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1410 citation(s) found for "Ha, Christina".

Inactivation of Histone Chaperone HIRA Unmasks a Link Between Normal Embryonic Development of Melanoblasts and Maintenance of Adult Melanocyte Stem Cells
Jaber‐Hijazi, Farah , Arnold, Rouven, Swaminathan, Karthic , Gilroy, Kathryn , Lagnado, Anthony B. , Kirschner, Kristina , Robertson, Neil , Reid, Claire , Fullarton, Neil J., Baranyk, Ian J , Shi, Christina Huan , Yip, Kevin Y. , Mesirov, Jill P. , Kirschner, Kristina , Robertson, Neil A , Rai, Taranjit Singh , Baranyk, Ian , Yip, Kevin Y , Passos, João F , Adams, Peter , Wenzel, Alexander T. , Reid, Claire, Pawlikowski, Jeff S. , Blyth, Karen , Harris, Melissa L. , Passos, João F. , Machesky, Laura M. , Adams, Peter D.

Aging Cell | May 15, 2025 | Volume: 24 | Issue: 7 | Pages: No page available

10.1111/acel.70070 | PMID 40669469 Get It

ABSTRACT Evidence indicates that the integrity of in utero development influences late life healthy or unhealthy aging; however, specific links between them are unclear. Histone chaperone HIRA is thought to play a role in both life stages, and here, we explore this role using the murine pigmentary system by investigating and comparing the effects of its lineage‐specific knockout, either conditionally during embryogenesis or postnatally. Embryonic knockout of Hira in tyrosinase+ neural crest‐derived lineages, including melanoblasts, led to reduced melanoblast numbers during embryogenesis, with single‐cell RNA sequencing analysis indicating evidence of lineage‐specificity defects. This was supported in an in vitro model using melb‐a melanoblasts in which Hira knockdown affected lineage identity and melanoblast differentiation potential, with ATAC‐seq data indicating a role of HIRA in orchestrating chromatin accessibility. Interestingly, however, newborn Hira knockout mice had wild type numbers of differentiated melanocytes, albeit functionally defective, as demonstrated by very mild hypopigmentation of the first hair coat, increased melanocyte telomere‐associated DNA damage foci, and impaired response to proliferative challenge. Moreover, as they aged, mice with embryonic melanoblast Hira knockout displayed marked defects in melanocyte stem cell maintenance and premature hair graying. Importantly, this phenotype was not observed after postnatal inducible knockout, indicating an essential role for HIRA at embryonic stages that is transmitted to adulthood, rather than a direct postnatal requirement within the pigmentary system. This genetic model shows that HIRA function during early development lays a foundation for maintaining lineage identity and subsequent maintenance of adult tissue‐specific stem cells during aging.
A Phase II Multicenter Trial of Trabectedin in Combination with Olaparib in Patients with Advanced Unresectable or Metastatic Sarcoma
Siontis, Brittany L. , Rice, John D. , Schuetze, Scott M. , Rottmann, Douglas , Angeles, Christina V. , Fox, Amanda K. , Zyczynski, Laurie E. , Hayek, Salim S. , Robinson, Steven I. , Okuno, Scott H. , Ho, Thanh P. , Hayek, Salim , Chugh, Rashmi , Siontis, Brittany L , Robinson, Steven I , Chugh, Rashmi

Clinical Cancer Research | May 13, 2025 | Volume: 31 | Issue: 14 | Pages: 2919-2925

10.1158/1078-0432.ccr-25-0298 | PMID 40358615 Get It

Abstract Purpose: Soft-tissue sarcomas are rare malignancies with poor prognosis and limited systemic treatment options. We conducted a phase II study to assess the efficacy and safety of trabectedin and olaparib in patients with advanced disease. Patients and Methods: Patients with soft-tissue sarcoma who received ≥1 prior therapy were recruited into two cohorts. Cohort 1 included leiomyosarcoma and liposarcoma; cohort 2 included other histologies. All patients received trabectedin (1.1 mg/m2 24-hour infusion every 21 days) and olaparib (150 mg twice daily continuously). The study was conducted using a Simon minimax two-stage design with a primary endpoint of objective response (OR) rate per RECIST 1.1. Results: Twenty-nine (cohort 1, 16; cohort 2, 13) patients enrolled; one patient in cohort 2 was not evaluable. There were no confirmed ORs in cohort 1; the best response was stable disease in 12 (75%) patients and progressive disease in four (25%). Two partial responses were observed in cohort 2 (n = 12). The most common adverse events were fatigue (75%), neutropenia (75%), anemia (68%), and thrombocytopenia (68%). The median progression-free survival and overall survival for all patients were 3.5 (95% confidence interval, 3.3–8.2) and 13.2 months (95% confidence interval, 10.3–20.9), respectively. Next-generation sequencing of 17 tumors revealed multiple abnormalities, most commonly in TP53, RB1, and ATRX. Conclusions: Trabectedin plus olaparib conferred high rates of toxicity and failed to demonstrate ORs in leiomyosarcoma and liposarcoma. Preliminary evidence of clinical benefit in two patients in cohort 2 suggests potential value of either or both drugs in other sarcomas.
Primary Aldosteronism: An Endocrine Society Clinical Practice Guideline
Adler, Gail K. , Stowasser, Michael , Correa, Ricardo , Khan, Nadia , Mulatero, Paolo , Murad, M. Hassan , Vaidya, Anand , Young, William F., Zennaro, Maria‐Christina , Corrigan, Maureen D. , Kline, Gregory , Mulatero, Paolo , Murad, M Hassan , Vaidya, Anand , Yang, Jun , Stowasser, Michael , McGowan, Michael , Touyz, Rhian M. , Williams, Tracy Ann , Yang, Jun , Brito, Juan P.

The Journal of Clinical Endocrinology & Metabolism | May 13, 2025 | Volume: 110 | Issue: 9 | Pages: 2453-2495

10.1210/clinem/dgaf284 | PMID 40658480 Get It

Abstract Background Primary aldosteronism (PA), a primary adrenal disorder leading to excessive aldosterone production by one or both adrenal glands, is a common cause of hypertension. It is associated with an increased risk of cardiovascular complications compared with primary hypertension. Despite effective methods for diagnosing and treating PA, it remains markedly underdiagnosed and undertreated. Objective To develop an updated guideline that provides a practical, clinical approach to identifying and managing PA to improve diagnosis rates and encourage targeted treatment. Methods The Guideline Development Panel (GDP), composed of a multidisciplinary panel of clinical experts and experts in systemic review methodology, used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to define 10 questions related to the diagnosis and treatment of PA. Systematic reviews were conducted for each question. The GDP used the GRADE Evidence to Decision (EtD) framework to consider contextual factors, such as stakeholder values and preferences, costs and required resources, cost-effectiveness, acceptability, feasibility, and the potential impact on health equity. Results We suggest that all individuals with hypertension be screened for PA by measuring aldosterone and renin and determining the aldosterone to renin ratio, and that subsequent clinical care be guided by the results. We suggest that individuals with PA receive PA-specific therapy, either medical or surgical. In individuals who screen positive for PA, we suggest (1) commencement of PA-specific medical therapy in individuals who do not desire or are not candidates for surgery and in situations where the probability of lateralizing PA (excess aldosterone produced by one adrenal) is low based on screening results; and (2) aldosterone suppression testing in situations when screening results indicate an intermediate probability for lateralizing PA and individualized decision making confirms a desire to pursue eligibility for surgical therapy. In those who test positive by aldosterone suppression testing, and in those in whom screening results show a high probability of lateralizing PA (obviating the need for aldosterone suppression testing), we suggest adrenal lateralization with computed tomography scanning and adrenal venous sampling prior to deciding the treatment approach (medical vs surgical). In all individuals with PA and an adrenal adenoma, we suggest performing a 1-mg overnight dexamethasone suppression test. We suggest the use of mineralocorticoid receptor antagonists (MRAs) over epithelial sodium-channel (ENaC) inhibitors in the medical treatment of PA. We suggest the use of spironolactone over other MRAs, given its lower cost and greater availability; however, all MRAs, when titrated to equivalent potencies, are anticipated to have similar efficacy in treating PA. Thus, MRAs with greater mineralocorticoid receptor specificity and fewer androgen/progesterone receptor-mediated side effects may be preferred in some situations. In individuals receiving MRA therapy, we suggest monitoring renin and, in those whose hypertension remains uncontrolled and renin is suppressed, titrating the MRA to increase renin. Conclusion These recommendations provide a practical framework for the diagnosis and treatment of PA. They are based on currently available literature and take into consideration outcomes that are important to key stakeholders. The goal is to increase identification of individuals with PA and, by initiating PA-specific medical or surgical therapy, improve blood pressure control and reduce PA-associated adverse cardiovascular events. The guidelines also highlight important knowledge gaps in PA diagnosis and management.
The Role of Senolytics in Reducing Senescence Induced by Cannabinoids and Nicotine in Prenatal Human Lung
Alam, I. El, Belgacemi, R., Glass, I., Zana-Taeib, Elodie, Boyer, L., Danopoulos, S., Alam, D. Al, Glass, I., Zana‐Taïeb, Elodie , Boyer, L., Rehan, Virender Kumar , Prakash, Y. S. , Pabelick, Christina M. , Alam, D. Al

American Journal of Respiratory and Critical Care Medicine | May 11, 2025 | Volume: 211 | Issue: Supplement_1 | Pages: A7706-A7706

10.1164/ajrccm.2025.211.abstracts.a7706 Get It

Abstract Rationale: 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.Methods: 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.Results: 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 ɣH2A.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.Conclusion: 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.
Male Survival Disadvantage in Pulmonary Hypertension in the PVRI Godeep Meta-registry
Annis, Jeffrey , Meike, F., Wilhelm, Jochen , Kiely, David G. , Balasubramanian, A., Eichstaedt, Christina A. , Zamanian, Roham T. , Elwing, Jean , Pepke-Zaba, J., Hernandez, Nadia , Frauendorf, Marlize , Williams, Paul , Anthi, Anastasia , Dima, Efrossini, Majeed, Rehan, Tello, Khodr , Kiely, David , Yogeswaran, Athiththan , Howard, Luke , Lawrie, Allan , Wilkins, Martin R. , Balasubramanian, A. , Hassoun, Paul M. , Grünig, Ekkehard , Sweatt, Andrew J. , Kovács, Gábor , Olschewski, Horst , Ghouleh, Imad Al , Chan, Stephen Y. , Jose, Arun , Cannon, J., Pepke-Zaba, J., Frantz, Robert P. , Sіrenko, Yu.M. , Torbas, O.O. , Sahay, Sandeep , Hernandez, N., Arvanitaki, Alexandra , Giannakoulas, George , Sabbour, Hani Mohamed , Saleh, Khaled Musa Mohammad , Ghio, Stefano , Scelsi, Laura , Majeed, R., Ghofrani, Hossein Ardeschir , Grimminger, Friedrich , Cajigas, Héctor , Brittain, Evan L , Seeger, Werner

American Journal of Respiratory and Critical Care Medicine | May 11, 2025 | Volume: 211 | Issue: Supplement_1 | Pages: A7097-A7097

10.1164/ajrccm.2025.211.abstracts.a7097 Get It

Abstract Introduction Sex-based differences in morbidity and mortality for pulmonary hypertension (PH) are insufficiently addressed in current research. However, recognizing these differences is crucial for optimal clinical management and improving outcomes. This study assesses the effect of sex on survival among PH patients, while accounting for disease severity, comorbidities, treatment, and race. Methods We analyzed data from the PVRI GoDeep meta-registry, including all incident patients with complete hemodynamic profiles. Survival was evaluated using Kaplan-Meier and Cox proportional hazards models, adjusted for various confounders. Analyses included both PAH and non-PAH groups and risk assessment by the ESC/ERS 2022, REVEAL lite 2, and COMPERA 4-strata scores. All analyses were performed using R (The R Foundation). Results A total of 19,663 incident PH patients were included in the analysis, with 5,581 patients (28%) diagnosed with Group 1 PH and a median age of 64 years [IQR: 52-73]. Among these, male patients (8,704, 44%) had a significantly higher mortality risk than female patients across the entire cohort and within all PH subtypes. The adjusted hazard ratio for mortality in male versus female patients was 1.391 [95% CI: 1.260-1.536] in the overall population and 1.404 [95% CI: 1.264-1.561] for those with PAH. This survival difference was consistent across various severity levels, age groups, and in the presence of comorbidities such as obesity and cardiovascular diseases, as well as among those receiving PAH-specific therapies as well as patients who remained without treatment during the observation period. Notably, male disadvantage in survival was observed in low, intermediate, and high-risk categories for ESC/ERS 2022, REVEAL lite 2, and COMPERA scores but not within REVEAL 2.0, which includes male sex as a non-modifiable risk factor. Racial analysis revealed a greater mortality risk for males among White patients, with no significant differences noted in Black or Asian populations. Conclusion Our PVRI GoDeep meta-registry analysis demonstrates that male PH patients face higher mortality risk across both PAH and non-PAH groups, independent of disease etiology, age, severity, comorbidities, and treatment factors, with this risk amplified in White patients. These findings suggest that male sex should be further considered as a risk factor to refine predictive models for survival in PH.
Class C GPRC5A in Human Airway Smooth Muscle
Thompson, Martin W., Venkatachalem, S., Prakash, Y.S., Hamrick, Samantha K. , Thompson, M., Drake, Li Y. , Venkatachalem, S., Pabelick, Christina M. , Prakash, Y. S.

American Journal of Respiratory and Critical Care Medicine | May 11, 2025 | Volume: 211 | Issue: Supplement_1 | Pages: A3084-A3084

10.1164/ajrccm.2025.211.abstracts.a3084 Get It

Abstract Rationale: Asthma involves airway inflammation, hyperresponsiveness (AHR), and remodeling (cell proliferation and fibrosis), with both aspects not fully alleviated by current therapies. GPCR-based drugs represent a major aspect of current asthma therapy. Asthmatic airways express several orphan receptors with unknown physiological roles, highlighting a potentially novel and significant area for therapeutic exploration. Herein, we focus on orphan retinoic acid (RA)-induced Class C GPCR members GPRC5A (RAIG1; 5A) and GPRC5B (RAIG2; 5B). We leveraged recently identified 5A agonists to test the hypothesis that these GPCRs have alleviating effects in airways. Methods: Primary human airway smooth muscle cells (ASM) originating from non-asthmatic (NA) and asthmatic (Asth) individuals were obtained post-surgery from lung tissues after approval by the Mayo Clinic Institutional Review Board. PRESTO-Tango assay was used to determine 5A and 5B activity. cADDis assay was used to assess cAMP levels. Fluorescence imaging was used to determine calcium regulation. Recently identified 5A agonists [tryptamine, 7 fluoro-tryptamine (7FT), L-tryptophan, N-methyltryptamine, and indole-3-acetic acid] were used in assays, along with RA and 5A vs. 5B siRNAs. Results: PRESTO-Tango assay showed that tryptamine (10/100 µM) and 7FT (1/10/100 µM) increased 5A activity while high concentrations of 7FT (100 µM) increased 5B activity as well. cADDis assay showed 100 µM tryptamine increased cAMP more than 1/10 µM tryptamine and that 10 µM 7FT increased cAMP more than 1/100 µM 7FT in NA ASM.Calcium imaging showed that 5A agonist blunts responses to histamine, especially in Asth ASM. Calcium responses were higher in Asth ASM and 5A siRNA-treated ASM while 5B siRNA had an alleviating effect. Conclusions: Class C GPCRs 5A and 5B interestingly have opposing effects in human ASM towards blunting calcium responses to bronchoconstrictor agonists in the context of asthma. Thus, 5A agonists and 5B antagonists may represent novel GPCR-based approaches in airway diseases.
Hydrogen Sulfide (H2S) Alleviates Hyperoxia-induced Changes in Intracellular Calcium Regulation in Human Fetal Airway Smooth Muscle
Borkar, N.A., Prakash, Y.S., Thompson, Michael D. , Bartman, Colleen M. , Hamrick, Samantha K. , Prakash, Y. S. , Pabelick, Christina M.

American Journal of Respiratory and Critical Care Medicine | May 11, 2025 | Volume: 211 | Issue: Supplement_1 | Pages: A3083-A3083

10.1164/ajrccm.2025.211.abstracts.a3083 Get It

Abstract Rationale: Moderate hyperoxia (<60% O2) in premature infants promotes bronchial airway hyperresponsiveness (AHR) and impaired bronchodilation involving airway smooth muscle (ASM). Understanding mechanisms by which hyperoxia initiates long-term bronchial airway changes in prematurity is critical for novel therapies for wheezing disorders and asthma in children. Underdeveloped lungs in prematurity have immature antioxidant systems, which may be due to disrupted dynamics that promote susceptibility to oxidative stress from O2. Cytoplasmic and mitochondrial calcium signaling mechanisms and O2 metabolism are pathways highly relevant to ASM and airway disease. We propose that the novel gasotransmitter hydrogen sulfide (H2S) attenuates effects of O2 in developing ASM and hypothesize that hyperoxia in prematurity promotes cellular and mitochondrial calcium signaling dysfunction, effects which are counteracted by H2S.Methods: Human fetal (fASM) cells isolated from tracheobronchial samples of de-identified 18-22 week fetuses following fetal demise (Mayo IRB approved as exempt) were exposed to 21% vs 40% O2. fASM were treated 24-72 hours with H2S donor GYY4137, mitochondrial-specific H2S donor AP39, cystathione-β-synthase (CBS) stabilizer AdoMet, cAMP inhibitors SQ22536 or KT5720, or vehicle control (DMSO). CBS shRNA lentiviral particles were used to generate stable knockdown cell lines. Protein markers were measured by Western blot. Intracellular calcium ([Ca2+]i) was measured using 5μM Fura-2/AM and mitochondrial calcium ([Ca2+]m) with 1μM Rhod-2 AM using fluorescence microscopy. Results: CBS expression was lower in fASM exposed to 40% O2 compared to 21% O2. Lentivirus induced CBS KD was exacerbated by 40% O2. Hyperoxia increased [Ca2+]i and [Ca2+]m response to histamine (10μM) in vehicle and Scr controls compared to normoxia. CBS KD increased [Ca2+]i and [Ca2+]m responses to histamine compared to Scr fASM in 21% O2. CBS KD fASM exposed to hyperoxia showed increased [Ca2+]i and [Ca2+]m responses to histamine, but the effect was not amplified by CBS KD. [Ca2+]i and [Ca2+]m responses to histamine were decreased in normoxia by H2S donors GYY4137 (50μM) and AP39 (100nM) and CBS stabilizer AdoMet (100nM); effects which also blunted hyperoxia induced increases. SQ22536 and KT5720 inhibited effects of AP39 and GYY4137 in hyperoxia. Conclusions:Our findings suggest hyperoxia leads to [Ca2+]i and [Ca2+]m dysfunction in developing airway cells, which can be alleviated through modulation of H2S pathways, offering potential targets for future therapies to blunt hyperoxia effects on bronchoconstriction and bronchodilation. Acknowledgment: Supported by AHA Postdoctoral Fellowship 20POST35210002 (Bartman), NIH R01 HL-056470 (Prakash), and HL-160570 (Pabelick).
Novel Synthesized KpSAT Peptides Regulates Airway Smooth Muscle Remodeling
Ramakrishnan, Y. , Tesch, J., Balraj, Premanand , Kumar, A. , Seetharaman, J. , Ambhore, Nilesh Sudhakar , Pabelick, Christina M. , Prakash, Y. S. , Sathish, Venkatachalem

American Journal of Respiratory and Critical Care Medicine | May 11, 2025 | Volume: 211 | Issue: Supplement_1 | Pages: A3082-A3082

10.1164/ajrccm.2025.211.abstracts.a3082 Get It

Abstract Background: Kisspeptins (Kp) are a group of hypothalamic peptides that aid in regulating pubertal development and sex hormone signaling. In our recent studies, we observed the important role of Kp-10 (Kp peptide) and its receptor KISS1R signaling in regulating the airway smooth muscle (ASM) structure and function. In these studies, we observed significantly reduced expression of KISS1R during asthma pathophysiology suggesting a loss of protective mechanism and exogeneous Kp-10 may be protective in the context of asthma. Studies have shown that specific modifications to the amino acids of Kp peptides can result in increased binding efficiency and receptor activation. Accordingly, we developed three novel Kp peptides, named KpSATs (13A, 13B, and 13C), and tested the potential effects/efficiency on ASM cell remodeling. Methods: The Molecular docking of the KpSAT peptides (13A, 13B and 13C) with the receptor KISS1R were performed using HPEPDOCK. KpSATs were synthesized by GenScript (New Jersey, US) with purity of ≥97%. Primary human ASM cells isolated from surgical lung resections (Mayo Clinic IRB-approved) were cultured in DMEM-F12. Cells were treated with PDGF (2ng/mL) and/or TGF-β (2ng/mL) with/without treatments of KpSATs (13A, 13B, and 13C: 250nM-1µM) and Kp-10 (1µM). ASM cell proliferation was measured using MTT. Extracellular matrix (ECM) deposition (fibronectin and collagen-I/III) studies were performed using In-Cell Western (LiCor-odyssey). The mechanistic signaling pathway (phospho-PKC-δ) were measured using Western blot analysis. Results: In the novel KpSATs, we substituted three amino acids in the endogenous Kp-13 sequence, Y10W and P12T for KpSAT-13A; S6A and P12T for KpSAT-13B; and S6A and Y10W for KpSAT-13C. The peptides dock in the orthosteric ligand binding pocket attained with docking scores ranging from -250 to -280. The MTT assay indicated a reduction in PDGF-induced ASM cell proliferation upon exposure to KpSATs. Notably, we found that KpSAT-13A and KpSAT-13B had significant effects in reducing proliferation at lower concentrations of 500nM compared to 1µM of Kp-10. Furthermore, ECM deposition studies showed a significant reduction of TGF-β1-induced collagen-I/III and fibronectin in ASM cells exposed to KpSAT-13A and 13B. In addition, we observed significant inhibition of PDGF-induced phospho-PKC-δ by KpSAT-13A and 13B. Conclusion: Overall, these findings highlight that modification in amino acid sequence in endogenous Kp-13 sequence significantly increases the potency of synthesized novel KpSATs on ASM cells. In addition, KpSATs showed better inhibitory effects with a lower concentration compared to Kp-10 and could be considered as a promising therapeutic strategy to mitigate asthma.
Dysregulated Iron Metabolism in Airways of Aging Asthmatic Humans
Pfeffer-Kleemann, D.A., Ngassie, Maunick Lefin Koloko , Pfeffer-Kleemann, D, Hamrick, Samantha K. , Pabelick, Christina M. , Prakash, Y. S.

American Journal of Respiratory and Critical Care Medicine | May 11, 2025 | Volume: 211 | Issue: Supplement_1 | Pages: A2557-A2557

10.1164/ajrccm.2025.211.abstracts.a2557 Get It

Abstract Rationale: With an increasing elderly population, understanding mechanisms that contribute to structural and functional changes in aging lung is important in the context of healthy aging and diseases such as asthma and pulmonary fibrosis that disproportionately affect the elderly. Asthma in the elderly (AIE) is a particular challenge, with thickened fibrotic bronchial airways (remodeling) and inflammation compared to non-asthmatic elderly: issues not addressed by current therapies. Factors such as iron regulation that are critical for normal physiology can become dysregulated in disease. Iron overload can catalyze a Fenton reaction that increases ROS which oxidizes lipids and proteins, i.e. iron-mediated lipid peroxidation cell death (ferroptosis).The goal of this study was to determine iron regulation in aging- and AIE-associated in human ASM (hASM), a cell type important in airway contractility and remodeling. Methods: hASM cells and lung tissues from young (<45y), and aged (>65y) male/female patients with/without asthma were used (approved by Mayo IRB #16-009655). Cells were treated with ferroptosis inhibitor deferoxamine (DFO) [100µM], inducer RSL3 [125 nM] or vehicle (DMSO) for 24 hrs. Levels of intracellular iron (Fe2+) were determined using FerroOrange. Cell lysates were examined for iron accumulation and ferroptosis markers (4-HNE, FTH1, TfR1, SLC7A11, and KEAP1), cell proliferation, and ECM production (COL1A1 and FN1), and supernatants analyzed for proinflammatory mediators IL-6 and IL-8. Results: Non-asthmatic and asthmatic elderly hASM cells showed a higher cytosolic Fe2+ and lower end-product of lipid peroxidation (4-HNE), higher level of SLC7A11 and KEAP1 (regulators of redox systems) compared to cells from young individuals. High level of iron storage (FTH1) was observed in asthmatics compared to non-asthmatic elderly, but no difference was observed for iron transporters (TfR1). Furthermore, COL1A1 and FN1 were higher in AIE hASM, compared to young hASM. COL1A1 was higher in aging hASM compared to young. DFO reduced COL1A1 in elderly, but upregulated in AIE. Cell proliferation was inhibited by DFO in aging hASM but not in young and AIE. The ferroptosis inducer RLS3 impaired antioxidant system and increased lipid peroxidation and IL-8 levels. Conclusions: Our findings suggest that iron regulation is impaired in aging and AIE hASM, resulting in iron accumulation which modulates airway remodeling via cell proliferation and ECM production. While ferroptosis per se can be targeted, it will be important to explore modulation of specific iron regulatory pathways in alleviating the impact of aging and asthma.
Targeting Airway Remodeling Via Polymer Nanoparticles
Lee, K. , Lehot, Victor , Cickek, Y.A., Prakash, Y.S., Thompson, Michael A. , Hamrick, Samantha K. , Goswami, R., Nagaraj, Harini , Rotello, Vincent M. , Pabelick, Christina M. , Prakash, Y. S.

American Journal of Respiratory and Critical Care Medicine | May 11, 2025 | Volume: 211 | Issue: Supplement_1 | Pages: A2546-A2546

10.1164/ajrccm.2025.211.abstracts.a2546 Get It

Abstract Rationale : Airway remodeling in asthma involves increased airway smooth muscle (ASM) mass, changes to bronchial epithelial cell (BEC) layer, and increased fibrosis. ASM and BECs actively contribute by secreting growth factors and cytokines, regulating extracellular matrix (ECM) composition and enhancing cell proliferation/migration. Altering mechanisms which modulate remodeling presents a key to novel therapeutic strategies. BDNF increases ASM [Ca2+]i and contractility, and potentiates the effects of inflammation. Importantly, studies show that ASM is not only a target, but also a source of BDNF, raising the possibility of local autocrine/paracrine effects. Arginase 1 and 2 are expressed by BECs, but their roles in asthma are still under investigation with studies showing arginase 1 inhibition blunting epithelial remodeling and ASM hyperplasia. Knockdown of appealing targets such as ASM BDNF and epithelial arginases using small interfering RNA (siRNA) is a promising approach to combating inflammatory lung remodeling. Polymer based nanoparticles have been constructed which demonstrate cell-type specificity and high efficiency in delivering siRNA. Thus, we hypothesize that BDNF and arginases are central to airway remodeling and can be targeted via nanopartiacles.Methods: Primary human ASM and BEC cells from non-asthmatic vs. asthmatic individuals were obtained post-surgery from lung tissues after approval Mayo Clinic IRB. PONI-Guan NP were generated using block copolymer engineering. PCR, immunoblotting and ELISA were performed using standard techniques. Contractility studies were conducted in adult mouse precision cut lung slices. In vivo lung function studies were conducted in 6-8 week old mice, with or without mixed allergen (MA) treatment and Scireq Flexivent system. Results: PONI-Guan NP uptake demonstrates cell-type specificity in BEC/ASM co-culture and mouse lung. Arginase I/II and ECM expression is upregulated in BECs when exposed to BDNF and cytokines. In ASM, BDNF is increased in asthmatics compared to non-asthmatic controls; ECM expression is increased in response to BDNF and TNF-α. In BEC, PONI-Guan NP/siRNA inhibits Arg I/II expression, even in the presence of TNF-α. In ASM, TNF-α increases in BDNF secretion and ECM deposition are blunted by NP-delivered siRNA. PCLS and mouse lung function studies show contractility to MCh: effects suppressed by NP-delivered BDNF and Arg I siRNA. Conclusions: Our studies show the importance of BDNF/Arginase pathways in airway remodeling and efficacy of PONI-based siRNA delivery vectors in blunting remodeling processes.