Simon Wächter  

Home Institution
Charité Universitätsmedizin Berlin

Host Institution
Cardiovascular Research Center, Massachusetts General Hospital,
Harvard Medical School, Boston, Massachusetts
Research Mentor: Jing X. Kang, M.D., Ph.D.

E-Mail: simon.waechter@charite.de
Research Topic
see Abstract
Personal Reactions to the U.S. Experience
Until my time in Boston, I had only been to the States once when I was 12, and that was for vacation, so everything I experienced was quite new and exciting to me.
The first thing that caught my eye when I arrived in Boston was that the streets, houses and surroundings in most parts of the city were by far not as fancy as I had imagined an American city to be like. I realized very quickly that the German sense for neatness and orderlyness was not as universally present as it is back home. This became even more obvious once I started appartement-hunting and using public transport. However, since there are always both advantages and disadvantages, I was soon to figure out that the American attitude of not being so fussy about everything made a lot of things easier and oftentimes more efficient.
What I liked most about living in Boston was, for one thing, the city’s internationality, as well as the politeness and openness of its people. Although Americans are oftentimes stereotyped as superfical, I found that people simply treated me, and each other, with very much respect and courtesy. Beyond this, people’s openness made it very easy to get to know interesting people and find new friends. Because of all this as well as the circumstance that Boston is, in my eyes, not that different from Germany, settling in was not as difficult as I would have expected.
Greatest Difficulties Encountered
- Getting used to American units: Pounds, ounces, feet, inches and such
- Finding a cheap grocery store
Most humorous incident
When my friend (American) came back from a stay in Muenster, Germany and described everything that I had noticed was different in the States, just from another perspective.
Helpful Hints for Future Students
- Make use of the great Dollar-Euro exchange rate.
- Take advantage of the cheap inner-American air fares.
- Visit New York at least once, if you are on the East Coast.
- Start early with your U.S. visa application. Even though the visa itself was issued in two days, it took more than one month until I got the DS-2019.

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Abstract on Research Topic

Antiinflammatory Effects of Omega-3-Fatty-Acids in Zymosan A Induced Murine Peritonitis
Author: Simon Wächter

Institution:
CVRC, Massachusetts General Hospital, Harvard Medical School, Boston, MA

Background:
Numerous publications have previously confirmed that omega-3 (n-3) fatty acids, such as DHA (Docosahexaenoic Acid) and EPA (Eicosapentaenoic Acid) show an anti-inflammatory effect by functioning as precursor molecules of anti-inflammatory lipid mediators. Transgenic Fat-1 mice, unlike their wild-type counterparts, express a desaturase enzyme that enable them to endogenously synthesize those n-3 fatty acids. This setting offers an interesting approach to further elucidate the role that these fatty acids play in the process of inflammation and its resolution.

Materials and Methods:
We induced a peritonitis in both Fat-1 and wild type (WT) mice with Zymosan A, a cell wall component of the yeast Saccharomyces cerevisiae. 24 hours after injection, mice were sacrificed by Isoflurane anesthesia. First, a transthoracic cardiocentesis was performed to obtain blood samples. Subsequently, a peritoneal lavage was performed with 10 ml PBS. Total cell number was counted. Besides, spleens were snap-frozen for a later LC-MS analysis. The cell suspension was used for a Wright Giemsa stain, for rtPCR as well as FACS analysis.
The blood samples we were used for a TNF-alpha ELISA.
Wright Giemsa stains were prepared to clarify the cellular composition of the exudates.
Real Time PCR was used to determine the quantity RNA levels of both pro- and anti-inflammatory mediators such as TNF-alpha, IL-1, TGF-beta and IL-1ra. Besides this, we also used primers for BLT1, ChemR23 and ALX, which are cellular receptors that are assumed to function as receptors for n-3 derived lipid mediators.
For FACS analysis, we used FITC labeled F4/80 (Macrophage surface marker) and PE-labeled Ly-6G (PMN surface marker) Antibodies. First, we performed a surface stain with FITC-F4/80, followed by a permeabilization step with saponin and a subsequent intracellular stain with PE-Ly-6G. The objective of this procedure was to conduct an in-vivo phagocytosis assay to determine whether n-3 fatty acids have an impact on phagocytotic activities of macrophages and therefore on inflammation resolution.
Apart from this mouse model, we performed cell culture experiments in which we incubated both THP-1 cells (human monocytic leukemic cells) as well as RAW 264.7 cells (murine Abelson leukemia virus transformed cell line) with various n-3 and n-6 fatty acids. Supernatants were used for TNF-alpha ELISA .

Results:
Analysis of the collected data will be performed soon.