ABSTRACT
Differentiated kidney organoids from induced pluripotent stem cells hold promise as a treatment for patients with kidney diseases. Before these organoids can be translated to the clinic, shortcomings regarding their cellular, extracellular compositions and developmental plateau needs to be overcome. We performed a proteomic analysis on kidney organoids cultured for a prolonged culture time and we found a specific change in the extracellular matrix composition with increased expression of types 1a1, 2 and 6a1 collagen. Such an excessive accumulation of specific collagen types is a hallmark of renal fibrosis that causes a life-threatening pathological condition by compromising key functions of the human kidney. Here we hypothesized the need for a three-dimensional environment to grow the kidney organoids, which could better mimic the in vivo surroundings of the developing kidney than standard culture on a transwell filter. Encapsulating organoids for four days in a soft, thiol-ene cross-linked alginate hydrogel resulted in decreased type 1a1 collagen expression. Furthermore, the encapsulation did not result in any changes of organoid structural morphology. Using a biomaterial to modulate collagen expression allows for a prolonged kidney organoid culture in vitro and a reduction of abnormal type 1a1 collagen expression bringing kidney organoids closer to clinical application.
HIGHLIGHTS
Prolonging kidney organoid culture results in a developmental plateau instead of improved in vitro maturation.
Proteomic analyses point to an increased expression of specific collagen subtypes associated with renal fibrosis.
Encapsulating kidney organoids using a soft thiol-ene cross-linked alginate hydrogel reduces collagen type 1a1 and αSMA deposition.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
CRediT author statement Thomas Geuens: Conceptualization, Performing of experiments, Investigation, Data analyses, Writing. Floor A.A. Ruiter: Conceptualization, Performing of experiments, Investigation, Data analyses, Writing. Anika Schumacher: Performing of experiments. Francis L. C. Morgan: Performing of experiments, Data analyses. Timo Rademakers: Performing of experiments. Loes E. Wiersma: Experimental Support. Cathelijne W. van den Berg: Experimental Support, Supervision. Ton J. Rabelink: Experimental Support, Supervision. Matthew B. Baker: Conceptualization, Reviewing, Editing, Supervision. Vanessa L.S. LaPointe: Conceptualization, Writing, Reviewing, Editing, Supervision.
The authors declare no conflict of interest.