Hsa_circ_0007460 affects the survival of intracellular Mycobacterium tuberculosis by regulating autophagy and apoptosis of macrophages.

Circular RNA (circRNA) is a category of non-coding RNAs characterized by the absence of a 5'-cap and 3'-poly(A) tail, and participates in the physiological processes of various human diseases. Nonetheless, the diagnostic and functional significance of circRNAs in active pulmonary tuberculosis (ATB) remains uncertain. Consequently, the purpose of this study is to investigate whether hsa_circ_0007460 can be employed as a potential diagnostic biomarker in ATB patients and explore its function. The result of real-time quantitative fluorescent PCR (RT-qPCR) validated a notable increase in the expression of hsa_circ_0007460 in the peripheral blood of 32 ATB patients, as well as in THP-1 human macrophages infected with Bacillus Calmette Guerin (BCG) which is an attenuated strain of Mycobacterium bovis. Additionally, the receiver operating curve (ROC) illustrated that the area under the ROC curve (AUC), sensitivity and specificity were 0.7474, 76.67%, and 78.13% respectively. RNase R, Actinomycin D and other experiments confirmed that hsa_circ_0007460 was stabler than its linear mRNA, indicating that hsa_circ_0007460 has potential as a diagnostic biomarker of ATB. Furthermore, Western blot (WB), Cell Counting Kit-8 (CCK-8), plate counting, and immunofluorescence experiments revealed that hsa_circ_0007460 could regulate apoptosis and autophagy of macrophages. The downstream miRNAs and mRNAs were subsequently predicted using bioinformatics, and the hsa circ 0007460/hsa-miR-3127-5p/PATZ1 axis was built. These above results suggest that hsa_circ_0007460 is substantially up-regulated in the peripheral blood of patients with ATB and can be utilized as a potential diagnostic biomarker. In addition, hsa_circ_0007460 can promote apoptosis of macrophages and inhibit autophagy of macrophages, thereby promoting the survival of BCG.

Recurrent pulmonary tuberculosis after treatment success: a population-based retrospective study in China.

OBJECTIVES: Post-treatment recurrence remains a challenge for the global control of tuberculosis (TB). This study investigated longitudinal data on pulmonary TB recurrence rates and risk factors for recurrence among successfully treated smear-positive tuberculosis cases in China. METHODS: Between 1st January 2009 and 31st December 2016 we evaluated 33 441 treatment-naïve patients diagnosed with sputum-smear-positive, non-multidrug-resistant TB in Hangzhou, China. We included the data of 9828 patients with TB who were treated successfully. RESULTS: A total of 4.9% of the cases were recurrent (479/9828), identified within a median observation period lasting 1565 days. Altogether, 51.1% (245/479) of the recurrences occurred within 1 year. The cumulative 2- and 5-year recurrence rates were 3.90% (95% confidence interval (CI) 3.3-4.5%) and 5.4% (95%CI 4.8-6.0%), respectively. Prolonged treatment (over 7 months) occurred in 64.7% (6363/9828), with a median treatment duration of 242 days (interquartile range 195-348 days). Male sex (adjusted hazard ratio (aHR) (95%CI) 1.61 (1.30-2.00), p < 0.001), age 60 years old or older (aHR (95%CI) 2.03 (1.70-2.44), p < 0.001), pulmonary cavity (aHR (95%CI) 1.51 (1.25-1.82), p < 0.001) and sputum positivity at 2 months (aHR (95%CI) 1.39 (1.05-1.81), p 0.02) all increased the risk of TB recurrence. Prolonged treatment was associated with reduced TB recurrence (aHR (95%CI) 0.73 (0.61-0.88), p 0.001). CONCLUSIONS: Recurrence remains a problem for successfully treated patients with sputum-smear-positive pulmonary TB, especially those with independent risk factors. Further analysis of prolonged treatment is required.

Transcriptional signatures of human peripheral blood mononuclear cells can identify the risk of tuberculosis progression from latent infection among individuals with silicosis.

CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02430259).

Gracillin inhibits apoptosis and inflammation induced by lipopolysaccharide (LPS) to alleviate cardiac injury in mice via improving miR-29a.

Sepsis induces critical myocardial dysfunction, resulting in an increased mortality. Gracillin (GRA) is a natural steroidal saponin, showing strong capacities of anti-inflammation, but its pharmacological effects on lipopolysaccharide (LPS)-induced acute cardiac injury still remain unclear. In this study, we attempted to explore if GRA was effective to attenuate cardiac injury in LPS-challenged mice and the underlying mechanisms. First, we found that GRA treatments markedly up-regulated the expression of miR-29a in cardiomyocytes. LPS-induced cytotoxicity in cardiomyocytes was significantly alleviated by GRA treatment, as evidenced by the improved cell viability and reduced lactate dehydrogenase (LDH) release. In addition, LPS-triggered apoptotic cell death was clearly ameliorated in cardiomyocytes co-treated with GRA. Notably, LPS-exposed cells showed significantly reduced expression of miR-29a, while being rescued by GRA treatment. In vivo, LPS apparently impaired cardiac function in mice, which was, however, alleviated by GRA administration. In addition, GRA markedly attenuated apoptosis in hearts of LPS-challenged mice by decreasing the expression of cleaved Caspase-3. LPS-triggered inflammatory response in cardiac tissues was also suppressed by GRA through blocking nuclear factor κB (NF-κB) signaling pathway. We also found that miR-29a expression was highly reduced in hearts of LPS-treated mice but was rescued by GRA pretreatment. Besides, miR-29a mimic alleviated LPS-induced apoptosis and inflammation in cardiomyocytes; however, LPS-caused effects were further accelerated by miR-29a. Of note, the protective effects of GRA on LPS-injured cardiac tissues were significantly abrogated by miR-29a suppression. In conclusion, our findings demonstrated that GRA exerted an effective role against LPS-induced acute cardiac injury through impeding apoptosis and inflammation regulated by miR-29a.

Immunoprotection against influenza virus H9N2 by the oral administration of recombinant Lactobacillus plantarumNC8 expressing hemagglutinin in BALB/c mice.

The H9N2 avian influenza virus (AIV) has become increasingly concerning due to its role in severe economic losses in the poultry industry. Transmission of AIV to mammals, including pigs and humans, has accelerated efforts to devise preventive strategies. To develop an effective oral vaccine against H9N2 AIV, a recombinant Lactobacillus plantarum NC8 strain expressing the hemagglutinin (HA) gene of H9N2 AIV was constructed in this study. Mice were orally immunized with the recombinant NC8-pSIP409-HA strain, and sIgA, IgG and HI antibodies were produced by the NC8-pSIP409-HA strain, which also induced CD8(+) T cell immune responses. Most importantly, oral administration produced complete protection against challenge with mouse-adapted H9N2 virus. These results indicate that the recombinant NC8-pSIP409-HA was more effective at inducing the mucosal, humoral and cellular immune responses. Therefore, L. plantarum NC8-pSIP409-HA could become a promising oral vaccine candidate against H9N2 AIV.

Inhibition activities of polysaccharide (RG4-1) from Gentiana rigescens against RSV.

Respiratory syncytial virus (RSV) is the most important cause of lower respiratory tract infection in infants and young children. With the emergence of drug-resistant strains of RSV, new antiviral agents are needed urgently. Gentiana rigescens is a kind of Chinese herb, belonging to Gentianaceae, which has long been used as a folk medicine for curing inflammation, bacterial infection, viral infection, and so on. In this research, polysaccharide designated RG4-1 was isolated from G. rigescens by hot water extraction, ethanol precipitation, and macroreticular adsorbing resin column chromatography, and its antiviral activity, cytotoxicity, and possible antiviral mechanisms were assayed by cytopathogenic effect inhibition assay, 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and plaque reduction assay. RG4-1 was a fructose-binding lectin. In host cell cultures, RG4-1 was found to be an effective antiviral component against RSV. It showed good inhibitory effect against RSV when it was added 2 h after virus infection with 50% effective concentration of 12.86 µg/ml. RG4-1 also displayed its direct inactivation, attachment inhibition effect, and penetration inhibition effect against RSV. A time-dependent experiment was set up to confirm that RG4-1 blocked RSV infection at early stages of the infection. But RG4-1 seemed to be ineffective against intracellular virus and viral biosynthesis.

[Effect of an active component from Forsythia suspensa (Thunb.) Vahl against respiratory syncytial virus in vitro].

OBJECTIVE: To study the extraction of an active component LC-4 from Forsythia suspensa (Thunb.) Vahl and anti-respiratory syncytial virus (RSV) effect in vitro. METHODS: The extration from boiling water of Forsythia suspensa were extracted by hot water extraction and were precipitated by ethanol and were elicited by macroporous adsorptive resins column chromatography. Then the antiviral active component LC-4 was separated from the production by eluting. The cytotoxicities and antiviral effect of LC-4 were tested by the Neutral Red assay and the cytopathic effect (CPE) inhibition assay. Ribavirin was used as the positive drug in the study. The antiviral effect of prevention and treatment of maximum dose of non-cytotoxicity of LC-4 was tested in Hela cell line. RESULTS: LC-4 showed that the concentration were 25.4 microg/ml with the medium cytotoxicity and were 2.11 microg/ml with the medium effective concentration (EC50). The corresponding treatment index of LC-4 was 12.04. It also exhibited obviously inhibition effect on RSV replications when LC-4 was added at 2 h, 4 h, 6 h and 8 h after infection (P < 0.05). The CPE was significant difference in comparison with control group, when the concentration of LC-4 between 31.25 microg/ml and 3.91 microg/ml was added at 2 h before infection (P < 0.05). CONCLUSION: LC-4 could significantly prevent and inhibit RSV replications in vitro.

An improved embryonated chicken egg model for the evaluation of antiviral drugs against influenza A virus.

Influenza is a serious global public health problem and an economic burden. With the continual emergence of new influenza A virus strains, new antiviral drugs are needed urgently. In this study, an improved embryonated chicken egg model for evaluating antiviral activity against Influenza A virus was developed. In the model, the influenza A virus was injected into the allantoic cavity and ribavirin was injected into the albumen of the egg. The levels of influenza A virus in the allantoic fluid was titrated by the hemagglutination test after incubation for 72 h at 35.5 degrees C and 12 h at 4 degrees C. Ribavirin treatment at a dose of 25 mg/kg to 100 mg/kg decreased significantly the hemagglutination titers both of Influenza virus A/FM1, H1N1 (IVA1) (p < 0.01) and influenza virus A/Wuhan/359/95, H3N2 (IVA3) (p < 0.01). In a time-dependent drug addition assay, significant efficacy of ribavirin against both IVA1 and IVA3 was observed when the drug was administered before and shortly after viral inoculation (p < 0.01 or p < 0.05). In conclusion, ribavirin treatment showed significant antiviral activity against IVA1 and IVA3 in this model, suggesting that the improved model would be useful for evaluating the anti-influenza virus activity of potential inhibitors.

[Effect of vitamin C antioxidative protection on human red blood cells].

In order to investigate the effect of antioxidants on human blood, vitamin C was selected and added into plastic blood storage bags with CPD, and stored at 25 degrees C. During 6 days of storage, some indexes as ATP, SOD, MDA, K(+) concentration and superoxide radicals were detected and were compared with control group, The results showed that ATP and SOD activity in whole blood with vitamin C during 6 days of storage was higher then that in control group (P < 0.05, P < 0.01), the MDA and plasma K(+) concentrations in stored whole blood with vitamin C during 6 days of storage were lower than that in control group (P < 0.05, P < 0.01), the superoxide radical concentrations in stored whole blood with vitamin C decreased lower than that in control group (30%). The conclusion was made that vitamin C increases activities of ATP and SOD, decreases concentrations of MDA, plasma K(+) and superoxide radicals during blood preservation.