Ahn, Maarsingh, Walker et al. report that a recently identified positive allosteric modulator (PAM) of the β2-adrenergic receptor potentiates the bronchoprotective effect of a β agonist in an asthma model. The cover image illustrates how addition of a β2-adrenergic receptor–selective PAM, compound-6 (orange/red/blue), enhances fenoterol-activated (blue/red), β2-adrenergic receptor–mediated (green) airway dilation in a guinea pig lung slice. This finding highlights the potential utility of β2-adrenergic receptor–selective PAMs in the treatment of airway narrowing for patients with asthma.
Idiopathic Pulmonary Fibrosis (IPF) is a progressive scarring disease arising from impaired regeneration of the alveolar epithelium after injury. During regeneration, type 2 alveolar epithelial cells (AEC2s) assume a transitional state that upregulates multiple keratins, and ultimately differentiate into AEC1s. In IPF, transitional AECs accumulate with ineffectual AEC1 differentiation. However, whether and how transitional cells cause fibrosis, whether keratins regulate transitional cell accumulation and fibrosis, and why transitional AECs and fibrosis resolve in mouse models but accumulate in IPF are unclear. Here, we show that human keratin (KRT) 8 genetic variants are associated with IPF. Krt8-/- mice are protected from fibrosis and accumulation of the transitional state. Keratin (K) 8 regulates expression of macrophage chemokines and macrophage recruitment. Profibrotic macrophages and myofibroblasts promote accumulation of transitional AECs, establishing a K8-dependent positive feedback loop driving fibrogenesis. Finally, rare murine transitional AECs are highly senescent, basaloid, and do not differentiate into AEC1s, recapitulating the aberrant basaloid state in human IPF. We conclude that transitional AECs induce and are maintained by fibrosis in a K8-dependent manner; in mice, most transitional cells and fibrosis resolve, whereas in human IPF, transitional AECs evolve into an aberrant basaloid state which persists with progressive fibrosis.
Fa Wang, Christopher Ting, Kent A. Riemondy, Michael T. Douglas, Kendall M. Foster, Nisha Patel, Norihito Kaku, Alexander E. Linsalata, Jean Nemzek, Brian M. Varisco, Erez Cohen, Jasmine A. Wilson, David W.H. Riches, Elizabeth F. Redente, Diana M. Toivola, Xiaofeng Zhou, Bethany B. Moore, Pierre A. Coulombe, M. Bishir Omary, Rachel L. Zemans
BACKGROUND. Macrophage activation syndrome (MAS) is a life-threatening complication of Still’s disease (SD) characterized by overt immune cell activation and cytokine storm. We aimed to further understand the immunologic landscape of SD and MAS. METHOD. We profiled peripheral blood mononuclear cells (PBMC) from healthy controls and patients with SD with or without MAS using bulk RNA sequencing (RNA-seq) and single-cell RNA-seq (scRNA-seq). We validated and expanded the findings by mass cytometry, flow cytometry and in vitro studies. RESULTS. Bulk RNA-seq of PBMC from patients with SD-associated MAS revealed strong expression of genes associated with type I interferon (IFN-I) signaling and cell proliferation, in addition to the expected IFN-γ signal, compared to healthy controls and SD patients without MAS. scRNA-seq analysis of > 65,000 total PBMC confirmed IFN-I and IFN-γ signatures and localized the cell proliferation signature to cycling CD38+HLA-DR+ cells within CD4+ T cell, CD8+ T cell and NK cell populations. CD38+HLA-DR+ lymphocytes exhibited prominent IFN-g production, glycolysis, and mTOR signaling. Cell-cell interaction modeling suggested a network linking CD38+HLA-DR+ lymphocytes with monocytes through IFN-γ signaling. Notably, the expansion of CD38+HLA-DR+ lymphocytes in MAS was greater than in other systemic inflammatory conditions in children. In vitro stimulation of PBMC demonstrated that IFN-I and IL-15 – both elevated in MAS patients – synergistically augmented the generation of CD38+HLA-DR+ lymphocytes, while Janus kinase inhibition mitigated this response. CONCLUSION. MAS associated with SD is characterized by overproduction of IFN-I, which may act in synergy with IL-15 to generate CD38+HLA-DR+ cycling lymphocytes that produce IFN-γ.
Zhengping Huang, Kailey E. Brodeur, Liang Chen, Yan Du, Holly Wobma, Evan E. Hsu, Meng Liu, Joyce C. Chang, Margaret H. Chang, Janet Chou, Megan Day-Lewis, Fatma Dedeoglu, Olha Halyabar, James A. Lederer, Tianwang Li, Mindy S. Lo, Meiping Lu, Esra Meidan, Jane W. Newburger, Adrienne G. Randolph, Mary Beth F. Son, Robert P. Sundel, Maria L. Taylor, Huaxiang Wu, Qing Zhou, Scott W. Canna, Kevin Wei, Lauren A. Henderson, Peter A. Nigrovic, Pui Y. Lee
Aberrant androgen receptor (AR) signalling drives prostate cancer (PC) and is a key therapeutic target. Although initially effective, the generation of alternatively spliced AR variants (AR-Vs) compromises efficacy of treatments. In contrast to full-length AR (AR-FL), AR-Vs constitutively activate androgenic signalling and are refractory to the current repertoire of AR-targeting therapies, which together drives disease progression. There is an unmet clinical need therefore to develop more durable PC therapies that can attenuate AR-V function. Exploiting the requirement of co-regulatory proteins for AR-V function has the capacity to furnish tractable routes for attenuating persistent oncogenic AR signalling in advanced PC. DNA-PKcs regulates AR-FL transcriptional activity and is upregulated in both early and advanced PC. We hypothesised that DNA-PKcs is critical for AR-V function. Using a novel proximity biotinylation approach, we demonstrate that the DNA-PK holoenzyme is part of the AR-V7 interactome and is a key regulator of AR-V-mediated transcription and cell growth in models of advanced PC. Crucially, we provide evidence that DNA-PKcs controls global splicing, and via RBMX, regulates the maturation of AR-V and AR-FL transcripts. Ultimately, our data indicates that targeting DNA-PKcs attenuates AR-V signalling and provides evidence that DNA-PKcs blockade is an effective therapeutic option in advanced AR-V positive PC patients.
Beth Adamson, Nicholas Brittain, Laura Walker, Ruaridh Duncan, Sara Luzzi, Pasquale Rescigno, Graham R. Smith, Suzanne McGill, Richard J.S. Burchmore, Elaine Willmore, Ian Hickson, Craig N. Robson, Denisa Bogdan, Juan M. Jimenez-Vacas, Alec Paschalis, Jonathan Welti, Wei Yuan, Stuart R. McCracken, Rakesh Heer, Adam Sharp, Johann de Bono, Luke Gaughan
Background: Proglucagon can be processed to Glucagon-Like Peptide-1 (GLP-1) within the islet but its contribution to islet function in humans remains unknown. We sought to understand whether ‘pancreatic’ GLP-1 alters islet function in humans and whether this is affected by type 2 diabetes.Methods: We therefore studied individuals with and without type 2 diabetes on 2 occasions in random order. On one occasion exendin 9-39, a competitive antagonist of the GLP-1 Receptor (GLP1R), was infused, while on the other saline was infused. The tracer dilution technique ([3-3H] glucose) was used to measure glucose turnover during fasting and during a hyperglycemic clamp.Results: Exendin 9-39 increased fasting glucose concentrations; fasting islet hormone concentrations were unchanged, but inappropriate for the higher fasting glucose observed. In people with type 2 diabetes fasting glucagon concentrations were markedly elevated and persisted despite hyperglycemia. This impaired suppression of endogenous glucose production by hyperglycemia. These data show that GLP1R blockade impairs islet function, implying that intra-islet GLP1R activation alters islet responses to glucose and does so to a greater degree in people with type 2 diabetes.
Andrew A. Welch, Rahele A. Farahani, Aoife M. Egan, Marcello C. Laurenti, Maya Zeini, Max Vella, Kent R. Bailey, Claudio Cobelli, Chiara Dalla Dalla Man, Aleksey Matveyenko, Adrian Vella
The BCL-2 inhibitor venetoclax is effective in chronic lymphocytic leukemia (CLL); however, resistance may develop over time. Other lymphoid malignancies such as diffuse large B-cell lymphoma (DLBCL) are frequently intrinsically resistant to venetoclax. Although genomic resistance mechanisms such as BCL-2 mutations have been described, this likely only explains a subset of resistant cases. Using two complementary functional precision medicine techniques -- BH3-profiling and high throughput-kinase activity mapping -- we found that hyperphosphorylation of BCL-2 family proteins, including anti-apoptotic MCL-1 and BCL-2 and pro-apoptotic BAD and BAX, underlies functional mechanisms of both intrinsic and acquired resistance of venetoclax in CLL and DLBCL. Additionally, we provide evidence that anti-apoptotic BCL-2 family protein phosphorylation alters the apoptotic protein interactome, thereby changing the profile of functional dependence on these pro-survival proteins. Targeting BCL-2 family protein phosphorylation with phosphatase-activating drugs re-wired these dependences, thus restoring sensitivity to venetoclax in a panel of venetoclax resistant lymphoid cell lines, resistant mouse model, and paired patient samples pre-venetoclax and at time of progression.
Stephen Jun Fei Chong, Fen Zhu, Olga Dashevsky, Rin Mizuno, Jolin X.H. Lai, Liam Hackett, Christine E. Ryan, Mary C. Collins, J. Bryan Iorgulescu, Romain Guièze, Johany Penailillo, Ruben Carrasco, Yeonjoo C. Hwang, Denise P. Muñoz, Mehdi Bouhaddou, Yaw Chyn Lim, Catherine J. Wu, John N. Allan, Richard R. Furman, Boon Cher Goh, Shazib Pervaiz, Jean-Philippe Coppé, Constantine S. Mitsiades, Matthew S. Davids
JCI This Month is a digest of the research, reviews, and other features published each month.
The lungs are regularly exposed to airborne irritants, pathogens, and other sources of inflammation that cause injury to the lung epithelium and its underlying structure. Repair and regeneration are essential for healthy lung function throughout life, yet these processes can also influence development and progression of acute and chronic conditions. Series editor Suzanne Herold developed this review series on lung inflammatory injury and tissue repair to reveal the many cell populations involved in normal and aberrant reparative responses. Ranging from discussion of lung stroma and vasculature to adaptive and innate immune systems, the reviews in this series describe the many complex mechanisms that influence pathogen-, inflammation-, and aging-driven injury to the lung and can contribute to aberrant healing, resolution of inflammation, and fibrosis. Reviews also discuss a wide range of potential therapies targeting injury and repair processes that represent promising progress toward better clinical options for patients with acute and chronic lung conditions.
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