HMOX1-Reporter Cell Model for Skin Sensitization Evaluation
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Solution Overview
Problem
Current in vitro methods for evaluating skin sensitization, such as reporter cell models, indirectly reflect target gene expression and are unable to quantify sensitization strength, limiting their accuracy and sensitivity in distinguishing sensitizing compounds from non-sensitizing ones.
Innovation Solution
A cell model is constructed by targeting a reporter gene into the HMOX1 gene using CRISPR/CAS9, allowing for real-time expression of the luciferase gene with the HMOX1 gene, enabling more accurate evaluation of skin sensitization reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reporter gene is randomly inserted into a transgenic cell model, then the model can indirectly evaluate target gene expression through luciferase expression, but it cannot simultaneously track endogenous gene expression and quantify sensitization strength
Solution Approach 1:
The patent creates a copy of the endogenous HMOX1 gene's regulatory elements (promoter and enhancer) and links them to a reporter gene (luciferase or GFP). This copied regulatory sequence drives reporter expression that mirrors endogenous HMOX1 expression patterns, enabling accurate tracking of sensitization responses without disrupting the original gene's function
Solution Approach 2:
The reporter gene acts as an intermediary that translates endogenous HMOX1 gene expression into measurable signals. The regulatory elements of HMOX1 serve as mediators that connect the endogenous gene's transcriptional activity to the reporter gene's expression, allowing indirect measurement of sensitization strength while maintaining quantitative accuracy
2Reliability
If animal experiments are used for skin sensitization evaluation, then comprehensive in vivo responses can be observed, but animal welfare concerns and species differences from human responses arise
Solution Approach 1:
The patent employs in vitro cell-based assays that use cultured human keratinocytes or dendritic cells as disposable test systems. These cell models can be repeatedly used, cryopreserved, and discarded after testing, eliminating the need for living animals while maintaining human-relevant biological responses through the use of human-derived cells
Solution Approach 2:
The patent replaces the complex in vivo animal system with a simplified in vitro cell culture system. The mechanical and physiological complexity of whole animals is substituted with controlled cell cultures that specifically measure the relevant immunological endpoints (IL-8, IL-6, CCL20) through reporter gene expression, removing the need for animal subjects while preserving human-specific response mechanisms
3Measurement precision
If conventional reporter cell models are used, then sensitization evaluation can be performed, but real-time reporter gene expression and quantitative sensitization strength cannot be measured
Solution Approach 1:
The patent employs luciferase and GFP reporter genes that produce measurable optical signals - bioluminescence for luciferase and green fluorescence for GFP. These color/light changes provide real-time, quantitative readouts of reporter gene expression that directly correlate with endogenous HMOX1 activation and sensitization strength, enabling precise measurement without complex operational procedures
Solution Approach 2:
The reporter gene expression provides immediate feedback on endogenous HMOX1 gene activation in response to test compounds. The luciferase or GFP signal intensity directly reflects the level of sensitization-induced gene expression, creating a real-time feedback system that quantifies sensitization strength and enables high-throughput screening with simple detection protocols
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
This approach provides a more specific and sensitive method for differentiating sensitizing compounds, achieving higher accuracy and sensitivity in evaluating skin sensitization by simultaneously expressing the luciferase and HMOX1 genes, thereby enhancing the evaluation of skin sensitization reactions.
Implementation Method 1
allowing for real-time expression of the luciferase gene with the HMOX1 gene, enabling more accurate evaluation of skin sensitization reactions
Data Source
AI summary
A cell model for in vitro evaluation of compound-induced skin sensitization and a constructing method therefor. The method for constructing the cell model comprises the steps of: designing and constructing an sgRNA expression vector based on CRISPR/Cas9 vector system; designing and constructing a homologous recombinant vector capable of knocking a reporter gene linked to a self-cleaving peptide sequence into a specific site of the expression frame of the HMOX1 gene; co-transfecting the homologous recombinant vector, an hCas9 plasmid and the sgRNA expression vector into a cell, and carrying out monoclonal expansion to obtain the cell model. The present invention obtains a HaCaT cell model in which a luciferase gene is knocked in before the stop codon of the HMOX1 gene by combination of CRISPR/CAS9 and a monoclonal cell technique. The cell model realizes synchronous expression of the luciferase gene and the HMOX1 gene, thereby effectively distinguishing sensitizing compounds from non-sensitizing compounds.