Lab-grown kidney tissue gets better structure

Kidney organoids are small pieces of kidney tissue grown in the laboratory from stem cells. They resemble a real kidney but often lack the correct spatial organisation. Researchers used synthetic cells that secrete a protein signal normally responsible for guiding development (the Wnt signalling pathway). By placing these artificial ‘organisers’ at specific positions, the organoids developed a better internal structure. The study was published in Science.

Wnt signals direct tissue patterning

The Wnt signalling pathway is a communication system that tells cells where they are in an organ and what role they should play. In a developing kidney, this system produces an orderly arrangement of different cell types. Existing organoids often lacked this spatial structure. The synthetic organisers mimicked this signal in a location-specific way, resulting in more accurate tissue patterning.

The technique uses so-called ‘sender’ cells: cells engineered to deliver exactly the right signal at the right time and place. This differs from adding growth factors to the culture medium, which provides less spatial control.

Relevance for disease research and ageing

Kidney function declines with age. Better models of kidney tissue are relevant for understanding both congenital kidney disorders and age-related decline. Organoids with improved structure could in future be used to test drugs or study the mechanisms of kidney deterioration.

The step towards clinical applications remains large. These organoids are not functional kidneys and cannot currently be used for transplantation. The study does show that it is possible to direct tissue self-organisation more precisely, which represents a step forward in tissue engineering.

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