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Abstract
Leber’s hereditary optic neuropathy (LHON) is a maternally inherited eye disease. X-linked nuclear modifiers were proposed to modify the phenotypic manifestation of LHON-associated mitochondrial DNA (mtDNA) mutations. By whole exome sequencing, we identified the X-linked LHON modifier (c.157C>T, p. Arg53Trp) in the PRICKLE3 encoding a mitochondrial protein linked to biogenesis of ATPase in three Chinese families. All affected individuals carried both ND4 11778G>A and p.Arg53Trp mutations, while subjects bearing only single mutation exhibited normal vision. The cells carrying the p.Arg53Trp mutation exhibited the defective assembly, stability and function of ATP synthase, verified by PRICKLE3 knock-down cells. Co-immunoprecipitation indicated the direct interaction of PRICKLE3 with ATP synthase via ATP8. Strikingly, mutant cells bearing both p.Arg53Trp and m.11778G>A mutations displayed greater mitochondrial dysfunctions than those carrying only single mutation. These indicated that the p.Arg53Trp mutation acted in synergy with m.11778G>A mutation and deteriorated mitochondrial dysfunctions necessary for the expression of LHON. Furthermore, we demonstrated that Prickle3 deficient mice exhibited the pronounced ATPase deficiencies. Prickle3 knock-out mice recapitulated LHON phenotypes with retina deficiencies including degeneration of retinal ganglion cells and abnormal vasculature. Our findings provided new insights into pathophysiology of LHON that were manifested by interaction between mtDNA mutation and X-linked nuclear modifier.
Authors
Jialing Yu, Xiaoyang Liang, Yanchun Ji, Cheng Ai, Junxia Liu, Ling Zhu, Zhipeng Nie, Xiaofen Jin, Chenghui Wang, Juanjuan Zhang, Fuxin Zhao, Shuang Mei, Xiaoxu Zhao, Xiangtian Zhou, Minglian Zhang, Meng Wang, Taosheng Huang, Pingping Jiang, Min-Xin Guan
Abstract
The brain has evolved in an environment where food sources are scarce and foraging for food is one of the major challenges for survival of the individual and species. Basic and clinical studies show that obesity/overnutrition leads to overwhelming changes in the brain in animals and humans. However, the exact mechanisms underlying the consequences of excessive energy intake are not well understood. Neurons expressing the neuropeptide hypocretin/orexin (Hcrt) in the lateral/perifonical hypothalamus (LH) are critical for homeostatic regulation, reward seeking, stress response, and cognitive functions. In this study, we examined adaptations in Hcrt cells regulating behavioral responses to salient stimuli in diet-induced obese mice. Our results demonstrated changes in primary cilia, synaptic transmission and plasticity, cellular responses to neurotransmitters necessary for reward seeking and stress responses in Hcrt neurons from obese mice. Activities of neuronal networks in the LH and hippocampus were impaired as a result of decreased hypocretinergic function. The weakened Hcrt system decreased reward seeking while altering responses to acute stress (stress coping strategy), which were reversed by selectively activating Hcrt cells with chemogenetics. Taken together, our data suggest that a deficiency in the Hcrt signaling may be a common cause of behavioral changes (such as lowered arousal, weakened reward seek and altered stress response) in obese animals.
Authors
Ying Tan, Fu Hang, Zhong-Wu Liu, Milan Stoiljkovic, Mingxing Wu, Yue Tu, Wenfei Han, Angela M. Lee, Craig Kelley, Mihaly Hajos, Lingeng Lu, Luis de Lecea, Ivan de Araujo, Marina Picciotto, Tamas L. Horvath, Xiao-Bing Gao
Abstract
Broadly activating innate immunity, which has been achieved via unrelated vaccines or Type-I INF-like factors, may effectively treat or prevent COVID-19 and future coronavirus diseases.
Authors
Leonard Angka, Marisa Market, Michele Ardolino, Rebecca C. Auer
Abstract
BACKGROUND. Despite an increasing appreciation of the roles that myeloid cells play in tumor progression and therapy, challenges remain in interpreting the tumor-associated myeloid response balance and its translational value. We aimed to construct a simple and reliable myeloid signature for hepatocellular carcinoma (HCC). METHODS. Using in situ immunohistochemistry, we assessed the distribution of major myeloid subtypes in both peri- and intratumoral regions of HCC. A 2-feature-based, myeloid-specific prognostic signature, named the myeloid response score (MRS), was constructed using an L1-penalized Cox regression model based on data from a training subset (n=244) and in a test subset (n=244), an independent internal (n=341), and two external (n= 94; n=254) cohorts. RESULTS. The MRS and the MRS-based nomograms displayed remarkable discriminatory power, accuracy, and clinical usefulness for predicting recurrence and patient survival, superior to current staging algorithms. Moreover, an increase in MRS was associated with a shift in the myeloid response balance from antitumor to protumor activities, accompanied with enhanced CD8+ T cell exhaustion patterns. Additionally, we provide evidence that the MRS was associated with the efficacy of sorafenib treatment for recurrent HCC. CONCLUSION. We identified and validated a simple myeloid signature for HCC which showed remarkable prognostic potential and may serve as a basis for the stratification of HCC immune subtypes. FUNDING. This work was supported by the National Science and Technology Major Project of China, the National Natural Science Foundation of China, the Science and Information Technology of Guangzhou, the Fundamental Research Funds for the Central Universities, and the China Postdoctoral Science Foundation.
Authors
Chong Wu, Jie Lin, Yulan Weng, Dan-Ni Zeng, Jing Xu, Shufeng Luo, Li Xu, Mingyu Liu, Qiaomin Hua, Chao-Qun Liu, Jin-Qing Li, Jing Liao, Cheng Sun, Jian Zhou, Min-Shan Chen, Chao Liu, Zhenhong Guo, Shi-Mei Zhuang, Jin-Hua Huang, Limin Zheng
Abstract
Posttranslational modifications are a common feature of proteins associated with neurodegenerative diseases including prion protein (PrPC), tau and α-synuclein. Alternative self-propagating protein states or strains give rise to different disease phenotypes and display strain-specific subsets of posttranslational modifications. The relationships between strain-specific structure, posttranslational modifications and disease phenotype are poorly understood. We previously reported that among hundreds of PrPC sialoglycoforms expressed by a cell, individual prion strains recruited PrPC molecules selectively, according to the sialylation status of their N-linked glycans. Here we report that transmission of a prion strain to a new host is accompanied by a dramatic shift in the selectivity of recruitment of PrPC sialoglycoforms giving rise to PrPSc with a unique sialoglycoform signature and disease phenotype. The newly emerged strain has the shortest incubation time to disease, is characterized by a colocalization of PrPSc with microglia and a very profound proinflammatory response, features that are linked to a unique sialoglycoform composition of PrPSc. The current work provides experimental support for a hypothesis that strain-specific patterns of PrPSc sialoglycoforms formed as a result of selective recruitment dictate strain-specific disease phenotypes. This work suggests a causative relationship between a strain-specific structure, posttranslational modifications and disease phenotype.
Authors
Natallia Makarava, Jennifer Chen-Yu Chang, Kara Molesworth, Ilia V. Baskakov
Abstract
FTY720 (Gilenya, Novartis), is a treatment for relapsing remitting multiple sclerosis (MS). It is an analog of sphingosine-1-phosphate (S1P) and targets S1P receptors 1,3,4, and 5. Recent reports indicate an association between long term exposure to FTY720 and cases of cryptococcal infection. Here, we studied the effect of FTY720 and its derivative, BAF312 (Mayzent, Novartis), which only target S1P receptors 1 and 5, in a mouse model of cryptococcal infection. We found that treatment with FTY720, but not with BAF312, lead to decreased survival and increased organ burden in mouse cryptococcal granulomas. Both FTY720 and BAF312 caused a profound CD4+ and CD8+ T cell depletion in blood and lungs but only treatment with FTY720 lead to cryptococcal reactivation. Treatment with FTY720, but not with BAF312, was associated with disorganization of macrophages and with a M2 polarization at the granuloma site. In a cell system, FTY720 decreased phagocytosis and production of reactive oxygen species by macrophages, a phenotype recapitulated in the S1pr3-/- knockout macrophages. Our results suggest that FTY720 reactivates cryptococcosis from the granuloma through a S1P receptor 3-mediated mechanism and support the rationale for development of more specific receptor modulators for therapeutic use of MS.
Authors
Arielle M. Bryan, Jeehyun Karen You, Travis McQuiston, Cristina Lazzarini, Zhijuan Qiu, Brian S. Sheridan, Barbara Nuesslein-Hildesheim, Maurizio Del Poeta
Abstract
T helper cells integrate signals from their microenvironment to acquire distinct specialization programs for efficient clearance of diverse pathogens or for immunotolerance. Ionic signals have recently been demonstrated to affect T cell polarization and function. Sodium chloride (NaCl) was proposed to accumulate in peripheral tissues upon dietary intake and to promote autoimmunity via the Th17 cell axis. Here we demonstrate that high NaCl conditions induced a stable, pathogen-specific, anti-inflammatory Th17 cell fate in human T cells in vitro. The p38/MAPK pathway, involving NFAT5 and SGK1, regulated FoxP3 and interleukin (IL)-17A-expression in high-NaCl conditions. The NaCl-induced acquisition of an anti-inflammatory Th17 cell fate was confirmed in vivo in an experimental autoimmune encephalomyelitis (EAE) mouse model, which demonstrated strongly reduced disease symptoms upon transfer of T cells polarized in high NaCl conditions. However, NaCl was coopted to promote murine and human Th17 cell pathogenicity, if T cell stimulation occurred in a pro-inflammatory and TGF-β-low cytokine microenvironment. Taken together, our findings reveal a context-dependent, dichotomous role for NaCl in shaping Th17 cell pathogenicity. NaCl might therefore prove beneficial for the treatment of chronic inflammatory diseases in combination with cytokine-blocking drugs.
Authors
Julia Matthias, Sylvia Heink, Felix S.R. Picard, Julia Zeiträg, Anna Kolz, Ying-Yin Chao, Dominik Soll, Gustavo P. de Almeida, Elke Glasmacher, Ilse D. Jacobsen, Thomas Riedel, Anneli Peters, Stefan Floess, Jochen Huehn, Dirk Baumjohann, Magdalena Huber, Thomas Korn, Christina E. Zielinski
Abstract
Peripheral neurotoxicity is a debilitating toxicity that afflicts up to 90% of patients with colorectal cancer receiving oxaliplatin-containing therapy. Although emerging evidence has highlighted the importance of various solute carriers to the toxicity of anticancer drugs, the contribution of these proteins to oxaliplatin-induced peripheral neurotoxicity remains controversial. Among candidate transporters investigated in genetically-engineered mouse models, we provide evidence for a critical role of the organic cation transporter 2 (OCT2) in satellite glial cells to oxaliplatin-induced neurotoxicity, and demonstrate that targeting OCT2 using genetic and pharmacological approaches ameliorates acute and chronic forms of neurotoxicity. The relevance of this transport system was verified in transporter-deficient rats as a secondary model organism, and translational significance of preventative strategies was demonstrated in preclinical models of colorectal cancer. These studies suggest that pharmacological targeting of OCT2 could be exploited to afford neuroprotection in cancer patients requiring treatment with oxaliplatin.
Authors
Kevin M. Huang, Alix F. Leblanc, Muhammad Erfan Uddin, Ji Young Kim, Mingqing Chen, Eric D. Eisenmann, Alice Gibson, Yang Li, Kristen W. Hong, Duncan DiGiacomo, Sherry Huinan Xia, Paola Alberti, Alessia Chiorazzi, Stephen N. Housley, Timothy C. Cope, Jason A. Sprowl, Jing Wang, Charles L. Loprinzi, Anne Noonan, Maryam Lustberg, Guido Cavaletti, Navjotsingh Pabla, Shuiying Hu, Alex Sparreboom
BET bromodomain inhibition attenuates cardiac phenotype in myocyte-specific Lamin A/C-deficient mice
Abstract
Mutation in the LMNA gene, encoding Lamin A/C, cause a diverse group of diseases called laminopathies. Cardiac involvement is the major cause of death and manifests as dilated cardiomyopathy (DCM), heart failure, arrhythmias, and sudden death. There is no specific therapy for LMNA-associated cardiomyopathy. We report that deletion of Lmna in cardiac myocytes in mice leads to severe cardiac dysfunction, conduction defect, ventricular arrhythmias, fibrosis, apoptosis, and premature death within 4 weeks. The phenotype is similar to LMNA-associated cardiomyopathy in humans. RNA sequencing, performed prior to the onset of cardiac dysfunction, led to identification of 2,338 differentially expressed genes (DEGs) in Lmna-deleted cardiac myocytes. DEGs predicted activation of bromodomain-containing protein 4 (BRD4), a regulator of chromatin-associated proteins and transcription factors, which was confirmed by complementary approaches, including chromatin immunoprecipitation-sequencing. Daily injection of JQ1, a specific BET bromodomain inhibitor partially reversed the DEGs, including those encoding secretome, improved cardiac function, abrogated cardiac arrhythmias, fibrosis, and apoptosis, and prolonged the median survival time by 2-fold in the myocyte-specific Lmna-deleted mice. The findings highlight the important role of LMNA in cardiac myocyte and identify BET bromodomain inhibition as a potential therapeutic target in LMNA-associated cardiomyopathy, for which there is no specific effective therapy.
Authors
Gaelle Auguste, Leila Rouhi, Scot J. Matkovich, Cristian Coarfa, Matthew J. Robertson, Grazyna Czernuszewicz, Priyatansh Gurha, Ali J. Marian
Abstract
No known therapies can prevent anaphylaxis. Bruton’s tyrosine kinase (BTK) is an enzyme thought to be essential for high-affinity IgE receptor (FcεRI) signaling in human cells. We tested the hypothesis that FDA-approved BTK inhibitors (BTKi’s) would prevent IgE-mediated responses including anaphylaxis. We showed that irreversible BTKi’s broadly prevented IgE-mediated degranulation and cytokine production in primary human mast cells and blocked allergen-induced contraction of isolated human bronchi. To address their efficacy in vivo, we created and utilized what we believe to be a novel humanized mouse model of anaphylaxis that does not require marrow ablation or human tissue implantation. After a single intravenous injection of human CD34+ cells, NSG-SGM3 mice supported the population of mature human tissue-resident mast cells and basophils. These mice showed excellent responses during passive systemic anaphylaxis using human IgE to selectively evoke human mast cell and basophil activation, and response severity was controllable by altering the amount of allergen used for challenge. Remarkably, pretreatment with just two oral doses of the BTKi acalabrutinib completely prevented moderate IgE-mediated anaphylaxis in these mice and also significantly protected against death during severe anaphylaxis. Our data suggest that BTKi’s may be able to prevent anaphylaxis in humans by inhibiting FcεRI-mediated signaling.
Authors
Melanie C. Dispenza, Rebecca A. Krier-Burris, Krishan D. Chhiba, Bradley J. Undem, Piper A. Robida, Bruce S. Bochner
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ISSN: 0021-9738 (print), 1558-8238 (online)