CMDA's The Point

Ample Alternatives to Fetal Failures

February 7, 2022
05182021POINTBLOG

by David Prentice, PhD

Fairy tales and science usually don’t coincide; fairy tales are the stuff of myth and fancy, science of objective fact. Yet the continued push for fetal tissue research is extensively constructed of flimsy fairy tales, with proponents willfully ignoring objective fact in hopes of gaining some taxpayer dollars. The falsehoods about fetal tissue research have been repeatedly debunked by factual evidence, but fetal tissue research advocates continue to apply the Illusory Truth Effect: repeat something often enough, even if false, and people will begin to believe it. Unwilling to let a good crisis go to waste, fetal tissue proponents have even tried to exploit the COVID-19 pandemic, claiming that fetal tissue is essential for study of SARS-CoV-2 infections, making humanized “lung-only mice” using fetal tissue from abortion. Sadly, the unphysiological and anatomically inappropriate mouse model highlights the lengths to which some scientists will go to justify unethical practices. And while the Biden administration in 2021 removed sound ethical reviews and prohibitions on taxpayer-funded fetal tissue research, clinging to this antiquated research holds back modern, productive science. Here is just a small sampling of the scientifically and ethically superior methods and models that should be receiving attention.

Organ(oid) recital can play COVID-19 tune. Adult stem cells have been used to make lung organoids, miniature collections of cells that accurately model normal lungs. The “mini-lungs” even spontaneously assemble into structures that closely resemble alveoli, and they have already been used to study SARS-CoV-2 infection and potential therapies. In fact, organoid technology has proven to faithfully recapitulate the structural and functional properties of multiple adult organs. Numerous different types of organoids have been used to study COVID-19, including lung, liver, kidney, brain, tonsil and bronchial organoids.

Can you hear me now? Hair cell degeneration in the cochlea is a major source of hearing loss, and humans and other mammals do not normally regenerate hair cells, making hearing restoration a difficult proposition. However, a study in mice shows that cochlear organoids formed from adult stem cells can be induced to grow differentiated hair cells. These cochlear organoids also serve to screen drugs that could stimulate hair cell regeneration and potentially restore hearing.

Glandular gains. The thyroid gland maintains systemic metabolic balance and homeostasis, but loss of thyroid function can cause severe problems. Two different groups have now grown three-dimensional thyroid organoids from adult thyroid tissue of mice and humans. The organoids show normal hormone production. The thyroid organoids also show clinically relevant responses in modeling the autoimmune Graves’ disease when exposed to patient sera.

Thoughtful development. Brain organoids have been developed and used as model systems over many years, including in drug discovery for neurological conditions. They have been demonstrated to form the normal cellular diversity found in the human cerebral cortex, and they have even been shown to model some developmental aspects of the postnatal brain. The systems and diverse methods have become ever more complex, including showing formation of choroid plexus organoids that secrete cerebrospinal fluid.

And the beat goes on. Cardiac organoids are also becoming more sophisticated and can be used to model the normal heart and various types of cardiac disease and injury. The self-assembling heart organoids also can be used to study congenital heart defects, as well as the beginnings of heart chamber formation.

Show some guts. Another type of organoid under intensive study is the intestinal organoid. Researchers have now developed a tubular intestinal organoid that shows similar cell types and tissue architecture as the adult intestine, including a lumen, crypts and villi.

Totally tubular. Another tubular organoid that has been developed are fallopian tube organoids. In this case, the iPS cells used to form the organoids were from patients with human BRCA1 mutations, so that the fallopian tube organoids could model early-stage cancer.

Crying. It’s certain that Roy Orbison wasn’t singing about tear gland organoids in his song, but scientists may be crying tears of joy because they were able to create lacrimal gland organoids using adult stem cells. And then they made them cry.

Besides this sampling of organoids, a large number of cell-based therapies and transplants have also been under development. Two brief examples:

Free blind mice. Scientists have also used a technique that skips the stem cell step to create functional retinal cells. The technique, called direct reprogramming, directly alters a cell and changes it from one differentiated character to another. In this case, skin cells were turned into functional retinal cells in the lab, and when transplanted into the eyes of mice that were blind, the new retinal cells restored their sight. In this technique, seeing is believing.

Krabbe Disease, a neurological genetic disease, is usually fatal by age two for children born with this condition. However, donor adult stem cell transplants, including transplants using umbilical cord blood stem cells, have shown significant promise in arresting the disease. Regann Moore is a little girl who is living proof of the healing properties of adult stem cells, and she is closing in on her fourth birthday.

The fetal fairy tales are mirages. Adult stem cells and organoids are the reality and hope for the future.

About David Prentice, PhD

CMDA Member.

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