Pulmonary fibrosis model using micro-CT analyzable human PSC-derived alveolar organoids containing alveolar macrophage-like cells

Advances in an In Vitro Tuberculosis Infection Model Using Human Lung Organoids for Host-Directed Therapies

The emergence of drug-resistant Mycobacterium tuberculosis (M.tb) has led to the development of novel anti-tuberculosis (anti-TB) drugs. Common methods for testing the efficacy of new drugs, including two-dimensional cell culture models or animal models, have several limitations. Therefore, an appropriate model representative of the human organism is required. Here, we developed an M.tb infection model using human lung organoids (hLOs) and demonstrated that M.tb H37Rv can infect lung epithelial cells and human macrophages (hMφs) in hLOs. This novel M.tb infection model can be cultured long-term and split several times while maintaining a similar number of M.tb H37Rv inside the hLOs. Anti-TB drugs reduced the intracellular survival of M.tb in hLOs. Notably, M.tb growth in hLOs was effectively suppressed at each passage by rifampicin and bedaquiline. Furthermore, a reduction in inflammatory cytokine production and intracellular survival of M.tb were observed upon knockdown of MFN2 and HERPUD1 (host-directed therapeutic targets for TB) in our M.tb H37Rv-infected hLO model. Thus, the incorporation of hMφs and M.tb into hLOs provides a powerful strategy for generating an M.tb infection model. This model can effectively reflect host-pathogen interactions and be utilized to test the efficacy of anti-TB drugs and host-directed therapies.

Human Pluripotent Stem Cell-Derived Alveolar Organoids: Cellular Heterogeneity and Maturity

Chronic respiratory diseases such as idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, and respiratory infections injure the alveoli; the damage evoked is mostly irreversible and occasionally leads to death. Achieving a detailed understanding of the pathogenesis of these fatal respiratory diseases has been hampered by limited access to human alveolar tissue and the differences between mice and humans. Thus, the development of human alveolar organoid (AO) models that mimic in vivo physiology and pathophysiology has gained tremendous attention over the last decade. In recent years, human pluripotent stem cells (hPSCs) have been successfully employed to generate several types of organoids representing different respiratory compartments, including alveolar regions. However, despite continued advances in three-dimensional culture techniques and single-cell genomics, there is still a profound need to improve the cellular heterogeneity and maturity of AOs to recapitulate the key histological and functional features of in vivo alveolar tissue. In particular, the incorporation of immune cells such as macrophages into hPSC-AO systems is crucial for disease modeling and subsequent drug screening. In this review, we summarize current methods for differentiating alveolar epithelial cells from hPSCs followed by AO generation and their applications in disease modeling, drug testing, and toxicity evaluation. In addition, we review how current hPSC-AOs closely resemble in vivo alveoli in terms of phenotype, cellular heterogeneity, and maturity.

hPSC-derived lung organoids: Potential opportunities and challenges

Three-dimensional hPSC-derived lung organoids resemble the fetal lung stage, making them an excellent model for studying human lung development. However, current hPSC-derived lung organoids remain incomplete as they lack native lung components such as vasculature, neurons and immune cells. This highlights the need to generate more complex hPSC-derived lung organoids that can faithfully mimic native human lungs for studying human lung development, regeneration, disease modeling and drug screen. In this review, we will discuss the current studies related to the generation of hPSC-derived lung organoids, highlighting how hPSC-derived lung organoids can contribute to the understanding of human lung development. We further focus on potential approaches to generate more complex hPSC-derived lung organoids containing native cellular components. Finally, we discuss the present limitations and potential applications of hPSC-derived lung organoids in the future.

Investigating nanoplastics toxicity using advanced stem cell-based intestinal and lung in vitro models

Plastic particles in the nanometer range-called nanoplastics-are environmental contaminants with growing public health concern. As plastic particles are present in water, soil, air and food, human exposure via intestine and lung is unavoidable, but possible health effects are still to be elucidated. To better understand the Mode of Action of plastic particles, it is key to use experimental models that best reflect human physiology. Novel assessment methods like advanced cell models and several alternative approaches are currently used and developed in the scientific community. So far, the use of cancer cell line-based models is the standard approach regarding in vitro nanotoxicology. However, among the many advantages of the use of cancer cell lines, there are also disadvantages that might favor other approaches. In this review, we compare cell line-based models with stem cell-based in vitro models of the human intestine and lung. In the context of nanoplastics research, we highlight the advantages that come with the use of stem cells. Further, the specific challenges of testing nanoplastics in vitro are discussed. Although the use of stem cell-based models can be demanding, we conclude that, depending on the research question, stem cells in combination with advanced exposure strategies might be a more suitable approach than cancer cell lines when it comes to toxicological investigation of nanoplastics.

Lysophosphatidylcholine inhibits lung cancer cell proliferation by regulating fatty acid metabolism enzyme long-chain acyl-coenzyme A synthase 5

Lung cancer is a widespread malignancy with a high death rate and disorder of lipid metabolism. Lysophosphatidylcholine (lysoPC) has anti-tumour effects, although the underlying mechanism is not entirely known. The purpose of this study aims at defining changes in lysoPC in lung cancer patients, the effects of lysoPC on lung cancer cells and molecular mechanisms. Lung cancer cell sensitivity to lysoPC was evaluated and decisive roles of long-chain acyl-coenzyme A synthase 5 (ACSL5) in lysoPC regulation were defined by comprehensively evaluating transcriptomic changes of ACSL5-downregulated epithelia. ACSL5 over-expressed in ciliated, club and Goblet cells in lung cancer patients, different from other lung diseases. LysoPC inhibited lung cancer cell proliferation, by inducing mitochondrial dysfunction, altering lipid metabolisms, increasing fatty acid oxidation and reprograming ACSL5/phosphoinositide 3-kinase/extracellular signal-regulated kinase-regulated triacylglycerol-lysoPC balance. Thus, this study provides a general new basis for the discovery of reprogramming metabolisms and metabolites as a new strategy of lung cancer precision medicine.