Citations

Repair and regeneration of a diseased lung using stem cells or bioengineered tissues is an exciting therapeutic approach for a variety of lung diseases and critical illnesses. Over the past decade, increasing evidence from preclinical models suggests that mesenchymal stromal cells, which are not normally resident in the lung, can be used to modulate immune responses after injury, but there have been challenges in translating these promising findings to the clinic. In parallel, there has been a surge in bioengineering studies investigating the use of artificial and acellular lung matrices as scaffolds for three-dimensional lung or airway regeneration, with some recent attempts of transplantation in large animal models. The combination of these studies with those involving stem cells, induced pluripotent stem cell derivatives, and/or cell therapies is a promising and rapidly developing research area. These studies have been further paralleled by significant increases in our understanding of the molecular and cellular events by which endogenous lung stem and/or progenitor cells arise during lung development and participate in normal and pathological remodeling after lung injury. For the 2023 Stem Cells, Cell Therapies, and Bioengineering in Lung Biology and Diseases Conference, scientific symposia were chosen to reflect the most cutting-edge advances in these fields. Sessions focused on the integration of “omics” technologies with function, the influence of immune cells on regeneration, and the role of the extracellular matrix in regeneration. The necessity for basic science studies to enhance fundamental understanding of lung regeneration and to design innovative translational studies was reinforced throughout the conference.

Rationale: Lung associated diseases are one of the leading causes of death in Down syndrome/Trisomy21 (DS/T21). DS is often considered a progeroid syndrome, associated with increased cellular senescence and oxidative stress in dermal T21 fibroblasts. Senescence plays a crucial role in development and organogenesis. We recently demonstrated that T21 lung anomalies are initiated in utero. We aim to better understand the role of senescence in lung disease in T21. Methods: Fresh T21 and, age- and sex-matched non-T21 human fetal lungs were collected, dissociated, and human fetal lung fibroblast (HFLF) cultures were established using differential adhesion. Baseline senescence levels were determined in whole tissue and isolated fibroblasts using TAF staining for tissue only and RT-qPCR and immunofluorescence (IF) for both. β-galactosidase, CellROX/MitoSOX, and calcium release (FURA2/AM imaging) assays were performed on T21 and non-T21 fibroblasts, cultured in the absence or presence of an ER stress inhibitor (4-PBA, 2mM) or a mitochondriogenesis stimulator (PQQ, 20μM). Results: Whole tissue sections demonstrated increased TAF and γ-H2AFX staining in T21 vs non-T21. RT-qPCR demonstrated significantly increased expression of several senescence markers including CDKN1A, CDKN2A, TP53, CDKN2B and PAI1 (p<0.05; n=6) at baseline in T21 HFLF as compared to non-T21. IF for γ-H2AFX and P21 were also significantly increased in T21 cultures vs non-T21 (p<0.01, n=6). Upregulated senescence was further confirmed in T21 HFLF by increased β-galactosidase activity (6-fold vs non-T21, p<0.05, n=4) as well as increased ER and mitochondria stress markers (CellROX and mitoSOX, p<0.05, n=6) in T21 cultures. Fura2/AM assay revealed that T21 HFLF exhibit greater intracellular calcium release (p<0.01, n=3) than non-T21 HFLF at both baseline and post Acetylcholine (10uM) challenge, an indicator of increased ER stress. In addition, several mitochondria morphology genes ( FIS1, DNML1 and MFN1) increased in T21 HFLF (p<0.05, n=6). Both 4-PBA or PQQ treatments reversed senescence in T21 HFLF as shown by decreased β-galactosidase staining (p<0.01; n = 4). No differences were observed in non-T21 HFLF after treatment. However, gene expression analyses of CDKN1A, CDKN2A, TP53 and CDKN2B demonstrated attenuated expression in T21 HFLF only following PQQ treatment but not 4-PBA (p<0.05, n=4). Conclusion: In this study, we established that fibroblasts from T21 lungs present with both ER and mitochondria-associated senescence. However, only PQQ, the mitochondriogenesis stimulator, was able to completely reverse the senescence observed at baseline in T21 HFLF. Understanding this increase in senescence in the lungs of individuals with Down Syndrome may help address the respiratory issues that arise after birth. CIRM (EDUC4-12837) Postdoctoral Training Grant (RB) NIH/NHLBI R01HL141856 (DA); NIH/NHLBI Offce of The Director, National Institutes of Health (OD) R01HL155104 (SD); NIH/NHLBI R21HL165411 (SD and DA). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Mechanical forces on the airway can contribute to altered contractility and remodeling in airway diseases, but the mechanisms are not clearly understood. Using human airway smooth muscle cells exposed to cyclic forces with static stretch to mimic breathing and static pressure, we found that the effects of stretch are mediated through STIM1, resulting in the activation of multiple pathways, including Piezo channels and the inflammasome, with potential downstream influences on contractility and remodeling.

The current study establishes functional links between endoplasmic reticulum (ER) stress and cellular senescence per se in the specific context of aging human lung fibroblasts. Recognizing that the process of aging per se is complex, modulated by the myriad of lifelong and environmental exposures, it is striking to note that chronic ER stress may play a crucial role in the establishment and maintenance of cellular senescence in lung fibroblasts.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Non–Small Cell Lung Cancer (NSCLC) provide recommendations for the treatment of patients with NSCLC, including diagnosis, primary disease management, surveillance for relapse, and subsequent treatment. The panel has updated the list of recommended targeted therapies based on recent FDA approvals and clinical data. This selection from the NCCN Guidelines for NSCLC focuses on treatment recommendations for advanced or metastatic NSCLC with actionable molecular biomarkers.

AbstractINPP4A has been shown to be involved in the regulation of cell proliferation and apoptosis of multiple cell types including fibroblasts. Previous reports from our group have demonstrated the role of inositol polyphosphate 4‐phosphatase Type I A (INPP4A) in these functions. Though existing evidences suggest a critical role for INPP4A in the maintenance of lung homeostasis, its role in chronic lung diseases is relatively under explored. In the current study, we made an attempt to understand the regulation of INPP4A in idiopathic pulmonary fibrosis (IPF). Through integration of relevant INPP4A gene expression data from public repositories with our results from in vitro experiments and mouse models, we show that INPP4A is altered in IPF. Interestingly, the direction of the change is dependent both on the disease stage and the region of the lung used. INPP4A was found to be upregulated when analyzed in lung sample representative of the whole lung, but was downregulated in the fibrotic regions of the lung. Similarly, INPP4A was found to be high, compared to controls, only in the early stage of the disease. Though the observed increase in INPP4A was found to be negatively correlated to physiological indices, FVC, and DLCO, of lung function, treatment with anti‐INPP4A antibody worsened the condition in bleomycin treated mice. These contrasting results taken together are suggestive of a nuanced regulation of INPP4A in IPF which is dependent on the disease stage, cellular state and extent of fibrosis in the lung region being analyzed.