Spaceflight 🚀Jun 16, 2023

#Reuters 📆 June 8, 2023 #Astronauts 👩‍🚀 who traveled on the #ISS or #NASA #SpaceShuttles on missions lasting at least six months experienced significant #expansion of the cerebral ventricles - spaces 🕳️ in the middle of the brain containing cerebrospinal fluid. It took three years ⏳ for the ventricles to fully recover after such journeys https://www.reuters.com/science/scientists-document-how-space-travel-messes-with-human-brain-2023-06-08/

#HumanSpaceflightHealth

Picture : https://commons.wikimedia.org/wiki/File:Human_ventricular_system_-_animation.gif

Scientists document how space travel messes with the human brain

Space can be an <a href="/lifestyle/science/astronaut-study-reveals-effects-space-travel-human-bones-2022-07-02/">unfriendly place</a> for the human body, with microgravity conditions and other factors tampering with our physiology, from head to toe - head, of course, being a primary concern.

Reuters
Show threadSpaceflight 🚀Jun 25, 2023

Gene expression was at about one third the normal levels while in #space, the study found. This occurred within the first few days in space, but then remained at a stable level.
Other documented effects of #SpaceTravel include #bone 🦴 and #muscle 💪 atrophy, #cardiovascular changes, issues with the balance system in the inner ear and a syndrome involving the #eyes 👁️. Cancer risk from greater #radiation exposure is another concern. https://www.reuters.com/technology/space/study-reveals-how-immune-system-astronauts-breaks-down-2023-06-22/

#HumanSpaceflightHealth

Study reveals how immune system of astronauts breaks down

Evidence is <a href="/science/scientists-document-how-space-travel-messes-with-human-brain-2023-06-08/">growing</a> about the <a href="/lifestyle/science/astronaut-study-reveals-effects-space-travel-human-bones-2022-07-02/">many ways</a> that traveling in the microgravity environment of space tampers with the human body, with new research showing how it dials down the activity of genes in white blood cells crucial to the immune system.

Reuters
Show threadDNAvinciJun 25, 2023
@spaceflight
Physics shouldn't write biology, or even excerpt it, honestly.
That's a pretty rough cut. Makes it sound like all expression is 1/3
Show threadSpaceflight 🚀Jun 25, 2023
@dnavinci has the other expression been tested ?
Show threadDNAvinciJun 25, 2023

@spaceflight
Paper is only talking about leukocytes. The excerpt makes it sound like all human tissues are functioning 3 times higher hack on Earth.

Also, while I'm here: 3 isn't a transcriptionally reasonable number to observe. Transcripts are produced in doublings. We normally express the number in terms of log2-fold changes for this reason. You can get a number like 3 through averages between subjects.

Show threadDNAvinciJun 25, 2023
@spaceflight
Holy crap, I realized I have a LOT pro problems with this pop science study:
This is their PCA. It's got an "arch" effect as you might expect with samples collected over time, except their starting point is in the middle, not the end.
They threw out 68/139 samples for low quality (guess you can't take RNAlater into space?)
Their final sample set looks like it's only 3 astronauts completing the entire 10 point time series. Those 3 astronauts are NOT consistent with themselves.
Show threadDNAvinciJun 25, 2023
@spaceflight
Blood is a pretty variable tissue, and even modest circadian sampling time differences could produce 250 LFC>1 genes.
It would have been trivial to include the daily variability with the same sequencing kits of 20 more terrestrial astronauts over the same time period, and see if the changes that the astronauts observed were outside the confidence intervals for normal variation.
Of course, maybe a NASA budget isn't what it used to be...
Show threadDNAvinciJun 25, 2023

@spaceflight
Oh, and remember I was just saying that gene expression moves as "doubles"
```
Genes with adjusted p-values <0.1 and LFC values >|0.5| were identified as gene candidates differentially expressed between a given time-point comparison.
```
They're just ignoring that and going for half a doubling, and a p-value of 0.1 after FDR

Also no conveniently published results table and no data on the usual subject protection system of NIH.
It's behind some obscure, "email someone at NASA"

Show threadSpaceflight 🚀Jun 25, 2023
@dnavinci @dnavinci in case you're talking about this article https://www.frontiersin.org/articles/10.3389/fimmu.2023.1171103/full
You may either contact one of the authors at the University of Ottawa or Damien Chaussabel, Jackson Laboratory for Genomic Medicine, United States /
Jean-Pol Frippiat, Université de Lorraine, France
Sulev Kõks, Murdoch University, Australia
The transcriptome response of astronaut leukocytes to long missions aboard the International Space Station reveals immune modulation

IntroductionSpaceflight leads to the deconditioning of multiple body systems including the immune system. We sought to characterize the molecular response involved by capturing changes in leukocyte transcriptomes from astronauts transitioning to and from long-duration spaceflight.MethodsFourteen male and female astronauts with ~6-month- long missions aboard the International Space Station (ISS) had 10 blood samples collected throughout the three phases of the study: one pre-flight (PF), four in-flight (IF) while onboard the ISS, and five upon return to Earth (R). We measured gene expression through RNA sequencing of leukocytes and applied generalized linear modeling to assess differential expression across all 10 time points followed by the analysis of selected time points and functional enrichment of changing genes to identify shifts in biological processes.ResultsOur temporal analysis identified 276 differentially expressed transcripts grouped into two clusters (C) showing opposite profiles of expression with transitions to and from spaceflight: (C1) decrease-then-increase and (C2) increase-then-decrease. Both clusters converged toward average expression between ~2 and ~6 months in space. Further analysis of spaceflight transitions identified the decrease-then-increase pattern with most changes: 112 downregulated genes between PF and early spaceflight and 135 upregulated genes between late IF and R. Interestingly, 100 genes were both downregulated when reaching space and...

Frontiers
Show threadDNAvinci
@spaceflight
``` Aggregated data (read count tables and metadata) have been deposited in NASA’s Life Sciences Data Archives (LSDA) under dataset name “MARROW payload”. Investigators can request access to the astronaut data at [email protected].
```
It's the accepted norm in this field to upload the data to automated retrieval platforms such as SRA/GEO - or if there's a subject privacy risk - dbGAP
RNA alone at this point is not considered personally identifying
Jun 25, 2023 at 1:38pmWeb