Stress Response Mechanisms in Health and Disease
Heat shock proteins are critical players in maintaining the health of cells. They are produced by cells under both normal conditions and in response to many types of injury. Their functions include protection of cell structural elements, known as the cytoskeleton, as well as maintenance of protein folding, oxidative homeostasis and cell death signaling systems. Altered heat shock protein synthesis is seen in many diesease states, including cancer and heart disease. In addition, mutation of some heat shock proteins leads to disorders of nerve and muscle tissues.
Small heat shock proteins
The major focus of the lab is the function and regulation of a family of heat shock proteins known as small heat shock proteins. Hsp27, one of the best known members of this family, is overexpressed in cancers including cancers of the reproductive organs and nervous system. It is also highly expressed under normal conditions in muscle cells, where it seems to bind to critical components of the contractile aparatus, known as sarcomeres, during cell injury. Hearts of transgenic mice overexpressing Hsp27 have been shown to tolerate an injury model of heart attack better than wild-type controls. There are a number of potential binding sites for Hsp27 in muscle cells, but we have recently published data indicating that Hsp27 interacts with titin filaments in injured muscle cells (Tucker and Shelden, 2009).
Our model systems
Much of our work has been conducted using cultured cells. However, since 2005 we have been using the zebrafish and other fish species as an experimental model system. The teleost embryo is easily accessible to the imaging methods used in our laboratory. In addition, techniques are available that allow researchers in the lab to introduce engineered proteins into living fish or alternatively, to prevent their expression. These features allow us to cross easily between molecular genetics, cell biology and tissue physiology studies. The images on the left below show whole mount in situ hybridization of Hsp27 mRNA in skeletal and cardiac muscle of a developing zebrafish embryo (some expression is also seen in the lens and brain). The images on the right are of living zebrafish expressing a cyan-fluorescent protein under the control of the proximal zebrafish Hsp27 promoter. You can see expression in the heart under control conditions, and enhanced expression of the fluorescent reporter after heat shock (HS).
- Sanchez EJ, Hayes RP, Barr JT, Lewis KM, Webb BN, Subramanian AK, Nissen MS, Jones JP, Shelden EA, Sorg BA, Fill M, Schenk JO, Kang C (2013) Potential role of cardiac calsequestrin in the lethal arrhythmic effects of cocaine. Drug Alcohol Depend. 133(2), 344-51 PMID: 23876860 PMCID: PMC4097383
- Middleton RC, Shelden EA (2013) Small heat shock protein HSPB1 regulates growth of embryonic zebrafish craniofacial muscles. Exp Cell Res. 319(6), 860-74 PMID: 23313812
- Tucker NR, Middleton RC, Le QP, Shelden EA (2011) HSF1 is essential for the resistance of zebrafish eye and brain tissues to hypoxia/reperfusion injury. PLoS One 6(7) PMID: 21814572 PMCID: PMC3141033
- Karlsson AB, Maizels ET, Flynn MP, Jones JC, Shelden EA, Bamburg JR, Hunzicker-Dunn M (2010) Luteinizing hormone receptor-stimulated progesterone production by preovulatory granulosa cells requires protein kinase A-dependent activation/dephosphorylation of the actin dynamizing protein cofilin. Mol Endocrinol. 24(9), 1765-81 PMID: 20610540 PMCID: PMC2940477
- Tucker NR, Shelden EA (2009) Hsp27 associates with the titin filament system in heat-shocked zebrafish cardiomyocytes. Exp Cell Res. 315(18), 3176-86 PMID: 19580808 PMCID: PMC2908402
- Tucker NR1, Ustyugov A, Bryantsev AL, Konkel ME, Shelden EA (2009) Hsp27 is persistently expressed in zebrafish skeletal and cardiac muscle tissues but dispensable for their morphogenesis. Cell Stress Chaperones. 14(5), 521-33 PMID: 19238587 PMCID: PMC2728285
- Bryantsev AL, Chechenova MB, Shelden EA (2007) Recruitment of phosphorylated small heat shock protein Hsp27 to nuclear speckles without stress. Exp Cell Res. 313(1), 195-209 PMID: 17123510 PMCID: PMC1893088
- Mao L, Shelden EA (2006) Developmentally regulated gene expression of the small heat shock protein Hsp27 in zebrafish embryos. Gene Expr Patterns. 6(2), 127-33 PMID: 16326146
- Mao L, Bryantsev AL, Chechenova MB, Shelden EA (2005) Cloning, characterization, and heat stress-induced redistribution of a protein homologous to human hsp27 in the zebrafish Danio rerio. Exp Cell Res. 306(1), 230-41 PMID: 15878347
- Hirano S, Sun X, DeGuzman CA, Ransom RF, McLeish KR, Smoyer WE, Shelden EA, Welsh MJ, Benndorf R. (2005) p38 MAPK/HSP25 signaling mediates cadmium-induced contraction of mesangial cells and renal glomeruli. Am J Physiol Renal Physiol. 288(6), F1133-43 PMID: 15687248
- Yancy SL, Shelden EA, Gilmont RR, Welsh MJ (2005) Sodium arsenite exposure alters cell migration, focal adhesion localization and decreases tyrosine phosphorylation of focal adhesion kinase in H9C2 myoblasts. Toxicol Sci. 84(2), 278-86 PMID: 15537746
- Bonham RT, Fine MR, Pollock FM, Shelden EA (2003) Hsp27, Hsp70, and metallothionein in MDCK and LLC-PK1 renal epithelial cells: effects of prolonged exposure to cadmium. Toxicol Appl Pharmacol. 191(1), 63-73 PMID: 12915104
- Shelden EA, Weinberg JM, Sorenson DR, Edwards CA, Pollock FM (2002) Site-specific alteration of actin assembly visualized in living renal epithelial cells during ATP depletion. J Am Soc Nephrol. 13(11), 2667-80 PMID: 12397036
- Shelden EA, Borrelli MJ, Pollock FM, Bonham R (2002) Heat shock protein 27 associates with basolateral cell boundaries in heat-shocked and ATP-depleted epithelial cells. J Am Soc Nephrol. 13(2), 332-41 PMID: 11805160