New Advances in Regenerative Medicine
Imagine living in a world without Alzheimer’s disease. That reality seems closer than ever, as scientists at Cedars Sinai successfully reversed memory decline and Alzheimer’s disease symptoms in aging mice using regenerative medicine!
Regenerative medicine is a field that seeks to repair damaged cells with stem cells (i.e., unspecialized cells capable of self-renewal and giving rise to other cells). Stem cells’ relationship with neurodegenerative diseases is highly intriguing to scientists, as it is believed that these cells can improve cognitive function by regenerating neurons and reducing neuroinflammation.
Experiment Layout and Findings
In their experiment, researchers used lab-grown, human-induced pluripotent stem cells to create “young” immune cells that they infused into the mice. Simply put, they reprogrammed adult cells into early embryonic-like stem cells. These stem cells are differentiated into “mononuclear phagocytes,” a type of immune cell responsible for engulfing and destroying bacteria and viruses that enter our bodies. In younger populations, these cells are normally circulating throughout the body. However, as we age, their function diminishes, meaning we have a harder time clearing our bodies of debris and inflammation.
The experiment revealed that the aged mice displayed improvements in their memory and Alzheimer’s disease symptoms, as their neuronal cells’ health and function were rejuvenated following treatment. In fact, the treated mice outperformed the untreated mice on memory tests.
Furthermore, mice receiving the young mononuclear phagocytes displayed more “mossy cells” in their hippocampus, which are cells involved in memory sequencing and regulating adult neurogenesis (i.e., production of neurons). This finding is crucial because, just like mononuclear phagocytes, mossy cells decline with age.
Lastly, scientists also noted how their treated mice had healthier microglia cells, which are immune cells responsible for maintaining the brain’s normal functioning and clearing out waste. Microglia cells do this through the extension of their branches, which are used to detect and remove harmful substances that enter the body. However, similar to mononuclear phagocytes and mossy cells, microglia cells’ function worsens over time, as their branches shrink.
These results prove to be quite monumental, as they challenge the common pathways these cells undergo with age. Most importantly, such findings lend themselves to future stem-cell-based anti-aging therapies that seek to treat neurodegenerative diseases, which are currently incurable.
Study’s Significance
Scientists are still not entirely sure how these young mononuclear phagocytes impact the brain because they do not cross the brain barrier. Until they know for sure, researchers are continuing to perform studies to understand this relationship to implement their results into anti-aging therapies for humans. According to Dr. Jeffrey A. Golden, who is the executive vice dean for Education and Research at Cedars Sinai, the study’s findings are important, ‘“Because these young immune cells are created from stem cells {and} they could be used as personalized therapy with unlimited availability.”’
Despite the uncertainties of this study, it is still revolutionary, as it brings new insights into the neurodegenerative sphere and suggests that we may be getting closer to finding a cure for Alzheimer’s disease one day. Such research efforts are inspiring, as they bring hope to those experiencing Alzheimer’s disease and their loved ones.
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