mmp

Home / Modules / MMP

MMP

Matrix metalloproteinase dynamics mediating extracellular matrix remodeling during wound healing.

Biology

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that degrade extracellular matrix components. During wound healing, M1 macrophages produce MMP-9 (gelatinase B) for debris clearance, while fibroblasts produce MMP-1 (interstitial collagenase) and MMP-3 (stromelysin) for ECM remodeling. MMPs degrade collagen, fibronectin, dermis, and elastin. Tissue inhibitors of metalloproteinases (TIMPs) provide natural negative regulation.

In diabetic wounds, MMP production is elevated 3-fold while TIMP-mediated decay is halved, creating an MMP/TIMP imbalance that prevents collagen accumulation and impairs wound healing (Lobmann et al. 2002).

Model

MMP PDE with diffusion 0.02 and TIMP-mediated decay 0.02.

Sources: M1 macrophages produce MMP-9 at m1_rate per step; fibroblasts produce MMP-1/3 at fibroblast_rate per step.

Degradation targets (applied in FusedWoundSourceOp):

• Collagen: collagen -= collagen_degradation * local_mmp per step
• Fibronectin: fibronectin -= fibronectin_degradation * local_mmp per step
• Dermis: dermis -= dermis_mmp_degradation * local_mmp per step (from dermis module)
• Elastin: elastin -= elastin_mmp_degradation * local_mmp per step (from elastin module)

Parameters

From modules/mmp/config.toml:

Parameter	Default	Units	Description	Source
enabled	true	bool	Master switch	Convention
diffusion	0.02	-	MMP diffusion coefficient	Nagase et al. 1999 (DOI)
decay	0.02	per step	TIMP-mediated inactivation	Calibrated
m1_rate	0.003	per step	MMP-9 per M1 macrophage	Lobmann et al. 2002 (DOI)
fibroblast_rate	0.001	per step	MMP-1/3 per fibroblast	Nagase et al. 1999
collagen_degradation	0.002	per step	MMP-mediated collagen lysis	Ladwig et al. 2002 (DOI)
fibronectin_degradation	0.002	per step	MMP-mediated fibronectin lysis	Calibrated

Coupling

Reads

Field	Source module	How used
(none)	-	MMP is written by agents, not read from other fields

Writes

Field	Consumer modules	What is written
MMP	collagen (degradation), fibronectin (degradation), dermis (degradation), elastin (degradation)	MMP concentration from immune and fibroblast agents

Validation

Dataset	Observable	Sources	Notes
mmp_ecm_remodeling	MMP levels, collagen/fibronectin degradation	Lobmann 2002, Nagase 1999, Ladwig 2002	Parameter derivation and diabetic imbalance

Literature data

Reference curves for validation (full citations in SOURCES.yaml):

Dataset	File	Normalization
MMP kinetics	mmp_kinetics.csv	Peak = 1.0

Metrics

Column	Units	Description
mean_mmp_wound	a.u.	Mean MMP in wound

Source files

File	Purpose
mmp_pde.h	MMP diffusion field with TIMP decay
config.toml	Module configuration