Integrated network systems and evolutionary developmental endocrinology

A conceptual review on systems biology in health and diseases: from biological networks to modern therapeutics

Human physiology is an ensemble of various biological processes spanning from intracellular molecular interactions to the whole body phenotypic response. Systems biology endures to decipher these multi-scale biological networks and bridge the link between genotype to phenotype. The structure and dynamic properties of these networks are responsible for controlling and deciding the phenotypic state of a cell. Several cells and various tissues coordinate together to generate an organ level response which further regulates the ultimate physiological state. The overall network embeds a hierarchical regulatory structure, which when unusually perturbed can lead to undesirable physiological state termed as disease. Here, we treat a disease diagnosis problem analogous to a fault diagnosis problem in engineering systems. Accordingly we review the application of engineering methodologies to address human diseases from systems biological perspective. The review highlights potential networks and modeling approaches used for analyzing human diseases. The application of such analysis is illustrated in the case of cancer and diabetes. We put forth a concept of cell-to-human framework comprising of five modules (data mining, networking, modeling, experimental and validation) for addressing human physiology and diseases based on a paradigm of system level analysis. The review overtly emphasizes on the importance of multi-scale biological networks and subsequent modeling and analysis for drug target identification and designing efficient therapies.

The coordinated expression, interaction and evolution of the neuroendocrine genes

The neuroendocrine system is a complex biological system controlled by various neuropeptides and hormones. The evolution and network properties of neuroendocrine genes are analyzed along with their expression profiles. The neuroendocrine genes show very similar expression profiles and local network properties across a wide range of tissues consistent with the physiological roles of their proteins. Moreover, the coordinated evolution of 10 neuroendocrine genes involved in mammalian reproduction and homeostasis is demonstrated using several methods, such as correlated evolution, relative-rate test, relative-ratio test and codon usage bias. The neuroendocrine genes seem to evolve predominantly under similar selective strengths and regimes of purifying selection, which is well reflected in their evolutionary fingerprints. This result demonstrates for the first time a key role of natural selection in creating and maintaining a well-designed neuroendocrine system at the genomic level. It also indicates that component properties of a complex system at a higher physiological scale may determine component properties at a lower genomic scale and/or vice versa.

Explanation of the insulin paradox from the evolutionary point of view

No abstract supplied by author

Species-specific actions of incretin: from the evolutionary perspective

Two modes of incretin-based therapy, incretin mimetics (ie, glucagon-like peptide-1 (GLP-1) agonists) and incretin enhancers (ie, inhibitors of dipeptidyl peptidase IV (DPP-IV)), have recently been introduced into the clinical use. From the viewpoint of evolutionary endocrinology of GLP-1 and their receptors, the incretin action of GLP-1 seems to be relatively recent. Exendin-3 and exendin-4 are paralogs of GLP-1 from the lizards, and the synthetic exendin-4, exenatide, is a paralog of GLP-1. It has recently been indicated that GLP-1 and its receptor are expressed in the taste buds of the tongue, suggesting their possible function in the taste sensing signal pathway. In order to elucidate unknown functions of GLP-1 and its agonists and enhancers, ie, other than incretin actions in humans, it is possibly useful to consider GLP-1 from the viewpoint of integrated systems biology and evolutionary endocrinology.