Detection of B-type natriuretic peptide by establishing a low-cost and replicable fluorescence resonance energy transfer platform.

Aiming at the establishment of a sensitive and specific diagnostic method for early heart failure (HF), we developed a cost-effective fluorescence resonance energy transfer (FRET) platform for the detection of B-type natriuretic peptide (BNP), a characteristic biomarker of HF. Graphene oxide (GO) was selected as the FRET receptor in view of its advantages including commercial availability, low-cost and chemical stability, and dye-modified aptamer was used as the energy donor of FRET as well as in charge of the specific recognition of BNP. Based on the ON (strong emission) and OFF (quenching) states of FRET in the presence and absence of BNP, respectively, specific detection of BNP was achieved in the range 0.074-0.56 pg/mL with a limit of detection as low as 45 fg/mL (3σ). This FRET platform was applied to detect BNP in 45 blood samples to demonstrate its practicability in clinical diagnosis. Compared to the commonly used Siemens method (chemiluminescence immunoassay, CLIA) in hospital, our approach is more accurate and specific for HF diagnosis with areas under the receiver operating characteristic curves of 0.869 (95% CI 0.733-1.00, P < 0.05) vs 0.850 (95% CI 0.703-0.997, P < 0.05) and specificity of 68.8% vs 65.6%. This platform is promising in early diagnosis of HF through ultrasensitive and specific detection of BNP. Graphical abstract To solve the clinical diagnostic problem for early heart failure (HF) which lacks sensitivity and specificity, we established a cost-effective and rapid fluorescence analysis method based on fluorescence resonance energy transfer (FRET) platform for the detection of B-type natriuretic peptide (BNP), a characteristic biomarker of HF.

Paeonol alleviates CCl4-induced liver fibrosis through suppression of hepatic stellate cells activation via inhibiting the TGF-ß/Smad3 signaling.

Objective: Paeonol is a natural phenolic component isolated from the root bark of peony with multiple pharmacological activities. We investigated the anti-fibrotic effect and underlying mechanism of paeonol. Methods: Twenty-four male C57BL/6J mice were divided into 4 groups (n = 6 in each group), injected with CCl4 to induce liver fibrosis and administrated with paeonol according to the regimen. The serum activity of ALT and AST, and H&E staining were to assess liver injury. Sirius and Masson staining, and hydroxyproline content were to evaluate the degree of liver fibrosis. TNF-α, IL-6, TGF-ß, MDA, GSH-PX, SOD, and CAT were detected to reflect inflammation and oxidative stress. RT-qPCR and Western blot analysis to assess the activation of HSCs and TGF-ß/Smad3 signaling. Results: Paeonol ameliorated liver injury and liver fibrosis, reflected by the decrease of ALT, AST, less lesion in H&E staining, mitigated fibrosis in Sirius and Masson staining, lessened content of hydroxyproline. Paeonol attenuated the level of IL-6 and TNF-α, and elevated the activity of GSH-PX, SOD, and CAT with reducing the level of MDA. The expression of col 1a, α-SMA, vimentin, and desmin were down-regulated and TGF-ß/Smad3 signaling pathway was inhibited. Conclusion: These data demonstrated that paeonol could alleviate CCl4-induced liver fibrosis through suppression of hepatic stellate cells activation via inhibiting the TGF-ß/Smad3 signaling.

Differential Immune Responses and Protective Effects in Avirulent Mycobacterial Strains Vaccinated BALB/c Mice.

Screening live mycobacterial vaccine candidates is the important strategy to develop new vaccines against adult tuberculosis (TB). In this study, the immunogenicity and protective efficacy of several avirulent mycobacterial strains including Mycobacterium smegmatis, M. vaccae, M. terrae, M. phlei, M. trivial, and M. tuberculosis H37Ra were compared with M. bovis BCG in BALB/c mice. Our results demonstrated that differential immune responses were induced in different mycobacterial species vaccinated mice. As BCG-vaccinated mice did, M. terrae immunization resulted in Th1-type responses in the lung, as well as splenocytes secreting IFN-γ against a highly conserved mycobacterial antigen Ag85A. M. smegmatis also induced the same splenocytes secreting IFN-γ as BCG and M. terrae did. In addition, M. terrae and M. smegmatis-immunized mice predominantly increased expression of IL-10 and TGF-ß in the lung. Most importantly, mice vaccinated with H37Ra and M. vaccae could provide the same protection in the lung against virulent M. tuberculosis challenge as BCG. The result may have important implications in developing adult TB vaccine.

[Study on macrophages infected with Mycobacterium tuberculosis H37Ra in vitro].

AIM: To study the production of nitric oxide and secretion of cytokines after infection of macrophages with Mycobacterium tuberculosis H37Ra. METHODS: 24 hours after infection of RAW264.7 cells with Mycobacterium tuberculosis H37Ra, the production of NO and H(2);O(2); as well as the secretion levels of IL-12 and TNF-α in the supernatants of culture were determined by Griess method, chemical method and ELISA assay respectively. The expression of IL-12 and TNF-α mRNA in macrophages was detected by reverse transcription polymerase chain reaction (RT- PCR). RESULTS: Macrophages infected with Mycobacterium tuberculosis H37Ra produced effectively more NO, H(2);O(2);, and enhanced the release of IL-12, TNF-α and the expression of IL-12, TNF-α mRNA (P<0.05). CONCLUSION: Mycobacterium tuberculosis H37Ra can induce the production of more nitric oxide and cytokines which play important roles in the host immune response.