iPSC Reprogramming with Ascorbic Acid and Hypoxia
Solution Overview
Problem
Current methods for obtaining induced pluripotent stem cells (iPSCs) often result in aberrant hypermethylation at imprinted loci, leading to loss of imprinting and instability, which hinders the development of accurate cellular models for studying imprinting disorders and testing therapies.
Innovation Solution
A method involving the culture of peripheral blood mononuclear cells (PBMCs) in a specific sequence of media and conditions, including transduction with Yamanaka factors, hypoxic conditions, and the addition of ascorbic acid, to maintain balanced methylation at imprinted loci and ensure stable iPSC generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional reprogramming methods are used to obtain iPSCs, then iPSC generation is achieved, but aberrant hypermethylation at imprinted loci occurs leading to loss of imprinting and instability
Solution Approach 1:
The invention changes the chemical parameters of the culture medium by adding ascorbic acid (vitamin C) at concentrations of 50-150 μg/mL, and modifies physical parameters by culturing cells under hypoxic conditions (1-5% oxygen). These parameter changes prevent aberrant hypermethylation at imprinted loci during reprogramming, thereby maintaining imprinting stability and methylation balance in the generated iPSCs
Solution Approach 2:
Ascorbic acid acts as a chemical intermediary that modulates the reprogramming process. It interferes with the aberrant methylation mechanism by donating electrons and reducing methyl groups, thereby preventing hypermethylation at imprinted loci without interfering with the core reprogramming function of Yamanaka factors
2Productivity
If standard culture conditions are used during iPSC reprogramming, then reprogramming efficiency is maintained, but loss of imprinting occurs through hypermethylation of paternally methylated ICRs
Solution Approach 1:
The invention modifies culture conditions by implementing hypoxia (1-5% oxygen atmosphere) and adding ascorbic acid to the culture medium. These parameter changes create an environment that simultaneously maintains high reprogramming efficiency while preventing hypermethylation of paternally methylated ICRs, thus preserving imprinting during the reprogramming process
3Ease of manufacture
If iPSCs are cultured without ascorbic acid and hypoxia, then culture simplicity is maintained, but epigenetic modifications including aberrant hypermethylation occur
Solution Approach 1:
The invention introduces two relatively simple modifications to standard culture protocols: adding ascorbic acid to the culture medium and maintaining hypoxic conditions. These changes are easy to implement but effectively prevent aberrant epigenetic modifications including hypermethylation, thereby maintaining epigenetic stability without significantly complicating the culture process
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 yields iPSCs with stable phenotype and genotype, balanced methylation, and preserved pluripotency, enabling the creation of reliable cellular models for studying imprinting disorders and testing therapeutic strategies.
Implementation Method 1
maintain balanced methylation at imprinted loci
Implementation Method 2
culture of the transduced or transformed cells obtained in step b) in hypoxic conditions
Data Source
Figure 1a~2
Figure 3
Figure 4A~4F
AI summary
The invention relates to a method for obtaining Induced pluripotent stem cells (iPSC) and to a kit for implementing the method for obtaining Induced pluripotent stem cells (iPSC). The present invention finds applications in the biological research field, and diagnostic medical technical fields and also in veterinary technical fields.