Icotinib inhibits EGFR signaling and alleviates psoriasis-like symptoms in animal models

MicroRNA-215-5p inhibits the proliferation of keratinocytes and alleviates psoriasis-like inflammation by negatively regulating DYRK1A and its downstream signalling pathways

Psoriasis is a chronic inflammatory disease characterized by abnormal hyperproliferation and differentiation. The object of this study is to explore the role of microRNA-215-5p in psoriasis-like inflammation. The expression of miR-215-5p was found to be down-regulated in pro-inflammatory factor-stimulated HaCaT cells and imiquimod (IMQ)-treated skin tissues. Overexpression of miR-215-5p suppressed the proliferation and cell cycle progression of HaCaT cells. Further, miR-215-5p agomir alleviated the disease severity, pathological features and Ki67 positive cells in IMQ-treated mice. Luciferase assay confirmed that miR-215-5p could bind to the 3'UTR of DYRK1A. The in vitro and in vivo results showed that miR-215-5p negatively regulates DYRK1A, which further inhibited EGFR and its downstream signalling pathways, AKT and ERK. Collectively, our results provide evidence that overexpression of miR-215-5p inhibits the proliferation of HaCaT cells and alleviates psoriasis-like inflammation partly by DYRK1A mediated inhibition of the EGFR signalling pathway. miR-215-5p may serve as a novel small molecule for therapeutic intervention in psoriasis.

DGT, a novel heterocyclic diterpenoid, effectively suppresses psoriasis via inhibition of STAT3 phosphorylation

BACKGROUND AND PURPOSE

Psoriasis is a chronic immune-mediated inflammatory skin disease that easily recurs and is difficult to cure. DGT is a novel synthetic heterocyclic diterpenoid, whose structure has not been previously reported. We have investigated the action of DGT against psoriasis, specifically the hyperproliferation of epidermal keratinocytes, angiogenesis and pathogenic inflammatory responses.

EXPERIMENTAL APPROACH

We investigated its pharmacokinetics in skin after topical administration. We characterized its pharmacological actions in vitro and in vivo using cell proliferation assay, cell apoptosis assay, diethylstilbestrol-induced mouse vaginal epithelial cell mitosis model, tube formation assay, cell migration assay, chick embryonic chorioallantoic membrane (CAM) assay, histological, flow cytometric analysis and imiquimod (IMQ)-induced psoriasis-like model.

KEY RESULTS

DGT was found to be mainly distributed in the epidermis and dermis, which indicated that DGT was suitable as a topical treatment. DGT inhibited cell proliferation and induced apoptotic cell death of keratinocytes in vitro and in vivo. Moreover, DGT inhibited endothelial cell proliferation, tube formation and migration of in vitro angiogenesis, as well as in vivo CAM angiogenesis. In an IMQ-induced psoriasis-like skin inflammation murine model, topical application of DGT ameliorated keratinocyte proliferation and inflammatory response, especially in IL-17-related psoriasiform dermatitis. Furthermore, our results demonstrated that DGT prevented these pathological processes of psoriasis through suppression of STAT3 phosphorylation.

CONCLUSION AND IMPLICATIONS

DGT has great potential as a novel therapeutic agent for the treatment of psoriatic skin disease.

Formulation and evaluation of a topical liposomal gel containing a combination of zedoary turmeric oil and tretinoin for psoriasis activity

This study was to develop a combination of zedoary turmeric oil (ZTO) and tretinoin (TRE)-loaded liposomal gel as a topical drug delivery system. We used a combination of single-factor experiment and orthogonal experiment to systematically optimize encapsulation process of the compound liposomes. The optimized liposome vesicles were incorporated into Carbopol gel matrix and studied by continuous in vitro (skin penetration and retention) and in vivo (anti-psoriatic activity using mouse vaginal model and mouse tail model) experiments. The optimized liposomes had an entrapment efficiency (EE) of ZTO was (64.63 ± 1.00)%, EE of TRE was (90.33 ± 0.72)%, drug loading (DL) of ZTO was (9.09 ± 0.14)%, DL of TRE was (1.43 ± 0.02)%, particle size of 257.41 ± 7.58 nm, polydispersity index (PDI) of 0.10 ± 0.04 and zeta potential of -38.77 ± 0.81 mV. Transmission electron microscopy showed liposomes had a regular spherical surface. After 1-month storage at (4 ± 2)°C, the optimized liposome preparations maintained its stability. In vitro study indicated that liposome formulations could significantly prolong the penetration of drugs into the hair follicles of mice and keep more drugs in the skin compared with conventional gel formulations. In vivo study showed that liposomal gel was more effective than conventional gel in treating psoriasis and had a significant dose-dependent effect on psoriasis. In summary, liposomal gel is expected to be an ideal carrier for topical drug delivery systems of ZTO and TRE.

Pharmacokinetics and Safety of Icotinib Hydrochloride Cream in Patients with Mild to Moderate Chronic Plaque Psoriasis: A Randomized Double-Blind Vehicle-Controlled Phase 1 Study

Objective

This phase I study aimed to systematically assess the safety, local tolerability, pharmacokinetics, and preliminary efficacy of topical icotinib hydrochloride cream in patients with mild to moderate plaque psoriasis.

Materials and Methods

Eligible Chinese adult patients with mild to moderate psoriasis were assigned to the icotinib cream or vehicle group. Icotinib cream with increasing concentrations (0.5%, 1.0%, 2.0%, and 4.0%) or vehicle were administered by the fingertip unit method to the skin lesions twice a day for 4 weeks. Safety assessments included the incidence and severity of adverse events (AEs), local tolerability at the treatment area, vital signs, and laboratory examinations. Plasma levels of icotinib were also measured for the pharmacokinetics calculation. The efficacy was preliminarily explored by assessing the improvement in the severity level using Target Plaque Severity Score (TPSS) and overall improvement using the Psoriasis Area Severity Index (PASI) and Dermatological Quality Life Index.

Results

Forty-one patients were enrolled and qualified for safety analysis. 27 (65.9%) patients experienced at least one AE, of which application-site adverse drug reactions (ADRs) were reported in 6 (14.6%) patients. All ADRs were of grade 1 or 2, most common irritation (4.5%), itching (3.1%), and erythema (2.4%), and resolved during follow-up. The systemic exposure to icotinib was very low; the highest plasma concentration was 0.214 ng/mL, while the area under the curve from 0 to 12 hours was 1.626 h·ng/mL. The TPSS improved for all icotinib groups after treatment in a dose- and time-dependent manner.

Conclusion

This phase 1 study demonstrated favorable safety, tolerable toxicity, and preliminary efficacy of icotinib cream in patients with mild to moderate psoriasis. The dose concentration of 2.0% (twice daily based on the fingertip unit method) is recommended for further study.

Study Design

This is a single-center, randomized, double-blind, and vehicle-controlled study.

The RTK Interactome: Overview and Perspective on RTK Heterointeractions

Receptor tyrosine kinases (RTKs) play important roles in cell growth, motility, differentiation, and survival. These single-pass membrane proteins are grouped into subfamilies based on the similarity of their extracellular domains. They are generally thought to be activated by ligand binding, which promotes homodimerization and then autophosphorylation in trans. However, RTK interactions are more complicated, as RTKs can interact in the absence of ligand and heterodimerize within and across subfamilies. Here, we review the known cross-subfamily RTK heterointeractions and their possible biological implications, as well as the methodologies which have been used to study them. Moreover, we demonstrate how thermodynamic models can be used to study RTKs and to explain many of the complicated biological effects which have been described in the literature. Finally, we discuss the concept of the RTK interactome: a putative, extensive network of interactions between the RTKs. This RTK interactome can produce unique signaling outputs; can amplify, inhibit, and modify signaling; and can allow for signaling backups. The existence of the RTK interactome could provide an explanation for the irreproducibility of experimental data from different studies and for the failure of some RTK inhibitors to produce the desired therapeutic effects. We argue that a deeper knowledge of RTK interactome thermodynamics can lead to a better understanding of fundamental RTK signaling processes in health and disease. We further argue that there is a need for quantitative, thermodynamic studies that probe the strengths of the interactions between RTKs and their ligands and between different RTKs.