Diagnostic utility of total NT-proBNP testing by immunoassay based on antibodies targeting glycosylation-free regions of NT-proBNP.

OBJECTIVES: The N-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP) is a widely used heart failure (HF) biomarker. Commercial NT-proBNP immunoassays detect only a subfraction of endogenous NT-proBNP, as the antibodies target a region of NT-proBNP that could be glycosylated at Ser44. The diagnostic utility of immunoassays measuring total NT-proBNP remains unclear. METHODS: NT-proBNP was measured in 183 HF and 200 non-HF patients diagnosed by two independent cardiologists blinded to NT-proBNP results. Plasma samples either non-treated or treated with a mixture of glycosidases were analyzed by the Elecsys proBNP II assay (Roche Diagnostics, based on antibodies targeting a glycosylated region of NT-proBNP) and the SuperFlex NT-proBNP assay (PerkinElmer, based on antibodies targeting regions of NT-proBNP that are free of O-glycans). The diagnostic accuracy of the two assays was analyzed by comparison of ROC curves. RESULTS: The ROC-AUC for the proBNP II assay was 0.943 (95% CI 0.922-0.964) for NT-proBNP measured in untreated samples and 0.935 (0.913-0.958) for NT-proBNP measured in glycosidase-treated samples. The SuperFlex NT-proBNP assay in untreated samples gave a ROC-AUC of 0.930 (95% CI 0.907-0.954). The median percentage of non-glycosylated NT-proBNP to total NT-proBNP was 1.5-1.6-fold lower in the non-HF group compared to that in the HF group. CONCLUSIONS: The clinical value of total NT-proBNP for HF diagnosis was similar to the subfraction of NT-proBNP that was non-glycosylated at Ser44. The lower percentage of non-glycosylated NT-proBNP to total NT-proBNP in non-HF patients suggests that total NT-proBNP might be more sensitive in individuals without current or prior symptoms of HF.

PDK-1 mediated Hippo-YAP-IRS2 signaling pathway and involved in the apoptosis of non-small cell lung cancer cells.

Pyruvate dehydrogenase kinase-1 (PDK-1), a gatekeeper enzyme, was involved in cancer progression, such as tumor angiogenesis, cell survival, and growth. Recent evidence indicated that PDK-1 may be involved in lung cancer, however, the function and underlying mechanism of PDK-1 is remaining unclear. In the present study, our aim was to investigate the role and mechanisms of PDK-1 in human non-small cell lung cancer (NSCLC) cells. We first observed that PDK-1 was highly expressed in NSCLC cell lines. PDK-1 silence resulted in the inhibition of NSCLC cell survival. Also, cell apoptosis and caspase-3 activity were increased by PDK-1 knockdown in H1299 and A549 cells. Attenuation of PDK-1 expression blocked YAP and insulin receptor substrate 2 (IRS2) expression, and PDK-1 silence suppressed IRS2 expression dependent on Hippo-YAP signaling pathway. Moreover, further studies confirmed that YAP or IRS2 overexpression reversed the action of PDK-1 in NSCLC cells. In conclusion, our findings indicate that PDK1/Hippo-YAP/IRS2 signaling pathway plays a critical role in NSCLC cell survival and apoptosis.

Long non-coding RNA H19 modulates proliferation and apoptosis in osteoarthritis via regulating miR-106a-5p.

Osteoarthritis (OA), a type of joint diseases, could result in breakdown of joint cartilage and underlying bone. Accumulating evidences suggested that long non-coding RNAs play important roles in OA progression. However, the underlying mechanism of H19 in OA is still not fully explored. The expression levels of H19 and miR-106a-5p in OA samples from patients or cultured chondrocytes were examined by quantitative real time polymerase chain reaction. Cell proliferation and apoptosis were analysed by MTT assay and flow cytometry, respectively. Western blotting was employed to detect the expression levels of PCNA, CyclinD1, Caspase 3 and Cleaved Caspase 3. StarBase database, luciferase assay and RNA immunoprecipitation were introduced to confirm the relationship between H19 and miR-106a-5p. The correlation of H19 and miR-106a-5p was analysed by Spearman rank analysis. H19 expression was upregulated, while miR-106a-5p level was downregulated in OA samples and IL-1b-treated chondrocytes. H19 overexpression inhibited the proliferation and induced apoptosis in IL-1b-treated chondrocytes, while H19 knockdown induced the opposite effect. Luciferase and RIP assay demonstrated that miR-106a-5p was a direct target of H19. miR-106a-5p overexpression led to proliferation promotion and apoptosis inhibition in chondrocytes treated by IL-1ß and it reversed the effect of H19 addition. We conclude that H19 could regulate proliferation and apoptosis of chondrocytes treated by IL-1ß in OA via sponging miR-106a-5p.

Cytotoxic polyketide derivatives from the South China Sea sponge Plakortis simplex.

Five new polyketides, plakortoxides A (1) and B (2), simplextones C (3) and D (4), and plakorsin D (5), together with six known analogues (6-11) were isolated from the South China Sea sponge Plakortis simplex. Their structures were identified by spectroscopic and chemical methods, including NMR, MS, and IR. Experimental and calculated ECD spectra and the modified Mosher's method were used to determine the absolute configurations. Structurally, both plakortoxides A and B feature a butenolide coupled to an epoxide moiety, while simplextones C and D consist of γ-butyrolactone and cyclopentane moieties, and plakorsin D is a furan acetic acid polyketide. The cytotoxic activities of the isolates were tested, and compounds 8, 10, and 11 showed potent cytotoxicity against both K562 and HeLa tumor cell lines with IC50 values ranging from 0.8 to 5.3 µM. Compound 3 showed significant inhibitory activity against c-Met kinase.