Table 1 Overview of mouse studies with altered expression of Smad7

Zygote

Overexpression

The embryos do not develop beyond 2-cell stage

Inhibiting TGF-β and BMP signaling

none

[14]

Lung

Overexpression

Anti-fibrosis, anti-inflammation, tumorigenic, involved in lung branching morphogenesis and epithelial differentiation

Blocking synthesis of ECM, preventing NFκB activation and inhibiting EMT

Lung fibrosis, neonatal hyperoxia, allergic asthma and lung cancer

[15, 26, 52]

Eyes

Over-expression

Anti-fibrosis, anti-inflammation, and improving healing from chemical burn injury

Blocking EMT and accelerating healing after injury

Retinal pigment fibrosis

[30, 58, 59]

Skin

Overexpression

Shifting skin differentiation from hair follicles to sebaceous glands, accelerating squamous cell carcinogenesis, tumorigenic, anti-inflammation

Suppressing Wnt/β-catenin signaling, inducing EGF-like growth factors expression, blocking NFκB signaling

Scleroderma, skin cancer, inflammation

[16, 36, 49, 56]

Liver

Overexpression

Knockout

Anti-fibrosis, anti-inflammation, inhibiting EMT and apoptosis, reducing alcoholic liver injury

Blocking ECM production, anti-oxidative stress, activating ADH1, suppressing alcoholic steatosis

Liver fibrosis, cirrhosis, alcoholic fatty liver

[32, 33, 39]

Pancreas

Overexpression

Abolishing β-cell differentiation in embryo, inhibiting insulin secretion in adults, anti-fibrosis, inducing early tumorigenesis

Inhibiting TGF-β signaling, pro-proliferative

Pancreatic fibrosis, pancreatitis, pancreatic cancer, diabetes

[29, 50, 57]

Kidney

Overexpression

Knockout

Anti-fibrosis, anti-inflammation, protecting against diabetic injury

Reducing ECM accumulation, blocking NFκB signaling

Nephritis, kidney fibrosis, diabetic kidney injury

[27, 28, 37, 38]

Colon

Overexpression

Knockdown

Enhancing inflammatory reaction, increasing cancer metastasis

CD4+ T cell overactivation and resistance to regulatory T cell, reduced growth inhibition and apoptosis

IBD, colitis, colorectal cancer

[42, 51]

CNS

Overexpression

Knockdown

Pro-inflammatory, craniofacial and cardiac defects

Promoting T cell activation, blocking Wnt, BMP and TGF-β signaling

Autoimmune encephalomyelitis, craniofacial defects

[18, 44]

Immune cells

Overexpression

Knockout

Involved in proliferation of T cell and B cell response to antigen stimulation, pro-inflammatory, tumor suppression

Involved in immune cell maturation, proliferation and activation

Allergic asthma, autoimmune disorder, colitis, colon cancer

[19, 40, 41, 45, 55]

Bone

Overexpression

Inhibiting chondrocyte differentiation

Down-regulating p38 MAPK pathway

Joint disease and repair

[17]

Systemic

Knockout

Important for early heart development and B cell function

Apoptosis, inhibiting TGF-β signaling

Congenital heart defects

[19, 20]