Coexistence of acne inversa with psoriasis and Dowling-Degos disease harboring impaired PSENEN-Notch signaling

Genetic factors associated with hidradenitis suppurativa, a literature review

Background

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by deep-seated, painful lesions most frequently occurring in intertriginous areas of the skin. HS leads to poor quality of life in affected individuals and is difficult to diagnose and treat.

Objective

Understanding the genetics associated with familial inheritance may lead to a better understanding of the pathogenesis of this debilitating disease.

Methods

Articles published until March 9, 2023, were identified in PubMed using the following search terms: hidradenitis suppurativa and gene* or acne inversa and gene*.

Results

The rate of monogenic mutations associated with HS is less than 7%, with the most common genetic mutations reported in sporadic and familial HS cases being in NCSTN and less frequently in PSENEN. Individuals with mutations in the gamma-secretase complex tended to have more severe HS and an early age of onset.

Limitations

This study was limited to the case studies available in PubMed, the majority of which used targeted gene panels to detect genetic mutations.

Conclusion

Approximately 30% of individuals diagnosed with HS report having a positive family history; however, very few studies demonstrate monogenic familial transmission of HS. The case studies of syndromic HS reported a variety of genetic mutations associated with HS, some of which were familial, while others were sporadic, suggesting that other pathways may be involved in the pathogenesis of HS and other potential mutations that have yet to be evaluated. More research is needed to understand the genetic mutations in HS.

Immunological and prognostic analysis of PSENEN in low-grade gliomas: An immune infiltration-related prognostic biomarker

Metformin is widely used in the treatment of type 2 diabetes (T2D) and plays a role in antitumor and antiobesity processes. A recent study identified its direct molecular target, PEN2 (PSENEN). PSENEN is the minimal subunit of the multiprotein complex γ-secretase, which promotes the differentiation of oligodendrocyte progenitors into astrocytes in the central nervous system. This study was mainly based on gene expression data and clinical data from the TCGA and CGGA databases. Analysis of differential expression of PSENEN between tissues from 31 cancers and paracancerous tissues revealed that it had high expression levels in most cancers except 2 cancers. Using univariate Cox regression analysis and Kaplan-Meier survival analysis, a high expression level of PSENEN was shown to be a risk factor in low-grade gliomas (LGG). Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses indicated that PSENEN is widely involved in immune-related signaling pathways in LGG. PSENEN expression level was significantly associated with TMB, MSI, tumor stemness index, and the expression levels of immunomodulatory genes in LGG. Finally, immune infiltration analysis revealed that PSENEN level was associated with the presence of various immune infiltrating cells, among which PSENEN was strongly associated with the presence of M2 macrophages and played a synergistic pro-cancer role. In conclusion, PSENEN may partially influence prognosis by modulating immune infiltration in patients with LGG, and PSENEN may be a candidate prognostic biomarker for determining prognosis associated with immune infiltration in LGG.

The Genomic Architecture of Hidradenitis Suppurativa-A Systematic Review

Hidradenitis suppurativa is a chronic, suppurative condition of the pilosebaceous unit manifesting as painful nodules, abscesses, and sinus tracts mostly in, but not limited to, intertriginous skin. Great strides have been made at elucidating the pathophysiology of hidradenitis suppurativa, which appears to be the product of hyperkeratinization and inflammation brought about by environmental factors and a genetic predisposition. The identification of familial hidradenitis suppurativa has sparked research aimed at identifying underlying pathogenic variants in patients who harbor them. The objective of this review is to provide a broad overview of the role of genetics in various aspects of hidradenitis suppurativa, specifically the pathophysiology, diagnosis, and clinical application.

Dowling-Degos Disease Presenting With Associated Epidermal Inclusion Cysts: A Case Report and Review of the Literature

ABSTRACT

Dowling-Degos Disease (DDD) is a rare and disfiguring autosomal dominant genodermatosis characterized by reticulate hyperpigmented macules or follicular comedone-like papules in the intertriginous areas that typically presents in the third or fourth decade of life. It is a progressive disease that is often treatment-resistant. Although its association with hidradenitis suppurativa has been well described, DDD has also been less commonly reported in conjunction with other dermatologic diseases with unknown etiologic associations. Herein, we present a case of DDD with associated epidermal inclusion cysts and conduct a literature review of dermatologic conditions reported in association with DDD.

Mutations in γ-secretase subunit-encoding PSENEN gene alone may not be sufficient for the development of acne inversa

BACKGROUND

The effects of PSENEN mutations in patients with acne inversa (AI) are poorly understood. Hyperproliferation of follicular keratinocytes and resulting occlusion may constitute the initial pathophysiology.

OBJECTIVE

To investigate the effects of PSENEN knockdown on γ-secretase subunits, biological behaviors, and related signaling pathways in keratinocytes.

METHODS

HaCaT cells were divided into an experimental group (PSENEN knock down), a negative control group, and a blank control group. Whole transcriptome sequencing was used to measure differences in mRNA expression of the whole genome; real-time PCR and Western blotting were performed to determine the interference efficiency and the effects of interference on the components of γ-secretase and related molecules. CCK-8 was used to measure cell proliferation, and flow cytometry was used to measure apoptosis and the cell cycle.

RESULTS

A comparison of five healthy controls with three patients with PSENEN mutation (c.66delG, c.279delC, c.229_230insCACC) revealed decreased expression of mRNA and protein in skin lesions of the experimental group. In this group, expression of the other components of γ-secretase presenilin C-terminal fragment decreased, expression of immature nicastrin increased, expression of mature nicastrin decreased, and expression of anterior pharynx defective-1 remained unchanged. KEGG analysis revealed that differentially expressed molecules were enriched in m-TOR signaling pathways. Subsequent verification confirmed that differences in PI3K-AKT-mTOR signaling pathway molecules, cell proliferation, apoptosis, cell cycle and the expression levels of Ki-67, KRT1, and IVL between the groups were not statistically significant.

CONCLUSIONS

PSENEN mutations alone may be insufficient to cause the development of AI, or they may only induce a mild phenotype of AI.