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Kruppel-like Factors (KLF) are responsible for regulating many genes involved in physiological and pathological processes. They are characterized by three conserved zinc-fingers in the DNA-binding domain, wherein mutations could affect the binding efficiency and transcription regulation. This study aimed to perform bioinformatics analysis to determine the most deleterious non-synonymous variants in KLFs involved in cardiac development and diseases, and their effects over the protein structure and stability. Eight hundred and fifty non-synonymous variants were found in seven KLFs related to cardiac diseases. Seventeen algorithms were used to predict the effect of selected variants over the structure and function of seven KLFs. The Top3 variants were selected in each category of conserved and non-conserved residues in the zinc-finger (ZF) domain. KLF5 p.Cys410Phe was the only variant predicted as deleterious in all algorithms, occurring in a conserved residue of zinc ion interaction. KLF15 p.Arg364Pro was the only variant predicted to affect the DNA-binding, and also occurs in a conserved ZF-domain. Our bioinformatics analysis determined potential variants that may lead to development of cardiac diseases, as well as reinforced the importance of KLF analysis in vitro and in vivo . [ABSTRACT FROM AUTHOR]

Abstract: Recent work has provided compelling evidence that increased levels of acetylcholine (ACh) can be protective in heart failure, whereas reduced levels of ACh secretion can cause heart malfunction. Previous data show that cardiomyocytes themselves can actively secrete ACh, raising the question of whether this cardiomyocyte derived ACh may contribute to the protective effects of ACh in the heart. To address the functionality of this non-neuronal ACh machinery, we used cholinesterase inhibitors and a siRNA targeted to AChE (acetylcholinesterase) as a way to increase the availability of ACh secreted by cardiac cells. By using nitric oxide (NO) formation as a biological sensor for released ACh, we showed that cholinesterase inhibition increased NO levels in freshly isolated ventricular myocytes and that this effect was prevented by atropine, a muscarinic receptor antagonist, and by inhibition of ACh synthesis or vesicular storage. Functionally, cholinesterase inhibition prevented the hypertrophic effect as well as molecular changes and calcium transient alterations induced by adrenergic overstimulation in cardiomyocytes. Moreover, inhibition of ACh storage or atropine blunted the anti-hypertrophic action of cholinesterase inhibition. Altogether, our results show that cardiomyocytes possess functional cholinergic machinery that offsets deleterious effects of hyperadrenergic stimulation. In addition, we show that adrenergic stimulation upregulates expression levels of cholinergic components. We propose that this cardiomyocyte cholinergic signaling could amplify the protective effects of the parasympathetic nervous system in the heart and may counteract or partially neutralize hypertrophic adrenergic effects. [Copyright &y& Elsevier]