InteRPlays between Mesenchymal Stem Cells and Immune Responses
Mesenchymal stem cells (MSCs) exist in almost all tissues and are crucial in maintaining the cellular homeostasis of multicellular organisms. They provide the ultimate cell source for tissue repair and regeneration. Under pathological conditions, these cells are awakened, activated, and mobilized to damaged tissue sites. Since tissue damages are often accompanied by inflammatory factors, from both innate immune response and adaptive immune response, it is sensible that MSCs delicately interact with inflammatory factors at the sites of tissue damages.
Depending on the type and persistence of the inflammatory factors, the activated MSCs could lead either to complete or partial tissue repair, or to chronic inflammation and further tissue damage, such as cancer and fibrosis. Indeed, recent studies have shown that there is a bidirectional interaction between MSCs and inflammatory cells and cytokines. However, much information of this information remains to be elucidated. Further investigations in this newly emerging exciting research area will undoubtedly lead to better understanding of pathogenesis of various diseases and novel treatment strategies.
我与SNURPs的缘分
Steitz' story begins in 1977 when introns, exons and RNA splicing had just been discovered. She goes on to tell us of the importance of serendipity in her lab's discovery of SNURPS, the small nuclear ribonucleoproteins that are key to the splicing of pre-messenger RNA.
Stability of MoRPhogen Gradients & Movement of Molecules
In my second lecture I describe experiments using EGFP tagged Bicoid to follow Bcd gradient establishment in living embryos, and to test various aspects of the simple model. Despite continuous synthesis of new Bcd protein at the anterior end of the egg, we find that the concentration of Bcd in nuclei at any given point along the anterior posterior axis is constant over time and is reproducible from embryo to the next. This reproducibility means that the gradient is sufficiently robust to provide positional information and thus can accurately direct gene activities. One the other hand, quantitative imaging experiments point to several features of the gradient that are hard to explain - how target genes activated by Bcd distinguish relatively subtle differences in low concentrations, and how Bcd molecules move from the anterior site of their synthesis to the site of their transcriptional activity. See more at http://www.ibioseminars.org