Hemodynamics and right-ventricle functional characteristics of a swine carotid artery-jugular vein shunt model of pulmonary arterial hypertension: An 18-month experimental study.

The continuous changes in pulmonary hemodynamic properties and right ventricular (RV) function in pulmonary arterial hypertension (PAH) have not been fully characterized in large animal model of PAH induced by a carotid artery-jugular vein shunt. A minipig model of PAH was induced by a surgical anastomosis between the left common carotid artery and the left jugular vein. The model was validated by catheter examination and pathologic analyses, and the hemodynamic features and right-ventricle functional characteristics of the model were continuously observed by Doppler echocardiography. Of the 45 minipigs who received the surgery, 27 survived and were validated as models of PAH, reflected by mean pulmonary artery pressure ≥25 mmHg, and typical pathologic changes of pulmonary arterial remodeling and RV fibrosis. Non-invasive indices of pulmonary hemodynamics (pulmonary artery accelerating time and its ratio to RV ventricular ejection time) were temporarily increased, then reduced later, similar to changes in tricuspid annular displacement. The Tei index of the RV was elevated, indicating a progressive impairment in RV function. Surgical anastomosis between carotid artery and jugular vein in a minipig is effective to establish PAH, and non-invasive hemodynamic and right-ventricle functional indices measured by Doppler echocardiography may be used as early indicators of PAH.

The role of microRNAs during the genesis of medulloblastomas induced by the hedgehog pathway.

Constitutive hedgehog (Hh) signaling is associated with the genesis of medulloblastomas (MB). The objective of this study is to identify special microRNAs (miRNAs) regulated by the Hh pathway, and to clarify the role of miRNAs during the genesis of MB induced by sustained Hh activation. In the primary screening, we used stem-loop RT-PCR to test the expression of 90 different miRNAs in the wildtype (WT) and Ptc-/- MEF cell lines. In the secondary screening, the miRNAs screened from the first screening were validated in the Sufu-/- MEF cell lines. We then verified the expression of miRNAs both in the normal cerebellar tissues and the MB induced by activated Hh pathway, and examined the expression of the other 21 miRNA members of the miR-154 cluster in the MB and normal cerebellum. In the first screening, 13 miRNAs showed significant differential expression in WT and Ptc-/- MEF cell lines, while 10 of them had significant difference in the Sufu-/- MEF cell line. Compared to the normal mouse cerebellum, only 2 miRNAs in 15 miRNAs were differentially expressed between the MB and normal cerebellar tissues. Among 21 members of the miR-154 cluster, 6 miRNAs were downregulated in the MB. Our study demonstrated that miR-154 may be regulated by the Hh pathway, and the activation of the Hh pathway led to the downregulation of the miR-154 cluster, resulting in the genesis of MB.

MicroRNA-214 promotes myogenic differentiation by facilitating exit from mitosis via down-regulation of proto-oncogene N-ras.

Vertebrate muscle differentiation is coordinated by an intricate network of transcription factors requiring proliferating myogenic precursors to withdraw irreversibly from the cell cycle. Recent studies have implicated a large number of microRNAs exerting another layer of control in many aspects of muscle differentiation. By annealing to short recognition sequences in the 3'-untranslated region, microRNAs attenuate target gene expression through translation repression or mRNA degradation. Here, we show that miR-214 promotes myogenic differentiation in mouse C2C12 myoblasts at a step preceding the induction of p21 and myogenin. Blocking miR-214 function with a 2'-O-methylated double-stranded inhibitor maintained C2C12 cells in the active cell cycle, thereby inhibiting the myogenic differentiation. By global gene expression profiling, we identified the proto-oncogene N-ras as one of miR-214 targets. Furthermore, manipulating the N-Ras level with small interfering RNA or adenovirus-mediated forced expression either augmented or attenuated the effect of miR-214, respectively. Thus, our data uncovered a novel microRNA-mediated mechanism that controls myogenic differentiation.

[Studies on solubility enhancement of curcumin by Polyvinylpyrrolidione K30].

OBJECTIVE: To study solubility enhancement of curcumin by Polyvinylpyrrolidione K30 (PVP K30). METHODS: Solid dispersion systems (SDS) of curcumin in PVP K30 were prepared at various weight ratios by co-evaporation of curcumin and PVP K30 ethanol solution. The differential scanning calorimetry (DSC) and powder X-ray diffractometer method were used to describe the status of curcumin in carriers, the UV spectrometry method for determination of curcumin in mediums was established. RESULTS: The curcumin SDS was successfully prepared, the UV spectrometry method was accurate and reliable, and no interference occurred from carrier. The solubility rate in vitro of curcumin was significantly raised. Compared to curcumin, the solubility of curcumin in SDS increased at least 880 folds. CONCLUSION: PVP K30 improves the solubility of curcumin well.