Person:
Chen, Michael J.

Profile Picture

Email Address

AA Acceptance Date

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Chen

First Name

Michael J.

Name

Chen, Michael J.
Author's Publications: search.filters.isAuthorOfPublication.10084dd8-96d0-48f8-a3b6-741d5ab576b2

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Flow-induced protein kinase A–CREB pathway acts via BMP signaling to promote HSC emergence
    (The Rockefeller University Press, 2015) Kim, Peter Geon; Nakano, Haruko; Das, Partha Pratim; Chen, Michael J.; Rowe, R. Grant; Chou, Stephanie S.; Ross, Samantha J.; Sakamoto, Kathleen M.; Zon, Leonard; Schlaeger, Thorsten; Orkin, Stuart; Nakano, Atsushi; Daley, George
    Fluid shear stress promotes the emergence of hematopoietic stem cells (HSCs) in the aorta–gonad–mesonephros (AGM) of the developing mouse embryo. We determined that the AGM is enriched for expression of targets of protein kinase A (PKA)–cAMP response element-binding protein (CREB), a pathway activated by fluid shear stress. By analyzing CREB genomic occupancy from chromatin-immunoprecipitation sequencing (ChIP-seq) data, we identified the bone morphogenetic protein (BMP) pathway as a potential regulator of CREB. By chemical modulation of the PKA–CREB and BMP pathways in isolated AGM VE-cadherin+ cells from mid-gestation embryos, we demonstrate that PKA–CREB regulates hematopoietic engraftment and clonogenicity of hematopoietic progenitors, and is dependent on secreted BMP ligands through the type I BMP receptor. Finally, we observed blunting of this signaling axis using Ncx1-null embryos, which lack a heartbeat and intravascular flow. Collectively, we have identified a novel PKA–CREB–BMP signaling pathway downstream of shear stress that regulates HSC emergence in the AGM via the endothelial-to-hematopoietic transition.
  • Thumbnail Image
    Publication
    Simple filter microchip for rapid separation of plasma and viruses from whole blood
    (Dove Medical Press, 2012) Wang, ShuQi; Sarenac, Dusan; Chen, Michael J.; Huang, Shih-Han; Giguel, Francoise F; Kuritzkes, Daniel; Demirci, Utkan
    Sample preparation is a significant challenge for detection and sensing technologies, since the presence of blood cells can interfere with the accuracy and reliability of virus detection at the nanoscale for point-of-care testing. To the best of our knowledge, there is not an existing on-chip virus isolation technology that does not use complex fluidic pumps. Here, we presented a lab-on-a-chip filter device to isolate plasma and viruses from unprocessed whole blood based on size exclusion without using a micropump. We demonstrated that viruses (eg, HIV) can be separated on a filter-based chip (2-μm pore size) from HIV-spiked whole blood at high recovery efficiencies of 89.9% ± 5.0%, 80.5% ± 4.3%, and 78.2% ± 3.8%, for viral loads of 1000, 10,000 and 100,000 copies/mL, respectively. Meanwhile, 81.7% ± 6.7% of red blood cells and 89.5% ± 2.4% of white blood cells were retained on 2 μm pore–sized filter microchips. We also tested these filter microchips with seven HIV-infected patient samples and observed recovery efficiencies ranging from 73.1% ± 8.3% to 82.5% ± 4.1%. These results are first steps towards developing disposable point-of-care diagnostics and monitoring devices for resource-constrained settings, as well as hospital and primary care settings.