In this issue, Tang et al. characterize cerebral organoid–derived induced pluripotent stem cells from individuals with trisomy 21 to explore cell type–specific changes associated with Down syndrome. The cover image shows immunostaining for the neural progenitor marker SOX1 (red), doublecortin (green), and the mitotic marker phosphorylated histone H3 (gray); and Hoechst staining of nuclei (blue) in trisomy 21 organoids.
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Glioblastoma, the most aggressive brain cancer, recurs because glioblastoma stem cells (GSCs) are resistant to all standard therapies. We showed that GSCs, but not normal astrocytes, are sensitive to lysis by healthy allogeneic natural killer (NK) cells in vitro. Mass cytometry and single cell RNA sequencing of primary tumor samples revealed that glioblastoma-infiltrating NK cells acquired an altered phenotype associated with impaired lytic function relative to matched peripheral blood NK cells from glioblastoma patients or healthy donors. We attributed this immune evasion tactic to direct cell-cell contact between GSCs and NK cells via integrin-mediated TGF-β activation. Treatment of GSC-engrafted mice with allogeneic NK cells in combination with inhibitors of integrin or TGF-β signaling, or with TGFBR2 gene-edited allogeneic NK cells prevented GSC-induced NK cell dysfunction and tumor growth. These findings revealed an important mechanism of NK cell immune evasion by GSCs and implicated the integrin-TGF-β axis as a potentially useful therapeutic target in glioblastoma.
Hila Shaim, Mayra Shanley, Rafet Basar, May Daher, Joy Gumin, Daniel B. Zamler, Nadima Uprety, Fang Wang, Yuefan Huang, Konrad Gabrusiewicz, Qi Miao, Jinzhuang Dou, Abdullah Alsuliman, Lucila N. Kerbauy, Sunil Acharya, Vakul Mohanty, Mayela Mendt, Sufang Li, JunJun Lu, Jun Wei, Natalie W. Fowlkes, Elif Gokdemir, Emily Ensley, Mecit Kaplan, Cynthia Kassab, Li Li, Gonca Ozcan, Pinaki P. Banerjee, Yifei Shen, April L. Gilbert, Corry M. Jones, Mustafa Bdiwi, Ana K. Nunez-Cortes, Enli Liu, Jun Yu, Nobuhiko Imahashi, Luis Muniz-Feliciano, Ye Li, Jian Hu, Giulio Draetta, David Marin, Dihua Yu, Stephan Mielke, Matthias Eyrich, Richard E. Champlin, Ken Chen, Frederick F. Lang, Elizabeth J. Shpall, Amy B. Heimberger, Katayoun Rezvani
Pyridoxine-dependent epilepsy (PDE-ALDH7A1), also known as antiquitin deficiency, is an inborn error of lysine metabolism that presents with refractory epilepsy in newborns. Bi-allelic ALDH7A1 variants lead to deficiency of α-aminoadipic semialdehyde dehydrogenase, resulting in accumulation of piperideine-6-carboxylate (P6C), and secondary deficiency of the important co-factor pyridoxal-5’-phosphate (PLP, active vitamin B6) through its complexation with P6C. Vitamin B6 supplementation resolves epilepsy in patients, but despite this treatment, intellectual disability may occur. Early diagnosis and treatment, preferably based on newborn screening, potentially optimize long-term clinical outcome. However, the currently known diagnostic PDE-ALDH7A1 biomarkers are incompatible with newborn screening procedures. Combining of the innovative analytical methods untargeted metabolomics and infrared ion spectroscopy, we were able to discover a novel biomarker for PDE-ALDH7A1,2S,6S- and 2S,6R-oxopropylpiperidine-2-carboxylic acid (2-OPP), and confirmed 6-oxopiperidine-2-carboxylic acid (6-oxoPIP)as biomarker. We demonstrated the applicability of 2-OPP as a PDE-ALDH7A1 biomarker in newborn screening. Additionally, we showed that 2-OPP accumulates in brain tissue of patients and aldh7a1 knock-out mice, and induced epilepsy-like behavior in a zebrafish model system. We speculate that 2-OPP may contribute to ongoing neurotoxicity, also in treated PDE-ALDH7A1 patients. As 2-OPP formation appears to increase upon ketosis, we emphasize the importance of avoiding catabolism in PDE-ALDH7A1 patients.
Udo F.G. Engelke, Rianne E. van Outersterp, Jona Merx, Fred A.M.G. van Geenen, Arno van Rooij, Giel Berden, Marleen C.D.G. Huigen, Leo A.J. Kluijtmans, Tessa M.A. Peters, Hilal H. Al-Shekaili, Blair R. Leavitt, Erik de Vrieze, Sanne Broekman, Erwin van Wijk, Laura A. Tseng, Purva Kulkarni, Floris P.J.T. Rutjes, Jasmin Mecinovic, Eduard A. Struys, Laura A. Jansen, Sidney M. Gospe, Jr., Saadet Mercimek-Andrews, Keith Hyland, Michel A.A.P. Willemsen, Levinus A. Bok, Clara D.M. Van Karnebeek, Ron A. Wevers, Thomas J. Boltje, Jos Oomens, Jonathan Martens, Karlien L.M. Coene
Disordered lysosomal/autophagy pathways initiate and drive pancreatitis, but the underlying mechanisms and links to disease pathology are poorly understood. Here, we show that mannose-6-phosphate (M6P) pathway of hydrolase delivery to lysosomes critically regulates pancreatic acinar cell cholesterol metabolism. Ablation of the Gnptab gene coding for a key enzyme in M6P pathway disrupted acinar cell cholesterol turnover, causing accumulation of non-esterified cholesterol in lysosomes/autolysosomes, its’ depletion in the plasma membrane, and upregulation of cholesterol synthesis and uptake. We found similar dysregulation of acinar cell cholesterol, and a decrease in GNPTAB levels, in both WT experimental pancreatitis and human disease. The mechanisms mediating pancreatic cholesterol dyshomeostasis in Gnptab-/- and experimental models involve disordered endolysosomal system, resulting in impaired cholesterol transport through lysosomes and blockage of autophagic flux. By contrast, in Gnptab-/- liver the endolysosomal system and cholesterol homeostasis were largely unaffected. Gnptab-/- mice developed spontaneous pancreatitis. Normalization of cholesterol metabolism by pharmacologic means alleviated responses of experimental pancreatitis, particularly trypsinogen activation, the disease hallmark. The results reveal the essential role of M6P pathway in maintaining exocrine pancreas homeostasis and function, and implicate cholesterol disordering in the pathogenesis of pancreatitis.
Olga A. Mareninova, Eszter T. Vegh, Natalia Shalbueva, Carli J.M. Wightman, Dustin L. Dillon, Sudarshan Malla, Yan Xie, Toshimasa Takahashi, Zoltan Rakonczay Jr, Samuel W. French, Herbert Y. Gaisano, Frederick Sanford Gorelick, Stephen J. Pandol, Steven J. Bensinger, Nicholas O. Davidson, David W. Dawson, Ilya Gukovsky, Anna S. Gukovskaya
BACKGROUND. Matrix metalloproteinases (MMPs) are implicated as key regulators of tissue destruction in tuberculosis (TB) and may be a target for host-directed therapy. Here, we conducted a Phase 2 randomized, double-blind, placebo-controlled trial investigating doxycycline, a licensed broad spectrum MMP inhibitor, in pulmonary TB patients. METHODS. Thirty pulmonary TB patients were enrolled within 7 days of initiating anti-TB treatment and randomly assigned to receive either doxycycline 100 mg or placebo twice a day for 14 days in addition to standard care. RESULTS. There were significant changes in the host transcriptome, and suppression of systemic and respiratory markers of tissue destruction with the doxycycline intervention. Whole blood RNA-sequencing demonstrated that doxycycline accelerated restoration of dysregulated gene expression patterns in TB towards normality, with more rapid down-regulation of type I and II interferon and innate immune response genes and concurrent up-regulation of B-cell modules relative to placebo. The effects persisted for 6 weeks after doxycycline was discontinued, concurrent with suppression of plasma MMP-1. In respiratory samples, doxycycline reduced MMP-1, -8, -9, -12 and -13 concentrations, suppressed type I collagen and elastin destruction, and reduced pulmonary cavity volume despite unchanged sputum Mycobacterium tuberculosis loads between the study arms. Two weeks of adjunctive doxycycline with standard anti-TB treatment was well-tolerated, with no serious adverse events related to doxycycline. CONCLUSION. These data demonstrate that adjunctive doxycycline with standard anti-TB treatment suppresses pathological MMPs in pulmonary tuberculosis patients, and suggest that larger studies on adjunctive doxycycline to limit immunopathology in TB are merited.
Qing Hao Miow, Andres F. Vallejo, Yu Wang, Jia Mei Hong, Chen Bai, Felicia S.W. Teo, Alvin Dingyuan Wang, Hong Rong Loh, Tuan Zea Tan, Ying Ding, Hoi Wah She, Suay Hong Gan, Nicholas I. Paton, Josephine Lum, Alicia Tay, Cynthia B.E. Chee, Paul A. Tambyah, Marta E. Polak, Yee Tang Wang, Amit Singhal, Paul Elkington, Jon S. Friedland, Catherine W.M. Ong
Tuberculosis (TB) is a persistent global pandemic and standard treatment has not changed for thirty years. Mycobacterium tuberculosis (Mtb) has undergone prolonged co-evolution with humans, and patients can control Mtb even after extensive infection, demonstrating the fine balance between protective and pathological host responses within infected granulomas. We hypothesised that whole transcriptome analysis of human TB granulomas isolated by laser capture microdissection could identify therapeutic targets, and that comparison with a non-infectious granulomatous disease, sarcoidosis, would identify disease-specific pathological mechanisms. Bioinformatic analysis of RNAseq data identified numerous shared pathways between TB and sarcoidosis lymph nodes, and also specific clusters demonstrating TB results from a dysregulated inflammatory immune response. To translate these insights, we compared three primary human cell culture models at the whole transcriptome level, and demonstrated that the 3D collagen granuloma model most closely reflected human TB disease. We investigated shared signaling pathways with human disease and identified twelve intracellular enzymes as potential therapeutic targets. Sphingosine kinase 1 inhibition controlled Mtb growth, concurrently reducing intracellular pH in infected monocytes and suppressing inflammatory mediator secretion. Immunohistochemical staining confirmed that sphingosine kinase 1 is expressed in human lung TB granulomas, and therefore represents a host therapeutic target to improve TB outcomes.
Michaela T. Reichmann, Liku B. Tezera, Andres F. Vallejo, Milica Vukmirovic, Rui Xiao, James Reynolds, Sanjay Jogai, Susan Wilson, Ben Marshall, Mark G. Jones, Alasdair Leslie, Jeanine M. D'Armiento, Naftali Kaminski, Marta E. Polak, Paul Elkington
JCI This Month is a digest of the research, reviews, and other features published each month.
Cancer cells in a solid tumor are supported by vasculature, extracellular matrix, nerves, and an immunological milieu collectively known as the tumor microenvironment. Elements within the tumor microenvironment can act in a coordinated fashion to support tumor growth, immune evasion, and metastasis. In this series, reviews curated by Series Editor Andrew Ewald highlight the tumor microenvironment’s complex effects in cancer, describing its modulation of immune cells and the tumor stroma as well as its role in disseminating metastases.