Tag Archives: peripheral blood mononuclear cells

Glucose deprivation-induced glycogen degradation and viability are altered in peripheral blood mononuclear cells of type 2 diabetes patients

K. S. Praveen Kumar1, P. Kamarthy2, S. Balakrishna1*

1Department of Cell Biology and Molecular Genetics, Sri Devaraj Urs Academy of Higher Education, Kolar, India;
2Department of General Medicine, Sri Devaraj Urs Medical College, Tamaka, Kolar, India;
*e-mail: sharath@sduu.ac.in

Received: 07 September 2021; Accepted: 21 January 2022

The glycogen pathway plays an important role in glucose homeostasis. Impairment of the glycogen pathway has been linked to diabetes mellitus. The aim of the study is to compare the levels of glucose deprivation-induced glycogen degradation and cell viability in peripheral blood mononuclear cells from type 2 diabetes mellitus patients and healthy controls. This was a case-control study comprising 45 T2DM patients and 45 healthy controls. PBMCs were prepared from peripheral blood by density gradient centrifugation. Glycogen levels were measured by the periodic acid-schiff (PAS) staining method. Glycogen degradation was measured as percent change in PAS-stained cells before and after glucose deprivation. PBMC viability was measured by trypan-blue assay. The levels of glucose deprivation-induced glycogen degradation were 55.4% (IQR: 50.6–61.3) in the T2DM group and 70.5% (IQR: 63.9–72.2) in the healthy control group. The difference between the two groups was statistically significant (P = 0.001). The levels of glucose deprivation-induced cell viability were 70.9% (IQR: 66.3–77.1) in the T2DM group and 87.8% (IQR: 83.7–90.7) in the healthy control group. The difference between the two groups was statistically significant (P = 0.001). Together these results indicate that the glucose deprivation-induced glycogen degradation and viability are reduced in PBMCs of T2DM patients.

Activation of the PI3K/AKT/MTOR/P70S6K1 signaling cascade in peripheral blood mononuclear cells in patients with type 2 diabetes

T. S. Vatseba1*, L. K. Sokolova2, V. M. Pushkarev2,
O. I. Kovzun2, B. B. Guda2, V. V. Pushkarev2,
M. D. Tronko2, N. V. Skrypnyk1, L. M. Zaiats1

1Ivano-Frankivsk National Medical University, Ivano-Frankivsk, Ukraine;
2SI “V.P. Komisarenko Institute of Endocrinology and Metabolism of NAMS of Ukraine”, Kyiv;
*e-mail: tamara.vatseba@gmail.com

Received: 17 April 2020; Accepted: 13 November 2020

Modern research shows that patients with diabetes mellitus have an increased risk of cancer. PI3K/Akt/mTOR/p70S6K1 signaling pathway plays an important role in the pathogenesis of cancer and diabetes. The aim of this study was to determine the state of РІ3K/Akt/mTORC1/p70S6K signaling cascade activity in peripheral mononuclear blood cells (PBMC) of patients with type 2 diabetes (T2D) relatively to the insulin and insulin-like growth factor (IGF-1) concentrations in blood plasma. Enzyme-linked immunosorbent assay was used to examine the levels of insulin and IGF-1 in blood plasma as well as the content of phosphorylated forms of Akt (Ser473), PRAS40 (Thr246), and p70S6K (Thr389) in PMBC. It was shown that in the blood plasma of patients with T2D the levels of insulin and IGF-1 were increased. Phosphorylation and activation of Akt by the mTORC2 protein kinase complex was not observed. At the same time, the relative degree of phosphorylation of mTORC1 inhibitor, PRAS40, and its substrate, p70S6K, was higher in PMBC of T2D patients in comparison with control values. These data suggest that phosphoinositide-dependent protein kinase 1 (PDK1) and, possibly, mitogen-activated protein kinase (MAPK) could mediate the effects of IGF-1 on Akt activation under type 2 diabetes.