AIM: To investigate the role and signal mechanism of PPAR-α in the pathogenesis of cardiac hypertrophy. METHODS: Small interfering RNA (siRNA) was applied to efficiently silence the gene expression of PPAR-α in cardiac myocytes. [~3H] leucine incorporation assay was performed to measure protein synthesis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to analyze the mRNA level of atrial natriuretic factor (ANF) and PPAR-α. Western blotting analysis was performed to investigate the levels of phosphorylation of protein kinase B (PKB/Akt) and glycogen synthase kinase 3β (GSK3β). Immunofluorescence analysis was used to examine the cellular localization of NFATc4. RESULTS: (1)RSS304168 was the most efficient stealth RNAi duplex to specifically inhibit PPAR-α expression. (2)RSS304168 significantly potentiated the ET-1-induced cardiomyocyte hypertrophy and enhanced ET-1-induced protein synthesis and ANF mRNA expression in cardiomyocytes. Moreover, RSS304168 completely reversed the inhibitory effects of fenofibrate on ET-1-induced protein synthesis and ANF mRNA expression. (3)RSS304168 enhanced ET-1-induced phosphorylation of Akt at Ser473 and GSK3β at Ser9. The effects of ET-1 or ET-1 combined with RSS304168 on phosphorylation of Akt/GSK3β were completely blocked by LY294002, a PI3K specific inhibitor. Fenofibrate markedly inhibited ET-1-induced phosphorylation of Akt/GSK3β while RSS304168 abolished these effects of fenofibrate. (4)Fenofibrate prevented the nuclear translocation of NFATc4 induced by ET-1 while RSS304168 abolished this effect of fenofibrate. CONCLUSION: Activation of PPAR-α inhibits ET-1-induced cardiomyocyte hypertrophy through blocking Akt/GSK3β-NFATc4 signaling pathways.

Objective: To describe the characteristics of clinical manifestations and epidemiology of children with 2019 novel coronavirus (2019-nCoV) infection. Methods: All 34 children with laboratory-confirmed 2019-nCoV infection by quantitative real-time reverse transcription-PCR through nasopharyngeal swab specimens were admitted to the Third People’s Hospital of Shenzhen from January 19 to Febuary 7, 2020. Clinical data and epidemiological history of these patients were retrospectively collected and analyzed. Results: Among the 34 cases, 14 were males, and 20 were females. The median age was 8 years and 11 months. No patients had underlying diseases. There were 28 children (82%) related with a family cluster outbreak. There were 26 children (76%) with a travel or residence history in Hubei Province. These patients could be categorized into different clinical types, including 22 (65%) common cases, 9 (26%) mild cases and 3 (8.8%) asymptomatic cases. No severe or critical cases were identified. The most common symptoms were fever (17 cases, 50%) and cough (13 cases, 38% ). In the 34 cases, the white blood cell counts of 28 cases (82%) were normal. Five cases had white blood cell counts more than 10×10⁹/L. One case had white blood cell counts less than 4×10⁹/L. Neutropenia and lymphopenia was found in one case, respectively. C-reactive protein levels and erythrocyte sedimentation rates were elevated in 1 and 5 case, respectively. Elevated procalcitonin was found in 1 case and D-Dimer in 3 cases. The levels of lactic dehydrogenase (LDH) were more than 400 U/L in 10 cases. The CT images of these patients showed bilateral multiple patchy or nodular ground-glass opacities and/or infiltrating shadows in middle and outer zone of the lung or under the pleura. Twenty patients were treated with lopinavir and ritonavir. Glucocorticoids and immunoglobulin were not used in any cases. All the cases improved and were discharged from hospital. Further following up was need. Conclusions The clinical manifestations in children with 2019-nCoV infection are non-specific and are milder than that in adults. Chest CT scanning is heplful for early diagnosis. Children's infection is mainly caused by family cluster outbreak and imported cases. Family daily prevention is the main way to prevent 2019-nCoV infection.