Gene Expression in Intracranial Aneurysms-Comparison Analysis of Aneurysmal Walls and Extracranial Arteries with Real-Time Polymerase Chain Reaction and Immunohistochemistry
WORLD NEUROSURGERY
Authors: Tyagi, Gaurav; Srinivas, Dwarakanath; Nanjaiah, Nandakumar Dalavaikodihalli; Purushottam, Meera; Somanna, Sampath; Santosh, Vani; Jain, Sanjeev
Abstract
BACKGROUND: This study was aimed at evaluating the gene expression levels of 4 genes in the intracranial aneurysm wall and comparing them with extracranial arteries. The analysis was done using real-time polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). Also, a correlation of the differential genetic expression was done with various patient clinical and radiologic factors. METHODS: The quantitative assessment of ribonucleic acid levels was done with RT-PCR and was validated with IHC. The genes studied were collagen 1A2 (COL1A2), tissue inhibitor of metalloproteinase 4 (TIMP4), cathepsin B (CTSB), and alpha-1 antitrypsin (alpha-1 AT). The analysis was done on 24 aneurysm sacs and superficial temporal/occipital artery samples from patients undergoing surgical clipping. RESULTS: The mean fold change of COL1A2 in the aneurysm sample was 8.89, that of TIMP4 was 10.16, that of CTSB was 1.02, and that of alpha-1 ATwas 1.46 when compared with normal control vessel on PCR. On semiquantitative IHC, COL1A2 was 94.44%, alpha-1 AT was 77.8% overexpressed, CTSB was positive in 50%, and the expression of TIMP4 was 94.4% underexpressed in aneurysmal walls. There was no statistically significant correlation between patient profile and gene expression. CONCLUSIONS: On RT-PCR and IHC analysis, COL1A2and alpha-1 AT were overexpressed, CTSB was marginally overexpressed, and TIMP4 had equivocal expression in the aneurysmal sac when compared with the normal extracranial vessel. This is the first study of its kind in the Indian population with the largest sample size on live human patients.
Diabetic Impairment of C-Kit(+) Bone Marrow Stem Cells Involves the Disorders of Inflammatory Factors, Cell Adhesion and Extracellular Matrix Molecules
PLOS ONE
Authors: Li, Tao-Sheng; Ikeda, Satoshi; Kubo, Masayuki; Ohshima, Mako; Kurazumi, Hiroshi; Takemoto, Yoshihiro; Ueda, Kazuhiro; Hamano, Kimikazu
Abstract
Bone marrow stem cells from diabetes mellitus patients exhibit functional impairment, but the relative molecular mechanisms responsible for this impairment are poorly understood. We investigated the mechanisms responsible for diabetes-related functional impairment of bone marrow stem cells by extensively screening the expression levels of inflammatory factors, cell cycle regulating molecules, extracellular matrix molecules and adhesion molecules. Bone marrow cells were collected from type 2 diabetic (db/db) and healthy control (db/m+) mice, and c-kit(+) stem cells were purified (purity>85%) for experiments. Compared with the healthy control mice, diabetic mice had significantly fewer c-kit(+) stem cells, and these cells had a lower potency of endothelial differentiation; however, the production of the angiogenic growth factor VEGF did not differ between groups. A pathway-focused array showed that the c-kit(+) stem cells from diabetic mice had up-regulated expression levels of many inflammatory factors, including Tlr4, Cxcl9, Il9, Tgfb1, Il4, and Tnfsf5, but no obvious change in the expression levels of cell cycle molecules. Interestingly, diabetes-related alterations of the extracellular matrix and adhesion molecules were varied; Pecam, Mmp10, Lamc1, Itgb7, Mmp9, and Timp4 were up-regulated, but Col11a1, Fn1, Admts2, and Itgav were down-regulated. Some of these changes were also confirmed at the protein level by flow cytometry analysis. In conclusion, c-kit(+) bone marrow stem cells from diabetic mice exhibited an extensive enhancement of inflammatory factors and disorders of the extracellular matrix and adhesion molecules. Further intervention studies are required to determine the precise role of each molecule in the diabetes-related functional impairment of c-kit(+) bone marrow stem cells.