Chronological ageing and photoageing of the human sebaceous gland

Moura

et al. 2017

Braz. J. Vet. Pathol.

Werner, et al.; Canine tarsal gland epitheliomas and adenomas: a retrospective study of 290 cases in Brazil. Braz J Vet Pathol, 2017, 10(1), 2 -9. DOI: 10.24070/bjvp.1983-0246.v10i1p2-9 Brazilian Abstract A total of 290 cases of tarsal gland adenomas and epitheliomas from canine patients were analyzed to determine the frequency and to better characterize their histopathological features. Tissue samples were examined in two veterinary pathology laboratories in Curitiba, Brazil, which receive samples from all over the country. Tarsal epitheliomas were significantly more frequent than tarsal adenomas (77.9% and 20.7%, respectively). In four cases (1.4%), the lesion contained both types of neoplasms. A total of 39 breeds were represented. The most common breeds were: English cocker spaniel (12.4%), poodle (10.3%) and Labrador retriever (9.3%). Mixed breed dogs represented 13.1% of the total. The upper eyelids were most commonly affected (65.2%), males and females were equally represented and there did not appear to be a predilection for either side of the face. Mitotic figures were most common in epitheliomas. The pigmented subtype was the most common form of epithelioma (59.7%). Whereas within the adenomas, the classic subtype (without inflammation or pigmentation) was the most common form (61.7%); and the inflamed subtype was also highly represented (20.0%).

Section: Discussionmentioning

confidence: 99%

Canine tarsal gland epitheliomas and adenomas: a retrospective study of 290 cases in Brazil

Moura

et al. 2017

Braz. J. Vet. Pathol.

“…In particular, morphological changes of the sebaceous gland cells and alterations of their activity play a distinct role in the aging phenotype of the skin. The size of sebaceous gland cells tends to decrease with advancing age, while their number remains approximately the same throughout life (Zouboulis & Boschnakow, 2001). Furthermore, sebaceous gland cells show an age-related reduced secretory output, which results in a decrease in the surface lipid levels and skin xerosis (Pochi et al ., 1979;Engelke et al ., 1997) -a major characteristic of aged skin.…”

Section: Introductionmentioning

confidence: 99%

Age‐specific hormonal decline is accompanied by transcriptional changes in human sebocytes in vitro

et al. 2006

SummaryThe importance of hormones in endogenous aging has been displayed by recent studies performed on animal models and humans. To decipher the molecular mechanisms involved in aging we maintained human sebocytes at defined hormone-substituted conditions that corresponded to average serum levels of females from 20 (f20) to 60 (f60) years of age. The corresponding hormone receptor expression was demonstrated by reverse transcriptionpolymerase chain reaction (RT-PCR), Western blotting and immunocytochemistry. Cells at f60 produced significantly lower lipids than at f20. Increased mRNA and protein levels of c-Myc and increased protein levels of FN1, which have been associated with aging, were detected in SZ95 sebocytes at f60 compared to those detected at f20 after 5 days of treatment. Expression profiling employing a cDNA microarray composed of 15 529 cDNAs identified 899 genes with altered expression levels at f20 vs. f60. Confirmation of gene regulation was performed by real-time RT-PCR. The functional annotation of these genes according to the Gene Ontology identified pathways related to mitochondrial function, oxidative stress, ubiquitin-mediated proteolysis, cell cycle, immune responses, steroid biosynthesis and phospholipid degradation -all hallmarks of aging. Twentyfive genes in common with those identified in aging kidneys and several genes involved in neurodegenerative diseases were also detected. This is the first report describing the transcriptome of human sebocytes and its modification by a cocktail of hormones administered in age-specific levels and provides an in vitro model system, which approximates some of the hormone-dependent changes in gene transcription that occur during aging in humans.

Molecular and Cellular Biology

“…Abnormal high sebum secretion in humans has been associated with several skin diseases (2,19). In contrast, insufficient sebum secretion causes skin xerosis and xerophthalmia (20,21).…”

mentioning

confidence: 99%

Cidea Control of Lipid Storage and Secretion in Mouse and Human Sebaceous Glands

Zhang

Shui

Wang

et al. 2014

f Sebaceous glands are skin appendages that secrete sebum onto hair follicles to lubricate the hair and maintain skin homeostasis. In this study, we demonstrated that Cidea is expressed at high levels in lipid-laden mature sebocytes and that Cidea deficiency led to dry hair and hair loss in aged mice. In addition, Cidea-deficient mice had markedly reduced levels of skin surface lipids, including triacylglycerides (TAGs) and wax diesters (WDEs), and these mice were defective in water repulsion and thermoregulation. Furthermore, we observed that Cidea-deficient sebocytes accumulated a large number of smaller-sized lipid droplets (LDs), whereas overexpression of Cidea in human SZ95 sebocytes resulted in increased lipid storage and the accumulation of large LDs. Importantly, Cidea was highly expressed in human sebaceous glands, and its expression levels were positively correlated with human sebum secretion. Our data revealed that Cidea is a crucial regulator of sebaceous gland lipid storage and sebum lipid secretion in mammals and humans.