Inhibiting Keratinocyte-Derived Signal Transducer and Activator of Transcription 6 Improved Atopic Dermatitis in Mice

Evaluating dermal toxicity of the flame retardant aluminum diethylphosphinate by in silico-in vitro testing strategy

Flame retardants (FRs) are a group of chemicals used in different products to improve fire safety; however, many of them negatively impact human health, encouraging the use of safer alternatives. The aluminum diethylphosphinate (AlPi) is one of the potential alternatives to harmful FRs; however, close data gaps on human toxicity and enhanced mechanistic understanding are still needed. This study evaluated the dermal toxicity potential of AlPi using in silico models (OECD QSAR Toolbox, Toxtree) and a multi-biomarkers approach with human keratinocyte models (HaCaT cell line and reconstructed human epidermis (RHE) model). Our findings revealed no significant increases in reactive oxygen species (ROS, H2DCFDA) or pro-inflammatory cytokines (IL-6, IL-8, IL-10, IL-1β, IL12p70, TNF) in HaCaT cells exposed to AlPi at non-cytotoxic concentrations (30, 60, 120 μg/ml). This suggests that AlPi does not induce oxidative stress or inflammatory responses in the skin. Additionally, in silico predictions and in vitro assays (HaCaT - IL-6; OECD TG 439 with SkinVitro-RHE) did not classify AlPi as a skin sensitizer or skin irritant. Regarding changes in DNA, AlPi-exposed HaCaT cells did not show significant levels of γ-H2AX; however, this FR increased the level of 5-hydroxymethylcytosine (5-hmC) and TET1 expression, which is a gene involved in the regulation of the DNA methylation. In summary, most biomarker responses indicated that AlPi poses minimal toxic effects on the skin; however, further research is needed to understand better the biological consequences of its effect on DNA methylation.

STATs, promising targets for the treatment of autoimmune and inflammatory diseases

Cytokines play a crucial role in the pathophysiology of autoimmune and inflammatory diseases, with over 50 cytokines undergoing signal transduction through the Signal Transducers and Activators of Transcription (STAT) signaling pathway. Recent studies have solidly confirmed the pivotal role of STATs in autoimmune and inflammatory diseases. Therefore, this review provides a detailed summary of the immunological functions of STATs, focusing on exploring their mechanisms in various autoimmune and inflammatory diseases. Additionally, with the rapid advancement of structural biology in the field of drug discovery, many STAT inhibitors have been identified using structure-based drug design strategies. In this review, we also examine the structures of STAT proteins and compile the latest research on STAT inhibitors currently being tested in animal models and clinical trials for the treatment of immunological diseases, which emphasizes the feasibility of STATs as promising therapeutic targets and provides insights into the design of the next generation of STAT inhibitors.

Critical Players and Therapeutic Targets in Chronic Itch

Chronic itch is one of the most prominent clinical characteristics of diverse systematic diseases. It is a devastating sensation in pathological diseases. Despite its importance, there are no FDA-labelled drugs specifically geared toward chronic itch. The associated complex pathogenesis and diverse causes escalate chronic itch to being one of the top challenges in healthcare. Humanized antibodies against IL-13, IL-4, and IL-31 proved effective in treatment of itch-associated atopic dermatitis but remain to be validated in chronic itch. There are still no satisfactory anti-itch therapeutics available toward itch-related neuropeptides including GRP, BNP, SST, CGRP, and SP. The newly identified potential itch targets including OSM, NMB, glutamate, periostin, and Serpin E1 have opened new avenues for therapeutic development. Proof-of-principle studies have been successfully performed on antagonists against these proteins and their receptors in itch treatment in animal models. Their translational interventions in humans need to be evaluated. It is of great importance to summarize and compare the newly emerging knowledge on chronic itch and its pathways to promote the development of novel anti-itch therapeutics. The goal of this review is to analyze the different physiologies and pathophysiologies of itch mediators, whilst assessing their suitability as new targets and discussing future therapeutic development.