Methods and compositions for diagnosing and treating arthritic disorders and regulating bone mass

A method of determining the suitability of an agent for altering mitochondrial function in a chondrocyte, comprising:

• comparing the rate of mitochondrial ATP synthesis in a biological sample obtained from a subject before and after administering to said subject a candidate agent, wherein the biological sample comprises a chondrocyte, and wherein an altered rate of mitochondrial ATP synthesis indicates that the agent alters mitochondrial function;
• and therefrom determining the suitability of said candidate agent for altering mitochondrial function in a chondrocyte.

A method of identifying an agent suitable for altering mitochondrial function in a chondrocyte, comprising:

• comparing, in the absence and presence of transforming growth factor-beta, the rate of ATP synthesis in one or more biological samples obtained from a subject in the presence and absence of a candidate agent, wherein the biological sample comprises an articular chondrocyte, and wherein an altered rate of ATP synthesis indicates that the agent alters mitochondrial function;
• and therefrom determining the suitability of said candidate agent for altering mitochondrial function in a chondrocyte.

A method of determining the suitability of an agent for altering mitochondrial function in a chondrocyte, comprising:

• comparing, in the absence and presence of transforming growth factor-beta, the rate of ATP synthesis in a biological sample obtained from a subject before and after administering to said subject a candidate agent, wherein the biological sample comprises an articular chondrocyte, and wherein an altered rate of ATP synthesis indicates that the agent alters mitochondrial function;
• and therefrom determining the suitability of said candidate agent for altering mitochondrial function in a chondrocyte.