BACKGROUND: Psoriasis is a common chronic inflammatory skin disease with 2% to 3% prevalence worldwide and a heavy social-psychological burden for patients and their families. As the exact pathogenesis of psoriasis is still unknown, the current treatment is far from satisfactory. Thus, there is an urgent need to find a more effective therapy for this disease. Keratin 17 (K17), a type I intermediate filament, is overexpressed in the psoriatic epidermis and plays a critical pathogenic role by stimulating T cells in psoriasis. Therefore, we hypothesized that inhibiting K17 may be a potential therapeutic approach for psoriasis. This study aimed to investigate the therapeutic effect of K17-specific small interfering RNA (siRNA) on mice with imiquimod (IMQ)-induced psoriasis-like dermatitis. METHODS: Eight-week-old female BALB/c mice were administered a 5% IMQ cream on both ears to produce psoriatic dermatitis. On day 3, K17 siRNA was mixed with an emulsion matrix and applied topically to the left ears of the mice after IMQ application every day for 7 days. The right ears of the mice were treated in parallel with negative control (NC) siRNA. Inflammation was evaluated by gross ear thickness, histopathology, the infiltration of inflammatory cells (CD3+ T cells and neutrophils) using immunofluorescence, and the expression of cytokine production using real-time quantitative polymerase chain reaction. The obtained data were statistically evaluated by unpaired t-tests and a one-way analysis of variance. RESULTS: The severity of IMQ-induced dermatitis on K17 siRNA-treated mice ears was significantly lower than that on NC siRNA-treated mice ears, as evidenced by the alleviated ear inflammation phenotype, including decreased ear thickness, infiltration of inflammatory cells (CD3+ T cells and neutrophils), and inflammatory cytokine/chemokine expression levels (interleukin 17 [IL-17], IL-22, IL-23, C-X-C motif chemokine ligand 1, and C-C motif chemokine ligand 20) (P < 0.05 vs. the Blank or NC siRNA groups). Compared to the NC siRNA treatment, the K17 siRNA treatment resulted in increased K1 and K10 expression, which are characteristic of keratinocyte differentiation (vs. NC siRNA, K17 siRNA1 group: K1, t = 4.782, P = 0.0050; K10, t = 3.365, P = 0.0120; K17 siRNA2 group: K1, t = 4.104, P = 0.0093; K10, t = 4.168, P = 0.0042; siRNA Mix group: K1, t = 3.065, P = 0.0221; K10, t = 10.83, P < 0.0001), and decreased K16 expression, which is characteristic of keratinocyte proliferation (vs. NC siRNA, K17 siRNA1 group: t = 4.156, P = 0.0043; K17 siRNA2 group: t = 2.834, P = 0.0253; siRNA Mix group: t = 2.734, P = 0.0250). CONCLUSIONS Inhibition of K17 expression by its specific siRNA significantly alleviated inflammation in mice with IMQ-induced psoriasis-like dermatitis. Thus, gene therapy targeting K17 may be a potential treatment approach for psoriasis.
Animals ; Dermatitis ; Disease Models, Animal ; Female ; Humans ; Imiquimod ; Inflammation ; Keratin-17/genetics* ; Mice ; Mice, Inbred BALB C ; Psoriasis/genetics* ; RNA, Small Interfering/genetics* ; Skin

Objective To establish the finite element model of spinal canal reconstruction and internal fixation,analysis influence of spinal canal reconstruction and internal fixation on spinal stability,and verify the effectiveness and reliability of spinal canal reconstruction and internal fixation in spinal canal surgery.Methods A 30-year-old male healthy volunteer with a height of 172 cm and weight of 75 kg was selected and his lumbar CT data were collected to establish a finite element model of normal lumbar Lo3-L,and the results were compared with in vitro solid results and published finite element analysis results to verify the validity of the model.They were divided into normal group,laminectomy group and spinal canal reconstruction group according to different treatment methods.Under the same boundary fixation and physiological load conditions,six kinds of ac-tivities were performed,including forward bending,backward extension,left bending,right bending,left rotation and right rota-tion,and the changes of range of motion(ROM)of L3-L4,L4-L5 segments and overall maximum ROM of L3-L5 were analyzed under the six conditions.Results The ROM displacement range of each segment of the constructed L3-L5 finite element model was consistent with the in vitro solid results and previous literature data,which confirms the validity of the model.In L3-L4,ROM of spinal canal reconstruction group was slightly increased than that of normal group during posterior extension(＞5％dif-ference),and ROM of other conditions was similar to that of normal group(＜5％difference).ROM in laminectomy group was significantly increase than that in normal group and spinal canal reconstruction group under the condition of flexion,extension,left and right rotation.In L4-L5,ROM in spinal canal reconstruction group was similar to that in normal group(＜5％differ-ence),while ROM in laminectomy group was significantly higher than that in normal group and spinal canal reconstruction group(＞5％difference).In the overall maximum ROM of L3-L5,spinal canal reconstruction group was only slightly higher than normal group under the condition of posterior extension(＞5％difference),while laminectomy was significantly higher than normal group and spinal canal reconstruction group under the condition of anterior flexion,posterior extension,left and right rotation(＞5％difference).The changes of each segment ROM and overall ROM of L3-L5 showed laminectomy group＞spinal canal reconstruction group＞normal group.Conclusion Laminectomy could seriously affect biomechanical stability of the spine,but application of spinal canal reconstruction and internal fixation could effectively reduce ROM displacement of the responsi-ble segment of spine and maintain its biomechanical stability.

Objective To explore the effect and the mechanism of vitamin D(Vit D) promotes proliferation and differentiation of mesenchymal stem cells (MSCs) through regulates extracts of plastrum testudinis (PTE).Methods Established the PGL3-Id1 promoter and transfered rat MSCs.PTE combined with 10-6,10-7,10-8mol/L Vit D respectively were acted on the transfected MSCs for 36 hours.The level of Id1 promoter were detected by luciferase activity measurement.1,3,30,100 pg/mL PTE combined with Vit D of 10-7 mol/L were acted on MSCs for 36 hours,3 days and 7 days,and the VDR expression were detected by RT-PCR test.Results PTE promoted the expression of Id1 in MSCs,the expression of Id1 was inhibited when PTE combined with Vit D (P ＜ 0.01),and it was significantly different among different dosis of Vit D(P ＜0.01).The expression of VDR was inhibited in different degree when PTE combined with Vit D for 36 hours,3 days and 7 days.PTE combed with large dose of Vit D for 36 hours had significant effect of inhibition,and the difference was statistically significant (P ＜ 0.05).The inhibiting effect was more obvious when PTE combined with large dose of Vit D for 3 days and 7 days.When different doses of PTE combined with Vit D for a same duration,the difference of VDR expression was statistically significant (P ＜ 0.05).Meanwhile,when same doses of PTE combined with Vit D for different durations,the difference of VDR expression at 7 days and 36 hours was statistically significant (P ＜ 0.05).Conclusion The proliferation of MSCs which promoted by PTE was inhibited by Vit D,and the nuclear receptor VDR may be one of the targets of drug action for PTE regulating proliferation and differentiation of MSCs.

Background/Aims: The accuracy of endosonographers in diagnosing gastric subepithelial lesions (SELs) using endoscopic ultrasonography (EUS) is influenced by experience and subjectivity. Artificial intelligence (AI) has achieved remarkable development in this field. This study aimed to develop an AI-based EUS diagnostic model for the diagnosis of SELs, and evaluated its efficacy with external validation. Methods: We developed the EUS-AI model with ResNeSt50 using EUS images from two hospitals to predict the histopathology of the gastric SELs originating from muscularis propria. The diagnostic performance of the model was also validated using EUS images obtained from four other hospitals. Results: A total of 2,057 images from 367 patients (375 SELs) were chosen to build the models, and 914 images from 106 patients (108 SELs) were chosen for external validation. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the model for differentiating gastrointestinal stromal tumors (GISTs) and non-GISTs in the external validation sets by images were 82.01%, 68.22%, 86.77%, 59.86%, and 78.12%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the external validation set by tumors were 83.75%, 71.43%, 89.33%, 60.61%, and 80.56%, respectively. The EUS-AI model showed better performance (especially specificity) than some endosonographers.The model helped improve the sensitivity, specificity, and accuracy of certain endosonographers. Conclusions We developed an EUS-AI model to classify gastric SELs originating from muscularis propria into GISTs and non-GISTs with good accuracy. The model may help improve the diagnostic performance of endosonographers. Further work is required to develop a multi-modal EUS-AI system.