Bringing out the Dead: What We Know about Zika Virus Effect on Human Tissue

[(A) Control neurosphere (B) Zika-infected neurosphere Source: Science, 13MAY2016 http://science.sciencemag.org/content/352/6287/816.full]

[(A) Control neurosphere
(B) Zika-infected neurosphere
Source: Science, 13MAY2016
http://science.sciencemag.org/content/352/6287/816.full]

Because unproven claims persist that chemical exposure — specifically the pyridine-based pesticide pyriproxyfen — causes the birth defects seen in children born to women exposed to Zika virus, I am bringing out the dead, laying out the bodies.

By ‘bodies’ I mean sharing here pictures of cells you see in the embedded photos from a peer-reviewed study published this May.

In these images you’ll see the damage done to human tissue in lab conditions.

No pyriproxyfen was present.

How Researchers Studied Zika
This is the methodology researchers used:

1) The researchers used human stem cells to create neurospheres — the kind of cells which turns into nerve and brain tissue in an actual embryo.

2) They set aside control samples of neurospheres which were not infected.

3) They infected test samples neurospheres with Brazilian Zika virus.

4) They observed the changes in the infected neurospheres.

5) They compared them to the uninfected control samples.

6) They wrote and published a report on their findings.

The image above is the best example from their report of the difference between Zika-infected cells and the uninfected test samples.

What Researchers Found in this Study
In short, Zika inhibits, damages, and kills infected neurospheres.

This is what we can expect to happen to a fetus’ brain or nerve tissues when infected by Zika under the right conditions during early pregnancy.

[(A) Control mock-infected organoid (B) Zika-infected organoid (damage noted at arrows; growth was also inhibited)]

[(A) Control mock-infected organoid
(B) Zika-infected organoid (damage noted at arrows)]

What Else Researchers Found in this Study
The researchers also conducted a very similar test on human brain organoids. These are not single neurospheres but neuro-tissue grown from stem cells so that they form a model like a tiny brain. Not a brain, a tissue-based model of a brain.

They used the same six steps above using a mock-infected model, a Zika-infected model, and a dengue virus-infected model. (Dengue fever is caused by a flavivirus — the same family of viruses to which Zika and yellow fever belong.) Researchers found Zika virus caused similar destructive damage on these larger models while limiting their growth; they did not find the same damage or destruction in the dengue-infected models and none in the mock-infected control models. Zika alone damaged neurological tissue models.

Researchers also studied neural stem cells (NSCs) — the simplest neuro tissue model — and found similar results in which the Zika virus killed off NSCs. Studying NSCs, neurospheres, and organoids, the researchers observed Zika’s actions on different stages of neuro tissue maturity. In each of these models, from the simplest (NSCs) to the most complex (organoids), Zika was destructive.

[ZIKV (Zika virus) induces death in human neurospheres. These micrographs show the ultrastructure of mock- and ZIKV-infected neurospheres after 6 days in vitro. (A) Mock-infected neurosphere showing cell processes and organelles. (B) ZIKV-infected neurosphere showing a pyknotic nucleus, swollen mitochondria, smooth membrane structures, and viral envelopes (arrow). (C) Viral envelopes on the cell surface (arrows). (D) Swollen mitochondria. (E) Viral envelopes inside the endoplasmic reticulum (arrows). (F) Viral envelopes close to smooth membrane structures (arrows).]

[ZIKV (Zika virus) induces death in human neurospheres. These micrographs show the ultrastructure of mock- and ZIKV-infected neurospheres after 6 days in vitro.
(A) Mock-infected neurosphere showing cell processes and organelles.
(B) ZIKV-infected neurosphere showing a pyknotic nucleus, swollen mitochondria, smooth membrane structures, and viral envelopes (arrow).
(C) Viral envelopes on the cell surface (arrows).
(D) Swollen mitochondria.
(E) Viral envelopes inside the endoplasmic reticulum (arrows).
(F) Viral envelopes close to smooth membrane structures (arrows).]

Other Research on Zika Using Mouse Tissue
Three other studies published in May this year using mice or mouse tissues likewise showed evidences of neurological tissue and brain damage or growth suppression when infected by Zika virus. The studies came from research facilities in Brazil, China, and the U.S. — and in each study, pyriproxyfen was not included. The Zika-infected specimens showed damage and the control specimens did not.

The study from Brazil at the University of São Paulo also included research using human stem cells, comparing a Brazilian strain of Zika against an African strain:

Beltrão-Braga, Muotri, and their colleagues also grew brain organoids from human stem cells and infected these in vitro models with the Brazilian and African strains of the virus. In the human mini brains, both strains of the virus caused cell death, but the Brazilian strain appeared to also interfere with the formation of cortical layers. The virus didn’t replicate in the brain organoids grown from chimpanzee stem cells, suggesting it may have adapted to human tissue, the researchers noted in their paper.

Emphasis mine. Research published earlier showed Zika has already mutated rapidly after arriving in Brazil, with at least nine variants found inside the last two years.

What’s Next in Zika Research
What researchers don’t yet know, for starters: How Zika works — how does it damage or kill cells? When exactly does the virus do the most damage? What mechanisms interfere with Zika’s operations and can they be used in vaccines or drug therapy? What makes Zika different from dengue or other flavivirus? What does Zika do to adult neuro tissue to cause Guillain-Barre Syndrome? Which adults are most at risk? Will the different mutations in Brazil respond differently to vaccines? How long can humans carry live Zika virus? Has the virus mutated and become transmissible by bodily fluids or aerosol? These are just a few of the questions we still have about Zika.

There are some good guesses about Zika’s mechanisms — like this hypothesis focusing on vitamin A storage in the liver, which also suggests Zika may negatively affect liver cells (yet another avenue of research needed). But will a vaccine targeting this activity work for other flavivirus, too? What if this guess is wrong; are there other approaches we’ve yet to hear about?

We won’t have any of these answers in a reasonable period of time if we don’t have adequate funding.

It’s not just birth defects we are talking about here, either. Look at the damage in those images again; this virus not only damages fetal nerve and brain tissue, it kills fetuses. Infants born with Zika-related defects may be blind and may lead short, painful lives. And it may kill and maim adults, too, if they develop a serious case of Zika-related Guillain-Barre Syndrome.

Let’s not bring out any more Zika dead.

(Note: Forgive me for the simplistic terms used in this post if you have a background in science. I had to make this as brief and succinct as possible for those who don’t have that background.)
___________

Source:
Zika virus impairs growth in human neurospheres and brain organoids
BY PATRICIA P. GARCEZ, ERICK CORREIA LOIOLA, RODRIGO MADEIRO DA COSTA, LUIZA M. HIGA, PABLO TRINDADE, RODRIGO DELVECCHIO, JULIANA MINARDI NASCIMENTO, RODRIGO BRINDEIRO, AMILCAR TANURI, STEVENS K. REHEN
SCIENCE13 MAY 2016 : 816-818
Zika virus infection in cell culture models damages human neural stem cells to limit growth and cause cell death.
URL: http://science.sciencemag.org/content/352/6287/816.full

Zika Studies Using Mice:
F. Cugola et al., “The Brazilian Zika virus strain causes birth defects in experimental models,” Nature, doi:10.1038/nature18296, 2016.

C. Li et al., “Zika virus disrupts neural progenitor development and leads to microcephaly in mice,” Cell Stem Cell, doi:10.1016/j.stem.2016.04.017, 2016.

J. Miner et al., “Zika virus infection during pregnancy in mice causes placental damage and fetal demise,” Cell, doi:10.1016/j.cell.2016.05.008, 2016.

Blogger since 2002, political activist since 2003, geek since birth. Opinions informed by mixed-race, multi-ethnic, cis-female condition, further shaped by kind friends of all persuasions. Sci-tech frenemy, wannabe artist, decent cook, determined author, successful troublemaker. Mother of invention and two excessively smart-assed young adult kids. Attended School of Hard Knocks; Rather Unfortunate Smallish Private Business School in Midwest; Affordable Mid-State Community College w/evening classes. Self-employed at Tiny Consulting Business; previously at Large-ish Chemical Company with HQ in Midwest in multiple marginalizing corporate drone roles, and at Rather Big IT Service Provider as a project manager, preceded by a motley assortment of gigs before the gig economy was a thing. Blogging experience includes a personal blog at the original blogs.salon.com, managing editor for a state-based news site, and a stint at Firedoglake before landing here at emptywheel as technology’s less-virginal-but-still-accursed Cassandra.
16 replies
  1. jo6pac says:

    “I had to make this as brief and succinct as possible for those who don’t have that background”

    Thanks for doing just that;)

  2. bloopie2 says:

    Times three.
    .
    And for a non-scientist, this sentence alone is fascinating: “The researchers used human stem cells to create neurospheres — the kind of cells which turns into nerve and brain tissue in an actual embryo.” Was this type of work even possible twenty years ago? I have sure fallen behind on my knowledge base.

  3. rugger9 says:

    Very well presented, but one must realize that facts are irrelevant to anti-vaxxers and others of their ilk so convincing them will take more than this. It shouldn’t, but it will. If you have a chance to listen to John Oliver on YouTube from last night (the GOP convention clip is about 11 minutes long, and can fit into a lunch hour. I also recommend the campaign songs at 8 minutes), you’d hear N. Leroy Gingrich observing that for most politicians and voters, what they feel is more important than what the facts are. The discussion in the clip is about the crime stats quoted by Trump, but the concept ran throughout the RNC.
    *
    I still hear about how there were “stand down” orders for the Benghazi attack from those who really should know better, when there never were any such orders and not one communication saying so has been found (as opposed to “manufactured” by RW trolls like the Kenyan birth certificate that almost lasted a day before being debunked). Seriously, if such orders actually existed, why would Gowdy, Chaffetz and Issa hide them (unless they came from GOP-Bushie holdovers)?

  4. rugger9 says:

    The GOP will pay attention to Zika as a real problem when it touches one of their own, like Nancy Reagan’s Alzheimers conversion and several other conversions / epiphanies like when Darth Cheney’s daughter came out of the closet. Mind you that his spawn Liz won’t have anything to do with Mary as much as she can.
    *
    Until it hits home to a significant GOP , it’s somebody else’s problem and as we all should have understood from the Hitchhiker’s Guide to the Galaxy series, it is the most effective way to get people to ignore something.

  5. wayoutwest says:

    We’re fortunate you simplified this complex issue for those of us not able to understand what our White Coat Establishment does with their wizardry and they need this simplified PR to pry funding from the troglodytes in DC for more of this worthwhile enterprise.

    Without this help and simple reporting from sources such as the political blog The Hill I and others might have made the horrible mistake of thinking this research proved that if you feed human embryonic tissue to a voracious virus in vitro , it will eat it but it proves nothing else. Even these researchers usually use weasel words such as ‘could’ or ‘might. when describing their conclusions but you have to actually read their reports to find these caveats.

    To be more effective in creating and projecting this immediate and somewhat panicked need for action that seems to ignore all other variables the PR campaign will need more than pictures of horrors in a dish, they’ll need to bring out the poor little bodies lined up for display even if there is no proof they were actually affected by this virus.

    • John Casper says:

      “Weasel words,” like, “white coat establishment” for the Wall Street suits who run Big Pharma?

      “THE VALEANT MELTDOWN AND WALL STREET’S MAJOR DRUG PROBLEM:
      By 2015, C.E.O. Michael Pearson had built Valeant Pharmaceuticals into a nearly $90 billion colossus. Today, the company is under investigation for price gouging, and major Wall Street players are feeling the side effects. Pearson’s fall (which came with a $9 million severance package last week), exposes more than the dark side of the the health-care system—it indicts some of finance’s biggest players.”

      http://www.vanityfair.com/news/2016/06/the-valeant-meltdown-and-wall-streets-major-drug-problem

    • rugger9 says:

      Well, this proves my points from the 12:45 post.
      *
      If WOW had an actual peer-reviewed study or two to link to I might actually be impressed, but alas it’s the same old anti-scientist BS one also hears from the Bible-thumpers that cherry pick scripture and version. Note to WOW, please understand that peer review means other experts in the field (who are frequently not in agreement with the author) will examine the methodology to see if holes can be poked in the study. Only then will the journal publish it as peer reviewed. In the recent past we have seen studies published by non-peer reviewed magazines and organizations (using artistic license, like Billy Bob’s Lab Skool, Most Excellent Bible Kolleje and Bait Shop) that have been used to justify anti-vaxxer propaganda. Even though they get just as routinely debunked and typically withdrawn as fiction, these studies are still “out there” per Cokie’s Law and so will continue to be used to make harmful decisions.
      *
      Of course, WOW’s point about weasel words is BS, because any scientist worth their salt is not so arrogant to assume absolutely every possible factor can be accounted for in analytical work, especially for microbial / viral issues. Between Murphy’s Law, the Heisenberg Uncertainty Principle and Schrodinger’s Cat there will always be wiggle room and nature frequently reminds us of things we humans missed. That’s not the case here. The point here is that Zika has a clearly significant effect WITHOUT the presence of the insecticide. That doesn’t mean that the combination of the two factors would be better or worse, but it is quite clear Zika ALL BY ITSELF is a problem to be addressed now.
      *
      However, if WOW will put his/her money up front to pay for those victims created by this delay in response, we would actually be more impressed by his/her trolling.
      *
      WOW, until you have a study as academically rigorous as Rayne’s please stop trying to toss out falsehoods.

      • John Casper says:

        Thank you very much.

        My apologies for my scientific illiteracy. I wasn’t clear on exactly what wayoutwest wrote that you were addressing.

        Was it, “…this research proved that if you feed human embryonic tissue to a voracious virus in vitro , it will eat it but it proves nothing else.”

  6. Denis says:

    Great effort on this extremely important topic.
    .
    Rayne: What researchers don’t yet know, for starters: How Zika works — how does it damage or kill cells?
    .
    The buzz now is AXL receptors. Google will pull up a bunch of stuff, here’s a couple articles for lay-folks.
    .
    https://www.sciencedaily.com/releases/2016/03/160330135248.htm
    .
    http://www.theatlantic.com/health/archive/2016/07/how-zika-breaks-into-the-brain/491873/
    .
    Atlantic cites a paper by Kriegstein that was published on the internet before it was reviewed and accepted by the journal. This stunt has caused a lot of controversy as it allegedly by-passes accepted norms of peer review. The sub-story here is that there are all sorts of stinky maneuvers in science to claim priority; one of those is extending a review so that others can publish first in another journal. Nothing is sacred, least of all science.

  7. Rayne says:

    bloopie2 (9:42) — Come on, bloopie, catch up. ~sigh~

    ADD: My boldface emphasis in the quote about the virus’ adaptation to humans is the very reason why researchers cannot rely on non-human tissue to make all their conclusions. Even the mice used posed a challenge; there were two genetically different types of mice used in one of the studies, and one type was resistant to Zika infection. Once researchers figure out how Zika selects and destroys human neuro tissue, they may go back and look at why some animals are resistant. We’re not ready for that yet.

    rugger9 (12:54) — I give it 6-9 months, a reasonable amount of time after the Olympics end in Rio. Unfortunately it’ll happen during the next Congress, not the one currently seated.

    + + + + +

    With regard to persistent claims about pyriproxyfen exposure versus Zika causing microcephaly and birth defects:

    Em entrevista à BBC Brasil, por telefone, ele* afirmou ainda que Recife – a cidade com o maior número de casos notificados e confirmados do Estado – não usa o piriproxifeno e, sim, um larvicida biológico, o BTI.
    “Há lugares onde se usa o piriproxifeno e não há casos de microcefalia. E também lugares em que não se usa esse larvicida, mas há muitos casos, como Recife”, explica.
    “Essa falta de correlação espacial enfraquece a ideia de que o larvicida causaria o problema.”

    Translation:

    In an interview with BBC Brazil, by phone, he* also said that Recife – the city with the highest number of reported and confirmed cases of the state – do not use pyriproxyfen and, yes, a biological larvicide, the BTI.
    “There are places where pyriproxyfen has been used and no cases of microcephaly. There are also places that do not use this larvicide, but there are many cases, such as Recife,” he explains.
    “This lack of spatial correlation weakens the idea that the larvicide cause the problem.”

    * George Dimech, director of Disease Control and Diseases of the Health Department of (state of) Pernambuco, Brazil. Dimech’s CV here.

    WHO has approved the use of pyriproxyfen as a larvicide; it is used elsewhere in the world, and yet only where there is a 1) an epidemic of Zika, 2) with a high rate mutations over a short time frame, is the incidence of microcephaly and other neurological birth defects unusually high.

    There’s research on pyriproxyfen. There is not enough on Zika. Period.

  8. lefty665 says:

    Nice post Rayne, very good on Zika.
    .
    You might want to note that you’ve set up a straw man in your opening paragraph. To wit:
    .
    “claims persist that chemical exposure — specifically the pyridine-based pesticide pyriproxyfen — causes the birth defects seen in children born to women exposed to Zika virus,”
    .
    It would be correct to say “CAN cause the birth defects…”. I have not seen any claims that pyriproxyfen is the cause of birth defects and Zika causes none.
    .
    Statistical data from Columbia is now coming in showing that microcephaly in infants whose mothers were exposed to Zika in the first trimester are similar to those found in French Polynesia. The rate is about 1% of infants.
    .
    The reports from Brazil that touched off Zika hysteria have the percentage at 29%. A reanalysis of that data lowers the percentage by more than half to around 12-14%. That is still an order of magnitude higher than the rate developing in neighboring Columbia or found in French Polynesia.
    .
    The next question is why are Brazil’s rates so much higher? From the data you presented, mutations in Brazilian Zika may explain some of the difference. However, there does not seem to be a high likelyhood that Zika mutations would respect national borders and not show up in neighboring Columbia.
    .
    Another possibility is that there is a second agent that causes fetal abnormalities, or that acts as a catalyst to exacerbate the effects of Zika. One such possibility is the insecticide pyriproxyfen that was widely used in drinking water in Brazil. Sumitomo’s (its maker) testing shows it has the potential to cause microcephaly.
    .
    We’re learning more about microcephaly and its causes than any of us ever expected to know. There’s still some twists and turns we have not yet seent. With regard to putting insecticide in the drinking water, it does not seem like a good idea. If it turns out to be the cause of excess infant disease and death in Brazil, the treatment will have been worse than the disease. It goes back to the prime rule of Docs, “First do no harm”.
    .
    Pyriproxyfen is widely used in the US. If I were a woman thinking about getting pregnant I would avoid it. It’s especially common in pet flea and tick collars.
    .
    ps: Pyriproxyfen was not used in Refice City, but was widely used in the surrounding area also referred to as Refice. There is come confusion about that.

  9. lefty665 says:

    Here’s a pretty good statistical analysis of Zika and emerging microcephaly in Columbia. There are several good posts on that page about Zika. The statistics are first class and the data comes from places like New England Journal of Medicine.
    http://necsi.edu/research/social/pandemics/statusreport2
    .
    Pyriproxyfen Warning label, see especially precautions at bottom of page 2 about preventing contamination of food… rivers or dams, and triple rinsing of containers.
    http://www.villacrop.co.za/afrfiles/Pyriproxyfen%20100EC%20E_UCP.pdf

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