Abnormal expression of miR-let-7b in primary biliary cirrhosis and its clinical significance / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To evaluate the expression of microRNA (miR)-let-7b in peripheral blood cells of patients with primary biliary cirrhosis (PBC) and investigate its relationship to clinical disease parameters.</p><p><b>METHODS</b>Peripheral blood and serum samples were obtained for study from 60 PBC patients and 60 healthy controls. Peripheral blood cells were extracted and subjected to real-time PCR to measure miR-let-7b expression. Serum levels of interleukin (IL)-18, total bilirubin (TBIL), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) were measured by standard biochemical assays. The relationship between miR-let-7b expression and disease parameters was assessed by Spearman's rank correlation test.</p><p><b>RESULTS</b>PBC patients showed significantly lower expression of miR-let-7b in peripheral blood cells than healthy controls (P less than 0.001); moreover, the miR-let-7b expression level decreased in parallel to increases in disease severity (stage I > II / III > IV). In PBC patients, the miR-let-7b expression was significantly correlated with Mayo risk scores (r = -0.4930, P less than 0.001), IL-18 (r = -0.4643, P less than 0.001) and ALP (r = -4119, P less than 0.001), but not with TBIL or GGT.</p><p><b>CONCLUSION</b>Decreased expression of miR-let-7b may be associated with development and progression of PBC, and this miRNA may represent a novel target of improved diagnostic and preventive strategies for PBC.</p>

Cytotoxic effects of granulysin on Candida albicans / 第二军医大学学报

Objective: To study the cytotoxic effects of granulysin on Candida albicans. Methods: Candida albicans were cultured with different concen trations of granulysin peptides and the colonies of Candida albicans on Sabouraud dextrose agar were calculated. Broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of granulysin and fluconazole on Candida albicans. Results: When granulysin peptides 2 and 3 (corresponding to G2 and G3 peptides) were at 20 μg/ml, the average colonies of Candida albicans decreased from 838 and 927 to 203 and 218, respectively; G1, G4 and G5 did not reduce the average colony of Candida albicans even at 40 μg/ml. Three strains of Candida albicans were sensitive to granulysin, with their MICs being 26, 22, 29 μg/ml, and their MICs to fluconazole were 4, 20 and 128 μg/ml. Conclusion: Granulysin has cytotoxic effects on Candida albicans and is one of the natural anti-fungi proteins in human body; it has a promising future for anti-fungi drug development.

Decrease of natural killer cell activity in patiens with cryptococcosis and its clinical significance / 第二军医大学学报

Objective: To investigate the interactions between natural killer (NK) cells and Cryptococcus neoformans(C. neoformans) in patients with cryptococcosis, so as to pave a way for treatment and prevention of cryptococcosis. Methods: The peripheral blood samples of 40 cryptococcosis patients and 40 healthy controls were collected. Expression of CD2, CD3, CD4, CD8, CD28, CD18, CD19, and CD56 in patients peripheral blood mononuclear cells(PBMC) were detected by FACS. Cytotoxic activity of NK cells was analyzed by MTT using K562 cells as target cells and the influence of IFN-α and IL-2 on NK cell activity was also studied. The level of IFN-γ in the culture supernatant was assayed by ELISA and the cytotoxic activity of the supernatant was determined. The transcription levels of perforin, granzyme B and granulysin were examined by quantative real-time PCR. C. neoformans and NK cells were cocultured to investigate the inhibition of NK cells on C. neoformans. Results: Compared with that in healthy controls, CD56+ cells decreased significantly (P<0.01) in the PBMC of patients with cryptococcosis, CD8+,CD19+ and CD18+ cells increased significantly (P<0.05 or P<0.01),and the ratio of CD8+/CD28+ increased and of CD4+/CD8+ declined significantly (P<0.05). However, the levels of CD2+, CD3+ and CD4+ cells had no change. Compared with that in healthy controls, the NK cells cytotoxicity in patients with cryptococcosis decreased significantly(P<0.01), but increased when IFN-α or IL-2 was added (P<0.01). IFN-γ level in the PBMC supernatant of patients with cryptococcosis was much lower than that in healthy controls(P<0.01). Transcription of perforin, granzyme B and granulysin in PBMC of patients with cryptococcosis decreased markedly in contrast to those of healthy controls(P<0.01). The inhibitory effect of NK cells on growth of C. neoformans was significantly lower in cryptococcosis patients than that in healthy controls (P<0.05). Conclusion: The quantity and function of NK cells decrease in patients with cryptococcosis. Cytokines such as IL-2 and IFN-α can upregulate the cytotoxicity of NK cells, which suggests a new way for treatment of cryptococcosis.