Cartilage and the Chondrocyte: Proteoglycans

Question 1

Why does muscle wasting occur in arthritis?

Answer 1

• Fibrilations of cartilage cause effusion
• Fibrous capsule in synovial joint has stretch receptors
• Arthritic effusions stimulate stretch receptors
• Cause reflex muscle inhibition
• Wasting

Question 2

What are environmental risks for osteoarthritis?

Answer 2

Obesity, biomechanics (prev injury) and meniscetomy

Question 3

What are genetic risk factors for osteoarthritis

Answer 3

Female + family history

Question 4

What are catabolic regulatory factors in cartilage that are released in inflammation?

Answer 4

IL-1, 17, 18

TNF

Question 5

What broken down molecules stimulate the TLR4 receptor?

Answer 5

Fibronectin, hyaluronan, Tenascin-C

Question 6

What broken down substance stimulates DDR2 receptors?

Answer 6

Collagens

Question 7

What kind of proteins/receptors does fibromodulin stimulate?

Answer 7

Complement

Question 8

What drugs can act centrally to treat OA pain?

Answer 8

Duloxetine

Opiates

Amitriptyline

Question 9

How can we directly treat the joint for OA pain?

Answer 9

• effusion - aspiration, corticosteroids
• capsaicin
• hylauronic acid
• synovium - NSAIDs, corticosteroids

All help to alleviate symptoms

Question 10

What growth factors can be potentially used for cartilage structure modification?

Answer 10

FGF-18 (in trials), act as an anabolic agent - for cartilage repair

Question 11

Can we use chondroitin sulfate for cartilage structure modification in OA?

Answer 11

No - but large clinical trials, used for good improvement in pain, if it doesn’t cause any harm then ok to buy them.