Airway regeneration using iPS cell-derived airway epithelial cells with Cl- channel function

Lung Progenitor and Stem Cell Transplantation as a Potential Regenerative Therapy for Lung Diseases

Chronic lung diseases are debilitating illnesses ranking among the top causes of death globally. Currently, clinically available therapeutic options capable of curing chronic lung diseases are limited to lung transplantation, which is hindered by donor organ shortage. This highlights the urgent need for alternative strategies to repair damaged lung tissues. Stem cell transplantation has emerged as a promising avenue for regenerative treatment of the lung, which involves delivery of healthy lung epithelial progenitor cells that subsequently engraft in the injured tissue and further differentiate to reconstitute the functional respiratory epithelium. These transplanted progenitor cells possess the remarkable ability to self-renew, thereby offering the potential for sustained long-term treatment effects. Notably, the transplantation of basal cells, the airway stem cells, holds the promise for rehabilitating airway injuries resulting from environmental factors or genetic conditions such as cystic fibrosis. Similarly, for diseases affecting the alveoli, alveolar type II cells have garnered interest as a viable alveolar stem cell source for restoring the lung parenchyma from genetic or environmentally induced dysfunctions. Expanding upon these advancements, the use of induced pluripotent stem cells to derive lung progenitor cells for transplantation offers advantages such as scalability and patient specificity. In this review, we comprehensively explore the progress made in lung stem cell transplantation, providing insights into the current state of the field and its future prospects.

Advanced In Vitro Lung Models for Drug and Toxicity Screening: The Promising Role of Induced Pluripotent Stem Cells

The substantial socioeconomic burden of lung diseases, recently highlighted by the disastrous impact of the coronavirus disease 2019 (COVID-19) pandemic, accentuates the need for interventive treatments capable of decelerating disease progression, limiting organ damage, and contributing to a functional tissue recovery. However, this is hampered by the lack of accurate human lung research models, which currently fail to reproduce the human pulmonary architecture and biochemical environment. Induced pluripotent stem cells (iPSCs) and organ-on-chip (OOC) technologies possess suitable characteristics for the generation of physiologically relevant in vitro lung models, allowing for developmental studies, disease modeling, and toxicological screening. Importantly, these platforms represent potential alternatives for animal testing, according to the 3Rs (replace, reduce, refine) principle, and hold promise for the identification and approval of new chemicals under the European REACH (registration, evaluation, authorization and restriction of chemicals) framework. As such, this review aims to summarize recent progress made in human iPSC- and OOC-based in vitro lung models. A general overview of the present applications of in vitro lung models is presented, followed by a summary of currently used protocols to generate different lung cell types from iPSCs. Lastly, recently developed iPSC-based lung models are discussed.

Negative chronotropic and inotropic effects of lubiprostone on iPS cell-derived cardiomyocytes via activation of CFTR

Background

Lubiprostone (LBP) is a novel chloride channel opener that has been reported to activate chloride channel protein 2 (ClC-2) and cystic fibrosis transmembrane conductance regulator (CFTR). LBP facilitates fluid secretion by activating CFTR in the intestine and is used as a drug for treating chronic constipation. While ClC-2 and CFTR expression has been confirmed in cardiomyocytes (CMs), the effect of LBP on CMs has not yet been investigated. Thus, the present study aimed to investigate the effect of LBP on CMs using mouse-induced pluripotent stem (iPS) cell-derived CMs (iPS-CMs).

Methods

We induced mouse iPS cells into CMs through embryoid body (EB) formation. We compared the differentiated cells to CMs isolated from adult and fetal mice using gene expression, spontaneous beating rate, and contraction ratio analyses.

Results

Gene expression analysis revealed that, in the iPS-CMs, the mRNA expression of the undifferentiated cell markers Rex1 and Nanog decreased, whereas the expression of the unique cardiomyocyte markers cardiac troponin I (cTnI) and cardiac troponin T (cTNT), increased. Immunostaining showed that the localization of cTnI and connexin-43 in the iPS-CMs was similar to that in the primary fetal CMs (FCMs) and adult CMs (ACMs). LBP decreased the spontaneous beating rate of the iPS-CMs and FCMs, and decreased the contraction ratio of the iPS-CMs and ACMs. The reduction in the beating rate and contraction ratio caused by LBP was inhibited by glycine hydrazide (GlyH), which is a CFTR inhibitor.

Conclusion

These results suggest that LBP stimulates CFTR in CMs and that LBP has negative chronotropic and inotropic effects on CMs. LBP may be useful for treating cardiac diseases such as heart failure, ischemia, and arrhythmia.