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MicroRNAs are small highly conserved noncoding RNAs that are widely expressed in multicellular organisms and participate in the regulation of various cellular processes including autophagy and viral replication. Evidently, microRNAs are able to modulate host gene expression and thereby inhibit or enhance hepatitis B virus (HBV) replication. The miR-99 family members are highly expressed in the liver. Interestingly, the plasma levels of miR-99 family in the peripheral blood correspond with HBV DNA loads. Thus, we asked whether the miR-99 family regulated HBV replication and analyzed the underlying molecular mechanism. Compared with primary hepatocytes, miR-99 family expression was downregulated in hepatoma cells. Transfection of miR-99a, miR-99b, and miR-100 markedly increased HBV replication, progeny secretion, and antigen expression in hepatoma cells. However, miR-99 family had no effect on HBV transcription and HBV promoter activities, suggesting that they regulate HBV replication at posttranscriptional steps. Consistent with bioinformatic analysis and recent reports, ectopic expression of miR-99 family attenuated IGF-1R/Akt/mTOR pathway signaling and repressed insulin-stimulated activation in hepatoma cells. Moreover, the experimental data demonstrated that the miR-99 family promoted autophagy through mTOR/ULK1 signaling and thereby enhanced HBV replication. In conclusion, the miR-99 family promotes HBV replication posttranscriptionally through IGF-1R/PI3K/Akt/mTOR/ULK1 signaling-induced autophagy.

BACKGROUND MicroRNAs (miRNAs) are present in body fluids and may have the potential to serve as disease biomarkers. This study explored the clinical value of miRNAs in serum and urine as biomarkers for idiopathic childhood nephrotic syndrome (NS). METHODS We obtained serum samples from 159 NS children (24 steroid resistant and 135 steroid sensitive), 109 age/sex-matched healthy controls and 44 children with other kidney diseases. Serum miRNAs were analyzed with the TaqMan Low Density Array and then validated with a quantitative reverse-transcription PCR assay with 126 individual samples. Moreover, we collected paired serum samples from 50 patients before and after treatment to determine the value of these miRNAs for condition assessment. In addition, urine samples from these patients were examined for candidate miRNAs. RESULTS The concentrations of serum miR-30a-5p, miR-151-3p, miR-150, miR-191, and miR-19b were highly increased in NS children compared with controls (P < 0.0001). The urinary miR-30a-5p concentration was also increased in NS (P = 0.001). The area under the ROC curve and the odds ratio for the combined 5 serum miRNAs were 0.90 (95% CI, 0.86–0.94; P < 0.0001) and 40.7 (95% CI, 6.06–103; P < 0.0001), respectively. Moreover, the concentrations of the 5 serum miRNAs and urinary miR-30a-5p markedly declined with the clinical improvement of the patients. CONCLUSIONS We determined that 5 distinct serum miRNAs and urinary miR-30a-5p were increased in NS children. These circulating or urinary miRNAs may represent potential diagnostic and prognostic biomarkers for idiopathic pediatric NS.

The first example of a direct catalytic asymmetric intermolecular aldol reaction of 3-isothiocyanato oxindoles to simple ketones with bifunctional thiourea-tertiary amine as catalyst is reported. This strategy provides a promising approach for the asymmetric synthesis of a range of enantioenriched spirocyclic oxindoles bearing two highly congested contiguous tetrasubstituted carbon stereocenters. Versatile transformations of the spirocyclic oxindole products into other structurally diverse spirocyclic oxindoles have also been demonstrated.The catalytic asymmetric aldol reaction is one of the most important methods for the asymmetric formation of CÀC bonds and has found widespread application in organic synthesis.1 In this respect, in contrast to the remarkable advances that have been made with aldehydes as electrophiles, 1,2 the development of aldol additions to ketones was quite slow.3 This state is attributable, at least in part, to the lower reactivity of ketones and the decreased steric discrimination compared to aldehydes. 4 Therefore, the direct asymmetric ketoneÀaldol reactions to date mainly focus on the activated ketone electrophiles 5 or intramolecular aldol additions based on enamine catalysis.