Hormonal Imprinting: The First Cellular-level Evidence of Epigenetic Inheritance and its Present State

Abstract

Hormonal imprinting takes place perinatally at the first encounter between the developing hormone receptor and its target hormone. This process is needed for the normal function of the receptor- hormone pair and its effect is life-long. However, in this critical period, when the developmental window is open, related molecules (members of the same hormone family, synthetic hormones and hormone-like molecules, endocrine disruptors) also can be bound by the receptor, causing life-long faulty imprinting. In this case, the receptors’ binding capacity changes and alterations are caused at adult age in the sexual and behavioral sphere, in the brain and bones, inclination to diseases and manifestation of diseases, etc. Hereby, faulty hormonal imprinting is the basis of metabolic and immunological imprinting as well as the developmental origin of health and disease (DOHaD). Although the perinatal period is the most critical for faulty imprinting, there are other critical periods as weaning and adolescence, when the original imprinting can be modified or new imprintings develop. Hormonal imprinting is an epigenetic process, without changing the base sequence of DNA, it is inherited in the cell line of the imprinted cells and also transgenerationally (up to 1000 generations in unicellulars and up to the 3rd generation in mammals are justified). Considering the enormously growing number and amount of faulty imprinters (endocrine disruptors) and the hereditary character of faulty imprinting, this latter is threatening the whole human endocrine system.

Gender Specific Differences in Disease Susceptibility: The Role of Epigenetics

“…These findings are considered consistent with an intergenerational transmission of epigenetic alterations affecting the primordial germ cells of the DES-exposed fetus [167]. This can be manifested in altered binding capacity of the receptor, with the disturbed transmission of the message (contained in the hormone-like molecule) and the disturbed response of the receptor-bearing cell [166].…”

“…It refers to a physiological process in which the developing hormone receptor encounters the target hormone for the first time and consequently the receptor-hormone pair is established, and this effect lasts for life. However, during embryogenesis, in particular in the phases of endocrine system development, receptors do not show complete specificity, consequently molecules similar to the target hormone (such as synthetic molecules, hormone analogues, endocrine disruptors) are also able to be tied up by the receptors, causing defective hormonal imprinting, with potential lifelong consequences [166].…”

“…According to Csaba (2019), this process can be viewed as an epigenetic process. Faulty hormonal imprinting is a disturbance of gene methylation pattern, which is epigenetically inherited to the further generations (transgenerational imprinting), as it would imply an epigenetic reprogramming of both receptor cells and germ cells, with transgenerational transmission.…”

Non-Neuronal Transmitter Systems in Bacteria, Non-Nervous Eukaryotes, and Invertebrate Embryos

“…In particular, 5-HT was found in the flagellated protozoan Crithidia fasciculata and the ciliated protozoan Tetrahymena pyriformis [ 55 ]. Currently, the synthesis of classical transmitters such as 5-HT, ACh, DA, histamine, γ-aminobutyric acid (GABA), etc., has been discovered in various unicellular organisms [ 57 , 58 , 59 , 60 ].…”

The Critical Role of Epigenetic Regulation in Developmental Programming of Higher Organisms

“…), the authors explain how sequence duplication may function as an evolutionary strategy to regulate the transcriptional expression at genome-level. In the next article, Csaba [2] provides a review on the mechanisms associated with the hormonal imprinting, an epigenetic phenomenon that involves the first encounter between a hormone and the target receptor, which occurs in the perinatal period. Remarkably, Dr. Csaba postulated the theory of hormonal imprinting [3], and his laboratory has made important research efforts to understand the faulty hormonal imprinting in the Developmental Origin of Health and Disease (DOHaD).…”