Danopoulos, Soula

Abstract Rationale Respiratory disease is a major cause of mortality in Down syndrome (DS; trisomy 21, T21). DS is considered a progeroid syndrome, with elevated cellular senescence (SEN) and oxidative stress. Because SEN shapes organogenesis, its dysregulation may impair lung morphogenesis. We previously found SEN/SASP (senescence-associated secretory phenotype) abnormalities in prenatal human T21 lungs. Here, we test whether these alterations persist and change after birth. Methods We analyzed human lung single-nuclear RNA (snRNA-seq) datasets (prenatal and postnatal) to quantify epithelial and mesenchymal SEN/SASP signatures. Sex- and age-matched T21 and non-T21 prenatal and postnatal lungs were studied; fibroblasts were isolated as prenatal human lung fibroblasts (HFLF) and postnatal human lung fibroblasts (HLF). SEN/SASP were measured by RT-qPCR and immunofluorescence (IF) in tissue and HFLF/HLF. HFLF/HLF were assayed for SA-β-gal, oxidative stress (CellROX/MitoSOX), and Ca²+ dynamics (Fura-2 AM). 48h treatments with tunicamycin (1µM, SEN inducer), 4-phenylbutyrate (4-PBA, 2 mM, ER Stress inhibitor), or pyrroloquinoline quinone (PQQ, 20 μM, antioxidant) were performed on T21 and non-T21 HFLF/HLF. Conditioned media (CM) were collected after 48h from untreated cultures and then applied to cells of the opposite genotype for 24, 48, and 72h. Results Overall SEN profile was similar in epithelium and mesenchyme across ages, but pathway signatures differed. Epithelium shows an inflammatory SASP, while mesenchyme shows a less-inflammatory, remodeling/growth-factor SASP. These lineage patterns were more evident postnatally. Whole-tissue IF showed increased γ-H2AX and p21 in T21 vs non-T21 both prenatally and postnatally (p < 0.05). At baseline, T21 HFLF/HLF had higher CDKN1A, CDKN2A, TP53, CDKN2B, and SERPINE1 (p < 0.05; n = 5-6), with increased γ-H2AX/p21 IF (p < 0.01; n = 6), SA-β-gal (p < 0.05; n = 5-6), and ER/mitochondrial stress (p < 0.05; n = 5-6). Fura-2 AM showed greater Ca²+ release in T21 HFLF/HLF at baseline and after acetylcholine (10 μM, p < 0.01; n = 5). Mitochondrial-morphology genes (FIS1, DNM1L, MFN1) were elevated in T21 HFLF/HLF (p < 0.05; n = 6). In T21 HFLF, 4-PBA and PQQ each reduced SA-β-gal (p < 0.01; n = 6). In postnatal HLF, PQQ had the stronger effect (p < 0.05; n = 5). T21 CM induced progressively greater SEN/SASP over 24/48/72h in non-T21 cells (p < 0.05; n = 5-6), while non-T21 CM partially rescued T21-HLF phenotypes at 24h only (p < 0.05; n = 5-6). Conclusion These data indicate that lung senescence in T21 initiates in utero and intensifies after birth and reflects lineage-specific pathways. ER-stress-related mechanisms are more prominent prenatally, while mitochondrial/redox mechanisms are predominant postnatally. This evidence suggests age and lineage-dependent drivers of senescence that may help explain DS lung disease and highlight potential new mechanistic targets. This abstract is funded by: NIH/NHLBI

Rationale: Respiratory disease is a major cause of mortality in Down syndrome (DS; trisomy 21, T21). DS is considered a progeroid syndrome, with elevated cellular senescence (SEN) and oxidative stress. Because SEN shapes organogenesis, its dysregulation may impair lung morphogenesis. We previously found SEN/SASP (senescence-associated secretory phenotype) abnormalities in prenatal human T21 lungs. Here, we test whether these alterations persist and change after birth. Methods: We analyzed human lung single-nuclear RNA (snRNA-seq) datasets (prenatal and postnatal) to quantify epithelial and mesenchymal SEN/SASP signatures. Sex- and age-matched T21 and non-T21 prenatal and postnatal lungs were studied; fibroblasts were isolated as prenatal human lung fibroblasts (HFLF) and postnatal human lung fibroblasts (HLF). SEN/SASP were measured by RT-qPCR and immunofluorescence (IF) in tissue and HFLF/HLF. HFLF/HLF were assayed for SA-β-gal, oxidative stress (CellROX/MitoSOX), and Ca 2 + dynamics (Fura-2 AM). 48h treatments with tunicamycin (1µM, SEN inducer), 4-phenylbutyrate (4-PBA, 2 mM, ER Stress inhibitor), or pyrroloquinoline quinone (PQQ, 20 μM, antioxidant) were performed on T21 and non-T21 HFLF/HLF. Conditioned media (CM) were collected after 48h from untreated cultures and then applied to cells of the opposite genotype for 24, 48, and 72h. Results: Overall SEN profile was similar in epithelium and mesenchyme across ages, but pathway signatures differed. Epithelium shows an inflammatory SASP, while mesenchyme shows a less-inflammatory, remodeling/growth-factor SASP. These lineage patterns were more evident postnatally. Whole-tissue IF showed increased γ-H2AX and p21 in T21 vs non-T21 both prenatally and postnatally (p< 0.05). At baseline, T21 HFLF/HLF had higher CDKN1A, CDKN2A, TP53, CDKN2B, and SERPINE1 (p< 0.05; n=5–6), with increased γ-H2AX/p21 IF (p< 0.01; n=6), SA-β-gal (p< 0.05; n=5–6), and ER/mitochondrial stress (p< 0.05; n=5–6). Fura-2 AM showed greater Ca 2 + release in T21 HFLF/HLF at baseline and after acetylcholine (10 μM, p< 0.01; n=5). Mitochondrial-morphology genes (FIS1, DNM1L, MFN1) were elevated in T21 HFLF/HLF (p< 0.05; n=6). In T21 HFLF, 4-PBA and PQQ each reduced SA-β-gal (p< 0.01; n=6). In postnatal HLF, PQQ had the stronger effect (p< 0.05; n=5). T21 CM induced progressively greater SEN/SASP over 24/48/72h in non-T21 cells (p< 0.05; n=5-6), while non-T21 CM partially rescued T21-HLF phenotypes at 24h only (p< 0.05; n=5-6). Conclusion: These data indicate that lung senescence in T21 initiates in utero and intensifies after birth and reflects lineage-specific pathways. ER-stress-related mechanisms are more prominent prenatally, while mitochondrial/redox mechanisms are predominant postnatally. This evidence suggests age and lineage-dependent drivers of senescence that may help explain DS lung disease and highlight potential new mechanistic targets. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Tandem exposure to cannabinoids and nicotine during pregnancy poses significant risks to fetal development and health including low birth weight, preterm birth, and perinatal death. However, the effect of co-exposure with the most prominent cannabinoids found in Cannabis sativa (Trans-Δ-9- tetrahydrocannabinol (THC) and cannabidiol (CBD)) alongside nicotine on fetal lung development is not well understood. This study aims to investigate the combinatorial impact of CBD, THC, and nicotine, on human lung development through investigating cellular senescence and the potential role of senolytics in alleviating these effects. Human fetal lung explants from 10 to 16 weeks gestation were cultured on air-liquid interface and treated with various concentrations of nicotine (1µM), CBD, and THC (5µM, or 2.5µM each when used in combination), for 72 hours. To assess the effect of senolytics, the explants were also treated for 48 hours with a combination of CBD, THC, and nicotine. Subsequently, senolytics, Dasatinib (D, 250nM) and Quercetin (Q, 375nM), were added or not for an additional 24 hours. After the 72-hour treatment, explants were collected and either fixed for immunofluorescence staining (IF) analyses or used for RNA extraction and quantitative reverse transcription PCR (qRT-PCR). Additionally, the supernatants were used to evaluate the expression of the senescence-associated secretory phenotype (SASP), conducted by Eve Technologies Corporation-Canada. This study used Luminex xMAP technology for multiplexed quantification of 96 Human cytokines, chemokines, and growth factors. Our results demonstrated that co-exposure to CBD, THC, and nicotine increases the expression of the senescence markers CDKN1A (0.1163±0.02384, p=0.0094, n=8) and CDKN2A (0.005793±0.002157, p=0.0516, n=8) encoding P21 and P16 respectively. Moreover, the IF staining showed increased expression of the DNA damage marker γH2A.X following treatment with CBD+THC+nicotine (7.375±2.154% vs 2.245±0.8329%, p=0.0604, n=6). Furthermore, the lung explants treated with cannabinoids and nicotine released cytokines and chemokines involved in immune responses and inflammation among others IL-6, IL-8, M-CSF, MCP-3, MIP-1β, TNFα, MIP-3β, and TSLP (p<0.05). The addition of D+Q reduced SASP secretion and showed a decreasing trend in expression of the senescence genes CDKN1A and CDKN2A compared to the triple treatment. Taken together, our results showed that the combinatorial exposure to CBD, THC, and nicotine increases senescence, DNA damage, and the senescence-associated secretory phenotypes (SASP) secretion. The use of senolytics (D+Q) may prove to be a promising therapeutic option, alleviating several of the negative effects induced by the different substances. RO1HL171915-01A1 RO!HL155104 RO1HL158532-03 ROIHL160570 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Abstract Human chromosomal anomalies, notably trisomies, disrupt gene expression, leading to diverse cellular and organ phenotypes. Increased cellular senescence (SEN) and oxidative stress in trisomies have gained recent attention. We assessed SEN, SEN-associated secretory phenotype (SASP), and oxidative stress on trisomy 13 (T13), T18, and T21 human fetal lung tissues and isolated primary human fetal lung fibroblasts. Telomerase-associated foci staining showed DNA damage primarily within T21 and T18 lungs. These results were confirmed by real-time quantitative PCR showing an increase of the SEN marker CDKN2B and SASP markers IL-6 and CXCL8. In contrast, lung tissues from T13 showed an upregulation of CDKN2A, whereas no significant changes in SASP marker genes were observed. γ-H2AX (H2A histone family member X) was upregulated in each genotype, particularly in T21. Isolated fibroblasts demonstrated a strong association between T21 and several SEN markers. An increase of γ-H2AX–positive cells were observed in fibroblasts from T21, T18, and T13, but only T21 exhibited an increase in P21 expression. Only T21 fibroblasts displayed a significant increase in reactive oxygen species levels, as indicated by MitoSOX and CellROX. This study provides the first evidence of a link between SEN and trisomy anomalies during prenatal human lung development, particularly in T21.

Rationale Human chromosomal anomalies, notably trisomies, induce several alterations in gene expression, leading to various disease phenotypes. Recent studies showed that dermal fibroblasts from patients with trisomy 13 (T13), T18 or T21 present features of increased senescence and oxidative stress. We recently demonstrated that T21 lungs present abnormalities prenatally. Senescence is a state of cell division arrest that plays an important role in organogenesis. However, little is known about cellular senescence in fetal human lung with T13, T18 and T21. We therefore sought to characterize cellular senescence in these lung tissues. Methods Fresh human fetal lung tissues with T13, T18 and T21 were collected along with euploid age and sex matched controls. RT-qPCR and immunofluorescence staining (IF) were performed to assess the expression of senescence markers as well as Senescence-Associated Secretory Phenotype (SASP) elements in the various lung compartments (epithelial and mesenchymal). In addition, fibroblasts were isolated and cultured from each sample to determine the extent of senescence on isolated mesenchyme by IF and RT-qPCR. Staining for oxidative stress detection and Reactive oxygen species were assessed by CellROX and MitoSOX. Results RT-qPCR analysis in T13 whole lung tissues demonstrated no significant differences in the expression of either senescence or SASP markers as compared to control ( P16/ P21/ TP53 and IL6/ IL1 β/ TGF β/ CXCL8 respectively; n=5). Interestingly however, IF staining in T13 tissues showed a significant increase of γ-H2AFX, a marker of senescence, in the mesenchyme (n=4) as well as significantly decreased P21 staining in both the epithelial and mesenchymal compartments. Additionally, isolated fibroblasts from T13 lungs expressed significantly more IL6 as compared to control (n=3), with IF staining demonstrating a significant increase of γ-H2AFX. T18 lungs displayed significantly increased expression of P16 as compared to control (n=6), whereas IF staining revealed an increase of γ-H2AFX in whole tissue (n=4). Fibroblasts isolated from T18 lungs revealed no significant difference in any markers (gene or protein). Lastly, T21 lungs showed a significant increase of CXCL8 expression as compared to control (n=6). IF staining of T21 lungs demonstrated an increase γ-H2AFX in both the epithelium and mesenchyme (n=8). However, isolated T21 lung fibroblasts displayed significantly increased expression of P16, P21, TP53, and CXCL8. Furthermore, IF staining of T21 lung fibroblasts displayed significantly more γ-H2AFX and P21 positive cells as compared to controls (n=5). Interestingly, only cells from T21 lungs presented a significant increase of CellROX and MitoSOX staining (n=5). Conclusion In this study we established that expression of both senescence and SASP markers differ depending on the trisomy. Our results suggest that cellular senescence is more pronounced in lungs from individuals with trisomy 21. These authors acknowledge funding from NIH/NHLBI R01HL141856 (to DAA); NIH/ Office Of The Director, National Institutes Of Health (OD) R01HL155104 (SD); NIH/NHLBI R21HL165411 (SD and DAA); CIRM training grant EDUC4-12837 (RB) and NIH/NICHD 2R24HD000836-52 (IG). This is the full abstract presented at the American Physiology Summit 2023 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.