Unique Quantitative Trait Loci in Synergy Permanently Improve Diastolic Dysfunction

Genetics of systolic and diastolic heart failure

Heart failure accounts for a significant portion of heart diseases. Molecular mechanisms gradually emerge that participate in pathways leading to left ventricular dysfunction in common systolic heart failure (SHF) and diastolic heart failure (DHF). A human genome-wide association study (GWAS) identified two markers for SHF and no GWAS on DHF has been documented. However, genetic analyses in rat models of SHF and DHF have begun to unravel the genetic components known as quantitative trait loci (QTLs) initiating systolic and diastolic function. A QTL for systolic function was detected and the gene responsible for it is identified to be that encoding the soluble epoxide hydrolase. Diastolic function is determined by multiple QTLs and the Ccl2/monocyte chemotactic protein gene is the strongest candidate. An amelioration on diastolic dysfunction is merely transient from changing such a single QTL accompanied by a blood pressure reduction. A long-term protection can be achieved only via combining alleles of several QTLs. Thus, distinct genes in synergy are involved in physiological mechanisms durably ameliorating or reversing diastolic dysfunction. These data lay the foundation for identifying causal genes responsible for individual diastolic function QTLs and the essential combination of them to attain a permanent protection against diastolic dysfunction, and consequently will facilitate the elucidation of pathophysiological mechanisms underlying hypertensive diastolic dysfunction. Novel pathways triggering systolic and diastolic dysfunction have emerged that will likely provide new diagnostic tools, innovative therapeutic targets and strategies in reducing, curing and even reversing SHF and DHF.

Dr Lewis Kitchener Dahl, the Dahl rats, and the "inconvenient truth" about the genetics of hypertension

Lewis K. Dahl is regarded as an iconic figure in the field of hypertension research. During the 1960s and 1970s he published several seminal articles in the field that shed light on the relationship between salt and hypertension. Further, the Dahl rat models of hypertension that he developed by a selective breeding strategy are among the most widely used models for hypertension research. To this day, genetic studies using this model are ongoing in our laboratory. While Dr. Dahl is known for his contributions to the field of hypertension, very little, if any, of his personal history is documented. This article details a short biography of Dr. Lewis Dahl, the history behind the development of the Dahl rats and presents an overview of the results obtained through the genetic analysis of the Dahl rat as an experimental model to study the inheritance of hypertension.