Tag Archives: animal model

Opinions, evidence, and anti-research agendas: A recap of a session at the American Society of Primatologists/International Primatological Society Meeting 2016

Research with nonhuman primates in laboratory settings is a tiny fraction of both laboratory research and nonhuman primate research. The topic is of disproportionate interest, however, for many reasons, and is reflected by a recent symposium at the joint meeting of The American Society of Primatologists and International Primatological Society. The session was titled “Use and care of captive non-human primates: Evaluating and improving ethical requirements.”  The session was notable for a number of reasons.

  • Despite its inclusion in the scientific program of scientific societies, the session presented little evidence and little balance.
  • The panelists were tied to organizations and/or campaigns opposed to laboratory research with nonhuman primates, yet did not disclose these ties upfront and failed to provide their basic starting assumptions or to acknowledge their positions.
  • The fact-less rhetoric did not provide a basis for productive discussion about captive primate care or changes to existing regulations, as would have been provided with evidence-based presentations.
Rhesus monkeys at the California National Primate Research Center. Photo credit: Kathy West

Rhesus monkeys at the California National Primate Research Center. Photo credit: Kathy West

Starting assumptions

We wrote yesterday about why providing basic starting assumptions is key when entering any dialogue, particularly when that dialogue involves conversations about the ethical and moral considerations related to the use of animals in biomedical research. If basic starting assumptions are not put forth at the start of a dialogue, then potential areas for agreement cannot be identified – if they in fact exist at all.

Unfortunately, this tenet was not practiced during the symposium. The organizers, anthropologists Drs. Barbara J. King and Marni M. LaFleur, wrote that the symposium was intended to“invite IPS and ASP members to come together and discuss how we may best manage the care and oversight of captive-living nonhuman primates.” At face value, this invitation seemed like a safe haven for “discussion and collaboration amongst researchers, veterinarians, technicians, and caregivers.” (In fact, data-driven sessions like these occur regularly at ASP meetings amongst the experts who care for and study captive primates.) However, the organizers and panelists failed to disclose their basic assumptions upfront, namely that they oppose the use of nonhuman primates in biomedical research.

Several speakers in the symposium have affiliated with campaigns by PETA, an organization that very clearly offers an absolutist position stating that animals should never be experimented on. The Vice President of Animal Research Issues at the Humane Society of the United States (HSUS), Kathleen Conlee, was also featured. HSUS’ position is less clear, though one of Conlee’s slides stated that the organization’s aim is to “Promote 3R’s but push for replacement of invasive research as quickly as possible.”

Macaques. Kathy West. CNPRC. 17

Macaques. Photo credit: Kathy West

As many attendees of the session attested after it concluded, the panelists’ failure to establish positions upfront resulted in a session with a very narrow focus that did not actually result in constructive discussion. Although the speakers’ stances on biomedical research were not stated upfront, they became readily apparent in each presentation.

The symposium followed a roundtable format, with the 6 speakers each presenting for about 5 minutes and a Q&A session for about an hour and a half afterward. Notably, the speakers did not include information on the well-established regulations and processes that are in place to balance research objectives, animal welfare, and public interests in scientific advances. (In 2015, ASP held a roundtable that thoroughly addressed these topics with evidence-based material.) Some presenters did show historical timelines of a few pieces of legislation enacted to address and ensure animal welfare (e.g., the passage of and amendments to the Animal Welfare Act), though nearly all presentations were lacking in evidence-based arguments. Instead, they often relied on outdated and out-of-context photographs (some from undercover investigations, which Conlee proudly acknowledged to the audience that HSUS had undertaken). Granted, the 5-minute time-slot for each speaker precluded the ability to delve into details, but one has to wonder if this format was a means to deliberately exclude the evidence-based regulations and processes that exist for laboratory animals.

Macaque. Kathy West. CNPRC.

Macaque. Kathy West. CNPRC.

Who should evaluate primate research?

The first speaker, LaFleur, wrote in the abstract of her presentation: “Ethical standards and cost-benefit analyses of non-human primates in research must continually be evaluated and reevaluated, by a diverse range of experts (including those without vested interests).” By “vested interests,” LaFleur presumably meant those working in primate research. What wasn’t clear is whether the panelists believe that they themselves and organizations such as PETA and HSUS also have clearly vested interests. For example, PETA has an extremely vested interests in this issue, yet nowhere during the session was it disclosed that panelist King has worked actively on campaigns organized by PETA (for other panelists’ ties to PETA; see below).

Most important though, from the perspective of beginning with fact:  The analyses of non-human primates in research to which LaFleur refers already routinely occurs by experts in the field: the trained scientists, veterinarians, and colony managers, including many members of ASP, who work with primates in captive settings on a daily basis and dedicate much of their research programs toward understanding and improving their welfare (see, for one recent example, this special issue of the American Journal of Primatology, dedicated solely to the well-being of laboratory nonhuman primates).

LaFleur also wrote in her abstract, “I argue that experimental procedures which cause permanent and irreversible harm on individual non-human primates should not be deemed ethically permissible.”

Macaques. Kathy West. CNPRC. 19

Photo credit: Kathy West

Yet, LaFleur failed to make a clear case for exactly why her position is justified in a way that is more appropriate than the position held by others who were part of the multi-level review that weighs scientific objectives and animal welfare and grants approval for research projects.

Furthermore, the slides that LaFleur presented at the conference showed data-free descriptions not of experimental procedures broadly, but of a single research topic. Her focus was on studies of infant development in monkeys (work she termed “maternal deprivation”) at the NIH and the criticism that she, King, and others leveled at ASP in regards to the society’s open support for research at the NIH. For example, in one of her slides, LaFleur stated that 54 members of ASP had signed a letter she co-authored to ASP asking for a reconsideration of their support letter for an NIH research project. In fact, in reading through the list of signatories, it is not at all clear to long-time members of ASP whether many of the signatories had ever been members of the society. One must question why this misinformation was presented at such a large meeting and also why this single research topic was the focus.

Another slide asked the question, “Can we not have differing opinions from our friends and colleagues?” Of course differing opinions may exist. What we strive for, however, are regulations and policies that are based in scientific evidence in order to provide for animal health and well-being. In the context of dialogue and the supposed focus on the symposium, the larger question is whether focusing on differing opinions about one research project and one area of study is a good substitute for serious and thoughtful consideration to identify core principles that can guide continuing changes in practice and policy.

Dr. Stacy Lopresti-Goodman came closest to laying out her basic assumptions upfront in her abstract, in which she wrote, “the primate research community should consider whether retirement of all NHP from biomedical research to sanctuary is warranted.” Lopresti-Goodman provided a few slides that cited research studies to back her written statement that “many individuals who experience…adverse conditions exhibit abnormal and/or stereotypic behaviors, and develop symptoms of psychological distress that mirror those of psychopathology in humans,” though it is notable that she did not disclose at any time during the session that she has co-authored articles with PETA employees and others staunchly opposed to animal research.

Zebrafish: Wellcome Trust Sanger Institute

Zebrafish: Wellcome Trust Sanger Institute

Moreover, several in the audience questioned her direct knowledge, experience, and expertise on the topic given her training and publication record in human perception and cognition.

 

Evaluating a claim from HSUS:  What is the evidence on environmental enrichment for nonhuman primates in captive settings?

In the US, all facilities registered or licensed to house nonhuman primates by the federal agency charged with oversight and enforcement of the Animal Welfare Act (AWA) are required to have a plan for environmental enrichment for those animals. Evidence-based evaluation of practices aimed at meeting the goal of maintaining animals’ health and well-being, in balance with scientific objectives, is the subject of research by many ASP members and those scientific results are on display at most ASP meetings.  The findings inform practices across the range of settings in which nonhuman primates live in captivity.

Conlee’s symposium presentation took a very narrow view, focusing on an analysis that her organization (HSUS) completed of enrichment plans from 38 universities and 18 federal facilities. Those plans were obtained, in part, via use of open records laws. The analysis was aimed at evaluating whether the plans were compliant with federal law. The abstract made a startling claim:  “Plans were scored according to compliance with the minimum Animal Welfare Act standards … The analysis revealed a majority of plans (44) were not adequate.”  To be clear, what that claim suggests is that 44% of the facilities — facilities that are regularly inspected by a federal agency, the USDA– are failing to comply with federal law.

Marmosets. Kathy West. CNPRC.

Titi monkeys. Photo credit: Kathy West

Serious claim – can it be evaluated?  Unfortunately, not well.  The analysis is unpublished and unavailable for public view or critique. Conlee provided no details about the methodology, including critical definitions of coding schemes for “plans [that] were scored according to compliance with the minimum Animal Welfare Act standards” and the subsequent data analysis.

The results Conlee presented were confined to bullet points on one slide rather than actual data with accompanying statistical analysis. Collectively, the “study” did not meet ASP’s (and other societies’) criteria for scientific presentations, but was nonetheless was presented as though it were an empirical study. While that is disappointing enough, the fact that the presentation and abstract made serious claims potentially misrepresenting a large number of dedicated research centers is even more reason to hold presenters to a standard of evidence.

Finally, Conlee presented a slide stating, “USDA requirements for all regulated facilities: no change in 30 years.” However, this statement is misleading. As Justin McNulty, IACUC & IBC Manager at The University of Texas at Austin, pointed out in the discussion following the presentations, “The Guide for the Care and Use of Laboratory Animals was just revised in 2011 and was reviewed by some of the people in this room. The recommendations contained in the Guide were based on published data, scientific principles, and expert opinion.” As described in the preface to the 8th Edition of The Guide, “The Guide is intended to assist investigators in fulfilling their obligation to plan and conduct animal experiments in accord with the highest scientific, humane, and ethical principle.”

Lack of evidence for the benefit-risk ratio in laboratory primate research?

LaFleur also gave King’s presentation in her absence. In her written abstract, King wrote, “I will discuss case studies that are lab-based and involve maternal-deprivation and other invasive experiments on cercopithecines; peer-reviewed scientific material from both the cercopithecine and also the comparative chimpanzee literature will provide context for discussing the benefit-harm ratio of such research on monkeys.” However, this presentation also lacked evidence-based claims and relied on references from the news media, as in one slide that touted the primate facilities that closed, or are in the process of phasing out, in 2015. In giving the presentation, LaFleur incorrectly stated that, with respect to the phasing out of the NICHD’s primate research, “those 300 monkeys [were] from the maternal deprivation work.”  This is false: only a small percentage of the colony at this facility each year has undergone nursery-rearing. Furthermore, as noted above, the actual process in place for evaluating balance of potential benefit and scientific objectives with animal welfare was not well addressed by the panelists.

Summary

Collectively, the session left much to be desired for those seeking data-driven suggestions for improving the captive care of non-human primates. As Dr. Karen Hambright, Professor of Psychology at the College of Coastal Georgia and long-time ASP member, stated during the discussion period, “As an educator who has worked with and is familiar with the conditions of animals in both zoos and labs, it my job to teach people to think critically and to base their views on evidence and not on emotional responses to polarizing rhetoric.”

King and LaFleur’s symposium abstract ended with the question, “How specifically can productive discussion about ethics be furthered among primatologists who work primarily on lab science and primatologists who work primarily on animal welfare, always acknowledging that these two groups may overlap?” A good start would be to enact practices that are foundational to any honest dialogue: namely, spelling out basic positions upfront and disclosing any potential conflicts of interest. Productive discussion could then ensue with evidence-based comments and suggestions.

Amanda Dettmer

Amanda M. Dettmer, PhD, is a Postdoctoral Fellow at the Eunice Kennedy Shriver National Institute of Child Health & Human Development. Her writing does not reflect the opinions of the NICHD or the NIH.

 

En Passage, an Approach to the Use and Provenance of Immortalized Cell Lines

This guest post is by Lisa Krugner-Higby, DVM, PhD.  Dr. Krugner-Higby is a scientist and also a research veterinarian within the Research Animal Resource Center at the University of Wisconsin-Madison. Dr. Krugner-Higby’s research is in development of extended-release formulations of analgesic and antimicrobial drugs. She previously worked in anti-HIV drug development.

I am always fascinated by the idea promoted by some animal rights activists – repeated in many versions and for many decades – that all preclinical biomedical research can be conducted using in vitro cell culture. I have never found one of them who has spent much time working with cell culture. On the other hand, I have spent approximately seven years of my life working with cell cultures, looking at the stainless steel back wall of a laminar flow work station day after day. One thing I can say about immortalized cell lines, or cells that reproduce indefinitely, is that they are not alive in the same way that a mouse is alive.

 

Cell culture

Cell culture

The first thing that a graduate student learns when they begin to work with cell culture is how to take cells that have overgrown the sterile plastic flask they inhabit and put them into a fresh flask with fresh growth medium. It’s called ‘splitting’ the number of cells and ‘passaging’ them into a new home. Split and passage, split and passage… I knew that with every passage, the cell line became a little more different than normal cells and even a little more different than the original cell line. The remedy for this type of genetic drift was to freeze low passage cells in liquid nitrogen and re-order the line from the repository when the low passage stocks were depleted. I was careful with my sterile technique, cleaned the laminar flow hood, and used a new sterile pipet every time in order to avoid contamination of my cells. Unfortunately, the day came when I opened the incubator door and the flasks were black and fuzzy with fungus, and all of my carefully tended cells were dead. An anguished conversation with the tissue culture core technician revealed that this happened every Spring in North Carolina when the physical plant turned on the air conditioning for the year, blowing a Winter’s worth of fungal spores out of the ductwork and into the air. She recommended doing other things for about 6 weeks until the spore load had blown out of the ducts. I have had other cell line disasters in my scientific career: the malfunctioning incubator thermostat that turned a colleague’s two months’ worth of cell culture growth into flasks of overheated goo or that generally reputable vendor that sold us a case of tissue culture flasks that were not properly sterilized resulting in clouds of bacteria in the warm, moist, nutrient-rich environment of the incubator.

I never thought to ask, in those early days, if the cells that I fussed, worried, and wept over, were actually the cells that they were supposed to be. Raji Cells, A549s, U937s, I knew them all, worked with them every day, and never doubted that they were the cells that I thought that they were. I knew that some cell lines had been contaminated with the HeLa cell line. HeLa cells are very hardy and could spread quite easily from one flask to another. But I thought that was in the past. It turns out that there was more to the story than I realized. Cell lines have a provenance, like paintings or other works of art. They have an origin, a laboratory where the line was first isolated and propagated. From there, it may have been distributed to other laboratories and to repositories like the American Type Culture Collection or ATCC. Some cell lines are used by only a few laboratories, and some become used very widely and in a large number of biomedical disciplines. Whereas some paintings are intentionally forged, many cell lines have now been shown to be unintentionally forged. A recent article in the journal Science estimated that 20% of all immortalized cell lines are not what they were thought to be1.

Download original file2400 × 1999 px jpg View in browser You can attribute the author Show me how Multiphoton fluorescence image of cultured HeLa cells with a fluorescent protein targeted to the Golgi apparatus (orange), microtubules (green) and counterstained for DNA (cyan). Nikon RTS2000MP custom laser scanning microscope. National Institutes of Health (NIH).


Multiphoton fluorescence image of cultured HeLa cells with a fluorescent protein targeted to the Golgi apparatus (orange), microtubules (green) and counterstained for DNA (cyan). Nikon RTS2000MP custom laser scanning microscope. National Institutes of Health (NIH).

We now have better methods of identifying cell lines by their DNA, called short tandem repeat (STR) profiling, and scientific journals are beginning to require this testing for cell lines prior to publication. Currently, 28 scientific journals require STR profiling to establish cell line provenance prior to publishing a manuscript from a particular laboratory. Some scientists are also beginning to create catalogs of contaminated cell lines in an attempt to quantitate the damage done by some misidentified, but widely studied, cell lines. The same Science article, notes that the International Cell Line Authentication Committee (ICLAC) maintains a database of misidentified cell lines that now numbers 475 different lines. A cell line geneticist, Dr. Christopher Korch, recently estimated that just two of the immortalized cell lines that were found to be misidentified, HEp-2 and INT 407, have generated 5,789 and 1,336 articles in scientific journals, respectively. These studies cost an estimated $713 million dollars and generated an estimated $3.5 billion in subsequent work based on those papers1. This is because the usual trajectory for testing a new therapeutic modality, especially in cancer research, is to test a compound or technique in cell culture. It will then be tested in mice that express a tumor derived from the cultured cancer cells. If those studies are successful, the compound and/or technique undergoes further toxicity testing in other animal models before entering its first Phase I trial in human volunteers.

A lot of compounds that show early promise in cell culture and in cell line-injected mice turn out not to have efficacy in animal models or in human patients. Sometimes this is simply a matter of the compound being too toxic to organs or cell types that are not represented in the initial cell culture. Often, the reason why particular compounds or strategies fail is not known, and most granting agencies are not keen to fund laboratories to find out why things don’t work. I have wondered if the failure of some compounds or techniques is in part due to misidentified cell lines. I have also wondered if it is a reason why testing in animal models, particularly in animal models with spontaneously-occurring tumors, is necessary.

Testing anti-cancer compounds in models of spontaneously-occurring tumors in animals and/or testing in human tumor cells taken directly from patients and injected into mice (the ‘mouse hospital’ approach) is more time and resource intensive than screening in immortalized tumor cell lines. This approach, however, has the advantage of knowing that the investigator is not just treating misidentified HeLa cells in error. It is always necessary to go from in vitro cell culture models to in vivo animal models to confirm the viability of a therapy.

Science makes claim to no enduring wisdom, except of its method. Scientists only strive to be more right about something than we were yesterday, and efforts are underway to weed out misidentified cell lines. But the fundamental issues behind cell line misidentification highlight one of the reasons why we should not rely on immortalized cell lines without animal models, and why granting agencies should fund more studies to try to identify the disconnect between the results of in vitro and in vivo studies when things do not go as planned. That is a part of good science and part of creating better cell culture models to refine, reduce, and sometimes replace the use of animals in biomedical research.

Lisa Krugner-Higby, DVM, PhD

1) Line of Attack. Science. 2015. Vol. 347, pp. 938-940.

From the bench and the bedside; how animal research is taming Multiple Sclerosis

Multiple sclerosis (MS) is one of the most common diseases of the central nervous system – the brain and spinal cord – affecting about one person in every thousand in the USA. It is an inflammatory condition, where the immune system attacks the myelin sheath that surrounds the axons of nerve cells. Myelin is a fatty material that insulates nerves, acting much like the covering of an electric wire and allowing the nerve to transmit its impulses rapidly. It is the speed and efficiency with which these impulses are conducted that permits smooth, rapid and co-ordinated movements to be performed with little conscious effort. Loss of myelin interrupts these impulses, and the nerve cells themselves are also damaged and eventually die. 

The consequences for people with MS can be devastating, and MS is associated with a wide variety of symptoms, including muscle weakness, spasms, ataxia, problems with speech and vision, acute and chronic pain, and fatigue.  MS is a very variable disorder, and the rate at which it progresses varies considerably from one patient to another, but a defining characteristic of it is the lesions that are visible by MRI where the myelin has come under attack. The relapses, attacks of worsening neurological function that are often found in MS, are closely associated appearance of new lesions in the CNS, although not all new lesions cause a relapse.

Until about 20 years ago there were no treatments available that could prevent relapses or slow the progression of MS – known as disease modifying treatments – but thanks to the efforts of scientists working around the word this situation has begun to change.   A number of effective disease modifying treatments are now available, the most recent to receive FDA approval is Fingolimod (known as FTY720 during its development), a drug whose immunosuppressant properties in reducing transplant rejection and as a treatment for MS were evaluated in a range of animal models during its development.

These drugs may soon be joined by another. A couple of years ago I wrote about the crucial role of studies in mice, rats, and dogs in the development of a new disease modifying treatment called Laquinimod, which safely -though relatively modestly conpared to other new therapies – reduced the number of relapses, while slowing progression of disability more that current disease modifying drugs in a Phase III clinical trial. This is good news, and one more step towards turning MS form being an incurable disease to being a manageable disease.

One reason I say manageable rather than curable is that while these treatments are effective in reducing the number of relapses for many patients they do not work for all patients and all forms of MS (particularly for primary progressive MS), and can sometimes have serious side effects that prevent patients from continuing treatment. That is why scientists are continuing to study the biological mechanisms in MS, a disease whose origin is still not fully understood, though clinical and animal research indicates that both genetic and environmental factors play a role, their ultimate goal is to develop treatments that can stop relapses altogether.

Another reason for not referring to disease modifying treatments as “cures” is that they do not directly repair the damaged myelin sheath at the lesions. Spontaneous repair of the damaged myelin sheath in MS lesions does happen and plays an important role in limiting neurological damage, but until now the molecular basis of myelin regeneration by cells called oligodentrocytes, in the central nervous system (CNS) has been poorly understood. The Guardian reports on how scientists at the University of Cambridge have discovered how to promote remyelination in MS lesions by activating a population of stem cells in the CNS called oligodentrocyte precursor cells (1).

The team led by Professor Robin Franklin generated a comprehensive transcriptional profile of 22,000 genes during the separate stages of spontaneous remyelination that follow focal toxin-induced demyelination in the rat CNS, and found that the level of retinoid acid receptor RXR-gamma expression was increased during remyelination. Cells of the oligodendrocyte lineage expressed RXR-gamma in rat tissues that were undergoing remyelination, in both active lesions and in older remyelinated  lesions. By examining post-mortem brain samples from MS patients, they were able to show that RXR-gamma expression was also elevated in oligodendrocyte precursor cells at the active lesion sites, supporting a general role for RXR-gamma in remyelination. Interesting as these findings were they did not demonstrate that RXR-gamma is actually required for remyelination, so they next performed studies to determine whether blocking the function of RXR-gamma would prevent remyelination.

Rats are crucial to many areas of MS research. Image courtesy of Understanding Animal Research.

Knockdown of RXR-gamma by RNA interference or RXR-specific antagonists severely inhibited the differentiation of oligodendrocyte precursor cells into mature oligodendrocytes in culture. In mice that lacked RXR-gamma, adult oligodendrocyte precursor cells efficiently repopulated lesions after demyelination, but showed delayed differentiation into mature oligodendrocytes. The next question was whether increasing the activity of RXR-gamma would speed up remyelination. Administration of the RXR agonist 9-cis-retinoic acid to demyelinated mouse cerebellar slice cultures and then to aged rats in vivo after focal demyelination caused an increase in remyelinated axons. Focal toxin-induced demyelination was used to produce the lesions, rather than an immunity mediated model of demyelination such as experimental autoimmune encephalomyelitis, in order to determine that the increased remyelination was due to promotion of oligodendrocyte differentiation rather than to the anti-inflammatory effects of 9-cis retinoic acid.

The results indicate that RXR-gamma plays an important role in endogenous oligodendrocyte precursor cell differentiation and remyelination, and might be a pharmacological target for regenerative therapy in MS. The discovery that 9-cis-retinoic acid, a compound already in limited clinical use, can be used to stimulate myelin regeneration raises the possibility that within the next decade treatments that repair the neurological damage in MS will begin to enter clinical trials.

For people with MS these scientific and clinical advances are a great source of hope for a better future.

Paul Browne

1)      Huang J.K. et al. “Retinoid X receptor gamma signalling accelerates CNS remyelination” Nature Neuroscience Published Online 05 December 2010 DOI: 10.1038/nn.2702

Holder in LA

Speaking of Research founder, Tom Holder (pictured below), will be in the US between Sunday April 4th, and Monday April 12th. During this time he will be speaking with UCLA students at a number of events including an open event at the Gonda building at 12 noon, Tuesday April 6th. Holder will be around the UCLA campus in the run up to the Thursday rally, leafleting the event to students, and is available to speak to students on the issue of animal testing / research.

If you wish to contact him during his stay, please do so via:

  • skype – tom.holder
  • email – tom@speakingofresearch.com
  • phoneUPDATE: +1 310 498 0881

Tom Holder at the Pro-Test for Science Rally 2009

If you see Holder around campus, please go up and introduce yourself – he welcomes conversation, both from those who agree with research, and those who are less sure.

Regards

Speaking of Research

The Similarity of Human and Animal Models

Most scientists who incorporate animals in their research do so under the strong belief that modern animals (particularly those closest to us in evolutionary terms) exhibit an amazing genetic, physiological and behavioral similarity to Homo sapiens, making them effective model systems in which to understand both humans and animals alike. This is particularly true of monkeys and great apes, and it is the reason that primatologists and physical anthropologists have – for nearly a century – studied these species in the wild and in laboratories. They believe that apes and monkeys are so similar to us that this study can reveal insights into the origins of the human species, to our culture and to our evolutionary history.

This homology is not just contained solely within the primate family, however. Dogs also share a remarkable amount in common with us. This is probably because the human species has spent millenia shaping the genome of the domesticated dog through selective breeding in order to make it an ideal companion who shares our emotional and cognitive lives. Not long ago, it was shown that domesticated dogs have a unique ability to understand the social cues embedded in subtle human behavior, like eye gaze, while many chimpanzees do not. This is probably why we favor them as companions – they seem to understand our thoughts and emotions because they have this ability. Importantly, many patients with Autism Spectrum Disorders have difficulty with understanding the thoughts and feelings of others, impairing their ability to relate socially. This suggests that the study of domesticated dogs may provide a unique opportunity to explain the basis of aspects of autism. We can ask what is it that differentiates dogs from other animals that conferred upon them this ability to understand the minds of others. We can then test whether interventions that work through that mechanism are useful treatments for social problems in autism.

A recent paper by researchers in Boston, published in the journal Molecular Psychiatry, further exposes the potential for bio-behavioral studies in dogs. These scientists noted that a significant number of Dobermans had a tendency to engage in behaviors reminiscent of human Obsessive Compulsive Behavior (OCD; including abnormal self grooming – called trichotillomania – and other repetitive motor movements like pacing and checking). By studying a large family of Dobermans who exhibited these traits, the scientists were able to show that there were genetic causes to the behavior and to provide evidence that mutations on dog chromosome 7 were associated with these symptoms. Upon further analysis of their data, they identified an interesting gene (cadherin 2) which is expressed within the brain and may directly relate to these behaviors. We now have an important set of questions to test: what brain circuits is cadherin 2 expressed in? Does the same gene, which is known to be present in humans, relate to OCD? If so, can we treat the symptoms and lessen the distress of patients with OCD by targeting this gene? The millions of patients with OCD undoubtedly await an answer to these questions. What is more, we now have important information that may help to make the lives of these dogs better through lessening the behavioral problems they have inherited through their genes.

Of additional note, these researchers made this discovery by observing the dogs’ behavior and by obtaining a blood sample, revealing the fact that – as many researchers have long asserted – the descriptions of all biomedical research as “vivisection” is a far cry from the truth. Scientists typically refine their approaches in order to use the least invasive and distressing methods to uncover the facts that are required. This is particularly true when considering complex species with evolved cognitive and emotional abilities – like dogs and monkeys. I personally care for two small dogs, and because of this, I – like other scientists – am exceptionally sensitive to the impact of an experiment on the animals that live in our labs. It is with that in mind that we struggle to carry out our research in as refined a manner as is possible given the scientific question being investigated. Indeed, as I have previously asserted, there are many scientific questions that cannot be answered well if the welfare of the subject is ignored and/or if the animal is exposed to stress that will alter its behavior.

While invasive methods are sometimes required to make progress towards treatments for human disease, at other times they are not. Researchers judiciously choose the method that produces the necessary data with the least impact on the subject, and Institutional Animal Care and Use Committees review the decision of any scientist about the level of invasiveness of his/her study. That not withstanding, studies in non-human animals continue to be foundational for our understanding of ourselves, and discoveries regarding the function of the brain and body in health and disease will continue to be made thanks to animal research.

Regards

David Jentsch

Breakthrough of the Year (almost!)

As the year draws to a close it’s time to reflect on an exciting year of animal research, and there seems no better place to start than with the top 10 breakthroughs of the year as selected by the prestigious scientific journal Science. Science is of course a general science magazine, and the choices reflect this with research in diverse fields ranging from astronomy to paleontology.

Last year our sister organization in the United Kingdom reported that Science had selected cell reprogramming to produce induced pluripotent stem cells (iPS cells) as their breakthrough of the year.  Since then we have reported how the safety of iPS technology continues to improve while others have discussed exciting research which shows just how powerful the technique is by reprogramming fibroblast cells to generate healthy mice that can themselves produce offspring.

This year the top slot went to the discovery and study of Ardi, a 4.4 million year old ape who promises to shed a great deal of light on early human evolution, though it remains to be seem if she and her kind are a direct ancestor of modern humans.

We did have the consolation that one of the nine runner ups is an area of medicine to which animal research has made an enormous contribution , the return of gene therapy with Science claiming that  this year “… gene therapy turned a corner, as researchers reported success in treating several devastating diseases”. These diseases include X-Linked adrenoleukodystrophy, a usually fatal disease of the brain and nervous system, Leber’s congenital amaurosis, an inherited eye disorder that leads to blindness, and severe combinedimmunodeficiency (SCID)due to a lack of an enzyme called adenosinedeaminase.

Only last month I wrote about the crucial role of research with mice in developing the gene therapy for X-Linked adrenoleukodystrophy, while both Anna Matynia and I have written about Leber’s congenital amaurosis.  However,  we have not yet had an opportunity to discuss the therapy developed for treating SCID  in patients whose immune system has collapsed because they lack an enzyme named adenosine deaminase (ADA) which is crucial for removing toxic metabolites from cells.

A clinical trial published in January by the New England Journal of Medicine (1) reported how an Italian team had successfully treated  children with SCID by harvesting bone marrow stem cells from the boys and treating these cells with a retroviral vector containing the ADA gene that produces adenosine deaminase, and then transplanting the modified cells back into them.  In 5 of the boys the therapy restored normal function and significant improvements in the function of the immune system were observed in the other 5.  This therapy has been a couple of decades in development and one of the key investigators involved in this effort, and indeed in the recent clinical trial,  has been Dr. Claudio Bordignon of the University of Milan. Dr. Bordignon developed techniques that enabled scientists to study the ability of retrovirus transformed bone marrow cells from patients with ADA-SCID  to restore immune function in  the NOD/SCID mice that lack a functioning immune system (2).  This enabled him and his team to develop retroviral vectors that could safely drive the production of adenosine deaminase in bone marrow stem cells that survived for long periods after transplantation and are suitable for use in ADA-SCID patients where they need to function for many years.

It’s great to see an area of medical research that we’ve been following closely over the past year receive this recognition from Science, and we hope that as with iPS cells in 2009 gene therapy continues to show what it can do in 2010.

Paul Browne

1)      Aiuti A. et al.”Gene therapy for immunodeficiency due to adenosine deaminase deficiency.” N Engl J Med. Volume 360(5), Pages 447-458 (2009) DOI:10.1056/NEJMoa0805817

2)      Ferrari G. et al “An in vivo model of somatic cell gene therapy for human severe combined immunodeficiency.” Science. Volume 251(4999), Pages 1363-1366 (1991) PubMed:1848369

Mice uncover the secrets of Congenital Heart Defect

Every time your heart beats it pumps blood through the pulmonary artery and into your lungs where it soaks up oxygen before bring returned via the pulmonary vein to the heart, where the next beat pumps it out through the aorta and on to provide oxygen to all the tissues of your body.  All this is of course welcome to those of us who enjoy being alive, but there was one time in your life when such pulmonary circulation was a potential threat.  During fetal development the lungs are bathed in amniotic fluid and the body is supplied with oxygen via the placenta, and at this stage the pressure of blood being circulated through them would damage the delicate fetal lungs. Fortunately evolution has provided mammals with a means of avoiding this damage, a blood vessel called the ductus arteriosus which connects the pulmonary artery to the aorta, allowing most of the circulating blood to bypass the lungs.  As a baby takes its first breaths after birth the ductus arteriosus begins to close to allow normal pulmonary circulation to take place, a process that is normally complete within a few days. Unfortunately the ductus arteriosus does not always close, causing a condition known as Patent Ductus Arteriosus (PDA). If left untreated PDA can cause breathing difficulties and eventually lead to congestive heart failure, and is a particularly common and serious condition for preterm infants.  While it sometimes resolves itself with minimal intervention in many cases surgery is required to correct the fault.  Now research on mice has enabled scientists to uncover a key process in the closure of the ductus arteriosus that may show the way to less invasive treatments (1).

RA=right atrium, RV=right ventricle, PA=pulmonary artery, AO=aorta, LA=left atrium and LV=left ventricle

The team lead by  Dr Steffen Massberg and Dr Katrin Echtler in Munich knew from previous research that the closing of the ductus arteriosus was associated with the release of cytokines that are usually associated with the inflammatory response seen when tissue is damaged.  Knowing that such inflammatory responses recruit platelets, irregularly-shaped bodies produced by bone marrow cells that are crucial to blood clotting, to the damaged tissue they investigated the role of platelets in the closing of the ductus arteriosus. They decided to study the process in mice because the availability of a variety of tissue staining and genetic modification techniques which would allow them to study the whole process in great detail. They observed that within an hour of birth cells lining the ductus arteriosus were detached to provide attachment sited for platelets, and the platelets themselves quickly accumulated and soon formed a plug that stopped blood flow. They next used monoclonal antibodies and GM modification to remove two proteins that are required for platelet adhesion and activation, and found that the ductus arteriosus failed to close in the newborn mice, leading to the same problems seen in human babies with PDA.  The role of platelets was not confined to the initial blocking of the ductus arteriosus, Dr Echtler and her colleagues found that the platelets also attracted the specialized precursor cells that are required to remodel the ductus arteriosus and replace the temporary plug with a more permanent closure.

So it appears that platelets play a key role in the closure of the ductus arterious in mice, but what about humans?  While they could not study the process in the same detail in human babes as in mice they were able to obtain good evidence supporting a vital role for platelets in humans too.  First they examined samples of ductus arteriosus taken from newborn infants who had undergone heart surgery, and observed the same modifications to the lining of the ductus arteriosus  and platelet accumulation that they had seen in the mice.  They then studied a group of 123 premature infants and found a strong association between low platelet counts and PDA , further evidence that platelets are required for closure of the ductus arteriosus in humans just as they are in mice.

In an interview for the BBC stated that  “It is conceivable that transfusion of platelets reduces the risk of ductus arteriosus patency (lack of closure) in preterm newborns with low platelet count.”. We hope that he is right and that this discovery leads to a revolution in the treatment of PDA.  As for the question of where the platelets for such treatment will come from, that part is all up to you.

Regards

Paul Browne

1)    Echtler K. Et al “Platelets contribute to postnatal occlusion of the ductus arteriosus” Nature Medicine Published online: 6 December 2009 | doi:10.1038/nm.2060