ADVANCES IN NUTRITION- NUTRIENTS IN HEALTH AND DISEASE : Lecture 1, Module introduction
Concepts linking homeostasis and health
Introduction to '-omics '
Nutrient homeostasis
Diet -> gene vs gene -> diet interactions
terminology
Nutrigenetics and nutrigenomics research
relevance to nutrition and dietetics- concepts of 'personalised medicine' and personalised
Nutrient homeostatic control mechanisms
Nutrient gene direct interaction examples - nutrients into body then alter gene expression / epigenetics as part of homeostatic control
What do we mean by health/healthy? static biomarkers are indicators but may not tell us if we are healthy.
Challenge tests
epigenetic interactions (nutrient -> gene -> nutrient) = environment can change chromatin structure, altering gene expression chronically
Goal of molecular cell biology (nutrition related) research
DNA
Regulation of gene expression= 1. transcriptional regulation- increase / decrease RNA
- translational regulation- RNA to protein
- product/protein regulation- usage of proteins
functional effects of vitamin D : vitamin D triggers pathways by binding to Vitamin D receptor or effecting vitamin D receptor RXR complex which alters DNA transcription
cellular iron homeostasis- 1. IRP1 when bound to iron, becomes enzyme.
- If Fe deficient in cell, IRP1 loses Fe and therefore, enzyme activity and changes shape and property= activated RNA binding properties = translation of ferritin (iron storage protein) stopped if binds to 5' end and increases transferrin to bring more Fe into cell
SUMMARY
• Nutrients / nutritional status control gene expression → homeostatic control → health/disease
– Nutrient-gene interactions = response to nutrients
– Gene-nutrient interaction = inter-individual variation in response to/ requirements for health
Define the genomics, transcriptomics , proteomics and metabolomics
Understand that new experimental methods permit analysis at the 'omic' level
Omic data analysis is complex and challenging! Bioinformatics a developing discipline
reasoning why most of us manage to meet requirements without realising
How does this work? sensing mechanisms in response to food intake which then results in metabolic/transport adjustments e.g. In SHORT term, glucose and insulin response
homeostatic control mechanisms can also happen over years e.g. mice calorically restricted will rapidly lose weight initially then reach plateau as they have adapted to energy metabolism (also live longer so ? health benefits)
need to understand homeostatic control
blood sugar response- can use to detect early signs of nutrient homeostasis
homeostatic processes are driven by diet/nutrient and gene interactions= understand genetics and underlying mechanisms to understand homeostatic control and optimal level of nutrients
Gene-> nutrient interactions (genetic differences alter expression/function of genes -> change in response to or requirement for nutrients
genomics- study of entire genome (DNA) (structural genomics)
Transcriptomics- study of trasncription
proteomics- study of transcription to protein
metabolomics- study of metabolism / protein function
human genome project- sequenced human genome. 95% 'junk DNA' so unsure of function. other 5% codes for proteins
study of mRNA
study of totality of proteins. harder to study. Mass spectrometry used to analyse proteins in large quantity
with mass spectrometry , can quantify metabolites in a sample
Study of genomes creates difficulty with analysis = bioinformatics created to analyse and interpret LARGE biological datasets
Personalised medicine- if can take persons DNA and analyse and determine response to certain diet / treatment, can have personalised treatment
Nutrigenetics: how specific genetic makeup of person influences response to diet , considering underlying genetic polymorphisms e.g. PKU (gene to nutrient interactions)
Nutrigenomics- study of genome-wide influences of nutrition / impact of nutrients on gene expression (general nutrition advice based on mechanistic understanding
difference between the 2 debated
Types of personalised nutrition- pharmacogenomics (px of drugs depending on persons genome), nutrigenomics (nutrigenetics- px of nutrition based on individuals genome)
Personalised nutrition- can be achieved with info not JUST ON GENETICS but molecular phenotype, lifestyle, life stage, health status, etc.