Fibroblast Reprogramming to Limb Progenitors via PRDM16 and ZBTB16

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Solution Overview

Problem

Current methods fail to effectively reprogram non-limb fibroblasts into limb progenitor-like cells, lacking the ability to confer the unique properties and patterning capabilities of endogenous limb progenitors.

Innovation Solution

A direct reprogramming approach using a set of factors including PRDM16, ZBTB16, LIN28, and LIN41, delivered via engineered nucleic acids or proteins, transforms non-limb fibroblasts into cells with limb progenitor-like properties, enhancing proliferation and suppressing differentiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional reprogramming methods are used on non-limb fibroblasts, then some cellular transformation occurs, but the cells fail to acquire true limb progenitor properties and patterning capabilities

Engineering Contradiction:

Improvereprogramming efficacyVSAvoidlimb progenitor properties

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The reprogramming process is divided into two distinct phases: first, fibroblasts are reprogrammed into induced pluripotent stem cells (iPSCs) using standard factors; second, limb-specific progenitor properties are induced by introducing limb-specific transcription factors and culturing in limb-mimicking conditions. This segmentation allows each phase to be optimized independently, achieving both reliable reprogramming and authentic limb progenitor characteristics.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by first establishing a pool of iPSCs from fibroblasts before attempting limb progenitor conversion. This preliminary pluripotent state serves as an intermediate platform that makes subsequent limb-specific reprogramming more efficient and reliable, as the cells are already primed for differentiation potential.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If factors are delivered to induce limb progenitor characteristics, then cellular identity changes, but proliferation and differentiation balance is disrupted

Engineering Contradiction:

Improvelimb progenitor characteristicsVSAvoidproliferation and differentiation balance

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent systematically varies multiple parameters including the combination of transcription factors (Tbx5, Tbx4, Lmx1b, Meis1, Meis2), culture conditions (growth factors, extracellular matrix composition), and timing of factor introduction. By optimizing these parameters, the method achieves a balanced state where cells maintain proliferative capacity while expressing limb progenitor markers and retaining differentiation potential.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The reprogramming protocol maintains continuous exposure to limb-specific factors and limb-mimicking culture conditions throughout the differentiation process, ensuring sustained expression of limb progenitor characteristics without interrupting the cellular transformation. This continuous action prevents loss of limb-specific properties while allowing controlled progression through differentiation stages.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS20240093156A1Methods for reprogramming fibroblasts into limb progenitors

Publication Date: 2024.03.21 THE BRIGHAM & WOMEN S HOSPITAL INC

AI summary

The disclosure provides methods and compositions for reprogramming fibroblasts into limb progenitors.