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Abstract
BACKGROUND. Decoding the clinical impact of genetic variants is particularly important for precision medicine in cancer. Genetic screening of mainly breast and ovarian cancer patients has identified numerous BRCA1/BRCA2 ‘variants of uncertain significance’ (VUS) that remain unclassified due to a lack of pedigrees and functional data. METHODS. Here, we used CRISPR-Select — a technology that exploits unique inbuilt controls at the endogenous locus — to assess 54 rare ClinVar VUS located in the PALB2-binding domain (PBD) of BRCA2. Variant deleteriousness was examined in the absence and presence of PARPi, Cisplatin, or Mitomycin C. RESULTS. Marked functional deficiency was observed for variants in the exon 2-donor splice region (A22 = (c.66A>C), A22 = (c.66A>G), A22 = (c.66A>T), and D23H) and Trp31 amino acid (W31G, W31L, and W31C), both critical for BRCA2 function. Moreover, T10K and G25R resulted in an intermediate phenotype, suggesting these variants are hypomorphic in nature. Combining our functional results with the latest ClinGen BRCA1/2 Variant Curation Expert Panel recommendations, we could classify 49 of the 54 VUS as either likely benign (n = 45) or likely pathogenic (n = 4). CONCLUSION. Hence, CRISPR-Select is an important tool for efficient variant clinical classification. Application of this technology in the future will ultimately improve patient care. FUNDING. Danish Cancer Society, Novo Nordisk Foundation, Sygeforsikring Danmark, Børnecancerfonden, Neye-Fonden, Roche, Novartis, Pfizer, AstraZeneca, MSD, and Daiichi Sankyo Europe GmbH.
Authors
Muthiah Bose, Manika Indrajit Singh, Morten Frödin, Bent Ejlertsen, Claus S. Sørensen, Maria Rossing
Abstract
Cancer cachexia is a multifactorial condition characterized by skeletal muscle wasting that impairs quality of life and longevity for many cancer patients. A greater understanding of the molecular etiology of this condition is needed for effective therapies to be developed. We performed a quantitative proteomic analysis of skeletal muscle from cachectic pancreatic ductal adenocarcinoma (PDAC) patients and non-cancer controls, followed by immunohistochemical analyses of muscle cross-sections. These data provide evidence of a local inflammatory response in muscles of cachectic PDAC patients, including an accumulation of plasma proteins and recruitment of immune cells into muscle that may promote the pathological remodeling of muscle. Our data further support the complement system as a potential mediator of these processes, which we tested by injecting murine pancreatic cancer cells into wild type (WT) mice, or mice with genetic deletion of the central complement component 3 (C3–/– mice). Compared to WT mice, C3–/– mice showed attenuated tumor-induced muscle wasting and dysfunction and reduced immune cell recruitment and fibrotic remodeling of muscle. These studies demonstrate that complement activation is contributory to the skeletal muscle pathology and dysfunction in PDAC, suggesting that the complement system may possess therapeutic potential in preserving skeletal muscle mass and function.
Authors
Andrew C. D'Lugos, Jeremy B. Ducharme, Chandler S. Callaway, Jose G. Trevino, Carl Atkinson, Sarah M. Judge, Andrew R. Judge
Abstract
In the kidney, cells of thick ascending limb of the loop of Henle (TAL) are resistant to ischemic injury, despite high energy demands. This adaptive metabolic response is not fully understood even though the integrity of TAL cells is essential for recovery from acute kidney injury (AKI). TAL cells uniquely express uromodulin, the most abundant protein secreted in healthy urine. Here, we demonstrate that alternative splicing generates a conserved intracellular isoform of uromodulin, which contributes to metabolic adaptation of TAL cells. This splice variant was induced by oxidative stress and was up-regulated by AKI that is associated with recovery, but not by severe AKI and chronic kidney disease (CKD). This intracellular variant was targeted to the mitochondria, increased NAD+ and ATP levels, and protected TAL cells from hypoxic injury. Augmentation of this variant using antisense oligonucleotides after severe AKI improved the course of injury. These findings underscore an important role of condition-specific alternative splicing in adaptive energy metabolism to hypoxic stress. Enhancing this protective splice variant in TAL cells could become a novel therapeutic intervention for AKI.
Authors
Azuma Nanamatsu, George J. Rhodes, Kaice A. LaFavers, Radmila Micanovic, Virginie Lazar, Shehnaz Khan, Daria Barwinska, Shinichi Makino, Amy Zollman, Ying-Hua Cheng, Emma H. Doud, Amber L. Mosley, Matthew J. Repass, Malgorzata M. Kamocka, Aravind Baride, Carrie L. Phillips, Katherine J. Kelly, Michael T. Eadon, Jonathan Himmelfarb, Matthias Kretzler, Robert L. Bacallao, Pierre C. Dagher, Takashi Hato, Tarek M. El-Achkar
Abstract
Type 2 innate lymphoid cells (ILC2) regulate the proliferation of preadipocytes that give rise to beige adipocytes. Whether and how ILC2 downstream Th2 cytokines control beige adipogenesis remain unclear. We employed cell systems and genetic models to examine the mechanism through which interleukin-13 (IL-13), an ILC2-derived Th2 cytokine, controls beige adipocyte differentiation. IL-13 priming in preadipocytes drives beige adipogenesis by upregulating beige-promoting metabolic programs, including mitochondrial oxidative metabolism and PPARγ-related pathways. The latter is mediated by increased expression and activity of PPARγ through IL-13 receptor α1 (IL-13Rα1) downstream effectors, STAT6 and p38 MAPK, respectively. Il13 knockout (Il13KO) or preadipocyte Il13ra1 knockout (Il13ra1KO) mice are refractory to cold- or β-3 adrenergic agonist-induced beiging in inguinal white adipose tissue, whereas Il4 knockout mice show no defects in beige adipogenesis. Il13KO and Il13ra1KO mouse models exhibit increased body weight/fat mass and dysregulated glucose metabolism but have a mild cold intolerant phenotype, likely due to their intact brown adipocyte recruitment. We also find that genetic variants of human IL13RA1 are associated with body mass index and type 2 diabetes. These results suggest that IL-13 signaling-regulated beige adipocyte function may play a predominant role in modulating metabolic homeostasis rather than in thermoregulation.
Authors
Alexandra R. Yesian, Mayer M. Chalom, Nelson H. Knudsen, Alec L. Hyde, Jean Personnaz, Hyunjii Cho, Yae-Huei Liou, Kyle A. Starost, Chia-Wei Lee, Dong-Yan Tsai, Hsing-Wei Ho, Jr-Shiuan Lin, Jun Li, Frank B. Hu, Alexander S. Banks, Chih-Hao Lee
Abstract
Aortic aneurysm is a high-risk cardiovascular disease without effective cure. Vascular Smooth Muscle Cell (VSMC) phenotypic switching is a key step in the pathogenesis of aortic aneurysm. Here, we revealed the role of histidine triad nucleotide-binding protein 1 (HINT1) in aortic aneurysm. HINT1 was upregulated both in aortic tissue from patients with aortic aneurysm and Ang II-induced aortic aneurysm mice. VSMC-specific HINT1 deletion alleviated aortic aneurysm via preventing VSMC phenotypic switching. With the stimulation of pathological factors, the increased nuclear translocation of HINT1 mediated by nucleoporin 98 (Nup98) promoted the interaction between HINT1 and transcription factor AP-2 alpha (TFAP2A) and further triggered the transcription of integrin alpha 6 (ITGA6) mediated by TFAP2A, and consequently activated the downstream focal adhesion kinase (FAK)/STAT3 signal pathway, leading to aggravation of VSMC phenotypic switching and aortic aneurysm. Importantly, Defactinib treatment was demonstrated to limit aortic aneurysm development by inhibiting the FAK signal pathway. Thus, HINT1/ITGA6/FAK axis emerges as potential therapeutic strategies in aortic aneurysm.
Authors
Yan Zhang, Wencheng Wu, Xuehui Yang, Shanshan Luo, Xiaoqian Wang, Qiang Da, Ke Yan, Lulu Hu, Shixiu Sun, Xiaolong Du, Xiaoqiang Li, Zhijian Han, Feng Chen, Aihua Gu, Liansheng Wang, Zhiren Zhang, Bo Yu, Chenghui Yan, Yaling Han, Yi Han, Liping Xie, Yong Ji
Abstract
Acute myeloid leukemia (AML) is an aggressive and often deadly malignancy associated with proliferative immature myeloid blasts. Here, we identified CD84 as a critical survival regulator in AML. High levels of CD84 expression provided a survival advantage to leukemia cells, whereas CD84 downregulation disrupted their proliferation, clonogenicity and engraftment capabilities in both human cell lines and patient derived xenograft cells. Critically, loss of CD84 also markedly blocked leukemia engraftment and clonogenicity in MLL-AF9 and inv(16) AML mouse models, highlighting its pivotal role as survival factor across species. Mechanistically, CD84 regulated leukemia cells’ energy metabolism and mitochondrial dynamics. Depletion of CD84 altered mitochondrial ultra-structure and function of leukemia cells, and it caused down-modulation of both oxidative phosphorylation and fatty acid oxidation pathways. CD84 knockdown induced a block of Akt phosphorylation and down-modulation of nuclear factor erythroid 2-related factor 2 (NRF2), impairing AML antioxidant defense. Conversely, CD84 over-expression stabilized NRF2 and promoted its transcriptional activation, thereby supporting redox homeostasis and mitochondrial function in AML. Collectively, our findings indicated that AML cells depend on CD84 to support antioxidant pro-survival pathways, highlighting a therapeutic vulnerability of leukemia cells.
Authors
Yinghui Zhu, Mariam Murtadha, Miaomiao Liu, Enrico Caserta, Ottavio Napolitano, Le Xuan Truong Nguyen, Huafeng Wang, Milad Moloudizargari, Lokesh Nigam, Theophilus Tandoh, Xuemei Wang, Alex Pozhitkov, Rui Su, Xiangjie Lin, Marc Denisse Estepa, Raju Pillai, Joo Song, James F. Sanchez, Yu-Hsuan Fu, Lianjun Zhang, Man Li, Bin Zhang, Ling Li, Ya-Huei Kuo, Steven Rosen, Guido Marcucci, John C. Williams, Flavia Pichiorri
Abstract
GM1 gangliosidosis is a lysosomal storage disorder (LSD) and caused by genetic defects in the lysosomal β-galactosidase (β-gal). The primary substrate of the β-gal is GM1 ganglioside (GM1), a sialylated glycosphingolipid abundant in the central nervous system (CNS). β-gal deficiency causes GM1 to accumulate in neural cells leading to a rapid decline in psychomotor functions, seizures, and premature death. There is currently no therapy available. Although enzyme replacement therapy (ERT) has been approved for other LSDs, its effects on the CNS are limited owing to the blood-brain barrier (BBB). Here, we assessed the therapeutic efficacy of a systemic infusion of an AAV vector carrying a gene expressing a BBB-penetrable enzyme under the control of a liver-specific promotor in GM1 gangliosidosis model mice. The BBB-penetrable enzyme consisted of the variable region of the anti-transferrin receptor-antibody fused with β-gal. The BBB-penetrable enzyme was only produced in the liver and secreted into the blood, which was efficiently distributed to various organs, including the brain. GM1 accumulation in the CNS was completely normalised, with improved neurological functions and animal survival. This therapeutic approach is expected to be applied for the treatment of several hereditary neurological diseases with CNS involvement.
Authors
Saki Kondo Matsushima, Yohta Shimada, Masafumi Kinoshita, Takashi Nagashima, Shinichiro Okamoto, Sayoko Iizuka, Haruna Takagi, Shunsuke Iizuka, Takashi Higuchi, Hiroyuki Hioki, Ayako M. Watabe, Hiroyuki Sonoda, Toya Ohashi, Hiroshi Kobayashi
Abstract
Background: Men with chronic kidney disease (CKD) experience faster kidney function decline than women. Studies in individuals undergoing sex hormone therapy suggest a role for sex hormones, as estimated glomerular filtration rate (eGFR) increases with feminizing therapy and decreases with masculinizing therapy. However, effects on measured GFR (mGFR), glomerular and tubular function, and involved molecular mechanisms remain unexplored. Methods: This prospective, observational study included individuals initiating feminizing (estradiol and antiandrogens; n=23) or masculinizing (testosterone; n=21) therapy. Baseline and three-month assessments included mGFR (Iohexol clearance), kidney perfusion (para-aminohippuric acid clearance), tubular injury biomarkers, and plasma proteomics. Results: During feminizing therapy, mGFR and kidney perfusion increased (+3.6% and +9.1%, respectively; p<0.05), without increased glomerular pressure. Tubular injury biomarkers, including urine neutrophil gelatinase-associated lipocalin, EGF, monocyte chemoattractant protein-1, and chitinase 3-like protein 1 (YKL-40), decreased significantly (-53%, -42%, -45%, and -58%, respectively). During masculinizing therapy, mGFR and kidney perfusion remained unchanged, but urine YKL-40 and plasma TNFR-1 increased (+134% and +8%, respectively; p<0.05). Proteomic analysis revealed differential expression of 49 proteins during feminizing, and 356 proteins during masculinizing therapy. Many kidney-protective proteins were positively associated with estradiol and negatively associated with testosterone, including proteins involved in endothelial function (SFRP4, SOD3), inflammation reduction (TSG-6), and maintaining kidney tissue structure (agrin). Conclusion: Sex hormones influence kidney physiology, with estradiol showing protective effects on glomerular and tubular function, while testosterone predominantly exerts opposing effects. These findings emphasize the role of sex hormones in sexual dimorphism observed in kidney function and physiology and suggest new approaches for sex-specific precision medicine.
Authors
Sarah A. van Eeghen, Laura Pyle, Phoom Narongkiatikhun, Ye Ji Choi, Wassim Obeid, Chirag R. Parikh, Taryn G. Vosters, Irene GM van Valkengoed, Merle M. Krebber, Daan J. Touw, Martin den Heijer, Petter Bjornstad, Daniël Raalte, Natalie J. Nokoff
Abstract
Neuronal hyperexcitability precedes synapse loss in certain neurodegenerative diseases, yet the synaptic membrane interactions and downstream signaling events remain unclear. The disordered amino terminus of the prion protein (PrPC) has been implicated in aberrant signaling in prion and Alzheimer’s disease. To disrupt neuronal interactions and signaling linked to the amino terminus, here we CRISPR-engineered a knock-in mouse expressing mutant PrPC (G92N), generating an N-linked glycosylation site between two functional motifs. Mice developed seizures and necrosis of hippocampal pyramidal neurons, similar to prion-infected mice and consistent with excitotoxicity. Phosphoproteomics revealed phosphorylated glutamate receptors and calcium-sensitive kinases, including protein kinase C (PKC). Additionally, 92N-PrPC-expressing neurons show persistent calcium influx as well as dendritic beading, which was rescued by an NMDA receptor antagonist. Finally, survival of Prnp92N mice was prolonged by blocking active NMDA receptor channels. We propose dysregulated PrPC – NMDA receptor - induced signaling can trigger excitatory – inhibitory imbalance, spongiform degeneration, and neurotoxicity, and that calcium dysregulation is central to PrPC-linked neurodegeneration.
Authors
Joie Lin, Julia A. Callender, Joshua E. Mayfield, Daniel B. McClatchy, Daniel Ojeda-Juárez, Mahsa Pourhamzeh, Katrin Soldau, Timothy D. Kurt, Garrett A. Danque, Helen K. Khuu, Josephina E. Ronson, Donald P. Pizzo, Yixing Du, Maxwell A. Gruber, Alejandro M. Sevillano, Jin Wang, Christina D. Orrú, Joy Chen, Gail Funk, Patricia Aguilar-Calvo, Brent D. Aulston, Subhojit Roy, Jong M. Rho, Jack D. Bui, Alexandra C. Newton, Stuart A. Lipton, Byron Caughey, Gentry N. Patrick, Kim Doré, John R. Yates III, Christina J. Sigurdson
Abstract
Telomere biology disorders (TBD) are genetic diseases caused by defective telomere maintenance. TBD patients often develop bone marrow failure and have an increased risk of myeloid neoplasms. To better understand the factors underlying hematopoietic outcomes in TBD, we comprehensively evaluated acquired genetic alterations in hematopoietic cells from 166 pediatric and adult TBD patients. 47.6% of patients (28.8% of children, 56.1% of adults) had clonal hematopoiesis. Recurrent somatic alterations involved telomere maintenance genes (7.6%), spliceosome genes (10.4%, mainly U2AF1 p.S34), and chromosomal alterations (20.2%), including 1q gain (5.9%). Somatic variants affecting the DNA damage response (DDR) were identified in 21.5% of patients, including 20 presumed loss-of-function variants in ATM. Using multimodal approaches, including single-cell sequencing, assays of ATM activation, telomere dysfunction-induced foci analysis, and cell growth assays, we demonstrate telomere dysfunction-induced activation of ATM-dependent DDR pathway with increased senescence and apoptosis in TBD patient cells. Pharmacologic ATM inhibition, modeling the effects of somatic ATM variants, selectively improved TBD cell fitness by allowing cells to bypass DDR-mediated senescence without detectably inducing chromosomal instability. Our results indicate that ATM-dependent DDR induced by telomere dysfunction is a key contributor to TBD pathogenesis and suggest dampening hyperactive ATM-dependent DDR as a potential therapeutic intervention.
Authors
Christopher M. Sande, Stone Chen, Dana V. Mitchell, Ping Lin, Diana M. Abraham, Jessie M. Cheng, Talia Gebhard, Rujul J. Deolikar, Colby Freeman, Mary Zhou, Sushant Kumar, Michael Bowman, Robert L. Bowman, Shannon Zheng, Bolormaa Munkhbileg, Qijun Chen, Natasha L. Stanley, Kathy Guo, Ajibike Lapite, Ryan Hausler, Deanne M. Taylor, James Corines, Jennifer J.D. Morrissette, David B. Lieberman, Guang Yang, Olga Shestova, Saar Gill, Jiayin Zheng, Kelcy Smith-Simmer, Lauren G. Banaszak, Kyle N. Shoger, Erica F. Reinig, Madilynn Peterson, Peter Nicholas, Amanda J. Walne, Inderjeet Dokal, Justin P. Rosenheck, Karolyn A. Oetjen, Daniel C. Link, Andrew E. Gelman, Christopher R. Reilly, Ritika Dutta, R. Coleman Lindsley, Karyn J. Brundige, Suneet Agarwal, Alison A. Bertuch, Jane E. Churpek, Laneshia K. Tague, F. Brad Johnson, Timothy S. Olson, Daria V. Babushok
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Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)