Study on apoptosis and expression of P53, bcl-2, Bax in cardiac myocytys of congestive heart failure induced by ventricular pacing

SKA1 is overexpressed in laryngocarcinoma and modulates cell growth via P53 signaling pathway

Laryngocarcinoma is one of the most frequent malignancies occurring in the head and neck. The roles of spindle- and kinetochore-associated complex 1 (SKA1) in the malignant progression of several cancers have already been discussed. However, the precise significance and action's mechanism of SKA1 in laryngocarcinoma remain largely unknown. In this study, SKA1 was shown to be strongly expressed in laryngocarcinoma tissues and cells, and higher expression of SKA1 was associated with more severe tumor infiltration, larger tumor diameter, higher risk of lymphatic metastasis and later pathological stage. Additionally, loss-of-function assays in vitro suggested that SKA1 depletion caused a reduction in cell proliferation, migration, and colony formation as well as an increase in apoptosis. In animal experiments, tumors generated from AMC-HN-8 cells with SKA1 depletion exhibited declined tumor volume and weight. Similarly, the detection of Ki67 protein in xenograft tumor tissues reflected that knocking down SKA1 curbed tumor growth in vivo. Further exploration on downstream mechanism revealed that after treatment with Pifithrin-α, the suppression in proliferation level caused by SKA1 knockdown was reversed, while the increase of cell apoptosis was withdrawn; at the molecular level, Pifithrin-α treatment caused p-P53 and Bax diminished, while Bcl-2 ameliorated. In short, SKA1 promotes the development of laryngocarcinoma via activating the P53 signaling pathway.

Arterial structural changes in rats immunized by AT1-receptor peptide

Accumulating evidence suggests that anti-AT1 (angiotensin II receptor type 1) receptor antibodies are involved in the pathogenesis of hypertension. We assessed the hypothesis that changes in vascular structure could be induced in rats immunized with AT1-receptor peptide. In this study, an animal model was made by immunizing Wistar rats aged 4 weeks with the synthetic peptide corresponding to the second extracellular peptide of human AT1 as the antigen and raising them for 1 year, while monitoring their blood pressure, heart rate, and anti-AT1-receptor antibodies. A year later the aorta and mesenteric artery of the immunized rats were collected to detect their structural changes. Anti-AT1-receptor antibodies purified by affinity chromatography were prepared to detect their effect on vascular smooth muscle cell (VSMC) proliferation by the method of bromodeoxyuridine incorporation and cell cycle distribution, and their effect on the expression of VSMC c-jun and c-fos mRNA by reverse transcription-polymerase chain reaction and Western blot. Anti-AT1-receptor antibodies were detected in immunized rats throughout the year without significant changes in blood pressure or heart rate, but pathological changes in the arteries were noted at the end of the study period. Purified anti-AT1-receptor antibodies improved proliferation of VSMC and upregulated c-jun expression, which were both attenuated by losartan. In summary, anti-AT1-receptor antibodies can be prepared by active immunization with the peptide of AT1 as the antigen, without changes in blood pressure or heart rate. Anti-AT1-receptor antibodies may play a role in hypertension through upregulation of c-jun expression, thus improving VSMC proliferation and finally inducing vascular recombination.