Characterization of Human Immortalized Keratinocyte Cells Infected by Monkeypox Virus.

Monkeypox virus (MPXV) can induce systemic skin lesions after infection. This research focused on studying MPXV proliferation and the response of keratinocytes. Using transmission electron microscopy (TEM), we visualized different stages of MPXV development in human immortalized keratinocytes (HaCaT). We identified exocytosis of enveloped viruses as the exit mechanism for MPXV in HaCaT cells. Infected keratinocytes showed submicroscopic changes, such as the formation of vesicle-like structures through the recombination of rough endoplasmic reticulum membranes and alterations in mitochondrial morphology. Transcriptome analysis revealed the suppressed genes related to interferon pathway activation and the reduced expression of antimicrobial peptides and chemokines, which may facilitate viral immune evasion. In addition, pathway enrichment analysis highlighted systemic lupus erythematosus pathway activation and the inhibition of the Toll-like receptor signaling and retinol metabolism pathways, providing insights into the mechanisms underlying MPXV-induced skin lesions. This study advances our understanding of MPXV's interaction with keratinocytes and the complex mechanisms leading to skin lesions.

Sulforaphane alleviates psoriasis by enhancing antioxidant defense through KEAP1-NRF2 Pathway activation and attenuating inflammatory signaling.

Psoriasis is a chronic inflammatory skin disease that affects millions of people worldwide. Sulforaphane (SFN) has been shown to have anti-inflammatory and antioxidant properties. In this study, we investigated the effects of SFN on a mouse model of psoriasis induced by imiquimod (IMQ) and its underlying molecular mechanism. Mice treated with SFN showed significant improvement in psoriatic symptoms, including reduced erythema, scales, and cutaneous thickness. Histopathological analysis and immunohistochemical staining revealed decreased expression of K16, K17, and Ki67 in SFN-treated mice, indicating reduced abnormal differentiation of keratinocytes and cutaneous inflammation. SFN treatment also reduced the activation of STAT3 and NF-κB pathways and downregulated pro-inflammatory cytokines IL-1ß, IL-6, and CCL2. In vitro experiments using HaCaT cells demonstrated that SFN inhibited IL-22 and TNF-α-induced activation of inflammatory pathways and keratinocyte proliferation. Network pharmacology analysis suggested that the KEAP1-NRF2 pathway might be involved in the protective effects of SFN on psoriasis. We observed reduced NRF2 expression in human psoriatic lesions, and subsequent experiments showed that SFN activated KEAP1-NRF2 pathway in vivo and in vitro. Importantly, NRF2-deficient mice exhibited aggravated psoriasis-like symptoms and reduced response to SFN treatment. Our findings indicate that SFN ameliorates psoriasis symptoms and inflammation through the KEAP1-NRF2 pathway, suggesting a potential therapeutic role for SFN in the treatment of psoriasis.

Vitamin D attenuates DNCB-induced atopic dermatitis-like skin lesions by inhibiting immune response and restoring skin barrier function.

Atopic dermatitis (AD) is a common chronic inflammatory skin disease causing erythema and itching. The etiology of AD is complex and not yet clear. Vitamin D is a fat-soluble vitamin that promotes skin cell growth and differentiation and regulates immune function. This study aimed to explore the therapeutic effect of calcifediol, the active metabolite of vitamin D, on experimental AD and the possible mechanism of action. We found that the levels of vitamin D binding protein (VDBP) and vitamin D receptor (VDR) in biopsy skin samples from AD patients decreased compared with controls. We used 2,4-dinitrochlorobenzene (DNCB) to induce an AD mouse model on the ear and back of BALB/c mice. A total of five groups were used: the control group, the AD group, the AD + calcifediol group, the AD + dexamethasone group, and the calcifediol alone group. Under calcifediol treatment, mice exhibited reduced spinous layer thickening, reduced inflammatory cell infiltration, downregulated aquaporin 3 (AQP3) expression, and restored the barrier function of the skin. Simultaneous calcifediol treatment decreased STAT3 phosphorylation, inhibited inflammation and chemokine release, decreased AKT1 and mTOR phosphorylation, and suppressed epidermal cell proliferation and abnormal differentiation. In conclusion, our study demonstrated that calcifediol significantly protected mice against DNCB-induced AD. In a mouse model of AD, calcifediol may reduce inflammatory cell infiltration and chemokines by inhibiting the phosphorylation of STAT3 and may restore skin barrier function through the downregulation of AQP3 protein expression and inhibition of cell proliferation.