Extracellular Vesicles from Human Plasma Show a Distinctive Proteome and miRNome Profile in Patients with Severe Cutaneous Adverse Reactions

SERS and electrochemical dual-mode detection of miRNA-141 by using single Au@Ag nanowire as a new platform

As biomarkers of cancer, the accurate and sensitive detection of microRNAs is of great significance. Therefore, we proposed a surface-enhanced Raman scattering (SERS)/electrochemical (EC) dual-mode nanosensor for sensitively detecting miRNA-141. The nanosensor uses Au@Ag nanowires as a novel SERS/EC sensing platform, which has the advantages of good biocompatibility, fast response, and high sensitivity. The dual-mode nanosensor can not only effectively overcome the problem of insufficient reliability of single signal, but also realize the amplification and stable output of the detection signal, to ensure the reliability and repeatability of miRNA detection. With this sensing strategy, the target miRNA-141 can be detected over a wide linear range (100 fM to 50 nM) (LOD of 18.4 fM for SERS and 16.0 fM for electrochemical methods). In addition, the process shows good selectivity and can distinguish miRNA-141 from other interfering miRNAs. The actual analysis of human serum samples also proves that our strategy has good reliability, repeatability, and has broad application prospects in the field of analysis and detection.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part II diagnosis and management

Drug-induced hypersensitivity syndrome, also known as drug reaction with eosinophilia and systemic symptoms, is a severe cutaneous adverse reaction characterized by an exanthem, fever, and hematologic and visceral organ involvement. The differential diagnosis includes other cutaneous adverse reactions, infections, inflammatory and autoimmune diseases, and neoplastic disorders. Three sets of diagnostic criteria have been proposed; however, consensus is lacking. The cornerstone of management is immediate discontinuation of the suspected drug culprit. Systemic corticosteroids remain first-line therapy, but the literature on steroid-sparing agents is expanding. Longitudinal evaluation for sequelae is recommended. Adjunctive tests for risk stratification and drug culprit identification remain under investigation. Part II of this continuing medical education activity begins by exploring the differential diagnosis and diagnosis of drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms and concludes with an evidence-based overview of evaluation and treatment.

Involvement of Extracellular Vesicles in the Proinflammatory Response to Clozapine: Implications for Clozapine-Induced Agranulocytosis

Most idiosyncratic drug reactions (IDRs) appear to be immune-mediated, but mechanistic events preceding severe reaction onset remain poorly defined. Damage-associated molecular patterns (DAMPs) may contribute to both innate and adaptive immune phases of IDRs, and changes in extracellular vesicle (EV) cargo have been detected post-exposure to several IDR-associated drugs. To explore the hypothesis that EVs are also a source of DAMPs in the induction of the immune response preceding drug-induced agranulocytosis, the proteome and immunogenicity of clozapine- (agranulocytosis-associated drug) and olanzapine- (non-agranulocytosis-associated drug) exposed EVs were compared in two preclinical models: THP-1 macrophages and Sprague-Dawley rats. Compared with olanzapine, clozapine induced a greater increase in the concentration of EVs enriched from both cell culture media and rat serum. Moreover, treatment of drug-naïve THP-1 cells with clozapine-exposed EVs induced an inflammasome-dependent response, supporting a potential role for EVs in immune activation. Proteomic and bioinformatic analyses demonstrated an increased number of differentially expressed proteins with clozapine that were enriched in pathways related to inflammation, myeloid cell chemotaxis, wounding, transforming growth factor-β signaling, and negative regulation of stimuli response. These data indicate that, although clozapine and olanzapine exposure both alter the protein cargo of EVs, clozapine-exposed EVs carry mediators that exhibit significantly greater immunogenicity. Ultimately, this supports the working hypothesis that drugs associated with a risk of IDRs induce cell stress, release of proinflammatory mediators, and early immune activation that precedes severe reaction onset. Further studies characterizing EVs may elucidate biomarkers that predict IDR risk during development of drug candidates. SIGNIFICANCE STATEMENT: This work demonstrates that clozapine, an idiosyncratic drug-induced agranulocytosis (IDIAG)-associated drug, but not olanzapine, a safer structural analogue, induces an acute proinflammatory response and increases extracellular vesicle (EV) release in two preclinical models. Moreover, clozapine-exposed EVs are more immunogenic, as measured by their ability to activate inflammasomes, and contain more differentially expressed proteins, highlighting a novel role for EVs during the early immune response to clozapine and enhancing our mechanistic understanding of IDIAG and other idiosyncratic reactions.

Exosomal miRNAs in autoimmune skin diseases

Exosomes, bilaterally phospholipid-coated small vesicles, are produced and released by nearly all cells, which comprise diverse biological macromolecules, including proteins, DNA, RNA, and others, that participate in the regulation of their biological functions. An increasing number of studies have revealed that the contents of exosomes, particularly microRNA(miRNA), play a significant role in the pathogenesis of various diseases, including autoimmune skin diseases. MiRNA is a class of single-stranded non-coding RNA molecules that possess approximately 22 nucleotides in length with the capability of binding to the untranslated as well as coding regions of target mRNA to regulate gene expression precisely at the post-transcriptional level. Various exosomal miRNAs have been found to be significantly expressed in some autoimmune skin diseases and involved in the pathogenesis of conditions via regulating the secretion of crucial pathogenic cytokines and the direction of immune cell differentiation. Thus, exosomal miRNAs might be promising biomarkers for monitoring disease progression, relapse and reflection to treatment based on their functions and changes. This review summarized the current studies on exosomal miRNAs in several common autoimmune skin diseases, aiming to dissect the underlying mechanism from a new perspective, seek novel biomarkers for disease monitoring and lay the foundation for developing innovative target therapy in the future.

Advances in Our Understanding of the Interaction of Drugs with T-cells: Implications for the Discovery of Biomarkers in Severe Cutaneous Drug Reactions

Drugs can activate different cells of the immune system and initiate an immune response that can lead to life-threatening diseases collectively known as severe cutaneous adverse reactions (SCARs). Antibiotics, anticonvulsants, and antiretrovirals are involved in the development of SCARs by the activation of αβ naïve T-cells. However, other subsets of lymphocytes known as nonconventional T-cells with a limited T-cell receptor repertoire and innate and adaptative functions also recognize drugs and drug-like molecules, but their role in the pathogenesis of SCARs has only just begun to be explored. Despite 30 years of advances in our understanding of the mechanisms in which drugs interact with T-cells and the pathways for tissue injury seen during T-cell activation, at present, the development of useful clinical biomarkers for SCARs or predictive preclinical in vitro assays that could identify immunogenic moieties during drug discovery is an unmet goal. Therefore, the present review focuses on (i) advances in the understanding of the pathogenesis of SCARs reactions, (ii) a description of the interaction of drugs with conventional and nonconventional T-cells, and (iii) the current state of soluble blood circulating biomarker candidates for SCARs.