Table 1

Therapeutic strategies to augment cell-based cartilage repair

Impairment

Pathomechanism

Therapeutic strategy

References


Differentiation insufficiencies

Un- or dedifferentiated cells

Timed growth factor release systems/gene delivery

TGF-β superfamily members

[76,85,88,134]

FGFs

[131]

SOX/Smads

[119-121,124-126]

Cell selection

Growth factor selection

[52-54,64]

Immunophenotype selection

[41,46]

Hypertrophic differentiation

Inhibition of hypertrophy

BMP inhibitors: noggin, chordin, siRNAs

[89,90,160]

PTHrP/IHH

[81,91-95]

Wnt5a

[29,103,163]

No dexamethasone

[75]

Osteogenesis

Inhibition of osteogenesis

BMP inhibitors (noggin, chordin), siRNAs

[89,90,160]

Establishment of a barrier/tidemark to bone

[49,198]

Senescence

Senescence protection

Age

Low oxygen tension

[107,110]

Telomere erosion

Use of telomerized cells

[117]

Oxidative damage

Anti-oxidative selenoproteins, superoxide dismutase

[115,117,118,151,187]

Chemical stress

Anti-inflammatory agents (IL-1Ra, sIL-1R, sTNFR)

[132,185-188,190,191,193-195]

Mechanical stress

Mechanoprotection

[157,168,169]

Cell loss

Inefficient cell delivery

Guided, homogeneous cell delivery

[2,48]

Apoptosis (NO induced, stress)

Anti-apoptotic measures

Bcl-2, Bcl-XL, anti-FasL

[151,161,162,164]

Anti-inflammatory agents (see also above)

[132,185-188,190,191,193-195]

Anti-oxidative agents

[115,117,118,151,187]

Necrosis

Necrosis

Age

Surgical protection (no needle stitches, no unnecessary harm to cartilage lesion borders)

[2,48]

Mechanical stress

Mechanoprotection

[2,48;168,169]

Chemical stress

Anti-inflammatory agents

[132,185-188,190,191,193-195]

Oxidative stress

Anti-oxidative agents

[115,117,118,151,187]

Matrix degradation

Matrix degradation

Delivery of matrix components

[197]

Inflammation

Anti-inflammatory agents (IL-1Ra, sIL-1R, ICE inhibitor, sTNFR, anti-TNF-antibodies, TACE inhibitor, TIMP-1, -2, MMP inhibitors, IL-4, -10, -11, -13, GFAT)

[132,185-188,190,191,193-195]

Mechanical stress (shear stresses, compressive forces)

Mechanoprotection

No trauma

[2,48;168,169]

Avoidance of non-physiological loads

[1,2,8,9,12,20]

Establishment of correct knee axis and stability

[1,2,8,9,12,20]

Antioxidants

[115,117,118,151,187]

Integration

Cartilage to cartilage

Cartilage matrix crosslinks

[20,49,200-202]

Cartilage to bone

Tidemark formation

[49,198]

Stimulation of cell migration

[27,29,66]

Chondroblasts above tidemark

Osteoblasts below tidemark


BMP, bone morphogenetic protein; FasL, Fas-Ligand; FGF, fibroblast growth factor; GFAT, fructose-6-phosphatase amido transferase; ICE, IL-1 converting enzyme; IHH, indian hedgehog; IL, interleukin; IL-1Ra, IL-1 receptor antagonist; MMP, matrix metalloproteinase; NO, nitric oxide; PTHrP, parathyroid hormone related peptide; sIL-1R, soluble IL-1 receptor; siRNA, small interfering RNA; SOX, SRY (sex determining region Y)-box; sTNFR, soluble TNF receptor; TACE, TNF-alpha converting enzyme; TGF, transforming growth factor; TIMP, tissue inhibitor of matrix metalloproteinases; TNF, tumor necrosis factor.

Steinert et al. Arthritis Research & Therapy 2007 9:213   doi:10.1186/ar2195