1
|
Kang H, Lee SG. Comparative molecular dynamics study on the features of binding and non-binding modes of retinoic acid in cellular retinol-binding protein (I). J Mol Graph Model 2023; 123:108509. [PMID: 37209439 DOI: 10.1016/j.jmgm.2023.108509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/28/2023] [Accepted: 05/04/2023] [Indexed: 05/22/2023]
Abstract
Retinoids play crucial roles in various biological processes by interacting with their carrier proteins such as cellular retinol-binding protein (CRBP). Understanding the molecular interactions between retinoids and CRBP enables their pharmacological and biomedical applications. Experimentally, CRBP(I) does not bind to retinoic acid, but when arginine is introduced into 108th residue instead of glutamine (Q108R), it binds to retinoic acid. Here, molecular dynamics simulations were performed to understand the differences in the microscopic and dynamic behaviors of the non-binding wild-type CRBP(I)-retinoic acid and binding Q108R variant-retinoic acid complexes. The ligand RMSD and RMSF, the binding poses of binding motif amino acids, and the number of hydrogen bonds and salt-bridges revealed the relative instability of the non-binding complex. In particular, the ligand's terminal group showed very different dynamics and interactions. So far, most studies have focused on the binding characteristics of retinoids, but the features of their non-binding modes have not been studied well. This study provides some structural insights into the non-binding modes of a retinoid in CRBP, which may be applicable in retinoid-based drug discovery and protein engineering through computational modeling.
Collapse
Affiliation(s)
- Hyeona Kang
- Department of Chemical and Biomolecular Engineering, Pusan National University, Busan, South Korea
| | - Sun-Gu Lee
- Department of Chemical and Biomolecular Engineering, Pusan National University, Busan, South Korea.
| |
Collapse
|
2
|
Wu X, Xuan J, Yu Q, Wu W, Lu Y, Zhu Q, Chen Z, Qi J. Converting Tretinoin into Ionic Liquids for Improving Aqueous Solubility and Permeability across Skin. Pharm Res 2022; 39:2421-2430. [DOI: 10.1007/s11095-022-03238-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/17/2022] [Indexed: 11/28/2022]
|
3
|
Ferreira R, Napoli J, Enver T, Bernardino L, Ferreira L. Advances and challenges in retinoid delivery systems in regenerative and therapeutic medicine. Nat Commun 2020; 11:4265. [PMID: 32848154 PMCID: PMC7450074 DOI: 10.1038/s41467-020-18042-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 08/01/2020] [Indexed: 12/19/2022] Open
Abstract
Retinoids regulate a wide spectrum of cellular functions from the embryo throughout adulthood, including cell differentiation, metabolic regulation, and inflammation. These traits make retinoids very attractive molecules for medical purposes. In light of some of the physicochemical limitations of retinoids, the development of drug delivery systems offers several advantages for clinical translation of retinoid-based therapies, including improved solubilization, prolonged circulation, reduced toxicity, sustained release, and improved efficacy. In this Review, we discuss advances in preclinical and clinical tests regarding retinoid formulations, specifically the ones based in natural retinoids, evaluated in the context of regenerative medicine, brain, cancer, skin, and immune diseases. Advantages and limitations of retinoid formulations, as well as prospects to push the field forward, will be presented.
Collapse
Grants
- MC_U137973817 Medical Research Council
- MR/N000838/1 Medical Research Council
- The authors would like to thank Andreia Vilaça for the illustrations and the financial support of ERA Chair project (ERA@UC, ref:669088) through EU Horizon 2020 program, the POCI-01-0145-FEDER-016390 (acronym: CANCEL STEM) and POCI-01-0145-FEDER-029414 (acronym: LIghtBRARY) projects through Compete 2020 and FCT programs, projects 2IQBIONEURO (reference: 0624_2IQBIONEURO_6_E) and NEUROATLANTIC (reference: EAPA_791/2018) co-funded by INTERREG (Atlantic program or V-A Spain-Portugal) and European fund for Regional Development (FEDER), FCT (Portugal, SFRH/BPD/102103/2014), National Funds by Foundation for Science and Technology (UID/Multi/00709/2013), “Programa Operacional do Centro, Centro 2020” through the funding of the ICON project (Interdisciplinary Challenges On Neurodegeneration; CENTRO-01-0145-FEDER-000013), EXPL/BIM-MED/0822/2013 (LB), (SFRH/BPD/94228/2013, IF/00178/2015) (RF), Cerebrovascular Disease Grant and L’Oréal-UNESCO Portugal for Women in Science for supporting this work. Authors declare there are no conflict of interests.
Collapse
Affiliation(s)
- Raquel Ferreira
- Health Sciences Research Centre (CICS-UBI), Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal
| | - Joseph Napoli
- Nutritional Sciences and Toxicology, University of California, 231 Morgan Hall, MC#3104, Berkeley, CA, 94720, USA
| | - Tariq Enver
- UCL Cancer Institute, University College London, London, UK
| | - Liliana Bernardino
- Health Sciences Research Centre (CICS-UBI), Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal.
| | - Lino Ferreira
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
| |
Collapse
|
4
|
Chen W, Zhao S, Zhu W, Wu L, Chen X. Retinoids as an Immunity-modulator in Dermatology Disorders. Arch Immunol Ther Exp (Warsz) 2019; 67:355-365. [PMID: 31552446 DOI: 10.1007/s00005-019-00562-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 09/13/2019] [Indexed: 12/11/2022]
Abstract
The skin is the largest epithelial surface protecting the body from invading microbes. Vitamin A plays vital roles in the host defence of the skin, including promoting epithelial cell integrity, proliferation, and differentiation and even mediating immune responses. Furthermore, vitamin A derivatives, retinoid drugs, are widely used to treat skin diseases, such as acne and psoriasis. However, the immunoregulatory mechanisms of retinoids in dermatology have not been systematically described. In this paper, we discuss the immunological functions of retinoids during disease treatment, especially in skin disorders caused by exogenous infections.
Collapse
Affiliation(s)
- Wangqing Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Shuang Zhao
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Wu Zhu
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Lisha Wu
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- Institute of Medical Sciences, Xiangya Hospital, Central South University, Changsha, China.
| | - Xiang Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
| |
Collapse
|
5
|
İslamoğlu ZGK, Altınyazar HC. Effects of isotretinoin on the hair cycle. J Cosmet Dermatol 2018; 18:647-651. [DOI: 10.1111/jocd.12800] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 07/19/2018] [Accepted: 09/07/2018] [Indexed: 12/28/2022]
|
6
|
Lapteva M, Möller M, Gurny R, Kalia YN. Self-assembled polymeric nanocarriers for the targeted delivery of retinoic acid to the hair follicle. NANOSCALE 2015; 7:18651-18662. [PMID: 26498006 DOI: 10.1039/c5nr04770f] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Acne vulgaris is a highly prevalent dermatological disease of the pilosebaceous unit (PSU). An inability to target drug delivery to the PSU results in poor treatment efficacy and the incidence of local side-effects. Cutaneous application of nanoparticulate systems is reported to induce preferential accumulation in appendageal structures. The aim of this work was to prepare stable polymeric micelles containing retinoic acid (RA) using a biodegradable and biocompatible diblock methoxy-poly(ethylene glycol)-poly(hexylsubstituted lactic acid) copolymer (MPEG-dihexPLA) and to evaluate their ability to deliver RA to skin. An innovative punch biopsy sample preparation method was developed to selectively quantify follicular delivery; the amounts of RA present were compared to those in bulk skin, (i.e. without PSU), which served as the control. RA was successfully incorporated into micelle nanocarriers and protected from photoisomerization by inclusion of Quinoline Yellow. Incorporation into the spherical, homogeneous and nanometer-scale micelles (dn < 20 nm) increased the aqueous solubility of RA by >400-fold. Drug delivery experiments in vitro showed that micelles were able to deliver RA to porcine and human skins more efficiently than Retin-A(®) Micro (0.04%), a marketed gel containing RA loaded microspheres, (7.1 ± 1.1% vs. 0.4 ± 0.1% and 7.5 ± 0.8% vs. 0.8 ± 0.1% of the applied dose, respectively). In contrast to a non-colloidal RA solution, Effederm(®) (0.05%), both the RA loaded MPEG-dihexPLA polymeric micelles (0.005%) and Retin-A(®) Micro (0.04%) displayed selectivity for delivery to the PSU with 2-fold higher delivery to PSU containing samples than to control samples. Moreover, the micelle formulation outperformed Retin-A(®) Micro in terms of delivery efficiency to PSU presenting human skin (10.4 ± 3.2% vs. 0.6 ± 0.2%, respectively). The results indicate that the polymeric micelle formulation enabled an increased and targeted delivery of RA to the PSU, potentially translating to a safer and more efficient clinical management of acne.
Collapse
Affiliation(s)
- Maria Lapteva
- School of Pharmaceutical Sciences, University of Geneva & University of Lausanne, 30 Quai Ernest Ansermet, 1211 Geneva, Switzerland.
| | | | | | | |
Collapse
|
7
|
Rao PK, Bhat RM, Nandakishore B, Dandakeri S, Martis J, Kamath GH. Safety and efficacy of low-dose isotretinoin in the treatment of moderate to severe acne vulgaris. Indian J Dermatol 2014; 59:316. [PMID: 24891681 PMCID: PMC4037971 DOI: 10.4103/0019-5154.131455] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background: Isotretinoin is indicated for moderate to severe cases of acne which are unresponsive to conventional therapy. The classical recommended dose is 0.5 to 1.0 mg/kg/day. As the side effects are dose related, low-dose isotretinoin therapy for acne is an attractive option; however, but little data exists on the safety and efficacy of this strategy. Materials and Methods: In this prospective, non-comparative study, 50 participants, both male and female, having moderate to severe acne vulgaris were enrolled and treated with isotretinoin at a dose of 20 mg/day (approximately 0.3-0.4 mg/kg/day), for a period of 3 months. Participants were evaluated by means of clinical and laboratory investigations before starting isotretinoin. Investigations were repeated at the end of the first and third months following completion of treatment, and participants were followed up for 6 months to look for any relapse. Results: At the end of the treatment, very good results were observed in 90% of participants. Cheilitis was the most common among the side effects observed and was seen in 98% of the participants. One participant developed vitiligo as a side effect, which is a new finding, and has not reported in literature before. Elevated serum lipid levels were observed in 6% of the participants, and relapse occurred in 4% of the participants over a 6 month follow up period. Conclusion: Three months of treatment with low-dose isotretinoin (20 mg/day) was found to be effective in the treatment of moderate to severe acne vulgaris, with a low incidence of serious side effects. This dose also was more economical than the higher doses.
Collapse
Affiliation(s)
- Parinitha K Rao
- Department of Dermatology, Father Muller Medical College, Mangalore, Karnataka, India
| | - Ramesh M Bhat
- Department of Dermatology, Father Muller Medical College, Mangalore, Karnataka, India
| | - B Nandakishore
- Department of Dermatology, Father Muller Medical College, Mangalore, Karnataka, India
| | - Sukumar Dandakeri
- Department of Dermatology, Father Muller Medical College, Mangalore, Karnataka, India
| | - Jacintha Martis
- Department of Dermatology, Father Muller Medical College, Mangalore, Karnataka, India
| | - Ganesh H Kamath
- Department of Dermatology, Father Muller Medical College, Mangalore, Karnataka, India
| |
Collapse
|
8
|
Loignon M, Brodeur H, Deschênes S, Phaneuf D, Bhat PV, Toma E. Combination antiretroviral therapy and chronic HIV infection affect serum retinoid concentrations: longitudinal and cross-sectional assessments. AIDS Res Ther 2012; 9:3. [PMID: 22296672 PMCID: PMC3305370 DOI: 10.1186/1742-6405-9-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 02/01/2012] [Indexed: 12/18/2022] Open
Abstract
Background Several lines of evidence suggest that retinoids (retinol-ROL or vitamin A, and its active metabolites, retinoic acids-RAs) play important pathogenic roles in HIV infection and combination antiretroviral therapy (cART)-related events. We previously reported that antiretrovirals alter RAs synthesis in vitro. We hypothesised that in vivo serum retinoid concentrations are affected by both cART and HIV infection. This might explain several clinical and laboratory abnormalities reported in HIV-infected patients receiving cART. Methods The effects of optimal cART and chronic HIV on serum retinoids were firstly assessed longitudinally in 10 HIV-infected adults (group1 = G1): twice while on optimal cART (first, during long-term and second, during short term cART) and twice during 2 cART interruptions when HIV viral load (VL) was detectable. Retinoid concentrations during optimal long term cART in G1 were compared with cross-sectional results from 12 patients (G2) with suboptimal cART (detectable VL) and from 28 healthy adults (G3). Serum retinoids were measured by HPLC with ultraviolet detection. Retinoid concentrations were correlated with VL, CD4+ T- cell count and percentages, CD8+38+ fluorescence, triglycerides, cholesterol and C-peptide serum levels. Results During optimal cART, G1 participants had drastically reduced RAs (0.5 ± 0.3 μg/dL; P < 0.01) but the highest ROL (82 ± 3.0 μg/dL) concentrations. During cART interruptions in these patients, RAs slightly increased whereas ROL levels diminished significantly (P < 0.05). G3 had the highest RAs levels (7.2 ± 1.1 μg/dL) and serum ROL comparable to values in North Americans. Serum ROL was decreased in G2 (37.7 ± 3.2 μg/dL; P < 0.01). No correlations were noted between RA and ROL levels or between retinoid concentrations and CD4+ T- cell count, CD8+38+ fluorescence, VL. ROL correlated with triglycerides and cholesterol in G1 (rs = 0.8; P = 0.01). Conclusions Serum RAs levels are significantly diminished by cART, whereas ROL concentrations significantly decreased during uncontrolled HIV infection but augmented with optimal cART. These alterations in retinoid concentrations may affect the expression of retinoid-responsive genes involved in metabolic, hormonal and immune processes and be responsible for some adverse events observed in HIV-infected persons treated with antiretrovirals. Further studies should assess concomitant serum and intracellular retinoid levels in different clinical situations in larger, homogenous populations.
Collapse
|
9
|
Obulesu M, Dowlathabad MR, Bramhachari PV. Carotenoids and Alzheimer's disease: an insight into therapeutic role of retinoids in animal models. Neurochem Int 2011; 59:535-41. [PMID: 21672580 DOI: 10.1016/j.neuint.2011.04.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 03/16/2011] [Accepted: 04/20/2011] [Indexed: 01/09/2023]
Abstract
Carotenoids play a pivotal role in prevention of many degenerative diseases mediated by oxidative stress including neurodegenerative diseases like Alzheimer's Disease (AD). The involvement of retinoids in physiology, AD pathology and their therapeutic role in vitro and in vivo has been extensively studied. This review focuses on the role of carotenoids like retinoic acid (RA), all trans retinoic acid (ATRA), lycopene and β-carotene in prevention of AD symptoms primarily through inhibition of amyloid beta (Aβ) formation, deposition and fibril formation either by reducing the levels of p35 or inhibiting corresponding enzymes. The role of antioxidant micronutrients in prevention or delaying of AD symptoms has been included. This study emphasizes the dietary supplementation of carotenoids to combat AD and warrants further studies on animal models to unravel their mechanism of neuroprotection.
Collapse
Affiliation(s)
- M Obulesu
- Department of Biotechnology, Rayalaseema University, Kurnool, Andhra Pradesh, India.
| | | | | |
Collapse
|
10
|
Shudo K, Fukasawa H, Nakagomi M, Yamagata N. Towards retinoid therapy for Alzheimer's disease. Curr Alzheimer Res 2009; 6:302-11. [PMID: 19519313 PMCID: PMC2765081 DOI: 10.2174/156720509788486581] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 11/05/2008] [Accepted: 11/12/2008] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease(AD) is associated with a variety of pathophysiological features, including amyloid plaques, inflammation, immunological changes, cell death and regeneration processes, altered neurotransmission, and age-related changes. Retinoic acid receptors (RARs) and retinoids are relevant to all of these. Here we review the pathology, pharmacology, and biochemistry of AD in relation to RARs and retinoids, and we suggest that retinoids are candidate drugs for treatment of AD.
Collapse
Affiliation(s)
- K Shudo
- Research Foundation ITSUU Laboratory, Tokyo, Japan.
| | | | | | | |
Collapse
|
11
|
Sardana K, Garg VK, Sehgal VN, Mahajan S, Bhushan P. Efficacy of fixed low-dose isotretinoin (20 mg, alternate days) with topical clindamycin gel in moderately severe acne vulgaris. J Eur Acad Dermatol Venereol 2009; 23:556-60. [DOI: 10.1111/j.1468-3083.2008.03022.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
12
|
Sehgal VN, Srivastava G, Aggarwal AK, Sardana K, Jain M. Efficacy of isotretinoin in pityriasis rubra pilaris: unapproved use. Int J Dermatol 2007; 45:1238-40. [PMID: 17040451 DOI: 10.1111/j.1365-4632.2006.02932.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Sehgal VN, Srivastava G, Sardana K. Isotretinoin - unapproved indications/uses and dosage: a physician's reference. Int J Dermatol 2006; 45:772-7. [PMID: 16796650 DOI: 10.1111/j.1365-4632.2006.02830.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Virendra N Sehgal
- Dermato-Venereology (Skin/VD) Center, Sehgal Nursing Home, Delhi, Skin Institute and School of Dermatology, Greater Kailash, New Delhi, India.
| | | | | |
Collapse
|
14
|
Rigopoulos D, Ioannides D, Kalogeromitros D, Katsambas AD. Comparison of topical retinoids in the treatment of acne. Clin Dermatol 2005; 22:408-11. [PMID: 15556727 DOI: 10.1016/j.clindermatol.2004.03.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Topical retinoids are been used to successfully treat acne for almost 3 decades. At the beginning, a retinoid was a compound of similar structure and action to retinol (vitamin A).(1) Changes at the carboxylic end group, the polyene chain, and the aromatic ring can result in the modification of the original molecule. To date, three generations of retinoids have been developed: the nonaromatics (retinol, tretinoin, and isotretinoin), the monoaromatics (etretinate and acitretin), and the polyaromatics (arotinoid, adapalene, and tazarotene). The new synthetic retinoid molecules have little resemblance with retinol but nonetheless are included in this family because they have the ability to bind with or activate retinoid receptors. Therefore, retinoids are vitamins and also hormones.(3)
Collapse
|
15
|
Affiliation(s)
- Virendra N Sehgal
- Dermato-Venereology (Skin-VD) Centre, Sehgal Nursing Home, Delhi 110 033, India.
| | | |
Collapse
|
16
|
Sehgal VN, Sardana K, Sharma S, Raut D. Hereditary palmoplantar (epidermolytic) keratoderma: illustration through a familial report. Skinmed 2004; 3:323-30; quiz 331-2. [PMID: 15538081 DOI: 10.1111/j.1540-9740.2004.03243.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Hereditary palmoplantar keratoderma, a well-known clinical entity, is illustrated through a familial report of an unmarried young man who is the product of a consanguineous marriage (paternal and maternal grandmothers were sisters). The lesions were characterized by immense yellow waxy thickening of the skin surrounded by erythematous border (halo) and fissures/cracks associated with extensive scaling of the palms and soles. The lesions were bilateral and symmetrical. These features were supported by orthokeratotic hyperkeratosis hypergranulosis and acanthosis in hematoxylin-eosin stained tissue sections prepared from the soles. Mycelia/spores could not be identified on Periodic acid-Schiff (PAS) reaction. An autosomal dominant trait was revealed through family pedigree. An abridged update to recap the current status is highlighted.
Collapse
Affiliation(s)
- Virendra N Sehgal
- Dermato-Venereology (Skin/VD) Centre, Sehgal Nursing Home, Panchwati, Azadpur, Delhi, India.
| | | | | | | |
Collapse
|
17
|
Abstract
Acne vulgaris is a common skin disease, affecting about 70-80% of adolescents and young adults. It is a multifactorial disease of the pilosebaceous unit.(1) The influence of androgens at the onset of adolescence leads to an enlargement of the sebaceous gland and a rise in sebum production. Additional increased proliferation and altered differentiation of the follicular epithelium eventually blocks the pilosebaceous duct, leading to development of the microcomedo as the primary acne lesion. Concomitantly and subsequently, colonization with Propionibacterium acnes increases, followed by induction of inflammatory reactions from bacteria, ductal corneocytes, and sebaceous proinflammatory agents (Fig 1).(2-5)
Collapse
Affiliation(s)
- Andrea Krautheim
- Department of Dermatology and Venerology, Otto von Guericke University, Leipzoger Strasse 44, D-39120 Magdeburg, Germany
| | | |
Collapse
|