[Possible Role of Prep 1 Homeodomain Transcription Factor in Cardiac Mesenchymal Stromal Cells].

Homeodomain transcription factors play a significant role in mesenchymal stromal cells (MSCs). Previously, the role of Meis1, Pbx1 and Prep1 proteins from the TALE (Three Amino acid Loop Extension) family in adipocytic and osteogenic differentiation of mouse mesenchymal stromal cells was established. In this work, using ChIP-seq and bioinformatic analysis we investigated the binding pattern of PREP1 with the genomic DNA of human heart MSCs, identified nearby genes, and analyzed their ontology. The target genes of the PREP1 factor in cardiac MSCs have been established. Based on the results, the possible involvement of transcription factor PREP1 in the direct reprogramming of fibroblasts into cardiomyocytes is discussed.

[The Involvement of Cardiomyocyte-Specific Transcription Factors Meis in Adipocyte Differentiation].

Homeodomain transcription factors play a significant role in adipocyte differentiation. The role of Pbx1 and Prep1, proteins of the TALE family (the three amino acid loop extension), was previously established in adipocyte differentiation of mesenchymal stromal cells and 3T3-L1 cell line. In this study, with the use of RNA interference technology we show that another transcription factor from the same family, Meis1, which is a core protein of mature cardiomyocytes, represses adipogenesis to a greater degree than its paralog Meis2. A number of Meis target genes, markers of adipocytes, are identified. This may indicate the transcriptional mechanism of the effect of Meis1 on the adipocyte differentiation of mouse preadipocytes.

Transcriptional control of insulin-sensitive glucose carrier Glut4 expression in adipose tissue cells.

In search for new targets for obesity treatment, we have studied the effect of several transcription factors on the conversion of murine preadipocytes from the 3T3-L1 cell line into adipocytes. We have found that knockdown of Prep1 gene expression affects adipogenic differentiation and results in significant increase in the insulin-sensitive glucose carrier Glut4 gene expression.

Insulin resistance and adipogenesis: role of transcription and secreted factors.

Insulin stimulates carbohydrate uptake by cells and induces their conversion into lipids as a more efficient form of energy storage. Insulin resistance is associated with a decrease in glucose uptake by muscle and adipose cells and also with a decrease in glycogen synthesis on retention of glucose synthesis by liver cells. Disorders in the insulin signaling cascade on development of insulin resistance can be caused by both changes in functioning of transcriptional factors and in the secretion profile of hormone-like substances. Diacylglycerols and ceramides responsible for activation of some kinases and phosphatases can directly trigger these changes in muscle and liver cells. In adipose tissue, insulin mainly stimulates adipogenesis (adipocyte differentiation) and lipogenesis (lipid accumulation in the cells). Thus, studies on the action mechanisms of factors influencing adipogenesis can be of help for understanding the molecular mechanisms of insulin resistance.

Cancer-associated antigens and antigen arrays in serological diagnostics of malignant tumors.

The appearance of antibodies to cancer-associated antigens in biological fluids (particularly, in blood sera) of cancer patients is now a well-established fact, and their detection by immunochemical methods is a promising approach to diagnostics of malignant neoplasms. In this review, we consider some immunobiological aspects of the most extensively studied cancer-associated B-cell antigens, various applications of autoantibodies as cancer biomarkers, and prospects for the use of antigen arrays for improving diagnostic sensitivity.