Placenta Research

Placenta Research – Summer 2010 – Dr. Bryan Larsen, Des Moines University

For the summer, I’m doing placental research at the medical school I attend, Des Moines University. Yes, I said “placental.” You know, the placenta; that magical thing that facilitates gas/nutrient/waste exchange between mother and fetus. Let me better explain:

The Big Picture

During pregnancy, membranes (the amniotic sac) can rupture prematurely; an early water break. Delivery must occur shortly thereafter, whether the pregnancy is term or not. What does it take to break a membrane? The other medical student in the lab, Rob, is looking at that. Specifically, at what tensile strength the amnion’s integrity will fail. But what weakens the membrane in the first place? Bacteria can be somehow involved, but specifically, the membrane is thought to be directly weakened by enzymes called collagenases. If you deduced that collagenases degrade collagen, you get a gold star. My research involves seeing which specific enzymes are upregulated in response to some common infectious organisms. If only it were that simple…

The Nitty-Gritty

What I called “collagenases” are really MMPs (matrix metalloproteinases). I’m now testing what levels they are expressed in the placental decidua. We will eventually be looking to see if the levels are different in mothers who were diabetic, obese, or hypertensive, along with pregnancies that had PPROM (preterm premature rupture of membranes) or were premature. In addition, we will be innoculating the placental tissue samples with a sampling of microorganisms (GBS, Strep, E.coli…) to see how the MMP expression responds.

What It Looks Like

Science isn’t boring, folks. Rob runs to the hospital to pick up some really fresh placenta and brings it back to the lab. Normally, placenta is delivered fifteen minutes after the baby.  Most of them so far have come from scheduled Caesarean-sections, so things are fairly predictable. He separates the chorion from the amnion and keeps the latter. His rig for testing breaking-tension is a testament to simple apparatus build mostly from spare things around the lab. He hangs the amnion and attaches a basket that fills with water. When the amnion breaks, he measures the volume of water which is then easily converted to mass.

Meanwhile, I cut into the meat of the placenta, which looks like an incredibly-bloody overly-tenderized pie-sized disc of tissue with an umbilical cord coming out of the center. Search for some pictures on the internet if you don’t believe me. I cut about a pill capsule-sized sample out of the middle “core” of the placenta, and get it ready for preservation and RNA/DNA isolation. The rest is all tubes and pipetting tiny amounts of various chemicals and running expensive machines and gels; all that stereotypical laboratory work stuff.