Differential lineage-specific regulation of murine CD45 transcription by Oct-1 and PU.1
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Authors: Kwon, UK; Yen, PH; Collins, T; Wells, RA
Abstract
Although it has been established that CD45 expression is regulated at the transcriptional level, neither the regulatory elements that are responsible for its unique expression pattern nor the relevance of its three distinct transcriptional start sites (P1a, P1b, and P2) has been fully characterized. We studied the contribution of the three start sites to CD45 mRNA production in haematopoietic cell lines and primary haematopoietic cells. In myeloid and lymphoid cells and cell lines most CD45 transcripts originate from P1b with the exception of the thymoma-derived T cell line EL4, in which similar to 90% of CD45 transcripts originate from P1a. The degree of contribution of P1a is highest in lymphoid cells and increases in T cells following mitogen stimulation. In vitro evaluation of sequence upstream of the start sites shows that the P2 start site is sufficient for CD45 expression in lymphoid but not in myeloid cells, confirms the presence of a PU.1-binding site essential for myeloid expression of CD45, and reveals an Octamer-binding site that interacts with both Oct-1 and Oct-2 and activates CD45 transcription in lymphoid and myeloid cells. These findings are the first evidence that Octamer-binding factors are involved in the control of CD45 expression. (c) 2006 Elsevier Inc. All rights reserved.
Quantitative Single-Cell Transcript Assessment of Biomarkers Supports Cellular Heterogeneity in the Bovine IVD
VETERINARY SCIENCES
Authors: Li, Kangning; Kapper, Devin; Mondal, Sumona; Lufkin, Thomas; Kraus, Petra
Abstract
Severe and chronic low back pain is often associated with intervertebral disc (IVD) degeneration. While imposing a considerable socio-economic burden worldwide, IVD degeneration is also severely impacting on the quality of life of affected individuals. Cell-based regenerative medicine approaches have moved into clinical trials, yet IVD cell identities in the mature disc remain to be fully elucidated and tissue heterogeneity exists, requiring a better characterization of IVD cells. The bovine coccygeal IVD is an accepted research model to study IVD mechano-biology and disc homeostasis. Recently, we identified novel IVD biomarkers in the outer annulus fibrosus (AF) and nucleus pulposus (NP) of the mature bovine coccygeal IVD through RNA in situ hybridization (AP-RISH) and z-proportion test. Here we follow up on Lam1, Thy1, Gli1, Gli3, Noto, Ptprc, Scx, Sox2 and Zscan10 with fluorescent RNA in situ hybridization (FL-RISH) and confocal microscopy. This permits sub-cellular transcript localization and the addition of quantitative single-cell derived values of mRNA expression levels to our previous analysis. Lastly, we used a Gaussian mixture modeling approach for the exploratory analysis of IVD cells. This work complements our earlier cell population proportion-based study, confirms the previously proposed biomarkers and indicates even further heterogeneity of cells in the outer AF and NP of a mature IVD.