Periodic Reporting for period 4 - MicroAdiPSChip (Micro-Fat Tissue on Chip)
Berichtszeitraum: 2022-12-01 bis 2024-05-31
Obesity has been defined as abnormal or excessive fat accumulation. The prevalence of obesity in the Western world has reached more than 35 % of the population, and thus has grown to epidemic proportions. The most effective treatment for obesity is dietary and lifestyle changes; however, these approaches are difficult to maintain over the long term. Therefore, existing pharmacological and surgical interventions largely act by either suppressing caloric intake or reducing stomach size, respectively. Despite all efforts, obesity and related diseases remain major health risks for patients and are associated with high healthcare costs in most countries. An attractive alternative for treating obesity is to reduce the lipid storage function of the adipose tissue by reprogramming its cell type composition. The human fat is mainly composed of white adipose tissue, which exhibits low capacities to burn fat on its own. Nevertheless, a small fraction of fat cells, named brown and beige fat cells, is able to burn fat and produce heat in order to maintain the body temperature. The cells are present primarily in newborns before reducing in number upon aging. Knowledge of the developmental factors, which govern fat cell type specification can potentially be used to increase the brown-like properties of white fat depots in obese patients. This interdisciplinary research project investigated the in vitro adipogenesis of hiPSCs under diverse chemical, architectural, and mechanical microenvironments. MicroAdiPSChip’s overarching goal was to engineer a microfluidic chip technology for 3D cell cultures, focusing on identifying factors of the cells’ micro-environment required for differentiating hiPSCs into metabolically active adipocytes. The project’s key biological question was whether adipocytes could be shifted from white (= excess fat storage, low metabolic activity) to beige (= high metabolic activity) in vitro, hypothesizing that enhancing metabolic rates in adipocytes could serve as an intervention for obesity.
During the MicroAdiPSChip funding period, we achieved several research milestones.
Engineering Achievements: We developed microfluidic chip technologies for 3D adipocyte tissue models, methods to assemble adipose tissues with different architectures, and optically controlled hydrogels for tissue printing. We also advanced techniques for single-cell transcriptome analysis with spatial data. By enhancing microfluidic large-scale integration (mLSI) for 3D cell cultures, we created platforms supporting numerous cell culture chambers, successfully culturing hiPSCs in 3D. This optimized differentiation protocols, reducing off-target effects and material use. Additionally, we integrated automated imaging workflows for high-throughput analysis of 3D cultures, improving immunofluorescence histology and label-free imaging throughput.
Biological Achievements: Using mLSI technology, we differentiated human adipocytes from patient-derived stromal vascular fractions in 3D cultures, simulating periodic food intake andrevealing a shift from white to beige adipocytes. To overcome challenges with differentiating hiPSCs into mature adipocytes, we developed vascularized adipocyte organoids. Additionally, we applied our advancements in cell culture technology to generate pancreatic ductal organoids, further advancing pancreatic cancer models. Our new Organ-on-Chip (OoC) platform enabled the integration of advanced technologies, such as single-cell RNA sequencing. The Vessel-on-Chip model demonstrated endothelial cell maturation and arterial toning, supporting research in vascular biology.
Finally, we developed xDBiT, a cost-effective spatial transcriptomics method that improves gene counts and resolution. This technology has been applied to studies on aging and liver function under a high-fat diet, providing new insights into liver zonation.
In summary, our work highlights the significant impact of advanced microfluidic and organoid technologies on addressing complex biological challenges, especially in the creation of clinically relevant tissue models.
Engineering Achievements: We developed microfluidic chip technologies for 3D adipocyte tissue models, methods to assemble adipose tissues with different architectures, and optically controlled hydrogels for tissue printing. We also advanced techniques for single-cell transcriptome analysis with spatial data. By enhancing microfluidic large-scale integration (mLSI) for 3D cell cultures, we created platforms supporting numerous cell culture chambers, successfully culturing hiPSCs in 3D. This optimized differentiation protocols, reducing off-target effects and material use. Additionally, we integrated automated imaging workflows for high-throughput analysis of 3D cultures, improving immunofluorescence histology and label-free imaging throughput.
Biological Achievements: Using mLSI technology, we differentiated human adipocytes from patient-derived stromal vascular fractions in 3D cultures, simulating periodic food intake andrevealing a shift from white to beige adipocytes. To overcome challenges with differentiating hiPSCs into mature adipocytes, we developed vascularized adipocyte organoids. Additionally, we applied our advancements in cell culture technology to generate pancreatic ductal organoids, further advancing pancreatic cancer models. Our new Organ-on-Chip (OoC) platform enabled the integration of advanced technologies, such as single-cell RNA sequencing. The Vessel-on-Chip model demonstrated endothelial cell maturation and arterial toning, supporting research in vascular biology.
Finally, we developed xDBiT, a cost-effective spatial transcriptomics method that improves gene counts and resolution. This technology has been applied to studies on aging and liver function under a high-fat diet, providing new insights into liver zonation.
In summary, our work highlights the significant impact of advanced microfluidic and organoid technologies on addressing complex biological challenges, especially in the creation of clinically relevant tissue models.
The MicroAdiPSChip project led to the following novel technologies and scientific advances beyond the state of the art:
1) The generation of two new microfluidic chip platforms for long-term culturing and processing 3D of human stem cell cultures.
2) A new additive manufacturing technology for microfluidic chip production.
3) A differentiation platform to derive white adipocytes from human induced pluripotent stem cell in high yield.
4) The engineering of vascularized human adipose organdies and tissue on a Organ-on-Chip platform.
5) A single cell study of in vitro blood vessel formation from stem cell-derived endothelial cells within chip compatible hydrogel.
6) A new spatial transcriptomic technology to investigate spatial architecture of human tissues.
7) New AI imaging tools to infer stem cell states within high throughput image data sets.
With these advances, we set the foundation to provide much needed insights into adipocyte cell type development and therewith create the basis for new strategies for obesity therapies as proposed.
1) The generation of two new microfluidic chip platforms for long-term culturing and processing 3D of human stem cell cultures.
2) A new additive manufacturing technology for microfluidic chip production.
3) A differentiation platform to derive white adipocytes from human induced pluripotent stem cell in high yield.
4) The engineering of vascularized human adipose organdies and tissue on a Organ-on-Chip platform.
5) A single cell study of in vitro blood vessel formation from stem cell-derived endothelial cells within chip compatible hydrogel.
6) A new spatial transcriptomic technology to investigate spatial architecture of human tissues.
7) New AI imaging tools to infer stem cell states within high throughput image data sets.
With these advances, we set the foundation to provide much needed insights into adipocyte cell type development and therewith create the basis for new strategies for obesity therapies as proposed.