Adipokines as an important link between hidradenitis suppurativa and obesity: a narrative review

Subcutaneous adipose tissue: Implications in dermatological diseases and beyond

Subcutaneous adipose tissue (SAT) is the deepest component of the three-layered cutaneous integument. While mesenteric adipose tissue-based immune processes have gained recognition in the context of the metabolic syndrome, SAT has been traditionally considered primarily for energy storage, with less attention to its immune functions. SAT harbors a reservoir of immune and stromal cells that significantly impact metabolic and immunologic processes not only in the skin, but even on a systemic level. These processes include wound healing, cutaneous and systemic infections, immunometabolic, and autoimmune diseases, inflammatory skin diseases, as well as neoplastic conditions. A better understanding of SAT immune functions in different processes, could open avenues for novel therapeutic interventions. Targeting SAT may not only address SAT-specific diseases but also offer potential treatments for cutaneous or even systemic conditions. This review aims to provide a comprehensive overview on SAT's structure and functions, highlight recent advancements in understanding its role in both homeostatic and pathological conditions within and beyond the skin, and discuss the main questions for future research in the field.

Upregulation of TLR2 in keratinocytes activates the MAPK pathway and plays a role in the pathogenesis of hidradenitis suppurativa

BACKGROUND

Mutations in gamma-secretase complex (GSC) genes are associated with hidradenitis suppurativa (HS), and toll-like receptor (TLR) 2 is elevated in HS lesions. However, it remains unclear whether TLR2 is upregulated in the skin lesions of patients with HS with GSC gene variants, and the role of its upregulation in the pathogenesis of this disease are unknown.

OBJECTIVE

To investigate the role of TLR2 upregulation in NCSTN and PSENEN knockdown keratinocytes.

METHODS

Human immortalized keratinocyte line (HaCaTs) was treated with potent short-hairpin RNA targeting NCSTN or PSENEN. RNA sequencing was used to assess the effects of PAM2CSK4 treatment on gene expression in HaCaT cells. Altered signaling pathways were confirmed in both HaCaT cells, as well as in skin lesions from patients with HS and in Ncstn keratinocyte-specific knockout (NcstnΔKC) mice.

RESULTS

TLR2 agonist stimulation exacerbated the increased phosphorylation levels of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase (MAPK) in NCSTN- and PSENEN- knockdown keratinocytes. Similar findings were observed in skin lesions from patients with HS and NcstnΔKC mice.

CONCLUSION

Novel variations were identified within the GSC gene in Chinese patients with HS. Moreover, our study indicates that TLR2/MAPK signaling pathways play a key role in the pathogenesis of HS associated with GSC gene mutations and represent a crucial therapeutic target.

The glycolysis-related AMPK/ULK signaling pathway mediates the inhibitory effect of adiponectin in prostate cancer cells

OBJECTIVE

Reduced adiponectin (ADPN) levels have been implicated in the pathogenesis of prostate cancer (PCa). The role of glycolysis in cancer development and treatment has attracted increasing attention. The present study aimed to elucidate its impact on PCa and to explore the mechanistic involvement of glycolysis.

METHODS

An RM-1 cell xenograft model of Adpn-knockout mice was used to corroborate the effects of glycolysis, AMP-activated protein kinase (AMPK) signaling, and autophagy on tumor xenograft progression. The effect of ADPN on PCa cells was evaluated using the Cell Counting Kit-8 (CCK-8), lactate levels, and flow cytometry. The expression of glycolysis-related genes was detected using real-time RT-PCR in LNCaP and PC-3 cells after incubation with ADPN. Autophagic flux after ADPN treatment was quantified by chloroquine intervention and confocal analysis of mRFP-GFP-LC3. Alterations in the levels of adiponectin receptor 1 (AdipoR1), AMPK, Unc-51-like kinase 1 (ULK1), autophagy-related protein 7 (ATG7), p62, and microtubule-associated protein 1 light chain 3 beta (LC3B) were assessed after incubation of LNCaP cells with ADPN.

RESULTS

Proteomic analysis of xenograft tumors demonstrated significant upregulation of glycolysis in Adpn-/- mice. Lower levels of ADPN accelerated tumor xenograft growth, diminished p-AMPKα/AMPKα ratio and LC3B II/I ratio, and elevated levels of proliferating cell nuclear antigen (PCNA) within the tumor microenvironment. ADPN inhibited proliferation and glycolysis and potentiated apoptosis in both cell lines. Expression of glycolysis-related genes decreased after ADPN treatment. Autophagic flux was elevated, as evidenced by changes in autophagy-related proteins and confocal microscopy analysis of mRFP-GFP-LC3. It led to the suppression of p62 while inducing phosphorylation of AMPKα and upregulating AdipoR1, ULK1, ATG7, and LC3B II/I ratio.

CONCLUSION

ADPN inhibited the proliferation and progression of PCa cell-derived tumor xenografts by inhibiting glycolysis. Specifically, ADPN effectively inhibits glycolysis and activates the downstream AMPK/ULK1 signaling pathway to suppress proliferation of PCa cells.

The Therapeutic Potential of GLP-1 Receptor Agonists in the Management of Hidradenitis Suppurativa: A Systematic Review of Anti-Inflammatory and Metabolic Effects

Background: Glucagon-like peptide-1 receptor agonists (GLP1-RAs) are synthetic peptides that mimic the natural activity of GLP-1, widely known for lowering blood glucose levels and promoting weight reduction. These characteristics make them a valuable tool in managing type 2 diabetes and obesity-related conditions. Recent findings indicate that GLP1-RAs may also offer therapeutic benefits in managing hidradenitis suppurativa (HS), a chronic inflammatory skin disorder closely associated with metabolic abnormalities, including obesity, diabetes, and dyslipidemia. This review explores the potential role of GLP1-RAs in managing HS. Methods: A systematic review was conducted by searching electronic databases, including MEDLINE and Google Scholar, without date limitations. Key search terms included "GLP-1" or "GLP-1 agonists" combined with "hidradenitis suppurativa" or "acne inversa". Inclusion criteria were set for studies reporting on the use of GLP1-RAs as a treatment for HS, with articles discussing theoretical applications excluded. Data synthesis included findings from 25 relevant studies. Results: The analysis revealed that GLP1-RAs, specifically liraglutide and semaglutide, led to significant reductions in weight and systemic inflammation in HS patients. Notably, improvements in lesion severity and quality of life were reported. The anti-inflammatory effects of GLP1-RAs were attributed to the suppression of key inflammatory pathways involving TNF-α, IL-17, and NF-κB. Conclusions: GLP1-RAs demonstrate significant potential as an adjunct therapy for HS, addressing both the metabolic and inflammatory aspects of the condition. While early results are promising, further research is necessary to determine their long-term efficacy in managing HS.

Profound Sexual Dysfunction Among Patients with Hidradenitis Suppurativa: A Cross-sectional Study

INTRODUCTION

Sexual health, a critical aspect of overall well-being, is often compromised in individuals with chronic disorders. Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that mainly affects intertriginous areas, potentially impacting sexual health as a result of its specific symptoms and psychosocial burden.

METHODS

This cross-sectional study utilized data from the EpiCAi project, focusing on 199 patients with HS. Participants completed digital questionnaires assessing sexual health via sex-specific instruments: the Female Sexual Function Index (FSFI) for women and the International Index of Erectile Function (IIEF) for men, alongside different psychosocial scales. The disease severity was assessed using the Hurley stage and the Lesion Identification Scheme for Acne Inversa (LISAI).

RESULTS

The majority of the participants reported impaired sexual health, with significant clinical sexual dysfunctions noted in 71.8% of women (FSFI score < 26) and erectile dysfunction in 63.8% of men. Sexual dysfunction was associated with several factors, including age, and marital status. Psychosocial factors, notably depression and quality of life, showed strong correlations with sexual health outcomes. Notably, women over 40 and those treated with biologics reported more severe dysfunction, while among men, employment status significantly influenced sexual health.

CONCLUSIONS

HS profoundly affects the sexual health of both male and female patients, with significant impacts on their quality of life and psychological well-being. The findings underscore the necessity for healthcare providers to address sexual health proactively in the management of HS, considering both physical symptoms and psychosocial impacts. This holistic approach is essential for improving patient outcomes and overall quality of life.

TRIAL REGISTRATION

German Register for Clinical Trials, identifier DRKS00025315.

Risk of cardiovascular disorders in hidradenitis suppurativa patients: a large-scale, propensity-matched global retrospective cohort study

BACKGROUND

Patients with hidradenitis suppurativa (HS) often suffer from comorbid diabetes, metabolic syndrome, and hyperlipidemia and, therefore, are susceptible to the development of cardiovascular diseases (CVDs). Moreover, systemic inflammation plays a vital role in the development of atherosclerosis. The creation of atherosclerotic plaque is characterized by endothelial dysfunction driven by elevated concentrations of interleukin (IL)-1, IL-6, and IL-18 among others, as well as tumor necrosis factor (TNF) alpha.

METHODS

This study aimed to assess the risk of HS patients developing CVDs. We performed a large-scale, propensity-matched global retrospective cohort study analyzing the risk of development of CVDs in patients suffering from HS. The analysis included 144,100 HS patients with 144,100 healthy controls (HC). The cohorts were matched regarding demographics and history of diseases relevant to CVDs, e.g., diabetes, obesity, and nicotine dependence. A total of 90 cardiovascular disorders were identified. The identification of cardiovascular disorders was based on ≥1% appearance of the event, based on absolute numbers, in both cohorts.

RESULTS

Before the matching, HS patients displayed a higher frequency in excess weight or obesity (25 vs. 14.4%, respectively), nicotine dependence, and diabetes mellitus, but lower odds of primary hypertension in comparison to healthy controls. A total of 47 CVDs are associated with an increased risk of onset in HS patients. Although the highest hazard ratio (HR; 2.1; 95% CI: 1.95-2.269) was found for unspecified heart failure, the HS cohort was exceptionally predisposed to developing myocardial infarction (HR: 2.06; 95% CI: 1.88-2.27) and an acute embolism and deep vein thrombosis of the lower extremity (HR: 1.93; 95% CI: 1.74-2.14).

CONCLUSIONS

This is the most extensive study on the association of HS with CVDs. We demonstrated that HS patients are at significantly greater risk of developing various CVDs compared to matched controls, with heart failure being the most common one.

The NLRP3 Inflammasome Gene Is Overexpressed in Hidradenitis Suppurativa Lesions: A Preliminary Study on the Role of Pyroptosis in Disease Pathogenesis

Hidradenitis suppurativa (HS) is a debilitating inflammatory skin disorder, and its pathogenesis remains incompletely understood. This study aimed to investigate the role of the P2X7 receptor (P2X7R) and NLRP3 inflammasome in HS pathogenesis. RNA sequencing and real-time PCR were performed to assess the gene expression levels of P2X7R and NLRP3 in the skin biopsies of HS patients and healthy controls (HC). The results of our study revealed a significantly increased expression of the NLRP3 gene in both the lesional and perilesional skin of HS patients compared to healthy controls. Moreover, the mRNA levels of NLRP3 were significantly higher in lesional skin compared to non-lesional skin in HS patients, indicating the spread of inflammation to adjacent tissues. In contrast, no significant differences in P2X7R gene expression were observed between the three groups. These findings suggest the involvement of NLRP3 inflammasomes in HS pathogenesis, while P2X7R may not play a significant role in the disease. This research sheds light on the complex inflammatory pathways in HS, highlighting the potential of NLRP3 as a therapeutic target. Understanding the molecular mechanisms underlying HS is crucial for the development of targeted treatment modalities for this debilitating condition.

Pathological and Therapeutical Implications of Pyroptosis in Psoriasis and Hidradenitis Suppurativa: A Narrative Review

This manuscript explores the role of pyroptosis, an inflammatory programmed cell death, in the pathogenesis of two chronic dermatoses, psoriasis and hidradenitis suppurativa (HS). The diseases, though clinically diverse, share common pathogenetic pathways involving the unbalanced interaction between the adaptive and innate immune systems. This review focuses on the molecular changes in psoriatic and HS skin, emphasizing the activation of dendritic cells, secretion of interleukins (IL-17, IL-22, and TNF-α), and the involvement of inflammasomes, particularly NLRP3. This manuscript discusses the role of caspases, especially caspase-1, in driving pyroptosis and highlights the family of gasdermins (GSDMs) as key players in the formation of pores leading to cell rupture and the release of proinflammatory signals. This study delves into the potential therapeutic implications of targeting pyroptosis in psoriasis and HS, examining existing medications like biologics and Janus kinase inhibitors. It also reviews the current limitations and challenges in developing therapies that selectively target pyroptosis. Additionally, the manuscript explores the role of pyroptosis in various inflammatory disorders associated with psoriasis and HS, such as inflammatory bowel disease, diabetes mellitus, and cardiovascular disorders. The review concludes by emphasizing the need for further research to fully elucidate the pathomechanisms of these dermatoses and develop effective, targeted therapies.

Biology of Interleukin-17 and Novel Therapies for Hidradenitis Suppurativa

Skin disorders affect ∼40% of the human population. One of the most debilitating cutaneous disorders is Hidradenitis suppurativa (HS), a noncommunicable chronic inflammatory disease with an estimated global prevalence of 0.4% to 2.5%. In January 2011, high levels of IL-17 were discovered in skin lesions of HS patients. In the following years, translational and clinical research led to a better understanding of the pathogenesis of HS. In June 2023, more than 12 years after the initial note, secukinumab, an anti-IL-17A monoclonal antibody, was approved for the treatment of moderate to severe HS. This is the next milestone in improving the treatment of these patients after the approval of the anti-TNF-α monoclonal antibody adalimumab in 2015. In this review article, we present the IL-17 pathway in HS and discuss the use of secukinumab as a therapeutic option for this disease. Our review starts with a description of the epidemiology, clinical features, etiology, and pathogenesis of HS. An overview of the IL-17/IL-17 receptor system in general and a detailed description of the known facts about the expression and action of IL-17 in HS follow. Afterward, we consider the results of clinical trials evaluating the safety and efficacy of IL-17 inhibitors in HS. Finally, a comparison is made between secukinumab and adalimumab and the characteristics of the patients that may be particularly suitable for each of these biologics are described.

CCN3/NOV serum levels in coronary artery disease (CAD) patients and its correlation with TNF-α and IL-6

INTRODUCTION

Dysregulation in the secretion of adipokines or adipocytokines plays a significant role in triggering a pro-inflammatory state, leading to endothelial dysfunction and insulin resistance, and ultimately elevating the risk of atherosclerosis and coronary artery disease (CAD). Previous studies have shown a link between NOV/CCN3 (an adipokine) and obesity, insulin resistance, and inflammation. However, no research has explored the relationship between CCN3 serum levels and CAD. Therefore, we conducted the first investigation to examine the correlation between CCN3 and CAD risk factors in patients.

METHODS

In a case-control study, we measured the serum levels of CCN3, IL-6, adiponectin, and TNF-α in 88 angiography-confirmed CAD patients and 88 control individuals using ELISA kits. Additionally, we used an auto analyzer and commercial kits to measure the biochemical parameters.

RESULTS

In patients with CAD, the serum levels of CCN3, TNF-α, and IL-6 were significantly higher compared to the control group, whereas lower levels of adiponectin were observed in the CAD group (P < 0.0001). A positive correlation was found between CCN3 and IL-6 and TNF-α in the CAD group ([r = 0.38, P < 0.0001], [r = 0.39, P < 0.0001], respectively). A binary logistic regression analysis showed the risk of CAD in the model adjusted (OR [95% CI] = 1.29 [1.19 - 1.41]), (P < 0.0001). We determined a cut-off value of CCN3 (3169.6 pg/mL) to distinguish CAD patients from the control group, with good sensitivity and specificity obtained for this finding (83.8% and 87.5%, respectively).

CONCLUSION

This study provides evidence of a positive association between CCN3 serum levels and CAD, as well as inflammation markers such as IL-6 and TNF-α. These findings suggest that CCN3 may serve as a potential biomarker for CAD, and further investigations are necessary to validate this association and explore its potential use in clinical settings.

Targeting Metabolic Syndrome in Hidradenitis Suppurativa by Phytochemicals as a Potential Complementary Therapeutic Strategy

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by the appearance of painful inflamed nodules, abscesses, and pus-draining sinus tracts in the intertriginous skin of the groins, buttocks, and perianal and axillary regions. Despite its high prevalence of ~0.4-1%, therapeutic options for HS are still limited. Over the past 10 years, it has become clear that HS is a systemic disease, associated with various comorbidities, including metabolic syndrome (MetS) and its sequelae. Accordingly, the life expectancy of HS patients is significantly reduced. MetS, in particular, obesity, can support sustained inflammation and thereby exacerbate skin manifestations and the chronification of HS. However, MetS actually lacks necessary attention in HS therapy, underlining the high medical need for novel therapeutic options. This review directs attention towards the relevance of MetS in HS and evaluates the potential of phytomedical drug candidates to alleviate its components. It starts by describing key facts about HS, the specifics of metabolic alterations in HS patients, and mechanisms by which obesity may exacerbate HS skin alterations. Then, the results from the preclinical studies with phytochemicals on MetS parameters are evaluated and the outcomes of respective randomized controlled clinical trials in healthy people and patients without HS are presented.