Tag Archives: HSPA5

Insulin resistance in obese adolescents and adult men modifies the expression of proliferation related genes

O. H. Minchenko1, Y. M. Viletska1, D. O. Minchenko1,2, V. V. Davydov3

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: ominchenko@yahoo.com;
2Bohomolets National Medical University, Kyiv, Ukraine
3SI “Institute of Children and Adolescent Health Care,
National Academy of Medical Sciences of Ukraine”, Kharkiv

Received: 11 December 2018; Accepted: 14 March 2019

Numerous data demonstrate that key regulatory factors, enzymes and receptors including HSPA5, MEST, SLC1A3, PDGFC, and ADM represent poly-functional, endoplasmic reticulum stress-dependent proteins, which control variable metabolic pathways. The expression level of genes of these proteins in the blood and subcutaneous adipose tissue of obese adolescents and adult men with and without insulin resistance was studied. It was shown that in blood of obese adolescents without insulin resistance the expression level of SLC1A3, HSPA5, MEST, and PDGFC genes was significantly increased, but development of insulin resis­tance led to down-regulation of these genes expression except HSPA5 gene as compared to the control group as well as to the group of obese adolescents without insulin resistance. At the same time, the expression level of ADM gene did not change significantly in obese adolescents without insulin resistance, but the development of insulin resistance led to down-regulation of this gene expression. In subcutaneous adipose tissue of obese adult men without insulin resistance the level of SLC1A3 gene expression was decreased, although ADM, MEST, and HSPA5 genes – increased. It was also shown that the development of insulin resistance in obese men affected the expression level of ADM and SLC1A3 genes only. Results of this investigation provide evidence that insulin resistance in obese adolescents and adult men is associated with specific changes in the expression of genes, which related to proliferation and development of obesity and insulin resistance as well as to endoplasmic reticulum stress and contribute to the development of obesity complications.

ERN1 modifies the effect of glutamine deprivation on tumor growth related factors expression in U87 glioma cells

O. H. Minchenko, A. P. Kharkova, O. S. Hnatiuk, O. Y. Luzina, I. V. Kryvdiuk, A. Y. Kuznetsova

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: ominchenko@yahoo.com

The expression of a subset of genes encoding important tumor growth related factors in U87 glioma cells with ERN1 (endoplasmic reticulum to nucleus signaling 1) loss of function as well as upon glutamine deprivation was studied. It was shown that glutamine deprivation down-regulated the expression level of ATF6 (activating transcription factor 6), EIF2AK3/PERK (eukaryotic translation initiation factor 2 alpha kinase 3), GLO1 (glyoxalase I), BIRC5 (baculoviral IAP repeat-containing 5), and RAB5C (RAB5C, a member of RAS oncogene family) mRNAs in control glioma cells. At the same time, the expression level of HSPB8 (heat shock 22kDa protein 8) and HSPA5/GRP78 (heat shock protein family A (Hsp70) member 5) mRNAs was resistant to glutamine withdrawal in these glioma cells. It was also shown that inhibition of ERN1, which controled cell proliferation and tumor growth, modified the effect of glutamine deprivation on the expression levels of most studied genes in U87 glioma cells: up-regulated the expression of ATF6 and HSPA5 genes and enhanced sensitivity of EIF2AK3 and BIRC5 genes to glutamine withdrawal. Furthermore, the expression of all studied genes, except EIF2AK3, was down-regulated in ERN1 knockdown glioma cells in the presence of glutamine. It was demonstrated that glutamine deprivation affected the expression of most studied genes in ERN1 depen­dent manner and that these changes possibly contributed to the suppression of glioma growth from cells without ERN1 signaling enzyme function.