New developments in our understanding of acne pathogenesis and treatment

A combination of improved differential and global RNA-seq reveals pervasive transcription initiation and events in all stages of the life-cycle of functional RNAs in Propionibacterium acnes, a major contributor to wide-spread human disease

BACKGROUND

Sequencing of the genome of Propionibacterium acnes produced a catalogue of genes many of which enable this organism to colonise skin and survive exposure to the elements. Despite this platform, there was little understanding of the gene regulation that gives rise to an organism that has a major impact on human health and wellbeing and causes infections beyond the skin. To address this situation, we have undertaken a genome-wide study of gene regulation using a combination of improved differential and global RNA-sequencing and an analytical approach that takes into account the inherent noise within the data.

RESULTS

We have produced nucleotide-resolution transcriptome maps that identify and differentiate sites of transcription initiation from sites of stable RNA processing and mRNA cleavage. Moreover, analysis of these maps provides strong evidence for 'pervasive' transcription and shows that contrary to initial indications it is not biased towards the production of antisense RNAs. In addition, the maps reveal an extensive array of riboswitches, leaderless mRNAs and small non-protein-coding RNAs alongside vegetative promoters and post-transcriptional events, which includes unusual tRNA processing. The identification of such features will inform models of complex gene regulation, as illustrated here for ribonucleotide reductases and a potential quorum-sensing, two-component system.

CONCLUSIONS

The approach described here, which is transferable to any bacterial species, has produced a step increase in whole-cell knowledge of gene regulation in P. acnes. Continued expansion of our maps to include transcription associated with different growth conditions and genetic backgrounds will provide a new platform from which to computationally model the gene expression that determines the physiology of P. acnes and its role in human disease.

Infantile acne treated with oral isotretinoin

In contrast to adolescent acne, infantile acne (IA) is a rare condition with only a limited body of available literature. In this descriptive, retrospective study, we reviewed six cases from 2002 to 2010 treated with oral isotretinoin. The average age of onset was 6.16 months (range 0-21 mos). Consistent with the previous, limited literature, we found predominantly boys are affected, a predilection for the cheeks, and a polymorphic inflammatory morphology. Two patients had a family history of acne. All cases were successfully and safely treated with oral isotretinoin. The suggested treatment of childhood acne is similar to that of adolescents (graded according to the severity of the skin disease and risk of scarring). Oral isotretinoin appears to be an effective and safe treatment for severe IA.

Chitosan against cutaneous pathogens

Propionibacterium acnes and Staphylococcus aureus are cutaneous pathogens that have become increasingly resistant to antibiotics. We sought to determine if chitosan, a polymer of deacetylated chitin, could be used as a potential treatment against these bacteria. We found that higher molecular weight chitosan had superior antimicrobial properties compared to lower molecular weights, and that this activity occurred in a pH dependent manner. Electron and fluorescence microscopy revealed that chitosan forms aggregates and binds to the surface of bacteria, causing shrinkage of the bacterial membrane from the cell wall. Of special relevance, clinical isolates of P. acnes were vulnerable to chitosan, which could be combined with benzoyl peroxide for additive antibacterial effect. Chitosan also demonstrated significantly less cytotoxicity to monocytes than benzoyl peroxide. Overall, chitosan demonstrates many promising qualities for treatment of cutaneous pathogens.

Expression of Inflammatory Biomarkers from Cultured Sebocytes was Influenced by Treatment with Vitamin D

BACKGROUND

Inflammatory cytokines are the key factor in the pathophysiology of acne. It is well known that keratinocytes synthesize many kinds of inflammatory cytokines. In addition, it is reported that inflammatory cytokines are also expressed from sebocytes, which originate from the same stem cells with keratinocytes.

AIM

To clarify changes in the expression of inflammatory biomarkers from cultured sebocytes after treatment with vitamin D.

MATERIALS AND METHODS

Reverse transcription-polymerase chain reaction (RT-PCR) was done to measure changes in the expression of inflammatory biomarkers, including interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor-α (TNF-α), and several subtypes of matrix metalloproteinases (MMPs) after treatment of a group of cultured sebocytes with vitamin D. Vitamin D receptor (VDR) small interfering RNA (siRNA) was added in the other group of cultured sebocytes to assure the role of vitamin D on the expression of inflammatory biomarkers. Enzyme-linked immunosorbent assay (ELISA) was also performed in the vitamin D-treated sebocytes.

RESULTS

Cultured sebocytes showed non-significant changes in the gene expression of inflammatory biomarkers after treatment with vitamin D. In cultured sebocytes treated with a VDR siRNA, the expression of inflammatory biomarkers was not blocked after treatment with vitamin D. ELISA showed a significant decrease in the expression of IL-6, IL-8, and MMP-9, but a significant increase in the expression of MMP-1 and MMP-3, after treatment with vitamin D (10(-6) M).

CONCLUSION

Expression of inflammatory biomarkers is influenced by treatment with vitamin D in cultured sebocytes, but not through VDR.

Dermatological problems of the puberty

Puberty is a period of life between childhood and adulthood. It is characterized by many changes in morphology and appearance of the body (biological maturation), in the psyche - development of personality (psychological maturation), and in the attitude towards one's own and the opposite sex (psychosexual maturation), and in the social role (social maturation). Dermatological problems of adolescence are mainly related to fluctuations in hormone levels, mainly androgens. They include acne, hair problems and excessive sweating. Acne vulgaris is the most frequently diagnosed dermatosis in patients aged between 11 and 30 years. It is believed that it affects about 80% of persons in this age group or even, taking into account lesions of low intensity, 100% of young people. Excessive sweating is a condition characterised by excessive production of sweat, resulting from high activity of sweat glands. The sweat glands are localised in almost all areas of the body surface but on the hands, feet, armpits and around the groin they are found at the highest density. Seborrhoeic dermatitis of the scalp is a chronic, relapsing, inflammatory dermatosis, which currently affects about 5% of the population. It affects mostly young people, particularly men.

PLIN2, the major perilipin regulated during sebocyte differentiation, controls sebaceous lipid accumulation in vitro and sebaceous gland size in vivo

BACKGROUND

Lipid synthesis and storage are accomplished by lipid droplets (LDs). The perilipin family of LD-associated proteins, comprising 5 members (PLIN1-PLIN5), has been well characterized in adipocytes but not in sebocytes, epithelial cells in which LD formation is a key feature of the cellular differentiation.

METHODS

Perilipin expression in the sebaceous gland cell line SZ95 and in human sebaceous glands was studied by qRT-PCR, Western blots, and immunohistochemistry. Lipid accumulation was evaluated by Nile red staining and mass spectrometry.

RESULTS

PLIN2 and PLIN3 are the most abundant perilipins in undifferentiated sebocytes. Induction of lipogenesis by linoleic acid (LA) resulted in increased transcript levels of all perilipins except for PLIN3 and in a time-dependent increase of PLIN2 protein. Nile red staining revealed that siRNA-mediated downregulation of PLIN2 significantly impaired basal and LA-induced lipid accumulation. Mass spectrometry revealed PLIN2 deficiency to cause a reduction in the amount of several specific lipid fractions, including di- and triacyl-glycerol esters, phosphatidylcholine lipids, and ceramides in sebocytes under basal conditions. In contrast, PLIN2 downregulation exerted a statistically significant inhibitory effect only on the accumulation of specific LA-induced triglycerides. PLIN2-deficient mice showed normal morphology of sebaceous glands. However, their sebaceous glands were significantly reduced in size and showed less cell proliferation.

CONCLUSIONS

PLIN2 is the major perilipin regulated during sebocyte differentiation in vitro. PLIN2 is also important for sebaceous lipid accumulation in vitro and regulates sebaceous gland size in vivo.

GENERAL SIGNIFICANCE

Our study provides the first systematic analysis of LD-associated proteins in sebocytes.

Androgenic hormone profile of adult women with acne

Acne in adult women is a hard-to-manage frequent disease with many relapse cases. It mostly interferes with quality of life and causes major social and metabolic losses for patients. This is a transversal retrospective study and the aim was to standardize the research on circulating androgenic hormone levels and to detect hyperandrogenic states early, showing the frequency and the pattern of the altered hormones, useful resources to correctly evaluate each patient. In this study 835 women above 15 years of age, with acne or aggravation cases, were analyzed. The aim was to verify the percentage of androgen examinations with levels above normal. The levels of the hormones dehydroepiandrosterone sulfate, dehydroepiandrosterone (DHEA), dehydrotestosterone, androstenedione and total testosterone were measured in all patients. The evaluation of the hormone profile showed that 54.56% of the patients had hyperandrogenism, and the levels of DHEA were most frequently elevated. Therefore, in the face of the importance of hyperandrogenism in the pathogenesis of acne, standardizing the research of the hormone profile is paramount for the treatment and control of relapses in case of a surge of acne breakouts during a woman's adult life.

Rosmarinus officinalis extract suppresses Propionibacterium acnes-induced inflammatory responses

Propionibacterium acnes is a key pathogen involved in the progression of acne inflammation. The development of a new agent possessing antimicrobial and anti-inflammatory activity against P. acnes is therefore of interest. In this study, we investigated the inhibitory effect of rosemary (Rosmarinus officinalis) extract on P. acnes-induced inflammation in vitro and in vivo. The results showed that ethanolic rosemary extract (ERE) significantly suppressed the secretion and mRNA expression of proinflammatory cytokines, including interleukin (IL)-8, IL-1β, and tumor necrosis factor-α in P. acnes-stimulated monocytic THP-1 cells. In an in vivo mouse model, concomitant intradermal injection of ERE attenuated the P. acnes-induced ear swelling and granulomatous inflammation. Since ERE suppressed the P. acnes-induced nuclear factor kappa-B (NF-κB) activation and mRNA expression of Toll-like receptor (TLR) 2, the suppressive effect of ERE might be due, at least partially, to diminished NF-κB activation and TLR2-mediated signaling pathways. Furthermore, three major constituents of ERE, carnosol, carnosic acid, and rosmarinic acid, exerted different immumodulatory activities in vitro. In brief, rosmarinic acid significantly suppressed IL-8 production, while the other two compounds inhibited IL-1β production. Further study is needed to explore the role of bioactive compounds of rosemary in mitigation of P. acnes-induced inflammation.

[Pathophysiology of acne. What is confirmed?]

Acne is the most common skin disease worldwide. Choosing the appropriate therapeutic regimens for the clinically diversified disease phenotypes require good knowledge of its pathophysiology. New concepts in this field have been developed in the last 15 years. Acne vulgaris is an inflammatory disorder in which androgens, PPAR ligands, regulating neuropeptides and environmental factors are probably involved as triggers. These factors interrupt the natural cycling process in the sebaceous gland follicle and support the transition of microcomedones to comedones and clinically inflammatory lesions. Proinflammatory lipids, chemokines and cytokines overtake the role of mediators for the further development of acne lesions. Bacterial antigens can potentate the inflammatory phenomena.

Radical scavenging activity-based and AP-1-targeted anti-inflammatory effects of lutein in macrophage-like and skin keratinocytic cells

Lutein is a naturally occurring carotenoid with antioxidative, antitumorigenic, antiangiogenic, photoprotective, hepatoprotective, and neuroprotective properties. Although the anti-inflammatory effects of lutein have previously been described, the mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, in the present study, we aimed to investigate the regulatory activity of lutein in the inflammatory responses of skin-derived keratinocytes or macrophages and to elucidate the mechanism of its inhibitory action. Lutein significantly reduced several skin inflammatory responses, including increased expression of interleukin-(IL-) 6 from LPS-treated macrophages, upregulation of cyclooxygenase-(COX-) 2 from interferon-γ/tumor necrosis-factor-(TNF-) α-treated HaCaT cells, and the enhancement of matrix-metallopeptidase-(MMP-) 9 level in UV-irradiated keratinocytes. By evaluating the intracellular signaling pathway and the nuclear transcription factor levels, we determined that lutein inhibited the activation of redox-sensitive AP-1 pathway by suppressing the activation of p38 and c-Jun-N-terminal kinase (JNK). Evaluation of the radical and ROS scavenging activities further revealed that lutein was able to act as a strong anti-oxidant. Taken together, our findings strongly suggest that lutein-mediated AP-1 suppression and anti-inflammatory activity are the result of its strong antioxidative and p38/JNK inhibitory activities. These findings can be applied for the preparation of anti-inflammatory and cosmetic remedies for inflammatory diseases of the skin.

Prospective, Randomized, Open-Label Trial Comparing the Safety, Efficacy, and Tolerability of an Acne Treatment Regimen with and without a Probiotic Supplement and Minocycline in Subjects with Mild to Moderate Acne

Background:

Systemic antibiotics are an effective treatment for acne vulgaris. However, intolerable side effects may invariably occur.

Objective:

To determine whether probiotics reduce the side effects imparted by systemic antibiotics while working synergistically with the latter in treating inflammatory acne.

Methods:

Forty-five 18- to 35-year-old females were randomly assigned to one of three arms in this prospective, open-label study. Group A received probiotic supplementation, whereas group B received only minocycline. Group C was treated with both probiotic and minocycline. Clinical and subjective assessments were completed at baseline and during the 2-, 4-, 8-, and 12-week follow-up visits.

Results:

All patients demonstrated a significant improvement in total lesion count 4 weeks after treatment initiation ( p < .001), with continued improvement seen with each subsequent follow-up visit ( p < .01). At the 8- and 12-week follow-up visits, group C had a significant decrease in total lesion count versus groups A ( p < .001) and B ( p < .01). Two patients (13%) from group B failed to complete the study secondary to vaginal candidiasis.

Conclusion:

Probiotics may be considered a therapeutic option or adjunct for acne vulgaris by providing a synergistic antiinflammatory effect with systemic antibiotics while also reducing potential adverse events secondary to chronic antibiotic use.

Reduced size of sebaceous gland and altered sebum lipid composition in mice lacking fatty acid binding protein 5 gene

Fatty acid binding proteins (FABPs) are capable of binding long-chain FA and are involved in intracellular FA transport and signal transduction. In sebaceous glands, FABP5 is highly expressed in differentiated sebocytes; though, its function remains unclear. In this study, we examined the role of FABP5 in sebocytes using FABP5-deficient mice. The size of sebaceous glands was significantly reduced, while the sebum volume was increased with altered lipid composition in FABP5-deficient mice. However, no significant differences were discerned in the expression of proliferation or differentiation markers including Blimp1, c-myc, Ki67 and peroxisome proliferator-activated receptors (PPAR)γ between wild-type and FABP5-deficient sebaceous glands. The expression of cellular retinoic acid binding protein-2 (CRABP2) that is a competitor of FABP5 for RA signalling was increased in FABP5-deficient mice. These results suggest that FABP5 is involved in the regulation of sebaceous gland activity through modulation of cellular lipid signalling and/or metabolism in the sebocytes.

Intrascrotal Abscess, Propionibacterium acnes and Staphylococcus cohnii ssp. cohnii: A Case Report and Review of the Literature

Introduction. The Propionibacterium acnes and the Staphylococcus cohnii ssp. cohnii are occasional pathogenic bacteria. The intrascrotal localization of the Propionibacterium acnes is exceptional. The Staphylococcus cohnii ssp. cohnii is not able to colonize the urogenital apparatus but it is the most frequently responsible for blood culture contamination even if it can sustain, in particular conditions, systemic infections. Case Presentation. We report the case of a 72-year-old man who is under observation for pain and swelling of the left hemiscrotum associated to high fever. The scrotal ultrasound shows the presence of a left intra-scrotal abscess with didymus, epididymis, and intact didymus-epididymis tunicae. The blood culture executed for evening fever during antibiotic therapy has underlined an infection with Propionibacterium acnes. A following blood culture has shown an increase in Staphylococcus cohnii ssp. cohnii. Due to fever the patient has undergone left orchifunicolectomy with inguino-scrotal toilet. The anatomical pathological examination has also shown the presence of nonspecific granulomatous inflammation compatible with Propionibacterium acnes infection. Conclusion. The onset of an intrascrotal abscess likely sustained by Propionibacterium acnes complicated by a possible systemic Staphylococcus cohnii ssp. cohnii suprainfection is an exceptional event that, in our case, has been resolved with surgical toilet.

Propionibacterium acnes-induced iNOS and COX-2 protein expression via ROS-dependent NF-κB and AP-1 activation in macrophages

BACKGROUND

Propionibacterium acnes (P. acnes), a gram-positive anaerobic bacterium, plays a critical role in the development of inflammatory lesion as a result of cytokines production by keratinocytes and macrophages activation. However, effect of P. acnes on iNOS/NO and COX-2/PGE2 production in macrophages is still uninvestigated.

OBJECTIVE

This study aimed at determining the reactive oxygen species (ROS), inducible nitric oxide (NO) synthase (iNOS)/nitric oxide (NO), and cyclooxygenase (COX)-2/prostaglandin (PG)E2 produced by macrophages upon P. acnes infection, and dissecting the mechanism of P. acnes-stimulated multiplicity of infection (MOI)-dependent increases in iNOS and COX-2 protein expressions in accordance with the elevation of NO and PGE2 production by RAW264.7 macrophages.

METHODS

Using an in vitro cell culture system, the effects of P. acnes on iNOS/NO, COX-2/PGE2, ROS production, ERK/JNK, and AP-1/NF-κB activation were examined via Western blotting, a flow cytometric analysis, and luciferase assay. In pharmacological studies, the ROS scavenger, N-acetyl cysteine (NAC), the NADPH oxidase inhibitor, diphenylene iodide (DPI), and mitogen-activated protein kinase (MAPK) inhibitors (U0126 and SP600125) were applied to investigate the mechanism.

RESULTS

We found that P. acnes exposures increased iNOS/NO and COX-2/PGE2 expression in RAW264.7, J774A.1, and peritoneal macrophages via a MOI-dependent manner. Increased ROS production, ERK/JNK protein phosphorylation, and elevated AP-1/NF-κB luciferase activity are identified in P. acnes-induced iNOS/NO and COX-2/PGE2 production. Additionally, hispolon but not its analogs, hispolon methylether or dehydroxyhispolon, showed significant inhibition of P. acnes-induced iNOS/NO and COX-2/PGE2 production, indicating an important role of OH at C5 for hispolon's inhibition of P. acnes-induced inflammatory events in macrophages.

CONCLUSION

ROS-dependent stimulation of ERK, JNK, NF-κB, and AP-1 activation contributes to P. acnes-induced iNOS/NO and COX-2/PGE2 in macrophages, and chemicals such as hispolon possessing ability to block iNOS/NO and COX-2/PGE2 production reserve potential to be further developed for treatment of the early phase of inflammation elicited by P. acnes.

New antibiotic therapies for acne and rosacea

Acne and rosacea compromise a substantial portion of the dermatology clinical practice. Over the past century, many treatment modalities have been introduced with antibiotics playing a major role. Today, both oral and topical antibiotics are used in the management of acne and rosacea, with several novel formulations and/or combination regimens recently introduced. The latest studies suggest anti-inflammatory actions to be the most likely mechanism of antibiotics in acne and rosacea, shifting the focus to subantimicrobial-dose oral antibiotics and/or topical antibiotic regimens as the preferred first-line agents. Here we will discuss the most recent oral and topical antibiotic therapies available for treatment of acne and rosacea, with special focus on efficacy data, indication, dosing, and mechanism of action.

Draft genome sequence of an antibiotic-resistant Propionibacterium acnes strain, PRP-38, from the novel type IC cluster

Propionibacterium acnes, a non-spore-forming, anaerobic gram-positive bacterium, is most notably recognized for its association with acne vulgaris (I. Kurokawa et al., Exp. Dermatol. 18:821-832, 2009). We now present the draft genome sequence of an antibiotic-resistant P. acnes strain, PRP-38, isolated from an acne patient in the United Kingdom and belonging to the novel type IC cluster.

Propionibacterium acnes host cell tropism contributes to vimentin-mediated invasion and induction of inflammation

The contribution of the human microbiota to health and disease is poorly understood. Propionibacterium acnes is a prominent member of the skin microbiota, but is also associated with acne vulgaris. This bacterium has gained recent attention as a potential opportunistic pathogen at non-skin infection sites due to its association with chronic pathologies and its isolation from diseased prostates. We performed comparative global-transcriptional analyses for P. acnes infection of keratinocytes and prostate cells. P. acnes induced an acute, transient transcriptional inflammatory response in keratinocytes, whereas this response was delayed and sustained in prostate cells. We found that P. acnes invaded prostate epithelial cells, but not keratinocytes, and was detectable intracellularly 7 days post infection. Further characterization of the host cell response to infection revealed that vimentin was a key determinant for P. acnes invasion in prostate cells. siRNA-mediated knock-down of vimentin in prostate cellsattenuated bacterial invasion and the inflammatory response to infection. We conclude that host cell tropism, which may depend on the host protein vimentin, is relevant for P. acnes invasion and in part determines its sustained inflammatory capacity and persistence of infection.

Efficacy of chlorhexidine gluconate ointment (Oronine H(®)) for experimentally-induced comedones

BACKGROUND

Oronine H(®) ointment, which contains chlorhexidine gluconate as its active component, is a well known disinfectant, and has been widely used for treatment of acne in Japan. In this study, we investigated the inhibitory effect of this ointment on the formation of comedones induced by application of 50% oleic acid on the orifices of the external auditory canals of rabbits.

METHODS

The application sites were observed with a dermatoscope, and the area of the hair pores was measured using an Image analysis software program.

RESULTS

The chlorhexidine gluconate ointment inhibited comedone formation significantly more effectively than the liquid paraffin used as a control (P < 0.001). We also investigated the therapeutic effect of this ointment on comedones. After starting application of chlorhexidine gluconate ointment or liquid paraffin on the comedone area, the hair pore size was gradually decreased in the group treated with chlorhexidine gluconate ointment compared with the hair pore size at baseline.

CONCLUSION

These results suggest that chlorhexidine gluconate ointment is effective for inhibiting comedone formation as well as for treating already formed comedones. Chlorhexidine gluconate ointment is a useful topical medicine for the treatment of early-stage acne and for preventing acne.

Epigallocatechin-3-gallate suppresses IGF-I-induced lipogenesis and cytokine expression in SZ95 sebocytes

Acne vulgaris is the most common disease of the pilosebaceous unit. The pathogenesis of this inflammatory disease is complex, involving increased sebum production and perifollicular inflammation. To identify effective agents for factors that induce acne vulgaris, we explored the pharmacological potential of epigallocatechin-3-gallate (EGCG), which has been widely investigated as an anti-proliferative and anti-inflammatory agent. In this study, we demonstrated that topical application of EGCG to rabbit auricles reduced the size of the sebaceous glands. When applied to cultured human SZ95 sebocytes, EGCG strongly suppressed cell proliferation and lipogenesis. These actions of EGCG were reproduced in IGF-I-differentiated SZ95 sebocytes. To investigate the anti-inflammatory potential of EGCG, we evaluated pro-inflammatory cytokine synthesis in IGF-I-differentiated SZ95 sebocytes and found that expression of IL-1, IL-6, and IL-8 was decreased. These results provide early evidence that EGCG is an effective candidate for acne therapy whose mechanisms of action in IGF-I-differentiated SZ95 sebocytes include the inhibition of lipogenesis and inflammation.

Polyphenon-60 displays a therapeutic effect on acne by suppression of TLR2 and IL-8 expression via down-regulating the ERK1/2 pathway

Propionibacterium acnes (P. acnes) is a well-known acne-inducing factor which causes inflammatory skin lesions by enhancing cytokine production through toll-like receptor 2 (TLR2). Green tea extract catechin has been documented to possess anti-inflammatory effects. However, little is known about the mechanisms involved or any direct effect of green tea catechin on acne. The present study investigated the therapeutic effects and mechanism of polyphenon-60, also known as green tea catechin compound, on acne in vitro and in vivo. In a clinical study using topical polyphenon-60 treatment, acne patients showed symptomatic improvement with decrease in the number of comedos and pustules. To investigate the mechanism underlying the activity of polyphenon-60 in acne therapy, an in vitro study was performed. We found that polyphenon-60 reduced the levels of P. acnes-enhanced TLR2 and interleukin-8 (IL-8) in THP-1 cells, human monocyte cell line and human primary monocytes. Taken together, these data demonstrate that polyphenon-60 has a therapeutic effect on acne by suppressing inflammation, specifically by inhibiting TLR2 expression and IL-8 secretion via down-regulation of extracellular signal-regulated kinases 1/2 (ERK1/2) pathway and activator protein-1 (AP-1) pathway.

Complete genome sequences of three Propionibacterium acnes isolates from the type IA(2) cluster

Propionibacterium acnes is an anaerobic Gram-positive bacterium that has been linked to a wide range of opportunistic human infections and conditions, most notably acne vulgaris (I. Kurokawa et al., Exp. Dermatol. 18:821-832, 2009). We now present the whole-genome sequences of three P. acnes strains from the type IA(2) cluster which were recovered from ophthalmic infections (A. McDowell et al., Microbiology 157:1990-2003, 2011).

Syk/Src pathway-targeted inhibition of skin inflammatory responses by carnosic acid

Carnosic acid (CA) is a diterpene compound exhibiting antioxidative, anticancer, anti-angiogenic, anti-inflammatory, anti-metabolic disorder, and hepatoprotective and neuroprotective activities. In this study, the effect of CA on various skin inflammatory responses and its inhibitory mechanism were examined. CA strongly suppressed the production of IL-6, IL-8, and MCP-1 from keratinocyte HaCaT cells stimulated with sodium lauryl sulfate (SLS) and retinoic acid (RA). In addition, CA blocked the release of nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin E₂ (PGE₂) from RAW264.7 cells activated by the toll-like receptor (TLR)-2 ligands, Gram-positive bacterium-derived peptidoglycan (PGN) and pam3CSK, and the TLR4 ligand, Gram-negative bacterium-derived lipopolysaccharide (LPS). CA arrested the growth of dermatitis-inducing Gram-positive and Gram-negative microorganisms such Propionibacterium acnes, Pseudomonas aeruginosa, and Staphylococcus aureus. CA also blocked the nuclear translocation of nuclear factor (NF)-κB and its upstream signaling including Syk/Src, phosphoinositide 3-kinase (PI3K), Akt, inhibitor of κBα (IκBα) kinase (IKK), and IκBα for NF-κB activation. Kinase assays revealed that Syk could be direct enzymatic target of CA in its anti-inflammatory action. Therefore, our data strongly suggest the potential of CA as an anti-inflammatory drug against skin inflammatory responses with Src/NF-κB inhibitory properties.

Peptides with antimicrobial and anti-inflammatory activities that have therapeutic potential for treatment of acne vulgaris

The pathogenesis of acne vulgaris is multifactorial involving infection of the pilosebaceous unit with Propionibacterium acnes and a cytokine-mediated inflammatory response. Five frog skin-derived antimicrobial peptides ([D4k]ascaphin-8, [G4K]XT-7, [T5k]temporin-DRa, brevinin-2GU, and B2RP-ERa), chosen for their low hemolytic activity against human erythrocytes, were assessed for their effects on the growth of clinical isolates of P. acnes and on the release of pro-inflammatory and anti-inflammatory cytokines from peripheral blood mononuclear (PBM) cells. All peptides inhibited the growth of P. acnes with the highest potency exhibited by [D4k]ascaphin-8 (minimum inhibitory concentration, MIC=3-12.5 μM). Release of TNF-α from concanavalin A (ConA)-stimulated PBM cells was significantly reduced by [D4k]ascaphin-8, [G4K]XT-7, brevinin-2GU, and B2RP-ERa (1 and 20 μg/ml) and by [T5k]temporin-DRa (20 μg/ml). Release of IFN-γ from unstimulated PBM cells was significantly reduced by [D4k]ascaphin-8 and brevinin-2GU (1 and 20 μg/ml). No peptide showed significant effects on Il-17 release. Release of the anti-inflammatory cytokines TGF-β, IL-4, and IL-10 from both unstimulated and ConA-treated PBM cells was significantly increased by [T5k]temporin-DRa and B2RP-ERa (1 and 20μg/ml). The potent activities of [D4k]ascaphin-8 and [T5k]temporin-DRa in inhibiting the growth of P. acnes and the release of pro-inflammatory cytokines, and in stimulating the release of anti-inflammatory cytokines suggest a possible therapeutic role in the treatment of acne vulgaris.

CRISPR/cas loci of type II Propionibacterium acnes confer immunity against acquisition of mobile elements present in type I P. acnes

Propionibacterium acnes is a skin commensal that occasionally acts as an opportunistic pathogen. The population structure of this species shows three main lineages (I–III). While type I strains are mainly associated with sebaceous follicles of human skin and inflammatory acne, types II and III strains are more often associated with deep tissue infections. We investigated the occurrence and distribution of the clustered regularly interspaced short palindromic repeats (CRISPR) in P. acnes, assessed their immunological memory, and addressed the question if such a system could account for type-specific properties of the species. A collection of 108 clinical isolates covering all known phylotypes of P. acnes was screened for the existence of CRISPR/cas loci. We found that CRISPR loci are restricted to type II P. acnes strains. Sequence analyses of the CRISPR spacers revealed that the system confers immunity to P. acnes-specific phages and to two mobile genetic elements. These elements are found almost exclusively in type I P. acnes strains. Genome sequencing of a type I P. acnes isolate revealed that one element, 54 kb in size, encodes a putative secretion/tight adherence (TAD) system. Thus, CRISPR/cas loci in P. acnes recorded the exposure of type II strains to mobile genetic elements of type I strains. The CRISPR/cas locus is deleted in type I strains, which conceivably accounts for their ability to horizontally acquire fitness or virulence traits and might indicate that type I strains constitute a younger subpopulation of P. acnes.

Caspase-1 level is higher in the scalp in androgenetic alopecia

BACKGROUND AND OBJECTIVES

Inflammasomes that activate caspase-1 govern the innate immune inflammatory response. Whether hair loss associated with androgenetic alopecia (AGA) involves caspase-1 activation is not known.

METHODS

Immunohistochemical staining for caspase-1 was performed on scalp tissue sections, and protein lysates were analyzed from individuals with AGA (no treatment), and individuals with AGA taking finasteride with apparent hair growth, individuals with AGA taking finasteride without noted hair growth, and normal controls. In vitro studies of human keratinocytes were conducted to establish effects of finasteride, dihydrotestosterone (DHT), and testosterone on caspase-1 levels using immunoblot analysis.

RESULTS

Caspase-1 is expressed in normal human adult epidermal keratinocytes. Caspase-1 expression is greater in men with AGA. In contrast, in men taking finasteride, caspase-1 levels were lower and were similar to those in normal controls. In vitro studies showed that keratinocytes treated with finasteride in combination with testosterone or DHT resulted in a significant decrease in caspase-1 expression.

CONCLUSION

In vivo and in vitro finasteride treatment resulted in lower caspase-1 expression, supporting the idea that androgens influence innate immunity involved in the hair cycle in AGA. These findings may provide a basis for development of novel treatments for inflammatory skin and hair diseases.

Current drugs acting on Toll-like receptors in the treatment of inflammatory dermatoses M.A. iONESCU

The article presents the results of a study of the oil-in-water emulsion comprising TLR2-regul®, a complex patented by Uriage Laboratories. At the first stage of the study, skin explants from healthy donors were incubated in the physiological salt solution, oil-in-water indifferent cream excipient, with monoclonal anti-TLR2 antibodies and with the oil-in-water study emulsion, and then samples in each groups were divided into three sub-groups and incubated with extracts of M. furfur, p. acnes и S. aureus. The immune-enzyme assay method demonstrated a significant reduction in the production of IL-8 and higher quantity of β-defensin 2 in case of incubation with the study emulsion vs. the control group. At the second stage, the authors assessed the efficiency of the study emulsion in the treatment of patients suffering from seborrheic dermatitis (n = 143), acne (n = 34) and atopic dermatitis (n = 48) as a monotherapy vs. the cream base. After four weeks, patients with seborrheic dermatitis had a considerable reduction of erythema, peeling, itching and stinging, reduction in the number of recurrences; after three months, the group of acne patients had a considerably reduced number of inflammatory elements; after three weeks of treatment, patients with atopic dermatitis had a considerable reduction of erythema, infiltration and exudation as well as itching and shrinking. Thus, the study drug suggests new approaches to the treatment of inflammatory skin diseases with the pathogenesis complicated by P. acne, S. aureus or M. furfur due to its ability to modulate the immune response.

Genome sequence of Propionibacterium acnes type II strain ATCC 11828

Propionibacterium acnes is an anaerobic Gram-positive bacterium that forms part of the normal human cutaneous microbiota and is occasionally associated with inflammatory diseases (I. Kurokawa et al., Exp. Dermatol. 18:821-832, 2009). Here we present the complete genome sequence for the commercially available P. acnes type II reference strain ATCC 11828 (I. Nagy et al., Microbes Infect. 8:2195-2205, 2006) recovered from a subcutaneous abscess.

Acne vulgaris

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinisation, inflammation, and bacterial colonisation of hair follicles on the face, neck, chest, and back by Propionibacterium acnes. Although early colonisation with P acnes and family history might have important roles in the disease, exactly what triggers acne and how treatment affects the course of the disease remain unclear. Other factors such as diet have been implicated, but not proven. Facial scarring due to acne affects up to 20% of teenagers. Acne can persist into adulthood, with detrimental effects on self-esteem. There is no ideal treatment for acne, although a suitable regimen for reducing lesions can be found for most patients. Good quality evidence on comparative effectiveness of common topical and systemic acne therapies is scarce. Topical therapies including benzoyl peroxide, retinoids, and antibiotics when used in combination usually improve control of mild to moderate acne. Treatment with combined oral contraceptives can help women with acne. Patients with more severe inflammatory acne usually need oral antibiotics combined with topical benzoyl peroxide to decrease antibiotic-resistant organisms. Oral isotretinoin is the most effective therapy and is used early in severe disease, although its use is limited by teratogenicity and other side-effects. Availability, adverse effects, and cost, limit the use of photodynamic therapy. New research is needed into the therapeutic comparative effectiveness and safety of the many products available, and to better understand the natural history, subtypes, and triggers of acne.

Multilocus sequence typing and phylogenetic analysis of Propionibacterium acnes

Propionibacterium acnes is a commensal of human skin but is also implicated in the pathogenesis of acne vulgaris, in biofilm-associated infections of medical devices and endophthalmitis, and in infections of bone and dental root canals. Recent studies associate P. acnes with prostate cancer. As the species includes evolutionary lineages with distinct association with health and disease, there is a need for a high-resolution typing scheme. Recently, two multilocus sequence typing (MLST) schemes were reported, one based on nine and one based on seven housekeeping genes. In the present study, the two schemes were compared with reference to a phylogenetic tree based on 78 P. acnes genomes and their gene contents. Further support for a basically clonal population structure of P. acnes and a scenario of the global spread of epidemic clones of P. acnes was obtained. Compared to the Belfast scheme, the Aarhus MLST scheme (http://pacnes.mlst.net/), which is based on nine genes, offers significantly enhanced resolution and phylogenetic inferences more concordant with analyses based on a comprehensive sampling of the entire genomes, their gene contents, and their putative pathogenic potential.

Hypogonadism in the aging male diagnosis, potential benefits, and risks of testosterone replacement therapy

Hypogonadism in older men is a syndrome characterized by low serum testosterone levels and clinical symptoms often seen in hypogonadal men of younger age. These symptoms include decreased libido, erectile dysfunction, decreased vitality, decreased muscle mass, increased adiposity, depressed mood, osteopenia, and osteoporosis. Hypogonadism is a common disorder in aging men with a significant percentage of men over 60 years of age having serum testosterone levels below the lower limits of young male adults. There are a variety of testosterone formulations available for treatment of hypogonadism. Data from many small studies indicate that testosterone therapy offers several potential benefits to older hypogonadal men. A large multicenter NIH supported double blind, placebo controlled study is ongoing, and this study should greatly enhance the information available on efficacy and side effects of treatment. While safety data is available across many age groups, there are still unresolved concerns associated with testosterone therapy. We have reviewed the diagnostic methods as well as benefits and risks of testosterone replacement therapy for hypogonadism in aging men.

The channel physiology of the skin

During embryonic development, the skin, the largest organ of the human body, and nervous system are both derived from the neuroectoderm. Consequently, several key factors and mechanisms that influence and control central or peripheral nervous system activities are also present and hence involved in various regulatory mechanisms of the skin. Apparently, this is the case for the ion and non-ion selective channels as well. Therefore, in this review, we shall focus on delineating the regulatory roles of the channels in skin physiology and pathophysiology. First, we introduce key cutaneous functions and major characteristics of the channels in question. Then, we systematically detail the involvement of a multitude of channels in such skin processes (e.g. skin barrier formation, maintenance, and repair, immune mechanisms, exocrine secretion) which are mostly defined by cutaneous non-neuronal cell populations. Finally, we close by summarizing data suggesting that selected channels are also involved in skin diseases such as e.g. atopic dermatitis, psoriasis, non-melanoma cancers and malignant melanoma, genetic and autoimmune diseases, etc., as well as in skin ageing.

Intratumoral injection of Propionibacterium acnes suppresses malignant melanoma by enhancing Th1 immune responses

Malignant melanoma (MM) is an aggressive cutaneous malignancy associated with poor prognosis; many putatively therapeutic agents have been administered, but with mostly unsuccessful results. Propionibacterium acnes (P. acnes) is an aerotolerant anaerobic gram-positive bacteria that causes acne and inflammation. After being engulfed and processed by phagocytes, P. acnes induces a strong Th1-type cytokine immune response by producing cytokines such as IL-12, IFN-γ and TNF-α. The characteristic Th2-mediated allergic response can be counteracted by Th1 cytokines induced by P. acnes injection. This inflammatory response induced by P. acnes has been suggested to have antitumor activity, but its effect on MM has not been fully evaluated.We analyzed the anti-tumor activity of P. acnes vaccination in a mouse model of MM. Intratumoral administration of P. acnes successfully protected the host against melanoma progression in vivo by inducing both cutaneous and systemic Th1 type cytokine expression, including TNF-α and IFN-γ, which are associated with subcutaneous granuloma formation. P. acnes-treated tumor lesions were infiltrated with TNF-α and IFN-γ positive T cells. In the spleen, TNF-α as well as IFN-γ producing CD8(+)T cells were increased, and interestingly, the number of monocytes was also increased following P. acnes administration. These observations suggest that P. acnes vaccination induces both systemic and local antitumor responses. In conclusion, this study shows that P. acnes vaccination may be a potent therapeutic alternative in MM.