Zinc Signals 2007

4 June 2007

LIZ ADLER

In the Sunday morning session on zinc sensors, Richard Thompson spoke about carbonic anhydrase-based fluorescence zinc sensors; Paul Bentley talked about the development of new dipyrrin-based zinc probes; and Leonard Giblin spoke about issues related to dye-based methods of measuring free zinc in complex medium (medium that contains components that buffer zinc and compete with the dye for zinc binding). Carol Fierke noted that some "zinc metalloenzymes" also bind exchangeable iron (typically present at higher intracellular concentrations than exchangeable zinc) and discussed the intriguing notion that "metal switching" could provide a novel mechanism for regulating the function of such enzymes. Zeev Rosenzweig wrapped up the Sunday morning session by speaking about the possibilities inherent in using modified surfaces, on which cells could be cultured, or targeted probes as optochemical sensors for detecting released zinc.

Wolfgang Maret started off the first afternoon session with a discussion of the subtleties of metallothionein-zinc interaction, noting that the seven metallothionein zinc-binding sites did not all have the same binding affinity and that the zinc buffering capacity of metallothionein was affected by redox state. Hajo Haase discussed the effects of zinc on the response of monocytes to LPS, describing the cell signaling mechanisms whereby low concentrations of zinc could facilitate the production of inflammatory cytokines and high concentrations of zinc could have an anti-inflammatory effect. Wojciech Bal spoke about a nucleasomal zinc binding site and John Weiss discussed zinc disruption of mitochondrial function and its possible role in ischemic injury in hippocampal pyramidal neurons.

Zinc deficiency leads to a syndrome characterized by growth retardation, immune dysfunction, and cognitive impairment. The second Sunday sesssion had talks by Harold Sandstead, on zinc nutriture, Katherine Lorenz, on the introduction of amaranth to combat malnutrition in Oaxaca, and Jane Flynn on implications of the relationship between dietary copper and zinc for cognitive function.

The Sunday evening keynote speech was by Ananda Prasad, on his discovery of the zinc deficiency syndrome, which affects some two billion people, and how zinc deficiency affects immune function.