title: New developments in our understanding of acne pathogenesis and treatment.
abstract: Interest in sebaceous gland physiology and its diseases is rapidly increasing. We provide a summarized update of the current knowledge of the pathobiology of acne vulgaris and new treatment concepts that have emerged in the last 3 years (2005-2008). We have tried to answer questions arising from the exploration of sebaceous gland biology, hormonal factors, hyperkeratinization, role of bacteria, sebum, nutrition, cytokines and toll-like receptors (TLRs). Sebaceous glands play an important role as active participants in the innate immunity of the skin. They produce neuropeptides, excrete antimicrobial peptides and exhibit characteristics of stem cells. Androgens affect sebocytes and infundibular keratinocytes in a complex manner influencing cellular differentiation, proliferation, lipogenesis and comedogenesis. Retention hyperkeratosis in closed comedones and inflammatory papules is attributable to a disorder of terminal keratinocyte differentiation. Propionibacterium acnes, by acting on TLR-2, may stimulate the secretion of cytokines, such as interleukin (IL)-6 and IL-8 by follicular keratinocytes and IL-8 and -12 in macrophages, giving rise to inflammation. Certain P. acnes species may induce an immunological reaction by stimulating the production of sebocyte and keratinocyte antimicrobial peptides, which play an important role in the innate immunity of the follicle. Qualitative changes of sebum lipids induce alteration of keratinocyte differentiation and induce IL-1 secretion, contributing to the development of follicular hyperkeratosis. High glycemic load food and milk may induce increased tissue levels of 5alpha-dihydrotestosterone. These new aspects of acne pathogenesis lead to the considerations of possible customized therapeutic regimens. Current research is expected to lead to innovative treatments in the near future.
authors: Department of Dermatology, Mie Universtity Graduate School of Medicine, Tsu, Mie, Japan. kuroichi@clin.medic.mie-u.ac.jp
authors: Ichiro
authors: I
authors: Kurokawa
authors: F William
authors: FW
authors: Danby
authors: Qiang
authors: Q
authors: Ju
authors: Xiuli
authors: X
authors: Wang
authors: Leihong Flora
authors: LF
authors: Xiang
authors: Longqing
authors: L
authors: Xia
authors: Wenchieh
authors: W
authors: Chen
authors: István
authors: I
authors: Nagy
authors: Mauro
authors: M
authors: Picardo
authors: Dae Hun
authors: DH
authors: Suh
authors: Ruta
authors: R
authors: Ganceviciene
authors: Silke
authors: S
authors: Schagen
authors: Fragkiski
authors: F
authors: Tsatsou
authors: Christos C
authors: CC
authors: Zouboulis
mesh_terms: D000152:Acne Vulgaris / Q000209:etiology* / Q000378:metabolism / Q000628:therapy*; D000818:Animals; D006801:Humans; D012627:Sebaceous Glands / Q000382:microbiology / Q000473:pathology / Q000502:physiology