| Psoriasis is a chronic inflammatory skin disease with clinical manifestations of erythema,thickening,and scaling,and its histopathological features are hyperkeratosis,dyskeratosis,spinous thickening,and dermal inflammation.As the terminal target cells of the local immune response of psoriasis,the abnormal proliferation and differentiation of keratinocytes lead to the shedding of psoriasis plaques,and eventually lead to the destruction of the protective barrier of the skin.The treatment drugs for psoriasis mainly include biological agents,traditional Chinese medicine preparations,small molecule targeted drugs,etc.These drugs are often associated with adverse effects and their clinical use is limited.Therefore,it is of great significance to seek economical clinical treatment drugs for psoriasis with few side effects.Crisaborole（Cri）is a topical boron-containing anti-inflammatory compound and a non-steroidal phosphodiesterases 4（PDE4）inhibitor,which can effectively inhibit PDE4 activity and increase the concentration of cyclic adenosine monophosphate（c AMP）in cells to exert anti-inflammatory effects.Cri ointment can significantly reduce the itching response of atopic dermatitis for the treatment of mild or moderate atopic dermatitis in adults and children older than 3 months,and it has also been reported that Cri is effective in psoriasis,but the mechanism is unclear.In this study,the therapeutic effect of Cri ointment on IMQ-induced psoriasis in IMQ mice was observed by establishing a model of imiquimod（IMQ）-induced psoriasis.In vitro,normal human keratinocytes were used to explore the inhibitory effect of Cri on the excessive activation of keratinocytes,and explore the relationship between this effect and the c AMP-PKA-CREB pathway,which provided an experimental basis for the development of new indications of Cri.Aim:1.To clarify the therapeutic effect of Cri on IMq-induced psoriasis in mice2.To clarify the regulatory effect of Cri on keratinocyte function and the restoration of c AMP-PKA-CREB pathway.Method:1.In vivo experiment the IMQ-induced psoriasis model of mice was selected for the experiment.The 48 Balb/c mice were divided into model group,normal group,Cri(7.5,15,30 mg.cm-2)group,halometasone,(15 mg.cm-2),8 mice in each group,and each dorsal hair removal（2 cm×3 cm）3 days before modeling.After molding,d 1～d 3,vaseline was applied to the normal group.Mice in other groups applied 62.5 mg IMQ（5%）ointment on the back skin once a day.From d 4,62.5 mg IMQ（5%）ointmentwas applied to each administration group,once a day,and then the corresponding dose of Cri（45,90,180 mg）was applied once after absorption for 4days,and the mice were sacrificed on the 8th day.Psoriasis area and severity index（PASI）scores was used to evaluate the severity of lesions.HE staining was used to observe pathological changes in the skin.The expression of keratin（K）6,16,17,1,and 10 in mouse skin tissues were determined by immunohistochemistry.The levels of PKA,c AMP,TNF-α,IL-6,CXCL2 and CXCL9 in mouse skin and cell supernatant were determined by ELISA.2.In vitro experiments,human keratinocyte Ha Ca T was used.CCK-8 assay was used to detect Ha Ca T cell viability.Ha Ca T cell proliferation was detected by high content detection.The Western blot method was used to detect the expression of proteins in skin tissues and Ha Ca T cells.Results:1.Therapeutic effect of Cri on IMQ-induced psoriasis in miceThe normal mice had smooth skin.The skin of mice in model group was scalythickened,and the lesion degree increased with the increase of molding days.From day 5,the skin damage of Cri group and halomethanone group began to improve.Compared with the model group,Cri(7.5,15,30 mg.cm-2)and Hal improved erythema,scaling and thickening,and decreased PASI score.Compared with the normal group,the epidermis of mice in the model group was significantly thickened,including angiogenesis,inflammatory cell infiltration,incomplete keratosis,hyperkeratosis,granular layer thinning,spinous layer hypertrophy,and irregular length.All the above pathological changes could be improved to varying degrees in each administration group.Compared with the model group,the epidermal thickness of rats in Cri(7.5,15,30 mg.cm-2)groups and Hal groups was significantly reduced.Compared with Cri(7.5 mg.cm-2),the epidermal thickness in Cri(15,30 mg.cm-2)and Hal groups was significantly reduced.Spleen index and spleen pathological score were decreased in the administration group,while thymus index showed no significant difference among all groups.In the drug group,the expressions of K6,K16 and K17 decreased,while the expressions of K1 and K10increased.The dosage of Cri and Hal significantly decreased the levels of TNF-α,IL-6,CXCL2 and CXCL9 in IMQ-induced skin tissue of mice,while Cri increased the levels of c AMP and PKA and increased the expression of p-CREB in the skin tissue of mice.2.Clitoromine inhibits abnormal activation of Ha Ca T cellsHuman keratinocytes Ha Ca T cells were cultured in vitro,and stimulated with CXCL12 for 24 h to detect the viability of Ha Ca T cells.CXCL12 was stimulated by adding different concentrations(0,5,10,20,40,80,100 ng.cm-1)to human keratinocyte Ha Ca T cells in vitro,and cultured for 24 hours to detect Ha Ca T cell viability.DEX（1μM）and Cri（0.1μM,1μM,10μM）could reduce Ha Ca T cell viability and inhibit Ha Ca T cell proliferation.DEX（1μM）and Cri（1μM）reduced the levels of TNF-α,IL-6,CXCL2 and CXCL9 in Ha Ca T cell supernatant.The expression of Ha Ca T cell proliferation proteins K6,K16 and K17 was reduced after CXCL12(100 ng.cm-1)stimulation,and the expression of cell differentiation marker proteins K1 and K10 was increased.DEX（1μM）and Cri（1μM）could increase the levels of c AMP and PKA in the skin of mouse lesions and increase the expression of p-CREB.Conclusion:1.Crisaborole has therapeutic effect on IMQ-induced psoriasis in mice.2.Crisaborole alleviates psoriasis in mice by inhibiting overactivation of keratinocytes3.The inhibition of keratinocyte hyperactivation by Crisaborole is related to the activation of c AMP-PKA-p CREB pathway... |
PDF Full Text Request