Project description:Single cell RNA seq to compare the gene expression profile of hepatocytes cultured in expansion or differentiation media to primary hepatocytes
Project description:Adult primary human hepatocytes (PHHs) are the gold standard in ex vivo toxicological studies and possess the clinical potential to treat patients with liver disease as advanced therapy medicinal products (ATMPs). However, the utility of this valuable cell type has been limited by short-term functionality and limited expansion potential in vitro. While notable advances have been made in the long-term maintenance of primary hepatocytes, there has been limited success in driving the efficient generation and expansion of adult PHH-derived organoids which recapitulate both liver tissue architecture and function, hampering in vitro studies and regenerative medicine applications. Here we describe the mass generation and long-term expansion of hepatocyte organoids with functionally interconnected hepatic and biliary-like structures from adult primary human hepatocytes. Hepatocyte organoids retain the expression of lineage and functional markers, closely resembling PHH, while also acquiring the expression of regeneration, fetal and biliary markers. Organoids perform key hepatocyte functions while proliferating and can be matured to enhance their functionality. As a proof-of-principle, we demonstrate that hepatocyte organoids can recapitulate hallmarks of cholestasis and steatosis in vitro. Moreover, we show that hepatocytes can be transfected, transduced and gene edited in 3D prior to organoid generation, facilitating a wide range of applications. Our novel hepatocyte organoid system bridges the gap between short-term functionality of primary human hepatocytes and the need for scalable, long-term organoid models of the adult liver, offering immense potential for drug testing, disease modeling, and advanced therapeutic applications.
Project description:In the healthy adult liver, most hepatocytes proliferate minimally. However, upon physical or chemical injury to the liver, hepatocytes proliferate extensively in vivo under the direction of multiple extracellular cues, including Wnt and pro-inflammatory signals. Currently, liver organoids can be generated readily in vitro from bile-duct epithelial cells, but not hepatocytes. Here, we show that TNFα, an injury-induced inflammatory cytokine, promotes the expansion of hepatocytes in 3D culture and enables serial passaging and long-term culture for more than 6 months. Single-cell RNA sequencing reveals broad expression of hepatocyte markers. Strikingly, in vitro-expanded hepatocytes engrafted, and significantly repopulated, the injured livers of Fah-/- mice. We anticipate that tissue repair signals can be harnessed to promote the expansion of otherwise hard-to-culture cell-types, with broad implications.
Project description:3D spheroids of primary human hepatocytes (3D PHH) keep a differentiated phenotype with retained metabolic function and proteome fingerprint for weeks in culture. As a result, 3D PHH are gaining ground as a model for mechanistic studies on liver homeostasis and in vitro to in vivo (IVIV)predictions in drug discovery. However, the function of drug-transporting proteins has not yet been studied in the 3D PHH. Here we used the organic cation transporter 1 (OCT1/SLC22A1) as a model to explore both transporter kinetics and long-term regulation of transporter activity via different pathways. The 3D PHH were cultured for one week and then used for short- and long-term studies. The OCT1 transporter kinetics was assessed using the fluorescent model substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium (ASP+) and known OCT1 inhibitors in individual 3D PHH. For long-term studies, the 3D PHH were exposed to xenobiotics for seven days, after which protein expression and OCT1 function were assessed. Global proteomics analysis was used to track prototypical changes of other regulated proteins. ASP+ kinetics indicated a fully functional OCT1 transporter with a Km value of 14.14±3.97 using three donors. Established OCT1 inhibitors reduced the uptake of ASP+ in the 3D PHH spheroids, resulting in 40-60% of the maximal uptake rate of ASP+. The long-term exposure studies showed that OCT1 is relatively stable to the activation of a broad range of pathways known to regulate ADME proteins. Importantly, while expression levels of other ADME proteins, such as CYP3A4 and MDR1 were regulated as expected, OCT1 levels remained stable. In conclusion, our results show for the first time that 3D PHH spheroids express fully active OCT1 and that transporter kinetics can be studied in 3D PHH. We also confirm that OCT1 remains stable and functional during activation of various pathways that alter the expression and function of other ADME proteins.
Project description:Primary hepatocytes have been widely explored as cell sources for the study of in vitro drug metabolism and pharmacokinetics (DMPK). Aiming toward establishing an in vitro drug screening method, the current study illustrated a comprehensive increase in the DMPK-related gene expression of nanopillar (NP)-cultured 3D-spheroid. To examine the expressional changes in DMPK-related genes under four different conditions, namely, NP-, sandwich (SW)-, monolayer (ML)-cultured rat hepatocytes, and freshly isolated hepatocytes, genome-wide gene-expression analysis using a DNA microarray was performed. Among the DMPK-related genes, cytochrome P450, UDP-glucuronosyltransferase, and transporter genes were focused on. Principal component analysis showed that the global gene expression profile in sample from NP culture is closer to that from freshly isolated hepatocytes than that from SW culture. The expressions of almost all Cyp 1 to 3 and Ugt genes of NP-cultured 3-D spheroid were higher than those of ML and SW. The expression of Abcc2 gene whose translation product has a critical role in excretion of metabolized bile acids in hepatocyte to bile canaliculi was three times higher in NP than in ML. From these results, 3-D spheroid formed by the NP culture was suggested to possess higher ability of metabolism and excretion than conventional 2-D monolayer culture. The NP culture has a potential as an alternative culturing technique for evaluating metabolism and toxicity toward the development of new drugs. Gene expression in rat hepatocyte was measured under four different conditions, namely, Nanopillar (NP)-, sandwich (SW)-, monolayer (ML)-cultured rat hepatocytes, and freshly isolated hepatocytes. Three independent experiments were performed at 95 hours of post-seeding.
Project description:In vitro models that mimic ovaries are instrumental in unraveling physio-pathological mechanisms underlining follicle activation and growth. Three-dimensional (3D) systems that replicate the heterogeneity and cell-cell communication among different ovarian cell types are biologically most relevant. However, such models using human primary ovarian cells have not yet been established and standardized. Here, we developed and characterized long-term cultured 3D models of primary ovarian somatic cells, isolated from normal adult tissues, using Biosilk as a scaffold. We successfully created both cortex- and medulla-derived 3D systems (Silk-Ovarioids). Through transcriptomics, proteomics, and immunostaining, we identified the presence of key ovarian somatic cell types (granulosa, stroma, endothelial and perivascular cells). Notably, the Silk-Ovarioids exhibit the formation of a proangiogenic hypoxic core, as evidenced by the formation of vessel-like structures after 6 weeks of culture. The Silk-Ovarioids have low inter/intra-batch variability and long-term culture stability, highlighting their potential as a robust step towards a bioengineered patient-specific artificial ovary.