UVB-Induced Skin Autoinflammation Due to Nlrp1b Mutation and Its Inhibition by Anti-IL-1β Antibody

Lycopene mitigates paclitaxel-induced cognitive impairment in mice; Insights into Nrf2/HO-1, NF-κB/NLRP3, and GRP-78/ATF-6 axes

Chemotherapy-induced cognitive impairment, referred to as "chemobrain", is widely acknowledged as a significant adverse effect of cancer therapy. Paclitaxel, a chemotherapeutic drug, has been reported to cause cognitive impairment clinically and in animal models. However, the precise mechanisms are not fully understood. The current study explored the potential neuroprotective effect of lycopene in paclitaxel-induced cognitive impairment in mice and its potential underlying mechanisms. Mice were randomly allocated into six groups: control, paclitaxel-treated (10 mg/kg), lycopene-treated (5, 10, and 20 mg/kg) + paclitaxel, and lycopene alone-treated (20 mg/kg) groups. The effect of lycopene treatment on behavioral function and histological examination was assessed. Lycopene (20 mg/kg) was selected for additional investigation into the underlying mechanisms. Lycopene treatment counteracted paclitaxel-induced oxidative stress by reducing lipid peroxidation and enhancing catalase levels. Additionally, lycopene-treated mice demonstrated a significant elevation in nuclear factor erythroid 2-related factor 2 with no significant effect on hemeoxygenase-1. Moreover, paclitaxel administration elevated endoplasmic reticulum stress markers; glucose-regulated protein78, activating Transcription Factor 6, C/EBP homologous protein, and apoptosis marker annexin V which were significantly reduced by lycopene treatment. Furthermore, lycopene mitigated paclitaxel-induced neuroinflammation through the reduction of the levels of the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome axis markers; nuclear factor-κB, NLRP3, caspase-1, interleukin-1β, and interleukin-18. Our study findings may provide new evidence that lycopene mitigates paclitaxel-induced cognitive impairment in mice by reversing oxidative stress, endoplasmic reticulum stress, and inflammatory mechanisms.

Diseases categorized as autoinflammatory keratinization diseases (AiKDs), and their pathologies and treatments

Whole-exome and whole-genome sequencing have become widespread in approximately the last 15 years, and the predisposing factors and pathomechanisms of inflammatory keratinization diseases, which have been unknown for a long time, have gradually been revealed. Hence, various inflammatory keratinization diseases are recognized to cause innate immunity hyperactivation. Therefore, we have been advocating for the clinical entity, "autoinflammatory keratinization diseases (AiKDs)" since 2017. AiKDs are inflammatory keratinization diseases caused by autoinflammatory-related pathomechanisms in the skin. The aberrant activation of innate immunity and the resultant autoinflammation in the epidermis and the superficial dermis in AiKDs cause hyperkeratosis in the epidermis. Our initially proposed concept of AiKDs included generalized pustular psoriasis and related conditions, pityriasis rubra pilaris type V, and familial keratosis lichenoides chronica. Since then, the number of diseases known to be AiKDs has increased as previously unknown disease-causing factors and pathogenetic mechanisms of inflammatory keratinization diseases have been clarified one by one. To date, porokeratosis, hidradenitis suppurative, keratosis linearis with ichthyosis congenita and sclerosing keratoderma (KLICK) syndrome, and AiKDs associated with epidermal growth factor receptor (EGFR) deficiency or with hepatitis and autism have been recognized as AiKDs. The concept of AiKDs is considered extremely useful in our precise understanding of the pathogeneses behind inflammatory keratinization diseases and our appropriate treatment method selection. The number of AiKDs is expected to grow with the clarification of the pathomechanisms of further inflammatory keratinization diseases.

A homozygous p.Leu813Pro gain-of-function NLRP1 variant causes phenotypes of different severity in two siblings

BACKGROUND

A trio exome sequencing study identified a previously unreported NLRP1 gene variant resulting in a p.Leu813Pro substitution of the LRR (leucine-rich repeats) domain of the NLRP1 protein (NACHT, LRR and PYD domains-containing protein 1). This homozygous mutation was shared by two sisters with different clinical presentation: the younger sister had generalized inflammatory nodules with keratotic plugs, clinically resembling multiple keratoacanthomas, while the older had manifestations of familial keratosis lichenoides chronica.

OBJECTIVES

To analyse the consequences of this NLRP1 variant in two siblings with a different clinical spectrum of severity.

METHODS

To demonstrate the pathogenicity, p.Leu813Pro was recombinantly expressed, and its effect on inflammasome assembly was assessed. Exome sequencing and RNA-Seq were performed to identify factors with potentially modifying effects on the severity of the skin manifestation between each sibling.

RESULTS

The variant p.Leu813Pro triggered activation of the NLRP1 inflammasome leading to ASC (apoptosis-associated speck-like protein containing a CARD) speck formation and interleukin (IL)-1β release. The more severely affected sister had several additional genomic variants associated with atopy and psoriasis that were not present in her sibling. IL-5 and IL-17 emerged as dominant cytokines driving prominent inflammation in the skin of the severely affected sibling.

CONCLUSIONS

To the best of our knowledge, this is the first report of a NLRP1 variant that leads to a different clinical spectrum of severity within the same sibship. IL-5 and IL-17 were the main cytokines expressed in the inflammatory lesions of the severely affected patient and might be regarded as disease modifying factors, and therefore may be considered as therapeutic targets.