Blocking the janus-activated kinase pathway reduces tumor necrosis factor alpha-induced interleukin-18 bioactivity by caspase-1 inhibition

Tofacitinib for the treatment of severe rare skin diseases: a narrative review

PURPOSE

Autoimmune bullous diseases, connective tissue diseases, and vasculitis represent a group of severe rare skin diseases. While glucocorticoids and immunosuppressive agents serve as standard treatments for these diseases, their efficacy is limited due to adverse side effects, indicating the need for alternative approaches. Biologics have been used in the management of some rare skin diseases. However, the use of biologics is associated with concerns, such as infection risk and high costs, prompting the quest for efficacious and cost-effective alternatives. This study discusses the safety issues associated with tofacitinib and its potential in treating rare skin diseases.

METHODS

This narrative review focuses on the pharmacodynamic properties of tofacitinib and its impact on the JAK/STAT pathway. In addition, we present a comprehensive discussion of the effects and mechanism of action of tofacitinib for each severe rare skin disease.

RESULTS

This role of tofacitinib in treating severe rare skin diseases has been discussed, shedding light on its promising prospects as a treatment modality. Few reports of serious adverse events are available in patients treated with tofacitinib.

CONCLUSION

We explored the mechanism of action, efficacy, and safety considerations of tofacitinib and found that it can be used as a treatment option for rare skin diseases. However, multicenter clinical studies are needed to confirm the efficacy and safety of JAK inhibitors.

The role of interleukin-18 and interleukin-18 binding protein in K/BxN serum transfer-induced arthritis

Background

Interleukin-18 is a proinflammatory cytokine, the activity of which is regulated by its natural inhibitor, IL-18 binding protein (IL-18BP). Elevated circulating levels of IL-18 have been observed in patients with systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still's disease (AOSD), two conditions associated with dysregulated innate immune responses. This study examines the expression and function of IL-18 and IL-18BP in K/BxN serum transfer arthritis (STA), a model that is uniquely dependent on innate immune responses.

Methods

Naïve and serum transfer-induced arthritis (STA) wild-type (WT) mice were used to examine the articular levels of IL-18 and IL-18BP mRNA by RT-qPCR. The cellular sources of IL-18BP in the joints were determined by using Il18bp-tdTomato reporter knock-in mice. The incidence and severity of arthritis, including mRNA levels of different cytokines, were compared in IL-18BP or IL-18 knock-out (KO) mice and their WT littermates.

Results

IL-18 and IL-18BP mRNA levels were significantly increased in arthritic as compared to normal joints. Synovial neutrophils, macrophages, and endothelial cells represented the cellular sources of IL-18BP in arthritic joints, whereas IL-18BP production was limited to endothelial cells in non-inflamed joints. The incidence and severity of arthritis were similar in IL-18BP KO and IL-18 KO compared to their WT littermates. Transcript levels of different inflammatory cytokines were not different in the two KO mouse lines compared to WT mice.

Conclusion

Although IL-18 and IL-18BP levels were increased in arthritic joints, our results show that the IL-18/IL-18BP balance is not involved in the regulation of STA.

YAP Transcriptional Activity Dictates Cell Response to TNF In Vitro

YAP/TAZ are transcription co-factors recently described responsive to pro-inflammatory cytokines and involved in inflammatory-related disorders. However, the role of tumor necrosis factor (TNF), a major pro-inflammatory cytokine, on YAP signaling is not well understood and controversial. Here, we observe in vitro, using wild type and YAP knockout HEK293 cells, that TNF triggers YAP nuclear translocation and transcriptional activity, thus being dependent on Rho family of GTPases. In response to TNF, YAP transcriptional activity orientates cell fate toward survival. Transcriptional analysis with Nanostring technology reveals that YAP modulates TNF-induced increase in fibro-inflammatory pathways such as NF-κB, inflammasomes, cytokines or chemokines signaling and pro-fibrotic pathways involving TGF-β and extracellular matrix remodeling. Therefore, in response to TNF, YAP acts as a sustainer of the inflammatory response and as a molecular link between inflammation and fibrotic processes. This work identifies that YAP is critical to drive several biological effects of TNF which are involved in cancer and inflammatory disorders.