Effect of oral isotretinoin on the nucleo‐cytoplasmic distribution of FoxO1 and FoxO3 proteins in sebaceous glands of patients with acne vulgaris

Correlation between depression scores and serum NF-ĸB/NLRP3 axis, biotinidase, and HMGB1 after treatment with isotretinoin in patients with acne vulgaris

BACKGROUND

Acne vulgaris (AV) is an inflammatory skin disorder leading to scars and discomfort, its intensity has major psychological consequences such as depression.

AIM

To investigate the effect of isotretinoin (ISO) on NF-κB/NLRP3, biotinidase, and HMGB and correlation with depression.

PATIENTS AND METHODS

This was a case-control study that involved two groups. Group 1 is 20 healthy control, and group 2 is 20 patients diagnosed with AV according to Global Acne Grading System (GAGS) and received 20 mg ISO for 2 months. Before and after therapy, the Hamilton Depression Rating Scale (HDRS) was applied to assess each participant's level of depression. Nuclear factor kappa B (NF-ĸB), biotinidase, high mobility group box protein (HMGB1), nucleotide-binding domain, leucine-rich-containing family, and pyrin domain-containing-3 (NLRP-3) were measured in serum samples.

RESULTS

There was no significant difference in all measured markers of healthy group before and after 2 months. Regarding group 2, there was a statistically significant decrease in all measured markers after 2 months of treatment and significant correlations between GAGS, NF-ĸB, HMGB1, NLRP3, biotinidase, and depression score.

CONCLUSION

Increased GAGS, HMGB1, NLRP3, and biotinidase were associated with depression severity in AV patients and ISO treatment significantly reduced these parameters and reduced depressive symptoms.

Autocrine IL-8 Contributes to Propionibacterium Acnes-induced Proliferation and Differentiation of HaCaT Cells via AKT/FOXO1/ Autophagy

OBJECTIVE

Proprionibacterium acnes (P. acnes)-induced inflammatory responses, proliferation and differentiation of keratinocytes contribute to the progression of acne vulgaris (AV). P. acnes was found to enhance the production of interleukin-8 (IL-8) by keratinocytes. This study aimed to investigate the role of IL-8 in P. acnes-induced proliferation and differentiation of keratinocytes and the underlying mechanism.

METHODS

The P. acnes-stimulated HaCaT cell (a human keratinocyte cell line) model was established. Western blotting and immunofluorescence were performed to detect the expression of the IL-8 receptors C-X-C motif chemokine receptor 1 (CXCR1) and C-X-C motif chemokine receptor 2 (CXCR2) on HaCaT cells. Cell counting kit-8 (CCK-8) assay, 5-ethynyl-20-deoxyuridine (EdU) assay and Western blotting were performed to examine the effects of IL-8/CXCR2 axis on the proliferation and differentiation of HaCaT cells treated with P. acnes, the IL-8 neutralizing antibody, the CXCR2 antagonist (SB225002), or the CXCR1/CXCR2 antagonist (G31P). Western blotting, nuclear and cytoplasmic separation, CCK-8 assay, and EdU assay were employed to determine the downstream pathway of CXCR2 after P. acnes-stimulated HaCaT cells were treated with the CXCR2 antagonist, the protein kinase B (AKT) antagonist (AZD5363), or the constitutively active forkhead box O1 (FOXO1) mutant. Finally, autophagy markers were measured in HaCaT cells following the transfection of the FOXO1 mutant or treatment with the autophagy inhibitor 3-methyladenine (3-MA).

RESULTS

The expression levels of CXCR1 and CXCR2 were significantly increased on the membrane of HaCaT cells following P. acnes stimulation. The IL-8/CXCR2 axis predominantly promoted the proliferation and differentiation of P. acnes-induced HaCaT cells by activating AKT/FOXO1/autophagy signaling. In brief, IL-8 bound to its receptor CXCR2 on the membrane of keratinocytes to activate the AKT/FOXO1 axis. Subsequently, phosphorylated FOXO1 facilitated autophagy to promote the proliferation and differentiation of P. acnes-induced keratinocytes.

CONCLUSION

This study demonstrated the novel autocrine effect of IL-8 on the proliferation and differentiation of P. acnes-induced keratinocytes, suggesting a potential therapeutic target for AV.

Untargeted Lipidomics Analysis to Discover Lipid Profiles and Biomarkers of Rabbit Acne Model and Reveal Action Mechanism of Isotretinoin

Background

Acne vulgaris (AV), a chronic inflammatory pilosebaceous disorder, affects 80-90% of teenagers. This study aimed to discover lipid profiles and biomarkers of the rabbit ear acne model, and investigate the mechanism of isotretinoin in treating acne at the lipid level.

Methods

Untargeted lipidomic analysis using ultra-high performance liquid chromatography system (UHPLC) coupled to q-extraction plus was performed to identify skin lipid metabolites in blank control (groups C), model group (group M) and isotretinoin group (group T). Multivariate statistical analysis was used to process the lipidomics data.

Results

A total of 43 lipid classes comprising 6989 lipid species were identified from the mass spectrometry data. The orthogonal partial least squares discriminant analysis (OPLS-DA) model demonstrated significant separation in skin lipidomic profiles between group M and group C. With variable influence on projection (VIP) > 1.0 and P-value < 0.05, 299 significantly different lipid metabolites were identified. These lipid metabolites consisted mainly of ceramides (Cer) (53.85%), phosphatidylethanolamines (PE) (9.03%), phosphatidylcholines (PC)(5.35%), and sphingomyelin (SM)(4.01%). Combining with AUC ≥ 0.9 as the elected criteria, Cer (d18;1_24:0), zymosterol (ZyE)(33:5), Cer (t43:1), ZyE (33:6), ZyE (24:7), and ZyE (35:6) have "high" accuracy. Isotretinoin treatment normalized 25 lipid metabolites in the acne model.

Conclusion

Our findings provide new insights into the role of lipid metabolism in the pathogenesis of acne and the action mechanism of isotretinoin.

Genetic polymorphisms in FABP2, CYP2E1, and TP53 genes are potentially associated with colorectal cancer susceptibility

Colorectal cancer (CRC) is among the most prevalent cancers with a high mortality rate. Both genetic and environmental factors contribute to CRC development. This study aimed to assess the association of single nucleotide polymorphisms (SNPs) in the fatty acid binding protein-2 (rs1799883), Cytochrome P450 2E1 (rs3813865), TP53 (rs1042522), and Murine double minute 2 (rs1042522) genes with CRC. A cross-sectional case-control study was conducted at the Institute of Molecular Biology and Biotechnology from May 2020 to March 2021, involving CRC patients (N = 100) and controls (N = 100) recruited from the Multan district in Pakistan. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) were employed to investigate the studied SNPs. The association of SNPs in all genes with CRC was examined either individually or in various combinations. Genotypes at three SNPs, rs1799883 in FABP2, rs3813865 in CYP2E1, and rs1042522 in TP53, were found to be associated with the development of CRC, while rs1042522 in MDM2 was not. Patients who were married, smoked, lacked exercise habits or had a family history of CRC were at a greater risk of acquiring the disease. FABP2 gene rs1799883, CYP2E1 gene rs3813865, and TP53 gene rs1042522 polymorphisms are significant in the development of CRC in Pakistani participants.

The Effect of Isotretinoin on Insulin Resistance and Serum Adiponectin Levels in Acne Vulgaris Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Isotretinoin is the drug of choice for severe acne. We sought to examine the potential link between isotretinoin and insulin resistance.

METHODS

We conducted a systematic review and meta-analysis in accordance with the PRISMA statement. A comprehensive search of the PubMed/MEDLINE, SCOPUS, and Cochrane databases was performed until 12 January 2022 utilizing the PICO (Patient, Intervention, Comparison, Outcome) tool. Fifteen English-language studies focusing on isotretinoin-treated acne patients were included. Serum levels of insulin, glucose, and adiponectin were evaluated before and after treatment, and insulin sensitivity was assessed using the HOMA-IR. A meta-analysis was conducted using RevMan 5.4.1 software, and a quality assessment was undertaken using the ROBINS-I tool.

RESULTS

The meta-analysis unveiled a statistically significant rise in the post-treatment levels of adiponectin, an anti-inflammatory agent, which inhibits liver glucose production while enhancing insulin sensitivity (SMD = 0.86; 95% confidence interval (95% CI) = 0.48-1.25, p-value < 0.0001; I2 = 58%). Our subgroup analysis based on study type yielded consistent findings. However, no statistically significant outcomes were observed for insulin, glucose levels, and the HOMA-IR.

CONCLUSIONS

There is not a clear association between isotretinoin and insulin resistance, but it appears to enhance the serum levels of adiponectin, which participates in glucose metabolism.

Combination of Fractional Microneedling Radiofrequency and Ablative Fractional Laser versus Ablative Fractional Laser Alone for Acne and Acne Scars

PURPOSE

Fractional microneedle radiofrequency (FMR) systems are used to treat inflammatory acne and scarring. Nonetheless, few controlled studies have combined this treatment with the traditional ablative fractional laser (AFL). We aimed to assess the safety and efficacy of the combination of FMR and AFL versus AFL alone in treating acne and acne scars.

MATERIALS AND METHODS

In this 20-week, randomized, split-face study, 23 Korean patients with facial acne and acne scars underwent FMR and AFL treatments. One half of each patient's face was randomly assigned to receive FMR+AFL, whereas the other half received AFL alone. Treatments were administered in three consecutive sessions at 4-week intervals. This study investigated the severity of inflammatory acne, acne scars, individual lesion counts, depressed scar volumes, as well as patient and physician satisfaction. In addition, five patients underwent skin biopsy, and sebum output was measured.

RESULTS

The FMR+AFL treatment demonstrated superior efficacy compared to AFL alone in terms of inflammatory acne and acne scar grading, lesion counts, and subjective satisfaction. The side effects were minimal and well-tolerated in both groups. Immunohistochemical findings from skin biopsy samples revealed that the application of FMR+AFL could induce an inhibitory effect on sebum secretion at the molecular level.

CONCLUSION

FMR combined with AFL is a well-tolerated and effective treatment modality for inflammatory acne and acne scarring.

Acne Transcriptomics: Fundamentals of Acne Pathogenesis and Isotretinoin Treatment

This review on acne transcriptomics allows for deeper insights into the pathogenesis of acne and isotretinoin's mode of action. Puberty-induced insulin-like growth factor 1 (IGF-1), insulin and androgen signaling activate the kinase AKT and mechanistic target of rapamycin complex 1 (mTORC1). A Western diet (hyperglycemic carbohydrates and milk/dairy products) also co-stimulates AKT/mTORC1 signaling. The AKT-mediated phosphorylation of nuclear FoxO1 and FoxO3 results in their extrusion into the cytoplasm, a critical switch which enhances the transactivation of lipogenic and proinflammatory transcription factors, including androgen receptor (AR), sterol regulatory element-binding transcription factor 1 (SREBF1), peroxisome proliferator-activated receptor γ (PPARγ) and signal transducer and activator of transcription 3 (STAT3), but reduces the FoxO1-dependent expression of GATA binding protein 6 (GATA6), the key transcription factor for infundibular keratinocyte homeostasis. The AKT-mediated phosphorylation of the p53-binding protein MDM2 promotes the degradation of p53. In contrast, isotretinoin enhances the expression of p53, FoxO1 and FoxO3 in the sebaceous glands of acne patients. The overexpression of these proapoptotic transcription factors explains isotretinoin's desirable sebum-suppressive effect via the induction of sebocyte apoptosis and the depletion of BLIMP1(+) sebocyte progenitor cells; it also explains its adverse effects, including teratogenicity (neural crest cell apoptosis), a reduced ovarian reserve (granulosa cell apoptosis), the risk of depression (the apoptosis of hypothalamic neurons), VLDL hyperlipidemia, intracranial hypertension and dry skin.

Hidradenitis suppurativa and follicular occlusion syndrome: Where is the pathogenetic link?

The follicular occlusion tetrad complex encompasses several entities (hidradenitis suppurativa, acne conglobata, dissecting cellulitis of the scalp, and pilonidal cyst) that share common clinical features, risk factors, and pathophysiology. Follicular occlusion is a crucial triggering mechanism in the etiology in each of these disorders, leading to development of distinctive skin lesions such as deep-seated nodules, abscesses, comedones, and draining sinuses, often with accompanying scarring. Despite the fact that the follicular occlusion tetrad components manifest multiple similarities, they also exhibit many differences among themselves and require individual approaches and treatment.

Prevalence of adverse events varies with the different oral isotretinoin brands in acne treatment: a retrospective observational study

Oral isotretinoin remains the most effective treatment for acne. The aim of this retrospective single-center cohort study was to estimate the prevalence of adverse events with the different oral isotretinoin brands used in acne treatment. The population consisted of all patients who consulted for acne between January 2015 and January 2020. The inclusion criterion was the initiation of treatment with oral isotretinoin. The exclusion criteria were the use of two or more brands during the same course of treatment and previous treatment with oral isotretinoin. Statistical analysis was carried out using Chi-square and Mann-Whitney tests. We analyzed 468 patients of whom 68.6% were female. The median age was 21 years. The median weight was 65 kg. The treatment was Roaccutane®, Curacné®, Acnotren®, Isosupra®, Contracné®, or Acnogen® in 44.2%, 28%, 14.5%, 10.5%, 1.7% and 0.4% of cases, respectively. Xerosis was the most frequently reported side effect regardless of the brand. The highest frequencies of hypercholesterolemia (25.6%) and eczema (13%) were noted with Roaccutane®; hypertriglyceridemia (16.8%), epistaxis (9.9%) and fatigue (3.1%) with Curacné®; excessive sweating (4.1%) and headache (4.1%) with Isosupra®; and abnormal liver function tests (11%) with Acnotren®. We found a significant correlation mainly between abnormal ASAT and Acnotren® (p = 0.009), hypercholesterolemia and Roaccutane® [OR = 1.652 (95% CI 1.056-2.585)], hypertriglyceridemia and higher body weight (p = 0.004). Factors related to the drug brand and to characteristics of acne patients could explain the variability in the prevalence of some adverse events.

Isotretinoin treatment upregulates the expression of p53 in the skin and sebaceous glands of patients with acne vulgaris

The transcriptomic regulation induced by isotretinoin (13-cis retinoic acid) is still a matter of debate as short-term exposures of immortalized sebocytes with isotretinoin produced conflicting results. Based on translational evidence, it has been hypothesized that oral isotretinoin treatment upregulates the expression of the transcription factor p53. Twenty-five patients suffering from acne vulgaris were treated with isotretinoin (0.6 mg/kg body weight) for 6 weeks. Biopsies from back skin were taken before and after isotretinoin treatment for the determination of p53 expression by immunohistochemical staining, quantification of p53 protein concentration by enzyme-linked immunosorbent assay and TP53 gene expression by quantitative reverse transcription real time PCR. Fifteen socio-demographically cross-matched healthy volunteers served as controls. Isotretinoin treatment significantly increased the nuclear expression of p53 in sebaceous glands of treated patients compared to pre-treatment levels and p53 levels of untreated controls. Furthermore, the p53 protein and gene expression significantly increased in the skin after treatment. The magnitude of p53 expression showed an inverse correlation to acne severity score and body mass index. Under clinical conditions, isotretinoin induced the expression of p53, which controls multiple transcription factors involved in the pathogenesis of acne vulgaris including FoxO1, androgen receptor and critical genes involved in the induction of autophagy and apoptosis. Increased p53-FoxO1 signalling enhanced by systemic isotretinoin treatment explains the underlying transcriptomic changes causing sebum suppression but also the adverse effects associated with systemic isotretinoin therapy.

Absence of GSTT1 and polymorphisms in GSTP1 and TP53 are associated with the incidence of acne vulgaris

BACKGROUNDS

Acne vulgaris is a chronic inflammatory skin disease of the pilosebaceous unit affecting most teenagers and numerous adults throughout the world. The present study was designed to assess the association of the presence or absence of GSTM1, GSTT1, and single nucleotide polymorphisms rs1695 in GSTP1 and rs1042522 in TP53 gene with acne vulgaris.

METHODS

The cross-sectional case-control study was conducted at the Institute of Zoology from May 2020 to March 2021 and included acne vulgaris patients (N = 100) and controls (N = 100) enrolled in Dera Ghazi Khan district, Pakistan. Multiplex and tetra-primer amplification refractory mutation system-polymerase chain reactions were applied to investigate the genotype in analyzed genes. The association of rs1695 and rs1042522 with acne vulgaris was studied either individually or in various combinations with GATM1 and T1.

RESULTS

A significant association of absence of GSTT1 and mutant genotype at rs1695 (GG) and at rs1042522 (CC) in GSTP1 and TP53, respectively, was found to be associated with acne vulgaris in enrolled subjects. Subjects aged 10-25 years and smokers were more susceptible to acne vulgaris.

CONCLUSION

Our results suggest that genotypes of glutathione S-transferases (GSTs) and TP53 are involved in protection against oxidative stress and may influence disease progression in acne vulgaris.

Network Pharmacology and Molecular Modeling to Elucidate the Potential Mechanism of Neem Oil against Acne vulgaris

Acne vulgaris is a common skin disorder with a complicated etiology. Papules, lesions, comedones, blackheads, and other skin lesions are common physical manifestations of Acne vulgaris, but the individual who has it also regularly has psychological repercussions. Natural oils are being utilized more and more to treat skin conditions since they have fewer negative effects and are expected to provide benefits. Using network pharmacology, this study aims to ascertain if neem oil has any anti-acne benefits and, if so, to speculate on probable mechanisms of action for such effects. The neem leaves (Azadirachta indica) were collected, verified, authenticated, and assigned a voucher number. After steam distillation was used to extract the neem oil, the phytochemical components of the oil were examined using gas chromatography-mass spectrometry (GC-MS). The components of the oil were computationally examined for drug-likeness using Lipinski's criteria. The Pharm Mapper service was used to anticipate the targets. Prior to pathway and protein-protein interaction investigations, molecular docking was performed to predict binding affinity. Neem oil was discovered to be a potential target for STAT1, CSK, CRABP2, and SYK genes in the treatment of Acne vulgaris. In conclusion, it was discovered that the neem oil components with PubChem IDs: ID_610088 (2-(1-adamantyl)-N-methylacetamide), ID_600826 (N-benzyl-2-(2-methyl-5-phenyl-3H-1,3,4-thiadiazol-2-yl)acetamide), and ID_16451547 (N-(3-methoxyphenyl)-2-(1-phenyltetrazol-5-yl)sulfanylpropanamide) have strong affinities for these drug targets and may thus be used as therapeutic agents in the treatment of acne.

Hyaluronic acid-FGF2-derived peptide bioconjugates for suppression of FGFR2 and AR simultaneously as an acne antagonist

Acne is a chronic skin condition that has serious consequences for mental and social well-being because it frequently occurs on the face. Several acne treatment approaches have commonly been used but have been hampered by side effects or weak activity. Thus, the investigation of the safety and efficacy of anti-acne compounds is of considerable medical importance. Herein, an endogenous peptide (P5) derived from fibroblast growth factors 2 (FGF2) was conjugated to the polysaccharide hyaluronic acid (HA) to generate the bioconjugate nanoparticle HA-P5, which suppresses fibroblast growth factor receptors (FGFRs) to significantly rehabilitate acne lesions and reduce sebum accumulation in vivo and in vitro. Moreover, our results show that HA-P5 inhibits both fibroblast growth factor receptor 2 (FGFR2) and androgen receptor (AR) signalling in SZ95 cells, reverses the acne-prone transcriptome, and decreases sebum secretion. Furthermore, the cosuppression mechanism revealed that HA-P5 blocks FGFR2 activation, as well as the YTH N6-methyladenosine RNA binding protein F3 (YTHDF3) downstream molecules, including an N6-methyladenosine (m6A) reader that facilitates AR translation. More importantly, a significant difference between HA-P5 and the commercial FGFR inhibitor AZD4547 is that HA-P5 does not trigger the overexpression of aldo-keto reductase family 1 member C3 (AKR1C3), which blocks acne treatment by catalyzing the synthesis of testosterone. Overall, we demonstrate that a polysaccharide-conjugated and naturally derived oligopeptide HA-P5 can alleviate acne and act as an optimal FGFR2 inhibitor and reveal that YTHDF3 plays a crucial role in signalling between FGFR2 and AR.

The effect of the ketogenic diet on Acne: Could it be a therapeutic tool?

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinization, inflammation, and bacterial colonization of the hair follicles of the face, neck, chest and back by Propionibacterium acnes. Overall, inflammation and immune responses are strongly implicated in the pathogenesis of acne. Although early colonization with Propionibacterium acnes and family history may play an important role in the disease, it remains unclear exactly what triggers acne and how treatment affects disease progression. The influence of diet on acne disease is a growing research topic, yet few studies have examined the effects of diet on the development and clinical severity of acne disease, and the results have often been contradictory. Interestingly, very low-calorie ketogenic diet (VLCKD) has been associated with both significant reductions in body weight and inflammatory status through the production of ketone bodies and thus it has been expected to reduce the exacerbation of clinical manifestations or even block the trigger of acne disease. Given the paucity of studies regarding the implementation of VLCKD in the management of acne, this review aims to provide evidence from the available scientific literature to support the speculative use of VLCKD in the treatment of acne.

Isotretinoin Impairs the Secretory Function of Meibomian Gland Via the PPARγ Signaling Pathway

Purpose

To investigate the effects of isotretinoin on the ocular surface and to explore the possible mechanisms.

Methods

Rats were treated with isotretinoin 20 mg/kg/d for five months and tested monthly for tear secretion, fluorescein staining, and infrared photography. After five months of treatment, tissues were harvested for routine staining to evaluate the morphological changes; and real-time polymerase chain reaction, Western blot, and immunohistochemistry to study the expression of associated genes and their products such as forkhead box protein O1 (FoxO1), forkhead box protein O3, peroxisome proliferator–activated receptor γ (PPARγ), adipose differentiation–related protein, elongation of very long chain fatty acids protein 4, fatty acid binding protein 4, matrix metalloproteinase-9, and interleukin-6.

Results

Systemically, isotretinoin-treated rats have a significantly lower body weight that controls and apparent skin damage. Locally, although there was no alteration in tear secretion, a significant corneal involvement indicated by increased fluorescein staining scores, and also the contrast of meibomian gland was significantly reduced but no significant atrophy of the acinus was found. In addition, isotretinoin causes a decrease in conjunctival goblet cells. Furthermore, isotretinoin treatment did not cause the upregulation of FoxO1 and inflammation related genes but significantly suppressed the expression of PPARγ pathway.

Conclusions

Isotretinoin does not cause a significant atrophy of the acinus and a significant change of FoxO1 expression in the meibomian gland. Isotretinoin causes meibomian gland dysfunction, affecting meibocyte differentiation and qualitative and quantitative changes in the meibum, through PPARγ pathway.

The multi-functional roles of forkhead box protein O in skin aging and diseases

Forkhead box, class O (FoxO) family members are multifunctional transcription factors that are involved in several metabolic processes, including energy metabolism, apoptosis, DNA repair, and oxidative stress. However, their roles in skin health have not been well-documented. Recent studies have indicated that FoxOs are important factors to control skin homeostasis and health. The activation or deactivation of some FoxO family members is closely related to melanogenesis, wound healing, acne, and melanoma. In this review, we have discussed the recent findings that demonstrate the relationship between FoxOs and skin health as well as the underlying mechanisms associated with their functions.

The impact of isotretinoin on the pituitary-ovarian axis: An interpretative review of the literature

Isotretinoin (13-cis-retinoic acid), a derivative of vitamin A, is used in the treatment of severe acne resulting in sebum suppression induced by sebocyte apoptosis. Isotretinoin treatment is associated with several adverse effects including teratogenicity, hepatotoxicity, and dyslipidemia. Isotretinoin's effects on endocrine systems and its potential role as an endocrine disruptor are not yet adequately investigated. This review presents clinical, endocrine, and molecular evidence showing that isotretinoin treatment adversely affects the pituitary-ovarian axis and enhances the risk of granulosa cell apoptosis reducing follicular reserve. Isotretinoin is associated with pro-apoptotic signaling in sebaceous glands through upregulated expression of p53, forkhead box O transcription factors (FOXO1, FOXO3), and tumor necrosis factor-related apoptosis inducing ligand (TRAIL). Two literature searches including clinical and experimental studies respectively support the hypothesis that isotretinoin's toxicological mode of action on the pituitary-ovarian axis might be caused by over-expressed p53/FOXO1 signaling resulting in gonadotropin suppression and granulosa cell apoptosis. The reduction of follicular reserve by isotretinoin treatment should be especially considered when this drug will be administered for the treatment of acne in post-adolescent women, in whom fertility may be adversely affected. In contrast, isotretinoin treatment may exert beneficial effects in states of hyperandrogenism, especially in patients with polycystic ovary syndrome.

The PI3K/Akt Pathway: Emerging Roles in Skin Homeostasis and a Group of Non-Malignant Skin Disorders

The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway regulates cell proliferation, differentiation, and migration, along with angiogenesis and metabolism. Additionally, it could mediate skin development and homeostasis. There is much evidence to suggest that dysregulation of PI3K/Akt pathway is frequently associated with several human cutaneous malignancies like malignant melanoma (MM), basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (SCC), as well as their poor outcomes. Nevertheless, emerging roles of PI3K/Akt pathway cascade in a group of common non-malignant skin disorders including acne and psoriasis, among others, have been recognized. The enhanced understanding of dysfunction of PI3K/Akt pathway in patients with these non-malignant disorders has offered a solid foundation for the progress of updated therapeutic targets. This article reviews the latest advances in the roles of PI3K/Akt pathway and their targets in the skin homeostasis and progression of a wide range of non-malignant skin disorders and describes the current progress in preclinical and clinical researches on the involvement of PI3K/Akt pathway targeted therapies.

Transcriptome comparison of isotretinoin-effective and isotretinoin-ineffective severe acne vulgaris patients

BACKGROUND

Oral isotretinoin is the first-line treatment of severe nodular acne. However, patients presenting ineffective or poor effective to oral isotretinoin are still a clinical problem, and its molecular genetic mechanisms remain unclear.

AIMS

To compare the transcriptome profiles of isotretinoin-effective and isotretinoin-ineffective severe acne vulgaris patients and analyze the potential physiological roles to better understand the mechanisms of isotretinoin efficacy differences.

PATIENTS/METHODS

Peripheral blood of 43 patients with severe acne was collected before treatment. After 8-week isotretinoin, patients presented effective and ineffective to isotretinoin treatment were selected and their pretreatment peripheral blood was analyzed. High-throughput sequencing was used to detect gene expression profiles. Gene Ontology and KEGG were used to perform functional annotation and pathway enrichment analysis.

RESULTS

Ten acne patients (3 male and 7 female, age 31 ± 9.2) presented effectiveness by oral isotretinoin and 10 acne patients (4 male and 6 female, age 28 ± 7.7) presented ineffectiveness were included. Comparison of gene profiles of isotretinoin-effective and isotretinoin-ineffective patients revealed 2779 differentially expressed genes: 2723 upregulated and 56 downregulated. Differentially expressed genes were enriched in RNA degradation pathway, autophagy pathway, protein ubiquitination pathway, protein processing in endoplasmic reticulum pathway, T-cell receptor signaling pathway, spliceosome pathway, mRNA surveillance pathway, cell cycle pathway, long-term potentiation pathway, and FoxO signaling pathway.

CONCLUSION

Transcriptome expression differences not only participated in the acne pathogenesis, but also influenced the isotretinoin therapeutic effects. These findings might provide some evidence for exploring individualized therapy for acne patients.

Alleviating and exacerbating foods in hidradenitis suppurativa

While dietary triggers have been investigated in acne and other inflammatory follicular dermatoses, there is a paucity of data on diet and hidradenitis suppurativa (HS). We sought to identify exacerbating and alleviating foods in HS patients. An anonymous survey was distributed via HS Facebook support groups and in person at HS specialty clinics. Participants were asked to select all that apply from a list to indicate foods that worsen and make HS better including sweet foods, breads and pasta, red meat, chicken, fish, canned foods, fruits, vegetables, dairy, high-fat foods, I do not know, and no. Only 12.0% (n = 89/744) identified alleviating foods while 32.6% (n = 237/728) identified HS-symptom-exacerbating foods. The most commonly reported exacerbating foods were sweets (67.9%), bread/pasta/rice (51.1%), dairy (50.6%), and high-fat foods (44.2%). The most commonly reported alleviating foods included vegetables (78.7%), fruit (56.2%), chicken (51.7%), and fish (42.7%). Further studies are required to evaluate the mechanistic links between diet and HS. HS patients may benefit from receiving dietary counseling as part of a comprehensive HS management plan.

Putative Genes and Pathways Involved in the Acne Treatment of Isotretinoin via Microarray Data Analyses

Acne is the eighth most common disease worldwide. Disease burden of acne such as anxiety, reduced self-esteem, and facial scarring lowers the life quality of acne patients. Isotretinoin is the most potent treatment for moderate-severe acne. However, the adverse events of isotretinoin especially teratogenicity limit its use. This study aims at investigating the therapeutical mechanisms of isotretinoin using bioinformatics analysis. Differentially expressed genes (DEGs) were filtered from microarray datasets GSE10432, GSE10433, and GSE11792. Functional and pathway enrichment analyses of DEGs were performed. Protein–protein interaction (PPI) network and module analyses were also conducted based on DEGs. Using isotretinoin for 1 week, LCN2, PTGES, and GDF15 were upregulated and might mediate sebocytes apoptosis and thus decreased sebum production; CCL2 originated from activated TNF signaling pathway and S100A7 could be related with “acne-flare”. While treating with isotretinoin for 8 weeks, key genes were downregulated, including HMGCS1, HMGCR, FDFT1, MVD, IDI1, and FDPS, which may be associated with decreased sebum synthesis; HMGCS1, HMGCR, and FDFT1 also probably associated with apoptosis of sebocytes. There were only two common genes including ACSBG1 and BCAT2 which worked in both 1 week and 8 weeks and could associate with decreased sebum synthesis and apoptosis of sebocytes, respectively. These results indicate potential therapeutics and side effect mechanisms of isotretinoin in the acne treatment and provide a research direction to further investigate the therapeutic mechanism of isotretinoin and thus develop retinoid-like compounds with similar curative effect and without teratogenicity.

Autophagy regulates lipid production and contributes to the sebosuppressive effect of retinoic acid in human SZ95 sebocytes

BACKGROUND

Autophagy is a catabolic process for eliminating damaged organelles or proteins to maintain cellular homeostasis. Recently, lipids have been demonstrated to be targets for autophagosomal degradation. Therefore, autophagy might be involved in sebaceous gland homeostasis, however, relevant data are lacking.

OBJECTIVES

We investigated the role of autophagy in sebaceous lipogenesis and its regulatory mechanisms in human SZ95 sebocytes. We also examined the possible role of autophagy in 13-cis-retinoic acid (13-cis-RA)-mediated sebosuppression.

METHODS

Autophagy markers expression was examined by immunohistochemistry in normal and acne lesional skin. SZ95 sebocytes were treated with autophagy inhibitors under starvation or treated with a combination of testosterone and linoleic acid (testosterone/LA), with or without autophagy inducer rapamycin or 13-cis-RA. Lipids were assessed by BODIPY and quantitative Nile Red staining. Autophagy-related gene 7 small interference RNA was used to confirm the role of autophagy on the sebosuppressive effect of rapamycin or 13-cis-RA.

RESULTS

Autophagy markers were strongly expressed in the maturing sebaceous gland cells in healthy skin, whereas downregulated in the acne-involved sebaceous glands. Testosterone/LA or insulin-like growth factor-1 inhibited starvation-induced sebocyte autophagy. Pharmacological inhibition of autophagy led to increased sebaceous lipid accumulation. Contrary, rapamycin inhibited the testosterone/LA-induced lipogenesis and expression of fatty acid synthesis genes via activating the autophagy pathway. 13-cis-RA increased autophagy in SZ95 sebocytes, partly via FoxO1 activation, and inhibition of autophagy abolished the sebosuppressive effect of 13-cis-RA.

CONCLUSIONS

Autophagy plays an important role in the modulation of lipogenesis in human sebocytes and is involved in the sebostatic effect of 13-cis-RA.

Neuroendocrinology and neurobiology of sebaceous glands

The nervous system communicates with peripheral tissues through nerve fibres and the systemic release of hypothalamic and pituitary neurohormones. Communication between the nervous system and the largest human organ, skin, has traditionally received little attention. In particular, the neuro-regulation of sebaceous glands (SGs), a major skin appendage, is rarely considered. Yet, it is clear that the SG is under stringent pituitary control, and forms a fascinating, clinically relevant peripheral target organ in which to study the neuroendocrine and neural regulation of epithelia. Sebum, the major secretory product of the SG, is composed of a complex mixture of lipids resulting from the holocrine secretion of specialised epithelial cells (sebocytes). It is indicative of a role of the neuroendocrine system in SG function that excess circulating levels of growth hormone, thyroxine or prolactin result in increased sebum production (seborrhoea). Conversely, growth hormone deficiency, hypothyroidism, and adrenal insufficiency result in reduced sebum production and dry skin. Furthermore, the androgen sensitivity of SGs appears to be under neuroendocrine control, as hypophysectomy (removal of the pituitary) renders SGs largely insensitive to stimulation by testosterone, which is crucial for maintaining SG homeostasis. However, several neurohormones, such as adrenocorticotropic hormone and α-melanocyte-stimulating hormone, can stimulate sebum production independently of either the testes or the adrenal glands, further underscoring the importance of neuroendocrine control in SG biology. Moreover, sebocytes synthesise several neurohormones and express their receptors, suggestive of the presence of neuro-autocrine mechanisms of sebocyte modulation. Aside from the neuroendocrine system, it is conceivable that secretion of neuropeptides and neurotransmitters from cutaneous nerve endings may also act on sebocytes or their progenitors, given that the skin is richly innervated. However, to date, the neural controls of SG development and function remain poorly investigated and incompletely understood. Botulinum toxin-mediated or facial paresis-associated reduction of human sebum secretion suggests that cutaneous nerve-derived substances modulate lipid and inflammatory cytokine synthesis by sebocytes, possibly implicating the nervous system in acne pathogenesis. Additionally, evidence suggests that cutaneous denervation in mice alters the expression of key regulators of SG homeostasis. In this review, we examine the current evidence regarding neuroendocrine and neurobiological regulation of human SG function in physiology and pathology. We further call attention to this line of research as an instructive model for probing and therapeutically manipulating the mechanistic links between the nervous system and mammalian skin.

The Effects of Oral Isotretinoin in Women with Acne and Polycystic Ovary Syndrome

INTRODUCTION

Many patients who were diagnosed as polycystic ovary syndrome- (PCOS-) related acne were not capable of sustaining or beginning oral contraceptive pills (OCPs) due to pill scaring, contraindications of OCP use, migraine, or smoking. In this situation, oral isotretinoin treatment may become an important option for PCOS-related acne. The aim of the study was to determine the effects of isotretinoin treatment on PCOS patients who were complicated with severe cystic acne.

MATERIALS AND METHODS

This study consisted of 40 female patients diagnosed as PCOS complicated with severe cystic acne. These patients were not eligible candidates for OCP use due to migraine, thrombophilia, heavy smoking, or pill scare. To establish baseline values of hormone levels, on days 2-5 of the menstrual cycle, venous blood samples were obtained. Moreover Modified Ferriman-Gallwey (mFG) score, acne score (AS), follicle count, and bilateral ovarian volumes were evaluated both before and after isotretinoin treatment.

RESULTS

Isotretinoin treatment significantly decreased Ferriman-Gallwey score, free testosterone, insulin level, hemoglobin level, acne score, and ovarian volume. Increased triglyceride and cholesterol levels were detected after treatment.

CONCLUSION

Isotretinoin treatment may have beneficial effects on free testosterone, insulin, acne score, and Ferriman-Gallwey score. Solely isotretinoin administration may supply adequate healing in PCOS patients' symptoms complicated with severe cystic acne who is not eligible candidates for OCP use. This trial is registered with Clinicaltrials.gov NCT02855138.

From pathogenesis of acne vulgaris to anti-acne agents

Acne vulgaris is a cutaneous chronic inflammatory disorder with complex pathogenesis. Four factors play vital roles in acne pathophysiology: hyperseborrhea and dysseborrhea, altered keratinization of the pilosebaceous duct, Cutibacterium acnes (C. acnes) and inflammation. The main hormones responsible for the development of acne vulgaris include androgens, insulin and insulin-like growth factor-1. Other factors involved in this process are corticotropin-releasing hormone, α-melanocyte-stimulating hormone and substance P. Wnt/β-catenin signaling pathway, phosphoinositide 3-kinase (PI3K)/Akt pathway, mitogen-activated protein kinase pathway, adenosine 5'-monophosphate-activated protein kinase pathway and nuclear factor kappa B pathway participate in the modulation of sebocyte, keratinocyte and inflammatory cell (e.g. lymphocytes, monocytes, macrophages, neutrophils) activity. Among all the triggers and pathways mentioned above, IGF-1-induced PI3K/Akt/Forkhead box protein O1/mammalian target of rapamycin (mTOR) C1 pathway is the most important signaling responsible for acne pathogenesis. Commonly used anti-acne agents include retinoids, benzoyl peroxide, antibiotics and hormonal agents (e.g. spironolactone, combination oral contraceptive and flutamide). New approaches including peroxisome proliferator-activated receptor γ modifier, melanocortin receptor antagonists, epigallocatechin-3-gallate, metformin, olumacostat glasaretil, stearoyl-CoA desaturase inhibitor omiganan pentahydrochloride, K_DPT, afamelanotide, apremilast and biologics have been developed as promising treatments for acne vulgaris. Although these anti-acne agents have various pharmacological effects against the diverse pathogenesis of acne, all of them have a synergistic mode of action, the attenuation of Akt/mTORC1 signaling and enhancement of p53 signal transduction. In addition to drug therapy, diet with no hyperglycemic carbohydrates, no milk and dairy products is also beneficial for treatment of acne.