sirolimus and Aortic-Valve-Stenosis

The incidence of heart failure mainly resulting from cardiac hypertrophy and fibrosis increases sharply in post-menopausal women compared with men at the same age, which indicates a cardioprotective role of estrogen. Previous studies in our group have shown that the novel estrogen receptor G Protein Coupled Receptor 30 (GPR30) could attenuate myocardial fibrosis caused by ischemic heart disease. However, the role of GPR30 in myocardial hypertrophy in ovariectomized mice has not been investigated yet. In this study, female mice with bilateral ovariectomy or sham surgery underwent transverse aortic constriction (TAC) surgery. After 8 weeks, mice in the OVX + TAC group exhibited more severe myocardial hypertrophy and fibrosis than mice in the TAC group. G1, the specific agonist of GPR30, could attenuate myocardial hypertrophy and fibrosis of mice in the OVX + TAC group. Furthermore, the expression of LC3II was significantly higher in the OVX + TAC group than in the OVX + TAC + G1 group, which indicates that autophagy might play an important role in this process. An in vitro study showed that G1 alleviated AngiotensionII (AngII)-induced hypertrophy and reduced the autophagy level of H9c2 cells, as revealed by LC3II expression and tandem mRFP-GFP-LC3 fluorescence analysis. Additionally, Western blot results showed that the AKT/mTOR pathway was inhibited in the AngII group, whereas it was restored in the AngII + G1 group. To further verify the mechanism, PI3K inhibitor LY294002 or autophagy activator rapamycin was added in the AngII + G1 group, and the antihypertrophy effect of G1 on H9c2 cells was blocked by LY294002 or rapamycin. In summary, our results demonstrate that G1 can attenuate cardiac hypertrophy and fibrosis and improve the cardiac function of mice in the OVX + TAC group through AKT/mTOR mediated inhibition of autophagy. Thus, this study demonstrates a potential option for the drug treatment of pressure overload-induced cardiac hypertrophy in postmenopausal women.

Topics: Animals; Aortic Valve Stenosis; Autophagy; Cardiomegaly; Female; Fibrosis; Mice; Mice, Inbred C57BL; Myocardium; Myocytes, Cardiac; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Receptors, Estrogen; Receptors, G-Protein-Coupled; Sirolimus; TOR Serine-Threonine Kinases

Calcific aortic valve disease (CAVD) is an age-related and slowly progressive valvular disorder. We have previously found that the increased inflammatory and osteogenic responses to Toll-like receptor 4 (TLR4) stimulation is correlated with lower signal transducer and activator of transcription 3 (Stat3) activity in aortic valve interstitial cells (AVICs). Rapamycin, a drug used clinically, induces feedback activation of Akt. Akt in turn may upregulate Stat3. Therefore we hypothesized that rapamycin will decrease TLR4-induced osteogenic response in human AVICs through modulation of Stat3 activity.. AVICs were isolated from normal valves taken from the explanted hearts of patients undergoing transplantation. Cells were treated with TLR4 ligand lipopolysaccharide (LPS) or rapamycin, or both. The osteogenic markers runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and bone morphogenetic protein 2 (BMP-2), as well as activation of Stat3 and its associated signaling molecules, were analyzed.. LPS induces the expression of RUNX2, ALP, and BMP-2. Rapamycin decreased both the baseline and LPS-induced expression of RUNX2, ALP, and BMP-2. Rapamycin also decreased calcium deposit formation. Rapamycin activated both Stat3 and Akt in AVICs. Suppression of Akt resulted in abolishment of Stat3 activation. Inhibition of Stat3 enhanced expression of RUNX2, ALP, and BMP-2 at baseline and in response to LPS.. Rapamycin inhibits TLR4-induced osteogenic responses in AVICs by activation of Stat3 through Akt. Rapamycin may alleviate inflammation-induced initiation and progression of CAVD.

Topics: Aortic Valve; Aortic Valve Stenosis; Calcinosis; Cells, Cultured; Humans; Immunoblotting; Osteogenesis; Sensitivity and Specificity; Signal Transduction; Sirolimus; STAT3 Transcription Factor; Toll-Like Receptor 4

Iatrogenic left main coronary artery ostial stenosis is a rare and late life-threatening complication of aortic valve replacement. The exact causes of this critical condition, despite being still nowadays elusive, are possibly related to the insertion of perfusion catheters into the left coronary system for cardioplegia delivery. We describe the case of a 69-year-old man, with normal coronary arteries documented by preoperative coronary angiography before surgery, who developed 1 year after aortic valve replacement worsening effort angina. A second coronary angiography revealed a severe left main ostial stem stenosis, which was successfully treated by sirolimus-eluting stent deployment. This case demonstrates a new percutaneous approach of this poorly understood, yet potentially fatal complication following aortic valve replacement.

Topics: Aged; Angioplasty, Balloon, Coronary; Aortic Valve Stenosis; Blood Vessel Prosthesis Implantation; Coronary Angiography; Coronary Stenosis; Echocardiography, Doppler; Heart Valve Prosthesis Implantation; Humans; Male; Reoperation; Sirolimus; Stents