Department of Pathologyhttp://hdl.handle.net/10675.2/8552024-03-16T00:36:50Z2024-03-16T00:36:50ZAngiotensin II-Induced Protein Kinase D Activation and Regulation of Aldosterone ProductionOlala, Lawrence O.http://hdl.handle.net/10675.2/3198792020-08-11T15:04:17Z2013-02-01T00:00:00ZAngiotensin II-Induced Protein Kinase D Activation and Regulation of Aldosterone Production
Olala, Lawrence O.
Dysregulated aldosterone production leading to hypertension and its associated complications, such as congestive heart failure, cardiac fibrosis and renal failure, are important public health concerns with a huge impact on the economy and patient quality of life. Thus, there is a high level of interest in the development of medical interventions and lifestyle changes to reduce the incidence of hypertension. Stimulation of the adrenal zona glomerulosa with angiotensin II (AngII), potassium (K+) or adrenocorticotropic hormone (ACTH), increases aldosterone production, to result in increased sodium and water retention. We have recently shown a role for the serine/threonine protein kinase D (PKD) in the regulation of acute aldosterone synthesis upon AngII stimulation. In this study, using both molecular and pharmacological approaches, we demonstrate that Src family kinases and protein kinase C (PKC) activate PKD to increase aldosterone production in bovine adrenal glomerulosa cells. We have also shown that PKD positively regulates expression of steroidogenic acute regulatory (StAR) protein, a protein required for cholesterol transport into the mitochondria, and aldosterone synthesis. PKD plays this role, in part, through activating members of the activating transcription factor (ATF)/cAMP response element (CRE-) binding protein (CREB) family of leucine zipper transcription factors. Therefore, we hypothesize that PKC and Src family kinase-mediated PKD activation in response to AngII increases the phosphorylation and activation of ATF-2 and CREB, which bind the StAR proximal promoter thereby resulting in induction of StAR expression and stimulation of steroidogenesis.
2013-02-01T00:00:00ZTranscriptional Coactivator and Oncoprotein CoAABrooks, Yang Suihttp://hdl.handle.net/10675.2/3175982020-08-11T15:04:18Z2008-01-01T00:00:00ZTranscriptional Coactivator and Oncoprotein CoAA
Brooks, Yang Sui
CoAA contains two copies of RNA recognition motifs (RRM) and an intrinsic transactivation domain rich in repetitive tyrosines and glutamines (YxxQ domain). Previously, CoAA has been shown to be a transcriptional coactivator that stimulates transcriptional activation and regulates alternative splicing. A pattern and profile search revealed that the YxxQ domain in CoAA shared significant pattern homology with the oncogenic EWS activation domains (EAD) in TET family proteins, including, TLS/FUS, EWS and TAFII 68. It was further demonstrated that CoAA’s YxxQ domain and EWS’ EAD also shared functional similarities. Based on these findings, this work investigated the aberration of CoAA in cancers and its pathophysiological significance. The results showed that the CoAA gene was amplified in a high percentage of inflammation-related human cancers with recurrent loss of the 5’ regulatory element upstream of its promoter. This genomic aberration resulted in CoAA protein overexpression, which in turn, induced the transformation of NIH3T3 cells. Subsequently, it was shown that the lost 5’ regulatory element could modulate the alternative splicing of the CoAA gene during stem cell differentiation and that the unbalanced expression of CoAA and its splice variant, CoAM could potentially impact the cell differentiation process. To further characterize the regulation of CoAA alternative splicing, two conserved trans-splicing events between CoAA and its downstream RBM4 were identified. These events yield a novel zinc finger- containing coactivator, CoAZ, and a non-coding splice variant, ncCoAZ. Both variants regulated their parental genes’ mRNA expression as well as activities, suggesting a linked control between CoAA and RBM4. Moreover, the expression patterns of CoAA, RBM4 and their trans-splicing variants switched during neural stem cell differentiation, resulting in lineage-specific expression of each variant. Our phylogenetic analysis suggests that mammalian CoAA and RBM4 share a common ancestor with the Drosophila melanogaster gene, Lark. In this regard, the trans-splicing events between CoAA and RBM4 represent a functional regulation preserved during evolution. This study established the connection between CoAA and human cancer and provides evidence for CoAA’s involvement in the regulation of cell differentiation. Moreover, this study is the first to report a functional trans-splicing variant in mammalian cells.
2008-01-01T00:00:00ZIsolation of Osteoprogenitors from Human Jaw Periosteal Cells: A Comparison of Two Magnetic Separation MethodsOlbrich, MarcusRieger, MelanieReinert, SiegmarAlexander, Dorotheahttp://hdl.handle.net/10675.2/8362019-08-30T07:17:09Z2012-10-19T00:00:00ZIsolation of Osteoprogenitors from Human Jaw Periosteal Cells: A Comparison of Two Magnetic Separation Methods
Olbrich, Marcus; Rieger, Melanie; Reinert, Siegmar; Alexander, Dorothea
Human jaw periosteum tissue contains osteoprogenitors that have potential for tissue engineering applications in oral and maxillofacial surgeries. To isolate osteoprogenitor cells from heterogeneous cell populations, we used the specific mesenchymal stem cell antigen-1 (MSCA-1) antibody and compared two magnetic separation methods. We analyzed the obtained MSCA-1+ and MSCA-1â fractions in terms of purity, yield of positive/negative cells and proliferative and mineralization potentials. The analysis of cell viability after separation revealed that the EasySep method yielded higher viability rates, whereas the flow cytometry results showed a higher purity for the MACS-separated cell fractions. The mineralization capacity of the osteogenic induced MSCA-1+ cells compared with the MSCA-1â controls using MACS was 5-fold higher, whereas the same comparison after EasySep showed no significant differences between both fractions. By analyzing cell proliferation, we detected a significant difference between the proliferative potential of the osteogenic cells versus untreated cells after the MACS and EasySep separations. The differentiated cells after MACS separation adjusted their proliferative capacity, whereas the EasySep-separated cells failed to do so. The protein expression analysis showed small differences between the two separation methods. Our findings suggest that MACS is a more suitable separation method to isolate osteoprogenitors from the entire jaw periosteal cell population.
2012-10-19T00:00:00ZThe Early Stage Adjacent Disc Degeneration after Percutaneous Vertebroplasty and Kyphoplasty in The Treatment of Osteoporotic VCFsQian, JunYang, HuilinJing, JuehuaZhao, HongNi, LiTian, DashengWang, Zhengfeihttp://hdl.handle.net/10675.2/8302019-08-30T07:17:09Z2012-10-08T00:00:00ZThe Early Stage Adjacent Disc Degeneration after Percutaneous Vertebroplasty and Kyphoplasty in The Treatment of Osteoporotic VCFs
Qian, Jun; Yang, Huilin; Jing, Juehua; Zhao, Hong; Ni, Li; Tian, Dasheng; Wang, Zhengfei
Shi, Xing-Ming
Background: The purpose of this paper is to determine the early incidence of disc de- generation adjacent to the vertebral body of osteoporotic fracture treated with percutaneous vertebroplasty or balloon kyphoplasty and whether adjacent disc degeneration is accelerated by this two procedures.; Methods: 182 patients with painful vertebral compression fractures were treated. A total of 97 patients were enrolled in this prospective study. 97 patients with a mean age of 65.3 years were classified into control group and surgical treatment group of non-random. 35 patients were in contol group and 62 patients who were performed percutaneous vertebroplasty or balloon kyphoplasty in treatment group. X-ray and Magnetic resonance imaging were done at the first and final visit. The grade of disc degeneration above the fractured vertebral was confirmed by evaluation of bony oedema in the fat suppressed sequences and T2-weighted image of magnetic resonance imaging. The height of degenerative disc was measured on X-ray film.; Results: All patients were followed up two years after the first visit and the follow-up rate was 90.7% (88/97). The incidence of degeneration of adjacent disc above the fractured vertebral was 29.0% (9/31) in control group and 52.6% (30/57) in treatment group. It presented a statistically significant difference between two groups about the incidence of adjacent disc degeneration (P =0.033). The percentage of adjacent disc height reduction in control group was 13.5% and 17.6% in treatment group. Statistically significant difference of VAS score and ODI was not found between the first evaluation postoperatively and the final follow-up in treatment group (P>0.05).; Conclusions: Disc degeneration adjacent to the fractured vertebral is accelerated by VP and BK procedures in the early stage, but clinical outcomes has not been weakened even in the presence of accelerated disc degeneration.
2012-10-08T00:00:00Z