Somatic Cell Reprogramming via Nuclear Remodeling and Cytoplasmic Transfer
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Solution Overview
Problem
Current methods for reprogramming somatic cells to a pluripotent state are inefficient, particularly due to limitations in accessing sufficient human oocytes and the inefficiency of cross-species nuclear transfer, leading to incomplete reprogramming and challenges in producing viable, expandable stem cells for therapeutic use.
Innovation Solution
A three-step process involving nuclear remodeling to replace somatic cell nuclear envelope components with those of undifferentiated cells, followed by transfer into undifferentiated cytoplasm, and subsequent characterization for quality control, using cell-free extracts from embryonic stem cells or germ cells to enhance reprogramming efficiency and telomerase reactivation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If cross-species nuclear transfer is used to reprogram somatic cells, then the availability of human oocytes is reduced, but the reprogramming efficiency decreases and complete reprogramming becomes difficult to achieve
Solution Approach 1:
The patent segments the reprogramming process into two distinct steps: (1) nuclear remodeling where the nuclear envelope is replaced with one from undifferentiated cells, and (2) cytoplasmic transfer where the remodeled nucleus is transferred to undifferentiated cytoplasm. This segmentation allows each step to be optimized independently, achieving both high efficiency and completeness of reprogramming without requiring human oocytes.
Solution Approach 2:
The patent introduces an intermediary nuclear remodeling step using cell-free extracts from undifferentiated cells before the final cytoplasmic transfer. This intermediary process prepares the nucleus by replacing its envelope with undifferentiated cell components, making it more receptive to reprogramming and enabling complete reprogramming without human oocytes.
2Reliability
If traditional nuclear transfer methods are used, then reprogramming can occur, but the process is inefficient and produces incomplete reprogramming
Solution Approach 1:
The patent performs preliminary nuclear remodeling before cytoplasmic transfer, where the nuclear envelope is replaced with one from undifferentiated cells using cell-free extracts. This preliminary action prepares the nucleus in advance, ensuring that when the nucleus is transferred to undifferentiated cytoplasm, reprogramming occurs efficiently and completely.
Solution Approach 2:
The patent changes the composition parameters of the nuclear envelope by replacing somatic cell envelope proteins with those from undifferentiated cells. This parameter change in nuclear envelope composition is crucial for enabling complete reprogramming and improving reprogramming efficiency.
3Reliability
If human oocytes are used for nuclear transfer, then reprogramming efficiency can be maintained, but the scalability and therapeutic applicability are limited
Solution Approach 1:
The patent replaces expensive and scarce human oocytes with readily available undifferentiated cell lines that can be easily cultured and expanded. The cell-free extracts from these undifferentiated cells serve as a disposable reagent system that can be produced in large quantities, enabling scalable reprogramming for therapeutic applications.
Solution Approach 2:
The patent uses undifferentiated cell lines that can serve multiple functions: providing nuclear envelope components for remodeling, providing cytoplasm for transfer, and serving as a renewable source for large-scale reprogramming. This universality enables both high efficiency and scalability.
Data Source
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AI summary
This invention generally relates to methods to obtain mammalian cells and tissues with patterns of gene expression similar to that of a developing mammalian embryo or fetus, and the use of such cells and tissues in the treatment of human disease and age-related conditions. More particularly, the invention relates to methods for identifying, expanding in culture, and formulating mammalian pluripotent stem cells and differentiated cells that differ from cells in the adult human in their pattern of gene expression, and therefore offer unique characteristics that provide novel therapeutic strategies in the treatment of degenerative disease.