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Nattamai, K.

Publications and source records attributed to Nattamai, K..

2 recordsLinked to original sources

Engineering Large-Scale and Innervated Functional Human Gut for Transplantation

A confined culture system (CCS) establishes methods to generate complex functional human gastrointestinal tissues. This approach yields large-scale innervated small intestinal, colonic and gastric organoids with an elongated tubular shape for both in vitro and in vivo studies. Transcriptomic and electrophysiological data demonstrate the co-development of a functional de novo enteric nervous system, which is absent from conventional organoids. When compared to traditional methods, CCS derived small intestinal, colonic and gastric organoids reached maturation supporting transplantation in half of the time, resulting in enhanced engraftment rates and sizes. Murine luminal content exposure within CCS organoids in vivo further augmented function, supporting the potential translational benefits required to model complex intestinal diseases. In summary, the CCS methodology simplifies current protocols while adding complexity and expediting the generation of clinically relevant functional gut tissues.

bioengineering↗

A Wnt5a-Cdc42 axis controls aging and rejuvenation of hair-follicle stem cells

Normal hair growth occurs in cycles, comprising growth (anagen), cessation (catagen) and rest (telogen). Upon aging, the initiation of anagen is significantly delayed, which results in impaired hair regeneration. Hair regeneration is driven by hair follicle stem cells (HFSCs). We show here that aged HFSCs present with a decrease in canonical Wnt signaling and a shift towards non-canonical Wnt5a driven signaling which antagonizes canonical Wnt signaling. Elevated expression of Wnt5a in HFSCs upon aging results in elevated activity of the small RhoGTPase Cdc42 as well as a change in the spatial distribution of Cdc42 within HFSCs. Treatment of aged HFSC with a specific pharmacological inhibitor of Cdc42 activity termed CASIN to suppress the aging-associated elevated activity of Cdc42 restored canonical Wnt signaling in aged HFSCs. Treatment of aged mice in vivo with CASIN induced anagen onset and increased the percentage of anagen skin areas. Aging-associated functional deficits of HFSCs are at least in part intrinsic to HFSCs and can be restored by rational pharmacological approaches.

cell biology↗