion of meibomian and preputial glands. Immunoreactivities for FATP4 and E-FABP appeared diffusely in the cytoplasm of secretory cells. Genetic deletion of CD36 did not affect the immunolocalization of the three other molecules. The sebaceous glands were judged to be useful for analyzing the functions and relation of fatty acid transporters and binding proteins.

Urothelial Carcinoma with shadow cell, lipid cell and sebaceous (skin adnexal) differentiation: Clinicopathological and immunohistochemical study of 10 cases.

We discuss the histological and immunohistochemical features of 6 cases of urothelial carcinomas of lipid cell variant and 4 cases with shadow cell differentiation, one of which showed additionally sebaceous differentiation, one of which shows additional sebaceous differentiation, from our archive cases from the last 15 years. Conventional urothelial carcinoma (UC) was seen in all lipid cell variant cases, and micropapillary carcinoma was seen in 3. The ratio of the lipid cell component was between 10% and 40% in these 6 cases. Typical histologic features of the lipid cell variant include lipoblast-like cells with a notched nuclear appearance, abundant vacuoles, an eccentric nucleus, and pagetoid spread in some areas. GATA3 and pancytokeratin AE1/AE3 immunohistochemical staining were positive in all cases. Adipophilin was positive in various degrees in 5 of the 6 lipid cell variant cases but was also positive in the case with sebaceous differentiation. α-methylacyl-CoA racemase was positive in the lipid cell areas and negative or focal weakly positive in the conventional UC areas in 4 of the 6 cases. Vimentin, S-100 protein, and PAX8 were negative in the lipid cell component. Follow-up information was available for all cases with follow-up ranging from 6 to 84 months (mean, 34 months). Four patients died of the disease. One pT4 patient who had been followed up for 6 months lives with the disease, whereas another is disease free. In conclusion, the lipid cell variant is a rare UC variant that usually presents at an advanced stage, and tumor cells are histologically similar to lipoblasts, resemble sebaceous differentiation, and show positive immunohistochemical staining with adipophilin.

Study regarding the microscopic aspects of pilo-sebaceous units after antiandrogen treatment in hirsute women.

AIM: To analyze the morphological data of pilo-sebaceous units in hirsute women before and 12 months after the antiandrogen treatment with Cyproterone acetate (CPA) 100 mg÷day. MATERIALS AND METHODS: Fourteen female patients with idiopathic hirsutism that followed an antiandrogen treatment with CPA were biopsied from the androgen-dependent area of the chin before and 12 months after the treatment. Routine sections were stained with Hematoxylin-Eosin, Masson, Van Gieson, Sirius red and picric-indigocarmine, while additional sections were immunostained for S100 protein and vimentin. Electron microscopy was performed in two cases with Langerhans cell hyperplasia. RESULTS: On biopsies-stained sections, an increased number of hair follicles, the deeper part of the epithelial sheath of the hair follicle with epithelial buds, hyperplasia of sebaceous glands, and no inflammatory infiltrate were noticed. Langerhans cells identified with S100 protein and vimentin were normal in terms of numbers and distribution. After the administration of the treatment, atrophy of the pilo-sebaceous units was visible in nine (64.2%) cases, while inflammatory infiltrate and cells included in the vacuoles of the basal layer of the epidermis became apparent. In six of the cases treated with antiandrogens, a marked hyperplasia of Langerhans cells was noticed. In conclusion, the benefit of antiandrogen treatments is supported by atrophy of the hair follicle and the sebaceous glands. The activation of Langerhans cells associated with inflammatory infiltrate in the dermis and hair follicles could be considered as a local consequence of the involution process of hair follicles after the administration of the treatment.

Sebaceous gland, hair shaft, and epidermal barrier abnormalities in keratosis pilaris with and without filaggrin deficiency.

Although keratosis pilaris (KP) is common, its etiopathogenesis remains unknown. KP is associated clinically with ichthyosis vulgaris and atopic dermatitis and molecular genetically with filaggrin-null mutations. In 20 KP patients and 20 matched controls, we assessed the filaggrin and claudin 1 genotypes, the phenotypes by dermatoscopy, and the morphology by light and transmission electron microscopy. Thirty-five percent of KP patients displayed filaggrin mutations, demonstrating that filaggrin mutations only partially account for the KP phenotype. Major histologic and dermatoscopic findings of KP were hyperkeratosis, hypergranulosis, mild T helper cell type 1-dominant lymphocytic inflammation, plugging of follicular orifices, striking absence of sebaceous glands, and hair shaft abnormalities in KP lesions but not in unaffected skin sites. Changes in barrier function and abnormal paracellular permeability were found in both interfollicular and follicular stratum corneum of lesional KP, which correlated ultrastructurally with impaired extracellular lamellar bilayer maturation and organization. All these features were independent of filaggrin genotype. Moreover, ultrastructure of corneodesmosomes and tight junctions appeared normal, immunohistochemistry for claudin 1 showed no reduction in protein amounts, and molecular analysis of claudin 1 was unremarkable. Our findings suggest that absence of sebaceous glands is an early step in KP pathogenesis, resulting in downstream hair shaft and epithelial barrier abnormalities.

Longitudinal, 3D in vivo imaging of sebaceous glands by coherent anti-stokes Raman scattering microscopy: normal function and response to cryotherapy.

Sebaceous glands perform complex functions, and they are centrally involved in the pathogenesis of acne vulgaris. Current techniques for studying sebaceous glands are mostly static in nature, whereas the gland's main function-excretion of sebum via the holocrine mechanism-can only be evaluated over time. We present a longitudinal, real-time alternative-the in vivo, label-free imaging of sebaceous glands using Coherent Anti-Stokes Raman Scattering (CARS) microscopy, which is used to selectively visualize lipids. In mouse ears, CARS microscopy revealed dynamic changes in sebaceous glands during the holocrine secretion process, as well as in response to damage to the glands caused by cooling. Detailed gland structure, plus the active migration of individual sebocytes and cohorts of sebocytes, were measured. Cooling produced characteristic changes in sebocyte structure and migration. This study demonstrates that CARS microscopy is a promising tool for studying the sebaceous gland and its associated disorders in three dimensions in vivo.

[Cellular dynamics of the outer layers of the hair follicle of fine-wool sheep during the phase of stable hair growth].

The structure, origin, and migration of outer sheath cells of the hair follicles of domestic sheep were studied by electron microscopic, autoradiographic, and histochemical (glycogen) in order to understand the role of this layer in hair morphogenesis. We demonstrated that the cells of the outer layers of the outer sheath interpose into the inner "companion" layer of the outer sheath. Although this process takes place all along the hair follicle from the lower bulb up to the sebaceous glands orifices, it mainly takes place over the bulb. Labeled cells interposed into the companion layer move towards sebaceous glands orifices more than 24 hours faster than labeled cells of the inner sheath and hair, because these cells included the label not in the bulb cambium (as hair and inner sheath) but over the bulb, and from this point they start movement. Interposition of cells into the companion layer must cause increase of its volume and additional volume supposed to be led away into the pillar canal around the hair near the sebaceous glands orifices. This can provide the mechanism for the propagation of the hair and inner sheath promotion to sebaceous gland orifices.

[Age peculiarities of the sebaceous glands in the temporal area of the scalp skin in men].

The changes of the sebaceous gland number, size and sebocyte proliferative activity were studied in the temporal area of the scalp skin in the male individuals aged 10 to 70 years (n=77, autopsy material). The minimal number of the sebaceous glands was observed in children. This index rapidly increased thereafter, reaching a peak at 20 years, then gradually decreased. These parameters correlated with the sebaceous gland size, sebocyte proliferative activity and total blood testosterone level. In older men the size of the sebaceous glands was increased.

Study of poroscopy among South Indian population.

Poroscopy is the term applied to a specialized study of pore structure found on papillary ridges of skin as a means of identification. It comes under level 3 detail of identification and hence is more reliable and accurate. The goal of this study is to estimate the importance of poroscopy for identification of individuals and to determine the gender based on frequency, type, and shape of pores. Left plain thumb prints of 200 individuals (100 men and 100 women) aged between 18 and 60 belonging to South Indian population were observed. The results have shown that women tend to have a significantly higher frequency of pores than men. Number of pores ≤ 8 pores/25 mm(2) is more likely to be of male origin and ≥9 pores/25 mm(2) is more likely to be of female origin. There was no significant sex difference based on type and shape of pores.

Variability of hair coat and skin traits as related to adaptation in Criollo Limonero cattle.

The variation in hair coat and skin histology traits of Criollo Limonero cattle was analyzed using 213 Criollo Limonero females. Skin biopsies were obtained from slick-haired (N=16) and normal-haired (N=14) animals. Measured traits included hair length (HL), color coat (CC), number of hair follicles per square centimeter (NHF), sweat glands per square centimeter (NSG), sweat glands size (SGS), sebaceous glands per square centimeter (NSBG), blood vessels per square centimeter (NBV), and thickness of epidermis (TE). Hair length differed (P<0.001) between slick- and normal-haired animals (4.9 ± 0.12 vs 10.9 ± 0.20, respectively). Differences (P<0.01) in CC (Bayo = 144/67.6% vs Red = 69/32.4%) and HL (slick-haired = 199/93.4% vs normal-haired = 14/6.5%) were found. Distribution of slick- and normal-haired animals differed (P<0.01) between bayo-coated and red-coated (139/62.2% vs 9/4.2%; respectively). Most (P<0.05) red-coated animals belonged to a single family. No differences (P>0.05) were found between slick-haired and normal-haired animals in NHF (637 ± 164 vs 587 ± 144, respectively), NSG (556 ± 134 vs 481 ± 118, respectively), NSBG (408 ± 87 vs 366 ± 77, respectively), NBV (1628 ± 393 vs 1541 ± 346, respectively), and TE (1.24 ± 0.14 vs 1.32 ± 0.12, respectively). However, SGS was greater (P<0.01) in slick-haired than normal-haired animals. In conclusion, Criollo Limonero cattle are predominantly bayo-coated, slick-haired, with a reduced number of hair follicles relative to Zebu cattle, sweat and sebaceous glands in proportion to hair follicle numbers, and with a high blood flow irrigating the skin. There is a sub-group of red-coated animals with yellow or cream skin, thicker epidermis, and with a higher frequency of normal-haired animals. It appears that the slick hair gene has been favored by natural selection in this breed.

Functional morphological characteristics of the interdigital sinus in the sheep.

The present paper describes two distinct morphological features of ovine interdigital sinus, which were examined by means of scanning electron microscopy. In the sweat glandular component, acini with epithelial cells exhibiting a paved appearance and apocrine secretion were observed. In the same gland, other acini with cells exhibiting different luminal surfaces and simultaneous apocrine and merocrine secretion were recorded. The numerous hairs embedded within the waxy material of the sinus exhibited two types. The first type, with a round profile, had a special leaflet structure on the tip, whereas the second type had a convex profile. The comparative differences and probable functional relations of these integumentary structures are discussed. The mixed picture of the epithelial cells of the sweat glands suggests the release of different products. The hair microstructure correlated with the mechanism of hold and release of the secretory material of the interdigital sinus.

Sexual autophagic differences in the androgen-dependent flank organ of Syrian hamsters.

The flank organ of the Syrian hamster shows a biodynamic response to androgenic stimulation and is, therefore, a suitable model for the study of androgenic effects on hair and sebaceous glands. This organ is susceptible to programmed cell death (PCD), a prominent feature associated with sexual organ adjustment. In the present report, the type of PCD (apoptosis or autophagy) exhibited by this organ was evaluated. Caspase-3 activity, indicative of apoptosis, was not detectable in flank organ homogenates. Furthermore, cytokeratins, which are normally degraded during apoptosis, remained intact. On the other hand, Western blotting of Beclin 1 and light chain 3-II, both important autophagy markers, revealed autophagic processes in the flank organ in both sexes, especially in females. Cathepsin D activity, higher in males than in females, and procathepsin D expression were also consistent with autophagy and not apoptosis. Taken together, these data indicate that macroautophagy, and not apoptosis, is the main mechanism by which the flank organ responds to androgen. This is the first direct evidence establishing the relationship between autophagy and morphological changes in androgen-dependent organs.

Ultrastructural evidence for thermal injury to pilosebaceous units during the treatment of acne using photopneumatic (PPX) therapy.

BACKGROUND AND OBJECTIVE: Acne is a very prevalent skin disorder, and several devices, such as blue light, pulsed dye laser, diode laser, LED, RF and pulsed light systems, have been reported to have varying degrees of efficacy for treatment. Photopneumatic therapy (PPX) is a novel technology that combines pneumatic energy with a broadband light source to manipulate the optical characteristics of the skin. A vacuum suction raises target structures in the dermis closer to the surface of the skin prior to exposure, allowing for more efficient energy transmission. This study tested the hypothesis that a combination of pulsed light and suction would affect sebaceous plugging within diseased pilosebaceous apparati at a histological level, resulting in the rapid clearance of acne lesions. METHODS: Eight individuals were treated with PPX once per week for a total of five treatments. Punch biopsies of the treated areas were obtained just after the first exposure, just before the third exposure and immediately after the fifth exposure. Those specimens were examined by conventional and by electron microscopy for any alterations following treatment. RESULTS: Immediately following the first treatment, the mechanical extrusion of comedo contents from the infundibulum was observed histologically. One week after the second treatment, thermally injured bacteria as well as direct thermal injury to pilosebaceous apparati were observed ultrastructurally. CONCLUSION: These results correlate with clinical reports on decreased sebaceous gland activity after PPX treatment and may mechanistically give rise to the rapid regression of acne lesions.

First evidence of unicellular glands in the general epidermis of terrestrial reptiles.

The general integument of reptiles is traditionally defined as being dry, but we report here the discovery of unicellular mucoid glands (UCMG) in the dorsal skin of lizards of the genus Phelsuma (Gekkonidae). To this end, the skin of these lizards and of some others for comparison was studied by scanning electron microscopy and transmission electron microscopy. These photographs showed that the development and function of the UCMGs are related to the skin's sloughing cycle. The UCMGs differentiate at scattered locations from Oberhäutchen cells of the inner (new) epidermal generation, above the differentiating beta-keratin layer. While the inner generation matures, the UCMG increases in size; unlike the surrounding Oberhäutchen cells, it does not develop the spinules that characterize gecko skin. When, upon sloughing, the inner generation becomes the new outer generation, and the Oberhäutchen forms the skin surface, the UCMGs, several per scale, dot the surface as mucus-inflated "blebs" projecting from the surrounding spinulate Oberhäutchen, each nesting in a shallow pit of the underlying beta-keratin. On the surface, the UCMGs rupture and the mucus appears to dissipate in cords, flowing over the tips of the spinules, and incorporating minute foreign bodies. It is concluded that, due to the low wettability of the spinulate surface (derived from the spacing of the spinules), the cords brush off easily, with the mucus functioning as a cleaning agent.

Scanning electron microscopic features of the ovine interdigital sinus.

This article describes the scanning electron microscopic (SEM) features of the ovine interdigital sinus. The lumen was filled with a dense secretory material and quite a number of hairs embedded in the luminal content. For SEM purposes, the sinus was divided into three parts: base, body and neck. At the cut surface, the wall exhibited significant folds which were almost absent in the base, the very short blind end of the sinus. The wall had three layers: epidermis, dermis and fibrous capsule. Stratified epithelium with a prominent keratin layer faced the lumen. The inner surface was similar to the skin surface; however, it was coarser due to folds. The fibrous capsule was composed mainly of dense connective tissue, constituting the outermost layer of the wall. The dermis contained common skin structures including sebaceous glands, hair follicles, arrector pili muscles and apocrine glands. Sebaceous glands appeared as groups of bubbles if they were not collapsed. Apocrine glands generally appeared as a group of coiled tubules. They frequently exhibited apocrine blebs, which is a feature of apocrine secretion. SEM was able to locate some secretory vesicles in the lumen of apocrine tubules which is frequently filled by secretory content. Thus, the apocrine tubules exhibited classical features of apocrine secretion.

Morphology of the intermandibular gland of the Lesser mouse deer, Tragulus javanicus.

The morphology of the intermandibular gland of the Lesser mouse deer (Tragulus javanicus), which plays an important function in marking area and territory and in the reproductive behaviour of the animal, was examined using immunohistochemistry, lectin histochemistry and scanning electron microscopy. The gland was composed of sebaceous and apocrine glandular material. Sebaceous glands occupied a greater area of the total gland and consisted of many large lobules with polyhedral cells having a pale cytoplasm. The sebaceous gland, being holocrine, possessed no special secretory ducts. The apocrine gland was lined by cuboid cells and the secretory products were often seen in the apical portions of the cells. Myoepithelial cells contained actin filaments lining the basal membranes of the apocrine gland and were surrounded by nerve fibres which immunostained with protein gene product 9.5. The secretion of the gland appears to be a mixture of larger amounts of lipid material from sebaceous glands, and glycoconjugates secreted by both sebaceous and apocrine glands. Lectin histochemistry detected these as galactose, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, D-mannose and D-glucose. The male gland was larger in size and contained more N-acetyl galactosamine and N-acetyl glucosamine in its secretion than the gland of the female. This implied the presence of sexual differences in secretions in the intermandibular gland of the Lesser mouse deer.

Ultrastructural analysis of the integument of a desert-adapted mammal, the one-humped camel (Camelus dromedarius).

In this study, we conducted a light microscopic and ultrastructural analysis of the integument of the one-humped camel (Camelus dromedarius). In general, the epidermal strata of the camel integument appeared typical of those found in non-desert mammals. Two cell populations were noted in the stratum basale: one with a flat, non-serrated base and the other with a highly serrated base. Typical fine structure was observed in keratinocytes of the stratum spinosum and stratum granulosum. The stratum corneum was six to 10 cells thick. Within the different strata, overall cell morphologies and the general distribution and relative abundance of cellular organelles appeared typical. Dermal features included the presence of myoepithelial cells surrounding apocrine tubular glands. Inter- or intracellular canaliculi within the secretory cells of the apocrine glands, reported to be present in certain other non-desert mammals, were not evident in the camel. Together, these data indicate that while the camel is clearly adapted for a desert lifestyle, these adaptations do not include significant specializations at the cellular or subcellular level in the integument.

[Histology of skin and hair follicle]. / Histologie de la peau et des follicules pileux.

The skin consists of an outer epidermis, the dermis, and the hypodermis. It includes nerves, blood vessels, glands and hair follicles. Epidermis is a continually renewing, stratified squamous epithelium. It is populated by keratinocytes (80 %) and dendritic cells (20 %) : melanocytes, Langerhans and Merkel cells. In standard histology, keratinocytes are arranged in layers that represent different stages of their differentiation while melanocytes and Langerhans cells appear as clear cells respectively between the basal and the supra-basal cells of epidermis. The Merkel cells cannot be clearly identified. Dendritic processes of the dendritic cells can only be recognized by immunocytochemistry. At the dermal-epidermal junction, a PAS reactive basement membrane follows the contour of the basal cells. Dermis consists of collagenous and elastic fibers embedded into an amorphous ground substance. Fibroblasts, macrophages, mast cells and lymphocytes are its resident cells. Hypodermis is composed of adipocyte lobules defined by fibrous connective tissue septa. Hair follicle consists of 3 parts : the lower portion, from the base of the follicle including hair bulb to the insertion of the arrector pili muscle or buldge ; the isthmus, from the insertion of the arrector pili to the entrance of the sebaceous duct, and the infundibulum, from the entrance of the sebaceous duct to the follicular orifice. The lower portion is composed of the dermal hair papilla, the hair matrix, the hair, and the inner and the outer root sheaths. The hair matrix cells within hair bulb give rise to the hair and to the inner root sheath. With the electron microscope, one can obtain a more detailed view of the characteristic skin structures. Much of them can now be explained in terms of function and in many instances, in correlation with its biochemical composition. An attempt has been made in this paper to precisely give the location of molecules that are relevant in basic skin functions and understanding of auto-immune and genetic diseases.