Andreyeva et al. generated a mouse model that uncovers how immune cells destroy the adrenal glands in Addison’s disease and identified IFN-γ as a promising target for future therapies. The cover image shows characteristic granuloma formation within the adrenal cortex. Immunofluorescence staining was performed for DAPI (blue) to visualize nuclei and CYP11A1 (red) to identify steroidogenic adrenocortical cells. Granulomatous lesions appear green because of the strong intrinsic autofluorescence of lipid-laden macrophages within the granulomas. Image credit: Arina Andreyeva and Ales Neuwirth.
Right ventricular pressure overload (RVPO) is a critical pathophysiological feature of numerous pediatric cardiovascular diseases. Transverse tubules (T-tubules) form the foundation for efficient excitation-contraction coupling in mature cardiomyocytes. We hypothesized that RVPO impairs T-tubule maturation through the regulatory protein BIN1 (Bridging Integrator 1). In right ventricular samples from children with tetralogy of Fallot, characterized by RVPO, and in a neonatal rat RVPO model induced by pulmonary artery banding (PAB), T-tubule maturation was disrupted. RNA sequencing revealed significant downregulation of T-tubule–associated genes, with Bin1 among the most suppressed. Bin1 overexpression restored T-tubule maturation in PAB rats. Assay for Transposase-Accessible Chromatin with sequencing (ATAC-seq) showed reduced chromatin accessibility at Bin1 loci; motif analysis identified Mef2d (myocyte enhancer factor 2D) as the top enriched transcription factor. Mef2d knockdown rescued Bin1 expression and T-tubule maturation, and mutation of the Mef2d binding sites within the Bin1 promoter abolished the inhibitory effect of Mef2d on Bin1 promoter activity. This study delineates a phenomenon and a mechanism of cardiomyocyte maturation under pathological stress. The findings not only advance our understanding of this most pivotal event in postnatal cardiac development but also unveil a potential therapeutic direction for pediatric cardiovascular diseases associated with RVPO.
Yuqing Hu, Yiting Xue, Xudong Chen, Linghui Kong, Debao Li, Zheng Wang, Sixie Zheng, Siqi She, Hao Li, Sijuan Sun, Hao Chen, Lijun Chen, Peisen Ruan, Kai Wang, Lincai Ye
Sex-specific mechanisms in chronic obstructive pulmonary disease (COPD) remain poorly defined. Sphingolipids are bioactive mediators that regulate airway epithelial integrity, inflammation, and bronchial smooth muscle tone, and their dysregulation contributes to airway hyperresponsiveness. We tested whether sphingolipid metabolism is regulated by sex in COPD. Lung tissue and paired plasma from female and male never-smoking controls (NSC), ever-smoking controls (SC), and COPD subjects were analyzed for sphingolipid enzyme expression and metabolite levels. Bronchial rings from mice and human bronchial smooth muscle cells (HBSMCs) were exposed to estradiol or cigarette smoke extract (CSE) ± ceramidase or sphingosine kinase inhibitors. Expression of sphingolipid regulators ASAH1 and ORMDL3 was increased in COPD airways, significantly higher in women, and correlated with airway smooth muscle remodeling. Plasma from females with COPD showed increased sphingosine-1-phosphate (S1P), whereas males exhibited higher ceramide levels. Female mice displayed greater CSE-induced bronchial reactivity, attenuated by sphingosine kinase inhibition. In male-donor HBSMCs, estradiol increased ASAH1, ORMDL3, S1P, and smooth muscle protein expression and enhanced contractility. CSE further augmented molecular responses in estradiol-treated cells but reduced collagen-gel contraction, whereas ceramidase inhibition attenuated estradiol-dependent effects. These findings suggest that estrogen-dependent alterations in sphingolipid metabolism contribute to airway hyperreactivity and remodeling in females with COPD.
Elisabetta Granato, Xiaoyun Wang, Yun Zhang, Joselyn Rojas-Quintero, Ida Cerqua, Scott A. Ochsner, Jeff Thomas Kue, Luca Cecchetto, Maor Sauler, Farrah Kheradmand, Joshua Malo, Fiorentina Roviezzo, Irina Petrache, Francesca Polverino
Type 2 innate lymphoid cells (ILC2) are a population of lineage-negative cells in the lung, gastrointestinal tract, and skin which have emerged as a significant component of type 2 allergic inflammation. The regulation of cyclooxygenase-2 (COX-2) metabolites is critical to the pathophysiology of many inflammatory disorders, including allergic asthma. While COX-2 regulates Th9 and Th17 cell differentiation and function during allergic lung inflammation, it remains unknown whether COX-2 also regulates ILC2 cell differentiation and function under similar conditions. To address this question, we examined lung ILC2 cells from COX-2+/+ and COX-2-/- mice after ovalbumin (OVA)- or Alternaria-induced allergic lung inflammation. ILC2 cells were significantly increased in COX-2-/- lungs compared with COX-2+/+ lungs after OVA exposure in vivo. The increase in ILC2 cells was accompanied by an increase in expression of the cytokines IL-5 and IL-13, and the transcription factor GATA3. Both genetic disruption and selective inhibition of COX-2 significantly increased ILC2 cell differentiation from isolated common lymphoid progenitor cells (CLP) in vitro. Furthermore, COX-2-derived PGE2 acting via EP2 receptors significantly reduced IL-33 and TSLP expression, and attenuated ILC2 cell differentiation in vitro and in vivo. Thus, during allergic lung inflammation, COX-2-derived PGE2 signals through the EP2 receptor to negatively regulate lung ILC2 cell differentiation and function.
Hong Li, Matthew L. Edin, Daniel Menendez, J. Alyce Bradbury, Joan P. Graves, Artiom Gruzdev, Gregory S. Whitehead, Maria I Sifre, Laura M. DeGraff, Darryl C. Zeldin
Sterile tissue injury triggers a rapid neutrophil response that can be either pathogenic or protective, reflecting substantial functional heterogeneity of neutrophils; however, the neutrophil subsets underlying these divergent functions remain poorly defined. Here, using a well-established sterile corneal injury model, we delineate the time-dependent functional and transcriptional heterogeneity of neutrophils following sterile injury. Temporal neutrophil depletion revealed that neutrophils recruited at day 1, but not day 7, are essential for suppressing inflammation, promoting epithelial healing, and preserving nerve density. Single-cell RNA sequencing uncovered substantial transcriptional heterogeneity among circulating neutrophils and their rapid reprogramming within 24 hours after injury. Specifically, Il1r2 was highly enriched in these early injury-responsive neutrophils. Functional validation demonstrated that adoptive transfer of IL-1R2+ neutrophils markedly attenuated inflammation and accelerated epithelial and nerve repair, restoring tissue integrity, whereas IL-1R2- neutrophils exacerbated inflammatory responses. Together, these findings identify IL-1R2+ neutrophils as an early protective neutrophil subset expanded by sterile injury that restrains excessive inflammation and preserves tissue homeostasis, providing mechanistic insight into injury-induced neutrophil reprogramming and highlighting a potential therapeutic target for enhancing tissue repair.
Hyun Ju Lee, Jung Hwa Ko, Joo Youn Oh
Both elevated plasma cell-free hemoglobin (CFH) and heparanase-driven endothelial glycocalyx shedding are contributors to microvascular dysfunction and organ injury in sepsis. However, the mechanisms governing heparanase activation, and the potential role of CFH in this process, are not understood. Utilizing patient samples, mice with cecal slurry-induced (CS) peritonitis and elevated CFH, and human lung microvascular endothelial cells (HLMVECs), we tested the hypothesis that CFH upregulates heparanase production to drive endothelial glycocalyx degradation. In human sepsis, elevated circulating CFH was associated with higher heparanase and heparan sulfate levels, which in turn correlated with adverse clinical outcomes. CS+CFH-treated mice had increased plasma heparanase, glycocalyx degradation, and pulmonary and systemic inflammation; endothelial heparanase deletion abrogated these effects. Additionally, in both pulmonary endothelial cells isolated from CS+CFH-treated mice and HLMVECs exposed to CFH and TNF, heparanase transcription and active enzyme production were increased. The deleterious effects of CFH were attenuated by acetaminophen, a hemoprotein reductant. In summary, we demonstrate that CFH oxidation stimulates endothelial heparanase expression and activation during sepsis, leading to endothelial glycocalyx degradation, which may disrupt the endothelial barrier and result in organ injury. Our findings highlight the CFH-heparanase axis as a potential therapeutic target for endothelial glycocalyx preservation in sepsis.
Avery M. Bogart, Anisa S. Haffizulla, Jason Lin, Nathan D. Putz, Han Noo Ri Lee, David M. Aslaner, Samantha K. Gonski, Nancy Wickersham, Kyle Riedmann, Jamie E. Meegan, Kaori Oshima, Ciara M. Shaver, Julie A. Bastarache, Eric P. Schmidt, Lorraine B. Ware