Premature ovarian failure (POF) or primary ovarian insufficiency is a condition characterized by loss of normal ovarian function before age 40. POF causes low levels of the hormone estrogen and irregular ovulation (release of eggs). POF causes infertility.
Some medical professional call POF premature menopause, even though these two conditions are not exactly the same. Women with POF may have irregular or occasional menstrual cycles for years and may even become pregnant. However, women with premature menopause cease having periods and can’t become pregnant.
The symptoms of POF are similar to those of menopause: irregular or skipped periods (amenorrhea), which may be present for years or may develop after a pregnancy or after stopping birth control pills; hot flashes, night sweats, vaginal dryness, irritability or difficulty concentrating, and decreased sexual desire.
In women with POF, infertility is very hard to treat, but restoring estrogen levels can avert many of the complications.
There are several causes of POF. Particular chromosomal defects such as Turner’s syndrome, in which a woman has only one X chromosome instead of the usual two, and fragile X syndrome, a major cause of intellectual disability can cause POF. Likewise, exposure to various toxins can also cause POF. Chemotherapy and radiation therapy are probably the most common causes of toxin-induced POF. Other toxins such as cigarette smoke, industrial chemicals, pesticides and viruses may also hasten POF. If the immune system mounts an immune response to ovarian tissue (autoimmune disease), then it might produce antibodies against the woman’s own ovarian tissue. Such antibodies will harm the egg-containing follicles and damage the egg. What triggers the immune response is unclear, but exposure to certain viruses is one possibility. Also various sundry unknown factors may also contribute to it.
There are no treatments for POF that restore the ovaries. For this reason a recent paper in the journal Stem Cells and Development represents a great advance in POF treatment.
Te Liu from the Shanghai Institute of Chinese Medicine and colleagues have used stem cells isolated from human menstrual blood to treat toxin-induced POF in mice.
Human endometrial stem cells exhibit stem cell properties in culture. These human endometrial stem cells are easily isolated from human menstrual blood. Other laboratories have even used them to treat heart conditions in clinical trials.
In this present study, Liu and colleagues treated female mice with the anti-cancer/anti-organ rejection drug cyclophosphamide. This drug pushed the mice into POF. Then one group of mice had human menstrual stem cells injected into their ovaries whereas another group received an injection of phosphate-buffered saline.
After 14 days, ovaries from those mice injected with human menstrual stem cells expressed higher levels of ovarian-specific proteins. Also, the blood levels of estrogen of the stem cell-injected mice were also higher. Postmortem examination also showed that the average ovarian weight of the stem cell-injected mice was much higher, as was the number of normal follicles. Follicles contain eggs surrounded with follicle cells and their absence is indicative of an ovary from a woman who is in menopause. That fact that the stem cell-treated POF mice had normal follicles and more of them suggests that the injected stem cells beefed up the supply of existing eggs and helped them survive and flourish.
These results suggest that these human menstrual stem cells, which are derived from the endometrium, can survive when introduced into a living organism and promote the regeneration of ovaries. There is no evidence that these cells differentiate into eggs, but instead they probably create an environment where the existing moribund eggs are rejuvenated and revitalized. This treatment for POF might be a viable option for human patients; all without destroying human embryos.