Regulation of human COL9A1 gene expression - Activation of the proximal promoter region by SOX9
JOURNAL OF BIOLOGICAL CHEMISTRY
Authors: Zhang, P; Jimenez, SA; Stokes, DG
Abstract
The COL9A1 gene contains two promoter regions, one driving expression of a long alpha1(IX) chain in cartilage (upstream) and one driving expression of a shorter chain in the cornea and vitreous (downstream). To determine how the chondrocyte-specific expression of the COL9A1 gene is regulated, we have begun to characterize the upstream chondrocyte-specific promoter region of the human COL9A1 gene. Transient-transfection analyses performed in rat chondrosarcoma (RCS) cells, human chondrosarcoma (HTB) cells, and NIH/3T3 cells showed that the COL9A1 promoter was active in RCS cells but not HTB or NIH/3T3 cells. Inclusion of the first intron had no effect on promoter activity. In transient-transfection analyses with promoter deletion constructs, it was found that full promoter activity in RCS cells depended on the region from -560 bp to +130 bp relative to the transcriptional start site (+1). Sequence analysis of the region from -890 bp to the transcriptional start predicted five putative SOX/Sry-binding sites. Mutation analysis revealed that two of three putative SOX/Sry binding sites within the -560 to +130 bp region are responsible for most of the COL9A1 promoter activity in RCS cells. Co-transfection experiments with a SOX9 expression plasmid revealed that a construct containing the five putative SOX/Sry-binding sites was transactivated 20- to 30-fold in both HTB and NIH/3T3 cells. Further co-transfection experiments showed that two of the SOX/Sry-binding sites located within the -560 to + 130 bp region were required for full transactivation. However, mutation and deletion analyses indicated that a region from -560 to -357 bp, which does not contain any other conspicuous SOX9 sites, is also important for full promoter activity. DNA-protein binding assays and super-shift analysis revealed that SOX9 can form a specific complex with one of the SOX/Sry-binding sites with in the -560 to +130 region.
NON-ABLATIVE RADIO-FREQUENCY REJUVENATION: A HISTOLOGICAL AND BIO-MOLECULAR REPORT
JOURNAL OF BIOLOGICAL REGULATORS AND HOMEOSTATIC AGENTS
Authors: Avantaggiato, A.; Bassi, M. Andreasi; Cura, F.; Pascali, M.; Carinci, F.
Abstract
Radiofrequency machines for medical use are known to produce moderate clinical improvement of skin laxity without invasive procedures. Numerous equipment with different characteristics have been proposed after the introduction in 2002 of the first FDA approved device. This report is aimed to test if RF treatment is effective when performed at low frequency and low energy level. Two RF treatments were performed unilaterally 7 and 2 days before a planned eyebrow lifting surgery, with a radiofrequency device with 0.52 to 0.7 MHz frequencies, maximum energy of 200 W, used at 40% of its power. A bipolar handpiece with a diameter of 30 mm and a maximum power of 9-9.5 W was massaged along the temporal area for 10 min. Skin samples of treated and untreated sides were collected during surgery and processed for histologic examination and RT-PCR analysis, to test differences in gene activation in a panel of proteins that are relevant in extracellular matrix of dermal connective tissue. The histological examination of the samples showed that the treatment induced a loss of the typical oriented structure in the reticular dermis. The study through RT-PCR evidenced that ELN, the gene codifying for Elastine was strongly enhanced. Some collagen-tested genes (COL1A1, COL3A1 and COL9A1) were inhibited by the treatment, whereas COL2A1 and COL11 were activated. The genes responsible for Metallo-proteases (MMP) 2, 3 and 13 were depressed, while the MMP9 was stimulated. Gene codifying for Hyaluronic synthase 1 (HAS1), Hyluronidase 1 (HYAL1), Neutrophyl elastase (Elane), Desmoplakin (DSP) and GDF6 were inhibited. Insulin like growth factor (IGF1) gene activity was enhanced. RF treatment, with the tested non-ablative equipment, produced histological effects and change in DNA expression of some extracellular matrix related genes, confirming the biostimulatory role of this procedure.