Interleukin-18 exacerbates skin inflammation and affects microabscesses and scale formation in a mouse model of imiquimod-induced psoriasis / 中华医学杂志(英文版)

BACKGROUND@#As a potent pro-inflammatory cytokine of the interleukin (IL)-1 family, IL-18 was elevated in early active and progressive plaque-type psoriatic lesions and that serum or plasma levels of IL-18 correlated with the Psoriasis Area and Severity Index (PASI). Although results from previous studies have established that IL-18 may aggravate psoriatic inflammation, the mechanisms of this process remain unknown. In this study, IL-18 knock out (KO) mice and wild-type (WT) mice were used to investigate the effects of IL-18 within a mouse model of psoriasis.@*METHODS@#WT and IL-18 KO mice were divided into four groups, including imiquimod (IMQ)-treated IL-18 KO group (n = 11) and WT group (n = 13) as well as their respectively gene-matched control mice (receiving vaseline; n = 12). PASI scores were used to evaluate psoriatic lesions in IMQ-treated mice. Pathological features and dermal cellular infiltration were investigated by hematoxylin and eosin staining. The levels of psoriasis-related cytokines including IL-23, IL-17, IL-12, IL-1β, IFNγ, IL-15, IL-27, and IL-4 were tested by real-time polymerase chain reaction (PCR). The protein level of IL-1β, IL-27, CXCL1, and Ly6 g were investigated by immunohistochemistry (IHC).@*RESULTS@#Acanthosis (98.46 ± 14.12 vs. 222.68 ± 71.10 μm, P < 0.01) and dermal cell infiltration (572.25 ± 47.45 vs. 762.47 ± 59.59 cells/field, P < 0.01) were significantly milder in IMQ-induced IL-18 KO mice compared with that in WT mice. IMQ-induced IL-18 KO mice manifested larger areas of Munro microabscesses (11,467.83 ± 5112.09 vs. 4093.19 ± 2591.88 μm, P < 0.01) and scales (100,935.24 ± 41,167.77 vs. 41,604.41 ± 14,184.10 μm, P < 0.01) as compared with WT mice. In skin lesions of IL-18 KO mice, the expressions of IL-1β, IL-4, and IL-27 were all significantly upregulated but IL-17 was decreased. Histologically, strong positive signals of Ly6g were observed within the epidermis of IL-18 KO mice but expressions of CXCL1 were decreased.@*CONCLUSIONS@#IL-18 may exacerbate prominent inflammation and influence pathological features in IMQ-induced mouse model of psoriasis. IL-18 may upregulate pro-inflammatory cytokines and reduce protective cytokines, thus aggravating psoriatic inflammation. In addition, IL-18 may be involved in the formation of Munro microabscesses and scales.

Hepatic lineage differentiation of hepatic progenitor cells by bone morphogenetic protein or leukemia inhibitory factor / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To search for the optimal approach for hepatocyte-directed differentiation of hepatic progenitor cells and investigate the molecular mechanism of the hepatic differentiation.</p><p><b>METHODS</b>Hepatic progenitor cells were infected with recombinant adenovirus which containing human LIF, BMP2 or BMP9 gene. The maturation and differentiation of progenitor cells were examined by PAS staining and ICG uptake methods at 4, 7 and 10 days post infection. The production of Albumin (Alb) was measured by luciferase activity at day 4, 7, 10 and 14.</p><p><b>RESULTS</b>PAS staining assay revealed that BMP2 and BMP9 enhanced glycogen storage in hepatic progenitor cells most obviously at day 7. The percentages of positive cells were 30% and 45% respectively at 7 days post-infection. Meanwhile, 40% and 30% cells were positive by ICG uptake assay after BMP2 and BMP9 induction. Luciferase activity indicated that BMP9 induced ALB-Luc activity most significantly at day 7. However, less inductive activity was found in LIF-treated group.</p><p><b>CONCLUSION</b>These results indicated tuat hepatic progenitor cells were differentiated into hepatocyte-like cells by BMPs and LIF induction.</p>