The SIVB’s In Vitro Animal Cell Sciences Section (IVACS) held the Student and Post-Doctoral Oral Presentation Competition on Monday, June 12. This session was moderated by Dr. Addy Alt-Holland (Tufts University) and Dr. Kolla Kristjansdottir (Midwestern University). Many abstracts were submitted to be considered for this competition, and following a rigorous, peer-review process, three abstracts were selected based on their scientific merit and quality. The top three contestants delivered highly professional oral presentations, and answered numerous questions both from the judges and the SIVB members that attended that session. The panel of nine IVACS experts that evaluated the contestants included: Dr. Mae Ciancio and Dr. Michael J. Fay (Midwestern University), Dr. Justin Colacino and Michael Dame (University of Michigan), Dr. Brad L. Upham (Michigan State University), Dr. Barbara Doonan (New York Medical College) and Dr. John W. Harbell (JHarbell Consulting LLC). The panel also included both session moderators, Dr. Kolla Kristjansdottir and Dr. Addy Alt-Holland.

We were delighted to present certificates and monetary awards to the three contestants during the IVACS Section Business Meeting later that day. Robert Garcia from Midwestern University won the 1st place award for his presentation “Enhanced Directional Axon Outgrowth of Peripheral Nerve Fiber Using Submicron Topographic Cues and Live Cell Imaging.” Sara J. Poynter from University of Waterloo won the 2nd place award with her presentation “Scavenging for Bacteria: Identification and Characterization of Rainbow Trout MARCO.” Shawn J. Waller from University of North Carolina – Charlotte won the 3rd place award for her presentation titled “Characterizing Functional Differences in Sea Anemone Hsp70 Isoform Using Budding Yeast.”

The IVACS Student and Post-Doctoral Oral Presentation Competition is a unique session designed to enrich public-speaking experience of students and Post-Doctoral candidates in a national conference. It also provides a competitive platform for them to present their research work and achievements to an expert audience, and receive invaluable feedback in a supportive environment. We highly encourage all qualified individuals to submit their research abstracts to the upcoming 2018 competition in St. Louis, Missouri.

Submitted by Addy Alt-Holland and Kolla Kristjansdottir

 

First Place Award

Enhanced Directional Axon Outgrowth of Peripheral Nerve Fibers Using Submicron Topographic Cues and Live Cell Imaging

Peripheral nerve injury is a debilitating disease characterized by a loss of sensation and/or motor function at the affected site. Unlike the central nervous system, the peripheral nervous system spontaneously regenerates after injury. In many cases, however, full functional restoration is not achieved. One likely explanation is the propensity of axons to migrate in undesired directions in the absence of proper biochemical and biophysical cues. Therefore, the aim of this study is to optimize directional axon outgrowth using surfaces with nano- to micro-scale anisotropic topographic patterns as a biophysical guide. Previous work in our lab has shown that mouse dorsal root ganglia (DRGs) cultured ex vivo on surfaces with repeating groove widths of 700nm or 2000 nm had longer and more controlled axon outgrowth than a flat surface. Our hypothesis is that the speed and directionality of axon growth parallel to the grooves will be enhanced when observed in time-lapse and at specific time points, both on tissue culture plates and tube-like structures. We harvested cervical and thoracic DRGs from mice and cultured them on chemically identical surfaces, with groove widths of 700nm or 2000nm as well as a flat control. Axon growth was observed for 24 hours in time-lapse 1-2 days and 3-4 days after initial plating. Our analysis indicates that DRGs grown on topographic surfaces exhibit significantly more directional axon growth parallel to the grooves compared to the flat control, as well as a marginally faster axon growth speed. In addition, DRGs were cultured in 5 mm diameter half-tube structures with similar topography on the inner wall, and imaged 6 days after initial plating. Analysis showed that DRGs grown on half-tubes with inner-wall topography exhibited longer axon outgrowth than control half tubes with no topography. In conclusion, our results may be used to better understand the various mechanisms of peripheral nerve regeneration and applied towards the fabrication of implantable biomaterials with specialized topography to ultimately restore nerve function.

Robert Garcia, Department of Biomedical Sciences, Midwestern University, 555 31st Street, Downers Grove, IL 60515. In Vitro Cellular and Developmental Biology, 53:S25-26, 2017

 

Second Place Award

Scavenging for Bacteria: Identification and Characterization of Rainbow Trout MARCO

Class A scavenger receptors (SR-As) are a family of key innate immune receptors, which bind to a wide range of polyanionic ligands including bacterial components and nucleic acids.  Macrophage receptor with collagenous structure (MARCO) is a SR-A that has been studied in mammals largely for its role in binding bacteria.  To date there is little information about SRAs in fish, and what ligands specific SR-A family members bind remains largely unknown.  In this present study a novel rainbow trout MARCO transcript has been identified and its sequence and putative protein domains have been analyzed.  While there is only moderate sequence similarity to mammalian MARCO sequences there are notable protein domain similarities and MARCO clusters with MARCO sequences from other species more closely than other fish scavenger receptors.  MARCO transcript was found in rainbow trout gonadal cell line RTG-2 and the macrophage/monocyte splenic cell line RTS-11; presence was not detected in the gut or gill cell lines RTgutGC or RTgill-W1.  When overexpressed in CHSE-214, a cell line that lacks functional scavenger receptors, rainbow trout MARCO is able to bind the class SR-A ligand, acLDL as well as gram-positive, and gram-negative bacteria (of both mammalian and aquatic sources).  MARCO did not show any binding to the yeast cell wall component zymosan.  When the MARCO sequence was truncated to remove a domain necessary for bacterial binding in mammals, the scavenger receptor cysteine-rich domain, MARCO no longer bound bacteria or acLDL.  This is the first time rainbow trout MARCO has been identified, and the first in-depth study exploring a fish class A scavenger receptor ligand binding profile.  This study provides novel insight into the role of rainbow trout MARCO in bacterial innate immunity.

Sarah J. Poynter, Department of Biology, University of Waterloo, Waterloo CANADA. In Vitro Cellular and Developmental Biology, 53:S25, 2017

 

Third Place Award

Characterizing Functional Differences in Sea Anemone Hsp70 Isoforms Using Budding Yeast

Heat shock protein 70s (Hsp70s) are a highly conserved class of chaperone proteins involved in cellular processes such as the stress response, homoeostatic maintenance, and cell cycle progression. Thestarlet sea anemone Nematostella vectensis is found in a variety of environments that cause organisms physiological stress through abiotic factors such as temperature, UV radiation, salinity, and oxygen concentration. N. vectensis is found throughout a range of latitudes and elevations that may promote the evolution of divergent functions of Hsp70 isoforms among different populations. Preliminary data shows dramatic differences among expression profiles of the NvHsp70 isoforms under stress. To bypass the lack of in vivo protein technologies for marine invertebrates, we expressed the 3 major NvHsp70 isoforms in yeast lacking native Hsp70. These cells while viable grow at substantially different rates and display altered tolerance to a variety of cell stressors including hydroxyurea, cadmium, copper, hydrogen peroxide and high temperature. Going forward, chimeras of these isoforms in yeast will be created and expressed in order to pinpoint the specific amino acid differences that determine cellular tolerance to stress. In addition, we intend to isolate the individual isoforms and their respective complexes (‘interactomes”) to characterize the molecular cause of isoform-specific stress responses.

Shawn J. Waller, University of North Carolina, 9201 University City Blvd, Charlotte, NC 28223. In Vitro Cellular and Developmental Biology, 53:S25, 2017