fibroblasts
Snapshots of Life: Wild Outcome from Knocking Out Mobility Proteins
Posted on by Dr. Francis Collins
Credit: Praveen Suraneni and Rong Li, Stowers Institute for Medical Research
When biologists disabled proteins critical for cell movement, the result was dramatic. The membrane, normally a smooth surface enveloping the cell, erupted in spiky projections. This image, which is part of the Life: Magnified exhibit, resembles a supernova. Although it looks like it exploded, the cell pictured is still alive.
To create the image, Rong Li and Praveen Suraneni, NIH-funded cell biologists at the Stowers Institute for Medical Research in Kansas City, Missouri, disrupted two proteins essential to movement in fibroblasts—connective tissue cells that are also important for healing wounds. The first, called ARPC3, is a protein in the Arp2/3 complex. Without it, the cell moves more slowly and randomly [1]. Inhibiting the second protein gave this cell its spiky appearance. Called myosin IIA (green in the image), it’s like the cell’s muscle, and it’s critical for movement. The blue color is DNA; the red represents a protein called F-actin.
Snapshots of Life: Nanotechnology Meets Cell Biology
Posted on by Dr. Francis Collins
Caption: Scanning electron micrograph of silica beads (yellow) on the surface of a human fibroblast cell.
Source: Matthew Ware and Biana Godin Vilentchouk, Houston Methodist Research Institute, Texas
Many of the most exciting frontiers in biomedical research sound like the stuff of science fiction, but here’s some work that even looks like it’s straight from the set of Star Trek! This scanning electron micrograph captures the pivotal moment when nanospheres—a futuristic approach to drug delivery—are swallowed up by a human fibroblast cell.
The NIH-funded researchers who took this stunning photograph, one of the winners in the Federation of American Societies for Experimental Biology’s 2013 BioArt Competition, are using tiny silica beads (yellow in the image above) to investigate how drug-laden nanoparticles are transported into cells. They are focusing on fibroblasts because although they produce vital molecules that give healthy tissue its structure and strength, they also surround and nourish many types of cancer.
Exploiting Stem Cell Stickiness for Sorting
Posted on by Dr. Francis Collins
Caption: Adult human fibroblast cells (left) are reprogramed into human induced pluripotent stem cells
(iPS cells). The iPS cells have a characteristic stickiness that lets them to adhere to sorting devices
(right) with different strengths than other cells.
Credit: Ankur Singh and Andres Garcia, Institute for Bioengineering & Bioscience, Georgia Tech
There is much excitement about the potential of stem cells for many applications, including regenerative medicine and treating human diseases. But growing pure cultures of stem cells by reprograming adult cells—like human fibroblasts—into a less differentiated cell type called a human induced Pluripotent Stem cell (iPS cell), is a tricky business. These stem cell cultures are often contaminated with other normal cells that do not have the same coveted therapeutic potential. Manually sorting these stem cells is time consuming and difficult; using chemical approaches can damage the DNA inside. Now, we have a better option: NIH funded researchers from the Georgia Institute of Technology in Atlanta have invented a cell-sorting device that exploits specific characteristics of iPS cells.
iPS cells have a characteristic ‘stickiness’ that allows them to adhere to surfaces inside the sorting chip with different strengths than other cells. This stickiness is due to a signature set of proteins on the surface of these stem cells. Normal cells are coated in other proteins that give their surfaces different adhesive properties.
The researchers say the method is gentle, efficient, rapid, and generates collections of stem cells that are 95–99% pure.
Reference:
Adhesion strength-based, label-free isolation of human pluripotent stem cells. Singh A, Suri S, Lee T, Chilton JM, Cooke MT, Chen W, Fu J, Stice SL, Lu H, McDevitt TC, García AJ. Nat Methods. 2013 May;10(5):438-44.
NIH support: National Institute of General Medical Sciences; National Institute of Neurological Disorders and Stroke; National Cancer Institute
Previous Page
