Juliette Hadchouel: Nourishing the child within

Curious, free to explore their interests and futures, scientists are perpetual children who never stop asking questions. The career of Juliette Hadchouel is one of an Inserm researcher who grew up surrounded by science, and who cultivates this space for others, particularly children, in the hope of getting them to think about public health issues.

Like many children, Hadchouel had her future all mapped out. She dreamt of becoming a veterinarian. But brought up short by the reality of the profession, and drawn to laboratory work, she embarked on a thesis at Institut Pasteur, focusing on developmental biology and molecular genetics. “It was fantastic to find out how, from a single cell, you could obtain arms, legs, eyes, etc.”, she describes. And she quickly began to think bigger: “In general, studying the developing embryo means working over a very short period of time and on a specific population of cells. In the end, it’s quite reductive and I wanted to go back to a broader form of study, on the animal as a whole, as I was able to do in veterinary school.”

Next step: Scotland

Hadchouel then began a postdoc in physiology in Edinburgh. With a researcher mother whose focus was the liver, Hadchouel – although delighted to share the same profession – refused to study the same organ. The choice of studying the kidneys was made almost by itself: “It was above all a geographical choice. I wanted to go to Scotland and so I made it happen. I found a renal physiology unit that I was interested in. My career so far is also a combination of circumstances.” And as it happened, the end of Hadchouel’s thesis coincided with numerous discoveries of genes responsible for genetic diseases. “But the story ended with the identification of the gene, describes the researcher. I wanted to find out what happens next, about the transition from mutation to disease. This is what I did by combining my knowledge of renal physiology with the genetic tools developed during my thesis.”

When she returned to Paris, she passed her competitive examination first time around to become an Inserm Research Fellow. She found a position in which she analysed the role of the WNK1 gene in Gordon’s syndrome, a rare form of high blood pressure that originates in the kidney. “It was the project I’d always dreamed of”, she says. By dissecting the molecular and physiological mechanisms that lead to this pathology, Hadchouel would also contribute to understanding a physiological paradox that had remained unresolved for decades – that of aldosterone, a hormone that acts on the absorption of salt and the secretion of potassium by the kidneys. “While our discovery didn’t make the headlines, we addressed a problem that was in the physiology textbooks.”

Hadchouel worked on this physiological process for 14 years. Then, in 2016, she changed research unit and field, switching from renal physiology to renal pathologies at CoRaKiD in Tenon Hospital in Paris – the only research unit in France to work exclusively on kidney diseases. It was a big change: “We had told a great story. I was starting to go round in circles, limited by the tools at my disposal. But that’s the beauty of the research profession: it isn’t routine. If we want to change, we can. Right now, I’m discovering a new field of research. Although I work on the same organ, it’s as if I’ve changed my subject of study.”

Hadchouel is now passionate about a rapidly expanding field: that of acute kidney injury, which is characterised by a sudden loss of kidney function. Although normal function is often regained, this event weakens the kidney, which keeps the aggression in its memory. How, why and what are the means to repair, limit or prevent damage? These are all questions that the researcher now wishes to solve, not just for her own personal satisfaction, but also for her favourite audience: schoolchildren.

Making discoveries and sharing knowledge

For Hadchouel, being a researcher is not just about making discoveries. It is also about passing on knowledge, both to her peers and a wider audience: “Civil-service researchers have a duty to share knowledge.” Hadchouel makes the most of the versatility of her position at Inserm to work with children from primary to the end of sixth form. She shares her knowledge and discoveries in the classroom and by opening the doors to her laboratory. “I see in them my desire to understand,” she explains. Children are like scientists: they are curious. It’s in their nature to ask questions. Scientists are children who still had questions. And when the people around them no longer had the answers, they decided to look for them alone!”

Now spokesperson for this type of initiative for her colleagues and Inserm, Hadchouel offers fun and interactive formats that inform and encourage reflection on research practices and public health issues. Based on her work on the kidneys, she explains the burden of chronic disease on our societies while emphasising the role of prevention. “Children understand by themselves the importance of looking after their health, she explains. But they don’t feel all that concerned by the problems of old age. By understanding what is at stake, they quickly realise that you need to start young.”

The messages also inspire the researcher’s initiatives, which aim to democratise these practices and re-engage Inserm’s interaction with schoolchildren. “By working with children, I reconnect with a part of myself and give meaning to what I do, she concludes. It puts our discoveries into perspective. This aspect of a researcher’s work is just as important, not just for me but for society. I’d like to see it get more recognition.” A new mission that Hadchouel will certainly put her heart into accomplishing.

Juliette Hadchouel co-leads the Common and Rare Kidney Diseases: From Molecular Mechanisms to Precision Medicine research unit (CoRAKiD, unit 1155 Inserm/Sorbonne University) at Tenon Hospital, Paris.