Pyroptosis and its role in autoimmune skin disease.

Autoimmune skin disease is a kind of heterogeneous disease with complicated pathogenesis. Many factors such as genetic, infectious, environmental and even psychological factors may interact together to trigger a synergistic effect for the development of abnormal innate and adaptive immune responses. Although the exact mechanisms remain unclear, recent evidence suggests that pyroptosis plays a pivotal role in the development of autoimmune skin disease. The feature of pyroptosis is the first formation of pores in cellular membranes, then cell rupture and the release of intracellular substances and pro-inflammatory cytokines, such as interleukin-1 beta (IL-1ß) and IL-18. This hyperactive inflammatory programmed cell death damages the homeostasis of the immune system and advances autoimmunity. This review briefly summarises the molecular regulatory mechanisms of pyrin domain-containing protein 3 (NLRP3) inflammasome and gasdermin family, as well as the molecular mechanisms of pyroptosis, highlights the latest progress of pyroptosis in autoimmune skin disease, including systemic lupus erythematosus, psoriasis, atopic dermatitis and systemic scleroderma and attempts to identify its potential advantages as a therapeutic target or prognostic biomarker for these diseases.

Downregulation of Ebp1Khib210 promotes keratinocyte proliferation through induction of TIF-IA-mediated rRNA synthesis.

BACKGROUND: Psoriasis is a prevalent chronic inflammatory dermatosis characterized by excessive proliferation of keratinocytes. Protein lysine 2-hydroxyisobutyrylation (Khib) is a newly identified post-translational modification that regulates various biological processes. Abnormal Khib modification has been closely associated with the development of autoimmune diseases. OBJECTIVE: To investigate the abnormal Khib profile and its pathogenic role in psoriasis. METHODS: We utilized liquid chromatography-tandem mass spectrometry to analyze Khib-modified proteins in the epidermis of psoriasis and healthy controls. Mutated cells and mice with downregulated Ebp1Khib210 were generated to investigate its functional effects in psoriasis. RESULTS: The omic analysis revealed dysregulation of Khib modification in psoriatic lesions, exhibiting a distinct profile compared to controls. We observed the downregulation of Ebp1Khib210 in psoriatic lesions and IMQ-induced psoriatic mice. Notably, the expression of Ebp1Khib210 was upregulated in psoriatic patients following effective treatment. Decreased Ebp1Khib210 enhanced keratinocyte viability, proliferation, and survival while inhibiting apoptosis in vitro. Additionally, Pa2g4K210A mice with downregulated Ebp1Khib210 exhibited more severe psoriatic lesions and enhanced keratinocyte proliferation. Moreover, we found that Ebp1K210A mutation increased the interaction between Ebp1 and nuclear Akt, thereby inhibiting MDM2-mediated TIF-IA ubiquitination, and resulting to increased rRNA synthesis and keratinocyte proliferation. The downregulation of Ebp1Khib210 was attributed to inflammation-induced increases in HDAC2 expression. CONCLUSION: Our findings demonstrate that downregulation of Ebp1Khib210 promotes keratinocyte proliferation through modulation of Akt signaling and TIF-IA-mediated rRNA synthesis. These insights into Khib modification provide a better understanding of the pathogenesis of psoriasis and suggest potential therapeutic targets.

Selective sensing Ca2+ with a spiropyran-based fluorometric probe.

Spiropyran (SP) and its derivatives operate between their ring opening and closing forms as a versatile molecular platform for the fluorescence detection of cations and anions, using a colour change for signalling. A functionalized SP fluorescence probe, L, was prepared and characterized. Probe L can detect Ca2+ with a fluorescence 'turn-on' response in ethanol solution. It selectively binds Ca2+ to form a 1:1 ligand/metal complex, which produced a new emission band centred at 604 nm. The sensing result was clearly observed by the solution colour change from colourless to pink under visible light, and from blue to red under ultraviolet light. The detection limit was calculated to be 4.53 × 10-8  M for Ca2+ . The probe provides another possibility that SP-based derivatives could be used for the development and detection of metal ions in environmental and physiological systems.

Psoriatic Dermal-Derived Mesenchymal Stem Cells Induced C3 Expression in Keratinocytes.

Purpose: Our recent studies found a splice region mutation in C3 accompanied by a significantly increased C3 in psoriatic peripheral blood. Mesenchymal stem cells (MSCs) are a key immunological suppression cell. We further investigate the regulation of MSCs on C3 in psoriasis. Patients and Methods: We analyzed the C3 and its upstream S100A9, S100A8 and downstream MCP1 in psoriatic and control skin, and in normal human epidermal keratinocytes (NHEKs) co-cultured with psoriatic versus control dermal-derived mesenchymal stem cells (DMSCs) by mRNA, iTRAQ (isobaric tags for relative and absolute quantitative) and simple Western analysis. Results: The mRNA and Simple Western analysis showed that the expression of C3, S100A8 and S100A9 are upregulated in psoriatic lesion (C3: mRNA, 9.23-fold, p = 0.0092; protein, 3.56-fold, p = 0.0244. S100A8: mRNA, 28.35-fold, p = 0.0015; protein, 4.68-fold, p = 0.0215. S100A9: mRNA, 79.45-fold, p = 0.0066; protein, 12.42-fold, p > 0.05). Moreover, the iTRAQ showed that C3 and S100A9 were significantly increased in NHEKs after co-cultured with psoriatic DMSCs compared to that of control DMSCs (C3: 3.40-fold, p = 0, FDR = 0; S100A9: 2.30-fold, p = 9.86E-241, FDR = 6.50E-239), verified by Simple Western. However, the expression of S100A8 and MCP1 was slightly different between the two groups. Conclusion: Our results suggest that psoriatic DMSCs contribute to the increased C3 expression in psoriatic lesion via upregulating S100A9, providing the theoretical basis for the role of C3 and DMSCs in the pathogenesis of psoriasis.