NASA study of twins ex­plores ge­netic fron­tier

The Charlotte Observer (Sunday) - - Insight - BY LAURAN NEERGAARD As­so­ci­ated Press

From his eyes to his immune sys­tem, astronaut Scott Kelly’s body some­times re­acted strangely to nearly a year in or­bit, at least com­pared to his Earth-bound iden­ti­cal twin – but newly pub­lished re­search shows noth­ing that would can­cel even longer space treks, like to Mars.

The good news: Kelly largely bounced back after re­turn­ing home, say sci­en­tists who re­leased fi­nal re­sults from NASA’s “twins study,” a ne­ver­be­fore op­por­tu­nity to track the bi­o­log­i­cal con­se­quences of space­flight in ge­netic dou­bles.

It marks “the dawn of hu­man ge­nomics in space,” said Dr. An­drew Fein­berg of Johns Hop­kins Uni­ver­sity. He led one of 10 teams of re­searchers that scru­ti­nized the twins’ health down to the molec­u­lar level be­fore, dur­ing and after Kelly’s 340-day stay at the In­ter­na­tional Space Sta­tion.

More im­por­tantly, the study “rep­re­sents more than one small step for mankind” by point­ing out po­ten­tial risks of longer­du­ra­tion space­flight that need study in more astro­nauts, said Markus Lo­brich of Ger­many’s Darm­stadt Uni­ver­sity and Penny Jeggo of the Uni­ver­sity of Sus­sex, who weren’t in­volved in the work.

The find­ings were pub­lished in Fri­day’s edi­tion of the jour­nal Sci­ence, on some notable space anniversaries – when Soviet cos­mo­naut Yuri Ga­garin be­came the first per­son in space in 1961, and the first launch of the space shut­tle in 1981.

Key find­ings: NASA al­ready knew some of the toll of space travel, such as bone loss that re­quires ex­er­cise to counter. This time, NASA-funded sci­en­tists looked for a gamut of phys­i­o­logic and ge­nomic changes that Scott Kelly ex­pe­ri­enced in space, com­par­ing them to his DNA dou­ble on the ground, for­mer astronaut Mark Kelly. Some re­sults had been re­ported in Fe­bru­ary.

Pos­si­bly the weird­est find­ing had to do with some­thing called telom­eres, the pro­tec­tive ends of chro­mo­somes. Those tips grad­u­ally shorten as we get older, and are thought to be linked to age-re­lated dis­eases in­clud­ing some can­cers.

But in space, Scott Kelly’s telom­eres got longer. “We were sur­prised,” said Colorado State Uni­ver­sity telom­ere ex­pert Su­san Bai­ley. She can’t ex­plain it al­though it doesn’t mean Kelly got younger. Back on Earth, his telom­eres mostly re­turned to pre­flight av­er­age al­though he did have more short telom­eres than be­fore.

Next, Kelly’s DNA wasn’t mu­tated in space but the ac­tiv­ity of many of his genes – how they switch on and off – did change, es­pe­cially in the last half of the voy­age, which ended in March 2016.

Immune sys­tem genes es­pe­cially were af­fected, putting it “al­most on high alert as a way to try and un­der­stand this new en­vi­ron­ment,” said study co-au­thor Christo­pher Ma­son, a Weill Cor­nell Medicine ge­neti­cist in New York.

Again, most gene ex­pres­sion re­turned to nor­mal back home, but some of the immune-re­lated genes were hy­per­ac­tive six months later.

“We learned that the hu­man body is pretty re­silient and we can sur­vive and to some ex­tent maybe even thrive on th­ese long-du­ra­tion flights,” Mark Kelly said. Other find­ings:

Some changes in the

● struc­ture of Kelly’s eye and thick­en­ing of his retina sug­gested that, like about 40% of astro­nauts, he ex­pe­ri­enced symp­toms of “space­flight-as­so­ci­ated neuro-oc­u­lar syn­drome.” It may be caused by flu­ids shift­ing in the ab­sence of grav­ity.

●He ex­pe­ri­enced some chro­mo­so­mal in­sta­bil­ity that might re­flect ra­di­a­tion ex­po­sure in space.

●● flu shot given in space worked as well as one on Earth.

Kelly aced cog­ni­tive

● tests in space but slowed down after his re­turn, maybe as more things com­peted for his at­ten­tion.

What the Kellys say: “It was a real priv­i­lege to be part of this study,” said Scott Kelly, who spent the year in space along with Rus­sia’s Mikhail Kornienko. Kelly re­tired from NASA soon after his re­turn.

He said it prob­a­bly took him six months once back on Earth be­fore he felt 100% again, but ac­knowl­edged his wife said it seemed more like eight months. What was par­tic­u­larly hard, he said, was get­ting used to not hav­ing a sched­ule dic­tat­ing his life in five-minute in­cre­ments ev­ery sin­gle day, like there was in space.

Dur­ing a tele­con­fer­ence he joked with his twin, “I got all the glory and you got a lot of work.”

“I got peo­ple com­ing to my house, right, for tubes of blood,” re­sponded Mark Kelly.

“But it’s great we saw and we learned that the hu­man body is pretty re­silient and we can sur­vive and to some ex­tent maybe even thrive on th­ese long-du­ra­tion flights,” he added.

As for trips to Mars, Mark Kelly said: “I hope it’s sooner rather than later, and hopefully, our par­tic­i­pa­tion in this study will help us get closer to mak­ing a mis­sion like that a suc­cess.”

Ul­tra long-dis­tance test­ing: Re­searchers needed months’ worth of blood, urine and fe­cal sam­ples, along with cog­ni­tive and phys­i­cal tests and ul­tra­sound scans. That meant get­ting cre­ative: Some blood sam­ples re­quired anal­y­sis so rapidly that Kelly would time col­lec­tion so the blood could travel on Rus­sian Soyuz cap­sules car­ry­ing other astro­nauts back to Earth.

That wouldn’t be an op­tion on a three-year trip to Mars. One of the study’s tech­no­log­i­cal ad­vances: Por­ta­ble DNAse­quenc­ing equip­ment that will let astro­nauts run some of their own ge­nomic analy­ses on fu­ture mis­sions, said Weill Cor­nell’s Ma­son.

PAT SULLIVAN AP

Spend­ing nearly a year in space had some strange ef­fects on NASA astronaut Scott Kelly, left, com­pared to his Earth-bound twin, Mark.

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