TAT-SNX9 Polypeptide Inhibits Smad3 Nuclear Import

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Solution Overview

Problem

Current treatments for fibrotic diseases, such as lung, kidney, and liver fibrosis, are inadequate in effectively reducing disease severity, as they often rely on non-specific methods that do not target the underlying Smad3 signaling pathway responsible for fibrosis.

Innovation Solution

Development of polypeptides, specifically TAT-SNX9(SH3) fusion polypeptides, which include a cell-penetrating amino acid sequence and an SH3 domain of a SNX9 polypeptide, to inhibit Smad3 activities by blocking its nuclear import, and the use of RNA interference using siRNA or shRNA to target SNX9 nucleic acid expression, thereby reducing fibrosis severity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If non-specific treatment methods are used for fibrotic diseases, then treatment coverage is broad, but effectiveness in reducing disease severity is inadequate

Engineering Contradiction:

Improveeffectiveness in reducing disease severityVSAvoidspecificity to Smad3 signaling pathway

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention segments the treatment approach by specifically targeting the Smad3 signaling pathway through polypeptides that bind to Smad3 or components involved in Smad3 nuclear import, rather than using broad non-specific treatments. This segmentation allows for precise inhibition of fibrotic processes mediated by Smad3 while maintaining overall treatment effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces polypeptides as intermediary molecules that specifically interact with Smad3 or its import machinery. These polypeptides act as mediators to block the Smad3 signaling pathway at the nuclear import step, thereby preventing fibrotic gene expression without affecting other cellular processes.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If polypeptides with cell penetrating sequences are used to inhibit Smad3 nuclear import, then Smad3-mediated fibrotic responses are reduced, but polypeptide structure complexity increases

Engineering Contradiction:

Improveinhibition of Smad3-mediated fibrotic responsesVSAvoidpolypeptide structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts only the essential functional elements needed for Smad3 inhibition: a cell-penetrating sequence for cellular uptake and a Smad3-binding domain for specific interaction. By taking out only these critical components rather than using full-length complex proteins, the polypeptide structure is simplified while maintaining therapeutic effectiveness.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention applies local quality by concentrating the inhibitory function in specific localized regions of the polypeptide: the cell-penetrating sequence at the N-terminus for cellular entry and the Smad3-binding domain at specific positions for targeted interaction. This localized functional distribution achieves high efficacy without requiring complex overall structure.

Inventive Principle:

Principle #3Local quality

3Reliability

If RNA interference is used to target SNX9 nucleic acid expression, then fibrosis severity is reduced, but treatment mechanism complexity increases

Engineering Contradiction:

Improvereduction of fibrosis severityVSAvoidtreatment mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces direct protein-protein interaction mechanisms with an RNA-based interference mechanism. Instead of delivering complex polypeptides that must physically bind to and inhibit Smad3, the system uses siRNA to trigger cellular RNA interference pathways that reduce SNX9 protein expression, thereby indirectly inhibiting Smad3 nuclear import through a simpler molecular mechanism.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 polypeptides and RNA interference methods significantly reduce Smad3-mediated fibrotic responses and fibrosis severity by at least 25%, with the polypeptides inhibiting Smad3 nuclear import and RNA interference targeting SNX9 expression to decrease fibrotic gene expression and collagen production, thereby stabilizing lung function and improving histological outcomes.

Implementation Method 1

a cell penetrating amino acid sequence

Methodology Applied

Scientific EffectCell penetration:

Implementation Method 2

an amino acid segment of a SH3 domain of a SNX9 polypeptide

Methodology Applied

Scientific EffectProtein-protein binding:

Implementation Method 3

small interfering RNA (siRNA) or short hairpin RNA (shRNA) can be designed to target SNX9 nucleic acid and trigger RNA interference against SNX9 nucleic acid expression

Methodology Applied

Scientific EffectRNA interference:

Data Source

PatentUS10858654B2Polypeptide inhibitors of SMAD3 polypeptide activities

Publication Date: 2020.12.08 MAYO FOUNDATION FOR MEDICAL EDUCATION & RESEARCH

AI summary

This document provides polypeptide inhibitors of Smad3 polypeptide activities. For example, methods and materials for using polypeptides (e.g., polypeptides designed to include both a cell penetrating amino acid sequence and an amino acid segment of a SH3 domain of a SNX9 polypeptide) to inhibit one or more Smad3 polypeptide activities are provided. This document also provides methods and materials for using RNA interference to treat a disease (e.g., a fibrotic disease) in a mammal (e.g., a human).