Role of Extracellular Matrix and Inflammation in Abdominal Aortic Aneurysm.

Abdominal aortic aneurysm (AAA) is one of the most dangerous cardiovascular diseases, occurring mainly in men over the age of 55 years. As it is asymptomatic, patients are diagnosed very late, usually when they suffer pain in the abdominal cavity. The late detection of AAA contributes to the high mortality rate. Many environmental, genetic, and molecular factors contribute to the development and subsequent rupture of AAA. Inflammation, apoptosis of smooth muscle cells, and degradation of the extracellular matrix in the AAA wall are believed to be the major molecular processes underlying AAA formation. Until now, no pharmacological treatment has been implemented to prevent the formation of AAA or to cure the disease. Therefore, it is important that patients are diagnosed at a very early stage of the disease. Biomarkers contribute to the assessment of the concentration level, which will help to determine the level and rate of AAA development. The potential biomarkers today include homocysteine, cathepsins, osteopontin, and osteoprotegerin. In this review, we describe the major aspects of molecular processes that take place in the aortic wall during AAA formation. In addition, biomarkers, the monitoring of which will contribute to the prompt diagnosis of AAA patients over the age of 55 years, are described.

Osteogenesis Imperfecta: Current and Prospective Therapies.

Osteogenesis Imperfecta (OI) is a group of connective tissue disorders with a broad range of phenotypes characterized primarily by bone fragility. The prevalence of OI ranges from about 1:15,000 to 1:20,000 births. Five types of the disease are commonly distinguished, ranging from a mild (type I) to a lethal one (type II). Types III and IV are severe forms allowing survival after the neonatal period, while type V is characterized by a mild to moderate phenotype with calcification of interosseous membranes. In most cases, there is a reduction in the production of normal type I collagen (col I) or the synthesis of abnormal collagen as a result of mutations in col I genes. Moreover, mutations in genes involved in col I synthesis and processing as well as in osteoblast differentiation have been reported. The currently available treatments try to prevent fractures, control symptoms and increase bone mass. Commonly used medications in OI treatment are bisphosphonates, Denosumab, synthetic parathyroid hormone and growth hormone for children therapy. The main disadvantages of these therapies are their relatively weak effectiveness, lack of effects in some patients or cytotoxic side effects. Experimental approaches, particularly those based on stem cell transplantation and genetic engineering, seem to be promising to improve the therapeutic effects of OI.

Searching for new molecular markers for cells obtained from abdominal aortic aneurysm.

The aim of the study was to investigate specific potential markers for cells obtained from three layers of human AAA divided into three segments along the AAA based on morphological differences. The isolated cells were compared to control commercial cell types from healthy human abdominal aortas. For each type of aortic layer, three specimens from 6 patients were compared. Total RNA was isolated from 36 cell cultures for gene expression profiling and potential new cytometry markers were typed. Isolated cells were analyzed by flow cytometry by using fluorochrome-conjugated antibodies to markers: CNN1, MYH10, ENG, ICAM2, and TEK. The relative expression of 45 genes in primary cell cultures and control lines was analyzed. Statistically significant differences were found in the expression of most of the analyzed genes between individual layers and control lines. Based on relative expression, antibodies were selected for flow cytometry. Gene expression profiles allowed to select new potential cytometry markers: CNN1, MYH10, MYOCD, ENG, ICAM2, TEK. However, none of the tested markers seems to be optimal and characteristic for a specific layer of AAA.

Expression gradient of metalloproteinases and their inhibitors from proximal to distal segments of abdominal aortic aneurysm.

Abdominal aortic aneurysm refers to abnormal, asymmetric distension of the infrarenal aortic wall due to pathological remodelling of the extracellular matrix. The distribution of enzymes remodelling the extracellular matrix and their expression patterns in the affected tissue are largely unknown. The goal of this work was to investigate the expression profiles of 20 selected genes coding for metalloproteinases and their inhibitors in the proximal to the distal direction of the abdominal aortic aneurysm. RNA samples were purified from four lengthwise fragments of aneurysm and border tissue obtained from 29 patients. The quantities of selected mRNAs were determined by real-time PCR to reveal the expression patterns. The genes of interest encode collagenases (MMP1, MMP8, MMP13), gelatinases (MMP2, MMP9), stromelysins (MMP3, MMP7, MMP10, MMP11, MMP12), membrane-type MMPs (MMP14, MMP15, MMP16), tissue inhibitors of metalloproteinases (TIMP1, TIMP2, TIMP3, TIMP4), and ADAMTS proteinases (ADAMTS1, ADAMTS8, and ADAMTS13). It was found that MMP, TIMP, and ADAMTS are expressed in all parts of the aneurysm with different patterns. A developed aneurysm has such a disturbed expression of the main participants in extracellular matrix remodelling that it is difficult to infer the causes of the disorder development. MMP12 secreted by macrophages at the onset of inflammation may initiate extracellular matrix remodelling, which, if not controlled, initiates a feedback loop leading to aneurysm formation.

Potential of Induced Pluripotent Stem Cells for Use in Gene Therapy: History, Molecular Bases, and Medical Perspectives.

Induced pluripotent stem cells (iPSCs) are defined as reprogrammed somatic cells exhibiting embryonic stem cell characteristics. Since their discovery in 2006, efforts have been made to utilize iPSCs in clinical settings. One of the promising fields of medicine, in which genetically patient-specific stem cells may prove themselves useful, is gene therapy. iPSCs technology holds potential in both creating models of genetic diseases and delivering therapeutic agents into the organism via auto-transplants, which reduces the risk of rejection compared to allotransplants. However, in order to safely administer genetically corrected stem cells into patients' tissues, efforts must be made to establish stably pluripotent stem cells and reduce the risk of insertional tumorigenesis. In order to achieve this, optimal reprogramming factors and vectors must be considered. Therefore, in this review, the molecular bases of reprogramming safe iPSCs for clinical applications and recent attempts to translate iPSCs technology into the clinical setting are discussed.