The potentiator ivacaftor is essential for pharmacological restoration of F508del-CFTR function and mucociliary clearance in cystic fibrosis
Ivacaftor is an essential component of triple combination CFTR modulator therapy for pharmacological restoration of F508del-CFTR function and mucociliary clearance in cystic fibrosis airways. The cover image shows pseudocolored bead tracks that visualize mucociliary transport (MCT) velocity. MCT is determined from transport rates of fluorescent beads added on the surface of primary nasal epithelial cultures grown at air-liquid interface.
-
Review
Elisabeth Fließer, … , Andrew H. Baker, Grazyna Kwapiszewska Published May 22, 2025
Citation Information: JCI Insight. 2025;10(10):e191059. https://doi.org/10.1172/jci.insight.191059.
×Abstract
The cardiopulmonary vasculature and its associated endothelial cells (ECs) play an essential role in sustaining life by ensuring the delivery of oxygen and nutrients. Beyond these foundational functions, ECs serve as key regulators of immune responses. Recent advances in single-cell RNA sequencing have revealed that the cardiopulmonary vasculature is composed of diverse EC subpopulations, some of which exhibit specialized immunomodulatory properties. Evidence for immunomodulation includes distinct expression profiles associated with antigen presentation, cytokine secretion, immune cell recruitment, translocation, and clearance — functions critical for maintaining homeostasis in the heart and lungs. In cardiopulmonary diseases, ECs undergo substantial transcriptional reprogramming, leading to a shift from homeostasis to an activated state marked by heightened immunomodulatory activity. This transformation has highlighted the critical role for ECs in disease pathogenesis and their potential as future therapy targets. This Review emphasizes the diverse functions of ECs in the heart and lungs, particularly adaptive and maladaptive immunoregulatory roles in cardiopulmonary health and disease.
Authors
Elisabeth Fließer, Katharina Jandl, Shiau-Haln Chen, Mei-Tzu Wang, Jonas C. Schupp, Wolfgang M. Kuebler, Andrew H. Baker, Grazyna Kwapiszewska
-
Research Articles
Peiling Zhang, … , Zhi-Xiang Xu, Lin Lu Published May 22, 2025
Citation Information: JCI Insight. 2025;10(10):e175422. https://doi.org/10.1172/jci.insight.175422.
×Abstract
Stem cells play a pivotal role in the malignant behavior of gastric cancer (GC), complicating its treatment and prognosis. However, the regulatory mechanisms of GC stem cells (GCSCs) remain poorly understood. DAZ-associated protein 1 (DAZAP1), a splicing regulator linked to various malignancies, has an unclear role in GC. This study investigated DAZAP1’s impact on GC stemness and its mechanisms. DAZAP1 promoted tumor progression in GCSCs, as shown by sphere formation assays and stemness marker analysis. Functional enrichment analysis suggested that DAZAP1 enhanced tumor stemness by promoting oxidative phosphorylation (OXPHOS), which was validated through Seahorse assays and measurements of mitochondrial potential. Transmission electron microscopy and immunofluorescence analyses demonstrated that DAZAP1 promoted mitophagy. RNA immunoprecipitation and PCR analysis revealed that DAZAP1 regulated the splicing and expression of the mitophagy-related gene ULK1 through nonsense-mediated mRNA decay. Rescue experiments showed that overexpression of ULK1 reversed the suppression of GC stemness and OXPHOS levels induced by DAZAP1 silencing. Our findings indicate that DAZAP1 reduces ULK1 decay, thereby activating mitophagy and enhancing OXPHOS to fulfill the metabolic demands of cancer stem cells. These findings highlight the therapeutic potential of DAZAP1 as a target for treating GC.
Authors
Peiling Zhang, Wei Wang, Hong Xiang, Yun Zhou, Qian Peng, Guolong Liu, Zhi-Xiang Xu, Lin Lu
Patrick W. Mellors, … , Maria C. Basil, Saar Gill Published April 15, 2025
Citation Information: JCI Insight. 2025;10(10):e176596. https://doi.org/10.1172/jci.insight.176596.
×Abstract
Bronchiolitis obliterans syndrome (BOS) is a progressive, fatal obstructive lung disease that occurs following lung transplant, where it is termed chronic lung allograft dysfunction BOS (CLAD-BOS), or as the primary manifestation of pulmonary chronic graft versus host disease (cGVHD-BOS) following allogeneic hematopoietic stem cell transplant. Disease pathogenesis is poorly understood; however, chronic alloreactivity is common to both conditions, suggesting a shared pathophysiology. We performed single-cell RNA-Seq (scRNA-Seq) on explanted human lungs from 4 patients with CLAD-BOS, 3 patients with cGVHD-BOS, and 3 deceased controls to identify cell types, genes, and pathways enriched in BOS to better understand disease mechanisms. In both forms of BOS, we found an expanded population of CD8+ tissue resident memory T cells (TRM), which was distinct to BOS compared with other chronic lung diseases. In addition, BOS samples expressed genes and pathways associated with macrophage chemotaxis and proliferation, including in nonimmune cell populations. We also identified dysfunctional stromal cells in BOS, characterized by pro- and antifibrotic gene programs. These data suggest substantial cellular and molecular overlap between CLAD- and cGVHD-BOS and, therefore, common pathways for possible therapeutic intervention.
Authors
Patrick W. Mellors, Ana N. Lange, Bruno Casino Remondo, Maksim Shestov, Joseph D. Planer, Andrew R. Peterson, Yun Ying, Su Zhou, Jason D. Christie, Joshua M. Diamond, Edward Cantu, Maria C. Basil, Saar Gill
Jiali Cheng, … , Taochao Tan, Liang Huang Published May 22, 2025
Citation Information: JCI Insight. 2025;10(10):e178572. https://doi.org/10.1172/jci.insight.178572.
×Abstract
Expanding the repertoire of CAR therapies to include intracellular antigens holds promise for treating a broad spectrum of malignancies. TCR-like T cells, capable of recognizing intracellular antigen–derived peptides in complex with HLA molecules (pHLA), represent a promising strategy in the field of engineered cellular therapy. This study introduced antibody-like TCR (abTCR) T cells that specifically targeted HLA-A*02:01–restricted LMP2426 peptides, a typical Epstein-Barr virus (EBV) latency II protein, for the treatment of EBV-associated lymphoproliferative diseases (EBV-LPDs). Compared with classic CAR T cells targeting the same epitope, abTCR T cells demonstrated superior efficiency, including increased CD107A expression, enhanced cytotoxicity, and elevated IFN-γ secretion, even when engaging with target cells that naturally present antigens. Moreover, a costimulatory signal–armed abTCR (Co-abTCR), which integrated a costimulatory structure with the abTCR, further enhanced the proliferation and in vivo tumoricidal efficacy of transfected T cells. Collectively, our study developed a potentially novel TCR-like T cell therapy that targets HLA-A*02/LMP2426 for the treatment of EBV-LPDs, providing a potential therapeutic solution for targeting of intracellular antigens in cancer immunotherapy.
Authors
Jiali Cheng, Xuelian Hu, Zhenyu Dai, Yuhao Zeng, Jin Jin, Wei Mu, Qiaoe Wei, Xiangyin Jia, Jianwei Liu, Meng Xie, Qian Luo, Guang Hu, Gaoxiang Wang, Xiaojian Zhu, Jianfeng Zhou, Min Xiao, Jue Wang, Taochao Tan, Liang Huang
Rohan Gupta, … , Juan Amaral, Kapil Bharti Published May 22, 2025
Citation Information: JCI Insight. 2025;10(10):e179246. https://doi.org/10.1172/jci.insight.179246.
×Abstract
Dry age-related macular degeneration (AMD) is a leading cause of untreatable vision loss. In advanced cases, retinal pigment epithelium (RPE) cell loss occurs alongside photoreceptor and choriocapillaris degeneration. We hypothesized that an RPE-patch would mitigate photoreceptor and choriocapillaris degeneration to restore vision. An induced pluripotent stem cell–derived RPE (iRPE) patch was developed using a clinically compatible manufacturing process by maturing iRPE cells on a biodegradable poly(lactic-co-glycolic acid) (PLGA) scaffold. To compare outcomes, we developed a surgical procedure for immediate sequential delivery of PLGA-iRPE and/or PLGA-only patches in the subretinal space of a pig model of laser-induced outer retinal degeneration. Deep learning algorithm-based optical coherence tomography (OCT) image segmentation verified preservation of the photoreceptors over the areas of PLGA-iRPE–transplanted retina and not in laser-injured or PLGA-only–transplanted retina. Adaptive optics imaging of individual cone photoreceptors further supported this finding. OCT-angiography revealed choriocapillaris regeneration in PLGA-iRPE– and not in PLGA-only–transplanted retinas. Our data, obtained using clinically relevant techniques, verified that PLGA-iRPE supports photoreceptor survival and regenerates choriocapillaris in a laser-injured pig retina. Sequential delivery of two 8 mm2 transplants allows for testing of surgical feasibility and safety of the double dose. This work allows one surgery to treat larger and noncontiguous retinal degeneration areas.
Authors
Rohan Gupta, Irina Bunea, Bruno Alvisio, Francesca Barone, Rishabh Gupta, Dara Baker, Haohua Qian, Elena Daniele, Casey G. Contreary, Jair Montford, Ruchi Sharma, Arvydas Maminishkis, Mandeep S. Singh, Maria Teresa Magone De Quadros Costa, Amir H. Kashani, Juan Amaral, Kapil Bharti
Adrian Zietara, … , Oleg Palygin, Alexander Staruschenko Published April 15, 2025
Citation Information: JCI Insight. 2025;10(10):e181778. https://doi.org/10.1172/jci.insight.181778.
×Abstract
The dietary sodium/potassium ratio is positively correlated with blood pressure, and understanding this relationship is crucial for improving hypertension treatment. Moreover, few studies have examined these effects in both sexes. In this study, we aimed to investigate how supplementing (1.41% K+; HK) or depleting (DK) dietary potassium affects the development of salt-sensitive (SS) hypertension in male and female Dahl SS rats. Potassium supplementation attenuated blood pressure during 5 weeks of high-salt (4% NaCl) diet in male but not in female rats. In contrast, a potassium-deficient diet prevented the development of salt-induced hypertension in both sexes, though this effect is unlikely to be protective. Both males and females on the DK diet were hypokalemic and had diminished heart rates and reduced weight gain; furthermore, females experienced high mortality. RNA-Seq of kidney cortical tissue revealed a number of genes that may underlie the sex-specific differences in phenotype. Male rats supplemented with potassium exhibited a decreased number and size of WNK4 puncta, whereas in potassium-supplemented females, there was no difference in puncta count and there was an increase in puncta size. Our data indicate there are sex-dependent differences in response to dietary potassium in hypertension and that the distal nephron compensates for severe potassium deficiency.
Authors
Adrian Zietara, Lashodya V. Dissanayake, Melissa Lowe, Biyang Xu, Vladislav Levchenko, Vasundhara Kain, Ganesh V. Halade, Christine A. Klemens, Oleg Palygin, Alexander Staruschenko
Francis Migneault, … , Héloïse Cardinal, Marie-Josée Hébert Published May 22, 2025
Citation Information: JCI Insight. 2025;10(10):e181937. https://doi.org/10.1172/jci.insight.181937.
×Abstract
Microvascular rarefaction substantially contributes to renal dysfunction following ischemia-reperfusion injury (IRI). We characterized the microRNA signature of extracellular vesicles (EVs) released during endothelial apoptosis to identify biomarkers and regulators of microvascular rarefaction and renal dysfunction. Using in vitro models and RNA-Seq, we found miR-423-5p, let-7b-5p, and let-7c-5p enriched in small EVs from apoptotic endothelial cells. In mouse models of renal IRI and a cohort of 51 patients who have undergone renal transplant with delayed graft function, serum miR-423-5p correlated with circulating EVs, while let-7b-5p and let-7c-5p were also present in free form. Early acute kidney injury saw increased serum miR-423-5p levels linked to small EVs with endothelial markers. Over time, higher serum miR-423-5p levels were associated with large EVs and correlated with greater renal microvascular density and reduced fibrosis. Microvascular density and fibrosis predicted renal function 3 years after transplantation. We explored miR-423-5p’s role in renal homeostasis, finding that its injection during renal IRI preserved microvascular density and inhibited fibrosis. Endothelial cells transfected with miR-423-5p showed enhanced resistance to apoptosis, increased migration, and angiogenesis. Localized miR-423-5p injection in hindlimb ischemia model accelerated revascularization. These findings position miR-423-5p as a predictor of renal microvascular rarefaction and fibrosis, highlighting potential strategies for preserving renal function.
Authors
Francis Migneault, Hyunyun Kim, Alice Doreille, Shanshan Lan, Alexis Gendron, Marie-Hélène Normand, Annie Karakeussian Rimbaud, Martin Dupont, Isabelle Bourdeau, Éric Bonneil, Julie Turgeon, Sylvie Dussault, Pierre Thibault, Mélanie Dieudé, Éric Boilard, Alain Rivard, Héloïse Cardinal, Marie-Josée Hébert
×Abstract
Vascular smooth muscle cells (VSMCs) possess significant phenotypic plasticity, shifting between a contractile phenotype and a synthetic state for vascular repair/remodeling. Dysregulated VSMC transformation, marked by excessive proliferation and migration, primarily drives intimal hyperplasia. N6-methyladenosine (m6A), the most prevalent RNA modification in eukaryotes, plays a critical role in gene expression regulation; however, its impact on VSMC plasticity is not fully understood. We investigated the changes in m6A modification and its regulatory factors during VSMC phenotypic shifts and their influence on intimal hyperplasia. We demonstrate that METTL14, crucial for m6A deposition, significantly promoted VSMC dedifferentiation. METTL14 expression, initially negligible, was elevated in synthetic VSMC cultures, postinjury neointimal VSMCs, and human restenotic arteries. Reducing Mettl14 levels in mouse primary VSMCs decreased prosynthetic genes, suppressing their proliferation and migration. m6A-RIP-seq profiling showed key VSMC gene networks undergo altered m6A regulation in Mettl14-deficient cells. Mettl14 enhanced Klf4 and Serpine1 expression through increased m6A deposition. Local Mettl14 knockdown significantly curbed neointimal formation after arterial injury, and reducing Mettl14 in hyperplastic arteries halted further neointimal development. We show that Mettl14 is a pivotal regulator of VSMC dedifferentiation, influencing Klf4- and Serpine1-mediated phenotypic conversion. Inhibiting METTL14 is a viable strategy for preventing restenosis and halting restenotic occlusions.
Authors
Grace Chensee, Bob S.L. Lee, Immanuel D. Green, Jessica Tieng, Renhua Song, Natalia Pinello, Quintin Lee, Majid Mehravar, David A. Robinson, Mian Wang, Mary M. Kavurma, Jun Yu, Justin J.L. Wong, Renjing Liu
Kristina E.N. Clark, … , Christopher D. Buckley, Christopher P. Denton Published April 15, 2025
Citation Information: JCI Insight. 2025;10(10):e185618. https://doi.org/10.1172/jci.insight.185618.
×Abstract
Fibroblasts are central to pathogenesis of systemic sclerosis (SSc). However, studies of conventional explant fibroblast cultures incompletely reflect disease biology and treatment response. We isolated a second nonmigratory “resident” population of fibroblasts from skin biopsies after outgrowth of explant “migratory” cells. These nonmotile resident fibroblasts were compared with migratory cells from the same biopsy, using functional studies, bulk and single-cell RNA-seq, and localized in situ by multichannel immunofluorescence. Migratory and resident fibroblast populations in SSc showed distinct profibrotic characteristics and gene expression for pathogenic pathways differing by stage and autoantibody subgroup. TGF-β signaling was highly active in migratory fibroblasts in early-stage diffuse cutaneous SSc (dcSSc). Conversely, resident fibroblasts had less upregulated TGF-β signaling, especially in late-stage dcSSc. Increased chemokine expression was a hallmark of resident fibroblasts at all stages. In vitro studies confirmed differential response to TGF-β1 and CCL2 between migratory and resident cells. We suggest that migratory fibroblasts are especially important in early skin disease, whereas nonmigratory fibroblasts may have a regulatory role and contribute more to fibrosis in later-stage disease. Thus, we have identified a pathogenic fibroblast population in SSc, not isolated by conventional explant culture, that could play an important role in fibrosis and be targeted therapeutically.
Authors
Kristina E.N. Clark, Shiwen Xu, Moustafa Attar, Voon H. Ong, Christopher D. Buckley, Christopher P. Denton
Juliana S. Powell, … , Yoel Sadovsky, Adrian E. Morelli Published May 22, 2025
Citation Information: JCI Insight. 2025;10(10):e186335. https://doi.org/10.1172/jci.insight.186335.
×Abstract
Pregnancy is an immunological paradox where despite a competent maternal immune system, regulatory mechanisms at the fetoplacental interface and maternal secondary lymphoid tissues (SLTs) circumvent rejection of semi-allogeneic concepti. Small extracellular vesicles (sEVs) are a vehicle for intercellular communication; nevertheless, the role of fetoplacental sEVs in transport of antigens to maternal SLTs has not been conclusively demonstrated. Using mice in which the conceptus generates fluoroprobe-tagged sEVs shed by the plasma membrane or released from the endocytic compartment, we show that fetoplacental sEVs are delivered to immune cells in the maternal spleen. Injection of sEVs from placentas of females impregnated with Act-mOVA B6 males elicited suboptimal activation of OVA-specific CD8+ OT-I T cells in virgin females as occurs during pregnancy. Furthermore, when OVA+ concepti were deficient in Rab27a, a protein required for sEV secretion, OT-I cell proliferation in the maternal spleen was decreased. Proteomics analysis revealed that mouse trophoblast sEVs were enriched in antiinflammatory and immunosuppressive mediators. Translational relevance was tested in humanized mice injected using sEVs from cultures of human trophoblasts. Our findings show that sEVs deliver fetoplacental antigens to the mother’s SLTs that are recognized by maternal T cells. Alterations of such a mechanism may lead to pregnancy disorders.
Authors
Juliana S. Powell, Adriana T. Larregina, William J. Shufesky, Mara L.G. Sullivan, Donna Beer Stolz, Stephen J. Gould, Geoffrey Camirand, Sergio D. Catz, Simon C. Watkins, Yoel Sadovsky, Adrian E. Morelli
Mari Yokoi, … , Toyohiro Hirai, Hirotake Tsukamoto Published April 8, 2025
Citation Information: JCI Insight. 2025;10(10):e186483. https://doi.org/10.1172/jci.insight.186483.
×Abstract
Managing immune-related adverse events (irAEs) caused by cancer immunotherapy is essential for developing effective and safer therapies. However, cellular mechanism(s) underlying organ toxicity during anti–PD-(L)1 therapy remain unclear. Here, we investigated the effect of chronological aging on anti–PD-(L)1 therapy–induced irAE-like lung toxicity, utilizing tumor-bearing aged mice. Anti–PD-(L)1 therapy facilitated ectopic infiltration of T and B cells, and antibody deposition in lungs of aged but not young mice. Adoptive transfer of aged lung–derived CD4+ T cells into TCR-deficient mice revealed that both pathogenic CD4+ T cells and an aged host environment were necessary for the irAE-inducible responses. Single-cell transcriptomics of lung-infiltrating cells in aged mice demonstrated that anti–PD-(L)1 therapy elicited ICOS+CD4+ T cell activation. Disruption of the ICOS-ICOSL interaction attenuated germinal center B cell differentiation and subsequent lung damage, which were overcome by local administration of IL-21 in the lungs of anti–PD-1 therapy–treated aged mice. Therefore, ICOS+CD4+ T cells elicited under an aged environment exacerbated aberrant immune responses and the subsequent lung dysfunction. Consistent with the findings from the mouse model, ICOS upregulation in CD4+ T cells was associated with later irAE incidence in patients with cancer. These finding will help development of useful strategies for irAE management in patients with cancer, many of whom are elderly.
Authors
Mari Yokoi, Kosaku Murakami, Tomonori Yaguchi, Kenji Chamoto, Hiroaki Ozasa, Hironori Yoshida, Mirei Shirakashi, Katsuhiro Ito, Yoshihiro Komohara, Yukio Fujiwara, Hiromu Yano, Tatsuya Ogimoto, Daiki Hira, Tomohiro Terada, Toyohiro Hirai, Hirotake Tsukamoto
×Abstract
Oxidative stress driven by malfunctioning respiratory complex I (RC-I) is a crucial pathogenic factor in liver ischemia/reperfusion (I/R) injury. This study investigated the role of alkaline ceramidase 3 (ACER3) and its unsaturated long-chain ceramide (CER) substrates in regulating liver I/R injury through RC-I. Our findings demonstrated that I/R upregulated ACER3 and decreased unsaturated long-chain CER levels in human and mouse livers. Both global and hepatocyte-specific Acer3 ablation, as well as treatment with CER(d18:1/18:1), led to a significant increase in CER(d18:1/18:1) levels in the liver, which mitigated the I/R-induced hepatocyte damage and inflammation in mice. Mechanistically, ACER3 modulated CER(d18:1/18:1) levels in mitochondria-associated membranes and the endoplasmic reticulum (ER), thereby influencing the transport of CER(d18:1/18:1) from the ER to mitochondria. Acer3 ablation and CER(d18:1/18:1) treatment elevated CER(d18:1/18:1) in mitochondria, where CER(d18:1/18:1) bound to the RC-I subunit NDUFA6 to inactivate RC-I and reduced reactive oxygen species production in the I/R-injured mouse liver. These findings underscore the role of the CER(d18:1/18:1)-NDUFA6 interaction in suppressing RC-I–mediated oxidative-stress-driven pathogenesis in liver I/R injury.
Authors
Kai Wang, Leyi Liao, Hanbiao Liang, Pengxiang Huang, Qingping Li, Baoxiong Zhuang, Chen Xie, Xiangyue Mo, Xuesong Deng, Jieyuan Li, Yang Lei, Minghui Zeng, Cungui Mao, Ruijuan Xu, Cuiting Liu, Xianqiu Wu, Jie Zhou, Biao Wang, Yiyi Li, Chuanjiang Li
Michal Navon, … , Einav Nili Gal-Yam, Natalia T. Freund Published May 22, 2025
Citation Information: JCI Insight. 2025;10(10):e187392. https://doi.org/10.1172/jci.insight.187392.
×Abstract
The presence of B cells in tumors is correlated with favorable prognosis and efficient response to immunotherapy. While tumor-reactive antibodies have been detected in several cancer types, identifying antibodies that specifically target tumor-associated antigens remains a challenge. Here, we investigated the antibodies spontaneously elicited during breast and lung cancer that bind the cancer-associated antigen MET. We screened patients with lung (n = 25) and breast (n = 75) cancer and found that 13% had antibodies binding to both the recombinant ectodomain of MET, and the ligand binding part of MET, SEMA. MET binding in the breast cancer cohort was significantly correlated with hormone receptor–positive status. We further conducted immunoglobulin sequencing of peripheral MET-enriched B cells from 6 MET-reactive patients. The MET-enriched B cell repertoire was found to be polyclonal and prone to non-IgG1 subclass. Nine monoclonal antibodies were cloned and analyzed, and these exhibited MET binding, low thermostability, and high polyreactivity. Among these, antibodies 87B156 and 69B287 effectively bound to tumor cells and inhibited MET-expressing breast cancer cell lines. Overall, our data demonstrate that some patients with breast and lung cancer develop polyreactive antibodies that cross-react with MET. These autoantibodies have a potential contribution to immune responses against tumors.
Authors
Michal Navon, Noam Ben-Shalom, Maya Dadiani, Michael Mor, Ron Yefet, Michal Bakalenik-Gavry, Dana Chat, Nora Balint-Lahat, Iris Barshack, Ilan Tsarfaty, Einav Nili Gal-Yam, Natalia T. Freund
Hsueh-Han Lu, … , Michael Croft, Sujan Shresta Published April 3, 2025
Citation Information: JCI Insight. 2025;10(10):e187405. https://doi.org/10.1172/jci.insight.187405.
×Abstract
The SARS-CoV-2 pandemic highlighted the potential of mRNA vaccines in rapidly responding to emerging pathogens. However, immunity induced by conventional mRNA vaccines wanes quickly, requiring frequent boosters. Self-amplifying RNA (saRNA) vaccines, which extend antigen expression via self-replication, offer a promising strategy to induce more durable immune responses. In this study, we developed an saRNA vaccine encoding Zika virus (ZIKV) membrane and envelope proteins and evaluated its efficacy in mice. A single vaccination elicited strong humoral and cellular immune responses and reduced viral loads but only for 28 days. By day 84, antibody titers and T cell responses had significantly declined, resulting in reduced efficacy. To address this, we evaluated agonist antibodies targeting the T cell costimulatory molecules OX40 and 4-1BB. Coadministration of agonist antibodies enhanced CD8+ T cell responses to vaccination, resulting in sustained immunity and reduced viral loads at day 84. Depletion and passive transfer studies verified that long-term antiviral immunity was primarily CD8+ T cell dependent, with minimal contributions from antibody responses. These findings suggest that agonists targeting members of the tumor necrosis receptor superfamily, such as OX40 and 4-1BB, might enhance the durability of saRNA vaccine–induced protection, addressing a key limitation of current mRNA vaccine platforms.
Authors
Hsueh-Han Lu, Rúbens Prince dos Santos Alves, Qin Hui Li, Luke Eder, Julia Timis, Henry Madany, Kantinan Chuensirikulchai, Krithik V. Varghese, Aditi Singh, Linda Le Tran, Audrey Street, Annie Elong Ngono, Michael Croft, Sujan Shresta
×Abstract
In the bullous autoimmune disease pemphigus vulgaris (PV), autoantibodies directed mainly against desmoglein 1 (Dsg1) and Dsg3 cause loss of desmosomal adhesion. We recently showed that intracellular cAMP increase by the phosphodiesterase 4 inhibitor apremilast was protective in different PV models. Thus, we here analyzed the involvement of the cAMP effector exchange factor directly activated by cAMP1 (Epac1). In Epac1-deficient mice pemphigus antibody-induced blistering was ameliorated in vivo while apremilast had no additional effect. Interestingly, augmented protein levels of Dsg1 and Dsg3 as well as increased Dsg1 mRNA levels and higher numbers of Dsg1- and Dsg3-dependent single-molecule interactions were detected in keratinocytes derived from Epac1-deficient mice. This was paralleled by stronger intercellular adhesion under baseline conditions and prevention of pemphigus autoantibody-induced loss of intercellular adhesion. However, the protective effect of apremilast against loss of intercellular adhesion in response to the pathogenic Dsg3 antibody AK23 was attenuated in Epac1-deficient keratinocytes. Similarly, the Epac1 inhibitor Esi09 protected keratinocytes from pemphigus antibody-induced loss of adhesion. Mechanistically, Epac1 deficiency resulted in lack of apremilast-induced Rap1 activation and phosphorylation of Pg at S665. Taken together, these data indicate that Epac1 is involved in the regulation of baseline and cAMP-mediated stabilization of keratinocyte adhesion.
Authors
Anna M. Sigmund, Franziska C. Bayerbach, Daniela Kugelmann, Elisabeth Butz, Sina Moztarzadeh, Margarethe E.C. Schikora, Anja K.E. Horn, Mariya Y. Radeva, Sophia Engelmayer, Desalegn T. Egu, Matthias Goebeler, Enno Schmidt, Jens Waschke, Franziska Vielmuth
Anita Balázs, … , Simon Y. Graeber, Marcus A. Mall Published April 22, 2025
Citation Information: JCI Insight. 2025;10(10):e187951. https://doi.org/10.1172/jci.insight.187951.
×Abstract
Pharmacological rescue of F508del-CFTR by the triple combination CFTR modulator therapy elexacaftor/tezacaftor/ivacaftor (ETI) leads to unprecedented clinical benefits in patients with cystic fibrosis (CF). However, previous studies in CF primary human airway epithelial cultures demonstrated that chronic treatment with the potentiator ivacaftor can render the F508del protein unstable, thus limiting restoration of CFTR chloride channel function. Even so, quantitative studies of this unwanted effect of ivacaftor on F508del channel function with dependency on cell culture conditions remain limited, and the impact of chronic ivacaftor exposure on restoration of mucociliary clearance that is impaired in patients with CF has not been studied. In patient-derived primary nasal epithelial cultures, we found that different culture conditions (UNC-ALI medium vs. PneumaCult medium) have profound effects on ETI-mediated restoration of F508del-CFTR function. Chronic treatment with ivacaftor as part of ETI triple therapy limited the rescue of F508del-CFTR chloride channel function when CF nasal epithelial cultures were grown in UNC-ALI medium but not in PneumaCult medium. In PneumaCult medium, both chronic and acute addition of ivacaftor as part of ETI treatment led to constitutive CFTR-mediated chloride secretion in the absence of exogenous cAMP-dependent stimulation. This constitutive CFTR-mediated chloride secretion was essential to improve viscoelastic properties of the mucus layer and to restore mucociliary transport on CF nasal epithelial cultures. Furthermore, nasal potential difference measurements in patients with CF showed that ETI restored constitutive F508del-CFTR activity in vivo. These results demonstrate that ivacaftor as a component of ETI therapy is essential to restore mucociliary clearance and suggest that this effect is facilitated by its constitutive activation of F508del channels following their folding correction in patients with CF.
Authors
Anita Balázs, Tihomir Rubil, Christine K. Wong, Jasmin Berger, Marika Drescher, Kathrin Seidel, Mirjam Stahl, Simon Y. Graeber, Marcus A. Mall
Lasse Bach Steffensen, … , Mads Thomassen, Lars Melholt Rasmussen Published April 8, 2025
Citation Information: JCI Insight. 2025;10(10):e188281. https://doi.org/10.1172/jci.insight.188281.
×Abstract
The notion of clonal cell populations in human atherosclerosis has been suggested but not demonstrated. Somatic mutations are used to define cellular clones in tumors. Here, we characterized the mutational landscape of human carotid plaques through whole-exome sequencing to explore the presence of clonal cell populations. Somatic mutations were identified in 12 of 13 investigated plaques, while no mutations were detected in 11 non-atherosclerotic arteries. Mutated clones often constituted over 10% of the sample cell population, with genes related to the contractile apparatus enriched for mutations. In carriers of clonal hematopoiesis of indeterminate potential (CHIP), hematopoietic clones had infiltrated the plaque tissue and constituted substantial fractions of the plaque cell population alongside locally expanded clones. Our findings establish somatic mutations as a common feature of human atherosclerosis and demonstrate the existence of mutated clones expanding locally, as well as CHIP clones invading from the circulation. While our data do not support plaque monoclonality, we observed a pattern suggesting the coexistence of multiple mutated clones of considerable size spanning different regions of plaques. Mutated clones are likely to be relevant to disease development, and somatic mutations will serve as a convenient tool to uncover novel pathological processes of atherosclerosis in future studies.
Authors
Lasse Bach Steffensen, Stephanie Kavan, Pia Søndergaard Jensen, Matilde Kvist Pedersen, Steffen Møller Bøttger, Martin Jakob Larsen, Maja Dembic, Otto Bergman, Ljubica Matic, Ulf Hedin, Lars van Brakel Andersen, Jes Sanddal Lindholt, Kim Christian Houlind, Lars Peter Riber, Mads Thomassen, Lars Melholt Rasmussen
Philip F. Halloran, … , Patrick T. Gauthier, Christian Hinze Published April 15, 2025
Citation Information: JCI Insight. 2025;10(10):e188658. https://doi.org/10.1172/jci.insight.188658.
×Abstract
Background. Expression of acute kidney injury–associated (AKI-associated) transcripts in kidney transplants may reflect recent injury and accumulation of epithelial cells in “failed repair” states. We hypothesized that the phenomenon of failed repair could be associated with deterioration and failure in kidney transplants. Methods. We defined injury-induced transcriptome states in 4,502 kidney transplant biopsies injury-induced gene sets and classifiers previously developed in transplants. Results. In principal component analysis (PCA), PC1 correlated with both acute and chronic kidney injury and related inflammation and PC2 with time posttransplant. Positive PC3 was a dimension that correlated with epithelial remodeling pathways and anticorrelated with inflammation. Both PC1 and PC3 correlated with reduced survival, with PC1 effects strongly increasing over time whereas PC3 effects were independent of time. In this model, we studied the expression of 12 “new” gene sets annotated in single-nucleus RNA-sequencing studies of epithelial cells with failed repair in native kidneys. The new gene sets reflecting epithelial-mesenchymal transition correlated with injury PC1 and PC3, lower estimated glomerular filtration rate, higher donor age, and future failure as strongly as any gene sets previously derived in transplants and were independent of nephron segment of origin and graft rejection. Conclusion. These results suggest 2 dimensions in the kidney transplant response to injury: PC1, AKI-induced changes, failed repair, and inflammation; and PC3, a response involving epithelial remodeling without inflammation. Increasing kidney age amplifies PC1 and PC3. Trial registration. INTERCOMEX (ClinicalTrials.gov NCT01299168); Trifecta-Kidney (ClinicalTrials.gov NCT04239703). Funding. Genome Canada; Natera, Inc.; and Thermo Fisher Scientific.
Authors
Philip F. Halloran, Jessica Chang, Martina Mackova, Katelynn S. Madill-Thomsen, Enver Akalin, Tarek Alhamad, Sanjiv Anand, Miha Arnol, Rajendra Baliga, Mirosław Banasik, Christopher D. Blosser, Georg Böhmig, Daniel Brennan, Jonathan Bromberg, Klemens Budde, Andrzej Chamienia, Kevin Chow, Michał Ciszek, Declan de Freitas, Dominika Dęborska-Materkowska, Alicja Debska-Ślizień, Arjang Djamali, Leszek Domański, Magdalena Durlik, Gunilla Einecke, Farsad Eskandary, Richard Fatica, Iman Francis, Justyna Fryc, John Gill, Jagbir Gill, Maciej Glyda, Sita Gourishankar, Marta Gryczman, Gaurav Gupta, Petra Hruba, Peter Hughes, Arskarapurk Jittirat, Zeljka Jurekovic, Layla Kamal, Mahmoud Kamel, Sam Kant, Nika Kojc, Joanna Konopa, James Lan, Roslyn B. Mannon, Arthur Matas, Joanna Mazurkiewicz, Marius Miglinas, Thomas Mueller, Marek Myślak, Seth Narins, Beata Naumnik, Anita Patel, Agnieszka Perkowska-Ptasińska, Michael Picton, Grzegorz Piecha, Emilio Poggio, Silvie Rajnochová Bloudíčkova, Thomas Schachtner, Soroush Shojai, Majid L.N. Sikosana, Janka Slatinská, Katarzyna Smykal-Jankowiak, Ashish Solanki, Željka Veceric Haler, Ondrej Viklicky, Ksenija Vucur, Matthew R. Weir, Andrzej Wiecek, Zbigniew Włodarczyk, Harold Yang, Ziad Zaky, Patrick T. Gauthier, Christian Hinze
Ganlin Qu, … , Reinhard Laubenbacher, Borna Mehrad Published April 15, 2025
Citation Information: JCI Insight. 2025;10(10):e189151. https://doi.org/10.1172/jci.insight.189151.
×Abstract
Invasive aspergillosis is characterized by lung hemorrhage and release of extracellular heme, which promotes fungal growth. Heme can also mediate tissue injury directly, and both fungal growth and lung injury may induce hemorrhage. To assimilate these interdependent processes, we hypothesized that, during aspergillosis, heme mediates direct lung injury independent of fungal growth, leading to worse infection outcomes, and the scavenger protein hemopexin mitigates these effects. Mice with neutropenic aspergillosis developed a time-dependent increase in lung extracellular heme and a corresponding hemopexin induction. Hemopexin deficiency resulted in markedly increased lung injury, fungal growth, and lung hemorrhage. Using a computational model of the interactions of Aspergillus, heme, and the host, we predicted a critical role for heme-mediated generation of neutrophil extracellular traps (NETs) in this infection. We tested this prediction using a fungal strain unable to grow at body temperature and found that extracellular heme and fungal exposure synergized to induce lung injury by promoting NET release, and disruption of NET was sufficient to attenuate lung injury and fungal burden. These data implicate heme-mediated NETosis in both lung injury and fungal growth during aspergillosis, resulting in a detrimental positive feedback cycle that can be interrupted by scavenging heme or disrupting NETs.
Authors
Ganlin Qu, Henrique A.L. Ribeiro, Angelica L. Solomon, Luis Sordo Vieira, Yana Goddard, Nickolas G. Diodati, Arantxa V. Lazarte, Matthew Wheeler, Reinhard Laubenbacher, Borna Mehrad
×Abstract
Biliary atresia (BA) is a pediatric liver disease that often necessitates parenteral nutrition (PN) to support growth due to impaired liver function. While soy-based lipid emulsions (SLE) are commonly used in PN, they may contribute to cholestatic liver injury. In contrast, mixed lipid emulsions (MLE) show promise in preventing cholestasis in infants without BA, potentially by restoring bile flow. However, their effectiveness in patients of complete bile duct obstruction, as seen in BA, remains uncertain. To explore the potential benefits of MLE in BA, we utilized a neonatal pig model of bile duct ligation (BDL). Pigs underwent either BDL or sham surgery and were subsequently fed either MLE or SLE via PN, or enterally with formula. The MLE-BDL pigs exhibited significantly greater weight gain compared with those fed SLE or formula enterally. Additionally, MLE-BDL pigs showed higher serum bile acid and γ-glutamyl transferase concentrations compared with SLE-BDL pigs. However, no significant differences in liver injury, assessed by ductular reaction or fibrosis, were observed between MLE- and SLE-BDL pigs. Based on weight gain alone, MLE may be a superior lipid emulsion for use in neonates with obstructive cholestasis.
Authors
Greg Guthrie, Caitlin Vonderohe, Valeria Meléndez Hebib, Barbara Stoll, Douglas Burrin
Jyotsana Pandey, … , Nisarat Pinthong, A. Brent Carter Published April 10, 2025
Citation Information: JCI Insight. 2025;10(10):e189330. https://doi.org/10.1172/jci.insight.189330.
×Abstract
Asbestosis is a prototypical type of fibrosis that is progressive and does not resolve. ER stress is increased in multiple cell types that contribute to fibrosis; however, the mechanism(s) by which ER stress in lung macrophages contributes to fibrosis is poorly understood. Here, we show that ER stress resulted in protein kinase RNA-like ER kinase (PERK; Eif2ak3) activation in humans with asbestosis. Similar results were seen in asbestos-injured mice. Mice harboring a conditional deletion of Eif2ak3 were protected from fibrosis. Lung macrophages from asbestosis individuals had evidence of metabolic reprogramming to fatty acid oxidation (FAO). Eif2ak3fl/fl mice had increased oxygen consumption rate (OCR), whereas OCR in Eif2ak3–/– Lyz2-cre mice was reduced to control levels. PERK increased activating transcription factor 4 (Atf4) expression, and ATF4 bound to the Ppargc1a promoter to increase its expression. GSK2656157, a PERK-specific inhibitor, reduced FAO, Ppargc1a, and Aft4 in lung macrophages and reversed established fibrosis in mice. These observations suggest that PERK is a therapeutic target to reverse established fibrosis.
Authors
Jyotsana Pandey, Jennifer L. Larson-Casey, Mallikarjun H. Patil, Chao He, Nisarat Pinthong, A. Brent Carter
Liliya Tyutyunyk-Massey, … , Xi Liu, Ethan Dmitrovsky Published April 15, 2025
Citation Information: JCI Insight. 2025;10(10):e189901. https://doi.org/10.1172/jci.insight.189901.
×Abstract
Aneuploidy, a cancer hallmark, drives chromosomal instability, drug resistance, and clinically aggressive tumors. Cyclin-dependent kinase 2 (CDK2) antagonism with independent inhibitors or CDK2 knockdown triggered anaphase catastrophe. This disrupts supernumerary centrosome clustering, causing multipolar division and apoptosis. Time-lapse fluorescence microscopy of fluorescent ubiquitination-based cell cycle indicator (FUCCI) cell cycle probes transduced into aneuploid lung cancer cells revealed distinct fates of bipolar and polyploid cells after CDK2 inhibition. Apoptosis occurred in multipolar progeny but was repressed in persistent polyploid cancer cells. RNA-Seq analyses after CDK2 inhibition of 4N versus 2N lung cancer cells were enriched for CDK1 pathway and KIF family members. The Cancer Genome Atlas (TCGA) analysis of lung cancers indicated that CDK1 and KIF family member overexpression was associated with an unfavorable survival. Intravital microscopy of transplanted lung cancer cells in mice extended findings from the in vitro to in vivo settings. CDK2 inhibition of tumor-bearing mice produced polyploid cancer cells in vivo. These cancer cells were resistant to apoptosis and proliferated despite CDK2 inhibition. In contrast, polyploid populations were rarely detected in CDK2-inhibited human alveolar epithelial cells. These findings are translationally relevant. Combined targeting of CDK2 with CDK1 or kinesin family member antagonists should eliminate polyploid cancer cells, promote apoptosis, and augment antineoplastic effects.
Authors
Liliya Tyutyunyk-Massey, Zibo Chen, Xiuxia Liu, Masanori Kawakami, Adam Harned, Yeap Ng, Brian Luke, Samuel C. Okpechi, Blessing Ogunlade, Yair Alfaro, Roberto Weigert, Kedar Narayan, Xi Liu, Ethan Dmitrovsky
Mohammed Asker, … , Matthew R. Hayes, Karolina P. Skibicka Published May 22, 2025
Citation Information: JCI Insight. 2025;10(10):e190108. https://doi.org/10.1172/jci.insight.190108.
×Abstract
Oxytocin plays a key role in reproductive physiology but has recently garnered interest for its involvement in modulating feeding behavior. The vagus nerve contributes to feeding behavior control, as well as other gastrointestinal functions. Oxytocin receptors (OTR) are expressed on the vagus, but their role is poorly understood. Herein, we evaluated the contribution of the vagal OTR to food intake and body weight control in male and female rats. Virogenetic knockdown of vagal OTR resulted in reduced body weight and food intake in male rats. Loss of OTR in the vagus also resulted in suppressed locomotor activity in males but hyperactivity in females. Importantly, rats with vagal OTR knockdown, but not controls, exhibited a significantly elevated mortality rate starting 4 weeks after knockdown, with males being disproportionately affected. Mortality followed large eating bouts and was accompanied by abnormal presence of food in the mouth and esophagus, suggesting death by aspiration or food in the airways and suggesting a crucial role of vagal OTR in upper gastrointestinal tract motility. Furthermore, in vivo experiments revealed impaired esophageal transit. Ex vivo findings indicated oxytocin’s contribution to lower esophageal sphincter contraction. Our findings demonstrated a critical role for the oxytocin system: essential function of vagal OTR for esophageal transit and swallowing.
Authors
Mohammed Asker, Jean-Philippe Krieger, Ivana Maric, Emre Bedel, Jenny Steen, Stina Börchers, Yuxiang Wen, Francesco Longo, Patrik Aronsson, Michael Winder, Robert P. Doyle, Matthew R. Hayes, Karolina P. Skibicka
In-Press Preview - More
Abstract
Background. NK cell function is impaired in people with HIV (PWH), hindering their potential to reduce the lymphoid tissue (LT) reservoir. The IL-15 superagonist N-803 has been shown to enhance NK and T cell function, and thus may reduce viral reservoirs. Methods. To determine the impact of N-803 on LTs, we conducted a clinical trial where 10 PWH on effective antiretroviral therapy (ART) were given three 6 mcg/kg doses of N-803 subcutaneously. We obtained PBMCs and lymph node (LN) and gut biopsies at baseline and after the last N-803 dose. Results. We found a non-statistically significant ~0.50 median log reduction in the frequency of viral(v)RNA+ and vDNA+ cells/g in the 6 participants with baseline and post-treatment LNs. In the ileum, we observed reductions of vRNA+ cells in 8/10 participants and vDNA+ cells in all participants. We also found significant inverse correlations between NK cell proliferation and the frequency of vRNA+ cells, and between NKG2A expression on NK cells and the frequency of vRNA+ cells. Conclusions. Our findings suggest N-803 may reduce the HIV reservoir in LTs of PWH on ART, an effect likely mediated by enhanced NK cell function. Controlled studies assessing the impact of NK cell therapy on HIV LTs are needed.
Authors
Joshua Rhein, Jeffrey G. Chipman, Gregory J. Beilman, Ross Cromarty, Kevin Escandón, Jodi Anderson, Garritt Wieking, Jarrett Reichel, Rodolfo Batres, Alexander Khoruts, Christopher M. Basting, Peter Hinderlie, Zachary B. Davis, Anne Eaton, Byron P. Vaughn, Elnaz Eilkhani, Jeffrey T. Safrit, Patrick Soon-Shiong, Jason V. Baker, Nichole R. Klatt, Steven G. Deeks, Jeffrey S. Miller, Timothy W. Schacker
Abstract
Kidney thick ascending limb cells reabsorb sodium, potassium, calcium, magnesium and contribute to urinary concentration. These cells are typically viewed as a single type that recycles potassium across the apical membrane and generates a lumen-positive transepithelial voltage driving calcium and magnesium reabsorption, although variability in potassium channel expression has been reported. Additionally, recent transcriptomic analyses suggest that different cell types exist along this segment, but classifications have varied and have not led to a new consensus model. We used immunolocalization, electrophysiology and enriched single nucleus RNA-Seq to identify thick ascending limb cell types in rat, mouse and human. We identified three major TAL cell types defined by expression of potassium channels and claudins. One has apical potassium channels, low basolateral potassium conductance, and is bordered by a monovalent cation-permeable claudin. A second lacks apical potassium channels, has high basolateral potassium conductance and is bordered by calcium- and magnesium-permeable claudins. A third type also lacks apical potassium channels and has high basolateral potassium conductance, but these cells are ringed by monovalent cation-permeable claudins. The recognition of diverse cell types may resolve longstanding questions about how solute transport can be modulated selectively and how disruption of these cells leads to human disease.
Authors
Hasan Demirci, Jessica P. Bahena-Lopez, Alina Smorodchenko, Xiao-Tong Su, Jonathan W. Nelson, Chao-Ling Yang, Joshua N. Curry, Xin-Peng Duan, Wen-Hui Wang, Yuliya Sharkovska, Ruisheng Liu, Duygu Elif Yilmaz, Catarina Quintanova, Katie Emberley, Ben Emery, Nina Himmerkus, Markus Bleich, David H. Ellison, Sebastian Bachmann
Abstract
H7N9 avian influenza virus is a zoonotic influenza virus of public health concern, with a 39% mortality rate in humans. H7N9-specific prevention or treatments for humans have not been approved. We previously isolated a human monoclonal antibody (mAb) designated H7-235 that broadly reacts to diverse H7 viruses and neutralizes H7N9 viruses in vitro. Here, we report the crystal structure of H7 HA1 bound to the fragment antigen-binding region (Fab) of recombinant H7-235 (rH7-235). The crystal structure revealed that rH7-235 recognizes residues near but outside of the receptor binding site (RBS). Nevertheless, the rH7-235 IgG potently inhibits hemagglutination mediated by H7N9 viruses due to avidity effect and Fc steric hindrance. This mAb prophylactically protects mice against weight loss and death caused by challenge with lethal H7N9 viruses in vivo. rH7-235 mAb neutralizing activity alone is sufficient for protection when used at high dosed in a prophylactic setting. This study provides insights into mechanisms of viral neutralization by protective broadly reactive anti-H7 antibodies informing the rational design of therapeutics and vaccines against H7N9 influenza virus.
Authors
Iuliia M. Gilchuk, Jinhui Dong, Ryan P. Irving, Cameron D. Buchman, Erica Armstrong, Hannah L. Turner, Sheng Li, Andrew B. Ward, Robert H. Carnahan, James E. Crowe Jr.
Abstract
Loss-of-function mutations in the GBA1 gene are a prevalent risk factor for Parkinson’s disease (PD). Defining features are Lewy bodies that can be rich in α-synuclein (αS), vesicle- and other lipid membranes coupled with striatal dopamine loss and progressive motor dysfunction. Of these, lipid abnormalities are the least understood. An altered lipid metabolism in PD patient-derived neurons, carrying mutations in either GBA1, encoding for glucocerebrosidase, or αS can shift the physiological αS tetramer-monomer (T:M) equilibrium, resulting in PD phenotypes. We previously reported inhibition of stearoyl-CoA desaturase (SCD), the rate-limiting enzyme for fatty acid desaturation, stabilized αS tetramers and improved motor deficits in αS mice. Here we show that mutant GBA-PD cultured neurons have increased SCD products (monounsaturated fatty acids, MUFAS) and reduced αS T:M ratios that were improved by inhibiting SCD. Oral treatment of symptomatic L444P- and E326K Gba1 mutant mice with 5b also improved the αS T:M homeostasis and dopaminergic striatal integrity. Moreover, SCD inhibition normalized GCase maturation and dampened lysosomal and lipid-rich clustering, key features of neuropathology in GBA-PD. In conclusion, this study supports brain MUFA metabolism links GBA1 genotype and wildtype αS homeostasis to downstream neuronal and behavioral impairments, identifying SCD as a therapeutic target for GBA-PD.
Authors
Silke Nuber, Harrison Hsiang, Esra'a Keewan, Tim E. Moors, Sydney J. Reitz, Anupama Tiwari, Gary P. H. Ho, Elena Su, Wolf Hahn, Marie-Alexandre Adom, Riddhima Pathak, Matthew Blizzard, Sangjune Kim, Han Seok Ko, Xiaoqun Zhang, Per Svenningsson, Dennis J. Selkoe, Saranna Fanning
Abstract
In asthma, airway epithelial remodeling is characterized by aberrant goblet cell metaplastic differentiation accompanied by epithelial cell hyperplasia and hypertrophy. These pathologic features in severe asthma indicate a loss of control of proliferation, cell size, differentiation, and migration. mTOR is a highly conserved pathway that regulates protein synthesis, cell size, and proliferation. We hypothesized that the balance between mTOR and autophagy regulates mucous cell metaplasia. Airways from individuals with severe asthma showed increased mTOR signaling by RPS6 phosphorylation, which was reproduced using an IL-13-activated model of primary human airway epithelial cells (hAECs). mTOR inhibition by rapamycin led to a decrease of IL-13-mediated cell hypertrophy, hyperplasia, and MUC5AC mucous metaplasia. BrdU labeling during IL-13-induced mucous metaplasia confirmed that mTOR was associated with increased basal-to-apical hAEC migration. mTOR activation by genetic deletion of Tsc2 in cultured mouse AECs increased IL-13-mediated hyperplasia, hypertrophy, and mucous metaplasia. Transcriptomic analysis of IL-13-stimulated hAEC identified mTOR-dependent expression of genes associated with epithelial migration and cytoskeletal organization. In summary, these findings point to IL-13-dependent and independent roles of mTOR signaling in the development of pathogenic epithelial changes contributing to airway obstruction in severe asthma.
Authors
Katrina M. Kudrna, Luis F. Vilches, Evan M. Eilers, Shailendra K. Maurya, Steven L. Brody, Amjad Horani, Kristina L. Bailey, Todd A. Wyatt, John D. Dickinson
