The Sp1 and CBF/NF-Y Transcription Factors Cooperatively Regulate the Mouse Pro-alpha3(V) Collagen Gene (Col5a3) in Osteoblastic Cells

The purpose of this study was to clarify the mechanism responsible for the transcriptional regulation of the mouse Col5a3 gene in osteoblastic cells. Transient transfection into rat osteosarcoma ROS17/2.8 cells demonstrated that a region from nucleotides 337 to 1 was involved in the transcriptional activity of the Col5a3 gene. An electrophoretic mobility shift assay showed that Sp1/Sp3 and CBF/NF-Y bound to a GC-rich domain (194/186) and a CCAAT box (134/130) in the Col5a3 gene, respectively. Introduction of mutations or deletion into a GC-rich domain, the CCAAT box, or both elements decreased the transcription activity. Overexpression of Sp1 increases the transcription activity and interferes with Sp family binding to the GC-rich domain to decrease promoter activity. Therefore, the transcription of the mouse Col5a3 gene is cooperatively regulated by Sp1 and CBF/NF-Y in osteoblastic cells.</p

Multifactor complex containing B element binding factor, BBF, and repressors regulate the human alpha 1(III) collagen gene (COL3A1).

Type III collagen is found in fetal skin and blood vessels. Previously, we characterized the proximal promoter of the human alpha1(III) collagen gene (COL3A1) using the human rhabdomyosarcoma cell line, A204, and NIH3T3 cells (Yoshino et al., Biochim Biophys Acta, 2005). In the present study, we further analyzed this promoter using additional cell lines, namely a human embryonal rhabdomyosarcoma cell line (RD) and bovine vascular smooth muscle cells (vSMCs), both of which show high expression of type III collagen. Using a luciferase assay, electrophoretic mobility shift assays (EMSA), and DNase footprinting assay, 2 types of multifactor complexes were shown to bind to the DNA region in the vicinity of the B element (- 80 to - 58), depending on the cell type. Next, we used cells stably transfected with a GFP-linked type III collagen promoter fragment for analysis of promoter expression. Usually, transfected cells retained the characteristics of the original cells. However, in several clones derived from RD cells, promoter expression as well as cell shape changed to patterns characteristic of the A204 cell line. Nuclear factors expressed by these clones were also characteristic of the A204 line.</p

CREB-AP1 Protein Complexes Regulate Transcription of the Collagen XXIV Gene (Col24a1) in Osteoblasts

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Esophageal muscle physiology and morphogenesis require assembly of a collagen XIX–rich basement membrane zone

Collagen XIX is an extremely rare extracellular matrix component that localizes to basement membrane zones and is transiently expressed by differentiating muscle cells. Characterization of mice harboring null and structural mutations of the collagen XIX (Col19a1) gene has revealed the critical contribution of this matrix protein to muscle physiology and differentiation. The phenotype includes smooth muscle motor dysfunction and hypertensive sphincter resulting from impaired swallowing-induced, nitric oxide–dependent relaxation of the sphincteric muscle. Muscle dysfunction was correlated with a disorganized matrix and a normal complement of enteric neurons and interstitial cells of Cajal. Mice without collagen XIX exhibit an additional defect, namely impaired smooth-to-skeletal muscle cell conversion in the abdominal segment of the esophagus. This developmental abnormality was accounted for by failed activation of myogenic regulatory factors that normally drive esophageal muscle transdifferentiation. Therefore, these findings identify collagen XIX as the first structural determinant of sphincteric muscle function, and as the first extrinsic factor of skeletal myogenesis in the murine esophagus

Heat shock protein 72 expression in the right ventricle of patients undergoing congenital cardiac surgery.

While heat shock protein (HSP) 72 is known as a stress protein, there have been no reports of HSP 72 expression in patients who have undergone surgery for congenital heart disease. Fourteen patients (7 males and 7 females) who had undergone surgery for congenital heart disease were studied. The ages of the patients ranged from 2 months to 43 years old (mean 6.5 +/- 10.8 years old; median 3.0 years old). The diagnoses were Tetralogy of Fallot in seven, pulmonary atresia with ventricular septal defect (VSD) in three, complex anomalies in three, and VSD in one patient. Histological study and HSP analysis using Western blots and immunostaining with anti-HSP 72 monoclonal antibody were performed for right ventricular muscle samples resected during the surgery. The histological findings showed hypertrophic changes of ventricular cardiomyocytes in all samples studied. Western blots detected HSP 72 expression of various degrees in all specimens. Immunostaining using monoclonal antibody against HSP 72 showed that the protein was present in the nuclei and cytoplasm of cardiomyocytes. In conclusion, although it is difficult to determine the cause of the &#34;stress&#34; that triggers HSP 72 expression in cardiomyocytes, low O2 saturation and pressure overload might act as a &#34;stress&#34;, and the only common factor that induced HSP 72 in every sample was hypertrophy.</p