Transgenic Mouse Model for Tissue-Specific Thyroid Hormone Assessment
Solution Overview
Problem
Current models for assessing thyroid hormone action in vivo and in vitro are inadequate for tissue-specific and cell-type specific measurements, failing to account for endogenous thyroid hormone receptor isoforms and coregulators, and are unsuitable for evaluating the effects of thyroid hormone analogues and antagonists without causing hazardous side effects.
Innovation Solution
A transgenic mammalian model with a recombinant DNA construct containing thyroid hormone responsive elements, a minimal promoter, and an expression enhancer, which allows for the measurement of thyroid hormone action dependent on endogenously expressed thyroid hormone receptors and coregulators, enabling tissue and cell-type specific assessment of thyroid hormone activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If thyroid hormone treatment is administered to treat obesity and hypercholesterolaemia, then beneficial effects on weight and cholesterol levels are achieved, but unwanted cardiac side effects such as tachycardia occur
Solution Approach 1:
The patent applies local quality by creating tissue-specific thyroid hormone receptor agonists that selectively activate TRβ receptors in peripheral tissues (liver, adipose tissue) while avoiding TRα-rich cardiac tissue. This is achieved through engineered ligands with differential affinity for TR isoforms, allowing beneficial metabolic effects without cardiac stimulation
Solution Approach 2:
The patent segments the thyroid hormone receptor system into distinct isoform-specific pathways by developing selective TRβ agonists. This segmentation allows independent modulation of metabolic functions (via TRβ in liver/adipose) separate from cardiac functions (via TRα in heart), resolving the contradiction between therapeutic benefit and cardiac side effects
2Measurement precision
If current assessment models are used to evaluate thyroid hormone action, then general thyroid hormone effects can be measured, but tissue-specific and cell-type specific measurements cannot be obtained
Solution Approach 1:
The patent implements local quality by developing reporter constructs with tissue-specific promoters (e.g., liver-specific, adipose-specific promoters) that drive expression only in particular tissues. This enables precise measurement of thyroid hormone action in specific tissue compartments while maintaining the ability to assess overall thyroid hormone effects across multiple tissues
Solution Approach 2:
The patent applies universality by creating a modular reporter system that can be configured with different tissue-specific promoters and thyroid hormone responsive elements. This multi-functional platform can assess thyroid hormone action in any tissue of interest by simply changing the promoter component, providing both specific and general assessment capabilities
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The model enables sensitive detection of thyroid hormone action in live animals, tissues, and cultured cells, allowing for the evaluation of thyroid hormone receptor agonists and antagonists, modulators, and transporters, thereby facilitating the beneficial effects of thyroid hormone treatment while avoiding unwanted cardiac symptoms.
Implementation Method 1
Receptors for thyroid hormones (TR) are nuclear DNA-binding proteins that function as hormone-responsive ligand-induced transcription factors. A TR, if present and a TH, if present, forms a complex (TR-TH complex) in said cells; this complex, if present, up-regulates expression of the reporter via the thyroid hormone responsive segment
Data Source
AI summary
A transgenic animal model that is suitable for the cell or tissue specific assessing of thyroid hormone (TH) action in vivo is described. The recombinant DNA construct and methods suitable to generate such an animal are also provided. The assessment of TH action is based on a reporter that is dependent on an endogenously expressed thyroid hormone receptor (TR) and coregulators of said receptor.