Citations

ImportanceStudies suggest that everolimus may reduce the risk of rejection, cardiac allograft vasculopathy (CAV), chronic kidney disease (CKD), and cytomegalovirus (CMV) after heart transplant. Everolimus use is controversial because of data demonstrating higher infection deaths when everolimus is introduced de novo after transplant. It is unclear whether everolimus is safe and effective when initiated at 6 months posttransplant in children, a population in which median graft survival is limited to 15 years and randomized clinical trials are lacking.ObjectiveTo evaluate the safety and efficacy of everolimus combined with low-dose tacrolimus to prevent major adverse transplant events (MATEs) in children after heart transplant.Design, Setting, and ParticipantsMulticenter, randomized, open-label, clinical trial enrolling 211 patients who were alive 6 months after pediatric heart transplant at 25 US sites from February 2018 to August 2020. The last date of follow-up was April 17, 2023.InterventionsParticipants were randomized to receive everolimus and low-dose tacrolimus (n = 107) or standard-dose tacrolimus and mycophenolate mofetil (n = 104) for 30 months.Main Outcomes and MeasuresThe primary efficacy end point was the MATE-3 score at 30 months, a validated composite ordinal end point including acute cellular rejection, CAV, and CKD. The primary safety end point was the MATE-6 score, encompassing the MATE-3 score plus antibody-mediated rejection, infection, and posttransplant lymphoproliferative disorder.ResultsAmong 211 children randomized, the mean age was 8.2 (SD, 6.3) years, 97 (46%) underwent transplant for congenital heart disease, and 49 (23%) were treated for rejection before 6 months. At 30 months, the mean MATE-3 score did not differ between the 2 treatment groups (mean difference, −0.32; 95% CI, −0.90 to 0.20; P = .16). The mean MATE-6 score was no higher in the everolimus group than in the mycophenolate group (baseline-adjusted mean difference, −0.40; 95% CI, −1.81 to 0.93), meeting the success criterion for safety (noninferiority margin <3). There were no differences in graft survival, MATE-free survival, or freedom from any individual MATE. Everolimus was associated with greater improvement in estimated glomerular filtration rate at 12 months (mean difference, 10.5 mL/min/1.73 m2; 95% CI, 1.09-19.91 mL/min/1.73 m2) and a lower incidence of CMV infection (hazard ratio, 0.50; 95% CI, 0.26-0.93).Conclusions and RelevanceAmong 6-month pediatric heart transplant survivors, everolimus and low-dose tacrolimus did not differ from tacrolimus and mycophenolate in preventing the composite of cellular rejection, CAV, and CKD at 30 months. However, everolimus and low-dose tacrolimus appear to be safe based on the total burden of 6 MATEs and may be associated with improved kidney function and less CMV infection.Trial RegistrationClinicalTrials.gov Identifier: NCT03386539

Abstract Tisagenlecleucel (tisa-cel) is a CD19-directed chimeric antigen receptor T-cell therapy for relapsed/refractory precursor B-cell acute lymphoblastic leukemia (R/R B-ALL). We report infectious complications for 100 days (D100) following tisa-cel therapy in 471 pediatric and young adults (median age 13.8 years) with R/R B-ALL reported from September 2017 to June 2022. By D100, 137 (29%) patients had an infectious event, with an infection density of 0.542 per 100 person-days at risk. D100 cumulative incidences of bacterial, viral, and fungal infections were 14.1%, 11.6%, and 1.3%, corresponding to infection density scores of 0.296, 0.213, and 0.033 per 100 person-days at risk, respectively. In a multivariable analysis, receipt of ≥3 lines of therapy before tisa-cel (hazard ratio [HR], 1.86; 95% confidence interval [CI], 1.13-3.08; P = .015), any-grade cytokine release syndrome (HR, 1.78; 95% CI, 1.17-2.71; P = .007), and lack of neutrophil recovery (HR, 2.63; 95% CI, 1.47-4.69; P = .001) were associated with an increased risk for any infection. Similar associations were observed for bacterial infections, with the addition of younger age as an adverse risk (<6 vs 6-15 years; HR, 2.38; 95% CI, 1.23-4.61; P = .01). Risk factors for viral infections included increasing age (1-year increase; HR, 1.05; 95% CI, 1.01-1.09; P = .016), prior history of any infection (HR, 2.76, 95% CI, 1.40-5.46; P = .004), and prior hematopoietic cell transplant (HR, 2.10; 95% CI, 1.18-3.71; P = .011). D100 infection-related mortality (IRM) rate was low at 0.2% (95% CI, 0.0-0.8). In this multicenter real-world study, we observed a high incidence of infectious complications but a low IRM following tisa-cel for R/R B-ALL.

The indications for immune checkpoint inhibitor (ICI) use in cancer treatment continue to expand. This is attributable to their proven anticancer activity in addition to their tolerability and favorable toxicity profile as compared to conventional chemotherapeutic agents. ICIs work by blocking the inhibitory signals between tumor cells and T-cells, thereby enhancing the T-cell cytotoxic activity to inhibit tumor growth. Because of their immune-stimulating effect, ICIs are linked to adverse renal outcomes in both native and transplanted kidneys. The risk of kidney allograft rejection in the setting of ICI use has been reported to be around 40%, leading to an increased risk of graft loss. In this report, we review the literature examining outcomes in kidney transplant recipients receiving ICIs for various oncologic indications.

Mechanical stretch associated with respiratory support can impair airway development and function in neonates, but the mechanisms are not fully understood. Using developing human airway smooth muscle cells exposed to cyclic forces with static stretch to mimic continuous positive airway pressure, we found that stretch dysregulates long-term cell proliferation and inflammatory cytokine production, and mechanosensitive Piezo ion channels may play a role in the proliferation response.

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.

Background and PurposeThe aryl hydrocarbon receptor (AhR) is a ligand‐activated transcription factor that maintains cellular homeostasis. AhR in airway fibroblasts, epithelial and immune cells inhibit inflammatory responses. Nevertheless, its expression and role in airway smooth muscle (ASM), an airway structural cell indispensable in asthma pathophysiology, are obscure. This study uncovers AhR expression, underlying mechanisms, and activity in ASM during inflammation and asthma.Experimental ApproachCultured primary human nonasthmatic and asthmatic ASM cells were treated with TNFα/IL‐13, with/without pharmacological inhibitors targeting PI3K, p38MAPK, JNK, NFkB, and AP1. AhR expression was analysed using RNA‐sequencing, confocal microscopy, qPCR, and immunoblotting. AP1 specific role was confirmed using c‐JUN (AP1) siRNA and ChIP‐qPCR. AhR activity was determined by Nano luciferase in AhR agonist‐treated cells.Key ResultsWe found ubiquitous expression of AhR in ASM with up‐regulation in asthmatic ASM. TNFα increased AhR expression, whereas IL‐13 did not. Furthermore, p38 and JNK inhibition significantly reduced AhR expression with TNFα exposure, whereas PI3K inhibition had no effect. AP1 inhibition and c‐JUN knockdown significantly down‐regulated AhR expression, whereas NFkB inhibition showed no effect. TNFα promoted c‐JUN binding to AhR promoter and increased AhR mRNA expression. Additionally, AhR agonists significantly increased the xenobiotic response element (XRE) activity, CYP1B1, and AhR nuclear expression. TNFα exposure reduced XRE activity and AhR nuclear expression.Conclusion and ImplicationsOur findings suggest inflammation and asthma transcriptionally up‐regulates AhR through the p38/JNK‐AP1 pathway in ASM, identifying a potential therapeutic target for modulating AhR and its downstream effects in asthma.

Introduction: Throughout the lifetime of an asthmatic, the lung undergoes changes in the composition of its extracellular matrix (ECM) and becomes more fibrotic, a characteristic feature of airway remodeling. Due to this, lung functionality decreases as the lung becomes less elastic and airway resistance increases. The ECM proteins constantly network with their respective mechanosensory receptors and regulatory proteins on the cell membrane. These signaling interactions allow for continuous interactions and feedback between the ECM and airway smooth muscle cells (ASM). ASM cells are one of the major structural cells that regular airway remodeling and are the primary target for treating asthma. In this study, we investigated the specific alterations that occur in the ECM of ASM cells treated with TGF-β1. Methods: Human primary airway smooth muscle (ASM) cells were grown to confluency in DMEM/F-12 with 10% FBS and 1% AbAm in standard conditions. Cells were serum deprived for 48 hours prior to experiments. Cells were treated with TGF-β1 (2 ng/mL) in serum free media. Cells were harvested after 48 hours and 200 µg of protein lysate was prepared. Data-independent acquisition (DIA) mass spectrometry was performed at IDeA National Resource for Quantitative Proteomics. Fold changes for ECM class proteins were collected from DIA results. Pathway analysis was then done using Qiagen ingenuity pathway analysis. Furthermore, expression patterns of select proteins were confirmed via western blotting. Results: The effects of TGF-β1 on specific types of collagens, integrins, laminins, and additional ECM proteins were analyzed. Western blotting confirmed similar changes in expression as measured by DIA. TGF-β1 exposure upregulated LAMA4, LAMB2, and LAMC1 which is likely to increase the prevalence of Laminins 221 and 421. TGF-β1 augmented integrin signaling by upregulating ITGA7, ITGA11, ITGA1, ITGB1 and downregulating ITGA2 and ITGB8. TGF-β1 increased expression of TSP1, TSP2, TSP3, TNS-C, FB, Elastin and Versican while downregulating TNS-X. Several interactions between ECM proteins and their sensors and receptors were highlighted for their enrichment. Conclusion: The DIA analysis shows an upregulation of proteins involved in airway remodeling by TGF-β1 in ASM cells. These findings substantiate our previous results as well as provide insights into a more targeted approach in studying ECM-Cell interactions. NIH R01HL171245 (Venkatachalem), R01HL146705 (Venkatachalem), R01HL142061 (Pabelick, Prakash). and IDeA National Resource for Quantitative Proteomics (R24GM137786). 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.

Rationale: Asthma is a chronic inflammatory disease of conducting airways characterized by airway hyperresponsiveness and remodeling. Airway smooth muscle (ASM) is a major structural cell in the airway that contributes to airway hyperresponsiveness and remodeling. Mitochondrial dynamics is a fission/fusion process crucial for optimal function and signal transduction. Inflammation alters the mitochondrial dynamics in ASM, thereby disrupt mitochondrial function and contributes to asthma pathophysiology. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that regulates cellular homeostasis. Recently, we found upregulation of AhR in response to inflammation and asthma in ASM. Additionally, AhR activation inhibited inflammation-induced ASM proliferation and remodeling. However, the role of AhR in regulating mitochondrial dynamics in ASM during inflammation and asthma is obscure. Objective: The aim of this work is to unveil the role of AhR in regulating mitochondrial structure and function in human ASM during inflammation and asthma. Methods: Primary non-asthmatic and asthmatic human ASM cells isolated from surgical lung sections were cultured in DMEM-F12 medium supplemented with 10% FBS and 1% AbAm. Cells were serum deprived, treated with AhR agonist 6-Formylindolo[3,2-b]carbazole (FICZ: 10 nM) and antagonist CH223191 (10 μM), with/or without TNFα (20 ng/mL). Mitochondrial bioenergetics was determined by Seahorse XFp analyzer. Mitochondrial morphology was visualized using mitotracker dye. Expressions of fission and fusion mRNA and protein were determined by qPCR and immunoblotting. Additionally, AhR role in fusion and fission was confirmed in shRNA mediated AhR knockdown and AhR overexpressed ASM cells. Results: AhR activation by FICZ alleviated TNFα-induced disrupted mitochondrial bioenergetics in non-asthmatic ASM cells as well as in asthmatic ASM. Furthermore, TNFα-induced increased mitochondrial fission and reduced fusion was restored by AhR activation in both asthmatic and non-asthmatic ASM. AhR inhibition by CH223191 and knockdown promoted mitochondrial fission and blunted fusion in non-asthmatic ASM cells. Interestingly, AhR overexpression and activation by FICZ restored the mitochondrial dynamics altered by inflammation and asthma in ASM cells. Conclusion: Collectively, AhR activation promotes mitochondrial fusion and abolishes fission induced by inflammation and asthma in human ASM, thereby maintains mitochondrial structure and homeostasis. Therefore, AhR is a potential therapeutic target to mitigate altered mitochondrial dynamics in ASM during inflammation and asthma. Supported by NIH grants R01-HL171245 (Venkatachalem and Britt), R01-HL146705 (Venkatachalem), R01-HL155095 (Britt), R01-HL142061 (Pabelick, Prakash) 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.