PDK1 Knockout Cell Lysate

Classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) are a heterogeneous group of hematopoietic malignancies including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The JAK2V617F mutation plays a central role in these disorders and can be found in 90% of PV and similar to 50-60% of ET and PMF. Hypoxia-inducible factor 1 (HIF-1) is a master transcriptional regulator of the response to decreased oxygen levels. We demonstrate the impact of pharmacological inhibition and shRNA-mediated knockdown (KD) of HIF-1 alpha in JAK2V617F-positive cells. Inhibition of HIF-1 binding to hypoxia response elements (HREs) with echinomycin, verified by ChIP, impaired growth and survival by inducing apoptosis and cell cycle arrest in Jak2V617F-positive 32D cells, but not Jak2WT controls. Echinomycin selectively abrogated clonogenic growth of JAK2V617F cells and decreased growth, survival, and colony formation of bone marrow and peripheral blood mononuclear cells and iPS cell-derived progenitor cells from JAK2V617F-positive patients, while cells from healthy donors were unaffected. We identified HIF-1 target genes involved in the Warburg effect as a possible underlying mechanism, with increased expression of Pdk1, Glut1, and others. That was underlined by transcriptome analysis of primary patient samples. Collectively, our data show that HIF-1 is a new potential therapeutic target in JAK2V617F-positive MPN.

OBJECTIVE: Myocardial ischemia-reperfusion injury (MIRI) is a common problem in heart-related diseases. The aim of this study was to explore the protective effects of STRAP on cardiomyocytes in the MIRI process and its mechanisms. MATERIALS AND METHODS: We used SD rats to construct a MIRI model and increased the expression of STRAP in myocardial tissue by Entranster to detect the effect of STRAP on rat myocardial tissue. In addition, we cultured rat cardiomyocyte cell line H9c2 cells and constructed a hypoxia-reoxygenation model to detect the protective effect of STRAP on H9c2 cells. LY294002, an inhibitor of the PI3K/PDK1/Akt signaling pathway, was used to validate the mechanism by which STRAP protects cardiomyocytes. RESULTS: Overexpression of STRAP significantly reduced the activity of MDA in myocardial tissue and increased the activity of SOD. STRAP also substantially lowered CK and LDH levels in rat serum and increased Na+-K+-ATPase and Ca2+-Mg2+-ATPase activity. In addition, overexpression of STRAP considerably reduced endoplasmic reticulum stress (ERS) and apoptosis levels in H9c2 cells. However, LY294002 attenuated the protective effect of STRAP on cardiomyocytes. CONCLUSIONS: STRAP reduces ERS and apoptosis in cardiomyocytes by activating the PI3K/PDK1/Akt signaling pathway, thereby reducing myocardial MIRI.