Urokinase receptor deficiency results in EGFR-mediated failure to transmit signals for cell survival and neurite formation in mouse neuroblastoma cells
CELLULAR SIGNALLING
Authors: Rysenkova, K. D.; Klimovich, P. S.; Shmakova, A. A.; Karagyaur, M. N.; Ivanova, K. A.; Aleksandrushkina, N. A.; Tkachuk, V. A.; Rubina, K. A.; Semina, E., V
Abstract
Urokinase-type plasminogen activator uPA and its receptor (uPAR) are the central players in extracellular matrix proteolysis, which facilitates cancer invasion and metastasis. EGFR is one of the important components of uPAR interactome. uPAR/EGFR interaction controls signaling pathways that regulate cell survival, proliferation and migration. We have previously established that uPA binding to uPAR stimulates neurite elongation in neuroblastoma cells, while blocking uPA/uPAR interaction induces neurite branching and new neurite formation. Here we demonstrate that blocking the uPA binding to uPAR with anti-uPAR antibody decreases the level of pEGFR and its downstream pERK1/2, but does increase phosphorylation of Akt, p38 and c-Src Since long-term uPAR blocking results in a severe DNA damage, accompanied by PARP-1 proteolysis and Neuro2a cell death, we surmise that Akt, p38 and c-Src activation transmits a pro-apoptotic signal, rather than a survival. Serum deprivation resulting in enhanced neuritogenesis is accompanied by an upregulated uPAR mRNA expression, while EGFR mRNA remains unchanged. EGFR activation by EGF stimulates neurite growth only in uPAR-overexpressing cells but not in control or uPAR-deficient cells. In addition, AG1478-mediated inhibition of EGFR activity impedes neurite growth in control and uPAR-deficient cells, but not in uPAR-overexpressing cells. Altogether these data implicate uPAR as an important regulator of EGFR and ERK1/2 signaling, representing a novel mechanism which implicates urokinase system in neuroblastoma cell survival and differentiation.
Comparison of ambulatory central hemodynamics and arterial stiffness in patients with diabetic and non-diabetic CKD
JOURNAL OF CLINICAL HYPERTENSION
Authors: Loutradis, Charalampos; Schoina, Maria; Dimitroulas, Theodoros; Doumas, Michael; Garyfallos, Alexandros; Karagiannis, Asterios; Papagianni, Aikaterini; Sarafidis, Pantelis
Abstract
Increased arterial stiffness is independently associated with renal function decline in patients with diabetes mellitus (DM). Whether DM has additional deleterious effects on central hemodynamics and arterial stiffness in chronic kidney disease (CKD) patients is yet unknown. This study aimed to compare ambulatory central BP, arterial stiffness parameters, and trajectories between patients with diabetic and non-diabetic CKD. This study examined 48 diabetic and 48 non-diabetic adult patients (>18 years) with CKD (eGFR: <90 and >= 15 ml/min/1.73 m(2)), matched in a 1:1 ratio for age, sex, and eGFR within CKD stages (2, 3a, 3b and 4). All patients underwent 24-h ABPM with the Mobil-O-Graph device. Parameters of central hemodynamics [central systolic (cSBP) and diastolic blood pressure (cDBP), pulse pressure (PP)], wave reflection [augmentation index (AIx), and pressure (AP)] and pulse wave velocity (PWV) were estimated from the 24-h recordings. Diabetic CKD patients had higher 24-h cSBP (118.57 +/- 10.05 vs. 111.59 +/- 9.46, P = .001) and 24-h cPP (41.48 +/- 6.80 vs. 35.25 +/- 6.98, P < .001) but similar 24-h cDBP (77.09 +/- 8.14 vs. 76.34 +/- 6.75 mmHg, P = .625) levels compared to patients with non-diabetic CKD. During day- and nighttime periods, cSBP and cPP levels were higher in diabetics compared to non-diabetics. 24-h PWV (10.10 +/- 1.62 vs. 9.61 +/- 1.80 m/s, P = .165) was numerically higher in patients with DM, but no between-group differences were noted in augmentation pressure and index. In multivariate analysis, DM, female gender, and peripheral SBP were independently associated with higher cPP levels. Patients with diabetic CKD have higher ambulatory cSBP and increased arterial stiffness, as indicated by higher ambulatory cPP. These finding suggest that DM is a factor independently contributing to the adverse macrocirculatory profile of CKD patients.