Discovery offers hope for osteoarthritis sufferers

A University of Auckland scientist has uncovered a key difference in how men and women’s cells respond to osteoarthritis – a discovery that could pave the way for more effective, personalised treatments.

Osteoarthritis is a common joint condition where the cushioning between bones, called 'cartilage', wears down over time, leading to pain, stiffness, and difficulty moving. There's no cure as yet, but exercise, medication, and lifestyle changes can help manage symptoms.

Dr Raewyn Poulsen, a pharmacology researcher at Waipapa Taumata Rau, has received $1.2 million in Health Research Council funding to build on her findings and explore potential drug therapies.

Osteoarthritis affects around 670,000 New Zealanders, with women disproportionately impacted. Yet, no drug treatments currently exist.

“Menopause is often blamed, but the literature doesn’t make sense to me,” says Poulsen. “I think we tend to pin everything on menopause when it comes to women’s health.

“The prevalence of osteoarthritis is already higher in women than men from the age of 30 years, so that indicates we can’t pin this all on menopause.”

One challenge is that, in the past, preclinical testing has relied heavily on mice and rats, and female rodents rarely develop osteoarthritis.

Poulsen’s team analyses cartilage from consenting human joint-replacement patients.

They have found that men and women’s cells respond to joint stress in fundamentally different ways. While male cells focus on renewing tissue, female cells adopt a protective strategy.

“What we have found is that males are really good at renewing tissue, whereas females are much more defensive and try to preserve what they have already got.”

“If you push women’s cells to regenerate tissue, they struggle – but they’re good at preserving it. So, we need treatments that work with those natural tendencies,” Poulsen says.

“We hope to find out what is driving the disease in men and women and to come up with candidate drug treatments,” Poulsen says.

Poulsen says humans are complex and cellular differences may be too, but male and female gender is a useful place to start.

Her research will also examine bone tissue, as osteoarthritis affects the entire joint. She’s collaborating with orthopaedic surgeons, rheumatologists and other clinicians, and hopes to eventually work with medicinal chemists to develop new drugs or repurpose existing ones.

“We want to understand what drives the disease in men and women – and use that knowledge to design targeted therapies.”