Brain organoids have emerged as a novel model system for neural development, neurodegenerative diseases, and human-based drug screening. However, the heterogeneous nature and immature neuronal development of brain organoids generated from pluripotent stem cells pose challenges. Moreover, there are no previous reports of a three-dimensional (3D) hypoxic brain injury model generated from neural stem cells. Here, we generated self-organized 3D human neural organoids from adult dermal fibroblast-derived neural stem cells. Radial glial cells in these human neural organoids exhibited characteristics of the human cerebral cortex trend, including an inner (ventricular zone) and an outer layer (early and late cortical plate zones). These data suggest that neural organoids reflect the distinctive radial organization of the human cerebral cortex and allow for the study of neuronal proliferation and maturation. To utilize this 3D model, we subjected our neural organoids to hypoxic injury. We investigated neuronal damage and regeneration after hypoxic injury and reoxygenation. Interestingly, after hypoxic injury, reoxygenation restored neuronal cell proliferation but not neuronal maturation. This study suggests that human neural organoids generated from neural stem cells provide new opportunities for the development of drug screening platforms and personalized modeling of neurodegenerative diseases, including hypoxic brain injury.

Three-dimensional (3D) bioprinting is a promising technology to establish a 3D in vitro hepatic model that holds great potential in toxicological evaluation. However, in current hepatic models, the central area suffers from hypoxic conditions, resulting in slow and weak metabolism of drugs and toxins. It remains challenging to predict accurate drug effects in current bioprinted hepatic models. Here, we constructed a hexagonal bioprinted hepatic construct and incorporated a spinning condition with continuous media stimuli. Under spinning conditions, HepG2 cells in the bioprinted hepatic construct exhibited enhanced proliferation capacity and functionality compared to those under static conditions. Additionally, the number of spheroids that play a role in boosting drug-induced signals and responses increased in the bioprinted hepatic constructs cultured under spinning conditions. Moreover, HepG2 cells under spinning conditions exhibited intensive TGFβ-induced epithelial-to-mesenchymal transition (EMT) and increased susceptibility to acetaminophen (APAP)-induced hepatotoxicity as well as hepatotoxicity prevention by administration of N-acetylcysteine (NAC). Taken together, the results of our study demonstrate that the spinning condition employed during the generation of bioprinted hepatic constructs enables the recapitulation of liver injury and repair phenomena in particular. This simple but effective culture strategy facilitates bioprinted hepatic constructs to improve in vitro modeling for drug effect evaluation.

In TNF-treated cells, TNFR1, TNFR-associated death domain protein (TRADD), Fas-associated death domain protein, and receptor-interacting protein kinase proteins form the signaling complex via modular interaction within their C-terminal death domains. In this paper, we report that the death domain SXXE/D motifs (i.e., S381DHE motif of TNFR1-death domain as well as S215LKD and S296LAE motifs of TRADD-death domain) are phosphorylated, and this is required for stable TNFR1–TRADD complex formation and subsequent activation of NF-κB. Phospho-S215LKD and phospho-S296LAE motifs are also critical to TRADD for recruiting Fas-associated death domain protein and receptor-interacting protein kinase. IκB kinase β plays a critical role in TNFR1 phosphorylation of S381, which leads to subsequent T cell migration and accumulation. Consistently, we observed in inflammatory bowel disease specimens that TNFR1 was constitutively phosphorylated on S381 in those inflammatory T cells, which had accumulated in high numbers in the inflamed mucosa. Therefore, SXXE/D motifs found in the cytoplasmic domains of many TNFR family members and their adaptor proteins may serve to function as a specific interaction module for the α-helical death domain signal transduction.

Atopic dermatitis (AD) is a chronic and inflammatory disease. According to a recent study, administration of canine MSCs is a potential therapy for immunological diseases. However, most related studies involve short-term experiments and acute atopic dermatitis animal models. Thus, studies of repeated subcutaneous injection of canine MSCs for ameliorating long-term inflammatory skin disorders have not yet been established. In this study, we evaluated the effects of long-term canine amniotic mesenchymal stem cells (cAM-MSCs) and calcineurin inhibitors (CNIs) treatments in mouse AD model for up to 8 weeks and compared the differences in therapeutic effect through canine peripheral blood mononuclear cells (PBMCs). Using a mouse model, we validated the therapeutic impact of cAM-MSCs in comparison to pimecrolimus (Pime), the most widely used CNIs, as a therapy for canine AD. Based on our results, we verified that the cAM-MSC treatment group exhibited substantially lower scores for tissue pathologic alterations, inflammatory cytokines, and dermatologic symptoms than the PBS control group. Importantly, compared with Pime, cAM-MSCs were more effective at preventing wound dysfunction and regulating mast cell activity. Additionally, we confirmed that immune modulation proteins (TGF-β1, IDO1, and COX-2) were increased in the cAM-MSCs treatment group. Furthermore, we examined the immunoregulatory effect of cAM-MSCs through the proliferation of T lymphocytes from activated canine PBMCs. As a result, cAM-MSCs suppressed the proliferative capacity of effector T cells from canine PBMCs more effectively than Pime. In conclusion, this study suggested that the cAM-MSCS could be an effective canine treatment for long-term canine AD through regeneration and immunomodulation.