The hormone replacement therapy that most women take to offset the loss of estrogen in their late 40s and 50s is not advised long-term, since it increases the risk of heart disease and breast cancer.
Menopausal women could get lab-grown ovaries instead of hormone drugs to treat the debilitating symptoms without raising their risk of deadly diseases.New research in rats found bioengineering artificial ovaries could provide a safer and more natural hormone replacement therapy for women.
Now, a team from Wake Forest Institute for Regenerative Medicine in North Carolina has found that the engineered ovaries were more effective than hormone therapy drugs at improving bone and uterine health and body composition.
New research in rats by Wake Forest in North Carolina found bioengineering artificial ovaries could provide a safer and more natural hormone replacement therapy for women
‘The treatment is designed to secrete hormones in a natural way based on the body’s needs, rather than the patient taking a specific dose of drugs each day,’ said senior author Dr Emmanuel C Opara, a professor of regenerative medicine at the institute.
The cell-based system of hormone replacement is an attractive alternative to drugs. It can match the dose with the body’s needs and it is consistent with current guidelines in the US and Europe recommending the lowest possible doses of hormone replacement therapy.
WHY WOMEN TAKE HRT
Menopause, which commonly strikes women in their late 40s and early 50s, can cause depression, hot flushes, headaches and night sweats. Long term, it can also cause bone disease and memory loss.
HRT tackles these symptoms by replacing the female sex hormones – oestrogen and progestogen – as the body stops producing them. But while it can transform the lives of many women, it also raises the risk of cancer, meaning a small number will develop the disease who would otherwise not have.
To engineer the bioartificial ovary, the research team isolated the two types of cells found in ovaries (theca and granulosa) from rats. They used a thin membrane as a capsule for the cells, which was then implanted in rats that had their ovaries removed.
These rats were compared with animals with normal ovarian function, untreated rats and rats who received either a low- or high-dose of traditional hormone replacement drugs. The study looked at three areas commonly affected by the loss of ovarian function: body composition, bone health and uterine health. It is well known that loss of ovarian function leads to body fat accumulation and weight gain.
The study found that the cell-based constructs led to a substantially lower percentage of body fat levels than low-dose drug therapy and had the same results as animals with intact ovaries. Estrogen deficiency can also lead to osteoporosis and related fractures. In the rat study, the cell treatment led to better bone outcomes than the traditional hormone replacement drugs.
The loss of ovarian function is also known to have adverse effects on the genital and urinary system, including sexual dysfunction and urinary incontinence. The researchers evaluated uterine tissue in study animals and found that uterine health in the cell-treated animals was similar to the animals with intact ovaries.
‘Safe hormone replacement will likely become increasingly important as the population of aging women grows,’ said Dr Opara.
‘Whether the loss of ovarian function is due to surgical removal, chemotherapy or menopause, the effects can range from hot flashes and vaginal dryness to infertility and increased risk of osteoporosis and heart disease.
‘This study highlights the potential utility of cell-based hormone therapy for the treatment of conditions associated with the loss of ovarian function.’
The team now needs to determine that the treatment is effective in women.
One of the key issues will be to ascertain whether donor cells are a safe option, since women who need hormone therapy are unlikely to have enough ovarian cells for transplantation.
The capsule was designed to allow oxygen and nutrients to enter the capsule, but to prevent the patient from rejecting the cells. Allowing functional ovarian tissue from donors could to be used to engineer bioartificial ovaries for women with non-functioning ovaries.