I met Catherine Verfaillie several years ago. She was very nice. I was visiting her lab with a couple of students, and she found the time to give us all a personal tour and to discuss her recent experiments. Unfortunately, she must not have had the time to carefully vet her published data.

Years after questions were raised about their integrity, two of the University of Minnesota’s highest-profile scientific discoveries have been retracted in one week — one that offered hope over the therapeutic potential of stem cells and another that offered a promising path toward treating Alzheimer’s disease.

The studies are more than a decade old and superseded by other discoveries in their fields. But the retractions of the Alzheimer’s paper on Monday and the stem cell paper on June 17 are setbacks for an institution that is fighting to move up the U.S. rankings in academic reputation and federal research dollars.

Both studies were published in the prestigious journal Nature and collectively have been cited nearly 7,000 times. Researchers worldwide were using these papers to support their work years after they had been disputed.

I was familiar with the stem cell work and had even discussed it in my classes, years ago. I haven’t brought them up in a while, and I guess I won’t ever again.

Dr. Catherine Verfaillie and colleagues in 2002 reported that they coaxed mesenchymal stem cells from adult bone marrow into growing numerous other cell types and tissues in the body. Only stem cells from early-stage human embryos had shown such regenerative potential at that time, and they were controversial because they were derived from aborted fetuses or leftover embryos from infertility treatments. President George W. Bush had banned federal funding for embryonic research, fueling a search for alternative stem cell sources.

Dr. Karen Ashe and colleagues similarly gained global attention in 2006 when they found a molecular target that appeared influential in the onset of Alzheimer’s disease, which remains incurable and a leading source of dementia and death in America’s aging population. Mice mimicking that molecule, amyloid beta star 56, showed worse memory loss based on their ability to navigate a maze. Ashe theorized that a drug targeting that molecule could help people overcome or slow Alzheimer’s debilitating effects.

As often seems to be the case, these bad papers were a consequence of manipulating data and images.

Verfaillie and colleagues corrected the Nature paper in 2007, which contained an image of cellular activity in mice that appeared identical to an image in a different paper that supposedly came from different mice. The U then launched an investigation over complaints of image duplications or manipulations in more of Verfaillie’s papers.

It eventually cleared her of misconduct, but blamed her for inadequate training and oversight and claimed that a junior researcher had falsified data in a similar study published in the journal Blood. That article was retracted in 2009.

Concerns resurfaced in 2019 over the Nature stem cell paper when Elisabeth Bik, a microbiologist-turned-research detective, found more examples of image duplication.

Jesus. How does this happen in a non-pathological lab situation? When I was publishing papers, every figure and table went through multiple review sessions — we presented the work in lab meetings, and in meetings of scientific societies, and we had to discuss the provenance of every image. If we lacked some critical image, we wouldn’t be told to go through the old files and find something that looks like what we wanted to see, we had to go back in the lab and repeat the experiment and get good quality images. I once spent a year doing practically nothing but repeating transmission EM preps trying to find a particular synapse, and couldn’t…so we ended up dropping the claim, and if anybody asked about it, I’d just say it must be a rare contact and that we couldn’t verify it.

Republishing images, unless it was for a review paper and was properly credited, was unthinkable. As for the Alzheimer paper…

Bik also turned out to be a key critic of Ashe’s Alzheimer’s discoveries, raising concerns about images in her Nature paper and several related studies. Much of the blame so far has fallen on co-author Sylvain Lesne, a U neuroscientist who was responsible for the published images. Lesne did not reply to a request for comment, but authorized the university to disclose that it completed its internal investigation into the Nature paper without finding any evidence of misconduct. Reviews of other publications from Lesne’s lab are ongoing.

That just tells me that the University of Minnesota’s internal investigation was more of a whitewash. Faked or duplicated images ought to be a tremendous great red flag, complete with klaxons and arc lights, and there is no excuse for being that lazy/sloppy/incompetent, especially when the article is going into a prestigious journal that will get you a lot of attention.