A distinct adipose tissue distribution pattern was observed in patients with methylmalonyl-CoA mutase deficiency, an inborn error of branched-chain amino acid (BCAA) metabolism, characterized by centripetal obesity with proximal upper and lower extremities fat deposition and paucity of visceral fat, that resembles familial multiple lipomatosis syndrome. To explore brown and white fat physiology in methylmalonic acidemia (MMA), body composition, adipokines and inflammatory markers were assessed in 46 MMA subjects and 99 matched controls. Fibroblast growth factor-21 (FGF21) levels were associated with acyl-coenzyme A accretion, aberrant methylmalonylation in adipose tissue, and an attenuated inflammatory cytokine profile. In parallel, brown and white fat were examined in a liver-specific transgenic MMA mouse model (Mmut-/-;TgINS-Alb-Mmut). The MMA mice exhibited abnormal non-shivering thermogenesis with whitened brown fat and had an ineffective transcriptional response to cold stress. Treatment of the MMA mice with bezafibrates led to clinical improvement with beiging of subcutaneous fat depots, which resembled the distribution seen in the patients. These studies defined what we believe to be a novel lipodystrophy phenotype in patients with defects in the terminal steps of BCAA oxidation and demonstrated that beiging of subcutaneous adipose tissue in MMA could readily be induced with small molecules.
Irini Manoli, Justin R. Sysol, PamelaSara E. Head, Madeline W. Epping, Oksana Gavrilova, Melissa K. Crocker, Jennifer L. Sloan, Stefanos A. Koutsoukos, Cindy X. Wang, Yiouli P. Ktena, Sophia Mendelson, Alexandra R. Pass, Patricia M. Zerfas, Victoria J. Hoffmann, Hilary J. Vernon, Laura A. Fletcher, James C. Reynolds, Maria G. Tsokos, Constantine A. Stratakis, Stephan D. Voss, Kong Y. Chen, Rebecca J. Brown, Ada Hamosh, Gerard T. Berry, Xiaoyuan Chen, Jack A. Yanovski, Charles P. Venditti
Neonatal gene therapy has been shown to prevent inner ear dysfunction in mouse models of Usher syndrome type I (USH1), the most common genetic cause of combined deafness-blindness and vestibular dysfunction. However, hearing onset occurs after birth in mice and in utero in humans, making it questionable how to transpose murine gene therapy outcomes to clinical settings. Here, we sought to extend the therapeutic time window in a mouse model for USH1G to periods corresponding to human neonatal stages, more suitable for intervention in patients. Mice defective for Ush1g (Ush1g-/-) were subjected to gene therapy after the hearing onset. The rescue of inner ear hair-cell structure was evaluated by confocal imaging and electron microscopy. Hearing and vestibular function were assessed by recordings of the auditory brainstem response and vestibulo-ocular reflex, and by locomotor tests. Up to P21, gene therapy significantly restored both the hearing and balance deficits of Ush1g-/- mice. However, beyond this age and up to P30, vestibular function was restored, but not hearing. Our data shows that effective gene therapy is possible in Ush1g-/- mice well beyond neonatal stages, implying that the therapeutic window for USH1G may be wide enough to be transposable to newborn human patients.
Ghizlene Lahlou, Charlotte Calvet, François Simon, Vincent Michel, Lauranne Alciato, Baptiste Plion, Jacques Boutet de Monvel, Marie-José Lecomte, Mathieu Beraneck, Christine Petit, Saaid Safieddine
Histone deacetylase (HDAC) inhibitors have garnered considerable interest for the treatment of adult and pediatric malignant brain tumors. However, owing to their broad-spectrum nature and inability to effectively penetrate the blood-brain barrier, HDAC inhibitors have failed to provide substantial clinical benefit to patients with glioblastoma (GBM) to date. Moreover, global inhibition of HDACs results in widespread toxicity, highlighting the need for selective isoform targeting. Although no isoform-specific HDAC inhibitors are currently available, the second-generation hydroxamic acid–based HDAC inhibitor quisinostat possesses subnanomolar specificity for class I HDAC isoforms, particularly HDAC1 and HDAC2. It has been shown that HDAC1 is the essential HDAC in GBM. This study analyzed the neuropharmacokinetic, pharmacodynamic, and radiation-sensitizing properties of quisinostat in preclinical models of GBM. It was found that quisinostat is a well-tolerated and brain-penetrant molecule that extended survival when administered in combination with radiation in vivo. The pharmacokinetic-pharmacodynamic-efficacy relationship was established by correlating free drug concentrations and evidence of target modulation in the brain with survival benefit. Together, these data provide a strong rationale for clinical development of quisinostat as a radiosensitizer for the treatment of GBM.
Costanza Lo Cascio, Tigran Margaryan, Ernesto Luna-Melendez, James B. McNamara, Connor I. White, William Knight, Saisrinidhi Ganta, Zorana Opachich, Claudia Cantoni, Wonsuk Yoo, Nader Sanai, Artak Tovmasyan, Shwetal Mehta
We previously showed that ablation of tumor hypoxia can sensitize tumors to immune checkpoint blockade (ICB). Here, we used a Kras+/G12DTP53+/R172HPdx1-Cre (KPC) derived model of pancreatic adenocarcinoma (PDAC) to examine the tumor response and adaptive resistance mechanisms involved in response to two established methods of hypoxia-reducing therapy: the hypoxia-activated prodrug TH-302 and vascular endothelial growth factor receptor 2 (VEGFR-2) blockade. The combination of both modalities normalized tumor vasculature, increased DNA damage and cell death, and delayed tumor growth. In contrast to prior cancer models, the combination did not alleviate overall tissue hypoxia or sensitize these KPC tumors to ICB therapy despite qualitative improvements to the CD8 T cell response. Bulk-tumor RNA sequencing, flow cytometry, and adoptive myeloid cell transfer suggested that treated tumor cells increased their capacity to recruit granulocytic myeloid derived suppressor cells (G-MDSC) through CCL9 secretion. Blockade of the CCL9-CCR1 axis could limit G-MDSC migration, and depletion of Ly6G-positive cells could sensitize tumors to the combination of TH-302 and anti-VEGFR-2 with ICB. Together, these data suggest that pancreatic tumors modulate G-MDSC migration as an adaptive response to vascular normalization, and that these immunosuppressive myeloid cells act in a setting of persistent hypoxia to maintain adaptive immune resistance.
Arthur Liu, Seth T. Gammon, Federica Pisaneschi, Akash Boda, Casey R. Ager, David Piwnica-Worms, David S. Hong, Michael A. Curran
Poly (ADP-ribose) polymerase inhibitors (PARPis) are approved for cancer therapy according to their synthetic lethal interactions, and clinical trials have been applied in non–small cell lung cancer. However, the therapeutic efficacy of PARPis in lung adenocarcinoma (LUAD) is still unknown. We explored the effect of a mutated retinoblastoma gene (RB1) on PARPi sensitivity in LUAD. Bioinformatic screening was performed to identify PARPi-sensitive biomarkers. Here, we showed that viability of LUAD cell lines with mutated RB1 was significantly decreased by PARPis (niraparib, rucaparib, and olaparib). RB1 deficiency induced genomic instability, prompted cytosolic double-stranded DNA (dsDNA) formation, activated the cGAS/STING pathway, and upregulated downstream chemokines CCL5 and CXCL10, triggering immune cell infiltration. Xenograft experiments indicated that PARPi treatment reduced tumorigenesis in RB1-KO mice. Additionally, single-cell RNA sequencing analysis showed that malignant cells with downregulated expression of RB1 had more communications with other cell types, exhibiting activation of specific signaling such as GAS, IFN response, and antigen-presenting and cytokine activities. Our findings suggest that RB1 mutation mediates the sensitivity to PARPis through a synthetic lethal effect by triggering the cGAS/STING pathway and upregulation of immune infiltration in LUAD, which may be a potential therapeutic strategy.
Qi Dong, Tong Yu, Bo Chen, Mingyue Liu, Xiang Sun, Huiying Cao, Kaidong Liu, Huanhuan Xu, Yuquan Wang, Shuping Zhuang, Zixin Jin, Haihai Liang, Yang Hui, Yunyan Gu
The widely used chemotherapy cisplatin causes permanent hearing loss in 40-60% of cancer patients. One drug, sodium thiosulfate, is approved by the FDA for use in pediatric patients with localized solid tumors for preventing cisplatin-induced hearing loss, but more drugs are desperately needed. Here, we tested dabrafenib, an FDA-approved BRAF kinase inhibitor and anticancer drug, in a clinically relevant multi-dose cisplatin mouse model. The protective effects of dabrafenib, given orally twice daily with cisplatin, were determined by functional hearing tests and cochlear outer hair cells counts. Toxicity of the drugs co-treatment was evaluated, and levels of pERK were measured. Dabrafenib, in dose of 3 mg/kg/bw, twice daily, in mice, was determined to be the minimum effective dose and it is equivalent to one tenth of the daily FDA-approved dose for human cancer treatment. The levels of hearing protection acquired, 20-25 dB at the three frequencies tested, in both female and male mice, persisted for four months after completion of treatments. Moreover, dabrafenib exhibited a good in vivo therapeutic index (> 25), hearing protection in two different mouse strains, and diminished cisplatin-induced weight loss. Altogether, this study demonstrates that dabrafenib is a promising candidate drug for protection from cisplatin-induced hearing loss.
Matthew A. Ingersoll, Richard D. Lutze, Chithra K. Pushpan, Regina G. Kelmann, Huizhan Liu, Mark T. May, William J. Hunter, David Z.Z. He, Tal Teitz
Use of autologous cells isolated from elderly patients with multiple co-morbidities may account for the modest efficacy of cell therapy in patients with chronic limb threatening ischemia (CLTI). We aimed to determine whether pro-arteriogenic monocyte/macrophages (Mo/MΦs) from CLTI patients were functionally impaired and to demonstrate the mechanisms related to any impairment. Pro-arteriogenic Mo/MΦs isolated from CLTI patients were found to have an impaired capacity to promote neovascularization in vitro and in vivo compared with those isolated from healthy controls. This was associated with increased expression of human HIV-1 TAT interactive protein-2 (HTATIP2), a transcription factor known to suppress angiogenesis/arteriogenesis. Silencing HTATIP2 restored the functional capacity of CLTI Mo/MΦs which was associated with increased expression of arteriogenic regulators neuropilin-1 and angiopoietin-1, and their ability to enhance angiogenic (endothelial tubule formation) and arteriogenic (smooth muscle proliferation) processes in vitro. In support of the translational relevance of our findings, silencing HTATIP2 in pro-arteriogenic Mo/MΦs isolated from CLTI patients rescued their capacity to enhance limb perfusion in the ischemic hindlimb by effecting greater angiogenesis and arteriogenesis. Ex-vivo modulation of HTATIP2 may offer a strategy for rescuing the functional impairment of pro-angio/arteriogenic Mo/MΦs prior to autologous delivery and increase the likelihood of clinical efficacy.
Ashish S. Patel, Francesca E. Ludwinski, Angeles Mondragon, Katherine Nuthall, Prakash Saha, Oliver Lyons, Mario Leonardo Squadrito, Richard C. Siow, Michele De Palma, Alberto Smith, Bijan Modarai
New medicines are urgently required to treat the fatal neuromuscular disease, Duchenne muscular dystrophy (DMD). Dimethyl fumarate (DMF) is a potent immunomodulatory small molecule nuclear erythroid 2-related factor 2 (Nrf2) activator with current clinical utility in the treatment of multiple sclerosis and psoriasis that could be effective for DMD and rapidly translatable. Here, we tested two weeks of daily 100mg/kg DMF versus 5mg/kg standard care prednisone (PRED) treatment in juvenile mdx mice with early symptomatic DMD. Both drugs modulated seed genes driving the DMD disease program and improved force production in fast-twitch muscle. However, only DMF showed pro-mitochondrial effects, protected contracting muscles from fatigue, improved histopathology and augmented clinically compatible muscle function tests. DMF may be a more selective modulator of the DMD disease program than PRED warranting follow-up longitudinal studies to evaluate disease modifying impact.
Cara A. Timpani, Stephanie Kourakis, Danielle A. Debruin, Dean G. Campelj, Nancy Pompeani, Narges Dargahi, Angelo Patrick R. Bautista, Ryan M. Bagaric, Elya J. Ritenis, Lauren Sahakian, Didier Debrincat, Nicole Stupka, Patricia Hafner, Peter G. Arthur, Jessica R. Terrill, Vasso Apostolopoulos, Judy B. De Haan, Nuri Gueven, Dirk Fischer, Emma Rybalka
Hereditary spherocytosis (HS) is the most common non-immune hereditary chronic hemolytic anemia after hemoglobinopathies. The genetic defects in membrane function causing HS leads to perturbation of red cell metabolome, with altered glycolysis. In mice genetically lacking protein 4.2 (4.2-/-, Epb42), a murine model of HS, we show increased expression of pyruvate kinase (Pk) isoforms in whole and fractioned red cells in conjunction with abnormalities in the glycolytic pathway and in GSH system. Mitapivat, a PKs activator, metabolically re-programs 4.2-/- mouse red cells with amelioration of glycolysis and GSH cycle. This results in improved osmotic fragility, reduced phosphatidyl-serine (PS) positivity and decrease in erythroid vesicles release in vitro. Mitapivat treatment significantly decreases erythrophagocytosis and beneficially impacts iron homeostasis. In mild/moderate HS, the beneficial effect of splenectomy is still controversial. Here, we show that splenectomy improves anemia in 4.2-/- mice and that mitapivat is non-inferior to splenectomy. An additional benefit of mitapivat treatment is lower expression of markers of inflammatory vasculopathy in 4.2-/- mice with or without splenectomy, indicating a multi-systemic action of mitapivat. These findings support the notion that mitapivat treatment should be considered for symptomatic HS.
Alessandro Matte, Anand Babu Wilson, Federica Gevi, Enrica Federti, Antonio Recchiuti, Giulia Ferri, Anna Maria Brunati, Mario Angelo Pagano, Roberta Russo, Christophe Leboeuf, Anne Janin, Anna Maria Timperio, Achille Iolascon, Elisa Gremese, Lenny Dang, Narla Mohandas, Carlo Brugnara, Lucia De Franceschi
Overexpression of Phosphatases of Regenerating Liver 2 (PRL2), detected in numerous diverse cancers, is often associated with increased severity and poor patient prognosis. PRL2-catalyzed tyrosine dephosphorylation of the tumor suppressor PTEN results in increased PTEN degradation, and has been identified as a mechanism underlying PRL2 oncogenic activity. Overexpression of PRL2, coincident with reduced PTEN protein, is frequently observed in Acute Myeloid Leukemia (AML) patients. In the current study, a PTEN-knockdown AML animal model was generated to assess the impact of conditional PRL2 inhibition on the level of PTEN protein and the development and progression of AML. Inhibition of PRL2 resulted in a significant increase in median animal survival, from 40 weeks to greater than 60 weeks. The prolonged survival reflected delayed expansion of aberrantly differentiated hematopoietic stem cells into leukemia blasts, resulting in extended time required for clinically relevant leukemia blast accumulation in the bone marrow niche. Leukemia blast suppression following PRL2 inhibition was correlated with an increase in PTEN, and downregulation of AKT/mTOR regulated pathways. These observations directly established, in a disease model, the viability of PRL2 inhibition as a therapeutic strategy for improving clinical outcomes in AML and potentially other PTEN-deficient cancers by slowing cancer progression.
Colin Carlock, Yunpeng Bai, Allison Paige-Hood, Qinglin Li, Frederick Nguele Meke, Zhong-Yin Zhang
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