![\"Dr.](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/05\/img-baez-moraes-lab-2.jpg\")
<\/p>\n
Summary<\/p>\n
- \n
- Dr. Jose Barrera-Paez published a study in Science Translation Medicine discussing a base editing technique to treat mitochondrial disease.<\/li>\n
- The study found that base editing remains imprecise and at higher doses it can introduce detrimental errors.<\/li>\n
- There are no cures for people diagnosed with mitochondrial diseases.<\/li>\n<\/ul>\n
Dr. Jose Barrera-Paez\u2019s story with mitochondrial genetics is one of love at first read. As an undergraduate student studying in Spain, he stumbled across some papers about mitochondrial genetics\u2014the genes specific to tiny organelles that produce energy inside our cells. He felt an instant passion.<\/p>\n
\u201cI knew I wanted to do something related to mitochondrial genetic engineering,\u201d he said.<\/p>\n
That passion led him to the lab of Carlos T. Moraes, Ph.D.,<\/a> a professor of neurology at the University of Miami Miller School of Medicine, where Dr. Barrera-Paez spent the last six years completing his Ph.D. He and his team use a base editing technique to treat mitochondrial disease in an animal model, but they found that base editing remains imprecise and, at higher doses, it can introduce detrimental errors.<\/p>\n
The results were published in Science Translational Medicine<\/a>.<\/p>\n
\u201cThe field of mitochondrial gene editing is in its infancy still,\u201d said Dr. Moraes. \u201cIt was a major breakthrough that we could change bases in mitochondrial DNA, because we couldn\u2019t do that before. But the way we do it is not absolutely precise yet.\u201d<\/p>\n
Genetic Mitochondrial Diseases<\/p>\n
Genetic diseases typically refer to diseases caused by problems in an individual\u2019s nuclear DNA. These genes influence eye color, height, personality traits and disease risk. But that\u2019s not the only DNA in a person\u2019s body. Cells contain a network of interconnected mitochondria and approximately 1,000 copies of mitochondrial DNA per cell. Mutations in these genes can also cause a variety of illnesses that lead to devastating muscle weakness, neurological problems, heart disease and more<\/a>. \u00a0<\/p>\n
\u201cAs of today, there are no cures available to patients diagnosed with a mitochondrial disease,\u201d said Dr. Barrera-Paez.<\/p>\n
Over the past decade or so, researchers have made major progress in editing nuclear DNA. Those strategies don\u2019t always work as well for editing mitochondrial DNA. CRISPR, for example, is the gold standard for nuclear gene editing, but it does not work in mitochondria. <\/p>\n
![\"Dr.](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/05\/img-baez-lab.jpg\")
\u201cEvery study takes us a little closer to where we have to be,\u201d says Dr. Jose Barrera-Paez about his base editing research.<\/p>\nOne DNA-editing technique used by the Moraes Lab takes advantage of nucleases to root out and cut sequences of disease-causing mitochondrial DNA. Once it is cut, cellular machinery repairs the remaining nuclear DNA. But because there are so many mitochondrial DNA molecules within each cell, there\u2019s no machinery to repair them. Instead, a broken DNA molecule will disintegrate. The remaining healthy mitochondrial DNA will repopulate the missing mitochondria.<\/p>\n
\u201cOur cells don\u2019t have a good system to repair breaks on mitochondrial DNA,\u201d said Dr. Moraes.<\/p>\n
For some people, disease is caused by mutations in only some of the mitochondrial DNA. If this is the case, then this type of gene editing may theoretically help them. Mitochondria with damaged DNA would disintegrate, leaving mostly healthy mitochondrial DNA. But for disease caused by mutations present in all mitochondrial DNA, this strategy would leave no healthy mitochondrial DNA.<\/p>\n
Enter base editing. With base editing, scientists don\u2019t just cleave out the damaged DNA. They fix it to restore the correct sequence.<\/p>\n
The Next Step in Editing Mitochondrial DNA<\/p>\n
\u201cIn 2020, the first mitochondrial base editor was reported,\u201d said Dr. Barrera-Paez. Instead of just removing dysfunctional mitochondrial DNA, \u201cwe can try to directly correct it with the base editor. As soon as we got our hands on that, of course, we had a field day with the idea.\u201d<\/p>\n
Dr. Barrera-Paez, Dr. Moraes and their team used a mouse model that had a pathological mitochondrial DNA mutation. They were unable to directly edit the problematic mutation. But they were able to target a different section of mitochondrial DNA with AAV9-DdCBE that could compensate for the damage.<\/p>\n
Untreated mice had elevated levels of lactate in their hearts. These levels dropped once the mice had been treated with mitochondrial DNA base editing.<\/p>\n
But the system wasn\u2019t perfect. As the researchers raised the amount of base editing in hopes of increasing its therapeutic effect, they started seeing more and more off-target edits. At the highest doses, these edits caused severe, adverse effects which, in some cases, were fatal.<\/p>\n
\u201cThere were some issues we wanted to highlight in this paper,\u201d said Dr. Barrera-Paez. \u201cThe more editing that you generate with the system, the more likely you are to also generate toxic, off-target editing.\u201d<\/p>\n
The field is excited about the potential of base editing mitochondrial DNA to treat disease, but Dr. Barrera-Paez and Dr. Moraes emphasized that the system needs more precision before it\u2019s used in humans. <\/p>\n
\u201cEvery study takes us a little closer to where we have to be,\u201d said Dr. Moraes.<\/p>\n
Tags:<\/strong> CRISPR gene editing<\/a>, Dr. Carlos Moraes<\/a>, gene editing<\/a>, mitochondrial diseases<\/a>, student research<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"By: Emma Yasinski | May 01, 2025 | 6 min. read\u00a0|\u00a0 Share Summary Dr. Jose Barrera-Paez published a…\n","protected":false},"author":2,"featured_media":70300,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3846],"tags":[35232,35233,35234,267,35235,70,17426,16,15],"class_list":{"0":"post-70299","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-genetics","8":"tag-crispr-gene-editing","9":"tag-dr-carlos-moraes","10":"tag-gene-editing","11":"tag-genetics","12":"tag-mitochondrial-diseases","13":"tag-science","14":"tag-student-research","15":"tag-uk","16":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114442170816534762","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/70299","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=70299"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/70299\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/70300"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=70299"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=70299"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=70299"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}