Secretory leukocyte protease inhibitor modulates FcεRI-dependent but not Mrgprb2-dependent mastocyte function in psoriasis.

Psoriasis, which involves mast cells, is a chronic inflammatory skin disorder whose pathophysiology is still not fully understood. We investigated the role of secretory leukocyte protease inhibitor (SLPI), a potential inhibitor of mastocyte serine proteases, on mast cell-dependent processes of relevance to the skin barrier defense in psoriasis. Here, we demonstrate that the dermal mast cells of patients with psoriasis express SLPI but not those of healthy donors. Moreover, SLPI transcripts were found to be markedly upregulated in murine mast cells by mediators derived from psoriasis skin explant cultures. Using mast cells from SLPI-deficient mice and their SLPI+ wild-type controls, we show that SLPI inhibits the activity of serine protease chymase in mastocytes. SLPI was also found to enhance the degranulation of mast cells activated via anti-IgE Abs but not Mrgprb2 ligands. Finally, we demonstrate that the expression and function of Mrgprb2 in mast cells are suppressed by a normal and, to a larger extent, psoriatic skin environment. Together, these findings reveal mechanisms underlying FcεRI- and Mrgprb2-dependent mast cell function that have not been described previously.

The expression and clinical significance of secretory leukocyte proteinase inhibitor (SLPI) in mammary carcinoma using bioinformatics analysis.

BACKGROUND: Secretory leukocyte protease inhibitor (SPLI) was a secreted protein which belongs to a member of whey acidic protein four-disulfide core family. In breast cancer (BC) it may inhibit cell proliferation and promote cancer metastasis. In this study, a comprehensive bioinformatics analysis was performed to identify the expression and prognostic value of SLPI in breast cancer. METHODS: SLPI expression in breast cancer was analyzed in Oncomine online database, which was subsequently confirmed by quantitative PCR (qPCR) in 18 BC samples and western blotting in 26 BC samples. Breast cancer gene-expression miner v4.1 was used to access the expression level with clinicopathological parameters in breast cancer patients. The prognostic values of SLPI in breast cancer were evaluated using the PrognoScan database. RESULTS: Our results indicated that SLPI was downregulated in breast cancer than in normal tissues. SLPI expression was found to be negatively correlated with estrogen receptor (ER) and progesterone receptor (PR) status. SLPI expression level was decreased in negative basal-like status patients compared with positive basal-like status. Meanwhile, triple-negative breast cancer status positive correlated with SLPI. We confirmed a positive correlation between SLPI and interleukin 17 receptor B (IL17RB) express in breast cancer tissues via oncomine co-expression analysis. Ten proteins: Elastase, Granulin, Lipocalin, Defensin beta 103B, Defensin beta 103A, Tubulin, Heparin-binding EGF-like growth factor, Interleukin 6, Epidermal growth factor, Phospholipid scramblase 1 were determinate interactions with SLPI by STRING. CONCLUSION: SLPI could as a biomarker to predict the prognosis values of breast cancer. However, further comprehensive study and mining more evidence are needed to clarify our results.

SLPI in the perfusion solution helps to identify graft quality in kidney transplants.

Aim: It is important to find biomarkers that identify the graft quality in kidney transplantation. Results & methodology: The level of SLPI in the cold preservation solution was used as a marker to predict early kidney graft function after transplantation. Before transplantation, kidneys were washed and SLPI was measured in the discarded solution. A retrospective analysis showed that patients with delayed graft function or rejection episodes in post-trasplant, had higher SLPI concentrations in the perfusion solution than patients without delayed graft function or rejections. Furthermore, SLPI could discriminate between patients with better or worse estimated glomerular filtration rate among low-risk patients (kidney donor profile index <80). Discussion & conclusion: These results suggest that the SLPI concentration in the perfusion solutions could be a predictor of short-term organ function and a complement to the kidney donor profile index score.