Publikasjoner
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Harrison, Sean Philip; Baumgarten, Saphira Felicitas; Dugarte, Maria Eugenia Chollet; Stavik, Benedicte; Bhattacharya, Anindita & Almaas, Runar
[Vis alle 7 forfattere av denne artikkelen]
(2024).
Parenteral nutrition emulsion inhibits CYP3A4 in an iPSC derived liver organoids testing platform.
Journal of Pediatric Gastroenterology and Nutrition - JPGN.
ISSN 0277-2116.
78,
s. 1047–1058.
doi:
10.1002/jpn3.12195.
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Objectives Parenteral nutrition (PN) is used for patients of varying ages with intestinal failure to supplement calories. Premature newborns with low birth weight are at a high risk for developing PN associated liver disease (PNALD) including steatosis, cholestasis, and gallbladder sludge/stones. To optimize nutrition regimens, models are required to predict PNALD. Methods We have exploited induced pluripotent stem cell derived liver organoids to provide a testing platform for PNALD. Liver organoids mimic the developing liver and contain the different hepatic cell types. The organoids have an early postnatal maturity making them a suitable model for premature newborns. To mimic PN treatment we used medium supplemented with either clinoleic (80% olive oil/20% soybean oil) or intralipid (100% soybean oil) for 7 days. Results Homogenous HNF4a staining was found in all organoids and PN treatments caused accumulation of lipids in hepatocytes. Organoids exhibited a dose dependent decrease in CYP3A4 activity and expression of hepatocyte functional genes. The lipid emulsions did not affect overall organoid viability and glucose levels had no contributory effect to the observed results. Conclusions Liver organoids could be utilized as a potential screening platform for the development of new, less hepatotoxic PN solutions. Both lipid treatments caused hepatic lipid accumulation, a significant decrease in CYP3A4 activity and a decrease in the RNA levels of both CYP3A4 and CYP1A2 in a dose dependent manner. The presence of high glucose had no additive effect, while Clinoleic at high dose, caused significant upregulation of interleukin 6 and TLR4 expression.
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Harrison, Sean Philip; Siller, Richard; Tanaka, Yoshiaki; Dugarte, Maria Eugenia Chollet; Morena-Barrio, María Eugenia de la & Xiang, Yangfei
[Vis alle 36 forfattere av denne artikkelen]
(2023).
Scalable production of tissue-like vascularized liver organoids from human PSCs.
Experimental and Molecular Medicine.
ISSN 1226-3613.
55,
s. 2005–2024.
doi:
10.1038/s12276-023-01074-1.
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Abstract The lack of physiological parity between 2D cell culture and in vivo culture has led to the development of more organotypic models, such as organoids. Organoid models have been developed for a number of tissues, including the liver. Current organoid protocols are characterized by a reliance on extracellular matrices (ECMs), patterning in 2D culture, costly growth factors and a lack of cellular diversity, structure, and organization. Current hepatic organoid models are generally simplistic and composed of hepatocytes or cholangiocytes, rendering them less physiologically relevant compared to native tissue. We have developed an approach that does not require 2D patterning, is ECM independent, and employs small molecules to mimic embryonic liver development that produces large quantities of liver-like organoids. Using single-cell RNA sequencing and immunofluorescence, we demonstrate a liver-like cellular repertoire, a higher order cellular complexity, presenting with vascular luminal structures, and a population of resident macrophages: Kupffer cells. The organoids exhibit key liver functions, including drug metabolism, serum protein production, urea synthesis and coagulation factor production, with preserved post-translational modifications such as N-glycosylation and functionality. The organoids can be transplanted and maintained long term in mice producing human albumin. The organoids exhibit a complex cellular repertoire reflective of the organ and have de novo vascularization and liver-like function. These characteristics are a prerequisite for many applications from cellular therapy, tissue engineering, drug toxicity assessment, and disease modeling to basic developmental biology.
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Harrison, Sean; Baumgarten, Saphira Felicitas; Verma, Rajneesh; Lunov, Oleg; Dejneka, Alexandr & Sullivan, Gareth
(2021).
Liver Organoids: Recent
Developments, Limitations and
Potential.
Frontiers in Medicine.
8.
doi:
10.3389/fmed.2021.574047.
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Liver cell types derived from induced pluripotent stem cells (iPSCs) share the potential to investigate development, toxicity, as well as genetic and infectious disease in ways currently limited by the availability of primary tissue. With the added advantage of patient specificity, which can play a role in all of these areas. Many iPSC differentiation protocols focus on 3 dimensional (3D) or organotypic differentiation, as these offer the advantage of more closely mimicking in vivo systems including; the formation of tissue like architecture and interactions/crosstalk between different cell types. Ultimately such models have the potential to be used clinically and either with or more aptly, in place of animal models. Along with the development of organotypic and micro-tissue models, there will be a need to co-develop imaging technologies to enable their visualization. A variety of liver models termed “organoids” have been reported in the literature ranging from simple spheres or cysts of a single cell type, usually hepatocytes, to those containing multiple cell types combined during the differentiation process such as hepatic stellate cells, endothelial cells, and mesenchymal cells, often leading to an improved hepatic phenotype. These allow specific functions or readouts to be examined such as drug metabolism, protein secretion or an improved phenotype, but because of their relative simplicity they lack the flexibility and general applicability of ex vivo tissue culture. In the liver field these are more often constructed rather than developed together organotypically as seen in other organoid models such as brain, kidney, lung and intestine. Having access to organotypic liver like surrogates containing multiple cell types with in vivo like interactions/architecture, would provide vastly improved models for disease, toxicity and drug development, combining disciplines such as microfluidic chip technology with organoids and ultimately paving the way to new therapies.
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Sharma, Kulbhushan; Asp, Nagham Theres; Harrison, Sean; Siller, Richard; Baumgarten, Saphira Felicitas & Gupta, Swapnil
[Vis alle 10 forfattere av denne artikkelen]
(2021).
Autophagy modulates cell fate decisions during lineage commitment.
Autophagy.
ISSN 1554-8627.
s. 1–17.
doi:
10.1080/15548627.2021.2008691.
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Early events during development leading to exit from a pluripotent state and commitment toward a specific germ layer still need in depth understanding. Autophagy has been shown to play a crucial role in both development and differentiation. This study employs human embryonic and induced pluripotent stem cells to understand the early events of lineage commitment with respect to the role of autophagy in this process. Our data indicate that a dip in autophagy facilitates exit from pluripotency. Upon exit, we demonstrate that the modulation of autophagy affects SOX2 levels and lineage commitment, with induction of autophagy promoting SOX2 degradation and mesendoderm formation, whereas inhibition of autophagy causes SOX2 accumulation and neuroectoderm formation. Thus, our results indicate that autophagy-mediated SOX2 turnover is a determining factor for lineage commitment. These findings will deepen our understanding of development and lead to improved methods to derive different lineages and cell types.
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Publisert
28. nov. 2019 12:47
- Sist endret
28. nov. 2019 12:53
