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 PERK activation in human subjects 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 subjects 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 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 unique therapeutic target to reverse established fibrosis.
Jyotsana Pandey, Jennifer L. Larson-Casey, Mallikarjun H. Patil, Chao He, Nisarat Pinthong, A. Brent Carter
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 lung 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 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 ICOS-ICOSL interaction attenuated germinal center B-cell differentiation and subsequent lung damage, which were overcome by local administration of IL-21 in the lung of anti-PD-1 therapy-treated aged mice. Therefore, ICOS+CD4 T cells elicited under aged environment exacerbated aberrant immune responses and the subsequent lung dysfunction. Consistent with the findings from mouse model, ICOS up-regulation 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 cancer patients, many of whom are elderly.
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
Metastatic outgrowth in distant microscopic niches requires sufficient nutrients, including fatty acids (FAs), to support tumor growth and to generate an immunosuppressive tumor microenvironment (TME). However, despite the important role of FAs in metastasis, the regulation of FA supply in metastatic niches has not been defined. In this report, we show that tumor endothelium actively promotes outgrowth and restricts anti-tumor cytolysis by transferring FA into developing metastatic tumors. We describe a process of transendothelial FA delivery via endosomes that requires mTORC1 activity. Thus, endothelial-specific targeted deletion of Raptor (RptorECKO), a unique component of the mTORC1 complex, significantly reduced metastatic tumor burden that was associated with improved markers of T cell cytotoxicity. Low dose everolimus that selectively inhibited endothelial mTORC1 improves immune checkpoint responses in metastatic disease models. This work reveals the importance of transendothelial nutrient delivery to the TME, highlighting a future target for therapeutic development.
Deanna N Edwards, Shan Wang, Kelby Kane, Wenqiang Song, Laura C. Kim, Verra M. Ngwa, Yoonha Hwang, Kevin C. Ess, Mark R. Boothby, Jin Chen
Despite the accumulation of cisplatin in proximal tubules, direct visualization of the surrounding peritubular microcirculation, including its alteration in cisplatin-induced acute kidney injury (AKI), is lacking. Here, using fluorescence and cellular angiography through video-rate high-resolution intravital microscopy, progressive disturbance of peritubular microcirculation in cisplatin-induced AKI in mice was demonstrated. Fluorescence angiography revealed increasing perfusion defects, with a stepwise rise in time to peak (TTP), originating from capillaries surrounding S1 segments. Cellular angiography demonstrated a progressive decrease in the velocity and track length of individual erythrocytes during AKI progression, accompanied by a sequential decrease in the functional capillary ratio (FCR). Alterations in the perfusion area, TTP, and FCR preceded significant changes in blood urea nitrogen and cystatin C, suggesting the potential for early diagnosis. Although neutrophil infiltration near proximal tubules increased throughout the progression, it did not cause obstruction of the peritubular microcirculation. Depletion of neutrophils increased mortality due to systemic side effects, whereas functional inactivation of neutrophils using an anti-CD11b antibody improved peritubular microcirculation in cisplatin-induced AKI. This approach enables direct visualization and quantification of peritubular microcirculation and immune cell dynamics, providing insights into renal pathophysiology and potential therapeutic strategies.
Inwon Park, Seonghye Kim, Young Woo Um, Hee Eun Kim, Jae Hyuk Lee, Sejoong Kim, PILHAN KIM, You Hwan Jo
Junping Yin, Melanie Eichler, Clivia Lisowski, Jian Li, Sibylle von Vietinghoff, Natalio Garbi, Qi Mei, Anne-Kathrin Gellner, Christian Kurts
The inflammatory response after myocardial infarction (MI) is a precisely regulated process that greatly affects subsequent wound healing and remodeling. However, the understood about the process are still limited. Macrophages are critically involved in inflammation resolution after MI. Krüppel-like factor 9 (Klf9) is a C2H2 zinc finger-containing transcription factor that has been implicated in glucocorticoid regulation of macrophages. However, the contribution of Klf9 to macrophage phenotype and function in the context of MI remains unclear. Our study revealed that KLF9 deficiency results in higher mortality and cardiac rupture rate, as well as a considerable exacerbation in cardiac function. Single-cell RNA sequencing and flow cytometry analyses reveals that, compared to WT mice, Klf9-/- mice display excessive neutrophil infiltration, insufficient macrophage infiltration, and a reduced proportion of Monocyte-derived CD206+ macrophages post-MI. Moreover, the expression of IFN-γ-STAT1 pathway genes in Klf9-/- cardiac macrophages is dysregulated, characterized by insufficient expression at 1 day post-MI and excessive expression at day 3 post-MI. Mechanistically, Klf9 directly binds to the promoters of Stat1 gene, regulating its transcription. Overall, these findings indicates that Klf9 beneficially influences wound healing after MI through modulating macrophage recruitment and differentiation by regulating the IFN-γ-STAT1 signal pathway.
Sheng Xu, Hao Li, Jun Han, Yawei Xu, Niannian Li, Wenliang Che, Feng Liu, Wenhui Yue
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 CHIP (clonal hematopoiesis of indeterminate potential) carriers, 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 observe 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.
Lasse Bach Steffensen, Stephanie Kavan, Pia Søndergaard Jensen, Matilde Kvist Pedersen, Steffen Møller Bøttger, Martin J. Larsen, Maja Dembic, Otto Bergman, Ljubica Matic, Ulf Hedin, Lars vB Andersen, Jes Sanddal Lindholt, Kim Christian Houlind, Lars P. Riber, Mads Thomassen, Lars Melholt Rasmussen
Achondroplasia (ACH) and hypochondroplasia (HCH), the two most common types of dwarfism, are each caused by FGFR3 gain-of-function mutations that result in increased FGFR3 signaling, disrupting chondrogenesis and osteogenesis resulting in disproportionately shortened long bones. In this study, TYRA-300, a potent and selective FGFR3 inhibitor, was evaluated in three genetic contexts: wild-type mice, the Fgfr3Y367C/+ mouse model of ACH, and the Fgfr3N534K/+ mouse model of HCH. In each model, TYRA-300 treatment increased naso-anal length, tibia and femur length. In the two FGFR3-altered models, TYRA-300-induced growth partially restored the disproportionality of long bones. Histologic analysis of the growth plate in Fgfr3Y367C/+ mice revealed that TYRA-300 mechanistically increased both proliferation and differentiation of chondrocytes. Importantly, children with ACH can experience medical complications due to foramen magnum stenosis, and TYRA-300 significantly improved the size and shape of the skull and foramen magnum in Fgfr3Y367C/+ mice. Spinal stenosis is also a frequent complication, and TYRA-300 increased the lumbar vertebrae length and improved the shape of the intervertebral discs in both models. Taken together, these studies demonstrate that the selective FGFR3 inhibitor TYRA-300 led to a significant increase in bone growth in two independent FGFR3-driven preclinical models as well as in wild-type mice.
Jacqueline H. Starrett, Clara Lemoine, Matthias Guillo, Chantal Fayad, Nabil Kaci, Melissa Neal, Emily Pettitt, Melissandre Pache, Qing Ye, My Chouinard, Eric L. Allen, Geneviève Baujat, Robert L. Hudkins, Michael B. Bober, Todd Harris, Ronald V. Swanson, Laurence Legeai-Mallet
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 (M/E) 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. Co-administration of agonist antibodies enhanced CD8+ T cell responses to vaccination, resulting in sustained protection and reduced viral loads at day 84. Depletion and passive transfer studies confirmed that long-term protection 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.
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
Dipeptidase-1 (DPEP1) is highly upregulated in colorectal cancer (CRC), with its enzymatic function linked to invasion and metastasis. More recently, DPEP1 was found to serve as a receptor for neutrophils when expressed by activated endothelial cells. It is unknown whether neutrophils bind to DPEP1-expressing CRC cells and whether this impacts features of CRC. Neutrophils have been shown to be tumor-promoting in cancers including CRC, where they act to exclude CD8+ T cells. Herein, we show that neutrophils bind DPEP1-expressing CRC cells. In addition, DPEP1 is preferentially expressed in microsatellite stable (MSS) CRC, in which there are a paucity of CD8+ T cells, whereas DPEP1 is negatively correlated with microsatellite unstable (MSI-H) CRC, which are T cell-rich and are more responsive to immunotherapy. Remarkably, carcinogen-treated Dpep1 null mice develop multiple, large, plaque-like, locally invasive adenocarcinomas and squamous cell cancers in the distal colon. These adenocarcinomas exhibit a marked reduction of neutrophils and an influx CD8+ T cells, along with reduced expression of mismatch repair proteins, consistent with features of MSI-H CRC. These results establish DPEP1’s importance in maintaining MSS CRC and its ability to shape the tumor microenvironment.
Sarah E. Glass, Matthew E. Bechard, Zheng Cao, Radhika Aramandla, Ping Zhao, Samuel T. Ellis, Emily H. Green, Elizabeth G. Fisher, Ryan T. Smith, Chelsie K. Sievers, Maria Johnson Irudayam, Frank Revetta, M. Kay Washington, Gregory D. Ayers, Cody N. Heiser, Alan J. Simmons, Yanwen Xu, Yu Wang, Annika Windon, Martha J. Shrubsole, Nicholas O. Markham, Qi Liu, Ken S. Lau, Robert J. Coffey
An estimated 5-10% of cancer results from an underlying genetic predisposition, yet for the majority of these cases the genes in question remain unknown, suggesting a critical need to identify new cancer predisposition genes. The protein phosphatase 2A (PP2A) family exists as a trimeric holoenzyme and is a vital negative regulator of multiple oncogenic pathways. PP2A inhibition by somatic mutation, loss of expression, and upregulation of its exogenous inhibitors in tumors has been well described. However, it remains unknown whether germline loss of any PP2A subunits results in a predisposition to cancer in humans. In this study, we identified nine cancer patients with germline loss-of-function (LOF) variants in PPP2R1B (Aβ), the beta isoform of the PP2A scaffold subunit. All four patients for whom documentation was available also had a family history of cancer, including multiple indicators of hereditary cancer. The most highly represented cancer among the Aβ germline patients was breast cancer. Overexpression of these mutant forms of Aβ resulted in truncated proteins that were rapidly turned over. Characterization of an additional missense germline Aβ variant, R233C, that is also recurrently mutated at the somatic level found that it disrupts PP2A catalytic subunit binding resulting in loss of phosphatase activity. An analysis of Aβ expression among multiple breast cancer cohorts revealed that somatic, heterozygous loss of Aβ was a frequent event in this disease and decreased Aβ expression correlated with shorter disease-free and overall survival. Furthermore, Aβ levels were significantly lower in multiple histological subtypes of both in situ and malignant breast cancer compared to adjacent normal breast tissue, suggesting that Aβ loss is an early event in breast cancer development. Together, this highlights a role for Aβ as a predisposition gene in breast cancer and potentially additional cancers.
Sahar Mazhar, Caitlin M. O’Connor, Alexis Harold, Amanda C. Dowdican, Peter J. Ulintz, Erika N. Hanson, Yuping Zhang, Michelle F. Jacobs, Sofia D. Merajver, Mark W. Jackson, Anthony Scott, Anieta M. Sieuwerts, Arul M. Chinnaiyan, Goutham Narla
BACKGROUND. A priori knowledge of recurrence risk in patients with non-metastatic (FIGO stage I) uterine serous carcinoma (USC) would enable a risk-stratified approach to the use of adjuvant chemotherapy. This would greatly reduce treatment-related morbidity and be predicted to improve survival. METHODS. GATA2 expression was scored by immunohistochemistry (IHC) across a retrospective multi-institutional cohort of 195 primary USCs. Associations between GATA2 levels and clinicopathologic metrics were evaluated using Student’s t-test, Fisher’s exact test, Kaplan-Meier method, and Cox proportional hazards ratio. Invasion in patient-derived USC cells was assessed by Student’s t-test. RNA-seq, anti-GATA2 ChIP-seq, and confirmatory western blotting enabled identification of GATA2 targets. RESULTS. Patients with FIGO stage I GATA2high USCs had 100% recurrence-free and 100% cancer related survival, which was significantly better than patients with GATA2low USCs. In patients for whom adjuvant chemotherapy was omitted, patients with GATA2high USC had 100% recurrence free 5-year survival compared to 60% recurrence free survival in patients with GATA2low USC. Depletion of GATA2 in patient-derived USC cells increased invasion in vitro. CONCLUSIONS. Routine GATA2 IHC identifies 33% of FIGO stage I USC patients who have a greatly reduced risk of post-hysterectomy USC recurrence. Our results suggest that a GATA2 guided personalized medicine approach could be rapidly implemented in most hospital settings, would reduce treatment-related morbidity, and likely improve outcomes in USC patients. FUNDING. NIH grants R01 DK068634, P30 CA014520, S10 OD023526, K08 DK127244, T32 HL007899, the UW-Madison Department of Pathology and Laboratory Medicine, the UW-Madison Centennial Scholars Program, the Diane Lindstrom Foundation, the American Cancer Society, the V Foundation, The Hartwell Foundation, and the UMN Department of Obstetrics, Gynecology, and Women's Health.
Usha S. Polaki, Trey E. Gilpin, Apoorva T. Patil, Emily Chiu, Ruth Baker, Peng Liu, Tatiana S. Pavletich, Morteza Seifi, Paula M. Mañán-Mejías, Jordan Morrissey, Jenna Port, Rene Welch Schwartz, Irene M. Ong, Dina El-Rayes, Mahmoud A. Khalifa, Pei Hui, Vanessa L. Horner, María Virumbrales-Muñoz, Britt K. Erickson, Lisa Barroilhet, Stephanie M. McGregor, Emery H. Bresnick, Daniel R. Matson
The soluble variant of the ectopeptidase CD13 (sCD13), released from the cell surface by matrix metalloproteinase 14 (MMP14), is a potent pro-inflammatory mediator, displaying chemotactic, angiogenic, and arthritogenic properties through bradykinin receptor B1 (B1R). We reveal a link between sCD13 and amplified neutrophil-mediated inflammatory responses in SARS-CoV-2 infection. sCD13 was markedly elevated in COVID-19 patients and correlated with disease severity, variants, ethnicity, inflammation markers, and NETosis. Neutrophils treated with sCD13 showed heightened NETosis and chemotaxis which were inhibited by sCD13 receptor blockade. Meanwhile sCD13 did not induce platelet aggregation. Single-cell analysis of COVID-19 lungs revealed co-expression of CD13 and MMP14 by various cell types, and higher CD13 expression compared to controls. Neutrophils with high CD13 mRNA were enriched for genes associated with immaturity, though CD13 protein expression was lower. Histological examination of COVID-19 lungs revealed CD13-positive leukocytes trapped in vessels with fibrin thrombi. Flow cytometry confirmed the presence of B1R and a second sCD13 receptor, protease-activated receptor 4, on monocytes and neutrophils. These findings identify sCD13 as a potential instigator of COVID-19-associated NETosis, potentiating vascular stress and thromboembolic complications. The potent pro-inflammatory effects of sCD13 may contribute to severe COVID-19, suggesting that sCD13 and its receptors might be therapeutic targets.
Pei-Suen Tsou, Ramadan A. Ali, Chenyang Lu, Gautam Sule, Carmelo Carmona-Rivera, Serena Lucotti, Yuzo Ikari, Qi Wu, Phillip Campbell, Mikel Gurrea-Rubio, Kohei Maeda, Sharon E. Fox, William D. Brodie, Megan N. Mattichak, Caroline Foster, Ajay Tambralli, Srilakshmi Yalavarthi, M. Asif Amin, Katarina Kmetova, Bruna Mazetto Fonseca, Emily Chong, Yu Zuo, Michael Maile, Luisa Imberti, Arnaldo Caruso, Francesca Caccuri, Virginia Quaresima, Alessandra Sottini, Douglas B. Kuhns, Danielle L. Fink, Riccardo Castagnoli, Ottavia Delmonte, Heather Kenney, Yu Zhang, Mary Magliocco, Helen C. Su, Luigi D. Notarangelo, Rachel L. Zemans, Yang Mao-Draayer, Irina Matei, Mirella Salvatore, David C. Lyden, Yogendra Kanthi, Mariana J. Kaplan, Jason S. Knight, David A. Fox
As a major component of intracellular trafficking, the coat protein complex II (COPII) is indispensable for cellular function during embryonic development and throughout life. The four SEC24 proteins (A-D) are essential COPII components involved in cargo selection and packaging. A human disorder corresponding to alterations of SEC24 function is currently only known for SEC24D. Here, we report that biallelic loss of SEC24C leads to a syndrome characterized by primary microcephaly, brain anomalies, epilepsy, hearing loss, liver dysfunction, anemia, and cataracts in an extended consanguineous family with four affected individuals. We show that knockout of sec24C in zebrafish recapitulates important aspects of the human phenotype. SEC24C-deficient fibroblasts display alterations in the expression of several COPII components as well as impaired anterograde trafficking to the Golgi, indicating a severe impact on COPII function. Transcriptome analysis revealed that SEC24C deficiency also impacts the proteasome and autophagy pathways. Moreover, a shift in the N-glycosylation pattern and deregulation of the N-glycosylation pathway suggest a possible secondary alteration of protein glycosylation, linking the described disorder with the congenital disorders of glycosylation.
Nina Bögershausen, Büsranur Cavdarli, Taylor Nagai, Miroslav P. Milev, Alexander Wolff, Mahsa Mehranfar, Julia Schmidt, Dharmendra Choudhary, Óscar Gutiérrez-Gutiérrez, Lukas Cyganek, Djenann Saint-Dic, Arne Zibat, Karl Köhrer, Tassilo E. Wollenweber, Dagmar Wieczorek, Janine Altmüller, Tatiana Borodina, Dilek Kaçar, Göknur Haliloğlu, Yun Li, Christian Thiel, Michael Sacher, Ela W. Knapik, Gökhan Yigit, Bernd Wollnik
BACKGROUND. The graft-vs-leukemia (GVL) effect contributes to the efficacy of allogeneic stem cell transplantation (alloSCT). However, relapse, indicative of GVL failure, is the greatest single cause of treatment failure. Based on preclinical data showing that IFN-γ is important to sensitize myeloblasts to alloreactive T cells, we performed a phase I trial of IFN-γ combined with donor leukocyte infusions (DLI) in myeloblastic malignancies that relapsed post-HLA-matched alloSCT. METHODS. Patients with relapsed acute myeloid leukemia or myelodysplastic syndrome after alloSCT were eligible. Patients self-administered IFN-γ for 4 weeks (cohort 1) or 1 week (cohort 2), followed by DLI and concurrent IFN-γ for a total of 12 weeks. Bone marrow samples were analyzed by single-cell RNA sequencing (scRNAseq) to assess in vivo responses to IFN-γ by malignant myeloblasts. RESULTS. IFN-γ monotherapy was well tolerated by all subjects (n=7). Treatment-related toxicities after DLI included: grade I-II graft-versus-host disease (n=5), immune effector cell-associated neurotoxicity syndrome (n=2), and idiopathic pulmonary syndrome (n=1), all of which resolved with corticosteroids. Four of 6 DLI recipients achieved minimal residual disease-negative complete remissions and full donor hematopoietic recovery. Median overall survival was 579 days (range, 97-906) in responders. ScRNAseq confirmed in vivo activation of IFN-γ response pathway in hematopoietic stem cell-like or myeloid progenitor cells after IFN-γ in analyzed samples. CONCLUSIONS. IFN-γ was safe and well tolerated in this phase I study of IFN-γ for relapsed AML/MDS post-alloSCT, with a promising efficacy signal when combined with DLI. Larger studies are needed to formally test the efficacy of this approach. TRIAL RESGISTRATION. ClinicalTrials.gov NCT04628338. FUNDING. The research was supported by The UPMC Hillman Cancer Center Cancer Immunology and Immunotherapy Program (CIIP) Pilot Award and Cure Within Reach: Drug Repurposing Clinical Trials to Impact Blood Cancers. Recombinant IFN-gamma (Actimmune®) was donated by Horizon Therapeutics.
Sawa Ito, Emily Geramita, Kedwin Ventura, Biswas Neupane, Shruti Bhise, Erika M. Moore, Scott Furlan, Warren D. Shlomchik
Type 2 inflammatory diseases are common in cystic fibrosis (CF) including asthma, sinusitis, and allergic bronchopulmonary aspergillosis. CD4+ T helper 2 (Th2) cells promote these diseases through secretion of IL-4, IL-5, and IL-13. Whether the cystic fibrosis transmembrane conductance regulator (CFTR), the mutated protein in CF, has a direct effect on Th2 development is unknown. Using murine models of CFTR deficiency and human CD4+ T cells, we show CD4+ T cells expressed Cftr transcript and CFTR protein following activation. Loss of T cell CFTR expression increased Th2 cytokine production compared to control cells. Mice with CFTR-deficient T cells developed increased allergic airway disease to Alternaria alternata extract compared to control mice. Culture of CFTR-deficient Th2 cells demonstrated increased IL-4Rα expression and increased sensitivity to IL-4 with greater induction of GATA3 and IL-13 compared to control Th2 cell cultures. The CFTR potentiator ivacaftor reduced allergic inflammation and type 2 cytokine secretion in bronchoalveolar lavage of “humanized” CFTR mice following Alternaria alternata extract challenge and decreased Th2 development in human T cell culture. Together, these data support a direct role of CFTR in regulating T cell sensitivity to IL-4 and demonstrate a potential CFTR-specific therapeutic strategy for Th2 cell-mediated allergic disease.
Mark Rusznak, Christopher M. Thomas, Jian Zhang, Shinji Toki, Weisong Zhou, Masako Abney, Danielle M. Yanda, Allison E. Norlander, Craig A. Hodges, Dawn C. Newcomb, Mark H. Kaplan, R. Stokes Peebles Jr., Daniel P. Cook
Adult stem cells decline in number and function in old age and identifying factors that can delay or revert age-associated adult stem cell dysfunction are vital for maintaining healthy lifespan. Here we show that Vitamin A, a micronutrient that is derived from diet and metabolized into retinoic acid, acts as an antioxidant and transcriptional regulator in muscle stem cells. We first show that obstruction of dietary Vitamin A in young animals drives mitochondrial and cell cycle dysfunction in muscle stem cells that mimics old age. Next, we pharmacologically targeted retinoic acid signaling in myoblasts and aged muscle stem cells ex vivo and in vivo and observed reductions in oxidative damage, enhanced mitochondrial function, and improved maintenance of quiescence through fatty acid oxidation. We next detected the receptor for vitamin A derived retinol, stimulated by retinoic acid 6 or Stra6, was diminished with muscle stem cell activation and in old age. To understand the relevance of Stra6 loss, we knocked down Stra6 and observed an accumulation of mitochondrial reactive oxygen species, as well as changes in mitochondrial morphology and respiration. These results demonstrate that Vitamin A regulates mitochondria and metabolism in muscle stem cells and highlight a unique mechanism connecting stem cell function with vitamin intake.
Paula M. Fraczek, Pamela Duran, Benjamin A. Yang, Valeria Ferre, Leanne Alawieh, Jesus A. Castor-Macias, Vivian T. Wong, Steve D. Guzman, Celeste Piotto, Klimentini Itsani, Jacqueline A Larouche, Carlos A. Aguilar
Mitogen-activated protein kinase 8 interacting protein 3 (MAPK8IP3/JIP3) is a member of the kinesin family known to play a role in axonal transport of cargo. Mutations in the gene have been linked to severe neurodevelopmental disorders, resulting in developmental delay, intellectual disability, ataxia, tremor, autism, seizures, and visual impairment. A patient who has a missense mutation in the MAPK8IP3 gene (c. 1714 C>T, Arg578Cys) (R578C) manifests dystonia, gross motor delay and developmental delay. Here we show that the mutation is a toxic gain of function mutation which alters the interactome of JIP3, disrupts axonal transport of late endosomes, increases signaling via c-Jun N-terminal kinase (JNK), resulting in apoptosis, and disrupts the dopamine receptor 1 (D1) signaling while not affecting the dopamine receptor 2 (D2) signaling. Further, in the presence of the mutant protein, we show that 80% reduction of mutant JIP3>80% and 60% reduction of wild-type JIP3 by non-allele selective phosphorothioate (PS)-modified antisense oligonucleotides (ASOs) is well tolerated by several types of cells in vitro. Our study identifies several important new roles for JIP3 and provides important insights for therapeutic approaches, including antisense oligonucleotide reduction of JIP3.
Wei Zhang, Swapnil Mittal, Ria Thomas, Anahid Foroughishafiei, Ricardo Nunes Bastos, Wendy K. Chung, Konstantina Skourti-Stathaki, Stanley T. Crooke
Inflammation is a critical pathological process in myocardial infarction. Although immunosuppressive therapies can mitigate inflammatory responses and improve outcomes in myocardial infarction, they also increase the risk of infections. Identifying novel regulators of local cardiac inflammation could provide safer therapeutic targets for myocardial ischemia/reperfusion injury. In this study, we identified a previously unknown micropeptide, which we named Inflammation Associated MicroPeptide (IAMP). IAMP is predominantly expressed in cardiac fibroblasts, and its expression is closely associated with cardiac inflammation. Down-regulation of IAMP promotes, whereas its overexpression prevents, the transformation of cardiac fibroblasts into a more inflammatory phenotype under stressed/stimulated conditions, as evidenced by changes in the expression and secretion of pro-inflammatory cytokines. Consequently, loss of IAMP function leads to uncontrolled inflammation and worsens cardiac injury following ischemia/reperfusion surgery. Mechanistically, IAMP promotes the degradation of HIF-1α by interacting with its stabilizing partner HSP90, and thus suppresses the transcription of pro-inflammatory genes downstream of HIF-1α. This study underscores the significance of fibroblast-mediated inflammation in cardiac ischemia/reperfusion injury and highlights the therapeutic potential of targeting micropeptides for myocardial infarction.
Youchen Yan, Tingting Zhang, Xin He, Tailai Du, Gang Dai, Xingfeng Xu, Zhuohui chen, Jialing Wu, Huimin Zhou, Yazhi Peng, Yan Li, Chen Liu, Xinxue Liao, Yugang Dong, Jing-song Ou, Zhan-Peng Huang
BACKGROUND. Alterations in circulating metabolites have been described in obese metabolic dysfunction-associated steatotic liver disease (MASLD), but data on lean MASLD are lacking. We investigated serum metabolites, including microbial bile acids (BAs) and short-chain fatty acids (SCFAs), and their association with lean and obese MASLD. METHODS. Serum samples from 204 subjects of European descent were allocated to four groups: lean healthy (n=61), lean MASLD (n=49), obese healthy (n=47) and obese MASLD (n=47). LC/MS-based metabolomics was performed followed by linear model analysis. MASLD prediction was assessed based on LASSO regression. Functional effects of significantly altered molecules were confirmed in organotypic 3D primary human liver cultures. RESULTS. Lean MASLD was characterized by elevated isobutyrate, along with higher methionine sulfoxide, propionate and phosphatidylcholines. Patients with obese MASLD had increased sarcosine and decreased lysine and asymmetric dimethylarginine. Using metabolites, sex and body mass index, MASLD vs. healthy could be predicted with a median AUC of 86.5% and 85.6% in the lean and obese subgroups, respectively. Functional experiments in organotypic 3D primary human liver cultures showed that propionate and isobutyrate induced lipid accumulation and altered expression of genes involved in lipid and glucose metabolism. CONCLUSION. Our results indicate that lean MASLD is characterized by a distinct metabolite pattern related to amino acid metabolism, lipids and SCFAs, while metabolic pathways of lipid accumulation are differentially activated by microbial metabolites. Our findings highlight an important role of microbial metabolites in MASLD pathogenesis, with implications for the predictive and mechanistic assessment of liver disease across different weight categories. FUNDING. The work received funding from the Robert Bosch Stiftung, Stuttgart, Germany, the Swedish Research Council [grant numbers 2021-02801, 2023-03015 and 2024-03401], the ERC Consolidator Grant 3DMASH [101170408], Ruth and Richard Julin Foundation for Gastroenterology [grant number 2021-00158], the SciLifeLab and Wallenberg National Program for Data-Driven Life Science [WASPDDLS22:006], and the Novo Nordisk Foundation [NNF23OC0085944 and NNF23OC0084420]. JT was supported by PMU-FFF [grant number E-18/28/148-FEL].
Mathias Haag, Stefan Winter, Aurino M. Kemas, Julia Tevini, Alexandra Feldman, Sebastian K. Eder, Thomas K. Felder, Christian Datz, Bernhard Paulweber, Gerhard Liebisch, Oliver Burk, Volker M. Lauschke, Elmar Aigner, Matthias Schwab