Myeloid-Specific MMP12 Mouse Model for Lung Cancer Research
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current models fail to adequately understand the tissue-specific role of zinc-dependent matrix metalloproteinases (MMPs) in human and animal pathology, particularly in relation to tumorigenesis and inflammation, which is crucial for developing effective therapies for conditions like lung cancer.
Innovation Solution
A myeloid-specific c-fms-rtTA/(TetO)7-CMV-MMP12 bitransgenic mouse model is created to study the function of MMP12, where the MMP12 gene is specifically induced in myeloid lineage cells, allowing for the examination of its role in inflammation, immune suppression, and tumorigenesis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current models are used to study MMPs, then general understanding of MMP function is maintained, but tissue-specific role of MMPs in pathology cannot be adequately understood
Solution Approach 1:
The patent creates a mouse model with myeloid-specific MMP12 overexpression using the c-fms promoter to drive MMP12 expression specifically in myeloid lineage cells. This local quality approach allows precise study of MMP12 function in myeloid cells while maintaining normal MMP expression in other tissues, thereby resolving the contradiction between tissue-specific understanding and general applicability.
2Productivity
If MMP12 is over-expressed systemically, then the role of MMP12 in inflammation and tumorigenesis can be studied, but tissue-specific function of MMP12 cannot be determined
Solution Approach 1:
The patent segments MMP12 expression to occur only in myeloid lineage cells through the use of the c-fms promoter and rtTA/TetO7-inducible system. This segmentation allows high productivity in studying MMP12 function in relevant cell types while maintaining specificity, avoiding the contradiction between research output and expression specificity.
3Measurement precision
If a myeloid-specific inducible model is created, then tissue-specific role of MMP12 is clarified, but the model complexity increases
Solution Approach 1:
The patent uses an intermediary inducible system (rtTA/TetO7) that mediates between the c-fms promoter and MMP12 expression. This intermediary allows precise control of MMP12 expression in myeloid cells through doxycycline administration, achieving high measurement precision while managing model complexity through a well-established inducible system.
Data Source
AI summary
A myeloid-specific c-fms-rtTA/(TetO)7-CMV-MMP12 bitransgenic mouse model was created. Induction of MMP12 abnormally elevated frequencies and numbers of common myeloid progenitor (CMP) and granulocyte/macrophage progenitor (GMP) populations, and decreased the frequency and number of the megakaryocyte/erythrocyte progenitor (MEP) population in bone marrow. CD11b+/Gr-1+ immature cell population increased in multiple organs. An immunosuppressive function on T cell proliferation and function by CD11b+/Gr-1+ immature cells was seen in vitro and in vivo from MMP12 over-expression. MMP12 stimulated (Lin−) progenitor cells to differentiate into CD11b+/Gr-1+ immature cells showing immunosuppression on T cell proliferation and function in vitro. Regulatory T cells were increased. In the lung, concentration of interleukin (IL)-6 was increased, which activated oncogenic signal transducer and increased expression of Stat3 downstream genes in epithelial tumor progenitor cells. Spontaneous emphysema and lung adenocarcinoma sequentially developed after MMP12 over-expression. MMP12-induced myeloid cell autonomous defect led to abnormal myelopoiesis, immune suppression and lung adenocarcinoma.