Transcription of the centromeric regions has been reported to occur in G1 and S phase in different species. Here, we investigate whether transcription also occurs and plays a functional role at the mammalian centromere during mitosis. We show the presence of actively transcribing RNA polymerase II (RNAPII) and its associated transcription factors, coupled with the production of centromere satellite transcripts at the mitotic kinetochore. Specific inhibition of RNAPII activity during mitosis leads to a decrease in centromeric α-satellite transcription and a concomitant increase in anaphase-lagging cells, with the lagging chromosomes showing reduced centromere protein C binding. These findings demonstrate an essential role of RNA-PII in the transcription of α-satellite DNA, binding of centromere protein C, and the proper functioning of the mitotic kinetochore.chromatin | noncoding RNA | epigenetics T he centromere is an essential chromosomal structure that mediates microtubule attachment during cell division to ensure correct chromosome segregation. Although centromere function is highly conserved, centromere DNA sequences show no evolutionary conservation. Instead, centromeric chromatin typically is filled with species-specific satellite DNA sequences that lack transcribed genes. The presence of functional ectopic centromeres (neocentromeres) at genomic regions devoid of classical satellite DNA repeats confirmed the epigenetic nature of centromere function (1).The centromere is organized into two broad domains characterized by distinct sets of epigenetic determinants. The centromere core domain comprises the centromere-specific histone H3 variant centromere protein A (CENP-A) that is essential for kinetochore formation, whereas the pericentric heterochromatin is vital for sister chromatid cohesion (for review, see ref.2). In yeast, pericentric outermost DNA repeats are transcribed and processed by RNAi machinery into siRNAs, which direct the deposition of heterochromatic markers such as H3K9me3 and HP1 at the pericentric heterochromatin (3). The RNAi pathway also has been shown to be vital for the establishment of pericentric heterochromatin in plant and animal cells (4, 5). However, although the depletion of Dicer in human-chicken hybrid cells causes defective pericentric heterochromatin, it does not affect the binding of CENP-A and centromere protein C (CENP-C) at the centromere core domain (6), suggesting that the RNAi pathway is not required for core centromere function. Our previous studies showed that transcription is permissible within the kinetochore domain of a human neocentromere (7, 8), but others have reported the presence of active genes within the rice kinetochore domain (9). Consistent with these reports, the CENP-A domain in Drosophila and human cells is enriched with the euchromatin-like marker H3K4me2 (10). Such studies suggest that transcription of centromeric chromatin is permissible and compatible with centromere function. Furthermore, we and others have demonstrated the presence of RNA at th...

PurposeThiazolidinediones are insulin-sensitizing agents that reduce neointimal proliferation and the adverse clinical outcomes associated with percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM). There is little data on whether or not low dose pioglitazone reduces adverse clinical outcomes.Materials and MethodsThe study population included 121 DM patients with coronary artery disease and they were randomly assigned to 60 patients taking 15 mg of pioglitazone daily in addition to their diabetic medications and 61 patients with placebo after the index procedure with drug-eluting stents (DESs). The primary end points were rate of in-stent restenosis (ISR) and change in atheroma volume and in-stent neointimal volume. The secondary end points were all-cause death, myocardial infarction (MI), stent thrombosis and re-PCI.ResultsThere were no statistical differences in the clinical outcomes and the rate of ISR between the two groups [all-cause death; n=0 (0%) in the pioglitazone group vs. n=1 (1.6%) in the control group, p=0.504, MI; n=2 (3.3%) vs. n=1 (1.6%), p=0.465, re-PCI; n=6 (10.0%) vs. n=6 (9.8%), p=0.652, ISR; n=4 (9.3%) vs. n=4 (7.5%), p=1.000, respectively]. There were no differences in changes in neointimal volume, percent neointimal volume, total plaque volume and percent plaque volume between the two groups on intravascular ultrasonography (IVUS) study.ConclusionOur study demonstrated that low dose pioglitazone does not reduce rate of ISR, neointimal volume nor atheroma volume in DM patients who have undergone PCI with DESs, despite the limitations of the study.

PurposeAdipose-derived stem cells (ADSCs) are known to be potentially effective in regeneration of damaged tissue. We aimed to assess the effectiveness of intracoronary administration of ADSCs in reducing the infarction area and improving function after acute transmural myocardial infarction (MI) in a porcine model.Materials and MethodsADSCs were obtained from each pig's abdominal subcutaneous fat tissue by simple liposuction. After 3 passages of 14-days culture, 2 million ADSCs were injected into the coronary artery 30 min after acute transmural MI. At baseline and 4 weeks after the ADSC injection, 99mTc methoxyisobutylisonitrile-single photon emission computed tomography (MIBI-SPECT) was performed to evaluate the left ventricular volume, left ventricular ejection fraction (LVEF; %), and perfusion defects as well as the myocardial salvage (%) and salvage index. At 4 weeks, each pig was sacrificed, and the heart was extracted and dissected. Gross and microscopic analyses with specific immunohistochemistry staining were then performed.ResultsAnalysis showed improvement in the perfusion defect, but not in the LVEF in the ADSC group (n=14), compared with the control group (n=14) (perfusion defect, -13.0±10.0 vs. -2.6±12.0, p=0.019; LVEF, -8.0±15.4 vs. -15.9±14.8, p=0.181). There was a tendency of reducing left ventricular volume in ADSC group. The ADSCs identified by stromal cell-derived factor-1 (SDF-1) staining were well co-localized by von Willebrand factor and Troponin T staining.ConclusionIntracoronary injection of cultured ADSCs improved myocardial perfusion in this porcine acute transmural MI model.

Background: Primary percutaneous coronary intervention (PCI) is recommended for ST-segment elevation myocardial infarction (STEMI) patients (194 vs. 90 min, p < 0.001). The median door-toballoon time was significantly shorter in the transfer group vs. the direct-arrival group (75 vs. 91 min, p < 0.001). Total death and the composite of MACE were not significantly different during hospitalization (5.1 vs. 3.9%, p = 0.980; 5.4 vs. 4.8%, p = 0.435, respectively) and at 1-year (8.2 vs. 6.6%, p = 0.075; 13.7 vs. 13.9%, p = 0.922, respectively (Cardiol J 2016; 23, 3: 289-295)